Circuit system, a composite metal material for use therein, and a method for making the material
US4894293A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1988 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | Mar 10, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12486
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.