So you have your PCBs, cooled paste, your stencils and your stenciling machine. Only thing you need now is to apply it! This is the final tutorial in the SMT stencil series!
$5 Squeegees
We do manual paste deposition. We tried a whole bunch of different, expensive squeegees, but in the end we really just liked the nice rubber-gripped paint scrapers at the hardware store down the street.
We have two: one 4" and one 1" wide. We like a 1" one for mixing up paste after its taken from the fridge. This gets it warmed up and easier to work with.
We then use the paste spooned out to apply it to the larger spatula.
Pull the spatula against the stencil. Getting this right takes a lot of practice, you need to get angle, pressure, and amount of paste correct.
Sometimes we have a big stencil so we only do one side at a time.
We have a technique we use, we usually do two wipes. One is at a more acute angle, where we push the paste thru the stencil.
Then we go at a wider angle, to scrape the paste off.
That's it! It does take practice. We had to do 50 boards before we really got the hang of it.
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