Lead frame formed of a copper-zirconium alloy
AssigneeKabushiki Kaisha Toshiba
InventorsNobuaki Nakashima, Shinzo Sugai
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Abstract
A lead frame comprising a copper alloy containing 0.1 to 1 % by weight of chromium, 0.01 to 0.5% by weight of zirconium and having partial discolored regions caused by unbalanced precipitation of the zirconium distributed thereon at a rate of 2 grains/100 cm.sup.2 or less. The lead frame is, for example, obtained by an alloy containing 0.005% by weight of sulphur or less. The lead frame has an high reliability, high yield of production and high electrical conductivity.
Claims14
A lead frame comprising a copper alloy containing 0.1 to 1% by weight of chromium, 0.01 to 0.5% by weight of zirconium and having partial discolored regions caused by unbalanced precipitation of the zirconium distributed thereon at a rate of 2 grains/100cm.sup.2 or less.
A lead frame according to claim wherein the copper alloy contains less than 0.005% by weight of sulphur.
A lead frame according to claim wherein the copper alloy contains less than 0.05% by weight of iron, less than 0.1% by weight of nickel, less than 0.05% by weight of phosphorus, less than 0.1% by weight of tin and less than 0.1% by weight of zinc.
A lead frame according to claim wherein the conductivity of said copper alloy is not less than 75IACS%.
A lead frame according to claim I, wherein the Vickers hardness of said lead frame is not less than 150 Hv.
A lead frame material comprising a copper alloy containing 0.1 to 1 % by weight of chromium, 0.01 to 0.5% by weight of zirconium and having partial discolored regions caused by unbalanced precipitation of the zirconium distributed thereon at a rate of 2 grains/100cm.sup.2 or less.
Dependencies are inferred from the claim text.