JPS5839912B2 - Manufacturing method of copper alloy material for leads - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a copper alloy material suitable as a lead material for electronic components such as transistors and diodes, various electronic devices, and electrical devices, and more specifically, a method for manufacturing the above-mentioned components and devices. The present invention relates to a method of manufacturing a conductive copper alloy material having good soldering properties necessary for assembly process and use, excellent cyclic bending strength, strength, heat resistance, etc.

Traditionally, lead materials for electronic components such as transistors and diodes have been required to have good soldering properties, and copper-based alloys with good soldering properties have been required compared to iron-based and nickel-based alloys. However, it has been difficult to sufficiently satisfy the required properties such as heat resistance, high strength, and repeated bending strength, and a copper alloy material that has both of these properties has been desired.

In view of the above, the present invention aims to improve the drawbacks of the conventional alloys described above and provide a conductive material having various properties suitable as a lead material for electronic parts and devices.

The present invention uses a copper alloy containing 0.20 to 0.95% by weight of chromium (hereinafter simply referred to as "%") and 0.40 to 0.95% of tin, with the balance essentially consisting of copper, after solution treatment and quenching. This is a copper alloy material for leads, which is characterized by being subjected to cold working and aging annealing treatment (hereinafter simply referred to as annealing treatment).

In the present invention, chromium is specified as 0.20 to 0.95% because less than 0.20% chromium has little effect on improving strength, and strength tends to vary depending on the amount of chromium. %, it will only unnecessarily increase manufacturing costs and will not produce favorable results in terms of mechanical properties.

The reason why tin is specified as 0.40 to 095 is that if it is less than 040, it will have little effect on improving the strength and cyclic bending strength, and if it exceeds 0.95, cracks will occur during hot working.
This is because the product yield decreases and the scratches that remain at that time impair the subsequent workability of the header.

Note that even if the alloy composition of the present invention contains residual deoxidizers such as P, B, Ca, etc., and some other impurities in a total amount of 0.15% or less (i'1 etc.).

Further, in the present invention, it is preferable that the cold working before the final annealing treatment is carried out at a cold working rate of 96 or more, and further, as the age annealing condition, the cold working is carried out for 3 hours for 1 to 4 hours.
The aging annealing treatment is performed at a temperature of 50°C to 500°C.

The aging annealing temperature was 350°C to 500'C.
If the temperature is less than 50°C, the conductivity will not recover sufficiently, and
If the temperature exceeds 500°C, there is a risk of deterioration of mechanical properties, and the reason why the aging annealing time is set to 1 to 4 hours is that if the temperature is less than 1 hour, recovery of electrical conductivity is insufficient, and This is because if the time is exceeded, mechanical properties may deteriorate, which is economically disadvantageous.

Next, the present invention will be explained in detail with reference to Examples.

Example 1 A commonly used 99.9% copper ingot was melted, and after phosphorus deoxidation, chromium was added in the form of a copper-10 chromium master alloy and tin was added alone, stirred, and thoroughly dissolved. After that, 50r/1
The alloy ingots having the compositions shown in Table 1 were produced by casting into a 7rL square mold.

This was hot-rolled at approximately 870°C to form a wire rond with an diameter of 8 mm.

Note that the comparative composition alloy A66 in Table 1 cracked during hot rolling, so the following processing was canceled.

9 which was made into a size of 2mmφ by rough cold drawing.
After solution treatment at 70'C for 2 hours, water quenching, then cold wire drawing to 0.45 mmφ, and vacuum annealing at 350°C and 450°C for 1 hour in vacuum, or nitrogen Using an atmosphere tunnel furnace, the furnace temperature was 650℃ for 30 minutes.
The sample was subjected to continuous annealing treatment by passing through the sample for seconds.

*The stiffness values and bending values of the samples after annealing are shown in Table 2.

Here, the stiffness value is expressed as the value of the torque required to bend the sample to 35° by placing a weight on one end of the sample that is held horizontally.

The bending value is 0.1vurt for sample 1 as shown in Figure 1.
The sample is tightened by rotating the jig 3 900 times as shown in FIG. 0
．． The operation of bending 90° around a 1m1R edge and returning to the rear is repeated, and the number of times it takes to break is shown with one 90° bend.

The mechanical properties required for electronic component lead materials include, for example, a stiffness value of 65g, crrL or more (0.45mmφ
) and cyclic bending strength 1 under the above bending test conditions.
Five or more times is desirable.

Table 2 shows that the copper alloy material of the present invention can obtain the desired properties in terms of stiffness value and repeated bending strength both by batch annealing and by continuous annealing treatment at high temperature and short time.

In order to further investigate the heat resistance, samples with compositions /i61 to A63 annealed at 450°C for 1 hour were further annealed at 450°C.
Table 3 shows the properties after re-annealing at 0°C for 1 hour.

As shown in Table 3, even after reheating at 450°C for 1 hour, there is little deterioration in the properties, and it has good heat resistance.

Regarding the electrical conductivity, the values of the materials annealed once at 450° C. for 1 hour are shown in Table 4, and these values are sufficient for the lead material to perform the heat dissipation and conduction functions.

Further, an alloy with a composition of 0.45 φ/V; 1 to A6.3 (
Annealed at 450°C for 1 hour) wire, normal tough pitch copper wire, copper-0.65% chromium alloy wire, nickel wire, and iron-50% nickel alloy wire, 100 wires each were made into sets of two. - After applying a load of 200 g to the material wires and attaching them to each other (using eutectic solder and rosin flux), /I61 to /16.3, tough pitch copper, copper -
None of the 0.65% chromium alloy wires peeled off, but the nickel wires and iron-50 nickel alloy wires did not peel off.
There were cases where peeling occurred.

As described above, the alloy material according to the present invention has good solderability, similar to ordinary tough pitch copper and copper-0.65% chromium alloys.

As described above, the method for producing the copper alloy material of the present invention has the advantages of excellent strength and repeated bending strength, as well as heat resistance and soldering properties, and is particularly useful as a lead material for electronic components. This provides a suitable conductive material.

In addition, the present inventor added consideration to the cold working rate before the final annealing treatment, and found that when the material of the present invention is manufactured at a cold working rate of 96 coefficients or higher, after the final annealing treatment under the same conditions, It was found that both strength and cyclic bending strength were superior to those with a cold working rate of less than 96 modulus, and the improvement in strength was particularly remarkable.

Next, an example will be explained.

Example 2 The sample was 8m with the composition of /V; 1 to scrap 3 shown in Example 1.
mφ wire iron with this size at 970℃ 2
After time solution treatment, water quenching, cold wire drawing to 0.45 mmφ, vacuum annealing at 450°C for 1 hour, mechanical properties of the samples were measured, and the data shown in Table 2. The results of the comparison are shown in Table 5.

From Table 5, the cold working rate before final annealing treatment is 99.7%.
The steel alloy material of this example shows a slight improvement in cyclic bending strength and a large improvement in stiffness value compared to that of Example 1 with a cold working rate of 95.0%. It can be seen that the copper alloy material of the present invention manufactured by the manufacturing method shown in this example is even more suitable as a lead material for electronic parts and devices that require reliability.

As described above, the method for producing a copper alloy material of the present invention involves dissolving a copper alloy containing 0.20 to 0.95 parts of chromium, 0.40 to 0.95 parts of tin, and the remainder being essentially copper. Because it undergoes heat treatment, quenching, cold working, and aging annealing, it has excellent mechanical properties such as stiffness and repeated bending strength, as well as heat resistance and solderability. Therefore, it has the feature that it is suitable as a lead material for electronic parts, electronic equipment, electrical equipment, etc. that require reliability.

In addition, the aging annealing treatment has the advantage of being easy to manufacture, since the desired properties can be obtained even with continuous annealing as well as batch annealing.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams for explaining the method of repeated bending tests. 1...sample, 2...dice, 3...
...Tighten with a jig, W...Load.

Claims (1)

[Claims] 1 Chromium 0.20-0.95 weight ratio, tin 0.40-0
After solution treatment and quenching of a copper alloy containing 95% weight and the remainder consisting essentially of copper, cold working at a processing rate of 96% or more and at 350°C to 500°C for 1 to 4 hours.
A method for producing a copper alloy material for leads, characterized by subjecting it to an aging annealing treatment at a temperature of .