JPS59170231A - High tension conductive copper alloy - Google Patents

Abstract

PURPOSE:To provide a high-tension conductive copper alloy suitable for a lead material and spring material of a semiconductor apparatus by incorporating a specific amt. of Sn, P and other additive elements in Cu, and reducing an oxygen content as far as possible. CONSTITUTION:The titled Cu alloy contains 0.8-5.0wt%, Sn, 0.01-0.4wt% P, and in addition, 0.01-8.0wt% in total of 1 or >=2 kinds among 0.05-5.0wt% Zn, 0.2-1.0wt% Si, 0.2-1.0wt% Mn, 0.1-1.0wt% Al, and 0.01-0.3wt% Pb as auxiliary components and further contains <0.0020wt% O2. The alloy has high heat conductivity, heat resistance, solderability, plating adhesion and repeated flexural strength as well as an excellent spring property.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copper alloy suitable for lead materials for semiconductor devices such as transistors and integrated circuits (ICs), and spring materials for connectors and the like.

Conventionally, Kovar alloy (Fe-29Ni-160o) has been used as a lead material for semiconductor devices because it has a low coefficient of thermal expansion and has good adhesion and sealing properties with elements and ceramics.

High nickel alloys such as 42 alloy (Fe-42Ni alloy) have been preferred. However, in recent years, as the degree of integration of semiconductor circuits has improved, the number of circuits with high power consumption has increased. Furthermore, due to cost reduction, resin-sealed packages have become mainstream instead of ceramic-sealed ones. Therefore, the lead material used has come to be a copper-based alloy that has good heat dissipation, that is, good thermal conductivity, and has a coefficient of thermal expansion close to that of the resin. Currently, oxygen-free steel, phosphor bronze, soot-containing copper, and iron-containing steel are used, but the required properties for lead materials are good heat dissipation, good heat resistance, solderability, and plating adhesion. Good, high cyclic bending strength, y
Because of the wide range of properties such as high g value, no copper-based alloy has been found that satisfies all of these properties. Among these, phosphor bronze has the same strength and repeated bending strength as high nickel alloys, and phosphor bronze is used as an alternative to high nickel alloys.

It has the drawbacks of high price of 8n, which is a component of phosphor bronze, and poor hot workability. Phosphor bronze has traditionally been used as a spring material for connectors due to its excellent strength, but it is also expensive.
Cheaper materials are desired.

In view of these points, the present invention improves the drawbacks of conventional copper-based alloys while maintaining the excellent properties of phosphor bronze, and has various properties that are inexpensive and suitable as lead materials and spring materials for semiconductor devices. It provides copper alloys.

The copper alloy of the present invention contains 0.8% to 5% by weight of Sn, 0.01% to 0.4% by weight of P, and further contains 0.055% to 50% by weight of 2η, and SiO , more than 2% by weight and less than 1.0% by weight, Mn0
．． More than 2% by weight and not more than 1.0% by weight.

Amount selected from the group consisting of φ or more 0.5 weight percent △ 1 or more types in a total amount of 0.011% by weight or more aO
It is a high-strength conductive copper alloy characterized in that the content of oxygen among the inevitable impurities of the above-mentioned alloy is 0.0020% by weight or less.

Next, the reason for adding the alloy components constituting the alloy of the present invention and the reason for limiting the composition range thereof will be explained. Contains Eln゛;;;“
The reason for setting 0.8 to 5.0 to 5.0 is as follows:
If the Sn content is less than 0.8% by weight, the expected strength cannot be obtained even if P and other additive elements are added;
This is because if the content exceeds 5.0% by weight, hot workability deteriorates and the price of the raw material occupied by Sn also increases, resulting in a large increase in price.

The reason why the P content is set to 0.4 wt. 4
This is because if the content exceeds % by weight, the conductivity and workability will be significantly reduced.

The content of the subcomponents is individually limited and the total content is limited to 0.001% by weight or more and aO% by weight or less, although the subcomponents listed here improve strength.

With 00101% by weight, the effect cannot be expected much,
Moreover, if it exceeds 80 weight cI), the electrical conductivity decreases markedly, leading to a decrease in workability.

Further, the reason why the oxygen content is set to 0.0020% by weight or less is that plating adhesion deteriorates when the oxygen content is 0.0020020% by weight.

The material of the present invention exhibits excellent mechanical properties such as strength and elongation, and is easy to solder.

Plating adhesion is also good. Furthermore, it has good hot workability and low Sn content, making it an inexpensive copper alloy. Furthermore, the coefficient of thermal expansion is close to that of resin, making it suitable for resin-sealed lead materials.

The material of the present invention will be explained below with reference to Examples.

EXAMPLES Ingots having various compositions of the alloys of the present invention shown in Table 1 were melted and cast using electric steel or oxygen-free copper as raw materials in a high-frequency melting furnace in air, an inert atmosphere, or a reducing atmosphere. Next, this was hot rolled at 800°C to form a plate with a thickness of 4wn.

It was faced and cold rolled to a thickness of 1.0 mm.

After annealing this at 500° C. for 1 hour, it was cold rolled into a plate having a thickness of 0.8W++. As for the evaluation of the sample prepared in this way, the strength and elongation were shown by a tensile test, the heat resistance was shown by the softening temperature at a heating time of 5 minutes, and the electrical conductivity (heat dissipation) was shown by the conductivity (coefficient: cAcs). .

This is because electrical conductivity and heat transfer properties are proportional to each other and can be evaluated by electrical conductivity. Soldering was done using the vertical immersion method in a soldering bath at 260°C ± 5°C (Tin 60).

The solder wetting condition was evaluated by immersing it in lead (40% lead) for 5 seconds and visually observing the state of solder wetting. Plating adhesion was determined by applying 3μ thick Ag plating to the sample.

Evaluation was made by heating at 450° C. for 5 minutes and visually observing the presence or absence of blisters generated on the surface of 2.

In addition, hot workability was determined by visually observing cracks in the sample after hot rolling. These results are shown in Table 1 along with comparative alloys.

As shown in Table 1, the alloy of the present invention has excellent strength.

Conductivity, heat resistance, hunter attachment properties, plating adhesion.

It is clear that it exhibits hot workability, and it can be said to be a material suitable for lead materials and spring materials for high-quality semiconductor devices.

Claims (2)

[Claims] (1) Sn: 0.8% by weight or more and 5.0% by weight or less. P O, 01% by weight or more and 0.4% by weight or less. 0.055% to 5.0% by weight of Zn as a subcomponent. SiO, more than 2% by weight and less than 1.0% by weight. Mn exceeding 0.2% by weight and not more than 1.0% by weight. AtO, 1% by weight or more and 1.0% by weight or less. PI) 0.01% by weight or more [1 or 2 or more selected from the group consisting of 0.01% by weight or less [lL3% by weight or less in a total amount of 0.01% by weight or less]
1. A high-strength conductive copper alloy comprising 0.011% by weight and 80% by weight or less, with the remainder consisting of Cu and unavoidable impurities. (2) Sn: 0.8% by weight or more and 51% by weight or less. P O, 01% by weight or more and 0.4% by weight or less. and Zn' as a subcomponent in an amount of 0.055% by weight to 5.0% by weight. More than 0.2% by weight and less than 1.0% by weight of Si. Mn exceeding 0.2% by weight and not more than 1.0% by weight. A/-0.1% by weight or more and 1.0% by weight or less. Pb O, 01: Contains one or more selected from the group consisting of i weight coefficient or more and α5 weight coefficient or less in a total amount of 001 weight % or more and aO weight ratio or less, and the remainder is composed of Cu and unavoidable impurities. , the content of oxygen among the impurities is 0.0
A high-strength conductive copper alloy characterized by having a content of 0.020% by weight or less.