PURPOSE: To make it possible to arbitrarily change the rheological behavior of heated and melted resin, by a method wherein, after fine-grain of inorganic material are uniformly dispersed on a substrate, and this is mounted on a base plate coated with thermosetting resin in a half-cured state, lamination forming is performed.

CONSTITUTION: For an alumina paper 1 as a base material, alumina fiber whose fiber length is more than or equal to 10 times the fiber diameter is used to make paper together with micro-fibrillated organic fiber as binder. In this surface, fine-grain of alumina whose diameter is 0.1∼50μm are uniformly dispersed. This is mounted an aluminum plate 3 coated with solution of phenol-curing-type epoxy resin. By holding this between heating plates 5 together with a copper plate 2 turning to a conducting layer, and heating them, a metal base substrate is obtained. Epoxy resin 4 on the aluminum plate 3 is melted by heating at the time of forming laminated layers, and permeates the mounted alumina paper 1. Then, in accordance with the compression and deformation of the alumina paper 1 as a base material, the impregnated resin is discharged outside the system. There is correlation between the amount of alumina fine-grain and the amount of discharged resin, so that the rheological behavior of resin can be controlled.