PCB manufacturing and design is a very complex process. This process involves mounting and connecting several components on a PCB. Therefore, it is crucial to have a check on this process. One of the best ways to ensure an error-free PCB design and manufacturing is through a design rule check (DRC).
Early detection of errors in the design stage will prevent further errors. PCB design rule check is crucial in ensuring the fabrication of quality boards. DRC errors in PCB design are very common. Also, it is important to detect these errors and correct them on time.
What is DRC PCB?
DRC PCB is a set of rules adopted by PCB designers. It helps to verify their schematic matches the manufacturing considerations of a board. With a DRC, a design can verify that the schematic and layout reflects the design margins you are incorporating in a design.
PCB design rule check is widely adopted to detect mismatches and errors. These errors include traces and widths in a PCB design. PCB designers use software to design the layout of a circuit board. Every PCB manufacturer works with a set of rules that describes various parameters. Some of the parameters specified are the minimum size of vias and the spacing between each line.
Once a PCB manufacturer gets a design, it carries out a DRC test. This test helps to verify that the design submitted matches their published standard. If there is any mismatch, the DRC PCB detects them. The designer will have to update the layout or design according to the right standards.
However, the PCB design rule check varies among manufacturers. Before PCB users submit a design to the manufacturer, they should check the DRC PCB.
PCB DRC Rules
There are a set of rules that help to detect several mistakes. These rules include:
Vertical plane change rule
Trace routing from one layer to another is a design practice that accommodates dense PCB layout. However, it is important to minimize the risk of mode radiation. Also, this rule detects the transitioning of signals from one layer to another. Also, it detects how stitching vias or stitching capacitors are placed near nets.
Crosstalk coupling rule
This rule helps to detect areas where unwanted crosstalk appears on sensitive nets. Also, crosstalk can result in functionality errors. Furthermore, it can be difficult to detect this problem manually on a PCB.
Filer placement rule
The filter placement rule detects any filter close to the pins of a connector. Filters minimize noise that may occur on a connector. Therefore, this helps to prevent radiation and shield sensitive signals. The misplacement or absence of filters can result in EMI failures.
Decoupling capacitor placement rule
It is important your PCB designs meet the demands of every component. Checking the placement of decoupling capacitors on every net is important. However, this can be time-consuming if you are checking manually. The decoupling capacitor placement rule identifies all decoupling capacitors placed improperly.
Signal supply rule
This identifies discontinuities between the supply planes of an integrated component and the reference plane of connected traces. Any violation as regards this can result in EMI failures and EMI radiation.
Ground/power width rule
This rule detects ground traces and narrow traces that aren’t wide enough. If these traces aren’t wide enough, there can be an insufficient current on the net. Therefore, this can result in several problems. Some of these problems include unnecessary heat production. Also, it can cause an inadequate power supply to components.
How DRCs can Reduce Board Re-spins
Sometimes, PCB designs experience re-spins. This will cause a significant cost for each re-spin. Therefore, electrical DRC via pcb capabilities make sure designs meet specific requirements. This can be achieved by reducing and getting rid of possible re-spins. These checks include signal integrity, electromagnetic interference, and safety checks.
Checking for Differential Symmetry with DRC
A PCB design may comprise several differential pairs. This includes 100ohm and 50ohm differential impedance. Such differential pairs are inside the constraint manager of the layout tool within a separate constraint class. The constraint class within the PCB tool will be automatically defined within the DRC tool. This is because of the tight integration between DRC and layout. Therefore, designers can make an object list from the constraint class. This enables them to choose to manage the next rule on the two differential nets.
Differential impedance traces should be properly designed for great functionality. However, there are properties that determine this functionality. They include the position of the pairs, spacing, and symmetry in the length. Therefore, the differential pair rule helps to check the consistency of these properties.
PCB designers can specify rule parameters like maximum and minimum allowable trace length. This is because the tested differential traces have particular differential impedance. Therefore, the PCB DRC helps to customize every rule for individual design parameters.
Online DRC PCB Tools
Altium Designer
This is a great online tool for PCB design rule check. Altium designer is a powerful tool that checks the integrity of a PCB design. Also, it features various options for checking PCB designs.
EasyEDA offers you a DRC function. This online tool will allow you to detect several errors. Also, this tool runs on macOS, Windows, and Linux. It is a reliable tool that features various component libraries. Also, this online tool has a cloud-based feature that allows several users to work on a similar project simultaneously.
This is one of the most reliable PCB design tools that help you to create a high-quality PCB. Furthermore, KiCad EDA runs on macOS, Windows, and Linux. Also, it offers all necessary files for PCB designs. This easy-to-install online tool is very easy to use.
What is Depth Control Routing PCB?
Depth control routing PCB is the partial routing in PCB manufacturing with a level elevation within PCB. This helps to support a high end market. Depth control routing in PCB allows the processing of bent PCBs and complex designs with great precision. Depth control routing has great benefits in a PCB assembly.
Conclusion
DRC errors in PCB design are very common. Therefore, PCB design rule check is crucial to fabricating high-quality boards. Therefore, manufacturers must ensure, they adopt this rule in their fabrication processes.
