METHOD OF FORMING A COHESIVE CONNECTION BETWEEN A SEMICONDUCTOR WITH AN ALUMINIUM COATED CONTACT SURFACE AND A SHAPED METAL BODY, AS WELL AS A SEMICONDUCTOR MODULE COMPRISING AND A SHAPED METAL BODY COHESIVELY ATTACHED TO A SEMICONDUCTOR

摘要

A method of forming a cohesive connection between a semiconductor (20) comprising an aluminium coated contact surface (30) and a shaped metal body (50) comprises the following steps: placing a preform on the contact surface of the semiconductor (20), wherein the preform comprises a dried sinter paste (40) enclosing a metallic structure (60) designed as a metallic grid or wavy metallic structure, placing the shaped metal body (50) on the preform, and processing the assembled components to form the cohesive connection, wherein the processing comprises the step of at least partially removing an oxide layer on the surface of the shaped metal body (50) and/or the contact surface of the semiconductor (20) by moving the metallic structure (60) in contact with the shaped metal body (50) and/or the semiconductor (20) relative to these. The movement of the metallic structure (60) may be at an ultrasonic frequency. The processing may comprise the movement of the shaped metal body (50) relative to the semiconductor (20). The shaped metal body (50) may comprise aluminium or an aluminium alloy, or alternatively copper or a copper alloy. The processing may comprise the application of pressure and/ or temperature. The melting point of the metallic structure (60) may be higher than the melting point of the sinter paste (40). The preform is preferably low temperature melting, with the melting point of the preform being < 230 °C in particular. Highly preferred is a preform made of a low temperature melting metal or a metal alloy, such as SnAg with a melting temperature of 221°C. In particular, the metallic sintered material may be an alloy, preferably an alloy of tin and silver. The destruction of the oxide on aluminium surfaces may lead to the diffusion of the dried sinter paste (40) into the aluminium of the contact surface (30) and the shaped metal body (50), wherein this process can preferably take place at temperatures below the melting point of the dried sinter paste (40). The metallic structure (60) may also be a braided wire.