JPS61141686A - Method of roughening ceramic surface - 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] (Industrial application field) The present invention relates to a method for surface roughening ceramics.

(Prior art and its problems) Conventional ceramic wiring boards form wiring patterns by plating metal directly onto the surface of ceramics.

In order to increase the adhesion between the plated metal and the ceramic, acid or alkali was used to roughen the ceramic surface.

However, when acids such as hydrofluoric acid and hot phosphoric acid are used, they not only selectively roughen only the grain boundaries of ceramics, making the surface of the ceramics rough, but also roughen one grain boundary, causing the gaps between grains to become rough. This has the disadvantage of weakening the bond and reducing the strength of the ceramic itself. On the other hand, in roughening using an alkali, the surface is generally roughened by heating sodium hydroxide, potassium hydroxide, etc. above the melting point and immersing the ceramic in this alkaline melt.

However, in this method, a thermal shock is applied to the ceramics when the ceramics are immersed in the alkaline melt, causing a crank in the ceramics. The roughening ability of the alkali gradually decreases due to the ceramics melted into the alkali melt, making the management of the alkali melt complicated. Furthermore, this method has the disadvantage that a large amount of alkali is used and a large-scale processing equipment is required to dispose of the alkali.

(Object of the Invention) An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a method for roughening the surface of ceramics using a trace amount of alkali and having good workability.

(Structure of the Invention) The present invention includes a step of sandwiching ceramics between metal nets, and dropping an alkaline aqueous solution having a concentration of 5 weight or more and a saturated solution or less at a rate of 0.005 to 10 cc/cm from the top surface of the metal net. The present invention relates to a method for surface roughening ceramics, which includes a step of heating ceramics, a metal mesh, and an aqueous alkali solution adhering thereto at a temperature of 100 to 1390°C.

In the present invention, aluminum ceramics and the like are used as the ceramics, and strong alkalis such as sodium hydroxide and potassium hydroxide are used as the alkali. The concentration of the alkaline aqueous solution is set to be 5% by weight or more and not more than a saturated solution, and if it is less than 5% by weight, the roughening ability decreases.

It is preferable to use an alkaline earth resistant metal such as nickel or silver for the metal mesh, but even if stainless steel is used, it will not affect the surface roughening ability of the ceramic. Although there are no particular restrictions on the wire diameter and aperture ratio of the net, it is preferable to use a net with a wire diameter of 160 μm and an aperture ratio of 55% or less.

The dropping amount of alkaline aqueous solution is 0.005 to 10 cc/am
If it is less than 0.005 cc/am, the roughening ability will decrease, and if it exceeds 10 cc/cm, it will sag from the ceramic and metal meshes and become wasteful.

Ceramics, metal nets, and the alkaline aqueous solution attached to them must be heated at a temperature of 100 to 1390°C, and if the temperature is less than 100°C, there will be no roughening effect.
Moreover, when the temperature exceeds 1390°C, the alkali evaporates and the roughening ability decreases.

(Example) The present invention will be explained below with reference to Examples.

Example 1 An alumina ceramic substrate with a thickness of 1 mm and dimensions of 40 x 40 mm, an alumina content of 94% by weight, and a glass frit of 6% by weight consisting of silica, calcia, and magnesia was prepared with a wire diameter of 40 μm, an aperture ratio of 50%, and dimensions of 50 x 5.
Sandwiched with a nickel net of 0 mm, the concentration of 20
Weight - 0.0063 cc of sodium hydroxide aqueous solution
/cm” after dropping.

The alumina ceramic substrate was placed in a dryer set at 300° C. and heated for 2 hours to roughen the surface of the alumina ceramic substrate.

After heating, it was taken out of the dryer and cooled naturally, the nickel net was removed, and only the alumina ceramic substrate was washed with running water for 10 minutes, then ultrasonically washed for 5 minutes in sulfuric acid with a concentration of 20% by weight, and then washed with ion-exchanged water. The surface of the alumina ceramic substrate was sensitized and activated using a sensitizing solution (manufactured by Nippon Kanigen Co., Ltd., trade name: Pink Shuma) and an activating solution containing palladium (manufactured by Nippon Kanigen Co., Ltd., trade name: Red Shuma).

Next, electroless nickel plating (manufactured by Nippon Kanigen Co., Ltd.).

Product name 5-680. Nickel was deposited to a thickness of 2 μm on the surface of a sialumina ceramic substrate using N1-P plating solution. Next, a plating resist (manufactured by Taiyo Ink, trade name M-808) was printed on the reverse pattern part of the desired wiring pattern (the part other than the part where the wiring pattern is formed).
After drying for 10 minutes at a temperature of .degree. C., copper was deposited to a thickness of 30 .mu.m by electrolytic steel plating (for the sulfuric acid steel plating tower side, manufactured by Hitachi Chemical Co., Ltd.). Furthermore, the plating resist was removed by shower cleaning with an aqueous solution of sodium hydroxide having a concentration of 5% by weight, and then the exposed nickel was removed using a nickel remover (manufactured by Okuno Pharmaceutical Co., Ltd., trade name: Top Lip AZ), and then a hydrogen atmosphere was removed. A ceramic wiring board was obtained by heat treatment for 20 minutes at a temperature of 400°C. The peel strength of the obtained ceramic wiring board was 4 kgf/mm'' on average.

Example 2 Thickness I lXl11. Silicon carbide substrate with dimensions 20 x 20 (manufactured by Hitachi, trade name Hitaseram, product name 5C-10)
1) was sandwiched between nickel nets with a wire diameter of 30 μm and an aperture ratio of 50%, and a sodium hydroxide aqueous solution with a concentration of 40 wt. The surface of the silicon carbide substrate was roughened by heating in a tunnel furnace for 45 minutes.After cooling, the nickel mesh was removed, and only the silicon carbide substrate was washed with running water for 10 minutes, followed by ultrasonic cleaning for 5 minutes in hydrochloric acid with a concentration of 15% by weight. Then, a ceramic wiring board was obtained through the same steps as in Example 1. The peel strength of the obtained ceramic wiring board was 3 kgf on average.
/w' was.

Comparative example 1 The alumina ceramic substrate used in Example 1.

The surface of the alumina ceramic substrate was roughened by immersing it in a 55% by weight aqueous hydrochloric acid solution at room temperature. Thereafter, a ceramic wiring board was obtained through the same steps as in Example 1. The peel strength of the obtained ceramic wiring board was as low as 1 kgf/mm'' on average.

Comparative example 2 The alumina ceramic substrate used in Example 1.

When the alumina ceramic substrate was immersed in a hydroxide (IJ) melt heated to 350°C, a thermal shock was applied to the alumina ceramic substrate and cracks were generated.

(Effects of the Invention) According to the present invention, the surface of the ceramic can be roughened with good workability without reducing the strength of the ceramic itself or causing cracks in the ceramic by using only a very small amount of aqueous alkaline solution. .

Claims (1)

[Claims] 1. A step of sandwiching ceramics with a metal net, a step of dropping an alkaline aqueous solution with a concentration of 5% by weight or more and a saturated solution or less at a rate of 0.005 to 10 cc/cm^2 from the top of the metal net, and ceramics, metals. 1. A method for roughening the surface of ceramics, the method comprising the step of heating an aqueous alkaline solution adhering to a mesh made of aluminum at a temperature of 100 to 1390°C.