Electronics Forum | Sun Sep 07 13:33:50 EDT 2014 | horchak
Edri PCBA design and pad geometry is one of the critical factors for BGAs. Typically the pad size for collapsible balls is 80% of the ball diameter. Pad size consistency is critical. In your situation what will happen the larger pads will wick the s
Electronics Forum | Tue Aug 03 18:11:21 EDT 2004 | davef
Improper washing of water soluable flux residues can be a major contributor to flux residues remaining on the board surface. ;-O That you appear to be only complaining about the pathetic state of the ability of your washer to clean under BGA, it may
Electronics Forum | Sat Jan 08 11:12:49 EST 2000 | S. Evers
Hi all, Best Thing Since Sliced Bread? No doubt many of you have seen Phil Zarrow's "over-the-top" review in Circuits Assembly of the new Ersa scope, a device that allows viewing a really neat close up a side view of the component substrate interface
Electronics Forum | Thu Apr 27 21:20:38 EDT 2000 | Dean
Here are some pointers to use during your X-ray inspection. Microcracking is virtually impossible to determine with X-ray. However, I suspect you are looking for "hard" opens. Those are much easier to find visually. If using a paste-and-place pro
Electronics Forum | Mon Jan 29 11:11:29 EST 2001 | Casey Scheu
The solder ball collapse is associated with overheating. Of coarse there's no problem taking it off, your nuking it. The problem, as your aware, is in the replacement. The machine your using is overdriving the process. The key to this repair is in
Electronics Forum | Tue Jun 25 15:30:49 EDT 2002 | Steve L
Hi everyone. I am now faced with a problem on soldering PBGA. At first, I ran the board (FR4, 7" X 10" with 12 layer) at Peak Temp: 205 C and 54 seconds above 183 C. After reflow, I found several cold solder joints and one ball without second collaps
Electronics Forum | Mon Apr 12 09:09:25 EDT 2004 | russ
If they are reflowing pbfree balls to bare PCB pads they are getting that component very hot tpo melt the balls and get them to wet to the pads! I would not recommend this process at all for hightemp solder balls, for 63/37 this process is fine. As
Electronics Forum | Tue Nov 02 09:05:15 EST 2004 | russ
I have never experienced voids when using the flux only for application. Search the archives for void causes. As far as "more paste is better" I think that could be a true statement if we are talking about adapting to co-planarity type issues. My
Electronics Forum | Thu Jul 07 18:10:20 EDT 2005 | russ
You should use Xray to qualify your process. Frequency of Xray inspection after that will need to be determined by your process capability. If you use paste inspection process, once you verify that your profile and placement are good you in theory
Electronics Forum | Tue Feb 26 05:10:17 EST 2008 | adetuc
Thanks for the reply Hege, I calibrate the machines every 3 months and have checked that the board carrier to nozzle parralelism is ok. Have tried many different profile settings using a MOLE for readings but still collapsing on one corner. I did
