JPS602638A - Softening resistant copper alloy having high conductivity - Google Patents

Abstract

PURPOSE:To obtain a Cu alloy having superior softening resistance and high conductivity, requiring no hardening, and suitable for use as a lead material for a semiconductor apparatus and a material for a heat exchanger by adding specified amounts of Fe, Ni and P to Cu. CONSTITUTION:This Cu alloy consists of, by weight, 0.02-0.5% Fe, 0.01-0.6% Ni, 0.05-0.2% P and the balance Cu. The Cu alloy is equal to a conventional Cu alloy in electric conductivity, yet it has considerably improved softening resistance and requires no hardening. Accordingly, this Cu alloy is suitable for use as a lead material for a semiconductor apparatus, a material for electric parts such as a terminal, a switch and a clip, and a fin material for a radiator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copper alloy that has excellent softening resistance and good conductivity and is suitable for use in lead materials for semiconductor devices, electrical components, radiator fin materials, and the like.

As a general lead material for semiconductor devices, 42Al toy (Fe-
42wt%NL) has been used, but in recent years, with the widespread use of resin packages, the adoption of copper alloy lead materials has rapidly increased. In particular, copper containing 0.15 wt% Sn and low Fe alloys have been used as lead materials for discretes. However, although 3n-containing copper has excellent conductivity, it has insufficient softening resistance.

Further, the low Fe alloy preferably has an Fo content of around 0.1 wt%, and has excellent conductivity and softening resistance, but requires quenching treatment.

The present invention has been made to solve these drawbacks.
The purpose of the present invention is to provide a copper alloy that has both excellent softening resistance and conductivity, and that does not require hardening treatment and is suitable for use in lead materials for semiconductor devices, electrical parts, heat exchangers, etc.

As a result of intensive studies in line with this objective, the inventors have determined that F.
The present invention has been achieved by discovering that a copper alloy containing specific amounts of Fe, NL, and P satisfies the above objectives.
．． 6 wt%, P0105 to 0.2 wt%, and the balance is in a copper alloy.

In the present invention, Fe and P have a synergistic effect to improve the softening resistance and conductivity, but N and P also have a synergistic effect to improve the softening resistance and conductivity. If three components, FeN3 and P, coexist, this effect is remarkable.

This suggests that the Fe-NL-P compound formed in the copper alloy of the present invention improves the properties of the copper alloy. Fe then converts into N and improves softening resistance and conductivity due to its synergistic effect with P, but if its content is less than 0.02 wt%, it is difficult to obtain sufficient softening resistance, and if its content exceeds 0.5 wt%. This results in poor workability and tends to result in non-uniform structures.

For such a content of Fe, NL and P necessary for improving properties (7) ffl Lt, so: h soh NL Ka0
．． 01 to 0.6 wt%, P is 0.05 to 0.2 wt%, and if llk is less than 0.01 wt%, there is little improvement in the softening resistance, and if it exceeds 0.6 wt%, the softening resistance decreases. At the same time, conductivity also decreases. P is o, os wt%
If it is less than 0.2 wt%, P, which does not form a compound with FeXNL, will increase in the alloy, leading to a large decrease in conductivity, which may cause problems in the heat dissipation of the device.

The present invention will be specifically described below based on Examples and Comparative Examples.

Examples 1 to 5 and Comparative Examples 1 to 4 Electrolytic copper was melted in the atmosphere under charcoal coating in a high frequency melting furnace, and phosphorous copper and Ni were added to form the composition shown in Table 1.
An ingot measuring 5 mm x 85 mm x 200 mm was produced.

Both sides were face-milled by 2 mm and then hot rolled at 650°C to form a plate with a thickness of 3 mm. Next, this plate was annealed and cold rolled to obtain a 0.6 mm plate. Furthermore, this board is annealed and pickled,
A plate having a thickness of 0.48 mm was obtained by performing 20% cold rolling. This plate was divided into many pieces, annealed for 5 minutes between 350°C and 550°C, and the Vickers hardness was measured. In property evaluation, the softening resistance was determined by comparing the Vickers hardness of the as-rolled plate with the Vickers hardness when annealed at 450°C for 5 minutes, and the softening temperature (annealing temperature at which the hardness of the rolled material reaches 80%). The conductivity is evaluated by the thickness of 0.
Evaluation was made based on the electrical conductivity (%IAC8) on the rolling side of 48 mm. Also, the solderability is M I L-8TD-202F
The adhesion status of the solder was visually observed according to the following.

The results are also shown in Table 1.

In addition, for comparison, p-5n-Cu alloy, Fe-p-
G alloy, Fe NL Cu alloy, NL -P -Ctt
The composition and properties of the alloy are also shown in Table 1.

As can be seen from Table 1, Examples 1 to 5, which are copper alloys of the present invention, have comparable electrical conductivity compared to Comparative Examples 1 to 2, which are conventionally used copper alloys. However, its softening resistance is much better.

Furthermore, it can be seen that Comparative Example 3, which does not contain P, and Comparative Example 4, which does not contain Fe, are inferior to Examples 1 to 5 in both electrical conductivity and softening resistance.

As is clear from the above results, the copper alloy of the present invention containing specific amounts of h, NL, and P has excellent softening resistance and good conductivity, and does not require hardening treatment, so it is suitable for semiconductors. Suitable for electrical parts such as equipment lead materials, terminals, switches, terminals, clips, radiator fin materials, etc. Patent applicant: Mitsui Kinzoku Mining Co., Ltd., Patent Attorney □ Tatsuo Ito, Patent Attorney Tetsuya Higashi 6-

Claims (1)

[Claims] Fe 0002~0.5wt%, Nip, 01~0.6
Copper alloy with excellent softening resistance and conductivity, consisting of 105 to 0.2 wt% PO and the balance.