Electronics Forum | Mon Aug 07 10:22:13 EDT 2000 | genglish
Ramon, I have had experience in the problems you are witnessing. The problem can relate to a number of factors. Obviously the printing process is the first place to start your investigations, try looking at the stencil apertures for bleed under the
Electronics Forum | Thu Aug 24 15:37:50 EDT 2006 | Chunks
Hi Any, This is from an earlies thread "Solder Ball After Reflow Process". Date: August 16, 2006 01:52 PM Author: Russ Subject: Solder Ball After Reflow Process Oven settings are meaningless here. What does the board see? It is the paste we a
Electronics Forum | Mon Jul 16 16:42:40 EDT 2007 | pnguyvu
Hi Jacky, It seems you have solder bead problem, beading occurs when the solder paste brick splatter as a component is placed into it, after reflow, the splatter becomes a spherical solder ball. Hope this will help. Steve USA STENCILS
Electronics Forum | Wed Sep 21 16:25:43 EDT 2005 | GS
IPC-7525 tells you how to make stencil apertures for BGA IPC-7095 tells you how much should be the paste volume in order to get a reliable BGA solder joint. How are your PCB finisced? (HASL, ENIG, OSP, etc?) In case of not HASL, it could be necessa
Electronics Forum | Tue Jan 11 07:46:23 EST 2000 | Dave F
Wolfgang: Boy it's tough to convey context in this medium, isn't it? Clipped from our paste storage work instruction, environmental effects on paste are: 1a Avoid excessive heat (over 80� F). It causes flux separation, reducing print quality. 1b
Electronics Forum | Thu Feb 19 12:56:29 EST 1998 | Earl Moon
| I'd like someone gives me a tip for elemating of voids | in the mico BGA solder joint and the method of inspection | of them, very exactly. Voids in excess of 20% by each solder ball volume is cause for rejection. Causes are improperly managed proc
Electronics Forum | Sat Sep 18 12:10:19 EDT 2004 | Steve Gregory
I have a question about solder masking via's in a BGA pattern, and want to see if I'm thinking correctly about this. This problem is kind of along the same line as Carol's problem earlier. I think it's a bad idea to leave the via's free from solder
Electronics Forum | Thu May 26 08:52:42 EDT 2011 | davef
Phil Zarrow wrote a useful paper that could help in evaluating paste. Here read it ... Evaluating Solder Paste � Not An Option Contributed by Phil Zarrow of ITM an Independent SMT consulting firm With soldering being the dominant source of assembly
Electronics Forum | Tue Jan 06 16:31:41 EST 2015 | jacklucas
In switching to lead free processing, we find ourselves having over 400 PCB part numbers with Sn63 HASL finish. And there is no hope of quickly purging inventory and getting our drawings changed to call out a lead free finish. I want to avoid having
Electronics Forum | Wed Aug 16 13:52:24 EDT 2006 | russ
Oven settings are meaningless here. What does the board see? It is the paste we are concerned about not what the heaters are running at hehe. These solder balls are at the end of pad, which end? under the part or away from the part. I believe you
