Method of mounting a semiconductor device with a eutectic layer

Abstract

A method of manufacturing a semiconductor device (10) including a semiconductor element (1), such as a transistor, which is provided, on the rear side, with a conductive layer (3) including gold, and which is attached, on said side, to a conductive plate (2), such as a lead frame (2), by way of a silver-containing organic matrix (4) which is thermally cured. Subsequently, the element (1) is connected to the plate (2) by way of wire connectors (5) and provided with an encapsulation (6). The silver paste (4) is cured at a temperature of at least 350° C., preferably approximately 400° C. In this way, an excellent adhesion of the element (1) to the plate (2) is obtained, enabling the wired connectors (5) to be subsequently provided by way of wire bonding without elements (1) becoming detached from the plate (2). Moreover, the connection is still sufficiently flexible to deal with a difference in thermal expansion between the element (1) and the plate (2), even if the latter is made of copper. The method is fast and very suitable for large-scale production of a reliable device (10). The gold used must be sufficiently mobile. Therefore, use is made of a low-melting gold layer including a eutectic composition of gold and antimony or preferably gold and germanium.

Dependencies are inferred from the claim text.