PURPOSE: To obtain the titled lead material satisfying sufficiently various characteristics required of the material and having strength and elongation showing, respectively, by far the highest values by composing the said Cu alloy which contains specified quantity of Cr or/and Zr and C and in which respective average grain sizes of crystallized substances, precipitates and grains are specified.
CONSTITUTION: The titled lead material is composed of the Cu alloy containing, by weight, 0.05W1% Cr or/and 0.005W0.3% Zr and 5W60ppm C and having the balance consisting of Cu and inevitable impurities among which oxygen content is regulated to ≤35ppm, and further, this material satisfies the following requirements; that is, the average grain sizes of crystalline substances, precipitates and grains are regulated, respectively, to ≤10μm, ≤0.1μm and ≤50μm. this lead material has tensile strength of ≥52kgf/mm2, elongation of ≥6.2%, electric conductivity of ≤53% JACS and softening temp. of ≥410°C. The above values sufficiently satisfies various characteristics required of lead material form semiconductor device and, particularly, strength and elongation show by far the highest values, respectively.
IWAMURA TAKURO
KOBAYASHI MASAO
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