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 Nov 13 02:37:36 EST 2017 | slah6678
Recently we facing the Golden finger reject due to contamination with solder after the reflow. Any solution for this kind of reject ?
Electronics Forum | Mon Nov 13 13:49:16 EST 2017 | slthomas
Preemptively you can apply Kapton tape to protect the gold fingers during reflow. I think that's what most people do. After the fact, there are services available to clean them up but as it was described in another thread here, it is not in-expensiv
Electronics Forum | Mon Nov 13 21:27:02 EST 2017 | slah6678
Hi, thanks for reply. Kapton tape is costly and it may create another handling issue. BTW can you share the thread for the cleaning process ?
Electronics Forum | Mon Nov 13 21:31:11 EST 2017 | slah6678
Hi David, thanks for reply We did doing some study, most properly this problem was due to reflow process. Any thing that we can do for the reflow profile ? slow down the ramp up rate or .....
