Electronics Forum | Sun Sep 07 17:16:57 EDT 2008 | gregoryyork
OK Pizza it is then, here goes. Dewetting of Ni/Au pads, paste favouring the Tinned component lead hence excess paste wicking on top of the components. Reason is EITHER Nickel migration into the gold due to high levels of Ionics from poor rinse OR mo
Electronics Forum | Thu Jul 30 13:52:34 EDT 2009 | davef
Thoughts are: * 215-220 temperature at the leads is not real hot for leaded assembly. * It's peculiar for component leads to dewet. Sometimes non-wetting occurs along the edge of the lead where the lead is not plated. * How do the leads of a removed
Electronics Forum | Wed Jun 16 11:49:55 EDT 2010 | tim_wright
A customer wants to coat a no-clean assembly to cut cost and cycle time. I know what wave flux I can use to make it work, but the Indium SMQ92J paste we use causes dewets. Any other no-clean pastes out there that play nice with acrylic?
Electronics Forum | Fri Jul 09 10:32:47 EDT 2010 | rafacadiz
Hi Sean, I have seen this issue with lead free component on Sn-Pb solder process, I don´t know if it´s your case. Some times, pins not reach the necessary T for solder due to lead free metalization and in other case due to a groud pad, with a big T d
Electronics Forum | Tue Sep 18 21:48:26 EDT 2012 | vergara1
Sorry. I don't see any solder balls. > > To me, it > looks like the solder wetted the pad and then > pulled back. It's called dewetting. It's a > defect. Ask your supplier for a SEM analysis. I'm > interested to know what he / she says. I see
Electronics Forum | Fri Nov 08 18:32:39 EST 2013 | hegemon
Dave is right, though apparently a bit grumpy today. What he's saying is that the ring de-wetting is a bad thing, and should have been called out by your lab. You might consider a lab change in the future. Some information about your processes, an
Electronics Forum | Wed Feb 12 22:02:47 EST 2014 | rober864
Has anyone ever encountered contaminants from the immersion silver process, whether it be from the board house or not...as it relates to conformal coating. The failure mode is severe de-wetting of acrylic conformal coating. All over solver resist, to
Electronics Forum | Thu Oct 30 21:55:13 EDT 2014 | davef
Why soldering issues? I'd guess the nickel is corroded. It is very difficult to solder to oxidized nickel. Your SAC305 would get kicked all the way down the conveyor by nickel oxide. A lack of Ni-Sn-IMC formation will confirm this dewetting . What's
Electronics Forum | Thu Oct 06 12:18:31 EDT 2016 | davef
Looks like moisture bubbling out of the board. I doubt that your baking at 60*C for a half hour is going to do very much to dewet the board. 60*C is warm to the touch, that's it!!! Water boils at 100*C. 60*C is the temperature of a cup of Dunkin. Cr
Electronics Forum | Mon Jun 05 17:37:51 EDT 2017 | stevezeva
Hi Zac, In looking at your photos, you may not be having a problem with your machine, but with the solderability of the PCB. I've zoomed in to an area that looks to me like the solder has de-wet from the pad. The leads appear like it almost has a fi
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