Electronics Forum | Mon Oct 15 11:27:48 EDT 2001 | rob_thomas
Hello all, Does anyone have any experience using solder quick preforms for ball attach on Flex? Thanks, Rob
Electronics Forum | Thu Apr 03 11:57:38 EST 2003 | davef
R4: We see the ball left on the PCB with a flat top and the BGA pad appears to be virgin. D4: Not good. The flat top indicates that the ball melted at one time or another. This pad and ball have seen at least two solder cycles with solder and flux. S
Electronics Forum | Tue Apr 01 18:42:18 EST 2003 | rdr
Well, here is what I have found so far. I have removed the top of the BGA and found that the ball had detached from the package. Three balls were removed with the two adjacent balls pulling the pads off the board and stayed attached to the BGA while
Electronics Forum | Wed Jan 01 22:19:33 EST 2020 | sssamw
Solder ball attached on solder joint without violation minimum electrical clearance is acceptable. If your process parameter including stencil not changed, suggest you check if solder pasted being pushed out after IC placement, also check if solder j
Electronics Forum | Thu Apr 03 09:48:31 EST 2003 | davef
R1: Contacting Altera to find out if the BGA pads are gold. D1: Bet money the pads were ENIG. R2: Contacting Altera to find out if they use abrasives. D2: If abrasives were the problem, you�d see it in many pads, especially those close to the probl
Electronics Forum | Tue Apr 01 17:29:58 EST 2003 | davef
R1: So if I understand you right, it could be possible that gold dissolved, but the ball still didn't wet to the underlying nickel. D1: Correct. The gold dissolves into the solder first. The solder wets to the nickel second. If you nickel is corro
Electronics Forum | Thu Apr 03 09:08:50 EST 2003 | rdr
Thanks Scott,Iman, The problem has been isolated to detachment from package so I believe that there are no fabrication issues related to the Gold on the PCB. What is a Moyet analisys? where can I find more info? Dave, I am still waiting on Altera t
Electronics Forum | Tue Apr 01 11:50:08 EST 2003 | rdr
Dave, thanks for the info. This sounds like it would verify the presence of an open. We have verified that these balls are open and I am trying to figure out if we are fracturing or not wetting. causing these opens. I would use the die method on ne
Electronics Forum | Thu Apr 03 11:17:17 EST 2003 | rdr
Well, first off now I'm just starting to believe that we are fracturing again. But here is some more input D1 ENIG? I would not have thought that they would be but as usual you are probably right. D2 Again I would have to agree about it should affe
Electronics Forum | Tue Apr 01 08:59:06 EST 2003 | rdr
Hi all, I've got a question that hopefully someone can provide insight. We have a gold immersion assembly that we believe is experiencing fractures or non wetting on a certain BGA. To be sure that it is a fracture and not a wetting issue I would li
