JP2007042683A - Method of forming conductive pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming conductive pattern in which a high-resolution conductive pattern having a conductivity and durability can be obtained without requiring complicated process and an expensive apparatus, even when it is applied to the formation of an interconnection, etc. which is used for a plurality of different materials. <P>SOLUTION: The method includes: a step of manufacturing a surface hydrophilic member in which hydrophilic graft polymer chains exist over the entire surface of at least one face of a support; a step of providing an electroless plating catalyst or its precursor locally to the surface hydrophilic member and making the member adsorb the catalyst; and a step of applying electroless plating on the surface hydrophilic member which has locally adsorbed the electroless plating catalyst or its precursor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a conductive pattern forming method, and more particularly to a conductive pattern forming method capable of easily forming a conductive pattern useful for forming a wiring board or the like.

Conventionally, various conductive patterns are used as a wiring board. As a typical method for forming these conductive patterns, a thin film conductive material formed by a known method such as vacuum vapor deposition is provided on an insulator, which is subjected to resist treatment, and prepared in advance by pattern exposure. A part of the resist that has been removed is removed, and then an etching process is performed to form a desired pattern (for example, see Patent Document 1). In this method, at least four steps are required, and when the wet etching process is performed, a treatment process for the waste liquid is also required, so that complicated processes have to be taken.
As another pattern forming method, a conductive pattern forming method using a photoresist is also known. This method is a method in which a substrate coated with a photoresist polymer or a photoresist on a dry film is exposed to UV through an arbitrary photomask to form a pattern such as a lattice. It is useful for forming an electromagnetic wave shield that requires high performance.

On the other hand, in recent years, a method for forming a pattern directly from digitized data without using a mask or the like has attracted attention and various proposals have been made.
If such a digitized pattern forming method is used, it is expected that an arbitrary pattern can be easily formed. One of such methods is a method using a self-assembled monolayer. This utilizes a molecular assembly that is spontaneously formed when the substrate is immersed in an organic solvent containing surface active molecules. For example, a combination of an organic silane compound and a substrate of SiO ₂ or Al ₂ O ₃ In addition, a combination of alcohol or amine and a platinum substrate can be used, and pattern formation by an optical lithography method or the like is possible. Such a monomolecular film enables the formation of a fine pattern, but it is necessary to use a limited combination of substrates and materials, so that it is difficult to deploy to actual applications, wiring suitable for practical use, etc. Currently, the conductive pattern forming technology has not been established yet.
JP 2004-31588 A

The present invention has been made in view of the drawbacks of the prior art, and it is an object of the present invention to achieve the following objects.
That is, the object of the present invention is not to require a complicated process or an expensive apparatus, and even when applied to the formation of wiring using a plurality of different materials, the high-resolution conductivity having conductivity and durability. An object of the present invention is to provide a conductive pattern forming method capable of obtaining a pattern.

  As a result of diligent investigations focusing on the strong ion adsorptivity of the hydrophilic graft polymer chain, the present inventors have used a surface hydrophilic member having the hydrophilic graft polymer chain, and the surface hydrophilic member has an electroless plating catalyst or After the precursor was locally applied and adsorbed, the above object was achieved by performing electroless plating, and the present invention was completed.

  That is, the conductive pattern forming method of the present invention includes a step of producing a surface hydrophilic member in which a hydrophilic graft polymer chain is present over the entire surface of at least one surface of a support, and A step of locally applying and adsorbing an electroplating catalyst or a precursor thereof, and a step of performing electroless plating on the surface hydrophilic member on which the electroless plating catalyst or the precursor thereof is locally adsorbed. It is characterized by having.

In the present invention, as an aspect in which the electroless plating catalyst or its precursor is locally applied to the surface hydrophilic member, a fluid electroless plating catalyst or its precursor is discharged in a pattern using an ink jet recording apparatus. And a mode using a known pattern printing method such as screen printing is preferable.
When an ink jet recording apparatus is used, it is possible to form a pattern directly on a support based on digital data, and its application range is wide.

  Moreover, in this invention, after performing the said electroless plating, it is also preferable to perform electroplating further from a viewpoint of electroconductivity improvement.

Although the operation of the present invention is not clear, it is presumed as follows.
That is, the hydrophilic graft polymer present in the surface hydrophilic member used in the present invention is directly chemically bonded onto the support constituting the member. When the electroless plating catalyst or a precursor thereof is locally applied to the surface hydrophilic member, the electroless plating catalyst or the precursor thereof and the hydrophilic graft polymer chain are caused by the function of the hydrophilic group of the hydrophilic graft polymer chain. Are ionically adsorbed, and the adsorbed electroless plating catalyst or precursor thereof is firmly fixed (in a state close to a monomolecular film) to form a high-density uniform layer. When electroless plating is performed on such a surface hydrophilic member, the metal (conductive material) can be deposited only on the portion where the electroless plating catalyst or its precursor is adsorbed. It is considered that a conductive pattern having high durability (abrasion resistance) and having no disconnection can be formed.

  Furthermore, in the present invention, it is preferable to use, for example, an ink jet apparatus as a means for locally applying an electroless plating catalyst or a precursor thereof to the surface hydrophilic member. In this case, a dipping method or the like is applied. Compared to, the object can be achieved with a simple and small amount of material. In addition, even when it is necessary to form a plurality of different conductive patterns, it is possible to locally apply an electroless plating catalyst or a precursor thereof, so that a conductive pattern made of a desired conductive material can be formed. Each can be formed independently, and the obtained conductive patterns do not have physical and chemical influences on each other. For this reason, the method of the present invention can be suitably used for the purpose of sequentially forming different conductive patterns on the same substrate.

  According to the present invention, a high-resolution conductive pattern having conductivity and durability can be obtained even when applied to the formation of wiring using a plurality of different materials without requiring a complicated process or an expensive apparatus. The conductive pattern formation method obtained can be provided.

The present invention is described in detail below.
The conductive pattern forming method of the present invention is a step of producing a surface hydrophilic member in which a hydrophilic graft polymer chain exists over the entire surface of at least one surface of a support (hereinafter referred to as “surface hydrophilic member producing step” as appropriate). And a step of locally applying and adsorbing an electroless plating catalyst or a precursor thereof to the surface hydrophilic member (hereinafter referred to as “electroless plating catalyst applying step” as appropriate). A step of performing electroless plating on the surface hydrophilic member on which the electroless plating catalyst or its precursor is locally adsorbed (hereinafter referred to as “electroless plating step” as appropriate). To do.

[Surface hydrophilic member manufacturing process]
In this step, a surface hydrophilic member in which a hydrophilic graft polymer chain exists over the entire surface of at least one surface of the support is produced.

[Surface hydrophilic member]
The surface hydrophilic member produced in this step is a member in which a hydrophilic graft polymer chain exists over the entire surface of at least one surface of the support.
That is, the surface hydrophilic member in the present invention is uniformly hydrophilic because of the presence of the hydrophilic graft polymer chain over the entire surface of the support on which the hydrophilicity is required. Cost. As long as these requirements are satisfied, the hydrophilic graft polymer chain may be directly bonded to the support surface, or an intermediate layer on which the graft polymer is easily bonded is provided on the support surface. It may be one having a hydrophilic polymer grafted thereon.

Further, as the surface hydrophilic member, a polymer in which a hydrophilic graft polymer chain is bonded to a trunk polymer compound, or a functional group that has a hydrophilic graft polymer chain bonded to a trunk polymer compound and can be crosslinked is introduced. By coating or coating and crosslinking using a composition comprising a member disposed on the support surface by coating or coating crosslinking, or a composition containing a hydrophilic polymer having a crosslinking group at the polymer terminal and a crosslinking agent. Also included is a member disposed on the support surface.
In the following, the surface on which the hydrophilic graft polymer chain exists may be referred to as “hydrophilic surface” as appropriate.

The hydrophilic graft polymer in the present invention is characterized in that the polymer terminal is bonded to the support surface or the support surface layer, and the hydrophilic graft portion is not substantially crosslinked. This structure is characterized in that high mobility can be maintained without restricting the mobility of the polymer portion exhibiting hydrophilicity or being buried in a strong crosslinked structure. For this reason, it is considered that superior hydrophilicity is expressed as compared with a hydrophilic polymer having a normal crosslinked structure.
The molecular weight of such a hydrophilic graft polymer chain is in the range of Mw 500 to 5,000,000, preferably in the range of Mw 1000 to 1,000,000, and more preferably in the range of Mw 2000 to 500,000.

  In the present invention, (a) a hydrophilic graft polymer chain directly bonded to the support surface or an intermediate layer provided on the support surface is referred to as “surface graft”, and (b) hydrophilic graft When using a polymer chain introduced into a polymer crosslinked membrane structure, it may be referred to as a “hydrophilic graft chain-introduced crosslinked hydrophilic layer”. Moreover, in this specification, the material which provided the intermediate body on the support body or a support body may be called a "base material."

(A) Method for producing surface graft As a method for producing a surface on which a hydrophilic graft polymer chain is present on a substrate, a method in which a functional group on the substrate surface and a graft polymer are attached by chemical bonding, and a substrate There are two methods of polymerizing a compound having a double bond that can be polymerized from the base point into a graft polymer.

First, a method for attaching the functional group on the substrate surface and the graft polymer by chemical bonding will be described.
In this method, a polymer having a functional group that reacts with the substrate at the terminal or side chain of the polymer is used, and the functional group can be grafted by chemically reacting with the functional group on the substrate surface. The functional group that reacts with the substrate is not particularly limited as long as it can react with the functional group on the substrate surface. For example, a silane coupling group such as alkoxysilane, an isocyanate group, an amino group, a hydroxyl group, Examples thereof include a carboxyl group, a sulfonic acid group, a phosphoric acid group, an epoxy group, an allyl group, a methacryloyl group, and an acryloyl group. Particularly useful compounds as a polymer having a reactive functional group at the terminal or side chain of the polymer are a hydrophilic polymer having a trialkoxysilyl group at the polymer terminal, a hydrophilic polymer having an amino group at the polymer terminal, and a carboxyl group at the polymer terminal. A hydrophilic polymer having an epoxy group at the polymer terminal, and a hydrophilic polymer having an isocyanate group at the polymer terminal.
In addition, the hydrophilic polymer used at this time is not particularly limited as long as it is hydrophilic. Specifically, polyacrylic acid, polymethacrylic acid, polystyrene sulfonic acid, poly-2-acrylamido-2-methyl Examples thereof include propanesulfonic acid and salts thereof, polyacrylamide, and polyvinyl acetamide. In addition, a hydrophilic monomer polymer used in the following surface graft polymerization or a copolymer containing a hydrophilic monomer can be advantageously used.

Next, a method of polymerizing a compound having a double bond that can be polymerized from a base material to obtain a graft polymer will be described.
A method of polymerizing a compound having a double bond that can be polymerized from a base material to form a graft polymer is generally called surface graft polymerization. The surface graft polymerization method is a method in which an active species is provided on the surface of a substrate by a method such as plasma irradiation, light irradiation, or heating, and a compound having a polymerizable double bond disposed so as to be in contact with the substrate is polymerized. Refers to the method of bonding with the material.

Any known method described in the literature can be used as the surface graft polymerization method for carrying out the present invention. For example, New Polymer Experimental Science 10, edited by Polymer Society, 1994, published by Kyoritsu Shuppan Co., Ltd., p135 describes a photograft polymerization method and a plasma irradiation graft polymerization method as surface graft polymerization methods. In addition, the adsorption technique handbook, NTS Co., Ltd., supervised by Takeuchi, 1999.2, p203, p695 describes radiation-induced graft polymerization methods such as γ rays and electron beams. As a specific method of the photograft polymerization method, the methods described in JP-A-63-92658, JP-A-10-296895, and JP-A-11-119413 can be used. In the plasma irradiation graft polymerization method and the radiation irradiation graft polymerization method, the literatures described above and Y.C. Ikada et al. , Macromolecules vol. 19, page 1804 (1986) and the like can be applied.
Specifically, a polymer surface such as PET is treated with plasma or electron beam to generate radicals on the surface, and then the active surface is reacted with a monomer having a hydrophilic functional group. A graft polymer surface layer, i.e. a surface on which hydrophilic graft polymer chains are present, can be obtained.
In addition to the above-mentioned documents, photograft polymerization can be performed on the surface of the substrate as described in JP-A-53-17407 (Kansai Paint) and JP-A-2000-212313 (Dainippon Ink). It can also be carried out by applying a photopolymerizable composition to the film, and then irradiating it with an aqueous radical polymerization compound in contact.

-Compounds having polymerizable double bonds useful for surface graft polymerization-
A compound useful for forming a hydrophilic graft polymer chain is required to have a polymerizable double bond and to have a hydrophilic property. As these compounds, any of these compounds can be used as long as it has a double bond in the molecule, whether it is a hydrophilic polymer, a hydrophilic oligomer, or a hydrophilic monomer. Particularly useful compounds are hydrophilic monomers.
The hydrophilic monomer useful in the present invention is a monomer having a positive charge such as ammonium or phosphonium, or a negative charge or negative charge such as a sulfonic acid group, a carboxyl group, a phosphoric acid group, or a phosphonic acid group. And monomers having an acidic group that can be dissociated. In addition, for example, a hydrophilic monomer having a nonionic group such as a hydroxyl group, an amide group, a sulfonamide group, an alkoxy group, or a cyano group can be used.

  In the present invention, specific examples of particularly useful hydrophilic monomers include the following monomers. For example, (meth) acrylic acid or its alkali metal salt and amine salt, itaconic acid or its alkali metal salt and amine salt, allylamine or its hydrohalide salt, 3-vinylpropionic acid or its alkali metal salt and amine salt Vinyl sulfonic acid or its alkali metal salt and amine salt, styrene sulfonic acid or its alkali metal salt and amine salt, 2-sulfoethylene (meth) acrylate, 3-sulfopropylene (meth) acrylate or its alkali metal salt and amine salt 2-acrylamido-2-methylpropanesulfonic acid or its alkali metal salts and amine salts, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate or their salts, 2-dimethylaminoethyl (medium) ) Acrylate or its hydrohalide, 3-trimethylammoniumpropyl (meth) acrylate, 3-trimethylammoniumpropyl (meth) acrylamide, N, N, N-trimethyl-N- (2-hydroxy-3-methacryloyloxypropyl) ) Ammonium chloride, etc. can be used. In addition, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-monomethylol (meth) acrylamide, N-dimethylol (meth) acrylamide, N-vinylpyrrolidone, N-vinylacetamide, polyoxyethylene glycol mono (meth) ) Acrylate is also useful.

(B) Method for Producing Hydrophilic Graft Polymer Chain-Introduced Crosslinked Hydrophilic Layer In the present invention, the crosslinked hydrophilic layer into which the hydrophilic graft polymer chain is introduced is generally a graft polymer using a method known as a graft polymer synthesis method. Can be produced by cross-linking it. Specifically, the synthesis of the graft polymer is “graft polymerization and its application” written by Fumio Ide, published in 1977, “Polymer Publishing”, and “New Polymer Experimental Studies 2, Synthesis and Reaction of Polymers”. Edition, Kyoritsu Publishing Co., Ltd. (1995).

The synthesis of the graft polymer is basically as follows: 1. Polymerize the branch monomer from the trunk polymer. 2. Link the branch polymer to the trunk polymer. It can be divided into three methods of copolymerizing a branch polymer with a trunk polymer (macromer method). Any of these three methods can be used to produce the hydrophilic surface in the present invention, but “3. Macromer method” is particularly excellent from the viewpoints of production suitability and film structure control. Yes. The synthesis of graft polymers using macromers is described in the aforementioned “New Polymer Experiments 2, Polymer Synthesis / Reaction” edited by Polymer Society of Japan, Kyoritsu Shuppan Co., Ltd. 1995. It is also described in detail in Yamashita Yu et al., “Chemical Monomer Chemistry and Industry”, IPC, 1989.
Specifically, according to the method described in the literature, using hydrophilic monomers specifically described as the organic cross-linked hydrophilic layer, such as acrylic acid, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylacetamide and the like. Hydrophilic macromers can be synthesized.

Among the hydrophilic macromers used in the present invention, particularly useful are macromers derived from carboxyl group-containing monomers such as acrylic acid and methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, And sulfonic acid macromers derived from monomers of the salts thereof, amide macromers such as acrylamide and methacrylamide, amide macromers derived from N-vinylcarboxylic acid amide monomers such as N-vinylacetamide and N-vinylformamide, Macromers derived from hydroxyl-containing monomers such as hydroxyethyl methacrylate, hydroxyethyl acrylate, glycerol monomethacrylate, methoxyethyl acrylate, methoxypolyethylene glycol acrylate, polyethylene Macromers derived from alkoxy group or ethylene oxide group-containing monomers such as recall acrylate. A monomer having a polyethylene glycol chain or a polypropylene glycol chain can also be usefully used as a macromer in the present invention.
Among these macromers, the useful molecular weight is in the range of 400 to 100,000, the preferred range is 1000 to 50,000, and the particularly preferred range is 1500 to 20,000. When the molecular weight is 400 or less, the effect cannot be exhibited, and when it is 100,000 or more, the polymerizability with the copolymerization monomer forming the main chain tends to be deteriorated.

  After synthesizing these hydrophilic macromers, as one method for producing a crosslinked hydrophilic layer in which a hydrophilic graft polymer chain is introduced, the hydrophilic macromer is copolymerized with another monomer having a reactive functional group, Examples thereof include a method in which a graft copolymer is synthesized, and then the synthesized graft copolymer and a crosslinking agent that reacts with a reactive functional group of the polymer are coated on a support and reacted by heat to be crosslinked. In addition, as another method, there is a method of synthesizing a graft polymer having a hydrophilic macromer and a photocrosslinkable group or a polymerizable group, applying it on a support and reacting it with light irradiation to form a crosslink. Can be mentioned.

  In this manner, a surface hydrophilic member having a hydrophilic graft polymer chain on the substrate can be produced. The thickness of the layer forming the hydrophilic surface can be selected depending on the purpose, but generally it is preferably in the range of 0.001 μm to 10 μm, more preferably in the range of 0.01 μm to 5 μm, and in the range of 0.1 μm to 2 μm. Most preferred. If the film thickness is too thin, the scratch resistance tends to decrease, and if it is too thick, the effect of improving the adhesion tends to be low.

  The support (substrate) in the present invention is preferably a dimensionally stable plate, for example, paper, paper laminated with plastic (for example, polyethylene, polypropylene, polystyrene, etc.), metal plate (for example, , Aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc. ), Paper or plastic film on which a metal as described above is laminated or vapor-deposited. As a support body used for this invention, a polyester film, a cellulose acetate, or an aluminum plate is preferable, and a polyester film is especially preferable among these.

  Following the “surface hydrophilic member preparation step” described above, the following “electroless plating catalyst application step” is performed.

[Electroless plating catalyst application process]
In this step, an electroless plating catalyst or a precursor thereof is locally applied and adsorbed on the surface hydrophilic member obtained in the surface hydrophilic member preparation step.
As an aspect in which the electroless plating catalyst or its precursor is locally applied to the surface hydrophilic member and adsorbed, the electroless plating catalyst or its precursor is locally applied to the hydrophilic surface of the surface hydrophilic member. The method is not particularly limited as long as it is a method that can be applied and adsorbed.
1. A mode in which a fluid containing an electroless plating catalyst or a precursor thereof is ejected in a pattern from an ink jet recording head using an ink jet recording apparatus.
2. A mode in which an electroless plating catalyst or a precursor thereof is printed in a pattern by a known printing method.
Among these, “1. A mode using an ink jet recording apparatus” is particularly preferable from the viewpoints of supply accuracy and controllability of the supply amount of the electroless plating catalyst or its precursor to a predetermined region.
Hereinafter, the first and second aspects will be described.

<1. A mode in which a fluid containing an electroless plating catalyst or a precursor thereof is ejected in a pattern from an ink jet recording head using an ink jet recording apparatus>
Hereinafter, in the present invention, the above-mentioned 1. most preferable means for imparting an electroless plating catalyst or a precursor thereof to a surface hydrophilic member. Will be described.

The application of the electroless plating catalyst or the precursor thereof in this embodiment is performed using a fluid containing the electroless plating catalyst or the precursor thereof.
This fluid can be used in various modes depending on the desired conductive pattern. Here, the fluid in the present invention is not particularly limited as long as it has fluidity that can be ejected from an ink ejection nozzle of an ink jet apparatus described later at room temperature (25 ° C.). In addition to the solution, it may be a solid substance such as fine particles, or a dispersion liquid such as latex.

-Inkjet recording device-
Hereinafter, an ink jet recording apparatus suitably used in the present invention will be described.
In such an ink jet recording apparatus, first, pattern information of an image to be formed on a substrate (surface hydrophilic member) is transmitted from an information supply source such as a computer through a transmission means such as a bus. To supply.
As such an ink jet recording apparatus, an apparatus provided with an ink jet recording head provided so as to be able to eject liquid droplets and a control system for driving the head according to an arbitrary pattern may be used. By this apparatus, the fluid adheres according to the pattern information by ejecting the droplet of the fluid from the nozzle hole (ejection port) of the inkjet recording head moving according to the pattern information to a predetermined position on the surface hydrophilic member. To do.
The inkjet recording head provided in the inkjet recording apparatus is provided with a cavity configured to be filled with a fluid, and any piezoelectric element configured to be capable of causing a volume change in the cavity. By applying a voltage according to the pattern and changing the volume in the cavity, the fluid stored in the inside is made into fine droplets from the discharge port and supplied on the surface hydrophilic member in a predetermined image form Then, the solvent and the dispersion medium in the fluid are removed, and the electroless plating catalyst or its precursor adheres in a pattern.

<2. Aspect of Printing Electroless Plating Catalyst or its Precursor in Pattern by Known Printing Method>
In the present invention, as means for imparting an electroless plating catalyst or a precursor thereof to a surface hydrophilic member, the above-mentioned 2. The embodiment is also preferably used.
In this embodiment, as a method for forming the electroless plating catalyst or its precursor, a known printing method may be applied. For example, a screen printing method or the like is preferably used.
The electroless plating catalyst or precursor thereof in this embodiment is not particularly limited as long as it can be applied to a printing method. The same fluid as in the embodiment can be used as the printing liquid.
In addition, this aspect using a printing method for applying an electroless plating catalyst or a precursor thereof can easily obtain a conductive pattern at a low cost, so that a remarkably high resolution is not required for the conductive pattern. In this case, it is particularly suitable.

(Electroless plating catalyst or its precursor)
In the present invention, an electroless plating catalyst or a precursor thereof that can be adsorbed on a surface hydrophilic member will be described.

<Electroless plating catalyst>
The electroless plating catalyst used in this step is mainly a zero-valent metal, and examples thereof include Pd, Ag, Cu, Ni, Al, Fe, and Co. In the present invention, Pd and Ag are particularly preferable because of their good handleability and high catalytic ability. As a method for imparting a zero-valent metal to a surface hydrophilic member, generally, a metal colloid whose charge is controlled is used, and this metal colloid includes a charged surfactant or a charged protective agent. It can be prepared by reducing the metal ion of the metal in a solution. The charge varies depending on the surfactant used here, and it can be selectively adsorbed on the hydrophilic graft polymer chain by interacting with the hydrophilic group of the hydrophilic graft polymer chain present in the surface hydrophilic member. it can.

<Electroless plating catalyst precursor>
The electroless plating catalyst precursor used in this step can be used without particular limitation as long as it can become an electroless plating catalyst by a chemical reaction. Mainly, metal ions of zero-valent metal used in the electroless plating catalyst are used. The metal ion that is an electroless plating catalyst precursor becomes a zero-valent metal that is an electroless plating catalyst by a reduction reaction. The metal ion may be separately changed to a zero-valent metal by a reduction reaction, or may be immersed in an electroless plating bath as a precursor and changed to a metal by a reducing agent in the electroless plating bath.

In fact, metal ions that are electroless plating precursors interact as metal salts. The metal salt used is not particularly limited as long as it is dissolved in a suitable solvent and dissociated into a metal ion and a base (anion), and M (NO ₃ ) _n , MCl _n , M _{2 / n} ( SO ₄ ), M _{3 / n} (PO ₄ ) (M represents an n-valent metal atom), and the like. As a metal ion, the thing which said metal salt dissociated can be used suitably. Specific examples include Ag, Cu, Al, Ni, Co, Fe, and Pd, and Ag and Pd are preferable in terms of catalytic ability.

  As a method for applying a metal colloid that is an electroless plating catalyst or a metal salt that is an electroless plating precursor on a surface hydrophilic member, the metal colloid is dispersed in an appropriate dispersion medium, or the metal salt is appropriately applied. The solution containing the dissociated metal ions dissolved in the solvent is applied to the surface of the surface hydrophilic member where the hydrophilic graft polymer chain exists, or the surface hydrophilic member where the hydrophilic graft polymer chain exists in the solution May be immersed. By contacting a solution containing a metal ion, the hydrophilic group of the hydrophilic graft polymer chain can adsorb the metal ion using ion-ion or bipolar-ion interaction. From the viewpoint of sufficient adsorption, the metal ion concentration or the metal salt concentration of the solution to be contacted is preferably in the range of 1 to 50% by mass, and more preferably in the range of 10 to 30% by mass. preferable. The contact time is preferably about 1 minute to 24 hours, more preferably about 5 minutes to 1 hour.

[Electroless plating process]
Next, by applying the electroless plating catalyst or the surface hydrophilic member to which the electroless plating catalyst or its precursor is locally adsorbed by the electroless plating catalyst etc. application step, a metal is deposited in a pattern, A high-density conductive film is formed, and a conductive pattern is obtained. The formed conductive pattern exhibits excellent conductivity, durability, and adhesion.

<Electroless plating>
Electroless plating refers to an operation in which a metal is deposited by a chemical reaction using a solution in which metal ions to be plated are dissolved. In the electroless plating in this step, for example, the surface hydrophilic member obtained by applying the electroless plating catalyst or the precursor obtained in the electroless plating catalyst or the like in a pattern is washed with water to remove excess metal. After removing the metal salt, it is immersed in an electroless plating bath. As the electroless plating bath to be used, a generally known electroless plating bath can be used. Similarly, an electroless plating bath used to form a conductive film using an electroless plating catalyst precursor that is adsorbed or impregnated on a surface hydrophilic member is also generally known. Any electroless plating bath can be used.

The composition of a general electroless plating bath is as follows: 1. metal ions to be plated, 2. reducing agent; Additives (stabilizers) that improve the stability of metal ions are mainly included. In addition to these, the plating bath may contain known additives such as a plating bath stabilizer. As the types of metals used in the electroless plating bath, copper, tin, lead, nickel, gold, palladium, and rhodium are known, and among these, copper and gold are particularly preferable from the viewpoint of conductivity.
In addition, there are optimum reducing agents and additives according to the above metals. For example, a copper electroless plating bath contains Cu (SO ₄ ) ₂ as a copper salt, HCOH as a reducing agent, and a chelating agent such as EDTA or Rochelle salt as a copper ion stabilizer as an additive. The plating bath used for electroless plating of CoNiP includes cobalt sulfate and nickel sulfate as metal salts, sodium hypophosphite as a reducing agent, sodium malonate, sodium malate and sodium succinate as complexing agents. It is included. Further, the electroless plating bath of palladium contains (Pd (NH ₃ ) ₄ ) Cl ₂ as metal ions, NH ₃ and H ₂ NNH ₂ as reducing agents, and EDTA as a stabilizer. These plating baths may contain components other than the above components.

The film thickness of the conductive film thus formed can be controlled by the metal salt or metal ion concentration of the plating bath, the immersion time in the plating bath, or the temperature of the plating bath. From the viewpoint, it is preferably 0.5 μm or more, and more preferably 3 μm or more.
Further, the immersion time in the plating bath is preferably about 1 minute to 3 hours, and more preferably about 1 minute to 1 hour.

  In the metal film part of the conductive pattern obtained as described above, the electroless plating catalyst and the fine particles of the plating metal are closely dispersed in the surface graft film by cross-sectional observation by SEM. It was confirmed that large particles were deposited. Since the interface is in a hybrid state of the graft polymer and fine particles, the unevenness at the interface between the base material (organic component) and the inorganic substance (electroless plating catalyst or plating metal) is 500 nm or less, and more preferably 100 nm or less. Even the adhesion was good.

[Electroplating process]
In the conductive pattern forming method of the present invention, after the electroless plating, electroplating can be performed using the conductive film formed in the previous step as an electrode. As a result, a conductive film having an arbitrary thickness can be easily formed on the basis of the conductive pattern having excellent adhesion to the substrate. By adding this step, a patterned conductive film can be formed to a thickness according to the purpose, and therefore, the conductive pattern of the present invention is suitable for application to various applications such as a wiring pattern.

  As the electroplating method in the present invention, a conventionally known method can be used. In addition, as a metal used for the electroplating of this process, copper, chromium, lead, nickel, gold, silver, tin, zinc, etc. are mentioned. From the viewpoint of conductivity, copper, gold, and silver are preferable. More preferred.

  The film thickness of the electroconductive film obtained by electroplating varies depending on the application, and can be controlled by adjusting the concentration of metal contained in the plating bath, the immersion time, or the current density. . In addition, from the viewpoint of conductivity, the film thickness when used for general electric wiring or the like is preferably 0.3 μm or more, and more preferably 3 μm or more.

The conductive pattern obtained by the present invention can be used for various circuit formations, and an arbitrary conductive region can be formed by selecting a pattern forming means. Therefore, it is expected to be widely used including circuit formation for LSI and the like. Is done.
Furthermore, when a transparent film such as PET is used for the support, it can be used as a patterned transparent conductive film. Applications of such transparent conductive films include transparent electrodes for displays, light control devices, solar cells, touch panels, and other transparent conductive films, but are particularly useful as electromagnetic wave shielding filters for CRTs and plasma displays. . Since such an electromagnetic wave shielding filter requires high conductivity and transparency, it is preferable to provide a conductive pattern in a lattice shape. Such a lattice line width is preferably about 20 to 100 μm, and the opening is preferably about 50 to 600 μm. This lattice does not necessarily have to be regular and configured with straight lines, but may be configured with curved lines. In the present invention, since such an arbitrary conductive pattern can be easily formed, various settings according to the purpose are possible.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

[Example 1]
[Production of surface hydrophilic member]
A biaxially stretched polyethylene terephthalate film (A4100, manufactured by Toyobo Co., Ltd.) with a film thickness of 188 μm was used, and a lithographic magnetron sputtering apparatus (CFS-10-EP70, manufactured by Shibaura Eletech) was used as the glow treatment. Processed.

-Oxygen glow treatment conditions-
Initial vacuum: 1.2 × 10 ⁻³ Pa
Oxygen pressure: 0.9 Pa
RF glow: 1.5 kW, processing time: 60 sec

  Next, the glow-treated film was immersed in an aqueous solution of sodium styrenesulfonate (10 wt%) bubbled with nitrogen at 70 ° C. for 7 hours. The soaked membrane was washed with water for 8 hours to obtain a hydrophilic surface member A having a surface grafted with sodium styrenesulfonate.

[Application of electroless plating catalyst precursor]
An aqueous electroless plating catalyst precursor aqueous solution containing 0.1% by mass of palladium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) with a surface particle size of 30 μm is applied to the surface hydrophilic member A obtained as described above with an ink jet apparatus. Thus, the ink was discharged every 30 μm to give a pattern. Thereafter, the surface hydrophilic member A provided with the electroless plating catalyst precursor was immersed in an electroless plating bath having the following composition for 20 minutes to obtain a conductive pattern A.

<Electroless plating bath components>
・ OPC Kappa-H T1 (Okuno Pharmaceutical Co., Ltd.) 6mL
・ OPC Kappa-H T2 (Okuno Pharmaceutical Co., Ltd.) 1.2mL
・ OPC Kappa-H T3 (Okuno Pharmaceutical Co., Ltd.) 10mL
・ Water 83mL

[Example 2]
In Example 1, except that acrylic acid was used in place of sodium styrenesulfonate used for preparation of surface hydrophilic member A, and surface hydrophilic member B having acrylic acid graft polymerized on the surface was prepared. In the same manner as in Example 1, a conductive pattern B was obtained.

[Example 3]
The conductive pattern B obtained in Example 2 was further electroplated for 15 minutes using the following electroplating bath to produce a conductive pattern C.
<Composition of electroplating bath>
・ Copper sulfate 38g
・ 95 g of sulfuric acid
・ Hydrochloric acid 1mL
・ Capper Gream PCM (Meltex Co., Ltd.) 3mL
・ Water 500g

[Example 4]
In Example 2, instead of the 0.1% by mass aqueous solution of palladium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.), an aqueous solution of 1% by mass silver nitrate was used as the electroless plating catalyst precursor aqueous solution in the same manner as in Example 2. Thus, a conductive pattern D was obtained.

[Example 5]
In Example 2, instead of applying the electroless plating catalyst precursor aqueous solution with an ink jet apparatus, the 1% by mass silver nitrate aqueous solution, which is the electroless plating catalyst precursor aqueous solution used in Example 4, was used as a silk screen ink. The conductive pattern E was obtained in the same manner as in Example 2 except that silk screen printing was used.
As a screen used for printing, nylon monofilament X-XO, 420S was used.

<Evaluation>
The conductive patterns A to E obtained above were evaluated for conductivity, resolution, and durability as follows. The durability was evaluated by evaluating the wear resistance.

1. Evaluation of conductivity The surface resistance values of the conductive patterns A to E were measured by a four-probe method using LORESTA-FP (manufactured by Mitsubishi Chemical Corporation). The results are shown in Table 1.

2. Evaluation of Resolution The resolution (line / space, μm) of the conductive patterns A to E was measured using an electron microscope (S700, manufactured by JEOL Ltd.). The results are shown in Table 1.

3. Evaluation of Abrasion Resistance The surfaces of the conductive patterns A to E were rubbed 30 times by hand using a cloth (BEMCOT, manufactured by Asahi Kasei Kogyo Co., Ltd.) moistened with water. After rubbing, the surface was observed with a transmission electron microscope (JEOL JEM-200CX) at a magnification of 100,000 times. As for any conductive pattern, the conductive pattern was observed as before the rubbing treatment. It was confirmed that the conductive pattern was not damaged by rubbing.

  As shown in the above evaluations, it can be seen that according to the present invention, a conductive pattern excellent in resolution, conductivity, and durability can be obtained.

Claims (1)

Producing a surface hydrophilic member in which a hydrophilic graft polymer chain exists over the entire surface of at least one side of the support;
A step of locally applying and adsorbing an electroless plating catalyst or a precursor thereof to the surface hydrophilic member;
A step of performing electroless plating on the surface hydrophilic member on which the electroless plating catalyst or its precursor is locally adsorbed;
A method for forming a conductive pattern, comprising: