In this forum I have recently asked for your views on the relative
effectiveness of plugging vias with LPI solder mask versus tenting vias
with dry film and then applying LPI solder mask.

I also asked for your views on the advisability of applying LPI solder mask
over vias with no attempt to plug or tent.

Each of your replies was helpful--apparently the worst option is to apply
LPI over vias with no plugging or tenting.  We are reconsidering our
original intent--tent with dry film and then apply LPI.

Let me pose a few more related questions:  Do any of you tent vias with dry
film before applying LPI?  If so how well does this work?  Is this a common
practice in the industry?  Has any one ever heard of this practice?

Dry film tenting is the only option offered by our supplier.  However in
all of the replies I've received, no one has said he uses this method of
sealing vias.  We want to make our switch from dry film to LPI solder mask
effective with the beginning of the calendar year.  But we don't want to
adopt some nonstandard, idiosyncratic practice.

Thanks again for sharing the results of your experience.

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