WO2013145954A1

WO2013145954A1 - Liquid composition, copper metal film, conductive wiring line, and method for producing copper metal film

Info

Publication number: WO2013145954A1
Application number: PCT/JP2013/054176
Authority: WO
Inventors: 保田　貴康
Original assignee: 富士フイルム株式会社
Priority date: 2012-03-28
Filing date: 2013-02-20
Publication date: 2013-10-03
Also published as: KR20140134305A; TW201343809A; CN104185880A; CN104185880B; TWI564352B; JP2013206722A

Abstract

Provided is a copper metal film which has less voids and good electrical conductivity, while exhibiting good adhesion to a base. A liquid composition which contains (a) at least one substance that is selected from the group consisting of formic acid and copper formate, (b) copper oxide particles and (c) a solvent.

Description

Liquid composition, metallic copper film, conductor wiring, and method for producing metallic copper film

The present invention relates to a liquid composition suitable as a material for forming a metal copper film having few internal voids and excellent conductivity, a metal copper film obtained by using the liquid composition, a conductor wiring, and a metal copper film. It relates to the manufacturing method.

As a method of forming a metal film on a base material, a metal particle or metal oxide particle dispersion is applied to the base material by a printing method, dried, heat-treated and sintered to form a metal film or wiring on a circuit board. A technique for forming such an electrically conductive portion is known.
Since the above method is simpler, energy-saving, and resource-saving than conventional high-heat / vacuum processes (sputtering) and plating processes, it is highly anticipated in the development of next-generation electronics.
However, even if the metal particles are sintered, voids (voids) remain to some extent, so that a decrease in conductivity due to an increase in electric resistance value is a problem.

For example, Patent Document 1 describes a method for producing a copper metal film by heat-treating copper oxide particles in a formic acid gas atmosphere.
Patent Document 2 describes a conductive ink composition having fine particles of a copper salt composed of a carboxylic acid having a reducing power such as copper formate and copper ions, and a coordinating compound such as alkanethiol or aliphatic amine. Has been.
Patent Document 3 describes a photosintering method in which an exposed portion is made conductive by exposing a film containing copper nanoparticles.

Japanese Unexamined Patent Publication No. 2011-238737 Japanese Unexamined Patent Publication No. 2011-241309 Japanese National Table 2010-528428

However, in patent document 1, since it heat-processes in a formic acid gas atmosphere, it is necessary to perform by a batch process using a chamber, and is inferior in productivity.
The copper film obtained using the ink composition disclosed in Patent Document 2 had many voids (high void ratio) and was inferior in conductivity.
Moreover, in patent document 3, since photo-sintering is performed, although deterioration of a base material etc. can be prevented, the space | gap of the metal film obtained cannot be decreased and there exists a problem that it is inferior to electroconductivity. there were.

The present invention has been made paying attention to the above circumstances, and has a dense microstructure with few voids and a liquid composition capable of forming a metallic copper film with good conductivity, and formed using the liquid composition. An object of the present invention is to provide a metal copper film and a conductor wiring, and a method for producing the metal copper film.

As a result of intensive studies by the inventor of the present application, it has been found that the above problems can be solved by the following means, and the present invention has been completed.

[1]
(A) A liquid composition containing at least one selected from the group consisting of formic acid and copper formate, (b) copper oxide particles, and (c) a solvent.
[2]
(A) As a liquid composition as described in [1] containing formic acid.
[3]
The liquid composition according to [1] or [2], wherein the average particle diameter of the copper oxide particles is 1 nm or more and less than 1 μm.
[4]
The liquid composition according to any one of [1] to [3], wherein the average particle diameter of the copper oxide particles is 1 nm or more and less than 200 nm.
[5]
The solvent is derived from water, an aliphatic alcohol having 1 to 3 hydroxyl groups, an alkyl ether derived from an aliphatic alcohol having 1 to 3 hydroxyl groups, and an aliphatic alcohol having 1 to 3 hydroxyl groups. The liquid composition according to any one of [1] to [4], which is at least one selected from the group consisting of alkyl esters.
[6]
The liquid composition according to any one of [1] to [5], wherein (a) contains formic acid, and the content of formic acid is 0.5% by mass or more and 20% by mass or less with respect to the copper oxide particles. object.
[7]
The liquid composition according to any one of [1] to [5], wherein (a) contains formic acid and the content of formic acid is 5% by mass or more and 15% by mass or less with respect to the copper oxide particles.
[8]
[1], [3] to [5], wherein copper formate is contained as (a), and the content of copper formate is 1% by mass to 30% by mass with respect to the copper oxide particles. The liquid composition as described.
[9]
The liquid composition according to any one of [1] to [8], wherein the content of the copper oxide particles is 5% by mass or more and 60% by mass or less based on the total amount of the liquid composition.
[10]
A metallic copper film having a void ratio of 25% or less, obtained by photo-sintering the liquid composition according to any one of [1] to [9].
[11]
Conductor wiring obtained from the liquid composition according to any one of [1] to [9] or the metallic copper film according to [10].
[12]
On the substrate, a liquid composition containing (a) at least one selected from the group consisting of formic acid and copper formate, (b) copper oxide particles, and (c) a solvent is applied, and the applied liquid composition A method for producing a metallic copper film in which at least a part of an object is irradiated with light.
[13]
A liquid composition containing (b) copper oxide particles and (c) a solvent is applied on the base material, and at least one selected from the group consisting of (a) formic acid and copper formate is added to the applied liquid composition. The manufacturing method of the metal copper film | membrane which light-irradiates after providing the solution containing a seed and drying.
[14]
On the base material, (b) a liquid composition containing copper oxide particles and (c) a solvent is applied, and at least a part of the applied liquid composition is irradiated with light. (A) A method for producing a metallic copper film, wherein a solution containing at least one selected from the group consisting of formic acid and copper formate is applied, dried, and then irradiated or heated.
[15]
The method for producing a metallic copper film according to any one of [12] to [14], wherein (a) is formic acid.
[16]
The method for producing a metallic copper film according to any one of [12] to [15], wherein the average particle diameter of the copper oxide particles is 1 nm or more and less than 1 μm.
[17]
The method for producing a metallic copper film according to any one of [12] to [16], wherein the average particle diameter of the copper oxide particles is 1 nm or more and less than 200 nm.
[18]
The method for producing a metallic copper film according to any one of [12] to [17], wherein the light irradiation is light irradiation by a flash lamp.
[19]
[12] A conductor wiring using a metal copper film obtained by the manufacturing method according to any one of [18].

According to the present invention, a liquid composition capable of forming a metallic copper film having a fine microstructure with few voids and good electrical conductivity, a metallic copper film and a conductor wiring formed using the liquid composition, and A method for producing a metallic copper film can be provided. Moreover, according to the manufacturing method of the metal copper film of this invention, since it sinters by light irradiation, there is little deterioration of a base material and it can obtain a metal copper film with favorable adhesiveness with a base material. Furthermore, when a metal copper film is formed on the resin substrate using the liquid composition of the present invention, a conductive material exhibiting excellent bending resistance in addition to conductivity and adhesion can be provided.

Hereinafter, although described based on typical embodiment of this invention, unless it exceeds the main point of this invention, this invention is not limited to described embodiment.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

<Liquid composition>
The liquid composition of the present invention contains (a) at least one selected from the group consisting of formic acid and copper formate, (b) copper oxide particles, and (c) a solvent.

(A) At least one selected from the group consisting of formic acid and copper formate The liquid composition of the present invention contains at least one selected from the group consisting of formic acid and copper formate (also referred to as component (a)). .
Formic acid can erode copper oxide particles to produce copper formate, and the copper formate can be sublimated by the energy of the sintering process to fill voids in the metal copper film. Similarly, copper formate can be sublimated by the energy of the sintering process to fill the voids in the metal copper film.
From the viewpoint of availability at a lower cost, the liquid composition of the present invention preferably contains formic acid.

When the liquid composition of the present invention contains formic acid as the component (a), the content of formic acid is preferably 0.5% by mass or more and 20% by mass or less with respect to the copper oxide particles. It is more preferably 0% by mass or more and 18% by mass or less, and further preferably 5.0% by mass or more and 15% by mass or less. When the formic acid content is 0.5% by mass or more with respect to the copper oxide particles, the voids of the obtained metal copper film are reduced and the conductivity is improved, and the copper oxide particles are preferably 20% by mass or less. This ratio is preferable because the thickness of the copper metal film after sintering does not decrease and the film thickness of the sintered metal copper film becomes sufficient.

The liquid composition of the present invention contains copper formate as the component (a), and the content of the copper formate is from 1% by mass to 30% by mass with respect to the copper oxide particles from the viewpoint of reducing the void ratio. It is preferably 2% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less. When the content of copper formate is 1% by mass or more with respect to the copper oxide particles, voids of the obtained metal copper film are reduced and conductivity is improved, and when the content is 30% by mass or less, This is preferable because the ratio does not decrease and the thickness of the sintered metal copper film is sufficient.

(B) Copper oxide particles The liquid composition of the present invention contains copper oxide particles.

The “copper oxide” in the present invention is a compound that substantially does not contain copper that has not been oxidized. Specifically, in crystal analysis by X-ray diffraction, a peak derived from copper oxide is detected, and is derived from a metal. Refers to a compound in which no peak is detected. Although it does not contain copper substantially, it means that copper content is 1 mass% or less with respect to copper oxide microparticles | fine-particles.

As the copper oxide, copper oxide (I) or copper oxide (II) is preferable, and copper oxide (II) is more preferable because it is available at low cost and has low resistance.

The average particle diameter of the copper oxide particles is preferably less than 1 μm, and more preferably less than 200 nm. Moreover, it is preferable that the average particle diameter of a copper oxide particle is 1 nm or more.
A particle diameter of 1 nm or more is preferable because the activity on the particle surface does not become too high and does not dissolve in the liquid composition. Moreover, if it is less than 1 micrometer, it will become easy to perform pattern formation of wiring etc. by a printing method using a liquid composition as an inkjet ink composition, and when making a liquid composition into a conductor, it will reduce to metallic copper Is sufficient, and the resulting conductor has good conductivity, which is preferable.
In addition, the average particle diameter in this invention points out an average primary particle diameter. The average particle diameter can be determined by observation with a transmission electron microscope (TEM) or a scanning electron microscope (SEM).

The content of the copper oxide particles in the liquid composition is preferably 5 to 60% by mass, more preferably 5 to 50% by mass, and still more preferably 10 to 30% by mass. If it is 5 mass% or more, the film thickness of the metal copper film obtained will become enough. Moreover, if it is 60 mass% or less, the viscosity of a liquid composition will not become high, and this composition can be used as an inkjet ink composition.
The viscosity of the liquid composition is preferably 1 to 50 cP, more preferably 1 to 40 cP, from the viewpoint of ink jet discharge suitability.

(C) Solvent The liquid composition of the present invention contains a solvent. The solvent can function as a dispersion medium for copper oxide particles.
As the solvent, water, alcohols, ethers, esters, and other organic solvents can be widely used, and there is no particular limitation as long as the liquid composition of the present invention can be adjusted to a predetermined viscosity. From the viewpoint of compatibility with formic acid or copper formate, at least selected from the group consisting of water, an aliphatic alcohol having a monovalent to trivalent hydroxyl group, an alkyl ether derived from the alcohol, and an alkyl ester derived from the alcohol. One type is preferably used.

When water is used as the solvent, a solvent having a level of purity such as ion exchange water is preferable.

Examples of aliphatic alcohols having a monovalent to trivalent hydroxyl group include methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, cyclohexanol, 1-heptanol, 1-octanol, and 1-nonanol. 1-decanol, glycidol, methylcyclohexanol, 2-methyl 1-butanol, 3-methyl-2-butanol, 4-methyl-2-pentanol, isopropyl alcohol, 2-ethylbutanol, 2-ethylhexanol, 2- Octanol, terpineol, dihydroterpineol, 2-methoxyethanol, 2-ethoxyethanol, 2-n-butoxyethanol, 2-phenoxyethanol, carbitol, ethyl carbitol, n-butyl carbitol, diacetone alcohol , Ethylene glycol, diethylene glycol triethylene glycol, tetraethylene glycol, propylene glycol, trimethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol , Pentamethylene glycol, hexylene glycol, glycerin and the like.
Among them, aliphatic alcohols having 1 to 3 carbon atoms having 1 to 3 valent hydroxyl groups have a high boiling point and are difficult to remain after sintering, and are highly polar and easily compatible with formic acid and copper formate. More specifically, methanol, ethylene glycol, glycerin, 2-methoxyethanol, and diethylene glycol are preferred.

Examples of the ethers include alkyl ethers derived from the alcohols, such as diethyl ether, diisobutyl ether, dibutyl ether, methyl-t-butyl ether, methyl cyclohexyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl. Examples include ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane and the like. Among these, alkyl ethers having 2 to 8 carbon atoms derived from aliphatic alcohols having 1 to 3 carbon atoms and having 1 to 3 valent hydroxyl groups are preferable, and specifically, diethyl ether, diethylene glycol dimethyl ether, and tetrahydrofuran. It is preferable.

Examples of the esters include alkyl esters derived from the alcohols such as methyl formate, ethyl formate, butyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate, butyl propionate, and γ-butyrolactone. Illustrated. Of these, alkyl esters having 2 to 8 carbon atoms derived from aliphatic alcohols having 1 to 3 carbon atoms and having 1 to 3 valent hydroxyl groups are preferable, and specifically, methyl formate, ethyl formate, and methyl acetate. It is preferable.

Among the above solvents, it is particularly preferable to use water as the main solvent because the boiling point is not too high. The main solvent is a solvent having the highest content in the solvent.

The solvent included in the present invention is preferably 5 to 95% by mass, more preferably 10 to 90% by mass, and particularly preferably 15 to 80% by mass with respect to the total amount of the liquid composition. .
As will be described later, the metallic copper film of the present invention can be obtained by applying the liquid composition on a substrate, drying it, and then baking it. If the boiling point of the solvent is 300 ° C. or lower, it is easy to volatilize during drying, and it does not vaporize and expand in the firing process to generate minute cracks or voids. Since it becomes favorable, it is preferable.
The firing includes sintering by light irradiation (photosintering) and sintering by heating (thermal sintering). In the present invention, photosintering is preferable.

(Other ingredients)
In addition, the liquid composition may contain a polymer compound as a binder component. The polymer compound may be any of natural, synthetic polymers, or a mixture thereof, and examples thereof include vinyl polymers, polyethers, acrylic polymers, epoxy resins, urethane resins, and rosin compounds. When other components are included, the addition amount of the other components is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% by mass with respect to the total amount of the liquid composition. Preferably, it is 1 to 13% by mass.

<Metal copper film>
The present invention also relates to a metallic copper film obtained from the above liquid composition. By using the above liquid composition, the metallic copper film of the present invention has a dense microstructure with few voids and good electrical conductivity. Moreover, it becomes a metal copper film with high adhesiveness with a base material by performing sintering by light irradiation mentioned later in manufacture of a metal copper film.

The porosity (void ratio) of the metallic copper film is calculated from the ratio of white and black dots by digitizing a cross-sectional observation photograph taken with a scanning electron microscope (SEM) by digital processing, for example. can do. The void ratio is preferably 25% or less, more preferably 15% or less, and still more preferably 10% or less. When the void ratio is larger than 25%, it is not preferable because it causes a decrease in the adhesion between the metal copper film and the substrate and a decrease in the conductivity.

The volume resistance value of the metallic copper film is preferably 1 × 10 ⁻³ Ωcm or less, more preferably 1 × 10 ⁻⁴ Ωcm or less, and further preferably 1 × 10 ⁻⁵ Ωcm or less. . The volume resistance value can be calculated by, for example, multiplying the obtained surface resistance value by the film thickness after measuring the surface resistance value of the metal copper film by the four-probe method.

Examples of the method for sintering the liquid composition include heat sintering and photo-sintering, but photo-sintering is preferable from the viewpoint that the deterioration of the base material is small and the adhesion between the metal copper film and the base material does not decrease. . Photo sintering will be described later.
In the case of heat sintering, the heating temperature is preferably 50 ° C. to 250 ° C., more preferably 80 ° C. to 200 ° C.

<Method for producing metal copper film>
The present invention also relates to a method for producing a metallic copper film using the above-mentioned liquid composition. Specifically, the method for producing a metal copper film of the present invention comprises (a) at least one selected from the group consisting of formic acid and copper formate, (b) copper oxide particles, and (c) on a substrate. It is a method for producing a metallic copper film in which a liquid composition containing a solvent is applied, and at least a part of the applied liquid composition is irradiated with light. The exposed portion can be made conductive by the light irradiation.

Moreover, this invention also includes another aspect as a manufacturing method of a metallic copper film | membrane, and specifically, the following two types of aspects are mentioned.
<A> A liquid composition containing (b) copper oxide particles and (c) a solvent is applied on the base material, and the applied liquid composition is selected from the group consisting of (a) formic acid and copper formate. The manufacturing method of the metal copper film | membrane which light-irradiates after providing the solution containing at least 1 sort (s) to be dried.
<B> On the base material, a liquid composition containing (b) copper oxide particles and (c) a solvent is applied, and light irradiation is performed on at least a part of the applied liquid composition. (A) A method for producing a metallic copper film, which comprises applying (a) a solution containing at least one selected from the group consisting of formic acid and copper formate and drying or applying light after heating.

(Base material)
In the production method of the present invention, a known substrate can be used as the substrate, and is not particularly limited. For example, resin, paper, glass, silicon-based semiconductor, compound semiconductor, metal oxide, metal nitriding 1 type, 2 types or more, or 2 types or more composite base materials which consist of a thing, wood, etc. are mentioned.

Specifically, low density polyethylene resin, high density polyethylene resin, ABS resin (acrylonitrile-butadiene-styrene copolymer synthetic resin), acrylic resin, styrene resin, vinyl chloride resin, polyester resin (polyethylene terephthalate), polyacetal resin, polysulfone Resin, polyetherimide resin, polyetherketone resin, cellulose derivatives and other resin base materials; uncoated printing paper, finely coated printing paper, coated printing paper (art paper, coated paper), special printing paper, copy paper (PPC paper), unbleached wrapping paper (both kraft paper for heavy bags, both kraft paper), bleached wrapping paper (bleached kraft paper, pure white roll paper), coated paper, chip ball, corrugated cardboard and other paper base materials; Glass substrates such as soda glass, borosilicate glass, silica glass and quartz glass; Silicon-based semiconductors such as silicon and polysilicon; compound semiconductors such as CdS, CdTe, and GaAs; metal substrates such as copper plates, iron plates, and aluminum plates; alumina, sapphire, zirconia, titania, yttrium oxide, indium oxide, ITO (indium tin) Oxide), IZO (indium zinc oxide), Nesa (tin oxide), ATO (antimony-doped tin oxide), fluorine-doped tin oxide, zinc oxide, AZO (aluminum-doped zinc oxide), gallium-doped zinc oxide, aluminum nitride group Materials, other inorganic base materials such as silicon carbide; paper-phenolic resin, paper-epoxy resin, paper-resin composite such as paper-polyester resin, glass cloth-epoxy resin, glass cloth-polyimide resin, glass cloth-fluorine Examples thereof include composite base materials such as glass-resin composites such as resins. Among these, polyester resins, polyetherimide resins, paper base materials, and glass base materials are preferably used.

(Liquid composition)
In the production method of the present invention, the above-described liquid composition of the present invention can be preferably used. The liquid composition may be prepared in any way as long as it includes the components (a) to (c).

(Application of liquid composition to substrate)
In the production method of the present invention, the method of applying the liquid composition of the present invention to a substrate is preferably a coating method. Although it does not specifically limit as a coating method, For example, the screen printing method, the dip coating method, the spray coating method, the spin coating method, the inkjet method, the coating method with a dispenser etc. are mentioned. There is no problem even if the shape of application is planar or dot-like, and there is no particular limitation. The coating amount for applying the liquid composition to the substrate may be appropriately adjusted according to the desired film thickness of the electrically conductive portion. Usually, the film thickness of the liquid composition after drying is 0.01 to 5000 μm. The film may be applied in a range of 0.1 to 1000 μm.

(Dry)
In the production method of the present invention, it is desirable that the liquid composition is dried after being applied to the substrate and free from liquid components before being sintered. If the liquid component does not remain, the liquid component does not vaporize and expand in the firing step, and fine cracks and voids are not generated, which is preferable from the viewpoints of adhesion of the conductor to the base material and conductivity.
As a drying method, a hot air dryer or the like can be used, and the temperature is preferably 40 ° C. to 200 ° C., more preferably 50 ° C. to 150 ° C.

(Light irradiation)
In the production method of the present invention, a metallic copper film is produced by applying the liquid composition on a substrate and irradiating at least part of the applied liquid composition.
By irradiating with light, the copper oxide particles in the liquid composition can be reduced to copper and further sintered to form a metal copper film.
Photo-sintering is different from sintering by heating, and it becomes possible to sinter by irradiating light to a part to which a liquid composition is applied at room temperature for a short time. Does not occur, and the adhesion of the metallic copper film to the base material is improved.

Examples of the light source include a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, and a carbon arc lamp. Examples of radiation include electron beams, X-rays, ion beams, and far infrared rays. Also, g-line, i-line, deep-UV light, and high-density energy beam (laser beam) are used.
Specific examples of preferred embodiments include scanning exposure with an infrared laser, high-illuminance flash exposure such as a xenon discharge lamp, and infrared lamp exposure.

The light irradiation is preferably light irradiation with a flash lamp, and more preferably pulsed light irradiation with a flash lamp. The irradiation of high energy pulsed light is because the surface of the part to which the liquid composition is applied can be concentrated and heated in a very short time, so that the influence of heat on the substrate can be extremely reduced. is there.

A preferable range for the irradiation energy of the pulsed light is 1 J / cm ² to 100 J / cm ² , and a pulse width is preferably 1 μsec to 100 msec.

The irradiation time of the pulsed light is preferably 1 to 100 milliseconds, more preferably 1 to 50 milliseconds, and further preferably 1 to 20 milliseconds. Light irradiation energy is preferably 1 ~ 30J / cm ^2, more preferably 3 ~ 25J / cm ^2, more preferably 5 ~ 20J / cm ^2.

In the aspect of <B>, after the copper oxide particles are irradiated with light, (a) a solution containing at least one selected from the group consisting of formic acid and copper formate is applied, dried, and then irradiated or heated. However, the application, drying, and light irradiation of the component (a) can be performed in the same manner as described above. Moreover, about the heating of (a) component, it can carry out similarly to the said drying.

<Conductor wiring>
The present invention also relates to a conductor wiring obtained from the liquid composition.
The conductor wiring can be obtained by a method of printing the liquid composition in a pattern or by etching a metal copper film obtained from the liquid composition in a pattern.

(Etching process)
This step is a step of etching the metal copper film in a pattern. That is, in this step, a desired metal pattern can be formed by removing unnecessary portions of the metal copper film formed on the entire substrate surface by etching.
Any method can be used to form the metal pattern, and specifically, a generally known subtractive method or semi-additive method is used.

In the subtractive method, a dry film resist layer is provided on the formed metal copper film, the same pattern as the metal pattern part is formed by pattern exposure and development, and the metal copper film is removed with an etching solution using the dry film resist pattern as a mask. And forming a metal pattern. Any material can be used as the dry film resist, and negative, positive, liquid, and film-like ones can be used. Moreover, as an etching method, any method used at the time of manufacturing a printed wiring board can be used, and wet etching, dry etching, and the like can be used, and may be arbitrarily selected. In terms of operation, wet etching is preferable from the viewpoint of simplicity of the apparatus. As an etching solution, for example, an aqueous solution of cupric chloride, ferric chloride, or the like can be used.

The semi-additive method is to provide a dry film resist layer on the formed metal copper film, form the same pattern as the non-metal pattern part by pattern exposure and development, and perform electroplating using the dry film resist pattern as a mask. This is a method for forming a metal pattern by performing quick etching after removing the dry film resist pattern and removing the metal copper film in a pattern. The dry film resist, the etching solution, etc. can use the same material as the subtractive method. Moreover, the above-mentioned method can be used as the electroplating method.
Through the above steps, a conductor wiring having a desired metal pattern is manufactured.

On the other hand, a conductor wiring can also be manufactured by forming the said liquid composition in a pattern shape, exposing with respect to a pattern-like liquid composition, and performing light sintering.
Specifically, a liquid composition may be ejected in a pattern on a substrate by an ink jet method, and the liquid composition molding portion may be exposed to light to form a conductor.

As with the metal copper film of the present invention, the conductor wiring of the present invention has a dense microstructure with few voids and good electrical conductivity. Moreover, it becomes a conductor wiring with high base-material adhesiveness by performing sintering by the above-mentioned light irradiation.
When the conductor wiring in the present invention is configured as a multilayer wiring board, an insulating layer (insulating resin layer, interlayer insulating film, solder resist) is further laminated on the surface of the metal pattern material, and further wiring (metal pattern) is formed on the surface. May be formed.

Insulating film materials that can be used in the present invention include epoxy resin, aramid resin, crystalline polyolefin resin, amorphous polyolefin resin, fluorine-containing resin (polytetrafluoroethylene, perfluorinated polyimide, perfluorinated amorphous resin, etc.) , Polyimide resin, polyether sulfone resin, polyphenylene sulfide resin, polyether ether ketone resin, liquid crystal resin and the like.
Among these, from the viewpoints of adhesion, dimensional stability, heat resistance, electrical insulation, and the like, it is preferable to contain an epoxy resin, a polyimide resin, or a liquid crystal resin, and more preferably an epoxy resin. Specific examples include ABF GX-13 manufactured by Ajinomoto Fine Techno Co., Ltd.

The solder resist, which is a kind of insulating layer material used for wiring protection, is described in detail in, for example, Japanese Patent Application Laid-Open No. 10-204150 and Japanese Patent Application Laid-Open No. 2003-222993. These materials can also be applied to the present invention if desired. As the solder resist, commercially available products may be used. Specific examples include PFR800 manufactured by Taiyo Ink Manufacturing Co., Ltd., PSR4000 (trade name), SR7200G manufactured by Hitachi Chemical Co., Ltd., and the like.

Examples of the present invention will be described below, but the present invention is not limited to these examples. In the examples, “%” and “parts” as the contents are based on mass.

<Example 1>
(Preparation of liquid composition)
0.8 g of formic acid, 24.2 g of copper (II) oxide particles (manufactured by Kanto Chemical; average primary particle size 60 nm), 68 g of water, 4 g of ethylene glycol, and 3 g of glycerin are mixed and treated with an ultrasonic homogenizer for 5 minutes to obtain a liquid composition It was a thing. The average primary particle size was observed and measured with a scanning electron microscope (SEM: S-5500, manufactured by Hitachi High-Technologies).

(Apply to substrate and dry)
The above liquid composition is printed on a slide glass (Preclin water rim polish (manufactured by MATUNAMI)) in a 1 cm square surface using an inkjet (IJ) printer (DMP2831 (manufactured by Dimatix)), and 120 mm by a hot air dryer. Dry at 30 ° C. for 30 minutes. The film thickness of the dried liquid composition was 0.8 μm as measured with a laser microscope.

(Light irradiation)
The portion coated and dried with the liquid composition is irradiated with a Xe flash lamp (Sinteron 2000 (manufactured by Xenon), set voltage 3 kV, irradiation energy 7 J / cm ² , pulse width 2 msec.), Sintered, and metal copper A membrane was obtained.

<Examples 2 to 4>
A metal copper film was obtained in the same manner as in Example 1 except that the substrate type to be used, the type and addition amount of the component (a), and the addition amount of the copper oxide particles were changed as shown in Table 1. The composition ratio of each component of the solvent used in Examples 2 to 4 was the same as that in Example 1. Tetron Tetoron was used as the PET substrate.

<Example 5>
(Preparation of liquid composition)
23.5 g of copper (II) oxide particles (manufactured by Kanto Chemical; average particle size 60 nm), 64 g of water, 4 g of ethylene glycol, and 3 g of glycerin were mixed and treated with an ultrasonic homogenizer for 5 minutes to obtain a liquid composition.

(Apply to substrate and dry)
The liquid composition is printed on a PET substrate (Teijin Tetoron) with a 1 cm square surface using an inkjet (IJ) printer (DMP2831 (manufactured by Dimatix)), and dried at 100 ° C. for 30 minutes with a hot air dryer. did.

(Formic acid added)
A formic acid aqueous solution in which formic acid (1.5 g) was dissolved in water (4 g) was applied to the above-mentioned 1 cm square printed portion by IJ and dried at 100 ° C. for 10 minutes by a hot air dryer. The film thickness after drying was 0.9 μm.

(Light irradiation)
The portion where formic acid is applied and dried is irradiated with a Xe flash lamp (Sinteron 2000 (manufactured by Xenon), set voltage 3 kV, irradiation energy 7 J / cm ² , pulse width 2 msec.) And sintered to form a metallic copper film. Obtained.

<Example 6>
(Preparation of liquid composition)
Copper (II) oxide particles (manufactured by Kanto Chemical; average particle size 60 nm) (23.5 g), water 64 g, ethylene glycol 4 g, and glycerin 3 g were mixed and treated with an ultrasonic homogenizer for 5 minutes.

(Apply to substrate and dry)
The liquid composition is printed on a PET substrate (Teijin Tetoron) on a 1 cm square surface using an inkjet (IJ) printer (DMP2831 (manufactured by Dimatix)), and dried in a hot air dryer at 100 ° C. for 30 minutes. did. The film thickness after drying was 0.8 μm.

(Light irradiation)
The portion where the liquid composition was applied and dried was irradiated with a Xe flash lamp (setting voltage 3 kV, irradiation energy 7 J / cm ² , pulse width 2 msec.).

(Formic acid added)
A formic acid aqueous solution in which formic acid (1.5 g) was dissolved in water (4 g) was applied to the above-mentioned 1 cm square printed portion by IJ and dried at 100 ° C. for 10 minutes by a hot air dryer.

(Post-heating process)
It heat-processed at 150 degreeC with the warm air dryer for 1 hour.

<Example 7>
A metal copper film was obtained in the same manner as in Example 2 except that the light-irradiation was not performed, and the sintering method was changed to the light sintering and the heat sintering was performed at 200 ° C. for 2 hours under nitrogen.

<Example 8>
A metal copper film was obtained in the same manner as in Example 3 except that the light-irradiation was not performed and the sintering method was changed to the light sintering and the heat sintering was performed at 200 ° C. for 2 hours under nitrogen.

<Example 9>
A metal copper film was obtained in the same manner as in Example 2 except that the metal oxide particles used were changed to copper (II) oxide particles (manufactured by American Elements; average primary particle size 550 nm).

<Example 10>
A metal copper film was obtained in the same manner as in Example 2 except that the metal oxide particles used were changed to copper (II) oxide particles (manufactured by High Purity Chemical Laboratory; average primary particle size 1.2 μm).

<Examples 11 to 13>
A metallic copper film was obtained in the same manner as in Example 3 except that the irradiation energy of the Xe flash lamp in the light irradiation was changed as shown in Table 1.

<Comparative Example 1>
A metal copper film was obtained in the same manner as in Example 1 except that formic acid and copper formate were not added, and the addition amount of the copper oxide fine particles was changed as shown in Table 1.

<Comparative example 2>
A metal copper film was obtained in the same manner as in Example 8 except that formic acid and copper formate were not added, and the addition amount of the copper oxide fine particles was changed as shown in Table 1.

[Evaluation]
Each obtained metal copper film was evaluated by the following method. The results are shown in Table 1.
(Volume resistivity)
The surface resistance value of the metallic copper film was measured by a four probe method using Loresta EP MCP-T360 (manufactured by Mitsubishi Chemical Analytech). Volume resistivity was calculated by multiplying the obtained surface resistance value by the film thickness.

(Void rate)
The metal copper film was cross-section processed with a focused ion beam (FIB, SMI3050R (SII NanoTechnology), and a cross-sectional observation photograph was taken using a scanning electron microscope (SEM: Hitachi High-Technologies S-5500). The cross-section observed in the cross-sectional observation photograph refers to a cross section perpendicular to the base material, and the obtained cross-sectional observation photograph is a threshold value by using image software (“Adobe Photoshop” manufactured by Adobe Systems, Inc.). Is binarized into a white region where copper is present and a black region where voids are present, and the ratio of the area of the black region (void) to the area of the entire cross section is calculated from the following formula, Void rate was used.
Void ratio (%) = (area of black region / area of entire cross section) × 100

(Tape peeling test)
The metal copper film was tested according to JIS K5600-5-6 and evaluated according to the following criteria.
A: No abnormality at all after the test B: About 10% peeling was observed during the test

Since the metal copper films of Comparative Examples 1 and 2 that do not use formic acid or copper formate in the liquid composition have a high void ratio and a high volume resistivity, sufficient conductivity is not obtained. On the other hand, in the examples using the liquid composition of the present invention, the void ratio was low in all cases, and the conductivity was good. Further, in the case where the photo-sintering according to the production method of the present invention was performed, the tape peelability was better than that in the case where the heat-sintering was performed. This is thought to be because the base material adhesion was improved because the deterioration of the substrate could be prevented by sintering at a low temperature in a short time.

Furthermore, a bendability test was performed on the examples in which PET was used as a substrate and photo sintering was performed. When the PET substrate having the sintered metal copper film was bent at a substantially right angle and the substrates were visually observed, no abnormality was found at all, and it was confirmed that the substrate was not deteriorated by sintering.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application filed on Mar. 28, 2012 (Japanese Patent Application No. 2012-075453), the contents of which are incorporated herein by reference.

Claims

(A) A liquid composition containing at least one selected from the group consisting of formic acid and copper formate, (b) copper oxide particles, and (c) a solvent.
The liquid composition according to claim 1, comprising formic acid as (a).
The liquid composition according to claim 1 or 2, wherein the copper oxide particles have an average particle diameter of 1 nm or more and less than 1 µm.
The liquid composition according to any one of claims 1 to 3, wherein an average particle diameter of the copper oxide particles is 1 nm or more and less than 200 nm.
The solvent is at least one selected from the group consisting of water, an aliphatic alcohol having a monovalent to trivalent hydroxyl group, an alkyl ether derived from the alcohol, and an alkyl ester derived from the alcohol. Liquid composition of any one of these.
The liquid according to any one of claims 1 to 5, wherein formic acid is contained as (a), and the content of the formic acid is 0.5% by mass or more and 20% by mass or less with respect to the copper oxide particles. Composition.
The liquid composition according to any one of claims 1 to 5, wherein formic acid is contained as (a), and the content of the formic acid is 5% by mass or more and 15% by mass or less with respect to the copper oxide particles. .
The copper formate is contained as the (a), and the content of the copper formate is 1% by mass or more and 30% by mass or less with respect to the copper oxide particles. Liquid composition.
The liquid composition according to any one of claims 1 to 8, wherein the content of the copper oxide particles is 5% by mass or more and 60% by mass or less based on the total amount of the liquid composition.
A metal copper film having a void ratio of 25% or less, obtained by photosintering the liquid composition according to any one of claims 1 to 9.
A conductor wiring obtained from the liquid composition according to any one of claims 1 to 9 or the metal copper film according to claim 10.
On the substrate, a liquid composition containing (a) at least one selected from the group consisting of formic acid and copper formate, (b) copper oxide particles, and (c) a solvent is applied, and the applied liquid A method for producing a metallic copper film, wherein at least a part of the composition is irradiated with light.
On the base material, (b) a liquid composition containing copper oxide particles and (c) a solvent is applied, and the applied liquid composition is at least selected from the group consisting of (a) formic acid and copper formate. The manufacturing method of the metal copper film | membrane which light-irradiates after providing the solution containing 1 type, and drying.
On the substrate, a liquid composition containing (b) copper oxide particles and (c) a solvent is applied, and at least a part of the applied liquid composition is irradiated with light, and the light irradiated part (A) A method for producing a metallic copper film, wherein a solution containing at least one selected from the group consisting of formic acid and copper formate is applied, dried, and then irradiated or heated.
The method for producing a metallic copper film according to any one of claims 12 to 14, wherein (a) is formic acid.
The method for producing a copper metal film according to any one of claims 12 to 15, wherein an average particle diameter of the copper oxide particles is 1 nm or more and less than 1 µm.
The method for producing a copper metal film according to any one of claims 12 to 16, wherein an average particle diameter of the copper oxide particles is 1 nm or more and less than 200 nm.
The method for producing a metallic copper film according to any one of claims 12 to 17, wherein the light irradiation is light irradiation by a flash lamp.
A conductor wiring using a metallic copper film obtained by the manufacturing method according to any one of claims 12 to 18.