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piercing of test vias at ICT

Jon O'Connell

#22398

piercing of test vias at ICT | 14 November, 2002

Has anyone had experiences of ICT test fixtures actually damaging the PCB boards - typically when they have moved away from HASL finish to OSP.

I would also like to hear more about any specific issues seen at ICT for non HASL pcb finishes

thanks - Jon

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MA/NY DDave

#22402

piercing of test vias at ICT | 14 November, 2002

Hi

Making contact has been one reported problem, so some testers put in higher force probes that then might cause problems.

If fixturing is done correctly, the OSP is done correctly, and test follows close in time after soldering little problems should occur.

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J O'connell

#22403

piercing of test vias at ICT | 14 November, 2002

What about when debugging the board

I recently saw a case where we damaged a board between - 5-10 cycles of the fixture

It's a catch 22 - where you need high force probes to breal the OSP - but the copper is hard surface, not like the solder HASL and can be damaged by strong probes if you test a board multiple times.

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MA/NY DDave

#22416

piercing of test vias at ICT | 15 November, 2002

OK

I know it is funny to have two different PWB/PCB processes, one for pre production and one post production yet it is possible if controlled and implemented in a strategy. In debug if your company's experience has been for a repeated need to do ICT, and probably functional, in some cycle of development, then HASL or one of the lower contact resistance materials are a better match for your temporary debug needs. More - -

OSP is a bummer from an automated many points test strategy if you have to go through repeated tests after heat is applied to the OSP as well as go through cycles of testing refinement. Oxides after soldering just build too fast for most of the environments we live in and make the lives of many points test engineers, much more difficult. NOW give us a technique that uses two hands with a mouth and other body parts to hold probes then maybe we could do OK. Yet the cost is prohibitive on a circuit by circuit basis to create a manufactuing process. Bummer.

YiE, MA/NY DDave

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