Patent ID: 8808607

Claim:
A method for producing a thermally conductive sheet comprising at least the steps of: extruding a thermally conductive composition containing a polymer, an anisotropic thermally conductive filler and another filler through an extruder, thereby extrusion molding an extrusion molded product in which the anisotropic thermally conductive filler is oriented along the extrusion direction; curing the extrusion molded product to form a cured object; and cutting the cured object in a direction perpendicular to the extrusion direction into a given thickness with an ultrasonic cutter, wherein the anisotropic thermally conductive filler is prepared as carbon fibers and has an average fiber length of 100 μm or more, and the other filler is prepared as spherical alumina particles and has an average particle size in a range from 1 μm to 40 μm.