Prepreg production method and prepeg production device and prepreg obtained by the production method and production method for insulating layer attached copper foil and insulating layer attached copper foil obtained by the production method

Abstract

A production method capable of stably producing a prepreg and a copper foil with thin insulating layer using a thin backbone material capable of securing excellent laser hole-making property. A method for producing a prepreg for use in producing a printed wiring board having a backbone material impregnated with a thermosetting resin comprising the following steps is adopted: (1) a liquid resin coat forming step for forming a liquid resin layer on a flat work plane using a liquid thermosetting resin; (2) a pre-drying step for changing the liquid resin layer to a dry resin layer; (3) a backbone material pre-adhesion step for heating and pressure bonding the backbone material on the above described dry resin layer on the work plane to form a dry resin layer with backbone material; (4) a resin impregnation step for heating the dry resin layer with backbone material to a temperature where the resin is reflowable, and impregnating the backbone material with the resin component; and (5) a cooling step for carrying out a temperature decreasing operation immediately after finishing the resin impregnation, and maintaining a half-cured state of the thermosetting resin impregnated in the backbone material to form the prepreg. A method for producing a copper foil with insulating layer in the similar manner is further provided.

Dependencies are inferred from the claim text.