JPS6123738A - 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 Pb, Sb and Cu. CONSTITUTION:This Cu alloy consists of 0.02-0.15wt% in total of >=0.006% each of Pb and Sb and the balance essentially Cu and has superior characteristics such as 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 Pb and Sb and <0.02% Pb+Sb, the heat resistance of the Cu alloy is not satisfactorily improved, and in case of >0.15% Pb+Sb, the electric conductivity is reduced. 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 particularly, to electronic device parts such as resistors, capacitors, and silicon or germanium semiconductors. Copper alloy suitable for terminal lead wires, lead frames, etc.

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 parts, so they are softened and placed under conditions where they are easily bent. 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 semiconductor devices, after the soldering of the lead wires at both ends is heat treated at 300 to 400° C. for about 10 minutes, the soldering portions are molded with synthetic resin. In particular, in some cases, the wire is pure copper wire, which has high electrical conductivity and thermal conductivity, but when heat treated at around 200℃, it recrystallizes, softens, and reduces bending strength. A bend occurs in the east line during the barrel plating process.

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 advantages of automation are 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 thread alloys are not fully satisfactory mainly in terms of price and heat resistance. .

OBJECTS OF THE INVENTION The 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.

Structure of the Invention The inventor of the present invention aimed to obtain an inexpensive copper alloy that has the high performance required for electronic device component materials. The present invention has been completed based on the discovery that the total content of lead and antimony is 0.02 to 0.15% by weight, and each content is 0. This invention relates to a copper alloy having excellent heat resistance and electrical conductivity, characterized in that the balance is substantially copper.

In the present invention, the contents of lead and antimony are each 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%. When the content of both is less than 0.02%, heat resistance can be sufficiently improved, while when it exceeds 0.15%,
Conductivity decreases. Furthermore, if the content of either lead or antimony is less than 0.006%, heat resistance will not be sufficiently improved.

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. It is useful as strands of terminal lead wires and lead frames for electronic equipment parts. 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 0.0001 to 0.005% by weight.

Dear Mr. S, 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 lead, antimony, or silver was added to copper in a high-frequency melting furnace to obtain a uniform molten metal. Next, the molten metal was poured into a carbon mold to obtain an ingot with a diameter of 130+uax and a length of 700IllIIl.

The cast ingot was cut, surface-finished, and hot extruded to obtain a rough wire with a diameter of 1111111, and then cold drawn to a diameter of 0.8n+m.

After annealing the copper alloy wire with a diameter of 0.8 meters 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 0.8 mm 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 lead-antimony alloy are shown, and the results for a copper-silver alloy are shown as a conventional example.

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 in a vortex, 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 lead and antimony, which are extremely cheap compared to silver. It is.

(that's all) 7.-ri J.

Claims (1)

[Claims] (1) Total content of lead and antimony is 0.02 to 0.1
5% by weight and each content is 0.006% by weight
As described above, there is provided a copper alloy with excellent heat resistance and electrical conductivity, characterized in that the remainder essentially consists of copper.