Electronics Forum | Sun Aug 10 21:57:25 EDT 2014 | cmchoue
Does IPC definition for "QFN Void Ration" ? Like IPC 7095 susgestion the BGA Void ratio.
Electronics Forum | Tue Mar 14 14:15:03 EDT 2017 | dontfeedphils
I've always been happy with ~25% or less combined voiding on QFN ground pads (depending on the pad dimensions).
Electronics Forum | Sat Nov 11 11:11:28 EST 2017 | spoiltforchoice
One suggestion I have seen for packages like this is to have the device balled first.
Electronics Forum | Fri Dec 01 13:30:08 EST 2017 | kojotssss
Stencil thickness is 4 mil. Via's are plugging from bottom. Gas may be developed under the component? Take Reflow Ovens Thermal Profiling changes? In your opinion?
Electronics Forum | Fri Dec 01 14:11:24 EST 2017 | kojotssss
EMIL, The first stencil was with 4 squares. then there was a worse percentage. Changed to the circles. Is better, but still not perfect. Stencil thickness did not change. I added 2 types of stencil openings. Pictures of watch:
Electronics Forum | Fri Dec 01 14:50:30 EST 2017 | kojotssss
How about step down in the middle of thermo pad? I mean 0.075mm This can help?
Electronics Forum | Fri Dec 01 14:55:51 EST 2017 | kojotssss
Rework said that with hot air gun, heated the solder paste comes out of the middle part out to the side terminals and soldering extending beyond is perfect.
Electronics Forum | Fri Dec 01 15:22:46 EST 2017 | kojotssss
Recommended land and solder pattern says: VIA wall plating, via holes should be tented with solder mask on the backside and filled with solder. Solutions at this moment ? Thanks for all :)
Electronics Forum | Mon Mar 11 03:40:18 EDT 2019 | jineshjpr
BOT SIDE QFN DROP DURING TOP SIDE REFLOW; Bot & Top side solder profile temperatures are almost similar with a 5 Deg variation
Electronics Forum | Tue Mar 26 10:30:28 EDT 2019 | pavel_murtishev
Hello, Could you please tell me if there is any industry standard specifying QFN to PCB standoff after soldering? Is any gap allowed? Browsing IPC-A-610, I have found nothing. Any input would be appreciated. Regards