Patent ID: 6177357
Filing Date: 2001-01-23
Classification: H01L,H05K

Abstract:
A process for making a flexible printed circuit wherein etching of a polymeric film is accomplished by dissolving portions thereof with concentrated aqueous base, using a UV-curable, 100% active liquid photoresist as a mask, comprising the steps ofa) laminating said resist on a flexible substrate comprising a layer of polymeric film and a thin layer of copper,b) exposing at least a portion of said resist thereby crosslinking said exposed portions,c) plating circuitry atop said thin copper layer to desired thickness,d) etching portions of said polymeric film not covered by the crosslinked resist with a concentrated base at a temperature of from about 70.degree. C. to about 120.degree. C.,e) stripping said resist off said polymeric film with dilute basic solution, andf) etching said thin copper layer to obtain circuitry.