JPH1081927A - Terminal-connector material made of cu alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain terminal-connector material excellent in spring property and bending by constituting the material of a Cu alloy having the compsn. contg. specified amounts of Ni,Ti,Cr and Zr, and the balance Cu. SOLUTION: A terminal-connector material is composed of a Cu alloy having a compsn. contg., by weight, 1 to 3.5% Ni, 0.3 to 1.5% Ti, 0.2 to 1% Cr, 0.05% Zr, and the balance Cu. This terminal-connector material has excellent spring properties and bending workability and also has good strength, electric conductivity and plating and soldering adhesion. In the case the contents of Ni and Ti are less than the lower limits, excellent spring properties can not be secured, and in the case of above the lower limits, the excellent electric conductivity owing to Cu is deteriorated. As for Cr, in the case of less than the lower limit, the effect of improving the plating adhesion without deteriorating the excellent plating properties owing to Cu can not be obtd., as for Zr, in the case of less than the lower limit, the effect of improving the peeling resistance of solder, bending workability or the like can not be obtd., and as for the Cr and Zr, in the case above the upper limits, the plating adhesion is damaged, and its melting and casting are made difficult.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Cu alloy terminal / connector material having particularly excellent spring properties and bending workability, and further having good conductivity, good plating and good solder adhesion.

[0002]

2. Description of the Related Art In general, materials used for manufacturing terminals, connectors, relays, and switches (hereinafter collectively referred to as terminals / connectors) suffer from (a) a decrease in contact pressure due to fatigue or the like. (B) good bending workability to prevent cracking during bending, (c) high conductivity to eliminate voltage drop loss at the contact part, (d) good Since it is required to have the adhesion shown in (a) to (d) above, the adhesion between plating and solder is, for example, disclosed in JP-A-61-1834.
No. 26, page 3, Cu-Ti- described in Table 1.
Zr alloy, Cu-Ti-Ni alloy, and Cu-Ti-
Cu alloys such as Ni-Cr alloys are used.

[0003]

On the other hand, in recent years, the miniaturization and high performance of electric equipment have been remarkable, and accordingly, the structural members such as terminals and connectors have been strongly required to be thinner and more complicated in shape. It has become so. However, the above-mentioned conventional Cu alloy terminal / connector material cannot satisfy these requirements satisfactorily because of particularly insufficient spring property and bending workability.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above-mentioned viewpoints, as a result of conducting research to develop a terminal / connector material having particularly excellent spring properties and bending workability, the terminal / connector material was obtained by weight% (hereinafter,% means weight%). Ni: 1 to 3.5%, Ti: 0.3 to 1.5%, Cr: 0.2 to 1%, Zr: 0.05 to 0.5
%, And the remainder is composed of a Cu alloy having a composition consisting of Cu and inevitable impurities, the resulting Cu alloy terminal / connector has excellent spring properties and bending workability, and has good strength, They have obtained the knowledge that they will have conductivity and adhesion to plating and solder.

[0005] The present invention has been made based on the above findings, and the reason for limiting the component composition range as described above will be described below. (A) Ni and Ti These two components combine to form an intermetallic compound (Ni _x Ti _y ) which is finely dispersed and precipitated in the crystal grains (in the base material), thereby dramatically improving the spring property. Has an effect,
If the content of either Ni or Ti is less than 1% for Ni and less than 0.3% for Ti, the amount of intermetallic compound deposited becomes insufficient and a desired excellent spring is obtained. Properties cannot be ensured, while Ni and T
If any of i exceeds 3.5% for Ni and 1.5% for Ti, the excellent conductivity provided by Cu as the main component is impaired. The content is Ni: 1 to 3.5%, Ti:
It was determined to be 0.3 to 1.5%.

(B) The Cr terminal / connector material may be subjected to soldering during the manufacturing process, but it is necessary that the applied solder does not peel off, for example, even when used in a high temperature environment. hand,
This has the effect of improving the adhesion of the solder without impairing the excellent plating properties provided by Cu, the main component of which is a Cr component. That is, the Cr component diffuses to the interface between the base material and the solder layer, and serves as a barrier, and in general, a compound layer generated at the interface, for example, Cu ₃ Sn
(Ε phase) and Cu ₆ Sn ₅ (η phase) are remarkably inhibited from growing, and thus have the effect of improving the solder adhesion.
If the content is less than 0.2%, the desired effect cannot be obtained, whereas if the content exceeds 1%, coarse C
Since r crystallized substances are generated and the adhesion of the plating is hindered, and melting and casting become difficult, the content is set to 0.2 to 1%.

(C) Zr The Zr component promotes the barrier effect and the compound growth inhibitory effect brought about by the Cr component, and is an essential component for securing excellent peeling resistance of the solder. Combines with Cu to form intermetallic compounds such as Cu ₃ Zr, which are finely precipitated in crystal grains and at crystal grain boundaries, and also refines crystal grains to improve ductility, thereby improving bending workability. The Cu ₃
In the coexistence of an intermetallic compound of Zr and an intermetallic compound of Ni _x Ti _{y which} is finely precipitated and dispersed, there is an effect of further improving the spring property. Is not obtained, while its content is 0.5
%, Melting and casting becomes difficult,
Since the adhesion of the plating is inhibited by the generation of a large amount of inclusions, the content is set to 0.05 to 0.5%.
It was decided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The Cu alloy terminal / connector material of the present invention will now be specifically described with reference to examples. Using a normal vacuum melting furnace, in a graphite crucible,
5 kg of molten Cu alloy having the component composition shown in 2 is cast in a mold, cast and chamfered, and then subjected to hot forging and hot rolling to obtain a sheet material having a width of 150 mm and a thickness of 10 mm. Then, this plate material was subjected to a solution treatment such as water cooling and quenching after holding at a temperature of 980 ° C. for 30 minutes, and the surface was cut to a plate thickness of 8 mm.
In this state, cold rolling and intermediate annealing (temperature: kept at 500 ° C. for 1 hour) are repeatedly performed, and final rolling is performed at a rolling reduction of 50% to obtain a cold-rolled material having a thickness of 0.25 mm. Specifically, by subjecting this to low-temperature annealing at a temperature of 350 ° C. for 5 minutes, the Cu alloy terminal / connector material (hereinafter referred to as “terminal / connector material”) of the present invention is obtained.
9. Comparative Cu alloy terminal / connector material (hereinafter referred to as comparative terminal / connector material) 1 to 8 and conventional Cu alloy terminal / connector material (hereinafter referred to as conventional terminal / connector material) 1 to 3 were manufactured, respectively. . The comparison terminal
The connector materials 1 to 8 have a component content of any of the components constituting the Cu alloy (marked with * in Table 2) outside the scope of the present invention. Nos. 3 to 3 correspond to the above-mentioned JP-A-61-183426.
Publication, page 3, Cu-Ti-Zr described in Table 1
Alloy, Cu-Ti-Ni alloy, and Cu-Ti-Ni
-It is composed of a Cu alloy having a composition corresponding to a Cr alloy.

Next, the strength, elongation, and electrical conductivity (IA) of various terminal / connector materials obtained as a result are described.
CS%), and for the purpose of evaluating the spring property, the spring limit value is measured. Further, a repeated bending test, a plating adhesion test, and a solder peeling resistance test are performed. , And solder adhesion were evaluated. The spring limit value was measured by a JIS H3130 repeated bending test. In the repeated bending test, width: 10 mm x length: 200 mm x thickness: 0.25 mm
In the state where the specimen having the size of is upright in the length direction, the lower part from the center is supported by a block (50 mm × 50 mm × 50 mm) with a 0.2 mmR chamfered corner at the corner. The center of the test piece is defined as a bent portion, and the test piece is repeatedly bent by 90 ° alternately on the left and right sides.
Number of bends (90 °
Bending is performed once). The plating adhesion test
Specimens having dimensions of width: 35 mm × length: 100 mm × thickness: 0.25 mm were subjected to electro-Ag plating with an average layer thickness of 2 μm, which was kept at a temperature of 400 ° C. for 3 minutes and then allowed to cool. Was performed by observing the presence or absence of “bulging” after the heat treatment. Further, in the peeling resistance test of the solder, a eutectic solder having a composition of 63% Sn-37% Pb was used, and the width: 10 mm × length: 30 mm × thickness: 0.25 mm
Is immersed in a 230 ° C. bath of the solder to adhere the solder to the surface. In this state, the temperature is set to 150 ° C. for 1000 hours and to 100 ° C. for 10000 hours. The sample is taken out every 100 hours when the heating temperature is 150 ° C. and every 1000 hours when the heating temperature is 100 ° C., and the interface (cross section) between the sample and the solder is observed with an optical microscope. Then, the peeling time was checked. The results are shown in Tables 1 and 2.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

According to the results shown in Tables 1 and 2, the terminal / connector materials 1 to 9 according to the present invention have the best characteristics among the conventional terminal / connector materials 1 to 3. While having the same good strength, elongation, conductivity, plating adhesion, and solder adhesion as those of the above, the spring property and bending workability are significantly better than those of the conventional terminal / connector materials 1-3. It has become
Also, as seen in the comparison terminal and connector materials 1 to 8,
It is clear that even if the content of any one of the constituent components of the Cu alloy is out of the range of the present invention, at least one of the above-mentioned characteristics will be inferior. As described above, the Cu alloy terminal / connector material of the present invention has sufficient electrical conductivity, plating adhesion, and solder adhesion, and further excellent spring properties and bending. Since it has workability, it is possible to make the electric equipment thinner and more complicated in shape to cope with recent miniaturization and higher performance of electric equipment, and to exhibit excellent performance.

Claims (1)

[Claims] 1. Ni: 1 to 3.5%, Ti: 0.1%.
3 to 1.5%, Cr: 0.2 to 1%, Zr: 0.05 to 0.5
%, With the balance being composed of a Cu alloy having a composition (more than weight%) consisting of Cu and unavoidable impurities.