Electronics Forum | Fri Sep 03 14:20:38 EDT 1999 | David
| Could someone shares their experience on the causes of 'Open' in the BGA after reflow. | | You must have been in the same meeting I was in earlier today. We are currently having some opens on BGAs. The problem joints are all on the perimeter of
Electronics Forum | Thu Sep 02 21:19:25 EDT 1999 | NAZEEH CHAUDRY
| | Could someone shares their experience on the causes of 'Open' in the BGA after reflow. | | | | | Insufficient solderpaste. "No flux" (sat too long after print). | | Those are what I've experienced. | cbga or pbga if pbga check thermal prof
Electronics Forum | Thu Oct 05 00:48:22 EDT 2006 | KEN
What is the surface finish of the PCB? What type of BGA? What type of solder / flux are you using?
Electronics Forum | Sun Feb 13 01:35:55 EST 2000 | Dean
Without further information my first guess would be lack of flux to "cut through" the ENTEK layer. Question: In X-ray is the suspect ball of equal diameter when compared to adjacent balls? If no then the volume of solder is different which would po
Electronics Forum | Wed Aug 04 20:06:24 EDT 2004 | C.W
Customer returned a brd claim that one of the FPGA is having "cold solder joint". I inspected the the BGA location with X-ray and Ersascope, balls' shape look fine, voids are not detected, perimeter joints show shinny and smooth appearance, i have se
Electronics Forum | Wed Nov 01 13:44:50 EST 2000 | Thomas Ballhausen
Using convection type reflow we observed following problem: One ball of a 313-PBGA appears to be dewetting. This happens randomly, i.e. no specific ball location, failure rate is rather low (3-4%), but since there are 12 PBGAs on one board the failu
Electronics Forum | Mon Nov 06 09:38:55 EST 2000 | Dean Stadem
We have seen this problem several times. It always goes back to pad solderability, very seldom does it have anything to do with ball size. If there is no evidence of wetting on that pad, but all of the other pads did solder, you need to ask yourself
Electronics Forum | Wed Jan 17 20:48:14 EST 2001 | davef
We find that the raw BGA's pad sheared surface has the SnPb solder at various Z heights whereas the assembled BGAs pad leave a smooth layer of SnPb along the pad. Like to understand the cause for the difference. Who could guess? Solder joint streng
Electronics Forum | Thu Jan 18 21:52:24 EST 2001 | arul2000
>>>>Dave, The BGA substrate surface finish is NiAu, while the PCBA pad surface is HASL. The solder ball composition is SnPb 63/37 and the solder paste used on the PCBA is also the same but with 2% Silver.>>> Dave, sorry I don't have the picture with
Electronics Forum | Mon Nov 06 21:06:13 EST 2000 | Dave F
Thomas: Wheeee, a 40% failure rate. Now, that make your boss chase you around the room won�t it? As you indicated, x-ray won�t do dip about helping to identifying problems [or ball cracks either]. Consider using an ERSA scope [er whatever they ca
