JP2023114323A - Manufacturing method of structure with conductive pattern - Google Patents

Abstract

To provide a manufacturing method of a structure with a conductive pattern capable of forming the structure with the conductive pattern with a good interlayer adhesion.SOLUTION: A manufacturing method of a structure with a conductive pattern that has a base material and the conductive pattern on the base material includes: a pretreatment step where one or more treatments selected from a group consisting of an organic solvent treatment and an alkaline treatment are performed for the base material; a coating film formation step where after the pretreatment step, a coating film is obtained by applying a dispersion containing a copper oxide-containing particle and/or a copper-containing particle on the base material; a drying step where the coating film is dried; and a plating step where after the drying step, a plating is performed on the coating film. In the drying step, after the drying step and before the plating step and/or before the plating step, a vacuum drying for drying the coating film under a pressure of less than atmospheric pressure is performed.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a structure with a conductive pattern.

A circuit board has a structure in which conductive wiring is provided on a base material. A method of manufacturing a circuit board is generally as follows. First, a photoresist is applied on a base material to which a metal foil is attached. The photoresist is then exposed and developed to obtain the negative features of the desired circuit pattern. Next, the portion of the metal foil not covered with the photoresist is removed by chemical etching to form a pattern. Thereby, a high-performance circuit board can be manufactured. However, the conventional method has drawbacks such as a large number of steps, being complicated, and requiring a photoresist material.

On the other hand, a direct printing technique for directly printing a desired wiring pattern on a base material with a dispersion in which metal or metal oxide particles are dispersed has attracted attention. This technique has a small number of steps, does not require the use of photoresist materials, and is highly productive. However, when metal particles are used, there may be a problem in stability due to oxidation of the metal particles themselves. On the other hand, when metal oxide particles are used, a reduction firing step is required to obtain conductivity, so the substrate that can be used is limited, and a reducing gas is required, resulting in high cost. There is a problem.

With respect to the above, for example, Patent Document 1 describes a method of forming a conductive film in which a conductive film having a predetermined pattern is formed on a substrate. In this method, a metal film containing metal particles is formed on a substrate by a droplet discharge method so as to have a pattern substantially equal to the pattern of the conductive film, and then electroless plating is performed at least once to deposit the metal film. A conductive film is obtained by forming a plated film so as to cover the surface of the film.

JP 2006-128228 A

The method described in Patent Document 1 attempts to form a conductive film having excellent conductivity and reliability by combining pattern formation using metal particles and plating. and/or the adhesion between layers in the conductive film (in the present disclosure, these are collectively referred to as interlayer adhesion).

In view of such circumstances, an object of one aspect of the present invention is to provide a method for manufacturing a conductive patterned structure that can form a conductive patterned structure with good interlayer adhesion.

The present disclosure includes the following aspects.
[1] A method for producing a conductive patterned structure having a substrate and a conductive pattern on the substrate, comprising:
a pretreatment step of subjecting the substrate to one or more treatments selected from the group consisting of organic solvent treatment and alkali treatment;
A coating film forming step of obtaining a coating film by applying a dispersion containing copper oxide-containing particles and / or copper-containing particles to the substrate after the pretreatment step;
A drying step of drying the coating film;
A plating step of plating the coating film after the drying step;
including
In the drying step, after the drying step and before the plating step and/or after the plating step, the coating film is dried under an atmospheric pressure less than atmospheric pressure. A method of manufacturing a structure.
[2] The method for producing a structure with a conductive pattern according to Aspect 1, wherein in the drying step, the reduced-pressure drying and the non-reduced-pressure drying of drying the coating film under an atmospheric pressure equal to or higher than the atmospheric pressure are performed.
[3] The method for producing a conductive patterned structure according to the aspect 1 or 2, further including a reduction step after the drying step and before the plating step.
[4] The method for producing a conductive patterned structure according to Aspect 3, wherein the reduction step is a wet reduction step.
[5] The method for producing a conductive patterned structure according to any one of the above aspects 1 to 4, wherein the pressure in the reduced pressure drying is 90 kPa or less and 0.000001 kPa or more.
[6] The method for producing a structure with a conductive pattern according to any one of the above aspects 1 to 5, wherein the substrate is polyimide.
[7] The conductive patterned structure according to any one of the above aspects 1 to 6, wherein the dispersion contains at least one selected from the group consisting of 1-hexanol, 1-heptanol, and 1-octanol. manufacturing method.

According to one aspect of the present invention, it is possible to provide a method for manufacturing a structure with a conductive pattern, which can form a structure with a conductive pattern having good interlayer adhesion.

FIG. 2 is a schematic cross-sectional view showing the relationship between copper oxide and a phosphate ester salt in a dispersion that can be used in one embodiment of the present invention. It is a cross-sectional schematic diagram which shows the manufacturing procedure of the structure with a conductive pattern which concerns on one aspect|mode of this invention.

Embodiments of the present invention are exemplified below, but the present invention is not limited to these embodiments.

One aspect of the present invention provides a method of manufacturing a conductive patterned structure having a substrate and a conductive pattern on the substrate. In one aspect, the method comprises:
a pretreatment step of subjecting the substrate to one or more treatments selected from the group consisting of organic solvent treatment and alkali treatment;
A coating film forming step of obtaining a coating film by applying a dispersion containing copper oxide-containing particles and / or copper-containing particles to a substrate after the pretreatment step;
A drying step of drying the coating film;
A plating step of plating the coating film after the drying step;
including. In one aspect, in the drying step, after the drying step and before the plating step and/or after the plating step, vacuum drying is performed to dry the coating film under an atmospheric pressure lower than the atmospheric pressure. In one aspect, in the drying step, drying under reduced pressure and drying without reduced pressure in which the coating film is dried under an atmospheric pressure equal to or higher than the atmospheric pressure are performed.
The method according to one aspect further includes a reduction step after the coating film forming step and before the plating step.
Preferred examples of each step are described below.

[Base material]
The substrate used in the present embodiment has a surface on which a coating film is formed, and can be exemplified by a substrate material for a circuit board sheet for forming a wiring pattern. The substrate may be composed of an inorganic material or an organic material, or a combination thereof, and may have an adhesion layer in one aspect.

Examples of inorganic materials include glasses such as soda lime glass, alkali-free glass, borosilicate glass, and quartz glass, and ceramic materials such as alumina.

Examples of organic materials include paper materials such as cellulose, and polymeric materials such as resin films. Polymer materials include polyimide (PI), polyester (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.), polyethersulfone (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), polyetherketone (PEK), polyphthalamide (PPA), polyethernitrile (PENt), polybenzimidazole (PBI), polycarbodiimide, silicone polymer (poly siloxane), 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), poly Vinyl chloride (PVC), polyvinylidene fluoride (PVDF), polyetheretherketone (PEEK), 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 the like. Polyimide (PI), polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are preferred from the viewpoint of flexibility and cost. Among them, polyimide (PI) is preferable because it has an imide bond and can satisfactorily exhibit the effects of the pretreatment step and/or posttreatment step of the present disclosure.

The substrate may be, for example, a composite substrate such as a glass composite substrate, a glass epoxy substrate, a Teflon (registered trademark) substrate, an alumina substrate, a low temperature and low humidity co-fired ceramics (LTCC), a silicon wafer, or the like. .

The thickness of the substrate is preferably 1 μm or more, or 25 μm or more, and preferably 10 mm or less, or 5 mm or less, or 1 mm or less, or 250 μm or less. When the thickness of the substrate is 250 μm or less, the produced electronic device can be made lighter, more space-saving, and more flexible, which is preferable. The substrate may be a housing, and the thickness in this case can be 1 μm or more, 25 μm or more, 100 μm or more, or 200 μm or more, and can be 10 mm or less, or 5 mm or less. Having the thickness of the housing within the above range is advantageous in terms of good mechanical strength and heat resistance after molding the base material.

<Pretreatment process>
The pretreatment step is performed for the purpose of improving the adhesion between the substrate and the copper oxide and/or copper layer. This step is a step of subjecting the substrate to one or more treatments selected from the group consisting of organic solvent treatment and alkali treatment before the coating film forming step. By using two or more of the above treatments in combination, there is a tendency for the effect of improving the adhesion to be better.

Organic solvent treatment is a treatment in which the substrate is brought into contact with an organic solvent. The contact may be immersion of the substrate in an organic solvent, spraying of the organic solvent onto the substrate, etc., preferably immersion of the substrate in the organic solvent. As the organic solvent, a solvent that dissolves or swells the substrate is preferable. By bringing such a solvent into contact with the substrate under controlled conditions, it is possible to dissolve or swell only the surface of the substrate. Specifically, amide solvents such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide; γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone , α-methyl-γ-butyrolactone, etc.; chain ester solvents, such as butyl acetate, ethyl acetate, isobutyl acetate; carbonate solvents, such as ethylene carbonate and propylene carbonate; glycol solvents, such as triethylene glycol. glycol ether solvents such as ethyl cellosolve and butyl cellosolve; glycol ester solvents such as propylene glycol methyl acetate, 2-methyl cellosolve acetate, ethyl cellosolve acetate and butyl cellosolve acetate; phenol, o-cresol, m-cresol, p-cresol, Phenolic solvents such as 3-chlorophenol and 4-chlorophenol; Ketones such as acetophenone, 1,3-dimethyl-2-imidazolidinone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methyl ethyl ketone and acetone sulfone, dimethylsulfoxide and the like; xylene, toluene, chlorobenzene, hexane, benzene and other hydrocarbon solvents; chloroform and other halogen solvents; dimethylaniline and other aniline solvents; tetrahydrofuran, dimethoxyethane, Ether solvents such as diethoxyethane, dibutyl ether and diethylene glycol dimethyl ether; alcohol solvents such as ethanol, 1-butanol, 2-butanol, 1-heptanol and 1-octanol; are preferred. In particular, when using a polyimide base material, N-methylpyrrolidone is most preferable because it can swell the polyimide. Due to the swelling of the substrate, after the dispersion has been applied to the substrate, an anchoring effect works between the layer of copper oxide and/or copper and the substrate, resulting in good adhesion therebetween.

The treatment conditions for the organic solvent treatment may be appropriately adjusted so that only the surface of the substrate is treated. For example, the immersion time is preferably 1 minute or more, or 5 minutes or more, preferably 120 minutes. or less, or 60 minutes or less. The immersion temperature is preferably 10°C or higher, or 20°C or higher, and preferably 100°C or lower, or 60°C or lower.

Alkaline treatment is a treatment in which the substrate is brought into contact with an alkaline treatment agent. The contact may be immersion of the substrate in the alkaline treating agent, spraying of the alkaline treating agent on the substrate, or the like, preferably immersion of the substrate in the alkaline treating agent. Examples of alkaline treating agents include potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, 2-aminoethanol aqueous solution, and diethylenetriamine aqueous solution. The pH of the alkaline treatment agent is preferably 8 or higher, or 9 or higher, or 10 or higher, and preferably 13 or lower. Alkaline treatment chemically modifies the surface of the base material to form a chemical structure capable of firmly holding a layer of copper oxide and/or copper on the surface of the base material. For example, when using a polyimide base material, by cutting the imide bond of the polyimide by alkali treatment, hydrogen bonding by the amide site derived from the imide group, copper coordination to the carboxylate anion generated by the above cutting, etc. The adhesion between the layer of copper oxide and/or copper and the substrate is improved.

The treatment conditions for the alkali treatment may be appropriately adjusted so that only the surface of the substrate is treated. For example, the immersion time is preferably 1 minute or more, or 5 minutes or more, and preferably 120 minutes or less. , or 60 minutes or less. The immersion temperature is preferably 10°C or higher, or 20°C or higher, and preferably 100°C or lower, or 60°C or lower.

<Coating film forming process>
In this step, a coating film is obtained by coating a substrate with a dispersion containing copper oxide-containing particles and/or copper-containing particles (also simply referred to as a dispersion in the present disclosure).

[Dispersion containing copper oxide-containing particles and/or copper particles]
The dispersion contains copper oxide-containing particles and/or copper particles. The copper oxide-containing particles are typically made of copper oxide, but may contain other components as long as the effects of the present invention are not impaired. Similarly, the copper-containing particles are typically made of copper, but may contain other components as long as the effects of the present invention are not impaired. The dispersion may further contain a dispersion medium, a dispersing agent and/or a reducing agent.

(copper oxide or copper)
Copper oxides include cuprous oxide (Cu ₂ O) and cupric oxide (CuO), with cuprous oxide being preferred. Cuprous oxide is advantageous in that it is less expensive than precious metals such as silver because it is copper and is less likely to migrate. As copper oxide or copper, commercially available products or synthetic can be used.

For example, the method for synthesizing cuprous oxide includes the following method.
(1) Add water and a copper acetylacetonato complex to a polyol solvent, heat and dissolve the organocopper compound once, then add water necessary for the reaction, and raise the temperature to the reduction temperature of the organocopper. A method of heating and reducing by heating.
(2) A method of heating an organocopper compound (eg, copper-N-nitrosophenylhydroxyamine complex) at a high temperature of about 300° C. in the presence of a protective agent such as hexadecylamine in an inert atmosphere.
(3) A method of reducing a copper salt dissolved in an aqueous solution with hydrazine.
Among these, the method (3) is preferable because the operation is simple and cuprous oxide having a small average particle size can be obtained.

Methods for synthesizing cupric oxide include the following methods.
(1) A method of adding sodium hydroxide to an aqueous solution of cupric chloride or copper sulfate to generate copper hydroxide, followed by heating.
(2) A method of thermally decomposing copper nitrate, copper sulfate, copper carbonate, copper hydroxide or the like by heating to a temperature of about 600° C. in air.
Among them, the method (1) is preferable because cupric oxide having a small particle size can be obtained.

After completion of copper oxide synthesis, the product solution (as supernatant) and copper oxide (as precipitate) may be separated using known methods such as centrifugation. As described above, copper oxide-containing particles can be obtained.

In preparing the dispersion, the below-described dispersion medium and optionally the below-described dispersant may be added to the copper oxide-containing particles and/or the copper-containing particles, and the mixture may be stirred and dispersed by a known method such as a homogenizer. Depending on the dispersion medium, copper oxide may be difficult to disperse and may be insufficiently dispersed. After dispersing, the copper oxide can be well dispersed in the desired dispersion medium by substituting with a desired dispersion medium and concentrating to a desired concentration. Examples of the method include concentration using a UF membrane, a method of repeating dilution and concentration using an appropriate dispersion medium, and the like. Thus, a dispersion containing copper oxide-containing particles and/or copper-containing particles can be obtained.

In one aspect, the average particle size of the copper oxide-containing particles and copper-containing particles is preferably 1 nm or more, or 3 nm or more, or 5 nm or more, and preferably 100 nm or less, or 50 nm or less, or 40 nm or less. Here, the average particle size is the particle size at the time of dispersion in a dispersion, and is a value when measured by a cumulant method (using, for example, FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.). That is, the average particle size is not limited to the primary particle size, and may be the secondary particle size. When the average particle diameter is 100 nm or less, the pattern can be formed at a low temperature, which is preferable in terms of widening the versatility of the base material and tending to facilitate the formation of a fine pattern on the base material. Further, when the average particle size is 1 nm or more, the dispersion stability of the copper oxide-containing particles and the copper-containing particles in the dispersion is good, the long-term storage stability of the dispersion is good, and a uniform thin film It is preferable in that it can be produced. In one aspect, the particles in the dispersion are substantially only copper oxide-containing particles and/or copper-containing particles. In this case, the value of the average particle size measured for the dispersion can be regarded as the average particle size of the copper oxide-containing particles and the copper-containing particles.

In one aspect, the copper oxide-containing particles and/or copper-containing particles comprise hydrazine. Hydrazine may form a hydrate (that is, hydrazine in the present disclosure is a concept that also includes hydrazine hydrate). Hydrazine may be a copper oxide-containing particle or a residue of hydrazine used as a reducing agent for copper oxide during the production of the copper-containing particles, or may be added separately during the production of the particles.

The content of copper oxide in the copper oxide-containing particles and the content of copper in the copper-containing particles are preferably 10% by mass or more, or 30% by mass or more, or 50% by mass or more, or 70% by mass or more. Yes, preferably 100% by mass or less, or 99% by mass or less, or 98% by mass or less.

The content of hydrazine in the copper oxide-containing particles or in the copper-containing particles is preferably 0.000000001% by mass or more, or 0.0000001% by mass or more, or 0.0000005% by mass or more, and preferably 10% by mass % or less, or 5% by mass or less, or 1% by mass or less.

The mass ratio of hydrazine to copper oxide in the copper oxide-containing particles or copper in the copper-containing particles is preferably 0.00001 or more, or 0.0001 or more, or 0.0002 or more, preferably 1 or less, or 0.1 or less, or 0.01 or less.

The mass ratio of copper oxide, the mass ratio of copper, or the total mass ratio of copper oxide and copper in 100% by mass of the dispersion is preferably 5% by mass or more, or 10% by mass or more, or 15% by mass or more. and preferably 60% by mass or less, or 55% by mass or less, or 50% by mass or less.

(dispersion medium)
The dispersion medium is capable of dispersing the copper oxide-containing particles and/or the copper-containing particles. In one aspect, the dispersion medium can dissolve the dispersant. From the viewpoint of forming a conductive pattern using a dispersion, the volatility of the dispersion medium affects workability. Therefore, it is preferable that the dispersion medium is suitable for the conductive pattern forming method, for example, the coating method (especially printing). That is, it is preferable to select the dispersion medium in accordance with dispersibility and printing workability.

As the dispersion medium, alcohols (monohydric alcohol and polyhydric alcohol (eg, glycol)), ethers of alcohol (eg, glycol), esters of alcohol (eg, glycol), and the like can be used. Specific examples of dispersion media include 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, and propylene glycol. Tertiary butyl ether, dipropylene glycol monomethyl ether, ethylene glycol butyl ether, ethylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2-pentanediol, 2-methylpentane -2,4-diol, 2,5-hexanediol, 2,4-heptanediol, 2-ethylhexane-1,3-diol, diethylene glycol, hexanediol, octanediol, triethylene glycol, tri-1,2- Propylene glycol, glycerol, ethylene glycol monohexyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl acetate, diethylene glycol monoethyl ether acetate, methanol, ethanol, n-propanol, i-propanol, n-butanol, i- butanol, 2-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol, 2-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, 1-hexanol, 2-hexanol, 2-ethylbutanol, 1-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, 1-octanol, 2-octanol, n-nonyl alcohol, 2,6 Dimethyl-4-heptanol, n-decanol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, diacetone alcohol and the like. These may be used alone or in combination of multiple types. Depending on the coating method, consideration should be given to evaporativity, equipment used for coating, solvent resistance of the base material (i.e., base material to be coated), etc. and select. The dispersion is preferably 1- One or more dispersion media selected from the group consisting of hexanol, 1-heptanol, and 1-octanol, more preferably one or more dispersion media selected from the group consisting of 1-heptanol and 1-octanol including.

The boiling point of the dispersion medium is preferably as high as possible from the viewpoint of improving printing continuity. On the other hand, the boiling point is preferably 400° C. or lower, more preferably 300° C. or lower, and even more preferably 250° C. or lower, from the viewpoint of obtaining a good function as a dispersion medium.

The content of the dispersion medium is preferably 30% by mass or more, or 40% by mass or more, or 50% by mass or more, and preferably 95% by mass or less, or 90% by mass or less, in the entire dispersion.

(dispersant)
As the dispersant, a compound capable of dispersing copper oxide-containing particles and/or copper-containing particles in a dispersion medium can be used. The number average molecular weight of the dispersant is preferably 300 or more, or 350 or more, or 400 or more, preferably 300,000 or less, or 200,000 or less, or 150,000 or less. Note that the number average molecular weight of the present disclosure is a value determined in terms of standard polystyrene using gel permeation chromatography. When the number average molecular weight is 300 or more, the insulating property is excellent and tends to contribute greatly to the dispersion stability of the dispersion. The dispersant preferably has groups having an affinity for the copper oxide-containing particles and/or the copper-containing particles, especially the copper oxide-containing particles. From this point of view, the dispersant preferably comprises or is a phosphorus-containing organic substance, or comprises or is a phosphate ester, or comprises or is a polymeric phosphate ester, or comprises or is a polymeric phosphate ester. Acid ester. As the polymer phosphate ester, for example, the following formula (1):

(Wherein l is an integer from 1 to 10000, m is an integer from 1 to 10000, and n is an integer from 1 to 10000.)
The structure represented by is excellent in adsorption to copper oxide, especially cuprous oxide, and adhesion to substrates, and is therefore preferable.
In chemical formula (1), l is more preferably 1-5000, still more preferably 1-3000.
In the chemical formula (1), m is more preferably 1-5000, more preferably 1-3000.
In the chemical formula (1), n is more preferably 1-5000, still more preferably 1-3000.

In one aspect, the decomposition temperature of the phosphorus-containing organic substance is preferably 600° C. or lower, more preferably 400° C. or lower, and even more preferably 200° C. or lower. The decomposition temperature may be 50° C. or higher, 80° C. or higher, or 100° C. or higher from the viewpoint of facilitating the selection of a dispersant that is excellent in improving the dispersion stability of the dispersion. In one aspect, the boiling point of the phosphorus-containing organic substance is preferably 300° C. or lower, more preferably 200° C. or lower, and even more preferably 150° C. or lower. The boiling point may be 30°C or higher, or 50°C or higher, or 80°C or higher. In the present disclosure, decomposition temperature is a value measured by thermogravimetric differential thermal analysis.

In one aspect, the phosphorus-containing organic substance is preferable in that peeling of the coating film and the plating layer is less likely to occur when plating is performed.

A known dispersant may be used. For example, polymers having basic groups, such as salts of long-chain polyaminoamides and polar acid esters, unsaturated polycarboxylic acid polyaminoamides, polycarboxylic acid salts of polyaminoamides, salts of long-chain polyaminoamides and acid polymers, etc. is mentioned. Also included are alkylammonium salts, amine salts and amidoamine salts of polymers such as acrylic (co)polymers, modified polyester acids, polyether ester acids, polyether carboxylic acids and polycarboxylic acids. A commercially available dispersant can also be used as such a dispersant.

Examples of the commercially available products include DISPERBYK (registered trademark)-101, DISPERBYK-102, DISPERBYK-110, DISPERBYK-111, DISPERBYK-112, DISPERBYK-118, DISPERBYK-130, DISPERBYK-140, DISPERBYK-142, DISPERBYK- 145, DISPERBYK-160, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-2155, DISPERBYK-2163, DISPERBYK-2164, DISPERBYK-180, DISPERBYK-2000, DISPERBYK-2025, DISP ERBYK-2163, DISPERBYK-2164, BYK-9076, BYK-9077, TERRA-204, and 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, and Floren KTG-2400 (manufactured by Kyoeisha Chemical Co., Ltd.), ED-117, ED-118, ED-212, ED-213, ED-214, ED-216, ED-350, and ED-360 (manufactured by Kusumoto Kasei Co., Ltd.), Plysurf M208F, and Plysurf DBS (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). These may be used alone, or may be used in combination of multiple types.

The acid value (mgKOH/g) of the dispersant is preferably 20 or more, or 30 or more, and preferably 130 or less, or 100 or less. When the acid value is within the above range, the dispersion stability of the dispersion is good, which is preferable. In particular, when the average particle size of the copper oxide-containing particles and/or the copper-containing particles is small, the acid value within the above range is effective. Specifically, BYK Chemie "DISPERBYK-102" (acid value 101), "DISPERBYK-140" (acid value 73), "DISPERBYK-142" (acid value 46), "DISPERBYK-145" (acid value 76 ), “DISPERBYK-118” (acid value 36), “DISPERBYK-180” (acid value 94) and the like are preferred.

Further, the difference between the amine value (mgKOH/g) and the acid value of the dispersant ([amine value]−[acid value]) is preferably −50 or more and 0 or less. The amine number indicates the total amount of free base and free base-derived moieties, and the acid number indicates the total amount of free fatty acids and free fatty acid-derived moieties. Amine value and acid value are each measured by a method based on JIS K 7700 or ASTM D2074. When the value of [amine value] - [acid value] is -50 or more and 0 or less, the dispersion stability of the dispersion is good, which is preferable. The value of [amine value]-[acid value] is more preferably -40 or more and 0 or less, and still more preferably -20 or more and 0 or less.

The content of the dispersing agent is proportional to the amount of copper oxide and copper, and should be adjusted in consideration of the required dispersion stability. The mass ratio of the dispersant to copper oxide and copper in the dispersion (mass of dispersant/total mass of copper oxide and copper) is preferably 0.0050 or more, or 0.050 or more, or 0.10 or more. , preferably 0.30 or less, or 0.25 or less, or 0.23 or less. The amount of the dispersant affects the dispersion stability of the dispersion. If the amount is small, the copper oxide-containing particles and/or the copper-containing particles tend to aggregate, and if the amount is large, the dispersion stability of the dispersion tends to improve. However, when the content of the dispersant in the dispersion is 35% by mass or less, the influence of the residue derived from the dispersant can be suppressed in the copper-containing film obtained after the plating step, and the electrical conductivity can be improved. In one aspect, the amount of dispersant in 100% by weight of the dispersion is preferably 0.5% by weight or more, or 0.8% by weight or more, or 1.0% by weight or more, preferably 35% by weight. %, or 30% by mass or less, or 25% by mass or less.

(reducing agent)
When the dispersion contains copper oxide-containing particles, the dispersion may contain a reducing agent. Reducing agents include hydrazine, sodium, sodium borohydride, potassium iodide, sulfite, sodium thiosulfate, formic acid, oxalic acid, ascorbic acid, iron (II) sulfide, tin (II) chloride, and diisobutylaluminum hydride. , carbon, etc., preferably hydrazine. Hydrazine may be in the form of hydrazine hydrate (that is, hydrazine in the present disclosure is a concept that also includes hydrazine hydrate). By containing hydrazine in the dispersion, hydrazine contributes to the reduction of copper oxide, especially cuprous oxide, in the plating process, and a reduced copper layer (as a copper-containing film) with lower resistance can be formed. Hydrazine is also advantageous in maintaining the dispersion stability of the dispersion, and is also preferable from the viewpoint of improving productivity during plating. Hydrazine in the dispersion may be present as a component in the copper oxide-containing particles and/or separately from the copper oxide-containing particles.

The content of the reducing agent in the dispersion (in the case of a hydrate, the amount excluding water of hydration) is proportional to the amount of copper oxide and should be adjusted in consideration of the required reducibility. In one aspect, the mass ratio of reducing agent to copper oxide in the dispersion (reducing agent mass/copper oxide mass) is preferably 0.0001 or more, preferably 0.1 or less, or 0.05 or less, Or it is 0.03 or less. When the mass ratio of the reducing agent is 0.0001 or more, the dispersion stability of the dispersion is good and the resistance of the reduced copper layer is low. Good properties.

Two or more reducing agents may be used in combination. For example, when hydrazine and a reducing agent other than hydrazine are used together, the total content of hydrazine and a reducing agent other than hydrazine in the dispersion is proportional to the amount of copper oxide and adjusted in consideration of the required reducing property. Better to In one aspect, the total mass ratio of hydrazine and a reducing agent other than hydrazine to copper oxide in the dispersion (total mass of reducing agent/mass of copper oxide) is preferably 0.0001 or more, preferably 0.1. or less, or 0.05 or less, or 0.03 or less. When the total mass ratio of the reducing agent is 0.0001 or more, the dispersion stability of the dispersion is good and the resistance of the reduced copper layer is low. Good long-term stability.

Dispersion is prepared by mixing ingredients and using a mixer method, ultrasonic wave method, three-roll method, two-roll method, attritor, homogenizer, Banbury mixer, paint shaker, kneader, ball mill, sand mill, rotation/revolution mixer, etc. It can be manufactured by dispersing treatment with The viscosity of the dispersion can be designed according to the intended mode of application. For example, the viscosity of the dispersion for screen printing is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, still more preferably 200 mPa·s or more, preferably 50000 mPa·s or less, more preferably 10000 mPa·s or less. and more preferably 5000 mPa·s or less. The viscosity of the dispersion is a value measured at 23° C. using a cone-plate type rotational viscometer.

(Relationship between copper oxide and dispersant in dispersion)
FIG. 1 is a schematic cross-sectional view showing the relationship between copper oxide and a phosphate ester salt in a dispersion (copper oxide ink) that can be used in one embodiment of the present invention. Referring to FIG. 1, in one aspect of the present invention, when copper oxide ink 100 contains copper oxide 12 and phosphate ester salt 13 (an example of a phosphate ester as a dispersant), the surroundings of copper oxide 12 are , the phosphate ester salt 13 surrounds the phosphorus 13a toward the inside and the ester salt 13b toward the outside. Since the phosphate ester salt 13 exhibits electrical insulating properties, the electrical conduction between the copper oxides 12 adjacent to each other is prevented by the phosphate ester salt 13 . In addition, the phosphate ester salt 13 suppresses aggregation of the copper oxide ink 100 due to the steric hindrance effect. Therefore, although the copper oxide 12 is a semiconductor (that is, has some degree of conductivity), the copper oxide ink 100 exhibits electrical insulation because it is coated with the phosphate ester salt 13 that exhibits electrical insulation.

On the other hand, when the copper oxide 12 is reduced to copper, such as in a plating process, a conductive pattern area having excellent electrical conductivity is formed. When a phosphorus-containing organic substance is used as the dispersant, elemental phosphorus remains in the conductive pattern region. The elemental phosphorus exists as at least one of elemental elemental phosphorus, phosphorus oxide, and phosphorus-containing organic matter. However, since such residual phosphorus elements are usually segregated in the conductive pattern region, there is no risk of increasing the resistance of the conductive pattern region.

[Formation of coating film]
As a method for applying the dispersion, inkjet printing, screen printing, intaglio direct printing, intaglio offset printing, flexographic printing, offset printing, or the like can be used. Coating can be performed using methods such as die coating, spin coating, slit coating, bar coating, knife coating, spray coating, and dip coating. The application method is preferably inkjet printing. The ink-jet method does not require a printing plate and does not allow extra components to adhere between the wirings, so it is excellent in migration resistance.

The layer thickness of the coating film after drying is preferably 1 nm or more, 10 nm or more, or 100 nm or more, and preferably 10000 nm or less, or 8000 nm or less, or 7000 nm or less, in that a uniform conductive pattern can be formed. is.

The substrate may have an adhesion layer (also referred to as an ink-receiving layer), and the coating film may be formed by printing the dispersion onto the adhesion layer. The compound forming the adhesion layer (also referred to as “coating compound” in the present disclosure) preferably has —OH groups and/or Ar—O structure and/or MO structure. Here, Ar represents an aromatic structure and M represents a metal atom. When the adhesion layer is present, a layer of copper oxide and/or copper can be formed on the base material with good adhesion, and heat is difficult to be transmitted to the main body of the base material. PET) resin can also be used as the base material, which is advantageous in terms of versatility.

The —OH group is particularly an aromatic hydroxyl group (that is, an —OH group that constitutes an —Ar—OH group) or a hydroxyl group that is bonded to a metal atom (that is, an —OH group that constitutes a —M—OH group) is preferred. —OH groups constituting —Ar—OH groups and —M—OH groups are highly active, and provide adhesion between the adhesion layer and the substrate body, and/or adhesion between the copper oxide and/or copper layer and the adhesion layer. It tends to be excellent in adhesion.

The aromatic structure (Ar) in the —Ar—OH group includes, for example, aromatic hydrocarbons such as benzene, naphthalene, anthracene, tetracene, pentacene, phenanthrene, pyrene, perylene, and triphenylene; Heteroaromatic compounds such as furan, pyridine, pyrazole, imidazole, pyridazine, pyrimidine, and pyrazine; be done. The number of electrons contained in the π-electron system of the aromatic structure is preferably 22 or less, more preferably 14 or less, even more preferably 10 or less. When the number of electrons contained in the π electron system is 22 or less, the crystallinity does not become too high, and it becomes easy to obtain a flexible and highly smooth adhesion layer. The aromatic structure may have some of the hydrogens attached to the aromatic ring replaced by functional groups. Functional groups include, for example, halo groups, alkyl groups (e.g., methyl group, isopropyl group, tertiary butyl group, etc.), aryl groups (e.g., phenyl group, naphthyl group, etc.), heteroaromatic groups (thienyl group, etc.), haloaryl groups (eg, pentafluorophenyl group, 3-fluorophenyl group, 3,4,5-trifluorophenyl group, etc.), alkenyl groups, alkynyl groups, amido groups, acyl groups, alkoxy groups (eg, methoxy groups, etc.), aryloxy groups (eg, phenoxy group, naphthoxy group, etc.), haloalkyl groups (eg, perfluoroalkyl groups, etc.), thiocyano groups, hydroxyl groups and the like. As the -Ar-OH group, a hydroxyphenyl group (-Ph-OH) is particularly preferred.

The metal atom (M) in the -M-OH group includes silicon, silver, copper, aluminum, zirconium, titanium, hafnium, tantalum, tin, calcium, cerium, chromium, cobalt, holmium, lanthanum, magnesium, manganese, molybdenum, Nickel, antimony, samarium, terbium, tungsten, yttrium, zinc, indium, and the like. A --Si--OH group or --Zr--OH group is preferred when the adhesion layer requires insulation, and a ---Ti--OH group or --Zn--OH group is preferred when the adhesion layer requires conductivity.

The aromatic structure (Ar) in the Ar—O structure may be a structure obtained by removing one or more hydrogen atoms from the same aromatic compound as the aromatic compound exemplified for the —Ar—OH group. A Ph—O structure is particularly preferable as the Ar—O structure.

As the metal atom in the MO structure, the same metal atoms as those exemplified for the -M-OH group can be used. In particular, Si--O structure, Ti--O structure, Zn--O structure and Zr--O structure are preferable as the MO structure.

Examples of coating compounds having a Si—O structure include silica-based compounds (eg, silicon dioxide (SiO ₂ )) and silicone-based compounds (eg, polysiloxanes, such as alkylpolysiloxanes, such as dimethylpolysiloxanes).

Examples of coating compounds include polyimide, polyester (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.), polyethersulfone (PES), polycarbonate (PC), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB). , polyacetal, polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyetherketone (PEK), polyphthalamide ( PPA), polyether nitrile (PENt), polybenzimidazole (PBI), polycarbodiimide, silicone polymer (polysiloxane), polymethacrylamide, nitrile rubber, acrylic rubber, polyethylene tetrafluoride, epoxy resin, phenolic resin, melamine resin , urea resin, polymethyl methacrylate resin (PMMA), polybutene, polypentene, ethylene-propylene copolymer, ethylene-butene-diene copolymer, polybutadiene, polyisoprene, polychloroprene, ethylene-propylene-diene copolymer, Nitrile rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, urethane rubber, butyl rubber, fluororubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer, polyethylene (PE), polyvinyl chloride ( PVC), polyvinylidene fluoride (PVDF), polyether ether ketone (PEEK), phenol novolak resin, benzocyclobutene, polyvinylphenol, polychloropyrene, polyoxymethylene, polysulfone (PSF), etc., the above -OH group, Ar Examples include materials into which one or more of the —O structure and the MO structure are introduced. Phenolic resins, phenol novolac resins, polyvinylphenols, and polyimides are particularly preferred as coating compounds.

The upper limit of the thickness of the adhesion layer is not particularly limited, but is preferably 20 μm or less, more preferably 5 μm or less, and still more preferably 1 μm or less, and the lower limit is preferably 0.01 μm or more, more preferably 0.05 μm or more. More preferably, it is 0.2 μm or more.

<Drying process>
In this step, the coating film obtained in the coating film forming step is dried. In the method of the present disclosure, vacuum drying for drying the coating film under atmospheric pressure below atmospheric pressure is performed in the drying step after the drying step and before the plating step and/or after the plating step. In one aspect, in the drying step, drying under reduced pressure and drying without reduced pressure in which the coating film is dried under an atmospheric pressure equal to or higher than the atmospheric pressure are performed.

Vacuum drying and non-vacuum drying are processes for vaporizing the dispersion medium, respectively. In the present disclosure, vacuum drying means drying under an atmospheric pressure that is less than atmospheric pressure (1 atmosphere) at the temperature during drying, and non-vacuum drying is an atmosphere that is 1 atmosphere or more at the temperature during drying. means drying under pressure. The dispersion medium in the coating film typically has a high boiling point and/or has a hydroxyl group, thereby easily forming a hydrogen bond. Therefore, using at least vacuum drying for drying the coating film is advantageous in that the dispersion medium can be satisfactorily removed and the interlayer adhesion can be improved. Drying under reduced pressure is advantageous for interlayer adhesion and its reproducibility (that is, stable expression of good interlayer adhesion) in that the solvent adsorbed to the interface between the substrate and the coating film can be removed satisfactorily. .

When non-vacuum drying is further performed in addition to vacuum drying, the removal of the dispersion medium at the interface between the substrate and copper oxide or copper further progresses, thereby further increasing the adhesion between the substrate and copper oxide or copper. When both vacuum drying and non-vacuum drying are performed, either vacuum drying or non-vacuum drying may be performed first, but from the viewpoint of drying efficiency, non-vacuum drying is preferably performed before vacuum drying.

In the method of the present disclosure, organic solvent treatment and/or alkali treatment are performed in the pretreatment step, so these chemicals usually remain on the substrate after the pretreatment step. Drying under reduced pressure is advantageous in terms of improving interlayer adhesion and reproducibility, since the above-mentioned chemicals can also be satisfactorily removed. That is, using the pretreatment step and the reduced-pressure drying step together is advantageous in improving the adhesion between the substrate and copper oxide or copper.

[Drying under reduced pressure]
In the vacuum drying that can be performed at each of the timings described above, the dispersion medium may be vaporized at room temperature (20° C. in one aspect), or under heating in an oven or the like. The temperature for drying under reduced pressure is preferably 20° C. or higher, or 30° C. or higher, or 40° C. or higher, or 50° C. or higher from the viewpoint of drying efficiency, and is preferably 150° C. in consideration of the heat resistance of the substrate. or 140° C. or lower, or 130° C. or lower, or 120° C. or lower, or 110° C. or lower, or 100° C. or lower.

The pressure in the reduced pressure drying is preferably 90 kPa or less, 55 kPa or less, or 1 kPa or less from the viewpoint of good removal of the dispersion medium in the coating film, and preferably 0.000001 kPa or more, or from the cost viewpoint. It is 0.00001 kPa or more, or 0.0001 kPa or more. Decompression may be performed by a decompression pump or the like. Further use of a desiccant such as silica gel in vacuum drying is preferable from the viewpoint of further enhancing the effect of drying.

The drying time under reduced pressure is preferably 10 minutes or more, or 30 minutes or more from the viewpoint of good removal of the dispersion medium in the coating film. A longer drying time under reduced pressure is advantageous, but there is a tendency that the desired dispersion medium removal can be satisfactorily achieved with a drying time of about 10 days, so from the viewpoint of cost, preferably 10 days or less, or 3 days or less. is.

[Non-vacuum drying]
Non-reduced pressure drying may be heat drying, drying with a desiccant (such as silica gel), or the like, and heat drying is preferable from the viewpoint of drying efficiency. The temperature for non-vacuum drying is preferably 30°C or higher, or 40°C or higher, or 50°C or higher, or 60°C or higher, and preferably 150°C or lower, or 140°C or lower, or 130°C or lower, or 120°C or higher. °C or lower, or 110 °C or lower, or 100 °C or lower. The pressure for non-vacuum drying is typically 1 atmosphere (ie atmospheric pressure). The non-vacuum drying time is preferably 10 minutes or more, or 30 minutes or more, and preferably 10 days or less, or 3 days or less.

In vacuum drying and optionally non-vacuum drying, nitrogen or hydrogen-mixed nitrogen (for example, a mixed gas containing about 3% by volume of hydrogen in 100% by volume of hydrogen and nitrogen in total) may be introduced into the system.

<Reduction process>
If the dispersion contains copper oxide-containing particles, the method of the present disclosure may include a reduction step. The reduction step may be performed simultaneously with the drying step or the plating step, or may be performed separately from these steps. In one aspect, the reduction step is performed after the drying step and before the plating step. In the reduction step, a copper-containing film is obtained by reducing a copper oxide-containing film that is a coating film (in one aspect, the coating film after the drying step). In this step, the copper oxide-containing particles in the copper oxide-containing film are reduced to generate copper, and the copper itself is fused and integrated to form a copper-containing film (reduced copper layer). However, when plating the copper oxide-containing particles as they are, this step may be omitted. As a reduction method, a method of reducing at a temperature of 100 ° C. or higher and 500 ° C. or lower in a nitrogen atmosphere, a hydrogen mixed nitrogen (for example, a mixed gas containing about 3% by volume of hydrogen in a total of 100% by volume of hydrogen and nitrogen) Among them, a method of reducing at a temperature of 100° C. or higher and 500° C. or lower, a method of reducing by irradiating laser light, a method of immersing a copper oxide-containing film in a reducing solution (that is, wet reduction), and the like can be mentioned. In one aspect, the reduction step is a step of immersing the copper oxide-containing film in a reducing solution, that is, a wet reduction step.

[Reduction by laser light]
As a reduction method using laser light, a known laser light irradiation device having a laser light irradiation unit may be used. A laser beam is preferable in that high-intensity light can be exposed for a short period of time, and the dried coating film formed on the base material can be raised to a high temperature for a short period of time and baked. The laser beam method is advantageous in that the firing time can be shortened, so that the base material is less damaged and can be applied to base materials with low heat resistance (for example, resin film substrates). In addition, the laser light 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 light method, exposure by beam scanning is possible, so it is easy to adjust the exposure range. Irradiation (drawing) is possible.

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

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

Laser light is preferably applied to the dry coating film through a galvanometer scanner. Metal wiring of any shape can be obtained by scanning the dry coating film with laser light using a galvanometer scanner.

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

[Wet reduction]
In wet reduction, a reducing liquid containing a reducing agent is used. The reducing agent may be inorganic or organic. Examples of inorganic reducing agents include sodium borohydride, sulfur dioxide, sodium nitrite, aluminum metal, cerium chloride, sodium thiosulfate, etc. Examples of organic reducing agents include hydrazine, formaldehyde, methanol, citric acid and their salts, oxalic acid and its salts, formic acid and its salts, glycerin, glucose, ethylene glycol, glycine and its derivatives, L-ascorbic acid and its salts, thioglycolic acid, hydroxylamine hydrochloride, hydroquinone, hydrosulfite, erythorbic acid, Examples include erythorbate, thiourea, tin-based reducing agents, iron-based reducing agents, and zinc-based reducing agents.

Glycine derivatives include, for example, N-[N-(benzyloxycarbonyl)glycyl]-L-proline, N-carbobenzoxyglycine 4-nitrophenyl, L-(2-chlorophenyl)glycine chloride, BOC-NA-methyl -L-phenylglycine, ethyl acetylamino(cyano)acetate, xylenol orange, D-(-)-2-(2,5-dihydrophenyl)glycine, Cbz-cyclohexyl-L-glycine, (R)-α -[(3-ethoxy-1-methyl-3-oxo-1-propenyl)amino]benzene potassium acetate, N-(diphenylmethylene)glycine tert-butyl, D-propargylglycine, (S)-α-amino-4 -fluorobenzeneacetic acid, N-(tert-butoxycarbonyl)-L-2-cyclohexylglycine, glycine methyl hydrochloride, D-2-allylglycine hydrochloride, (S)-2-cyclohexyl-2-aminoacetic acid, (2S )-N-[[(carboxymethyl)aminocarbonyl]methyl]-2-amino-4-methylpentanamide, (R)-2-amino-4-pentynoic acid, (R)-N-BOC-propargylglycine, N-benzylglycine, (S)-N-BOC-α-allylglycine dicyclohexylamine, BOC-D-cyclopropylglycine, N-(tert-butoxycarbonyl)-D-2-phenylglycine, (R)-(- )-N-(3,5-dinitrobenzoyl)-α-phenylglycine, L-2-chlorophenylglycine, 4-fluoro-D-phenylglycine, BOC-L-cyclopropylglycine, glycinebenzyl p-toluenesulfonate, (S)-N-BOC-allylglycine, (R)-N-BOC-allylglycine, (R)-4-hydroxy-α-[(3-methoxy-1-methyl-3-oxo-1-propenyl) amino]benzene potassium acetate, N-[(9H-fluoren-9-ylmethoxy)carbonyl]-D-2-phenylglycine, DL-leucylglycylglycine, glycylglycylglycine, N-(tert-butoxycarbonyl)- L-propargylglycine, 2-amino-2-[3-(trifluoromethyl)phenyl]acetic acid, (S)-N-BOC-3-hydroxyadamantylglycine, N-[tris(hydroxymethyl)methyl]glycine, 2 -propargyl-L-glycine, N-(triphenylmethyl)glycine, N-benzylglycineethyl, 2-(2-oxo-2-hydroxyethylamino)benzoic acid, FMOC-D-allylglycine, L-2-( 4-chlorophenyl)glycine, D-2-cyclohexylglycine, N,N-di(2-hydroxyethyl)glycine, N-(benzyloxycarbonyl)-D-phenylglycine, N-[(9H-fluoren-9-ylmethoxy ) carbonyl]-L-2-phenylglycine, benzyloxycarbonylamino(dimethoxyphosphinyl)methyl acetate, N-(tert-butoxycarbonyl)glycinemethyl, 4-(trifluoromethyl)phenylglycine, glycyl-DL-leucine , N-tosylglycine, N-(tert-butoxycarbonyl)-D-2-cyclohexylglycine, N-formylglycine, N-T-butylglycine HCL, (R)-2-allylglycine, H-glycine benzyl ester hydrochloride salt, N-carbobenzoxy-L-2-phenylglycine, ethyl (diphenylmethyleneamino)acetate (diphenylmethyleneamino)ethyl acetate, oxphenicine, L-methionylglycine, (4-hydroxyphenyl)(amino)acetic acid , (R)-α-aminobenzene methyl acetate hydrochloride, L-α-cyclopropylglycine, N-benzylglycine hydrochloride, D-cyclopropylglycine, α-amino-4-fluorobenzeneacetic acid, glycine tert-butyl hydrochloride, N-(tert-butoxycarbonyl)-2-phosphonoglycine trimethyl, N-[(9H-fluoren-9-ylmethoxy)carbonyl]glycine, N-(4-hydroxyphenyl)glycine, DL-2-( 4-chlorophenyl)glycine, L-α-cyclohexylglycine, ethyl glycine hydrochloride, benzyl N-[(methoxycarbonyl)methyl]carbamate, DL-2-(2-chlorophenyl)glycine, L-cyclopentylglycine, N-BOC -2-(4′-chlorophenyl)-D-glycine, BOC-L-cyclopentylglycine, D-(2-chlorophenyl)glycine chloride, N-phthaloylglycine, N-formylglycine ethyl, N-(tert-butoxy carbonyl)-L-2-phenylglycine, N-(tert-butoxycarbonyl)glycine, N-(2-aminoethyl)glycine, N-phenylglycine, N,N-dimethylglycine hydrochloride, (S)-N- FMOC-allylglycine, D-(-)-2-(4-hydroxyphenyl)glycine, L(+)-2-phenylglycine methyl ester hydrochloride, trisodium edetate, N-(tert-butoxycarbonyl)glycyl glycine, ethyl (2R)-2-amino-2-phenylacetate/hydrochloride, ethyl N-acetylglycine, L-leucylglycine hydrate, L-2-allylglycine hydrochloride, and the like.

As the glycine derivative, a compound having a structure having two or more hydroxy groups in the molecule is suitable. The use of a glycine derivative having two or more hydroxyl groups is advantageous in that the speed of the subsequent plating process can be increased and the peeling of the film is less likely to occur during the process. Preferred examples of compounds having a structure having two or more hydroxy groups in the molecule are N,N-di(2-hydroxyethyl)glycine, N-[tris(hydroxymethyl)methyl]glycine, and the like.

When the reduction step is a wet reduction step, the reducing agent concentration in the reducing liquid is, for example, 1.0 g/L or more, or 3.0 g/L or more, from the viewpoint of a good reduction rate and stable reduction, or 5.0 g/L or more, or 10.0 g/L or more, such as 600 g/L or less, or 570 g/L or less, or 550 g/L or less, or 520 g/L or less, or 500 g/L or less. It's okay.

The concentration of the reducing agent in the reducing liquid is, for example, 0.1% by mass or more, or 0.3% by mass or more, or 0.5% by mass or more, or 1.5% by mass or more, from the viewpoint of achieving a good reduction rate and stable reduction. It may be 0% by mass or more, and may be, for example, 60% by mass or less, or 57% by mass or less, or 55% by mass or less, or 52% by mass or less, or 50% by mass or less.

In one aspect, the reducing liquid comprises a glycine derivative. The concentration of the glycine derivative in the reducing liquid is preferably 1% by mass or more, 8% by mass or more, or 16% by mass or more, and preferably 50% by mass or less, or 32% by mass or less.

In typical embodiments, the reducing liquid comprises a solvent. The solvent system may be water-based or organic solvent-based. Examples of solvents include water, ethanol, 1-butanol, 2-propanol, toluene, hexane, benzene, chloroform, methylene chloride, acetic acid, ethyl acetate, tetrahydrofuran, acetone, acetonitrile, N,N-dimethylformamide, dimethylsulfoxide, and the like. is mentioned. Water, ethanol, 1-butanol, and 2-propanol are particularly preferred from the viewpoint of reuse.

Water is particularly preferred as the solvent in the reducing solution, and a combination of a glycine derivative and water is particularly preferred from the viewpoint of cost and productivity. The reducing liquid is particularly preferably an aqueous solution having a glycine derivative concentration of 1% by mass or more and 50% by mass.

In one aspect, the reducing liquid preferably contains N,N-di(2-hydroxyethyl)glycine and/or citric acid from the viewpoint of productivity, that is, from the viewpoint of rapid reduction. In particular, when N,N-di(2-hydroxyethyl)glycine is used, copper becomes divalent ions in the reducing solution to form a complex with glycine, which is preferable in that the reduction of copper oxide to copper is promoted.

During the reduction, it is preferable to immerse the coating film while stirring so that the concentration of the reducing agent in the reducing solution is constant.

The reducing liquid preferably contains at least a predetermined amount of copper ions and/or copper oxide. This makes it possible to prevent the coating film from coming off during the wet reduction. The concentration of copper ions, the concentration of copper oxide, or the total concentration of copper ions and copper oxide in the reducing solution is preferably 1% by mass or more, or 5% by mass or more, and preferably 99% by mass or less, Or it is 90% by mass or less. In one embodiment, one or more selected from the group consisting of copper acetate, copper chloride, copper oxide, copper metal, and a dispersion containing the copper oxide-containing particles of the present disclosure is added to a solvent to prepare a reducing solution. According to the method, copper ions and/or copper oxide may be contained in the reducing solution. In one embodiment, the reducing solution may contain copper oxide by diffusing the copper oxide from the coating film into the solvent.

From the viewpoint of productivity, the temperature in the wet reduction step is preferably 20° C. or higher, more preferably 30° C. or higher, and even more preferably 40° C. or higher, so that the reduction proceeds quickly. Moreover, from the viewpoint of obtaining a uniform copper-containing film, the temperature is preferably 100° C. or lower, more preferably 90° C. or lower.

The wet reduction process and the electroless plating in the plating process can be performed simultaneously. From the viewpoint of improving productivity, it is preferable to perform the wet reduction step and the plating step at the same time. Specifically, the wet reduction process and the plating process can be performed at the same time by including a reducing agent in the plating solution, which will be described later. In this case, the solvent amount can be adjusted so that the reducing agent concentration and the plating substance concentration (copper concentration in one aspect) in the plating solution are within the ranges exemplified for the reducing solution and the plating solution in the present disclosure. preferable.

<Washing process>
When wet reduction is performed, an appropriate washing liquid may be used to remove the unreduced portion and the reducing liquid after the wet reduction. This leaves a clean reduced area on the substrate. On the other hand, the washing process may not be performed. In either case, a substrate (hereinafter also referred to as a conductive substrate) imparted with conductivity by the reduced region as the conductive pattern is obtained. However, when plating the copper oxide-containing film as it is, this step may be omitted in some cases.

As a cleaning liquid for cleaning, a liquid that disperses or dissolves copper oxide can be used. Specific examples include water, 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 tarsier. libbutyl ether, dipropylene glycol monomethyl ether, ethylene glycol butyl ether, ethylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2-pentanediol, 2-methylpentane- 2,4-diol, 2,5-hexanediol, 2,4-heptanediol, 2-ethylhexane-1,3-diol, diethylene glycol, hexanediol, octanediol, triethylene glycol, tri-1,2-propylene Glycol, glycerol, ethylene glycol monohexyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl acetate, diethylene glycol monoethyl ether acetate, methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol , 2-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol, 2-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, 1 -hexanol, 2-hexanol, 2-ethylbutanol, 1-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, 2-octanol, n-nonyl alcohol, 2,6 dimethyl-4-heptanol , n-decanol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, diacetone alcohol, and acetone. Especially when the coating film contains a dispersant, the above solvent is suitable because it can wash off the copper oxide well. Particularly preferred solvents are water, ethanol, butanol, i-propanol and acetone. Note that the above cleaning liquid may contain a dispersant in addition to the solvent. As the dispersant, those mentioned above can be used, and a phosphorus-containing organic substance is more preferable.

<Degreasing process>
One aspect of the method of the present disclosure may have a step of degreasing the coating film prior to the plating step. In one aspect, productivity can be improved by directly degreasing the copper oxide without reducing it. In yet another aspect, the copper oxide may be reduced (eg, in the reduction step described above) and then degreased. Examples of degreasing methods include a UV method and a wet degreasing method. The degreasing process increases the growth rate of the subsequent plating and improves productivity. In addition, this step reduces the porosity of the conductive layer after plating (that is, the plating layer and the copper oxide and / or copper layer when the layer contains copper), that is, the final conductive layer contributes to the porosity of Note that degreasing may be performed along with the electroless plating, and in this case, the degreasing step may be omitted.

From the viewpoint of interlayer adhesion of the conductive patterned structure, the degreasing step is preferably carried out by immersing the coating film in a degreasing solution containing a compound containing an amino group. Compounds containing an amino group include amino acids such as alanine, arginine, asparagine, cysteine, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine, and methylamine. , dimethylamine, ethylamine, trimethylamine, diethylamine, triethylamine, propylamine, isopropylamine, diisopropylamine and other alkylamines, 2-aminoethanol, diethanolamine, triethanolamine, N-methylethanolamine, N,N-dimethylethanolamine alkanolamines such as ethylenediamine, diethylenetriamine, tetraethylenepentamine, tris(hydroxymethyl)aminomethane, m-xylylenediamine, p-xylylenediamine, 1,3-bis(aminomethyl)cyclohexane and other polyamines, Examples include aminosulfonic acids such as taurine, aminothiols such as 2-aminoethanethiol, and nitrogen-containing heterocyclic compounds such as 3-picolylamine and 3-pyridinemethanol. 2-Aminoethanol is particularly preferred from the viewpoint of contributing to the plating growth rate.

The degreasing liquid may be a commercially available product, specifically, ALC-009 (including 2-aminoethanol as a compound having an amino group) available from Uyemura Kogyo Co., Ltd., available from Atotech Japan Co., Ltd. and Cleaner Securigant 902 (containing 2-aminoethanol as a compound having an amino group).

The concentration of the compound containing an amino group in the degreasing liquid is preferably 5 mmol/L or more, more preferably 10 mmol/L or more, and more preferably 20 mmol/L or more from the viewpoint of removing inhibitors of the plating reaction. From the viewpoint of promoting the plating reaction, it is preferably 100 mmol/L or less, more preferably 90 mmol/L or less, and more preferably 80 mmol/L or less.

The immersion time of the coating film in the degreasing solution is preferably 1 minute or longer, more preferably 2 minutes or longer, from the viewpoint of contributing to the plating growth rate. Moreover, from the viewpoint of reducing damage to the substrate, it is preferably within 15 minutes, more preferably within 10 minutes. Immersion under stirring is preferable from the viewpoint of uniform degreasing.

The immersion temperature is preferably 15° C. or higher, more preferably 30° C. or higher, and even more preferably 40° C. or higher, in order to enhance the effect of accelerating the growth rate of the plating. Moreover, from the viewpoint of reducing damage to the substrate, the temperature is preferably 70° C. or lower, more preferably 60° C. or lower.

<Plating process>
In one aspect of the present invention, the coating film that has undergone or has not undergone the reduction step and/or the degreasing step after the drying step may be plated. In one aspect, the plating is electroless plating. In one aspect, the productivity can be improved by directly plating the copper oxide-containing film without reducing it. Electroless plating may reduce some or all of the copper oxide in the copper oxide-containing film, or may not reduce the copper oxide. In another aspect, electroless plating of a copper-containing film obtained by reducing (for example, wet reduction) a copper oxide-containing film can improve conductivity. Electroless plating can form a conductive pattern composed of a layer of copper oxide and/or copper and a plated layer. Thereby, a structure with a conductive pattern can be manufactured. Electroless plating is advantageous in terms of wide applicability to patterns. As a plating method, a general electroless plating method may be applied. For example, electroless plating may be performed along with a reduction step, a degreasing step, or a cleaning step.

A plating solution is used for electroless plating. Since the coating film after the drying process is likely to peel off due to external stress, the coating film may peel off during the plating process if the plating deposition varies and the stress concentrates on one part. In one aspect, the plating solution contains EDTA (ethylenediaminetetraacetic acid). EDTA functions as a complexing agent and forms a highly stable complex with copper ions. It is thought that it contributes to the prevention of peeling. Therefore, the use of a plating solution containing EDTA contributes to the production of a conductive patterned structure with excellent interlayer adhesion. In addition, EDTA is stable even in a high-temperature liquid, and thus contributes to increasing the plating rate when a plating solution containing EDTA is used under heating (for example, 30° C. or higher). Further, it is particularly preferable to perform plating with a plating solution containing EDTA (ethylenediaminetetraacetic acid) after wet reduction, because the growth of copper plating is promoted and the productivity is improved. The amount of EDTA in the plating solution is preferably 7 g/L or more, or 10 g/L or more, or 15 g/L or more, from the viewpoint of obtaining the advantages of EDTA well, to reduce impurities in the plating deposit. , preferably 50 g/L or less, or 45 g/L or less, or 40 g/L or less, from the viewpoint of lowering the electrical resistance.

In typical embodiments, the plating solution includes a copper ion source and a reducing agent. The copper ion source may exist as ions in the liquid. For example, the coating film may be immersed in the plating solution while performing air bubbling. Copper ions in the plating solution are reduced by electroless plating, and copper is deposited on the surface of the coating film to form a plated copper layer. When the coating film contains copper oxide, in electroless plating, part or all of the copper oxide may or may not be reduced by the plating solution. A plated copper layer is formed over the layer comprising

From the viewpoint of improving the plating speed, the copper concentration of the plating solution is preferably 1.5 g/L or more, or 1.8 g/L or more, or 2.0 g/L or more, and the uniformity of the plating film is improved. From the viewpoint, it is preferably 5.0 g/L or less, or 4.0 g/L or less, or 3.5 g/L or less, or 3.0 g/L or less. In particular, when wet reduction and plating are combined, the copper concentration of the plating solution is preferably 1.8 g/L or more and 3.5 g/L or less.

CuSO _{4 ,} CuCl _{2 ,} CuCl, CuNO ₃ , Cu ₃ (PO ₄ ) ₂ and the like can be exemplified as the copper ion source contained in the plating solution. is preferred.

The plating solution may contain, as a reducing agent, one or more selected from the group consisting of formaldehyde (CH ₂ O), potassium tetrahydrochloride, dimethylamine borane, glyoxylic acid, and phosphinic acid. The amount of reducing agent in the plating solution is preferably 0.1 g/L or more, or 0.5 g/L or more, or 1.0 g/L or more, and preferably 15.0 g/L or less, or 12 .0 g/L or less, or 9.0 g/L or less.

The plating solution may further contain an additional complexing agent in addition to EDTA (ethylenediaminetetraacetic acid). Additional complexing agents include Rochelle's salt, triethanolamine, ammonium sulfate, citric acid, glycine, and the like. or 40 g/L or less.

The plating solution may further contain a surfactant as desired.

The plating solution may be a commercially available product. Commercially available products include Sulcup ELC-SP available from Uyemura & Co., Ltd., Melplate CU-390 and Melplate CU-5100P available from Meltex Inc., and Okuno Chemical Industry Co., Ltd. OPC Copper NCA, C4500 available from Rohm and Haas Co., Ltd., Printganth UPlus available from Atotech Co., Ltd., Cu-510 available from MacDermid Japan Co., Ltd., and the like can be used.

The temperature of the electroless plating bath of the plating solution is preferably 25° C. or higher, or 30° C. or higher, or 35° C. or higher, and preferably 80° C. or lower, or 70° C., since faster plating growth can be expected. or less, or 65° C. or less. The plating time is preferably 5 minutes or longer, or 10 minutes or longer, and preferably 60 minutes or shorter, or 50 minutes or shorter, or 40 minutes or shorter.

The layer thickness of the plated layer (plated copper layer in one aspect) is preferably 300 nm or more, or 500 nm or more, or 1 μm or more, in that the current required for the conductive patterned structure can flow, or 2 μm or more, preferably 100 μm or less, or 50 μm or less, or 30 μm or less.

In one aspect, electroless plating may be followed by electroplating. A general electroplating method can be applied to the electroplating. For example, an electrode and a conductive substrate to be plated are placed in a solution (plating bath) containing copper ions. Then, a DC current is applied between the electrode and the conductive substrate from an external DC power supply. In one aspect, a current can be applied to the reduced copper layer on the conductive substrate by connecting a jig (for example, a clip) connected to one of the electrode pair of the external DC power supply to the reduced copper layer. As a result, copper is deposited on the surface of the reduced copper layer on the conductive substrate by the reduction of the copper ions to form a plated copper layer.

As the electrolytic plating bath, for example, a copper sulfate bath, a copper borofluoride bath, a copper cyanide bath, and a copper pyrophosphate bath can be used. A copper sulfate bath and a copper pyrophosphate bath are preferred from the viewpoint of safety and productivity.

As the copper sulfate plating bath, for example, a sulfuric acid acid copper sulfate plating bath containing copper sulfate pentahydrate, sulfuric acid and chlorine is preferably used. The concentration of copper sulfate pentahydrate in the copper sulfate plating bath is preferably 50 g/L or more, or 100 g/L or more, and preferably 300 g/L or less, or 200 g/L or less. The concentration of sulfuric acid is preferably 40 g/L or more, or 80 g/L or more, and preferably 160 g/L or less, or 120 g/L or less. The solvent of the plating bath is usually water. The temperature of the plating bath is preferably 20° C. or higher, or 30° C. or higher, and preferably 60° C. or lower, or 50° C. or lower. The current density during electrolytic treatment is preferably 1 A/dm ² or more, or 2 A/dm ² or more, and preferably 15 A/dm ² or less, or 10 A/dm ² or less.

As the copper pyrophosphate plating bath, for example, a plating bath containing copper pyrophosphate and potassium pyrophosphate is suitable. The concentration of copper pyrophosphate in the copper pyrophosphate plating bath is preferably 60 g/L or more, or 70 g/L or more, and preferably 110 g/L or less, or 90 g/L or less. The concentration of potassium pyrophosphate is preferably 240 g/L or more, or 300 g/L or more, preferably 470 g/L or less, or 400 g/L or less. The solvent of the plating bath is usually water. The pH of the plating bath is preferably 8.0 or higher, or 8.2 or higher, and preferably 9.0 or lower, or 8.8 or lower. Ammonia water or the like may be added to adjust the pH value. The temperature of the plating bath is preferably 20° C. or higher, or 30° C. or higher, and preferably 60° C. or lower, or 50° C. or lower. The current density during electrolytic treatment is preferably 0.5 A/dm ² or more, or 1 A/dm ² or more, and preferably 10 A/dm ² or less, or 7 A/dm ² or less.

A plating bath for electrolytic plating may further contain a surfactant.

<Post-treatment process>
One aspect of the disclosed method includes a post-treatment step to improve adhesion between the substrate and the copper oxide and/or copper layer. The post-treatment step is a step of performing a humidification treatment and/or a heat treatment in one or more of between the coating film forming step and the drying step, between the drying step and the plating step, and after the plating step. . When both the moistening treatment and the heating treatment are performed, they may be performed simultaneously or sequentially. In the case of sequential, the order of humidification treatment and heat treatment is not limited.

According to the humidification treatment, moisture enters the interface between the base material and the copper oxide and/or copper layer, so that an effect of improving interlayer adhesion can be obtained. Without being bound by theory, the interlayer adhesion improvement described above is due to the combination of the components contained in the copper oxide and/or copper layer (e.g., the dispersant component derived from the dispersion) and the moisture provided by the humidification process. , is thought to be caused by forming a hydrogen bond with the substrate. Base materials include polyimide, polyester (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.), polyethersulfone (PES), polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), and polyacetal. , polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyetherketone (PEK), polyphthalamide (PPA) , polyethernitrile (PENt), polybenzimidazole (PBI), and the like, especially in the case of polyimide, the effect of improving layer adhesion is good due to the contribution of imide bonds, which are chemical structures capable of forming hydrogen bonds.

Moreover, it is believed that the heat treatment improves the interlayer adhesion between the substrate and the layer of copper oxide and/or copper due to the improvement of the mechanical strength of the substrate. In one aspect, when the material of the substrate is polyimide, the imide bond in the polyimide may be broken in the plating process, but the once broken imide bond can be repaired by heat treatment. It is believed that such a change in molecular structure due to heat treatment brings about an improvement in the mechanical strength of the base material.

A constant temperature and humidity bath, a desiccator, or the like can be used as the humidifying means.

As a heating means, a drying furnace, an oven, or the like can be used.

The relative humidity of the humidification treatment is preferably 50% or higher, or 60% or higher, or 70% or higher, and preferably 100% or lower.

The duration of the humidification treatment is preferably 1 hour or longer, or 10 hours or longer, or 24 hours or longer, and preferably 14 days or shorter, or 10 days or shorter, or 8 days or shorter.

Heat treatment may be performed, for example, in air. In one aspect, the humidification treatment and the heating treatment may be carried out simultaneously in a gas (air, inert gas, etc.) whose humidity is controlled within the range exemplified above. The temperature of the heat treatment is preferably 100° C. or higher, or 200° C. or higher, or It is 250° C. or higher, and preferably 400° C. or lower, or 350° C. or lower, or 300° C. or lower from the viewpoint of avoiding thermal deterioration of the base material (in one aspect, from the viewpoint of heat resistance of the polyimide base material).

<Preferred example of method for manufacturing structure with conductive pattern>
Hereinafter, a more specific preferred example of the method for manufacturing a structure with a conductive pattern will be described with reference to FIG.
First, copper acetate B is dissolved in mixed solvent A of water and propylene glycol (PG), hydrazine C is added, and the mixture is stirred (Fig. 2(a)).
Then, by centrifugation, the product solution (supernatant 2a) and cuprous oxide (precipitate 2b) are solid-liquid separated (Fig. 2(b)).
Next, dispersing agent D and alcohol E are added to precipitate 2b (Fig. 2(c)) to disperse the precipitate to obtain dispersion 2c containing copper oxide (Fig. 2(d)).
Separately, a substrate 1 is prepared (FIG. 2(e)), and a treated surface S is formed on the substrate 1 by the pretreatment process of the present disclosure (FIG. 2(f)).
Next, the dispersion 2c containing copper oxide is printed on the treated surface S of the substrate 1 by an inkjet method, gravure printing method, or the like to form a coating film (coating film forming step), and then dried (drying step). . As a result, a copper oxide-containing film (copper oxide layer) 2d containing copper oxide and a dispersing agent is formed on the substrate 1 (FIG. 2(g)).

Next, the copper oxide-containing film is immersed in a degreasing solution containing an amino group-containing compound to perform a degreasing step, followed by a plating step. Note that the degreasing step may be omitted. Some or all of the copper oxide in the copper oxide layer may be reduced before the plating step or during the plating step. As a result, a copper oxide and/or copper layer 2e and a plated copper layer 2f are formed on the substrate 1 (FIG. 2(h)).
A structure with a conductive pattern can be manufactured by the above procedure.

In the method of the present disclosure, the following can be exemplified as a preferred order of the steps following the pretreatment step and coating film forming step. In the following examples, the steps in parentheses indicate optional steps.
(1) Perform vacuum drying at least before reduction (non-vacuum drying) - vacuum drying - (non-vacuum drying) - reduction - (washing) - (degreasing) - (vacuum drying) - plating - (post-treatment) - ( vacuum drying)
(2) Perform vacuum drying at least after reduction and before plating (vacuum and/or non-vacuum drying)-reduction-(washing)-(degreasing)-vacuum drying-plating-(post-treatment)-(vacuum drying)
(3) Perform vacuum drying at least after plating (vacuum and/or non-vacuum drying)-reduction-(washing)-(degreasing)-(vacuum drying)-plating-(post-treatment)-vacuum drying

As described above, according to the method of the present disclosure, a conductive layer having excellent interlayer adhesion to a substrate can be produced at very low cost and with low energy, so that a structure with a conductive pattern can be produced more easily. can be done.

<Formation of additional layers>
The conductive patterned structures of the present disclosure may have additional layers in addition to the substrate and conductive layers as previously described. A resin layer and a solder layer can be exemplified as additional layers.

[Resin layer]
In one aspect, it is preferable that part of the conductive layer is covered with a resin layer. By partially covering the conductive layer with the resin layer, oxidation of the conductive pattern is prevented and reliability is improved. In addition, since there is a part of the conductive layer that is not covered with the resin layer, the components can be electrically joined.

An example of a resin layer is a sealing material layer. The resin layer can be formed by, for example, transfer molding, compression molding, or the like. Examples of resins that can be used include polyethylene (PE), polypropylene (PP), polyimide (PI), polyester (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.), polyethersulfone. (PES), polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacetal (POM), polyarylate (PAR), polyamide (PA) (PA6, PA66, etc.), polyamideimide (PAI), poly Etherimide (PEI), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyphenylene sulfide (PPS), polyetherketone (PEK), polyetheretherketone (PEEK), polyphthalamide (PPA), poly Ether nitrile (PENt), polybenzimidazole (PBI), polycarbodiimide, silicone polymer (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, 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 (PTFE), polychlorotrifluoroethylene (PCTFE), etc. is mentioned. The thickness of the resin layer is preferably 0.1 μm or more, or 0.5 μm or more, and preferably 1 mm or less, or 800 μm or less.

The encapsulant layer protects the conductive pattern from external stress in the finished product (the structure with the conductive pattern itself and the product including the same) after manufacturing, and enhances the long-term stability of the structure with the conductive pattern. can improve.

From the viewpoint of ensuring good long-term stability, the moisture permeability of the sealing material layer, which is an example of the resin layer, is preferably 1.0 g/m ² /day or less, more preferably 0.8 g/m ² /day. 0.6 g/m 2 /day or less, more preferably 0.6 g/m ² /day or less. By reducing the moisture permeability, it is possible to prevent moisture from entering the sealing material layer from the outside and suppress oxidation of the conductive pattern. The lower the moisture permeability, the better. The moisture permeability is a value measured by the cup method.

The encapsulant layer can be a functional layer that provides an oxygen barrier function to the conductive patterned structure even after peeling off an oxygen barrier layer that may be used during manufacturing. Other functions include scratch resistance when handling a structure with a conductive pattern, antifouling properties to protect the structure with a conductive pattern from contamination from the outside, and a conductive pattern when a tough resin is used. It may have a function such as improving the rigidity of the structure.

[Solder layer]
In one aspect, it is preferable that a solder layer is formed on part of the conductive layer on the side opposite to the substrate side. A solder layer can connect the conductive layer to another member. A solder layer can be formed by, for example, a reflow method. The solder layer includes Sn--Pb system, Pb--Sn--Sb system, Sn--Sb system, Sn--Pb--Bi system, Bi--Sn system, Sn--Cu system, Sn--Pb--Cu system, Sn--In system, It may be a solder layer of Sn--Ag system, Sn--Pb--Ag system, Pb--Ag system, or the like. The thickness of the solder layer is preferably 0.1 μm or more, or 0.5 μm or more, and preferably 2 mm or less, or 1 mm or less.

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Evaluation method>
[Method for quantifying hydrazine]
Hydrazine was quantified by the standard addition method.
33 μg of hydrazine, 33 μg of surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ), and 1 ml of acetonitrile solution of 1 mass % benzaldehyde were added to 50 μL of sample (dispersion). Finally, 20 μL of phosphoric acid was added, and 4 hours later, GC/MS (gas chromatograph/mass spectrometry) measurement was performed.

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

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

Finally, to 50 μL of the sample (dispersion), add 33 μg of a surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ), 1 mL of benzaldehyde 1% by mass acetonitrile solution without adding hydrazine, and finally add 20 μL of phosphoric acid. After 4 hours, GC/MS measurements were performed.

A peak area value of hydrazine was obtained from the chromatogram at m/z=207 from the 4-point GC/MS measurement. Next, the surrogate peak area value was obtained from the mass chromatogram at m/z=209. The mass of added hydrazine/mass of surrogate substance added is plotted on the x-axis, and the peak area value of hydrazine/peak area value of surrogate substance is plotted on the y-axis to obtain a calibration curve according to the standard addition method.

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

[Average particle size measurement]
The average particle size of the dispersion was measured by the cumulant method using Otsuka Electronics' FPAR-1000.

<Example 1>
[Application and drying of dispersion]
In a mixed solvent consisting of 30240 g of water and 13976 g of 1,2-propylene glycol (manufactured by Asahi Glass Co., Ltd.), 3224 g of copper (II) acetate monohydrate (manufactured by Nihon Kagaku Sangyo Co., Ltd.) is dissolved, and hydrazine hydrate (manufactured by Nippon Finechem Co., Ltd.) is dissolved. After adding 940 g and stirring, the mixture was separated into a supernatant and a precipitate using centrifugation.

794 g of the mixture liquid was added to 345 g of the obtained precipitate, and dispersed using a homogenizer under a nitrogen atmosphere to obtain a dispersion containing cuprous oxide particles containing cuprous oxide (copper (I) oxide). Ta. The above mixed solution was prepared by adding 72 g of DISPERBYK-145 (trade name, manufactured by BYK-Chemie) (BYK-118) as a phosphorus-containing organic compound and 764 g of 1-heptanol (manufactured by Toyo Gosei Co., Ltd.) as a dispersion medium. . Further, 5 g of DISPERBYK-145 and 82 g of 1-heptanol were added to 1,063 g of the above dispersion, and dispersed using a homogenizer under a nitrogen atmosphere to obtain the desired dispersion. Also, the amount of hydrazine in the ink was 0.2% by mass. At this time, the solid content residue (cuprous oxide particles) when the dispersion was heated at normal pressure at 60° C. for 4.5 hours was 26.1% by mass.

[Substrate washing and pretreatment process]
The polyimide substrate was cleaned by irradiating ultrasonic waves in ultrapure water for 5 minutes and then in ethanol for 5 minutes. After that, the surface of the base material was subjected to UV ozone treatment. The substrate was then immersed in N-methylpyrrolidone (NMP) at room temperature for 15 minutes (pretreatment step). After that, the substrate was washed with water, and the surface of the substrate was air-blown to remove the water.

[Coating film forming step]
Printing was performed on the surface with an inkjet printer (Dimatix DMP-2835, Fuji Film). The head was DMC-11601, the voltage was 25 V, and the frequency was 25 kHz. A pattern of 1 mm x 70 mm was drawn.

[Drying process]
The printed sample was dried in a heating oven at 60° C. under normal pressure for 1 hour (non-vacuum drying). Subsequently, the above sample was placed in a desiccator, decompressed by a decompression pump connected to the desiccator, and held at 25° C. and 1 kPa for 5 days (drying under reduced pressure).

[Reduction step]
The above sample was baked at 300° C. for 1 hour in a mixed gas atmosphere of 4% by volume of hydrogen and 96% by volume of nitrogen to obtain a copper-containing film.

[Plating process]
Next, an electroless plating solution containing EDTA, OPC Copper NCA (containing 2.2 g/L of formaldehyde) manufactured by Okuno Chemical Industry Co., Ltd. was heated to 60° C., and the sample was immersed for 10 minutes. After treatment, the samples were removed and washed with water.

[Adhesion evaluation]
Adhesion was evaluated by a tape peel test. A Kapton adhesive tape (6563#50) was adhered to the surface of the sample, and pulled off at once so that the angle between the surface of the sample and the tape was 60 degrees. A case where no peeling occurred or peeling occurred in a range of less than 20% of the entire bonding area was rated as ◯, and a case where peeling occurred in a range of 20% or more of the entire bonding area was rated as x. As a result of the tape peeling test, peeling of the copper-containing film was not observed.

<Example 2>
It was carried out in the same manner as in Example 1, except that the drying under reduced pressure was carried out at 51 kPa for 1 day.
As a result of the tape peeling test, peeling of the copper-containing film was not observed.

<Example 3>
It was carried out in the same manner as in Example 1, except that the reduction step was wet reduction. Wet reduction was carried out by the following method. N,N-di(2-hydroxyethyl)glycine was dissolved in water to prepare a 35 wt% solution. Using this as a reducing solution, the copper oxide-containing film was immersed in the reducing solution heated to 60° C. for 5 minutes. Then, it was washed with water to obtain a copper-containing film.
As a result of the tape peeling test, peeling of the copper-containing film was not observed. Since the wet reduction process can be carried out at a low temperature, it can be applied even if the base material is a general-purpose base material, which is preferable.

<Example 4>
The same method as in Example 3 was used except that drying under reduced pressure was performed for one day at 1 kPa after plating.
As a result of the tape peeling test, peeling of the copper-containing film was not observed.

<Comparative Example 1>
It was carried out in the same manner as in Example 1, except that the washing of the substrate, the pretreatment step, and the drying under reduced pressure were changed as follows.
[Substrate washing and pretreatment process]
The polyimide substrate was cleaned by irradiating ultrasonic waves in ultrapure water for 5 minutes and then in ethanol for 5 minutes. After that, the surface of the base material was subjected to UV ozone treatment.
[Drying process]
Only non-vacuum drying was performed, and no vacuum drying was performed.
As a result of the tape peeling test, peeling of the copper-containing film was observed in a range of 90% of the entire adhesion area.

<Comparative Example 2>
[Substrate washing and pretreatment process]
did not implement.
[Coating film forming step]
1 ml of the dispersion was dropped on the surface of the polyimide substrate and spin-coated (500 rpm, 300 seconds).
[Drying process]
Heat drying was performed at 90° C. and normal pressure for 2 hours to obtain a sample having a dry coating film formed on the substrate. No vacuum drying was performed.
[Reduction step]
The above sample was baked at 300° C. for 1 hour in a nitrogen atmosphere to obtain a copper-containing film.
[Plating process]
It was carried out in the same manner as in Example 1.
[evaluation]
As a result of the tape peeling test, peeling of the copper-containing film was observed in a range of 90% of the entire adhesion area.

<Examples 5 to 8>
(Evaluation of inkjet suitability)
Same as Example 1 except that the dispersion solvent was changed to 1-butanol (Example 5), 1-hexanol (Example 6), 1-heptanol (Example 7), or 1-octanol (Example 8). A dispersion (ink) was prepared in the same manner. The obtained ink was evaluated for intermittent ink jet stability. The time until clogging of the nozzle occurred during intermittent ejection was measured and evaluated as follows: 1 hour or more: A, 30 minutes or more and less than 1 hour: B, and less than 30 minutes: C. Evaluation conditions for intermittent stability are as follows.
Equipment: DIMATIX material printer DMP-2831
Head: DMC-11610
Voltage: 25V
Number of ejection nozzles: 7 (No. 5 to 11)
Judgment of ejection presence/absence: visual inspection with DropWatcher

The 1-butanol solvent ink was evaluated C, the 1-hexanol solvent ink was evaluated B, and the 1-heptanol solvent ink and the 1-octanol solvent ink were evaluated A. From these results, it was found that inks using 1-hexanol, 1-heptanol or 1-octanol, especially 1-heptanol or 1-octanol as a solvent have good inkjet suitability.

It should be noted that the present invention is not limited to the above embodiments or examples. Based on the knowledge of a person skilled in the art, design changes or the like may be added to the above embodiments or examples, and the above embodiments or examples may be combined arbitrarily. Included within the scope of the present invention.

One aspect of the present invention can be suitably applied to the production of printed wiring boards, electronic devices, electromagnetic wave shields, antistatic films, and the like.

REFERENCE SIGNS LIST 100 copper oxide ink 12 copper oxide 13 phosphate ester salt 13a phosphorus 13b ester salt 1 substrate 2a supernatant 2b precipitate 2c dispersion 2d copper oxide-containing film 2e copper oxide and/or copper layer 2f plated copper layer

Claims (7)

A method for producing a conductive patterned structure having a substrate and a conductive pattern on the substrate,
a pretreatment step of subjecting the substrate to one or more treatments selected from the group consisting of organic solvent treatment and alkali treatment;
A coating film forming step of obtaining a coating film by applying a dispersion containing copper oxide-containing particles and / or copper-containing particles to the substrate after the pretreatment step;
A drying step of drying the coating film;
A plating step of plating the coating film after the drying step;
including
In the drying step, after the drying step and before the plating step and/or after the plating step, the coating film is dried under an atmospheric pressure less than atmospheric pressure. A method of manufacturing a structure. 2. The method for manufacturing a structure with a conductive pattern according to claim 1, wherein in said drying step, said drying under reduced pressure and non-reduced pressure drying in which said coating film is dried under atmospheric pressure or higher are performed. 3. The method for manufacturing a conductive patterned structure according to claim 1, further comprising a reduction step after said drying step and before said plating step. 4. The method for manufacturing a conductive patterned structure according to claim 3, wherein said reduction step is a wet reduction step. The method for producing a conductive patterned structure according to any one of claims 1 to 4, wherein the pressure in the reduced pressure drying is 90 kPa or less and 0.000001 kPa or more. 6. The method for producing a conductive patterned structure according to any one of claims 1 to 5, wherein the base material is polyimide. The conductive patterned structure according to any one of claims 1 to 6, wherein the dispersion contains at least one selected from the group consisting of 1-hexanol, 1-heptanol, and 1-octanol. Production method.

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