Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Travis A Gora

#13648

Plating Processes | 29 October, 1998

I am a recently graduated Process Engineer. I am working for a company developing and manufacturing printed circuit boards. I am looking for a web link, magazine article, book, etc which describes the processes which happen at a board house. More specifically, I want some info on the procedures (old and new) used in barrel plating on the boards. Any references will be appreciated. Thanks

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Earl Moon

#13649

Re: Plating Processes | 30 October, 1998

| I am a recently graduated Process Engineer. I am working for a company developing and manufacturing printed circuit boards. I am looking for a web link, magazine article, book, etc which describes the processes which happen at a board house. More specifically, I want some info on the procedures (old and new) used in barrel plating on the boards. Any references will be appreciated. Thanks | I too am a PCB fab and assembly process engineer with many years experience plating, imaging, drilling, and laminating. Besides the obvious PC Fabrication magazines, the best place to start is with the old MIL-STD-275 and MIL-P-55110 series design standards and fabrication specifications, respectively.

My reason for this recommendation is both documents clearly define drilling (quality, nail heading, etc.), hole wall preparation (etch back and smear removal), electroless copper deposition (quality, voiding, amount, etc.), and final plating requirements (thickness, voiding, cracking, etc.) for holes and surface conditions. Also, quality conformance test circuitry, and attendant test coupons, are defined and test requirements (before and after thermal stress) are clearly called out.

One of the big issues, and one of my favorites, always has been plating ductillity relative to process management and Z axis expansion in the hole wall under thermal stress during soldering and operation. Also, as one newly arived, we would all appreciate your focus on phosphorous content in nickel plating solutions and its affect on solder joint reliability using "flash" (electroless) gold.

Of course, these documents have given way (or are in the process of being converted) to IPC documentation that is under continual transition or improvement. Start with the Document Center in Belmont, CA (don't have number with me but 415 area code) and ask them for modest pricing on such documentation. If you are an IPC member (or not), it is possible to get all kinds of information there about the new documentation. Check out their web site.

Earl Moon

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