Study on the Development of Direct Joining of Metal and Resin by Thermocompression

Abstract

This paper describes a method to find the optimum conditions for direct joining between metal and resin by measuring pressure and temperature of the joining interface and the vicinity. In this process, the metal treatment for direct joining is carried out by laser irradiation, which forms fine irregularities and metal oxides on the metal surface. Direct joining takes place between the treated metal and the resin using an apparatus equipped with induction heating and thermocompression. Temperature control in this apparatus is performed by measuring near the joint of the metal with a radiation thermometer. The temperature at the interface is measured by a thermocouple sandwiched between the metal and the resin. The result between the temperature of the joining interface and the tensile shear strength indicated that the optimum temperature was below the melting point of the resin. Cross-sectional observation of the joined sample by SEM also indicated that the resin flows into the fine irregularities of the metal at a temperature below the melting point. This method is useful for optimizing the conditions for direct joining of metals and resins and elucidating the mechanism.