Electronics Forum | Tue Sep 20 08:53:13 EDT 2011 | jocelynlauzon
My company is looking for an IPC expert consultant in BGA underfilling to support an important contract that is being prepared. We are looking for someone with hands-on experience with large (~2"x2", with as much as 1800 pin, 1mm pitch, 0.5mm ball di
Electronics Forum | Mon Jan 21 11:37:35 EST 2008 | rayjr1491
Is there a tool to check for voiding in a Underfill process?
Electronics Forum | Mon Jan 21 15:45:05 EST 2008 | davef
Yes. It's called a surface acoustic microscope. Rent time at your local university or college.
Electronics Forum | Mon Jan 21 16:02:41 EST 2008 | rayjr1491
hi dave Is there another tool besides SAM (Scanning Acoustic Microscopy)? Regards, Ray
Electronics Forum | Fri Mar 19 10:27:42 EDT 2010 | karlo
No clean pastes leave more flux residues. These can result in void formation and inhibtion of underfill curing. Selection of an underfill that is compatible with the flux residue is important. One company that has written about the effect of flux
Electronics Forum | Wed Jan 23 13:48:06 EST 2008 | flipit
You can do a destructive test to sort of check your process. Break off the flipchip and look for voids. I have used Namics 8437-2 for the last 7 or 8 years. Good stuff. Flows under a 0.001" gap with no voids. Chris
Electronics Forum | Mon Jan 21 18:58:21 EST 2008 | davef
We have read papers espousing using xray, but have never seen such a thing. It seems the contrast provided in the xray images is insufficient for analysis of the underfill.
Electronics Forum | Tue Jan 22 09:48:09 EST 2008 | davef
Here's an article on flux / underfill compatibility http://ap.pennnet.com/articles/print_toc.cfm?p=36&v=16&i=6
Electronics Forum | Tue Jan 22 07:50:20 EST 2008 | rayjr1491
Thanks Dave, I spoke with a Loctite application person yesterday and the mentioned SAM as well. best regards, Ray
Electronics Forum | Wed Jun 06 11:19:21 EDT 2007 | ramseyn
Hello. What kind of void are you seeing? You said the part was a BGA, is it being underfilled or is it a solder void?
