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July 2000

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Subject:
From:
Mike Lang <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Tue, 25 Jul 2000 10:07:08 -0400
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We are experiencing problems with soldering of PLCC's.

We find that a significant number of these devices are received from the vendor with non-coplanar leads.  The lack of co-planarity causes open solder joints.

Investigation has resulted in the knowledge that approximately 5% of the PLCC device we receive are not within the 0.004" co-planarity requirement.  We find some to be out as far as 0.012".  I cannot currently define the point at which the lack of co-planarity becomes an issue.  

The supplier is a major manufacturer of these devices.  The parts are on tape and reel.  We have inspected them prior to any processing at our facility, so we know that it is not a question of in-house handling, placement, etc.

1) Does anyone else see co-planarity problems with PLCC's?

2) What steps have you successfully taken to correct this problem, and what was the result?

3) Are there pieces of equipment I can put inline to screen <*gasp*> out these devices?

4) Any assembly or processing tricks you have used successfully to compensate?




Thanks,

Lang
x5046


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