Joining of Metals by Super-Spread Wetting on Surface Fine Crevice Structure Created by Reduction-Sintering Copper Oxide Powder

Abstract

A surface fine crevice structure, created by laser irradiation, results in a region-selective super-spread wetting and the joining of metals is possible by taking advantage of this wetting. Through reduction-sintering of copper oxide (CuO) powder, we are able to obtain a sintered-Cu layer that possesses a complex sponge-like structure in which a porous network is formed. The wettability of molten tin (Sn) on the obtained sintered-Cu layer is investigated to confirm whether the super-spread wetting occurs on the surface fine crevice structure created by the method of reduction-sintering CuO powder. In addition, a joining experiment is accomplished using two Cu substrates. Therefore, a successful super-spread wetting of Sn on the surface fine crevice structure and the joining of Cu substrates are demonstrated.

Fig. 3 (a) Surface and (b) cross section of the surface fine crevice structure on a Cu substrate created by reduction-sintering of CuO powder.