JP2016058227A - Method for producing conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a conductive film, which enables production of a conductive film which is suppressed in occurrence of defects, and is excellent in adhesion to a substrate and conductivity.SOLUTION: A production method comprises: a precursor film-forming step of forming a precursor film 12 containing copper oxide nanoparticles and an organic reducing agent on a substrate by coating a conductive film-forming composition containing copper oxide nanoparticles, an organic reducing agent, and a solvent on a substrate 10; and an irradiation step of forming a conductive film 18 containing metallic copper by relatively scanning the precursor film at a linear velocity of Vwhile irradiating the same with laser light 16 having a wavelength of 532 nm at an output of W, and by reducing the copper oxide nanoparticles in the region scanned by the laser light. The linear velocity Vof the laser light and the output Wof the laser light satisfy the following relationship, and the output Wof the laser light is 4 W or less: 1.0≤V/W≤120, where the unit of Vis mm/s and the unit of Wis W.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a conductive film.

As a method of forming a metal film on a base material, a dispersion of metal particles or metal oxide particles is applied to the base material by a printing method, and is locally irradiated with a laser to be sintered to be used in a metal film or a circuit board. A technique for forming an electrically conducting portion such as a wiring 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.

  For example, Patent Document 1 discloses that metal oxide or metal hydroxide fine particles and metal oxide or metal hydroxide fine particles have substantially no reducing property at room temperature, but are reduced by energy irradiation. A conductive film-forming composition comprising a dispersion containing a reducing agent to be exhibited, wherein at least a part of metal oxide or metal hydroxide fine particles are reduced to metal by energy irradiation. A film forming composition is described. And a step of drawing a pattern on the substrate with the conductive film forming composition, and a step of forming a conductive film by reducing at least a part of metal oxide or metal hydroxide fine particles to metal. The manufacturing method of the base material with the electrically conductive film characterized is described. Furthermore, copper (Cu) is described as a metal constituting the metal oxide fine particles, and an organic reducing agent is described as a reducing agent.

JP 2004-253794 A

On the other hand, in recent years, development of a method for forming a conductive film containing a metal having excellent conductivity using a composition containing copper oxide particles has been demanded from the viewpoint of cost reduction.
In recent years, in order to meet the demand for miniaturization and high functionality of electronic devices, wirings are becoming increasingly finer and highly integrated in printed wiring boards and the like. Along with this, there are demands for the formed conductive film to be free of defects and to further improve the adhesion and conductivity of the conductive film to the substrate.

  With reference to Patent Document 1, the present inventors applied a conductive film-forming composition containing copper oxide fine particles, an organic reducing agent and a solvent on a substrate, and applied to the layer containing copper oxide fine particles. When the conductive film was manufactured by scanning laser light, the conductive film excellent in base material adhesion and conductivity was not necessarily produced under the conditions specifically disclosed in Patent Document 1. I found out.

  Then, in view of the said situation, this invention aims at providing the manufacturing method of the electrically conductive film which can suppress the generation | occurrence | production of a defect and can manufacture the electrically conductive film excellent in base-material adhesiveness and electroconductivity. .

As a result of intensive studies on the problems of the prior art, the present inventors have found that the above-mentioned problems can be solved by controlling the components of the composition for forming a conductive film, the irradiation conditions / scanning conditions of laser light, and the like.
That is, it has been found that the above object can be achieved by the following configuration.

(1) A conductive film-forming composition containing copper oxide nanoparticles, an organic reducing agent and a solvent is applied on a substrate, and a precursor film containing copper oxide nanoparticles and an organic reducing agent is applied on the substrate. A precursor film forming step to be formed; and
The precursor film is relatively scanned at a linear velocity V ₁ while irradiating laser light having a wavelength of 532 nm with an output W ₁ , and the copper oxide nanoparticles in the scanning region irradiated with the laser light are reduced to form metallic copper. An irradiation step of forming a conductive film containing
An output W ₁ of the laser beam of the linear velocity V ₁ and the laser beam satisfies the relationship of Equation 1, the production method of the conductive film output W ₁ of the laser beam is not more than 4W.
Formula 1 1.0 ≦ V ₁ / W ₁ ≦ 120
However, the unit of the output W ₁ of the laser beam is W, and the unit of the linear velocity V ₁ of the laser beam is mm / s.
(2) Further, a precursor film removing step of irradiating a laser beam having a wavelength of 532 nm with an output W ₂ and removing the precursor film in the region irradiated with the laser beam,
The method for producing a conductive film according to (1), wherein the output W ₂ of the laser beam in the precursor film removing step and the output W ₁ of the laser beam in the irradiation step satisfy the relationship of Formula 2.
Formula 2 W ₂ > W ₁
However, the units of the laser light outputs W ₁ and W ₂ are both W.
(3) The manufacturing method of the electrically conductive film as described in (1) or (2) whose copper oxide nanoparticle is a cupric oxide nanoparticle.
(4) The manufacturing method of the electrically conductive film of any one of (1)-(3) whose average primary particle diameter of a copper oxide nanoparticle is 3-25 nm.
(5) The manufacturing method of the electrically conductive film of any one of (1)-(4) whose organic reducing agent is an alcohol compound.
(6) The method for producing a conductive film according to (5), wherein the alcohol compound includes polyethylene glycol and / or a polyhydric alcohol other than polyethylene glycol.
(7) The conductive film forming composition further includes fine particles of Group 8 to 10 heavy metal elements and / or salts of Group 8 to 10 heavy metal elements, according to any one of (1) to (6) The manufacturing method of the electrically conductive film of description.
(8) In any one of (1) to (7), the substrate is any one selected from the group consisting of a polyethylene terephthalate substrate, a polyethylene naphthalate substrate, and a cycloolefin polymer substrate. The manufacturing method of the electrically conductive film of description.
(9) The manufacturing method of the electrically conductive film of any one of (1)-(8) whose output of a laser beam is 0.5-3.6W.
(10) The manufacturing method of the electrically conductive film of any one of (1)-(9) whose spot diameter of a laser beam is 10-40 micrometers.
(11) The manufacturing method of the electrically conductive film of any one of (1)-(10) whose linear velocity of a laser beam is 10-120 mm / s.
(12) The method for producing a conductive film according to any one of (1) to (11), wherein the film thickness of the precursor film is 0.1 μm or more and less than 5 μm.

  ADVANTAGE OF THE INVENTION According to this invention, the reduction | restoration from a copper oxide nanoparticle to metal copper progresses efficiently, generation | occurrence | production of a defect is suppressed, and the electrically conductive film which can manufacture the electrically conductive film excellent in base-material adhesiveness and electroconductivity can be manufactured. A manufacturing method can be provided.

  Further, according to the present invention, the occurrence of defects is suppressed on a low heat resistant substrate such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cycloolefin polymer (COP), etc., and substrate adhesion and conductivity are reduced. It is possible to produce a fine wiring having excellent properties.

FIG. 1 is a schematic view showing an aspect of an irradiation process. FIG. 2 is a schematic view showing a preferred embodiment of the irradiation process.

Below, the suitable aspect of the manufacturing method of the electrically conductive film of this invention is explained in full detail. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
First, the feature point compared with the prior art of this invention is explained in full detail.
As described above, the characteristic point of the present invention is that the laser light irradiation condition and the scanning condition are controlled. More specifically, the wavelength of the laser beam is 532 nm, the output W ₁ [W] is 4 W or less, the output W ₁ [W] and the linear velocity (scanning speed) V ₁ [mm / s] are expressed by the following formula 1. It has been found that a desired effect can be obtained by controlling the laser light irradiation condition and the scanning condition so as to satisfy the above.
Formula 1 1.0 ≦ V ₁ / W ₁ ≦ 120

A mechanism that can obtain a desired effect by controlling the conditions in this way will be described as follows.
First, when a precursor film (irradiated object) containing copper oxide nanoparticles is irradiated with laser light, the laser light absorbed by the irradiated object is converted into thermal energy. Since laser light with a wavelength of 532 nm overlaps with the absorption wavelength of copper oxide, efficient photothermal conversion is realized. At this time, the amount of thermal energy in the precursor varies depending on the output of the laser beam and the linear velocity (scanning velocity). Specifically, when the laser beam output is constant, if the linear velocity is too high, the amount of thermal energy in the precursor film is small, the reduction of the copper oxide nanoparticles does not proceed sufficiently, and the linear velocity is If it is too small, the thermal energy in the precursor film remains and an unnecessary side reaction proceeds. Also, when the linear velocity (scanning speed) of the laser beam is constant, if the output is too large, the thermal energy in the precursor film remains and unnecessary side reactions proceed, and the output is too small. The amount of heat energy in the precursor film is small, and the reduction of the copper oxide nanoparticles does not proceed sufficiently. Based on the above findings, the present invention has found a relationship between laser light output and linear velocity (scanning velocity) suitable for reduction of copper oxide nanoparticles.

The suitable aspect of the manufacturing method of the electrically conductive film of this invention has at least 2 of the precursor film | membrane formation process which forms a precursor film | membrane, and the irradiation process which irradiates a precursor film | membrane with a laser beam.
The materials and procedures used in each process will be described in detail below.

[Precursor film forming step]
In the precursor film forming step, a composition for forming a conductive film containing copper oxide nanoparticles, an organic reducing agent and a solvent is applied on a substrate, and the precursor film containing copper oxide nanoparticles and an organic reducing agent is used as a base. It is a process of forming on a material.
By performing this step, a precursor film to be irradiated with a laser beam to be described later is formed.
Below, the material used at this process is explained in full detail first, and the procedure of a process is explained in full detail after that.

(Copper oxide nanoparticles)
The composition for forming a conductive film contains copper oxide nanoparticles. The copper oxide nanoparticles are reduced by a laser light irradiation process described later to constitute metallic copper in the conductive film.
The “copper oxide” in the present invention is a compound that substantially does not contain copper that has not been oxidized. Specifically, in a crystal analysis by X-ray diffraction, a peak derived from copper oxide is detected, and is derived from a metal. Refers to a compound for 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.

  As the copper oxide, cuprous oxide or cupric oxide is preferable, and cupric oxide is more preferable because it is available at low cost and is stable.

  The upper limit of the average primary particle diameter of the copper oxide nanoparticles is not particularly limited, but is preferably 100 nm or less, and since the reduction from copper oxide to metallic copper proceeds well and a desired conductive film is obtained, 50 nm or less. More preferred. In terms of more excellent effects, 25 nm or less is preferable, 20 nm or less is more preferable, 15 nm or less is further preferable, 10 nm or less is more preferable, and 5 nm or less is even more preferable. The lower limit of the average primary particle diameter of the copper oxide nanoparticles is not particularly limited, but is preferably 1 nm or more and more preferably 3 nm or more from the viewpoint that the activity on the particle surface does not become too high and the handleability is excellent. More specifically, the average primary particle diameter of the copper oxide nanoparticles is preferably 1 to 50 nm, more preferably 1 to 25 nm, further preferably 3 to 25 nm, still more preferably 3 to 20 nm, and more preferably 3 to 15 nm. More preferably, 3 to 10 nm is even more preferable.

  The average primary particle diameter of the copper oxide nanoparticles is the horizontal ferret diameter and the vertical ferret diameter of 1000 particles randomly selected from a scanning electron microscope (hereinafter sometimes referred to as “SEM”) image. And the measurement value of the smaller one of them is calculated as the primary particle diameter of the particles by arithmetic averaging. However, when the horizontal ferret diameter and the vertical ferret diameter are equal, either measurement value may be used.

  Moreover, although the average aspect-ratio of a copper oxide nanoparticle is not specifically limited, 1.2-4.0 are preferable. The average aspect ratio is obtained by measuring and averaging the aspect ratios of the 1000 particles. When the average aspect ratio is within this range, the conductivity of the obtained conductive film is more excellent.

  The average aspect ratio of the copper oxide nanoparticles is obtained by dividing the measured value of the horizontal ferret diameter and the vertical ferret diameter of 1000 randomly selected particles by the smaller measured value. It is the average of what was found.

  The ratio of the copper oxide nanoparticles having a particle diameter of 25 nm or more is not particularly limited, but is preferably 4% or less, more preferably 2% or less. By increasing the proportion of copper oxide nanoparticles with a smaller particle size, the reduction of copper oxide and the fusion of metallic copper generated by reduction during sintering are more likely to proceed, and substrate adhesion and conductivity are improved. It is because it improves.

As a synthesis method (granulation method) of copper oxide nanoparticles, there are a dry granulation method in which granulation is performed in a gas phase and a wet granulation method in which granulation is performed in a liquid phase. In order to produce smaller particles, wet granulation is suitable.
Specifically, as described in JP2003-183024A, etc., a dispersion of copper hydroxide particles is produced by reacting a divalent copper salt such as copper nitrate with a base in a solvent. A method of synthesizing copper oxide by heating and dehydrating copper hydroxide to obtain a dispersion of copper oxide nanoparticles is preferable. It can be synthesized at a lower temperature and in a shorter time, and can be easily controlled to have a desired particle shape / distribution.
When granulating by the above reaction, it is preferable to use water or a polyhydric alcohol having a boiling point of 150 to 300 ° C. as a solvent. It is preferable because it does not volatilize when heated and dehydrated and is excellent in dispersion stability of the produced copper oxide nanoparticles.

(Organic reducing agent)
The composition for forming a conductive film contains an organic reducing agent. The organic reducing agent is decomposed by a laser light treatment described later to generate a reducing substance, and reduces the copper oxide in the precursor film.
Although an organic reducing agent will not be specifically limited if it is an organic compound which can reduce | restore the copper oxide of a copper oxide nanoparticle to metal copper, Since the electroconductivity of the electrically conductive film obtained is not impaired, an alcohol compound is preferable.

  The alcohol compound is not particularly limited as long as it is a compound having one or more alcoholic hydroxy groups in the molecule. Specifically, for example, methanol, ethanol, propanol, 2-propanol, allyl alcohol, butanol, 2-butanol, Pentanol, 2-pentanol, 3-pentanol, cyclopentanol, hexanol, 2-hexanol, 3-hexanol, cyclohexanol, heptanol, 2-heptanol, 3-heptanol, 4-heptanol, cycloheptanol, octanol, 2-octanol, 3-octanol, 4-octanol, cyclooctanol, nonanol, 2-nonanol, 3,5,5-trimethyl-1-hexanol, 3-methyl-3-octanol, 3-ethyl-2,2-dimethyl 3-pentanol, 2,6-dimethyl-4-heptanol, decanol, 2-decanol, 3,7-dimethyl-1-octanol, 3,7-dimethyl-3-octanol, undecanol, dodecanol, 2-dodecanol, 2 -Butyl-1-octanol, tridecanol, tetradecanol, 2-tetradecanol, pentadecanol, hexadecanol, 2-hexadecanol, heptadecanol, octadecanol, 1-phenethyl alcohol, 2-phenethyl alcohol Monohydric alcohols such as ethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentane Diol, 1,2-hexanediol, 1,5-hexane All, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,2-octanediol, 1,8-octanediol, 1,3-nonanediol, 1,9-nonanediol 1,2-decanediol, 1,10-decanediol, 2,7-dimethyl-3,6-octanediol, 2,2-dibutyl-1,3-propanediol, 1,2-dodecanediol, 1, 12-dodecanediol, 1,2-tetradecanediol, 1,14-tetradecanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,4-pentanediol, 1,2-cyclohexanedimethanol, , 3-cyclohexanedimethanol, 1-hydroxymethyl-2- (2-hydroxyethyl) cyclohexane, 1-hydroxy Ci-2- (3-hydroxypropyl) cyclohexane, 1-hydroxy-2- (2-hydroxyethyl) cyclohexane, 1-hydroxymethyl-2- (2-hydroxyethyl) benzene, 1-hydroxymethyl-2- (3 -Hydroxypropyl) benzene, 1-hydroxy-2- (2-hydroxyethyl) benzene, 1,2-benzyldimethylol, 1,3-benzyldimethylol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, Divalent alcohols such as 1,4-cyclohexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol; glycerin (propane-1,2,3-triol), butane-1,2,4-triol, hexane-1,2, 6-triol, 3-methylpentane Trivalent alcohols such as 1,3,5-triol and trimethylolpropane (2- (hydroxymethyl) -2-ethylpropane-1,3-diol); cyclooctane-1,3,5,7-tetraol And tetravalent alcohols such as pentaerythritol (2,2-bis (hydroxymethyl) -1,3-propanediol).

As the organic reducing agent, a polyhydric alcohol having a boiling point of 250 ° C. or higher is preferable. When a polyhydric alcohol having a boiling point of 250 ° C. or higher is used, the polyhydric alcohol remains in the precursor film even during the laser irradiation treatment, and the copper oxide can be sufficiently reduced. It will be good. The polyhydric alcohol having a boiling point of 250 ° C. or higher is preferably a dihydric alcohol such as polyethylene glycol or polypropylene glycol, or a trihydric alcohol such as trimethylolpropane. As an organic reducing agent, it is preferable to contain polyhydric alcohols other than polyethylene glycol and / or polyethylene glycol, and it is more preferable to contain polyhydric alcohols other than polyethylene glycol and polyethylene glycol. Trimethylolpropane is particularly preferable as the polyhydric alcohol other than polyethylene glycol.
The content ratio of the polyethylene glycol and the polyhydric alcohol other than polyethylene glycol is not particularly limited, but is preferably 10/10 to 30/10 in terms of mass ratio (polyhydric alcohol other than polyethylene glycol) / (polyethylene glycol). 20/10 is particularly preferable.

  The content of the organic reducing agent in the composition for forming a conductive film is not particularly limited, but the number of defects in the obtained conductive film is less, and the adhesiveness to the base material and the conductivity are excellent. On the other hand, 1-100 mass parts is preferable, 10-100 mass parts is more preferable, 10-75 mass parts is further more preferable, and 30-60 mass parts is still more preferable.

(solvent)
The composition for forming a conductive film contains a solvent.
Examples of the solvent include methanol, ethanol, propanol, 2-propanol, allyl alcohol, butanol, 2-butanol, pentanol, 2-pentanol, 3-pentanol, cyclopentanol, hexanol, 2-hexanol, 3- Alcohol solvents such as hexanol, cyclohexanol, ether solvents such as diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dioxane, triglyme, tetraglyme, methyl acetate, butyl acetate, benzyl benzoate , Ester solvents such as dimethyl carbonate, ethylene carbonate, γ-butyrolactone, caprolactone, benzene, toluene, ethyl Hydrocarbon solvents such as benzene, tetralin, hexane, octane, cyclohexane, halogenated hydrocarbon solvents such as dichloromethane, trichloroethane, chlorobenzene, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone (N -Methyl-2-pyrrolidone), amides such as hexamethylphosphoric triamide, N, N-dimethylimidazolidinone or cyclic amide solvents, sulfone solvents such as dimethylsulfone, sulfoxide solvents such as dimethylsulfoxide, water, etc. Is mentioned. A solvent can be used individually by 1 type or in combination of 2 or more types.
The boiling point of the solvent is not particularly limited, but it is preferably less than 250 ° C., more preferably less than 180 ° C. in that it does not remain in the conductive film, has fewer defects in the obtained conductive film, and is superior in substrate adhesion and conductivity. preferable.
As the solvent, water, ethanol, or a mixed solvent thereof is preferable, and water is more preferable because the dispersibility of the copper oxide nanoparticles is good.

  Although content of the solvent in the composition for electrically conductive film formation is not specifically limited, 1-1000 mass parts is preferable with respect to 100 mass parts of copper oxide nanoparticles, 5-500 mass parts is more preferable, 10-200 masses Part is more preferred.

(Group 8-10 heavy metal element fine particles and / or Group 8-10 heavy metal element salt)
The conductive film-forming composition may be a fine particle of Group 8-10 heavy metal element (hereinafter sometimes referred to as “heavy metal fine particle”) and / or a salt of Group 8-10 heavy metal element (hereinafter referred to as “heavy metal salt”). ) May be included. In other words, fine particles and / or salts containing at least one metal element selected from the group consisting of groups 8 to 10 of the periodic table may be included. When the composition for forming a conductive film contains heavy metal fine particles and / or a heavy metal salt, generation of defects in the conductive film is further suppressed, and a conductive film having more excellent conductivity is obtained.

  Specifically, the fine particles of Group 8-10 heavy metal elements include iron (Fe), cobalt (Co), nickel (Ni), rubidium (Ru), rhodium (Rh), palladium (Pd), osmium (Os ), Iridium (Ir), platinum (Pt) and the like, and fine particles made of a simple substance or an alloy of a group 8-10 heavy metal element. Examples of the alloy include ruthenium-platinum alloy and silver-palladium alloy. As the heavy metal fine particles, fine particles of palladium or platinum are preferable. The size of the heavy metal fine particles is not particularly limited, but is preferably 1 to 10 nm, and more preferably 1 to 5 nm.

  Specific examples of salts of Group 8 to 10 heavy metal elements include ruthenium trichloride, ruthenium tribromide, rhodium trichloride, iridium trichloride, sodium hexachloroiridate, palladium dichloride, potassium tetrachloroparadate, two Halide salts such as platinum chloride, potassium tetrachloroplatinate, nickel dichloride, iron trichloride, cobalt trichloride, acetates such as ruthenium acetate, rhodium acetate, palladium acetate, ruthenium trifluoroacetate, rhodium trifluoroacetate, tri Trifluoroacetates such as palladium fluoroacetate, sulfates such as ferrous sulfate, ruthenium nitrate, rhodium nitrate, nitrates such as cobalt nitrate and nickel nitrate, carbonates such as cobalt carbonate and nickel carbonate, cobalt hydroxide, hydroxide Nickel and other hydroxides, tri (acetylacetonato) Ruthenium, di (acetylacetonato) can be exemplified nickel, di (acetylacetonato) acetylacetonate salts such as palladium or the like. Of these, palladium or platinum salts are preferred.

  The total content of heavy metal fine particles and heavy metal salt when the composition for forming a conductive film contains heavy metal fine particles and / or heavy metal salt is not particularly limited, but there are fewer defects in the obtained conductive film and it is more excellent in conductivity. The amount is preferably 0.01 to 20 parts by mass, more preferably 0.01 to 10 parts by mass, further preferably 0.1 to 10 parts by mass, and 0.5 to 9 parts by mass with respect to 100 parts by mass of the copper oxide nanoparticles. Part is more preferred, 1 to 5 parts by weight is still more preferred, and 3 to 5 parts by weight is even more preferred.

(Other ingredients)
The conductive film forming composition may contain other components in addition to the copper oxide nanoparticles, the organic reducing agent, the solvent, and the heavy metal fine particles and / or the heavy metal salt.

  For example, the composition for forming a conductive film may contain a surfactant. Surfactant plays the role which improves the dispersibility of a copper oxide nanoparticle. The type of the surfactant is not particularly limited, and examples thereof include an anionic surfactant, a cationic surfactant, a nonionic surfactant, a fluorine surfactant, and an amphoteric surfactant. These surfactants can be used alone or in combination of two or more.

(Process procedure)
The method for applying the composition for forming a conductive film on a substrate is not particularly limited, and a known method can be adopted. For example, coating methods such as a screen printing method, a dip coating method, a spray coating method, a spin coating method, and an ink jet method can be used.
The shape of application is not particularly limited, and may be a surface covering the entire surface of the substrate or a pattern (for example, a wiring or a dot).

In this step, if necessary, the conductive film-forming composition may be applied to the substrate and then dried to remove the solvent. By removing the remaining solvent, it is possible to suppress the generation of minute cracks and voids due to the vaporization and expansion of the solvent in the irradiation step described later, which is preferable in terms of conductivity of the conductive film and adhesion of the substrate. .
As a method for the drying treatment, heating of the base material by a hot air dryer, a hot plate or the like can be used. It is preferable to perform the heat treatment at less than 70, and more preferably heat treatment at 70 to 90 ° C. The drying process may be performed in either a non-oxidizing atmosphere or an oxidizing atmosphere. Examples of the non-oxidizing atmosphere include an inert gas atmosphere such as nitrogen and argon, and a reducing gas atmosphere such as hydrogen. Examples of the oxidizing atmosphere include an air atmosphere and an oxygen atmosphere.

(Precursor film)
A precursor film | membrane contains a copper oxide nanoparticle and an organic reducing agent, and a copper oxide nanoparticle is reduce | restored to metallic copper by the light irradiation mentioned later, and becomes a electrically conductive film.
The precursor film contains copper oxide nanoparticles and an organic reducing agent, and particularly preferably contains copper oxide nanoparticles as main components. Here, the main component means that the mass occupied by the copper oxide nanoparticles in the total mass of the precursor film is 20% by mass or more, and preferably 50% by mass or more. The upper limit is not particularly limited, but 95% by mass can be mentioned.
The precursor film may contain components other than the copper oxide nanoparticles and the organic reducing agent (for example, heavy metal fine particles and / or heavy metal salt, surfactant, etc.).

Although the thickness (film thickness) of the precursor film is not particularly limited, it is preferably 0.1 to 15 μm, more preferably 0.1 to 10 μm, in that the reduction efficiency of the copper oxide nanoparticles by light irradiation described later is more excellent. More preferably, it is 0.1 μm or more and less than 5.0 μm. In particular, when the film thickness of the precursor film is in the range of 0.1 μm or more and less than 5.0 μm, the generation of defects is suppressed, and a conductive film with better substrate adhesion and conductivity can be manufactured.
In addition, the thickness (film thickness) of the said precursor film | membrane is an average thickness (average film thickness), The thickness (film thickness) of arbitrary 10 points | pieces is measured, and those are arithmetically averaged.
In addition, the precursor film may be provided on the entire surface of the substrate, or may be provided in a pattern.

(Base material)
Examples of the material used for the substrate used in this step include resin, paper, glass, silicon-based semiconductor, compound semiconductor, metal oxide, metal nitride, wood, or a composite thereof.
More specifically, low density polyethylene resin, high density polyethylene resin, ABS resin, acrylic resin, styrene resin, vinyl chloride resin, polyester resin (polyethylene terephthalate), polyacetal resin, polysulfone resin, polyetherimide resin, polyether Resin base materials such as ketone resins and cellulose derivatives; uncoated printing paper, fine 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, kraft paper for double bags), bleached wrapping paper (bleached kraft paper, pure white roll paper), coated substrates such as coated balls, chip balls, cardboard; soda glass, borosilicate glass, silica glass Glass substrates such as quartz glass; silicon-based semiconductor substrates such as amorphous silicon and polysilicon; Compound semiconductor substrates such as dS, CdTe, GaAs; metal substrates such as copper plate, iron plate, aluminum plate; alumina, sapphire, zirconia, titania, yttrium oxide, indium oxide, ITO (indium tin oxide), IZO (indium zinc) Oxides), 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 substrate, silicon carbide, and other inorganic materials Base materials: Paper-resin composites such as paper-phenolic resin, paper-epoxy resin, paper-polyester resin, glass cloth-epoxy resin, glass cloth-polyimide resin, glass cloth-fluorine resin, etc. And the like, and the like.

  Especially, as a base material, a polyimide base material, a polyethylene terephthalate base material, a polyethylene naphthalate base material, a polycarbonate base material, a cellulose ester base material, a polyvinyl chloride base material, a polyvinyl acetate base material, a polyurethane base material, for example At least one selected from the group consisting of a silicone substrate, a polyvinyl ethyl ether substrate, a polysulfide substrate, a polyolefin substrate, a polyacrylate substrate, a cycloolefin polymer substrate, and a glass epoxy substrate is preferable. Furthermore, it is preferably any selected from the group consisting of a polyethylene terephthalate (PET) substrate, a polyethylene naphthalate (PEN) substrate, and a cycloolefin polymer (COP) substrate.

[Irradiation process]
In the irradiation step, the precursor film obtained in the above step is scanned relatively with the linear velocity V ₁ [mm / s] while irradiating laser light having a wavelength of 532 nm with an output W ₁ [W]. This is a step of reducing the copper oxide nanoparticles in the scanning region irradiated with light to form a conductive film containing metallic copper. By performing laser light irradiation, the copper oxide nanoparticles absorb light, the absorbed light is converted into heat, and heat penetrates into the precursor film, so that copper oxide is converted into metal copper inside. The reduction reaction proceeds. That is, by performing the above treatment, metallic copper particles obtained by reducing the copper oxide particles are fused together to form grains, and the grains are bonded and fused together to form a conductive film. .

Below, this process is demonstrated in detail with reference to drawings.
In FIG. 1, a mode in which laser light 16 is irradiated from a laser light source 14 to a precursor film 12 disposed on a substrate 10 is shown. In FIG. 1, the laser light source 14 is moved in the direction of the arrow by a scanning mechanism (not shown), and a predetermined region is irradiated while scanning the surface of the precursor film 12. In the region irradiated with the laser beam 16 (scanning region of the laser beam 16), the reduction reaction from the copper oxide nanoparticles to the metallic copper proceeds, and the conductive film 18 containing metallic copper is formed.
In FIG. 1, the conductive film 18 has a linear pattern, but the shape is not limited to the form of FIG. 1. For example, it may be curved, and the conductive film may be formed over the entire surface of the substrate.

  In FIG. 1, a mode in which the laser light source 14 is moved by the scanning mechanism is illustrated, but the present invention is not limited to this mode, and it is sufficient that the laser light and the precursor film that is an object to be irradiated are relatively scanned. . For example, by placing a substrate with a precursor film, which is an object to be irradiated, on an XY axis stage that can move in the horizontal direction with respect to the scanning surface, and moving the stage with the laser beam fixed And a method of scanning the surface of the precursor film with laser light. Of course, a mode in which the laser beam and the precursor film that is the object to be irradiated move together may be employed.

The wavelength of the laser beam is 532 μm. If it is laser light of this wavelength, it can penetrate into the precursor film and also matches the absorption wavelength of copper oxide, so the copper oxide nanoparticles inside the precursor film absorb light and convert it into heat. Thus, copper oxide can be efficiently reduced to metallic copper.
As the laser, an Nd: YVO ₄ laser (neodymium-added yttrium vanadate laser) is preferable.

In this step, the linear velocity of the laser beam and the output of the laser beam satisfy the relationship of the following formula 1.
Formula 1 1.0 ≦ V ₁ / W ₁ ≦ 120
However, in Formula 1,
V ₁ : Linear velocity of laser light [mm / s]
W ₁ : Laser light output [W]

Moreover, it is preferable that the linear velocity of a laser beam and the output of a laser beam satisfy | fill the relationship of following formula 1-1.
Equation 1-1 is _{2.5 ≦ V 1 / W 1 ≦} 90.0
However, in Formula 1-1, V ₁ and W ₁ have the same meaning as described above.

  In this step, the output (irradiation energy) of the laser beam is 4 W or less, as long as the relationship of the above formula 1 is satisfied. If it exceeds 4 W, the thermal energy in the precursor film becomes excessive and the temperature of the precursor film rises rapidly, so that the precursor film can no longer stay on the substrate and scatters. The output (irradiation energy) of the laser beam is not particularly limited as long as it is 4 W or less, but it is 0 in that the reduction from copper oxide to copper proceeds more efficiently in the precursor film and the defects of the conductive film can be further suppressed. 0.5 to 3.6 W is preferable, 0.5 to 2.5 W is more preferable, and 1.0 to 2.0 W is more preferable.

  In this step, the linear speed (scanning speed) of the laser beam is not particularly limited as long as the relationship of the above formula 1 is satisfied, but the reduction from copper oxide to copper proceeds more efficiently in the precursor film and the conductive film. 10 to 120 mm / s is preferable, 10 to 80 mm / s is more preferable, and 10 to 60 mm / s is more preferable.

  The spot diameter of the laser beam irradiated on the precursor film surface is not particularly limited, and is appropriately adjusted according to the width of the conductive film to be formed. For example, when a conductive film is used as a wiring of a printed wiring board, the spot diameter is preferably 5 to 200 μm, more preferably 5 to 100 μm, still more preferably 10 to 60 μm, and more preferably 10 to 40 μm in that fine wiring can be formed. Even more preferable.

In this step, the irradiation time per spot on the surface of the precursor film is not particularly limited, but is preferably 1000 to 9000 μs and more preferably 1500 to 8000 μs in that the conductive film has fewer defects and is more excellent in conductivity.
Here, the irradiation time means the time during which the laser beam is irradiated at an arbitrary point on the precursor film surface irradiated with the laser beam. The irradiation time can be calculated from the linear velocity (scanning velocity) and the spot diameter. For example, when the spot diameter (diameter) in the scanning direction of the continuous wave laser beam irradiated onto the precursor film surface is 60 μm and the scanning speed is 10 m / s, the irradiation time is calculated as 6 μs.

  The atmosphere for performing the laser light irradiation treatment is not particularly limited, and examples thereof include an air atmosphere, an inert atmosphere, and a reducing atmosphere. The inert atmosphere is, for example, an atmosphere filled with an inert gas such as argon, helium, neon, or nitrogen, and the reducing atmosphere is a reducing gas such as hydrogen or carbon monoxide. It refers to the atmosphere.

As a preferable aspect of the laser beam scanning condition, when the laser beam is used to scan a region adjacent to the first scanning region irradiated with the laser beam, the laser beam is irradiated so as to partially overlap the first scanning region. And the aspect whose width | variety of the area | region which overlaps is 15 to 30% of the spot diameter of a laser beam is mentioned.
The said aspect is demonstrated using FIG. As shown in FIG. 2, the adjacent region 22 adjacent to the first scanning region 20 irradiated with the laser beam 16 from the laser light source 14 is irradiated with the laser beam 16 on the precursor film 12 arranged on the substrate 10. When scanning, the laser beam 16 is irradiated so that the first scanning region 20 and the adjacent region 22 partially overlap. At that time, the laser beam 16 is irradiated so that the width W of the overlapping region 24 (hatched portion) corresponds to 15 to 30% of the spot diameter D of the laser beam 16. In other words, the laser light is irradiated so that the ratio {(W / D) × 100} (overlap ratio) of the width W of the overlapping region 24 to the spot diameter D of the laser light 16 is 15 to 30%. By performing the scanning method, a conductive film with fewer defects and excellent conductivity can be obtained.
In FIG. 2, the first scanning region 20 has a linear pattern, but is not limited to this mode.

(Conductive film)
By carrying out the above steps, a conductive film (metal film) containing metallic copper is obtained.
Although the film thickness of a conductive film is not specifically limited, 0.1-15 micrometers is preferable, 0.1-10 micrometers is more preferable from the point of a printed wiring board use, and 0.1 micrometer or more and less than 5.0 micrometers are more preferable.
In addition, the thickness (film thickness) of the said electrically conductive film is an average thickness (average film thickness), The thickness (film thickness) of arbitrary 10 points | pieces is measured, and those are arithmetically averaged.

From the viewpoint of conductivity, the volume resistivity of the conductive film is preferably less than 300 μΩ · cm, more preferably less than 100 μΩ · cm, and even more preferably less than 50 μΩ · cm.
The volume resistivity can be calculated by measuring the surface resistance value of the conductive film by the four-probe method and then multiplying the obtained surface resistance value by the film thickness of the conductive film.

The conductive film may be provided on the entire surface of the base material or in a pattern. The patterned conductive film is useful as a conductor wiring (wiring) such as a printed wiring board.
As a method of obtaining a patterned conductive film, a method of applying a conductive film forming composition to a substrate in a pattern and performing a laser light irradiation treatment, or a conductive film provided on the entire surface of the substrate is patterned. Examples thereof include a method of etching and a method of irradiating a precursor film provided on the entire surface of the substrate with laser light in a pattern. The etching method is not particularly limited, and a known subtractive method, semi-additive method, or the like can be employed.

  When the conductive film is provided in a pattern, an unirradiated region of the precursor film that is not irradiated with laser light may be removed as necessary. The method for removing the unirradiated region is not particularly limited, and examples thereof include a method of etching using an etching solution such as an acid, and a method of removing by irradiating with laser light.

As a method for irradiating the unirradiated region of the precursor film with laser light, specifically, the precursor film is irradiated with laser light having a wavelength of 532 nm with an output W ₂ [W], and laser light is emitted. And a method of removing the precursor film in the region irradiated with.
Here, the output W ₂ [W] of the laser beam and the output W ₁ [W] of the laser beam in the irradiation process satisfy the relationship of the following formula 2.
Formula 2 W ₂ > W ₁
Preferably, W ₂ > 4 [W].
This method can be carried out as a step after the irradiation step.

  When a patterned conductive film is configured as a printed wiring board, an insulating layer (insulating resin layer, interlayer insulating film, solder resist) is further laminated on the surface of the patterned conductive film, and further wiring (metal) is formed on the surface. Pattern) may be formed.

The material of the insulating film is not particularly limited. For example, 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. Specifically, ABF TECH-13, ABF GX-13, etc. are mentioned.

  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, Japanese Patent Application Laid-Open No. 2003-222993, and the like. These materials can also be applied to the present invention if desired. A commercially available solder resist may be used, and specific examples include PFR800 manufactured by Taiyo Ink Manufacturing Co., Ltd., PSR4000 (trade name), SR7200G manufactured by Hitachi Chemical Co., Ltd., and the like.

  The base material (base material with a conductive film) having the conductive film obtained above can be used for various applications. For example, a printed wiring board, TFT, FPC, RFID, etc. are mentioned.

[Synthesis of copper oxide nanoparticles]
<Synthesis Example 1>
(Copper oxide nanoparticles with an average primary particle size of 5 nm)
Copper nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in purified water to prepare a 0.1 mol / L aqueous copper nitrate solution. Next, sodium hydroxide was dissolved in purified water to prepare a 0.2 mol / L sodium hydroxide aqueous solution.
100 mL of ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) was placed in a 200 mL heat-resistant glass flask and heated to 90 ° C. in an oil bath. To the flask, the prepared 0.1 mol / L aqueous copper nitrate solution and 0.2 mol / L aqueous sodium hydroxide solution were each added in 20 mL portions within 10 seconds and heated at 90 ° C. for 10 minutes to obtain copper oxide nanoparticles. Was obtained as a dispersion. This dispersion liquid contains sodium ions and nitrate ions in addition to the copper oxide nanoparticles.
The obtained dispersion was centrifuged at 20000 × g for 30 minutes, and the precipitate was redispersed in water. This centrifugation-redispersion process was repeated three times. By this treatment, sodium ions and nitrate ions were removed from the dispersion of copper oxide nanoparticles, and a copper oxide dispersion having a particle concentration of 20% by mass was obtained.
To the obtained copper oxide nanoparticle dispersion, zirconia beads having the same mass as the dispersoid were added, and stirred and dispersed with Awatori Rentaro for 3 minutes to obtain a copper oxide nanoparticle dispersion.
By XRD analysis, strong diffraction peaks derived from the (002) and (111) planes were observed near 35.5 ° and 38 °, respectively, and it was confirmed that the obtained copper oxide nanoparticles were made of cupric oxide. .
Moreover, as a result of a transmission electron microscope (TEM observation), the obtained copper oxide nanoparticles had an average primary particle diameter of 5 nm, an average aspect ratio of 1.5, and particles having a primary particle diameter of 25 m or more. The percentage was 2%.
The copper oxide nanoparticles thus obtained are hereinafter referred to as “copper oxide nanoparticles 1”.

<Synthesis Example 2>
(Copper oxide nanoparticles with an average primary particle size of 3 nm)
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 0.05 mol aqueous copper nitrate solution (20 mL) and 0.1 mol / L aqueous sodium hydroxide solution (20 mL) The copper oxide nanoparticle dispersion was obtained by synthesizing in the same manner as in the copper oxide nanoparticle 1 except that was used.
It was confirmed by XRD analysis that the obtained copper oxide nanoparticles were made of cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained copper oxide nanoparticles was 3 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 25 nm or more was 0%. It was.
The copper oxide nanoparticles thus obtained are hereinafter referred to as “copper oxide nanoparticles 2”.

<Synthesis Example 3>
(Copper oxide nanoparticles with an average primary particle size of 8 nm)
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 3 mol / mL aqueous copper nitrate solution (20 mL) and 6 mol / L aqueous sodium hydroxide solution (20 mL) were used. A copper oxide nanoparticle dispersion was obtained by synthesizing in the same manner as copper oxide nanoparticle 1 except for the points used.
It was confirmed by XRD analysis that the obtained copper oxide nanoparticles were made of cupric oxide.
As a result of TEM observation, the obtained copper oxide nanoparticles had an average primary particle diameter of 8 nm, an average aspect ratio of 1.5, and a ratio of particles having a primary particle diameter of 25 nm or more was 2%. It was.
The copper oxide nanoparticles thus obtained are hereinafter referred to as “copper oxide nanoparticles 3”.

<Synthesis Example 4>
(Copper oxide nanoparticles with an average primary particle size of 15 nm)
A copper oxide nanoparticle dispersion was obtained by synthesizing in the same manner as copper oxide nanoparticle 1 except that water (100 mL) was used instead of ethylene glycol (100 mL).
It was confirmed by XRD analysis that the obtained copper oxide nanoparticles were made of cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained copper oxide nanoparticles was 15 nm, the average aspect ratio was 3.8, and the ratio of particles having a primary particle diameter of 25 nm or more was 15%. It was.
The copper oxide nanoparticles thus obtained are hereinafter referred to as “copper oxide nanoparticles 4”.

<Synthesis Example 5>
(Copper oxide nanoparticles with an average primary particle size of 20 nm)
A copper oxide nanoparticle dispersion was obtained by synthesizing in the same manner as copper oxide nanoparticle 1 except that water (100 mL) was used instead of ethylene glycol (100 mL).
It was confirmed by XRD analysis that the obtained nanoparticles were nanoparticles made of cupric oxide.
As a result of TEM observation, the obtained copper oxide nanoparticles had an average primary particle diameter of 20 nm, an average aspect ratio of 4.0, and a ratio of particles having a primary particle diameter of 25 nm or more was 18%. It was.
The copper oxide nanoparticles thus obtained are hereinafter referred to as “copper oxide nanoparticles 5”.

<Synthesis Example 6>
(Copper oxide nanoparticles with an average primary particle size of 15 nm)
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 0.5 mol aqueous copper nitrate solution (20 mL) and 1.0 mol / L aqueous sodium hydroxide solution (20 mL) Was synthesized in the same manner as the copper oxide nanoparticles 1 except that water (100 mL) was used instead of ethylene glycol (100 mL), and a copper oxide nanoparticle dispersion was obtained.
It was confirmed by XRD analysis that the obtained copper oxide nanoparticles were made of cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained copper oxide nanoparticles was 25 nm, the average aspect ratio was 4.8, and the ratio of particles having a primary particle diameter of 25 nm or more was 20%. It was.
The copper oxide nanoparticles thus obtained are hereinafter referred to as “copper oxide nanoparticles 6”.

<Synthesis Example 7>
(Copper oxide nanoparticles with an average primary particle size of 49 nm)
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 10 mol / mL aqueous copper nitrate solution (20 mL) and 20 mol / L aqueous sodium hydroxide solution (20 mL) were used. A copper oxide nanoparticle dispersion was obtained by synthesizing in the same manner as copper oxide nanoparticle 1 except for the points used.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the obtained copper oxide nanoparticles had an average primary particle diameter of 49 nm, an average aspect ratio of 2.0, and a ratio of particles having a primary particle diameter of 25 nm or more was 80% or more. there were.
The copper oxide nanoparticles thus obtained are hereinafter referred to as “copper oxide nanoparticles 7”.

[Example 1]
<Preparation of composition for forming conductive film>
Copper oxide nanoparticles 1 (obtained in Synthesis Example 1, 100 parts by mass), polyethylene glycol (manufactured by Aldrich, 10 parts by mass), trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd., 20 parts by mass), acetic acid Palladium (manufactured by Tokyo Chemical Industry Co., Ltd., 5 parts by mass) and water (100 parts by mass) are mixed and treated with a rotating and rotating mixer (manufactured by THINKY Co., Ltd., Awatori Kentaro ARE-310) for 5 minutes. A forming composition was obtained. The conductive film forming composition thus obtained is referred to as conductive film forming composition 1.
Table 1 shows each component of the composition for forming a conductive film and its content.

<Manufacture of conductive film>
Using a bar coater, the conductive film-forming composition 1 was coated with a PET substrate (Teijin ^(R) Tetron ^(R) film K, thickness = 50 μm, thermal conductivity = 0.3 W / (m / K), Teijin DuPont film. A base material having a coating film (precursor film) having a thickness of 4 μm is prepared, and then the base material having a coating film is dried at 100 ° C. for 60 minutes using a hot plate. Then, a substrate with a precursor film was produced.
Next, by using MD-T1000 (YVO ₄ laser, wavelength 532 nm) manufactured by Keyence Corporation, a laser beam having a spot diameter of 20 μm is applied onto the precursor film at a linear velocity (scanning speed) of 10 mm / s and an output of 1.8 W. The conductive film was formed on the base material by scanning twice. The base material with the conductive film thus obtained is referred to as Sample 1.
Further, a separately prepared precursor film with a precursor film was scanned alternately with a laser beam at a pitch of 15.6 μm to form a 6 mm square square conductive film for conductivity evaluation. The overlapping rate at this time is 22%. The base material with the conductive film thus obtained is referred to as Sample 2.
The overlap rate is the ratio {(W / D) × 100} of the width W of the overlap region 24 between the first scanning region 20 and the adjacent region 22 described in FIG. 2 to the spot diameter D of the laser light 16. Intended. Thereafter, the same rule is applied.

<Evaluation of conductive film>
<< Base material adhesion >>
The cellophane tape (width 24 mm, manufactured by Nichiban Co., Ltd.) was brought into close contact with the conductive film of Sample 2 and then peeled off. The appearance of the conductive film after peeling was observed with the naked eye, and the substrate adhesion was evaluated according to the following evaluation criteria. Practically, the evaluation of the substrate adhesion is preferably “3” or more.
5: Adhesion of the conductive film is not observed on the tape, and peeling at the interface between the conductive film and the substrate is not observed.
4: Although adhesion of the electrically conductive film is slightly seen on the tape, peeling at the interface between the electrically conductive film and the substrate is not seen.
3: The adhesion of the conductive film is clearly seen on the tape, and the peeled area is seen in the range of less than 5% at the interface between the conductive film and the substrate.
2: Adhesion of the conductive film is clearly seen on the tape, and the peeled area is seen in the range of 5% or more and less than 50% at the interface between the conductive film and the substrate.
1: Adhesion of the conductive film is clearly seen on the tape, and the peeled area is seen in the range of 50% or more at the interface between the conductive film and the substrate.
The evaluation results are shown in Table 1.

《Defect (Evaluation of appearance of conductive film)》
A lateral direction of 3 mm of the conductive film in Sample 1 was observed using an optical microscope with a magnification of 200 times, and defects were evaluated according to the following evaluation criteria. In addition, the defect | deletion of a magnitude | size below 10 micrometers square intends the defect | deletion of the magnitude | size which fits in the range of 10 micrometers in length x 10 micrometers in width. In practice, the defect evaluation is preferably “3” or more.
5: No defect 4: There are 1 to 5 defects with a size of 10 μm square or less 3: There are 6 or more defects with a size of 10 μm square or less 2: There is a defect larger than 10 μm square 1: The conductive film is Table 1 shows the evaluation results.

"Conductivity"
The conductivity was measured according to the following evaluation criteria by measuring the surface resistivity of the conductive film of Sample 2 by the four-terminal method, multiplying the film thickness of the conductive film, and calculating the volume resistivity. Here, the surface resistivity is measured using a specific resistance measuring instrument (Loresta, manufactured by Mitsubishi Chemical Corporation), and the film thickness of the conductive film is measured by a scanning electron microscope (SEM) (S800, manufactured by Hitachi, Ltd.). The film thickness of the conductive film was measured from the cross section of the conductive film using In addition, the film thickness of an electrically conductive film is the arithmetic average of the thickness of arbitrary 10 places. Practically, the electrical conductivity is preferably “3” or higher.
5: Volume resistivity is less than 50 μΩ · cm 4: Volume resistivity is 50 μΩ · cm or more and less than 100 μΩ · cm 3: Volume resistivity is 100 μΩ · cm or more and less than 300 μΩ · cm 2: Volume resistivity is 300 μΩ · cm or more and 1000 μΩ · cm Less than cm 1: Volume resistivity is 1000 μΩ · cm or more.

<Removal of unnecessary part of precursor film>
The precursor film not converted to the conductive film of the conductive film substrate (sample 1) produced as described above was manufactured using Keyence MD-T1000, a laser beam having a wavelength of 532 nm, a spot diameter of 20 μm, and a linear velocity of 10 mm. The precursor film on the substrate was removed by irradiation at a power of 4.2 W / s.

[Examples 2 to 7]
Examples 2 to 7 are the same as in Example 1 except that the linear velocity and output of the laser beam and “linear velocity / output” are set as shown in Table 1. Samples 1 and 2) were prepared and evaluated for substrate adhesion, defects and conductivity. The evaluation results are shown in Table 1.

[Examples 8 to 10]
As shown in Table 1, Examples 8 to 10 were the same as in Example 1 except that the overlapping rate was set to 0%, 40%, or 60%, respectively, as shown in Table 1. Samples 1 and 2) were prepared and evaluated for substrate adhesion, defects and conductivity. The evaluation results are shown in Table 1.

[Examples 11 to 13]
As shown in Table 1, Examples 11 to 13 were the same as in Example 1 except that the spot diameter of the laser beam was set to 15 μm, 40 μm, or 60 μm, respectively (Substrate with conductive film ( Samples 1 and 2) were prepared and evaluated for substrate adhesion, defects and conductivity. The evaluation results are shown in Table 1.

[Examples 14 to 17]
As shown in Table 1, Examples 14 to 17 were conducted in the same manner as Example 1 except that the film thickness of the precursor film was set to 0.5 μm, 2 μm, 7 μm, or 12 μm, respectively. Substrates with a film (Sample 1 and Sample 2) were prepared and evaluated for substrate adhesion, defects, and conductivity. The evaluation results are shown in Table 1.

[Examples 18 to 21]
Examples 18 to 21 are the same as in Example 1 except that the type and content of the organic reducing agent in the conductive film forming composition were set as shown in Table 1. (Sample 1 and Sample 2) were prepared and evaluated for substrate adhesion, defects, and conductivity. The evaluation results are shown in Table 1.

[Example 22]
Example 22 contains only PEG (30 parts by mass) as an organic reducing agent in the composition for forming a conductive film, and except that the spot diameter of the laser beam is set to 40 μm as shown in Table 1. In the same manner as in Example 1, substrates with a conductive film (Sample 1 and Sample 2) were produced, and the substrate adhesion, defects, and conductivity were evaluated. The evaluation results are shown in Table 1.

[Examples 23 to 26]
Examples 23 to 26 were conducted in the same manner as in Example 1 except that the content of heavy metal fine particles or heavy metal salt (palladium acetate) in the composition for forming a conductive film was set as shown in Table 1. Substrates with a film (Sample 1 and Sample 2) were prepared and evaluated for substrate adhesion, defects, and conductivity. The evaluation results are shown in Table 1.

[Examples 27 to 32]
Examples 27 to 32 were provided with a conductive film in the same manner as in Example 1 except that the average primary particle diameter of the copper oxide nanoparticles in the composition for forming a conductive film was set as shown in Table 1. Substrates (Sample 1 and Sample 2) were prepared and evaluated for substrate adhesion, defects, and conductivity. The evaluation results are shown in Table 1.

[Comparative Example 1]
Comparative Example 1 is an example except that MD-V9900A (manufactured by Keyence) was used instead of MD-T1000 (manufactured by Keyence) as a laser light irradiation apparatus, and the wavelength of the laser light was set to 1024 nm. In the same manner as in Example 1, substrates with conductive films (Sample 1 and Sample 2) were prepared, and substrate adhesion, defects, and conductivity were evaluated. The evaluation results are shown in Table 1.

[Comparative Examples 2 and 3]
Comparative Example 2 was the same as in Example 1 except that the value of “Linear speed of laser light / Laser light output” was set to be less than 1.0, and a substrate with a conductive film (Sample 1 and Sample 2) was prepared and evaluated for substrate adhesion, defects and conductivity. The evaluation results are shown in Table 1.
Comparative Example 3 is a substrate with a conductive film (Sample 1 and Sample 2) in the same manner as in Example 1, except that the value of “linear velocity of laser light / output of laser light” is set to be larger than 120. ) And the substrate adhesion, defects, and conductivity were evaluated. The evaluation results are shown in Table 1.

[Comparative Example 4]
Comparative Example 4 produced substrates with conductive films (Sample 1 and Sample 2) in the same manner as Example 1, except that the composition for forming a conductive film did not contain an organic reducing agent. The substrate adhesion, defects and conductivity were evaluated. The evaluation results are shown in Table 1.

<Contrast between Example and Comparative Example>
The conductive films of the examples were evaluated as “3” or more in terms of substrate adhesion, defects, and conductivity, and reached the required level.
On the other hand, in the conductive film of the comparative example, at least one of the substrate adhesion, the defect, and the conductivity was evaluated as “1” or “2”, and the required level was not reached.

<Contrast of Examples 1-7>
(1) Regarding the laser beam linear velocity In Example 1 where the laser beam linear velocity is 10 mm / s, both the substrate adhesion and the electrical conductivity evaluation are “5”, and the defect evaluation is “4”. The manufactured conductive film had excellent characteristics.
In Example 5 in which the linear velocity of the laser beam is 90 mm / s, the evaluation of the substrate adhesion is “5”, the evaluation of both defects and conductivity is “4”, and the manufactured conductive film has excellent characteristics. Had.
In Example 6 in which the linear velocity of the laser beam is 120 mm / s, both the base material adhesion and the electrical conductivity are evaluated as “5”, the defect is evaluated as “4”, and the manufactured conductive film has excellent characteristics. Had.
In Example 7 in which the linear velocity of the laser beam is 210 mm / s, both the substrate adhesion and the defect evaluation are “3” and the conductivity evaluation is “4”, and the manufactured conductive film satisfies the required level. I met.
From the comparison between Examples 1 and 5-7, when the linear velocity of the laser beam is within the range of 10 to 120 mm / s, the occurrence of defects is suppressed, and the substrate adhesion and conductivity are more excellent. It has been suggested that membranes can be produced.

(2) Regarding the output of laser light Example 1 in which the output of laser light is 1.8 W is manufactured with both substrate adhesion and conductivity evaluated as “5” and defect evaluated as “4”. The conductive film had excellent characteristics.
In Example 3 in which the output of the laser beam is 3.6 W, the substrate adhesion evaluation is “3”, the defect evaluation is “4”, and the conductivity evaluation is “4”. Met the required level.
In Example 4 in which the output of the laser beam is 0.5 W, the substrate adhesion evaluation is “4”, the defect evaluation is “4”, and the conductivity evaluation is “3”. Met the required level.
From the comparison of Examples 1, 3 and 4, when the output of the laser beam is within the range of 0.5 to 3.6 W, the occurrence of defects is suppressed, and the substrate adhesion and conductivity are more excellent. It was suggested that a conductive film can be manufactured.

(3) Regarding “Linear speed / output” In Example 1 in which “Linear speed / output” is 5.6, both the substrate adhesion and conductivity are evaluated as “5”, and the defect is evaluated as “4”. The manufactured conductive film had excellent characteristics.
In Example 2 where the “linear velocity / output” is 1.0, the base material adhesion and defect evaluation are “3”, and the conductivity evaluation is “4”. I met.
Example 3 with a “linear velocity / output” of 2.8 was manufactured with a substrate adhesion evaluation of “3”, a defect evaluation of “4”, and a conductivity evaluation of “4”. The conductive film met the required level.
Example 4 with a “linear velocity / output” of 20.0 was manufactured with a substrate adhesion evaluation of “4”, a defect evaluation of “4”, and a conductivity evaluation of “3”. The conductive film met the required level.
In Example 5 in which the “linear velocity / output” was 50.0, the evaluation of the substrate adhesion was “5”, the evaluation of defects and conductivity was both “4”, and the manufactured conductive film was excellent. Had characteristics.
In Example 6 in which the “linear velocity / output” was 66.7, the evaluation of the base material adhesion and conductivity was “5”, the evaluation of the defect was “4”, and the manufactured conductive film was excellent. Had characteristics.
In Example 7 where the “linear velocity / output” is 116.7, both the base material adhesion and the defect evaluation are “3”, the conductivity evaluation is “4”, and the manufactured conductive film has the required level. Was met.
From the comparison of Examples 1 to 7, when the “linear velocity / output” is in the range of 1.0 to 120, the occurrence of defects is suppressed, and the conductive film having better substrate adhesion and conductivity. It was suggested that can be manufactured. It was also suggested that a conductive film having better characteristics can be produced when the “linear velocity / output” is in the range of 2.5 to 90.0.

<Comparison of Examples 1 and 8 to 10>
In Example 1 in which the overlap ratio is 22%, both the base material adhesion and the electrical conductivity are evaluated as “5” and the defect is evaluated as “4”, and the manufactured conductive film has excellent characteristics. It was.
In Example 8 in which the overlapping ratio was 0%, both the base material adhesion and the electrical conductivity were evaluated as “4” and the defect was evaluated as “3”, and the manufactured conductive film satisfied the required level.
In Example 9 where the overlap ratio is 40%, the evaluation of the substrate adhesion is “5”, the evaluation of both defects and conductivity is “4”, and the manufactured conductive film has excellent characteristics. It was.
In Example 10 in which the overlapping ratio was 60%, both the base material adhesion and the defect evaluation were “3”, and the conductivity evaluation was “4”, and the manufactured conductive film satisfied the required level.
From the comparison of Examples 1 and 8 to 10, when the overlap ratio is in the range of 15 to 30%, the generation of defects is suppressed, and a conductive film with better substrate adhesion and conductivity can be produced. It was suggested that it can be done.

<Contrast of Examples 1, 11-13>
In Example 1 in which the spot diameter was 20 μm, both the substrate adhesion and conductivity were evaluated as “5” and the defect was evaluated as “4”, and the manufactured conductive film had excellent characteristics. .
In Example 11 in which the spot diameter was 15 μm, the evaluation of substrate adhesion, defects, and conductivity were all “5”, and the produced conductive film had particularly excellent characteristics.
In Example 12 with a spot diameter of 40 μm, both the substrate adhesion and the defect evaluation were “4”, and the conductivity evaluation was “5”, and the manufactured conductive film had excellent characteristics. .
In Example 13 in which the spot diameter was 60 μm, both the substrate adhesion and the defect evaluation were “3” and the conductivity evaluation was “4”, and the manufactured conductive film satisfied the required level.
From the comparison between Examples 1 and 11-13, when the spot diameter of the laser beam is within the range of 10 to 40 μm, the generation of defects is suppressed, and the conductive film with better substrate adhesion and conductivity is obtained. It was suggested that it can be manufactured.

<Comparison of Examples 1 and 14 to 17>
In Example 1 where the film thickness of the precursor film is 4 μm, both the substrate adhesion and the conductivity evaluation are “5”, the defect evaluation is “4”, and the manufactured conductive film has excellent characteristics. Had.
In Example 14 in which the thickness of the precursor film was 0.5 μm, both the base material adhesion and the electrical conductivity were evaluated as “5”, the defect was evaluated as “4”, and the manufactured conductive film was excellent. Had characteristics.
In Example 15 in which the thickness of the precursor film is 2 μm, both the substrate adhesion and the defect evaluation are “5”, and the conductivity evaluation is “4”, and the manufactured conductive film has excellent characteristics. Had.
In Example 16 in which the film thickness of the precursor film is 7 μm, the substrate adhesion evaluation is “4”, the defect evaluation is “3”, and the conductivity evaluation is “5”. Met the required level.
In Example 17, in which the film thickness of the precursor film was 12 μm, the evaluation of the substrate adhesion, the defect, and the conductivity were all “3”, and the manufactured conductive film reached the required level.
From the comparison between Examples 1 and 14 to 17, when the thickness of the precursor film is in the range of 0.1 μm or more and less than 5 μm, the occurrence of defects is suppressed, and the substrate adhesion and conductivity are more excellent. It was suggested that a conductive film can be manufactured.

<Comparison of Examples 1 and 18 to 21>
In Example 1 containing PEG (10 parts by mass) and TMP (20 parts by mass) in the composition for forming a conductive film, both the base material adhesion and the electrical conductivity were evaluated as “5”, and the defect was evaluated as “4”. The manufactured conductive film had excellent characteristics.
In Example 18 containing PEG (30 parts by mass) in the composition for forming a conductive film but not containing TMP, the evaluation of the substrate adhesion was “5”, and the evaluation of defects and conductivity was both “4”. The manufactured conductive film had excellent characteristics.
In Example 19 containing PEG (20 parts by mass) and TMP (40 parts by mass) in the composition for forming an electrically conductive film, both the substrate adhesion and conductivity were evaluated as “5”, and the defect was evaluated as “4”. The manufactured conductive film had excellent characteristics.
In Example 20 containing PEG (30 parts by mass) and TMP (60 parts by mass) in the composition for forming a conductive film, the substrate adhesion evaluation was “3”, and the defect and conductivity evaluation was “4”. The manufactured conductive film satisfied the required level.
Example 21 which contains TMP (30 parts by mass) in the composition for forming a conductive film but does not contain PEG has a substrate adhesion evaluation of “5” and a defect and conductivity evaluation of “4”. The manufactured conductive film had excellent characteristics.
From comparison of Example 1 and 18-21, when content of the organic reducing agent in the composition for electrically conductive film is in the range of 10-75 mass parts with respect to 100 mass parts of copper oxide nanoparticles, It was suggested that it is possible to produce a conductive film with suppressed substrate generation and better substrate adhesion and conductivity.

<Contrast of Examples 1, 23 to 26>
In Example 1 in which the composition for forming a conductive film contains heavy metal fine particles and / or palladium acetate (5 parts by mass) as a heavy metal salt, both the substrate adhesion and the conductivity evaluation are “5”, and the defect evaluation is “ 4 ”and the manufactured conductive film had excellent characteristics.
Example 23, in which the composition for forming a conductive film contained neither heavy metal fine particles nor heavy metal salts, was produced with both a substrate adhesion and defect evaluation of “3” and a conductivity evaluation of “4”. The conductive film met the required level.
In Example 24 in which the composition for forming a conductive film contains heavy metal fine particles and / or palladium acetate (1 part by mass) as a heavy metal salt, both the substrate adhesion and the defect evaluation are “4”, and the conductivity evaluation is “ 5 ”and the manufactured conductive film had excellent characteristics.
In Example 25 in which the conductive film forming composition contains palladium acetate (3 parts by mass) as heavy metal fine particles and / or heavy metal salt, both the substrate adhesion and conductivity evaluation are “5”, and the defect evaluation is “ 4 ”and the manufactured conductive film had excellent characteristics.
In Example 26 in which the composition for forming a conductive film contains heavy metal fine particles and / or palladium acetate (10 parts by mass) as a heavy metal salt, the substrate adhesion evaluation is “3”, the defect evaluation is “4”, the conductivity The evaluation of the property was “5”, and the manufactured conductive film satisfied the required level.
From the comparison between Examples 1 and 23 to 26, the total content of heavy metal fine particles and heavy metal salt in the composition for forming a conductive film is in the range of 0.5 to 9 parts by mass with respect to 100 parts by mass of the copper oxide nanoparticles. As a result, it was suggested that the generation of group defects can be suppressed, and a conductive film with better substrate adhesion and conductivity can be produced.

<Contrast of Examples 1, 27 to 32>
In Example 1 in which the composition for forming a conductive film contains copper oxide nanoparticles having an average primary particle diameter of 5 nm, both evaluation of substrate adhesion and conductivity was “5”, and evaluation of defects was “4”. The manufactured conductive film had excellent characteristics.
In Example 27 containing copper oxide nanoparticles having an average primary particle size of 3 nm in the composition for forming a conductive film, both the base material adhesion and the conductive evaluation were “5”, and the defect evaluation was “4”. The manufactured conductive film had excellent characteristics.
In Example 28 containing copper oxide nanoparticles having an average primary particle size of 8 nm in the composition for forming a conductive film, both the base material adhesion and the conductive evaluation were “5”, and the defect evaluation was “4”. The manufactured conductive film had excellent characteristics.
In Example 29 containing copper oxide nanoparticles having an average primary particle diameter of 15 nm in the composition for forming a conductive film, both the adhesion to the substrate and the evaluation of defects were “4”, and the evaluation of conductivity was “5”. The manufactured conductive film had excellent characteristics.
In Example 30 containing copper oxide nanoparticles having an average primary particle diameter of 20 nm in the composition for forming a conductive film, the substrate adhesion evaluation was “3”, the defect evaluation was “4”, and the conductivity Was 5 and the manufactured conductive film satisfied the required level.
In Example 31 containing copper oxide nanoparticles having an average primary particle size of 25 nm in the composition for forming a conductive film, both the substrate adhesion and the defect evaluation were “3”, and the conductivity evaluation was “4”. The manufactured conductive film satisfied the required level.
In Example 32 containing copper oxide nanoparticles having an average primary particle size of 49 nm in the composition for forming a conductive film, all of the evaluations of substrate adhesion, defects, and conductivity were “3” and manufactured. The conductive film had reached the required level.
From the comparison between Example 1 and 27 to 32, when the average primary particle diameter of the copper oxide nanoparticles contained in the composition for forming a conductive film is 25 nm or less, a conductive film having excellent conductivity can be produced. When the thickness is 20 nm or less, generation of defects can be suppressed and a conductive film having excellent conductivity can be produced. When the thickness is 15 nm or less, the substrate adhesion is excellent, and the defects and conductivity are excellent. It was suggested that the electrically conductive film which was further excellent in base-material adhesiveness and electroconductivity can be manufactured as it is 10 nm or less.

DESCRIPTION OF SYMBOLS 10 Base material 12 Precursor film | membrane 14 Laser light source 16 Laser beam 18 Conductive film 20 Scanning region 22 Adjacent region

Claims (12)

A conductive film-forming composition containing copper oxide nanoparticles, an organic reducing agent and a solvent is applied onto a substrate, and a precursor film containing the copper oxide nanoparticles and the organic reducing agent is applied onto the substrate. A precursor film forming step to be formed; and
The precursor film is relatively scanned at a linear velocity V ₁ while irradiating laser light having a wavelength of 532 nm with an output W ₁ to reduce the copper oxide nanoparticles in the scanning region irradiated with the laser light. And an irradiation step of forming a conductive film containing metallic copper,
The method of manufacturing a conductive film, wherein the linear velocity V ₁ of the laser beam and the output W _{1 of the} laser beam satisfy the relationship of Formula 1, and the output W _{1 of the} laser beam is 4 W or less.
Formula 1 1.0 ≦ V ₁ / W ₁ ≦ 120
However, the unit of the output W ₁ of the laser beam is W, and the unit of the linear velocity V ₁ of the laser beam is mm / s. Furthermore, it comprises a precursor film removing step of irradiating a laser beam having a wavelength of 532 nm with an output W ₂ and removing the precursor film in the region irradiated with the laser beam,
Meet the output W ₁ Togashiki 2 relationship of the laser beam in the irradiation step and the output W ₂ of the laser light, the production method of the conductive film of claim 1.
Formula 2 W ₂ > W ₁
However, the units of the laser light outputs W ₁ and W ₂ are both W.   The manufacturing method of the electrically conductive film of Claim 1 or 2 whose said copper oxide nanoparticle is a cupric oxide nanoparticle.   The manufacturing method of the electrically conductive film of any one of Claims 1-3 whose average primary particle diameter of the said copper oxide nanoparticle is 3-25 nm.   The manufacturing method of the electrically conductive film of any one of Claims 1-4 whose said organic reducing agent is an alcohol compound.   The manufacturing method of the electrically conductive film of Claim 5 with which the said alcohol compound contains polyhydric alcohols other than polyethyleneglycol and / or polyethyleneglycol.   The conductive film according to any one of claims 1 to 6, wherein the composition for forming a conductive film further contains fine particles of Group 8 to 10 heavy metal elements and / or salts of Group 8 to 10 heavy metal elements. Manufacturing method.   The conductive film according to any one of claims 1 to 7, wherein the substrate is any one selected from the group consisting of a polyethylene terephthalate substrate, a polyethylene naphthalate substrate, and a cycloolefin polymer substrate. Manufacturing method.   The manufacturing method of the electrically conductive film of any one of Claims 1-8 whose output of the said laser beam is 0.5-3.6W.   The manufacturing method of the electrically conductive film of any one of Claims 1-9 whose spot diameter of the said laser beam is 10-40 micrometers.   The manufacturing method of the electrically conductive film of any one of Claims 1-10 whose linear velocity of the said laser beam is 10-120 mm / s. The manufacturing method of the electrically conductive film of any one of Claims 1-11 whose film thickness of the said precursor film | membrane is 0.1 micrometer or more and less than 5 micrometers.