Electronics Forum | Tue Sep 14 14:22:11 EDT 2010 | grahamcooper22
If the HASL was poor quality and very thin you would find this defect....but you would expect to see it on more pads also. Also, you'd expect to see your solder from your solder paste either dewetted on the pad or reflowed onto the BGA sphere making
Electronics Forum | Wed May 14 12:42:16 EDT 2008 | rgduval
Dave, Realized I didn't respond to one of your questions. We pasted and reflowed one board, with no components. This board exhibited extreme dewetting on all pads. The board was LF-HASL, and the paste was Qualitek (which we've used for approximat
Electronics Forum | Wed Mar 11 10:58:58 EST 1998 | Earl Moon
| | What does the term "poor wetting" mean as a defect code ? "Poor" should mean unacceptable when surface (component or PCB solder termination areas) wetting does not provide acceptable solder joints. Unacceptable wetting of PCB solder termination
Electronics Forum | Tue Nov 11 19:41:06 EST 2008 | gregoryyork
Thats the problem residual residue from HASL fluxes Lead free especially are worse.Very hygroscopic and out gass and produce dewetting as well over wave soldered boards especially. Leave iron on blown joint and will after several seconds fizz and pop
Electronics Forum | Sun Mar 15 23:58:01 EST 1998 | Phill Hunter
| | I am having a problem with Entek coated boards. The solder past seem to just ball up on the pads. I had no problems with the board when it was hot air leveled. The board is double sided surface mount. I have tried adjusting the oven profiles m
Electronics Forum | Thu Apr 17 05:14:40 EDT 2008 | gregoryyork
I have seen similar things like this before with Solder Resist redepositig back on the pads, this is a clear residue very hard to see. Solder resist will obviously resist solder adhering to it. If you rework the boards then the heat of the iron will
Electronics Forum | Wed Mar 11 11:05:06 EST 1998 | Earl Moon
| I am having a problem with Entek coated boards. The solder past seem to just ball up on the pads. I had no problems with the board when it was hot air leveled. The board is double sided surface mount. I have tried adjusting the oven profiles mak
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