Sometime some electronic device need special layer stack up to get the performance , and sometime ,just PCB designer want to save cost , not do 4 layer . 

RayMing is 3 layer PCB manufacturer ,Welcome to send your design to sales@raypcb.com , We will give your quote asap

Introduction

A printed circuit board (PCB) forms the foundation for building electronic circuits by providing the base for mounting and interconnecting components. PCBs with multiple conductive layers enable increased component density and complex circuit routing. A 3 layer PCB refers to a board with three copper layers separated by insulating dielectric substrates.

This article provides a comprehensive overview of 3 layer PCB technology. We will cover the advantages of 3 layer boards, their construction, common design techniques, applications, and manufacturing considerations. With an understanding of their capabilities and limitations, engineers can effectively utilize 3 layer PCBs in many types of electronic designs.

Advantages of 3 Layer PCBs

Three layer boards provide the following benefits compared to simpler 2 layer PCBs:

• Added routing flexibility – The extra layer allows more interconnectivity and circuit optimization. Parts placement and routing are less constrained.
• Improved signal integrity – The middle layer can be a continuous ground plane. This provides controlled impedance signal routing on outer layers.
• Lower EMI/noise – Enclosing signals between power and ground layers reduces interference and crosstalk.
• Better power distribution – Additional layer allows power-ground plane pairs for each voltage domain.
• Higher component density – Components can be placed on both sides with vertical interconnects through the middle layer.
• Smaller board sizes – Miniaturization by utilizing both sides for SMT parts placement.
• Mixed signal designs – Analog and digital sections can be segregated across layers.

For these reasons, 3 layer construction provides excellent capability and cost-benefit for many electronic products.

Construction of 3 Layer PCBs

The fabrication of 3 layer printed circuit boards involves laminating conductive copper layers separated by insulating dielectric substrates:

• The center substrate is called the core. It provides mechanical support. The default material for core and prepreg layers is typically glass reinforced FR-4.
• A sheet of copper foil is laminated onto both sides of the core. These form the top and bottom conductive layers of the PCB.
• Photolithographic processing patterns the copper layers into the required circuit traces, pads, and features.
• Plated through holes and buried vias provide vertical interconnections between the layers.
• Soldermask selectively coats the copper layers for protection and isolation.

This creates a 3 layer board ready for component assembly. The sequence can be repeated to build multilayer boards.

Typical 3 Layer Stackups

While all 3 layers can be used for routing signals, some standard layer assignments provide good design starting points:

3 Layer With Ground Plane

• Layer 1 – Signals
• Layer 2 – Ground plane
• Layer 3 – Signals

This offers a continuous reference ground plane for controlled impedance routing and shielding.

3 Layer With Split Power Planes

• Layer 1 – Signals
• Layer 2 – Split power planes (VCC and VDD)
• Layer 3 – Signals

Separate power supply domains can be isolated between the split power planes.

3 Layer With Buried Signal Plane

• Layer 1 – Ground
• Layer 2 – Signals
• Layer 3 – Ground

The buried signal layer fully encompasses routing surrounded by ground planes.

The stackup can be customized based on signal isolation, thermal and EMI requirements.

Design Considerations for 3 Layer Boards

Here are some important design practices when working with 3 layer PCBs:

• Split power planes correctly for digital and analog domains based on current levels.
• Use a large number of via stitches to connect split power planes for lowest impedance.
• Assign critical signals to outer layers adjacent to the ground/power planes.
• Route opposing signal polarities on same layer to minimize crosstalk.
• Use diagonal routing over middle layer to change layers when needed.
• Enable thermal relief stitching for highest current paths.
• Maximize copper area on outer layers for best heat dissipation.
• Follow adequate design clearances between planes and traces.
• Model power and ground impedances to avoid resonance and coupling issues.
• Simulate signal integrity and radiated emissions to high frequencies.

Proper 3 layer stackup design and layout techniques result in schematics which transition smoothly through manufacturing.

Typical Applications of 3 Layer PCBs

Here are some examples of products where 3 layer boards are commonly used:

• Consumer electronics – IoT devices, smart home gadgets, wearable tech
• Vehicles – Auto infotainment panels, GPS display units
• Industrial – PLCs, motor controllers, sensors
• Instrumentation – Meters, analyzers, handheld testers
• Medical – Diagnostic equipment, body-worn monitors
• IT – Ethernet switches, modems, routers
• Communications – Radio transceivers, video gear

3 layer boards balance cost, complexity and performance for mid-range applications. The proliferation of digital electronics drives large volumes of 3 layer PCBs today.

3 Layer PCB Manufacturing Overview

3 layer PCB fabrication in volume involves the following key steps:

• Materials – Core substrates, prepreg, copper foils
• Imaging – Photoresists, direct laser/mechanical patterning
• Lamination – Stacking layers under heat and pressure
• Etching – Chemically etching away unwanted copper
• Drilling – Machines drilling holes for vias and mounting
• Plating – Electroplating copper over hole walls and surfaces
• Solder mask – Liquid photoimageable solder resist layers
• Silkscreen – Printed reference markings
• Testing – Electrical testing, quality inspection
• Assembly – SMT component placement and soldering

High-yielding fabrication lines enable cost-effective mass production of 3 layer boards.

Conclusion

With three conductive layers to work with, PCB designers have sufficient flexibility to route out interconnects and partition domains without undue complexity. 3 layer boards offer excellent capability per unit cost, enabling their ubiquity across industrial and consumer electronics. Advances in PCB materials, fabrication equipment and assembly technologies will continue to improve technical features, density and reliability while reducing manufacturing costs.

Frequently Asked Questions

Here are some common questions about 3 layer PCBs:

What are the typical substrate thicknesses used in 3 layer boards?

Standard cores are commonly 0.8mm, 1.0mm, 1.6mm while prepregs range from 0.1mm to 0.25mm. Overall thickness is usually between 1.6mm to 2.4mm.

What are the minimum track/spacing dimensions achievable on 3 layer boards?

With processes like direct imaging, trace/space down to 125um (5 mils) is routinely achievable on outer layers.

What are common 3 layer PCB sizes?

Smaller boards of around 50x50mm to 160x100mm are typical. Large boards up to 460x360mm area are also manufactured cost-effectively.

What are the limitations of 3 layer boards compared to 4+ layer ones?

Design constraints in routing congestion, inability to isolate multiple signals, lower component density and lack of flexibility for high pin-count parts.

What are common materials available for core and prepreg in 3 layer PCBs?

Standard FR-4, High Tg FR-4, Halogen-free FR-4, Rogers materials for high frequency, Polyimide for flexibility, Ceramic-filled substrates for thermal conduction.

The post What is 3 layer PCB? appeared first on RAYMING PCB.

4.8mm  20 Layer PCB Manufacturing  

: 4.8mm

Solder Mask : Green

Copper : 3OZ

RayMing is 20 layer PCB manufacturer ,Welcome to send your 20 layer PCB Design to sales@raypcb.com , We will give the best quote for you .

20 Layer PCB Stack Up

Introduction

20 layer PCBs enable remarkably dense and complex circuit designs for advanced applications. The multilayer board integrates signals, power distribution and components in a compact form factor. However, fabricating 20 layer boards reliably requires expertise in process control and testing. Selecting the right manufacturer is key to ensuring high yields and performance.

This article discusses capabilities required of a high quality 20 layer PCB production facility. We will go over recommendations for stringent process standards, precision equipment, rigorous testing and qualifications needed to deliver complex multilayer boards with high yields and low defects.

Key Capabilities for 20 Layer PCB Fabrication

Producing 20 layer PCBs pushes fabrication equipment and process limits. Here are some must-have capabilities:

• Handling board sizes exceeding 460mm x 610mm
• Stackup with 20 conductive copper layers interleaved with dielectric
• Tight layer to layer registration accuracy of ~50um
• Line width and spacing down to 3/3 mil with tolerances of +/- 0.5 mil
• Laser drilled and plated microvias with 5 mil diameter and pitch down to 8 mil
• 1 oz copper on outer layers, 0.5 oz for inner layers
• Various dielectric materials – FR4, Rogers, Polyimide, PTFE etc.
• Sequential lamination with advanced process controls
• Fine line imaging and etching on inner layers
• Excellent hole wall plating quality and copper bonding
• HDI technologies – microvias, stacked vias, blind/buried vias
• UL, ISO, and other certifications

Fabrication must also assure high yields across large board sizes typical for high layer count.

Critical Process Control Requirements

Achieving quality and repeatability involves refined process controls:

• Metrology tools to precisely monitor panel parameters in real-time
• Maintaining laminate and etchant integrity across long cycles
• Precise control of lamination temperature and pressure profiles
• Real-time drilling parameter adjustment – speed, depth, pressure
• High uniformity copper plating across panel with minimum voids
• Imaging, etching, stripping processes tuned for high yields
• Statistical feedback loops for continuous tolerance improvements

Refined process tuning, monitoring and control minimizes scrap and rework even when producing complex stackups.

Advanced Fabrication Equipment Essential

latest equipment allows holding the tight tolerances needed:

• Direct imaging with 50um lines/spaces rather than using artwork films
• High accuracy layer-to-layer registration system for stacking and lamination
• Laser microvia drilling machines with ~5mil capability
• Advanced plating equipment for uniform copper filling of blind and buried vias
• Automatic optical inspection systems to detect defects during fabrication
• Advanced patterning machinery capable of fine features on inner layers

Investment into cutting-edge fabrication tools enables reliable volume production of dense HDI boards.

Comprehensive Testing Is A Must

With the high layer count and complexity, testing assumes even more critical importance:

• Automated optical inspection after major fabrication steps
• Netlist testing of bare panels for opens, shorts and impedance
• Test point integration to enable probing all layers for shorts
• Microsection analysis of layer alignment, lamination and plated holes
• Complete functional testing of populated boards
• In-circuit tests for assembled boards with boundary scan capability

Extensive testing at bare board, assembly and functional stages is essential to achieve final yield targets for 20 layer PCBs.

Qualifications and Certifications

Validated capabilities, quality management and consistency controls differentiate tier-one manufacturers:

• ISO 9001, ISO 14001 certified facilities
• IPC 6012 Class 3, IPC 6018 Class 3 qualifications
• ITAR registration support for defense products
• UL listing for safety compliance assurance
• RoHS, REACH, Conflict Minerals compliance
• Ongoing reliability and improvement testing
• Statistical process control monitoring

These qualifications provide confidence in their process capabilities and infrastructure.

Finding Reliable 20 Layer PCB Manufacturers

Here are helpful tips when selecting a 20 layer PCB production partner:

• Review online capabilities – specifically for 20+ layer expertise
• Validate certifications are current and relevant
• Ask for customer references with 20 layer boards made
• Check facilities, equipment investments
• Review sample quality and test data
• Have initial engineering discussion – DFM, DFT, capabilities
• Assess supply chain – inventory, sourcing for prompt delivery
• Consider locations near your team for operational agility

Taking the time for thorough due diligence during selection ensures you choose the right long-term fabrication partner.

Conclusion

With stringent process controls, advanced fabrication equipment and comprehensive testing, capable manufacturers can reliably produce high-density 20 layer PCBs. Validated infrastructure and certifications provide confidence to take on challenging multilayer builds. Partnering early in design with an experienced 20 layer PCB producer helps navigate design and process complexities for a successful outcome. As electronics innovation pushes further, these partnerships continue enabling intricate products integrating multilayer boards with refined manufacturing.

Frequently Asked Questions

Here are some common FAQs on 20 layer PCB manufacturing:

What are typical 20 layer board thicknesses?

A 20 layer board with standard dielectrics and 1 oz copper can end up around 0.260” (6.6 mm) thickness. Using thinner dielectrics and copper under 0.5 oz reduces thickness.

What line width/space is achievable on 20 layer boards?

Leading manufacturers can achieve 3/3mil line/space on external layers and 5/5mil for internal layers using direct imaging down to 50um resolution.

What materials are used in 20 layer PCB construction?

FR-4 is common for cost-effective boards. High frequency boards use RF materials like Rogers RO4350b or ceramic-filled PTFE. Flexible boards may use polyimide films.

What are the main difficulties in fabricating 20 layer boards?

Maintaining tight layer registration and plating quality through many lamination cycles. Also achieving fine features on inner layers and high yields across large board sizes.

How is component density achieved on 20 layer boards?

High component density is enabled by HDI technologies like microvias, blind/buried vias and thinner dielectrics for routing channels.

The post High Quality 20 Layer PCB Manufacturer appeared first on RAYMING PCB.

Material:FR4,TG170 (ITE180).
Thickness: 2.0mm.
min hole: 0.2mm
min trace/space:0.11/0.11mm
200*300 mm per panel ,6 units/panel.
Immersion gold and press fit hole (tolerance 0.05mm)

16 Layer PCB Stack Up

Introduction

Printed circuit boards with a high layer count are needed for complex, dense electronic designs. 16 layers is typical in many advanced control systems, telecom/networking and medical applications. The layer stackup requires careful planning to optimize electrical performance, thermal management and manufacturability.

This article provides guidelines on how to best use the 16 layers. We discuss recommended approaches for partitioning the layers into signal, ground and power distributions. A sample reference stackup is presented that can be tailored to specific system requirements. We also go over key considerations for 16 layer PCB design and fabrication.

Layer Planning Guidelines

Here are some principles to follow when planning out the layers in a 16-layer board:

• Split layers evenly between top and bottom of the board for symmetry. This avoids warping.
• Assign at least 20% layers for ground and 20% for power distribution. This leaves 60% for signals.
• Place ground and power layers adjacent to signal layers for controlled impedance and decoupling.
• Locate ground layers outermost as much as possible for easiest routing and heat dissipation.
• Assign one full uninterrupted ground plane layer on each side adjacent to signal layers.
• Define several split power planes to isolate analog, digital and high-current power.
• Order signal layers for optimized grouping based on high-speed, RF or isolated sections of the system.

Using these guidelines results in a versatile stackup suited for mixed-signal, digital and RF system designs.

16 Layer PCB Stackup Example

Here is an example 16 layer stackup designed using the above guidelines:

This stackup ensures:

• Symmetric top and bottom layer distribution
• 40% of layers assigned for ground and 40% for various power domains
• Adjacent ground planes for controlled impedance routing
• Outer ground planes for easiest heat dissipation and routing
• Logical grouping of signal layers based on analog, digital, RF domains

The sequence can be modified to suit high density routing requirements and thermal design.

Key Design Considerations

Here are some key points to consider when designing a 16 layer PCB:

• Via technology – Laser drilled microvias with ~0.2mm holes allow dense interconnections between layers. Backdrilling clears unused sections of vias.
• Routing channels – Thinner dielectrics like 0.008″ prepregs between layers provide adequate trace routing channels.
• Controlled impedance – Ground + power layer next to signals allows impedance control for high-speed traces.
• Decoupling – Multiple power-ground pairs spread across layers provides decoupling capacitors access.
• Thermal – Thermal reliefs and thermal core layers help conduct heat out from inner layers.
• Signal integrity – Follow length matching, tuning and crosstalk guidelines for high-speed traces.
• ** manufacturability** – Work with fabricator early to check DFM, panel utilization, fabrication tolerances.

A disciplined approach is needed when laying out complex 16-layer designs while working closely with the PCB manufacturer to ensure producibility.

Fabrication and Testing Considerations

Here are some key considerations during fabrication and testing of densely packed 16 layer boards:

• Registration accuracy is critical for drilled holes to match pads across 16 layers when stacking up.
• Layer alignment must be highly precise over large board sizes typical of 16+ layer PCBs.
• Uniform heat dissipation across multilayer stackup requires careful processing during lamination.
• Plating quality and hole wall profiles should be strictly controlled for reliable interlayer connections.
• Electrical test coverage becomes more extensive with the high node count on large multilayer boards.
• Impedance control, signal integrity and RF performance testing requires advanced test equipment.

The fabrication facility must have proven experience in manufacturing complicated high layer count PCBs cost-effectively.

Recommendations When Ordering

• Partner with a fabricator experienced in building 16+ layer PCBs
• Request pre-DFM analysis before finalizing layer stackup
• Have quickturn prototypes made to validate design and process before committing to production
• Understand capabilities – layer tolerance, hole size ranges, line/space etc.
• Discuss any thermal design and signal integrity validation needs
• Review test coverage – bare board electrical testing, flying probe, ICT
• Get recommendations for optimal panel sizes, layout and breakout

Conclusion

A well-planned layer stackup strategy is key to effectively utilize the routing real-estate available in 16 layer designs. The layer sequence must balance signal routing needs, power distribution, heat dissipation and manufacture-ability constraints. A collaborative approach between designer and fabricator ensures a practical stackup optimized for cost, quality and performance. Rigorous design reviews and testing will validate the complex multilayer implementation before volume production.

Frequently Asked Questions

Here are some common FAQs about 16 layer PCB stackups:

What is a typical thickness for a 16 layer board?

A 16 layer board with standard 1oz copper and 0.008″ dielectric layers will result in a total thickness around 0.25″ (6.5mm). Thinner dielectrics can reduce thickness.

What are thermal cores used for in multilayer PCBs?

Thermal cores made of metallic or ceramic layers buried inside the stackup help conduct heat from inner layers to the board surfaces for efficient cooling.

What is backdrilling of PCB holes?

Backdrilling selectively removes the unused lower portions of through hole vias to avoid trapping heat inside multilayer boards. This improves thermal performance.

What are common dielectric materials used in 16 layer boards?

FR-4 glass epoxy is common. High frequency boards use RF materials like Rogers RO4350b. Flexible boards may use polyimide films. Ceramic filled PTFE substrates aid thermal conduction.

What testing is typically done on complicated multilayer PCBs?

Extensive bare board testing for shorts, opens, impedance control, signal integrity and review of fabrication quality before assembly and functional testing of populated boards.

The post Recommended 16 Layer PCB stackup From Manufacturer appeared first on RAYMING PCB.

Top Layer  ‐ 18um Copper Foil (plated to 35um+)
Pre‐Preg   ‐ 1 x 2116
Layer 2 & 3  ‐ 0.13mm Fr‐4 Core with 35um/35um Copper
Pre‐Preg   ‐ 1 x 2116
Layer 4 & 5  ‐ 0.13mm Fr‐4 Core with 35um/35um Copper
Pre‐Preg   ‐ 1 x 2116
Layer 6 & 7  ‐ 0.13mm Fr‐4 Core with 35um/35um Copper
Pre‐Preg   ‐ 1 x 2116
Layer 8 & 9  ‐ 0.13mm Fr‐4 Core with 35um/35um Copper
Pre‐Preg   ‐ 1 x 2116
Layer 10 & 11  ‐ 0.13mm Fr‐4 Core with 35um/35um Copper
Pre‐Preg   ‐ 1 x 2116
Bottom Layer   ‐ 18um Copper Foil (plated to 35um+)
Stardand 12 Layer PCB  1.6mm +/‐ 10%

12 Layer PCB 

Board thickness: 1.8mm

Solder mask :Green

Legend : White

Surface :Immersion gold

Material : Tg170 FR4

Rayming is 12 layer PCB manufacturer with board stack-up suggestion in China with 10 years experience, Welcome to send your design to sales@raypcb.com ,We will give the best support to you .

Introduction

As electronic devices become more complex and functionally packed, PCB designs are moving toward higher layer counts to provide adequate interconnections and circuit density. 12-layer boards are increasingly common in many advanced designs today. However, fabricating 12-layer PCBs reliably poses formidable manufacturing challenges that require mature capabilities.

This article provides an overview of 12-layer PCB stackups, the fabrication difficulties involved, critical manufacturing capabilities needed, and guidelines for optimizing 12-layer board design and performance.

What is a 12 Layer PCB?

A 12 layer PCB consists of 12 layers of circuitry laminated together including:

• 2 external layers (top and bottom) for component mounting and highest density routing.
• 10 internal layers for power distribution, ground planes, and high-speed signals requiring shielding.

The layer stackup is interleaved with dielectric prepreg material and bonded together under heat and pressure. Vias provide interconnection between layers.

Some key applications for 12 layer boards are complex digital systems, high-performance computing, network switches, telecom infrastructure, defense electronics, and advanced driver assistance automotive systems.

Benefits of 12 Layer PCBs

Key advantages of 12-layer PCBs compared to simpler 4-8 layer boards include:

• Higher interconnect density – More routing channels allows greater circuit complexity.
• Added power/ground planes – Provides cleaner power distribution over multiple planes.
• Signal isolation – Extra layers allows better separation of analog and digital signals.
• Higher component density – Smaller components can be more densely placed.
• Mixed signal integration – Digital and analog circuits can co-exist without interference.
• Miniaturization – Complex systems can be integrated in smaller form factors.
• Noise reduction – Additional power/ground planes lower EMI radiation.
• Thermal handling – Planes spread heat over larger area keeping devices cooler.
• High speed channels – Isolating fast signals on inner layers contains EMI.

Fabrication Challenges with 12 Layers

While providing significant advantages, reliably manufacturing quality 12 layer PCBs poses multiple production difficulties:

• Registration – Accumulating tolerance across 12 layers risks misalignment/skew.
• Aspect ratio – Plating high 12:1 aspect ratio vias is challenging.
• Lamination voids – Preventing voids or resin starvation within the stackup.
• Hole wall quality – Maintaining resin-rich smooth hole walls for plating adhesion.
• Surface finish – Achieving uniform plating thickness within small vias and over external traces.
• Via reliability – Eliminating cracks or opens within small buried vias.
• Bow and twist – Controlling warpage across the thicker panel during fabrication.
• Impedance control – Tight impedance matching of traces between different layer pairs.
• Signal integrity – Preventing cross-talk and interference within dense 12-layer routing.

Key Manufacturing Capabilities for 12 Layers

Fabricating reliable, high yield 12-layer PCBs demands advanced capabilities from the manufacturer:

1. Registration Accuracy

Tighter registration control during lamination minimizes layer-to-layer misalignment. Excellent registration around 0.08mm or less is needed.

2. Aspect Ratio Plating

Smooth, void-free copper plating of small vias with at least 12:1 aspect ratios without reliability issues.

3. Lamination Process Control

Sophisticated pressure, temperature and vacuum control to eliminate voids within the stackup.

4. Hole Wall Preparation

Use of chemical processes to create resin-rich hole walls that enable continuous plating.

5. Surface Finish Control

Uniform plating thickness of 2% or better across external and internal layers.

6. Via Reliability Methods

Testing vias under thermal shock, vibration, and pressure pot conditions to ensure reliability.

7. Panel Handling

Eliminating bow, twist and controlling thickness variation within 5% through panel support, stack sequencing, and balancing layers.

8. Impedance Tolerance

Tight impedance control of traces and planes within 5% of target value.

9. Signal Integrity

Extensive modeling, simulation and testing of critical signals to prevent interference.

10. Process Capability Control

Statistical control and continuous improvement of processes to stay within very tight tolerances.

12 Layer PCB Stackup Options

Several stackup configurations are possible with a 12 layer board depending on the application. Some examples are:

Stackup 1: Playground Stackup

Top Layer Ground Plane Signal Layer Power Plane Signal Layer Ground Plane
Signal Layer Power Plane Signal Layer
Ground Plane Signal Layer Bottom Layer

This provides alternating ground-power-signal layer pairs for isolation plus external layers for highest density routing.

Stackup 2: Split Ground/Power Stack

Top Layer Split Ground Plane 1 Split Power Plane 1 Ground Plane 1
Signal Layer Power Plane 1 Signal Layer Split Ground Plane 2 Split Power Plane 2 Ground Plane 2 Signal Layer Bottom Layer

Here the ground and power planes are split between two sets of layers. The central signal layers are isolated between continuous ground planes on either side.

Stackup 3: High Speed Signals Center

Top Layer Ground Plane 1 Power Plane 1 Signal Layer 1 Signal Layer 2 Signal Layer 3 Signal Layer 4 Power Plane 2 Ground Plane 2 Bottom Layer

In this stackup, high speed sensitive signals are isolated in the center layers between ground/power blocks. Top and bottom layers carry low frequency or digital routing.

Stackup 4: Multiple Signal Groups

Top Layer Ground Plane Signal Group A Power Plane
Signal Group B Ground Plane Signal Group C Power Plane Signal Group D Ground Plane Bottom Layer

This groups different types of signals together in sets of layers, separating analog and digital for example. Power and ground planes provide isolation between signal groups.

Design Guidelines for 12 Layer PCBs

To optimize 12 layer PCB design and performance, engineers should follow certain guidelines:

• Assign signals to layers based on their characteristics – high speed, low speed, analog, digital.
• Review layer transitions to minimize vias, crosstalk, and discontinuities.
• Use impedance matched traces and constraints for high speed channels.
• Model critical signals in PCB analysis tools and simulate entire layer stackup.
• Use power integrity analysis to shape plane splits and decoupling.
• Add a ground plane adjacent to each signal layer if possible.
• Watch for resonant cavities between parallel power and ground planes.
• Increase clearance gaps in dense boards to control crosstalk.
• Review key parameters like conductor current density, layer temperature rise, voltage drop.
• Probe signals internally during testing to validate internal layer performance.

Conclusion

With increasing design complexity, 12-layer PCB technology provides more routing channels, enables denser component mounting, better power distribution, and high speed signal isolation. But reliably manufacturing 12-layer boards requires stringent process capabilities from PCB fabricators. Utilizing robust stackup configurations and following disciplined design guidelines allows harnessing the maximum benefits from 12-layer PCBs. Partnering with expert manufacturers enables successfully implementing 12-layer designs to fulfill expanding interconnect needs.

The post 12 Layer PCB Manufacturing and Stack Up Options appeared first on RAYMING PCB.

Single side PCB is a one layer PCB, in which all electronic components are on one side of the board and all circuits at another layer.

Single Sided PCB is the simplest printed circuit board, only have one layer of conductive material and are best suited for low density designs,Holes in the board are usually not plated through.

Component parts is layouted on one side and the circuit is on the other side. As there is only layer conductor, it is called single sided pcb (Single-sided pcb or one layer pcb. It is restricted in the circuit design (because there is only one side conductor, and no cross permitted, each line must have its own path), so it is more frequently used in the early printed circuits pcb.

Single sided PCB diagram mainly use network printing (Screen Printing) .That is to print resist on the bare copper, etch and then print solder mask, finally punching to finish parts plated hole and profile. In addition, some small amount of various products usually use photoresist to pattern circuit.

Single Sided PCB Stack Up 

Single layer pcb Raw Material 

Fr4     Grade Fiberglass Laminates

Aluminum

Copper base

Cem 1

Cem 3

Single Side PCB Working Principle

PCB uses raw insulating material to isolate the surface copper foil conductive layer. Due to this, the current flows in various components along a pre-designed route to complete functions such as work, amplification, attenuation, modulation, demodulation, encoding, etc.

Single PCB Structure

The single PCB mainly consists of pads, vias, mounting holes, wires, components, connectors, filling, and electrical boundaries. Circuit board

The main functions of each part are as follow:

Pad: A metal hole used to solder the pins of components.

Via: A metal hole used to connect component pins between layers.

Mounting hole: Used to fix the circuit board.

Wire: The copper film of the electrical network used to connect the pins of the components.

Connectors: Used to connect components between circuit boards.

Filling: Used for copper coating of ground wire network, which can effectively reduce impedance.

Electrical boundary: Used to determine the size of the circuit board; all components on the circuit board cannot exceed the boundary.

Single Side PCB Technology  

Single Side PCB Function

After electronic equipment adopts circuit boards, manual wiring errors can be avoided due to the consistency of similar circuit boards. Electronic components can be automatically inserted or mounted, automatic soldering, and automatic detection, ensuring the quality of electronic equipment and improving labor productivity, reduce costs, and facilitate maintenance.

Single Side PCB Material

Printed single-sided PCB is generally made of foil-clad and copper-clad laminates. The plate selection should consider electrical performance, feasibility, processing requirements, economic indicators, etc. Commonly used copper-clad laminates include copper-clad phenol paper laminates, copper-clad epoxy paper laminates, and copper-clad laminates. For multilayer PCB, foil epoxy glass cloth laminate, copper-clad epoxy phenol glass cloth laminate, copper-clad PTFE glass cloth laminate, and epoxy glass cloth are used.

Single Side PCB Price

The single PCB price is accelerated and rationalized with the improvement of single side PCB production technology and equipment. Usually, suppliers will not directly provide quotations. You can consult Raypcb Electronics for single PCB quotations.

Single Side PCB Supplier

RayMing is a high-tech enterprise specializing in the production and R&D of various single-sided PCB. The single-sided PCB, single-sided aluminum PCB, single-sided circuit boards, and other various FR-4 circuit boards produced with comparable advanced foreign products. Product specifications apply to electronic watches, calculators, general-purpose computers, as large as computers, electronic communication equipment, and military weapon systems. Lastly, PCBs are used for electrical interconnection if there are electronic components such as integrated circuits.

Single Side PCB Production Time

What’s should be the focus on for single side PCB?

1. Production time:3-5 days for sample, 5-7 days for mass production
2. Quality request:The customer’s detailed requirements, size, thickness, craftsmanship, whether it is invoiced, can it be collected by express delivery, and are there any special requirements?
3. Are mass production required in the future? Is it long-term cooperation? All of them should be figure it out one by one.

How to improve long delivery time for single side PCB?
1. Make more boards in stock
2. Arrange the full day production
3. The delivery date needs to be negotiated with the customer

How to maintain Single Side PCB?

Circuit board engineers have their maintenance methods and ideas. However, the maintenance steps can be summarized in the following six steps. To understand the board’s failure to repair, first understand the failure situation and set the failure judgment within a smaller range to facilitate the maintenance work. Therefore, understanding the failure of the circuit board is very important for starting maintenance.

1. Board observation: Board observation is preliminary research. The purpose is to understand what input and output interfaces the board has, what functions the board implements, and the distribution of various control parts of the board.

2. Circuit test: After completing the fault observation and analysis, perform preliminary inspections on the board. The initial circuit test may not find the board’s fault point, but an experienced circuit board maintenance personnel manually perform the test, exclude a wide range of faults, and pave the way for the next repair.

3. Component inspection: In most component inspections, the components need to be removed from the PCBA circuit board with a soldering iron and inspected by professional equipment. This process will damage the circuit board’s external integrity, so under normal circumstances, maintenance personnel will not dismantle components.

4. Fault maintenance: Fromline testingto component inspection, the maintenance steps are designed to deal with the faults discovered, including line repair, component replacement, and transformation.

5. Test on the computer: The board that has completed the maintenance work needs to be tested again. After confirming that there is no fault, it is tested on the computer.

Single Side PCB Scrap Treatment Technology

Printed circuit boards are made of glass fiber, epoxy resin, and a variety of metal compounds. If waste aluminum substrates are not properly disposed of, the brominated flame retardants and other carcinogens in them will cause serious damage to the environment and human health. . At the same time, waste circuit boards also have a high economic value. The metal grade in the circuit boards is equivalent to dozens of times the metal grade in ordinary minerals. The metal content is as high as 10~60%, and the most content is copper. Gold, silver, nickel, tin, lead, and other metals are rare metals, and the content of rich ore metals in nature is only 3~5%.

The report shows 1 ton of computer components contain an average of 0.9 kg of gold, 270 kg of plastic, 128.7 kg of copper, 1 kg of iron, 58.5 kg of lead, 39.6 kg of tin, 36 kg of nickel, 19.8 kg of antimony, as well as palladium, platinum, and other precious metals. It can be seen that waste circuit boards are also a “gold mine.” According to a circuit board fabrication disposal survey, in most parts of the country, the waste circuit boards and frame materials are transported to remote areas for treatment by incineration and washing methods, causing severe secondary problems.

The State Environmental Protection Administration has banned the incineration method because it produces a large amount of odorous and toxic bromine compounds, which seriously pollutes the atmosphere. However, in remote mountainous areas, incineration workshops occur.

The water washing method has been widely used due to its simple process and low investment. However, a large amount of waste residues, such as non-metallic substances   (which account for about 80% of the weight of the aluminum substrate produced after washing), still cause great harm to the environment. It is difficult to treat or eliminate these waste residues. Most of the washing enterprises put the waste residue as domestic waste in landfills or handed over to the sanitation department for disposal.

Single Side PCB Application and Characteristics

The single-sided PCB is more and more widely used because it has many unique advantages; the summary is as follows.

High density – For decades, high density printed boards have developed with the improvement of integrated circuit integration and the advancement of mounting technology.

High reliability – Through a series of inspections, tests, and aging tests, the PCB can work reliably for an extended period (usually 20 years).

Designability – For the various performance (electrical, physical, chemical, mechanical, etc.) requirements of the single panel, the printed board can be designed through design standardization in a short time and with high efficiency.

Producibility – With modern production management, it can be standardized, scaled (quantified), automated, etc., to ensure product quality consistency.

Testability – Complete test methods, standards, various test equipment, and instruments have been established to detect and appraise the eligibility and service life of the single PCB.

Assembled – The circuit board facilitates the standardized assembly of various components and enables automated and large-scale mass production. At the same time, circuit boards and various component assembly parts can be assembled to form larger parts and systems, up to the complete machine

Maintainability – Circuit boards and various component assembly parts are manufactured in standardized design and scale. If the system fails, it is convenient to replace components quickly; the system can be restored promptly with such flexibility. There are more examples, such as miniaturization and weight reduction of the system, and high-speed signal transmission.

Features of single PCB：

The so-called single-sided board is the most basic PCB, as all the parts are concentrated on one side, and the wires are all concentrated on the other side. Because the wires only appear on one side, we call this PCB a single-sided. Because there are many strict restrictions on the design of the single-sided board (there is only one side, and the wiring can not cross and must go around a separate path), it is generally not used in modern times, but it was used in the early days.

Single PCB wiring diagrams are mainly network printing. It is a resist printed on the copper surface, and the mark is printed with a solder mask after etching. Finally, the part’s guide hole and shape are completed by punching. In addition, some of the products that are produced in small quantities and diversified use photoresist forming patterns.

PCB single-sided proofing design process

First, we look at a picture:

Let’s take a look at what the design process looks like.

1. Preparation part：

At the beginning of the PCB layout, you should first complete the schematic design and get the correct schematic. This is the basis of the single-sided PCB design. Through the schematic diagram, we can get a network table of the connection attributes of each device. According to the device’s parameters, we can find the relevant component information and establish the package of all components. It is also necessary for the structural part to cooperate to provide the size of the board frame, installation position, and the position of the function excuse.

2. Specific operation part：

First, you need to import all the package files and netlists into the PCB file with the frame. Some component packaging errors may occur during the import process; please eliminate the errors according to the error prompts.

3. Fixed structure related devices:

You have to fix devices such as LEDs, buttons, decks, liquid crystals, infrared transmitters, etc. Move these devices to the corresponding installation position, and select lock in the properties to prevent misoperation.

4. Carry out a rough layout:

The purpose of the general layout is to determine the location of each functional module. In PCB design, the default is generally:

• Except for the devices that need to be mounted on the surface, all SMD devices are placed on one side of the plug-in device, which is generally the bottom layer.
• The metering unit is placed in the lower-left corner for easy access.
• Place the MCU on the back of the LCD, and make the leads short enough.
• The interface part is placed in the lower-right corner of the PCB for an easy cable outlet.
• Keep the transformer away from transformers and manganin shunts that are sensitive to magnetic leakage.
• Keep enough creepage distance between circuits that need to be isolated.

5. Perform partial layout:

Complete the placement of the corresponding devices for each functional module. The factors that need to be considered in the local layout are:

• The crystal oscillator should be as close as possible to the crystal oscillator pin, and the trace should be as short as possible.
• The decoupling capacitor should be as close as possible to the power input pin of the IC.
• Devices with high-speed connections between ICs should be as close as possible.
• It is necessary to consider the convenience of maintenance and optimize the placement of some devices to avoid production difficulties.
• Leave a certain board margin, which should be 4mm or more. Otherwise, it is easy to cause accidental damage to the pick-up head during patching in the SMT workshop, causing the device to collide with the chain during wave soldering. It is impossible to use wave soldering at one time. To complete the plug-in welding, more stations need to be arranged to repair welding
• Varistors, polyester capacitors, transient suppression diodes,voltage regulator tubes, and filter capacitors should be placed in the device’s front end to be protected.
• Pay attention to the distance between high voltage and low voltage signals.

6. Wiring of components

The wiring of components is also a critical process. You need to pay attention to the following aspects when wiring:

• Knowing the magnitude of the current that each device may flow and the maximum inrush current, you can roughly understand the possible impact of the signal carried on the trace on other signalsto set the wire thickness.
• The wiring of the high-voltage signal to the varistor and the polyester capacitor should be as wide as possible. This is so that the protection device can release the overload energy in time and preventthe line from being burned by the instantaneous high current.
• The low-voltage power supply signal main circuit line uses 36mil to reduce the wire resistance, and the width of 24mil or less can be used near the chip.
• The small-signal connection can be 10mil or 12mil. Too thin will cause the scrap rate to be too high, andtoo thick is meaningless.
• Do not route wires near high-frequency signals, such as the bottom of a crystal oscillator.
• Minimize the connection of vias. The quality of the wiring directly affects the performance of the PCB. In actual wiring, it may need to be overthrown and restartedor even return to the schematic diagram to modify the IO port definition. This is the most time-consuming part.

7. Align the power cord:

• The power cord’s wiringshould be of sufficient width to avoid sudden changes in line width and right-angle corners. Also, the power cord cannot be formed into a loop.

8. Floor treatment:

• A large ground plane is formed, which is equivalent to completing the wiring of the ground wire.

9. Adjustment of device layout:

• When adjusting, prevent the large piece of ground from being connected to the main ground only through a few vias. Pay attention to the integrity of the floor under the chip. You can also better observe the appearance of wiring and device placementand whether the return loop of each signal is complete. In this step, complete the adjustment and modification of all device labels, and mark the company logo and PCB version number.

10. Check the drawing specifications of all PCB boards:

• Also,point out the error and highlight the error.

11. Export PCB:

• The export format is Protel PCB 2.8 ASCII File.

12. Send out proofing.

 How to DIY a Single-Layer PCB ?

The project is a self-made PCB to improve the anti-interference ability of the circuit. The following process can produce a high-precision PCB with a line width of 10 mils and a pitch of 8 mils that can be welded with 64-pin SMD packages with MSP430 chips. The probability of wire breakage is relatively small.

Tools and materials used

Altium Designer + home laser printer + thermal transfer machine + homemade PCB special corrosion tank + blue environmentally friendly corrosive + laser toner remover + small hand drill + glass fiber copper-clad laminate (or bakelite copper-clad laminate).

Draw PCB (using Altium Designer)

1.1000mil = 1 inch = 2.54cm, the hole spacing of the universal board is 2.54mm = 0.1 inch = 100 mil.

2. Use SMD components as much as possible to reduce drilling issues.
3. SMD components and wiring are on the same side, and in-line components are installed on the other side.
4. After the PCB is created, it is difficult to modify at will like a universal board, so the test points should be reserved appropriately.
5. PCB rules (Rules) reference value:

Track Width> 15mil (10 mil may be broken during transfer).

Clearance> 10 mil, preferably set to 30 mil or more. The distance that is too small will be difficult to weld.

Pad: The aperture is set to 20mil, and drilling is required later (after setting 20mil to be corroded, it is more convenient for the drill bit to be positioned when drilling). Diameter>80mil, the larger the diameter, the easier drilling will be later (if the outer diameter is too small, the drill will be slightly offset. The ring pad will be disconnected, which will cause the soldering to be unstable and the pad to fall off more easily). For common pins such as ICs and transistors with an interval of 100 mils, if the pad diameter is greater than 100 mils, adjacent pads will be connected, so it can generally be set to 85 mils.

Copper-clad Plane -> Polygon Connect: Relif Connect, Conductor width> 20 mil, Airgap width = 15 mil.

The PCB substrate is set according to the actual size of the copper-clad laminate. Generally, a single layer is used. If you make a double-layer board, it is relatively difficult to align the two sides.

Print

Delete unnecessary layers: When printing, only the Top Layer or Bottom Layer layer is printed, and the other layers are deleted.

If it is TopLayer, you should check Mirror.

The pad is printed as a hole (check Hole), so the later drilling will be better positioned.

The color is set to pure black, and the print mode is set to monochrome (Color Set: Mono).

Print size: ScalePrint 1.0, not Fit Document.

Turn off the printer’s ink-saving mode. See the printer manual for specific methods.

In order to prevent paper jams when directly inserting the thermal transfer paper, cut a piece of thermal transfer paper and stick it on ordinary A4 paper before printing, and print on the smooth side of the thermal transfer paper. After printing, wait until the thermal transfer paper has cooled down before the toner is completely fixed and transfer is performed.

Thermal transfer

The heat transfer machine needs to be preheated 5 minutes in advance and set to about 180°C.

The copper-clad laminate is polished with sandpaper first, and then the invisible oil stains on the surface are cleaned with washing powder. After cleaning, do not touch it with your hands and let it dry naturally (it is better not to wipe with paper).

Cut the printed thermal transfer paper into a suitable size, and fix it on the copper-clad laminate with heat-resistant paper tape.

Put it into the heat transfer machine; heat transfer about five times. Slowly peel off the heat transfer paper from one side. If the transfer is not acceptable, you can cover it and transfer it several times; if there is a small amount of broken lines, you can use a thin marker to draw on it (do not use an oily marker to smear a large area and it will be difficult to clean up later).

The copper-clad laminate should be completely cooled before it corrodes. Otherwise, it is easy to drop ink.

Corrosion

Fill the etching tank with etchant solution, turn on the heating rod, and heat the etching solution until the temperature reaches about 50 degrees; do not exceed more than 60 degrees. Put the completely cooled CCL into the corrosive solution. Turn on the air pump and let in air to accelerate the reaction. The color change is seen where there is no ink, the copper foil is corroded, and the substrate is exposed. When the ink is not corroded, it can be taken out. If it is left for too long, the ink area may start from the edge and slowly be eroded. 5. Remove the ink and clean it with a brush dipped in alcohol or laser toner remover, brush off the toner, and then clean with water.

Further processing

Use an electric drill to make holes. Generally, use a drill with a diameter of about 0.6mm for the pins. Be careful as the drill can break. A saw can also be used for cutting.

The post High Quality Single Sided PCB Manufacturer appeared first on RAYMING PCB.

Introduction

Printed circuit boards (PCBs) are becoming increasingly complex to accommodate higher density components and more sophisticated functionality. A growing trend is the use of boards with a large number of layers – 8, 10, 12 or more. In particular, many advanced designs are moving to 10 layer PCBs.

While providing more real estate for routing complex circuitry, manufacturing quality multilayer PCBs introduces challenges not present with simpler 2 layer or 4 layer designs. Great care must be taken designing the layer stackup and meeting fabrication capabilities to produce a fully functional 10 layer board.

This article provides a comprehensive guide to engineering and manufacturing considerations for high quality 10 layer PCBs. We’ll cover key stackup strategies, layer sequence, material selection and fabrication processes to yield a robust multilayer board.

Benefits of 10 Layer PCBs

Adding more layers provides several advantages that become essential for dense, high speed designs:

• More routing channels – With 10 layers, routing congestion is greatly reduced allowing complex, high pin count ICs.
• High speed design – Proper stackup essential for controlled impedance lines on inner layers.
• Smaller board sizes – More compact layout fitting into smaller enclosures.
• Higher component density – Allows minimum component spacing and footprint size.
• RF/high frequency design – Additional layers help control losses, parasitics and shielding.
• Complex power distribution – Extra layers provide power planes and decoupling capacitors near ICs.
• Mixed signal separation – Digital and analog signals can be isolated on separate layers.

For these reasons, the transition from 4 layer to 6 or more layers is common as PCBs must support more advanced functionality. However, the fabrication process also increases in complexity.

Challenges of High Layer Count PCBs

While offering advantages, moving to a 10 layer PCB also creates difficulties to address:

• Increased cost – Each additional layer adds expense for materials, processing time and lower yields.
• Panelization strategy – Must allow handling of thin multilayer panels with many small boards.
• Registration – Tighter alignment tolerances are needed for high density vias between layers.
• Aspect ratios – High layer count leads to thinner individual layers and higher aspect ratio holes.
• Fabrication limits – Not all shops can produce true 10 layer boards within their capabilities.
• Testing – Requires rigorous testing for potential issues like microvias or lamination voids.
• Rework difficulties – Repairing or modifying multilayer boards is much harder after fabrication.

With careful planning, these challenges can be avoided through robust stackup design, strict manufacturing standards and working with capable fabrication partners.

10 Layer Stackup Design

The sequence of material layers and their functions is key to maximizing routing area and isolating critical signals. Here are some best practices for 10 layer stackup:

Layer Sequence

The table below shows a typical 10 layer buildup sequence. Signal layers are labelled 1-10 while plane layers are labelled GND or PWR:

• Ground and power plane layers are inserted every 2-3 signal layers to provide decoupling capacitors the shortest distance to ICs.
• High speed signals requiring impedance control are routed on layers 4-7 near the board center to minimize skew and attenuation.
• Layer 10 should be avoided for critical signals since registration capability often decreases for outer layers.

Dielectric Materials

Common PCB laminates like FR-4 can be used for 10 layer boards. Some considerations:

• Standard 1.6 mm FR-4 thickness is difficult beyond 6-8 layers. Thinner laminates of 0.8-1.2mm are preferable.
• Low Dk glass reinforced materials are better for higher frequencies compared to standard FR-4.
• Tg (glass transition temperature) should be >170°C for lead-free soldering and high reliability.
• Tight weave glass styles minimize resin pocket depth for maximum dielectric consistency.

Copper Thickness

Ultra-thin copper foils down to 1⁄4 oz (7 μm) may be needed on inner layers to achieve fine trace/space. However, thicker copper is desirable for current carrying layers:

Mask Defined Pads

Solder mask defined land patterns are preferable for higher density component pads which improve registration tolerance. The solder mask layer defines the pad geometry rather than the copper layer.

Impedance Control

Controlled impedance lines require very tight stackup tolerances. Coordinate with your PCB fabricator on required stackup accuracy. 10 layers provides multiple possible configurations for matched Z0.

Following these guidelines will maximize the routability and performance of a 10 layer PCB while meeting fabrication capabilities.

10 Layer PCB Fabrication

Achieving a high quality 10 layer board requires advanced fabrication processes. Here are key considerations during manufacturing:

Layer Registration

Typical registration between layers is around 75-100 μm for lower layer counts. However, 10 layers may require 50 μm or tighter registration, involving precision drilling and careful layer alignment during lamination.

Hole Wall Quality

With over 30 drilled holes required for connectivity through all 10 layers, excellent hole wall copper and resin coverage is mandatory. Semi-additive or high throwing power electroless processes produce the most reliable via connections.

Thin Core Requirements

Most 10 layer boards will utilize thinner dielectric cores compared to typical 1.6mm. Panel yields decrease as core thickness drops below 0.8mm, so frame design and handling becomes critical.

Oxide Alternative Processes

Oxide alternative chemistries produce finer line resolution compared to traditional subtractive etch when working with ultra-thin inner layer copper foils. This avoids over-etching during multilayer inner layer patterning.

Test Coupons

Inclusion of microsection coupons on panels allows evaluating layer quality and registration under a microscope during fabrication. These can catch potential issues like resin voids before completing the multilayer build.

Electrical Test

Testing for potential shorts between traces requires flying probe testers or fixtures to access inner conductors. IST or boundary scan testing can also verify interconnect reliability of hidden vias.

Panel Design

Frame and panel layout must provide adequate tooling holes for registration while minimizing stress on thinner multilayer boards during depanelization. Large panels with many small boards require subdivision into smaller panels.

By partnering with a high density PCB manufacturer experienced in true 10+ layer boards, potential pitfalls can be avoided to produce a reliable, functional multilayer PCB. Expect higher costs but maximize value through optimized stackup design.

Thermal Management

The insulation property of FR-4 laminate materials leads to thermal challenges when sandwiching many conductive copper layers. Here are some ways to mitigate excessive thermal rise in multilayer PCBs:

• Incorporate thermally conductive dielectric materials like aluminum oxide or boron nitride filled polymers.
• Allow adequate airflow and heat sinking on outer surfaces where components dissipate significant thermal energy.
• Use multiple smaller vias in parallel to conduct heat between layers. Copper fills inside blocking air pockets in holes.
• Consider thermal vias under hot components connecting directly to backside metal heat sinking features.
• Specify laminates with higher thermal conductivity if high power components are used.
• Model the thermal performance early in design process using thermal simulation and finite element analysis tools.

With careful engineering, even high power dissipating 10 layer boards can be effectively cooled.

Design for Manufacturing

Here are some 10 layer board guidelines to maximize manufacturing yield and minimize cost:

• Allow 5-10X spacing around panel edges for tooling and clamping pressure.
• Follow minimum annular ring, hole size, and trace spacing rules provided by your fabricator.
• Use least number of different hole sizes. All holes below 0.15mm require advanced drilling equipment.
• Minimize use of blind and buried vias to reduce process steps. Through hole vias are most reliable.
• Maintain symmetry from board centerline whenever possible as registration decreases on outer layers.
• Allow test points access to internal layers for validation of all nets.

Early engagement with your PCB production partner can inform design choices and avoid problematic features.

Conclusion

Migrating to a 10 layer PCB stackup enables increased routing density, integrated shielding, impedance control, and power distribution needed for cutting edge electronics. However, fabricating quality multilayer boards requires careful stackup planning and advanced manufacturing capabilities.

By applying the guidelines in this article around stackup sequence, material selection, hole registration, panelization and thermal management, engineers can fully utilize 10 or more layers for their complex designs. Partnering with a shop experienced in high layer count boards ensures achieving the quality and functionality required to maximize your product’s capabilities and service life.

Frequently Asked Questions

What are the most common layer counts beyond 6 layer PCBs?

The most common complex PCBs are typically 8, 10, or 12 total layers. Component density and routing channels generally drive the need for more layers. High frequency designs may use additional layers for shielding.

What is a typical dielectric thickness for a 10 layer board?

Because of the total thickness constraints, 10 layer boards typically use thinner dielectric cores in the range of 0.8mm to 1.2mm, compared to 1.6mm commonly used in simpler 4 layer boards. This maintains a reasonable overall thickness.

What are the disadvantages of using thin laminate materials?

Thinner laminate cores decrease panel rigidity, making handling more difficult and lowering fabrication yield. Registration and line resolution also decrease on more flexible boards. Some exotic materials are limited in thin core availability.

Why is symmetry important in 10 layer PCB stackups?

A symmetric sequence of dielectric materials and copper layers minimizes warpage and internal stresses. Thermal expansion differences can cause bowing or delamination with an asymmetric construction.

What special considerations are needed for buried and blind vias?

Buried and blind vias require additional processing steps and yield loss over standard through hole vias. The layer transitions must also be carefully modeled for impedance control. Tighter registration capability is needed.

The post High Quality 10 Layer PCB Manufacturing and Stack-up Guidelines appeared first on RAYMING PCB.

8 Layers PCB Board

8 layers Printed circuit board is generally installed into compact devices that have very restrict requirements of spacing, such as laptop motherboard, communication backplane, wearable watch etc. Due to its complexity and high cost of manufacturing, your 8 layers PCB fabrication should be handled by a reliable and experienced manufacturer. RayMing particularly targets on high-end PCB Manufacturing and assembly services for 10 years and a variety of customers witness the good quality and outstanding services. Our advanced production lines and responsive team would make you stay comfortable without any hassle since you place the order to us.

8 Layer Prototype PCB

The 8-layered Prototype FR-4 PCB is a circuit board with 8 layers that are stacked firmly together with predefined and dependable mutual connections between the layers. An 8 layer FR-4 PCBs has more complex structure. Twisted Traces is a reputable name in the field of manufacturing 8 layer prototype PCBs.

1. It has multiple power and ground planes- a digital ground plane helps prevent noise coupling.
2. It provides more planes for shielding signals from other signals on adjacent layers
3. More layers aid in routing signals that need matching
4. For analog signals especially those with RF, isolation and impedance control on traces is needed.

8 Layer PCB Instant Quote

In terms of a custom printed circuit board, our 8 layer PCB Instant Quote is the fastest turn-time at the best price that we have to offer. For on-demand pricing and ordering for your next printed circuit board project,Get Fast Quote you can contact our online customer support , or send email to sales@raypcb.com , Get 8 Layer PCB Quote Now !

With the constant development in the electronics industry, there has been improvement in PCBs manufacturing. This development has pushed PCBs towards increasing demands such as high speed, reliability, miniaturization, and better functionality which lead to the fabrication of multilayer PCBs. Multilayer PCB are available in different layers which include 4 layers, 6 layers, 8 layers, 10 layers, etc.

These PCBs consist of prepreg and double-sided or single PCBs that are stacked together to produce multilayer PCBs via a predefined mutual connection between them.  8 layer PCBs have gained popularity in different fields due to their exceptional electrical and mechanical properties.  

What is an 8 layer PCB?

An 8 layer PCB is a type of multilayer PCB that provides ample routing space for applications that need multiple power islands. This printed circuit board can help to enhance EMC performance by the addition of two planes.

This board is often mounted on compact devices like motherboard, wearable watch, backplane, etc. The increase in the cost of 8 layers PCB justifies the cost increase to achieve great EMC performance. An 8-layer PCB stackup is made up of four planes and four wiring layers connected by seven rows of dielectric material.

This PCB features a six-layer board with improved EMC performance. An 8-layer PCB is sealed with a solder mask at the bottom and top.

An 8 layer stackup should follow this pattern;

• Signal 1
• Ground
• Signal 2
• Power
• Ground
• Signal 3
• Power
• Signal 4

Materials Used for Fabricating an 8-layer PCB

The type of material an 8 layer PCB stackup consists of determines its performance. Thus, you need to be careful when choosing materials during the production process. To produce high-performance PCB, the best materials are substrates and conductive materials.

Substrates

Substrates like glass-epoxy materials help to insulate heat and signals. This helps you to handle the stackup better even in applications with high temperatures. Substrate materials have a great glass transition temperature that maintains the solidness of the PCB stackup.

Conductive materials

Copper is the most effective conductive material utilized in the fabrication process of the layer stackup. This material is an ideal option since it is a good conductor of heat, allowing proper signal transfers and minimizing heat accumulation on the device. Copper is also a cheaper alternative to other materials like silver and gold which are very expensive.

Advantages of 8 Layers PCB Stackups

8 layer PCB stackups offer a number of benefits which makes them an ideal alternative to other circuit board materials. Below are the advantages of these PCBs;

Minimize vulnerability: 8 layers PCBs reduce the vulnerability of a device, hence, increase the overall performance. This helps to shield the internal layers from noise, thereby reducing its vulnerability to external forces.

Reduce Radiation: This type of multilayer stackup helps to get rid of any radiation that might occur in high-speed applications. Unlike other stackups, 8 layers PCBs get rid of electromagnetic interference radiation.

Reduce the cost of operation: 8 layers PCB stackups are a cost-effective option. As regards replacements and cleaning, this stackup saves a lot of money. This means that an 8-layer PCB stackup requires low maintenance and is very durable.

Increase functionality: Opting for an 8-layer PCB will help to improve the speed and functionality of the devices they are used for. This printed circuit board is more reliable and functional in different applications. This PCB features over 4 layers of conductive materials that enhance the signal traces.

Applications of the 8 layer PCB Stackup

The 8 layer PCB stackup is the commonest type of stackup used in most appliances. This multilayer PCB is functional in several applications such as;

• Medical industry
• Automobile industry
• Manufacturing industry
• Chemical processing industry
• Aviation industry

Factors that Determine the Cost of an 8 Layer PCB Stackup

The fabrication of an 8 layer stackup costs money and there are several factors that contribute to cost.  This type of multilayer PCB stackup goes for about $3, however, certain factors determine the price.

Size of the board: The printed circuit board’s size has to do with the components in it. When there are more components on the board, the size of the PCB will increase. An increase in size will result in an increase in the fabrication cost of the circuit board.

Type of finish: This is another factor that contributes to the cost of an 8 layer PCB stackup. There are several finish options, so the type you choose will determine the PCB cost. Finishes like HASL, ENIG, ENEPIG, and IMM Sn are some of the popular finishes available.

Thickness: The thickness of a circuit board has to do with the materials that enhance the strength of the board. The thicker a circuit board is, the higher its price. The type of materials used in designing the PCB can determine the thickness of the board.

Size of the holes: If the board requires more holes, the cost of design and manufacturing will increase. Thinner holes will require more work before the circuit board can be produced.

Custom specifications: If you request specific configurations for your PCB design, this will increase its cost. More demands for configurations and customizations often increase the cost of producing circuit boards.

Guidelines for a Standard 8-Layer PCB Stackup

It is important you understand that some guidelines need to be met to achieve better performance. If you want a board that delivers better performance, there are guidelines that help you achieve that.

Proper routing direction: For an 8 layer stackup, the application requirements determine the number of layers of signal layers. In a case where there are six signal layers, there must be a perpendicular routing for the signal traces on the adjacent layers. This helps to reduce crosstalk, signaling the significance of various signal routines on the layer stackups.

Ground planes alignment: When the ground planes are split it may result in discontinuity of impedance. The components on the external layer must have extremely low impedance. Also, the components must connect to the internal ground planes through the vias.

Proper return path: You must ensure that the return paths are short enough to eliminate interaction with other components on the PCB.

Buried or blind vias: Another option to consider is utilizing blind or buried vias which will maximize the available space for component routing.  You must ensure that you can place the blind via on the board.

The Designing Process of an 8 layer PCB Stackup

The design process of a standard 8-layer PCB starts with a working design. This means that you should determine the type of 8-layer stackup you intend to use. This process will help you achieve a good stackup.

Creation of Idea

First things first, you need to determine the type of 8-layer PCB you need. You can then look for the best way to ensure the PCB stackup works. Select designing software you can use in the designing process. After that, develop a schematic i.e the PCB blueprint.

After developing a schematic, you will add every single piece of information you want to the stackup. The designing process will start with a blank page on the designing software.

Inclusion of component

You will start the designing process by including all the required details on the stackup. Specify the stackup’s shape and the number of layers. Then, you will ink all the details on the schematic. Ensure you review all information on the design and change what is necessary.

Then, you must define the designing rules and be certain that you follow them in the designing process. Don’t take any of these rules for granted so that it won’t affect the stackup’s performance.

Placement of component: At this stage, you will have to determine where other components will be placed. You will also have to determine how to arrange the layers and position drill holes. After this, all the route traces on the stackup will be positioned and then add labels and identifiers. Doing all of these will help you produce the HDI PCB design.

Frequently Asked Questions

What type of vias can be utilized in an 8-layer stackup?

There are different types of vias you can utilize in this type of multilayer stackup. These vias include buried vias, through-hole vias, vias in pads, microvans, and blind vias.

What kinds of surface finishes can be applied on an 8-layer PCB stackup?

The kind of surface finish on an 8-layer PCB determines its performance.  Some surface finishes you can choose for your 8-layer PCB include; immersion silver, electroless nickel immersion gold, organic solder ability preservative, lead-free hot air solder level, etc.

Conclusion

In recent times, the 8-layer PCB stackup has become popular. It is important to know that the application of this multilayer stackup is increasing over time. Opting for an experienced 8 layer PCB manufacturer is vital. They will offer you the best stackups that suit your application requirements.

An 8-layer PCB increases the working speed of complex appliances. This stackup improves the signal integrity of various designs. The design of an 8 layer PCB might take some time due to its complexity. An 8 layer PCB manufacturer must be well-detailed to create a good design.

The post High Quality 8 Layer PCB Manufacturing appeared first on RAYMING PCB.

Printed circuit boards (PCBs) have evolved from simple single or double layer boards to complex multilayer boards with 6 or more layers to accommodate increasing component density and interconnectivity needs. 6 layer PCBs provide more flexibility for routing, plane separation and enable partitioning of circuits across layers.

However, designing the 6 layer stackup requires careful planning to utilize the layers effectively and avoid signal integrity issues. Key considerations include layer sequence, reference planes, material selection, copper weights, trace routing and via design. This article provides a detailed overview of 6 layer PCB stackup configurations, thickness calculations and manufacturing processes.

6 Layer PCB Stackup Configuration

The 6 conductive copper layers in a multilayer PCB are arranged in a predetermined sequence along with dielectric materials separating them. This is referred to as the layer stackup. Some key guidelines for 6 layer stackup design:

Layer Sequence

The conductors are numbered sequentially with the topmost layer being Layer 1. A typical 6 layer board stackup has:

Layer 1: Top/Component layer

Layer 2: Reference plane 1

Layer 3: Signal/Plane layer 2

Layer 4: Signal/Plane layer 3

Layer 5: Reference plane 2

Layer 6: Bottom layer

The top and bottom layers are used for component placement and routing. The inner layers are used for signals and reference planes.

Reference Plane Placement

The reference planes (ground and power) should be adjacent to routing layers for controlled impedance. A continuous ground plane next to signals is highly recommended.

Plane Splits

Reference planes can be split into analog and digital power sections to provide clean isolated supplies to sensitive analog circuits.

Symmetry

Symmetrical arrangement with reference planes above and below the mid layer provides optimal signal integrity. Asymmetrical stackups also used when needed.

Signal Routing

Route critical high speed or noise sensitive signals on inner layers sandwiched between planes. Avoid routing them on outer layers.

Breakout Vias

Use breakout/stub vias when routing inner layer traces to outer layers. Confines any stub effects.

Minimum Spacing

Follow board fabricator’s design rule check (DRC) guidelines for minimum trace width, spacing, annular rings.

Common 6 Layer Stackup Arrangements

1. Symmetrical Arrangement

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Layer 1: Signal Layer 2: Ground Layer 3: Signal Layer 4: Power Layer 5: Signal Layer 6: Ground Layer 7: Signal

• Identical reference planes above and below mid layer
• Excellent signal integrity performance
• Widely used for digital, analog, RF designs

2. Asymmetrical Arrangement

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Layer 1: Signal Layer 2: Ground Layer 3: Signal Layer 4: Power Layer 5: Power Layer 6: Ground Layer 7: Signal

• Permits splitting power plane into sections
• Discontinuous ground planes affect signal quality
• Used when power distribution needs warrant it

3. Hybrid Arrangement

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Layer 1: Signal Layer 2: Ground Layer 3: Signal Layer 4: Ground Layer 5: Power Layer 6: Ground Layer 7: Signal

• Top and bottom ground planes for signals
• Mid power plane for splitting
• Balances signal integrity and power needs

6 Layer PCB Stackup Thickness Considerations

The overall thickness of a 6 layer PCB depends on:

• Copper layer thickness
• Dielectric layer thickness
• Number of lamination cycles

Copper Layer Thickness

Typical copper weights:

• Outer layers : 1 oz (35 μm)
• Inner layers: 1 oz or 0.5 oz (18 μm)
• Plane layers: 2 oz (70 μm) recommended

Heavier copper allows higher current carrying capacity.

Dielectric Layer Thickness

Typical dielectric layer thickness:

• 8 mil to 14 mil per layer
• 112-170 μm glass epoxy FR4 material
• Thinner dielectrics help minimize layer to layer capacitance

Lamination Cycles

A 6 layer board can be fabricated by:

• 2 lamination cycles – Bottom 3 layers pressed first, then top 3 layers
• 3 lamination cycles – Bottom 2, mid 2 and top 2 layers bonded

2 lamination cycles results in lower thickness variation versus 3 cycles.

Example 6 Layer PCB Stackup Thickness

Here is a sample 6 layer PCB stackup with typical thickness values:

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Layer Type Thickness Layer 1 - Top Signal 1 oz (35 μm) Layer 2 Ground 2 oz (70 μm) Layer 3 Signal 1 oz (35 μm) Layer 4 Signal 1 oz (35 μm) Layer 5 Power 2 oz (70 μm) Layer 6 - Bottom Signal 1 oz (35 μm) Dielectric 10 mil (254 μm) Total Thickness 6 Layers 110 mils (2.79 mm)

This is a symmetrical arrangement with approximately 110 mils (2.79 mm) total board thickness. Thinner dielectrics or copper can be used to reduce overall thickness. 8 layer boards typically range from 130 mils to 200 mils thickness.

6 Layer PCB Design and Manufacturing Process

The typical workflow for assembling a 6 layer PCB is:

1. Design

• Create schematic, layout, stackup in PCB design software
• Floorplan components, route traces, assign plane layers
• Design rule checks, signal integrity simulations
• Panelization, generate Gerber and drill files

2. Fabrication Data

The board fabricator reviews:

• Layer stackup and netlist
• Material selection
• Trace widths, spacing, annular rings
• Hole sizes, drill data, test points
• Panel drawing, breakaway tabs, fiducials

3. Inner Layer Processing

• Coat photosensitive dry film on copper clad laminate
• Expose dry film with circuit pattern using artwork/laser
• Develop and strip to form desired copper pattern
• Etch away unwanted copper, remove resist coating
• Clean and prepare layers for lay up

4. Lay Up

• Stack material layers as per 6 layer sequence
• Align layers precisely using fixtures and tooling pins
• Layup can be symmetrical or asymmetrical
• 2 or 3 lamination cycles followed

5. Lamination

• Layers bonded using high pressure and temperature
• Adhesive prepregs melt, flow and cure to form multilayer
• Bonds layers with intermediate dielectric
• Autoclave, hydraulic or thermal press used

6. Outer Layer Processing

• Drill holes for vias using NC drill machines
• Plate copper in hole walls to form barrel interconnects
• Pattern outer layers using similar imaging process
• Strip/etch to form signal layers with pads/traces

7. Solder Mask & Silkscreen

• Liquid Photoimageable Solder Mask (LPSM) applied
• Exposed and developed to form solder masking
• Silkscreen layer printed for component legends

8. Surface Finish

• Exposed copper plated with finish like HASL, ENIG, Imm. Tin
• Provides solderability and protects copper traces

9. Routing and Scoring

• Individual boards routed from panel using V-cut saws
• Breakaway tabs retain boards in panel during fabrication
• Test points added for probing circuits

10. Final Testing

• Bare PCBs electrically tested for shorts, opens using fixtures
• Automated optical inspection (AOI) to check flaws in assembly
• Impedance, signal integrity tests for critical boards

The fabricated 6 layer PCBs are then delivered to customers for component assembly and device integration.

Key Benefits of 6 Layer PCBs

Some of the key benefits of using 6 layers versus 4 layers:

• Additional signal layers for routing dense designs
• Ability to segregate power and ground planes
• Inner signal layers shielded from EMI/noise
• Controlled impedance environment for high speed signals
• Flexible power distribution to circuits
• Handles greater component density
• Overall smaller board footprint area

However, 6 layer PCBs have higher fabrication cost and complexity versus 4 layer boards. The additional layers should be leveraged judiciously from a design perspective to maximize the advantages.

Guideline for Selecting 4 Layer vs 6 Layer

Here are some criteria to decide between 4 and 6 layer boards:

Consider 4 layers for:

• Low-mid complexity designs
• Smaller board size < 150 cm2
• Only 2 or 3 major voltage domains
• Lower signal speeds < 1 Gbps
• Standard density interconnects
• Cost sensitive applications

Consider 6 layers for:

• Complex, dense component layouts
• Larger board area >200 cm2
• Multiple power domains and levels
• High speed signals > 2 Gbps
• Sensitive analog and RF circuits
• Easy routing of traces on inner layers
• Looser impedance control requirements

Conclusion

Designing an optimal 6 layer PCB stackup requires careful planning to utilize the layers effectively. Key considerations include selecting the right symmetrical or asymmetrical arrangement, intelligent plane splits, optimal dielectric materials, and routing critical signals on inner layers. Following sound stackup, impedance and routing guidelines helps utilize the full capabilities of the 6 layer board. The fabrication process also necessitates strict process controls to bond and pattern the multiple layers reliably into the finished PCB. With growing complexity and higher performance requirements, 6 layer PCBs are becoming the norm for many advanced designs today.

Frequently Asked Questions

Q1. What are the typical dielectric materials used in a 6 layer PCB?

Some commonly used dielectrics in 6 layer PCBs are:

• FR-4 Glass Epoxy – Most widely used PCB material
• Nelco N4000-13, N4000-6e – Low loss, Tg 140°C-150°C grades
• Isola FR408, IS410 – High reliability, lead-free compatible
• Arlon 85N, 55N – Low Dk for high frequency applications
• Rogers RO4350B, RO4835 – High frequency circuit materials
• Panasonic Megtron 6 – Low Df glass fabric material

Q2. What are the key considerations when selecting dielectric thickness in a 6 layer board?

Important factors when choosing dielectric thickness are:

• Target impedance – Thinner dielectrics help achieve higher impedance
• Layer to layer capacitance – Thinner dielectrics reduce capacitive coupling
• Glass content – Higher glass assists in controlling shrinkage
• Fabrication capability – Thinner materials may need more lamination cycles
• Signal frequencies – Thinner dielectrics better for higher frequencies
• Overall thickness – 8-10 mils per layer typical; high layer count thinner
• Mechanical stability – Thicker materials provide more rigidity
• Cost – Thinner materials generally costlier

The post 6 layer PCB Stackup,Thickness and Manufacturing appeared first on RAYMING PCB.

4 layer PCB boards have many advantages over double-sided boards. They can be designed more compactly, they significantly improve noise immunity, and are much easier to lay out.

4 Layer PCB  Capability :

Provide free DFM Checking , We can suggest 4 layer PCB stack-up

Copper Thickness:  Max to 6 oz inner copper, 12 oz outer copper

Min Hole: 0.15mm by mechanical drilling    0.1mm by laser

PCB Thickness :0.4mm – 6.5mm

Surface Process: Immersion gold ,HASL-LF,Hard Gold,Immersion Tin

Soler Mask: Green Yellon White Black or custom

Silkscreen: White Black Yellow or custom

Accept 4 layer PCB with Blind or buried hole

100% Testing

How to Design a 4 Layer PCB Board

1. 4 Layer PCB Layer-out Guidance

Generally speaking, 4 layer circuit board includes the top layer, bottom layer, and two middle layers. The top and bottom layers are lay out with signal lines. The middle layer first uses the command DESIGN/LAYER STACK MANAGER to add INTERNAL PLANE1 and INTERNAL PLANE2 with ADD PLANE as the most used power layers such as VCC and ground layers such as GND that is, connect the corresponding network labels. Please note: you should not use ADD LAYER. This will increase MIDPLAYER, which is mainly used for multi-layer signal line placement.

PLANE1 and PLANE2 are two layers of copper connecting the power supply VCC and the ground GND. If there are multiple power sources such as VCC2 or GND2, first use a thicker wire in PLANE1 or PLANE2 or FILL. At this time, the wire or the corresponding copper ground is not visible, and the wire or filling can be clearly seen against the light.

To delimit the power or ground plane (mainly for the convenience of the PLACE/SPLIT PLANE command later), use PLACE/SPLIT PLANE to delimit the area in the corresponding areas of INTERNAL PLANE1 and INTERNAL PLANE2. VCC2 copper and GND2 copper should not be in the same PLANE as VCC. Please note that different network surface layers in the same PLANE should not overlap if possible.

Suppose SPLIT1 and SPLIT2 overlap in the same PLANE (SPLIT2 is inside SPLIT1). The two pieces are automatically separated according to the SPLIT2 border (SPLIT1 is distributed on the periphery of SPLIT). Pay attention to the pads or vias of SPLIT1 when overlapping; don’t try to connect SPLIT1 to the area of SPLIT2. At this time, the via holes in this area are automatically connected to the corresponding copper in the same layer. The DIP footprint components and plug-in parts that pass through the top and bottom boards will automatically get away from the PLANE in this area. Click DESIGN/SPLIT PLANES to view each SPLIT PLANES.

The Layer Setting and the Division of the Internal Electric Layer of Protel99

There are two types of electrical layers in PROTEL99. Open a PCB design file and press the shortcut key L, and the layer setting window appears. The one on the left (SIGNAL LAYER) is the positive layer, including TOP LAYER, BOTTOM LAYER, and MID LAYER. The one in the middle (INTERNAL PLANES) is the negative layer, also called the INTERNAL LAYER.

These two layers have different properties and usage methods. The positive layer is generally used for pure track lines, including outer and inner lines. The negative film layer is mostly used as a ground and power layer. In the multi-layer PCB board, the ground and power layers generally use the whole piece or several large copper partitions for the circuit. You must lay copper if you use the MID LAYER, also known as the positive layer. Paving copper will make the entire design data volume very large, which is not conducive to data communication and transmission, and will affect the HDI design refresh speed. With negative film, you only need to create a THERMAL PAD at the junction of the outer and inner layers, which is very beneficial for design and data transmission.

Add and Delete Inner Layer

In design, there are instances where it will need to add or delete layers. For example, the double-sided board is changed to a four-layer board, or the four-layer board with higher signal requirements is upgraded to a six-layer board, and so on. If you need to add an electrical layer, you can follow the steps below:

In the DESIGN-LAYER STACK MANAGER, there is a schematic diagram of the current stack structure on the left. Click the upper layer where you want to add a new layer, such as TOP, and then click ADD LAYER (positive film) or ADD PLANE (negative film) on the right to complete the addition of the new layer. If the new layer is a PLANE (negative film) layer, you must assign the corresponding network to the new layer by double-clicking the layer name.

There can only be one network assigned. Generally, a GND is sufficient for the ground layer. If you want to add a new network to this layer, such as a power layer, it can only be achieved by internal segmentation in the subsequent operations. Therefore, you first have to allocate a network with a large number of connections.

If you click ADD LAYER, a MID LAYER (positive film) will be added, and the application method is the same as the outer circuit. Suppose you want to apply a mixed electrical layer with both wiring and a large copper surface for power. In that case, you must use the positive layer generated by ADD LAYER to design (see the reason below).

Slip of the Inner Electrical Layer

If several groups of power supplies are in the design, you can use inner layer division in the power layer to distribute the power network. The command to be used here is PLACE-SPLIT PLANE. Then set the layer in the dialog box that appears, specify the network to be allocated for the split at CONNECT TO NET, and place the split area according to the copper paving method.

After the placement is complete, the holes with the corresponding network in this segmented area will automatically generate flower hole pads, which completes the electrical connection of the power layer. You can repeat this step until all power is allocated. When the inner electric layer needs to allocate more networks, it is more troublesome to divide the inner layer and require proper experience.

There is also a problem to be noted here: Excluding PLACE FILL, there are two electrical connection methods for large copper in PROTEL. The first is POLYGON PLANE or ordinary copper paving. This command can only be applied to the positive layer, including TOP /BOT/MID LAYER. The other is SPLIT PLANE or the internal electrical layer division. This command can only be applied to the negative film layer or INTERNAL PLANE. Attention should be paid to distinguish the scope of use of these two commands. Modify the command of split copper plating is EDIT-MOVE-SPLIT PLANE VERTICES.

2.How to design the stack up when designing a 4 layer PCB board?

In theory, there are three options.

Option 1:

One power supply layer, one ground layer, and two signal layers are arranged as below:

TOP (signal layer);

L2 (ground layer);

L3 (power layer);

BOT (signal layer).

Option 2:

One power supply layer, one ground layer, and two signal layers are arranged as below:

TOP (power layer);

L2 (signal layer);

L3 (signal layer);

BOT (ground layer).

Option 3:

One power supply layer, one ground layer, and two signal layers are arranged as below:

TOP (signal layer);

L2 (power layer);

L3 (ground layer);

BOT (signal layer).

Signal layer

Ground layer

Power layer

Signal layer

What are the advantages and disadvantages of these three options?

Option 1: The main stack-up design of the four-layer PCB is a ground plane under the component surface. The key signal is preferably the TOP layer. As for the layer thickness setting, here are the following suggestions: the impedance control core board (GND to POWER) should not be too thick in order to reduce the distribution impedance of the power supply and the ground plane to ensure the decoupling effect of the power plane.

Option 2: In order to achieve a certain shielding effect, the power and ground are placed on the top and bottom layers. However, this method has the following defects:

1) The power supply and the ground are too far apart. The plane impedance is large.

2) The power supply and ground plane are incomplete due to the influence of electronic component pads. Because the reference layer is incomplete, the signal impedance is not continuous.

In fact, due to a large number of surface-mount components, the power supply and ground of the solution can hardly be used as a complete reference layer. The expected shielding effect is excellent, but it is challenging to implement; it has a limited scope of use. However, in individual boards, it is the optimal layer setting option.

Option 3 is similar to option 1 and applies to the condition where the main device is wired in the bottom layout or the underlying signal.

1.6 mm standard 4 layer PCB stack-up 

0.2mm( PP thickness)+ 1.2mm(Double side core material)+0.2mm(PP thickness)=1.6mm 4 layer PCB stackup

1.2mm typical 4 layer PCB stack-up

1.2mm thickness=0.2mm PP & coil +0.8mm double side core material+0.2m PP with copper

How to Use Altium Designer10to Draw 4 Layer Board

If you could implement double side PCB, the same can be applied to 4 layer PCB boards. The following describes how to draw a 4-layer board based on a 2-layer board.

The above picture is a 2 layer board. The below shows two layers: the top and bottom layers. The layer is the signal layer, also known as the positive film, and can do circuit layout on this layer. Others include a mechanical layer, silkscreen layer, solder mask, and so on.

Below is the 3D drawing

In the English version, press and hold the ctrl + L keys to view frequently used layers.

As shown below:

The signal layer includes the top layer and bottom layer, and the mechanical layer includes 1, 13, 15 (of course, it can be added). The mask layer has top/bottom paste, top pad layer, or solder stencil layer, and top/bottom solder is the top or bottom solder mask to prevent it from being covered by green oil. There are two silkscreen layers below, top/bottom overlay. There are other layers, the keep-out layer used to define the shape of the board, the drill drawing layer, etc.

There is also an internal plane next to the signal layer, called the internal electric layer or negative film. Only layer division can be performed on this layer, and signal wiring cannot be performed.

Click Design — Layer Stack Manager in the menu bar, as shown in the figure below:

This is the layer manager. You can easily see the layer distribution in the above figure. This board has only two layers: the top and bottom layers, both of which are signal layers. There are two more options on the right. One is “Add Layer”, the other is “Add plane”. Add layer adds a signal layer, add plane adds an internal electric layer (negative film).

To add a layer, first select a base layer. Then click on “Add Layer” to add the signal layer under the top layer.

Then you can rename the added layer, such as VCC, and add another layer as GND, as shown in the following figure:

Back to the PCB interface, you can see that there are already 4 layers.

You already know how to create 4 layers, 6 layers, even 8 to 20 layers with the same operation.

When dividing the inner electric layer, we can only divide it and could not create a circuit layout, as shown in the following figure:

Adding the internal electrical layer is to add the “add plane” in the Layer Stack Manager.

The internal electrical layer split in the figure above can be split by drawing a line with the place—line command. After the split is completed, double-click to set the network label.

Pay attention to the distribution of components when splitting the internal electrical layer and distribute the same power supply in one area to facilitate the division.

The following is the signal distribution at different layers:

Top layer：

VCC layer：

GND layer:

Since the GND layer is a whole piece of GND, it is sufficient to lay the copper. Pay attention to maintaining the integrity of the GND layer.

Bottom layer:

When open all layers as below shown:

3D drawing：

Main points of 4-layer board wiring:

Pay attention to the distribution of power supply;

Pay attention to the signal line width setting and impedance control;

Distribution of layers, how to arrange 4-layer boards;

High-speed signal return problem;

Crosstalk between high-speed signals;

How to reduce the minimum loop and reduce the EMI problem;

Placement of decoupling capacitors;

If you learn to use Altium software to draw 4 layer boards, you can also use EasyEDA, Eagle, and KiCad to draw 4 layer boards.

2 layer vs. 4 layer PCB Prices

4 layer PCB board has GND and POWER layers in the middle of TOP and Bottom layers.

Features of the 4 layer board

1) Reference plane, impedance calculation can be done

2) Shorter return path

3) More layers, simpler design

4) Higher cost than 2-layer board

Based on the wiring density in the layout, look at the densest place of the flying lines, where there are crossovers. It is judged that at least 2 layers of wiring are required, and the cost (design multiple layers regardless of the cost), signal quality consider whether to choose 4-layer board.

After the layout, it is judged how many layers to use, mainly depending on the density of the signal and the place with the most flying lines.

Why Choose to Design 4 Layer PCB

1. When there is a BGA package, the outer 2 rows can be directly pulled out to go to the top layer. The third and fourth layers can be drilled to go to the bottom layer, and the fifth and sixth rows can be drilled to go to the bottom layer. However, the inside power and ground wirescannot go out, so an additional layer design is required, and two more layers are added.
2. The power lineblocks the signal line.
3. Whenline density is not high, you can use a 2-layer board, but you can choose a 4-layer board based on signal quality considerations.

Different Manufacturing Process

How Do You Make a 4 Layer PCB

The 4-layer board is laminated based on the double-sided board. When lamination, PP, and copper foil are added on both sides of the double-sided board, it is then pressed into a multilayer board through high temperature and high pressure. In short, the 4-layer board has an inner layer. In terms of the process, some lines will be etched through the inner layer formed by lamination. The double-sided board can be drilled after cutting the raw material sheet directly.

Technology Process difference

1. Double-sided PCB with HASL surface finished process:

Cutting material grinding → drilling → electroless copper → outer layer circuit → tin plating, etching tin removal → secondary drilling → inspection → printing solder mask → gold-plated → hot air leveling → printing silkscreen → outline processing → testing → inspection

2. How do you manufacturea 4 layer PCB:

Cutting material and grinding → drilling positioning holes → inner layer circuit → inner layer etching → inspection → black oxide → lamination → drilling → electroless copper → outer layer circuit → tin plating, etching tin removal → secondary drilling → inspection →print solder mask→Gold-plated→Hot air leveling→print silkscreen→routing outline→Test→Inspection

Price difference

PCB production costs are related to the actual area and specific technology requirements. If there are no special requirements, a 4-layer board’s cost is almost 1.8 to 2 times that of a 2-layer board. This is not a linear relationship. If the 4-layer board has impedance or even a blind buried hole design, the price difference is even greater.

Altium Designer 4-layer PCB Design Tutorial

This tutorial allows beginners to get started. The software I use is Altium Designer 13, but the basic operations are similar to other software.

1.Preparation

Create a new project file, create a related schematic file, and prepare the relevant PCB design. Create a new PCB file.

2.Set the layers

In the PCB interface, click the main menu Design and then click Layer Stack Manager

As shown below:

After clicking, the following layer manager dialog box will pop up. The default is double-panel in AD, so we see only two layers of circuit.

Now let’s add a layer. First, click Top Layer on the left, and then click the Add Plane button in the upper right corner of the layer manager to add an internal electrical layer. Because we are working with a 4-layer board using negative film, you need to add an internal electrical layer and not Add Layer. Afterward, a layer will be automatically added under Top Layer. Double-click the layer, and we can edit the related attributes of this layer, as shown in the figure below:

In the item corresponding to Name, fill in VCC and click OK to close the dialog box. Rename the layer to VCC as the power layer during design. In the same way, add another GND layer. Below is the figure after completion:

3.Import network

Back to the schematic interface, click the main menu Design ==> Update PCB Document.  As shown in the figure:

After finishing the layout of the components on the PCB drawing, draw the outline of the PCB on the Keep Out Layer, as shown below:

Modify the PCB drawing size to overlap the lines of the keep out layer. First, set the grid network width to 20mil. Then click the pad symbol in the shortcut toolbar, and move the mouse to the top left corner of the keep out layer. A circle should appear in the center of the pad. Click the arrow keys on the keyboard to move the pad (click in the left direction, click in the upper direction). Press the enter key, as shown in the figure:

Set the other four corners the same way.

Then click design -> board shape -> move board vertice, overlap the four points on the drawing with the pad placed just on the keep-out line, and click the right button.

Delete the pads on the four corners.

4.Set the inner electric layer; I have divided the inner electric layer in the process here.Then execute design -> layer stack management -> double-click the GND layer, and select the GND network in the NET NAME, which is defined as the GND layer (before, it was just a GND name).

Set the VCC layer: First, enter the VCC layer, use the line place -> line to divide the VCC layer (the closed line or both ends of the line are connected to the outer pullback line), divide into different NET layers, and then click on different areas to select different NET.

At this time, we can see a virtual circle around the pad of the corresponding internal electrical layer. The color of the cross on the pad represents the color of the corresponding internal electrical layer. For example, the inner layer GND is brown, and the cross of the pad is also brown.

p.s

The pullback automatically appears around the PCB drawing after the Layer Stack Manager is set. You can double-click the inner layer to set the pullback line width.

The cross of the pad only appears when the pad is placed on the corresponding net layer. If it is placed on other layers, it will not appear. As long as the cross passes through the VCC layer, it will appear.

The post 4 Layer PCB Layout Tutorial,Stack-up design,and Cost of manufacturing appeared first on RAYMING PCB.

What is a double sided PCB?

The 2 layer PCB ( double-sided PCB )is a printed circuit board with copper coated on both sides, top and bottom. There is an insulating layer in the middle, which is a commonly used printed circuit board. Both sides can be layout and soldered, which greatly reduces the difficulty of layout, so it is widely used.

To use circuits on both sides, there must be a proper circuit connection between the two sides, as shown in the pictures below. The “bridges” between such circuits are called vias. A via is a small hole on the PCB board filled or coated with metal, which can be connected with the circuits on both sides. Because the area of the double-sided board is twice as large as that of the single-sided board, the double-sided board solves the difficulty of the single-sided board due to the interlaced layout (it can be connected to the other side through the holes), and it is more suitable for more complicated circuits than the single-sided board.

We need electronic products with high performance, small size, and multiple functions, which promotes the development of printed circuit board manufacturing to be light, thin, short, and small. With limited space, more functions can be realized, layout density has become greater, and the hole diameter is smaller. The minimum hole diameter of mechanical drilling capacity has dropped from 0.4mm to 0.2mm or even smaller. The hole diameter of the PTH is getting smaller and smaller. The quality of the PTH (Plated Through Hole) on which the layer-to-layer interconnection depends is directly related to the reliability of the printed circuit board.

Double Layer PCB Production Manufacturing process

The production of double-sided board is more complicated than single-sided board. The main reasons are as follows:

(1) The top and bottom layers of the copper coated board/laminate must be layout

(2) The circuits on the top and bottom layers should be connected with PTH.

Particularly critical among these is the PTH, which is also the core process of double-sided board production. The so-called PTH is created by coating/plating a layer of metal on the inner wall of the via to connect the printed circuits of the top and bottom layers. At present, domestic PTH mainly adopts the electroless copper plating process in China. There are two types of electroless copper plating process:

① The thin copper is electrolessly plated first, then the whole board is electroplated to thicken the copper layer, and finally the pattern transfer is performed.

② The thick copper is electrolessly plated first, and then the pattern is transferred directly.

Both of these processes are widely adopted. However, the electroless copper plating method is harmful to the environment, and it will gradually be replaced by more advanced Black hole technology, tin/palladium direct plating technology, and polymer direct plating technology.

2 Layer PCB With HASL-LF /immersion gold surface production process

Cutting —> Drilling —> Sinking/1^ST Copper Plating —> Layout —> Pattern Plating/2^nd Copper Plating —> Etching —> Solder Mask —> Legend Printing —>Immersion Tin (or Immersion Gold) —> CNC Routing —> V Cut (some boards do not need this) —> Flying Probe Test —> Vacuum Packaging

Double-sided PCB with gold plating production process

Cutting —> Drilling —> 1^ST Copper Plating —> Layout —> Pattern Plating/2^nd Copper Plating —> Gold and Nickel Plating —> Etching —> Solder Mask —> Legend Printing —> CNC Routing —> V Cut —> Flying Probe Test —> Vacuum Packaging

Multilayer HASL-LF board/immersion gold board production process

Cutting —> Inner Layer —> Layer Stack —> Drilling —> Sinking/1^ST Copper Plating —> Layout —> 2^nd Copper Plating —> Etching —> Solder Mask —> Legend Printing —> Immersion Tin (or Immersion Gold) —> CNC Routing —> V Cut (some boards do not need this) —> Flying Probe Test —> Vacuum Packaging

Multilayer plate gold plate production process

Cutting —> Inner Layer —> Layer Stack —> Drilling —> Sinking/1^STCopper Plating —> Layout —> 2^ndCopper Plating —> Gold and Nickel Plating —> Etching —> Solder Mask —> Legend Printing —> CNC Routing —> V Cut —> Flying Probe Test —> Vacuum Packaging

1. Pattern plating process

Copper clad board/Laminate —> Cutting —> Punching and drilling benchmark —> CNC drilling —> Inspection —> Deburring —> Electroless thin copper plating —> Electroplating thin copper —> Inspection —> Brushing —> Filming —> Exposure and development (or curing) —> Inspection and repairing —> Pattern plating (Cn + Sn/Pb) —> Film removal —> Etching —> Inspection and repair board —> Nickel-plated and gold-plated plugs —> Hot melt cleaning —> Electrical continuity detection —> Cleaning —> Solder mask —> Curing —> Legend —> Curing —> Shape processing —> Washing and drying —> Inspection —> Packaging —> Finished product.

Thin copper —> Thin copper electroplating —> Electroplating thin copper can be replaced by a single process of electroless thick copper plating; both have their advantages and disadvantages.

The pattern plating —> etching method of double-sided board was typical in the 1960s and 1970s. The process of Solder Mask on Bare Copper (SMOBC) gradually developed in the 1980s, and has become the mainstream process especially in precision double-sided board manufacturing.

2. SMOBC process

The main advantage of SMOBC board is that it solves the short-circuit phenomenon of solder bridging between thin circuits. At the same time, due to the constant ratio of lead and tin, it has better solderability and storage properties than hot melt board.

There are many ways to manufacture SMOBC boards, including the SMOBC process of standard pattern electroplating subtraction and then lead-tin stripping; the subtractive pattern electroplating SMOBC process of using tin plating or immersion tin instead of electroplating lead-tin; the plugging or masking hole SMOBC process; additive method SMOBC technology; etc. The following mainly introduces the SMOBC process and the plugging method SMOBC process flow of the pattern electroplating method and then the lead-tin stripping.

The SMOBC process of pattern plating followed by lead-tin removal is similar to the pattern plating process, and changes only after etching.

Double-sided copper laminate —> According to the pattern electroplating process to the etching process —> Lead and tin removal —> Inspection —> Cleaning —> Solder mask —> Plug nickel plating and gold plating —> Plug sticking tape —> Hot air leveling —> Cleaning —> Legend —> Outline —> Cleaning and drying —> Finished product inspection —> Packaging —> Finished product.

3. Main process flow of the plugging method

Double-sided copper laminate —> Drilling —> Electroless copper plating —> Electroplating copper on the whole board —> Plugging holes —> Film (positive film) —> Etching —> Removing screen printing materials/Removing plugging material —> Cleaning —> Solder mask —> Plug nickel plating and gold plating —> Plug sticking tape —> Hot air leveling —> The following procedures are the same as above to the finished product.

The steps of this process are relatively simple, and the key is to plug the pores and clean the plugged solder mask.

In the hole plugging process, if the hole plugging solder mask is not used to block the holes and the screen printing imaging, but is replaced by a special masking dry film which is then exposed to make a positive image, this is the masking hole process. Compared with the hole plugging method, it fixes the problem of cleaning the solder mask in the hole, but it has higher requirements for masking the dry film.

The basis of the SMOBC process is to first produce the bare copper double layer board PTH, and then apply hot air leveling.

Pore mechanism

Drill holes on the copper-clad board first. It then undergoes electroless copper plating and electroplating copper to form plated through holes. Both play a crucial role in hole metallization.

1. The mechanism of electroless copper

In the manufacturing process of double-sided and multi-layer printed boards, it is necessary to metallize the non-conductive bare holes (NPTH), that is, to implement electroless copper to make them a conductor. The electroless copper precipitation solution is a catalytic “oxidation/reduction” reaction system. Under the catalytic action of metal particles such as Ag, Pb, Au, and Cu, copper is deposited.

2. The mechanism of copper electroplating

The definition of electroplating is to use a power source to push positively charged metal ions in a solution to form a coating on the surface of the cathode conductor. Copper electroplating is an “oxidation/reduction” reaction. The copper metal anode in the solution oxidizes the copper metal on its surface to become copper ions. On the other hand, a reduction reaction occurs on the cathode, and copper ions are deposited as copper metal. Both of them achieve the purpose of perforation through chemical exchange, and the exchange effect directly affects the quality of perforation.

Debris plug holes

In the long-term production control process, we found that when the hole diameter reaches 0.15-0.3mm, the proportion of plug holes increases by 30%.

1. The plugging problem in the process of perforation

When the printed board is processed, most small holes of 0.15-0.3mm still use the mechanical drilling process. In the long-term inspection, we found that impurities remained in the hole when drilling.

The following are the main reasons for drilling plug holes:

When a plug hole appears in a small hole, due to the small hole’s diameter, it is difficult to remove the impurities inside it by high-pressure water washing and chemical cleaning before copper plating, which prevents the exchange of the chemical solution in the hole during the electroless copper precipitation process and makes the electroless copper lose its effect.

When drilling holes, select suitable drill and backing plates according to the thickness of the laminate, keep the substrate clean, and do not reuse the backing plates. Effective dust collection (using an independent dust collection control system) is a factor that must be considered to solve the plugging hole.

Draw circuit diagram

1. There isa variety of dedicated PCB drawing software, such as Protel, etc., which can draw multilayer (including double-sided) circuit board diagrams. The positions of the layers are aligned, and there are vias to connect the layers.The circuit is connected to realize cross circuiting and facilitate typesetting. After the layout is completed, it can be handed over to a professional board factory to become a circuit board.

2. The double-sided circuit board should be drawn into the circuit schematic diagram in turn, which can be divided into two steps. Step 1: Draw the legends of the main components such as IC on the paper according to the position of the circuit board, arrange and draw the circuit of the pins and the peripheral components appropriately, and complete the sketch. Step 2: Analyze the principle and organize the circuit diagram according to the customary drawing method. You can also use the circuit schematic software to arrange the components and connect them, and then use its automatic typesetting function to organize.

The circuits on both sides of the board should be accurately aligned. You can use the tips of tweezers, the light transmission of a flashlight, and a multimeter to measure the connection and disconnection and determine the connection and direction of the solder and circuits. If necessary, remove the components to observe the layout.

What is the difference between single-sided PCB and 2 layer PCB ?

Single-sided and double-sided boards differ in the number of copper layers. Double-sided has copper on both sides of the board, which can be connected through vias. However, there is only one layer of copper on one-sided board, which can only be used for layout, and the holes made can only be used for SMT.

Single-sided board is the most basic PCB. The parts are concentrated on one side, and the circuits are concentrated on the other side. Because the circuits are only on one side, this kind of PCB is called single-sided. Single-sided boards have many strict restrictions on the design of the circuit (because there is only one side, the circuits cannot cross and must follow separate paths), so only early circuits use this type of board.

There is layout on both sides of a double-sided circuit board, but to use layout on both sides, there must be a proper circuit connection between the two sides. The “bridge” between such circuits is called a via. A via is a small hole filled or coated with metal on the PCB, which can be connected with the layout on both sides. Because the area of the double-sided board is twice as large as that of the single-sided board, it solves the difficulty of the single-sided board due to the staggered layout (it can be passed to the other side through vias), and is suitable for use in more complicated circuits than single-sided board.

1. Raw Material

Single-sided board: Has copper foil only on one side, such as TV board.

Double-sided board: There are copper traces on both sides, connected by conductive through holes. The price is generally 7 times different (not fully defined due to different materials). There is also a kind of false double-sided board in the industry, which has no through hole connection (much lower cost).

2. Process

Single-sided PCB board: The solder joints are concentrated on one side, and components are usually inserted on the other side. Some products still have SMD components on the copper-clad side. Double-sided board: Both sides can be layout, and both can have plug-in components or SMD components.

False double-sided PCB: Generally, only one side SMT and layout on the other side. The double-sided copper cladding is connected by circuit on both sides of the component foot.

3. PCB circuit board

Single-sided board: The metal circuit that provides the connection of the parts is arranged on an insulating substrate material, which is also a support carrier for installing the parts.

Double-sided PCB : When a single-sided circuit is not enough to provide the connection requirements of electronic parts, the circuit can be arranged on both sides of the substrate, and through hole circuits are deployed to connect the circuits on both sides of the board.

4. Production process

Single-sided board: CAD or CAM CCL cutting, drilling positioning —> Opening punching mold, making screen plate —> Printing conductive pattern, curing —> Etching, removing printing material, cleaning —> Printing solder mask pattern, curing —> Printing marking legends, curing —> Drilling and punching positioning holes, punching and blanking —> Circuit inspection, test —> Solder mask and OSP —> Inspection, packaging, finished product.

2 Layer PCB : AD and CAM CCL cutting/edging —> NC drilling —> PTH —> Pattern plating —> Full plate plating —> Dry film or wet film method masking or plugging holes —> (Negative pattern) (Positive pattern) —> Copper plating/tin lead pattern transfer —> Film removal, etching —> Tin and lead removal, plug plating removal, cleaning —> Printing solder mask/legends —> Hot air leveling or OSP —> Routing/punching shape —> Inspection/testing —> Packaging/finished products.

How do you make 2 layer PCB and precautions

At present, the mainstream circuit board assembly technology in the SMT industry is “full-board reflow soldering (reflow)”. Of course, there are other circuit board soldering methods, and this full-board reflow soldering can be divided into single-sided reflow soldering and double-sided reflow. Single-sided PCB reflow is rarely used now, because double-sided reflow can save space on the circuit board, which means that the PCB can be made smaller. For that reason, most of the boards seen on the market now belong to the double-sided reflow process.

Because the “double-sided PCB reflow process” requires two reflows, there will be some process restrictions. The most common problem is that when the board goes to the second reflow, the parts on one side will be falling due to gravity, especially when the board goes to the reflow zone at high temperatures.

Generally speaking, smaller parts are recommended to be placed on the first side to pass through the reflow oven, because the deformation of the PCB will be smaller on the first pass through the reflow oven, and the precision of solder paste printing will be higher, so it is more suitable to use smaller parts.

Secondly, the smaller parts will not fall off the second time through the reflow oven. Because the parts on the first side will be placed directly on the bottom side of the circuit board, when the board re-enters the reflow zone at high temperature, they are less likely to fall off the board due to excessive weight.

Third, the parts on the first side must go through the reflow oven twice, so their temperature resistance must be able to withstand the heat of the oven twice. The general resistance capacitor is usually required to be able to pass the high temperature at least three times. This meets the requirement that some boards may need to go through the reflow again for repair.

Which SMD parts should be placed on the second side through the reflow furnace? This should be the focus.

Large components or heavier components should be placed on the second side to pass through, to avoid the risk of parts falling into the reflow furnace.

LGA and BGA parts should be placed on the second side through as much as possible, so as to avoid unnecessary remelting risks during the second pass, and to reduce the chance of empty/false soldering. If there are smaller BGA parts, it is recommended to put them on the first side through the reflow furnace.

Placing the BGA on the first or second side through the furnace has always been controversial. Although placement on the second side can avoid the risk of remelting the tin and affecting its quality, the PCB will usually deform more seriously when the second side is passed through the reflow furnace. If the PCB is severely deformed, it can be a big problem for the delicate parts to be placed on the second side, because the solder paste printing position and the amount of solder paste will become inaccurate. Therefore, the focus should be to think of a way to avoid PCB distortion, instead of whether to put BGA on the first or second side.

Parts that cannot withstand overly high temperatures should be placed on the second side through the reflow furnace. This is to prevent parts from being damaged by high temperatures.

PIH/PIP parts should also be placed on the second side to pass through the furnace. Unless the length of the solder pin does not exceed the thickness of the board, the pin protruding from the PCB surface will interfere with the steel plate on the second side, so that the solder paste printed steel plate cannot be flatly attached to the PCB.

Some components may use soldering inside, such as a network cable connector with LED lights. It is necessary to pay attention to the temperature resistance of this part to pass the reflow oven twice. If it fails, it must be placed on the second side.

When parts are placed on the second side, it means that the circuit board has already been baptized by the high temperature of the reflow oven. At this time, the circuit board has become somewhat warped and deformed, which means that the tin quantity and printing position of the paste will become more difficult to control, so it is easy to cause problems such as empty soldering or short circuits. Therefore, it is recommended not to place 0201 and fine-pitch parts on the second side through the furnace. For BGA, try to choose a solder ball with a larger diameter.

In addition, in mass production, there are actually many process methods for soldering and assembling electronic parts on the circuit board, but each process is actually determined at the beginning of the circuit board design, because the placement of the parts will directly affect the soldering sequence and quality of the assembly, and the layout will be indirectly affected.

Soldering method of double-sided circuit board

In order to ensure the reliable conduction effect of the double-sided circuit board, the connection hole on the double-sided board (that is, the PTH) should be soldered with a wire, and the protruding part of the connection wire should be cut off to avoid stabbing the hand. This is in preparation for the wiring of the board.

The essentials of double-sided circuit board soldering

1. Devices that require reshaping should be processed according to the requirements of the process drawings:that is, reshaping first and then SMT.
2. The diode should face up after shaping, and there should be no discrepancyin the length of the two pins.
3. When inserting devices with polarity requirements, pay attention to ensure that their polarity is notreversed. Roll integrated block components after SMT. No matterwhether they are vertical or horizontal parts, there must be no obvious tilt.
4. The power of the iron used for soldering must bebetween 25~40W. The temperature of the soldering iron tip should be controlled at about 242℃. If the temperature is too high, the tip is close to useless,and the solder cannot be melted when the temperature is low. The soldering time is controlled at 3~4 seconds.
5. When soldering, generally follow the soldering principle of the device from short to high and from the inside to the outside. Thecorrectsoldering time must be mastered. If the time is too long, the device, as well as the circuits on the copper clad board, will be burnt.
6. Because the solderingis double-sided, a process frame for placing the circuit board should also be made, so as not to squeeze the components for the other side.
7. After the circuit board soldering is completed, a comprehensive check should be carried out to find any missing insertion orsoldering. After quality confirmation, trim the redundant device pins of the circuit board, and then go to the next process.
8. In anyspecific operation, the relevant process standards should be strictly followed to ensure the soldering quality of the product.

Re-soldering techniques for double-sided circuit boards

When re-soldering a double-sided circuit board, it is difficult to repair because it is dirty, messy, and may have faults such as false soldering, disconnection, and poor contact.

1. Observation: Based on drawings or prototypes, get a general understanding of the physical layout.
2. Dismantling: Remove the soldered components, pins andflying leads.
3. Cleaning: Use absolute alcohol to clean the rosin and soldering on the surface of the circuit board. When cleaning, if you use a soldering iron, it will be faster and the effect will be better.
4. Layout: Clarify the layout with reference to your observations. If there is no picture, use the drawing method to assist in annotation.
5. Soldering: Solder according to the clarifiedcircuits. When re-connecting circuit with circuit, try to arrange them on the back.
6. Inspection: According to the results of the drawing or prototype and the analysis of the layout, check whether the soldering is correct and reliable, and whether the process meets the requirements.
7. Power-on test.

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