Electronics Forum | Mon Aug 25 06:43:37 EDT 2008 | callckq
Dear All, Recently, we found a strange defect called "Head-in-pillow" defect at CPU socket BGA. The strange thing here is that this problem only appear on that CPU socket BGA and not on the others BGA which were also mounted on the PCB. We suspect
Electronics Forum | Fri May 23 11:14:15 EDT 2014 | rboguski
Agree with previous comment regarding possible head-in-pillow. Use 3D x-ray or CT-scan to verify.
Electronics Forum | Tue Aug 26 09:33:04 EDT 2008 | wavemasterlarry
If this board is waved soldered than you may want to look at the wave causing the BGA to reflow a 2nd time when it goes over the wave. The board bows down and the the joint liquidfies and then hardens before the board fully goes back to flat which c
Electronics Forum | Mon Aug 25 08:26:33 EDT 2008 | scottp
We've gone through this a couple times. Once it was because the device was warping in reflow. We confirmed with shadow moire that the corners were lifting up. The supplier fixed some things in their molding process to reduce the warpage. Another
Electronics Forum | Wed Aug 27 08:46:14 EDT 2008 | vladig
Hi Sean, It's an old problem with no definitive cure for now. However, there are a couple of things to look for. First of all the location(s) of HoP. If it was due to the componetn warpage, then it would be most probably in the middle and it should
Electronics Forum | Thu Jul 02 16:01:57 EDT 2009 | ewchong
thanks kpm. agree the cause of those pads lifting. all of them were no connects so they cannot be the cause of the electrical failure. when the bga was removed, all the solder balls on the pcb turned into conical shape due to the separation, except
Electronics Forum | Tue Jul 07 05:55:34 EDT 2009 | kpm135
I agree with your assessment of the two pins with irregular solder. The head-in-pillow or broken joint are both probable events for your defect. At this point in the process it will probably be difficult to pinpoint the exact cause. If it was a broke
Electronics Forum | Thu Jan 27 04:02:00 EST 2011 | richiereilly1
Hi, We had a similar issue to this. When we examined the boards at x-ray there were no apparent defects, We sent the boards for Dye and pry testing and we found that there were crack or gaps between the paste on the PCB and the BGA ball. basically th
Electronics Forum | Thu Apr 03 17:39:37 EDT 2014 | siddharth
You are correct. Both the machines are "semi-automatic". The program can focus on the part you want to inspect and perform basic inspections like void analysis (BGA, QFP) etc. But you have to manually navigate and look for defects like TH solder fill
Electronics Forum | Thu Apr 03 17:50:53 EDT 2014 | rboguski
We use it almost exclusively in manual mode for PCBA failure analysis. Our main purpose is to find head-in-pillow defects; secondarily incomplete wetting of ball to substrate. In two years of almost continuous use we have only had occasion to use t
