JPS63203738A - Cu alloy for relay and switch - Google Patents

Abstract

PURPOSE:To develop a Cu alloy excellent in strength, electric conductivity, high-temp. creep characteristics, and resistance to peeling in a soldered zone and suitable for relay and switch materials, by incorporating specific amounts of Mg and P to Cu. CONSTITUTION:As the material for relay and switch, the Cu alloy containing, by weight, 0.3-1.5% Mg and 0.001-0.1% P is used. Since this Cu alloy has characteristics excellent in strength, electric conductivity, high-temp. creep characteristics, and resistance to peeling in a soldered zone, the Cu alloy suitable for relay and switch can be inexpensively manufacture at a low cost without using expensive Ni and Be unlike conventional Cu alloys.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention has high strength and high conductivity, as well as excellent thermal creep properties and soldering resistance and peeling properties, and these properties are particularly required. The invention relates to Cu alloys suitable for use in the manufacture of relays and switches.

[Conventional technology]

Conventionally, in general, in the manufacture of relays and switches, the following ingredients were used in terms of weight (hereinafter, ``chi'' indicates weight %): Sn: 1.5 to 9%, P: 0.03 to 0.3.
5%, with the remainder consisting of Cu and unavoidable impurities;
Cu containing 0.2 to 0.79b% of Be2, with the balance consisting of Cu and inevitable impurities.
alloy.

etc. are used.

[Problem that the invention seeks to solve]

However, relays and switches require high strength and high conductivity, as well as excellent thermal creep properties and resistance to soldering and peeling, especially when miniaturized or used in environments that generate heat. However, although the conventional Cu alloys for relays and switches described above have high strength, they lack at least one of the following properties: conductivity, thermal creep properties, and soldering resistance. Not only is it not possible to deal with this satisfactorily, but also expensive Sn, Ni,
Currently, since it contains Co and further Be, it has problems such as high cost.

[Means for solving problems]

Therefore, from the above-mentioned viewpoint, the present inventors conducted research to develop a Cu alloy suitable for manufacturing relays and switches at low cost, and found that Mg: 0.3 to 1.5 , P:O,OO1-0.1%.

The Cu alloy with a composition containing CU and the rest consisting of CU and unavoidable impurities has high strength and high conductivity, as well as excellent thermal creep properties and solderability and peeling properties.
They found that it exhibits excellent performance when used in the manufacture of relays and switches that require these characteristics. 'This invention was made based on the above knowledge, and the reason why the component composition was limited to the above general composition will be explained below.

(a) Mg For the Mg component, by dissolving it in the Cu base.

It has the effect of improving strength and thermal creep properties without impairing the high conductivity of Cu itself, which is the main component, and improves soldering resistance and part peelability. If it is less than the desired effect, the desired effect cannot be obtained.
On the other hand, if the content exceeds 1.5%, not only the conductivity will be impaired, but also a tendency to embrittlement will appear, so the content is set at 0.3 to 1.5%.

(b) In addition to having a deoxidizing effect, the P component also has the effect of further improving strength and thermal leap properties when coexisting with the s''g component; however, if its content is less than 1% of the The desired effect cannot be obtained in the action, and on the other hand, if the content is 0.
If the content exceeds 1 inch, a tendency towards embrittlement appears, so the content was determined to be 0.001γ0.1%.

〔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 casted by a semi-continuous casting method to a thickness of:
150tll x width: 400mm x length = 15001! IK
After casting into an ingot with dimensions of 710
Hot-rolled at a predetermined rolling start temperature within the range of ~800°C to obtain a hot-rolled plate with a thickness of 11fi, and then water-cooled, and then the top and bottom sides of the hot-rolled plate were rolled in 0.5 pieces each. With a thickness of 10 km, cold rolling and annealing were performed alternately and repeatedly under normal conditions, and a cold rolled plate with a thickness of 0.25 mjl was obtained at a final finishing rolling rate of near 5 cm. This cold-rolled sheet is finally subjected to strain relief annealing under conditions of holding at a predetermined temperature within the range of 250 to 400°C for 30 minutes.

Present invention Cu alloy plate materials 1 to 7. and conventional Cu alloy plate material 1
~3 were produced, respectively.

Next, for the purpose of evaluating the strength of the various Cu alloy plates obtained as a result, the tensile strength and spring limit value were measured, and the electrical conductivity (AC8%) was measured for the purpose of evaluating the electrical conductivity. For the purpose of evaluating thermal creep properties,
In order to measure the stress relaxation rate after stress application and heating and to evaluate the reliability of the soldering part, a peeling test was conducted on the soldering resistance.

In addition, the spring limit value is measured by the moment type test according to %JIS-H3130, and the stress relaxation rate is.

A test piece with dimensions of width: 12.7 m x length: l 20111 (hereinafter referred to as Lo) was used, and this test piece was placed in a jig having a horizontal longitudinal groove of length: 110 mm x depth: 31 uE for the above test. Set the test piece in a curved manner so that the center part of the test piece bulges upward. At this time, the distance between both ends of the test piece is 2110t.
), and in this state, the temperature = 150℃ and 1
After being held for 000 hours and heated, the distance between both ends of the test piece (hereinafter referred to as L2) in the state of being removed from the jig was measured and calculated using the calculation formula % formula % (). I asked for it.

In addition, the soldering resistance was tested on the test pieces.

A Sn alloy solder material having a composition of Sn: 40% Pb was plated by a dipping method, and was heated to 100 °C in the atmosphere at a temperature of 150 °C.
The test was performed by heating under the condition of holding for 0 hours, bending it 180 degrees after heating, and observing whether or not the plated solder material peeled off at the bent portion when the sample was bent back to its original position. These results are shown in Table 1.

〔Effect of the invention〕

From the results shown in Table 1, 1 the present invention Cu alloy plate materials 1 to 7.
All exhibit tensile strength and spring limit values equivalent to conventional Cu alloy sheets 1 to 3, that is, high strength, and
It is clear that the U-alloy plates 1 to 3 have much better conductivity, thermal creep properties, soldering resistance, and peelability.

As mentioned above, the CU gold alloy of the present invention has high strength and high conductivity, as well as excellent thermal creep properties and soldering resistance, and has good peelability, so it is particularly suitable for manufacturing relays and switches that require these properties. When used in applications, the resulting relays and switches exhibit excellent long-term performance and have industrially useful effects such as low cost.

Claims (1)

[Scope of Claims] Mg: 0.3 to 1.5%, P: 0.001 to 0.1%, and the remainder is Cu and unavoidable impurities (weight %). Features Cu alloy for relays and switches.