JP3334157B2 - Copper alloy strip with less wear on stamping mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper alloy strip which is less likely to wear a working mold.

[0002]

2. Description of the Related Art It is generally known that when electrical and electronic parts are manufactured, copper alloy strips are subjected to processes such as press punching, embossing, and coining (these processes are collectively referred to as stamping). ing.

As the copper alloy strip for producing the above electric and electronic parts, a copper alloy strip having both high conductivity and high strength is used. As such a copper alloy strip, Cu-Ni-
A material such as a Si-based alloy (for example, a Corson-based alloy) is used.

[0004] As a method for producing the above-mentioned copper alloy strip,
The scale of the surface of the hot-rolled copper alloy thick plate obtained by hot-rolling the ingot of the copper alloy is removed, and then cold rolling and annealing are repeated, and final cold rolling is performed to obtain a final alloy strip. The method of obtaining, or repeating the cold-rolling and annealing of the hot-rolled copper alloy thick plate from which the scale has been removed, and then performing a solution treatment of water-quenching and quenching after heating, a final cold-rolling and aging treatment to obtain a final alloy material Methods are known.

[0005] The surface crystal grains of the copper alloy strip obtained by such a conventional method are drawn crystal grains obtained by rolling fine crystal grains having a crystal grain size of less than 5 µm, or have a crystal grain size of 40 µm.
, And stretched crystal grains obtained by rolling coarse crystal grains having a grain size exceeding.

[0006]

When a copper alloy strip having elongated crystal grains obtained by rolling the above-mentioned conventional fine crystal grains of less than 5 .mu.m is stamped, the stamping mold is severely worn, and the mold wear is reduced. Since stamping dies have to be polished frequently before they wear out because they adversely affect the shape of the processed product, which means that expensive dies are replaced in a short period of time, which means that electrical and electronic components Cost.

On the other hand, the conventional copper alloy strip having elongated crystal grains obtained by rolling coarse grains having a size exceeding 40 μm has a problem that surface roughness appears at a bent portion in bending of electric and electronic parts. There was a point.

[0008]

Means for Solving the Problems Accordingly, the present inventors have
As a result of conducting research to develop a copper alloy strip capable of withstanding the use of the stamped product with less wear of the mold even after stamping and having sufficient strength and hardness as an electric and electronic component, (1) weight %, Ni: 1-4%, Si: 0.1-1
%, Zn: 0.1 to 2%, and, if necessary, Sn: 0.1 to 3%, and the remainder is hot-rolled to a copper alloy ingot having a composition of Cu and inevitable impurities. And
Then, cold rolling and annealing are repeated, the average crystal grain size is adjusted to 10 to 35 μm in the annealing before final cold rolling, and the copper alloy obtained by rolling the final cold rolling at a rolling reduction of 30 to 85%. The strip material has extremely low abrasion of the stamping die, and the crystal grains of the rolled surface structure have an average minor axis of 10 to 35 μm and an average major axis of 23 to 200 μm.
And the value of average major axis / average minor axis is 1.4 to
(2) The copper alloy ingot having the above-mentioned composition is hot-rolled, and then cold-rolled and annealed repeatedly.
A solution treatment of heating to 00 to 1000 ° C. and quenching with water cooling is performed, and the particle size is adjusted to be fine crystal grains having an average particle size of 5 to 35 μm. ８５85% final cold-rolled to obtain crystal grains having an average minor axis of 10 to 35 μm and an average major axis of 23 to 200 μm.
μm, average major axis / average minor axis: a stretched shape in the range of 1.4 to 6.7, and further subjected to aging treatment. The copper alloy strip obtained in this way also wears the stamping mold. It was found that it was extremely unlikely to do so.

The present invention has been made on the basis of such findings, and in terms of% by weight, Ni: 1 to 4%, Si:
A copper alloy strip containing 0.1 to 1%, Zn: 0.1 to 2%, and further contains Sn: 0.1 to 3% as needed, with the balance being Cu and unavoidable impurities. In the material, the crystal grains of the surface texture of this strip have an elongated shape,
Assuming that the average minor axis of the stretched crystal grains is a and the average major axis is b, a: 10 to 35 μm, b: 23 to 200 μm, and a stamping die having a dimension of 1.4 ≦ b / a ≦ 6.7 It is characterized by a copper alloy strip that is less likely to wear.

In the present invention, the term "stretched crystal grains" refers to crystal grains that have been stretched by final cold rolling but do not completely form a striped structure, and the limbs of the stretched crystal grains can be distinguished. Say.

The copper alloy strip of the present invention is annealed at 450 to 600 ° C. for 1 to 5 hours, and is subjected to solution treatment by heating to 800 to 1000 ° C. and then water quenching. The aging treatment is performed by maintaining the temperature at 350 to 500 ° C. for 1 to 5 hours. The annealing at 450 to 600 ° C. for 1 to 5 hours can be replaced by continuous annealing at 650 to 950 ° C. for a short time.

Next, the reasons for limitation of the present invention will be described.

(A) Ni Ni has a function of improving the strength by producing nickel silicide (Ni ₂ Si, etc.) together with Si, but there is no significant effect when the content is less than 1%, and when the content exceeds 4%. Due to the fact that the decrease in conductivity becomes significant, the content is 1 to
It was set at 4%.

(B) Si Si has a function of deoxidizing at the time of melting, and has a function of improving the strength by forming nickel silicide with Ni. However, if it is less than 0.1%, there is no significant effect and the content exceeds 1%. The content is determined to be 0.1 to 1% for the reason that the hot workability becomes inferior.

(C) Zn Zn has a function of deoxidizing and degassing at the time of melting, and a function of improving heat-resistant peeling resistance and migration resistance.
If the content is less than 0.1%, there is no significant effect, and if the content exceeds 2%, the effect tends to be saturated, so the content is set to 0.1 to 2%.

(D) Sn Sn has the effect of improving the strength, but has no significant effect if it is less than 0.1%, and if it is contained in excess of 3%, its conductivity will be significantly reduced. To 0.
It was determined as 1-3%.

(E) Grain Size The crystal grains on the rolled surface of the copper alloy strip of the present invention have a stretched shape, and if the average minor axis a of the stretched shape crystal grains is less than 10 μm, the abrasion of the stamping mold is reduced. A sufficient effect cannot be obtained, while the average minor axis a of the stretched crystal grains is 35 μm.
If it exceeds m, the surface roughness becomes noticeable during bending of the part, and the abrasion of the stamping mold cannot be reduced further. In addition, the average major axis b of the elongated crystal grains is 23.
If it is less than μm, the strength cannot be expected to be improved by rolling work hardening, so that it is not preferable. On the other hand, if the average major axis b of the elongated grains exceeds 200 μm, the rolled structure becomes strong and the mold wear resistance is impaired, which is not preferable. .

Furthermore, the average major axis of the above-mentioned elongated crystal grains /
If the value of the average minor axis (b / a) exceeds 6.7, the metal structure becomes a completely rolled structure and the abrasion of the stamping die increases, which is not preferable. If it is smaller than 4, sufficient strength cannot be obtained, which is not preferable.

In order to control the growth of the crystal grain size in the alloy composition of the copper alloy strip of the present invention, Mg, Zr, Ti, Cr
May be contained in an amount of 0.001 to 0.1%. Further, B, Sb, Ca, As, Mn, Hf, A
Even if one or more of 1, Be, Mo, Te, Pb, Co, Fe, Nb, P, etc. are contained up to 0.05%, the gist of the present invention is not impaired. S and O ₂ are each 20pp
m or less.

On the other hand, after obtaining the final alloy strip, the flatness is improved by a tension leveler, stress strain is removed by a tension annealing or a batch annealing furnace, and the quality and properties are improved by a combination of these treatments. It does not impair the gist of the invention.

[0021]

EXAMPLES Example 1 A Cu alloy having the composition shown in Table 1 was prepared.
u alloy is melted using a coreless type induction melting furnace,
Next, thickness: 180mm, width: 450m by semi-continuous casting
An ingot of m, length: 3000 mm was obtained. Subsequently, the ingot was placed in a heating furnace, heated to 900 ° C., and then hot-rolled.
A 1 mm hot rolled plate was obtained. In order to remove the scale from the surface of the hot-rolled plate, a surface of 0.5 mm on one side was chamfered on both surfaces to obtain a surface-moulded plate having a thickness of 10 mm.

After cold-rolling the above-mentioned faced sheet, intermediate annealing and cold rolling of heating to 500 ° C. are repeatedly performed, and then final annealing immediately before final cold rolling is performed under the conditions shown in Table 1, and then the surface crystal is formed. The particle size was measured, and the results are shown in Table 1.

After the final annealing under the conditions shown in Table 1 above, the final cold rolling was further performed at the rolling rates shown in Table 1 to obtain the 0.25 mm thick strips 1 to 9 of the present invention and the comparative strip 1 ~
5 and conventional strips 1-2 were produced.

[0024]

[Table 1]

The strips 1 to 5 of the present invention thus obtained.
9. The average minor axis a, average major axis b and b / a of the elongated crystal grains of the surface texture of the comparative strips 1 to 5 and the conventional strips 1 and 2
And the results of these measurements are shown in Table 2, and the above-mentioned strips 1 to 9 of the present invention, comparative strips 1 to 5 and conventional strips 1 and 2 were each a W-Co based cemented carbide mold. To a rectangle of 1.0 mm long and 2.0 mm wide, 600
Punch at stroke speed, 100 strokes
The amount of wear of the mold when the number of times reached 10,000 was measured, and the measurement results are shown in Table 2.

[0026]

[Table 2]

Example 2 A copper alloy having the composition shown in Table 3 was melted and cast in the same manner as in Example 1 to produce an ingot, and the ingot was heated in the same manner as in Example 1 and hot rolled. Then, a facing plate having a thickness of 10 mm was obtained by performing facing.

After the cold-rolled sheet is subjected to intermediate annealing and cold rolling at 500 ° C., the copper alloy strip before final cold rolling is continuously heated and held under the conditions shown in Table 3. After that, a solution treatment for water quenching was performed.

After that, final cold rolling was performed at a rolling rate shown in Table 3 to produce a copper alloy strip having a thickness of 0.25 mm, followed by aging at 470 ° C. for 90 minutes. Invention strips 10 to 18, comparative strips 6 to 10 and conventional strips 3 to 4 were obtained.

[0030]

[Table 3]

The thus obtained strip of the present invention 10
18, the average minor axis a, the average major axis b, and the value of b / a of the elongated grains in the surface texture of the comparative strips 6 to 10 and the conventional strips 3 to 4 were measured, and the measurement results were shown in Table. 4
In addition to the above, the strips of the present invention 10 to 18, comparative strips 6 to 10 and conventional strips 3 to 4 were punched out in the same manner as in Example 1, and the amount of wear of the mold was measured. The results are shown in Table 4.

[0032]

[Table 4]

[0033]

From the results shown in Tables 1 to 4, it can be seen that the strips 1 to 18 of the present invention hardly wear the mold during stamping as compared with the conventional strips 1 to 4. In addition, comparative strips out of the range of the present invention (* marks in Tables 2 and 4 indicate values deviating from the present invention) 1 to 10 have a large amount of mold wear or a large amount of mold wear. It can be seen that at least the electrical or electronic components shown in the remarks exhibit undesirable properties.

When a lead frame is produced by trial using the copper alloy strip of the present invention, a lead frame strip in which a plurality of lead frames are connected from the copper alloy strip is produced by etching, and the lead of the plurality of units is formed. Although the lead frame band in which the frames are connected is cut to produce a lead frame one unit at a time, the copper alloy strip of the present invention has an effect that wears the cutting blade used for such cutting is extremely small. is there. As described above, when electrical and electronic parts are manufactured by stamping or cutting the copper alloy strip of the present invention, the number of times of changing the mold or the cutting blade can be reduced, so that the cost can be significantly reduced, It has excellent industrial effects.

Continued on the front page (72) Inventor Shunichi Chiba 128-7 Ogimachi, Aizuwakamatsu-shi, Fukushima Prefecture Mitsubishi Shindo Copper Co., Ltd. Wakamatsu Works (72) Inventor Nao Sakakibara 128-7 Ogimachi, Aizuwakamatsu-shi, Fukushima Mitsubishi Shindo Copper Co., Ltd. Inside Wakamatsu Works (72) Inventor Junichi Kumagai 128-7 Ogimachi, Aizuwakamatsu-shi, Fukushima Prefecture Mitsubishi Shindo Copper Co., Ltd. Examiner Hideo Tokunaga (56) References JP-A-2-170954 (JP, A) JP-A-3-188247 (JP, A) JP-A-6-33171 (JP, A) (58) Int.Cl. ⁷ , DB name) C22F 1/08 C22C 9/06

Claims (2)

(57) [Claims] (1) Ni: 1 to 4%, Si: 0.
In a copper alloy strip containing 1 to 1% and Zn: 0.1 to 2%, the balance being composed of Cu and unavoidable impurities, the crystal grains of the surface structure of the strip have a stretched shape (hereinafter referred to as “stretched”). , This shape is referred to as a stretched shape). When the average minor axis of the crystal grains in the elongated shape is a and the average major axis is b, a: 10 to 35 μm, b: 23 to 200 μm, 1.4 ≦ b / a ≦ 6.7 A copper alloy strip that is less likely to wear the stamping die, characterized by having the following dimensions: 2. Ni: 1-4% by weight, Si: 0.1% by weight.
A copper alloy strip containing 1 to 1%, Zn: 0.1 to 2%, and Sn: 0.1 to 3%, with the balance being composed of Cu and unavoidable impurities. The crystal grains have a stretched shape, and assuming that the average minor axis is a and the average major axis is b, a: 10 to 35 μm, b: 23 to 200 μm, 1.4 ≦ b / a ≦ 6. 7. A copper alloy strip which is less susceptible to abrasion of a stamping die having the following dimensions.