JPH02114404A - Thin cu alloy wire for electric/electronic apparatus - Google Patents

Abstract

PURPOSE:To enhance electric, mechanical properties and workability in wire drawing by allowing the material to contain specified amounts of Ni, Si and Y or one or more of rare earth elements, including as residue Cu plus inevitable impurities, and specifying the weight ratio of Ni to Si. CONSTITUTION:Material according to the presenting invention contains 0.6-3.5wt.% Ni, 0.1-0.8wt.% Si, and Y or one or more of rare earth elements in 0.01-1.0wt.% by weight, while the residue consists of Cu and inevitable impurities, wherein the ratio Ni/Si shall range within 3-6. In case this ratio is below 3, Si not forming intermetallic compound is produced to cause remarkable drop in the electroconductivity of a thin Cu alloy wire, while above 6 Ni not forming intermetallic compound to produced to result in a similar drop. This invention accomplishes sufficient electroconductivity, tensile strength, and bending strength, and processing of a thin wire under 0.08mm in dia. can be carried out in good performance.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a copper alloy thin wire, and particularly to a copper alloy thin wire used in electronic VI devices, xtap+ devices, medical devices, information communication devices, etc. It is.

L Prior Art j Conventionally, pure copper (tough pitch steel, oxygen-free copper) has been mainly used as a conductor for electronic equipment, duplex-1 equipment, medical equipment, information communication equipment, etc.

However, although pure copper has good electrical properties such as conductivity, it has poor mechanical properties such as tensile strength and bending strength.

Therefore, a copper-beryllium alloy, which is inferior to pure copper in electrical properties such as electrical conductivity but has good mechanical properties such as tensile strength and bending strength, is sometimes used as a conductor.

Further, a copper-tin alloy is sometimes used as a conductor, although it is inferior in mechanical properties such as tensile strength and bending strength to a copper-beryllium alloy, but has good electrical properties such as conductivity.

[Problems to be Solved by the Invention] As described above, conductors used in conventional electronic devices have good electrical properties such as electrical conductivity, but poor mechanical properties such as tensile strength and bending strength. Alternatively, mechanical properties such as tensile strength and bending strength were good, but electrical properties such as electrical conductivity were poor.

However, with the recent development of the electronics, electricity, and communication industries, there is a need for conductors for electrical/71i7-equipment that have both good electrical properties such as conductivity, and mechanical properties such as tensile strength and bending strength. became.

Corson alloy (
Cu-Ni-Si alloys (for example, Asa 0 Metal Engineering Series, Nonferrous Metal Materials Science, Yotabu Murakami and Kiyoshi Kamei, p. 352) are known, but they have poor wire drawability into thin wires (wire drawability: one-time wire breakage). There is a problem with the conductor 11 up to this point, and it cannot be used as a conductor for electrical or electronic equipment.

This invention was made in order to solve such conventional problems, and has good electrical properties such as conductivity and mechanical properties such as tensile strength and bending strength, and also has good wire drawing properties. One object of the present invention is to provide a fine copper alloy wire for electrical and electronic equipment with good durability.

[Means for Solving the Problem] In the invention of claim 1, Ni is 0.6 to 3.5 weight g6,
0.1 to 0.8 weight of Si? 6. Contains one or more elements selected from Y or rare earth elements at 96% by weight of C1.01 to 1.0, the remainder consists of Cu and impurities containing Ni+J, and the weight ratio Ni/Si to Si is 3 to 1.0%. Make it 6.

Claim J+! In the invention described in t'), the wire diameter is 0.0
8 mm or less.

[Action/Effect] The copper alloy of the present invention is an age hardenable copper alloy.

The reason why Ni and Si are included (-f) in the copper alloy is that the intermetallic compounds of Ni and Si that precipitate in the copper alloy improve the mechanical properties such as tensile strength and bending strength of the copper alloy thin wire. It is.

The weight ratio of Ni to Si was made to be Ni/Si, or 3 to 6, because SI and Ni were! Ii quantity ratio Ni/S
This is because when i is 3 to 6, an intermetallic compound a is formed.

In other words! When the Jlf amount ratio is less than 3, Si that cannot form an intermetallic compound is produced. Si alone is difficult to precipitate into copper alloys, so Si cannot form intermetallic compounds.
i remains dissolved in the copper alloy.

Since the electrical conductivity is lower in the solid solution state than in the precipitated state, the electrical conductivity of the copper alloy thin wire is significantly lowered due to the SL that cannot form intermetallic compounds.

Also,! When the Tf ratio is higher than 6, Ni is produced which cannot form an intermetallic compound.

Since Ni is difficult to produce at t+7 in a copper alloy when used alone, Ni, which cannot form an intermetallic compound, remains solidly dissolved in the copper alloy, and the electrical conductivity of the copper alloy thin wire decreases.

N i 3 (-7m'xo, 6~3.5mm", i
;s The reason why the Si content is 0.1 to 0.8 weight 91J is because the Ni content is 0, 61nlit96t, t
: 1. This is because if the tS i content is less than 0.1wt96, the amount of precipitated intermetallic compounds of Ni and Si will decrease, making it impossible to obtain sufficient tensile strength and bending strength. When the weight 96 or Si content increases more than 088% by weight, Ni, Si and Ni and S
This is because an excessive amount of the intermetallic compound i is dissolved in solid solution or released as a solid solution, resulting in a significant decrease in electrical conductivity.

The inclusion of one or more elements selected from Y or rare earth elements at 1°C makes it possible to form thin wires without adversely affecting electrical properties such as conductivity and mechanical properties such as tensile strength and bending strength. [Nakasenka] - This is to improve one's sexuality.

That is, each time R is added to one or more elements selected from Y or rare earth elements, the tli particles become finer and more uniform, and the wire drawability is improved.

The reason why Y or the rare earth element is limited to 0.01 to 1.0% by weight is because if the content is less than 0.01% by weight, the effect of making the precipitated particles finer and more uniform will be reduced. This is because if the content exceeds 1.0% by weight, Y or rare earth elements dissolved in solid solution or fli will increase, resulting in a significant decrease in electrical properties such as electrical conductivity.

The copper alloy of the present invention has excellent heat resistance, so it has excellent soldering properties, and even when plated with Sn, Ag, Ni, Au, etc., it has sufficient conductivity, tensile strength, bending strength, etc. can get. Note that heat resistance is improved by Ni and Si.
This is thought to be due to intermetallic compounds. Plating may be performed after wire drawing, or wire processing may be performed after plating.

Moreover, if the copper alloy thin wire of the present invention is twisted into a plurality of wires and used as a stranded wire, further improvement in mechanical properties such as tensile strength and bending strength can be expected.

In the copper alloy of the present invention, since the fine precipitated particles are uniformly distributed, it is possible to satisfactorily form a thin wire with a diameter of 0.08 mm or less. Furthermore, even such thin wires exhibit sufficient mechanical properties.

[Example] Alloys with compositions shown in Table 1 (Conventional Example 17 is tough pitch steel,
18 is a copper-tin alloy and 19 is a copper-beryllium alloy) were semi-continuously cast using a graphite mold, and the diameter was 8 m.
It was made into a bar of m. This was heated and held at 950° C. for 3 hours, and then rapidly cooled in water.

These bars were repeatedly subjected to cold wire drawing and heat treatment as shown below to produce fine wires with a diameter of 0.03 mm.

First, cold wire drawing was performed from a diameter of 8 mm to a diameter of 0.5 mm. The area reduction rate is 99.6%.

Next, heat treatment was performed at 450° C. for 3 hours, and then slowly cooled.

Next, cold wire drawing was performed from a diameter of 0.5 mm to a diameter of 0.03 mm. The area reduction rate is 9986%.

Next, heat treatment was performed at a temperature of 280° C. for 2 hours, followed by slow cooling.

Note that since No. 17 (tough pitch copper) is not an age-hardenable copper alloy, it was produced by cold wire drawing directly from 8 mm to a diameter of 0.03 mm without heat treatment, instead of using the above method.

The alloys shown in Table 1 were tested for tensile strength, elongation, electrical conductivity, bending strength at a diameter of 0.03 mrn, and wire drawability at a diameter of 0.03 mm.

The results are shown in Table 2.

The bending strength was evaluated based on how many times bending stress had to be repeatedly applied to the thin wire before it would break.

FIG. 1 shows an apparatus for carrying out this test.

As shown in FIG. 1, this device includes a fixed pulley 1, a movable pulley 2, and a weight 4. A fixed pulley l is installed under the wall 4, and a movable pulley 2 is placed next to it. One end of the thin wire 3 is attached to the wall 5, then passed through the lower part of the fixed pulley 1, then passed through the upper part of the movable pulley 2, and then attached to the weight 4. The weight 4 is 10 g, and the radius of the fixed pulley 1 and movable pulley 2 is 15 mm.

Next, the operation of this device will be explained. By moving the movable pulley 2 up and down as shown by the arrows in FIG. 1, repeated bending stress is applied to the portion of the thin wire 3 that corresponds to the fixed pulley 1 and the portion that corresponds to the movable pulley 2. One round trip up and down is counted as one time. The number of times is taken as the bending value.

(Left below) Copper alloy thin wires of No. 1 to No. 6 of the present invention have a diameter of 0.
．． In the case of Sn plating with a diameter of 0.03 mm and in the process of cold drawing from a diameter of 0.5 mm to 0.03 mm, the diameter of the wire was 0.03 mm.
For the 35 mm Ag-plated wires, tensile strength, elongation, electrical conductivity 8 bending strength, and wire drawability at a diameter of 0.03 mm were tested.

The results were the same as No. 1 to No. 6 in Table 2, respectively.

Furthermore, No. 1 to No. with a diameter of 0.03 mtn.

Table 3 shows the results of a bending strength test using 19 strands of each of the 19 alloys twisted to form twisted wires.

(Left below) [Considerations on Example 1 According to Table 2, Conventional Example 17 (oxygen-free copper) has a conductivity of
The wire drawability is 96%lAC3,2゜0kg/times, respectively.
Although very high, the tensile strength and flexural values are each 59 k
g/rnm2.35 [il, which is quite low.

On the other hand, in Conventional Example 19 (copper-beryllium alloy), the electrical conductivity and wire drawability are 23%lAC3,0°6kg/times, which are quite low, but the tensile strength and bending value are 100k each.
g/mm 2.560 times, which is high.

Furthermore, Conventional Example 18 (copper-tin based alloy) has values intermediate between Conventional Examples 17 and 19 in terms of electrical conductivity and tensile strength. but,
The bending value and wire drawability are each 40 times.

0.7 kg/time, which is very low.

Copper alloy thin wires for electrical and electronic equipment must have good tensile strength, electrical conductivity, bendability, and wire drawability; ideally, they should have a good balance of the above four properties.

Conventional Example 17 (oxygen-free copper) is good only in electrical conductivity and wire drawability.

Conventional Example 19 (copper-beryllium alloy) has tensile strength and J
Although the uJ curve value is good, the conductivity and wire drawability are poor.

In the present invention, the tensile strength and electrical conductivity are equivalent to those of copper-tin alloys, the bending value is equivalent to copper-beryllium alloys, and the wire drawability is 1" equivalent to 1 g of acid-free copper.

As shown in Table 2, the tensile strength, electrical conductivity, bending value, and wire drawability of the present invention are 67 kg/mouth Il112.6, respectively.
09i1i 1 A CS, 400 times, 1.8kg
/The same or higher.

Furthermore, even in the case of stranded wires, the bending value of the present invention is comparable to that of copper-beryllium alloys, as shown in Table 3.

[Brief explanation of drawings]

FIG. 1 shows an apparatus for evaluating bending strength. In the figure, 1 is a fixed pulley, 2 is a moving slide, 3 is a thin line, 4 is a weight, and 5 is a wall.

Claims (2)

[Claims] (1) Ni 0.6-3.5% by weight, Si 0.1-0
．． 8% by weight, 0.01 to 1.0% by weight of one or more elements selected from Y or rare earth elements, the remainder consisting of Cu and unavoidable impurities, and the weight ratio Ni/Si to Si is 3 to 1.0% by weight. Copper alloy thin wire for electrical and electronic equipment with a rating of 6. (2) The copper alloy fine wire for electrical and electronic equipment according to claim 1, having a wire diameter of 0.08 mm or less.