| hi, | i am working towards developing a no-clean process for a customer at contract manufacturing facility. the assemblies have gold fingers on them. these are masked to prevent from any damage to them during reflow soldering. the earlier process utilized a soluble mask that could be washed during the defluxing stage.i would be interested in a mask that can be peeled off after reflow soldering. | | thanking you, | | parag palshikar
Hello Parag,
There's a bunch of latex masks out there on the market. Companies like Tech Spray makes a peelable mask called Wondermask P, Chemtronics with their "Chemask", Weller makes some called "Spot mask", Kester has a TC-527, a TC-530, TC-533, TC-534, and a screen printable one called TC-580...all of the masks I listed are peelable.
But correct me if I'm wrong, you said you needed it to peel off after reflow...most of these masks are only rated for the temperatures of wave soldering. And besides, I would think that any mask you wanted to apply would be applied prior to assembly, which would interfere with your SMT solder printing.
Your best bet would be Kapton tape. You can put it on the fingers prior to printing, and it's so thin that you don't need to worry about it affecting your print. The one drawback is it's expense..it can come close to being $30-40.00 a 36-yard, 1" wide roll (that's for the tape from 3M, there's generic kapton tape that goes for quite a bit less than that!) But the peelable latex masks are not cheap either. They range from about $50.00 a gallon, on up to $150.00 per gallon.
I hope this helps...
-Steve Gregory-
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