COMPOSITE SHEET FOR MULTILAYERED WIRING BOARD

摘要

PROBLEM TO BE SOLVED: To prevent surface contamination of a metal foil coated with resin for a multilayered wiring board by covering the thermosetting resin surface of the metal foil with an easily strippable resin surface protective sheet. SOLUTION: A thermosetting polyphenylene ether resin layer 2 is formed on one surface of an electrolytic copper foil 3 for a printed board by applying a resin varnish composed of a thermosetting polyphenylene ether resin and a toluene solvent and drying the applied varnish film. Then the easily strippable protective sheet of the metallic foil 3 carrying the thermosetting polyphenylene ether resin layer 2 is formed by press contacting a polyethylene film with the surface of the resin layer 2 with a hot roll maintained at 100 deg.C. Therefore, the reliability of the metallic foil 3 can be improved because the surface of the foil 3 is not contaminated with the thermosetting resin at the time of preserving the foil 3.