Electronics Forum | Thu May 18 14:30:33 EDT 2006 | Chunks
Hi Mark, I feel like a broken record since I keep replying to this thread. BUT, I remembered a large lytic cap that we had a couple years ago, doing the same thing. The base of the cap would expand in reflow and the bottom would bulge out and only
Electronics Forum | Thu May 18 20:42:36 EDT 2006 | davef
Hypothesis #1: We agree with Steve. You are probably seeing the nickel underplate. The gold was absorbed into the solder in portions of a second, so that you don't see it is not surprising. We're guessing that the gold was porous and allowed the n
Electronics Forum | Thu Jan 29 00:12:39 EST 2009 | grayman
Hi Armando, I think you have to buy a bigger reflow let say 7 zones to get the correct profile. The reason you are getting that problem is due to short profile time. What is the size of your board? What is the composition of your solder paste? Ple
Electronics Forum | Wed Jan 28 21:47:56 EST 2009 | padawanlinuxero
Hello! I am having trouble with the new changes from lead joint to lead free joint, we are working on change to lead free, I am using a 3 zone oven reflow, the zone temps are : zone 1 zone 2 zone 3 (top and bottom) 128 208 260 th
Electronics Forum | Mon Jan 19 14:54:38 EST 2004 | cyber_wolf
How did you come to the conclusion that you are having a cold joint problem. Just by appearance ? As Dave stated if you have any of the metals that he listed in the joints they will appear to be dull and grainy sometimes. But... Dave, I will have t
Electronics Forum | Thu Nov 30 16:14:33 EST 2006 | darby
Maybe ask your customer where they got this idea from? It is possible they may have even got this idea from some white paper or article where they are trying to explain something else and show drawings with no solder between the pad and lead. It may
Electronics Forum | Wed Nov 29 10:10:50 EST 2006 | M. Sanders
I'm sorry, Dave - I didn't make myself very clear. Yes, this space (not really a "gap") is filled with solid solder. For instance, if you place a gull-wing component in solder paste, after reflow, there will probably be a thin film of solidied solder
Electronics Forum | Thu Feb 08 08:15:28 EST 2007 | tjcrume
I have received 10 customer returns for a cold solder joint on 1 lead of a 36 pin IC. Everytime it is on the #18 pin. The process is reflow and I can't figure out why the one leg is cold and the other legs look OK.
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 Feb 19 10:47:47 EST 2019 | rgduval
I'm with Steve. Check the datasheet, and make sure that the terminations are meant for solder application, and not conductive epoxy. I had that happen a year or so ago with an MLCC. Drove us nuts for two days (not to mention the significant rework
