JP2023145371A - Method for manufacturing metal wiring - Google Patents

Abstract

To provide a method for manufacturing a metal wiring capable of sufficiently removing a coating film remaining between metal wirings in a developing step and effectively utilizing resources by reusing a post-development coating film.SOLUTION: A method for manufacturing a metal wiring includes an application step, a drying step, a laser beam irradiation step, a development step, and a recovery step. The application step forms a dispersion element layer by applying a dispersion element including a particle component being a metal particle and/or a metal oxide particle onto a surface of a base material. The drying step forms a structure with a dry film including the base material and a dry film arranged on the base material by drying the dispersion element layer. The laser beam irradiation step forms a metal wiring by drawing by irradiating the dry film with a laser beam. The development step development-removes a region other than the metal wiring of the dry film with a developer. The recovery step recovers the used developer generated by the development step.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing metal wiring.

The circuit board has a structure in which conductive wiring is provided on the board. A method for manufacturing a circuit board is generally as follows. First, a photoresist is applied onto a substrate to which metal foil is bonded. The photoresist is then exposed and developed to obtain a negative form of the desired circuit pattern. Next, the portions of the metal foil not covered with the photoresist are removed by chemical etching to form a pattern. Thereby, a high-performance conductive substrate can be manufactured.

However, conventional methods have drawbacks such as being complicated and requiring a large number of steps, and requiring photoresist materials.

On the other hand, direct wiring printing involves directly printing a desired wiring pattern on a substrate using a dispersion (hereinafter also referred to as "paste material") in which particles selected from the group consisting of metal particles and metal oxide particles are dispersed. Technology is attracting attention. This technology has extremely high productivity, with a small number of steps and no need to use photoresist materials.

An example of direct printed wiring technology is to apply a paste material to the entire surface of the board to form a coating film, and then irradiate the coating film with laser light in a pattern and selectively heat it to create the desired shape. A method for obtaining a wiring pattern is known (for example, see Patent Documents 1 and 2).

Patent Document 2 states that when drawing was performed by irradiating a GaAlAs laser beam with a wavelength of 830 nm, the beam diameter on the copper oxide thin film was 5 μm, and the area to be irradiated with the laser beam was locally heated, so that the copper oxide It is described that the copper was reduced and a reduced copper region with a diameter of approximately 5 μm was formed.

International Publication No. 2010/024385 Japanese Patent Application Publication No. 5-37126

When wiring is formed by drawing using laser light irradiation as described above, a coating film remains in areas that are not irradiated with light. This remaining coating film causes problems such as metal growth outside the intended wiring pattern and short circuits due to migration during the plating operation after the wiring is formed. Therefore, after laser light irradiation, it is necessary to sufficiently remove the remaining coating film by a developing operation. On the other hand, the coating film removed by development contains useful substances such as metals, and it is desirable from the viewpoint of circular economy to reuse the useful substances. However, no technology has been proposed so far that can sufficiently recover and reuse such useful substances.

The present invention has been made in view of this point, and it is possible to effectively utilize resources by sufficiently removing the coating film remaining between the metal wirings during the development process and reusing the coating film after development. The purpose is to provide a method for manufacturing metal wiring.

This disclosure includes the following items.
[Item 1]
a coating step of coating a dispersion containing particle components that are metal particles and/or metal oxide particles on the surface of the base material to form a dispersion layer;
a drying step of drying the dispersion layer to form a structure with a dry coating film having the base material and a dry coating film disposed on the base material;
a laser light irradiation step of irradiating the dried coating film with laser light to form metal wiring by drawing;
a developing step of developing and removing an area of the dried coating film other than the metal wiring with a developer;
a recovery step of recovering the used developer generated in the development step;
A method of manufacturing metal wiring, including:
[Item 2]
The developer contains water and/or an organic solvent,
The method for manufacturing metal wiring according to item 1, wherein the total amount of metal particles and metal oxide particles in the used developer is 0.0001% by mass or more and 10% by mass or less.
[Item 3]
The method for manufacturing metal wiring according to item 2, wherein the organic solvent is an alcoholic solvent.
[Item 4]
The method for producing metal wiring according to item 3, wherein the alcohol solvent is one or more selected from the group consisting of ethanol, n-butanol, n-heptanol, and n-octanol.
[Item 5]
The method for producing metal wiring according to any one of items 1 to 4, wherein the developer contains 0.01% by mass or more and 20% by mass or less of a dispersant (A).
[Item 6]
The method for manufacturing metal wiring according to item 5, wherein the dispersion contains a dispersant (B), and the main components of the dispersant (A) and the dispersant (B) are the same.
[Item 7]
The method for manufacturing metal wiring according to item 5 or 6, wherein the dispersant (A) is a phosphorus-containing organic compound.
[Item 8]
In the laser light irradiation step, the laser light is scanned while overlapping in the line width direction of the scanning line,
8. The method for manufacturing a metal wiring according to any one of items 1 to 7, wherein the overlap ratio, which is the ratio of the overlap portion width to the line width of the scanning line, is in the range of 5% to 99.5%.
[Item 9]
further comprising a regeneration step of preparing a regenerated dispersion using the used developer collected in the collection step,
The method for producing metal wiring according to any one of items 1 to 8, wherein the regenerated dispersion is used as part or all of the dispersion.
[Item 10]
The method for manufacturing metal wiring according to item 9, wherein the used developer is concentrated in the recycling step.
[Item 11]
A method for producing a dispersion containing particle components that are metal particles and/or metal oxide particles, the method comprising:
a concentration step of concentrating the used developer recovered in the recovery step of the metal wiring manufacturing method according to any one of items 1 to 10 to obtain a concentrated solution;
an addition step of adding an additive containing water and/or an alcoholic solvent to the concentrated liquid to obtain an additive treatment liquid;
including;
The solid content of the concentrated liquid is 0.1% by mass or more and 80% by mass or less,
A method for producing a dispersion, wherein the solid content of the addition treatment liquid is 0.01% by mass or more and 70% by mass or less.
[Item 12]
The method for producing a dispersion according to item 11, wherein the additive further includes one or more selected from the group consisting of propylene glycol, hydrazine, hydrazine hydrate, and a dispersant.
[Item 13]
further comprising a dispersion step of dispersing the addition treatment liquid,
The method for producing a dispersion according to item 11 or 12, wherein the average particle diameter of the dispersion is 1 nm or more and 500 nm or less.
[Item 14]
The method for producing a dispersion according to any one of items 11 to 13, wherein the particle component is a copper oxide particle.
[Item 15]
a coating mechanism that forms a dispersion layer by coating a dispersion containing particle components that are metal particles and/or metal oxide particles on the surface of a base material;
a drying mechanism that dries the dispersion layer to form a structure with a dry coating film having the base material and a dry coating film disposed on the base material;
a laser light irradiation mechanism that irradiates the dried coating film with laser light to form metal wiring by drawing;
a developing mechanism that develops and removes an area of the dried coating film other than the metal wiring with a developer;
a developer recovery mechanism that recovers the used developer generated by the development mechanism;
A metal wiring manufacturing system equipped with
[Item 16]
The developer contains water and/or an alcoholic solvent,
The metal wiring manufacturing system according to item 15, wherein the total amount of metal particles and metal oxide particles in the used developer is 0.0001% by mass or more and 10% by mass or less.

According to one aspect of the present invention, there is provided a method for manufacturing metal wiring that can effectively utilize resources by sufficiently removing the paint film remaining between the metal wires in the development process and reusing the paint film after development. may be provided.

FIG. 2 is an explanatory diagram showing an example of a method for manufacturing metal wiring according to the present embodiment. FIG. 3 is a schematic diagram illustrating overlapping irradiation of laser light in the metal wiring manufacturing method according to the present embodiment. FIG. 2 is a schematic diagram showing an example of a jig for holding a structure with a conductive part in a developing step of the method for manufacturing metal wiring according to the present embodiment. FIG. 2 is a schematic diagram showing an example of a jig for holding a structure with a conductive part in a developing step of the method for manufacturing metal wiring according to the present embodiment. FIG. 2 is a schematic diagram showing an example of a jig for holding a structure with a conductive part in a developing step of the method for manufacturing metal wiring according to the present embodiment. FIG. 2 is an explanatory diagram showing an example of a process flow of a method for manufacturing metal wiring according to the present embodiment. FIG. 1 is an explanatory diagram showing an example of a metal wiring manufacturing system according to the present embodiment.

Hereinafter, one embodiment of the present invention (hereinafter abbreviated as "this embodiment") will be described in detail, but the present invention is not limited to these embodiments at all.

<Metal wiring manufacturing method>
One aspect of the present invention is
A coating step of forming a dispersion layer by applying a dispersion containing a particle component (in this disclosure, sometimes simply referred to as a particle component) that is a metal particle and/or a metal oxide particle on the surface of a base material. and,
a drying step of drying the dispersion layer to form a structure with a dry coating film having a base material and a dry coating film disposed on the base material;
A laser light irradiation step of forming metal wiring by drawing by irradiating the dry coating film with laser light;
a development step of developing and removing areas other than the metal wiring of the dried coating film with a developer;
a collection step of collecting the used developer generated in the development step;
Provided is a method for manufacturing metal wiring including.

The present inventors formed a region irradiated with laser light (hereinafter also referred to as "exposed area") of a dry paint film placed on a base material as a metal wiring, and the laser light of the dry paint film By developing and removing the areas that were not irradiated (hereinafter also referred to as unexposed areas) with a developer, and then collecting the used developer generated in the development process, the areas remaining between the metal wiring can be removed. It has been found that while the coating film is sufficiently removed, the useful substances in the coating film can be reused as a resource, for example, in the dispersion used for manufacturing the metal wiring of the present disclosure.

[Composition of developer]
In the method of this embodiment, a developer containing water and/or an organic solvent can be used as the developer. From the viewpoint of improving developability and improving the dispersibility of particles in the collected developer, the developer preferably contains a dispersant (also referred to as dispersant (A) in the present disclosure). The dispersant refers to something that can efficiently disperse (that is, efficiently remove) metal particles and/or metal oxide particles attached to a base material in a developer. Here, "efficiently" means, in one embodiment, that the concentration of metal remaining in the base material is 10% by mass or less in the developability evaluation described below. In one embodiment, the dispersant has a structure such that the metal particles and/or metal oxide particles have greater affinity for the dispersant than for the substrate. Examples of such structures include carboxy groups, phosphoric acid groups, sulfuric acid groups, sulfonic acid groups, hydroxyl groups, amino groups, and ester groups.

As the dispersant, it is preferable to use one whose main component is the same as that of the dispersant contained in the dispersion of the present disclosure. In the present disclosure, the main component of the dispersant is the component present in the largest amount among the components present as a dispersant in the dispersion or developer. The main components of the dispersant in the dispersion and the main components of the dispersant in the developer are the same, which improves developability and improves the efficiency when collecting used developer and reusing it as a dispersion. Processing operations are simple. As the dispersant that can be included in the dispersion of the present disclosure, those described below in the section [Composition of dispersion and dry coating film] are preferred.

As the dispersant, known ones can be used, such as salts of long chain polyaminoamides and polar acid esters, unsaturated polycarboxylic acid polyaminoamides, polycarboxylate salts of polyaminoamides, long chain polyaminoamides and acid polymers. Examples include polymers having basic groups, such as salts of Further examples include alkyl ammonium salts, amine salts, amidoamine salts of polymers such as acrylic polymers (homopolymers and copolymers), modified polyester acids, polyether ester acids, polyether carboxylic acids, and polycarboxylic acids. As such a dispersant, commercially available ones can also be used.

The above-mentioned commercial products include, for example, DISPERBYK (registered trademark)-101, DISPERBYK-102, DISPERBYK-110, DISPERBYK-111, DISPERBYK-112, DISPERBYK-118, DISPERBYK-130, DISPERBYK-14. 0, DISPERBYK-142, DISPERBYK- 145, DISPERBYK-160, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-2155, DISPERBYK-2163, DISPERBYK-2164, DISPERBYK-180, DI SPERBYK-2000, DISPERBYK-2025, DISPERBYK-2163, DISPERBYK-2164, BYK-9076, BYK-9077, TERRA-204, TERRA-U (manufactured by BYK Chemie), Floren DOPA-15B, Floren DOPA-15BHFS, Floren DOPA-22, Floren DOPA-33, Floren DOPA-44, Floren DOPA -17HF, Floren TG-662C, Floren KTG-2400 (manufactured by Kyoeisha Chemical Co., Ltd.), ED-117, ED-118, ED-212, ED-213, ED-214, ED-216, ED-350, ED -360 (manufactured by Kusumoto Kasei Co., Ltd.), Pricesurf (registered trademark) M208F, and Pricesurf DBS (manufactured by Dai-ichi Kogyo Seiyaku). These may be used alone or in combination.

For example, when a phosphorus-containing organic compound is used, the metal particles and/or metal oxide particles (particularly copper oxide particles) are well dispersed in the developer, making development easy. Therefore, in one embodiment, examples of suitable compounds for the dispersant in the developer are the same as those for the dispersant described later in the section [Composition of dispersion and dry coating].

The content of the dispersant in the developer is preferably such that metal particles and/or metal oxide particles attached to the base material can be efficiently dispersed in the developer (that is, efficiently removed). A high viscosity dispersant that is 0.01% by mass or more, or 0.1% by mass or more, or 0.5% by mass or more, or 1.0% by mass or more, and can suppress dissolution of metal wiring by the dispersant. It is preferable because it is possible to form a low-viscosity developer suitable for development even when used with is 20% by mass or less, or 15% by mass or less, or 10% by mass or less.

In one embodiment, the developing step includes:
(1) a first development process that develops the dried coating film with a first developer; (2) a second development process that develops the dried coating film with a second developer; and
(3) optionally an additional development process to develop the dried coating with an additional developer;
may include. The compositions of the first developer, second developer, and any additional developer may be different from each other, or two or more of them may be the same. The first developer, the second developer, and any additional developer may include water and/or an organic solvent in one embodiment. From the viewpoint of improving developability and improving the dispersibility of particles in the collected used developer, at least one of the first developer, the second developer, and any additional developer is Preferably, a dispersant is included. When the dispersant is contained in only one developer (for example, only the first developer), by collecting the developer after use, particles can be efficiently collected in one go, which is good from the viewpoint of recyclability. It is advantageous from

The developer can contain water and/or an organic solvent. Since organic solvents can dissolve and remove metals or metal oxides, they can prevent metals or metal oxides from remaining between interconnects and are suitable for finishing development. As the organic solvent, amine solvents, alcohol solvents, hydrocarbon solvents, ester solvents, ketone solvents, carbonate solvents, etc. are suitable, and one or more of these may be used.

Examples of amine-based solvents include amines (primary amines, secondary amines, and tertiary amines), alkanolamines, amides, etc. More specifically, diethylenetriamine, 2-aminoethanol, diethanolamine, triethanolamine, mono- Examples include isopropanolamine, diisopropanolamine, triisopropanolamine, N-methylethanolamine, N-methyldiethanolamine, dicyclohexylamine, n-methyl-2-pyrrolidone, and N,N-dimethylformamide.

Examples of alcoholic solvents include monohydric or polyhydric alcohols, and ethers and esters of the alcohols. The alcohol is preferably a glycol. More specific examples of alcohol-based solvents include:
Methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, sec-pentanol, t-pentanol, 2- Methylbutanol, 2-ethylbutanol, 3-methoxybutanol, n-hexanol, sec-hexanol, 2-methylpentanol, sec-heptanol, 3-heptanol, n-octanol, sec-octanol, 2-ethylhexanol, n- Monohydric alcohols such as nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, phenol, benzyl alcohol, diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 1,2-pentanediol, 2-methylpentane-2,4-diol, 2,5-hexanediol, 2,4-heptanediol, 2 - Trivalent glycols such as ethylhexane-1,3-diol, diethylene glycol, dipropylene glycol, 1,2-hexanediol, 1,2-octanediol, triethylene glycol, tri-1,2-propylene glycol, and glycerin Polyhydric alcohols such as alcohol;
Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol tertiary butyl ether, dipropylene glycol monomethyl ether;
Glycol esters such as propylene glycol monomethyl ether acetate;
etc.

Examples of the hydrocarbon solvent include pentane, hexane, octane, nonane, decane, cyclohexane, methylcyclohexane, toluene, xylene, mesitylene, and ethylbenzene.

Examples of the ester solvent include 3methoxy-3-methyl-butyl acetate, ethoxyethylpropionate, ethyl glycerol acetate, n-propyl acetate, isopropyl acetate, and the like.

Examples of ketone solvents include methyl ethyl ketone and methyl isobutyl ketone.

Examples of carbonate solvents include dimethyl carbonate, diethyl carbonate, and ethylmethyl carbonate.

In a preferred embodiment, the organic solvent includes or is an alcoholic solvent. Water or alcohol-based solvents are solvents in which the dispersant can be well dispersed, and when combined with the dispersant, the redispersibility of the particles on the substrate becomes better. /Or suitable for dispersing metal oxide particles in a developer. As the alcoholic solvent, from the viewpoint of efficient particle removal, alcohols having 10 or less carbon atoms are preferred, and ethanol, n-butanol, n-heptanol, and n-octanol are particularly preferred. From the viewpoint of printability, n-heptanol and n-octanol are particularly preferred.

In one embodiment, the content of water in the developer may be 10% by mass or more, 20% by mass or more, or 30% by mass or more, and in one embodiment, 99% by mass or less, or 98% by mass or less, Or it may be 97% by mass or less.

In one embodiment, the content of the alcoholic solvent in the developer may be 10% by mass or more, 20% by mass or more, or 30% by mass or more, and in one embodiment, 99% by mass or less, or 98% by mass. or less, or 97% by mass or less.

In one embodiment, the total content of water and alcoholic solvent in the developer may be 20% by mass or more, 40% by mass or more, 50% by mass or more, or 60% by mass or more. The total content may be 100% by mass in one embodiment, or 99% by mass or less, or 98% by mass or less, or 97% by mass or less in one embodiment.

In one preferred embodiment, the organic solvent contains or is an amine-based solvent from the viewpoint of developability. Examples of amine solvents include diethylenetriamine, 2-aminoethanol, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, N-methylethanolamine, N-methyldiethanolamine, dicyclohexylamine, n-methyl-2 -pyrrolidone, N,N-dimethylformamide and the like are preferred. From the viewpoint of developability, it is particularly preferable to use at least one of diethylenetriamine and 2-aminoethanol.

In one embodiment, the content of the organic solvent in the developer may be 1% by mass or more, 2% by mass or more, or 3% by mass or more. In one embodiment, the content may be 100% by mass, or in one embodiment, it may be 98% by mass or less, or 97% by mass or less, or 95% by mass or less. In this case, the remainder may include water and/or a dispersant.

In one embodiment, the water content in the developer may be 1% by mass or more, 2% by mass or more, or 3% by mass or more, and 99% by mass or less, or 98% by mass or less, or 95% by mass. It may be the following.

(solubility)
In the development process, when performing a first development process using a first developer and then a second development process using a second developer, particle components (i.e., metals contained in the dispersion) with respect to the second developer are The solubility of the particles and/or metal oxide particles is preferably higher than the solubility of the particle components in the first developer. The above-mentioned solubility is a value on a metal basis measured by inductively coupled plasma (ICP) emission spectrometry. When metal particles and metal oxide particles are present in the dispersion in a ratio of metal particles: metal oxide particles = A:B (mass ratio), the above solubility is defined as the A:B (mass ratio) of metal particles and metal oxide particles. Ratio) means the solubility of the mixture on a metal basis. The specific procedure for evaluating solubility is as follows. 0.10 g of powder of metal particles and/or metal oxide particles is added to 40 ml of developer, and the mixture is allowed to stand at room temperature of 25° C. for 6 hours. Thereafter, the developer containing the powder is filtered through a 0.2 μm filter, and diluted 100 times (based on mass) with 0.10 mol/L nitric acid. The metal concentration (unit: mg/L) of the obtained diluted solution is measured using an ICP light emitting device (for example, manufactured by SII Nanotechnology). From the metal concentration, the concentration (unit: mg/L) of the particle component on a metal basis is calculated and taken as the solubility of the particle component. According to the above solubility, by performing development with the first developer and then development with the second developer, metal particles and/or metal oxide particles attached to the substrate can be removed by development. Gain efficiency.

In particular, the solubility of the particle component in the second developer is higher than the solubility of the particle component in the first developer, and the first developer contains water and/or an alcoholic solvent and a dispersant (A). It is preferable.

As the dispersant (A), known ones can be used, such as salts of long chain polyaminoamides and polar acid esters, unsaturated polycarboxylic acid polyaminoamides, polycarboxylic acid salts of polyaminoamides, and long chain polyaminoamides. Examples include polymers having basic groups, such as salts of acid polymers. Further examples include alkyl ammonium salts, amine salts, amidoamine salts of polymers such as acrylic polymers (homopolymers and copolymers), modified polyester acids, polyether ester acids, polyether carboxylic acids, and polycarboxylic acids. As such a dispersant, commercially available ones can also be used.

The above-mentioned commercial products include, for example, DISPERBYK (registered trademark)-101, DISPERBYK-102, DISPERBYK-110, DISPERBYK-111, DISPERBYK-112, DISPERBYK-118, DISPERBYK-130, DISPERBYK-14. 0, DISPERBYK-142, DISPERBYK- 145, DISPERBYK-160, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-2155, DISPERBYK-2163, DISPERBYK-2164, DISPERBYK-180, DI SPERBYK-2000, DISPERBYK-2025, DISPERBYK-2163, DISPERBYK-2164, BYK-9076, BYK-9077, TERRA-204, TERRA-U (manufactured by BYK Chemie), Floren DOPA-15B, Floren DOPA-15BHFS, Floren DOPA-22, Floren DOPA-33, Floren DOPA-44, Floren DOPA -17HF, Floren TG-662C, Floren KTG-2400 (manufactured by Kyoeisha Chemical Co., Ltd.), ED-117, ED-118, ED-212, ED-213, ED-214, ED-216, ED-350, ED -360 (manufactured by Kusumoto Kasei Co., Ltd.), Pricesurf (registered trademark) M208F, and Pricesurf DBS (manufactured by Dai-ichi Kogyo Seiyaku). These may be used alone or in combination.

For example, when a phosphorus-containing organic compound is used, the metal particles and/or metal oxide particles (particularly copper oxide particles) are well dispersed in the developer, making development easy. Therefore, in one embodiment, preferred compound examples for the dispersant (A) are the same as preferred compound examples for the dispersant described below in the section [Composition of dispersion and dry coating film].

The dispersant (A) is particularly a phosphorus-containing organic compound, the dispersion contains a dispersant (also referred to as a dispersant (B) in this disclosure), and the dispersant (A) and the dispersant (B) are It is preferable that the components (ie, the component contained in the largest amount on a mass basis in the dispersant) are the same. In this case, the development removal efficiency of metal particles and/or metal oxide particles adhering to the substrate is particularly good.

In one embodiment, the solubility of copper oxide in the second developer is preferably higher than the solubility of copper oxide in the first developer. Such developers are particularly advantageous in improving development removal efficiency when the dispersion contains copper oxide as a particle component.

The solubility of the particle component in each developer is preferably 0.1 mg/L or more, or 1.0 mg/L or more, or 10 mg/L or more, or 100 mg/L or more, and preferably 10000 mg/L or less. , or 5000 mg/L or less, or 1000 mg/L or less, or 500 mg/L or less. In particular, when the particle component is copper oxide particles, if the solubility of copper oxide in the developer is 0.1 mg/L or more, the developing effect is high due to the high solubility of the copper oxide particles, and the solubility is 5000 mg/L or more. /L or less can particularly effectively reduce damage to metal wiring.

In one embodiment, the solubility of the particle component in the first developer is 0.1 mg/L to 100 mg/L, and the solubility of the particle component in the second developer is 1.0 mg/L to 500 mg/L. be.

(Surface free energy)
The surface free energy of each developer is preferably 10 mN/m or more, or 15 mN/m or more, or 20 mN/m or more, and preferably 75 mN/m or less, or 60 mN/m or less, or 50 mN/m It is as follows. In the present disclosure, surface free energy is a value measured by a pendant drop method using a contact angle meter.

The difference between the surface free energy of the developer and the surface free energy of the dispersion is preferably 50 mN/m or less, or 25 mN, from the viewpoint of improving the affinity between the developer and the dried coating film and increasing the development removal effect. /m or less, or 10 mN/m or less. The above difference is most preferably 0 mN/m, but may be, for example, 1 mN/m or more, or 5 mN/m or more, from the viewpoint of ease of manufacturing the developer and the dispersion.

[Composition of dispersion and dry coating film]
In one embodiment, the dry coating film containing a particle component that is a metal particle and/or a metal oxide particle of the present disclosure is a dispersion containing a particle component, a dispersion medium, and optionally a dispersant and/or a reducing agent. It is formed by coating it on a substrate and then drying it. Therefore, in one embodiment, the mass ratio of components other than the dispersion medium in the dry coating film may be considered to be the same as the mass ratio of components other than the dispersion medium in the dispersion. Alternatively, the content of metal elements in the dried coating film can be confirmed using a SEM (scanning electron microscope) and an EDX (energy dispersive X-ray analysis) device.

The content of the dispersant in the dispersion and in the dried coating film can be confirmed using a TG-DTA (thermogravimetric differential thermal analysis) device.

The content of the reducing agent in the dispersion can be confirmed by a surrogate method using a GC/MS (gas chromatograph/mass spectrometry) device. Further, the content of the reducing agent in the dried coating film can be confirmed by a surrogate method using a GC/MS device after redispersing the dried coating film in a dispersion medium.
An example of measurement using hydrazine as a reducing agent is shown below.

(Hydrazine quantitative method)
To 50 μL of the dispersion are added 33 μg of hydrazine, 33 μg of a surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ), and 1 ml of a 1% solution of benzaldehyde in acetonitrile. Finally, 20 μL of phosphoric acid is added, and 4 hours later, GC/MS measurement is performed.

Similarly, 66 μg of hydrazine, 33 μg of a surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ), and 1 ml of a 1% acetonitrile solution of benzaldehyde are added to 50 μL of the dispersion. Finally, 20 μL of phosphoric acid is added, and 4 hours later, GC/MS measurement is performed.

Similarly, 133 μg of hydrazine, 33 μg of a surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ), and 1 ml of a 1% acetonitrile solution of benzaldehyde are added to 50 μL of the dispersion. Finally, 20 μL of phosphoric acid is added, and 4 hours later, GC/MS measurement is performed.

Finally, 33 μg of the surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ) and 1 ml of benzaldehyde 1% acetonitrile solution were added to 50 μL of the dispersion without adding hydrazine, and finally 20 μL of phosphoric acid was added, and after 4 hours, GC/MS measurement was performed. I do.

The peak area value of hydrazine is obtained from the chromatogram at m/z=207 from the GC/MS measurements at the four points above. Next, the peak area value of the surrogate is obtained from the mass chromatogram at m/z=209. The weight of added hydrazine/weight of added surrogate substance is plotted on the x-axis, and the peak area value of hydrazine/peak area value of the surrogate substance is plotted on the y-axis to obtain a calibration curve by the surrogate method.

The Y-intercept value obtained from the calibration curve is divided by the weight of added hydrazine/weight of added surrogate substance to obtain the weight of hydrazine.

((i) Metal particles and/or metal oxide particles)
Metals contained in particle components that are metal particles and/or metal oxide particles include aluminum, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, ruthenium, rhodium, palladium, silver, and indium. , tin, antimony, iridium, platinum, gold, thallium, lead, bismuth, etc., and may be an alloy or a mixture containing one or more of these. Further, examples of the metal oxide include the metal oxides exemplified above. Among these, silver or copper metal oxide particles are preferred because they are easily reduced when irradiated with laser light and can form uniform metal wiring. In particular, copper metal oxide particles are preferable because they have relatively high stability in air and can be obtained at low cost, which is advantageous from a business standpoint. Copper oxides include, for example, cuprous oxide and cupric oxide. Cuprous oxide is particularly preferable because it has high absorbance to laser light, allows low-temperature sintering, and forms a sintered product with low resistance. Cuprous oxide and cupric oxide may be used alone or in combination.

The metal oxide particles include or are copper oxide particles in one embodiment. The copper oxide particles may have a core/shell structure, and either the core or the shell may contain cuprous oxide and/or cupric oxide.

The average secondary particle diameter of each of the metal particles and metal oxide particles (copper oxide particles in one embodiment) is not particularly limited, but is preferably 500 nm or less, or 200 nm or less, or 100 nm or less, or 80 nm or less, or 50 nm. or 20 nm or less. The average secondary particle diameter of the particles is preferably 1 nm or more, 5 nm or more, 10 nm or more, or 15 nm or more.

The average secondary particle diameter is the average particle diameter of aggregates (secondary particles) formed by a plurality of primary particles. It is preferable that the average secondary particle diameter is 500 nm or less because fine metal wiring tends to be easily formed on the support. It is preferable that the average secondary particle diameter is 1 nm or more, particularly 5 nm or more, since the long-term storage stability of the dispersion is improved. The average secondary particle diameter of the particles can be measured by a dynamic light scattering method in which particles dispersed in a dispersion are irradiated with laser light and the scattered light is observed with a photon detector.

The average primary particle diameter of the primary particles constituting the secondary particles is preferably 100 nm or less, more preferably 50 nm or less, even more preferably 20 nm or less. The average primary particle diameter is preferably 1 nm or more, more preferably 2 nm or more, even more preferably 5 nm or more.

When the average primary particle diameter is 100 nm or less, there is a tendency that the firing temperature described below can be lowered. The reason why such low-temperature firing is possible is considered to be that the smaller the particle size of the particles, the greater the surface energy and the lower the melting point.

Further, it is preferable that the average primary particle diameter is 1 nm or more because good dispersibility can be obtained. When forming a wiring pattern on a base material, the thickness is preferably 2 nm or more, or 5 nm or more, and preferably 100 nm or less, or 50 nm or less, from the viewpoint of adhesion with the base and lowering the resistance of the wiring. This tendency is remarkable when the base is resin. The average primary particle diameter of the particles can be measured using a transmission electron microscope or a scanning electron microscope.

The average particle diameter of the particle components that are metal particles and/or metal oxide particles in the dispersion is not particularly limited, but is preferably 500 nm or less, or 200 nm or less, or 100 nm or less, or 80 nm or less, or 50 nm. or less, or 40 nm or less, or 20 nm or less. The average particle diameter of the particles is preferably 1 nm or more, or 3 nm or more, or 5 nm or more, or 10 nm or more, or 15 nm or more. It is preferable that the average particle diameter is 500 nm or less because fine metal wiring tends to be easily formed on the base material. It is preferable that the average particle diameter is 1 nm or more because the long-term storage stability of the dispersion is improved. The average particle size herein refers to the particle size when dispersed in a dispersion, and is a value measured by the cumulant method using FPAR-1000 manufactured by Otsuka Electronics. In other words, the average particle diameter is not limited to the primary particle diameter or the secondary particle diameter.

Further, in the distribution of particles having the above average particle diameter, the polydispersity value is preferably 0.01 or more, or 0.05 or more, or 0.1 or more, or 0.2 or more, and preferably 0. .5 or less, or 0.4 or less, or 0.3 or less. Within this range, film formability is good and dispersion stability is also high.

The dispersion and dry coating may include metal particles. That is, the dispersions and dried coatings of the present disclosure may include metals.

The dispersion and dry coating may include metal oxide particles and metal particles. In this case, the mass ratio of metal particles to metal oxide particles (hereinafter referred to as "metal particles/metal oxide particles") is preferably 1.0 or more, or It is 1.5 or more, or 2.0 or more, and preferably 7.0 or less, or 6.0 or less, or 5.0 or less. In one aspect, the metal particles are copper particles, the metal oxide particles are copper oxide particles, and the mass ratio of the metal particles to the metal oxide particles is the mass ratio of the copper particles to the copper oxide particles (copper particles / copper oxide particles).

The content of particle components that are metal particles and/or metal oxide particles in the dispersion is the total content of metal particles and metal oxide particles, which is 0.50% by mass based on 100% by mass of the dispersion. It is preferably 60% by mass or less, more preferably 1.0% by mass or more and 60% by mass or less, and even more preferably 5.0% by mass or more and 50% by mass or less. When the total content is 60% by mass or less, aggregation of metal particles and/or metal oxide particles tends to be easily suppressed. When the above-mentioned total content is 0.50% by mass or more, the metal wiring (i.e., conductive film) obtained by baking the dried coating film by laser light irradiation does not become too thin and tends to have good conductivity. .

The content of particle components that are metal particles and/or metal oxide particles in the dry coating film is the total content of metal particles and metal oxide particles, which is 40% by mass based on 100% by mass of the dry coating film. It is preferably at least 55% by mass, more preferably at least 70% by mass, and even more preferably at least 70% by mass. Further, the content is preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less.

In addition, the content of particle components that are metal particles and/or metal oxide particles in the dry coating film is the total content of metal particles and metal oxide particles, which is 10% by volume with respect to 100% by volume of the dry coating film. % or more, more preferably 15 volume % or more, still more preferably 25 volume % or more. Moreover, it is preferable that the said content rate is 90 volume% or less, It is more preferable that it is 76 volume% or less, It is still more preferable that it is 60 volume% or less.

It is preferable that the content of the particle component in the dried coating film is 40% by mass or more or 10% by volume or more, since the particles are fused together by firing and exhibit good conductivity. The higher the concentration of the particle component, the better from the viewpoint of conductivity, but if the content is 98% by mass or less or 90% by volume or less, the dry coating film has a sufficient amount with respect to the base material to stably form metal wiring. Good adhesion is possible, and in particular, when the amount is 95% by mass or less or 76% by volume or less, the adhesion is stronger and is preferable. Moreover, when the content is 90% by mass or less or 60% by volume or less, the flexibility of the dried coating film is high, cracks are less likely to occur during bending, and reliability is increased.

((ii) Dispersant)
The dispersion and the dry coating film may contain a dispersant (dispersant (B) of the present disclosure) for well dispersing the particle components, which are metal particles and/or metal oxide particles, in a dispersion medium.

The number average molecular weight of the dispersant is not particularly limited, but is preferably 300 or more and 300,000 or less, more preferably 300 or more and 30,000 or less, and even more preferably 300 or more and 10,000 or less. preferable. When the number average molecular weight is 300 or more, the dispersion stability of the dispersion tends to increase, when it is 300,000 or less, it is easy to bake during wiring formation, and when it is 30,000 or less, it is easy to bake after baking. The amount of residual dispersant is smaller, and the resistance of metal wiring can be lowered. Note that in the present disclosure, the number average molecular weight is a value determined in terms of standard polystyrene using gel permeation chromatography.

As the dispersant, a phosphorus-containing organic compound is preferable since it has excellent dispersibility of metal particles and/or metal oxide particles. In addition, the dispersant preferably has a group (for example, a hydroxyl group) that has an affinity for the metal particles and/or metal oxide particles, from the viewpoint of adsorbing to the metal particles and/or metal oxide particles and suppressing particle aggregation due to steric hindrance effects. Particularly preferred is the combination of metal oxide particles and a hydroxyl group-containing dispersant. The dispersant preferably includes a phosphorus-containing organic compound. Particularly suitable examples of dispersants are phosphorus-containing organic compounds having phosphoric acid groups.

It is preferable that the phosphorus-containing organic compound is easily decomposed or evaporated by light and/or heat. By using an organic substance that is easily decomposed or evaporated by light and/or heat, residues of the organic substance are less likely to remain after firing, and metal wiring with low resistivity can be obtained.

Although the decomposition temperature of the phosphorus-containing organic compound is not limited, it is preferably 600°C or lower, more preferably 400°C or lower, and even more preferably 200°C or lower. From the viewpoint of stability of the phosphorus-containing organic compound, the decomposition temperature may be preferably 60°C or higher, 90°C or higher, or 120°C or higher. Note that in the present disclosure, the decomposition temperature is the value of the decomposition start temperature determined by thermogravimetric differential thermal analysis.

The boiling point of the phosphorus-containing organic compound is not limited, but is preferably 300°C or lower, more preferably 200°C or lower, and even more preferably 150°C or lower. From the viewpoint of stability of the phosphorus-containing organic compound, the boiling point may preferably be 60°C or higher, 90°C or higher, or 120°C or higher.

Although the absorption characteristics of the phosphorus-containing organic compound are not limited, it is preferable that it can absorb the laser light used for firing. In the present disclosure, being able to absorb the laser light used for baking means that the extinction coefficient at the emission center wavelength (532 nm in one embodiment) of the laser light used for baking is 0.10 cm ^- as measured by an ultraviolet-visible spectrophotometer. It means ¹ or more. More specifically, a phosphorus-containing organic compound that absorbs light having an emission wavelength (center wavelength) of a laser beam used for firing, such as 355 nm, 405 nm, 445 nm, 450 nm, 532 nm, or 1064 nm, is preferable. In particular, when the base material is a resin base material, a phosphorus-containing organic compound that absorbs light having a center wavelength of 355 nm, 405 nm, 445 nm, and/or 450 nm is preferable.

（式中、Ｒは１価の有機基である。）
で表されるリン酸モノエステルは、金属酸化物粒子への吸着性に優れるとともに、基材に対する適度な密着性を示すことで金属配線の安定形成と未露光部の良好な現像との両立に寄与する点で好ましい。Ｒとしては、置換又は非置換の炭化水素基等を例示できる。 It is preferable that the phosphorus-containing organic compound is a phosphoric acid ester also from the viewpoint of improving the atmospheric stability of the dispersion. For example, the following general formula (1):

(In the formula, R is a monovalent organic group.)
The phosphoric acid monoester represented by has excellent adsorption properties to metal oxide particles and exhibits appropriate adhesion to the substrate, making it possible to achieve both stable formation of metal wiring and good development of unexposed areas. This is preferable in terms of contribution. Examples of R include substituted or unsubstituted hydrocarbon groups.

で表される構造を有する化合物を例示できる。 As an example of phosphoric acid monoester, the following formula (2):

Examples include compounds having the structure represented by:

（式中、ｌ、ｍ及びｎは、それぞれ独立に、１～２０の整数である。）
で表される構造を有する化合物も例示できる。 In addition, as an example of phosphoric acid monoester, the following formula (3):

(In the formula, l, m and n are each independently an integer of 1 to 20.)
Compounds having the structure represented by can also be exemplified.

In the above formula (3), l is an integer of 1 to 20, preferably an integer of 1 to 15, more preferably an integer of 1 to 10, m is an integer of 1 to 20, preferably an integer of 1 to 15, More preferably, it is an integer from 1 to 10, and n is an integer from 1 to 20, preferably from 1 to 15, and more preferably from 1 to 10.

The organic structure of the phosphorus-containing organic compound includes polyethylene glycol (PEG), polypropylene glycol (PPG), polyimide, polyester (for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN)), and polyether sulfone (PES). , polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacetal, polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), Polyphenylene sulfide (PPS), polyetherketone (PEK), polyphthalamide (PPA), polyethernitrile (PENt), polybenzimidazole (PBI), polycarbodiimide, polysiloxane, polymethacrylamide, nitrile rubber, acrylic rubber, Polyethylene tetrafluoride, epoxy resin, phenol resin, melamine resin, urea resin, polymethyl methacrylate resin (PMMA), polybutene, polypentene, ethylene-propylene copolymer, ethylene-butene-diene copolymer, polybutadiene, polyisoprene , ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer, polyethylene (PE), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), Polyetheretherketone (PEEK), phenol novolac, benzocyclobutene, polyvinylphenol, polychloropyrene, polyoxymethylene, polysulfone (PSF), polysulfide, silicone resin, aldose, cellulose, amylose, pullulan, dextrin, glucan, fructan, chitin It may have a structure derived from a compound such as (specifically, through modification or modification of a functional group, or polymerization, etc.). A phosphorus-containing organic compound having a polymer skeleton selected from polyethylene glycol, polypropylene glycol, polyacetal, polybutene, and polysulfide is preferred because it is easily decomposed and hardly leaves residue in the metal wiring obtained after firing.

As specific examples of the phosphorus-containing organic compound, commercially available materials can be used, and specifically, DISPERBYK (registered trademark)-102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-109, and DISPERBYK- manufactured by BYK Chemie. 110, DISPERBYK-111, DISPERBYK-118, DISPERBYK-140, DISPERBYK-145, DISPERBYK-168, DISPERBYK-180, DISPERBYK-182, DISPERBYK-187, DISPE RBYK-190, DISPERBYK-191, DISPERBYK-193, DISPERBYK-194N, DISPERBYK-199, DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2008, DISPERBYK-2009, DISPERBYK-2010, DISPERBYK-2012, DISPERBYK-2013, DI SPERBYK-2015, DISPERBYK-2022, DISPERBYK-2025, DISPERBYK-2050, DISPERBYK- 2152, DISPERBYK-2055, DISPERBYK-2060, DISPERBYK-2061, DISPERBYK-2164, DISPERBYK-2096, DISPERBYK-2200, BYK (registered trademark) -405, BYK-607, BYK-90 76, BYK-9077, BYK-P105, Examples include Plysurf (registered trademark) M208F and Plysurf DBS manufactured by Daiichi Kogyo Seiyaku Co., Ltd. These may be used alone or in combination.

In the dispersion and the dry coating film, the content of the dispersant may be 5 parts by volume or more and 900 parts by volume or less, when the total volume of the metal particles and metal oxide particles is 100 parts by volume. The lower limit is preferably 10 parts by volume or more, more preferably 30 parts by volume or more, still more preferably 60 parts by volume or more. The upper limit is preferably 480 parts by volume or less, more preferably 240 parts by volume or less.

In terms of parts by mass, the content of the dispersant relative to 100 parts by mass of the metal particles and metal oxide particles is preferably 1 part by mass or more and 150 parts by mass or less. The lower limit is preferably 2 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more. The upper limit is preferably 80 parts by mass or less, more preferably 40 parts by mass or less. When the content of the dispersant is 5 parts by volume or more or 1 part by mass or more, a thin film with a submicron thickness can be easily formed. Further, if the content of the dispersant is 10 parts by volume or more or 5 parts by mass or more, a thick film with a thickness of, for example, several tens of μm can be easily formed. When the content of the dispersant is 30 parts by volume or more or 10 parts by mass or more, a highly flexible dry coating film that is resistant to cracking even when bent can be obtained. Moreover, if the content of the dispersant is 900 parts by volume or less or 150 parts by mass or less, a good metal wiring can be obtained by firing.

The content of the dispersant in the dispersion is preferably 0.10% by mass or more and 20% by mass or less, more preferably 0.20% by mass or more and 15% by mass or less, based on the total dispersion. More preferably, the content is .0% by mass or more and 8.0% by mass or less. When the content is 20% by mass or less, the conductive film obtained by firing tends to have good conductivity without a large amount of residue derived from the dispersant. Further, when the content is 0.10% by mass or more, the metal particles and/or metal oxide particles do not aggregate, and good dispersibility can be obtained.

((iii) Reducing agent)
The dispersion and dry coating may further include a reducing agent. The reducing agent may remain in the dispersion due to its use during the synthesis of the particle components, which are metal particles and/or metal oxide particles, and therefore may remain in the dried coating film. The reducing agent preferably includes hydrazine and/or hydrazine hydrate, more preferably hydrazine and/or hydrazine hydrate. When the dispersion contains metal oxide particles and the dried coating film contains a reducing agent, the metal oxide (e.g., copper oxide) is likely to be reduced to the metal (e.g., copper) when the dried coating film is irradiated with laser light. Furthermore, it is possible to lower the resistance of the metal (for example, copper) after reduction. The reducing agent remains in the unexposed areas of the dried coating film (that is, the areas not irradiated with laser light).

The mass ratio of the content of the reducing agent in the dispersion and in the dried coating film to the total content of metal particles and metal oxide particles is preferably 0.0001 or more, or 0.0010 or more, or 0.0020 or more, or 0.0040 or more, and preferably 0.10 or less, or 0.0040 or more, from the viewpoint of avoiding excessive residual reducing agent and obtaining low-resistance metal wiring. 050 or less, or 0.030 or less.

Further, it is preferable that the total content of hydrazine and hydrazine hydrate (based on the amount of hydrazine) and the content of copper oxide in the dispersion and in the dried coating film satisfy the following relationship.
0.0001≦(hydrazine mass/copper oxide mass)≦0.10

((iv) Dispersion medium)
The dispersion medium is included in the dispersion and in the dried coating film in order to disperse the particle components, which are metal particles and/or metal oxide particles.

Specific examples of the dispersion medium include alcohols (monohydric alcohols and polyhydric alcohols (e.g., glycol)), ethers of alcohols (e.g., glycol), esters of alcohols (e.g., glycol), and the like. As a more specific example,
Propylene glycol monomethyl ether acetate, 3-methoxy-3-methyl-butyl acetate, ethoxyethyl propionate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether , ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether,
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 1,2-pentanediol, 2-methylpentane-2,4-diol, 2,5-hexanediol, 2,4-heptanediol, 2 -Ethylhexane-1,3-diol, diethylene glycol, dipropylene glycol, 1,2-hexanediol, 1,2-octanediol, triethylene glycol, tri-1,2-propylene glycol, glycerol ethyl acetate, n-propyl acetate, isopropyl acetate,
Pentane, hexane, octane, nonane, decane, cyclohexane, methylcyclohexane, toluene, xylene, mesitylene, ethylbenzene,
Methyl ethyl ketone, methyl isobutyl ketone, dimethyl carbonate,
Methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, sec-pentanol, t-pentanol, 2- Methylbutanol, 3-methoxybutanol, n-hexanol, sec-hexanol, 2-methylpentanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, sec-octanol, 2-ethylhexanol, n- Examples include nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, phenol, benzyl alcohol, diacetone alcohol, and the like.

Among these, from the viewpoint of dispersibility of metal particles and/or metal oxide particles, monoalcohols or polyhydric alcohols having 10 or less carbon atoms are more preferable. Among the monoalcohols having 10 or less carbon atoms, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, and t-butanol are more preferred. These alcohols may be used alone or in combination.

The solid content of the dispersion is preferably 0.1% by mass or more, or 0.6% by mass or more, or 1% by mass or more, or 3% by mass, in that a dry coating film of a desired thickness can be easily formed. or 5% by mass or more, 8% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, and the metal particles and/or metal oxide particles can be easily dispersed well. In some respects, preferably 80% by weight or less, or 75% by weight or less, or 70% by weight or less, or 65% by weight or less, or 60% by weight or less, or 58% by weight or less, or 55% by weight or less, or 50% by weight or less. It is not more than 40% by mass, or not more than 30% by mass. The solid content percentage of the dispersion is the value obtained by measuring 0.5 to 1.0 g of the dispersion and heating it in air at 60°C for 4.5 hours, dividing the weight after heating by the weight before heating. You can ask for it. In one aspect, the solids content of the dispersion corresponds to the content of particle components that are metal particles and/or metal oxide particles in the dispersion. When the solid content is 0.6% by mass or more and 80% by mass or less, the dispersion can have a viscosity suitable for application to a substrate.

The viscosity of the dispersion is preferably 0.1 mPa·s or more and 100,000 mPa·s or less, more preferably 0.1 mPa·s or more and 10,000 mPa·s or less, and 1 mPa·s or more and 1,000 mPa·s or less. - It is more preferable that it is below s. When the viscosity is 0.1 mPa·s or more and 100,000 mPa·s or less, the dispersion can be more uniformly applied to the substrate. In this disclosure, viscosity is a value measured with an E-type viscometer.

The pH of the dispersion is preferably 4.0 or more, 5.0 or more, or 6.0 or more from the viewpoint of preventing dissolution of metal particles and/or metal oxide particles in the dispersion. From the viewpoint of reducing damage to the base material, the pH may be, for example, 10.0 or less, 9.0 or less, or 8.0 or less.

The surface free energy of the dispersion is preferably 10 mN/m or more, or 12 mN/m or more, or 15 mN/m or more, and preferably 50 mN/m or more, in that the dispersion can be evenly and uniformly applied to the substrate. m or less, or 35 mN/m or less, or 25 mN/m or less.

The thickness of the dry coating film is preferably 0.1 μm or more, 0.5 μm or more, or 1.0 μm or more, from the viewpoint of easily manufacturing metal wiring with low resistance and excellent mechanical properties, From the viewpoint of manufacturing metal wiring with high precision, the thickness may preferably be 50 μm or less, 25 μm or less, or 10 μm or less.

[Base material]
The base material constitutes a surface on which metal wiring is arranged. The material of the base material is preferably an insulating material in order to ensure electrical insulation between the metal wiring formed by laser light. However, the entire base material does not necessarily need to be an insulating material. It is sufficient if only the portion constituting the surface on which the metal wiring is arranged is made of insulating material.

Further, the material of the base material is preferably a material having a heat resistance temperature of 60° C. or higher in order to prevent the base material from being burnt by the laser light and generating smoke when irradiated with the laser light. The base material does not need to be made of a single material; for example, glass fiber or the like may be added to the resin in order to increase the heat resistance.

The surface of the base material on which the dried coating film is placed may be a flat surface or a curved surface, or may include a step or the like. More specifically, the base material may be a substrate (for example, a plate-shaped body, a film, or a sheet) or a three-dimensional object (for example, a housing, etc.). The plate-shaped body is, for example, a support body used for a circuit board such as a printed circuit board. The film or sheet is, for example, a base film that is a thin insulator used for flexible printed circuit boards.

Examples of three-dimensional objects include housings of electrical devices such as mobile phone terminals, smartphones, smart glasses, televisions, and personal computers. Other examples of three-dimensional objects include dashboards, instrument panels, steering wheels, chassis, etc. in the automobile field.

Specific examples of the base material include a base material made of an inorganic material (hereinafter referred to as an "inorganic base material") or a base material made of a resin (hereinafter referred to as a "resin base material").

The inorganic base material is composed of, for example, glass, silicon, mica, sapphire, crystal, clay film, ceramic material, and the like. The ceramic material is selected from, for example, alumina, silicon nitride, silicon carbide, zirconia, yttria and aluminum nitride, and mixtures of at least two of these. Further, as the inorganic base material, a base material made of glass, sapphire, crystal, etc., which has particularly high light transmittance, can be used.

Examples of the resin base material include polypropylene (PP), polyimide (PI), polyester (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.), polyether sulfone (PES), Polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacetal (POM), polyarylate (PAR), polyamide (PA) (PA6, PA66, etc.), polyamideimide (PAI), polyetherimide (PEI) ), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyphenylene sulfide (PPS), polyether ketone (PEK), polyether ether ketone (PEEK), polyphthalamide (PPA), polyether nitrile (PENt) ), polybenzimidazole (PBI), polycarbodiimide, polymethacrylamide, nitrile rubber, acrylic rubber, polyethylene tetrafluoride, epoxy resin, phenol resin, melamine resin, urea resin, polymethyl methacrylate resin (PMMA), polybutene, Polypentene, ethylene-propylene copolymer, ethylene-butene-diene copolymer, polybutadiene, polyisoprene, ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer Polymers, polyethylene (PE), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), phenol novolak, benzocyclobutene, polyvinylphenol, polychloropyrene, polyoxymethylene, polysulfone (PSF), polyphenylsulfone resin (PPSU) ), cycloolefin polymer (COP), acrylonitrile-butadiene-styrene resin (ABS), acrylonitrile-styrene resin (AS), polytetrafluoroethylene resin (PTFE), polychlorotrifluoroethylene (PCTFE), and silicone resin A support composed of, for example, can be used.

In addition to the above, a resin sheet containing cellulose nanofibers can also be used as the base material, for example.

In particular, at least one selected from the group consisting of PI, PET, and PEN has excellent adhesion to metal wiring, has good marketability and can be obtained at low cost, and is significant from a business perspective. ,preferable.

Furthermore, at least one selected from the group consisting of PP, PA, ABS, PE, PC, POM, PBT, m-PPE, and PPS has excellent adhesion to metal wiring, especially in the case of a case, and Excellent moldability and mechanical strength after molding. Furthermore, these materials are preferable because they have sufficient heat resistance to withstand laser beam irradiation and the like when forming metal wiring.

Moreover, the material of the three-dimensional object is selected from the group consisting of, for example, polypropylene resin, polyamide resin, acrylonitrile butadiene styrene resin, polyethylene resin, polycarbonate resin, polyacetal resin, polybutylene terephthalate resin, modified polyphenylene ether resin, and polyphenylene sulfide resin. At least one type is preferred.

The deflection temperature under load of the resin base material is preferably 400°C or lower, more preferably 280°C or lower, and even more preferably 250°C or lower. A base material having a deflection temperature under load of 400° C. or less is available at low cost, is advantageous from a business standpoint, and is therefore preferred. The deflection temperature under load is preferably 70°C or higher, 80°C or higher, 90°C or higher, or 100°C or higher, from the viewpoint of handleability of the resin base material. The deflection temperature under load in the present disclosure is a value obtained in accordance with JIS K7191.

The thickness of the base material, for example in the case of a plate, film or sheet, is preferably 1 μm or more, or 25 μm or more, or 200 μm or more, and preferably 100 mm or less, or 10 mm or less, or 250 μm or less. When the thickness of the base material is 250 μm or less, the manufactured electronic device can be made lighter, space-saving, and flexible, which is preferable.

In addition, when the base material is a three-dimensional object, its maximum dimension (that is, the maximum length of one side) is preferably 1 μm or more, or 200 μm or more, in order to achieve good mechanical strength and heat resistance of the base material. or more, preferably 1000 mm or less, or 100 mm or less, or 5 mm or less.

[Each step of the metal wiring manufacturing method]
FIG. 1 is a diagram illustrating an example of a method for manufacturing metal wiring according to this embodiment. Hereinafter, exemplary embodiments of each step will be described with reference to FIG.

(Preparation of dispersion)
In one embodiment, the dispersion is prepared prior to the coating step. Below, the case where a dispersion containing cuprous oxide particles is prepared will be explained as an example.
Cuprous oxide particles can be synthesized, for example, by the following method.
(1) Add water and copper acetylacetonate complex to a polyol solvent, heat and dissolve the organocopper compound, add the amount of water necessary for the reaction, and reduce by heating to the reduction temperature of the organocopper. Method.
(2) A method of heating an organocopper compound (copper-N-nitrosophenylhydroxylamine complex) at a high temperature of about 300°C in an inert atmosphere in the presence of a protective agent such as hexadecylamine.
(3) A method in which a copper salt dissolved in an aqueous solution is reduced with hydrazine (Figure 1(a)).

The method (1) above is described, for example, in Angewante Chemi International Edition, No. 40, Volume 2, p. 359, 2001.

The method (2) above is described, for example, in Journal of the American Chemical Society, 1999, Vol. 121, p. It can be carried out under the conditions described in 11595.

In the method (3) above, divalent copper salts can be suitably used as the copper salt, such as copper(II) acetate, copper(II) nitrate, copper(II) carbonate, Examples include copper(II) chloride and copper(II) sulfate. The amount of hydrazine used is preferably 0.2 mol to 2 mol, more preferably 0.25 mol to 1.5 mol, per 1 mol of copper salt.

A water-soluble organic substance may be added to the aqueous solution in which the copper salt is dissolved. Since the melting point of the aqueous solution is lowered by adding a water-soluble organic substance to the aqueous solution, reduction can be carried out at lower temperatures. As the water-soluble organic substance, for example, alcohol, water-soluble polymer, etc. can be used.

As alcohol, for example,
Methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, sec-pentanol, t-pentanol, 2- Methylbutanol, 2-ethylbutanol, 3-methoxybutanol, n-hexanol, sec-hexanol, 2-methylpentanol, sec-heptanol, 3-heptanol, n-octanol, sec-octanol, 2-ethylhexanol, n- Monohydric alcohols such as nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, phenol, benzyl alcohol, diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 1,2-pentanediol, 2-methylpentane-2,4-diol, 2,5-hexanediol, 2,4-heptanediol, 2 - Trivalent glycols such as ethylhexane-1,3-diol, diethylene glycol, dipropylene glycol, 1,2-hexanediol, 1,2-octanediol, triethylene glycol, tri-1,2-propylene glycol, and glycerin Polyhydric alcohols such as alcohol;
Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol tertiary butyl ether, dipropylene glycol monomethyl ether;
Glycol esters such as propylene glycol monomethyl ether acetate;
etc.
As the water-soluble polymer, for example, polyethylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol copolymer, etc. can be used.

The temperature during reduction in the method (3) above can be, for example, -20°C to 60°C, preferably -10°C to 30°C. This reduction temperature may be constant during the reaction, or may be raised or lowered during the reaction. At the initial stage of the reaction when hydrazine has high activity, it is preferable to reduce at 10°C or lower, more preferably at 0°C or lower. The reduction time is preferably 30 minutes to 300 minutes, more preferably 90 minutes to 200 minutes. The atmosphere during reduction is preferably an inert atmosphere such as nitrogen or argon.

Among the methods (1) to (3) above, method (3) is preferred because it is easy to operate and provides particles with small particle diameters.

Next, the reaction solution is centrifuged to separate a supernatant and a precipitate (FIG. 1(b)), and the copper oxide particles are recovered as a precipitate.

On the other hand, commercially available products may be used as the copper oxide particles. Commercially available products include, for example, cuprous oxide particles with an average primary particle diameter of 18 nm sold by EM Japan.

Next, a dispersion medium and, in one embodiment, a dispersant are added to the copper oxide particles, and the copper oxide particles are dispersed in the dispersion medium by, for example, stirring using a known method such as a homogenizer (FIG. 1(c)). .

Note that depending on the dispersion medium, the copper oxide particles may be difficult to disperse, and the dispersion may be insufficient. In such a case, for example, after dispersing copper oxide using an alcohol in which copper oxide particles are easily dispersed, such as 1-butanol, the solvent may be replaced with a desired dispersion medium and concentrated to a desired concentration. It is preferable to do this. Examples include a method of concentrating with an ultrafiltration (UF) membrane, and a method of repeating dilution with a desired dispersion medium and concentration.
For example, the desired dispersion can be obtained by the procedure described above (FIG. 1(d)). This dispersion may be combined with a regenerated dispersion prepared using the used developer obtained in the recovery step described below for the next step.

(polishing process)
In one embodiment, the dispersion coated surface of the substrate (FIG. 1(e)) may have a controlled arithmetic mean surface roughness. In typical embodiments, polishing the substrate surface controls the arithmetic mean surface roughness of the surface. That is, in one embodiment, the base material has a polished surface (FIG. 1(f)). In this disclosure, polishing includes both smoothing and roughening. Polishing methods are not particularly limited, but include physical polishing methods using grindstones (rotary grindstones, etc.), files, abrasive paper, abrasives, etc., chemical polishing methods such as electrolytic polishing, and solvent immersion. Examples include polishing methods. An appropriate polishing method may be selected depending on the material and surface morphology of the surface to be polished of the base material, the desired arithmetic mean surface roughness value, and the like.

The arithmetic mean surface roughness Ra of the dispersion-coated surface of the base material is preferably 70 nm or more, or 100 nm or more, or 150 nm or more, and may preferably be 10000 nm or less, or 5000 nm or less, or 1000 nm or less. In the present disclosure, the arithmetic mean surface roughness Ra is a value measured using a stylus surface profile measuring device. Note that the surface roughness of the base material on which the coating film has already been placed can be measured by the following method. The substrate on which the coating film is placed is immersed in 0.6% by mass of nitric acid or hydrochloric acid, the amount of which the entire substrate is immersed, and shaken at a speed of 60 rpm for 12 hours or more to dissolve the coating film. . When the coating film is completely dissolved, the substrate is washed with 50 ml or more of ultrapure water, and then measured using a stylus surface profile measuring device.

When the value of the arithmetic mean surface roughness Ra is 70 nm or more, the dispersion enters the uneven concave portions of the substrate surface with an anchor effect, so that the dry coating film and the substrate adhere well, making it easier to perform the development operation. A metal wiring is formed that is difficult to peel off even if it is removed. This is preferable because there is less damage to the metal wiring during the development operation and the resistance of the metal wiring is less likely to increase after development. Further, when the value of the arithmetic mean surface roughness Ra is 10,000 nm or less, the uneven shape of the surface of the base material is not excessively large, so that a coating film can be formed on the surface with a uniform thickness. Therefore, it is possible to obtain a metal wiring in which disconnection is less likely to occur and the variation in resistance value between parts is further reduced. Further, it is advantageous that the value of the arithmetic mean surface roughness Ra is 10,000 nm or less in terms of good development removability of unexposed areas.

(Coating process)
In this step, a dispersion layer is formed by applying a dispersion onto the surface of a base material whose arithmetic mean surface roughness may be controlled (FIG. 1(g)). The method for forming the dispersion layer is not particularly limited, but coating methods such as die coating, spin coating, slit coating, bar coating, knife coating, spray coating, and dip coating can be used. It is desirable to apply the dispersion to a uniform thickness on the substrate using these methods.

(drying process)
In this step, the base material and the dispersion layer formed on the base material are dried to form a dry coating film (FIG. 1(h)). Drying conditions may be adjusted so that the solids content of the dried coating is controlled within a desired range (in one embodiment, the ranges listed in this disclosure).

The drying temperature is preferably 40°C or higher, 50°C or higher, or 60°C or higher, since drying time can be shortened and industrial productivity can be increased. ), the temperature is preferably 120°C or lower, 110°C or lower, 100°C or lower, or 90°C or lower. The drying time prevents excessive volatilization of the dispersion medium in the dispersion layer and controls the solids content of the dried coating above a desired level, thereby facilitating the dispersion of the dried coating during development (i.e. From the viewpoint of improving developability, the time is preferably 8 hours or less, or 4 hours or less, or 2 hours or less, so that a small amount of dispersion medium contained in the dried coating film reacts with the base material (especially resin base material). However, it is possible to prevent the base material from dissolving and diffusing into the dry coating film, strengthening the bond between the dry coating film and the base material, and deteriorating developability. Preferably, the heating time is 10 minutes or more, or 20 minutes or more, or 30 minutes or more, since the content of organic components contained in the metal wiring can be reduced and metal wiring with low resistance can be manufactured. Drying pressure may typically be atmospheric pressure. In terms of increasing industrial productivity, the pressure may be reduced, preferably to -0.05 MPa or less, or -0.1 MPa or less in gauge pressure. By the drying process as described above, it is possible to form a structure with a dried coating film having a base material and a dried coating film disposed on the base material.

The solid content of the dry coating film is preferably 60% by mass or more and 99% by mass or less, more preferably 65% by mass or more and 95% by mass or less, and preferably 70% by mass or more and 90% by mass or less. More preferred. In the present disclosure, the solids content of a dried coating film can be measured using a TG-DTA (Thermogravimetric Differential Thermal Analysis) device. When the solid content of the dried coating film is 60% by mass or more, the volumetric shrinkage of the dried coating film when obtaining metal wiring by laser light irradiation is small, the amount of voids in the metal wiring is small, and the sinterability is high. Therefore, it is possible to obtain a wiring having low resistance and little variation in resistance value between parts. Moreover, when the solid content of the dry coating film is 60% by mass or more, the adhesion or bonding force between the unexposed area and the base material is small, and good development removability is obtained. For example, when the base material is a resin base material, the base material is slightly dissolved by the dispersion medium in the dry coating film, and the base material components are diffused into the dry coating film, so that the unexposed area and the base material are separated. Although they may be strongly bonded, such diffusion can be avoided if the solid content is 60% by mass or more. On the other hand, when the solid content of the dry coating film is 99% by mass or less, the metal particles and/or metal oxide particles in the dry coating film are well dispersed in the developer, and the solid content on the substrate after development is The remaining amount of metal particles and/or metal oxide particles can be reduced (that is, the developability is good).

(Storage process)
In one embodiment, a storage step may be performed in which the dry coated structure is stored for a predetermined period of time. In the storage step, the storage temperature is preferably 0°C or higher, 5°C or higher, or 10°C or higher, and preferably 40°C or lower, or 30°C or lower. Further, the relative humidity is preferably 20% or more, or 30% or more, and preferably 70% or less, or 50% or less. When storing a structure with a dried coating film, deterioration and migration of the coating film components may occur, and migration causes short circuits in metal wiring. When the storage temperature and relative humidity are within the above ranges, the dried coating film can be stored stably, thereby suppressing deterioration and migration of coating film components. The pressure during storage may typically be normal pressure, but it may also be under reduced pressure, preferably -0.05 MPa or less, or -0.1 MPa or less in gauge pressure.

The storage time of the structure with a dry coating film is such that the heat generated during the drying process can be cooled, and changes in the coating composition due to the dry coating film absorbing moisture in the air can be suppressed, and the laser beam irradiation described below can be carried out. Preferably, the time is 10 minutes or more, or 20 minutes or more, or 30 minutes or more, in order to suppress variations in the resistance value of metal wiring formed by laser irradiation in the process, and to reduce the trace amount contained in the dry coating film. It is possible to prevent deterioration of developability due to the dispersion medium reacting with the base material (especially resin base material), which causes the base material to dissolve and diffuse into the dried coating film, strengthening the bond between the dried coating film and the base material. In this respect, it is preferably 60 days or less, or 30 days or less, or 7 days or less.

(Laser light irradiation process)
In this process, the dried coating film is irradiated with laser light (Fig. 1 (i)), and the base material, the conductive part (exposed part) and the non-conductive part (unexposed part) arranged on the base material are exposed. A structure with a conductive part is formed (FIG. 1(j)). The conductive portion is formed as a metal wiring. For example, when using a dispersion containing copper oxide particles, in the laser light irradiation step, the copper oxide in the dry coating film is reduced to produce copper particles, and the produced copper particles are fused together to integrate them. Heat treatment is performed under conditions that cause oxidation to form metal wiring.

For laser light irradiation, a known laser light irradiation device having a laser light irradiation section may be used. Laser light is preferable because it allows short-time exposure to high-intensity light, raising the temperature of the dry coating film formed on the substrate to a high temperature for a short time, and baking it. The laser beam method is advantageous in that it can shorten the firing time, causing less damage to the base material, and can also be applied to base materials with low heat resistance (for example, resin film substrates). Further, the laser beam method has a large degree of freedom in wavelength selection, and is advantageous in that the wavelength can be selected in consideration of the light absorption wavelength of the dry coating film and/or the light absorption wavelength of the base material.

Furthermore, according to the laser beam method, exposure can be performed by beam scanning, and therefore the exposure range can be easily adjusted. This allows for example the sintering of metal particles or the sintering of metal oxide particles only in the desired areas of the dried coating film, without using a mask, by selectively irradiating (i.e. drawing) only the desired areas of the dry coating. By performing reduction and sintering of , it is possible to form metal wiring in an arbitrary shape.

As the type of laser light source, YAG (yttrium aluminum garnet), YVO (yttrium vanadate), Yb (ytterbium), semiconductor laser (GaAs, GaAlAs, GaInAs), carbon dioxide gas, etc. can be used. As for the laser, not only the fundamental wave but also harmonic waves may be extracted and used as necessary.

The center wavelength of the laser beam is preferably 350 nm or more and 600 nm or less. In particular, when cuprous oxide is used as the metal oxide, cuprous oxide absorbs laser light having a center wavelength within the above range well, so it is uniformly reduced and can form a metal wiring with low resistance.

It is preferable that the dried coating film is irradiated with laser light through a galvano scanner. Metal wiring in any shape can be obtained by scanning the dried coating film with laser light using a galvano scanner.

The irradiation output of the laser beam is preferably 100 mW or more, or 200 mW or more, or 300 mW or more, from the viewpoint of efficiently performing the desired firing (for example, reduction of cuprous oxide), and is preferably 100 mW or more, or 200 mW or more, or 300 mW or more. From the viewpoint of suppressing destruction of the metal wiring due to ablation and obtaining a metal wiring with low resistance, it is preferably 1500 mW or less, 1250 mW or less, or 1000 mW or less.

In one embodiment, the laser light may be repeatedly scanned to desired locations on the dried coating. In one embodiment, laser light is scanned while overlapping the scanning lines in the line width direction. In this case, the amount of movement of the laser beam is preferably set to such an amount that adjacent scanning lines overlap with each other. FIG. 2 is a schematic diagram illustrating overlapping irradiation of laser light in the metal wiring manufacturing method according to the present embodiment. Referring to FIG. 2, a first scanning line R1 and a second scanning line R2 adjacent thereto overlap each other. This increases the amount of heat storage in the overlapping region where the first scanning line R1 and the second scanning line R2 overlap, increasing the degree of sintering of the copper particles and, as a result, increasing the resistance value of the metal wiring. Can be made lower.

The overlap rate S is the ratio of the overlap part width to the line width of the scanning line, and is the ratio of the width S1 of the first scanning line R1 of the laser beam and the second scanning line R2 in the direction perpendicular to the scanning length direction. It can be determined from the width S2 overlapping with the first scanning line R1 using the following formula.
S=S2/S1×100(%)

The overlap rate is preferably in the range of 5% to 99.5%, more preferably in the range of 10% to 99.5%, and even more preferably in the range of 15% to 99.5%. preferable. When the overlap ratio is 5% or more, the degree of sintering of the metal wiring can be increased, and the amount of smoke generated can be suppressed. When it is 99.5% or less, the dried coating film can be sintered while moving the laser beam in the direction perpendicular to the scanning length direction at an industrially practical speed. According to the overlap ratio within the above range, the degree of sintering of the metal wiring can be increased compared to, for example, an overlap ratio below the above range, so that a metal wiring that is not brittle and hard can be manufactured. Thereby, for example, even when metal wiring is formed on a flexible substrate and bent, the metal wiring can follow the flexible substrate without breaking.

(Developing process)
In this step, the unexposed areas of the dried coating film are developed and removed with a developer (FIG. 1(k)). The form of development is not particularly limited. For example, the structure with a conductive part may be immersed in a developer and shaken, or the structure with a conductive part may be immersed in a developer and then irradiated with ultrasonic waves using an ultrasonic device. The developer may be directly sprayed onto the structure with a conductive portion, or may be brushed.

In the development step, a first development process using a first developer may be performed, followed by a second development process using a second developer. In one embodiment, the developing step is a combination of one or more first development treatments using a first developer and one or more second development treatments using a second developer. be. The types of developers used in the first development process performed twice or more may be the same or different, and similarly, the types of developer used in the second development processes performed twice or more may be the same or different. For example, a combination of a developer containing a dispersant and a developer not containing a dispersant may be used as the first or second developer. In this case, it is preferable to perform development with a developer containing a dispersant and then development with a developer not containing a dispersant, since this can reduce the amount of dispersant remaining on the structure with a conductive part.

According to the combination of the first development treatment and the second development treatment, the effect of dispersing the coating film in the developer is high, and the removability of the unexposed areas is good. In the developing step, it is preferable to use the first developer and the second developer separately by exchanging them (that is, not to mix them). By replacing the developer, the effect of dispersing the coating film in the developer can be enhanced and the developability can be improved.

In addition to the first and second development processes, the development step may further include an additional development process using an additional developer of the present disclosure. The timing of the additional development process is not limited, and may be, for example, before the first development process, between the first development process and the second development process, and/or after the second development process.

When the structure with a conductive part is immersed in a developer and subjected to ultrasonic irradiation using an ultrasonic device, the ultrasonic irradiation time is preferably 1 minute or more and 30 minutes or less. When irradiation is performed for 1 minute or more, the effect of dispersing the coating film attached to the base material is high, and when irradiation is performed for 30 minutes or less, damage to metal wiring can be suppressed.

In the developing step, it is preferable to use a jig that holds the structure with a conductive part. The shape of the jig is not particularly limited; however, when performing a developing operation, the structure with conductive parts may come into contact with the bottom surface, side wall surface, etc. It is desirable to have a shape that can prevent the metal wiring from being damaged or falling off due to contact between the structures when the structures are developed at the same time. The jig may be, for example, a jig having a recess for holding the structures with conductive parts one by one, a clip for holding the structures, or the like.

3 to 5 are schematic diagrams showing an example of a jig for holding a structure with a conductive part in the developing step of the method for manufacturing metal wiring according to the present embodiment. In FIG. 3, a jig 12 having a rack part 12a is arranged in a container 11, and a base material 13a and an irradiated coating film 13b (that is, a film having a conductive part and a non-conductive part) are placed on the rack part 12a. An example is shown in which a structure 13 with a conductive part is mounted. FIG. 4 shows a structure 23 with a conductive part, in which a jig 22 for forming a recess 22a is arranged in a container 21, and a three-dimensional base material 23a and an irradiated coating film 23b are provided in the recess 22a. This shows an example of inserting . In FIG. 5, the container 31 also functions as a jig by having a jig 32 portion that forms a recess 32a, and a three-dimensional base material 33a and an irradiated coating film 33b are formed in the recess 32a. An example is shown in which a structure 33 with a conductive part is inserted. The recesses 22a and 32a shown in FIGS. 4 and 5 are particularly useful when using a three-dimensional base material.

In particular, when irradiating the structures with conductive parts with ultrasonic waves during development, the rack part 12a shown in FIG. 3 and the recessed parts 22a and 32a shown in FIGS. To prevent.

It is more preferable that the jig has a structure that does not prevent contact between the developer and the structure with a conductive part while holding the structure with a conductive part well, for example, a mesh-like structure.

Furthermore, the jig may have any desired member or shape, such as a lid for preventing the structure with a conductive part from floating in the developer.

In the development step, the dried coating film may be brushed while in contact with the first developer. In one embodiment, a structure with a dried coating film is placed in a tank containing a first developer, and brushing is applied to the dried coating film. Highly efficient development can be achieved by using a developer together with brushing.
There are no particular limitations on the material and shape of the brush used for brushing, but examples include polyester, nylon, acrylic resin, polypropylene, polyvinyl chloride copolymer, fluorine resin, acrylonitrile-butadiene-styrene (ABS). etc. Brushing physically treats the dry paint film, but since it only treats the surface of the dry paint film, by selecting the material of the brush, compared to, for example, ultrasonic treatment, it is possible to treat the dry paint film more effectively. The damage caused is small. According to such brushing development, it is possible to achieve both good removal of unexposed areas and reduction of change in resistance value of the metal wiring before and after development.
Brushing methods include methods of rotating, vibrating, and/or moving the brush up and down and left and right while it is in contact with the coating film. The brushing treatment time is preferably 1 minute or more and 1 hour or less, more preferably 5 minutes or more and 45 minutes or less, and most preferably 10 minutes or more and 30 minutes or less. The force applied to the coating film is not particularly limited.
In one embodiment, when the metal oxide is cuprous oxide, reduction and sintering of the cuprous oxide proceed simultaneously by laser irradiation. Cuprous oxide exists in areas not irradiated with laser, and since copper and cuprous oxide have different properties, good developability can be obtained.

(Collection process)
In this step, the used developer produced in the developing step is collected. There are no particular limitations on the collection method, but there are methods such as using a pump to extract the used developer that has entered the processing tank, draining the used developer from the bottom of the tank, and transferring the used developer from the processing tank to the collection tank. Examples include a method of directly adding liquid. Further, in order to uniformly and efficiently recover components in the developer, the solution may be transferred while being stirred. Although there are no particular limitations on the collection tank, containers made of SUS, polyethylene, polypropylene, and the like that are resistant to the components of the developer are preferred. The collected used developer may be transported using a container made of SUS, polyethylene, polypropylene, etc. that is resistant to the components of the developer.

In one embodiment, the total amount of metal particles and metal oxide particles in the used developer is 0.0001% by mass or more, or 0.001% by mass or more, or 0.01% by mass or more, or 0.1% by mass. It may be 10% by mass or less, or 5% by mass or less, or 1% by mass or less. When the total amount of metal particles and metal oxide particles in the used developer is 0.0001% by mass or more, the efficiency of concentration can be improved in the recovery step. Further, when the amount is 10% by mass or less, aggregation of metal particles and/or metal oxide particles in the used developer can be suppressed. In a typical embodiment, the solid content in the used developer solution can be considered to be metal particles and metal oxide particles. Therefore, the total amount of metal particles and metal oxide particles of the present disclosure is a value measured by the same method as the solid content measurement of the dispersion. In one embodiment, the total amount of metal particles and metal oxide particles in the used developer is adjusted to a desired range by selecting the type of developer depending on the type and amount of components contained in the dispersion. It's fine.

In the developing solution of this embodiment, metals and the like that have been removed by development are dispersed without being almost dissolved. It can be reused by fine-tuning the ingredients. Therefore, the developer of this embodiment requires less energy when reused.

(Regeneration process)
The metal wiring manufacturing method according to one embodiment further includes a regeneration step of preparing a regeneration dispersion using the used developer collected in the collection step. The regenerated dispersion may be used as part or all of a dispersion. Collecting the used developer and reusing it for preparing a dispersion is preferable from the viewpoint of effective use of resources and cost reduction by reducing waste. When the main components of the dispersant in the dispersion and the main components of the dispersant in the developer are of the same type, the reuse efficiency of the developer is even better.

In particular, when the developer contains water and/or an alcoholic solvent and the used developer is regenerated to obtain a regenerated dispersion, in addition to the advantage of reusing resources, water or an alcoholic solvent is used. This also provides the advantage of being cheaper and reproducing in a cleaner environment.

In one embodiment, the used developer can be reused as it is as a raw material for a dispersion by simply adjusting the concentration as necessary. In this case, for example, there is no need to newly prepare a dispersant, so resources can be recovered with even higher efficiency.

Referring to FIGS. 1 and 6, a regenerated dispersion can be prepared by collecting a used developer and subjecting it to regeneration treatment. Part or all of the used developer may be reused. As dispersions of the present disclosure, virgin dispersions (i.e., freshly prepared dispersions) or regenerated dispersions or combinations thereof can be subjected to the coating process; An example is shown in which a combination with a dispersion is subjected to a coating process. Referring to FIGS. 1 and 6, the unused dispersion and the regenerated dispersion are applied to the base material, dried to form a dry coating film, and after laser light irradiation (i.e., baking), developed with a developer to conduct wiring. complete. The above-mentioned recycled dispersion is formed by recovering part or all of the used developer and subjecting it to recycling treatment.

Regeneration processing includes concentration adjustment (e.g., concentration or dilution), component adjustment (e.g., addition of additives or removal of certain components), purification (e.g., removal of impurities such as residue), and dispersion state adjustment (e.g., dispersion treatment). Can be mentioned. Additive means any substance added to the used developer solution. In one aspect, the additive may be one or more of metal particles and/or metal oxide particles, a dispersant, a reducing agent, and a dispersion medium, preferably water, an alcoholic solvent, hydrazine, hydrazine water one or more selected from the group consisting of hydrates and dispersants. Furthermore, prior to the recycling process, a component analysis of the used developer may be performed. In this case, the regeneration processing conditions may be determined based on the obtained component analysis results. When the used developer contains a dispersant, the regeneration treatment is preferably performed under conditions that avoid deterioration or loss of the dispersant.

In a preferred embodiment, the regeneration treatment comprises:
(1) Concentration processing to obtain a concentrated solution by concentrating the used developer,
(2) An addition treatment in which an additive containing water and/or an alcoholic solvent is added to the concentrated liquid to obtain an addition treatment liquid.
In a preferred embodiment, the regeneration treatment comprises:
(3) Dispersion treatment of used developer,
including. In a preferred embodiment, the dispersion treatment is a dispersion treatment of the addition treatment liquid obtained in the addition treatment in (2) above.

(1) Concentration process Methods for concentrating the used developer solution are not particularly limited, but include evaporative concentration by heating and/or reduced pressure with an evaporator, concentration using a separation membrane, freeze drying, etc. Examples include a method in which the powder is once dried using a drying method, and then the obtained powder is dispersed in a dispersion medium again. The solid content of the concentrated liquid obtained by the concentration treatment is preferably 0.1% by mass or more, or 0.6% by mass or more, or 1% by mass or more, or 3% by mass or more, or 5% by mass or more, or 8% by mass or more, or 10% by mass or more, or 15% by mass or more, or 20% by mass or more, preferably 80% by mass or less, 70% by mass or less, or 60% by mass or less, or 50% by mass or less, or 40% by mass or less, or 30% by mass or less. The solid content percentage can be measured by the same method as the solid content measurement of the dispersion described above. In one embodiment, the solid content corresponds to the content of metal particles and/or metal oxide particles.

(2) Additive treatment In the additive treatment, an additive is added to the concentrated liquid to obtain an additive treated liquid. In one embodiment, the additive includes water and/or an alcoholic solvent. Suitable examples of alcoholic solvents are the same as those mentioned above regarding the developer and the dispersion. Viscosity adjustment and/or solid content adjustment is possible by addition treatment. In one aspect, the additive is one or more of the components listed above as components of the dispersion, more specifically metal particles and/or metal oxide particles, a dispersant (specifically a dispersant (B)), a reducing agent, and a dispersion medium other than water and an alcoholic solvent. In one embodiment, water and/or alcoholic solvents and optionally one or more selected from the group consisting of propylene glycol, hydrazine, hydrazine hydrate, and dispersants of the present disclosure may be added. In one embodiment, among the desired components of the dispersion, components that are not included in the used developer solution or that are included in the used developer solution but in a lower than desired amount may be added.

Water and/or alcohol-based solvents are preferred from the viewpoint of improving printability. Propylene glycol, hydrazine, hydrazine hydrate, and a dispersant are each preferable as an additive for reducing and/or dispersing metal oxides, and are also preferable in terms of improving suitability for inkjet printing.

The solid content rate of the addition treatment liquid is preferably 0.01% by mass or more, or 0.1% by mass or more, or 0.6% by mass or more, or 1% by mass or more, or 3% by mass or more, or 5% by mass. % or more, or 8% by mass or more, or 10% by mass or more, or 15% by mass or more, or 20% by mass or more, preferably 70% by mass or less, or 60% by mass or less, or 50% by mass or less, or It is 40% by mass or less, or 30% by mass or less. In one embodiment, the addition process is a dilution. In this case, the solid content percentage of the addition treatment liquid is smaller than the solid content percentage of the concentrate. In one embodiment, the solid content corresponds to the content of metal particles and/or metal oxide particles.

(3) Dispersion Treatment When producing a regenerated dispersion, it is preferable to perform a dispersion treatment of the components contained in the used developer from the viewpoint of obtaining a high quality regenerated dispersion. The dispersion method is not particularly limited, but for example, the used developer may be placed in a container and continuously shaken with a shaker to promote dispersion by the flow of the liquid, or mechanical dispersion using a homogenizer or the like. Examples include processing methods. From the viewpoint of stability of the regenerated dispersion, the dispersion time is preferably 1 minute or more. The longer the dispersion time, the better, but from the viewpoint of production efficiency of the regenerated dispersion, it may be, for example, one hour or less. When the above (2) addition treatment is also performed, the dispersion treatment is preferably carried out after the above (2) addition treatment, that is, on the above addition treatment liquid.

The average particle diameter of the particles (more specifically metal particles and/or metal oxide particles) in the regenerated dispersion is not particularly limited, but is preferably 500 nm or less, or 200 nm or less, or 100 nm or less, or 80 nm or less. , or 50 nm or less, or 40 nm or less, or 20 nm or less. The average particle diameter of the particles is preferably 1 nm or more, or 3 nm or more, or 5 nm or more, or 10 nm or more, or 15 nm or more. It is preferable that the average particle diameter is 500 nm or less because fine metal wiring tends to be easily formed on the base material. It is preferable that the average particle diameter is 1 nm or more because the long-term storage stability of the regenerated dispersion is improved. The above average particle diameter is a value measured by the cumulant method using FPAR-1000 manufactured by Otsuka Electronics. In other words, the average particle diameter is not limited to the primary particle diameter or the secondary particle diameter.

Further, in the distribution of particles having the above average particle diameter, the polydispersity value is preferably 0.01 or more, or 0.05 or more, or 0.1 or more, or 0.2 or more, and preferably 0. .5 or less, or 0.4 or less, or 0.3 or less. Within this range, film formability is good and dispersion stability is also high.

Regenerated dispersions can be prepared via the processes exemplified above. The types of components contained in the regenerated dispersion, the content of each component, and various properties (solid content, viscosity, pH, surface free energy, etc.) may be the same as those described above for the dispersion.

<Method for producing dispersion>
Another aspect of the present invention is a method for producing a dispersion containing a particle component that is a metal particle and/or a metal oxide particle, the method comprising: a used developer collected in a recovery step of the method for producing metal wiring of the present disclosure; A method is provided that includes a concentration step of concentrating a liquid to obtain a concentrated liquid, and an addition step of adding an additive containing water and/or an alcoholic solvent to the concentrated liquid to obtain an additive treatment liquid. The procedure of the concentration step and the properties of the concentrated liquid may be the same as those explained in the above-mentioned concentration treatment, and the procedures of the addition step and the properties of the addition treatment liquid may be the same as those explained in the above-mentioned addition treatment. . In one embodiment, the method for producing a dispersion further includes a dispersion step. The procedure of the dispersion process and the properties of the regenerated dispersion may be the same as those described for the dispersion process above.

<Metal wiring manufacturing system>
One aspect of the invention also provides a metal wiring manufacturing system. Referring to FIG. 7, in one embodiment, the metal wiring manufacturing system 100 includes:
a coating mechanism 101 that coats a dispersion containing particle components that are metal particles and/or metal oxide particles on the surface of a base material to form a dispersion layer;
a drying mechanism 102 that dries the dispersion layer to form a structure with a dried coating film having a base material and a dried coating film disposed on the base material;
a laser light irradiation mechanism 103 that irradiates the dry coating film with laser light to form metal wiring by drawing;
a developing mechanism 104 that develops and removes areas of the dried coating film other than the metal wiring with a developer;
a developer recovery mechanism 105 that recovers the used developer generated by the development mechanism 104;
Equipped with
The metal wiring manufacturing system 100 can further include a developer regeneration mechanism 106.
The metal wiring manufacturing system of the present disclosure can be suitably applied to the metal wiring manufacturing method of the present disclosure. Therefore, each element of the metal wiring manufacturing system may have the configuration or function as exemplified above in the metal wiring manufacturing method.

The coating mechanism 101 may be one or more types selected from, for example, a die coater, a spin coater, a slit coater, a bar coater, a knife coater, a spray coater, a dip coater, and the like.

The drying mechanism 102 may be one or more types selected from an oven, a vacuum dryer, a nitrogen introduction dryer, an IR oven, a hot plate, and the like.

The laser beam irradiation mechanism 103 may include, for example, a laser beam oscillator (not shown) and a galvano scanner (not shown) that performs drawing by irradiating the oscillated laser beam onto the coating film.

In one embodiment, the developer contains water and/or an alcoholic solvent. In one embodiment, the total amount of metal particles and metal oxide particles in the used developer is 0.0001% by mass or more and 10% by mass or less.

In one aspect, the developing mechanism 104 includes:
(1) a first developing section 104a that develops the dried coating film with a first developer; and (2) a second developing section 104b that develops the dried coating film with a second developer;
has. In one embodiment, the first developer includes water and/or an alcoholic solvent, further includes a dispersant, and in one embodiment, the dispersant is contained in an amount of 0.01% by mass or more and 20% by mass or less. include. The second developer contains an organic solvent in one embodiment. Although the positional relationship between the first developing section 104a and the second developing section 104b is not limited, from the viewpoint of removal efficiency of metal particles and/or metal oxide particles, as shown in FIG. It is preferable that the developer be arranged so that it is provided to the first developing section 104a and then to the second developing section 104b.

In one embodiment, each of the first developing section 104a and the second developing section 104b may include a developing solution and a container containing the developing solution and the structure with a conductive part. Each of the first developing section 104a and the second developing section 104b preferably includes a mechanism for promoting development, such as a shaker that shakes the structure with a conductive part, and an ultrasonic wave applied to the structure with a conductive part. It has one or more of the ultrasonic irradiators etc. which irradiate. In one embodiment, each of the first developing section 104a and the second developing section 104b may include a developer and a sprayer that sprays the developer onto the structure with a conductive part.

The developer recovery mechanism 105 may be, for example, a liquid transfer pipe using gravity, a pump, or the like, and may also include a stirring device.

The developer regeneration mechanism 106 regenerates the used developer collected by the developer recovery mechanism 105 to generate a regenerated dispersion. The developer regeneration mechanism 106 may be, for example, a concentration device, a dilution device, a mixing device, an impurity removal device, a dispersion device, or the like.

In addition to the above-mentioned elements, the metal wiring manufacturing system may include additional elements such as a base material transport mechanism and a base material cleaning mechanism as desired.

<Application example>
As explained above, according to the method for manufacturing metal wiring according to the present embodiment and the combination of a structure with a dry coating film or a structure with a conductive part and a developer, a structure with metal wiring can be produced with good developability. Not only can the body be manufactured, but also the useful substances contained in the paint film removed during development can be reused. The structure with metal wiring according to the present embodiment can be formed on, for example, metal wiring materials such as electronic circuit boards (printed circuit boards, RFID, substitutes for wire harnesses in automobiles, etc.), and casings of mobile information devices (smartphones, etc.). It can be suitably applied to antennas, mesh electrodes (electrode films for capacitive touch panels), electromagnetic shielding materials, heat dissipation materials, etc.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Evaluation method>
[Arithmetic mean surface roughness Ra of base material]
The arithmetic mean surface roughness Ra of the surface of the base material to which the dispersion is applied was measured by the following method. The surface roughness of the base material was measured using a stylus type surface profile measuring device (DektakXT manufactured by Bruker) and analysis software (Vision 64). The measurement conditions are as follows.
Scan type: Standard Scan range: 65.5μm
Profile: Hills & Valleys
Stylus type: radius 12.5μm
Stylus force: 1mg
Length: 1000μm
Holding time: 5 seconds Resolution: 0.666μm/pt
After measuring the shape of the base material surface, surface roughness was analyzed. The roughness analysis conditions are as follows.
Filter type: Gaussian regression Long cutoff: Long cutoff applied / Standard cutoff used (0.25mm)
Roughness profile: Ra
Parameter calculation: ISO4287
Sample length used in calculation: Automatic selection The average value of the surface roughness value obtained under the above conditions and the surface roughness value measured in the direction perpendicular to the direction of the above measurement is calculated as the arithmetic average of the base material. It was taken as the value of surface roughness Ra.

[solubility]
0.10 g of powder of cuprous oxide particles (as a particle component which is a metal particle and/or metal oxide particle) was added to 40 ml of a developer, and the mixture was allowed to stand at room temperature of 25° C. for 6 hours. Thereafter, the developer containing the powder was filtered through a 0.2 μm filter, and diluted 100 times (based on mass) with 0.10 mol/L nitric acid. The metal concentration (unit: mg/L) of the obtained diluted solution was measured using an ICP light emitting device (manufactured by SII Nanotechnology), which was defined as solubility.

[viscosity]
Measurement was performed using an E-type viscometer (manufactured by Toki Sangyo, model number TVE-33L).

[Average particle size and polydispersity]
It was measured by the cumulant method using a concentrated particle size analyzer (manufactured by Otsuka Electronics, model number nanoSAQLA).

[Surface free energy]
It was measured by the pendant drop method using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., model number DM700). A syringe equipped with a 22G injection needle was filled with the measurement liquid, a 5 μL droplet was discharged from the injection needle, and the surface free energy was determined from the shape of the droplet at the needle tip using the Young-Laplace method.

[Resistance value of metal wiring and resistance value change before and after development]
For each metal wiring of a structure with a conductive part in which three metal wirings were formed by laser beam irradiation, a tester was applied to a position 0.5 mm from both ends in the longitudinal direction to measure the resistance value, and the number average of the three metal wirings was measured. The value _RA was calculated. Furthermore, the resistance values of the metal wirings after developing the structure with a conductive part were similarly measured, and the number average value _RB of the three metal wirings was calculated. It was determined that the value of R _B /R _A was good if it was 10 or less, better if it was 5 or less, and even better if it was 2 or less. Good is expressed as △, better as ○, and even better as ◎. On the other hand, when the value of R _B /R _A is larger than 10, or when the resistance value cannot be measured due to wire breakage, the evaluation is written as ×.

[Developability of structure with conductive part]
Developability was evaluated by the following method. A structure with a conductive part (i.e., a structure including copper wiring and a dry coating film that has not been irradiated with laser light) produced in the laser light irradiation process is heated in a developer (at 23°C) in an amount sufficient to immerse the entire structure. ) and irradiated with ultrasonic waves using an ultrasonic device for a period of 1 minute to 30 minutes to perform development.

After development, the part of the base material where there is no metal wiring was cut out into 10 mm square pieces, pasted on a SEM (scanning electron microscope) sample stage with carbon tape, and coated using a coater (MSP-1S manufactured by Vacuum Devices). Coated with platinum-palladium. At this time, the coating conditions were set to process time: 1.5 minutes. After coating, the remaining concentration of the coated metal on the surface of the substrate was measured using a SEM (FlexSEM1000 manufactured by Hitachi High-Tech Corporation) and an EDX (Energy Dispersive X-ray Analysis) device (AztecOne manufactured by Oxford Instruments). did. At this time, the electron beam conditions were acceleration voltage: 5 kV, spot intensity: 80, and focus position: 10 mm. After focusing on the sample surface, the magnification was increased to 200 times, and mapping analysis of the entire field of view was performed. The conditions for mapping acquisition were: resolution: 256, acquisition time: 50 frames, process time: high sensitivity, pixel dwell time: 150 μs, and frame live time: 0:00:08. In addition, the elements to be measured were carbon, oxygen, nitrogen, and metal elements coated (that is, included in the dispersion), and platinum and palladium used for coating were specified not to be included in the elements to be measured. Measurement was carried out under the above conditions, and the obtained metal element concentration (mass %) was taken as the concentration of the metal remaining on the base material without being developed.
(Developability evaluation criteria)
In the developability evaluation of the structure with a conductive part, it was determined that the concentration of metal remaining in the base material was good if it was 10% by mass or less, and even better if it was 2.0% by mass or less. Good is marked with ○, and even better is marked with ◎. On the other hand, if the concentration of metal remaining on the substrate is greater than 10% by mass, or if the coating film is clearly not dispersed in the developer during the development operation and remains on the substrate, it is indicated as ×. .
(Evaluation criteria after using regenerated dispersion)
A metal wiring is formed by coating, drying, and laser irradiation using the regenerated dispersion, and when the resistance of the metal wiring is measured by the method described above, if continuity is confirmed, mark it as ○, and if continuity cannot be confirmed, mark it as ×.

<Example 1>
[Manufacture of dispersion]
In a mixed solvent consisting of 30,240 g of water and 13,976 g of 1,2-propylene glycol (manufactured by Asahi Glass), 3,224 g of copper (II) acetate monohydrate (manufactured by Nippon Kagaku Sangyo) was dissolved, and hydrazine hydrate (manufactured by Nippon Finechem) was dissolved. After adding 940 g and stirring, the mixture was separated into a supernatant and a precipitate using centrifugation.
To 388 g of the obtained precipitate, 51 g of DISPERBYK-145 (trade name, BYK-145) as a phosphorus-containing organic compound and 415 g of n-butanol (manufactured by Sankyo Chemical) as a dispersion medium were added, and the mixture was stirred under a nitrogen atmosphere. A preliminary dispersion containing cuprous oxide particles containing cuprous oxide (copper(I) oxide) was obtained by dispersing using a homogenizer. Furthermore, 7.3 g of BYK-145 and 115 g of n-butanol were added to 788 g of the obtained preliminary dispersion, and the mixture was dispersed using a homogenizer under a nitrogen atmosphere to obtain the desired dispersion. At this time, the solid content residue (cuprous oxide particles) when the dispersion was heated at normal pressure and 60° C. for 4.5 hours was 35.9% by mass. The viscosity of the dispersion was 6.44 mPa·s, the average particle diameter of the particles (cuprous oxide particles) in the dispersion was 21.9 nm, and the polydispersity was 0.18. The surface free energy of the dispersion was measured to be 23 mNm.

[Base material polishing]
A polycarbonate (PC) substrate with width x depth x thickness of 50 mm x 50 mm x 1 mm was used without polishing. When the arithmetic mean surface roughness Ra was measured, it was 4 nm.

[Coating and drying of dispersion]
The base material after polishing was irradiated with ultrasonic waves for 5 minutes in ultrapure water, and then irradiated with ultrasonic waves for 5 minutes in ethanol to perform cleaning. Next, the surface of the base material was subjected to UV ozone treatment, and then 1 ml of the dispersion was dropped onto the surface, followed by heating and drying at 60° C. for 2 hours. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
The above sample was placed in a 200 mm long x 150 mm wide x 41 mm high box with the top surface made of quartz glass, with the dry coating facing upward, and the compressed air was separated into nitrogen and oxygen using a separation membrane. The separated nitrogen gas was blown into the box to reduce the oxygen concentration in the box to 0.5% by mass or less. Next, the dry coating film was repeatedly irradiated with laser light (center wavelength 355 nm, frequency 300 kHz, pulse, output 395 mW) while scanning while moving the focus position on the substrate surface at a maximum speed of 25 mm/sec using a galvano scanner. A copper metal wiring (ie, a wiring pattern) having the desired dimensions of 5 mm in length and 1 mm in width was obtained. At this time, the laser beam was repeatedly irradiated while moving in the scanning line width direction so that the overlap ratio was 93.2%. Two more copper interconnects were produced under the same conditions, resulting in a total of three copper interconnects.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.18Ω, 0.17Ω, and 0.17Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.17Ω. there were.

[Developability of structure]
The structure with a conductive part after laser light irradiation was immersed in 30 ml (23°C) of a 0.1% by mass DISPERBYK-145 aqueous solution (first developer), and then washed in an ultrasonic cleaner (USD-4R manufactured by As One). After 5 minutes of ultrasonic irradiation, the structure was pulled up with tweezers and washed with 50 ml of ultrapure water. Thereafter, the structure was immersed in 50 ml (23°C) of a 5% by mass diethylene triamine aqueous solution (second developer), irradiated with ultrasound for 5 minutes, pulled up with tweezers, and washed under running water with 50 ml of ultrapure water. I did it.
After the above-mentioned development operation, the copper concentration of the portion of the base material where no metal wiring was present was measured by the method described above, and the result was 0.2% by mass, and the evaluation was ◎.

[Wiring resistance after development]
After the development operation, the resistance was measured by the method described above, and the resistances of the three copper wirings were 0.16Ω, 0.15Ω, and 0.15Ω, respectively, and the average resistance value R _B after development was 0.15Ω. From this, R _B /R _A was 0.9, and the evaluation was ◎.

[Collection of developer]
The first developing solution after the development operation was transferred to a polypropylene container with width x depth x thickness of 6.5 mm x 100 mm x 25 mm and collected. At this time, the total amount of cuprous oxide particles in the first developer recovered was 1.2% by mass.

[Preparation of regenerated dispersion]
30 ml of the recovered first developing solution was heated and concentrated to 10 ml at 60° C. to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 3.1% by mass.

[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 3 nm, and dried by heating at 60° C. for 30 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as above, except that the output was 135 mW and only one copper wiring was produced, to obtain a copper metal wiring (i.e., a wiring pattern) with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 1.1Ω, and continuity was confirmed, so the evaluation was ◯.

<Example 2>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 1.

[Base material polishing]
The surface of an ABS substrate measuring 50 mm x 50 mm x 1 mm in width x depth x thickness was polished using #2000 abrasive paper. After polishing, the arithmetic mean surface roughness Ra was measured to be 186 nm.

[Coating and drying of dispersion]
Coating was carried out in the same manner as in Example 1.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1 to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.18Ω, 0.17Ω, and 0.17Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.17Ω. there were.

[Developability of structure]
A developing operation was performed as described in Example 1.
After the above-mentioned development operation, the copper concentration of the portion of the base material where no metal wiring was present was measured by the method described above, and as a result, it was 0.1% by mass, and the evaluation was ◎.

[Wiring resistance after development]
After the development operation, the resistance was measured by the method described above, and the resistances of the three copper wirings were 0.19Ω, 0.15Ω, and 0.15Ω, respectively, and the average resistance value R _B after development was 0.16Ω. From this, R _B /R _A was 0.9, and the evaluation was ◎.

[Collection of developer]
A recovery operation was performed using the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 1.0% by mass.

[Preparation of regenerated dispersion]
After the development operation, 30 ml of the first developer was heated and concentrated to 5 ml at 60° C. to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 4.2% by mass.

[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto an ABS substrate having an Ra of 6 nm, and dried by heating at 60° C. for 30 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 135 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.
[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 1.0Ω, and continuity was confirmed, so the evaluation was ◯.

<Example 3>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 1.

[Base material polishing]
A polycarbonate (PC) substrate with width x depth x thickness of 50 mm x 50 mm x 1 mm was used without polishing. When the arithmetic mean surface roughness Ra was measured, it was 4 nm.
It was.

[Coating and drying of dispersion]
Coating was carried out in the same manner as in Example 1.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1 to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.17Ω, 0.17Ω, and 0.19Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.18Ω. there were.

[Developability of structure]
The development operation was performed in the same manner as in Example 1, except that the first developer was ultrapure water and the second development was not performed.
After the above-mentioned development operation, the copper concentration of the portion of the base material where no metal wiring was present was measured by the method described above, and the result was 1.2% by mass, and the evaluation was ◎.

[Wiring resistance after development]
When the resistance was measured by the above method after the development operation, the resistances of the three copper wirings were 0.17Ω, 0.17Ω, and 0.18Ω, respectively, and the average resistance value R _B after development was 0.17Ω. From this, R _B /R _A was 1.0, and the evaluation was ◎.

[Collection of developer]
A recovery operation was performed using the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 1.1% by mass.

[Preparation of regenerated dispersion]
After the development operation, 30 ml of the first developer was heated and concentrated to 5 ml at 60° C. to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 3.5% by mass.
[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 6 nm, and dried by heating at 60° C. for 30 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 135 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured using the method described above, it was found to be 0.8Ω, and conductivity was confirmed, so the evaluation was ◯.

<Example 4>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 1.

[Base material polishing]
The surface of an ABS substrate measuring 50 mm x 50 mm x 1 mm in width x depth x thickness was polished using #2000 abrasive paper. After polishing, the arithmetic mean surface roughness Ra was measured to be 207 nm.

[Coating and drying of dispersion]
Coating was carried out in the same manner as in Example 1.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1 to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.18Ω, 0.18Ω, and 0.19Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.18Ω. there were.

[Developability of structure]
The development operation was performed in the same manner as in Example 1, except that the first developer was ultrapure water and the second development was not performed.
After the above-mentioned development operation, the copper concentration of the area on the base material where no metal wiring was present was measured by the method described above, and the result was 0.8% by mass, and the evaluation was ◎.

[Wiring resistance after development]
After the development operation, the resistance was measured by the method described above, and the resistances of the three copper wirings were 0.19Ω, 0.19Ω, and 0.16Ω, respectively, and the average resistance value R _B after development was 0.18Ω. From this, R _B /R _A was 1.0, and the evaluation was ◎.

[Collection of developer]
A recovery operation was performed using the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 0.9% by mass.

[Preparation of regenerated dispersion]
After the development operation, 30 ml of the first developer was heated and concentrated to 5 ml at 60° C. to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 3.6% by mass.

[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto an ABS substrate having an Ra of 9 nm, and dried by heating at 60° C. for 30 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 135 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured using the method described above, it was found to be 0.8Ω, and conductivity was confirmed, so the evaluation was ◯.

<Example 5>
[Manufacture of dispersion]
In a mixed solvent consisting of 30,240 g of water and 13,976 g of 1,2-propylene glycol (manufactured by Asahi Glass), 3,224 g of copper (II) acetate monohydrate (manufactured by Nippon Kagaku Sangyo) was dissolved, and hydrazine hydrate (manufactured by Nippon Finechem) was dissolved. After adding 940 g and stirring, the mixture was separated into a supernatant and a precipitate using centrifugation.
To 858 g of the obtained precipitate, 113 g of DISPERBYK-145 (trade name, BYK-145) as a phosphorus-containing organic compound and 916 g of n-butanol (manufactured by Sankyo Chemical) as a dispersion medium were added, and the mixture was heated under a nitrogen atmosphere. The mixture was dispersed using a homogenizer to obtain a dispersion containing cuprous oxide particles containing cuprous oxide (copper(I) oxide). At this time, the solid content residue (cuprous oxide particles) when the dispersion was heated at normal pressure and 60° C. for 4.5 hours was 36.1% by mass. The viscosity of the dispersion was 6.12 mPa·s, the average particle diameter of the particles (cuprous oxide particles) in the dispersion was 21.1 nm, and the polydispersity was 0.17. The surface free energy of the dispersion was measured to be 26 mN/m.

[Base material polishing]
The surface of an ABS substrate measuring 50 mm x 50 mm x 1 mm in width x depth x thickness was polished using #2000 abrasive paper. After polishing, the arithmetic mean surface roughness Ra was measured to be 212 nm.

[Coating and drying of dispersion]
The base material after polishing was irradiated with ultrasonic waves for 5 minutes in ultrapure water, and then irradiated with ultrasonic waves for 5 minutes in ethanol to perform cleaning. Next, after UV ozone treatment was applied to the surface of the base material, 1 ml of the dispersion was dropped onto the surface, spin coated (300 rpm, 300 seconds), and then heated and dried at 60° C. for 1 hour. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 79 mW, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, the resistance of the three copper wirings was 11Ω, 18Ω, and 18Ω, respectively, and the average resistance value _RA before development was 16Ω.

[Developability of structure]
Except that the first developer was ultrapure water, the ultrasonic irradiation time with the first developer was 1 minute, and the second developer was a 2% by mass DISPERBYK-145 aqueous solution. The developing operation was performed by the method described in Example 1.
After the above-mentioned development operation, the copper concentration of the area on the base material where no metal wiring was present was measured by the method described above, and the result was 8.9% by mass, and the evaluation was 0.

[Wiring resistance after development]
When the resistance was measured by the method described above after the development operation, the resistances of the three copper wirings were 26Ω, 27Ω, and 16Ω, respectively, and the average resistance value R _B after development was 22Ω. From this, R _B /R _A was 1.4, and the evaluation was ◎.

[Collection of developer]
The developer 1 was recovered by the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 0.06% by mass.

[Preparation of regenerated dispersion]
After the development operation, 50 ml of the first developer was heated and concentrated to 8 ml at 80° C. to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 0.14% by mass.

[Coating and drying of regenerated dispersion]
2 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 4 nm, and then heated and dried at 80° C. for 60 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 135 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 68Ω, and a metal wiring that was conductive using the regenerated dispersion was obtained.

<Example 6>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 1.

[Base material polishing]
A PC board (as a base material) with width x depth x thickness of 50 mm x 50 mm x 1 mm was used. The arithmetic mean surface roughness Ra of the surface coated with the dispersion was measured and found to be 2 nm.

[Coating and drying of dispersion]
Coating and drying were performed by the method described in Example 5.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 79 mW, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Developability of structure]
After irradiating the laser beam, the structure with a conductive part was immersed in 50 ml of ethanol (first developer) (23°C), brushed for 5 minutes, pulled up with tweezers, and rinsed with 50 ml of ultrapure water. Washed. The brush used for the above brushing was a nylon brush.
After the above-mentioned development operation, the copper concentration of the portion on the base material where no metal wiring was present was measured by the method described above, and the result was 2.3% by mass, and the evaluation was ◯.

[Wiring resistance measurement]
After the above development operation, the structure was subjected to plating treatment, and wiring resistance was measured.
The plating method is as follows. 424.8 g of industrial purified water, 15 ml of OPC Copper NCA-1 (manufactured by Okuno Pharmaceutical Co., Ltd.), 2.4 ml of OPC Copper NCA-4 (manufactured by Okuno Pharmaceutical Co., Ltd.), and OPC Copper NCA 150 ml of OPC Copper NCA-2 (manufactured by Okuno Pharmaceutical Co., Ltd.) and 2.4 ml of OPC Copper NCA-3 (manufactured by Okuno Pharmaceutical Co., Ltd.) were added and heated to 60° C. in a water bath. Next, 5.4 ml of electroless copper RH (manufactured by Okuno Pharmaceutical Industries, Ltd.) was added to prepare a plating solution. The structure was immersed in the plating solution for 30 minutes while air bubbling was performed in the plating solution. After immersion, the structure was pulled up, immersed in 300 ml of industrial purified water, and washed with running water using 50 ml of industrial purified water to obtain a plated structure.
After the above plating treatment, the resistance values of the copper wirings of the structure were measured by applying a tester to positions 0.5 mm from both ends in the longitudinal direction.The resistance values were 0.5mm for each of the three copper wirings. 05Ω, 0.05Ω, and 0.05Ω, and the average value was 0.05Ω.

[Collection of developer]
The developer 1 was recovered by the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 0.03% by mass.

[Preparation of regenerated dispersion]
After the development operation, 50 ml of the first developer was heated and concentrated to 5 ml at 80° C. to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 0.36% by mass.

[Coating and drying of regenerated dispersion]
2 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 4 nm, and then heated and dried at 80° C. for 60 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 79 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm length x 1 mm width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 93Ω, and a metal wiring that was conductive using the regenerated dispersion was obtained.

<Example 7>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 1.

[Base material polishing]
A PC board (as a base material) with width x depth x thickness of 50 mm x 50 mm x 1 mm was used. The arithmetic mean surface roughness Ra of the surface coated with the dispersion was measured and found to be 3 nm.

[Coating and drying of dispersion]
Coating and drying were performed by the method described in Example 5.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 79 mW, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Developability of structure]
After irradiating the laser beam, the structure with conductive parts is immersed in 50 ml of ultrapure water (first developer) (23°C), brushed for 1 minute, and then pulled up with tweezers and soaked in 50 ml of ultrapure water. I washed it with running water. The brush used for the above brushing was a nylon brush.
After the above-mentioned development operation, the copper concentration of the portion of the base material where no metal wiring was present was measured by the method described above, and the result was 0.7% by mass, and the evaluation was ◎.

[Wiring resistance measurement]
Plating was performed in the same manner as in Example 6, and the wiring resistance was measured. As a result, the resistance values were 0.06Ω, 0.04Ω, and 0.04Ω for the three copper wirings, respectively, and the average value was 0. It was .04Ω.

[Collection of developer]
The developer 1 was recovered by the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 0.05% by mass.

[Preparation of regenerated dispersion]
After the development operation, 50 ml of the first developer was heated and concentrated to 8 ml at 80° C. to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 0.16% by mass.

[Coating and drying of regenerated dispersion]
The regenerated dispersion was applied and dried in the same manner as in Example 6.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 6 to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 12Ω, and a metal wiring that was conductive using the regenerated dispersion was obtained.

<Example 8>
[Manufacture of dispersion]
In a mixed solvent consisting of 30,240 g of water and 13,980 g of 1,2-propylene glycol (manufactured by Asahi Glass), 3,220 g of copper (II) acetate monohydrate (manufactured by Nippon Kagaku Sangyo) was dissolved, and hydrazine hydrate (manufactured by Nippon Finechem) was dissolved. After adding 940 g and stirring, the mixture was separated into a supernatant and a precipitate using centrifugation.
To 388 g of the obtained precipitate, 51 g of DISPERBYK-145 (trade name, BYK-145) as a phosphorus-containing organic compound and 415 g of n-butanol (manufactured by Sankyo Chemical) as a dispersion medium were added, and the mixture was stirred under a nitrogen atmosphere. The mixture was dispersed using a homogenizer to obtain a dispersion containing cuprous oxide particles containing cuprous oxide (copper(I) oxide). At this time, the solid content residue (cuprous oxide particles) when the dispersion was heated at normal pressure and 60° C. for 4.5 hours was 36.0% by mass. The viscosity of the dispersion was 5.98 mPa·s, the average particle diameter of the particles in the dispersion was 20.7 nm, and the polydispersity was 0.19. The surface free energy of the dispersion was measured to be 25 mN/m.

[Base material polishing]
A PC board (as a base material) with width x depth x thickness of 50 mm x 50 mm x 1 mm was used. The arithmetic mean surface roughness Ra of the surface coated with the dispersion was measured to be 3 nm.

[Coating and drying of dispersion]
Coating was carried out in the same manner as in Example 1.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 342 mW, to obtain a copper metal wiring pattern with dimensions of 5 mm length x 1 mm width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.21Ω, 0.21Ω, and 0.23Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.22Ω. Met.

[Developability of structure]
The developing operation was carried out in the same manner as in Example 1, except that the first developer was a 0.5% by mass DISPERBYK-145 aqueous solution.
After the above-mentioned development operation, the copper concentration of the portion of the base material where no metal wiring was present was measured by the method described above, and as a result, it was 0.1% by mass, and the evaluation was ◎.

[Wiring resistance after development]
After the development operation, the resistance was measured by the method described above, and the resistances of the three copper wirings were 0.21Ω, 0.21Ω, and 0.23Ω, respectively, and the average resistance value R _B after development was 0.22Ω. From this, R _B /R _A was 1.0, and the evaluation was ◎.

[Collection of developer]
The developer 1 was recovered by the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 1.5% by mass.

[Preparation of regenerated dispersion]
The first developer solution after the development operation was heated and concentrated by the method described in Example 1 to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 3.1% by mass.

[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 8 nm, and dried by heating at 80° C. for 60 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 182 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was found to be 11Ω, and a metal wiring that was conductive using the regenerated dispersion was obtained.

<Example 9>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 8.

[Base material polishing]
A PC board (as a base material) with width x depth x thickness of 50 mm x 50 mm x 1 mm was used. When the arithmetic mean surface roughness Ra of the dispersion-coated surface was measured, it was 4 nm.

[Coating and drying of dispersion]
Coating was carried out in the same manner as in Example 1.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 8 to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.23Ω, 0.24Ω, and 0.23Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.23Ω. Met.

[Developability of structure]
The developing operation was carried out in the same manner as described in Example 1, except that the first developer was a 1.0% by mass DISPERBYK-145 aqueous solution.
After the above-mentioned development operation, the copper concentration of the portion of the base material where no metal wiring was present was measured by the method described above, and the result was 0.2% by mass, and the evaluation was ◎.

[Wiring resistance after development]
After the development operation, the resistance was measured by the method described above, and the resistance values of the three copper wirings were 0.23Ω, 0.26Ω, and 0.23Ω, respectively, and the average resistance value R _B after development was 0.24Ω. From this, R _B /R _A was 1.0, and the evaluation was ◎.

[Collection of developer]
The developer 1 was recovered by the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 1.8% by mass.

[Preparation of regenerated dispersion]
The first developer solution after the development operation was heated and concentrated by the method described in Example 1 to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 3.5% by mass.

[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 13 nm, and dried by heating at 80° C. for 60 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 434 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 70Ω, and a metal wiring that was conductive using the regenerated dispersion was obtained.

<Example 10>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 8.

[Base material polishing]
A PC board (as a base material) with width x depth x thickness of 50 mm x 50 mm x 1 mm was used. When the arithmetic mean surface roughness Ra of the dispersion-coated surface was measured, it was 4 nm.

[Coating and drying of dispersion]
Coating was carried out in the same manner as in Example 1.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 8 to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.27Ω, 0.27Ω, and 0.24Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.26Ω. Met.

[Developability of structure]
The developing operation was carried out in the same manner as in Example 1, except that the first developer was a 0.05% by mass DISPERBYK-145 aqueous solution.
After the above-mentioned development operation, the copper concentration of the portion of the base material where no metal wiring was present was measured by the method described above, and as a result, it was 0.1% by mass, and the evaluation was ◎.

[Wiring resistance after development]
After the development operation, the resistance was measured by the method described above, and the resistances of the three copper wirings were 0.23Ω, 0.25Ω, and 0.24Ω, respectively, and the average resistance value R _B after development was 0.23Ω. From this, R _B /R _A was 0.9, and the evaluation was ◎.

[Collection of developer]
The developer 1 was recovered by the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 0.8% by mass.

[Preparation of regenerated dispersion]
The first developer solution after the development operation was heated and concentrated by the method described in Example 1 to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 1.5% by mass.

[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 14 nm, and dried by heating at 80° C. for 60 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 342 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 2.1Ω, and a metal wiring that was conductive using the regenerated dispersion was obtained.

<Example 11>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 8.

[Base material polishing]
A PC board (as a base material) with width x depth x thickness of 50 mm x 50 mm x 1 mm was used. The arithmetic mean surface roughness Ra of the surface coated with the dispersion was measured to be 6 nm.

[Coating and drying of dispersion]
Coating was carried out in the same manner as in Example 1.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 8 to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured using the method described above, it was 0.21Ω, 0.24Ω, and 0.21Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.22Ω. Met.

[Developability of structure]
The developing operation was performed in the same manner as in Example 1, except that the first developer was a 0.1% by mass polyethylene glycol (molecular weight 400) aqueous solution.
After the above-mentioned development operation, the copper concentration of the portion of the base material where no metal wiring was present was measured by the method described above, and as a result, it was 0.3% by mass, and the evaluation was ◎.

[Wiring resistance after development]
After the development operation, the resistance was measured by the method described above, and the resistances of the three copper wirings were 0.23Ω, 0.19Ω, and 0.19Ω, respectively, and the average resistance value R _B after development was 0.20Ω. From this, R _B /R _A was 0.9, and the evaluation was ◎.

[Collection of developer]
The developer 1 was recovered by the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 0.9% by mass.

[Preparation of regenerated dispersion]
The first developer solution after the development operation was heated and concentrated by the method described in Example 1 to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 1.8% by mass.

[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 23 nm, and dried by heating at 80° C. for 60 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 259 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm length x 1 mm width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.2Ω, and a metal wiring that was conductive using the regenerated dispersion was obtained.

<Example 12>
[Manufacture of dispersion]
A dispersion was obtained in the same manner as in Example 8.

[Base material polishing]
A PC board (as a base material) with width x depth x thickness of 50 mm x 50 mm x 1 mm was used. When the arithmetic mean surface roughness Ra of the dispersion-coated surface was measured, it was 4 nm.

[Coating and drying of dispersion]
Coating was carried out in the same manner as in Example 1.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 8 to obtain a copper metal wiring pattern with dimensions of 5 mm in length x 1 mm in width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 0.38Ω, 0.36Ω, and 0.33Ω for the three copper wirings, respectively, and the average resistance value R _A before development was 0.36Ω. Met.

[Developability of structure]
The developing operation was performed in the same manner as in Example 1, except that the first developer was a 10% by mass ethanol aqueous solution.
After the above-mentioned development operation, the copper concentration of the area on the base material where no metal wiring was present was measured by the method described above, and the result was 0.5% by mass, and the evaluation was ◎.

[Wiring resistance after development]
After the development operation, the resistance was measured by the method described above, and the resistances of the three copper wirings were 0.36Ω, 0.38Ω, and 0.34Ω, respectively, and the average resistance value R _B after development was 0.36Ω. From this, R _B /R _A was 1.0, and the evaluation was ◎.

[Collection of developer]
The developer 1 was recovered by the method described in Example 1. At this time, the total amount of cuprous oxide particles in the first developer recovered was 0.8% by mass.

[Preparation of regenerated dispersion]
The first developer solution after the development operation was heated and concentrated by the method described in Example 1 to obtain a regenerated dispersion. At this time, the solid content of the regenerated dispersion was 2.4% by mass.

[Coating and drying of regenerated dispersion]
1 ml of the above regenerated dispersion was dropped onto a PC board having an Ra of 39 nm, and dried by heating at 80° C. for 60 minutes. After drying, the sample was stored for 10 minutes at normal pressure, room temperature of 23° C., and relative humidity of 40% to obtain a sample with a dried coating film formed on the substrate.

[Laser light irradiation]
Laser light was irradiated in the same manner as in Example 1, except that the output was 259 mW and only one copper wiring was produced, to obtain a copper metal wiring pattern with dimensions of 5 mm length x 1 mm width.

[Wiring resistance after laser beam irradiation]
When the resistance of the obtained metal wiring was measured by the method described above, it was 1.3Ω, and a metal wiring that was conductive using the regenerated dispersion was obtained.

Tables 1 and 2 summarize the above results.

According to the present invention, it is possible to efficiently remove metal particles and/or metal oxide particles in unexposed areas in the development process, and there is little change in resistance value before and after development. It is possible to provide a low-resistance structure with metal wiring that can avoid problems such as short circuits due to external precipitation and migration, and furthermore, according to aspects of the present invention, waste can be reduced by collecting and reusing the developer. can.

Such a structure with metal wiring can be suitably used for metal wiring materials such as electronic circuit boards, mesh electrodes, electromagnetic shielding materials, heat dissipation materials, and the like.

R1 First scanning line R2 Second scanning line S1 Width S2 Width 11, 21, 31 Containers 12, 22, 32 Jig 12a Rack parts 22a, 32a Hollow parts 13, 23, 33 Structures with conductive parts 13a, 23a , 33a Base material 13b, 23b, 33b Post-irradiation coating 100 Metal wiring manufacturing system 101 Coating mechanism 102 Drying mechanism 103 Laser light irradiation mechanism 104 Developing mechanism 104a First developing section 104b Second developing section 105 Developer recovery mechanism 106 Developer regeneration mechanism

Claims (16)

a coating step of coating a dispersion containing particle components that are metal particles and/or metal oxide particles on the surface of the base material to form a dispersion layer;
a drying step of drying the dispersion layer to form a structure with a dry coating film having the base material and a dry coating film disposed on the base material;
a laser light irradiation step of irradiating the dried coating film with laser light to form metal wiring by drawing;
a developing step of developing and removing an area of the dried coating film other than the metal wiring with a developer;
a recovery step of recovering the used developer generated in the development step;
A method of manufacturing metal wiring, including: The developer contains water and/or an organic solvent,
The method for manufacturing metal wiring according to claim 1, wherein the total amount of metal particles and metal oxide particles in the used developer is 0.0001% by mass or more and 10% by mass or less. The method for manufacturing metal wiring according to claim 2, wherein the organic solvent is an alcohol solvent. The method for manufacturing metal wiring according to claim 3, wherein the alcohol solvent is one or more selected from the group consisting of ethanol, n-butanol, n-heptanol, and n-octanol. The method for manufacturing metal wiring according to claim 1, wherein the developer contains 0.01% by mass or more and 20% by mass or less of a dispersant (A). The method for manufacturing metal wiring according to claim 5, wherein the dispersion contains a dispersant (B), and the main components of the dispersant (A) and the dispersant (B) are the same. The method for manufacturing metal wiring according to claim 5, wherein the dispersant (A) is a phosphorus-containing organic compound. In the laser light irradiation step, the laser light is scanned while overlapping in the line width direction of the scanning line,
2. The method of manufacturing a metal wiring according to claim 1, wherein an overlap ratio, which is a ratio of an overlap portion width to a line width of the scanning line, is in a range of 5% to 99.5%. further comprising a regeneration step of preparing a regenerated dispersion using the used developer collected in the collection step,
The method for manufacturing metal wiring according to claim 1, wherein the regenerated dispersion is used as part or all of the dispersion. The method for manufacturing metal wiring according to claim 9, wherein the used developer is concentrated in the recycling step. A method for producing a dispersion containing particle components that are metal particles and/or metal oxide particles, the method comprising:
A concentration step of concentrating the used developer recovered in the recovery step of the metal wiring manufacturing method according to any one of claims 1 to 10 to obtain a concentrated solution;
an addition step of adding an additive containing water and/or an alcoholic solvent to the concentrated liquid to obtain an additive treatment liquid;
including;
The solid content of the concentrated liquid is 0.1% by mass or more and 80% by mass or less,
A method for producing a dispersion, wherein the solid content of the addition treatment liquid is 0.01% by mass or more and 70% by mass or less. The method for producing a dispersion according to claim 11, wherein the additive further includes one or more selected from the group consisting of propylene glycol, hydrazine, hydrazine hydrate, and a dispersant. further comprising a dispersion step of dispersing the addition treatment liquid,
The method for producing a dispersion according to claim 11, wherein the average particle diameter of the dispersion is 1 nm or more and 500 nm or less. The method for producing a dispersion according to claim 11, wherein the particle component is a copper oxide particle. a coating mechanism that forms a dispersion layer by coating a dispersion containing particle components that are metal particles and/or metal oxide particles on the surface of a base material;
a drying mechanism that dries the dispersion layer to form a structure with a dry coating film having the base material and a dry coating film disposed on the base material;
a laser light irradiation mechanism that irradiates the dried coating film with laser light to form metal wiring by drawing;
a developing mechanism that develops and removes an area of the dried coating film other than the metal wiring with a developer;
a developer recovery mechanism that recovers the used developer generated by the development mechanism;
A metal wiring manufacturing system equipped with The developer contains water and/or an alcoholic solvent,
The metal wiring manufacturing system according to claim 15, wherein the total amount of metal particles and metal oxide particles in the used developer is 0.0001% by mass or more and 10% by mass or less.

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