Hi Ed,
1. How much time between first and second reflow? Is there enough for the board to absorb moisture which causes the outgas?
2. Could the outgas be from trapped flux? A longer TAL during first reflow may help if this is the case.
3. Can you lower the bottom side temperature during the second reflow? Since you have big heavy components on the top side probably not.
Good luck,
Jerry Dengler
Production Manager
Pergamon Corporation
380 Crooked Lane, Unit# 3
King of Prussia, PA 19406-2567
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ed Popielarski
Sent: Friday, May 08, 2015 1:08 PM
To: [log in to unmask]
Subject: [TN] Dpak outgassing second pass
Greetings fellow Technoids,
An interesting debacle arose, and I'm unsure if there is a solution.
Dpak components on side 1 solder fine, <25% voids, 100% edge wetting.
On 2nd pass (top side, big heavy components) the Dpaks on side 1 outgas and exceed 25% (not a spec, just a target) but violate edge wetting (S/B 100%) as the outgas tends to blow out the edge somewhere.
Any suggestion on how to eliminate this phenomena? Parts cannot be relocated due to aerospace re-qual cost.
Thanks in advance!
Ed Popielarski
Engineering Manager
[cid:[log in to unmask]]
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