JPH05171223A - Method for coating metal stock with metal - Google Patents

Abstract

PURPOSE:To enable metal coating in a patterned state while easily adjusting the thickness of the resulting coating film by applying a pasty kneaded material consisting of metal powder and an adhesive to metal stock by screen printing and carrying out baking in a prescribed atmosphere. CONSTITUTION:Metal powder such as Pd or Ag powder of about <=5mum diameter or alloy powder such as Ag-Cu alloy powder of about <=5mum diameter is kneaded with an adhesive such as ethylcellulose to prepare a pasty kneaded material. This material is applied to metal stock such as Cu or phosphor bronze by screen printing and baked at about 200-800 deg.C for about 5sec to 15min in the air or in an atmosphere of an inert gas such as nitrogen, a reducing gas such as hydrogen or a mixture of them. Metal coating is attained while easily adjusting the thickness of the resulting patterned coating film and facilitating alloying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating a metal on various metal materials, and particularly, the process is simplified, and the pattern coating of the coated metal and the adjustment of the thickness are easy, and alloying is also possible. The present invention relates to a metal coating method for a metal material that is easy.

[0002]

2. Description of the Related Art As a method for coating a metal material with a metal,
Conventionally, electroplating method, chemical plating method, vapor deposition method, thermal spraying method,
Although the clad method or the like is adopted, each has the following drawbacks.

That is, the electroplating method or the chemical plating method has difficulty in alloying and thick wearing, and the vapor deposition method has a poor metal yield and has a problem in mass production. further,
The thermal spraying method is inferior in adhesion strength and surface smoothness and requires further improvement. Further, the clad method has drawbacks such as a long process and high production cost. Further, in any of these known methods, it is difficult to adjust the pattern coating and the thickness of the coating.

[0004]

Therefore, the inventors of the present invention have variously studied a coating method that enables pattern coating when coating a metal on a metal material and facilitates thickness adjustment of the coating. As a result, a unique method was developed and the present invention was completed.

An object of the present invention is to coat a metal material with a metal in a simple process, which enables pattern coating of the coated metal and facilitates thickness adjustment, and
It is an object of the present invention to provide a novel metal coating method for a metal material which can be easily alloyed.

[0006]

In order to achieve the above-mentioned object, according to the present invention, metal powder or alloy powder is kneaded together with an adhesive in a paste form, and the obtained paste-like kneaded product is put on a metal material. It is characterized in that it is applied by a screen printing method and then baked in an atmosphere of air, an inert gas, a reducing gas or a mixed gas of an inert gas and a reducing gas.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention is described in detail below. The above metal powder used in the present invention is palladium,
A metal powder having a diameter of 5 μm or less, such as silver, tin, lead, gold, platinum, or copper. These may be used alone, or may be, for example, silver powder plated with palladium.

The alloy powder mentioned above has a diameter of 5 μm.
The following are silver-palladium alloy powder, silver-gold alloy powder, silver-copper alloy powder, gold-palladium alloy powder and the like.

In the present invention, first, the above-mentioned metal powder or alloy powder alone or in combination thereof is kneaded in a paste form together with an adhesive.

As the above-mentioned adhesive, ethyl cellulose,
A saturated fatty acid-modified alkyd resin or the like is used. These adhesives are kneaded with the above mixture together with a solvent such as turpentine oil to obtain a paste-like kneaded product. At this time, in order to improve the adhesion between the metal material and the powder, the kneaded material may further be kneaded with an arbitrary amount of flux such as pine resin or its derivative, or borax.

The paste-like kneaded material thus obtained is further applied onto a metal material and then baked in an atmosphere of air, an inert gas, a reducing gas or a mixed gas of an inert gas and a reducing gas. , Obtain a metal coating on a metal material. At this time, the coating of the kneaded material onto the metal material is performed by a screen printing method such as a silk screen method, so that the pattern coating and the thickness adjustment can be easily performed.

Examples of the metal material include copper, phosphor bronze, brass, nickel silver, stainless steel, iron, 42 alloy, precious metals and the like. Examples of the inert gas include nitrogen gas, gases belonging to rare gas elements such as argon gas, helium gas, neon and the like, and examples of the reducing gas include hydrogen gas and the like.

The baking temperature and time are optional depending on the kind of metal powder to be coated, but usually 200 to 800 ° C.
The temperature is 5 seconds to 15 minutes.

[0014]

In the above-described method of the present invention, the metal powder or alloy powder is kneaded in a paste form, and the paste-like kneaded product is applied onto the metal material by the screen printing method, so that not only the coating step is simplified but also the coating process is simplified. Also, pattern coating and thickness adjustment are facilitated. In addition, the present invention is heated by baking to readily alloy the metal to be coated.

[0015]

Examples of the present invention will be listed below. Example 1 2.6 g of ethyl cellulose, 5.2 g of turpentine oil, and ethylene glycol monoethyl ether were added to 40 g of powder in which silver powder having a diameter of 1 to 5 μm was coated with 5% palladium by a chemical plating method.
15.0 g was kneaded, and the obtained paste-like kneaded product was printed on a copper plate with a width of 2.0 mm and a thickness of 20 μm whose surface was cleaned by the silk screen method, and then baked in a nitrogen stream at 800 ° C for 20 seconds for adhesion. It was possible to coat the copper plate with a strong silver-palladium alloy. At this time, the copper plate was softened by the annealing effect, but hardened by lightly rolling it on a roller. The obtained silver-palladium alloy-coated copper plate was used as an electrical contact material.

Example 2 24.0 g of tin powder and 16.0 g of lead powder each having a diameter of 1 to 5 μm
, 2.0 g of pine resin, 1.0 g of ethyl cellulose, turpentine oil
5.0 g, ethylene glycol monoethyl ether 14.0 g
Was kneaded to obtain a paste-like kneaded material. Apply this by screen printing on a copper plate with a width of 3.0 mm and a thickness of 20 μm.
It was possible to coat the copper plate with solder by baking at 250 ° C for 5 minutes in a nitrogen stream. This was used as the leg of the connector.

[0017]

As described above, in the method of the present invention, a mixture of metal powder or alloy powder is applied and applied on a metal material by a screen printing method. The thickness and thickness are easy to adjust, the process is simplified, and alloying is easy, which is an extremely useful invention in practice.

Claims (5)

[Claims] 1. A metal powder or alloy powder is kneaded in a paste form together with an adhesive, and the resulting paste-like kneaded product is applied onto a metal material by a screen printing method, and then this is mixed with air, an inert gas, and a reducing gas. Alternatively, a metal coating method for a metal material, which comprises baking in an atmosphere of a mixed gas of an inert gas and a reducing gas. 2. The metal coating method according to claim 1, wherein the kneaded product further contains pine resin or a derivative thereof, or a flux. 3. The metal coating method according to claim 2, wherein the flux is borax. 4. The metal coating method according to claim 1, wherein the inert gas is nitrogen gas. 5. The metal coating method according to claim 1, wherein the reducing gas is hydrogen gas.