JPS5852452A - Electrical contact material and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a material for a contact made of Trigonium genus, particularly a contact for low current, and a method for manufacturing the same.

The contacts for low currents are made from silver-1-gold, palladium or platinum material, depending on the conditions of use.

In addition to cost, material selection takes into account switching voltage, rated current strength, switching frequency, switching reliability, mechanical load, and corrosive atmosphere. Abrasion resistance, good conductivity and low contact resistance are required.

Furthermore, the contact material must not corrode or rust. For these reasons, precious metals are ideal contact materials in their own right. The only disadvantages are that they are expensive and that their hardness and strength, and therefore their wear resistance, are too low for many applications.

Therefore, to increase strength and hardness, alloys of pure precious metals and base metals are often used.

Examples of such base metals are copper and nickel.

However, noble metal alloys as contact materials have lower electrical conductivity, higher contact resistance, and are more prone to oxidation and corrosion if the base metal content is high.

It is therefore an object of the present invention to develop a material for metal electrical contacts that has high wear resistance, high electrical conductivity, oxidation and corrosion resistance, and has as low a precious metal content as possible, as well as a method for producing the same. It was to find out.

This problem is solved according to the invention by a material containing 1 to 50 volumes of glass. Advantageously as glass, 4
All frits with a transition temperature of 00-750°C and a softening range greater than 100°C are used.

The transition temperature is the transition point of the frit from a brittle state to a viscoplastic state, and is determined by the angle in the temperature-physical property curve. The same measurement is I) I N (German Industrial Standard) 523
24, the expansion curve of the sample is drawn in four directions. Let the temperature corresponding to the intersection of the tangents be the transition temperature. Typically, the frit has a viscosity of about 10"Pa*sec at the same temperature.

The softening range is the temperature range between the softening start point of the frit and the hemisphere temperature, and both limit values are measured by observing the cylindrical sample with a heated microscope. The rounded edge determines the softening starting point, and the hemispherical temperature is determined by the cylindrical sample melting into a hemispherical shape. Softening range is a measure of the dependence of viscosity on temperature.

For A1, a frit containing 15 to 75% by weight of lead oxide and/or zinc oxide, 5 to 65% by weight of silicon dioxide, 0 to 25% by weight of boron oxide, and 90 to 20% of alkali oxide by weight is used. . Additionally, aluminum oxide, zirconium dioxide, titanium dioxide and/or tin dioxide can be added to the frit up to 1 (HHt%) each.

By using frits with low transition temperature and wide softening range, noble metals or The glass is already softened at temperatures significantly lower than the usual sintering temperatures for single metal alloys, and high densities and good processability of the material can be achieved by the process of liquid phase sintering.

The material according to the invention advantageously has as noble metal component: gold,
Contains silver and/or palladium, or alloys thereof.

By adding nitrification to Fritke precious metals of 1 to 50 units, especially 1 to 30 units! Ill, the noble metal content of the material can be significantly reduced without significantly lowering the electrical conductivity or reducing the corrosion resistance compared to the corresponding alloy. Furthermore, the material has higher wear resistance than comparable alloys, is solderable and electroplatable, and has good processability. It is also an advantage that the recovery of precious metals from processing waste is easier.

The figure shows the dependence of electrical conductivity on glass content in gold-glass materials. The isoelectric constant of ordinary gold alloys is within the shaded area.

The frit material of the present invention is prepared by mixing the noble metal powder with 1 to 50 volumes, preferably 2 to 30 volumes, of fine frit powder, pressing, sintering, and thermo-processing. A metal powder with a particle size of 250 μm and a special diameter of 63/4 nm is used.On the other hand, a frit with a particle size of 50 μm, preferably (
・It is clear that the particle size of tozzm is advantageous.
= was done. Furthermore, it is advantageous for the frit and the metal particles to have a spherical or approximately spherical shape. Powder admixture total room temperature and 5
Pressing at a pressure of 00-5000 bar, then sintering at 500-950 °C, followed by
Hot working is carried out, especially in an extrusion press, at 800 DEG C. and a pressure of 100 to 200 par.

Press pressure of 1000-3000 pars and 550--8
A sintering temperature of 0.000C is advantageous. The viscosity of the glass after processing is 109 to 103 Pa-3cc, preferably 10511
, +I3eC.

under. [Example 2] Detailed description of the material and method of making the same according to the invention.

Example 1 Gold powder with an average particle size of 6374 m was mixed with PbO10% by weight and hC%.
5i() + 50%, B2O315% s Al2O
Frit powder 12 with an average particle size of <10 μIn, having a composition of 35%, Z r 025 and alkali oxide 15
Add all of the volume t% and acetone and mix. The transition temperature of the frit is 430°C and the softening range is 170°C. The same powder mixture at room temperature and 1000 pearls,
It is pressed into a bolt shape with a compressed body density tW of approximately 65 mm of the theoretical density value and subsequently sintered at 900° C. for 1 hour. At this time, the density becomes the 85th factor of the theoretical density value. The entire sintered body is heated to 750°C, and then extrusion pressed at 500°C and a press pressure of 150 pars.The subsequent processing into thin plates is performed using equipment that reduces the reel gap of each pair by 0.5 mrn. It is carried out by hot rolling at a temperature of 800°C.In the middle, it is rolled at 550°C for 10 minutes.
) A thin plate with a thickness of 0.1+mm is obtained by cold rolling.

IZ! + 2 Silver powder having an average particle size of 63 μm' is mixed with a 25-y amount of frit powder described in Example 1, pressed into a compact at room temperature and 1000 pearls, and sintered at 750° C. for 1 hour. An extrusion press was performed at 700° C. and 150 pars to obtain a wire rod with a straight diameter of 11.5 mm. By normal temperature processing (peening and refining), the total diameter of the wire is 0.4
It can be reduced to mm.

[Brief explanation of the drawing]

FIG. 1A is a diagram showing the relationship between the conductivity ratio and the glass content of the gold-glass material according to the present invention.

Claims (1)

[Claims] ■ In the material of the electrical contact made of precious metal, glass is
An electrical contact material characterized in that it contains a capacitance of 50%. 2. The material according to claim 1, which contains gold, silver and/or noradium or an alloy thereof as a noble metal. 3. The material according to claim 1 or 2, which contains, as glass, a frit having a transition temperature of 400 to 750"C and a softening range greater than 100"C. 4. The frit contains lead oxide and/or oxide. Zinc 15-75% by weight, silicon dioxide 5-65% by weight, boron oxide 0-25% by weight, brewed alkali'J O-20% by weight aluminum oxide, zirconium oxide, titanium oxide and/or tin oxide each O- 5. The material according to any one of claims 1 to 3, in which the frit has a particle size of 10 μmf. The material described in item 1. 6. Mixing and pressing of noble metal powder and frit. Sintering and hot pressing 11 steps to produce a metal electrical contact material containing 1 to 50 parts of glass. In this case,
Press at room temperature and 5. IJO at a pressure of ~5000 par, subsequent sintering at a temperature of 500-950 °C, final thermal RBL processing at a temperature of 500-800 °C and a pressure of i o'o ~200 °C. The manufacturing method of electrical contact materials, which is characterized by all of our activities.