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X****Liu
stencil/paste technique?
940 1 Apr 04.2019, 14:01:36

I have a board with a 3-mm × 3-mm, 16-Pin QFN package - so I ordered the PCB with a stencil (multi-cb).
Their standard stencil is 100um (or 120um?) thick.
Seems I get quite a lot of paste on the board (see picture) with this setup. I taped the board to the table and then taped the stencil on top.
Any good techniques for getting less paste onto the board?
-thinner tape? thinner stencil?
-minimize buckling and bowing of stencil - how?
-paste-application technique? I ran a sharp knife-edge with paste tilted at ~45-deg across the stensil..
-paste type? I think this is chip-quick (don't remember part-nr...)
I hope I got the QFN soldered OK - after hot-air gun I applied a bit of flux and ran a soldering iron across the pins to remove solder-bridges on two of the four sides...

thanks for suggetions!

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A****min

Apr 10.2019, 10:40:27

Are you using paste designed for stencilling, as opposed to dispensing? The latter is more runny and will flow too much. 

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