JPH01180930A - Cu alloy for terminal and connector - Google Patents

Abstract

PURPOSE:To maintain the strength, spring characteristics and electric conductivity and to improve the heat creep characteristics and heat resistance in the title alloy by specifying Mg, P, Zr and Cu. CONSTITUTION:The Cu alloy for terminal and connector is formed with the compsn. consisting of, by weight, 0.3-1.5% Mg, 0.001-0.1% P, 0.001-0.3% Zr and the balance composed of Cu. The above alloy has excellent strength, spring characteristics and electric conductivity. The alloy furthermore gains excellent heat creep characteristics and heat resistance.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a Cu alloy that has particularly excellent heat resistance and thermal creep properties, and exhibits excellent performance over a long period of time when used as a terminal or connector. It is.

[Conventional technology]

In general, terminals, connectors, relays, switches, etc. are required to have strength, spring properties, conductivity, thermal creep properties, and heat resistance. Cu alloy, typically, weight % (hereinafter, % indicates weight %), Mg: OJ ~ 1.5%, P: 0.001 ~ 0
．． 1%.

A Cu alloy is used which has a composition containing Cu and the remainder consisting of Cu and unavoidable impurities.

[Problem that the invention seeks to solve]

On the other hand, electronic and electrical devices in recent years have been trending toward higher performance, smaller size, and higher density, and along with this, terminals and connectors are also required to be smaller and lighter. Currently, the above-mentioned conventional Cu alloy products cannot sufficiently meet these requirements, particularly due to insufficient thermal creep properties and heat resistance.

[Means for solving problems]

Therefore, from the above-mentioned viewpoint, the present inventors
- - In order to develop a Cu alloy with significantly improved thermal creep characteristics and heat resistance, we conducted research focusing on the conventional Cu alloy mentioned above, and found that Zr was added to the conventional Cu alloy as an alloying component. They found that the thermal creep properties and heat resistance were further improved, and that the material had the strength, springiness, and conductivity required for terminals and connectors.

This invention was made based on the above findings, and includes: Mg': 0.3 to 15%, P: 0.001 to
01%.

Zr: 0.001-0.3%.

It is characterized by a Cu alloy for terminals and connectors having a composition containing Cu and unavoidable impurities.

Next, the reason why the component composition of the Cu alloy of the present invention is limited as described above will be explained.

(a) Mg By solidly dissolving in the Cu matrix, the Mg component improves strength and thermal creep properties without significantly impairing the high conductivity of Cu itself, which is the main component, and has a solder-resistant property. Coating has the effect of improving releasability, but if its content is less than 0.3%, the desired effect cannot be obtained, while if its content exceeds 15%, the conductivity will simply be impaired. However, the content was determined to be 0.3 to 1.5% because the tendency of embrittlement appears instead.

(b) In addition to its deoxidizing effect, the P component also has the effect of improving spring properties, thermal creep properties, and heat resistance when coexisting with Mg. If the content exceeds 0.01%, a tendency towards embrittlement appears, so the content was set at 0.001 to 0.1%.

(c) Zr In addition to having a deoxidizing effect, the Zr component also has the effect of further improving thermal creep properties and heat resistance without impairing strength, springiness, and conductivity. If the content is less than 0.001%, the desired effect cannot be obtained, while if the content exceeds 0.03%, the conductivity will decrease and large Zr-rich precipitates will likely appear, resulting in the formation of unhealthy metals. From starting to form an organization,
Its content was determined to be 0001-03%.

〔Example〕

Next, the Cu alloy of the present invention will be specifically explained using examples.

Molten Cu alloys shown in Table 1 were prepared using an ordinary low-frequency groove induction furnace, and the thickness was determined by semi-continuous casting.
After casting into an ingot with dimensions of 150mm x width 400mm x length: 710~
A hot-rolled sheet with a thickness of 11 mm was obtained by hot rolling at a predetermined rolling start temperature within the range of 800°C, and after cooling with water, the top and bottom surfaces of the hot-rolled sheet were rolled with a thickness of 0.5 mm. After cutting to a thickness of 10 mm, cold rolling and annealing were alternately repeated under normal conditions to obtain a cold rolled plate with a thickness of 0.25 mm at a final finishing rolling rate of near 5%, This cold-rolled plate is finally heated to a predetermined temperature within the range of 250 to 500°C.
By performing strain relief annealing under the condition of holding for 0 minutes, the Cu alloy sheets 1 to 7 of the present invention and the conventional Cu alloy sheets 1 to 5
were manufactured respectively.

Next, for the various Cu alloy plate materials obtained as a result, the tensile strength, spring limit value, and electrical conductivity (IACS%) were determined for the purpose of evaluating the strength, spring properties, and electrical conductivity.
In order to further evaluate the heat resistance and thermal creep properties, the softening temperature and stress relaxation rate after stress heating were measured.

In addition, the spring limit value is measured by the moment test of JIS-H3130, and the stress relaxation rate is determined by the width
12.7mm x length 120mm (this length is Lo
), and set this test piece in a jig having a horizontal longitudinal groove of length 10 mm x depth 3 mvn so that the center part of the test piece expands upward. Distance between both ends of the test piece at this time:
110mm is Ll), temperature: 200° in this state
C for 500 hours, and after heating, the distance between both ends of the test piece (referred to as L2) after being removed from the jig was measured, and these results were calculated using the calculation formula (L −L > / (L
It is expressed by the value obtained by substituting it into (%) x100 (%), and therefore, the lower the stress relaxation rate, the better the thermal creep properties.

Furthermore, the softening temperature is determined by heating and holding each of the above-mentioned Cu alloy plates at various temperatures for 30 minutes, measuring the Vickers hardness of the Cu alloy plate after heating at each heating temperature, and based on the measurement results, Determine the temperature at which a sudden decrease in hardness is seen in the plate material, define this determined temperature as the softening temperature,
Heat resistance was evaluated.

〔Effect of the invention〕

From the results shown in Table 1, the Cu alloys 1 to 7 of the present invention are:
It is clear that all of them have excellent strength, spring properties, and conductivity equivalent to conventional Cu alloys 1 to 5 that do not contain Zr, and also have thermal creep properties and heat resistance that are even better than these.

As mentioned above, the Cu alloy of the present invention has excellent strength, springiness,
It has excellent conductivity, excellent thermal creep properties and heat resistance, so when used as terminals and connectors that require these properties, it exhibits excellent performance over a long period of time. Moreover, it can sufficiently cope with the reduction in size and weight.

Claims (1)

[Claims] (1) Mg: 0.3-1.5%, P: 0.001-0.
1%, Zr: 0.001 to 0.3%, and the remainder is Cu and unavoidable impurities (weight %).