| 摘要 |
1484608 Semi-conductor devices HITACHI Ltd 21 Oct 1974 [22 Oct 1973] 45464/74 Heading H1K In a semi-conductor device one face of a wafer of semi-conductor material, e.g. Si or Ge is bonded to a composite electrode consisting of fibres of a material having a thermal expansion coefficient substantially equal to or less than that of the wafer material embedded parallel to said wafer face in a matrix of metal of higher electrical and thermal conductivity than the fibre material so that the expansion coefficients of the wafer and the face of the electrode to which it is bonded are matched. Preferably the fibres are of tungsten, molybdenum, graphite or iron-nickel-cobalt alloy in a matrix of copper and lie parallel to the interface between the electrode and the body. They may form a series of rectangular grids stacked to form a laminar structure with an angular displacement between successive grids. The fibres should comprise more than 20% by volume of the electrode and the fibre content is preferably graded from 50% adjacent the body to zero on the opposite electrode face to achieve optimum expansion coefficient matching and permit corrosion-free attachment of a copper lead or base electrode. As described composite electrodes are attached to opposite faces of a silicon wafer which is mounted in a sealed envelope. Methods of forming the electrodes are described. Specifica- 1,158,994, is referred to. |
