JP2008075121A - Method for coating base material and surface coated base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for coating a base material capable of coating a base material weak to heat with a metal film made of at least one metal, a metal film made of two or more kinds of metals (including a metal film in which two or more kinds of metals are alloyed and a metal film in which two or more kinds of metals are made hybrid) and a metal film in which a metal oxide is incorporated therein at a low cost without applying a load on the environment. <P>SOLUTION: The method for coating a base material comprises: a sticking stage S1 where, using a dispersed liquid in which the particulates of a metal oxide in which a metal element(s) composing the film is oxidized are dispersed into a liquid, the particulates are stuck to the surface of the base material; and a plasma treatment stage S2 where the base material stuck with the particulates is subjected to plasma treatment. In the plasma treatment stage S2, a reaction gas including a reducing gas is introduced into a plasma region generated by discharge, and the particulates are reduced, so as to be a metal film composed of the above metal element(s), and the surface of the base material is coated with the metal film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate coating method and a surface-coated substrate, and more particularly to a substrate coating method and a surface-coated substrate in which a metal film is coated on a substrate using plasma.

  In recent years, a metal film made of one or more metals on the surface of a base material comprising a metal material such as aluminum or copper, a ceramic material such as glass or silicon, or an organic material such as fiber, wood or synthetic resin ( Attempts have been made to impart a function not found in the base material, for example, by coating a metal film containing a metal oxide or a metal film made of an alloy.

  For example, aluminum and aluminum alloys (hereinafter collectively referred to as “aluminum etc.”) are used as a heat sink material (heat sink) for semiconductor elements, but it is possible to solder a semiconductor directly to an aluminum heat sink. Since it is difficult, processing such as pressing is performed after a copper metal film is coated, and a heat sink with a semiconductor attached thereto is manufactured.

  Further, in a semiconductor device, a copper-based composite base material is used for wiring or the like, but in order to facilitate electrical connection, a coating layer made of tin or a tin-based alloy on the surface of a copper base material or a copper alloy base material ( In general, a metal coating is formed. Here, the copper-based composite substrate is not only pure copper but also various copper alloys, specifically, for example, Cu—Fe—P alloy, Cu—Ni—Si alloy, Cu—Cr—Zr alloy, Cu -The surface of a substrate made of various copper and copper alloys such as a Zn-based alloy and Cu-Sn-based alloy (hereinafter also referred to as a copper-based substrate) is tinned by a method such as electroplating, electroless plating or hot dipping. Alternatively, a metal film made of a tin-based alloy is formed. Furthermore, copper or copper alloy plates with high thermal conductivity are usually used for lead frames and heat sinks using copper base materials, and Ni plating to prevent discoloration is provided on the surface as needed. It may be given.

There are various methods for coating such a metal coating on a substrate.
For example, in addition to so-called dry processing methods such as chemical vapor deposition (CVD), physical vapor deposition (PVD) sputtering, and processing using a chemical reaction by plasma, There is a so-called wet process such as a plating process or a sol-gel method.

  As a method by dry treatment, a sputtering method is widely used industrially. In the sputtering method, a metal film is formed (coated) on a substrate by knocking out a target having a desired chemical composition with argon gas or oxygen gas in a vacuum vessel.

Recently, in order to obtain a uniform metal film at a high speed and in a large area, a processing method using a chemical reaction by plasma is being studied.
As a processing method using a chemical reaction by plasma, use of plasma CVD generated by a plasma CVD apparatus has been studied.
A general plasma CVD apparatus includes a parallel plate type electrode in a reaction vessel, applies high frequency power or DC power to one electrode, and generates plasma by generating plasma between the other electrode grounded. A reactive gas is supplied into the plasma, and the reactive gas is decomposed by the plasma to coat a desired metal film on the substrate.

Further, for example, Patent Document 1 proposes a plasma CVD apparatus having a rotating electrode. According to this plasma CVD apparatus, it is possible not only to obtain a metal film having desired characteristics without damaging the film-formed surface, but also to generate plasma at 1 atm or higher, and to generate a uniform film. A metal film can be obtained at high speed and in a large area.
Furthermore, in recent years, as in Non-Patent Document 1, for example, an atmospheric pressure CVD method using a thermal reaction that covers a low vapor pressure has been reported.

  On the other hand, a plating process is widely used as a wet process. The plating process is to deposit a metal from a liquid layer to form a metal film, and is generally performed in order to prevent corrosion and improve the wettability of solder.

  In addition, a metal film is generally formed by a sol-gel method using a metal oxide containing a metal element constituting the film. In the sol-gel method, a metal oxide containing a metal element constituting a film is applied to a substrate in a sol state, and then fired at a high temperature to form a metal film in a gel state.

  As a method by so-called wet treatment, for example, a method of baking after coating a metal oxide particle containing a metal element constituting a film mixed with a binder, and also described in, for example, Patent Document 2 Thus, there is a method of forming a copper film on a base material such as aluminum. In the method described in Patent Document 2, copper chloride powder is attached to a base material such as aluminum coated with a polybutene solution, and heated at a predetermined heating rate and a predetermined heating temperature. A copper film is formed on the substrate.

JP-A-9-104985 Japanese Patent No. 1658085 Journal of the Ceramic Society of Japan, 105, p.551 (1997)

However, the conventional techniques for coating a metal film on a substrate have the following problems.
(1) In film formation by sputtering, the film formation speed is naturally limited because it is governed by a so-called sputtering phenomenon in which atoms on the surface of the target are knocked out by accelerated ions. Also, the target is very expensive when the substrate is large or when a special material is used as the target. Furthermore, the sputtering apparatus itself for performing sputtering is also large, and in order to obtain a high-quality metal film, it is necessary to use an expensive vacuum pump for making the inside of the vacuum vessel an ultra-high vacuum. However, there is a problem that the cost becomes high in combination with low productivity.

  (2) In general plasma CVD apparatus, in order to reduce the cost, it is necessary to increase the deposition rate of the metal film, increase the area, etc., and in order to deposit a uniform thin film with a large area at high speed. It is necessary to supply the reaction gas uniformly and efficiently to the plasma space. However, when high-speed film formation is performed with the concentration of the reaction gas increased, the gap between the electrodes becomes narrower as the pressure increases, and the gas supply to the plasma space becomes non-uniform. It is extremely difficult to form a film at a high speed. In addition, if the applied power is increased to increase the deposition rate of the metal coating and the deposition rate is improved, excessive high energy generated in the plasma will damage the deposited metal coating. There is a problem that it is difficult to obtain a metal film having desired characteristics.

  (3) The plasma CVD apparatus described in Patent Document 1 includes a raw material for forming a metal coating when a metal coating such as titania or zircon, or a metal oxide such as silver or aluminum is formed. Although it is necessary to vaporize by heating a solid or liquid material, generally, such a raw material has a problem that the film forming speed becomes very slow because of low vapor pressure. In addition, many of the raw materials for forming the metal coating have a problem that they are not toxic or explosive like trimethylaluminum and are not suitable for industrial use for mass production.

  (4) In the method according to Non-Patent Document 1, since the energy necessary for forming the metal coating is given in the form of thermal energy, the reaction temperature is generally high, and the properties of the substrate to be treated are changed by heat. was there. Therefore, there is a problem that the method cannot be applied to a base material such as a steel plate, glass, or plastic that is vulnerable to heat.

(5) The process for performing the plating process is complicated. Specifically, it is necessary to repeat etching and washing with various acids and alkalis many times, and the treatment uses a strong acid or strong alkaline chemical solution. There was a problem that a great deal of cost was required.
(6) The sol-gel method needs to be fired at a high temperature, and there is a problem that an organic component contained in the sol remains and a high-purity film cannot be obtained.

(7) The method of baking after coating the metal oxide particles containing the metal element constituting the coating in a binder generally has poor adhesion and poor durability due to the binder. It was.
(8) The copper film formed by the method described in Patent Document 2 may react with moisture and chlorine in the atmosphere in which it is used, causing the substrate to corrode easily and fail to obtain the desired effect. It was.

  The present invention has been made in view of these problems, and does not place a burden on the environment on a base material that is vulnerable to heat or a base material that may change its internal structure or properties when heated. Metal coating made of one kind of metal, metal coating made of two or more metals (metal film made by alloying two or more metals, hybrid of two or more metals (hybrid) It is an object of the present invention to provide a method for coating a substrate and a surface-coated substrate that can be coated with a metal coating containing a metal oxide).

  The substrate coating method according to the present invention includes an attaching step of attaching the fine particles onto the substrate using a dispersion in which fine particles of a metal oxide in which a metal element constituting the film is oxidized is dispersed in a liquid, A plasma treatment step of plasma-treating the substrate on which the fine particles are adhered, wherein the plasma treatment step introduces a reactive gas containing a reducing gas into a plasma region generated by discharge. Is reduced to form a metal film composed of the metal element, and the metal film is coated on the base material.

  In the method for coating a substrate according to the present invention, by performing such a treatment in the plasma treatment step, a metal film made of a metal element constituting the film can be coated on the substrate.

  The substrate coating method according to the present invention includes an attaching step of attaching the fine particles onto the substrate using a dispersion in which fine particles of a metal oxide in which a metal element constituting the film is oxidized is dispersed in a liquid, A plasma treatment step of plasma-treating the substrate on which the fine particles are adhered, wherein the plasma treatment step introduces a reactive gas containing a reducing gas into a plasma region generated by discharge. By reducing the outermost surface, a metal oxide film in which the fine particles are bonded with the reduced metal element is formed, and the metal oxide film is coated on the substrate.

  The substrate coating method according to the present invention is a metal oxidation in which fine particles are bonded with the reduced metal element by reducing the outermost surface of the metal oxide fine particles by performing such treatment in the plasma treatment step. A physical coating can be coated on the substrate.

  The base material coating method according to the present invention includes an adhesion step in which the fine particles are deposited on the base material using a dispersion in which two or more kinds of metal oxide fine particles in which a metal element constituting the film is oxidized are dispersed in a liquid. And a plasma processing step of plasma-treating the substrate to which the fine particles are adhered, wherein the plasma processing step introduces a reactive gas containing a reducing gas into a plasma region generated by discharge. The fine particles are reduced to form a metal film formed by alloying two or more kinds of the metal elements, and the metal film is coated on the base material.

  The substrate coating method according to the present invention can coat a metal film, which is an alloy of metal elements constituting different types of films, on the substrate by performing such treatment in the plasma treatment process. .

  The base material coating method according to the present invention includes an adhesion step in which the fine particles are deposited on the base material using a dispersion in which two or more kinds of metal oxide fine particles in which a metal element constituting the film is oxidized are dispersed in a liquid. And a plasma processing step of plasma-treating the substrate to which the fine particles are adhered, wherein the plasma processing step introduces a reactive gas containing a reducing gas into a plasma region generated by discharge. And reducing the outermost surface of the fine particles to alloy two or more kinds of the metal elements and to form a metal oxide film in which the fine particles are bonded to each other by the alloyed metal elements. It is characterized in that the metal oxide film is coated.

  The substrate coating method according to the present invention includes two types by reducing the outermost surface of metal oxide fine particles of metal elements constituting different types of coatings by performing such treatment in the plasma treatment step. In addition to alloying the above metal elements, a metal oxide film in which fine particles are bonded to each other by the alloyed metal element can be coated on the substrate.

  The substrate coating method according to the present invention includes an adhesion step in which the fine particles are deposited on a metal substrate using a dispersion in which fine particles of a metal oxide in which a metal element constituting the coating is oxidized is dispersed in a liquid. And a plasma processing step of plasma-treating the substrate to which the fine particles are adhered, wherein the plasma processing step introduces a reactive gas containing a reducing gas into a plasma region generated by discharge. By reducing the fine particles, a metal film is formed by alloying a part of the metal base material with the metal element, and the metal film is coated on the metal base material. It is characterized by.

  The base material coating method according to the present invention includes a part of the base material by reducing the metal oxide fine particles in which the metal element constituting the coating is oxidized by performing such a treatment in the plasma processing step. A metal film formed by alloying a metal element can be coated on the substrate.

In the substrate coating method according to the present invention, it is preferable that the pressure in the plasma region is a pressure near atmospheric pressure, and the plasma generated in the plasma region is generated by glow discharge.
As described above, since the method for coating a substrate according to the present invention may be such that the pressure in the plasma region may be close to atmospheric pressure, an expensive vacuum vessel or vacuum pump is not required, and the operation for adjusting the pressure is omitted. Can be combined in-line with a wet process such as acid cleaning and degreasing before treatment. In addition, since plasma generated by glow discharge can be used, it is possible to prevent damage to the substrate due to arcing or the like and non-uniform coating. In addition, since the substrate is subjected to plasma treatment using plasma generated by glow discharge near atmospheric pressure, a large area and uniform metal film can be formed on the substrate at a high film formation rate. Further, by performing such plasma treatment, the substrate can be continuously subjected to plasma treatment.

In the substrate coating method according to the present invention, it is preferable that the reducing gas contains at least one selected from the group consisting of hydrogen, methane, and carbon monoxide.
In the method for coating a substrate of the present invention, by using these reducing gases, the metal element constituting the coating can be suitably reduced and the metal coating can be coated on the substrate.

In the substrate coating method according to the present invention, the average particle size of the fine particles is preferably 100 nm or less.
By using fine particles having such an average particle diameter, reduction by plasma treatment can be facilitated.

  In the base material coating method according to the present invention, the base material is preferably an aluminum member, a copper member, or a steel member. In the base material coating method according to the present invention, the base material is preferably a ceramic member or a member made of an organic material.

The surface-coated substrate of the present invention is characterized in that the surface is coated with the metal film or the metal oxide film by the above-described substrate coating method.
Thus, the surface-coated substrate of the present invention is a metal film composed of one kind of metal, or a metal film composed of two or more kinds of metals (a metal oxide film in which fine particles are bound by a reduced metal element, a metal Metal film formed by alloying elements (metal oxide film formed by alloying metal elements and bonding fine particles by the alloyed metal elements), part of the base material and metal elements are alloyed Since the metal coating) is coated, it is possible to impart a function not found in the base material.

The substrate coating method of the present invention is a low-cost, low-cost, environmentally friendly substrate that is vulnerable to heat or a substrate that may change its internal structure or properties when heated. Metal film composed of two or more kinds of metals, metal film composed of two or more kinds of metals (metal oxide film in which fine particles are combined with a reduced metal element, metal film formed by alloying metal elements (metal element alloy) And a metal oxide film in which fine particles are bonded to each other with an alloyed metal element), and a metal film formed by alloying a part of the base material with the metal element).
Thereby, since the coating method of the base material of this invention can coat | cover such a metal film on a base material, it is possible to provide the function which a conventional base material does not have.
Moreover, even if the surface covering base material of this invention is a heat-sensitive base material, it can give the function which a conventional base material does not have, without putting a burden on an environment.

  Next, the best mode for carrying out the substrate coating method of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a flowchart showing the process contents of the substrate coating method of the present invention.

(First embodiment)
As shown in FIG. 1, the substrate coating method according to the first embodiment of the present invention includes an adhesion step S <b> 1 and a plasma treatment step S <b> 2.
Hereinafter, the content of each process is explained in full detail.

In the attaching step S1, the above-mentioned fine particles are attached on the base material using a dispersion liquid in which fine particles of metal oxide in which a metal element constituting the coating is oxidized is dispersed in a liquid.
Here, as the metal element constituting the coating, it is preferable to use a metal element that is relatively easily reduced when a metal coating described later is coated. Specifically, a metal above Si in the Ellingham diagram, specifically, copper, lead, nickel, iron, cobalt, tin, zinc, manganese, chromium, or the like can be given.
And in the coating method of the base material of this invention, these metal elements are made into the state oxidized, ie, a metal oxide state, This metal oxide is used with the form of microparticles for the reason mentioned later. Note that the state of the metal oxide is not particularly limited, and various metal oxides can be used.

  The metal elements that can be used in the present invention are not limited to those described above. In the case of coating a metal oxide film, which will be described later, since metal is reduced using high energy by plasma near atmospheric pressure, even a metal that is relatively difficult to reduce can be used. For example, it is possible to use titanium oxide, aluminum oxide, magnesium oxide or the like having a large standard free energy for oxide formation.

The metal element constituting the above-described film can further form a metal oxide film by adjusting the conditions of reduction by plasma.
Further, the metal oxide fine particles obtained by oxidizing the metal element include other metal elements, pigments / dyes, etc. as long as the purpose of forming the metal coating is not impaired, in addition to the oxidized metal element. It may be.

  The metal oxide is preferably used as fine particles as described above. In general, when forming a coating on a substrate, the metal oxide (metal) is dissolved in a liquid or physically supplied to the surface of the substrate, and the metal oxide fine particles (molecules) deposited or adhered to the substrate It is necessary to bond firmly on the surface of the substrate by chemical reaction or physical adsorption. However, since metal fine particles have extremely high surface reactivity and easily cause explosion and combustion (dust explosion), it is difficult to supply as they are in terms of safety (industrial application).

  However, in the present invention, by using a stable oxide as a starting material and reducing by plasma treatment, it is possible to activate only a region exposed to plasma and form a strong bond. In addition, oxygen bound to the metal is released into the gas phase as water, so it absorbs moisture in the air and is corrosive, such as halide particles such as copper chloride. There is no change to high hydrochloric acid.

  In addition, the metal elements that make up coatings such as metal coatings and metal oxide coatings are supplied in an oxidized state as fine particles, so that the processing speed that is a problem when supplied under other dry conditions is also dispersed in the liquid. Since it is possible to control only by adjusting the concentration of the fine particles to be formed, the processing speed can be increased.

In the present invention, the average particle size of the metal oxide fine particles may be about 5 μm or less, preferably 1 μm or less, and more preferably 5 to 100 nm. When the metal oxide fine particles have an average particle diameter of 5 to 100 nm, the reduction proceeds easily and a uniform and complete metal film or metal oxide film can be obtained. Moreover, in the metal oxide film, it becomes easy to obtain a flat surface.
On the other hand, if the average particle size of the metal oxide fine particles exceeds 5 μm, reduction may be difficult even by plasma treatment, which is not preferable.

Two or more kinds of such metal oxide fine particles can be used in combination. In this case, it is preferable to disperse the metal oxide fine particles in advance by mixing them in two or more kinds of liquids.
If a plasma treatment is performed by adjusting the concentration of the reaction gas (reducing gas), the treatment temperature, and the treatment time by using such two or more kinds of metal oxide fine particles in combination, the reaction gas containing the reducing gas is used. It is also possible to coat a metal oxide film containing a metal and a metal oxide on the substrate by reducing the outermost surface of the fine particles.

In addition, by performing plasma treatment with the concentration of the reaction gas (reducing gas), treatment temperature, and treatment time adjusted, both can be reduced, and these fine particles can be alloyed to form an alloy metal on the substrate. It is also possible to coat the coating.
Also, in this case, for example, when a metal such as copper is used for the base material and an oxide of a metal having a relatively low melting point such as zinc or tin is used as the fine particles, the metal film in which the reduced fine particles and the base material are alloyed. It is also possible to coat.

  The metal oxide fine particles can be produced by appropriately setting the production conditions of the metal coating using these metal oxide fine particles, for example, the flow rate and type of reaction gas described later, and the temperature conditions for plasma treatment. A metal coating comprising a metal and a metal oxide on a base material by reducing only a portion (outermost surface) of the substrate (that is, a portion may not be reduced by plasma treatment). Can be coated.

As the liquid for dispersing the metal oxide fine particles, for example, water, alcohol, MIBK, xylene, toluene and the like can be used, but the liquid is not limited thereto. In addition, such liquids include surfactants and pH adjusters for preventing the aggregation of metal oxide fine particles containing the above-described film constituent elements within a range that does not interfere with the effects of the substrate coating method of the present invention. May be included.
Examples of such surfactants include sodium bis (2-ethylhexyl) sulfonate (AOT) and (poly) oxyethylene (20) sorbitan oleate. Examples of pH adjusters include acetic acid. -A sodium acetate buffer solution, sodium carbonate sodium hydrogencarbonate buffer solution, etc. can be used.

  The concentration at which the metal oxide fine particles are dispersed can be, for example, 0.1 to 30% by mass, but is not limited thereto. Such concentration is determined by the kind of metal oxide fine particles oxidized by the metal element constituting the film, the average particle diameter, the desired thickness and properties of the metal film, the adhesion process S1 leading to the metal film coating, and the plasma treatment process S2. It is preferable to set appropriately depending on conditions and the like, and it is preferable to obtain a suitable concentration by conducting an experiment in advance.

  And as a base material, organic materials, such as metal materials, such as aluminum and copper, ceramic materials, such as glass and silicon | silicone, fiber, wood, and a synthetic resin, etc. can be used, for example. The substrate can be of any form such as plate or fiber. In particular, the substrate coating method of the present invention can be applied to a large-area substrate or a long belt-like substrate. In the case of a member made of ceramic material or organic material, a metal film made of an alloy with the above-described metal element is obtained by attaching a metal such as aluminum or copper to the surface in advance and performing a plasma treatment step S2 described later. It is possible to coat (metal oxide coating).

  In order to attach the metal oxide fine particles oxidized with such metal elements to the base material, for example, the dispersion liquid is applied to the base material by a known technique such as a roll coater, a spin coater, or a spray, and is applied to the base material. be able to. The adhesion of the fine particles to the base material may be applied or dispersed in advance, or may be applied or dispersed in-line when the base material is introduced into a plasma apparatus described later.

And plasma treatment process S2 plasma-treats the base material to which the above-mentioned fine particles were made to adhere.
Specifically, in the plasma processing step S2 in the first embodiment, a metal film made of a metal element is formed by reducing a fine particle by introducing a reactive gas containing a reducing gas into a plasma region generated by discharge. Is coated on the substrate.
In such plasma treatment, it is preferable that the pressure in the plasma generation region is adjusted to a pressure in the vicinity of atmospheric pressure, and the plasma is generated by glow discharge. The glow discharge in the present invention means that it is not a continuous arc discharge or corona discharge, and means a broad concept discharge including a streamer discharge or the like found in a dielectric barrier discharge.

  Such plasma treatment is, for example, a method proposed in Japanese Patent Laid-Open No. 6-2149 or the like in which a plasma is generated by glow discharge under a pressure near atmospheric pressure to form a thin film on a substrate. For example, a method described in JP-A-2002-237480, in which a dielectric is formed on at least one of the opposing electrodes, plasma is generated at atmospheric pressure by a DC pulse or the like, and gas is blown onto the substrate with gas pressure, Further, for example, it can be performed by a plasma apparatus such as a plasma CVD apparatus capable of performing various methods such as a method of generating plasma using a rotating electrode as disclosed in JP-A-9-104985. . However, the present invention is limited to these methods as long as the above-described plasma treatment is performed to reduce the metal oxide fine particles oxidized by the metal elements constituting the coating, and the metal coating can be coated on the substrate. It is not something.

  The film thickness of the metal film to be coated by the plasma treatment is not particularly limited. From the relationship with the use of metal oxide fine particles in which the metal element constituting the film is oxidized, for example, 0.05 to The thickness may be 5 μm, for example, 0.5 μm. Needless to say, the metal coating may have a thickness of 5 μm or more, and the adhesion step S1 and the plasma treatment step S2 may be repeated a plurality of times in order to obtain such a thickness.

As a plasma apparatus for performing plasma treatment, it is preferable to use an apparatus provided with an electrode pair for generating plasma. Such an electrode pair is more preferably an electrode pair disposed to face each other. When electrode pairs arranged opposite to each other are used, discharge is performed by applying a voltage, plasma is generated in the region between the electrode pairs, and the reducing gas of the reaction gas is decomposed to form a plasma region A metal film can be coated on the substrate by disposing the substrate in the plasma region.
In the case of an electrode pair arranged to face each other, it is more preferable that at least one of the electrodes is a rotating electrode. When a rotating electrode is used, arc discharge is difficult to occur due to the absence of electric field concentration, and the gas flow is uniform in the width direction along the rotating electrode. Can be coated. The plasma apparatus will be described later.

  When such a plasma apparatus is used, when the base material to be coated with the metal coating is a large-area base material or a long base material, the plasma region generated between the electrode pairs by a transfer device or the like is used. It is possible to easily coat the metal film by sequentially transferring the substrate.

The reactive gas contains an inert gas for generating a stable glow discharge in an atmosphere that does not generate reactive radicals, and a reducing gas for generating reactive radicals.
As the inert gas, helium gas, argon gas, xenon gas, krypton gas, nitrogen gas, or the like can be used. As the inert gas, helium gas is preferably used from the viewpoint of a long life in the metastable excited state, and nitrogen gas or argon gas is preferably used from the viewpoint of cost.
As the reducing gas, hydrogen gas capable of generating a reactive radical and generating a plasma region when discharged in the region between the electrode pair can be suitably used. Also, methane gas, carbon monoxide gas, or the like can be used. Even when methane gas or carbon monoxide gas is used, the standardized energy of production is almost the same as the process of producing water from hydrogen, and the same reduction effect as hydrogen gas can be obtained.
It should be noted that the reducing gas that can be used in the present invention is not limited to this, and it is needless to say that other gases that can reduce the oxidation number of the fine particles by plasma can be used.

  The discharge between the electrode pairs is performed by applying high frequency power to the electrodes. Such discharge is preferably performed by glow discharge from the viewpoint that continuous and stable film formation is possible. The glow discharge can be generated by, for example, a high LF low LF or DC pulse of 13.56 MHz.

  It is preferable to use a transfer device for the base material because the film thickness can be adjusted or the ratio of metal to metal oxide can be adjusted by appropriately adjusting the transfer speed. The transfer speed is preferably adjusted according to the purpose, but the transfer speed is not particularly limited. In addition, by appropriately adjusting the transfer rate, it is possible to form an aggregate of fine particles, and to control the formation density, the network structure, and the like.

  In the plasma treatment step S2, the base material is preferably heated to 70 to 350 ° C, more preferably 70 to 200 ° C, and further preferably 70 to 150 ° C. When the temperature of the substrate is within such a temperature range, the adhesion of the metal film to the substrate can be enhanced. Moreover, if it is this temperature range, since the thermal deterioration of a base material can be decreased, it is preferable.

  According to the substrate coating method according to the first embodiment described above, a metal material such as aluminum or copper, a ceramic material such as glass or silicon using plasma generated under atmospheric pressure conditions near atmospheric pressure, The surface of a desired base material such as an organic material such as fiber, wood, or synthetic resin can be coated with a metal film to impart a function not found in a normal base material. By applying the substrate coating method of the present invention, for example, a substrate such as aluminum or copper, which is used for a semiconductor device or the like, which has a function not provided in a normal substrate, and a glass substrate are burdened on the environment. For example, it can be preferably used in applications such as a heat radiating plate or lead frame with good solder wettability, copper wiring for IC, and a corrosion prevention film.

Next, the substrate coating method according to the second to fifth embodiments of the present invention will be described. The substrate coating method according to the second to fifth embodiments of the present invention includes the same steps as the substrate coating method according to the first embodiment described above, but is attached in the attachment step S1. The difference is that two or more kinds of metal oxide fine particles are used, or the processing content in the plasma processing step S2 is different from that in the first embodiment.
Therefore, about the coating method of the base material which concerns on 2nd Embodiment-5th Embodiment of this invention, the description about the structure which overlaps with the content of the coating method of the base material which concerns on 1st Embodiment is abbreviate | omitted, and 1st Only the configuration different from the substrate coating method according to the embodiment will be described.

(Second Embodiment)
In the plasma treatment step S2 of the substrate coating method according to the second embodiment of the present invention, a reactive gas containing a reducing gas is introduced into a plasma region generated by discharge, and the metal elements constituting the coating are oxidized. The outermost surface of the fine metal oxide particles is reduced.
In the substrate coating method according to the second embodiment, by performing such a plasma treatment, a metal oxide film in which fine particles are bonded with the reduced metal element is formed, and the metal oxide is formed on the substrate. A coating can be applied.

(Third embodiment)
The substrate coating method according to the third embodiment of the present invention includes an adhesion step S1 and a plasma treatment step S2.
In the substrate coating method according to the third embodiment, the adhesion step S1 includes two types by using a dispersion in which two or more types of metal oxide fine particles oxidized by a metal element constituting the coating are dispersed in a liquid. The above fine particles are adhered on the substrate.
In the plasma treatment step S2, a reactive gas containing a reducing gas is introduced into the plasma region generated by the discharge to reduce the metal oxide fine particles in which the metal elements constituting the coating are oxidized.
In the base material coating method according to the third embodiment, by performing such an adhesion step S1 and the plasma treatment step S2, a metal film formed by alloying two or more kinds of metal elements is formed on the base material. The metal coating can be coated.

(Fourth embodiment)
The substrate coating method according to the fourth embodiment of the present invention includes an adhesion step S1 and a plasma treatment step S2.
The adhesion step S1 of the substrate coating method according to the fourth embodiment uses two or more types of dispersions in which two or more types of metal oxide fine particles obtained by oxidizing the metal elements constituting the coating are dispersed in a liquid. Of fine particles are deposited on the substrate.
In the plasma processing step S2, a reaction gas containing a reducing gas is introduced into a plasma region generated by discharge to reduce the outermost surface of two or more kinds of fine particles.
In the coating method of the base material according to the fourth embodiment, by performing the adhesion step S1 and the plasma treatment step S2, two or more kinds of metal elements are alloyed, and different kinds of materials depend on the alloyed metal elements. A metal oxide film in which fine particles are bonded to each other can be formed, and the metal oxide film can be coated on a substrate.

(Fifth embodiment)
In the plasma treatment step S2 of the base material coating method according to the fifth embodiment of the present invention, a reactive gas containing a reducing gas is introduced into a plasma region generated by discharge to reduce the fine particles.
In the base material coating method according to the fifth embodiment, by performing such a plasma treatment step S2, a metal film formed by alloying a part of a metal base material with a metal element is formed, and the metal coating is made. The metal film can be coated on the substrate.

  Next, a plasma apparatus capable of carrying out the contents of the substrate coating method according to the first to fifth embodiments of the present invention will be specifically described with reference to FIGS. In the drawings to be referred to, FIG. 2 is a schematic configuration diagram showing a configuration example of a plasma apparatus provided with a rotating electrode. FIG. 3 is a schematic configuration diagram showing a configuration example of a plasma apparatus provided with an endless belt electrode. FIG. 4 is a schematic configuration diagram showing another configuration example of the plasma apparatus provided with the rotating electrode.

The plasma apparatus shown in FIG. 2 includes opposed electrode pairs inside the chamber 1. A configuration in which one electrode of the electrode pair is a rotating electrode 9 and the other electrode is a planar electrode 6 that functions as a substrate holder can be given. Here, the rotating electrode 9 functions as a discharge electrode.
When the plasma apparatus having such a configuration is used, first, the substrate 7 is disposed on the planar electrode 6. A dispersion liquid in which a metal oxide in which a metal element constituting the film is oxidized is dispersed is applied to the base material 7 in advance. The dispersion liquid is preferably applied by a roll coater or a spin coater as described above. When the plasma generation atmosphere is at atmospheric pressure or in the vicinity thereof, the substrate 7 can be continuously carried into the plasma apparatus by providing a threshold with a gas curtain or the like.

  Then, a reaction gas is introduced into the chamber 1, and the pressure in the gap (hereinafter referred to as “narrow gap”) between the rotating electrode 9 and the base material 7 is maintained at a pressure near atmospheric pressure, Discharge to generate a line-shaped plasma region in a narrow gap. Then, the substrate 7 is transferred in the A direction at a predetermined speed by the transfer device so as to cross the plasma region. In the present invention, the pressure near atmospheric pressure means a pressure around 1 atm (0.1 MPa). In the present invention, the pressure does not exceed atmospheric pressure (that is, reduced pressure relative to atmospheric pressure). Preferably, it is about 0.01-0.11 MPa. Moreover, it is preferable that the pressure range shall be about 0.08-0.11 MPa from a viewpoint that pressure adjustment is easy and the apparatus structure mentioned later becomes simple or unnecessary.

As the rotating electrode 9, in addition to the cylindrical rotating electrode as shown in the configuration example of the plasma apparatus shown in FIGS. 2 and 4, an endless belt electrode as shown in FIG. 3 is used. be able to.
Further, the surface shape of the rotating electrode 9 is not particularly limited, and an uneven shape may be formed on the surface in addition to the smooth surface. The uneven shape is used to adjust the distance between the rotating electrode 9 and the substrate 7 at a desired position on the substrate 7. For example, when the uneven shape is formed along the rotation direction, the substrate 7 Plasma can be preferentially generated only in a portion facing the upper convex portion, and a metal film can be formed preferentially only in that portion. Therefore, irregularities can be formed on the surface of the formed metal film. When the concavo-convex shape is provided on the rotary electrode 9, there is also an effect of diffusing the reaction gas which is a laminar flow (viscous flow).

  The interval between the rotating electrode 9 and the substrate 7 placed on the flat electrode 6 (the interval between the narrow gaps) is appropriately determined depending on the high-frequency power applied to the rotating electrode 9, the type of reaction gas used, the composition ratio, and the like. Although it is adjusted, it is usually preferably 0.5 to 5 mm, and more preferably about 1 to 3 mm.

  If the narrow gap is too narrow, it is difficult to stably supply the reaction gas to the narrow gap. Therefore, since the variation of the narrow gap in the width direction of the rotating electrode 9 becomes remarkable, uniform film formation becomes difficult. In addition, in order to realize stable plasma generation when the narrow gap is too narrow, a high frequency of 100 MHz or more is required to capture plasma charged particles of electrons and ions, which is disadvantageous in terms of cost. Tend.

On the other hand, when the gap between the narrow gaps is too wide, the processing speed tends to decrease due to a decrease in electric field and a decrease in plasma density. Further, problems such as a decrease in film forming speed due to discharge of hydrogen radicals for reduction from the substrate 7 due to the laminar flow generated by the rotation of the rotating electrode 9 and contamination in the chamber 1 occur. There is.
The peripheral speed of the rotating electrode 9 is preferably 3000 cm / min or more. When the peripheral speed of the rotating electrode 9 is less than 3000 cm / min, the film forming speed tends to be low, and preferably 10,000 cm / min or more, but considering the improvement in yield, it is 100,000 cm / min. More preferably, it is less than or equal to minutes.

In this case, the life until recombination after ionization of the reactant gas molecules that have been plasmatized by glow discharge is short, and the mean free path of electrons is also short, so that glow discharge can be stably generated in the opposing narrow gap. It is necessary to capture charged particles of electrons and ions in a narrow gap.
Therefore, when high frequency power is applied to the rotary electrode 9, a frequency of 100 kHz or higher can be used, but a high frequency of 10 MHz or higher is particularly preferable. By using high frequency of 10 MHz or higher, for example, 13.56 MHz, which is the most readily available commercial frequency, and frequencies of 70 MHz, 100 MHz, and 150 MHz available as a power source, plasma density can be improved and stable plasma can be generated. become.

  According to such a plasma apparatus, plasma is generated between the electrode pair by discharge, the reducing gas changes to an active state such as hydrogen radicals, and the surface of the fine particles is reduced on the substrate 7. A metal coating can be coated.

  Below, the specific example of the coating method of the base material of this invention using the plasma apparatus provided with the rotating electrode in a chamber is demonstrated in detail. In addition to the following method, the present invention can naturally be implemented by, for example, a film forming method using a plasma apparatus using a rotating electrode having no chamber.

  In FIG. 2, 1 is a chamber, 2a is a load lock chamber for introducing a substrate, 2b is a load lock chamber for carrying out a substrate, 3a to 3d are gate valves, 4a to 4d are gas inlets, and 5a to 5c are leaks. Mouth, 6 is a planar electrode, 7 is a base material, 8 is a bearing, 9 is a rotating electrode, 10 is a mount, 11a to 11c are insulators for supporting a rotating electrode, 12 is a synthetic quartz glass, 13 is a near infrared lamp, 14 is Viewing window, 15 is a radiation thermometer, 16 and 19 are high-frequency power supplies, 17 and 20 are matching units, 18 is a heater built in the substrate holder, and 21 is a glow discharge region (plasma generation region).

  In the configuration of the plasma apparatus shown in FIG. 2, a base material introduction load lock chamber 2a and a base material carry-out load lock chamber 2b are connected to the chamber 1 through gate valves 3b and 3c, respectively. A carrier gas such as helium is always introduced into the load lock chambers 2a and 2b from the gas introduction ports 4a and 4b (V1 and V2 are flow rate adjusting valves), and is provided in each of the load lock chambers 2a and 2b. The pressure is adjusted by the leak ports 5a and 5b (V3 and V4 are flow rate adjusting valves), and the load lock chambers 2a and 2b are maintained at a normal pressure (about 0.1 MPa).

  A carrier gas containing an inert gas such as helium as a component is introduced into the chamber 1 through a mass flow (not shown) from the gas inlet 4c. Further, a gas containing a hydrocarbon gas and a fluorine-containing compound gas diluted by bubbling with an inert gas such as helium whose flow rate is adjusted through a mass flow (not shown) is introduced from the gas introduction port 4d. . The pressure in the chamber 1 is adjusted by adjusting the flow rate from the exhaust port 5c.

  A base material 7 is placed on the flat electrode 6. The flat electrode 6 is first transferred and stored in the load lock chamber 2 a with the gate valve 3 a opened. Thereafter, the gate valve 3a is closed, the gate valve 3b is opened, the base material 7 is transferred in the direction of arrow A and stored in the chamber 1, and then the gate valve 3b is closed. become.

In the state where the planar electrode 6 is stored in the chamber 1, a metal film is formed on the surface of the substrate 7 placed on the planar electrode 6. After the metal film is formed on the surface of the base material 7, the gate valve 3c is opened, and the base material 7 is stored in the load lock chamber 2b. Subsequently, the gate valve 3c is closed and the gate valve 3d is opened, and the planar electrode 6 and the base material 7 placed thereon are carried out of the load lock chamber 2b. These series of operations are continuously performed, and the stop and advance of the planar electrode 6 can be freely controlled. The rotating electrode 9 is preferably heated by infrared rays emitted from the near-infrared lamp 13 through the synthetic quartz glass 12 and heated to about 150 ° C. The temperature monitor rotating electrode 9 is performed by the radiation thermometer 15 via the observation window 14 made of, for example, BaF _2.

  In this plasma apparatus, a plasma is generated by glow discharge 21 in a narrow gap between the rotating electrode 9 and the base material 7, thereby forming a metal film on the base material 7. The principle of forming this metal film will be described. The rotating electrode 9 is made of, for example, aluminum, and its size is, for example, a cylindrical shape having a width of about 120 mm and a diameter of about 100 mm, and its edge portion has a curvature of R5 (mm) to prevent electric field concentration. It is rounded with a radius. In addition, the surface of the rotating electrode 9 is coated with a dielectric to prevent arcing. As the dielectric coating at this time, for example, white alumina is formed by thermal spray coating (thickness: about 150 μm).

  The surface of the rotating electrode 9 that forms a narrow gap with the base material 7 has a polishing specification, and an uneven shape is formed as necessary. The rotating electrode 9 is supported by the bearing 8 and the gantry 10. One shaft end of the rotating electrode 9 is a magnet coupling, which is coupled with a motor end magnet (not shown) arranged outside the chamber 1 so that the rotating electrode 9 is within a range of 0 to 3000 rpm. Can be rotated.

  The gantry 10 is made of, for example, stainless steel, and high frequency power from the high frequency power source 16 can be applied to the gantry 10 via a matching unit 17. When the scanning tip of the planar electrode 6 arrives directly under the rotating electrode 9, high frequency power is applied. First, the rotating electrode 9 and the planar electrode 6 (that is, the planar electrode 6 corresponds to the counter electrode of the rotating electrode 9). Glow discharge starts in the narrow gap. Next, the planar electrode 6 is sequentially scanned, and after the base material 7 placed on the planar electrode 6 arrives directly under the rotary electrode 9, the narrow gap is between the rotary electrode 9 and the base material 7.

  A heater 18 is embedded in the flat electrode 6, and the heater 18 is configured so that the temperature of the flat electrode 6 can be heated from room temperature to about 300 ° C. The surface of the flat electrode 6 is thermally sprayed with white alumina having a thickness of about 100 μm, and may basically be electrically grounded (grounded). However, as shown in FIG. The high frequency power from the high frequency power supply 19 may be applied via the device 20. In this way, by applying high-frequency power to the planar electrode 6, an increase in plasma density, a plasma containment effect, and the like are exhibited. As for the timing of applying the power from the high frequency power source 19 to the planar electrode 6, the high frequency power may be applied immediately after the power from the high frequency power source 16 is applied to the rotating electrode 9.

  The matching unit 17 performs frequency tuning and impedance adjustment to match the high frequency power supply 16 side and the load side including the matching unit 17, and maximizes power consumption in the entire load circuit including the matching unit 17. And protecting the high-frequency power supply 16 and the high-frequency oscillation circuit (the relationship between the matching unit 20 and the high-frequency power supply 19 is the same).

  As shown in FIG. 3, the plasma apparatus according to another configuration example for carrying out the substrate coating method of the present invention has a basic configuration similar to that of the plasma apparatus shown in FIG. . Therefore, the same reference numerals are given to the components corresponding to those of the plasma apparatus shown in FIG. 1, and the duplicate description will be omitted. In FIG. 3, although not shown in the drawing for convenience of explanation, in this plasma device as well as the plasma device shown in FIG. 1, the substrate introduction load lock chamber 2 a, the substrate carry out load lock chamber 2 b, and the same. An accompanying member is arranged.

  In the configuration of the plasma apparatus shown in FIG. 3, an endless belt electrode 22 is provided instead of the cylindrical rotating electrode 9, and the endless belt electrode 22 is made of, for example, a thin steel conductive material. It consists of members and is configured to run around two rollers 23 and 24.

  The rollers 23 and 24 have a cylindrical outer peripheral surface, and in the plasma generation region P, the surface of the endless belt electrode 22 and the surface of the base material 7 extending horizontally are parallel to each other, and the narrow gap between the rollers 23 and 24 is narrow. They are arranged so that the distance is constant. The endless belt electrode 22 travels in the same direction as the movement direction of the base material 7 in the plasma generation region P.

  Of these two rollers 23 and 24, the one located on the right side in FIG. 3 is a metallic drive / feed roller 24. The roller 24 is configured to rotate by rotating the roller 24 with a belt driving motor (not shown). In the chamber 1, the base material 7 placed on the planar electrode 6 is moved in the horizontal direction (arrow B direction) by the base material transfer mechanism 25.

  In the plasma irradiation apparatus shown in FIG. 3, a gas component is introduced into the chamber 1 from the gas inlet 4e and exhausted through the exhaust duct 5e to maintain the interior of the chamber 1 at a predetermined atmospheric pressure. Then, the endless belt electrode 22 is caused to travel by the rollers 23 and 24, and a relatively wide line-shaped plasma is generated by glow discharge in a narrow gap between the endless belt electrode 22 and the base material 7, and the base material 7 is moved. Then, a metal film is formed on the base material 7 by a chemical reaction (reduction reaction) of the reaction gas.

FIG. 4 is a schematic explanatory view showing still another configuration example of a plasma apparatus using a rotating electrode for carrying out the substrate coating method of the present invention.
In this plasma apparatus, productivity is improved by omitting the gas exhausting / replacement step, and the substrate can be directly inserted and removed from the atmosphere in order to avoid the use of an expensive vacuum vessel. In addition, since the structure of a basic rotating electrode part is the same as that of FIG. 2, description is abbreviate | omitted about the said same part.

  In this plasma apparatus, the base material 7 is transferred in one direction by the belt conveyor 26. The substrate 7 is placed on one end of the belt conveyor at regular intervals by a substrate handling robot (not shown). Thereafter, the base material 7 is transferred into the chamber 1 as the belt conveyor moves.

  In the plasma apparatus, the entrance (exit) is limited to the opening required to transfer the substrate 7 to the minimum size, and an air curtain 27 is provided to block outside air using a gas flow. . The inside of the chamber 1 is filled with an inert gas, and a gas component containing separately introduced hydrocarbon gas and fluorine-containing compound gas is guided to the plasma space by the rotation of the rotating electrode 9, and a metal film is formed on the substrate 7. Form.

  FIG. 5 is a schematic explanatory view showing still another configuration example of a plasma apparatus using a rotating electrode for carrying out the present invention. In this plasma apparatus, the base material 7 is coiled, the base material 7 is sent out from the feed roll 29, and the base material 7 is taken up by the take-up roll 30. The reaction vessel is separated from the outside air by a gas blocking roll 31 installed at the entrance / exit. With such a configuration, the base material 7 can be continuously processed, and the productivity can be remarkably improved.

Next, the substrate coating method and the surface-coated substrate of the present invention will be specifically described with reference to some examples.
(Example 1)
A zinc film was formed on the glass substrate 7 by using the plasma apparatus provided with the rotating electrode shown in FIG. In FIG. 2, a flat electrode 6 having a width of 170 mm and a length (length in the transfer direction): 170 mm is used, and a base material 7 is placed on the flat electrode 6 and stored in the chamber 1. .

  As the base material 7, a glass substrate (non-alkali glass Corning # 1737) having a width: 100 mm, a length (length in the transfer direction): 100 mm, and a thickness: 1.1 mm was used. As metal oxide fine particles, zinc oxide particles (purity 99.99%, 300 mesh) were used. The average particle size of the fine particles is 0.8 microns (800 nm). Fine particles were previously dispersed in an ethanol solution, applied to the surface by a dipping method, then dried, and then placed on the flat electrode 6.

Then, after the planar electrode 6 was moved directly below the rotating electrode 9, high-frequency power (frequency: 13.56 MHz, 700 W) was applied to the rotating electrode 9 from the high-frequency power source 16. The planar electrode 6 was connected to ground.
At this time, the set temperature of the planar electrode 6 was 200 ° C., the set temperature of the rotary electrode 9 was 100 ° C., the set temperature of the chamber 1 and its members was 100 ° C., and the temperature of the substrate 7 was also 100 ° C.
The rotational speed of the rotating electrode 9 was 1500 rpm (circumferential speed: 45000 cm / min), and the narrow gap between the rotating electrode 9 and the substrate 7 was set to 1 mm. In this experiment, the substrate 7 was fixed, and the plasma irradiation time was adjusted between 5 and 300 seconds.

  The pressure of the chamber 1 was adjusted by an auto pressure control (not shown) installed in the exhaust port 5c to a total pressure of 0.101 MPa near the atmospheric pressure. A mixed gas of helium gas and hydrogen was introduced into the chamber 1. Then, the partial pressure of each gas component was adjusted by adjusting the flow rate of each gas component, and the pressure in the gap between the rotating electrode 9 and the substrate 7 was also set to 0.101 MPa.

  When the substrate was treated with hydrogen plasma for 30 seconds according to the above procedure, the base material 7 on which the zinc oxide particles were adhered changed from white to metallic luster. That is, a metal film could be obtained from the deposited zinc oxide particles. At this time, when the components of the obtained metal film were analyzed by XPS (X-ray photoelectron spectroscopy), a peak appeared in the vicinity of 494 eV corresponding to the peak of zinc as shown in FIG. 6 (“Metal” in FIG. 6). Note that the oxygen peak is in the vicinity of 498 eV.) It was found that metal zinc was obtained. Note that no change was observed on the surface of the region not irradiated with plasma. FIG. 6 is a graph showing the results of XPS analysis. In FIG. 6, the horizontal axis represents binding energy (Binding Energy (eV)), and the vertical axis represents strength (Intensity (CPS)).

(Example 2)
Next, a copper metal film was coated on the glass substrate (non-alkali glass Corning # 1737) 7 and the aluminum base material 7. The glass substrate 7 was produced with the dimensions shown in Example 1, and the aluminum substrate 7 was produced with a width: 100 mm, a length (length in the transfer direction): 150 mm, and a thickness: 300 μm. Copper oxide was used as the fine particles. Here, a nanotech slurry (manufactured by C-I Kasei Co., Ltd.) diluted with water and having a purity of 99.9%, an average particle diameter of 48 nm, and 15% by mass was selectively applied onto the substrate 7 by a roll coater. And it processed by the method similar to Example 1 except the temperature of a base-material holder being 100 degreeC and making a total pressure into 0.09 MPa. The pressure was adjusted by setting the exhaust pump discharge amount to be larger than the gas introduction amount.

As a result, a metal film having a copper luster was obtained only in the selectively applied region. As shown in FIG. 7, it was confirmed that the fine particles were bonded to form a flat metal film. Further, when the electrical conductivity of the surface was examined, conduction was confirmed, and it was found that the metal coating was copper. Analysis by XPS showed that the oxygen contained in the metal film was 10% or less, copper was 90% or more, and carbon was hardly contained as shown in FIG.
FIG. 7 is a photograph of a cross section of a glass substrate 7 coated with a metal film taken with an SEM obliquely from above. The cross section of the glass substrate 7 can be observed in the lower part of FIG. 7, the cross section of the copper metal film in the middle part, and the surface of the copper metal film extending in the depth direction of the photograph in the upper part. FIG. 8 is a graph showing the results of XPS analysis. In FIG. 8, the horizontal axis represents sputter depth (Sputter Depth (nm)), and the vertical axis represents atomic concentration (Atomic Concentration (%)).

(Example 3)
As fine particles, fine particles in which copper oxide (average particle size 1 micron (1000 nm)) and zinc oxide (average particle size 0.8 microns (800 nm)) were mixed were used. In the same manner as in Example 1, it was dispersed in an ethanol solution, applied onto a glass substrate (non-alkali glass Corning # 1737) 7 and subjected to plasma treatment. As a result, only the region irradiated with plasma changed to gold. . When investigated by XPS, peaks were confirmed in the vicinity of 567 eV corresponding to the copper peak and 494 eV corresponding to the zinc peak (not shown). From this result, it was found that copper and zinc were both reduced to form an alloy metal film (metal film formed by alloying) that became brass.

Example 4
Aluminum oxide was used as the fine particles. A nanotech slurry (with a water dilution of 15% by mass) (manufactured by C-I Kasei Co., Ltd.) with fine particles having an average particle diameter of 31 nm was applied by a roll coater, and the temperature of the planar electrode was set to 300 ° C. to perform plasma treatment.
The rotation speed of the rotating electrode 9 was 500 rpm (peripheral speed: 15000 cm / min), and the narrow gap between the rotating electrode 9 and the glass substrate (non-alkali glass Corning # 1737) 7 was set to 3 mm. Since the scanning speed of the base material 7 at this time was 3.3 mm / second, the discharge time between ends in the scanning direction of the base material 7 was 51 seconds. When the obtained film was observed with an SEM, a metal oxide film in which flat aluminum oxide particles were bonded as shown in FIG. 9 was obtained on the entire surface. In addition, FIG. 9 is the photograph which image | photographed the cross section of the glass base material 7 which coat | covered the metal oxide film with the SEM from diagonally upward direction. The cross section of the glass substrate 7 can be observed in the lower part of FIG. 9, the cross section of the copper metal oxide film in the middle part, and the surface of the copper metal oxide film extending in the depth direction of the photograph in the upper part.

(Example 5)
Processing was performed using a copper plate as a base material 7. Zinc oxide fine particles (purity 99.99%, 300 mesh) were used as the fine particles. The average particle size of the fine particles is 0.8 microns (800 nm). The particles were previously dispersed in an ethanol solution, applied to the surface by spraying and dried, and then placed on the flat electrode 6.
When the plasma treatment was performed in the same manner as in Example 1, the plasma-treated region changed to gold. When analyzed by XPS, peaks were confirmed in the vicinity of 567 eV corresponding to the copper peak and 494 eV corresponding to the zinc peak (not shown). Therefore, as shown in FIG. 10, the copper of the base material and zinc of zinc oxide are alloyed to form an alloy metal film (metal film formed by alloying) that is brass (copper-zinc alloy). I understood it. At this time, almost no oxygen was detected. On the other hand, no change was observed in the non-plasma treated region. FIG. 10 is a graph showing the results of XPS analysis. In FIG. 10, the horizontal axis represents the sputtering depth (Sputter Depth (nm)), and the vertical axis represents the atomic concentration (Atomic Concentration (%)).

  The substrate coating method and the surface-coated substrate according to the present invention have been described in detail with reference to the best modes and examples for carrying out the invention, but the contents of the present invention are limited to these. It should not be determined based on the claims. Further, it goes without saying that the contents of the present invention can be appropriately changed and modified without departing from the spirit of the present invention.

  For example, as described in the first embodiment, the metal coating may be one that uniformly coats the entire surface of the substrate. However, by adjusting the conditions of the plasma treatment, the metal coating is coated on the substrate. The whole surface may be coated non-uniformly (discontinuously). As described above, when the metal film is non-uniformly coated and formed into an island shape, it is possible to make use of the characteristics and effects of both the base material and the metal film.

  In addition, in order to obtain the characteristics and effects of both the base material and the metal film, the metal film may repeat the adhesion step S1 and the plasma treatment step S2 a plurality of times as described above. Not too long.

In the case where the adhesion step S1 and the plasma treatment step S2 are repeated a plurality of times, a plurality of different types of metal coatings are coated by using two or more types of metal oxide fine particles obtained by oxidizing the coating metal elements. It is also possible to produce a substrate.
In addition, it cannot be overemphasized that the example which carried out the said change and modification is the same also about a metal oxide film.

It is a flowchart which shows the process content of the coating method of the base material of this invention. It is a schematic block diagram which shows the structural example of the plasma apparatus provided with the rotating electrode. It is a schematic block diagram which shows the structural example of the plasma apparatus provided with the endless belt electrode. It is a schematic block diagram which shows the other structural example of the plasma apparatus provided with the rotating electrode. It is a schematic explanatory drawing which shows another example of a structure of the plasma apparatus using a rotating electrode. It is a graph which shows the analysis result of XPS. It is the photograph which image | photographed the cross section of the glass-made base material which coat | covered the metal film with the SEM from diagonally upward direction. It is the photograph image | photographed with SEM. It is a graph which shows the analysis result of XPS. It is the photograph which image | photographed the cross section of the glass-made base material which coat | covered the metal oxide film from diagonally upward direction by SEM. It is the photograph image | photographed with SEM. It is a graph which shows the analysis result of XPS.

Explanation of symbols

S1 Adhesion process S2 Plasma treatment process 1 Chamber 2a Load lock chamber for substrate introduction 2b Load lock chamber for substrate removal 3a to 3d Gate valve 4a to 4f Gas introduction port 5a to 5f Leak port 6 Planar electrode 7 Substrate 8 Bearing 9 Rotating electrode 10 Base 11a to 11c Insulator 12 Synthetic quartz glass 13 Near-infrared lamp 14 Viewing window 15 Radiation thermometer 16, 19 High-frequency power source 17, 20 Matching device 18 Heater 21 Glow discharge area 22 Belt electrode 23, 24 Roller 25 Base material Transport mechanism 26 Belt conveyor 27 Air curtain 28 Counter electrode 29 Sending roll 30 Winding roll 31 Gas blocking roll

Claims (10)

An attaching step of attaching the fine particles on the base material using a dispersion liquid in which fine particles of metal oxide in which the metal element constituting the coating is oxidized is dispersed;
A plasma treatment step of plasma-treating the substrate to which the fine particles are attached;
Comprising
The plasma processing step includes
By introducing a reactive gas containing a reducing gas into the plasma region generated by the discharge and reducing the fine particles, a metal film made of the metal element is formed, and the metal film is coated on the substrate. A method for coating a base material characterized by the above. An attaching step of attaching the fine particles on the base material using a dispersion liquid in which fine particles of metal oxide in which the metal element constituting the coating is oxidized is dispersed;
A plasma treatment step of plasma-treating the substrate to which the fine particles are attached;
Comprising
The plasma processing step includes
By introducing a reactive gas containing a reducing gas into the plasma region generated by the discharge and reducing the outermost surface of the fine particles, there is no metal oxide film in which the fine particles are bonded to each other with the reduced metal element. A method for coating a base material, wherein the metal oxide film is coated on the base material. An attaching step of attaching the fine particles on the base material using a dispersion in which two or more kinds of fine metal oxide particles in which the metal element constituting the coating is oxidized are dispersed in a liquid;
A plasma treatment step of plasma-treating the substrate to which the fine particles are attached;
Comprising
The plasma processing step includes
By introducing a reactive gas containing a reducing gas into the plasma region generated by the discharge and reducing the fine particles, a metal film formed by alloying two or more kinds of the metal elements is formed on the base material. A method for coating a substrate, wherein the metal coating is coated on the substrate. An attaching step of attaching the fine particles on a metal substrate using a dispersion liquid in which fine particles of metal oxide in which a metal element constituting the coating is oxidized is dispersed;
A plasma treatment step of plasma-treating the substrate to which the fine particles are attached;
Comprising
The plasma processing step includes
A metal coating formed by alloying a part of the metal substrate and the metal element by introducing a reactive gas containing a reducing gas into a plasma region generated by discharge to reduce the fine particles. A method of coating a base material, wherein the metal film is coated on the metal base material.   5. The substrate according to claim 1, wherein the pressure in the plasma region is a pressure near atmospheric pressure, and the plasma generated in the plasma region is caused by glow discharge. Coating method.   The base material covering method according to any one of claims 1 to 5, wherein the reducing gas contains at least one selected from the group consisting of hydrogen, methane, and carbon monoxide.   The average particle size of the fine particles is 100 nm or less, and the method for coating a substrate according to any one of claims 1 to 6.   The said base material is an aluminum member, a copper member, or a steel member, The coating method of the base material of any one of Claims 1-7 characterized by the above-mentioned.   The said base material is a member consisting of a ceramic member or an organic material, The coating method of the base material of any one of Claims 1-3, 5-7 characterized by the above-mentioned.   A surface-coated substrate, wherein the surface is coated with the metal film or the metal oxide film by the method for coating a substrate according to any one of claims 1 to 9.