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Date: | Tue, 14 Jan 1997 21:05:22 +0100 |
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In the near future I have to start with pretinning of molded ring
carriers with a 0.5 mm leadpitch (CQFP256 and a 64 pin Dual Flatpack) ?
For 0.65 mm pitch devices we do it without any solder bridging, but I'm
afraid that the 0.5 mm pitch makes it a bit more critical.
We use a simple tinpot with a component holder and a lever to enable
steady vertical speed and a controlled dipping depth. Dross is skimmed
off manually after each component. Flux is RMA.
Since production volumes are relatively small we cannot afford to lose
many of these (expensive) components for process development. There is
very limited time between receiving the components and starting with
board-assembly, and I don't think I have dummies available by the time
the production starts. All this means that the pretinning just has to
work, without much process adjustments or equipment changes.
Should I be worried about this ? Does anyone have experience with
pretinning of 0.5 mm pitch devices ?
All comments and technical advices are wellcome.
--- Daan Terstegge ---
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