JPS6017039A - Copper alloy with superior heat resistance, mechanical characteristic, workability and electric conductivity - Google Patents

Abstract

PURPOSE:To obtain a Cu alloy for electronic parts with superior heat resistance, mechanical characteristics, workability and electric conductivity by adding a restricted amount of In to Cu and controlling the amount of oxygen. CONSTITUTION:This Cu alloy consists of, by weight, 0.01-1% In, <=0.01% oxygen and the balance essentially Cu. In the alloy composition, <0.01% In is not sufficient to improve the heat resistance and mechanical characteristics, and >1% In deteriorates the electric conductivity. <0.01% Oxygen deteriorates the electric conductivity and cold workability. The Cu alloy has superior physical properties such as superior heat resistance, mechanical strength, workability and electric conductivity and can be easily manufactured, so it can be used as a material for electronic parts such as a lead wire and a lead frame, a spring material, a fin material for a radiator, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inexpensive copper alloy that has excellent heat resistance, mechanical strength, workability, and electrical conductivity. The copper alloy of the present invention can be used, for example, in lead wires and lead frames of electronic components,
It is useful as a fin material for Fujiators, etc.

Copper alloys have been used for the past several thousand years, and a wide variety of copper alloys have been put into practical use for each purpose.In recent years, with the development of electronic and electrical technology, various properties have been further improved. A new copper alloy is expected to emerge. For example, with the miniaturization of electronic components, lead wires have also become significantly smaller in diameter, and therefore the copper alloy used has a higher heat resistance of 1.t.

Mechanical strength, workability, electrical conductivity, etc. have come to be considered. However, known copper alloys have not yet fully met these requirements.

The inventor of the present invention has conducted various studies to obtain a copper alloy with high performance required for electronic component materials, and has discovered that the objective can be achieved by adding indium and suppressing the oxygen content. He completed his invention. That is, the present invention has excellent heat resistance, mechanical properties, and processing properties, in which the indium content is 0.01 to 1% by weight, the oxygen content is 0.01% by weight or less, and the remainder is copper containing unavoidable impurities. This relates to copper alloys with excellent raw materials and electrical conductivity.

In the present invention, the oxygen content in the steel is 0.01% by weight.
In addition to keeping the indium content below 0.01 to 1
It is essential to set it as weight%. Indium content and oxygen content are closely related to each other and affect the physical properties of copper alloys, so it is not necessarily appropriate to discuss the reasons for each limitation separately, but the reasons for the limitations can be shown. , as follows. That is, if the indium content is less than 0.401% by weight, the heat resistance and mechanical properties will not be sufficiently improved, while if the indium content exceeds 1% by weight, the electrical conductivity will mainly deteriorate and the practicality will gradually be lost. Therefore, heat resistance,
The indium content value is within the range of 0.01 to 1% by weight, comprehensively considering various physical properties such as mechanical strength, workability, and electrical conductivity. When the oxygen content exceeds 0.01% by weight, the electrical conductivity decreases and the cold workability as a copper alloy particularly decreases.

That is, with the miniaturization of electronic components, lead wires for electronic components (hereinafter simply referred to as lead wires) have become thinner, and the mounting of electronic components has become automated.

Therefore, it is necessary to use hard wood for the lead wire so that it will not bend during work. However, when the oxygen content exceeds 0.01ii% in coexistence with indium,
The cold workability of the alloy, especially under impact conditions, is reduced, for example, when the lead wire is attached to an electronic component such as a resistor or capacitor. During the drawing process, cracks are likely to occur in the processed portion of the lead wire, making it difficult to put it into practical use.

The copper alloy of the present invention not only has the above-mentioned properties, but also is easy to manufacture and inexpensive, so it is useful not only as a material for electronic parts but also as a structural material such as springs and fugiator fins.

Hereinafter, a T1 example will be shown to further clarify the features of the present invention.

Example 1 After melting electrolytic copper while covering it with charcoal in a high-frequency melting furnace, a predetermined amount of indium was added to obtain a uniform molten metal. Next, the molten metal is poured into a carbon mold with a diameter of 180 mm.
An ingot with a length of mm x 'room' was obtained. On this occasion,
In order to prevent oxidation of the alloy, the work was carried out while blowing argon into the tap and tap. By cutting, surface finishing, and hot extruding the cast ingot,
After obtaining rough wires with a diameter of 11m1n, the diameter was 1mm each,
1.2 mm, 1.4 mm%i, e mm, 1. s
mm, 2. □ mm.

The wires were drawn to 2.2 mm, 2.4 mm, and 2.6 mm. Next, 40 pieces of alloy wire were drawn down to each diameter.
After vacuum softening at 0°C for 1 hour, the diameter was 6. The wire was cold drawn to Bmm to obtain an indium-copper alloy with a cold working ratio of 86% to 90%. The following tests were conducted using these various steel alloy wires.

(a) Heat resistance test The change in tensile strength when copper alloy wires with different indium contents and cold working ratios of 76% (oxygen content less than 0.01% by weight) are held at a predetermined temperature for 1 hour is measured in the first test. As shown in the figure. Curves (1) to (V) show the results for copper alloy wires with the following indium contents, respectively.

(1)...does not contain, (1)...0.01% by weight,
(II)...0.05% by weight, (■)...0.1% by weight, (V)...0.5% by weight Improving mechanical strength and heat resistance by adding indium and amount of indium added It is clear that the content should be 0.01% by weight or more.

(b) Conductivity test Figure 2 shows the measurement results of changes in conductivity of copper alloy wires with different indium contents and cold working rates of 50% (oxygen content less than 0.01% by weight). Changes in conductivity due to processing conditions and heat treatment conditions should remain within a range of about ±8%, and those with an oxygen content of less than 0.01% by weight have a lower conductivity than those with an oxygen content of 0.01% by weight or more. was found to be approximately 2% higher.

From FIG. 2, it is clear that in order to use it as a lead wire, the indium content should be about 1% by weight or less.

(C) Impact cold workability test Cold working rate 5 with different indium content and oxygen content
0% copper alloy wire was subjected to header beating under various conditions that are normally used for lead wires of electronic components, and impact cold workability was determined based on the occurrence of cracks. Table 1 shows the results. In Table 1, 110'' indicates that there is no problem in practical use, and @1×'' indicates that there is a problem in practical use or that it cannot be put to practical use.

Table 1 (d) Mechanical property test The results of examining the tensile strength and elongation of copper alloys with various cold working rates are shown in FIG.

Curves (VI) and (■) are respectively shown when the indium content is 0.
01% by weight and 1% by weight copper alloy (oxygen content 0.01
curves (Vl) and (Vl)
indicate the tensile strength of copper alloys containing 410.01% by weight and 1% by weight of indium (oxygen content less than 0.01% by weight), respectively.

It is clear that in the alloy according to the invention, the indium content and cold working rate can be selected to correspond to the mechanical properties depending on the application.

[Brief explanation of the drawing]

FIGS. 1 to 8 are diagrams showing the heat resistance, electrical conductivity, and mechanical properties of the copper alloy of the present invention. (that's all)

Claims (1)

[Claims] ■ Indium content 0.01-1% by weight and oxygen content 0
．． A copper alloy having excellent heat resistance, mechanical properties, workability, and electrical conductivity, characterized in that the content is 0.1% by weight or less, and the remainder is substantially copper.