JP2682577B2 - Manufacturing method of copper alloy for terminals and connectors - Google Patents

Description

TECHNICAL FIELD The present invention relates to a copper alloy for terminals / connectors having high conductivity and excellent spring characteristics (spring limit value), and a method for producing the same. .

[Conventional technology and problems]

Conventionally, as the copper alloy for terminals and connectors, inexpensive brass, nickel silver, phosphor bronze or the like having excellent spring characteristics have been used.

However, brass has inferior strength and spring properties for terminals and connectors, and phosphor bronze and nickel silver have excellent spring properties, but phosphor bronze contains 8 wt% Sn.
Further, nickel silver is an expensive alloy because it contains 18% by weight of Ni, and there are also processing restrictions such as poor hot workability in manufacturing. Further, it is considered that the terminals, connectors are made lighter, thinner, shorter, and smaller, and the above-mentioned copper alloys have low conductivity, which cannot be said to be satisfactory. Therefore, the appearance of an inexpensive alloy having excellent conductivity and excellent spring characteristics has been awaited.

[Configuration of the invention]

The present invention has been made in view of the above points, and an inexpensive alloy having good conductivity and excellent spring characteristics was sought, and a Cu-Cr-Zr alloy system was studied. Conventionally, Cu-Cr-Zr alloys have been known as high-strength, high-conductivity alloys, but their spring properties are insufficient and need to be improved. The present inventor has conducted intensive studies on a method for producing a Cu—Cr—Zr system, and has found that the characteristics can be improved.

That is, the present invention, Cr 0.1 ~ 1.5 wt%, Zr0.05 ~ 1.
After hot rolling a copper alloy containing 0 wt% and 0.01 to 3.0 wt% Zn and the balance Cu and unavoidable impurities, after aging treatment in the steps after hot rolling, cooling at a working degree of 10% or more is performed. A method for manufacturing a copper alloy for terminals and connectors, characterized by annealing for 10 seconds to 60 minutes at a temperature of 300 to 600 ° C after hot working, and Cr 0.1 to 1.5% by weight, Zr 0.05 to 1.0% by weight, Zn0 .01 ~
3.0% by weight and Ag, Al, Be, Co, Fe, Hf, Mg, Ni, P, S
One or two or more selected from the group consisting of n and Ti is included in a total amount of 0.01 to 1.0% by weight, and a copper alloy consisting of the balance Cu and unavoidable impurities is hot-rolled and aged after the hot-rolling. The present invention relates to a method for producing a copper alloy for a terminal / connector, which comprises performing cold working at a working degree of 10% or more and then annealing at a temperature of 300 to 600 ° C. for 10 seconds to 60 minutes.

[Specific description of the invention]

Next, the reasons for limiting the alloy components and the manufacturing method constituting the present invention will be described. The reason for setting the Cr content to 0.1 to 1.5% by weight is that precipitation hardening due to fine Cr particles can be expected without impairing the high conductivity of Cu itself, and further heat resistance accompanying it can be obtained. This is because if the Cr content is less than 0.1% by weight, the above-mentioned effects cannot be expected, and conversely, if it exceeds 1.5% by weight, the conductivity is significantly lowered. The reason for setting the Zr content to 0.05 to 1.0% by weight is to accelerate precipitation hardening and obtain heat resistance accompanying it. This is because if the Zr content is less than 0.05% by weight, the above-mentioned curing cannot be obtained, and conversely if it exceeds 1.0% by weight, the conductivity and workability are significantly deteriorated. Zn content of 0.01% by weight or more and 3.0% by weight or less is
This is because the addition of ZnO can improve the heat resistance peeling property of the solder without significantly lowering the conductivity. If the Zn content is less than 0.01% by weight, the above-mentioned effect cannot be expected. This is because sex deterioration occurs. Solder heat resistance peeling property has become extremely important in recent years because of the demand for improved reliability because Sn or solder plating is often applied to the material for the purpose of reducing contact resistance, improving corrosion resistance, and the like.

In addition, Ag, Al, Be, Co, Fe, Hf, Mg, Ni, P, Sn,
The total amount of one or more selected from the group consisting of Ti
The reason for adding 0.01 to 1.0% by weight is that these effects can be expected to have the effect of improving strength and heat resistance without significantly reducing conductivity. The reason why the total content is set to 0.01% by weight or more and 1.0% by weight or less is that if the content is less than 0.01% by weight, the above-mentioned effect cannot be expected, and if it exceeds 1.0% by weight, the conductivity is remarkably lowered.

Cold-worked with a workability of 10% or more, then 300-6
The reason for annealing for 10 seconds to 60 minutes at a temperature of 00 ° C is that the effect of improving the spring characteristics and the aging by the batch method are
This is because it is possible to expect an effect of straightening a curled material and an effect of making the bendability deteriorated due to cold rolling to have good bendability again. Ten%
In cold working with a working degree of less than the above effect cannot be expected,
Further, even if the annealing temperature is less than 300 ° C. and the annealing time is less than 10 seconds, the above effects cannot be expected. Conversely, if the annealing temperature is
Even if the temperature exceeds 600 ° C or if the annealing time exceeds 60 min, the material softens and the spring characteristics cannot be expected to improve. Preferably, tension annealing is performed to obtain a better shape.

 Next, examples of the present invention will be described.

〔Example〕

Alloys having the compositions shown in Table 1 were melted and cast from electrolytic copper or oxygen-free copper in a high-frequency melting furnace in the atmosphere, an inert or reducing atmosphere.

Next, the cast ingot was hot-rolled at 900 ℃,
Plate. After that, solution treatment is performed at 950 ° C for 1 hr,
Face cutting was performed and cold rolling was performed to adjust the plate thickness shown in Table 1.
The manufacturing conditions after aging treatment (400 ° C) at this plate thickness are as follows:
It is as shown in the table.

Tensile strength, elongation, and electrical conductivity of these test materials were measured, and the spring characteristics were evaluated by measuring the spring limit value (kb). Solderability is 230 ± by vertical dipping method
It was evaluated by immersing in a solder bath (Sn 60%, Pb 40%) at 5 ° C for 5 seconds and visually observing the state of solder leakage. Regarding the heat-resistant peeling resistance of the solder, the sample soldered by the above method was heated in air at 150 ° C. for 1500 hours, and then bent 90 ° at the same bending radius as the material plate thickness to evaluate the presence or absence of peeling.

The bendability was measured by performing W bending with the same bending radius as the material plate thickness and observing the bent portion. The shape of the annealed material was cut into a length of 200 mm in the rolling direction, placed on a surface plate, and evaluated by measuring the maximum material lifting height.

As is clear from Table 1, 1 of the present invention example is a basic alloy system containing no subcomponents, which has a high spring limit value, high tensile strength, and high conductivity. In particular, the heat-resistant peeling property of solder does not show peeling even after heating at 150 ° C for 1500 hours. Inventive Example 3 is an alloy to which subcomponents are added, and manufacturing conditions are the same as those of Inventive Example 1. The tensile strength and the spring limit value are slightly better, but the conductivity is slightly lower. The other properties are almost the same. Comparative Examples 1 to 8 are based on the basic alloy of the present invention, but are manufactured with a pre-annealing workability of less than 10%, and have spring limit values and tensile strengths higher than those of the inventive alloys. It can be seen that the material shape is also inferior.
In Comparative Example 9, since Zn was not added, the heat-resistant peeling property of the solder deteriorates. Comparative Example 10 does not contain Zr, and Comparative Example 12 has an annealing temperature as high as 700 ° C., so that the tensile strength and the spring limit value are inferior to those of the inventive alloys. In Comparative Example 11, the material shape is very bad because the pre-annealing process and the annealing are not performed. In Comparative Example 13, since the chromium content exceeds the present invention, a remarkable decrease in conductivity is recognized.

〔The invention's effect〕

The Cu-Cr-Zr-Zn-based alloy that has been subjected to the manufacturing method of the present invention has high conductivity and is an alloy excellent in spring characteristics.
It is suitable as a material for connectors.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C22F 1/00 684 8719-4K C22F 1/00 684C 685 8719-4K 685Z 686 8719-4K 686A 691 8719-4K 691B 8719-4K 691C 694 8719-4K 694A

Claims (2)

(57) [Claims] 1. A copper alloy containing 0.1 to 1.5% by weight of Cr, 0.05 to 1.0% by weight of Zr and 0.01 to 3.0% by weight of Zn, and the balance of Cu and unavoidable impurities is hot-rolled and after hot rolling. After aging treatment in the process of, and cold rolling at a working degree of 10% or more, 300
A method for producing a copper alloy for terminals and connectors, which comprises annealing at a temperature of ~ 600 ° C for 10 sec ~ 60 min. 2. Cr 0.1 to 1.5% by weight, Zr 0.05 to 1.0% by weight, Z
0.01 to 3.0 wt% and Ag, Al, Be, Co, Fe, Hf, Mg, Ni, P, Sn, T
The total amount of one or more selected from the group consisting of i
Hot-rolling a copper alloy containing 0.01 to 1.0% by weight and the balance Cu and unavoidable impurities, aging treatment in the steps after hot rolling, and cold working at a working degree of 10% or more, and then 300
A method for producing a copper alloy for terminals and connectors, which comprises annealing at a temperature of ~ 600 ° C for 10 sec ~ 60 min.