Texas Instruments Corporation

Karen A Auguston

Henry F Breit

Joseph M Gondusky

A novel composite metal material comprises a ferrous metal of relatively low thermal expansion properties and a silver metal substantially free of ferrous constituents having a relatively high thermal conductivity which cooperate in a novel way to provide the composite material with an effective thermal expansion coefficient corresponding to that of various silicon or gallium arsenide semiconductor devices and the like for reliably mounting the devices while also providing paths of high conductivity silver metal extending through the composite material to provide improved heat-dissipation from the semiconductor devices. A circuit system mounts a semiconductor device using the novel composite metal material alone, bonded to other support materials, or formed into a selected shape. In one preferred embodiment, the composite material is used in a novel heat-dissipating member having components of different shape which are bonded together. One component formed of the novel composite material has a selected shape for compactly mounting the semiconductor device and the second component is formed of high thermal conductivity metal and has a different shape particularly adapted to receive heat from the silver paths and to facilitate heat-dissipation from the member.

Composite material, a heat-dissipating member using the material in a

A novel composite metal material comprises a ferrous metal of relatively low thermal expansion properties and a silver metal substantially free of ferrous constituents having a relatively high thermal conductivity which cooperate in a novel way to provide the composite material with an effective thermal expansion coefficient corresponding to that of various silicon or gallium arsenide semiconductor devices and the like for reliably mounting the devices while also providing paths of high conductivity silver metal extending through the composite material to provide improved heat-dissipation from the semiconductor devices. A circuit system mounts a semiconductor device using the novel composite metal material alone, bonded to other support materials, or formed into a selected shape. In one preferred embodiment, the composite material is used in a novel heat-dissipating member having components of different shape which are bonded together. One component formed of the novel composite material has a selected shape for compactly mounting the semiconductor device and the second component is formed of high thermal conductivity metal and has a different shape particularly adapted to receive heat from the silver paths and to facilitate heat-dissipation from the member. Novel methods for making the member and the composite material are shown.

Composite material for a circuit system and method of making

A circuit system has a semiconductor device mounted on a substrate which includes a composite metal material comprising a plurality of discrete elements of ferrous metal material such as an alloy of 36 percent nickel and the balance iron having a relatively low coefficient of thermal expansion, the discrete elements being copper-coated by electroless copper plating or the like and being pressed together and heated for sintering or diffusion-bonding the copper coatings together to form a continuous copper matrix having the discrete elements secured in dispersed relation therein for providing the composite metal material with a coefficient of thermal expansion relatively much lower than that of the copper material, the heating of the coated particles for diffusion bonding thereof being regulated for forming the continuous copper matrix while leaving the copper material of the matrix substantially free of nickel, ferrous or other constituents diffused therein from the discrete elements for providing the composite material with improved thermal conductivity.

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Brigthon, MA, United States of America

Karen A Auguston