JPH06279895A - Lead material - Google Patents

Abstract

PURPOSE:To provide a lead material commonly having electrical conductivity, strength and mass producibility. CONSTITUTION:This lead material is the one using a copper alloy having a compsn. contg., by weight, 0.05 to <0.3% chromium and/or 0.05 to 0.5% zirconium, and the balance substantial copper and in which the grain size is regulated to >=7 in the size number of JIS-G-0551 or this lead material is another one using a copper alloy obtd. by incorporating 0.005 to 0.1% of one or >=two kinds selected from silicon, germanium, boron and magnesium into the same copper alloy.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a lead material.

[0002]

2. Description of the Related Art Generally, pure copper is used as a conductive material such as a lead material because of its excellent conductivity.

However, pure copper is weak in strength, and causes problems such as elongation and cutting during manufacturing. Therefore, in recent years, it has been attempted to improve the strength by adding an additional element such as chromium or zirconium and performing precipitation hardening treatment.

[0004]

However, a copper alloy such as chromium copper or zirconium copper which has been subjected to a precipitation hardening treatment by adding an additive element to improve the strength can improve the strength, but the conductivity However, it has a drawback that it is not suitable for mass production such as a lead material because the solution treatment is carried out by solution treatment or precipitation treatment.

The present invention solves the above-mentioned drawbacks of the copper alloy and provides a lead material having electrical conductivity, strength and mass productivity.

[0006]

The lead material according to the first aspect of the present invention contains, by weight, 0.05 to less than 0.3% of chromium and / or 0.05 to 0.5% of zirconium, and the balance is substantially copper. In addition, it is characterized by using a copper alloy having a grain size of 7 or more in the grain size number of JIS G 0551.

The lead material according to the second aspect of the present invention is one or two selected from chromium, 0.05 to less than 0.3% and / or zirconium, 0.05 to 0.5%, silicon, germanium, boron and magnesium. Species over 0.005
.About.0.1%, the balance being substantially copper, and a copper alloy having a grain size of 7 or more in the grain size number of JIS G 0551.

The most important point of the present invention is that the grain size of JIS G 0551 is No. 7 by repeating annealing and working without subjecting a copper alloy, which has been conventionally regarded as a precipitation hardening type material, to solution treatment. For the first time to obtain the above copper alloy,
This copper alloy is used as a lead material. Therefore, an advantage in terms of mass productivity exists as an industrial effect.

The present invention will be specifically described below by taking as an example a case where a copper alloy consisting of 0.15 wt% chromium, 0.3 wt% zirconium and the balance substantially copper is used as a lead material.

After melting and casting the above composition, hot working is performed at 700 to 850 ° C. to obtain a wire having a diameter of 7 to 10 mm, which is pickled and then cold worked and annealed at 500 to 650 ° C. repeatedly to obtain a diameter of 0.26.
mm wire rod.

At this time, the grain size after cold working is JIS
The particle size of G 0551 was 9, the conductivity was 90 IACS%, and the tensile strength was 49 kg / mm ² .

When further annealed at 550 ° C., the grain size is JIS G 0551 grain size number 10, and the conductivity is 93IA.
The CS% and the tensile strength were 44 kg / mm ² .

As described above, since the electric conductivity and the strength are variously changed depending on whether the work is finished or the finished work is annealed, desired characteristics can be easily obtained.

By setting the grain size to 7 or more in the grain size number of JIS G 0551, excellent characteristics can be obtained as compared with the case of performing the conventional precipitation hardening treatment, but from the various characteristics, the grain size of 8 or more is obtained. It is preferably a number, and more preferably a particle size number of 10 to 11.

In this case, the reason why the upper limit is intentionally defined is that the finer the crystal grain size (the larger the grain size number) is preferable in view of the conductivity and the strength, but the crystal grain size is considered from the economical point of the manufacturing method. Means that if the grain size number is 14 or less, or even 11 or less, it is relatively economical, and in order to improve its characteristics without considering economic efficiency, the upper limit of its grain size is Is not specified.

Further, the crystal grain shape is relatively elongated after rolling and becomes relatively disk-like after annealing.

The crystal grain size of the copper alloy when subjected to the conventional precipitation treatment is 5 to 6 in the grain size number of JIS G 0551.
No., conductivity 70-85IACS%, tensile strength 50-60kg / mm ²
Is.

Next, when this copper alloy is used as a lead wire, there is no problem of breakage or excessive elongation during manufacture when pure copper is used. According to the research conducted by the present inventors, such a problem of wire breakage and excessive elongation is related to proof stress and wire drawability, and in this respect, the present invention is excellent in proof stress and wire drawability, and is used as a lead material. It is suitable.

In the above description, the case where the chromium, zirconium copper alloy is used as the lead material has been described. However, the above-mentioned technical idea is applied when the copper alloy known as the precipitation effect type is used as the lead material. It will be easily understood that the above can also be applied.

Specific applications of the lead material of the present invention include stranded wires and leads for overhead wires which are required to have properties such as proof stress, wear resistance, repeated bending, heat conduction, conductivity, oxidation resistance and corrosion resistance. Line applications are preferred.

Further, it is more preferable to use it as a lead frame of a semiconductor device which is required to have characteristics such as repeated bending, conductivity, heat conduction and corrosion resistance.

By adjusting the grain size to 7 or more in the grain size number of JIS G 0551 without subjecting the copper alloy having the composition of the present invention to solution treatment, electrical conductivity, heat conduction, oxidation resistance,
Improvements in yield strength, repeated bending, fatigue, rupture, flexibility, plating properties, wire drawability, etc. have been made, which brings about effective improvements in the field of lead materials in which pure copper has been conventionally used.

Further, silicon, germanium, boron and magnesium are effective elements for suppressing strength and coarsening of crystal grains.

[0024]

EXAMPLES An example of a lead material will be described below in which a copper alloy consisting of 0.15 wt% chromium, 0.3 wt% zirconium and the balance substantially copper is used for the lead wire.

After melting and casting the above composition, hot working is carried out at 700 to 850 ° C. to obtain a wire having a diameter of 10 mm, which is pickled and then repeatedly cold worked to a diameter of 2 mm and annealed at 500 to 650 ° C. Cold working was performed to obtain a wire rod with a diameter of 0.26 mm. further
The characteristics are evaluated in the as-annealed state and the cold-worked state after annealing at 550 ° C.

Further, as a comparison, it can be understood that both the yield strength and the wire drawability are superior to those of pure copper and those subjected to the ordinary precipitation hardening treatment.

The evaluation methods shown in Table 1 were as follows.

(1) Conductivity: Specific resistance measured at room temperature was 0.72
41 (International standard copper resistivity) converted to 100 (IACS%) (2) Thermal conductivity: Material constant (cal / cm · deg) that gives the amount of heat that passes through a unit area for a certain period of time (3) Oxidation resistance Properties: Oxidation weight gain when heated at 400 ° C for 30 hours (mg / cm ² ) (4) Proof strength: Strength when strained by 0.2% (kg / mm ² ) (5) Cyclic bending: 0.3R with a load of 250gr (6) Flexibility: Presence or absence of flexibility when used as a stranded wire (7) Platability: Plating of Ag, Au, Sn, Ni, solder, etc. Good workability (8) Wire drawability: Ease of wire drawing (cutting resistance: compared with pure copper) (9) Grain size: JIS G 0551 grain size number

[0029]

[Table 1] As is clear from Table 1 above, the present invention is excellent in various characteristics such as yield strength and conductivity.

Next, Table 2 shows various characteristics of the copper alloy used as the lead material of the present invention.

[0031]

[Table 2] As is clear from Table 2 above, the copper alloy used in the lead material of the present invention has both conductivity and strength, and also has other properties (thermal conductivity, oxidation resistance, plating property, wire drawing property). Etc.) are also excellent.

[0032]

According to the present invention, it is possible to provide a lead material having both conductivity, strength and mass productivity.

Claims (2)

[Claims] 1. A content of chromium of 0.05 to less than 0.3% and / or zirconium of 0.05 to 0.5% by weight, the balance being substantially copper, and a grain size of 7 or more in JIS G 0551. A lead material made of a copper alloy. 2. Containing 0.005 to 0.1% by weight of chromium in an amount of 0.05 to less than 0.3% and / or zirconium of 0.05 to 0.5% and one or more selected from silicon, germanium, boron and magnesium. A lead material comprising a copper alloy having a balance of substantially copper and a grain size of 7 or more in JIS G 0551 grain size number.