Electronics Forum | Tue Jan 13 07:44:48 EST 2004 | Chris Cottreau
Upon inspection were seeing most if not all of these SOT 23 are not reflowed properly. The components just sit on top of the solder, this is creating insufficients, poor wetting, etc. There are about 25 SOTS per board, 2 boards per panel creating alo
Electronics Forum | Tue Jan 13 10:25:29 EST 2004 | James
Do you have a different reel of parts. The leads could be oxidized from age. If everything else is soldering well, I would try that. Is your profile on your oven correct?
Electronics Forum | Tue Nov 06 10:44:09 EST 2007 | tzawaide
Hi All, We are using BGAs from a new supplier, and the BGA solder balls are not collpasing properly. Can someone out there shed some light on what could be the root cause? Any help is greatly appreciated. Thanks!
Electronics Forum | Mon Aug 25 18:24:25 EDT 2008 | dyoungquist
The problem is occuring on more than one part # of our 0402 components. That is why I am looking at the reflow oven process very closely.
Electronics Forum | Wed Aug 27 15:48:05 EDT 2008 | grics
Again, our paste manufacturer specifies TAL to be 30-60 seconds. Out of curiousity, how would part placement cause de-wetting? I am fairly new to SMT so elaboration would be helpful... Thanks
Electronics Forum | Wed Aug 27 22:39:23 EDT 2008 | davef
Here's a good thread on lead free reflow recipes http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=47575
Electronics Forum | Thu Aug 28 22:33:20 EDT 2008 | vladig
Well, as I've said before, a simple cross-section will shed a lot of light on the root cause :-) Vlad www.sentec.ca
Electronics Forum | Fri Aug 29 07:39:44 EDT 2008 | realchunks
Slow your conveyor down and see what happens. Your profile looks like you just barely get into the reflow zones you need to be.
Electronics Forum | Thu Aug 28 08:43:56 EDT 2008 | rgduval
You wouldn't think that placement would affect dewetting or solderability....I wouldn't have either, until it was the only thing left in our process, and when we changed it, things got better. I couldn't begin to explain why, either. The only concl
Electronics Forum | Tue Sep 02 15:29:36 EDT 2008 | bvdl
small pads like 0402 tend to get hot quite easily. looks like excessive heat is your problem here. pads are wetted, component leads are not. this means solder paste flux on top layer was exhausted before entering in reflow. your profile is the 'in-be