Ngk Insulators, Inc.

Kazuo Ikushima

Takaharu Iwadachi

Toshiaki Ishihara

Yoshio Itoh

Kazumasa Takeuchi

Syuhei Ishikawa

An excellent material for lead frames is provided which is economical and easily punched out to produce lead frames without bending or breakage, and has both superior tensile strength and high electrical conductivity, as well as splendid heat dissipation properties and good soldering properties.

Material for lead frames

A low cost electroconductive spring material excellent in electroconductivity and spring performance, has from 1.8 to 3.0% by weight of Ni, from 0.15 to 0.35% by weight of Be, from 0.2 to 1.2% by weight of Si and the balance being copper. This low cost electroconductive spring material can be used in electric devices. As preferred embodiments, the electroconductive spring material may further contain from 0.05 to 3.0% by weight in a total amount of at least one component selected from Sn, Al and Zn provided that each of Sn, Al and Zn does not exceed 1.5% by weight, or from 0.01 to 1.5% by weight in a total amount of at least one component selected from Co, Fe, Zr, Ti and Mg, provided that each of Co, Fe, Zr, Ti and Mg does not exceed 1.0% by weight. Moreover, the electroconductive spring material is subjected to a final solidification heat treatment at a temperature of 880.degree.-950.degree. C., a cold processing of not greater than 80%, and an aging treatment at a temperature of 380.degree.-530.degree. C. for not more than 2 hours.

Electroconductive spring material

An age-hardening copper titanium alloy containing 2 to 6% by weight of titanium, and composed of a substantially fully solution heat-treated structure having an average crystal grain size not exceeding 25 microns. When the alloy is cold-rolled after its solution heat treatment, its elongation in the rolling direction and that in a direction perpendicular thereto have a difference of within 20% therebetween, and its bend radius to thickness ratios in those two directions are substantially equal to each other.

Age-hardening copper titanium alloy

A process for producing an age-hardened copper titanium alloy strip includes preparing a copper titanium alloy melt, casting it, hot-working the cast alloy, cold-working the hot-worked alloy as required, annealing the hot-worked or cold-worked alloy, solution heat-treating the annealed alloy, and then the solution heat-treated alloy is age-hardened. The alloy is annealed at a temperature of 500.degree. C. to 700.degree. C. for one to 20 hours. Its solution heat treatment is terminated before or approximately as soon as a precipitated secondary phase has formed a complete solid solution in a master phase, so that the master phase may have an average crystal grain size not exceeding 25 microns. It is preferably terminated within three minutes. The alloy has a titanium content of 2 to 6% by weight.

Growing community of inventors

Nagoya, Japan

Kazuo Ikushima