Electronics Forum | Fri Dec 27 01:26:08 EST 2002 | haran
Currently we are running a BGA with a big thermal pad in the middle of the package and encountered high defect of solder shorts.I would like to check whether anyone has experience this problem and how this can be rectified?.
Electronics Forum | Mon Jun 01 16:48:16 EDT 2009 | stevezeva
Mika, Have you ever worked with a 3-row I/O QFN? QFN180 to be exact? Steve
Electronics Forum | Tue Nov 09 23:32:11 EST 2010 | bising
Stencils are 5mils thickness, SS material. Printer is Accela.
Electronics Forum | Fri Nov 12 13:41:02 EST 2010 | scottp
I wouldn't count on solder bridging that kind of gap. I've never used solder preforms, but I wonder if that would be worthwhile to try?
Electronics Forum | Fri May 09 09:31:04 EDT 2014 | jorge_quijano
we are placing small QFNs with no major issues, but this one may not seem like a QFN with thermal pad... I'm attaching a picture of the component.
Electronics Forum | Fri Jul 21 07:01:33 EDT 2017 | emeto
Reflow oven profile and X-ray should give you all the answers that you need. Thermocouples should be attached to this ground plane.
Electronics Forum | Mon Apr 16 16:24:20 EDT 2018 | slthomas
Amazingly enough, every one of these held fast where we placed them with a paste brick sized 1:1 with the thermal pad, no sectioning. Yes, there were voids, but we can live with that in this application.
Electronics Forum | Sun May 06 21:06:59 EDT 2018 | jimpat
Thanks for the feedback. I was looking into solder pastes and saw some advertised specifically for low voiding by Indium and another supplier. This is customer driven - requesting voids in the single digit percent for components with thermal pad
Electronics Forum | Tue Nov 26 09:07:16 EST 2019 | scotceltic
I am more worried about those voids also instead of the voids in the thermal pads. I still can't find any IPC spec that calls out a min. void percentage other than on BGA packages.
Electronics Forum | Tue Jul 25 07:37:21 EDT 2017 | stephendo
There are lots of examples of changing a parameter in one direction to fix one issue causes a different problem. Once I asked a layout engineer to adjust thermal relief for through hole parts. First he said ok but a day later he said that he couldn't
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