Electronics Forum | Sat Mar 21 09:09:40 EDT 2009 | davef
Your puzzlement about blowholes in PTH solder connections during reflow soldering comes from: * Boards are hydroscopic. So, moisture content of the board is uniform. * Gold plating is uniform. * Nickle plating is uniform. * Copper plating on your PTH
Electronics Forum | Wed Apr 04 17:40:39 EDT 2007 | davef
Rob: How do you rework blow-holes and pin-holes? PTH plating thickness SB 1 thou or greater. Epoxy is hydroscopic. So, you should control the environment and/or bake the moisture from the boards before soldering. Search the fine SMTnet Archives f
Electronics Forum | Mon Jul 19 21:33:26 EDT 2004 | davef
Are you talking about small 'volcanos' that burst through PTH solder connections? If so, you have moisture outgassing through the PTH barrels: * Plating on the hole of your bare board is too thin. It should be greater than 1 thou [25um]. * Your bak
Electronics Forum | Fri Feb 28 08:57:34 EST 2003 | davef
We used to bake [100*C for 6 hours] all of our boards, but no longer bake at all. Before going off, your bake recipe is probaly OK. If anything, it's probably too short. Consider measuring the weight of wet boards, baking for a time, measure, bake
Electronics Forum | Tue Jul 06 07:49:08 EDT 2004 | davef
Q1)What is the MSD level for PCB? A1) There is none Q2)I have some PCB's with HIC (humidity indicator card ) has turn to pink at 50%. Should I bake the PCB prior to assembly process.This fab is a complex board with various kind advance package assem
Electronics Forum | Fri Oct 07 08:48:45 EDT 2016 | davef
Two things ... A friend in the contract coating business said: "... the board is not being baked out long enough, 30 min is certainly not long enough depending on how many layers this board is, as the vacuum (from the parylene process) is pulling t
Electronics Forum | Thu Jun 24 12:43:08 EDT 1999 | Earl Moon
| | Recently, there has been an upsurge in the Pin Hole/Blow Hole problem in our wave soldering process. We are baking the PCBs for 2 Hrs. at 125 degree C. The Wave Soldering profile seems to be O.K. Still the problem is persistent. Can somebody h
Electronics Forum | Fri Jun 25 01:11:31 EDT 1999 | Vinesh Gandhi
| | | Recently, there has been an upsurge in the Pin Hole/Blow Hole problem in our wave soldering process. We are baking the PCBs for 2 Hrs. at 125 degree C. The Wave Soldering profile seems to be O.K. Still the problem is persistent. Can somebody
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