JPS6123737A - Copper alloy having superior heat resistance and electric conductivity - Google Patents

Abstract

PURPOSE:To provide the titled inexpensive Cu alloy also having superior mechanical strength and easy to manufacture by restricting a composition consisting of Sn, Sb and Cu. CONSTITUTION:This Cu alloy consists of 0.02-0.15wt% in total of >=0.006% each of Sn and Sb and the balance essentially Cu and has superior heat resistance, mechanical strength, electric conductivity, heat conductivity and formability. The alloy is easily manufactured, is inexpensive and suitable for use as a material for a terminal lead wire for electronic machine parts, a lead frame or the like. In case of <0.006% each of Sn and Sb and <0.02% Sn+Sb, the heat resistance of the Cu alloy is not satisfactorily improved, and in case of >0.15% Sn+Sb, the electric conductivity is reduced, so the composition of the alloy is restricted as mentioned above. It is preferable that oxygen-free copper contg. about 0.0001-0.005% oxygen is used so as to attain far superior formability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an inexpensive copper alloy with excellent heat resistance and conductivity, and more specifically to electronic applications such as resistors, capacitors, silicon or germanium semiconductors, etc. This article relates to copper alloys suitable for terminal lead wires, lead frames, etc. of equipment parts.

BACKGROUND OF THE INVENTION Conventionally, pure copper, copper-silver thread alloy, copper-cadmium alloy, etc. have been used as wires for terminal lead wires of electronic device parts.

The lead wires are subjected to various heat treatments and unavoidable bending stress during the manufacturing process of electronic device components, so they are softened and placed under conditions that make them easy to bend. For example, lead wires used in resistors, capacitors, etc. are heated to approximately 250°C during manufacturing processes such as soldering, molding, painting, and stabilization.
undergoes heat treatment. In addition, in the case of a semiconductor device, after the soldering of the lead wires at both ends is heat treated at 30.0 to 400° C. for about 10 minutes, the soldered portions are molded with synthetic resin. In particular, when the wire is pure copper wire, it has high electrical conductivity and thermal conductivity, but heat treatment at around 200°C recrystallizes it, softens it, and reduces its bending strength. During the barrel plating process, bends occur in the wire.

These electronic device parts are manufactured using automated mass production methods, so if the terminal lead wires become soft and bend, it can cause problems when mounting these electronic device parts on printed circuit boards. Become. Furthermore, if the lead wires that have been bent in this manner are manually sorted and corrected one by one, the advantage of self-selection is completely lost. Therefore, the lead wire has a structure that does not easily soften even when subjected to heat treatment.
So-called heat resistance is required.

In addition to the above-mentioned heat resistance, which is a characteristic required when manufacturing electronic device components in mass production, the strands for this type of lead wire must have high electrical conductivity and excellent thermal conductivity. It is also necessary to meet requirements such as low cost.

From this point of view, known copper-cadmium alloys are not preferred due to the toxicity of cadmium, and copper-silver alloys are not fully satisfactory mainly in terms of cost and heat resistance. hard.

OBJECTS OF THE INVENTION An object of the present invention is to provide a copper alloy that fully satisfies the requirements for terminal lead wires, lead frames, etc. of electronic equipment components in terms of heat resistance, conductivity, cost, etc.

As a result of repeated research in order to obtain an inexpensive copper alloy that has the high performance required for electronic equipment component materials, the inventor has developed a new method by adjusting the amounts of tin and antimony added. The inventors have discovered that the object can be achieved, and have completed the present invention. That is, the present invention is characterized in that the total content of tin and antimony is 0.902 to 0.15% by weight, and each content is 0.006% by weight or more, with the balance substantially consisting of copper. This relates to a copper alloy with excellent heat resistance and conductivity.

In the present invention, the contents of tin and antimony are each reduced to 0.
．． 0.06% by weight (hereinafter simply referred to as %) or more, and the total amount is within the range of 0.02 to 0.15%. If the content of both is less than 0.02%, the heat resistance cannot be sufficiently improved, while if it exceeds 0.15%, the conductivity decreases. Furthermore, if the content of either tin or antimony is less than 0.006%, heat resistance will not be sufficiently improved.

111 11 The copper alloy of the present invention not only has excellent properties such as heat resistance, mechanical strength, electrical conductivity, and heat conductivity, but also has excellent formability, is easy to manufacture, and is inexpensive, so it can be used in electronic devices. It is useful as strands of terminal lead wires and lead frames for components. still,
In order to obtain better performance in molding processability,
For example, it is desirable to use oxygen-free copper having an oxygen content of about o, oooi to 0.005% by weight.

Tomo Naoko 1 In order to further clarify the features of the present invention, Examples, Comparative Examples, and Conventional Examples will be shown below.

A predetermined amount of tin, antimony, or silver was added to copper in a high frequency melting furnace to obtain a uniform molten metal. Then,
Directly by pouring molten metal into a carbon mold? ! ! 130 ■ Steel ×
An ingot with a length of 70 mm was obtained.

The cast ingot was cut, surface-finished, and hot extruded to obtain a rough drawn wire with a diameter of 11 mm, and then cold drawn to a diameter of Q and Qsm.

After annealing the copper alloy wire with a diameter of 0.81 obtained above at 300'C for 1 hour, bending strength and tensile strength were measured to determine heat resistance.

Furthermore, the conductivity of the copper alloy wire with a diameter of 0.8111 obtained above was measured.

These results are shown in Table 1. Table 1 shows pure copper and copper outside the composition range of the present invention as comparative examples.
The results for a tin-antimony alloy are shown, and the results for a copper-silver alloy as a conventional example are shown.

From the results of each example shown in Table 1, the copper alloy of the present invention:
It is clear that even after heat treatment at high temperatures, it has sufficient bending strength and tensile strength, and also maintains high electrical conductivity. In other words, it is clear that the copper alloy of the present invention has better performance than the copper-silver alloy in terms of overall properties of heat resistance and conductivity, even though it uses tin and antimony, which are extremely cheap compared to silver. It is.

(that's all) -1 and 1〒negative in heaven,

Claims (1)

[Claims] (1) The total content of tin and antimony is 0.02 to 0.
A copper alloy having excellent heat resistance and conductivity, characterized in that the content of each component is 0.006% by weight or more, and the remainder is substantially copper.