Copper alloy for electrical and electronic equipment, copper alloy thin sheet for electrical and electronic equipment, and conductive part and terminal for electrical and electronic equipment

Abstract

The present invention pertains to a copper alloy for electrical and electronic equipment, a copper alloy thin sheet for electrical and electronic equipment, and a conductive part and terminal for electrical and electronic equipment. The copper alloy for electrical and electronic equipment contains more than 2.0 mass% to 15.0 mass% of zinc, 0.10 mass% to 0.90 mass% of tin, 0.05 mass% to less than 1.00 mass% of nickel, 0.001 mass% to less than 0.100 mass% of iron, and 0.005 mass% to 0.100 mass% of phosphorus, with the remainder comprising copper and unavoidable impurities. The copper alloy satisfies 0.002 ≤ Fe / Ni < 1.500, 3.0 < (Ni + Fe) / P < 100.0, and 0.10 < Sn / (Ni + Fe) < 5.00 in terms of atomic ratios. The yield ratio (YS / TS), which is calculated from the tensile strength (TS) and 0.2% offset yield strength (YS) when a tension test is performed in a direction parallel to the rolling direction, is over 90%.

Description

technical field [0001] The present invention relates to a Cu-Zn-Sn based copper alloy for electrical and electronic equipment used as a conductive element for electrical and electronic equipment such as a connector of a semiconductor device, other terminals, or a movable conductive sheet or a lead frame of an electromagnetic relay. Copper alloy sheet for electrical and electronic equipment, conductive components and terminals for electrical and electronic equipment. [0002] This application claims priority to Patent Application No. 2012-288051 filed in Japan on December 28, 2012 and Patent Application No. 2013-252331 filed in Japan on December 5, 2013, and uses the contents thereof for this specification. Background technique [0003] Cu—Zn alloys have been widely used as raw materials for conductive elements for electrical and electronic equipment in view of the balance between strength, processability, and cost. [0004] In addition, in the case of terminals such as conn...

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Problems solved by technology

[0016] However, in Patent Documents 1 and 2, only the respective contents of Ni, Fe, and P are considered, and it is not always possible to reliably and sufficiently improve the stress relaxation resistance simply by adjusting these respective contents.

[0017] In addition, although Patent Document 3 discloses adjusting the Ni / Sn ratio, the relationship between the P compound and the stress relaxation resistance is not considered at all, and the improvement of the stress relaxation resistance cannot be sufficiently and reliably achieved.

[0018] Furthermore, in Patent Document 4, the stress relaxation resistance cannot be sufficiently improved only by adjusting the total amount of Fe, Ni, and P and the atomic ratio of (Fe+Ni) / P.

[0019] As described above, conventionally proposed methods cannot sufficiently improve the stress relaxation resistance of Cu-Zn-Sn alloys

Therefore, in the connector of the above-mentioned structure, the residual stress relaxes over time or in a high-temperature environment, and the contact pressure with the conductive member on the opposite side cannot be maintained, so that there is a problem that defects such as poor contact are likely to occur at an early stage.

To avoid this problem, in the past, the wall thickness of the material had to be increased, resulting in increased material cost and weight

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