Electronics Forum | Tue Jan 21 16:28:02 EST 2003 | tony_sauve
Sorry I didn't close this one off last year... We had some failure analysis done on these PCB's ( 3D x-ray,microsectioning,SEM) and the results definitively proved that there was some contamination @ the base of the uvia's that had the voiding. It ap
Electronics Forum | Thu Sep 21 17:50:43 EDT 2000 | Bill Boles
Does anyone have a quick reminder for a PCB with immersion gold surface finnish going through a reflow profile: Which of the following statements is more correct? A: In order to minimize gold in the intermetallics of the solder joint, the board temp
Electronics Forum | Wed Aug 22 21:42:54 EDT 2007 | davef
Questions are: * Do these pads take solder? How well? * Have you stripped the gold and evaluated the condition of the nickel?
Electronics Forum | Mon Aug 27 08:03:32 EDT 2007 | davef
Actually, you will be soldering and wire bonding to the palladium layer, so we should have asked if you checked that layer, rather than the nickel. We not sure of the source of the copper that your see on EDX. It's possible copper from the pad migra
Electronics Forum | Thu Aug 23 09:52:38 EDT 2007 | d0min0
Hi, in past we had an issue with ENIG surface, black was Ni that get pass the Au - but it was discovered after reflow (SnPb) and the IC was losing contact with Cu tracks...at customers application :| Reason was as I remember too thin Au sufrace... w
Electronics Forum | Sun Aug 26 11:27:12 EDT 2007 | vangogh
Hi Davef, Thanks for the reply. There seem to be no issues on SMT reflow based on some samples done. We have not stripped the gold yet. We did a X-section+EDX and we are seeing traces of copper on the nickel layer. Any idea what is the implication of
Electronics Forum | Thu Aug 30 09:49:32 EDT 2007 | blnorman
EDS @ 10kV maybe going too deep. I've talked to a surface science physicist that recommends Auger spectroscopy because it's more of a true "surface" examination tool.
Electronics Forum | Tue Aug 21 05:05:52 EDT 2007 | vangogh
Hi All, I would like to get some inputs regarding this.... I have bare PCB which were stored with kapton tape attached on the Au plated pads. These were stored for close to a year. Upon removal of kapton tape, we noticed discolorations on the edges o
Electronics Forum | Fri Oct 30 10:36:26 EDT 2009 | richie_puthotta
Hi, I see a huge solder mask shift on chip comp pads. This would result in mid-chip solder balls or solder beads. Overall, the solder mask workmanship is not acceptable. Mask is on pad.
Electronics Forum | Sun Nov 01 01:33:52 EST 2009 | isd_jwendell
Just my opinion: Top pic - Solder mask registration WAY too far off, without a doubt I would reject. Bottom pic - I would worry that there was/is a contamination that caused the poor looking mask. This may be cosmetic only, but unknown. I would rej
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