Dowa Mining Co., Ltd.

Toshihiro Kanzaki

Akira Sugawara

Koichi Hatakeyama

Isamu Amatsu

Kouichi Hatakeyama

Fumi Tanabe

A process for producing a fcc metal consisting of copper having random orientations comprising cross rolling which is performed to achieve a total draft of at least 20% with the rolling axis being offset at 15&deg; or more in each pass to a total offset of at least 90&deg;, and subsequent full annealing which is accompanied by recrystallization, the fcc metal satisfying the following relationships: I,/I,&lE;2.3 and I,/I,&lE;1.0, where I,, I,and I,are the integral intensities of the (111), (200) and (220) faces, respectively, of crystal faces as measured by X-ray diffractiometry.

Processes for producing fcc metals

A leadframe of a single frame structure for supporting leads on IC chips. The leadframe is made of a high-strength, high-electroconductivity copper alloy. The copper alloy is produced by preparing an ingot of a copper alloy of 0.05-0.40 wt. % Fe, 0.05-0.40 wt. % Ni, 0.01-0.30 wt. % P, and optionally a total of 0.03-0.50 wt. % of either Sn or Zn or both and a total of 0.05-0.50 wt. % of at least one element of Ag, Co, B, Mn, Cr, Si, Ti and Zr, with the balance being Cu and incidental impurities, heating the ingot to 800 to 950.degree. C. and hot working the ingot to a reduction ratio of 50% or more, quenching the hot worked material from 600.degree. C. or above down to 300.degree. C. or below at a cooling rate of at least 1.degree. C./seconds, heat treating the quenched material at 380 to 520.degree. C. for 60-600 minutes without cold working, and subsequently carrying out cold working and heat treating at 450.degree. C. or below, whereby an Fe--Ni--P system intermetallic compound is precipitated in the Cu matrix as uniform and fine grains not larger than 50 nm.

Leadframe made of a high-strength, high-electroconductivity copper alloy

High-strength, high-electroconductivity copper alloys are produced by preparing an ingot of a copper alloy containing 0.05-0.40 wt % Fe, 0.05-0.40 wt % Ni, 0.01-0.30 wt % P, and optionally a total of 0.03-0.50 wt % of either Sn or Zn or both and a total of 0.05-0.50 wt % of at least one element of Ag, B, Mn, Cr, Si, Ti or Zr, with the balance being Cu and incidental impurities, heating the ingot to 800.degree. to 950.degree. C. and hot working it by a reduction ratio of 50% or more, quenching the hot worked material from 600.degree. C. or above to 300.degree. C. or below at a cooling rate of at least 1.degree. C./sec, heat treating the quenched material at 380.degree. to 520.degree. C. for 60 to 600 minutes without performing cold working, and cold working and heat treating it at 450.degree. C. or below, to precipitate an Fe--Ni--P system intermetallic compound in the Cu matrix as uniform and fine grains not larger than 50 nanometers. The copper alloys thus produced are superior in hardness, tensile strength, electrical conductivity and amenability to bending. The copper alloys are useful for making electric and electronic components, such as leadframes.

Process for producing high-strength, high-electroconductivity

Electric and electronic parts, including leadframes made of a copper-based alloy having high strength and high electric conductivity said copper-based alloy is produced by a process which comprises the steps of preparing a copper-based alloy consisting essentially of 0.01-3.0 wt % Co and 0.01-0.5 wt % P with the balance being Cu and incidental impurities, quenching said alloy from a temperature not lower than 750.degree. C. down to 450.degree. C. and below at a cooling rate of at least 1.degree. C./sec, heat treating the quenched alloy at a temperature of 480.degree.-600.degree. C. for 30-600 minutes, cold working said alloy for a working ratio of 20-80%, further heat treating the alloy at a temperature of 440.degree.-470.degree. C. for 30-600 minutes, and subsequently performing cold working for a working ratio of at least 50% and heat treatment at 380.degree. C. and below. The electric and electronic parts preferably contain a plurality of conductive leads.

Copper-based electric and electronic parts having high strength and high

Copper-based alloys suitable for use as materials in fabricating electric and electronic parts as typified by leadframes and having high strength and high electric conductivity can be produced by a process which comprises the steps of preparing a copper-based alloy consisting essentially of 0.01- 3.0 wt % Co and 0.01- 0.5 wt % P with the balance being Cu and incidental impurities, quenching said alloy from a temperature not lower than 750.degree. C. down to 450.degree. C. and below at a cooling rate of at least 1.degree. C./sec, heat treating the quenched alloy at a temperature of 480.degree.-600.degree. C. for 30-600 minutes, cold working said alloy for a working ratio of 20-80%, further heat treating the alloy at a temperature of 440.degree.-470.degree. C. for 30-600 minutes, and subsequently performing cold working for a working ratio of at least 50% and heat treatment at 380.degree. C. and below.

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Tokyo, Japan

Toshihiro Kanzaki