JP7430483B2 - Structure with conductive pattern area and manufacturing method thereof - Google Patents

Description

The present invention relates to a structure with a conductive pattern region and a method for manufacturing the same.

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

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

Further, as another method for producing copper wiring, there is an electrolytic plating method. Since the electrolytic plating method requires the flow of electricity, it is necessary to first form a seed layer by electroless plating or the like. For example, as described in Patent Document 1, there is a method in which a copper foil is formed by electroless plating, unnecessary portions of the foil are removed by laser irradiation, and then copper wiring is produced by electrolytic plating.

Patent No. 2965803

Using electroless plating using a palladium catalyst to form a seed layer, as in the method described in Patent Document 1, has a problem in that it is costly.

One of the objects of the present invention is to provide a structure with a conductive pattern region that does not require an expensive palladium catalyst in electroless plating and can be manufactured more easily, and a method for manufacturing the same.

The structure with a conductive pattern region of the present invention includes a support, a reduced copper layer having a layer thickness of 1 nm or more and 10 μm or less, which is arranged on a surface constituted by the support, and which is arranged on the reduced copper layer. and a plated copper layer having a layer thickness of 1 μm or more and 50 μm or less , the reduced copper layer containing at least one selected from elemental phosphorus, phosphorus oxide, and phosphorus-containing organic matter. It is characterized by containing .

According to this configuration, a void-free and uniform reduced copper layer is formed, and a layer on which the necessary current can flow by electroless plating or electrolytic plating using reduced copper as a catalyst. Since the thick plated copper layer is provided, it is possible to provide a structure having a conductive pattern area with excellent conductivity and with few defects.

In one aspect of the structure with conductive pattern regions of the present invention, it is preferable that the reduced copper layer is a fired body.
In one aspect of the structure with conductive pattern regions of the present invention, at least one selected from the phosphorus element, phosphorus oxide, and phosphorus-containing organic substance may be present in a segregated manner in the reduced copper layer. preferable.

One embodiment of the method for manufacturing a structure with a conductive pattern area of the present invention includes a step of forming a coating layer containing copper oxide and a dispersant on a surface of a support, and selectively applying a light beam to the coating layer. irradiating to reduce the copper oxide to reduced copper to form a reduced copper layer; disposing a plated copper layer on the reduced copper layer by electroless plating or electrolytic plating using the reduced copper as a catalyst; The method is characterized in that it includes a step of obtaining a conductive pattern region composed of the reduced copper layer and the plated copper layer.

According to this configuration, the plated copper layer is formed by performing electrolytic plating using the reduced copper layer as a seed layer. Alternatively, electroless plating can be performed using reduced copper as a catalyst. In addition, selective irradiation with light allows the reduced copper layer to be easily formed in a desired pattern. As a result, an expensive palladium catalyst in electroless plating is not required, and a structure with a conductive pattern region can be manufactured more easily.

According to the present invention, an expensive palladium catalyst in electroless plating is not required, and a structure with a conductive pattern region can be manufactured more easily.

FIG. 2 is a schematic diagram showing the relationship between copper oxide and phosphate ester salt according to the present embodiment. FIG. 1 is a schematic cross-sectional view showing a conductive substrate according to the present embodiment. FIG. 3 is an explanatory diagram showing each step of the method for manufacturing a conductive substrate according to the present embodiment. FIG. 2 is a schematic cross-sectional view showing a structure with a conductive pattern region according to the present embodiment.

Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail for the purpose of illustrating it, but the present invention is not limited to this embodiment.

<Summary of the present invention>
The inventors of the present invention have conducted intensive studies on alternative methods to forming a seed layer by electroless plating. As a result, copper oxide ink containing copper oxide is applied onto the surface of a support such as a base material, a coating layer is placed, and the coating layer is selectively irradiated with light to ink copper oxide (reduced copper). ), unnecessary parts are removed to form a reduced copper layer with a desired pattern, and then electroless plating is performed using the reduced copper contained in this reduced copper layer as a catalyst, or the reduced copper layer is used as a seed layer. The present inventors have discovered that a plated copper layer can be formed by electrolytic plating, and have completed the present invention.

That is, the method for manufacturing a structure with a conductive pattern region according to the present embodiment includes the steps of forming a coating layer containing copper oxide and a dispersant on a surface of a support, and selectively applying a light beam to the coating layer. irradiation to reduce the copper oxide to reduced copper to form a reduced copper layer, and placing a plated copper layer on the reduced copper layer by electroless plating or electrolytic plating using the reduced copper as a catalyst. and a step of obtaining a conductive pattern region composed of the reduced copper layer and the plated copper layer.

According to this configuration, the plated copper layer is formed by performing electrolytic plating using the reduced copper layer as a seed layer. Alternatively, electroless plating can be performed using reduced copper as a catalyst. In addition, selective irradiation with light allows the reduced copper layer to be easily formed in a desired pattern. As a result, an expensive palladium catalyst in electroless plating is not required, and a structure with a conductive pattern region can be manufactured more easily.

Further, the structure with a conductive pattern region according to the present embodiment includes a support, a reduced copper layer having a layer thickness of 1 nm or more and 10 μm or less, which is disposed on a surface constituted by the support, and the reduced copper layer having a layer thickness of 1 nm or more and 10 μm or less. It is characterized by comprising a conductive pattern region formed of a plated copper layer having a layer thickness of 1 μm or more and 50 μm or less, disposed on the copper layer.

According to this configuration, a void-free and uniform reduced copper layer is formed, and a layer on which the necessary current can flow by electroless plating or electrolytic plating using reduced copper as a catalyst. Since the thick plated copper layer is provided, it is possible to provide a structure having a conductive pattern area with excellent conductivity and with few defects.

In this embodiment, the conductive pattern region is a pattern made of conductive metal. The conductive pattern region includes, for example, wiring, a metal layer of a heat dissipation sheet (eg, mesh-like), or an electromagnetic shielding metal layer (eg, mesh-like), but is not particularly limited. Here, the wiring is, for example, wiring for connecting multiple parts arranged on a support, wiring within an integrated circuit, wiring for connecting between electrical equipment or electronic equipment (for example, wiring for connecting a plurality of parts arranged on a support body, wiring for connecting between electrical equipment or electronic equipment (for example, , wiring between a switch and a device such as a light, or wiring between a sensor and an ECU (Electronic Control Unit), but is not particularly limited thereto.

Further, the support constitutes a surface on which a coating layer is formed. However, its shape is not particularly limited.

The material of the support is preferably an insulating material in order to ensure electrical insulation between the conductive pattern regions. However, the entire support body does not necessarily need to be made of an insulating material. It is sufficient if only the portion constituting the surface on which the coating layer is placed is made of an insulating material.

The support may more particularly be a plate, a film or a sheet. The plate-shaped body is, for example, a support (also called a base material) used for a circuit board such as a printed circuit board. The film or sheet is, for example, a base film that is a thin insulator used for flexible printed circuit boards.

The support may be a three-dimensional object. The coating layer can also be formed on a curved surface or a surface including steps, etc., included in the three-dimensional object.

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

<Copper oxide ink>
The copper oxide ink of this embodiment is characterized in that the dispersion medium contains (1) copper oxide and (2) a dispersant.

The content of the dispersant satisfies the range of formula (1) below. This suppresses aggregation of copper oxide and improves dispersion stability.

0.0050≦(dispersant mass/copper oxide mass)≦0.30 (1)

Further, the acid value of the dispersant is preferably 20 or more and 130 or less. This provides excellent dispersion stability.

Further, copper oxide is in the form of fine particles, and the average particle diameter thereof is preferably 3 nm or more and 50 nm or less, more preferably 5 nm or more and 40 nm or less. When the average particle diameter is 50 nm or less, low-temperature firing becomes possible and the versatility of the substrate increases. Further, it is preferable because it tends to easily form a fine pattern on the substrate. Moreover, when it is 3 nm or more, the dispersion stability is good when used in a copper oxide ink, and the long-term storage stability of the dispersion is improved, which is preferable. Moreover, a uniform thin film can be produced.

Further, the dispersion medium is preferably a monoalcohol having 8 or less carbon atoms. Thereby, in order to suppress a decrease in the dispersibility of copper oxide, the copper oxide is more stably dispersed through interaction with the dispersant. Moreover, the resistance value is also lowered.

Moreover, it is preferable that the content of the dispersion medium in the copper oxide ink is 30% by mass or more and 95% by mass or less.

The copper oxide ink of this embodiment can be subjected to baking treatment (described later) using flash light or laser light. This decomposes the organic matter in the copper oxide, promotes firing of the copper oxide, and forms a conductive film with low resistance. Therefore, it is possible to provide various conductive pattern areas such as wiring for passing electricity, heat dissipation sheets, electromagnetic shields, and circuits.

Next, the states of copper oxide and dispersant in the copper oxide ink will be explained using FIG. 1. FIG. 1 is a schematic diagram showing the relationship between copper oxide and phosphate ester salt according to the present embodiment. As shown in FIG. 1, in the copper oxide ink 1, a phosphoric acid ester salt 3, which is an example of a phosphorus-containing organic substance, is used as a dispersant around copper oxide 2, which is an example of copper oxide, and phosphorus 3a is placed inside. The ester salts 3b are respectively directed outward and surrounded. Since the phosphate ester salt 3 exhibits electrical insulating properties, electrical continuity between the adjacent copper oxides 2 is prevented. Further, the phosphoric acid ester salt 3 suppresses aggregation of the copper oxide ink 1 due to a steric hindrance effect.

Therefore, although the copper oxide ink 2 is a semiconductor and conductive, it is covered with the phosphate ester salt 3 that exhibits electrical insulation, so the copper oxide ink 1 exhibits electrical insulation and is Insulation between the conductive pattern regions adjacent to each other on both sides of the copper oxide ink 1 can be ensured in the cross section along the vertical direction shown in FIG.

On the other hand, in the conductive pattern region, light is irradiated to a partial region of the coating layer containing copper oxide and a phosphorous-containing organic substance, and the copper oxide is reduced to copper in the partial region. Copper obtained by reducing copper oxide in this way is called reduced copper. Further, in the part of the region, the phosphorus-containing organic substance is modified into a phosphorus oxide. Among phosphoric oxides, organic substances such as the above-mentioned ester salt 3b (see FIG. 1) are decomposed by heat such as a laser and no longer exhibit electrical insulation properties.

Further, as shown in FIG. 1, when copper oxide 2 is used, the copper oxide is changed into reduced copper and sintered by heat from a laser or the like, so that adjacent copper oxide 2 are integrated. As a result, a region having excellent electrical conductivity, that is, a conductive pattern region can be formed.

The conductive pattern region (reduced copper layer) is a fired body obtained by firing copper oxide in this manner.

Further, in the conductive pattern region, phosphorus element remains in the reduced copper. The phosphorus element exists as at least one of a simple phosphorus element, a phosphorus oxide, and a phosphorus-containing organic substance. In this way, the remaining phosphorus element exists in a segregated manner in the conductive pattern region, and there is no fear that the resistance of the conductive pattern region will increase.

[(1) Copper oxide]
In this embodiment, copper oxide is used as one of the metal oxide components. Copper oxide includes cuprous oxide (Cu ₂ O) and cupric oxide (CuO), with cuprous oxide being preferred. This is because it is easy to reduce among metal oxides, is easy to sinter by using fine particles, is cheaper than precious metals such as silver because it is copper, and is resistant to migration. This is because it is advantageous. In the following embodiment, a case where cuprous oxide is used will be described as an example.

As mentioned above, the copper oxide is preferably in the form of fine particles. The preferred range of the average particle diameter of the cuprous oxide particles is determined from the viewpoint of the density and electrical properties of the metal obtained by reducing the particles, and also from the viewpoint of the firing conditions for the substrate, taking into consideration the use of a resin substrate. In order to reduce the damage caused, it is necessary to lower the temperature. Therefore, the average particle diameter is preferably 3 nm or more and 50 nm or less, more preferably 5 nm or more and 40 nm or less, and even more preferably 10 nm or more and 30 nm or less. When the average particle diameter is 50 nm or less, low-temperature firing becomes possible and the versatility of the substrate increases. Further, it is preferable because it tends to easily form a fine pattern on the substrate. Moreover, when it is 3 nm or more, the dispersion stability is good when used in a copper oxide ink, and the long-term storage stability of the dispersion is improved, which is preferable. Moreover, a uniform thin film can be produced. The average particle size herein refers to the particle size when dispersed in copper oxide ink, and is a value measured by the cumulant method using FPAR-1000 manufactured by Otsuka Electronics. In other words, it is not limited to the primary particle size, but may be the secondary particle size.

Further, in the average particle size distribution, the polydispersity is preferably in the range of 0.1 or more and 0.4 or less. Within this range, film formability is good and dispersion stability is also high. Note that in this embodiment, the average particle size of the cuprous oxide particles does not affect the crack prevention effect of copper particles having wire-like, dendritic, and scale-like shapes, which will be described later.

Regarding cuprous oxide, a commercially available product may be used, or a synthesized product may be used. Examples of the synthesis method include the following methods.
(1) Add water and copper acetylacetonate complex to a polyol solvent, heat and dissolve the organocopper compound, then add water necessary for the reaction, and further raise the temperature to the reduction temperature of the organocopper. A method of heating and reducing.
(2) A method of heating an organocopper compound (copper-N-nitrosophenylhydroxyamine complex) at a high temperature of about 300°C in an inert atmosphere in the presence of a protective material such as hexadecylamine.
(3) A method in which a copper salt dissolved in an aqueous solution is reduced with hydrazine.

Among these, method (3) is preferred because it is easy to operate and produces cuprous oxide with a small average particle size.

After the synthesis is completed, the synthesis solution and cuprous oxide are separated using a known method such as centrifugation. Further, the obtained cuprous oxide is mixed with a dispersant and a dispersion medium, which will be described later, and stirred and dispersed using a known method such as a homogenizer. Depending on the dispersion medium, it may be difficult to disperse and the dispersion may be insufficient. In such cases, for example, after dispersing using a dispersion medium such as an alcohol that is easy to disperse, such as butanol, it is added to the desired dispersion medium. Perform substitution and concentration to desired concentration. An example of the method is a method in which concentration using a UF membrane, dilution with a desired dispersion medium, and concentration are repeated. The copper oxide dispersion thus obtained is mixed with copper particles and the like by a method described later to form the copper oxide ink of this embodiment. This copper oxide ink is used for printing and coating.

[(2) Dispersant]
Next, the dispersant will be explained. As the dispersant, for example, a phosphorus-containing organic substance is preferable. Phosphorus-containing organic substances may be adsorbed onto copper oxide, in which case agglomeration is inhibited by steric hindrance effects. Further, the phosphorus-containing organic substance is a material that exhibits electrical insulation in the insulating region. The phosphorus-containing organic substance may be a single molecule or a mixture of multiple types of molecules.

The number average molecular weight of the dispersant is not particularly limited, but is preferably 300 to 300,000, for example. When it is 300 or more, the insulation properties are excellent and the dispersion stability of the resulting copper oxide ink tends to increase, and when it is 30,000 or less, it is easy to bake. Moreover, as for the structure, a phosphoric acid ester of a high molecular weight copolymer having a group having an affinity for copper oxide is preferable. For example, the structure of chemical formula (1) is preferable because it adsorbs copper oxide, especially cuprous oxide, and has excellent adhesion to the substrate.

化学式（１）中、ｌは１～２０の整数、好ましくは１～１５の整数、より好ましくは１～１０の整数であり、ｍは１～２０の整数、好ましくは１～１５の整数、より好ましくは１～１０の整数であり、ｎは１～２０の整数、好ましくは１～１５の整数、より好ましくは１～１０の整数である。この範囲とすることで、酸化銅の分散性を高めつつ、さらに分散媒に分散剤が可溶となる。

In the chemical formula (1), l is an integer of 1 to 20, preferably an integer of 1 to 15, more preferably an integer of 1 to 10, and m is an integer of 1 to 20, preferably an integer of 1 to 15, and It is preferably an integer of 1 to 10, and n is an integer of 1 to 20, preferably an integer of 1 to 15, more preferably an integer of 1 to 10. By setting it within this range, the dispersibility of copper oxide is improved and the dispersant becomes soluble in the dispersion medium.

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

Although the decomposition temperature of the phosphorus-containing organic substance is not limited, it is preferably 600°C or lower, more preferably 400°C or lower, and even more preferably 200°C or lower. Although the boiling point of the phosphorus-containing organic substance is not limited, it is preferably 300°C or lower, more preferably 200°C or lower, and even more preferably 150°C or lower.

Although the absorption properties of the phosphorus-containing organic substance are not limited, it is preferable that it can absorb the light used for firing. For example, when using laser light as a light source for firing, it is preferable to use a phosphorus-containing organic substance that absorbs light at an emission wavelength of, for example, 355 nm, 405 nm, 445 nm, 450 nm, 532 nm, or 1056 nm. When the support is a resin, it is preferable to use a phosphorus-containing organic substance that absorbs light with a wavelength of 355 nm, 405 nm, 445 nm, or 450 nm.

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

Examples of the above commercial 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, DISP ERBYK-2000, DISPERBYK-2025, DISPERBYK-2163, DISPERBYK-2164, BYK-9076, BYK-9077, TERRA-204, TERRA-U (manufactured by BYK Chemie), Floren DOPA-15B, Floren DOPA-15BHFS, Floren DOPA-22, Floren DOPA-33, Floren DOPA-44, Floren DOPA- 17HF, Floren TG-662C, Floren KTG-2400 (manufactured by Kyoeisha Chemical Co., Ltd.), ED-117, ED-118, ED-212, ED-213, ED-214, ED-216, ED-350, ED-360 (manufactured by Kusumoto Kasei Co., Ltd.), Plysurf M208F, and Plysurf DBS (manufactured by Daiichi Kogyo Seiyaku). These may be used alone or in combination.

The required amount of the dispersant is proportional to the amount of copper oxide, and is adjusted in consideration of the required dispersion stability. The mass ratio of the dispersant (dispersant mass/copper oxide mass) contained in the copper oxide ink of this embodiment is 0.0050 or more and 0.30 or less, preferably 0.050 or more and 0.25 or less. , more preferably 0.10 or more and 0.23. The amount of dispersant affects dispersion stability; when the amount is small, agglomeration tends to occur, and when the amount is large, dispersion stability tends to improve. However, when the content of the dispersant in the copper oxide ink of this embodiment is 35% by mass or less, the influence of the residue derived from the dispersant can be suppressed in the conductive film obtained by firing, and the conductivity can be improved.

The acid value (mgKOH/g) of the dispersant is preferably 20 or more and 130 or less. More preferably, it is 30 or more and 100 or less. If it falls within this range, it is preferable because it provides excellent dispersion stability. This is particularly effective in the case of copper oxide having a small average particle size. Specifically, "DISPERBYK-102" (acid value 101), "DISPERBYK-140" (acid value 73), "DISPERBYK-142" (acid value 46), and "DISPERBYK-145" (acid value 76) manufactured by BYK Chemie. , "DISPERBYK-118" (acid value 36), and "DISPERBYK-180" (acid value 94).

Further, the difference between the amine value (mgKOH/g) and the acid value (amine value - acid value) of the dispersant is preferably -50 or more and 0 or less. The amine value indicates the total amount of free bases and bases, and the acid value indicates the total amount of free fatty acids and fatty acids. The amine value and acid value are measured according to JIS K 7700 or ASTM D2074. A value of −50 or more and 0 or less is preferable because dispersion stability is excellent. More preferably -40 or more and 0 or less, and even more preferably -20 or more and 0 or less.

[(3) Others]
In addition to the above-mentioned components (1) and (2), the copper oxide ink of this embodiment may contain a reducing agent and a dispersion medium as other components (3).

First, the reducing agent will be explained. Reducing agents include hydrazine, hydrazine hydrate, sodium, carbon, potassium iodide, oxalic acid, iron (II) sulfide, sodium thiosulfate, ascorbic acid, tin (II) chloride, diisobutylaluminum hydride, formic acid, and hydrogen. Examples include sodium borate and sulfites. In the firing process, the reducing agent is most preferably hydrazine or hydrazine hydrate, from the viewpoint of contributing to the reduction of copper oxide, especially cuprous oxide, and being able to produce a reduced copper layer with lower resistance. Thereby, the dispersion stability of the copper oxide ink can also be maintained. The required amount of reducing agent is proportional to the amount of copper oxide, and is adjusted in consideration of the required reducing property.

The mass ratio of the reducing agent (reducing agent mass/copper oxide mass) contained in the copper oxide ink of this embodiment is preferably 0.0001 or more and 0.1 or less, more preferably 0.0001 or more and 0.05 or less, More preferably, it is 0.0001 or more and 0.03. When the mass ratio of the reducing agent is 0.0001 or more, the dispersion stability is improved and the resistance of the reduced copper layer is reduced. Moreover, when it is 0.1 or less, the long-term stability of the copper oxide ink is improved.

Further, the dispersion medium used in this embodiment is selected from among those capable of dissolving the dispersant from the viewpoint of dispersion. On the other hand, from the perspective of forming a conductive pattern using copper oxide ink, the volatility of the dispersion medium affects workability, so it is not suitable for the method of forming the conductive pattern, such as printing or coating. There needs to be. Therefore, the dispersion medium may be selected from the following solvents depending on the dispersibility and workability of printing and coating.

Specific examples include the following solvents as dispersion media. Propylene glycol monomethyl ether acetate, 3-methoxy-3-methyl-butyl acetate, ethoxyethyl propionate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl Ether, ethylene glycol 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 mono Hexyl 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 the like. In addition to those specifically described above, alcohol, glycol, glycol ether, and glycol ester solvents can be used as the dispersion medium. These may be used alone or in combination, and are selected in consideration of evaporability, printing equipment, and solvent resistance of the printing substrate depending on the printing method.

Further, as the dispersion medium, a monoalcohol having 10 or less carbon atoms is more preferable. Further, in order to suppress a decrease in the dispersibility of copper oxide, and further to achieve more stable dispersion in interaction with a dispersant, it is more preferable that the carbon number of the monoalcohol is 8 or less. Further, since the monoalcohol has 8 or less carbon atoms, the resistance value is also lowered. Among monoalcohols having 8 or less carbon atoms, for example, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, and t-butanol are particularly suitable because of their dispersibility, volatility, and viscosity. Even more preferred. These monoalcohols may be used alone or in combination.

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

[Preparation of dispersion containing copper oxide and copper]
The copper oxide ink of this embodiment preferably contains copper particles in addition to copper oxide fine particles. A dispersion containing copper oxide fine particles and copper particles can be prepared by mixing the copper oxide dispersion described above with copper fine particles and, if necessary, a dispersion medium at predetermined ratios. It can be adjusted by dispersion treatment using a roll method, a two-roll method, an attritor, a homogenizer, a Banbury mixer, a paint shaker, a kneader, a ball mill, a sand mill, a rotation-revolution mixer, or the like.

A part of the dispersion medium is already contained in the copper oxide dispersion that has been created, so if the amount contained in the copper oxide dispersion is sufficient, there is no need to add it in this step, and it is necessary to reduce the viscosity. If necessary, you can add it at this step. Alternatively, it may be added after this step. The dispersion medium may be the same as that added when producing the copper oxide dispersion described above, or a different one may be added.

In addition, organic binders, antioxidants, reducing agents, metal particles, and metal oxides may be added as necessary, and metals, metal oxides, metal salts, and metal complexes may be included as impurities.

In addition, since wire-shaped, dendritic, and scale-shaped copper particles have a strong crack prevention effect, they can be added alone or in combination with copper particles in the shape of spheres, dice, polyhedrons, or other metals, and their surfaces can be oxidized. It may be coated with gold or other highly conductive metal, such as silver.

In addition, when adding one or more metal particles other than copper that have a wire-like, dendritic, or scale-like shape, they have the same crack prevention effect as copper particles with a similar shape. It can be used as a partial replacement or in addition to copper particles of a similar shape, but it is necessary to consider migration, particle strength, resistance value, copper erosion, formation of intermetallic compounds, cost, etc. Examples of metal particles other than copper include gold, silver, tin, zinc, nickel, platinum, bismuth, indium, and antimony.

As the metal oxide particles, cuprous oxide can be replaced with silver oxide, cupric oxide, etc., or can be used in addition. However, as in the case of metal particles, it is necessary to consider migration, particle strength, resistance value, copper corrosion, formation of intermetallic compounds, cost, etc. Addition of these metal particles and metal oxide particles can be used to adjust the sintering, resistance, conductor strength, absorbance during photo-baking, etc. of the conductive film. Even if these metal particles and metal oxide particles are added, cracks are sufficiently suppressed due to the presence of wire-like, dendritic, and scale-like copper particles. These metal particles and metal oxide particles may be used alone or in combination of two or more types, and there are no restrictions on the shape. For example, silver and silver oxide are expected to have effects such as lowering resistance and lowering firing temperature.

However, since silver is a noble metal and is expensive, and from the viewpoint of crack prevention, the amount of silver added is preferably within a range that does not exceed the amount of wire-like, dendritic, or flaky copper particles. Furthermore, tin has the advantage of being inexpensive and having a low melting point, making it easier to sinter. However, the resistance tends to increase, and from the viewpoint of preventing cracks, the amount of tin added is preferably within a range that does not exceed the amount of wire-like, dendritic, or scaly copper particles and cuprous oxide. Cupric oxide acts as a light absorber and heat ray absorber in methods that use light or infrared rays such as flash lamps and lasers. However, since cupric oxide is more difficult to reduce than cuprous oxide, and from the viewpoint of preventing peeling from the substrate due to the generation of a large amount of gas during reduction, the amount of cupric oxide added should be smaller than that of cuprous oxide. is preferred.

In this embodiment, even if metals other than copper, copper particles other than wire-shaped, dendritic, or scale-shaped, and metal oxides other than copper oxide are included, the effect of preventing cracks and improving the stability of resistance over time is not achieved. Demonstrated. However, the amount of metals other than copper, copper particles other than wire-like, dendritic, and flake-like, and metal oxides other than copper oxide should be smaller than those of wire-like, dendritic, and flake-like copper particles and copper oxide. is preferred. Additionally, the addition ratio of metals other than copper, copper particles other than wires, dendritic, and flakes, and metal oxides other than copper oxide to wire-shaped, dendritic, and scale-shaped copper particles and copper oxide is 50% or less. , more preferably 30% or less, still more preferably 10% or less.

<Conductive substrate>
In the method for manufacturing a structure with a conductive pattern region according to the present embodiment, first, a support is created that includes a reduced copper layer as a seed layer for electrolytic plating on a surface of the support. In the following description, a case where a substrate is used as a support will be exemplified. Further, a substrate provided with a reduced copper layer is called a conductive substrate.

The method for manufacturing a conductive substrate according to this embodiment includes a step of applying the copper oxide ink according to this embodiment onto a substrate to form a coating layer, and partially baking the coating layer (described later). forming a reduced copper layer on the substrate. According to this configuration, a reduced copper layer can be formed in a desired pattern by partially baking the coated layer, so productivity can be improved compared to the conventional method using photoresist. .

[Configuration of conductive substrate]
As shown in FIG. 2, the conductive substrate 10 is a part of a coating layer in which a copper oxide ink is applied to a substrate 11 and a surface formed by the substrate 11 in a cross-sectional view, and is not irradiated with light. It is characterized by comprising a single layer 14 in which an unfired region 12 and a fired region 13, which is part of the coating layer and is irradiated with light, are arranged adjacent to each other.

Here, the unfired region 12 includes, for example, (1) copper oxide and (2) a dispersant that constitute the copper oxide ink. Furthermore, the firing region 13 includes, for example, copper obtained by reducing copper oxide, that is, reduced copper.

[How to apply copper oxide ink to the board]
A coating method using copper oxide ink will be explained. The coating method is not particularly limited, and printing methods such as screen printing, intaglio direct printing, intaglio offset printing, flexo printing, and offset printing, and dispenser drawing methods can be used. As the coating method, methods such as die coating, spin coating, slit coating, bar coating, knife coating, spray coating, and dip coating can be used.

[Substrate or housing]
The substrate or casing used in this embodiment is not particularly limited, and is made of an inorganic material or an organic material. Further, the casing has a three-dimensionally processed shape, and there are various shapes depending on the form of use. According to the present invention, wiring can also be created on three-dimensional objects.

Examples of the inorganic material 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 polymer materials, paper, nonwoven fabrics, and the like. Resin films can be used as polymeric materials, such as polyimide (PI), polyethylene terephthalate (PET), polyether sulfone (PES), polyethylene naphthalate (PEN), polyester, polycarbonate (PC), polyvinyl alcohol (PVA), etc. ), polyvinyl butyral (PVB), polyacetal (POM), polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE) ), polyphenylene sulfide (PPS), polyetherketone (PEK), polyphthalamide (PPA), polyethernitrile (PEN), polybenzimidazole (PBI), polycarbodiimide, 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, ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer, polyethylene (PE), polyvinyl 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), nylon resin (PA6, PA66) polybutyl terephthalate resin (PBT) polyether sulfone resin (PESU), polytetrafluoroethylene resin (PTFE), polychloro Examples include trifluoroethylene (PCTFE) and silicone resin. In particular, PI, PET, and PEN are preferable from the viewpoint of flexibility and cost. The thickness of the substrate can be, for example, 1 μm to 10 mm, preferably 25 μm to 250 μm. If the thickness of the substrate is 250 μm or less, it is preferable because the manufactured electronic device can be made lighter, space-saving, and flexible.

Examples of paper include paper made from ordinary pulp such as high-quality paper, medium-quality paper, coated paper, cardboard, and corrugated paper, and paper made from cellulose nanofiber. In the case of paper, it is possible to use one in which a polymeric material is dissolved, or one in which a sol-gel material is impregnated and hardened. Further, these materials may be laminated together or used together. For example, composite substrates such as paper phenol base material, paper epoxy base material, glass composite base material, glass epoxy base material, Teflon (registered trademark) base material, alumina base material, low temperature and low humidity co-fired ceramics (LTCC), silicon wafer Examples include.

[Coating layer containing copper oxide]
The coating layer includes, for example, copper oxide, a dispersant, and hydrazine. By using hydrazine as a reducing agent, it contributes to the reduction of copper oxide in the firing process, and a reduced copper layer with lower resistance can be produced.

The mass ratio of the reducing agent contained in the copper oxide ink as a coating layer (reducing agent mass/copper oxide mass) is preferably 0.0001 or more and 0.1 or less, more preferably 0.0001 or more and 0.05 or less, and Preferably it is 0.0001 or more and 0.03. When the mass ratio of the reducing agent is 0.0001 or more, the dispersion stability is improved and the resistance of the reduced copper layer is reduced. Moreover, when it is 0.1 or less, the long-term stability of the copper oxide ink is improved.

The average particle diameter of the fine particles containing cuprous oxide in the coating layer is 3 nm or more and 50 nm or less, more preferably 5 nm or more and 40 nm or less, and most preferably 10 nm or more and 30 nm or less. It is preferable that the average particle diameter is 50 nm or less because it tends to easily form a fine pattern on the substrate. It is preferable that the average particle diameter is 3 nm or more because the long-term storage stability of the dispersion is improved.

The required amount of the dispersant is proportional to the amount of copper oxide, and is adjusted in consideration of the required dispersion stability. The mass ratio of the dispersant (dispersant mass/copper oxide mass) contained in the copper oxide ink of this embodiment is 0.0050 or more and 0.30 or less, preferably 0.050 or more and 0.25 or less. , more preferably 0.10 or more and 0.23. The amount of dispersant affects dispersion stability; when the amount is small, agglomeration tends to occur, and when the amount is large, dispersion stability tends to improve. However, when the content of the dispersant in the copper oxide ink of this embodiment is 35% by mass or less, the influence of the residue derived from the dispersant can be suppressed in the conductive film obtained by firing, and the conductivity can be improved.

The acid value (mgKOH/g) of the dispersant is preferably 20 or more and 130 or less. More preferably, it is 30 or more and 100 or less. If it falls within this range, it is preferable because it provides excellent dispersion stability. This is particularly effective in the case of copper oxide having a small average particle size.

The thickness of the coating layer is preferably 1 nm or more and 10 μm or less, more preferably 100 nm or more and 5 μm or less, and even more preferably 200 nm or more and 1 μm or less, since there are no voids and a uniform reduced copper layer can be formed. preferable.

[Firing treatment]
In this embodiment, fine particles of copper oxide in the coating layer are reduced to produce copper, and these particles are fused and integrated with themselves, and with copper particles added to the copper oxide ink. A conductive film (reduced copper layer) is formed by oxidation. This process is called firing treatment.

The baking treatment in this embodiment can be performed by selectively irradiating the coating layer with light. Selective irradiation with a light beam may be performed, for example, by a photobaking method using a flash lamp or a laser alone or in combination.

[Light firing method]
For the photo-baking method, a flash light method using a discharge tube of xenon or the like as a light source or a laser light method can be applied. These methods expose copper oxide ink coated on a substrate to a high temperature for a short period of time by exposing it to high-intensity light for a short period of time, and then baking it.This process reduces copper oxide, sinters copper particles, and integrates them. , and a method of forming a conductive film by decomposing an organic component. Since the firing time is extremely short, this method causes less damage to the substrate and can be applied to resin film substrates with low heat resistance.

The flash light method uses a xenon discharge tube to instantly discharge the charge stored in a capacitor. It generates a large amount of pulsed light and irradiates it onto the copper oxide ink formed on the substrate, causing oxidation. This method instantly heats copper to a high temperature and transforms it into a conductive film. The exposure amount can be adjusted by the light intensity, emission time, light irradiation interval, and number of times.If the substrate has high light transmittance, copper oxide ink can be used even on resin substrates with low heat resistance, such as PET, PEN, and paper. It becomes possible to form a conductive pattern region by

Although the light emitting source is different, similar effects can be obtained by using a laser light source. In the case of a laser, in addition to the adjustment items of the flash light method, there is a degree of freedom in wavelength selection, and it is also possible to make a selection in consideration of the light absorption wavelength of the copper oxide ink on which the pattern is formed and the absorption wavelength of the substrate. Furthermore, exposure can be performed by beam scanning, and the exposure range can be easily adjusted by selecting exposure to the entire surface of the substrate or partial exposure. Types of lasers that can be used include YAG (yttrium aluminum garnet), YVO (yttrium vanadate), Yb (ytterbium), semiconductor lasers (GaAs, GaAlAs, GaInAs), and carbon dioxide gas. Instead, harmonics may be extracted and used as necessary.

In particular, when using a laser beam, the center wavelength thereof is preferably 300 nm or more and 1500 nm or less. For example, it is preferable that the center wavelength is 355 nm or more and 532 nm or less because this is a region where a coating film containing copper oxide absorbs. When the substrate or the casing is made of resin, particularly preferably the center wavelength is a laser wavelength of 355 nm, 405 nm, 445 nm, 450 nm, or 532 nm.

Further, the oscillation mode of the laser beam may be continuous wave oscillation (CW) or pulse oscillation, and can be selected as appropriate. When selecting pulse oscillation, the pulse width is preferably 1 to 100 nanoseconds, more preferably 5 to 80 nanoseconds, and even more preferably 10 to 50 nanoseconds. By selecting this range, baking can be performed appropriately without ablating the coating film.

The thickness of the reduced copper obtained by irradiating the coating layer containing copper oxide with a laser is preferably 1 nm or more and 10 μm or less, and 10 nm or more, since a uniform reduced copper layer can be formed and plating can be performed suitably. , more preferably 5 μm or less, and even more preferably 50 nm or more and 3 μm or less.

Selective irradiation with light beams refers to irradiating some areas of the coating layer with light beams. Selective irradiation with a light beam can be achieved, for example, by irradiating the coated layer with a light beam through a mask in a flash light method or a laser light method, or by directly drawing a desired pattern on the coated layer by beam scanning in a laser light method. This can be done by

In the firing process in this embodiment, the surface (base) of the support does not need to be flat. For example, the present invention can be applied to a case in which the support is three-dimensional.

With reference to FIG. 3, the method for manufacturing a conductive substrate according to this embodiment will be described in more detail. In FIG. 3(a), copper acetate is dissolved in a mixed solvent of water and propylene glycol (PG), hydrazine is added, and the mixture is stirred.

Next, in FIGS. 3(b) and 3(c), the supernatant and the precipitate were separated by centrifugation. Next, in FIG. 3(d), a phosphorus-containing organic substance and alcohol are added as a dispersant to the obtained precipitate and dispersed.

Next, in (e) and (f) of FIG. 3, concentration and dilution using the UF membrane module are repeated, the solvent is replaced, and a dispersion I (copper oxide ink) containing copper oxide is obtained.

In FIGS. 3(g) and (h), dispersion I is applied onto a PET substrate (indicated as "PET" in FIG. 3(h)) by a spray coating method, and the dispersion I is coated with copper oxide and phosphorus. A coating layer (indicated as "Cu ₂ O" in FIG. 3(h)) containing an organic substance is formed.

Next, in FIG. 3(i), the coating layer is selectively irradiated with light, a part of the coating layer is selectively fired, and copper oxide is converted into copper ("Cu" in FIG. 3(i)). ”). As a result, in FIG. 3(j), an insulating region containing copper oxide and phosphorus-containing organic matter (denoted as "A" in FIG. 3(j)) and a reduced copper layer containing copper (denoted as "A" in FIG. 3(j)) are formed on the substrate. A conductive substrate 10 (see FIG. 2) is obtained in which a single layer is formed in which 3(j) and 3(j) are arranged adjacent to each other (denoted as "B").

[Removal of unfired area]
The unfired areas 12 shown in FIG. 2 may be removed using a suitable cleaning solution. In this case, a conductive substrate is obtained in which only the firing region 13 remains on the substrate 11.

[Resin layer]
In this embodiment, after the resin layer is disposed on the coating layer, the coating layer may be irradiated with light by passing through the resin layer. That is, in the conductive substrate 10 shown in FIG. 2, a resin layer may be disposed to cover the surface of the single layer 14.

(oxygen barrier layer)
An example of the resin layer is an oxygen barrier layer. The oxygen barrier layer can prevent the coating layer from coming into contact with oxygen during light irradiation and can promote the reduction of copper oxide. This eliminates the need for equipment for creating an oxygen-free or low-oxygen atmosphere around the coating layer during light irradiation, for example, a vacuum atmosphere or an inert gas atmosphere, and can reduce manufacturing costs.

Further, the oxygen barrier layer can prevent the firing region 13 from peeling off or scattering due to heat of light irradiation or the like. Thereby, the conductive substrate 10 can be manufactured with high yield.

The oxygen barrier layer may be peeled off after the baking process. In that case, the unfired regions 12 are then removed as described above.

(Encapsulant layer)
Another example of the resin layer is a sealant layer. The encapsulant layer is newly placed after removing the oxygen barrier layer.

The oxygen barrier layer plays an important role mainly during manufacturing. On the other hand, the encapsulant layer protects the conductive pattern area from external stress in the finished product after manufacturing (the structure itself with a conductive pattern area and a product including the same), and protects the conductive pattern area from external stress. The long-term stability of the attached structure can be improved.

In this case, the sealing material layer, which is an example of the resin layer, preferably has a moisture permeability of 1.0 g/m ² /day or less. This is to ensure long-term stability, and by making the moisture permeability sufficiently low, it is possible to prevent moisture from entering the sealing material layer from outside and to suppress oxidation of the conductive pattern region.

The encapsulant layer is an example of a functional layer that provides a function to the structure with a conductive pattern area after the oxygen barrier layer is peeled off. It is also possible to give the structure with conductive pattern regions rigidity by giving it antifouling properties to protect it from contamination from the outside world, and by using a strong resin.

<Electroless plating>
Electroless plating using reduced copper as a catalyst is performed on the reduced copper layer of the conductive substrate obtained as described above, a plated copper layer is arranged to a desired thickness, and the reduced copper layer and plated copper layer are A structured conductive pattern is obtained. As a result, a structure with a conductive pattern region can be manufactured.

A general electroless plating method can be applied to the electroless plating. For example, in the electroless plating method, copper ions are reduced and precipitated by electrons released when a reducing agent such as formaldehyde contained in the electroless plating solution is oxidized on the catalyst surface, thereby forming a copper film. In this embodiment, since the aforementioned reduced copper acts as a catalyst, copper is deposited on the surface of the reduced copper, forming a plated copper layer.

On the other hand, according to the electroless plating method that is usually used industrially, a palladium catalyst is coordinated on the surface of a base material such as a resin, and when a reducing agent such as formaldehyde contained in the electroless plating solution is oxidized on the surface of the palladium catalyst. Copper ions are reduced and precipitated by the electrons emitted to form a copper film. According to this method, it becomes necessary to coordinate an expensive palladium catalyst on the surface of the substrate.

In this embodiment, since reduced copper acts as a catalyst, there is no need to coordinate an expensive palladium catalyst to the support.

<Electrolytic plating>
Electroplating is performed on the reduced copper layer of the conductive substrate obtained as described above, and the plated copper layer is arranged to a desired thickness to obtain a conductive pattern composed of the reduced copper layer and the plated copper layer. . As a result, a structure with a conductive pattern region can be manufactured.

A general electrolytic plating method can be applied to electrolytic plating. For example, in the electrolytic plating method, an electrode is placed on one side and a conductive substrate to be plated is placed on the other side in a solution (plating bath) containing copper ions. Then, direct current is applied between the electrode and the conductive substrate from an external direct current power source. In this embodiment, a current is applied to the reduced copper layer on the conductive substrate by connecting a jig, such as a clip, connected to one electrode of an external DC power source. do. As a result, copper ions are reduced at the interface of the reduced copper layer on the conductive substrate, copper is deposited, and a plated copper layer is formed.

The thickness of the plated copper layer is preferably 1 μm or more and 50 μm or less so that the necessary current can flow.

<Structure with conductive pattern area>
FIG. 4 is a schematic cross-sectional view showing a structure with a conductive pattern region according to this embodiment. As shown in FIG. 4, the structure 20 with a conductive pattern region includes a substrate 11, which is an example of a support, and the above-mentioned firing region 13, which is a reduced copper layer, and is disposed on a surface constituted by the substrate 11. and a plated copper layer 21 disposed on the firing region 13 by electroless plating or electrolytic plating using reduced copper as a catalyst.

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 and Comparative Examples.

[Hydrazine quantitative method]
Hydrazine was determined by the standard addition method.

To 50 μL of the sample (copper nanoink) were added 33 μg of hydrazine, 33 μg of a surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ), and 1 ml of a 1% benzaldehyde acetonitrile solution. Finally, 20 μL of phosphoric acid was added, and 4 hours later, GC/MS measurement was performed.

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

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

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

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

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

(Example 1)
Dissolve 806 g of copper (II) acetate monohydrate (manufactured by Kanto Kagaku Co., Ltd.) in a mixed solvent of 7560 g of distilled water (manufactured by Kyoei Pharmaceutical Co., Ltd.) and 3494 g of 1,2-propylene glycol (manufactured by Kanto Kagaku Co., Ltd.), The liquid temperature was brought to -5°C using an external temperature controller. 235 g of hydrazine monohydrate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added over 20 minutes, and after stirring for 30 minutes, the liquid temperature was brought to 25° C. using an external temperature controller and stirred for 90 minutes. After stirring, the mixture was separated into a supernatant and a precipitate by centrifugation. To 390 g of the obtained precipitate, 13.7 g of DISPERBYK-145 (manufactured by Big Chemie) (dispersant content 4 g), 54.6 g of Surflon S611 (manufactured by Seimi Chemical), and 907 g of ethanol (manufactured by Kanto Kagaku Co., Ltd.) were added. Dispersion was performed using a homogenizer under a nitrogen atmosphere to obtain 1365 g of a cuprous oxide dispersion.

The dispersion was well dispersed. The content of cuprous oxide was 20 g, and the particle size was 21 nm. The amount of hydrazine was 3000 ppm.

The obtained dispersion was applied to a polyimide film (manufactured by DuPont Toray, Kapton 500H, thickness 125 μm) by a spin coating method, and kept in an oven at 40°C for 2 hours to volatilize the solvent in the coating film. I got 1. The coating thickness of the obtained sample 1 was 10 μm.

Using a gas vane scanner, irradiate the coating layer of sample 1 with laser light (center wavelength 445 nm, output 1.2 W, continuous wave (CW)) while moving the focal position at a maximum speed of 300 mm/sec. In this way, a conductive pattern area containing copper with the desired dimensions of 25 mm x 1 mm was obtained. A coating film remained in areas that were not irradiated with laser light.

The resistance value of the conductive pattern region was measured by a four-terminal measurement method and was found to be 15 μΩcm.

Next, copper was laminated on the conductive pattern region by subjecting Sample 1 on which the conductive pattern region was formed to electrolytic plating treatment. As the electrolytic plating solution, a copper sulfate plating solution SC-50 manufactured by ENTHONE was used, and a current of 0.1 A was applied for 10 minutes. The thickness of the laminated copper was about 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.8 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 2)
Copper was laminated on the conductive pattern region by electrolytic plating by performing the same operation as in Example 1 except that the current value of electrolytic plating was set to 0.3 A. The thickness of the laminated copper was about 50 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 4 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 3)
After obtaining Sample 1 by performing the operations described in Example 1, a PET film was placed as a resin layer on the coating film with an acrylic slightly adhesive layer interposed therebetween. By carrying out the same operation as above, a laser beam was transmitted through the resin layer and irradiated to obtain a conductive pattern area containing copper having the desired dimensions of 25 mm x 1 mm. Thereafter, the acrylic slightly adhesive layer was peeled off, and the same operation as in Example 1 was performed to laminate copper on the conductive pattern area by electrolytic plating. The thickness of the laminated copper was about 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.8 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 4)
After obtaining a conductive pattern area by carrying out the operation described in Example 1, the coating layer remaining on the area not irradiated with laser light was washed away using ethanol. Thereafter, by carrying out the operations described in Example 1, copper was laminated on the conductive pattern area by electrolytic plating. The thickness of the laminated copper was about 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.8 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 5)
By performing the same operation as in Example 4, except that ethanol was replaced with a 1% concentration 2-aminoethanethiol aqueous solution and the washing removal operation was performed, electrolytic plating was performed. Copper was laminated on top of the conductive pattern area. The thickness of the laminated copper was about 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 4 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 6)
Using a gas vane scanner, a laser beam (center wavelength 532 nm, output 0.23 W, pulse wave repetition frequency 300 kHz, pulse width 30 nanoseconds) was applied to the coating layer of sample 1 while moving the focal position at a maximum speed of 100 mm/sec. By irradiating, a conductive pattern area containing copper with the desired dimensions of 25 mm x 1 mm was obtained. A coating film remained in areas that were not irradiated with laser light.

The resistance value of the conductive pattern region was measured by a four-terminal measurement method and was found to be 11 μΩcm.

Next, copper was laminated on the conductive pattern region by subjecting Sample 1 on which the conductive pattern region was formed to electrolytic plating treatment. As the electrolytic plating solution, alkaline copper plating solution CF-2170 manufactured by Meltex was used, and a current value of 0.05 A was applied until the thickness of the copper reached 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.3 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 7)
The dispersion obtained in Example 1 was applied to a polyimide film (manufactured by DuPont-Toray, Kapton 500H, thickness 125 μm) by spin coating and kept in an oven at 90°C for 2 hours to remove the solvent in the coating film. Sample 2 was obtained by volatilization. The coating thickness of the obtained sample 2 was 8 μm.

Using a gas vano scanner, a laser beam (center wavelength 532 nm, output 0.71 W, pulse wave repetition frequency 300 kHz, pulse width 30 nanoseconds) was applied to the coating layer of sample 2 while moving the focal position at a maximum speed of 25 mm/sec. By irradiating, a conductive pattern area containing copper with the desired dimensions of 25 mm x 1 mm was obtained. A coating film remained in areas that were not irradiated with laser light.

The resistance value of the conductive pattern region was measured by a four-terminal measurement method and was found to be 14 μΩcm.

Next, copper was laminated on the conductive pattern region by electroplating the sample 2 on which the conductive pattern region was formed. As the electrolytic plating solution, an alkaline copper plating solution CF-2170 manufactured by Meltex was used, and a current value of 0.05 A was applied until the thickness of the copper reached 20 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.0 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 8)
The dispersion obtained in Example 1 was applied to a glass substrate (manufactured by Schott Co., Ltd., Tempax Float, thickness 0.7 mm) by a spin coating method, and kept in an oven at 60°C for 2 hours to remove the solvent in the coating film. was evaporated to obtain Sample 3. The coating thickness of the obtained sample 3 was 1 μm.

Using a gas vano scanner, a laser beam (center wavelength 532 nm, output 0.65 W, pulse wave repetition frequency 300 kHz, pulse width 30 nanoseconds) was applied to the coating layer of sample 3 while moving the focal position at a maximum speed of 25 mm/sec. By irradiating, a conductive pattern area containing copper with the desired dimensions of 25 mm x 1 mm was obtained. A coating film remained in areas that were not irradiated with laser light.

The resistance value of the conductive pattern region was measured by a four-terminal measurement method and was found to be 10 μΩcm.

Next, copper was laminated on the conductive pattern region by electroplating the sample 3 on which the conductive pattern region was formed. As the electrolytic plating solution, alkaline copper plating solution CF-2170 manufactured by Meltex was used, and a current value of 0.05 A was applied until the thickness of the copper reached 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.2 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 9)
Using a gas vano scanner, a laser beam (center wavelength 355 nm, output 0.16 W, pulse wave repetition frequency 320 kHz, pulse width 25 nanoseconds) was applied to the coating layer of sample 1 while moving the focal position at a maximum speed of 100 mm/sec. By irradiating, a conductive pattern area containing copper with the desired dimensions of 25 mm x 1 mm was obtained. A coating film remained in areas that were not irradiated with laser light.

The resistance value of the conductive pattern region was measured by a four-terminal measurement method and was found to be 16 μΩcm.

Next, copper was laminated on the conductive pattern region by subjecting Sample 1 on which the conductive pattern region was formed to electrolytic plating treatment. As the electrolytic plating solution, alkaline copper plating solution CF-2170 manufactured by Meltex was used, and a current value of 0.05 A was applied until the thickness of the copper reached 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.5 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 10)
Using a gas vane scanner, irradiate the coating layer of sample 1 with laser light (center wavelength 532 nm, output 0.4 W, continuous wave (CW)) while moving the focal position at a maximum speed of 100 mm/sec. In this way, a conductive pattern area containing copper with the desired dimensions of 25 mm x 1 mm was obtained. A coating film remained in areas that were not irradiated with laser light.

The resistance value of the conductive pattern region was measured by a four-terminal measurement method and was found to be 16 μΩcm.

Next, copper was laminated on the conductive pattern region by subjecting Sample 1 on which the conductive pattern region was formed to electrolytic plating treatment. As the electrolytic plating solution, alkaline copper plating solution CF-2170 manufactured by Meltex was used, and a current value of 0.05 A was applied until the thickness of the copper reached 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.6 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

(Example 11)
After obtaining a conductive pattern area by carrying out the operation described in Example 6, the coating layer remaining on the area not irradiated with laser light was washed away with water. Thereafter, by carrying out the operations described in Example 6, copper was laminated on the conductive pattern area by electrolytic plating. The thickness of the laminated copper was about 10 μm.

The resistance value of the laminated copper was measured by a four-terminal measurement method and was found to be 3.6 μΩcm. The resistance was shown to be low enough to form an electrical circuit.

Note that the present invention is not limited to the above embodiments and examples. Design changes, etc. may be made to the above embodiments and examples based on the knowledge of those skilled in the art, and the above embodiments and examples may be arbitrarily combined, and such changes, etc. Embodiments are also included within the scope of the present invention.

INDUSTRIAL APPLICATION This invention is suitably used for the manufacture of a printed wiring board, an electronic device, an electromagnetic shield, an antistatic film, etc.

1 Copper oxide ink 2 Copper oxide 3 Phosphate ester salt 10 Conductive substrate 11 Substrate (support)
12 Unfired area (coating layer)
13 Firing area (reduced copper layer)
14 Single layer 20 Structure with conductive pattern area 21 Plated copper layer 22 Conductive pattern area

Claims (3)

a support, and
Consisting of a reduced copper layer with a layer thickness of 1 nm or more and 10 μm or less, arranged on the surface constituted by the support, and a plated copper layer with a layer thickness of 1 μm or more and 50 μm or less, arranged on the reduced copper layer. a conductive pattern area;
A structure with a conductive pattern region, wherein the reduced copper layer contains at least one selected from elemental phosphorus, phosphorus oxide, and phosphorus-containing organic material. The structure with a conductive pattern region according to claim 1, wherein the reduced copper layer is a fired body. The electrical conductivity according to claim 1 or 2, characterized in that at least one selected from the phosphorus element, phosphorus oxide, and phosphorus-containing organic substance is present in a segregated manner in the reduced copper layer. Structure with pattern area.

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