Electronics Forum | Thu Jul 15 12:02:38 EDT 2004 | Yngwie
We have massive void problems on one of the BGA populated on the bottom side of the board. The board have 6 BGAs on the top and 1 on the bottom. No voids were observed during the first reflow (we reflowed bottom side first), but after the second refl
Electronics Forum | Fri Jul 16 03:35:34 EDT 2004 | Yngwie
We have massive void problems on one of the BGA populated on the bottom side of the board. The board have 6 BGAs on the top and 1 on the bottom. No voids were observed during the first reflow (we reflowed bottom side first), but after the second refl
Electronics Forum | Fri Jul 16 03:40:17 EDT 2004 | Rama
We are going to start producing product that require us to assemble Stacked BGAs. My question - how to rework this package, as the the process of either removing or re-placing them onto the PCB will the effect the BGA sitting on top of it. Pls help.
Electronics Forum | Sun Jul 18 21:36:42 EDT 2004 | KEN
This is the least desirable method (mirroring). 1. X-ray inspection becomes difficult. I will repeat: x-ray inspection becomes difficult. False fails go up. True fail detection goes down. 2. Remove and replace becomes challenging. You really
Electronics Forum | Fri Jul 16 15:15:39 EDT 2004 | waveroom
on the top of your screen there is a search area. Punch in Voids and hit enter. The first discussion covers the voiding issue very well.
Electronics Forum | Wed Aug 08 21:23:15 EDT 2001 | davef
Very smooth. First, describe how this thing wowls at the moon. Next, state that process time is so long that you can't afford to make it. Finally, you ask someone to make it for you. Let's get Mikie to do it. Hey, Mikie ...
Electronics Forum | Wed Jan 30 15:47:13 EST 2008 | tonyamenson
Just my humble opinion. Every place I've worked at uses x-ray over optical inspection for BGAs. Companies that had both often let the optical inspector collect dust becuase you can only really inspect the perimeter solder balls. Not to mention you c
Electronics Forum | Fri Jan 21 05:18:55 EST 2000 | Dean
If at all possible avoid mirror assembly BGA designs. It has a higher failure rate when compared to non-overlap designs (life testing). In addition, from a rework point of view, X-ray inspection yields no help when a failure occures. You can't det
Electronics Forum | Tue Sep 14 13:36:56 EDT 2004 | C Lampron
Hi Simon, I would recommend a thermal profile on a BGA that is mounted directly over another one. The best way to accomplish this is to drill through the first side BGA to just break through the second side. (assuming you have a board that you can d
Electronics Forum | Fri Jun 15 09:16:46 EDT 2001 | adam
Thanks Dave. About your second comment, the issue is placing BGA connectors mirror image (male, and female), the connector sometimes shifts during placement before reflow. we are using a six mil stencil for both sides with minimum paste deposit. a
