JPH03183678A - Method for plating ceramics - Google Patents

Abstract

PURPOSE:To improve the adhesion of a plating film to ceramics by coating the ceramics with a specified surface modifier, decomposing the modifier by heating, imparting a catalyst to the ceramics and carrying out electroless plating. CONSTITUTION:Ceramics is coated with 0.03-0.6mg/cm<2> surface modifier made of an aq. soln. contg. 50-700g/l org. Al compd., an aq. soln. contg. 20-500g/l org. Al compd. and 50-400g/l inorg. Al compd. or an aq. soln. contg. 50-450g/l inorg. Al compd. and an org. acid. The coated ceramics is heated at the decomposition temp. (600-1,400 deg.C) of the Al compd. for 15-6 min to decompose the Al compd. The ceramics is then subjected to ultrasonic cleaning at 25-65 deg.C for 10-60min, a catalyst is imparted to the ceramics and electroless plating is carried out.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for plating ceramics.

Conventional techniques and their problems Various methods of plating are known as techniques for plating on ceramics, and the general steps include cleaning, etching, catalyst application, activation, and electroless plating in sequence. There is a way to do it.

Among the above steps, the etching treatment chemically erodes the surface of the ceramic to form irregularities, and the anchoring effect of the irregularities improves the adhesion between the ceramic and the electroless plated film. Conventional etching treatments include immersion in an aqueous solution of hydrofluoric acid or ammonium fluoride, or immersion in an aqueous solution of an alkali metal compound, drying to adhere the alkali metal compound to the surface, and then heating to a temperature above the melting point of the alkali metal. There are various methods (for example, Japanese Patent Laid-Open No. 16886/1986). However, there is a limit to the improvement in the adhesion between ceramics and electroless plating films only by the anchoring effect due to the unevenness formed by these etching methods. Therefore, in the conventional method of etching ceramics and then electroless plating, it is difficult to obtain a strength sufficient for practical use in terms of adhesion between the ceramics and the electroless plating film. Furthermore, etching may cause a problem of deterioration of the physical properties of ceramics.

Furthermore, a technique is known in which the adhesion of an electroless plating film is improved by surface-modifying ceramics without etching. It consists of a binder (glass, a mixture of glass and oxides) and a vehicle (
A paste containing volatile substances and non-volatile substances is screen printed on ceramics and heated at 500 to 1000°C.
This is a method in which the surface is modified by baking, followed by catalyst application and electroless plating. in this way,
In baking the paste, first the volatile solvent evaporates, then the resin component burns, and as the temperature rises further, the binder melts and reacts with the ceramic. A glassy film of about 5 μm is formed on the ceramics modified by baking the paste in this way.
By utilizing the unevenness of the glassy surface, the adhesion of the electroless plating film is improved. However, in this method, a glassy layer exists between the ceramic and the plating film, so the properties of the plated product are affected by the glassy layer, and the characteristics of the ceramic may not be fully demonstrated. .

Means for Solving the Problems In view of the above-mentioned problems, the inventors of the present invention have developed a method for solving the problems on ceramics without deteriorating the physical properties of the ceramics.
We have been conducting extensive research to find a method that can form a plating film with good adhesion. As a result, by applying a surface modifier containing an aluminum compound onto the ceramic and then heating it above the decomposition temperature of the aluminum compound, a thin film with a thickness of about 0.5 μm or less and good adhesion can be created on the ceramic surface. By forming a modified layer and performing electroless plating on it, the plating film has excellent adhesion to ceramics.
We also discovered that since the thickness of the modified layer is very thin, it is possible to fully utilize the characteristics of ceramics.

That is, the present invention provides a method for applying a surface modifier consisting of an aqueous solution containing an organic aluminum compound, an aqueous solution containing an organic aluminum compound and an inorganic aluminum compound, or an aqueous solution containing an inorganic aluminum compound and an organic acid onto a ceramic. , relates to a method for plating ceramics, which comprises heating to a temperature above the decomposition temperature of an aluminum compound, followed by application of a catalyst and electroless plating.

The method of the present invention can be applied to various ceramic materials, such as alumina, silicon nitride,
Applicable to aluminum nitride, etc.

The surface modifier used in the present invention is either an aqueous solution containing an organoaluminum compound, an aqueous solution containing an organoaluminum compound and an inorganic aluminum compound, or an aqueous solution containing an inorganic aluminum compound and an organic acid.

In the organoaluminum compound-containing aqueous solution, the amount of the organoaluminum compound blended is suitably about 50 to 700 g/Q, preferably about 100 to 500 g/Q. In an aqueous solution containing an organoaluminum compound and an inorganic aluminum compound, the amount of the organoaluminum compound is 2
Approximately 0~500g/Q is suitable, 50~400g
/Q is preferable, and the appropriate amount of the inorganic aluminum compound is about 50 to 400 g/Q, and 80 to 300 g/Q.
About g/Q is preferable. For an aqueous solution containing an inorganic aluminum compound and an organic acid, the appropriate amount of the inorganic aluminum compound is about 50 to 450 g/Q;
Approximately 0 to 350 g/9 is preferable.

In the present invention, organic aluminum compounds to be added to the surface modifier include aluminum monocarboxylate such as aluminum formate, aluminum acetate, aluminum propionate, aluminum oxalate, aluminum succinate, aluminum malonate, aluminum maleate, etc. Examples include aluminum oxycarboxylate such as aluminum dicarboxylate, aluminum glycolate, aluminum lactate, aluminum salicylate, aluminum tartrate, and aluminum citrate.
It can be used as a food stall. Examples of the shadowless aluminum compound include aluminum sulfate, aluminum nitrate, aluminum chloride, aluminum ammonium sulfate, and aluminum hydroxide, which may be used alone or in combination. Examples of organic acids include monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, and acrylic acid; dicarboxylic acids such as oxalic acid, succinic acid, malonic acid, maleic acid, itaconic acid, and phthalic acid; glycolic acid; Examples include oxycarboxylic acids such as lactic acid, salicylic acid, tartaric acid, and citric acid, which can be used alone or in combination.

The uniformity of application onto ceramics can be improved by further adding a nonionic interfacial lubricant to the surface modifier, if necessary. For example, polyethylene glycol, polypropylene glycol, etc. to which ethylene oxide is added can be used, and the appropriate blending amount is in the range of about 0.3 to 10 g/Q.

In the method of the present invention, a surface modifier is applied after cleaning the ceramic according to a conventional method. The cleaning method should be determined appropriately depending on the type of ceramics used.
Treatments such as degreasing and ultrasonic cleaning may be carried out according to conventional methods.

The method of applying the surface modifier is not particularly limited, and can be performed by a spin code method, a dip coating method, a spray method, or the like. The coating amount is not particularly limited, and the modifier attached to the ceramics by coating may be subsequently heat-treated, but the coating amount may be 0. 03-0. 6mg/c
m2 or so, preferably 0.04~0.4 B/ca
It is preferable from the viewpoint of adhesion of the modified layer that the coating amount be in the range of about +2, and in this range of coating amount, the coating amount is usually 0.5 μm.
A modified layer with good adhesion of less than a certain degree is formed.

After applying the surface modifier, heat treatment is performed at a temperature higher than the decomposition temperature of the aluminum compound used, whereby the aluminum compound decomposes into alumina, which is combined with the ceramic to form a modified layer. Heat treatment temperature is 60
It is preferable to set it as about 0-1400 degrees Celsius, and it is 650-
More preferably, the temperature is about 1300°C. The processing time may be about 15 to 60 minutes.

After the heat treatment is completed, it is washed and a catalyst for electroless plating is applied. As a catalyst application method, for example, a known method such as a sensitizer/accelerator method or a catalyst/accelerator method may be employed.

Note that the adhesion of the plating film can be further improved by performing ultrasonic cleaning after the heat treatment and before applying the catalyst. Ultrasonic cleaning can be carried out according to the usual method, for example, 25
What is necessary is just to process in water of about 65 degrees Celsius for about 10 to 60 minutes.

After applying the catalyst, washing with water is performed, and then electroless plating is performed.

As the electroless plating solution, any known electroless plating solution such as an electroless copper plating solution or an electroless nickel plating solution can be used, and the processing conditions may be according to a conventional method.

After performing the electroless plating treatment, it is possible to perform electroplating as necessary.

Effects of the Invention According to the method of the present invention, a plating film with good adhesion can be formed on ceramics without deteriorating the properties of ceramic nox. For example, it is possible to form an electric circuit on ceramics. This is extremely useful as a method, etc.

Example The present invention will be described in detail below with reference to Examples.

Example 1 An aqueous solution containing 200 g/Q of aluminum oxalate was applied by dip coating onto a 96% α-alumina ceramic substrate (2×2 inches) that had been cleaned by ultrasonic cleaning. After drying, it was heat-treated at 800°C for 30 minutes.

Next, after performing ultrasonic cleaning in water at 50°C for 15 minutes at 45 KHz, 40° C. It was immersed at 40°C for 5 minutes, washed with water, and then immersed in an aqueous solution of 100 mQ/Q of 98% sulfuric acid at 40°C for 4 minutes.

After washing with water, apply an electroless nickel plating solution (trademark: Top Nijiron N-4F, manufactured by Okuno Seiyaku Gyokugyo) for 20 minutes at 90°C.
By dipping for minutes, a nickel plating film of 3 μm was formed. The adhesion strength of the obtained plating film was measured by the following method. The results are shown in Table 1.

Method for Measuring Adhesion Strength After electroless plating, the sample was heat treated at 300'C for 30 minutes, left to stand at room temperature, and etched resist was printed in a 2x2mtn pattern by screen printing. After drying, the electroless plated film was etched to form a 2×2 mm pattern. On this pattern, a tin-plated copper wire with a diameter of 0.64 mm was soldered in an L-shape, and tested directly against the ceramic using a tensile tester (Autograph 5D-100-C manufactured by Konsei Seisakusho). The adhesive strength was measured by pulling.

Example 2 Aluminum acetate 5 was added on the same ceramic as in Example 1.
An aqueous solution containing 00 g/Q was applied by dip coating. After drying, it was heat treated at 700°C for 30 minutes.

The process after ultrasonic cleaning was carried out in the same manner as in Example 1. Table 1 shows the adhesion strength between the ceramic and the electroless plating film.

Example 3 Aluminum lactate 3 was deposited on the same ceramic as in Example 1.
An aqueous solution containing 00 g/Q was applied by dip coating. After drying, it was heat-treated at 750°C for 30 minutes. The process after ultrasonic cleaning was carried out in the same manner as in Example 1. Table 1 shows the adhesion strength between the ceramic and the electroless plating film.

Example 4 Aluminum lactate 2 was placed on the same ceramic as in Example 1.
An aqueous solution containing 00 g/Q and 100 g/Q of aluminum sulfate was applied by dip coating. After drying, 8
Heat treatment was performed at 00°C for 30 minutes. Table 1 shows the adhesion strength between the electroless plated film and the ceramics treated in the same manner as in Example 1 after ultrasonic cleaning.

Example 5 Aluminum sulfate 3 was deposited on the same ceramic as in Example 1.
An aqueous solution containing 00 g/Q and 500 g/Q of lactic acid was applied by dip coating. After drying, at 700°C
Heat treatment was performed for 0 minutes. The process after ultrasonic cleaning was carried out in the same manner as in Example 1. Table 1 shows the adhesion strength between the ceramic and the electroless plating film.

Example 6 Implementation ff7! l On the same ceramic as 1, aluminum citrate 50 g/Q, aluminum oxalate 20
0g/Q, nonionic surfactant (PEG-1000)
An aqueous solution containing Ig/Q was applied by dip coating. After drying, it was heat treated at 1200°C for 30 minutes.

The process after ultrasonic cleaning was carried out in the same manner as in Example 1. Table 1 shows the adhesion strength between the ceramic and the electroless plating film.

Implementation Ff117 On the same ceramic as in Example 1, aluminum nitrate 1
00g/Q, acetic acid 100g/(2, lactic acid 100g/i2
An aqueous solution containing the above was applied by dip coating.

After drying, it was heat-treated at 1100°C for 30 minutes. The process after ultrasonic cleaning was carried out in the same manner as in implementation ff11. Table 1 shows the adhesion strength between the ceramic and the electroless plating film.

Comparative Example 1 The same ceramic as in Example 1 was subjected to a surface modification treatment. After ultrasonic cleaning, the ceramic was immersed in an aqueous catalyst solution, and then treated in the same manner as in Example 1. Table 2 shows the adhesion strength between the ceramic and the electroless plated film.

Comparative Example 2 The same ceramic as in Example 1 was treated with 12% ammonia fluoride.
Etching containing 0 g/Q and 80 g/Q of sodium chloride was immersed overnight at 50°C for 5 minutes, and the process after ultrasonic cleaning was carried out in the same manner as in Example 1.

Table 2 shows the adhesion strength between the ceramic and the electroless plated film.

Comparative Example 3 The same ceramics as in Example 1 were immersed in a 10% hydrofluoric acid aqueous solution at 50°C for 10 minutes, and were further treated in the same manner as in Example 1 after ultrasonic cleaning. Table 2 shows the adhesion strength between the ceramic and the starvation electroplating film.

Comparative Example 4 The same ceramics as Example 1 were treated with 10% sodium hydroxide.
Immersed in an aqueous solution containing 00g/Q at 60°C for 5 minutes,
After drying, etching treatment was carried out by heat treatment at 450° C. for 5 minutes. Furthermore, the process after ultrasonic cleaning was carried out in the same manner as in Example 1. Table 2 shows the adhesion strength between the ceramic and the electroless plated film.

Comparative Example 5 The same ceramics as in Example 1 were treated with 80% sodium hydroxide.
It was immersed in an aqueous solution containing 0g/Q and 200g/Q of lithium hydroxide at 70°C for 5 minutes, dried, and then heated at 450°C for 1
Etching treatment was performed by heat treatment for 0 minutes.

Furthermore, the process after ultrasonic cleaning was carried out in the same manner as in Example 1. Table 2 shows the adhesion strength between the ceramic and the electroless plated film.

Claims (2)

[Claims] (1) After applying a surface modifier consisting of an aqueous solution containing an organoaluminum compound, an aqueous solution containing an organoaluminum compound and an inorganic aluminum compound, or an aqueous solution containing an inorganic aluminum compound and an organic acid onto ceramics, the aluminum compound 1. A method for plating ceramics, which comprises heating above the decomposition temperature of , followed by applying a catalyst and electroless plating. (2) The method for plating ceramics according to claim (1), wherein ultrasonic cleaning is performed after heating the surface modifier and before applying the catalyst.