Electronics Forum | Tue Jul 15 10:01:15 EDT 2003 | davef
We don't use Sn50, but if we did, we'd use our paste supplier's recommendation as the starting point for developing our reflow recipe.
Electronics Forum | Wed Jul 16 11:01:58 EDT 2003 | russ
Who is the paste manufacturer? They are the ones who can tell you what to run.
Electronics Forum | Wed Oct 04 15:06:57 EDT 2006 | C.K. the Flip
Hmmm.. you are in a pickle then. I have AIM's "Reflow Profile Supplement" where they recommend a Low-Long-Soak (LSS) profile for situations like your's. It's an old-school type profiling approach where you ramp up to 120*C for about 1 min. then soa
Electronics Forum | Tue Jun 01 19:23:15 EDT 2004 | Ken
profile it for the tin/lead paste. The tin in the solder paste will begin to disolve the sac ball. This is exactly the same scenario as 90/10 (80/20)high temp balls found on ceramic bga and many super bga devices (except the sac balls are now tin r
Electronics Forum | Wed Oct 04 16:24:48 EDT 2006 | russ
try Alpha OM5100 this is a noclean paste that we use and have done the same thing you are now, reflowing pbfree with pb paste, we run to max temp of 230C with this paste and use a straight ramp with no soak profile is about 4 mins long from ambiant
Electronics Forum | Fri Oct 06 09:38:11 EDT 2006 | C.K. the Flip
Here's the BGA voids-reduction profile that I used: http://img323.imageshack.us/my.php?image=profileka0.jpg Keep in mind, this was for Sn/Pb BGA with Sn/Pb solder paste. For your situation, you might want to raise the peak temperatures to at least
Electronics Forum | Sun Sep 07 17:29:27 EDT 2008 | gregoryyork
Does look like a poor reflow profile needs to be hotter, is it Pb free
Electronics Forum | Thu Oct 26 11:49:54 EDT 2006 | sms_don
CW, The good news is that you are not trying to use SAC paste with SnPb balls for that would be a void generator due to the ball being liquidous while the SAC paste is still in a flux cleaning stage. Two points to consider: One, voids are not an i
Electronics Forum | Wed Oct 04 14:14:49 EDT 2006 | russ
Change mfgrs of paste OR better yet use pbfree paste, If you are collapsing the balls on the BGA then you are possibly overheating the paste/flux quite a bit. most lead pastes do not like much more than 230 C. I am assuming that you have a decent p
Electronics Forum | Wed Oct 04 14:18:05 EDT 2006 | C.K. the Flip
The main cause of voids is your flux out-gassing during reflow. Try a little "knee" or slight soak in your thermal profile to dry out the volatiles a bit. Typical soak ranges from 130 deg. C to 170 deg. C for around 30-90 seconds.