JPH0813066A - Copper alloy or copper alloy sheet, excellent in stamping property - Google Patents

Abstract

PURPOSE:To produce a copper alloy excellent in stamping property by preparing a copper alloy containing specific percentages of Mg, Cr, and Pb. CONSTITUTION:A copper alloy, consisting of, by weight, 0.2-0.8% Mg, 0.1-0.35% Cr, 0.001-0.01% Pb, and the balance Cu with inevitable impurities, is prepared. By this method, the copper alloy, having high strength, high electric conductivity, and heat resistance and excellent in stamping property, can be obtained. By using this copper alloy, die wear due to stamping can be minimized, and the electric or electronic parts manufacturing cost can be remarkably reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper alloy used for producing electric and electronic parts such as connectors and lead frames, or a thin plate made of the copper alloy.

[0002]

2. Description of the Related Art In general, electrical and electronic parts such as connectors and lead frames are formed by punching a thin plate made of a copper alloy having high strength, high conductivity and heat resistance and at the same time forming it into a predetermined shape (hereinafter, It is produced by performing stamping). The copper alloy having high strength, high conductivity and heat resistance for producing the electric and electronic parts contains Cr: 0.01 to 2.0% by weight,
Further, a copper alloy containing Mg: 0.001 to 2.0% by weight and the rest being Cu is known (see, for example, JP-A-59-193233), and a thin plate made of this copper alloy is It is supplied as a strip and is usually stamped at a high speed of 600 times per minute and molded into electrical or electronic parts such as connectors and lead frames.

[0003]

If the copper alloy thin plate having the above-mentioned high strength, high conductivity and heat resistance is stamped at such a high speed, the die will be worn out greatly and the expensive die will not be frequently replaced. There was a problem that not only the work efficiency was lowered, but also the cost was raised.

[0004]

Therefore, the present inventors have
While maintaining excellent properties such as high strength, high conductivity and heat resistance, as a result of conducting research to develop a copper alloy and a thin plate made of the copper alloy with less die wear due to stamping, in weight%, Mg: 0.2-0.8%, C
r: 0.1 to 0.35% and the balance Pb: 0.001 to 0.0 in a copper alloy composed of Cu and unavoidable impurities.
It has been found that a copper alloy containing 1% retains high strength, high electrical conductivity and heat resistance, and has very little die wear due to stamping (see , "Stamping"
That).

The present invention has been made on the basis of such findings, and in terms of weight%, Mg: 0.2 to 0.8%,
Cr: 0.1-3.5%, Pb: 0.001-0.01
%, And the balance is composed of Cu and unavoidable impurities, and is characterized by a copper alloy or copper alloy thin plate having excellent stamping properties.

The reason why the component composition of the copper alloy or copper alloy thin plate excellent in stamping property of the present invention is limited as described above will be described.

(A) Mg Mg has an action of improving the strength, but if it is less than 0.2%, it has no effect, and if it exceeds 0.8%, the melt castability becomes poor. As a result, defects occur in the ingot, the number of cut portions increases, and the yield greatly decreases. Therefore, the content is 0.2 to 0.
It was set at 8%. A more preferable range of Mg is 0.2-0.
5%.

(B) Cr Cr has a function of improving strength and heat resistance, but
If it is less than 1%, its action is not effective, and if it exceeds 0.35%, the precipitation of Cr becomes large and the metal structure becomes non-uniform. Therefore, the content was set to 0.1 to 0.35%. .

(C) Pb Pb has an effect of suppressing wear of the stamping die, but if it is less than 0.001%, it has no effect, and 0.0
If the content exceeds 1%, hot rolling cracks tend to occur, so the content was set to 0.001 to 0.01%. The more preferable range of Pb is 0.003 to 0.00.
8%.

[0010]

[Examples] Using a normal medium-frequency coreless induction furnace, a Cu alloy molten metal having a component composition shown in Tables 1 and 2 was prepared in a reducing atmosphere, and a semi-continuous casting method was performed using a water-cooled mold. A cake having a size of 150 mm thickness × 500 mm width × 2400 mm length was obtained. Next, hot rolling is started at a temperature within the range of 800 to 950 ° C. to obtain a hot rolled sheet having a thickness of 11 mm,
Immediately after water cooling, the upper and lower surfaces of the hot-rolled sheet are chamfered by 0.5 mm each to a thickness of 10 mm, and then cold rolling, annealing and pickling are repeated under these usual conditions to obtain a finish rolling rate of 50%. In the present invention, a Cu alloy thin plate 1 to 1 having a thickness of 0.25 mm is used.
4. Comparative Cu alloy thin plates 1 to 6 and conventional Cu alloy thin plates were manufactured.

Regarding these Cu alloy thin plates 1 to 14 of the present invention, comparative Cu alloy thin plates 1 to 6 and conventional Cu alloy thin plates,
After measuring the tensile strength, elongation, conductivity and softening point,
Furthermore, using a W-Co type cemented carbide die, length: 1.0 mm,
Horizontal: A 2.0 mm rectangle is punched at a speed of 600 strokes per minute, and at the same time stamping is performed to measure the amount of wear of the punching blade of the die when the stamping stroke reaches 1 million times. The measurement results are shown in Tables 1-2. The softening point was set to a temperature at which the material hardness after heating for 1 hour was measured and the material hardness became half of the initial hardness.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

From the results shown in Tables 1 and 2, the Cu alloy thin plates 1 to 14 of the present invention are different from the conventional Cu alloy plates.
(1) Excellent stamping property due to less die wear due to stamping, (2) Comparable to tensile strength, elongation and conductivity, (3) High softening point, so heat received in semiconductor device assembly process It can be seen that the mechanical properties do not change even by.

However, the comparative Cu alloy thin plates 1 to 6 having a composition outside the scope of the present invention are inferior in at least one of tensile strength, elongation, conductivity, softening point and die wear amount. From this, it is understood that it is not preferable as a material for producing electric and electronic parts.

As described above, since the copper alloy or the copper alloy plate of the present invention has less die wear due to stamping and has a high softening point, electrical and electronic parts are manufactured using the copper alloy or the copper alloy plate of the present invention. Then, the number of times of exchanging the mold can be reduced, and therefore, the manufacturing cost of the electric or electronic parts can be significantly reduced, and the mechanical characteristics do not change even if heat is applied during the assembly process of the semiconductor device, so that the electric and electronic parts are not changed. It has excellent industrial effects such as no variation in quality.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takuya Ishitashi 128-7 Ogimachi, Aizuwakamatsu, Fukushima Prefecture Wakamatsu Works, Mitsubishi Shindoh Co., Ltd.

Claims (2)

[Claims] 1. By weight%, Mg: 0.2-0.8%, C
r: 0.1 to 0.35%, Pb: 0.001 to 0.01
%, With the balance being Cu and inevitable impurities, the copper alloy having excellent stamping properties. 2. A copper alloy thin plate having excellent stamping properties, which is made of a copper alloy having the composition according to claim 1.