PCB design review

Question

Hi All, What are the steps after PCB design and before PCBA manufacturing ? i.e. PCB design review / testing process ? Please guide me !

dougw · Answer

There are lots of checklists on the net - like this one:

PCB Layout Checklist

First use all the tools in your CAD package to do net list checks and design rule checks - to ensure everything that should be connected is connected and no traces are too close together.

Make sure all ICs are properly connected to power rails.

Make sure all power traces on the card are wide enough to carry the required current.

Make sure you can access all signals of interest with a probe for troubleshooting. (appropriate test points)

Make sure every IC has adequate decoupling capacitors on its power pins.

Make sure all pins that need to be connected are connected.

Look for traces going nowhere (stubs).

Make sure you have appropriate mounting holes.

pettitda · Answer

In the old days, when PCB CAD software was new, we would go through and check the layout against the schematic to make sure all the connections were made. Now, the software is pretty sophisticated and will most likely catch any disconnected nets. If you are working on a team and there are others that have knowledge of the design then having them review the layout for compliance with design notes, component vendor layout notes, and best practices is a good idea. If you're working alone, that's not usually an option. Also, you can submit the layout to a PCB company for DFM (design for manufacturing) review. Usually this is free and will give you an indication if there is anything in the layout which will hinder manufacturing. It will also tell you if you fit into a certain category of pricing for PCBs such as trace/space requirements, number of vias, minimum/maximum drill sizes, etc. Hope this helps. In the end, the best way to find if a PCB is good or not is to build one and test it. All of the above just helps to catch dumb mistakes before you build and save time, money, etc.

PCB design review

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