Electronics Forum | Mon Sep 30 09:26:04 EDT 2002 | itempea
Russ, first step would be to get IPC-7095 on BGAs. A few notes: There can be voids in solder balls, or at the solder joints to the BGA, or at the solder joints to the PCB. Various sources or reasons can be responsible for these voids. Voids can be
Electronics Forum | Sun Aug 10 21:57:25 EDT 2014 | cmchoue
Does IPC definition for "QFN Void Ration" ? Like IPC 7095 susgestion the BGA Void ratio.
Electronics Forum | Mon Jan 12 18:06:38 EST 2004 | Kris
Hi, Is there any standard for voids in a leaded device or a chip component ? IPC 7095 lists maximum allowable voiding for BGA devices but has no information on leaded devices Appreciate your help- thanks
Electronics Forum | Tue Mar 09 17:52:05 EST 2004 | davef
Bryan: Comments are: * You're correct, solder paste formualtion is a major driver to voiding in BGA balls. * Voids are primarily process indicators. There is experimental evidence that voids retard crack propagation locally around the void on a temp
Electronics Forum | Wed Feb 02 21:56:11 EST 2005 | davef
Based on X-ray imaging, IPC-7095 standard specifies three categories for void size for BGA solder joints. These categories are based on the percentage of joint cross sectional area occupied by the voided area. Class III Small: Void area is LT 9% Cla
Electronics Forum | Sat Mar 06 02:54:25 EST 2004 | tommy
1)Solder paste selection 2)Reflow profile.Focus on soaking and TAL. 3)Moisture control for BGA. 4)Maybe the BGA solder ball already with void. 5)PCB design.Any via on bga land? 6)Solder masking type. 7)Solder paste volume apply on land. 8)IPC class 3
Electronics Forum | Tue Jul 26 08:20:46 EDT 2005 | Bob R.
All you can do is try it. I did a literature search last year on causes of BGA voiding and came up with a pretty long list, sometimes contradictory. I also discussed it with several paste suppliers. What I came away with is that what aggravates voi
Electronics Forum | Fri Aug 25 14:39:24 EDT 2006 | davef
1 When you peel the solder connection of a BGA, * If solder remains on the soldered surface [eg, component, substrate, etc], it's good. * If some solder remains and some base metal is present, it's marginal. * If no solder remains, it's NG. 2 Try I
Electronics Forum | Thu Nov 21 06:36:30 EST 2002 | Ben
I'm doing SMT of lead-free solder BGA on FR4 Ni-Au PCB. The solder paste I'm using is Sn/Ag/Cu and reflow with peak temp at 240C. I found there are voids(1-2) in almost every solder joint(500 micron in dia) under xray. And the void size is violate th
Electronics Forum | Tue Apr 13 09:46:39 EDT 2004 | davef
Now, that's different. We misunderstood the problem from your original descrtiption. We thought the voids were showing at the via in the pad. Now, we understand the voids appear to be in the solder balls. Suggestions are: * Search the SMTnet Arch
