JP2003217350A - Composition for forming conductive pattern and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for forming a conductive pattern capable of forming the conductive pattern on a material having low heat-resistance. <P>SOLUTION: The composition for forming a conductive pattern contains a metal colloidal particle, a polymer pigment dispersing agent and a photosensitive resin binder. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a conductive pattern forming composition, a method for producing the same, and a method for forming a conductive pattern.

[0002]

2. Description of the Related Art In recent years, electronic components such as multi-chip modules to be mounted on personal computers and PC cards, chip size packages or mobile communication devices such as mobile phones, chip inductors, multilayer capacitors and other electronic parts or ceramic multilayer substrates. On the other hand, demands for miniaturization, high density, high definition, and high reliability are increasing. Further, with the increase in definition of display devices such as plasma displays, there is an increasing demand for miniaturization of electrodes. To meet these demands, various fine conductor film forming methods have been proposed.

Typical methods include a thin film method, a plating method, and a thick film printing method. Above all, a thickness of a conductor formed by pattern-printing a paste composed of a conductor powder and a resin by screen printing and then firing the paste. In the film printing method, it is easy to increase the thickness of the conductor film and simultaneously form passive elements such as resistors, but on the other hand, L / S = 50/50 μm or less resolution and line formation of a constant width However, there is a problem in that the cross-sectional shape is a kamaboko and it is difficult to design the electrical characteristics.

A photosensitive paste method is used to improve the resolution and sectional shape of the thick film printing method. This is one in which a conductive paste for thick-film printing is used, and a high-resolution thick-film conductive pattern can be formed by printing on the entire surface of the substrate and then performing mask exposure and development steps. As the photosensitive paste, a mixture of metal powder and photocurable resin is often used.

However, the photosensitive paste method has a poor baking property as compared with the method using a non-photosensitive paste,
There is a problem that the resistance value of the conductor after firing is high. That is,
In the non-photosensitive paste, the binder resin only needs to be contained in the minimum amount necessary for connecting the conductor powders, but in the photosensitive paste, the binder resin has not only the connection for the conductor powders but also photosensitivity. Since it is a component responsible for pattern processability by photolithography, it is contained in a certain amount or more with respect to the conductor powder in order to obtain sufficient pattern processability, so during firing, organic components are thermally decomposed and volatilized. It takes time to do so, and it is not preferable from the viewpoint of calcination property. Further, when firing is performed, a glass frit is usually contained in order to supplement the binder component that decomposes or volatilizes. This glass frit is an inorganic component and has a problem of settling in the composition during storage.

Japanese Patent Laid-Open No. 2001-167631 discloses that
Disclosed is a method for producing an ultrafine particle conductor paste in which ultrafine particles of a conductive metal powder are generated in a solvent by a wet reduction method and then the obtained ultrafine particles are mixed and dispersed in a vehicle without being separated from the solvent. . This relates to an ultrafine particle conductor paste particularly suitable for forming a thin conductor having a thickness of 1 μm or less, but since a conductor film can be obtained at a firing temperature of 1000 to 1200 ° C., it is difficult to apply it to a material having low heat resistance. is there.

Japanese Unexamined Patent Publication No. 2001-194779 discloses that
Disclosed is a conductor paste containing a conductor powder and a photosensitive resin, in which the amount of carbon-carbon double bonds relative to the mass of the photosensitive resin is 2.0 mmol / g or more. This is an attempt to improve the calcination property at a low temperature, but it is difficult to apply it to a material having low heat resistance because it is heat-treated at a calcination temperature of 580 ° C. In addition, since the conductor is powdery, there is a risk of sedimentation.

[0008]

SUMMARY OF THE INVENTION In view of the above situation, it is an object of the present invention to provide a conductive pattern forming composition capable of forming a conductive pattern on a material having low heat resistance. is there.

[0009]

The present invention is a conductive pattern forming composition comprising metal colloid particles, a polymeric pigment dispersant, and a photosensitive binder component. The metal colloid particles are preferably formed by reducing a metal compound in a solution in the presence of a polymer pigment dispersant.

In the present invention, in the presence of a polymeric pigment dispersant,
A step (1) of reducing the metal compound to obtain a metal colloid solution, and a step (2) of adding a photosensitive binder component to the metal colloid solution obtained in the above step (1).
A method for producing a composition for forming a conductive pattern, which comprises: The present invention is a composition for forming a conductive pattern, which is obtained by the above production method.

The present invention also includes a step (3) of applying the conductive pattern forming composition onto a substrate, a step (4) of exposing the film obtained by the step (3) with a mask,
Conductivity, comprising: a step (5) of developing the film obtained in the step (4) to obtain a pattern, and a step (6) of heating the pattern obtained in the step (5). This is a pattern forming method. Hereinafter, the present invention will be described in detail.

The conductive pattern forming composition of the present invention comprises:
It contains metal colloid particles, a polymeric pigment dispersant, and a photosensitive binder component. The conductive pattern forming composition contains metal colloid particles. The metal colloidal particles are dispersed in the conductive pattern forming composition, and a conductive pattern can be obtained from the conductive pattern forming composition.

As the metal forming the metal colloidal particles, those usually used for forming conductive patterns are used, and examples thereof include gold, silver, platinum and copper. Among these, silver is preferable from the viewpoint of conductivity.

The metal colloid particles are preferably formed by reducing a metal compound in a solution in the presence of a polymeric pigment dispersant. That is, the metal colloid particles can be obtained as a metal colloid solution by reducing a metal compound in the presence of a polymer pigment dispersant, and for example, a step in the method for producing a conductive pattern forming composition described below. It is preferably obtained as a metal colloidal solution obtained by (1).

The content of the metal colloid particles is preferably 40 to 85% by mass in terms of the amount of metal with respect to the mass of the solid content in the conductive pattern forming composition. 40
If it is less than mass%, a conductive pattern may not be obtained, and if it exceeds 85 mass%, the pattern may not be drawn.

The conductive pattern forming composition contains a polymer pigment dispersant. The polymeric pigment dispersant is an amphipathic copolymer having a structure having a solvating portion, in which a functional group having a high affinity for the pigment surface is introduced into a high molecular weight polymer, and is usually It is used as a pigment dispersant during the production of a pigment paste.

It is considered that the above-mentioned polymer pigment dispersant coexists with the above-mentioned metal colloid particles and has a function of stabilizing dispersion of the above-mentioned metal colloid particles in a solvent. The polymer pigment dispersant has a number average molecular weight of 1,000.
It is preferably ˜1,000,000. If it is less than 1000, the dispersion stability may not be sufficient, and if it exceeds 1 million, the viscosity may be too high and handling may be difficult. It is more preferably 2000 to 500,000, and even more preferably 4000 to 500,000.

The polymer pigment dispersant is not particularly limited as long as it has the above-mentioned properties, and examples thereof include those exemplified in JP-A No. 11-80647. As the polymer pigment dispersant, various types can be used, but a commercially available one can also be used. Examples of the commercially available product include Sols Perth 20
000, Sols Perth 24000, Sols Perth 260
00, Sols Perth 27000, Sols Perth 2800
0, Sols Perth 41090 (above manufactured by Abyssia),
Dispervik 160, Dispervik 161, Dispervik 162, Dispervik 163, Dispervik 166, Dispervik 170, Dispervik 180, Dispervik 181, Dispervik 182, Dispervik-183, Dispervik 184, Dispervik 190, Disper Big 191, Disper Big 192, Disper Big-2000, Disper Big-2001 (above,
Manufactured by BIC Chemie), polymer 100, polymer 12
0, polymer 150, polymer 400, polymer 40
1, polymer 402, polymer 403, polymer 45
0, polymer 451, polymer 452, polymer 45
3, EFKA-46, EFKA-47, EFKA-4
8, EFKA-49, EFKA-1501, EFKA-
1502, EFKA-4540, EFKA-4550
(Above, manufactured by EFKA Chemical Co., Ltd.), Floren DOPA
-158, Floren DOPA-22, Floren DO
PA-17, Floren G-700, Floren TG-
720W, Floren-730W, Floren-740
W, Floren-745W, (all manufactured by Kyoeisha Chemical Co., Ltd.), Azisper PA111, Azisper PB711,
Addisper PB811, Addisper PB821, Addisper PW911 (above, Ajinomoto Co.), John Krill 6
78, John Krill 679, John Krill 62 (above,
Johnson Polymer Co., Ltd.) and the like. These may be used alone or in combination of two or more.

The content of the polymer pigment dispersant is 2 with respect to the mass of the solid content in the conductive pattern forming composition.
It is preferably about 20% by mass. If it is less than 2% by mass, the dispersion stability of the metal colloid particles in the conductive pattern composition may be lowered, and if it exceeds 20% by mass, the conductive pattern may not be obtained.

The conductive pattern forming composition contains a photosensitive binder component. The photosensitive binder component itself has the ability to form a film, and its solubility changes when it is irradiated with light having a wavelength in the ultraviolet to visible region. The one in which the light-irradiated portion does not dissolve is called the negative type, and the one in which it becomes soluble is called the positive type. These are generally widely used for resists and printing plates.

The main components of the negative photosensitive binder component include polymers and / or monomers having a double bond. The polymer having a double bond is not particularly limited, and examples thereof include acryloyl group, methacryloyl group (meth) acryloyl group, cinnamoyl group, vinyl group, allyl group and other photosensitive double bond as a terminal or pendant group. Examples thereof include acrylic resins, epoxy resins, urethane resins, polybutadiene resins, and maleated oil resins.

Examples of the method for preparing an acrylic resin having a photosensitive double bond as a terminal or a pendant group include unsaturated carboxylic acids (acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid). Acid, vinyl acetic acid, these acid anhydrides, etc.) and ethylenically unsaturated compounds (methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate,
n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, n-butyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert
-Butyl methacrylate, n-pentyl acrylate,
Copolymerization with n-pentyl methacrylate, styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene), and further, an ethylenically unsaturated compound having a glycidyl group (glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether) , Α-glycidyl ethyl acrylate, crotonyl glycidyl ether, crotonic acid glycidyl ether, isocrotonic acid glycidyl ether) and chloride acrylate compounds (chloride acrylate, chloride methacrylate, allyl chloride) can be mentioned. .

Examples of the monomer having a double bond include allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2-ethylhexyl acrylate. ,
Glycerol acrylate, glycidyl acrylate,
Heptadecafluorodecyl acrylate, 2-hydroxyethyl acrylate, isobonyl acrylate, 2-hydroxypropyl acrylate, isodexyl acrylate, isooctyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, methoxyethylene glycol acrylate, methoxydiethylene glycol acrylate, octa Fluoropentyl acrylate, phenoxyethyl acrylate, stearyl acrylate, trifluoroethyl acrylate, allylated cyclohexyl diacrylate, bisphenol A diacrylate, 1,4-butanediol diacrylate, 1,
3-butylene glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, ditrimethylolpropane tetraacrylate, glycerol diacrylate , Methoxycyclohexyl diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, triglycerol diacrylate, trimethylolpropane triacrylate; the above acrylates converted to methacrylate; γ-methacryloxypropyl trimethoxy Shi It can be mentioned 1-vinyl-2-pyrrolidone; down.

When the polymer and / or monomer having a double bond is used, a photopolymerization initiator is usually contained as a negative photosensitive binder component. Examples of the photopolymerization initiator include benzophenone, camphorquinone, 4,4-bis (dimethylamino) benzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 4,4′-dimethoxybenzophenone, 4-dimethylaminobenzophenone. , 4-dimethylaminoacetophenone, benzylanthraquinone, 2-tert-butylanthraquinone, 2-methylanthraquinone, xanthone, thioxanthone, 2-chlorothioxanthone,
2,4-diethylthioxanthone, fluorenone, acridone, bis (2,4,6-trimethylbenzoyl)-
Bisacylphosphine oxides such as phenylphosphine oxide; Acylphosphine oxides such as Lucirin TPO; Aromatic ketones such as α-hydroxy or α-aminoacetophenones, α-hydroxycycloalkylphenyl ketones and dialkoxyacetophenones; Benzoin and benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin phenyl ether; 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4 , 5-Di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diph Phenylimidazole dimer, 2-
2,4,6-triarylimidazole dimers such as (p-methoxyphenyl) -4,5-diphenylimidazole dimers; polyhalogens such as carbon tetrabromide, phenyltribromomethyl sulfone and phenyltrichloromethyl ketone Compound; 2,4,6-tris (trichloromethyl)-
S-triazine, 2-methoxy-4,8-bis (trichloromethyl) -S-triazine, 2-amino-4,6-
Bis (trichloromethyl) -S-triazine, 2- (P
-Methoxystyryl) -4,6-bis (trichloromethyl) -S-triazine and the like, S-triazine derivatives having a trihalogen-substituted methyl group described in JP-A-58-29803; methyl ethyl ketone peroxide, cyclohexanone peroxide, 3 , 3,5-Trimethylcyclohexanone peroxide, benzoyl peroxide, ditert-butyldiperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, tert-butylperoxybenzoate, a, a'-bis (tert-butylperoxyisopropyl) benzene, dicumyl peroxide,
3,3 ′, 4,4′-tetra- (tertiarybutylperoxycarbonyl) benzophenone, organic boron compound; phenylglyoxalic acid esters such as phenylglyoxalic acid methyl ester; bis (η5-2,4 -Cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl)
Titanocenes such as titanium; η5-cyclopentadienyl-η6-cumenyl-iron (1 +)-hexafluorophosphate (1-) and other iron arene complexes; diphenyliodonium salts and other diaryliodonium salts; triphenylsulfonium salts and the like The triarylsulfonium salts and the like can be mentioned.

When the photosensitive binder component contains both a polymer having a double bond and a monomer, the ratio of the polymer having a double bond, the monomer having a double bond and the photopolymerization initiator to the total mass is two. The polymer having a heavy bond is 5 to 80% by mass, the monomer having a double bond is 5 to 80% by mass, and the photopolymerization initiator is 0.1 to 20% by mass.
It is preferably mass%.

In addition to the above, as the negative photosensitive binder component, an aromatic diazo compound, an aromatic azide compound,
A mixture of a photosensitive compound such as an organic halogen compound and a suitable polymer binder; a photosensitive polymer obtained by pendenting a photosensitive group on an existing polymer or a modified one thereof; a diazo amine Examples thereof include so-called diazo resins such as condensation products with formaldehyde.

On the other hand, examples of the positive photosensitive binder component include a complex of an inorganic salt of a diazo compound or an organic acid; a mixture of quinonediazide and the like and a suitable polymer binder; and a quinonediazo compound as a suitable polymer binder. Bound materials such as naphthoquinone-1,2-diazide-5 of phenol, novolac resin
A sulfonic acid ester etc. can be mentioned.

The photosensitive binder component may contain a non-photosensitive polymer. The above non-photosensitive polymer can be used for ensuring film forming property, for example, when a monomer having a double bond is used as the above-mentioned negative photosensitive binder component.

Examples of the non-photosensitive polymer include polyvinyl alcohol, polyvinyl butyral, methacrylic acid ester polymer, acrylic acid ester polymer, acrylic acid ester-methacrylic acid ester copolymer, α-methylstyrene polymer, Butyl methacrylate resin etc. can be mentioned.

The content of the photosensitive binder component is preferably 10 to 50% by mass based on the mass of the solid content in the conductive pattern forming composition. If it is less than 10% by mass, the pattern may not be drawn, and 5
If it exceeds 0% by mass, a conductive pattern may not be obtained.

The conductive pattern forming composition of the present invention comprises
In the composition, the metal colloid particles are dispersed and stabilized as a colloid by the polymer pigment dispersant. Thereby, when a heat treatment is performed to form a conductive pattern using the conductive pattern forming composition, a conductive pattern having conductivity can be obtained by treating at a relatively low temperature as a heating temperature. Is something that can be done.

The conductive pattern forming composition of the present invention comprises
Since the metal colloidal particles stabilized by the polymer dispersant are contained, the metal does not settle, and since the glass frit as an inorganic component is not contained, long-term stability is maintained.

The method for producing a conductive pattern forming composition of the present invention comprises a step (1) of reducing a metal compound to obtain a metal colloid solution in the presence of a polymeric pigment dispersant, and the above step (1). The method includes the step (2) of adding a photosensitive binder component to the metal colloidal solution obtained in (1).

The metal compound used in the step (1) produces metal ions when dissolved in a solvent, and the metal ions are reduced to supply the metal colloid particles. Examples of the metal forming the metal colloidal particles include those mentioned above.

The above metal compound is not particularly limited as long as it contains the above metal, and examples thereof include tetrachloroauric (III) acid tetrahydrate (chloroauric acid), silver nitrate, silver acetate,
Silver (IV) perchlorate, hexachloroplatinate (IV) acid hexahydrate (chloroplatinic acid), potassium chloroplatinate, copper chloride (I
I) dihydrate, copper (II) acetate monohydrate, copper sulfate (I
I) etc. can be mentioned. These may be used alone or in combination of two or more.

The above metal compound is preferably used so that the molar concentration of the metal in the solvent is 0.01 mol / l or more. If it is less than 0.01 mol / l, the obtained metal colloid solution has too low a metal molar concentration and is not efficient. It is preferably 0.05 mol / l or more, more preferably 0.1 mol / l or more.

The above solvent is not particularly limited as long as it can dissolve the above metal compound, and for example,
Water, an organic solvent, etc. can be mentioned. The organic solvent and the like are not particularly limited, and examples thereof include alcohols having 1 to 4 carbon atoms such as ethanol and ethylene glycol; ketones such as acetone; esters such as ethyl acetate. These may be used alone or in combination of two or more. When the solvent is a mixture of water and an organic solvent, the organic solvent is preferably water-soluble, and examples thereof include acetone, methanol, ethanol and ethylene glycol. In the present invention,
When the ultrafiltration treatment is performed later, water, alcohol, and a mixed solution of water and alcohol are preferable.

The above-mentioned polymeric pigment dispersant can be used. The amount of the polymeric pigment dispersant used is preferably 25% by mass or less based on the total amount of the metal in the metal compound and the polymeric pigment dispersant.
If it exceeds 25% by mass, a conductive pattern may not be obtained. More preferably, it is 15 mass% or less.

The above metal compound can be reduced to a metal by using a reducing compound in the presence of the above-mentioned polymer pigment dispersant. As the reducing compound, amine is preferable, for example, by adding the amine to the solution of the metal compound and the polymer pigment dispersant, and stirring and mixing,
Metal ions are reduced to metal near room temperature. By using the above amine, it is not necessary to use a highly dangerous or harmful reducing agent, and 5 to 100 ° C., preferably 20 to 80 ° C., without heating or using a special light irradiation device.
The metal compound can be reduced at the reaction temperature of.

The amine is not particularly limited and, for example, those exemplified in JP-A No. 11-80647 can be used. Propylamine, butylamine, hexylamine, diethylamine, dipropylamine, dimethylethylamine. , Diethylmethylamine, triethylamine, ethylenediamine, N, N, N ',
N'-tetramethylethylenediamine, 1,3-diaminopropane, N, N, N ', N'-tetramethyl-1,
Aliphatic amines such as 3-diaminopropane, triethylenetetramine, tetraethylenepentamine; piperidine,
Alicyclic amines such as N-methylpiperidine, piperazine, N, N'-dimethylpiperazine, pyrrolidine, N-methylpyrrolidine, morpholine; aniline, N-methylaniline, N, N-dimethylaniline, toluidine, anisidine, phenetidine, etc. Aromatic amines; benzylamine, N-methylbenzylamine, N, N-dimethylbenzylamine, phenethylamine, xylylenediamine,
Examples thereof include aralkylamines such as N, N, N ', N'-tetramethylxylylenediamine and the like. Also,
Examples of the amine include methylaminoethanol,
Alkanolamines such as dimethylaminoethanol, triethanolamine, ethanolamine, diethanolamine, methyldiethanolamine, propanolamine, 2- (3-aminopropylamino) ethanol, butanolamine, hexanolamine and dimethylaminopropanol can also be mentioned. These may be used alone or in combination of two or more. Of these, alkanolamines are preferable, and dimethylaminoethanol is more preferable.

In addition to the above amines, alkali metal borohydrides such as sodium borohydride that have been conventionally used as reducing agents; hydrazine compounds; citric acid; tartaric acid; ascorbic acid; formic acid; formaldehyde; nithionite salts. , Sulfoxylate derivatives and the like can be used. Citric acid, tartaric acid, and ascorbic acid are preferable because they are easily available. These can be used alone or in combination with the above-mentioned amines, but when the amine is combined with citric acid, tartaric acid, ascorbic acid, citric acid, tartaric acid, ascorbic acid should be used in the form of their respective salts. preferable. In addition, citric acid and sulfoxylate derivatives can be used in combination with iron (II) ions to improve the reducibility.

The amount of the reducing compound added is preferably at least the amount required to reduce the metal in the metal compound. If it is less than this amount, the reduction may be insufficient. The upper limit is not particularly limited, but is preferably 30 times or less, and more preferably 10 times or less, the amount necessary for reducing the metal in the metal compound. In addition to the method of chemically reducing by adding these reducing compounds, it is also possible to use a method of light irradiation using a high pressure mercury lamp.

The method of adding the reducing compound is not particularly limited and can be carried out, for example, after the addition of the polymeric pigment dispersant. In this case, for example, first, the polymeric pigment dispersant is added to a solvent. The reduction can be promoted by dissolving and then adding the remaining one of the reducing compound or the metal compound to the solution obtained by dissolving either the reducing compound or the metal compound. As a method of adding the reducing compound, it is also possible to first mix the polymeric pigment dispersant with the reducing compound and add the mixture to a solution of the metal compound.

By the above reduction, the average particle size is about 5-10.
A solution containing 0 nm metal colloidal particles is obtained.
The solution after the reduction becomes a colloidal solution containing the metal colloid particles and the polymer pigment dispersant. With the colloidal solution, metal fine particles are dispersed in a solvent,
It means that it is in a state of being visible as a solution.

In the colloid solution after the reduction, the solid content containing the metal colloid particles and the polymer pigment dispersant is preferably 0.05 to 50% by mass. 0.0
If it is less than 5%, the molar concentration of the metal is too low, which is inefficient, and if it exceeds 50%, the dispersion stability of the colloidal solution may decrease.

The lower limit of the metal concentration in the solid content in the colloidal solution is preferably 80% by mass, more preferably 90% by mass. The preferable upper limit is 95% by mass. If it is less than 80% by mass, a conductive pattern may not be obtained,
When it exceeds the mass%, the production is difficult.

In the present specification, the metal concentration of the metal colloid solution or the colloid solution means the mass% of the metal in the solid content of the metal colloid solution or the colloid solution. The solid content and the metal content are 100 to 150 ° C. and the number 1
It can be determined by measuring the residue obtained by heating each at 00 ° C. Specifically, TG-DTA
After heating up to 140 ° C at 10 ° C / min using
The solid content was first determined by maintaining 140 ° C. for one minute. Then, the temperature was raised again to 500 ° C. at 10 ° C./minute, and then 30
The amount of metal was determined by maintaining 500 ° C. for one minute. The measurement of the metal concentration in this specification is performed by using this method unless otherwise specified. The metal concentration of the colloidal solution after the reduction can be determined by measuring with TG-DTA or the like. However, when the measurement is not performed, the value calculated from the blending amount used for the preparation is used. I don't mind.

The colloidal solution after the reduction contains, in addition to the metal colloidal particles and the polymeric pigment dispersant, miscellaneous ions such as chloride ions derived from the raw materials, salts produced by the reduction, and amine in some cases. I'm out. Since these miscellaneous ions, salts and amines may adversely affect the dispersion stability of the metal colloid, it is desirable to remove them. Methods such as electrodialysis, centrifugation, and ultrafiltration are used to remove these components, but in the present invention, ultrafiltration is used because the metal concentration can be increased simultaneously with the removal of these components. It is preferable.

By ultrafiltration of the colloidal solution, not only the impurities, salts and amines in the colloidal solution are removed, but also a part of the polymer pigment dispersant is removed. As a result, the metal concentration in the solid content of the colloidal solution can be increased.

In the ultrafiltration, the diameter of the substance to be separated is usually 1 nm to 5 μm. When it is less than 1 nm,
Unnecessary components may not be eliminated because they do not pass through the filtration membrane, and if it exceeds 5 μm, many of the metal colloid particles may pass through the filtration membrane, and the metal concentration of the colloid solution may not be increased.

The filtration membrane for the ultrafiltration is not particularly limited, but usually, for example, polyacrylonitrile, vinyl chloride / acrylonitrile copolymer, polysulfone,
Resins such as polyimide and polyamide are used. It is preferable to use a filtration membrane that can be backwashed for the purpose of the efficiency of washing.

The ultrafiltration membrane preferably has a molecular weight cutoff of 3,000 to 80,000. 3000
If it is less than 8, it is difficult to remove unnecessary components sufficiently,
When it exceeds 0000, the above metal colloid particles easily pass through the filtration membrane, so that the desired metal colloid solution may not be obtained in some cases. More preferably, 10000 to
It is 60,000.

The form of the filtration module for the ultrafiltration is not particularly limited, and examples thereof include a hollow paper type module (also called a capillary module), a spiral module, a tubular module and a plate type module depending on the form of the filtration membrane. To be Among these, a hollow paper type module having a compact shape for its filtration area is preferable from the viewpoint of efficiency. When the amount of colloidal solution to be treated is large, it is preferable to use one having a large number of ultrafiltration membranes.

The ultrafiltration method is not particularly limited, and, for example, a conventionally known method can be used. Usually, the colloid solution after the reduction is passed through an ultrafiltration membrane. The filtrate containing the above-mentioned miscellaneous ions, salts, amines and polymeric pigment dispersants is eliminated. The ultrafiltration is usually repeated until the contaminant ions in the filtrate are removed to a desired concentration or less. At that time, it is preferable to add the same amount of the solvent as the amount of the filtrate removed in order to keep the concentration of the colloidal solution to be treated constant. It is possible to replace the solvent of the colloidal solution by using a solvent different from the one used at the time of reduction as the solvent added at this time. For example, when the solvent of the colloidal solution to be treated is water, it can be made excellent in drying property, wettability to the substrate, etc. by substituting with alcohol such as ethanol, while the solvent is ethanol or the like. In the case of the above alcohol, it is possible to make it excellent in environmental friendliness by substituting it with water.

The above ultrafiltration can be carried out by an ordinary operation, for example, a so-called batch system. This batch method is a method in which a colloidal solution to be treated is added in proportion to the progress of ultrafiltration. The ultrafiltration can be further performed after the miscellaneous ions have been removed to a desired concentration or less to increase the solid content concentration.

The metal concentration of the colloidal solution obtained by the above ultrafiltration treatment is higher than the metal concentration of the solution before the treatment. For example, the difference in metal concentration before and after treatment is
It is preferably 0.5 to 10% by mass. A more preferred lower limit is 1% by mass and an upper limit is 5% by mass.

The metal concentration of the colloidal solution obtained by the above ultrafiltration treatment is preferably 80 to 95% by mass. If it is less than 80% by mass, the conductive pattern may not be obtained. If it exceeds 95% by mass,
The dispersion stability of the metal colloid particles may be reduced. A preferred lower limit is 90% by mass, and a preferred upper limit is
It is 95 mass%.

By the above step (1), a metal colloid solution containing metal colloid particles formed by reducing a metal compound in a solution in the presence of a polymer pigment dispersant can be obtained. The metal colloid solution contains metal colloid particles and a polymer pigment dispersant.

The step (2) is a step (2) of adding a photosensitive binder component to the metal colloid solution obtained in the step (1), and after the addition, the metal colloid particles,
There is no particular limitation as long as it is a step of obtaining a conductive pattern forming composition containing a polymeric pigment dispersant and a photosensitive binder component.

The above-mentioned photosensitive binder component can be used. The amount of the photosensitive binder component added is a mass ratio of the metal colloid particles to the photosensitive binder component (solid mass of the metal colloid particles / solid mass of the photosensitive binder component).
Is preferably 50/50 to 90/10. If it is less than 50/50, heat treatment at a high temperature may be required to obtain a conductive pattern,
If it exceeds 90/10, the pattern may not be drawn.

The method of forming a conductive pattern of the present invention comprises a step (3) of applying the above-mentioned composition for forming a conductive pattern to a substrate, and a film obtained by the step (3) is masked and exposed. It includes a step (4) of performing, a step (5) of developing the film obtained by the step (4) to obtain a pattern, and a step (6) of heating the pattern obtained by the step (5). .

The step (3) is a step of applying the conductive pattern forming composition to a substrate. In the step (3), as a method for applying the conductive pattern forming composition to the substrate, the conductive pattern forming composition is applied onto the substrate by a known application method and dried to form a layer (hereinafter referred to as a layer). , Sometimes referred to as a “photosensitive resin layer”.), A transfer material in which a conductive pattern forming composition is applied on a temporary support by a known coating method to form a layer, A method of forming a photosensitive resin layer on a substrate,
Etc. In the case of the method of forming the photosensitive resin layer on the base material by the above transfer, the layer formed on the temporary support is once peeled from the temporary support and used as an independent sheet (photosensitive sheet). You can also Examples of the base material include glass and plastic.

As the above-mentioned coating method, known coating methods can be used. For example, dip coating, coating rod, spinner coating, spray coating, roller coater, curtain coater, knife coater, wire bar coater, extruder and the like can be used. You can list the method you used.

After the above-mentioned application, a photosensitive resin layer or a photosensitive sheet can be obtained by drying. The above-mentioned drying can be carried out not only by leaving it at room temperature, but also by heating it at 200 ° C or lower for an appropriate time, for example, 1 to 60 minutes.

The thickness of the photosensitive resin layer after drying is usually about 0.1 to 10 μm. Further, an oxygen blocking layer may be provided on the photosensitive resin layer in order to prevent the polymerization inhibiting action by oxygen.

The oxygen barrier layer can be formed of a water-soluble polymer such as polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide or cellulose. Among them, those mainly containing polyvinyl alcohol having a high oxygen gas barrier property are particularly preferable. In some cases, vinylpyrrolidone may be partially contained in order to improve the adhesive force between the photosensitive resin layer and the oxygen barrier layer. The oxygen barrier layer is formed by the same coating method as described above, and the thickness of the oxygen barrier layer after drying is usually 0.1 to 1
It is about 0 μm.

The step (4) is a step of exposing the film obtained in the step (3) with a mask. In the step (4), when the photosensitive binder component in the conductive pattern forming composition used in the step (3) is a negative type photosensitive resin, the portion to be removed by the development treatment in the film. Is exposed with a mask, and in the case of a positive type photosensitive resin, a portion of the film other than the portion to be removed by the development process is exposed with a mask.

The film obtained in the step (3) means that when only the photosensitive resin layer is formed in the step (3),
It means a photosensitive resin layer, and when a photosensitive resin layer and an oxygen barrier layer are formed, it means a photosensitive resin layer and an oxygen barrier layer.

In the step (4), as a method of exposing with a mask, an ultraviolet exposure method using a photomask, a scanning exposure method using a laser beam, or the like can be performed.

The exposure light source applicable in the step (4) is not particularly limited, and examples thereof include carbon arc, high pressure mercury lamp, xenon lamp, metal halide lamp, fluorescent lamp, tungsten lamp, halogen lamp, helium cadmium laser and argon. Ion laser, YAG laser, helium neon laser and the like can be used particularly preferably. The photo mask above
It can be appropriately selected from known ones.

The step (5) is a step of developing the film obtained in the step (4) to obtain a pattern. The step (5) is a composition for forming an unnecessary conductive pattern in the film by developing the film having an exposed portion and an unexposed portion by exposing with the mask used in the step (4) ( An image (pattern) is formed on a base material by removing a photosensitive resin layer in an unnecessary area that does not participate in image formation.

In the case of a negative type photosensitive resin layer, a solvent that dissolves the unexposed portion and does not dissolve the exposed portion can be used as the developer used for the above-mentioned development treatment. In the case of a layer, a solvent that dissolves the exposed area can be used.

From the viewpoint of the recent environmental impact, the development is preferably performed with an alkaline aqueous solution as a solvent for both the negative type and the positive type. For example, a dilute aqueous solution of an alkaline substance or the above alkaline substance is used. And a small amount of an organic solvent miscible with water added to the dilute aqueous solution.

Examples of the alkaline substance include alkali metal hydroxides (eg, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc.), alkali metal carbonates (eg, sodium carbonate, potassium carbonate, etc.), and alkali metal heavy metals. Carbonates (eg, sodium hydrogen carbonate, potassium hydrogen carbonate, etc.), alkali metal silicates (eg, sodium silicate, potassium silicate, etc.), alkali metal metasilicates (eg, sodium metasilicate, potassium metasilicate, etc.) , Triethanolamine, diethanolamine, monoethanolamine, trimethylamine, diethylamine, isopropylamine, n-butylamine, morpholine, tetraalkylammonium hydroxides (eg, tetramethylammonium hydroxide, etc.), tertiary phosphorus Include sodium, dibasic sodium phosphate and the like. These may be used alone or in combination of two or more.

The developing treatment can be carried out by immersion development, spray development, brush development, ultrasonic development or the like. When removing the unnecessary region of the photosensitive resin layer, a method such as rubbing with a rotating brush or a wet sponge in a developing solution can be combined. The temperature of the developing solution is usually preferably around room temperature to 40 ° C. After the development processing, washing or drying can be performed.

The step (6) is a step of heating the pattern obtained in the step (5). In the step (6), the pattern (image) formed on the substrate in the step (5) is heat-treated to obtain a conductive pattern.

The heat treatment is preferably set appropriately so that a conductive pattern can be obtained.
It is preferably carried out at 0 to 400 ° C. for 30 to 120 minutes.
More preferable lower limit of heating temperature is 200 ° C., and upper limit is 3
It is 00 ° C.

In the conductive pattern forming method of the present invention,
In the step (6), the conductive pattern can be formed at a heating temperature of about 100 to 400 ° C. Although it is not clear why a conductive pattern having conductivity is obtained at a heating temperature of about 100 to 400 degrees, it is not considered that the photosensitive binder component is thermally decomposed at this heating temperature. Since it is difficult, it is presumed that the resin is softened by heating, which facilitates the movement of the metal colloid particles and changes the state in which conductivity is exhibited. Therefore, the method for forming a conductive pattern of the present invention can be applied to materials having low heat resistance, and a conductive pattern can be formed on these materials.

The conductive pattern (image) obtained by the above method for forming a conductive pattern means a pattern (image) having effective conductivity in the application to which the pattern (image) is applied. When used as a material, at a film thickness of 200 nm ± 15%, 1 × 10 ⁴ Ω
A pattern having a surface resistance value of / □ or less is preferable. It is more preferably 1 × 10 ² Ω / □ or less, and further preferably 10 Ω / □ or less. The surface resistance value can be measured using a commonly used measuring instrument, for example, Lorester FP (trade name, manufactured by Mitsubishi Chemical Corporation).

The film thickness of the conductive pattern obtained by the composition for forming a conductive pattern of the present invention is not particularly limited, but since it contains metal colloid particles having a minute particle size, It is suitable for forming a thin film of about 1 to 1.0 μm.

The use to which the conductive pattern forming composition of the present invention is applied is not particularly limited, and for example, the formation of a conductor circuit such as an electrode or wiring in a semiconductor substrate, a printed circuit board, a thermal head, an electronic component, or the like. Can be mentioned. In addition to these, electronic materials such as electromagnetic wave shields that take advantage of the characteristics of metal colloid particles; cosmetics, stationery, ink,
Color materials such as paints; craft decoration materials for imparting a metallic luster to the surface of articles; antibacterial materials, catalysts and the like.

The conductive pattern forming composition of the present invention comprises
Since it contains a metal colloid particle, a polymeric pigment dispersant, and a photosensitive binder component, the step of applying the composition for conductive pattern formation to a substrate, exposing the film obtained by application with a mask A conductive pattern can be formed by carrying out the step of carrying out, the step of developing the film obtained by exposure to obtain a pattern, and the step of heating the obtained pattern at a heating temperature of about 100 to 400 ° C. It is possible. Therefore, for example, a conductive pattern can be formed even on a substrate having a low heat resistant temperature and a conductive pattern on the surface of which could not be formed so far.

[0083]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In the examples, "parts" means "parts by mass" unless otherwise specified.

Example 1 (Production of silver colloidal solution) Disperse Bic 190 (manufactured by BYK Chemie, solid content 40) in 2 liters of Kolben.
Mass%) 13.8 g, and ion-exchanged water 420.5 g
I put it in. The Kolben was placed in a water bath and stirred at 50 ° C. until Disperbic 190 was dissolved.
To this, 100 g of silver nitrate dissolved in 420.5 g of ion-exchanged water was added with stirring, and the mixture was stirred at 70 ° C. for 10 minutes. Next, when 262 g of dimethylaminoethanol was added, the liquid turned black in an instant and the liquid temperature rose to 76 ° C. When the liquid temperature dropped to 70 ° C. by allowing it to stand as it was, stirring was continued for 2 hours while maintaining this temperature to obtain an aqueous solution of silver colloid showing a dark yellow color.

The obtained reaction solution was transferred to a 1-liter plastic bottle and allowed to stand in a constant temperature room at 60 ° C. for 18 hours. Next, an ultrafiltration module AHP1010 (manufactured by Asahi Kasei Co., Ltd .; molecular weight cut-off 50,000, number of used membranes 400), a magnet pump, a 3 liter stainless steel cup with a tube connection port at the bottom is connected with a silicon tube, and ultrafiltration is performed. The device. The reaction liquid that had been allowed to stand for 18 hours in a constant temperature room at 60 ° C. was placed in a stainless cup, 2 liters of ion-exchanged water was further added, and then a pump was operated to carry out ultrafiltration. About 40 minutes later, when the amount of the filtrate from the module reached 2 liters, 2 liters of ethanol was added to the stainless steel cup. After that, the conductivity of the filtrate is 300 μS
/ M was confirmed to be below, and the amount of mother liquor was 500m
Concentration was performed until it became 1.

Subsequently, a 500 ml stainless steel cup containing the mother liquor, an ultrafiltration module AHP0013 (manufactured by Asahi Kasei Co., Ltd .; molecular weight cutoff of 50,000, number of membranes used: 100), a tube pump, and an aspirator were assembled. . The mother liquor previously obtained was placed in this stainless cup and concentrated to increase the solid content concentration. When the mother liquor reached about 100 ml, the pump was stopped and the concentration was completed to obtain an ethanol solution of silver colloid with a solid content of 30%. The average particle size of the silver colloid particles in this solution was 27 nm. Also, TG-D
When the content of silver in the solid content was measured using TA (manufactured by Seiko Instruments Inc.), it was 95% by mass with respect to 92% by mass of the charged amount.

(Production of Conductive Pattern Forming Composition) Methyl methacrylate and 2-methacrylic acid as binders
Copolymer of hydroxyethyl and methacrylic acid (acid value 10
0) 70 g, Aronix M-20 as a polymerizable monomer
8 (ethylene oxide-modified diacrylate of bisphenol A, manufactured by Toagosei Co., Ltd.) 10 g and Aronix M-40
2 (mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, manufactured by Toagosei Co., Ltd.), 10 g of Irgacure-907 (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator, and DETX-S (2,4-diethyl). 2 g of thioxanthone (manufactured by Nippon Kayaku Co., Ltd.) and 233 g of ethanol as a solvent were mixed to obtain a photosensitive binder component having a solid content of 30%.
10 g of the obtained photosensitive binder component was added to 25 g of the obtained silver colloid ethanol solution, and the mixture was stirred to obtain a conductive pattern forming composition having a solid content of 30%.

(Production and Evaluation of Conductive Pattern) The obtained conductive pattern forming composition was dropped in the center of a 10 cm square glass plate, and a spin coater was used to set 400 rpm for 5 seconds and 600 rpm for the second step.
Was spin-coated under the condition of 30 seconds, the plate was put in an oven and dried at 100 ° C. for 10 minutes to form a photosensitive resin layer having a film thickness of 0.8 μm. The surface of this photosensitive resin layer was irradiated with a light beam of a high pressure mercury lamp at 500 mJ / cm ² through a photomask. Then, it was immersed in a 1% by mass aqueous solution of sodium carbonate for 30 seconds, vibrated and developed to obtain a pattern. After washing with water, heating at 250 ° C. for 60 minutes gave a patterned metallic coating. When the resolution of the obtained pattern was measured using a three-dimensional surface shape measuring instrument (manufactured by Keyence Corporation), L / S = 50 μm. The electrical conductivity of the obtained metallic coating is measured by Lorester FP
As a result of measuring the surface resistance value using (manufactured by Mitsubishi Chemical Corporation), it was 1.50 × 10 ² Ω / □. It should be noted that the composition for forming a conductive pattern showed no precipitation of metal colloidal particles even after being left for 3 months, no change in color or precipitation, and a conductive pattern formed by using the composition immediately after production. It didn't change compared to the one.

Comparative Example 1 A photosensitive silver paste having a solid content of 30% was obtained in the same manner as in Example 1 except that 7.5 g of silver powder and 17.5 g of ethanol were used instead of 25 g of the silver colloid ethanol solution. When the obtained photosensitive silver paste was left to stand, sedimentation of silver powder was observed after 1 day.

By using the conductive pattern forming composition of Example 1, a good conductive pattern with L / S = 100 μm or less was obtained. As a result, 60 at 250 ℃
It has been revealed that the conductive pattern can be formed under heating conditions that are milder than before, that is, for a minute. Further, while the storage stability thereof was also good, the product obtained in Comparative Example 1 caused sedimentation because it used the metal powder.

[0091]

Since the conductive pattern forming composition of the present invention has the above-mentioned constitution, it is 100 to 4 after irradiation with light.
A conductive pattern can be obtained by processing under a relatively low temperature heating condition such as about 00 ° C. Therefore, by using the composition for forming a conductive pattern, the conductive pattern can be formed on a material having a relatively low heat resistance temperature.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 5/24 C09D 5/24 H01B 13/00 503 H01B 13/00 503C 503D (72) Inventor Toshikatsu Kobayashi Osaka 19-17 Ikedanaka-machi, Neyagawa-shi, Japan F-term in Japan Paint Co., Ltd. (reference) 4D075 BB26Z BB40Y BB42Y BB44Y BB46Y CA22 CA25 CA47 CB04 CB13 DA06 DB13 DB31 DC18 DC21 DC38 EA07 EA12 EA12 EB31 EB31 EB20 EB20 4J038 FA011 FA111 FA211 FA221 FA231 FA251 FA281 HA066 KA08 KA09 KA12 KA20 LA02 LA06 NA18 NA20 PA17 PA19 5G301 DA02 DA03 DA42 DD01 5G323 CA01

Claims (5)

[Claims] 1. A metal colloid particle, a polymer pigment dispersant,
And a composition for forming a conductive pattern, which comprises a photosensitive binder component. 2. The composition for forming a conductive pattern according to claim 1, wherein the metal colloid particles are formed by reducing a metal compound in a solution in the presence of a polymer pigment dispersant. 3. A step (1) of obtaining a metal colloid solution by reducing a metal compound in the presence of a polymer pigment dispersant, and a photosensitive binder component in the metal colloid solution obtained by the step (1). A method for producing a conductive pattern forming composition, which comprises the step (2) of adding 4. A composition for forming a conductive pattern, which is obtained by the production method according to claim 3. 5. A step (3) of applying the composition for forming a conductive pattern according to claim 1, 2 or 4 to a substrate, and the film obtained by the step (3) is exposed with a mask. Including a step (4), a step (5) of developing the film obtained in the step (4) to obtain a pattern, and a step (6) of heating the pattern obtained in the step (5). A method for forming a characteristic conductive pattern.