JPH0465375A - Formation of thin palladium film - Google Patents

Abstract

PURPOSE:To form a dense uniform palladium film free from pinholes by coating a substrate with a mixed soln. contg. a palladium complex of an org. acid such as naphthenic acid or abietic acid and an org. binder, drying and firing the soln. CONSTITUTION:An org. palladium compd. contg. one or more kinds of palladium complexes of org. acids such as naphthenic acid, abietic acid, stearic acid, neodecanoic acid, decanoic acid and octanoic acid or acetylacetone is prepd. and a mixed soln. contg. the org. palladium compd., resin as an org. binder and an org. solven is produced. A glass or ceramic substrate is coated with the mixed soln. and this soln. is dried and fired to form a thin palladium film of <=1 mum thickness on the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for forming a palladium thin film on a glass or ceramic substrate used as an electronic component material.

(Prior art and its problems) Conventionally, a thick film was formed using dipalladium thick film paste on a glass or ceramic substrate, and it was used in capacitors, etc. ,1
Efforts are being made to realize a thin film of less than μm in size, and palladium fine powder is used, and the particle size is 0.
．． Since it is 5 μm or more, it is difficult to form a dense thin film, and for this reason, it is difficult to form fine patterns and compact capacitors, etc.

Furthermore, since the palladium paste is a suspension, it can be applied only by screen printing, which has the drawback of making it difficult to apply it onto objects with complex shapes.

In addition, vacuum sputtering and vapor deposition methods have low productivity for forming palladium thin films (approximately 20 to 30%) and expensive equipment, making them economically unsuitable for industrial production.

In addition, a thin film forming method using organic palladium has already been reported, but the conventional method contains sulfur or mercaptan, and this method has disadvantages such as forming sulfides with other metals such as silver electrodes. It was virtually impossible to use it industrially.

In particular, sulfides are very brittle and lack durability.

(Purpose of the Invention) The present invention has been accomplished in order to eliminate the drawbacks of the above-mentioned conventional methods. It is an object of the present invention to provide a method for forming a dense, pinhole-free, and uniform palladium thin film of 1 μm or less with a thickness of 1/2 or less.

(Means for Solving the Problems) The present invention involves coating a mixed solution containing an organic palladium compound, a resin as an organic binder, and an organic solvent on a base material of glass, ceramics, or metal, drying it, and baking it. A palladium thin film forming method characterized by forming a palladium thin film of 1 micron or less on the glass, ceramic or metal substrate, the method comprising the steps of forming a palladium thin film of 1 micron or less on the glass, ceramic or metal substrate, and the method comprises forming a palladium thin film of 1 micron or less on the glass, ceramic or metal substrate, and the method comprises forming a palladium thin film of 1 micron or less on the glass, ceramic or metal substrate. It contains one or more of acids, organic acid salts of octanoic acid, or palladium complexes of acetylacetone. Further, the palladium thin film forming method is selected from the method of applying the mixed solution, screen printing, intaglio printing, lithographic printing, spin coating, dipping method, brush painting, and stamping method.

The details of the present invention will be explained below.

The palladium organic acid salt or palladium complex can be decomposed into metallic palladium at a thermal decomposition temperature of 300°C or lower, and can be dissolved in the same organic solvent as the resin used as the organic binder. Moreover, there are no impurities left after firing.

In addition, if necessary, one or more selected from the group consisting of lead, bismuth, silicon, chromium, boron, antimony, vanadium, calcium, magnesium, manganese, zinc, zirconium, barium, strontium, lanthanum, and niobium. The adhesion of the palladium thin film can be improved by adding an appropriate amount of metal resin acid metal salt.

The resin used as the organic binder is selected from the group consisting of epoxy resin, acrylic resin, alkyd resin, urea resin, melamine resin, rosin derivative resin, and terpene resin, and is applied to form a palladium thin film with a uniform thickness. This is because it is possible to obtain an appropriate viscosity without sag during drying.

The organic solvent may be one or more selected from menthanol, terpineol, butyl calpitol, methyl ethyl ketone, ethyl acetate, ethylene glycol, amyl acetate, cellosolve, petroleum ether, chloroform, dipentene, carbon tetrachloride, essential oil, etc. It is possible to dissolve a palladium compound, a resin metal salt, and a resin as an organic binder into a uniform solution.

As described above, since the components of the mixed solution containing the organic palladium compound do not contain sulfur, no harmful sulfur compounds are generated.

The component ratio of the mixed solution containing the organic palladium compound is approximately 10 to 10% of the organic palladium compound as the main component.
65wt%, resin as an organic binder or 5~20w
t%, the organic solvent is 30 to 45 wt%.

In order to maintain the adhesion of the palladium thin film to the glass or ceramic substrate, other metal resin acids are added. In that case, the component ratio is approximately 10 to 65 wt% of the organic parallum compound as the main component and other resin acids. Metal salt or 0.
1 to 5 wt'N5, the resin as an organic binder is 5 to 20 wt%, and the organic solvent is 25 to 40 wt%.

When a mixed solution containing an organic palladium compound having the above-mentioned component ratios is applied, for example, by screen printing, dried and fired, a thin palladium film having a thickness of about 0.1 to 5 μm can be obtained.

In addition, the drying temperature is 100-125°C for 10 minutes.
The firing temperature may be 750 to 850°C for 10 minutes.

As for the coating method, intaglio printing, planographic printing, dipping, brush coating, stamping, spin coating, etc., which are other methods than the above-mentioned screen printing method, are possible, and any one of them can be used.

The disadvantages of the conventional method can be overcome by coating, drying, and baking using a mixed solution containing the organic palladium compound because the mixed solution containing the organic palladium compound is a uniform solution, so the component composition is It is uniform and does not partially agglomerate even when dried, and since it is an organic palladium compound when fired, it thermally decomposes and combines with metal components at the atomic level to form a uniform palladium thin film on the substrate. This is because it comes.

In addition, in order to adjust the thickness of the palladium thin film, is it possible to adjust the proportion of the organic palladium compound, adjust the printing conditions, or repeat the coating, drying, and baking operations? This is preferable because it reduces productivity.

Hereinafter, examples related to the present invention will be described, but the examples are not intended to limit the present invention.

(Example 1) 96% alumina substrate (100 squares x 100 lines x thickness 0.6
35mm), palladium neodecanoate (Pd20wt
%) 40wt! %, bismuth 2-ethylhexanoate (B
i 2945) 10wt%, phenolic resin 20
A mixed solution containing an organic palladium compound prepared with 30 wt% of α-terpineol and 30 wt% of α-terpineol was applied by screen printing, dried at room temperature for 10 minutes, heated to 120°C for 10 minutes, and then heated to 800°C for 10 minutes. Bake for 9 minutes
A thin film of palladium with a thickness of 05 μm was formed on a 6% alumina substrate.

(Example 2) Alumina pellets (2 to 3 mm in diameter) were added with 40 wt% of palladium rosinate (20 wt% of Pd) and 20 wt% of ethyl acetate.
A mixed solution containing an organic palladium compound prepared in wt% was applied by dipping, dried for 10 minutes at room temperature,
Next, bake at 830°C for 10 minutes to obtain a thickness of 0.1-02
A palladium thin film with a thickness of μm was formed.

(Example 3) Glass glaze substrate (400 mm x 250 order x 1 mm)
On top, palladium 2-ethylhexanoate (Pd15%)
30wt%, bismuth rosin acid (BilO%) 10wt
%, alkyd resin 15 wt%, α-terpineol 30 wt%, and butylcarpitol 15 wt% A mixed solution containing an organic palladium compound was directly printed with line and space or 50 μm-50 μm fine patterns using intaglio printing, and then heated at room temperature. After drying for 10 minutes, 12
Heat dry at 0°C for 10 minutes, then heat dry at 830°C for 10 minutes.
After firing for a minute, a palladium line-and-space pattern with a film thickness of 0.2 μm or a fine pattern of 70 μm to 30 μm was obtained.

(Effects of the Invention) The present invention can form the lower palladium thin film by a simple method of coating, drying, and baking without using a vacuum device, and has a palladium thickness of 1 μmJ), which could not be obtained with the conventional thick film paste method. The palladium thin film obtained is a dense, uniform film with no pinholes, and has strong adhesion, and depending on the printing conditions, it is possible to directly draw line-and-space or fine patterns of 25-50 μm without etching using intaglio printing. Furthermore, it can be said that the palladium thin film layer can be formed on a complex-shaped substrate using various coating methods, which is economical and extremely effective.

Applicant: Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (3)

[Claims] (1) A mixed solution containing an organic palladium compound, a resin as an organic binder, and an organic solvent is coated on a glass or ceramic substrate, dried, and fired to form a 1-micron layer on the glass or ceramic substrate. A palladium thin film forming method characterized by forming the following palladium thin film. (2) The palladium thin film according to claim 1, wherein the organic palladium compound contains one or more of an organic acid salt of naphthenic acid, abietic acid, stearic acid, neodecanoic acid, decanoic acid, or octanoic acid, or a palladium complex of acetylacetone. Formation method. (3) The palladium thin film forming method according to Claims 1 and 2, wherein the method for applying the mixed solution is selected from screen printing, intaglio printing, planographic printing, spin coating, dipping, brush painting, and stamping.