Electronics Forum | Sun Feb 04 15:06:20 EST 2007 | Scotty
Profile should have a longer cool soak. Verify as was mentioned all pin/fixture support through out the entire process. Print, Place, pre reflow hand load, post reflow, carriers, ICT, Depanel and FCT. Conformal Coated or Potted? Mylars work well for
Electronics Forum | Wed Jan 24 22:48:59 EST 2007 | frank63
Hello, we are facing some troubles with BGA opens in our production. PCB are both side popolated with BGA. BGA is array of 26*26, with some 6*6 center balls. PCB has 2 reflow processes, 4 pcs of BGA on each side. Now we are partly observing opens
Electronics Forum | Wed Feb 28 00:12:22 EST 2007 | Muhammad Haris
hi, Consider BGA1= bigger one BGA2= smaller one CONSIDERATION : 1. If bga2 is inside the bga1 then bga1 balls should not touch the bga2 upper surface i.e. the inside balls of bag1 package should b in ur mind, so choice is urs. METHOD: m
Electronics Forum | Mon Sep 15 20:17:52 EDT 2008 | vladig
Hi Adam, Since you don't see any cracking right after re-flow, then the most probable cause is the board flexture during handling/assembly. I bet you see cracking in the outer row(s) and mainly in the corner balls. Regards, Vlad
Electronics Forum | Tue Aug 25 13:30:35 EDT 2009 | rossi
It appears that the crack is between the paste and the ball. We physically pulled off the BGA by force and almost all the balls broke at the PCB. There was a thin layer of solder left on the pad. Maybe 1% of the balls stuck to the pad. I have attac
Electronics Forum | Wed Mar 17 19:41:15 EST 2004 | Dreamsniper
I'm hit with the above problem and found out that the BGA's themselves have fibres on their solder balls. I have soldered some without having the knowledge of the above fibres and found that the fibres are caught between the PCB pad and the BGA solde
Electronics Forum | Wed Oct 03 17:06:43 EDT 2001 | davef
Yes, moisture entrapment causes solder shorts 80% of the time. Cracks occur bottom side of the BGA. Use an acoustic microscope to find the cracks. So, what makes you think your BGA are blowing-off steam? I posted a vid on SMTnet that showed the b
Electronics Forum | Thu Oct 26 14:00:18 EDT 2017 | sambolian
Is there a threshold on ball size where we would not need to re-ball a BGA ( i.e. 8 ball / small type packages).
Electronics Forum | Thu Sep 10 21:48:37 EDT 1998 | Dave F
| I'm very familiar with the great board space savings of BGA and all the "claims to fame." However, can someone out there tell me if any concern exist in the inspection realm. Additionally, solder cracking, CTE/TCE mismatches, no leads for stress re
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
