Electronics Forum | Wed Mar 04 22:57:05 EST 2009 | davef
Underfill epoxies may be classified into major groups [Capillary Underfill Manufacturing Development and Characterization for 2nd Level Electronic Interconnect Processes; B Salom�n; University of Puerto Rico, Mayaguez Campus; Dec 2004]: * Capillary.
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 Mar 29 13:33:05 EST 2004 | Ron W
I was wondering if anyone has attempted to develop a process for the successful removal of a BGA and its underfill. Or, is it the general industry thought process that an underfilled BGA cannot be reworked.
Electronics Forum | Tue Apr 27 15:09:48 EDT 2004 | zymet
Hello Ron, Successful removal of an underfilled BGA requires the use of a reworkable underfill, which Zymet manufactures. For more information on such products, send an inquiry to info@zymet.com. Regards, Carol
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 | Thu Mar 27 07:56:04 EDT 2014 | rrosera
My company is researching the use of re-workable underfill for use on our avionics boards. We are currently testing Hysol UF3810. The Rework machine we use has a vacuum based removal system witch isn't strong enough to overcome the underfill. We have
Electronics Forum | Fri May 22 15:37:23 EDT 2009 | 1smtdude
Depending on the material chosen, it's possible to �rework� underfilled components. However, it's far from a production process. Two steps are usually required. First: remove the package from the PCB. Second: remove the residual underfill from the P
Electronics Forum | Tue Jun 11 14:16:03 EDT 2013 | bandjwet
We are involved in a project for microBGA SAC rework. The pitch is 0.4mm and the devices are underfilled (softening 150C). The underfill comes off fairly easily but the pressure underneath the package as the underfill softens pushes up on the undersi
Electronics Forum | Tue Jun 11 14:21:35 EDT 2013 | bandjwet
We are involved in a project for microBGA SAC rework. The pitch is 0.4mm and the devices are underfilled (softening 150C). The underfill comes off fairly easily but the pressure underneath the package as the underfill softens pushes up on the undersi
