ADHESIVE SHEET, METALLIC FOIL WITH ADHESIVE, MULTILAYER BOARD COVERED WITH METALLIC FOIL, AND LAYERED BOARD AND PRINTED CIRCUIT BOARD COVERED WITH METALLIC FOIL

摘要

PROBLEM TO BE SOLVED: To prepare the subject sheet having little deterioration of insulating properties with the laps of time and capable of being used for producing multilayer board covered with a metallic foil by compounding a thermosetting resin and an electrically insulating whisker as essential components. SOLUTION: This sheet is obtained by forming an adhesive comprising (A) a thermosetting resin (e.g. a bisphenol A novolak-type epoxy resin) and (B) an electrically insulating whisker as essential components into a sheet, and has a melt viscosity in the range of 100-1000 Pa.s. Further, the component B preferably has an average diameter of 0.3-3.0μm, an average length of 3-20μm and the maximum length of 50μm, and, for example, aluminum borate whisker is used for the purpose.