Screen Printing

Abstract

The two most common imaging techniques currently used in printed circuit manufacturing are screen printing and dry film photoresist. A major drawback of photoresist is the need to etch the copper surface of dry film imaged boards prior to pattern plating; this can only be done reliably if the panels have been copper plated after electroless copper deposition, or if a high deposition/high temperature electroless copper has been used to place extra copper inside the plated through holes. The only occasion where copper etching prior to plating is of no concern, is when the image is for print-and-etch, as with multilayer inner layers. This requirement for added copper in the holes is a real disadvantage of photoresist imaging. There is no such requirement for screen printing.