Electronics Forum | Sat Oct 06 05:33:47 EDT 2001 | spchua
I had recently encounter the "black and grey" pads problems for the BGA pad after the convection re-flow. The pads shows in in "black and grey" color and a litter solder in it, and it happen in ramdom, when applied heat and solder on the "black and g
Electronics Forum | Mon Sep 23 18:11:10 EDT 2002 | steveb
On an assembly reflowed in air saw the same thing: 0201's with a grainular solder joint, but 0402's and above with perfectly formed joints. Reflow profile all within acceptable tolerances. Reflowing in nitrogen solves this problem, but increases t
Electronics Forum | Wed Mar 12 07:33:40 EDT 2008 | callckq
Hi All, One PCBA failed test after went through the Shock Test(Vibration) and suspected to be BGA solder ball crack. We performed dye and pry and found PCB's pad lifted with red mark ink penetrate pad underneath, what does this mean? Can I say the
Electronics Forum | Wed Mar 12 23:00:10 EDT 2008 | davef
You can say: The pad was lifted after reflow and prior to the dye and pry failure analysis. When we see lifted pads, we think: * That's a good solder connection * Either it took a lot of force to lift that pad or the fabrication of the board in the
Electronics Forum | Tue Jun 29 14:42:55 EDT 2004 | davef
You're correct, for every dumpster full of paper written about solder, there's a sentance written about fluxes. There's dribs and drabs about fluxes in most of the soldering books [ie, Manko, Klein-Wassink, Judd, Strauss, etc] and most of that is ve
Electronics Forum | Mon Feb 19 11:25:07 EST 2001 | markt
I am currently cleaning solder paste and adhesive stencils and misprinted substrates manually by using IPA, chem wipes, Q-tips, etc. Can you recommend a machine and chemistry that will clean all these applications?
Electronics Forum | Tue Jun 01 19:25:19 EDT 2004 | Ken
...oops part 2: I will assume a sac 350 ball??? 217-218C this will completely reflow the ball and form a "normalized" joint with a collapsed structure.
Electronics Forum | Wed Mar 04 14:35:16 EST 2009 | clampron
Good Afternoon Everyone, I have a customer who is inquiring as to the use of a no clean solder paste on their RoHS assembly. We are currently building this with OA, cleaning and then underfilling the QFN, BGA comonents after a sucessful ICT. Does any
Electronics Forum | Tue Jan 31 14:23:39 EST 2006 | samir
Chunks, For our lead-free eval, we had the same problem with "charred looking" solder paste up the component termination of one of the smaller discretes, coupled with excessive solder balling...this smaller part did see peak temps in the 240 range -
Electronics Forum | Tue Jan 31 12:02:22 EST 2006 | aj
how would you apply both pastes.? anyway, I have succesfully run leadfree bga with lead paste. You gotta find a profile that kinda meets both requirements. Taking into consideration the peak temp and time above. dont have details on hand but I ca
