TSOP lead deformation (help)

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Can anyone help me determine the acceptability level for lea... - Jan 26, 2009 by John

It seems like your parts are acceptable regarding IPC610. ... - Jan 26, 2009 by emil

Emil, The issue that caused the problem has been solved a... - Jan 26, 2009 by John

Questions are: * Can you use the part fabricator's specific... - Jan 26, 2009 by davef

Your image does not clearly explain the problem. However, I ... - Jan 27, 2009 by sachu_70

John

#57878

TSOP lead deformation (help) | 26 January, 2009

Can anyone help me determine the acceptability level for lead deformation (see attachment). The outer two leads on the left side were bent during the pick and place centering operation. I've looked in the IPC-A-610 book and could only find information on the fillet and lead to pad placement (neither of which seem to be in question). All parts have been placed in QA hold; I would like to have some sort of documented acceptability criteria to determine if the parts need rework/scrap. Please, any information would help.

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emil

#57880

TSOP lead deformation (help) | 26 January, 2009

It seems like your parts are acceptable regarding IPC610. I would't bother if all in the specs. But the question is why you damage your partss in P&P process. I think you should avoid that instead of looking for standards.

Regards, Emil

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John

#57885

TSOP lead deformation (help) | 26 January, 2009

Emil,

The issue that caused the problem has been solved and corrected. The problem I'm having now is I need to prove their acceptability to others or I'm faced with scraping/reworking thousands of parts.

I agree that the parts should be acceptable in their current condition, but convincing others can be difficult without documentation to back me up.

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davef

#57887

TSOP lead deformation (help) | 26 January, 2009

Questions are: * Can you use the part fabricator's specification of lead coplanairity as the basis for accepting this build? * Beyond the issue of acceptable deformation of the leads, how do you know that whatever you did to bend the two outer leads on one side did not affect the package seal on those two leads?

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sachu_70

#57888

TSOP lead deformation (help) | 27 January, 2009

Your image does not clearly explain the problem. However, I can see a good heel fillet formation at the joint. In general, TSOP leads are delicate and should handled with immense caution and good ESD protection. First let us be clear that any "rework" to rectify physical deformation on leads will not reverse any damage if caused to lead plating. TSOP parts are best handled in trays, although Tape & Reel packaging is practiced by some suppliers. My recommendation would be to evaluate the Packaging Quality and decide to have the entire lot replaced. Manual corrections to align leads could cause further problem during production.

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