JPH08333685A - Plating method - Google Patents

Abstract

PURPOSE: To provide a plating method extremely excellent in plating adhesion to a substrate and corrosion resistance and needless of a conventional pretreating process for improving adhesive property. CONSTITUTION: An electroless plated film 5 is formed on the substrate l in an electroless plating solution by degreasing and cleaning the substrate 1 to be plated, forming a metallic sulfide film 3 composed of a metallic sulfide produced by thermally decomposing an organometallic complex containing carbon and sulfur on the substrate 1 and depositing a palladium film 4 on the substrate 1 in an activating solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating method, and particularly to an insulating substrate made of glass, ceramics, plastic, rubber or the like, or an alkaline earth metal such as aluminum or aluminum alloy, titanium, tantalum, The present invention relates to a method for plating a valve action metal substrate such as tungsten.

[0002]

[Industrial application] Conventionally, plating of non-conductive substrates such as glass, ceramics, plastics and rubber has been
The electroless plating method is used because the substrate is not conductive.

When performing electroless plating on a non-conductive substrate as described above, the substrate is thoroughly washed to remove oil and fat on the surface, and then the surface of the substrate is mechanically or chemically etched. The roughened surface enhances the adhesion strength of the plated metal film to the substrate.

For example, when electroless plating is performed on a ceramic substrate, the substrate is thoroughly washed in a washing step to remove oil and fat on the surface. In the surface roughening step, after chemically etching in a borohydrofluoric acid solution to roughen the surface, it is sufficiently washed with water so that hydrofluoric acid does not remain. In the sensitizing process, the tin compound is attached to the surface of the roughened substrate by immersing it in an aqueous solution of tin chloride. In the activation treatment step, the substrate having the tin compound attached to the surface is immersed in an aqueous palladium or platinum / hydrochloric acid solution to replace the tin compound attached to the surface with palladium or platinum having a catalytic action. In the electroless plating step, a substrate having palladium or platinum having a catalytic action attached to the surface is immersed in an electroless plating solution to chemically deposit a metal to be plated on the substrate. Further, when electroplating a conductive substrate such as valve metal such as aluminum, titanium, tantalum, tungsten and alloys of these metals, it is difficult to perform electroplating directly, and electroplating is difficult. Before performing, electroless plating is performed in advance.

The reason for this is that a non-conductive film of aluminum oxide, titanium oxide, tantalum oxide, tungsten oxide or the like is formed on the surface of these valve action metals, and these are used in a plating bath for electroplating. This is because the non-conductive film formed on the surface hinders the flow of electricity even when the metal of (2) is used as a negative electrode and electricity is applied.

When a high negative voltage is applied to these metals and a current is forced to flow, electrolysis of water occurs and a hydrogen gas generating reaction mainly occurs. As a result, at the electrode / plating bath interface, the plating bath becomes alkaline with the generation of hydrogen gas. Since many valve metals have the property of being soluble in alkali, it is difficult for the metal to be plated to deposit. or,
Even if deposited, the adhesion becomes extremely poor.

Therefore, in order to plate such a valve-action metal, a method of depositing a metal such as copper or nickel on the surface of the valve-action metal in advance by electroless plating is used before the electroplating. Has been.

Next, a method for electroless plating of valve metal is described.
An example of plating on aluminum will be described.

In the polishing step, the oxide film formed on the aluminum surface is removed by mechanical polishing or chemical etching. In the sensitizing treatment step, tin chloride is adhered to the aluminum surface from which the oxide film has been removed by immersing it in an aqueous tin chloride solution. In the activation treatment step, the aluminum having tin chloride attached to the surface is immersed in a catalyst solution such as palladium chloride or platinum chloride to replace the tin chloride with the catalyst metal. In the electroless plating step, aluminum having a catalytic metal on the surface is immersed in an electroless plating solution, and the metal to be plated, for example,
Copper, nickel, gold, etc. are deposited on the surface of the aluminum on which the catalyst metal is present. Further, if necessary, electroplating is performed on the electroless plated copper, nickel, gold or the like.

[0010]

However, the configuration of the above-mentioned conventional electroless plating method has a problem that it is necessary to add a step for obtaining adhesion between the plated substrate and the plated metal. .

For example, in the case of a non-conductive substrate made of glass, ceramics, plastic, rubber or the like, there is a problem that a roughening step for mechanically or chemically roughening the surface of the substrate is required.

Further, in the case of a valve action metal substrate such as aluminum, titanium, tantalum, tungsten and alloys of these metals, a non-conductive film removing step of removing a non-conductive film due to a metal oxide existing on the substrate surface. In addition, there is a problem that a sensitizing treatment step of depositing tin chloride on the surface of the substrate from which the non-conductive film has been removed is required.

Further, if any chemicals used for chemical etching in the conventional electroless plating method, such as hydrofluoric acid and nitric acid, remain in the plating film, corrosion from the plating surface is likely to proceed. There is a problem.

The present invention solves the above-mentioned problems, and the adhesion and corrosion resistance of the plating on the substrate are very good, and the pretreatment process for improving the adhesion, which is carried out in the prior art, becomes unnecessary, Moreover, it is an object to provide a plating method capable of pattern plating without a photoresist.

[0015]

In order to solve the above-mentioned problems, the plating method of the first invention of the present application involves degreasing and cleaning the substrate to be plated, and thermally decomposing the organometallic complex containing carbon and sulfur. Forming a metal sulfide film composed of a metal sulfide to be generated on the substrate, depositing a catalyst on the substrate in an activating solution, and electroless plating on the substrate in an electroless plating solution. Characterize.

In the plating method of the first invention of the present application, in order to solve the above problems, the substrate to be plated is glass,
An insulating substrate made of ceramics, plastics, rubber or the like, or a valve action metal substrate of alkaline earth metal such as aluminum or aluminum alloy, titanium, tantalum or tungsten is preferable.

Further, in order to solve the above-mentioned problems, the plating method of the first invention of the present application is such that the organometallic complex containing carbon and sulfur is a metal carbamic acid complex, a metal imidazole complex, a metal thiazole complex or a metal xanthate complex. A single substance or a mixture thereof is preferable.

In order to solve the above-mentioned problems, the plating method of the first invention of the present application is such that the organic metal complex is thermally decomposed by immersing the substrate to be plated in a solution of the organic metal complex and taking out the substrate. It is preferable to heat the substrate to a temperature above the thermal decomposition temperature of the organometallic complex.

In order to solve the above-mentioned problems, the plating method of the first invention of the present application is such that the organic metal complex is pyrolyzed in a vapor of the organic metal complex, and the substrate to be plated is the organic metal complex. It is preferable to heat above the thermal decomposition temperature of.

In order to solve the above-mentioned problems, the plating method of the second invention of the present application involves degreasing and cleaning the substrate to be plated, and removing the metal sulfide generated by thermally decomposing the organometallic complex containing carbon and sulfur. Forming a metal sulfide film on the substrate,
By selectively irradiating the substrate immersed in the electrolytic solution with ultraviolet rays, the metal sulfide film in the ultraviolet irradiation portion is eluted or remains, and the metal sulfide film on the substrate is removed in an activating solution. The catalyst is deposited on the remaining portion, and the portion of the substrate on which the catalyst is deposited is electroless plated.

[0021]

First, the operation of the plating method of the first invention of the present application will be described. In general, many insulating substrates made of glass, ceramics, plastics, rubber, etc. lack hydrophilicity, and tin adheres even after sensitizing treatment in an aqueous solution of tin chloride, which is a conventional electroless plating method. The condition is bad. Therefore, in the conventional electroless plating method, the roughening step of roughening the surface of the insulating substrate is indispensable in order to improve the adhesion.

Further, in the case of a valve action metal substrate such as an alkaline earth metal such as aluminum or aluminum alloy, titanium, tantalum or tungsten, the surface thereof is covered with a metal oxide film. These metal oxide films are electrically insulating and have a large number of fine pores on their surface. For example, in the case of aluminum, a very thin aluminum oxide film having fine pores of a honeycomb structure which does not reach the aluminum substrate exists on the surface thereof. Therefore, when the conventional electroless plating method is performed without removing the oxide film, a sensitizing solution for depositing a tin compound and an activating solution for depositing a catalytic metal remain in the fine pores, and these solutions Is a strong acid with strong corrosiveness, so it becomes a plating with poor corrosion resistance. Therefore, in the conventional electroless plating method, in order to improve the corrosion resistance and obtain the adhesion, the oxide film existing on the surface of the substrate is removed by mechanical polishing or chemical etching. Has become essential.

On the other hand, the plating method of the first invention of the present application is a metal sulfide consisting of a metal sulfide generated by degreasing and cleaning the substrate to be plated and thermally decomposing an organometallic complex containing carbon and sulfur. A film is formed on the substrate.

Then, the thermal decomposition of the organometallic complex is carried out by immersing the substrate to be plated in the solution of the organometallic complex and taking it out, and heating the substrate to a temperature above the thermal decomposition temperature of the organometallic complex. In the vapor of the organometallic complex,
By heating the substrate to be plated to a temperature above the thermal decomposition temperature of the organometallic complex.

As described above, when the metal sulfide film made of the metal sulfide by the thermal decomposition of the organometallic complex is formed on the substrate, the metal sulfide film is heated by the glass, ceramics, plastic, rubber or the like. It adheres firmly to the surface of the insulating substrate that is composed, and also in the fine pores of the oxide film existing on the surface of the valve action metal substrate such as alkaline earth metal such as aluminum and aluminum alloy, titanium, tantalum, and tungsten. It penetrates and adheres firmly, and no harmful corrosive substances remain due to thermal decomposition.

When the metal sulfide film is formed on the substrate, the catalyst can be deposited on the substrate in the activating solution, and further the catalyst can be deposited in the electroless plating solution. Electroless plating can be performed on the substrate on which the catalyst is deposited.

Therefore, according to the plating method of the first invention of the present application, plating having excellent adhesion to the substrate and excellent corrosion resistance can be obtained.

Next, the operation of the plating method of the second invention of the present application will be described.

The operation of the plating method of the second invention of the present application will be demonstrated by the second embodiment described later, and the reason is presumed as follows. That is, many metal sulfide films have the property of an n-type semiconductor or a p-type semiconductor, and when these semiconductors are irradiated with light having energy higher than the band energy, charge separation occurs inside the semiconductor and holes and electrons are generated. appear. When the semiconductor is irradiated with light in the electrolytic solution, n
In the case of a type semiconductor, the generated holes oxidize the semiconductor itself, and the semiconductor is eluted. It is known that this phenomenon is reversed in the case of a p-type semiconductor. Based on these phenomena, when the metal sulfide film is an n-type semiconductor, when the metal sulfide film is immersed in an electrolytic solution and a photomask is applied to irradiate it with ultraviolet rays, the portion of the metal sulfide film irradiated with ultraviolet rays is exposed. Is eluted and the metal sulfide film in the portion not irradiated with ultraviolet rays remains as it is. Therefore, in the case of a metal sulfide film composed of n-type semiconductors such as zinc sulfide and cadmium sulfide, by irradiating ultraviolet rays using a photomask in an electrolytic solution, the metal sulfide film in the portion not irradiated with ultraviolet rays is The product film can be left. When the metal sulfide film is copper sulfide which is a p-type semiconductor, the opposite phenomenon occurs, and the metal sulfide film in the portion irradiated with ultraviolet rays remains.

As described above, electroless plating or electrolytic plating having a desired pattern can be performed according to the shape of the photomask.

Therefore, in the plating method of the second invention of the present application, the substrate to be plated is degreased and washed, and the metal sulfide film composed of the metal sulfide generated by thermally decomposing the organometallic complex containing carbon and sulfur is generated. By selectively irradiating the substrate, which is formed on the substrate and immersed in an electrolytic solution, with ultraviolet rays, the metal sulfide film in the portion irradiated with ultraviolet rays is eluted or remains, and the metal sulfide film on the substrate is exposed in an activating solution. A catalyst is deposited on the portion where the metal sulfide film remains, and the portion where the catalyst is deposited on the substrate is electroless plated.

[0032]

EXAMPLE A first example of the plating method of the present invention will be described with reference to FIG.

In this embodiment, a metal sulfide film is formed on a substrate to be plated using various organometallic complexes containing carbon and sulfur, and then electroless plating and electrolytic plating are performed.

In FIG. 1, reference numeral 1 is a substrate to be plated. As the substrate 1, an insulating substrate 1a made of glass, ceramics, plastic, rubber or the like, and a valve action metal substrate 1b made of aluminum, titanium, tantalum, tungsten or an alloy of these metals can be used. In the case of the valve action metal substrate 1b, the oxide film 2 exists on the surface of the substrate.
In the prior art, the oxide film 2 interferes with the plating and must be removed. However, in this embodiment, the oxide film 2 does not interfere with the plating, but rather has an effect of improving the adhesion of the plating film to the substrate. Since it has, it is plated without removing it. It is preferable, but not essential, to form the oxide film 2 in advance by an anodic oxidation process in order to improve the corrosion resistance and the adhesion.

First, in the degreasing step, the insulating substrate 1a
Alternatively, the valve action metal substrate 1b is degreased with an organic solvent such as CFC.

In the metal sulfide film forming step, the metal sulfide film 3 is formed on the substrate to be plated by using various organic metal complexes containing carbon and sulfur. Examples of various organometallic complexes containing carbon and sulfur include a metal carbamic acid complex represented by the chemical formula (1), a metal imidazole complex represented by the chemical formula (2), a metal thiazole complex represented by the chemical formula (3), and a chemical formula (4). An organic metal complex containing carbon and sulfur, such as a metal xanthate complex, is used.

[0037]

Embedded image

In the chemical formula (1), R ₁ and R ₂ are C
H ₃ group, C ₂ H ₅ group, C ₃ H ₇ group, C ₄ H ₉ group, and other alkyl groups, cycloalkyl group, phenylalkyl group, and all other substitutable groups, each of which is the same or different. Is. In addition, X is an integer of 1 or more, and various metals (M
It is a number equal to the valence of e).

[0039]

Embedded image

In the chemical formula (2), R ₁ , R ₂ , R ₃
Represents an all-substitutable group such as an alkyl group such as a CH ₃ group, a C ₂ H ₅ group, a C ₃ H ₇ group, a C ₄ H ₉ group, a cycloalkyl group, a phenylalkyl group, etc., each of which is the same or different. It is a base. Further, X is an integer of 1 or more, which is a number equal to the valence of various metals (Me).

[0041]

Embedded image

In the chemical formula (3), R ₁ , R ₂ , R ₃
Represents an all-substitutable group such as an alkyl group such as a CH ₃ group, a C ₂ H ₅ group, a C ₃ H ₇ group, a C ₄ H ₉ group, a cycloalkyl group, a phenylalkyl group, etc., each of which is the same or different. It is a base. Further, X is an integer of 1 or more, which is a number equal to the valence of various metals (Me).

[0043]

[Chemical 4]

In the chemical formula (4), R ₁ is CH
₃ groups, C ₂ H ₅ groups, C ₃ H ₇ groups, C ₄ H ₉ groups, and other alkyl groups, cycloalkyl groups, phenylalkyl groups, and other substitutable groups are all represented by the same or different groups. is there. In addition, X is an integer of 1 or more, and various metals (M
It is a number equal to the valence of e).

There are the following two methods for forming the metal sulfide film 3 on the substrate 1 using the organometallic complex.

In the first method, the substrate 1 is immersed in an organic solvent in which a simple substance or a mixture of two or more kinds of these organometallic complexes is dissolved, taken out, and then the substrate 1 is heated and attached. The metal sulfide film 3 is formed by thermally decomposing the above-mentioned organometallic complex and decomposing the metal sulfide.

In this way, since the solution has good wettability, it wets the surface of the insulating substrate 1a and impregnates a large number of micropores existing in the oxide film on the surface of the valve action metal substrate 1b. In this state, the substrate 1 is taken out of the solution and heated to thermally decompose the organometallic complex to form a metal sulfide film. When the metal sulfide film is formed, the metal sulfide film adheres to the insulating substrate 1a by the action of heating. Of the metal sulfide film or the metal sulfide film becomes a metal sulfide film in a state where the metal sulfide penetrates into the fine pores present in the oxide film on the surface of the valve action metal substrate 1b in large numbers. Valve metal substrate 1
The adhesion to b is extremely improved.

As the organic solvent for dissolving the organometallic complex, dimethylformamide (DMF), acetonitrile (ACN), dimethylsulfoxide (DM) can be used.
Although an organic solvent such as SO), xylene, or benzene is used, the solvent is not limited to the organic solvent, and any solvent capable of dissolving the organometallic complex can be used. For example, in the case of the organometallic complex having a hydroxyl group at the terminal group of the complex, an aqueous solvent can be used.

In the second method, a single substance or a mixture of two or more kinds of the above-mentioned organometallic complex is heated to be vaporized, the substrate 1 is placed in the vapor of the organometallic complex, and the substrate 1 is placed in the organometallic complex. By heating above the thermal decomposition temperature of the complex, the metal sulfide film 3 is formed on the surface of the substrate 1.

Also in this case, the adhesion of the metal sulfide film to the insulating substrate 1a is improved by the action of heating,
Alternatively, since the metal sulfide becomes a metal sulfide film in a state in which a large number of fine holes exist in the oxide film on the surface of the valve action metal substrate 1b, the metal sulfide film is applied to the valve action metal substrate 1b. The adhesion is extremely good.

After the metal sulfide film 3 is formed on the substrate 1 as described above, the treatments after the activation treatment step of the conventional electroless plating method are performed. That is, the substrate 1 having the metal sulfide film 3 formed on the surface is immersed in a catalyst solution such as palladium chloride or platinum chloride to form a catalyst film such as a palladium film 4.

In the electroless plating step, the substrate 1 having the palladium film 4 on the surface is immersed in the electroless plating solution and plated with a metal, for example, an electroless plating solution film of copper, nickel, gold or the like. Precipitate 5. Furthermore, if necessary, desired electroplating is performed on the electroless plating film 5.

Electroless plating film 5 obtained by this embodiment
The feature is that the adhesiveness to the substrate 1 is excellent even though there is no roughening step performed in the prior art.

Examples of the case of using various organometallic complexes containing carbon and sulfur will be described below. Examples 1 to 9 of electroless plating and electrolytic plating of the alumina substrate 1a, and titanic acid. Tenth example of performing electroless plating and electrolytic plating on the barium substrate 1a, eleventh example of performing electroless plating and electrolytic plating on the antimony zirconate substrate 1a, and electroless plating on the valve action metal substrate 1b. Twelfth to fourteenth examples in the case of performing plating and electrolytic plating, fifteenth example in the case of performing electroless plating and electrolytic plating on the amorphous ceramics substrate 1a, and electroless plating and electrolytic plating on the plastic substrate 1a. Examples 16 to 18 in the case of performing the above, Example 19 in the case of performing electroless plating and electrolytic plating in the alumina substrate 1a, and Cases of performing the electroless plating and electrolytic plating in the antimony zirconate substrate 1a Second
It will be described based on FIG. 1 separately for 0 to 26 examples.

The first example is a substrate 1a made of ceramics mainly composed of alumina and having a thickness of 1 mm, a width of 1 cm and a length of 2 cm.
Is used to clean the substrate 1a with a chlorofluorocarbon cleaning agent, and subsequently, in a metal sulfide film forming step without roughening treatment, copper / dimethyldithiol represented by the chemical formula (5) is used. The substrate 1a was immersed in an organic solution in which 0.5 mol of a carbamic acid complex was dispersed and dissolved in xylene for 15 minutes, taken out, dried at 150 ° C., and then heated in an oven at 350 ° C. for 30 minutes to form copper sulfide. A metal sulfide film 3 mainly composed of is formed on the substrate 1a.

[0056]

Embedded image

Thereafter, the conventional electroless plating treatment was performed. That is, in the activation process step, 1 × 10
^-Metal sulfide film 3 in ³ molar palladium chloride / hydrochloric acid solution 3
The substrate 1a on which the substrate has been formed is dipped, the palladium film 4 is attached to the surface of the substrate 1a, and in the electroless plating process, it is dipped in an electroless copper plating solution (trade name: OPC copper) manufactured by Okuno Chemical Co., Ltd. for 15 minutes. Then, electroless copper plating was performed, and copper was electrolytically deposited on the deposited electroless copper plating in an electrolytic plating solution containing copper pyrophosphate to a thickness of about 10 μm.

A tensile strength test was conducted to investigate the adhesion strength of the plated copper to alumina, and a strength of 2.8 kg per 4 mm ² was obtained.

For comparison, a tensile strength test was carried out when the conventional electroless copper plating and electrolytic copper plating were performed on the same alumina substrate 1a which had not been roughened, and the results were obtained. It was 0.09 kg, and it was confirmed that this example obtains excellent adhesion strength without roughening treatment.

In this embodiment, the electroless plating process of the prior art is performed from the activating process step. However, the same result can be obtained by inserting the sensitizing process step before the activating process step. Is obtained.

[0061] The second example, in the first example, but using a zinc di-methyl di thiocarbamate complex instead of copper di-methyl di thiocarbamate complex to form a zinc sulfide layer 3, 4 mm ² per A strength of 2.5 kg was obtained.

[0062] third example, in the first example, which was in place of copper di-methyl di thiocarbamate complex using cadmium di-methyl di thiocarbamate complex to form a cadmium sulfide film 3, 4 mm ² per A strength of 2.6 kg was obtained.

[0063] The fourth example, in the first example, made by forming a copper-di-methyl di thiocarbamate tin sulfide film 3 using tin di-methyl di thiocarbamate complex instead of the complex, 4 mm ² per A strength of 2.3 kg was obtained.

[0064] The fifth example, in the first example, in which instead of the copper-di-methyl di thiocarbamate complex using copper-Dieci Rudy thiocarbamate complex to form copper sulfide film 3, 4 mm ² per 2 A strength of 0.0 kg was obtained.

[0065] Example 6 is a first example, in which copper is used di-butyl di thiocarbamate complex instead of copper di-methyl di thiocarbamate complex to form a copper sulfide film 3, 4 mm ² per A strength of 2.0 kg was obtained.

[0066] Example 7 is a first example, which was in place of copper di-methyl di thiocarbamate complex using copper-ethylphenyl di thiocarbamate complex to form a copper sulfide film 3, 4 mm ² per A strength of 2.7 kg was obtained.

The eighth example is the first example, in which copper dibenzyldithiocarbamate is used instead of the copper-dimethyldithiocarbamate complex to form the copper sulfide film 3.
A strength of 2.4 kg per 4 mm ² was obtained.

[0068] Example 9 is a first example, those using n- pentamethylene di thiocarbamate copper instead of copper di-methyl di thiocarbamate complex to form copper sulfide film 3, 4 mm ² per A strength of 2.4 kg was obtained.

The tenth example is the first example, which uses ceramics mainly containing barium titanate instead of ceramics mainly containing alumina, and a strength of 2.7 kg per 4 mm ² was obtained. For comparison, a tensile strength test was performed when copper plating was performed with the conventional electroless copper plating and electrolytic copper plating on the same barium titanate substrate 1a that had not been surface-roughened. The result is 0.1 kg
Therefore, it was confirmed that this example can obtain excellent adhesion strength without roughening treatment.

The eleventh example is the first example, in which ceramics mainly containing antimony zirconate was used instead of ceramics mainly containing alumina, and a strength of 1.9 kg per 4 mm ² was obtained. For comparison, a tensile strength test was performed when copper plating was performed on the same antimony zirconate substrate 1a that had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. The result is 0.
It was 1 kg, and it was confirmed that this example obtains excellent adhesion strength without roughening treatment.

In the twelfth example, instead of the ceramics containing alumina as the first example, a thickness of 1 mm made of aluminum is used.
A substrate 1b having a width of 1 cm and a length of 2 cm was used, and the substrate 1b was washed with a chlorofluorocarbon cleaning agent in the washing step without roughening the surface, and then in a 1N sulfuric acid solution in the anodizing step. A direct current voltage of 10 V is applied to form aluminum oxide on the aluminum surface, and the substrate 1b is added to dimethylformamide containing 1 mol of the copper-dimethyldithiocarbamic acid complex in the step of forming a metal sulfide film. It was immersed in the substrate for 1 minute, taken out, dried at 150 ° C., and then heated in an oven at 350 ° C. for 30 minutes to form a metal sulfide film 3 mainly containing copper sulfide on the substrate 1b.

Thereafter, the conventional electroless plating treatment was performed. That is, in the activation process step, 1 × 10
^-Metal sulfide film 3 in ³ molar palladium chloride / hydrochloric acid solution 3
Immersing the substrate 1b having formed thereon, depositing the palladium film 4 on the surface of the substrate 1b, and immersing it in an electroless copper plating solution (trade name: OPC copper) manufactured by Okuno Chemical Industries for 15 minutes in the electroless plating process. Then, electroless copper plating was performed, and copper was electrolytically deposited on the deposited electroless copper plating in an electrolytic plating solution containing copper pyrophosphate to a thickness of about 10 μm.

A tensile strength test was conducted to examine the adhesion strength of plated copper to alumina, and a strength of 2.5 kg per 4 mm ² was obtained.

For comparison, the same aluminum substrate 1b is used.
After forming aluminum oxide in the anodizing process on the
A tensile strength test was carried out when copper plating was performed using conventional electroless copper plating and electrolytic copper plating. The result was 0.
It was 03 kg, and it was confirmed that this example obtains excellent adhesion strength without roughening treatment.

Further, in order to examine the corrosion resistance, an ASTM test was conducted on an aluminum plate plated with copper in this example and the conventional example. In this test, a 5% sodium chloride solution adjusted to pH 3.2 with acetic acid was used as a test solution.
A salt fog test with this solution was performed at 60 ° C. As a result, after 250 hours, no corrosion was observed in the aluminum plate of this example, but significant pitting was observed in the aluminum plate of the conventional example.

The thirteenth example is the first example, in which the titanium substrate 1b is used instead of the ceramics mainly containing alumina, and a strength of 2.5 kg per 4 mm ² was obtained.

For comparison, a tensile strength test is conducted in the case where titanium oxide is formed on the same titanium substrate 1b by an anodic oxidation process, and then copper plating is performed using conventional electroless copper plating and electrolytic copper plating. However, the result was 0.02 kg, and it was confirmed that this example obtains excellent adhesion strength without roughening treatment.

The fourteenth example is the first example, in which the tungsten substrate 1b is used instead of the ceramics mainly containing alumina, and a strength of 1.7 kg per 4 mm ² was obtained.

For comparison, the same tungsten substrate 1b is used.
A tensile strength test was performed when copper was plated with conventional electroless copper plating and electrolytic copper plating after titanium oxide was formed by an anodizing process on the surface, and the result was 0.02 k.
It was confirmed that this example obtained excellent adhesion strength without roughening treatment.

The fifteenth example is the first example, in which an amorphous ceramics substrate 1a mainly made of lead glass is used instead of the ceramics substrate 1a mainly made of alumina.
A strength of 3.1 kg per mm ² was obtained.

For comparison, an amorphous ceramic substrate 1a mainly made of the same lead glass which has not been roughened.
A tensile strength test was performed when copper plating was performed on the above electroless copper plating and electrolytic copper plating of the prior art. The result was 0.6 kg, and this example is excellent without roughening treatment. It was confirmed that good adhesion strength was obtained.

The sixteenth example uses a substrate 1a made of polypropylene made of plastic and having a thickness of 1 mm, a width of 1 cm and a length of 2 cm, and the substrate 1a is subjected to a cleaning process without a roughening treatment. In a metal sulfide film forming step, the substrate 1a is immersed in 0.05 mol of a copper-methyl-ethylhydroxyldithiocarbamic acid complex / DFM solvent for 10 minutes and taken out, and the temperature is set to 100 ° C. By heating in an oven for 30 minutes, a metal sulfide film 3 mainly containing copper sulfide was formed on the substrate 1a.

Thereafter, the conventional electroless plating treatment was performed. That is, in the activation process step, 1 × 10
^-Metal sulfide film 3 in ³ molar palladium chloride / hydrochloric acid solution 3
The substrate 1a on which the substrate has been formed is dipped, the palladium film 4 is attached to the surface of the substrate 1a, and in the electroless plating process, it is dipped in an electroless copper plating solution (trade name: OPC copper) manufactured by Okuno Chemical Co., Ltd. for 15 minutes. Then, electroless copper plating was performed, and copper was electrolytically deposited on the deposited electroless copper plating in an electrolytic plating solution containing copper pyrophosphate to a thickness of about 10 μm.

A tensile strength test was conducted to examine the adhesion strength of plated copper to alumina, and a strength of 1.8 kg per 4 mm ² was obtained.

For comparison, the same polypropylene substrate 1
Without roughening the surface of a, a tensile strength test was performed when copper plating was performed using conventional electroless copper plating and electrolytic copper plating. The result was 0.1 kg, and the result was 0.1 kg. It was confirmed that the example obtained excellent adhesion strength without roughening treatment.

The seventeenth example uses a substrate 1a made of a plastic made of a polycarbonate resin instead of the polypropylene of the sixteenth example and having a thickness of 1 mm, a width of 1 cm and a length of 2 cm, and has a strength of 2.5 kg per 4 mm ^2. Got

For comparison, a tensile strength test was conducted when copper plating was performed on the same polycarbonate resin substrate 1a which had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. The result was 0.07 kg, and it was confirmed that this example obtains excellent adhesion strength without roughening treatment.

[0088] Example 18 is obtained by using a substrate 1a of the first 16 patients plastic thickness 1 mm × width 1 cm × length 2cm consisting of vinyl chloride resin in place of the polypropylene, of 4 mm ² per 1.7kg Gained strength.

For comparison, a tensile strength test was conducted on the same vinyl chloride resin substrate 1a which had not been surface-roughened by the conventional electroless copper plating and electrolytic copper plating. The result was 0.09 kg, and it was confirmed that this example obtains excellent adhesion strength without roughening treatment.

The nineteenth example uses a copper-2 mercaptomethylbenzimidazole complex in place of the copper-dimethyldithiocarbamic acid complex of the first example.
A strength of 2.5 kg per ² was obtained.

For comparison, a tensile strength test was carried out when copper plating was performed on the same alumina substrate 1a which had not been roughened by the conventional electroless copper plating and electrolytic copper plating. The result was 0.2 kg, and it was confirmed that this example obtains excellent adhesion strength without roughening treatment.

The twentieth example uses a zinc / 2-mercaptomethylbenzimidazole complex instead of the copper / dimethyldithiocarbamic acid complex of the eleventh example.
A strength of 2.3 kg per mm ² was obtained.

For comparison, a tensile strength test was conducted when copper plating was performed on the same antimony zirconate substrate 1a which had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. However, the result is 0.1 kg,
It was confirmed that this example can obtain excellent adhesion strength without roughening treatment.

In the 21st example, a tin / 2mercaptomethylbenzimidazole complex was used in place of the zinc / 2mercaptomethylbenzimidazole complex of the 20th example, and a strength of 2.7 kg per 4 mm ² was obtained.

For comparison, a tensile strength test was carried out when copper plating was performed on the same antimony zirconate substrate 1a which had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. However, the result is 0.3 kg,
It was confirmed that this example can obtain excellent adhesion strength without roughening treatment.

In the 22nd example, a copper / mercaptobenzothiazole complex was used in place of the copper / dimethyldithiocarbamic acid complex of the 11th example, and a strength of 2.6 kg per 4 mm ² was obtained.

For comparison, a tensile strength test was conducted when copper plating was performed on the same antimony zirconate substrate 1a which had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. However, the result is 0.2 kg,
It was confirmed that this example can obtain excellent adhesion strength without roughening treatment.

In the twenty-third example, a zinc-mercaptobenzothiazole complex was used in place of the copper-dimethyldithiocarbamic acid complex of the eleventh example, and a strength of 2.7 kg per 4 mm ² was obtained.

For comparison, a tensile strength test was carried out when copper plating was performed on the same antimony zirconate substrate 1a which had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. However, the result is 0.3 kg,
It was confirmed that this example can obtain excellent adhesion strength without roughening treatment.

In the 24th example, a tin-mercaptobenzothiazole complex was used in place of the copper-dimethyldithiocarbamate complex of the 11th example, and a strength of 2.0 kg per 4 mm ² was obtained.

For comparison, a tensile strength test was carried out when copper plating was performed on the same antimony zirconate substrate 1a which had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. However, the result is 0.1 kg,
It was confirmed that this example can obtain excellent adhesion strength without roughening treatment.

The 25th example uses a zinc-isopropylzanthate complex instead of the copper-dimethyldithiocarbamic acid complex of the 11th example, and a strength of 2.7 kg per 4 mm ² was obtained.

For comparison, a tensile strength test was conducted when copper plating was performed on the same antimony zirconate substrate 1a which had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. However, the result is 0.2 kg,
It was confirmed that this example can obtain excellent adhesion strength without roughening treatment.

The 26th example uses a copper-butyl xanthate complex in place of the copper-dimethyldithiocarbamic acid complex of the 11th example, and is 2.7 kg per 4 mm ^2.
Gained strength.

For comparison, a tensile strength test was conducted when copper plating was performed on the same antimony zirconate substrate 1a which had not been surface-roughened by conventional electroless copper plating and electrolytic copper plating. However, the result is 0.1 kg,
It was confirmed that this example can obtain excellent adhesion strength without roughening treatment.

In the first embodiment, the organometallic complex is used alone to obtain a metal sulfide film of a single metal. However, the organometallic complex is mixed and used, and the sulfides of different metals are mixed. Similar results can be obtained by forming the metal sulfide film.

Next, a second embodiment of the plating method of the present invention will be described with reference to FIG.

In this example, various organic metal complexes containing carbon and sulfur were used to form a metal sulfide film on a substrate to be plated in the same manner as in the first example, and then the substrate was electrolyzed. Irradiate ultraviolet rays by applying a photomask in, elute or leave the metal sulfide film in the portion irradiated with the ultraviolet ray, electroless plating only the portion where the metal sulfide film remains, electrolysis It is a plating process.

The present example demonstrates that the above is possible, and the reason is estimated as follows.
That is, many of the metal sulfide films have the property of an n-type semiconductor or a p-type semiconductor. When these semiconductors are irradiated with light that gives energy higher than the band energy, holes and electrons are generated inside the semiconductor due to charge separation. appear. When the semiconductor is irradiated with light in the electrolytic solution, in the case of an n-type semiconductor, the generated holes oxidize the semiconductor itself, and the oxidized semiconductor is eluted depending on the pH value of the electrolytic solution.
In the case of type semiconductors, this phenomenon is known to be reversed. Based on these phenomena, when the metal sulfide film is an n-type semiconductor, when the metal sulfide film is immersed in an electrolytic solution and a photomask is applied to irradiate it with ultraviolet rays, the portion of the metal sulfide film irradiated with ultraviolet rays is exposed. Is eluted and the metal sulfide film in the portion not irradiated with ultraviolet rays remains as it is. Therefore, in the case of a metal sulfide film composed of n-type semiconductors such as zinc sulfide and cadmium sulfide, by irradiating with ultraviolet rays using a photomask in an electrolytic solution, the metal sulfides in the non-ultraviolet rays are irradiated. The membrane can remain.
When the metal sulfide film is copper sulfide which is a p-type semiconductor, the opposite phenomenon occurs, and the metal sulfide film in the portion irradiated with ultraviolet rays remains.

As described above, electroless plating or electrolytic plating can be performed only on a desired pattern according to the shape of the photomask.

An example of using various organometallic complexes containing carbon and sulfur is shown in FIG. 1 as a first to third example of electroless plating and electrolytic plating on the alumina substrate 1a. It will be explained based on.

In the first example, a substrate 1a made of ceramics mainly composed of alumina and having a thickness of 0.5 mm × a width of 3 cm × a length of 5 cm is used, and the substrate 1a is washed with a chlorofluorocarbon cleaning agent in a washing step, Then, in the step of forming a metal sulfide film without performing a roughening treatment, the substrate was immersed in an organic solution in which 0.05 mol of a zinc-dimethyldithiocarbamic acid complex was dispersed and dissolved in dimethylformamide (DMF). 1a was soaked for 15 minutes, taken out, and heated in an oven at 300 ° C. for 30 minutes to form a metal sulfide film 3 which is an n-type semiconductor mainly containing zinc sulfide on the substrate 1a.

A stainless steel photomask was applied to the ceramics substrate 1a, and the ceramics substrate 1a was immersed in a sulfuric acid acidic solution having a pH of 6.0 and irradiated with ultraviolet rays for 10 minutes. Then, the ceramics substrate 1a was taken out from the sulfuric acid solution and washed with water.
A conventional electroless plating process was performed. That is, the substrate 1 on which the metal sulfide film 3 is formed in a 1 × 10 ⁻³ mol palladium chloride / hydrochloric acid solution in the activation treatment step.
a, and a palladium film 4 is attached to the surface of the substrate 1a. In the electroless plating step, the electroless copper plating is performed by immersing the palladium film 4 in an electroless copper plating solution (trade name: OPC Copper) manufactured by Okuno Chemical Co., Ltd. for 15 minutes. Further, copper was electrolytically deposited on the deposited electroless copper plating in an electrolytic plating solution containing copper pyrophosphate to a thickness of about 10 μm.

As a result, copper could not be deposited on the UV-irradiated portion, and copper could be deposited only on the UV-irradiated portion.

The second example is the first example, in which zinc / dimethyldithiocarbamic acid complex / dimethylformamide (D
Instead of MF), a cadmium-dimethyldithiocarbamic acid complex / dimethylformamide (DMF) was used to form a cadmium sulfide film which is an n-type semiconductor. No copper was deposited on the irradiated part, and copper could be deposited only on the part not irradiated with ultraviolet rays.

The third example differs from the first and second examples in that
A p-type semiconductor was formed on the surface of the substrate. First, an organic solution prepared by dissolving 0.05 mol of a copper-dimethyldithiocarbamic acid complex in dimethylformamide (DMF) was used, and a copper sulfide film that was a p-type semiconductor was formed on the substrate surface in the same manner as in the first example. The substrate was formed, and the surface thereof was plated with copper in the same manner as in the first and second examples.

As a result, contrary to the first and second examples,
Copper was not deposited on the portions other than the UV irradiation portion, and copper could be deposited only on the UV irradiation portion.

[0118]

The plating method of the present invention uses at least one metal-organic sulfide complex and thermally decomposes the metal-organic sulfide complex to form a metal composed of a sulfide of a single metal or a plurality of metals. Sulfide film, glass, ceramics,
Before forming an insulating substrate such as plastic or rubber or a valve action metallic substrate such as aluminum, titanium, tantalum, tungsten and alloys of these metals to improve the adhesion, which is performed in the prior art. It is possible to perform electroless plating and electrolytic plating that require no treatment step and have excellent adhesion and corrosion resistance of the plating to the substrate.

When the plating method of the present invention is used for a plastic molded product, a metal substitute decorative part having good durability,
For example, there is an effect that interior parts of a car can be obtained.

After forming a metal sulfide film on the substrate to be plated, the substrate is exposed to ultraviolet light by applying a photomask in an electrolytic solution, and the portion of the metal sulfide exposed to the ultraviolet light is exposed. This has the effect that the material film can be eluted or left, and only the portion where the metal sulfide film remains can be electrolessly plated or electrolytically plated.

When the patterned plating film obtained on the substrate is used as an electrode or an electronic circuit of a ceramic capacitor, the adhesion and corrosion resistance of the plating film are excellent, so that extremely stable electric characteristics can be obtained. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a plating film obtained by using the plating method of the present invention.

[Explanation of symbols]

 1 Substrate 1a Insulating Substrate 1b Valve Metallic Substrate 2 Oxide Film 3 Metal Sulfide Film 4 Palladium Film 5 Electroless Plating Film

Claims (6)

[Claims] 1. A substrate to be plated is degreased and washed, and a metal sulfide film made of a metal sulfide generated by thermally decomposing an organometallic complex containing carbon and sulfur is formed on the substrate.
A plating method comprising depositing a catalyst on the substrate in an activating solution and electroless plating the substrate in an electroless plating solution. 2. The substrate to be plated is an insulating substrate made of glass, ceramics, plastic, rubber or the like, or a valve action of an alkaline earth metal such as aluminum or aluminum alloy, titanium, tantalum or tungsten. The plating method according to claim 1, wherein the plating method is a metal substrate. 3. The plating method according to claim 1, wherein the organic metal complex containing carbon and sulfur is a metal carbamic acid complex, a metal imidazole complex, a metal thiazole complex, a metal xanthate complex, or a mixture thereof. 4. The thermal decomposition of the organometallic complex is carried out by immersing the substrate to be plated in a solution of the organometallic complex and taking out the substrate.
The plating method according to claim 1, wherein the substrate is heated to a temperature equal to or higher than the thermal decomposition temperature of the organometallic complex. 5. The plating method according to claim 1, wherein the thermal decomposition of the organometallic complex is performed by heating the substrate to be plated at a temperature not lower than the thermal decomposition temperature of the organometallic complex in the vapor of the organometallic complex. . 6. A substrate to be plated is degreased and washed, and a metal sulfide film made of a metal sulfide generated by thermally decomposing an organometallic complex containing carbon and sulfur is formed on the substrate.
By selectively irradiating the substrate immersed in the electrolytic solution with ultraviolet rays, the metal sulfide film in the ultraviolet irradiation portion is eluted or remains, and the metal sulfide film on the substrate is removed in an activating solution. A plating method, characterized in that a catalyst is deposited on the remaining portion and the portion of the substrate on which the catalyst is deposited is electrolessly plated.