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I have seen lots of tutorials about how to apply solder paste using a stencil, but all of them only show how to apply the stencil to one side of the PCB. My current project is 2 sided and I would like to make 2 stencils (one for the top and one for the bottom) for easier application.

Is it there any tips and tricks for doing it or DIY in this case will fail and I need something more industrial?

(In case someone didn't get the problem, once the first side is soldered it won't be flat anymore, so the application of the stencil becomes impossible by the usual DIY way).

mFeinstein
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1 Answers1

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Put a spacer all around underneath the edge of the board thicker than the layer of components on the bottom layer of the board, and bind a layer on top of it to secure the board in place (or fabricate it from a single piece in the first place). Make sure that the top of the holding layer and the top of the board are even to make spreading the solder paste easier.

UglyCAD image

Ignacio Vazquez-Abrams
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  • I thought about this but the board might bend while I spread the paste because of the push down force and blur the paste. Also it's sounds like more complicated then soldering all the chips by hand. – mFeinstein Nov 19 '13 at 11:56
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    @mFeinstein: The board can be supported in strategic places in the middle if required. It is more complicated, but it's the only way to get double-sided BGA boards done. – Ignacio Vazquez-Abrams Nov 19 '13 at 11:57