CLAD SHEET AND PROCESS AND APPARATUS FOR PRODUCING SAME

摘要

A clad sheet comprising a metal substrate and a metal cladding layer laminated on at least one surface of said substrate, wherein said cladding layer-laminated surface of said substrate includes a hardened layer portion formed by melting and rapid solidification through laser beam irradiation. In intermediate layer may be interposed between the substrate and the cladding layer through like hardened layer portion. Lamination is made by cold-cladding layer elements after irradiating any one of layer elements with laser beam to produce strong bonding through uniform microcrack formed in the hardened layer portion of several micrometer thick. The clad sheets are useful for making IC lead frames, for which the substrate is conductor metal and the cladding layer is solder applied to partial area of the substrate. The irradiation and cladding process is carried out continuously with a reduced draft.