In the manufacture of a semiconductor device, a method for bonding a semiconductor element to an adherend such as a metal lead frame (a so-called die bonding method) has been developed from a conventional method for using gold-silicon eutectic bonding to a method for using solder or a resin paste. At the present time, an electrically conductive resin paste may be used.
In recent years, a power semiconductor device for controlling and supplying electric power has been remarkably widely used. Since a current always flows in the power semiconductor device, the power semiconductor device has a large heat value. Therefore, an electrically conductive adhesive used for the power semiconductor device desirably has high heat dissipation properties and low electric resistivity.
Low loss and a high-speed operation are required for the power semiconductor device. Conventionally, semiconductors using Si such as IGBT (Insulated Gate Bipolar Transistor) and MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) have been used for the power semiconductor device. In recent years, power semiconductor devices using semiconductors such as SiC and GaN are developed, and are expected to expand from now on.
The semiconductors using SiC and GaN have features such as a large band gap and a high breakdown electrical field to achieve low loss, a high-speed operation, and a high-temperature operation. The high-temperature operation provides a merit in an automobile and a small power converter or the like used under a severe heat environment. In the semiconductor device used under a severe heat environment, a high-temperature operation at about 250° C. is assumed. This causes problems in heat characteristics and reliability in solder and an electrically conductive adhesive as conventional bonding and adhesive materials. Then, conventionally, a sintering metal particle-containing paste material has been proposed (for example, see Patent Document 1). The sintering metal particle-containing paste material contains nanomicro-sized metal particles. These metal particles are melted at a temperature lower than a usual melting point according to a nanosized effect, so that sintering between the particles is achieved.