PROCESS FOR PRODUCING COPPER-CLAD LAMINATE.

摘要

This new process consists of the following five steps. (1) pretreatment of a planar conductive base material, (2) formation by electrolysis on the planar conductive base material of a surface of copper foil at least several microns thick, (3) roughening this surface, (4) laminating the copper foil together with the conductive base material on an insulating base material and tightly integrating the assembly by application of pressure and heat, (5) peeling off the conductive base material. For the electrolysis of step (2) the negative electrode planar conductive base material is sepd. from the positive electrode planar copper foil by a distance of 3-30 mm., and the surface of copper foil is formed by high speed plating under a liquid contacting speed of 2.6-20.0 m/sec. and at a current density of 0.15-4.0 A/cm2. This liquid contacting speed can be obtd. by flowing the electrolysis soln. between the two electrodes or by rotating the negative electrode round the positive electrode. In step (3) the surface of the foil can be brought into contact with an acidic electrolysis soln. contg. copper ion and nitrate ion. Then the surface is chromium-treated. A highly pure metal film may be provided between the conductive base material and the copper foil. When the highly pure metal film has a thickness of 0.1-3.0 micron only the conductive base material is peeled off in step (5). When the thickness of the highly pure metal film is 70-250 micron it is peeledoff together with the conductive base material.