FORMATION OF COPPER FILM ON AL OR AL ALLOY MATERIAL

摘要

PURPOSE:To form a homogeneous and sound copper film on the surface of an Al material by soaking the Al material coated with polybutene in a fluidized bed contg. suspended copper chloride powder of a specified particle size and by heating the Al material under specified conditions. CONSTITUTION:Copper chloride powder of <=300mum particle size is suspended in dry gas at ordinary temp. to form a fluidized bed. An Al or Al alloy material coated with a polybutene soln. (binder) is soaked in the fluidized bed to stick copper chloride powder on the polybutene film. The polybutene soln. contains trichloroethane or the like as the solvent and has <=about 10% concn. The Al material is then heated to 300-500 deg.C at >=50 deg.C/min heating rate to form a homogeneous and sound copper film on the surface of the Al material. Thus, a copper coated Al heat sink suitable for use as a heat radiating plate for a semiconductor element is obtd.