Electronics Forum | Tue Feb 21 10:58:02 EST 2012 | ppcbs
Can anyone suggest a good underfill compound that is readily available for manual dispensing. I need to underfill a small BGA less that 12mm square.
Electronics Forum | Mon Sep 28 13:03:43 EDT 2015 | dyoungquist
The melting point of the solder itself does not change when you have underfill. If the underfill conducts heat better than air, it will take less heat (and/or less time) from your rework station to get the solder up to the melting point. That makes
Electronics Forum | Mon Jun 05 14:04:36 EDT 2006 | Brian
Check with the adhesive manufacturer. Not all underfill material is reworkable. Brian
Electronics Forum | Thu Aug 23 13:29:07 EDT 2001 | morefun
Some of our other divisions have had to do epoxy underfill with BGA devices to obtain adequate reliability for aerospace applications. Are there any special layout considerations required to ensure that we can do underfill if we deem it necessary du
Electronics Forum | Thu Aug 23 20:31:53 EDT 2001 | davef
We never underfill BGA, but then again our products are not blasted into space. Certainly you need to provide enough room for the dispense head to move around the component in the pattern appropriate for the underfill you plan to use. Probably more
Electronics Forum | Fri Apr 09 08:58:28 EDT 1999 | Justin Medernach
| I'm not sure about limits but perhaps underfilling the BGA might easy your mind. Treat the BGA as something similar to a flip chip and dispense underfill around the part. The rigidity gained by the cured underfill may be enough to alleviate some
Electronics Forum | Wed Jun 07 07:53:24 EDT 2006 | RLM
This is true but even the so called reworkable underfill takes a lot of effort. We use a loctite reworkable that requires heat to soften the underfill. Once the component is removed we use acetone and a swab to scrub the pcb clean. This can be very t
Electronics Forum | Fri Mar 28 10:21:16 EDT 2014 | davef
With heat, most underfills soften just before the solder melts. So, keep poking the underfill until you see it soften. Then, wait just the correct amount of time until the solder melts and quickly snap or torque the part from the board. BR davef
Electronics Forum | Tue Aug 26 17:50:52 EDT 2014 | dkrawchuk
Hi, We have some boards that we apply an underfill to a BGA. Some boards have underfill that covered the surrounding passives. The customer is concerned that the different expansion rates will damage the passives. Does anyone know of a company th
Electronics Forum | Thu Feb 26 10:33:01 EST 2015 | emeto
Take a look at articles that explain underfill process and how to remove/rework underfill: http://www.finetechusa.com/rework/applications/underfill-rework.html http://www.circuitnet.com/experts/86535.shtml
