Electronics Forum | Tue Jun 26 16:43:19 EDT 2001 | CPI
Yes a 6 mil solder deposite will reduce to approx 50% of it's original size. Does this happen on only 1 BGA? Is the BGA that its happening on have smaller balls than the others, what I'm getting to is, are you sure you are depositing the proper amo
Electronics Forum | Fri Jun 29 18:43:16 EDT 2001 | procon
Dear Danial, The only stupid thought is the one left only as a thought and not asked. The size of the board and the placement of the BGA on the board could play a big factor during reflow. If you are processing boards on an edge conveyor and the boa
Electronics Forum | Tue Jun 26 12:24:24 EDT 2001 | nifhail
Thanx for the reply Dave. We actually had a few thermocouples attached from underneath to see if there is any delta in temperature within the same BGA's ball. They looks OK, with the slope of 1 -2 Deg C,soak at 120 Deg C - 150 Deg C at about 90 sec,
Electronics Forum | Mon Jun 25 20:51:43 EDT 2001 | davef
Well, the paste must be OK, because other components don�t have this problem. The board must be OK, because other components don�t have this problem. So, it must be either the component or the profile. I�d speculate that you need to do some work t
Electronics Forum | Tue Jun 26 20:40:36 EDT 2001 | davef
Your profile seems reasonable, as you say. As CPI says: Sure it could be planiarity issues with the balls, but that is not something that makes me want to do a Pete Rose belly-flop, head-first slide into first base that this is the source of your p
Electronics Forum | Mon Jun 25 01:57:07 EDT 2001 | nifhail
We experienced a random no contact at ATE on our board. The board I'm building consist of 9 BGAs, all of them are OK except for one, intermittently the tester will prompt no-contact message. It's happened on a diff. I/O, but only happened on that pa
Electronics Forum | Fri Jun 29 23:10:02 EDT 2001 | Danial
Thanx for the reply guys!! The problem happened on only one PBGA, the balls are eutectic and the paste volume height is at 5.96 mil min. The stencil opening has been increased to 30 mil which initially was 20 mil. You guys are right!! One probable
Electronics Forum | Thu Sep 12 11:26:11 EDT 2002 | scottefiske
CK, If joints have been validated prior to ICT (under BGA Scope), more often than not repeatable joint fractures are due to undo stress being placed on the component during ICT test. Verify ICT probes and fixture. If after proving out fixture/pin com
Electronics Forum | Fri Sep 10 12:34:40 EDT 2004 | kbayram
Thanks again for your insights. I'm just learning the details of these machines so you'ill have to bear with me. The descision will be made in around 6 months so I thought I would start my research sooner rather than later. I did get the impression
Electronics Forum | Tue Jun 21 11:46:04 EDT 2005 | kenscj
Hi dave, Thanks for the comment. I have another issue. The board already pass Test and Burn-In processes, but after 2 months the BGA contact is found open (no contact on certain balls). How can that happen? Is it during build, the solder ball alrea
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