I guess the posting from Norm is going to lead to a lot of interest. 

We would like to know how to tent vias in a curtain coat environment!  

We use a number of techniques which are costly. e.g. screen printing the 
LPI 1st then processing wet through curtain coat or even printing with a 
stencil defined mask on  the vias only with LPI.  These procedures seem 
to work but they are very time consuming.  Obviously hole diameter is a 
consideration.  We use these methods on 12 to 20 mil holes.

Any other ideas?


Richard Wood-Roe
Artetch Circuits Ltd.
Littlehampton, UK
Email [log in to unmask]