JPS6158536B2 - - Google Patents

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-16Co), which has a low coefficient of thermal expansion and good adhesion and sealing properties with elements and ceramics, has been used as a lead material for semiconductor devices.
High nickel alloys such as Fe-42Ni alloy have been preferred. However, in recent years, as the degree of integration of semiconductor circuits has improved, the number of ICs 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 copper, phosphor bronze, tin-containing copper, and iron-containing copper are used, but the required characteristics for lead materials are good heat dissipation, good heat resistance, and good solderability and plating adhesion. , high cyclic bending strength, low price, etc., and 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 a substitute for high nickel alloys, but the price of Sn, which is a component of phosphor bronze, is It has the disadvantage of high hardness and poor hot workability. Additionally, phosphor bronze has traditionally been widely used as a spring material for connectors and the like due to its excellent strength, but due to its high price, 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 5.0% by weight of Sn, more than 0.01% by weight to 0.4% by weight of P, and further contains 0.05% to 5.0% by weight of Zn, and 0.2% by weight of Si. % but not more than 1.0% by weight, Mn more than 0.2% by weight and not more than 1.0% by weight, Al not less than 0.1% by weight and not more than 1.0
An alloy containing a total amount of 0.01% to 8.0% by weight of one or more selected from the group consisting of 0.01% to 0.3% by weight of Pb, and the balance consisting of Cu and inevitable impurities. , or if the oxygen content among the inevitable impurities in the above alloy is
It is a high-strength conductive copper alloy characterized by a content of 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 will be explained. The reason why the Sn content is set to 0.8% by weight or more and 5.0% by weight or less is that 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 amount 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 more than 0.01% by weight and 0.4% by weight or less is that unless the P content exceeds 0.01% by weight, the improvement in strength and heat resistance due to P content is not significant. This is because if it exceeds this, the conductivity and workability will be significantly lowered. Limiting the content of sub-ingredients individually and determining the total amount
The content was limited to 0.01% by weight or more and 8.0% by weight or less.
The subcomponents listed here improve strength, but 0.01
If the amount is less than % by weight, the effect cannot be expected much.
Moreover, when it exceeds 8.0% by weight, the conductivity decreases significantly,
0.01% by weight or more as it also causes a decrease in workability.
The content was 8.0% by weight or less. Further, the reason why the oxygen content is set to 0.0020% by weight or less is that the plating adhesion deteriorates when the oxygen content exceeds 0.0020% by weight. Such a material of the present invention exhibits excellent mechanical properties such as strength and elongation, and also has good solderability and plating adhesion. 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 using examples. Examples Ingots having various compositions of the alloy of the present invention shown in Table 1 were melted and cast using electrolytic copper or oxygen-free copper as a raw material 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 4 mm, followed by face cutting and cold rolling to a thickness of 1.0 mm. This is heated to 500℃
After annealing for 1 hour, it was cold rolled to a thickness of 0.8mm.
It was made into a board. In this way

[Table] As for the evaluation of the prepared sample, strength and elongation were measured by tensile test, heat resistance was measured by softening temperature at a heating time of 5 minutes, and electrical conductivity (heat dissipation) was measured by conductivity (%).
IACS). This is because electrical conductivity and thermal conductivity are proportional to each other and can be evaluated by electrical conductivity. Solderability is 230 using vertical dipping method.
It was immersed in a solder bath (60% tin, 40% lead) at ±5°C for 5 seconds, and the wetting state of the solder was evaluated by visually observing it. The plating adhesion is determined by the thickness of 3
The sample was plated with μ Ag, heated at 450°C for 5 minutes, and evaluated visually for the presence or absence of blisters on the surface. 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, solderability, plating adhesion,
It is clear that it exhibits hot workability, and it can be said to be a material suitable for inexpensive lead materials and spring materials for semiconductor devices.

Claims (1)

[Claims] 1 Contains 0.8% to 5.0% by weight of Sn, 0.01% to 0.4% by weight of P to 0.4% by weight, and further contains as subcomponents Zn 0.05% to 5.0% by weight, Si0. 2% by weight
more than 1.0% by weight, Mn more than 0.2% by weight and less than 1.0%, Al more than 0.1% by weight and less than 1.0% by weight,
Contains one or more selected from the group consisting of 0.01% by weight or more and 0.3% by weight or less of Pb in a total amount of 0.01% by weight or more and 8.0% by weight or less,
A high-strength conductive copper alloy characterized in that the remainder consists of Cu and unavoidable impurities. 2 Contains Sn0.8% by weight or more and 5.0% by weight or less, P0.01% by weight or more and 0.4% by weight or less, and additionally contains Zn0.05% by weight or more and 5.0% by weight or less, and Si0.2% by weight.
more than 1.0% by weight, Mn more than 0.2% by weight and less than 1.0%, Al more than 0.1% by weight and less than 1.0% by weight,
Contains one or more selected from the group consisting of 0.01% by weight or more and 0.3% by weight or less of Pb in a total amount of 0.01% by weight or more and 8.0% by weight or less,
A high-strength conductive copper alloy characterized in that the remainder consists of Cu and unavoidable impurities, and the content of oxygen among the impurities is 0.0020% by weight or less.