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 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 | 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 | 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 | 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 | Wed May 22 19:10:47 EDT 2013 | anvil1021
We do a lot of these devices and I guess I am not familiar the term "Dry Solder". The QFN device is not designed to have a drain hole, but needs to have thermal vias to control heat in most cases. We have used every possible gnd pad design and modifi
Electronics Forum | Thu Jul 20 05:04:30 EDT 2006 | bing007
We had a similar problem with gold contact pads. Cleanliness is paramount. If you are using foil tensioning system, wash the foil in a stencil wash before use as the cardboard cassettes may be contaminated. Be very careful when loading into a frame f
Electronics Forum | Thu Aug 06 09:51:20 EDT 1998 | Bob Willis
This text may be of interest to any one with tin lead spots Guide to Solder Spots - A New Plague in Manufacture ? So what are solder spots ? They appear to be the next big problem in modern reflow assembly in fact in any process that involves solder
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