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AssigneeCarpenter Technology Corporation
InventorEarl L. Frantz
Estimating the term…
A compacted article having low thermal expansivity and high thermal conductivity is made by compacting a mixture of two metal powders, one of which has low thermal expansivity and the other of which has high thermal conductivity, and strip material made therefrom which is suitable for use in forming the supportive lead frames in integrated circuit components. The powders are mixed together, formed into a green preform, sintered, and rolled to size to produce compacted or densified strip which has a unique combination of low thermal expansivity and high thermal conductivity. A low-expansivity metal disclosed in an alloy containing about 45-70% iron, 20-55% nickel, up to 25% cobalt, and up to 5% chromium which in powder form is mixed with a high-conductivity metal powder disclosed as substantially elemental iron, copper or nickel.
A low thermal expansion, low electrical resistivity sintered, shaped electronic device member including a lead, comprising 15-85 volume percent of compacted particles of a first metal powder having an average thermal expansion coefficient over the range of 25.degree. C. to 400.degree. C. of less than about 12.times.10.sup.-6 /.degree.C., and the balance compacted particles of a second metal powder having an electrical resistivity of less than 200 ohm/cmf, said compacted particles of both powders being substantially intermixed throughout said member, with said second metal powder having a corresponding 400.degree. C. thermal expansion coefficient greater than that of said first metal powder, said first metal powder having an electrical resistivity greater than that of said second metal powder, and the extent of alloying between the particles of said first and second metal powders being so small that said member has a 400.degree. C. thermal expansion coefficient less than that of said second metal powder and an electrical resistivity less than that of said first metal powder.
In a method for making a low thermal expansion, low electrical resistivity sintered, shaped electronic device member including a lead, the steps of making a mixture of about 15-85 volume percent of a first metal powder having an average thermal expansion coefficient over the range of 25.degree. C. to 400.degree. C. of less than about 12.times.10.sup.-6 /.degree.C. with the balance a second metal powder having an electrical resistivity of less than 200 ohm/cmf, said second metal powder having a corresponding 400.degree. C. thermal expansion coefficient greater than that of said first metal powder, and said first metal powder having an electrical resistivity greater than that of said second metal powder;
Dependencies are inferred from the claim text.