Sometimes, the struggle that surrounds choosing an ideal laminate material for your PCB design becomes painstaking. Perhaps, it is best understood by those who have designed printed circuit boards before. For instance, what material can work for PCB applications, yet avoid interfering with your PCB attributes?
Typically, your application area will determine and influence your PCB material choice. Regardless of the application, you must become smarter to ensure a reliable, consistent, and thermally stable PCB. It becomes more critical to design a PCB for a high-power application.
So why not forget about your typical FR4 material for a moment and think outside the box? An excellent alternative in the Taconic TSM-DS3M laminate can work wonders. This article will explore Taconic TSM-DS3M material, its attributes, and how it makes your PCB better for your unique application.
Taconic TSM-DS3M – An In-depth Perspective
TSM-DS3M comes as a trendsetting and thermally stable low loss core. You can already get the picture when you start considering its Df of 0.0011 at 10GHz. It gets fabricated with consistency and predictability of RF4 (glass-reinforced epoxies). However, TSM-DS3M is a unique ceramic-filled (to reinforce) material with a low fiberglass content – mostly less than 5%. It rivals epoxies mainly in the fabrication of large format complicated multilayers.
A TSM-DS3M PCB by design proves ideal for high power areas of application. In such applications, it becomes necessary to ensure the dielectric material of the PCB conducts the generated heat away from other sources of heat. Therefore, TSM-DS3M has low CTE (coefficients of thermal expansion), especially for exerting thermal cycling.
In most instances, you will find TSM-DS3M combined with a fastRise 27 prepreg. With a Df of 0.0014 at 10 GHz, the material combination proves a perfect solution with the least dielectric losses only comparable to epoxy-like fabrication temperatures of 420-degree Celsius. Further, the characteristic low insertion losses can only compare to fusion bonding – where Teflon laminates get melted within a range of 550 degrees faradays.
Why Avoid Fusion Bonding?
Fusion bonding proves an expensive technique. Besides, it also leads to excessive movement of the material. It would help if you also watched out for the extra stress the movement causes on the plated through-hole. In an instance where you want to design a multilayer, the price or cost of poor yields will increase the ultimate cost of the final product. Therefore, we at RayMing PCB often advise alternative materials and parts like Taconic TSM-DS3M. The fastRise component of the material will allow for the sequential lamination of the product – TSM-DS3M at a paltry 420-degree Fahrenheit.
Important Notes to Consider when Designing Your PCB Using Taconic TSM-DS3M
The intended application should rank the highest in the factors you must consider when designing your PCB using Taconic TSM-DS3M. For instance, if you want to use your printed circuit board for RF or microwave application, then TSM-DS3M can become useful. It will ensure that the vital spaces between traces in couplers and filters have little to no movement with temperature due to the low CTE values of the x, y, and z-axis. Additionally, TSM-DS3M can get deployed with low-profile copper foils, which yield smooth edges on either side of the coupled lines.
If you desire variation and yield in copper weights, you should consider registration over numerous layers. Further, copper etching across the panel at times leads to non-linear movements. Consequently, you may end up with a non-registration of some of the pad’s drilled holes, ultimately leading to open circuits.
TSM-DS3M comes compatible with OhmegaPly and Ticer resistive foils. The resistor foil’s stability comes when you laminate at a low temperature, primarily when using AGC’s fastRise family prepreg. Additionally, TSM-DS3M’s intended application entails RF circuitry and thus needs an original electronic manufacturer design validation when intended for digital circuits.
Taconic TSM-DS3M Product Features
- It is dimensionally stable and a laminate with low loss attributes
- Has a Dk+ tolerance of 2.94 with a plus or minus margin of 0.05
- It has a DF of 0.0011
- Low Z-axis expansion
- Compatibility with resistive foils
- Predictable and consistent attributes during manufacturing
Benefits of a TSM-DS3M
- Industry-leading PDF of 0.0011 at 10GHz)
- A low Z-axis expansion, especially for military areas of applications
- High thermal conductivity
- A low fiberglass content of less than 5%
- Excellent dimensional stability that rivals that of an epoxy
- It allows for large format, and high layer count printed wiring boards
- It builds complicated printed wiring boards in yield with predictability and consistency
- Stable temperature DK of +/- 0.25 (at -30°C to 120°C)
- It is compatible or in tune with resistive foils
Application Areas
- Stripline and microstrip circuitry, ideal for military areas of applications
- Couplers
- Radar Manifolds
- Automotive / mmWave Antenna
- Oil Drilling
- Phased Array Antennas
- ATE Testing/ semiconductor
Thermal Coefficient of Dielectric Constant
In most cases, the dielectric constant’s thermal coefficient gets abbreviated as T, K. However, the dielectric values from dielectric test approaches depend on the specific approaches. T, K proves similar and will rely on an approach that applies pressure with securing or clamping to eradicate air gaps between the pattern cards and dielectric substrates. Whenever you measure it with a fabricated printed circuit board, variations of circuitry patterns (width and length) can get observed. It explains why the PTFE consistently demonstrates a negative T, K.
Another crucial factor encompasses molecular vibrations or interactions that escalate with temperature. It thus results in an increase in dielectric constant (Dk) with temperature. It is a common occurrence with many epoxy-based laminates. For IPC standard approaches, clamping of the samples under pressure tends to prevent the normal expansion of the laminate in the z-axis. As a result, it may not represent the military or industrial application.
Typical Values for TSM-DS3M
| Property | Test Method | Unit | Value | Unit | Value |
| Dk at 10 GHz | IPC-650 2.5.5.5.1 (Modified) | 2.94 | 2.94 | ||
| T, K (-55 to 150 degree Centigrade) | IPC-650 2.5.5.6 | ppm/°C | -11 | ppm/°C | -11 |
| Df at 10 GHz | IPC-650 2.5.5.5.1 (Modified) | 0.0011 | 0.0011 | ||
| Dielectric Breakdown | IPC-650 2.5.6 (ASTM D 149) | kV | 47.5 | kV | 47.5 |
| Dielectric Strength | ASTM D 149 (Through Plane) | V/mil | 548 | V/mm | 21575 |
| Arc Resistance | IPC-650 2.5.1 | Seconds | 226 | Seconds | 226 |
| Moisture Absorption | IPC-650 2.6.2.1 | % | 0.07 | % | 0.07 |
| Flexural Strength (MD) | ASTM D 790/ IPC-650 2.4.4 | psi | 11811 | N/mm2 | 81 |
| Flexural Strength (CD) | ASTM D 790/ IPC-650 2.4.4 | psi | 7512 | N/mm2 | 51 |
| Tensile Strength (MD) | ASTM D 3039/IPC-650 2.4.19 | psi | 7030 | N/mm2 | 48 |
| Tensile Strength (CD) | ASTM D 3039/IPC-650 2.4.19 | psi | 3830 | N/mm2 | 26 |
| Elongation at Break (MD) | ASTM D 3039/IPC-650 2.4.19 | % | 1.6 | % | 1.6 |
| Elongation at Break (CD) | ASTM D 3039/IPC-650 2.4.19 | % | 1.5 | % | 1.5 |
| Young’s Modulus (MD) | ASTM D 3039/IPC-650 2.4.19 | psi | 973000 | N/mm2 | 6708 |
| Young’s Modulus (CD) | ASTM D 3039/IPC-650 2.4.19 | psi | 984000 | N/mm2 | 6784 |
| Poisson’s Ratio (MD) | ASTM D 3039/IPC-650 2.4.19 | 0.24 | 0.24 | ||
| Poisson’s Ratio (CD) | ASTM D 3039/IPC-650 2.4.19 | 0.20 | 0.20 | ||
| Comprehensive Modulus | ASTM D 695 (23°C) | psi | 310,000 | N/mm2 | 2137 |
| Flexural Modulus (MD) | ASTM D 790/IPC-650 2.4.4 | kpsi | 1860 | N/mm2 | 12824 |
| Flexural Modulus (CD) | ASTM D 790/IPC-650 2.4.4 | kpsi | 1740 | N/mm2 | 11996 |
| Unclad Thermal Conductivity | ASTM F 433/ASTM 1530-06 | W/M*K | 0.65 | W/M*K | 0.65 |
| Peel Strength (CVI) | IPC-650 2.4.8 Sec 5.2.2 | lbs/in | 8 | N/mm | 1.46 |
| Dimensional Stability (MD) | IPC-650 2.4.39 Sec. 5.4 (after bake) | mils/in | 0.21 | mm/M | 0.21 |
| Dimensional Stability (MD) | IPC-650 2.4.39 Sec. 5.5 (TS) | mils/in | 0.15 | mm/M | 0.15 |
| Dimensional Stability (CD) | IPC-650 2.4.39 Sec. 5.4 (after bake) | mils/in | 0.20 | mm/M | 0.20 |
| Dimensional Stability (CD) | IPC-650 2.4.39 Sec. 5.5 (TS) | mils/in | 0.10 | mm/M | 0.10 |
| Surface Resistivity | IPC-650 2.5.17.1 Sec. 5.2.1 (HC) | Mohms | 2.1 x 107 | Mohms | 2.1 x 107 |
| Surface Resistivity | IPC-650 2.5.17.1 Sec. 5.2.1 (ET) | Mohms | 2.3 x 106 | Mohms | 2.3 x 106 |
| Volume Resistivity | IPC-650 2.5.17.1 Sec. 5.2.1 (HC) | Mohms/cm | 1.8 x 108 | Mohms/cm | 1.8 x 108 |
| Volume Resistivity | IPC-650 2.5.17.1 Sec. 5.2.1 (ET) | Mohms/cm | 1.1 x 107 | Mohms/cm | 1.1 x 107 |
| CTE (x-axis) (Room temperature to 125 degrees centigrade) | IPC-650 2.4.41/TMA | ppm/°C | 10 | ppm/°C | 10 |
| CTE (y-axis) (Room temperature to 125 degrees centigrade) | IPC-650 2.4.41/TMA | ppm/°C | 16 | ppm/°C | 16 |
| CTE (z-axis) (Room temperature to 125 degrees centigrade) | IPC-650 2.4.41/TMA | ppm/°C | 23 | ppm/°C | 23 |
| Density (specific gravity) | IPC-650 2.4.41/TMA | g/cm3 | 2.11 | g/cm3 | 2.11 |
| Hardness | ASTM D 2240 (Shore D) | 79 | 79 | ||
| Td (2% weight loss) | IPC-650 2.4.24.6 (TGA) | °C | 526 | °C | 526 |
| Td (5% weight loss) | IPC-650 2.4.24.6 (TGA) | °C | 551 | °C | 551 |
Aspects to Consider for Your Taconic TSM-DS3M Laminate
To design, develop, and use a Taconic TSM-DSM PCB, you must understand some basic aspects of the material. It includes storage, handling, layer preparation, lamination, etc.
Storage
If you want your TSM-DS3 material or laminate to stay perfect, you need to store it flat in a clean area and at room temperature. Additionally, the core gets preserved well when stored between stiffeners. It helps avert any unnecessary layer bending. You can use soft slip sheets to keep debris and dust from embossing into the material. What’s more? The storage conditions determine the shelf-life of the Taconic TSM-DS3M laminate.
Handling
The composition of the TSM-DS3M makes it a unique laminate for Taconic TSM-DS3M PCBs. Because of its properties, it becomes crucial to avoid any mechanical scrubbing. You also have to stop picking up the panel horizontally using either side of the edge or end.
Other handling considerations should entail the prevention of contaminant deposits on the copper or material, avoiding any panel stack up – one on top of the other. It is also crucial to avoid mechanically abrading the PTFE surface post etching.
Layer Preparation
It is crucial to acclimatize and scale when preparing the layers for lamination. However, during the actual lamination, you need to follow the set guidelines to ensure a proper and functioning TSM-DS3M PCB,
Final Thoughts
Taconic TSM-DS3M is an excellent laminate material for high-RF applications. However, while picking it in isolation might appeal to anyone, you have to remember that it works in combination with fastRise prepreg for best results.
