Electronics Forum | Thu Dec 06 19:46:08 EST 2001 | davef
First, we�re assuming that we�re talking hot air solder leveled [HASL] bare boards, eh? Consider using A-600 - Acceptability of Printed Boards as the basis for discussing the bare board problems. It is the bare board analog of A-610 - Acceptability
Electronics Forum | Tue May 25 11:37:50 EDT 2010 | davef
Where on the assembly is the dewetting occurring? Factors that influence dewetting usually involve non-ionic contamination such as: * Residues from board manufacture including silicone surfactants from solder resist & HASL rinse contamination * Comp
Electronics Forum | Thu Dec 06 11:01:19 EST 2001 | Carol Stirling
This SMT process certainly makes a body want to win the $$$ and retire! We have been trying to stabalize the process and keep running into new problems. Any help would be appreciated on this issue. All pads on both sides have the same look - partial
Electronics Forum | Fri Mar 06 16:17:38 EST 2009 | aj
whats your board finish?
Electronics Forum | Wed Nov 06 10:03:59 EST 2013 | rgduval
Hi, Peter, I'm not an authority on surface finish thickness, and it's effect on reflowing, so, I can't advise on that front. If the boards are a week old, and ENIG, I would not suspect surface contamination. It's always a consideration, of course,
Electronics Forum | Tue Nov 05 09:57:45 EST 2013 | cuperpeter
Hello All, We have a problem with dewetting of solder paste. Problem is most visible on the pads without components (see attached pictures) and occurs randomly, 20% of PCB's. Pcb supplier sent us a cross-section of pads with thickness of Cu, Ni and
Electronics Forum | Wed Mar 12 15:26:46 EDT 2014 | dan_ems
Hello, in my SMT process I have some problems with the solderability (look like dewetting) on a PCB with finish HASL Lead Free with a composition that is melt at 230 degree Celsius. My oven is with vapor phase and the peak temperature is 230 degre
Electronics Forum | Wed Oct 06 04:11:35 EDT 2010 | grahamcooper22
I've done minimal research to this point and > understand my issue with solder on the double > sided boards is due to oxidation that occures on > the unpopulated pads when the board makes its > first trip through the reflow oven. > > We did run
Electronics Forum | Thu Oct 07 08:13:52 EDT 2010 | remullis
I just swapped from the HASL to Immersion Silver mainly because the board house we use could not maintain consistency in keeping the pads level. I was constantly battling bumps and bad finishes on the pads. They are able to give me a consistent board
Electronics Forum | Fri Jun 12 21:36:04 EDT 2020 | SMTA-Josh
Has anyone had an issue with changing from a HASL surface finish to a LF HASL finish if it is still being used in a leaded process? Also we are having issues with the planarity on the fiducials with the HASL finish. Are there any suggestions or ch
