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Allowable PCB Etch Repair - EPTAC - Train. Work Smarter. Succeed

Written by Admin | Mar 29, 2013 4:00:00 AM
 

Question: We received a PCB with 3 etches connected together that were not supposed to be. Is there anyway to repair these and if so, is it compliant to IPC 610 or JSTD 001? We do know how to repair these issues, but our inspector is requiring documentation as to the acceptability of this process. Can you help with this?

Answer: I’ve tried to answer your question based upon the information provided. If more is needed please let me know.

Image Courtesy of IPC

Image Courtesy of IPC

The spacing between the conductors is 20% reduction for Class 3 and 30% reduction for Class 2 and 1.

If they are shorted together, then you have a short and it is not acceptable, or as stated in IPC-A-600, it is non-conforming.

You have to go to this procedure to remove or cut the traces and repair them so they are separate and no longer electrically connected. This procedure is from Circuit Technology:

http://www.circuitrework.com/guides/4-3-1.shtml

You can also use procedure 4.3.1 from IPC 7721, which is the same procedure.
Is the work compliant to IPC-A-610 or J-STD-001? You have to keep in mind that this is a repair process and needs confirmation from the customer to make sure that the modification is acceptable.