JP2019210469A - Copper oxide ink for inkjet, and manufacturing method of conductive substrate to which conductive pattern is added by using he same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a conductive film having high dispersion stability as an ink and having low resistance on a substrate. SOLUTION: An inkjet copper oxide ink (1) of the present invention contains copper oxide (2), a dispersant (3), and a reducing agent in a solvent, and the content of the reducing agent is represented by the following formula (1). ), The content of the dispersant is in the range of the following formula (2), and two kinds of solvents having a boiling point of 100 ° C. or higher are contained. 0.0001 ≦ (mass of reducing agent / mass of copper oxide) ≦ 0.10 (1) 0.0050 ≦ (mass of dispersant / mass of copper oxide) ≦ 0.30 (2) According to the present invention, copper oxide for inkjet As the ink, a conductive film having high dispersion stability and low resistance can be formed on the substrate. [Selection diagram] Figure 1

Description

  The present invention relates to an ink-jet copper oxide ink and a method for producing a conductive substrate provided with a conductive pattern using the same.

  The circuit board has a structure in which conductive wiring is provided on the board. A circuit board manufacturing method is generally as follows. First, a photoresist is applied on a substrate on which a metal foil is bonded. Next, the photoresist is exposed and developed to obtain a negative shape of a desired circuit pattern.

  Next, a 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 many drawbacks such as a large number of steps and is complicated and requires a photoresist material.

  On the other hand, a direct wiring printing technique (hereinafter referred to as PE (printed electronics)) that directly prints a desired wiring pattern on a substrate with a dispersion in which fine particles selected from the group consisting of metal fine particles and metal oxide fine particles are dispersed. ) Is noted. This technique has extremely high productivity because it requires a small number of processes and does not require the use of a photoresist material.

  Among direct printing, in particular, ink jet is a printing method in which ink is directly ejected from a nozzle to a substrate, and an ink jet with high coating accuracy is desired due to advantages such as simple and compact equipment. Also, unlike other printing, it is not necessary to raise a plate, so it is suitable for small-quantity multi-product production.

  By the way, as a generally used ink, a metal ink and a metal paste are exemplified. The metal ink is a dispersion in which ultrafine metal particles having an average particle diameter of several to several tens of nanometers are dispersed in a dispersion medium. When the metal ink is applied to the substrate and dried, and then heat-treated, the metal ink sinters at a temperature lower than the melting point of the metal due to a melting point drop unique to the ultrafine metal particles. ) Can be formed. A metal film obtained using metal ink has a thin film thickness and is close to a metal foil.

  On the other hand, the metal paste is a dispersion in which micrometer-sized metal fine particles and a binder resin are dispersed in a dispersion medium. Since the size of the fine particles is large, in order to prevent sedimentation, the particles are usually supplied in a highly viscous state. Therefore, it is suitable for application by screen printing and dispenser suitable for a material having high viscosity. The metal paste has a feature that a metal film having a large film thickness can be formed because the size of the metal particles is large.

  Copper is attracting attention as a metal used for the metal particles contained in such ink. In particular, as an alternative to ITO (Indium Tin Oxide), which is widely used as an electrode material for projected capacitive touch panels, in terms of resistivity, ion (electrochemical) migration, performance as a conductor, price, reserves, etc. Therefore, copper is the most promising.

  However, copper is likely to be oxidized with ultrafine particles of several tens of nanometers and needs to be subjected to an antioxidant treatment. The antioxidant treatment has a problem that it hinders sintering.

  In order to solve such problems, a copper thin film is formed by reducing ultra-fine copper oxide as a precursor and reducing the copper oxide to copper by an energy such as heat and actinic rays in an appropriate atmosphere. Has been proposed (see, for example, Patent Document 1).

  Since the surface diffusion itself in the ultrafine particles of copper oxide occurs at a temperature lower than 300 ° C., when the copper oxide is reduced to copper by energy in an appropriate atmosphere, the copper ultrafine particles become dense due to sintering. A random chain is formed, and the whole becomes a network, and desired electrical conductivity is obtained.

International Publication No. 2003/051562

  A metal thin film obtained by a PE method using metal ink (or metal paste) is required not only to have low resistivity but also to have little change over time. For example, regarding silver paste, it is known that silver easily undergoes oxidation in the atmosphere and is oxidized to increase the resistivity, so that the resistivity between silver particles deteriorates with time.

  However, there is no prior art document in which the stability of the resistivity of the metal film obtained by the PE method using the copper oxide ultrafine particles disclosed in Patent Document 1 as a precursor has been studied.

  In industrial use, the dispersion is also required to have excellent dispersion stability against changes with time at a high concentration.

  This invention is made | formed in view of this point, and the electroconductivity which provided the conductive pattern using the copper oxide ink for inkjet which can form the electrically conductive film with high dispersion stability as an ink, and low resistance on a board | substrate. Another object is to provide a method for manufacturing a conductive substrate.

  In addition, since the ink jet does not require a plate, and is simple and compact in equipment, an ink suitable for ink jet is desired. Therefore, in addition to the above, an object of the present invention is to provide a copper oxide ink for inkjet that is excellent in ejection performance for inkjet, has high coating accuracy, and can be continuously produced without clogging.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

That is, the copper oxide ink for inkjet according to one embodiment of the present invention contains copper oxide, a dispersant, and a reducing agent in a solvent, and the content of the reducing agent is in the range of the following formula (1), The content of the dispersant is in the range of the following formula (2), and the solvent is characterized by containing at least two kinds of the solvents having a boiling point of 100 ° C. or higher.
0.0001 ≦ (reducing agent mass / copper oxide mass) ≦ 0.10 (1)
0.0050 ≦ (dispersant mass / copper oxide mass) ≦ 0.30 (2)

  With this configuration, by limiting the mass range of the reducing agent and the dispersing agent with respect to copper oxide, the dispersion stability is improved and the resistance of the conductive film is effectively reduced. Further, by limiting the type of solvent, high-definition L / S (line and space) formation becomes possible, and further, there is no nozzle clogging during ink jet printing, and an effect of excellent continuous productivity can be obtained. In addition, since baking treatment can be performed using plasma, light, and heat, organic substances in the copper oxide are decomposed, baking of the copper oxide is promoted, and a conductive film having low resistance can be formed.

  In the copper oxide ink for inkjet according to one embodiment of the present invention, the copper oxide is preferably cuprous oxide. With this configuration, the reduction of copper oxide is easy, and the copper produced by the reduction can be easily sintered.

  In the copper oxide ink for inkjet according to one embodiment of the present invention, the reducing agent is hydrazine, hydrazine hydrate, sodium, carbon, potassium iodide, oxalic acid, iron (II) sulfide, sodium thiosulfate, ascorbic acid, chloride. It is preferable to contain at least one selected from the group consisting of tin (II), diisobutylaluminum hydride, formic acid, sodium borohydride, and sulfite. With this configuration, the dispersion stability of copper oxide is improved and the resistance of the conductive film is lowered.

  In the copper oxide ink for ink jet of one embodiment of the present invention, the reducing agent is preferably hydrazine or hydrazine hydrate. With this configuration, the dispersion stability of the copper oxide is further improved, and it contributes to the reduction of the copper oxide in the firing, so that the resistance of the conductive film is further reduced.

  In the copper oxide ink for inkjet according to one embodiment of the present invention, the acid value of the dispersant is preferably 20 or more and 130 or less. Thereby, the dispersion stability of the copper oxide ink for inkjet can be improved.

In the copper oxide ink for inkjet according to one aspect of the present invention, the copper oxide ink for inkjet includes an inkjet regulator, and the number average molecular weight of the inkjet modifier is 350 or more and 30000 or less, and is in the range of the following formula (3). It is preferable. With this configuration, there is no nozzle clogging during ink jet printing, and an effect of excellent continuous productivity can be obtained. Further, when the baking treatment is performed using plasma, light, or heat, the organic matter in the copper oxide is decomposed, the baking of the copper oxide is promoted, and a uniform conductive film with low resistance can be formed.
0.010 ≦ (Mass of inkjet adjusting agent / Mass of copper oxide ink for inkjet) ≦ 0.40 (3)

  The conductive substrate manufacturing method of one embodiment of the present invention uses the above-described copper oxide ink for inkjet, forms a pattern on the substrate using an inkjet apparatus, generates plasma in an atmosphere containing a reducing gas, A baking process is performed on the pattern. This configuration enables low-temperature firing. Moreover, since the organic substance in copper oxide is decomposed | disassembled effectively, baking of copper oxide is accelerated | stimulated more and the electroconductive board | substrate provided with the electrically conductive film with lower resistance can be manufactured.

  According to a method for manufacturing a conductive substrate of one embodiment of the present invention, a pattern is formed on a substrate using the above-described copper oxide ink for inkjet and an inkjet apparatus, and then the pattern is subjected to heat or light irradiation treatment. It is characterized by performing. With this configuration, since the wavelength of light can be selected, the light absorption wavelength of the copper oxide ink and the substrate can be taken into consideration. In addition, since the baking time by heat or light can be shortened, the organic substance in the copper oxide is effectively decomposed while suppressing damage to the substrate, and a conductive substrate having a conductive film with low resistance can be manufactured. .

  According to the present invention, a conductive film having high dispersion stability and low resistance can be formed on a substrate as a copper oxide ink for inkjet.

It is a schematic diagram which shows the relationship between the copper oxide which concerns on this Embodiment, and phosphate ester salt. It is a cross-sectional schematic diagram which shows the electroconductive board | substrate which concerns on this Embodiment. It is explanatory drawing which shows each process of the manufacturing method of the electroconductive board | substrate which concerns on this Embodiment. It is a top view of the electroconductive board | substrate with which the solder layer which concerns on this Embodiment was formed.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail, but the present invention is not limited to the present embodiment. FIG. 1 is a schematic diagram showing the relationship between copper oxide and phosphate ester salt according to the present embodiment. FIG. 2 is a schematic cross-sectional view showing the conductive substrate according to the present embodiment. FIG. 3 is an explanatory view showing each step of the method for manufacturing the conductive substrate according to the present embodiment. FIG. 4 is a top view of the conductive substrate on which the solder layer according to the present embodiment is formed.

<Copper oxide ink for inkjet>
The copper oxide ink of the present embodiment is characterized in that the solvent contains (1) copper oxide, (2) a dispersant, and (3) a reducing agent. By including a reducing agent in the copper oxide ink, reduction of copper oxide to copper is promoted in firing, and copper sintering is promoted.

The content of the reducing agent satisfies the range of the following formula (1). When the mass ratio of the reducing agent is 0.0001 or more, the dispersion stability is improved and the resistance of the copper film is lowered. If it is 0.1 or less, the long-term stability of the copper oxide ink is improved.
0.0001 ≦ (reducing agent mass / copper oxide mass) ≦ 0.10 (1)

  The reducing agent is hydrazine, hydrazine hydrate, sodium, carbon, potassium iodide, oxalic acid, iron (II) sulfide, sodium thiosulfate, ascorbic acid, tin (II) chloride, diisobutylaluminum hydride, formic acid, It is preferable to contain at least one selected from the group consisting of sodium borohydride and sulfite. Thereby, the dispersion stability of copper oxide is improved and the resistance of the conductive film is lowered.

  The reducing agent is particularly preferably hydrazine or hydrazine hydrate. By using hydrazine or hydrazine hydrate as the reducing agent of the copper oxide ink, the dispersion stability of the copper oxide is further improved, contributing to the reduction of the copper oxide in the firing, and the resistance of the conductive film is further reduced.

Moreover, content of a dispersing agent satisfy | fills the range of following formula (2). Thereby, aggregation of copper oxide is suppressed and dispersion stability is improved.
0.0050 ≦ (dispersant mass / copper oxide mass) ≦ 0.30 (2)

  The acid value of the dispersant is preferably 20 or more and 130 or less. Thereby, the dispersion stability of the copper oxide ink is improved.

  The copper oxide is preferably cuprous oxide. Thereby, the reduction | restoration of copper oxide becomes easy and the copper produced | generated by reduction | restoration can be sintered easily.

  In the copper oxide ink for ink jet according to the present embodiment, by limiting the range of the mass ratio of the reducing agent and the dispersant to copper oxide, the dispersion stability is improved and the resistance of the conductive film is effectively reduced. Further, the dispersion stability is effectively improved by limiting the range of the acid value of the dispersant. In addition, since baking treatment can be performed using plasma, light, and heat, organic substances in the copper oxide are decomposed, baking of the copper oxide is promoted, and a conductive film having low resistance can be formed. For this reason, various copper wirings, such as wiring for carrying electricity, heat radiation, electromagnetic shielding, and circuits, can be provided. In the present embodiment, it is possible to obtain a copper oxide ink for inkjet which has high coating accuracy and can be continuously produced without clogging. Inkjet requires no plate, is simple and has compact equipment, so the copper oxide ink of this embodiment can be used to optimize the manufacturing process using inkjet, improving yield and reducing manufacturing costs. I can plan.

  Next, the state of the copper oxide and the dispersant in the copper oxide ink for inkjet will be described with reference to FIG.

  As shown in FIG. 1, in the copper oxide ink 1 for inkjet, around the copper oxide 2 which is an example of copper oxide, for example, a phosphate ester salt 3 which is an example of a phosphorus-containing organic substance is a phosphorous. 3a is surrounded on the inside and ester salt 3b is surrounded on the outside. Since the phosphate ester salt 3 exhibits electrical insulation, electrical conduction between the adjacent copper oxides 2 is hindered. Further, the phosphate ester salt 3 suppresses aggregation of the copper oxide ink 1 due to a steric hindrance effect. The copper oxide 2 is in a state dispersed in the solvent 4.

  Although the copper oxide 2 is a semiconductor and is conductive, it is covered and dispersed with the phosphate ester salt 3 that exhibits electrical insulation, so the copper oxide ink 1 exhibits electrical insulation.

  Copper oxide can be reduced to copper by applying a baking treatment with plasma, light, or heat to a coating containing copper oxide and a phosphorus-containing organic substance (a coating using the copper oxide ink 1). Copper in which copper oxide is thus reduced is referred to as reduced copper. Further, the phosphorus-containing organic substance in the coating film is modified to a phosphorus oxide. In the phosphor oxide, an organic substance such as the above-described ester salt 3b (see FIG. 1) is decomposed by heat of a laser or the like and does not exhibit electrical insulation.

  Further, as shown in FIG. 1, when copper oxide 2 is used, the copper oxide is changed into reduced copper and sintered by heat of a laser or the like, and adjacent copper oxides 2 are integrated. Thus, a region having excellent electrical conductivity (hereinafter referred to as “conductive pattern”) can be formed.

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

[(1) Copper oxide]
In this embodiment, copper or copper oxide is used as one of the metal oxide components. As the copper oxide, cuprous oxide (Cu ₂ O) is preferable. This is because it is easy to reduce among metal oxides, and further, it is easy to sinter by using fine particles, and because it is copper, it is cheaper than noble metals such as silver. This is because it is advantageous.

  The average secondary particle diameter of copper oxide is not particularly limited, but is preferably 500 nm or less, more preferably 200 nm or less, and still more preferably 80 nm or less. The average secondary particle diameter of copper oxide is preferably 5 nm or more, more preferably 10 nm or more, and further preferably 15 nm or more. Here, the average secondary particle diameter is an average particle diameter of an aggregate (secondary particle) formed by collecting a plurality of primary particles.

  The average secondary particle diameter of 500 nm or less is preferable because a fine pattern tends to be easily formed on the substrate. An average secondary particle diameter of 5 nm or more is preferable because long-term storage stability of the copper oxide ink is improved. The average secondary particle diameter of copper oxide can be measured by, for example, a transmission electron microscope or a scanning electron microscope.

  Further, the preferable range of the average primary particle diameter of the copper oxide is that the metal is obtained by reduction treatment, and from the viewpoint of electrical properties, the firing conditions are further changed to the substrate in consideration of the use of the resin substrate. From the viewpoint of reducing the damage given, it is necessary to lower the temperature. For this reason, a preferable average primary particle diameter is 100 nm or less, More preferably, it is 50 nm or less, More preferably, it is 20 nm or less. When the average primary particle diameter is 100 nm or less, the input energy can be reduced so as not to damage the substrate in the baking treatment described later. The lower limit of the average particle primary diameter of cuprous oxide is not particularly limited, but is preferably 1 nm or more from the viewpoint of ease of handling. Thereby, since the particle diameter is too small, it is possible to suppress an increase in the amount of the dispersant used in order to maintain dispersion stability. The average primary particle diameter can be measured with a transmission electron microscope or a scanning electron microscope. The average particle diameter can be measured by the cumulant method using, for example, FPAR-1000 manufactured by Otsuka Electronics.

  The copper oxide in the copper oxide ink is easily reduced to a metal by plasma treatment, heat treatment, and light treatment, and when it is sintered, it obtains conductivity, but further acts as a binder for the added copper particles. This contributes to lowering resistance and improving strength. In the present embodiment, the average particle size of the cuprous oxide particles does not affect the crack prevention effect by the copper particles having a wire shape, a dendritic shape, and a scale shape, which will be described later.

Regarding cuprous oxide, a commercially available product may be used, or it may be synthesized and used. As a commercially available product, there is one having an average primary particle diameter of 5 to 50 nm manufactured by Rare Metals Laboratory. Examples of the synthesis method include the following methods.
(1) Water and a copper acetylacetonate complex are added to a polyol solvent, and the organic copper compound is once heated and dissolved, then water necessary for the reaction is added afterwards, and the temperature is further raised to reduce the organic copper temperature. The method of reducing to heating.
(2) A method in which an organic copper compound (copper-N-nitrosophenylhydroxyamine complex) is heated 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 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 is obtained.

  Since the obtained cuprous oxide is a soft agglomerate, a copper oxide dispersion dispersed in a solvent is prepared and used for printing and coating. After the synthesis is completed, the synthesis solution and cuprous oxide are separated, and a known method such as centrifugation may be used. Further, the obtained cuprous oxide is added with a dispersant and a solvent described later, and is stirred and dispersed by a known method such as a homogenizer. Depending on the solvent, it may be difficult to disperse and the dispersion may be insufficient. In such a case, as an example, after dispersion using a solvent such as an easily dispersible alcohol such as butanol, substitution with a desired solvent and desired Concentration to a concentration of An example of the method is a method of repeating concentration with a UF membrane, dilution with a desired solvent, and concentration. The copper oxide dispersion obtained in this manner may be mixed with copper particles or the like by the method described later, and the copper oxide ink of the present embodiment can be obtained. This copper oxide ink is used for printing and coating.

[(2) Dispersant]
Next, the dispersant will be described. As a dispersing agent, phosphorus containing organic substance is mentioned, for example. The phosphorus-containing organic substance may be adsorbed on copper oxide, and in this case, aggregation is suppressed by a steric hindrance effect. The phosphorus-containing organic material 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 a plurality of types of molecules.

  Although the number average molecular weight of a dispersing agent does not have a restriction | limiting in particular, For example, it is preferable that it is 300-30000. When it is 300 or more, the insulating property is excellent, and the dispersion stability of the obtained copper oxide ink tends to increase. When it is 30000 or less, firing is easy. The structure is preferably a phosphate ester of a high molecular weight copolymer having a group having an affinity for copper oxide. For example, the structure of the chemical formula (1) is preferable because it adsorbs to copper oxide, particularly cuprous oxide, and is excellent in adhesion to the substrate.

  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, a residue of the organic substance is less likely to remain after firing, and a conductive pattern having a low resistivity can be obtained.

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

  Although the absorption characteristic of a phosphorus containing organic substance is not limited, It is preferable that the light used for baking can be absorbed. For example, in the case of performing light irradiation treatment (for example, light irradiation treatment with laser light) for firing, a phosphorus-containing organic substance that absorbs light having a light emission wavelength of, for example, 355 nm, 405 nm, 445 nm, 450 nm, 532 nm, or 1056 nm is used. It is preferable to use it. When the substrate is a resin, the wavelengths of 355 nm, 405 nm, 445 nm, and 450 nm are particularly preferable.

  As the dispersant, known ones can be used, for example, a salt of a long chain polyaminoamide and a polar acid ester, an unsaturated polycarboxylic acid polyaminoamide, a polycarboxylate of polyaminoamide, a long chain polyaminoamide and an acid polymer. And a polymer having a basic group such as a salt thereof. Also, acrylic polymers, acrylic copolymers, modified polyester acids, polyether ester acids, polyether carboxylic acids, polymer alkyl ammonium salts such as polycarboxylic acids, amine salts, amidoamine salts and the like can be mentioned. As such a dispersant, a commercially available one can be used.

  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, DISPERB 145, DISPERBYK-160, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-2155, DISPERBYK-2163, DISPERBYK-2164, DISPERBYK-180, DISPERBYK-2000, DISPERBY16-SP20 BYK-9076, BYK-9077, TERRA-204, TERRA-U (manufactured by Big 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 Enomoto Kasei Co., Ltd.), PRISURF (registered trademark) M208F, PRISURF DBS (manufactured by Daiichi Kogyo Seiyaku) and the like. 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 (dispersant mass / copper oxide mass) of the dispersant contained in the copper oxide ink of the present embodiment is 0.0050 or more and 0.30 or less, preferably 0.050 or more and 0.25 or less, More preferably, it is 0.10 or more and 0.23 or less. The amount of the dispersant affects the dispersion stability. When the amount is small, the dispersion tends to aggregate, and when the amount is large, the dispersion stability tends to be improved. However, when the content of the dispersant in the copper oxide ink of the present embodiment is 35% by mass or less, in the conductive film obtained by firing, the influence of the residue derived from the dispersant can be suppressed 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. It is preferable to enter this range because of 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), “DISPERBYK-145” (acid value) manufactured by BYK-Chemie 76), “DISPERBYK-118” (acid value 36), “DISPERBYK-180 (acid value 94)” and the like.

[(3) Reducing agent]
Next, the reducing agent will be described. As reducing agents, hydrazine, hydrazine hydrate, sodium, carbon, potassium iodide, oxalic acid, iron (II) sulfide, sodium thiosulfate, ascorbic acid, tin (II) chloride, diisobutylaluminum hydride, formic acid, hydrogen Examples thereof include sodium borohydride and sulfite. In the firing, the reducing agent is most preferably hydrazine or hydrazine hydrate from the viewpoint of contributing to reduction of copper oxide, particularly cuprous oxide, and capable of producing a copper film having lower resistance. Further, by using hydrazine or hydrazine hydrate, the dispersion stability of the copper oxide ink can be maintained, and the resistance of the copper film can be lowered.

  The required amount of reducing agent is proportional to the amount of copper oxide and is adjusted in consideration of the required reducing properties. The mass ratio of the reducing agent contained in the copper oxide ink of the present embodiment (reducing agent mass / copper oxide mass) is preferably 0.0001 or more and 0.10 or less, more preferably 0.0001 or more and 0.05 or less. More preferably, it is 0.0001 or more and 0.03 or less. When the mass ratio of the reducing agent is 0.0001 or more, the dispersion stability is improved and the resistance of the copper film is lowered. If it is 0.10 or less, the long-term stability of the copper oxide ink is improved.

[(4) Inkjet adjuster]
Next, the ink jet adjusting agent will be described. The copper oxide ink for inkjet according to the present embodiment can further contain an inkjet regulator. Examples of the inkjet modifier include graphene, graphene oxide, carbon nanotube, acrylic polymer, acrylic latex, silicone polymer, acrylic silicone latex, thiophene polymer, fluorine-containing organic compound, and polyethylene glycol. By including an ink jet adjusting agent in the copper oxide ink for ink jet, there is no nozzle clogging during ink jet printing, and an effect of excellent continuous productivity can be obtained. Moreover, the line after discharge can be printed neatly. When the baking treatment is performed using plasma, light, or heat, organic substances in the copper oxide are decomposed, the baking of the copper oxide is promoted, and a uniform conductive film with low resistance can be formed.

  The number average molecular weight of the inkjet adjusting agent is preferably 350 or more and 30000 or less, more preferably 500 or more and 20000 or less, and further preferably 1000 or more and 15000 or less. When it is 350 or more, clogging of nozzles during ink jet printing can be suppressed, and when it is 30000 or less, it is easy to mix with copper oxide ink for ink jet.

  The necessary amount of the inkjet adjusting agent is proportional to the amount of the copper oxide ink for inkjet, and is adjusted in consideration of the required inkjet printability. The mass ratio of the inkjet adjusting agent contained in the inkjet copper oxide ink of the present embodiment (inkjet adjusting agent mass / inkjet copper oxide ink mass) is preferably 0.010 or more and 0.40 or less, more preferably 0.8. It is 020 or more and 0.30 or less, More preferably, it is 0.050 or more and 0.20 or less. When the mass ratio of the inkjet adjusting agent is 0.00010 or more, the ejection stability during inkjet printing is improved. If it is 0.40 or less, the long-term stability of the copper oxide ink is improved.

[solvent]
The copper oxide ink for inkjet according to the present embodiment includes at least two types of solvents (dispersion media) having a boiling point of 100 ° C. or higher in addition to the above-described constituent components. By including at least two types of solvents (dispersion media) having a boiling point of 100 ° C. or higher, it is preferable to slow down drying and eliminate clogging of the head. Moreover, since it can be used for adjusting the contact angle with the substrate, it is good for high-definition printing. Furthermore, since one type is used for clogging of the head and the other type is used for adjusting the contact angle with the reduction aid or the substrate by heat, mixing of the two types is preferable.

  The solvent (dispersion medium) used in this embodiment is selected from those capable of dissolving the dispersant from the viewpoint of dispersion. On the other hand, from the viewpoint of forming a conductive pattern using copper oxide ink, since the volatility of the solvent affects workability, it is suitable for a conductive pattern formation method, for example, a printing or coating method. There must be. Therefore, the solvent may be selected from the following solvents according to the dispersibility and the workability of printing and coating.

  Specific examples of the solvent include the following solvents. 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 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, Ethylene 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- Tilbutanol, 1-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, 2-octanol, n-nonyl alcohol, 2,6 dimethyl-4-heptanol, n-decanol, cyclohexanol, methyl Examples include cyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, diacetone alcohol and the like. In addition to those specifically described, alcohol, glycol, glycol ether, glycol ester solvents can be used as the solvent. These may be used singly or may be used in combination, and are selected in consideration of the evaporation property, the printing equipment, and the solvent resistance of the substrate to be printed according to the printing method.

  It is preferable to add at least two types of solvents having boiling points of 100 ° C. or higher, particularly in the case of inkjet printing, in terms of high-definition printability and continuous production without clogging. Specifically, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol tertiary butyl ether, dipropylene glycol monomethyl ether, ethylene glycol butyl ether, ethylene glycol ethyl ether, ethylene Glycol mono-normal-butyl ether, ethylene glycol methyl ether, ethylene glycol, diethylene 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- All, 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, 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-trimethyl Examples include cyclohexanol, benzyl alcohol, decalin, tetralin, γ-butyrolactone, γ-valerolactone, N methylpyrrolidone, toluene, xylene, N-ethyl-2-pyrrolidone, acetonitrile, water, and the like.

  As the solvent, a monoalcohol having 10 or less carbon atoms is more preferable, and a carbon number of 8 or less is more preferable. Among monoalcohols having 8 or less carbon atoms, n-butanol, i-butanol, sec-butanol, and t-butanol are more preferable because dispersibility, volatility, and viscosity are particularly suitable. These monoalcohols may be used alone or in combination. In order to suppress a decrease in the dispersibility of copper oxide, the monoalcohol preferably has 8 or less carbon atoms in order to disperse more stably by interaction with the dispersant. Further, when the number of carbon atoms is selected to be 8 or less, the resistance value is preferably lowered.

  In the copper oxide ink for inkjet according to the present embodiment, selection and combination of solvents are important. Any of the above-mentioned solvents has a boiling point of 100 ° C. or higher, but in this embodiment, it is necessary to combine at least two of them.

  In the combination of two types of solvents, for example, at least one type is preferably ethylene glycol, diethylene glycol, or propylene glycol, and another type is n-butanol, i-butanol, 2-butanol, t-butanol, or 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-trimethyl cyclohexanol, benzyl alcohol, decalin, tetralin, gamma-butyrolactone, .gamma.-valerolactone, N-methyl pyrrolidone, toluene, xylene, N- ethyl-2-pyrrolidone, acetonitrile, may contain water preferable. According to the combination of the above solvents, the copper oxide ink for jets has a fine line width after printing, stable ink ejection, and excellent in mass production.

<Preparation of copper oxide and copper oxide ink (dispersion) containing copper>
The dispersion containing cuprous oxide and copper particles, that is, the copper oxide ink for inkjet, is prepared by mixing copper fine particles and, if necessary, a solvent (dispersion medium) at a predetermined ratio with the above-described copper oxide dispersion. , For example, by mixing with a mixer method, ultrasonic method, three-roll method, two-roll method, attritor, homogenizer, Banbury mixer, paint shaker, kneader, ball mill, sand mill, auto-revolving mixer, etc. can do. As a dispersion treatment method, it is preferable to use a homogenizer. In the present embodiment, when the dispersion is dispersed and dispersed by a known method such as a homogenizer, the dispersion is performed in an inert atmosphere such as a nitrogen atmosphere.

  Part of the solvent is already contained in the copper oxide dispersion that has already been prepared. If the amount contained in this copper oxide dispersion is sufficient, it is not necessary to add it in this step, and the viscosity must be reduced. In this case, it may be added in this step as necessary. Or you may add after this process. The solvent may be the same as or different from that added at the time of preparing the copper oxide dispersion.

  In addition, if necessary, an organic binder, an antioxidant, a reducing agent, metal particles, and a metal oxide may be added, and a metal, a metal oxide, a metal salt, and a metal complex may be included as impurities.

  In addition, since wire-like, dendritic, and scaly copper particles have a large crack-preventing effect, they may be added singly or in combination with a plurality of copper particles such as spherical, dice, polyhedron, and other metals, and the surface is oxidized. You may coat | cover with a thing and another metal with good electroconductivity, for example, silver.

  In addition, when adding one or a plurality of metal particles other than copper having a wire shape, a dendritic shape, or a scale shape, since it has a crack preventing effect in the same way as a similarly shaped copper particle, However, it is necessary to consider migration, particle strength, resistance value, copper erosion, formation of intermetallic compounds, cost, and the like. 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 or the like, or additionally used. However, as in the case of metal particles, it is necessary to consider migration, particle strength, resistance, copper erosion, formation of intermetallic compounds, cost, and the like. The addition of these metal particles and metal oxide particles can be used for adjusting the sintering of the conductive film, the resistance, the conductor strength, the absorbance at the time of light baking, and the like. Even if these metal particles and metal oxide particles are added, cracks are sufficiently suppressed due to the presence of wire-like, dendritic and scaly copper particles. These metal particles and metal oxide particles may be used alone or in combination of two or more, and there is no limitation on the shape. For example, silver and silver oxide are expected to have effects such as a decrease in resistance and a decrease in firing temperature.

  However, silver is a noble metal and is expensive, and from the viewpoint of preventing cracks, the addition amount of silver is preferably within a range that does not exceed wire-like, dendritic, and scaly copper particles. In addition, tin has an advantage that it is inexpensive and easy to sinter because of its low melting point. However, the resistance tends to increase, and from the viewpoint of preventing cracks, the addition amount of tin is preferably in a range not exceeding the wire-like, dendritic, scaly copper particles and cuprous oxide. Cupric oxide works as a light absorber and heat ray absorber in a method using light and infrared rays such as a flash lamp and a laser. However, cupric oxide is more difficult to reduce than cuprous oxide, and the amount of cupric oxide added is less than cuprous oxide from the viewpoint of preventing peeling from the substrate due to the large amount of gas generation during reduction. Is preferred.

  In this embodiment, even if it contains metals other than copper, copper particles other than wire, dendritic, and scaly, and metal oxides other than copper oxide, the effect of preventing cracks and improving the temporal stability of resistance are Demonstrated. However, metals other than copper, copper particles other than wire-like, dendritic, and flaky, and metal oxides other than copper oxide are less than wire-like, dendritic, and flaky copper particles and copper oxide. Is preferred. Further, the addition ratio of metal other than copper, copper particles other than copper, dendritic and scaly, and metal oxides other than copper oxide to the copper, dendritic, and flaky copper particles and copper oxide is 50% or less. More preferably, it is 30% or less, and more preferably 10% or less.

<Conductive substrate>
The method for manufacturing a conductive substrate according to the present embodiment uses the copper oxide ink according to the present embodiment, forms a pattern on the substrate using an inkjet apparatus, and bakes the pattern to conduct the conductive on the substrate. A pattern is formed.

[Configuration of conductive substrate]
As shown in FIG. 2, the conductive substrate 10 includes a substrate 11 and a conductive pattern 13 containing reduced copper on a surface formed by the substrate 11 in a sectional view. The conductive pattern 13 contains a phosphorus element. In the conductive pattern 13, the organic matter contained in the copper oxide ink is decomposed in the step of baking the copper oxide ink, so that the wettability of the solder in the conductive pattern 13 is increased. Therefore, a solder layer can be easily formed on the surface of the conductive pattern 13.

[Method of coating copper oxide ink for inkjet onto substrate]
A coating method using copper oxide ink will be described. The copper oxide ink for inkjet according to the present embodiment literally shows a remarkable effect in printing using inkjet. Here, a printing method of inkjet printing will be described.

  In the present embodiment, the ink jet ink is an ink used in a printing mode (ink jet printer) that uses a method in which ink is atomized and sprayed directly onto a printing medium.

  From the above printing method, in order to discharge the liquid without clogging from the head, the physical properties such as the particle diameter of copper oxide, a dispersant for imparting dispersion stability, and the boiling point of the solvent should be optimized. Is important, the ink of the present embodiment has a remarkable effect by satisfying the above requirements. Further, it is preferable to add a reducing agent since the wiring having reduced resistance can be made.

[substrate]
The substrate used in this embodiment is not particularly limited, and is composed of an inorganic material or an organic material.

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

  Examples of the organic material include a polymer material and paper. As the polymer material, a resin film can be used. Polyimide (PI), polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polyester, polycarbonate (PC), polyvinyl alcohol (PVA) ), Polyvinyl butyral (PVB), polyacetal (POM), polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE) ), Polyphenylene sulfide (PPS), polyether ketone (PEK), polyphthalamide (PPA), polyether nitrile (PEN), polybenzimidazole (PBI), polycarbodiimi , Polysiloxane, polymethacrylamide, nitrile rubber, acrylic rubber, polyethylene tetrafluoride, epoxy resin, phenol resin, melamine resin, urea resin, polymethyl methacrylate resin (PMMA), polybutene, polypentene, ethylene-propylene copolymer , Ethylene-butene-diene copolymer, polybutadiene, polyisoprene, ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer, polyethylene (PE), Polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polyetheretherketone (PEEK), phenol novolac, benzocyclobutene, polyvinylphenol, polychloropyrene, polyoxy Tylene, polysulfone (PSF), polyphenylsulfone resin (PPSU), cycloolefin polymer (COP), acrylonitrile / butadiene / styrene resin (ABS), acrylonitrile / styrene resin (AS), nylon resin (PA6, PA66) poly Examples thereof include butyl terephthalate resin (PBT), polyethersulfone resin (PESU), polytetrafluoroethylene resin (PTFE), polychlorotrifluoroethylene (PCTFE), and silicone resin. In particular, PI, PET, and PEN are preferable from the viewpoints of flexibility and cost. The thickness of the substrate can be, for example, 1 μm to 10 mm, preferably 25 μm to 250 μm. A thickness of the substrate of 250 μm or less is preferable because an electronic device to be manufactured can be reduced in weight, space saving, and flexibility.

  Examples of the paper include high-quality paper made from general pulp as raw material, medium-quality paper, coated paper, cardboard, and other paper such as cardboard and cellulose nanofiber. In the case of paper, one obtained by dissolving a polymer material or one obtained by impregnating and curing a sol-gel material can be used. Further, these materials may be laminated and used. For example, paper phenolic base materials, paper epoxy base materials, glass composite base materials, composite base materials such as glass epoxy base materials, Teflon (registered trademark) base materials, alumina base materials, low-temperature and low-humidity co-fired ceramics (LTCC), silicon wafers Etc. In addition, the board | substrate in this embodiment means the board | substrate material of the circuit board sheet | seat for forming a wiring pattern, or the housing | casing material of a housing | casing with wiring.

  In addition, since the printing system of inkjet printing is a system that directly ejects ink, it is not required that the printing medium be flat. That is, the print medium has a surface shape such as a curved surface, an inclined surface, a combination of a plurality of surfaces having different inclination angles, or a combination of a flat surface and a curved surface. It is not limited.

[Coating film containing copper oxide]
A coating film contains a hydrazine as a reducing agent with a copper oxide and a dispersing agent, for example. By using hydrazine, it is possible to produce a copper film having a lower resistance that contributes to reduction of copper oxide in firing.

<Products containing paint films>
In the present embodiment, the product including the coating film includes copper oxide, a dispersant, and a reducing agent, the content of the reducing agent is in the range of the following formula (1), and the content of the dispersing agent is the following formula. It is the range of (2).
0.0001 ≦ (reducing agent mass / copper oxide mass) ≦ 0.10 (1)
0.0050 ≦ (dispersant mass / copper oxide mass) ≦ 0.30 (2)

  With this configuration, by limiting the mass range of the reducing agent and the dispersing agent with respect to copper oxide, the dispersion stability of the copper oxide ink for inkjet is improved, and the resistance of the conductive film obtained by firing is effectively reduced. . In addition, since baking treatment can be performed using plasma, light, and heat, organic substances in the copper oxide are decomposed, baking of the copper oxide is promoted, and a conductive film having low resistance can be formed. In the present embodiment, the coating film can further contain an inkjet adjusting agent. The preferred material and number average molecular weight of the ink jet adjusting agent are as described above.

  The product including the coating film here refers to, for example, the state shown in FIG.

  In this embodiment, it is preferable that the copper oxide of a coating film is cuprous oxide. With this configuration, the reduction of the copper oxide is easy, and the copper generated by the reduction can be easily sintered, so that the conductive film can be easily formed.

  In this embodiment, the reducing agent of the coating film is hydrazine, hydrazine hydrate, sodium, carbon, potassium iodide, oxalic acid, iron (II) sulfide, sodium thiosulfate, ascorbic acid, tin (II) chloride, hydrogen. It is preferable to contain at least one selected from the group consisting of diisobutylaluminum hydride, formic acid, sodium borohydride, and sulfite. With this configuration, the dispersion stability of the copper oxide in the coating film is improved and the resistance of the conductive film is lowered.

  In the present embodiment, the coating film reducing agent is preferably hydrazine or hydrazine hydrate. With this configuration, the dispersion stability of the copper oxide in the coating film is further improved, contributing to the reduction of the copper oxide in the firing, and the resistance of the conductive film is further reduced.

  The average secondary particle diameter of the fine particles containing copper oxide in the coating film is not particularly limited, but is preferably 500 nm or less, more preferably 200 nm or less, and still more preferably 80 nm or less. The average secondary particle diameter of the fine particles is preferably 5 nm or more, more preferably 10 nm or more, and further preferably 15 nm or more. Here, the average secondary particle diameter is an average particle diameter of an aggregate (secondary particle) formed by collecting a plurality of primary particles.

  The average secondary particle diameter of 500 nm or less is preferable because a fine pattern tends to be easily formed on the substrate. An average secondary particle diameter of 5 nm or more is preferable because long-term storage stability of the copper oxide ink is improved. The average secondary particle diameter of the fine particles can be measured by, for example, a transmission electron microscope or a scanning electron microscope.

  The average primary particle diameter of the primary particles constituting the secondary particles is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 20 nm or less. The average primary particle diameter is preferably 1 nm or more, more preferably 2 nm or more, and further preferably 5 nm or more. When the average primary particle size is 100 nm or less, the firing temperature described later tends to be lowered. The reason why such low-temperature firing is possible is considered to be that the smaller the particle diameter, the larger the surface energy and the lower the melting point. Moreover, it is preferable if the average primary particle diameter is 1 nm or more because good dispersibility can be obtained. When the wiring is formed on the substrate, the thickness is preferably 2 nm or more and 100 nm or less, more preferably 5 nm or more and 50 nm or less from the viewpoint of adhesion to the substrate and low resistance. This tendency is remarkable when the substrate is a resin. The average primary particle diameter can be measured with a transmission electron microscope or a scanning electron microscope.

  The mass ratio (dispersant mass / copper oxide mass) of the dispersant contained in the coating film of the present embodiment is 0.0050 or more and 0.30 or less, preferably 0.050 or more and 0.25 or less, More preferably, it is 0.10 or more and 0.23 or less. The amount of the dispersant affects the dispersion stability. When the amount is small, the dispersion tends to aggregate, and when the amount is large, the dispersion stability tends to be improved. However, if the content rate of the dispersing agent in the coating film of this Embodiment is 35 mass% or less, in the electrically conductive film obtained by baking, the influence of the residue derived from a dispersing agent can be suppressed and electroconductivity can be improved.

  The acid value (mgKOH / g) of the dispersant is preferably 20 or more and 130 or less, and more preferably 30 or more and 100 or less. It is preferable to enter this range because of excellent dispersion stability. This is particularly effective in the case of copper oxide having a small average particle size. Specific examples of the dispersant include “DISPERBYK-102” (acid value 101), “DISPERBYK-140” (acid value 73), “DISPERBYK-142” (acid value 46), and “DISPERBYK-” manufactured by BYK-Chemie. 145 "(acid value 76)," DISPERBYK-118 "(acid value 36)," DISPERBYK-180 (acid value 94) ", and the like.

  Next, the reducing agent in the coating film will be described. As reducing agents, hydrazine, hydrazine hydrate, sodium, carbon, potassium iodide, oxalic acid, iron (II) sulfide, sodium thiosulfate, ascorbic acid, tin (II) chloride, diisobutylaluminum hydride, formic acid, hydrogen Examples thereof include sodium borohydride and sulfite. In the firing, the reducing agent is most preferably hydrazine or hydrazine hydrate from the viewpoint of contributing to reduction of copper oxide, particularly cuprous oxide, and capable of producing a copper film having lower resistance. Also, by using hydrazine or hydrazine hydrate, the dispersion stability of the copper oxide ink can be maintained, and the resistance of the copper film can be lowered.

  The mass ratio of the reducing agent contained in the coating film of the present embodiment (reducing agent mass / copper oxide mass) is preferably 0.0001 or more and 0.10 or less, more preferably 0.0001 or more and 0.05 or less, and further Preferably it is 0.0001 or more and 0.03 or less. When the mass ratio of the reducing agent is 0.0001 or more, the dispersion stability is improved and the resistance of the copper film is lowered. Moreover, when it is 0.10 or less, the long-term stability of a coating film will improve. The required amount of reducing agent in the coating film is proportional to the amount of copper oxide and is adjusted in consideration of the required reducing properties.

  The coating film of this embodiment can be produced on various materials and processed products such as a film substrate, a glass substrate, and a molded product. Another resin layer may be stacked on this film.

[Method for forming conductive film]
The method for producing a conductive film according to the present embodiment reduces copper oxide in a coating film to produce copper, and fuses itself with the copper particles added to the copper oxide ink for inkjet. By this, a conductive film (copper film) is formed. This process is called firing. Therefore, there is no particular limitation as long as it is a method capable of forming a conductive film by reduction and fusion of copper oxide and integration with copper particles. Firing in the method for manufacturing a conductive film of the present embodiment may be performed, for example, in a firing furnace, or may be performed using plasma, infrared light, flash lamp, laser, or the like alone or in combination.

With reference to FIG. 3, the manufacturing method of the electroconductive board | substrate which concerns on this Embodiment is demonstrated more concretely. In FIG. 3A, for example, copper acetate is dissolved in a mixed solvent of water and propylene glycol (PG), and hydrazine is added as a reducing agent and stirred. Adjustment is performed so that the content of the reducing agent falls within the range of the following formula (1).
0.0001 ≦ (reducing agent mass / copper oxide mass) ≦ 0.10 (1)

Next, in (b) and (c) in FIG. 3, the supernatant and the precipitate were separated by centrifugation. Next, in (d) in FIG. 3, a dispersant and a solvent are added to the obtained precipitate and dispersed. At this time, at least two kinds of solvents having boiling points of 100 ° C. or higher are contained. Moreover, it adjusts so that content of a dispersing agent may become the range of following formula (2).
0.0050 ≦ (dispersant mass / copper oxide mass) ≦ 0.30 (2)

  As described above, a copper oxide ink (dispersion) containing copper oxide is obtained as shown in FIG.

In FIG. 3 (f), for example, a copper oxide ink is printed in a desired pattern on a PET substrate using an ink jet device, and a coating film containing copper oxide and a phosphorus-containing organic substance (FIG. 3 (g)). (Described as “Cu ₂ O-containing coating film”).

  Next, in FIG. 3H, the pattern on the substrate is subjected to heat irradiation, light irradiation, or plasma irradiation, the pattern is baked, and copper oxide is added to copper (in FIG. Reduced to Cu). As a result, in FIG. 3I, a conductive substrate in which a conductive pattern (Cu layer) containing copper and phosphorus elements is formed on the substrate is obtained. Or the product which has the obtained electroconductive pattern is obtained by performing above-mentioned baking processing with respect to the product containing a coating film.

  In this way, by performing firing by plasma irradiation, heat irradiation, or light irradiation, the organic matter contained in the copper oxide ink is effectively decomposed, so that the wettability of the solder is effective in the obtained conductive pattern. To be high.

  As shown in FIG. 3, by forming a conductive pattern, a wiring having a line width of 0.1 μm or more and 1 cm or less can be formed, which can be used as a copper wiring or an antenna. Taking advantage of the nanoparticles of the copper oxide particles, the line width of the copper wiring is more preferably 0.1 μm or more and 500 μm or less, further preferably 0.1 μm or more and 100 μm or less, and more preferably 0.1 μm or more. Even more preferable is 5 μm or less. When the line width is 5 μm or less, the wiring cannot be visually recognized, which is preferable from the viewpoint of design.

[Formation of solder layer on conductive film]
In the conductive substrate manufactured using the copper oxide ink for inkjet according to this embodiment, the dispersant and the solvent that deteriorate the solderability are decomposed in the baking process, so that the conductive pattern is covered. When soldering a joined body (for example, an electronic component), there is an advantage that molten solder is easily applied.

  In this embodiment, the electronic component is an active component such as a semiconductor, an integrated circuit, a diode, or a liquid crystal display, a passive component such as a resistor or a capacitor, and a mechanical component such as a connector, a switch, an electric wire, a heat sink, or an antenna. , At least one.

  The solder layer is preferably formed on the conductive pattern by a reflow method. In the reflow method, first, soldering is performed by applying solder paste (cream solder) to a part of the conductive pattern formed in FIG. The solder paste is applied by, for example, contact printing using a metal mask and a metal squeegee. Thereby, a solder layer is formed on a part of the surface of the conductive pattern. That is, after the step of FIG. 3I, a conductive substrate is obtained in which a solder layer is formed on a part of the surface of the conductive pattern. A part of the surface of the conductive pattern on which the solder layer is formed is not particularly limited as long as the conductive pattern and the electronic component can be joined to each other.

[Join electronic components]
Next, the electronic component is placed on the conductive substrate so that the bonded portion of the electronic component is brought into contact with a part of the applied solder paste (solder layer). Thereafter, the conductive substrate on which the electronic component is placed is heated through a reflow furnace, and a part of the conductive pattern region (such as a land) and a bonded portion of the electronic component are soldered. FIG. 4 is a top view of the conductive substrate on which the solder layer according to the present embodiment is formed.

  As shown in FIG. 4, a conductive pattern B formed by baking a copper oxide ink is formed on a flexible substrate 11. A solder layer 20 is formed on the surface of the conductive pattern B. The conductive pattern B and the conductive wire 90 are appropriately soldered by the solder layer 20, and the conductive pattern B and the electronic component 91 are appropriately connected via the conductive wire 90.

  According to the method for manufacturing a conductive substrate and a product according to the present embodiment, since the copper oxide ink is baked to form a conductive pattern, the organic matter contained in the copper oxide ink is decomposed. In the conductive pattern, the wettability of the solder is increased, and a solder layer can be easily formed on the surface of the conductive pattern. For this reason, it becomes possible to solder electronic parts. As a result, it is possible to prevent the occurrence of a defect in the solder layer that joins the conductive pattern and the bonded portion of the electronic component, and to manufacture a conductive substrate on which the electronic component is soldered with a high yield.

  The method for the baking treatment is not particularly limited as long as a conductive film exhibiting the effects of the present invention can be formed. Specific examples include a method using an incinerator, a plasma baking method, a light baking method, and the like. .

[Baking furnace]
In the method of firing in a firing furnace or the like that is susceptible to oxygen, it is preferable to treat the copper oxide ink coating in a non-oxidizing atmosphere. In addition, when the copper oxide is difficult to be reduced only by the organic component contained in the copper oxide ink, it is preferable to fire in a reducing atmosphere. The non-oxidizing atmosphere is an atmosphere that does not contain an oxidizing gas such as oxygen, and is an atmosphere filled with an inert gas such as nitrogen, argon, helium, or neon. The reducing atmosphere refers to an atmosphere in which a reducing gas such as hydrogen or carbon monoxide exists, but may be used by mixing with an inert gas. The coating film of the copper oxide ink may be baked by filling these gases in a baking furnace and in a closed system or continuously flowing the gas. Further, the firing may be performed in a pressurized atmosphere or a reduced pressure atmosphere.

[Plasma firing method]
The plasma method of the present embodiment can be processed at a lower temperature than the method using a baking furnace, and is one of the better methods as a baking method when a resin film having low heat resistance is used as a base material. It is. Further, the plasma can remove the organic substance and the oxide film on the surface of the pattern, so that there is an advantage that good solderability can be secured. Specifically, a reducing gas or a mixed gas of a reducing gas and an inert gas is flowed into the chamber, plasma is generated by microwaves, and active species generated thereby are heated for reduction or sintering. As a source, it is a method of obtaining a conductive film by further utilizing organic substances contained in a dispersant or the like.

  In particular, in the metal portion, active species are often deactivated, the metal portion is selectively heated, and the temperature of the substrate itself is difficult to increase. Therefore, the metal portion can also be applied to a resin film. The copper oxide ink contains copper as a metal, and the copper oxide changes to copper as the baking proceeds, so that heating of only the pattern portion is promoted. Further, if organic substances such as a dispersant or a binder component remain in the conductive pattern, sintering tends to be hindered and resistance tends to increase. However, the plasma method has a large organic substance removal effect in the conductor pattern. Since the organic substance and the oxide film on the surface of the coating film can be removed by the plasma method, there is an advantage that the solderability of the conductive pattern can be effectively improved.

  Hydrogen or the like can be used as the reducing gas component, and nitrogen, helium, argon, or the like can be used as the inert gas component. These may be used alone or as a mixture of a reducing gas component and an inert gas component in an arbitrary ratio. Two or more inert gas components may be mixed and used.

  The plasma firing method can be adjusted with microwave input power, introduced gas flow rate, chamber internal pressure, distance from the plasma generation source to the processing sample, processing sample temperature, and processing time. Can be changed. Therefore, if the above adjustment items are optimized, not only inorganic material substrates but also organic material thermosetting resin films, paper, and low heat resistance thermoplastic resin films such as PET and PEN are used as substrates. Thus, a conductive film having low resistance can be obtained. However, since the optimum conditions vary depending on the device structure and sample type, they are adjusted according to the situation.

[Photo-baking method]
As the light baking method of this embodiment, a flash light method or a laser light method using a discharge tube such as xenon as a light source can be applied. In these methods, high intensity light is exposed for a short time and the copper oxide ink applied on the substrate is heated to a high temperature in a short time and fired. Reduction of copper oxide, sintering of copper particles, and integration of these. , And the organic component is decomposed to form a conductive film. Since the firing time is very short, it can be applied to a resin film substrate having low heat resistance by a method with little damage to the substrate.

  The flash light method uses a xenon discharge tube to instantaneously discharge the electric charge stored in the capacitor, generates a large amount of pulsed light, and oxidizes by irradiating the copper oxide ink formed on the substrate. In this method, copper is instantaneously heated to a high temperature to be changed into a conductive film. The amount of exposure can be adjusted by the light intensity, light emission time, light irradiation interval, and number of times, and if the substrate has high light transmittance, it is also possible to apply a copper oxide ink to a resin substrate having low heat resistance, such as PET, PEN or paper. A conductive pattern can be formed.

  Although the emission light source is different, the same effect 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 system, there is a degree of freedom in wavelength selection, and it is also possible to select in consideration of the light absorption wavelength of the copper oxide ink for inkjet forming the pattern and the absorption wavelength of the substrate. . Further, exposure by beam scanning is possible, and there is a feature that adjustment of an exposure range such as exposure to the entire surface of the substrate or selection of partial exposure is easy. As the type of laser, YAG (yttrium / aluminum / garnet), YVO (yttrium vanadate), Yb (ytterbium), semiconductor laser (GaAs, GaAlAs, GaInAs), carbon dioxide gas, etc. can be used. If necessary, harmonics may be extracted and used.

  In particular, when laser light is used, the emission wavelength is preferably from 300 nm to 1500 nm. For example, 355 nm, 405 nm, 445 nm, 450 nm, 532 nm, and 1056 nm are preferable. When the substrate and the housing are made of resin, the laser wavelengths are particularly preferably 355 nm, 405 nm, 445 nm, and 450 nm.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these Examples and a comparative example.

[Method for quantifying hydrazine]
The hydrazine was quantified by the standard addition method.

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

Similarly, 66 μg of hydrazine, 33 μg of 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). Finally, 20 μL of phosphoric acid was added, and after 4 hours, GC / MS measurement was performed.

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

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

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

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

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

[Dispersion stability]
The dispersion stability of the copper oxide ink is as follows: A: 3 months or more, B: 1 month or more, 3 months until the particle size immediately after adjustment is -17 ° C and the copper oxide ink is doubled after storage Less than C, evaluated as less than 1 month.
[Inkjet printability]
The inkjet printability of the copper oxide ink was evaluated as follows.
S: No break or blur is observed on the line, and no break or blur is observed on the line even after reprinting after 1 hour A: No break or blur is observed on the line B: Discontinuity or blur occurs on the line C : Lines are interrupted or faint, and droplets land on non-line lines and cannot be lined

Example 1
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  As a dispersant, 490 g of DISPERBYK-145 (produced by BYK Chemie) (hereinafter abbreviated as BYK145) and 490 g of diethylene glycol (produced by Wako Pure Chemical Industries, Ltd.) and 490 g of a homogenizer are added to 390 g of the resulting precipitate. Used to disperse.

Subsequently, concentration with a UF membrane module and dilution with diethylene glycol were repeated to obtain a cuprous oxide dispersion containing cuprous oxide having an average secondary particle size of 20 nm. To the obtained cuprous oxide dispersion, γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.) was added and adjusted so as to have the following composition ratio to obtain a copper oxide ink for inkjet (1).
Cu ₂ O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/4 / 39.7 / 0.3 (unit: mass%).

  The copper oxide ink was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 21 nm. The amount of hydrazine was 2700 ppm. The dispersant content was 4 g.

  In Example 1, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass was 0.014, the dispersing agent mass / copper oxide mass was 0.2, and the dispersion stability was A.

  The solvent contained in the copper oxide ink in Example 1 was diethylene glycol and γ-butyrolactone. The boiling point of diethylene glycol was about 245 ° C., and the boiling point of γ-butyrolactone was about 200 ° C.

  The obtained copper oxide ink was filled in a DMC-11601 cartridge (manufactured by Fujifilm), and ink jet printing was performed using a Dimatrix material printer (manufactured by Fujifilm) under the conditions of line: 20 μm and space: 20 μm. Inkjet printability was B.

[Resistance measurement]
The pattern obtained by inkjet with a plasma baking apparatus for 1.5 s for 420 seconds was reduced by heating and baking to produce a copper film. The volume resistivity of the conductive film was measured using a low resistivity meter Lorester GP manufactured by Mitsubishi Chemical. As a result, it was 20 μΩcm.

(Example 2)
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  As a dispersant, 82.2 g of BYK145 and 490 g of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) were added to 390 g of the resulting precipitate, and the mixture was dispersed using a homogenizer under a nitrogen atmosphere.

Subsequently, concentration with a UF membrane module and dilution with diethylene glycol were repeated to obtain a cuprous oxide dispersion (copper oxide ink). To the obtained cuprous oxide dispersion, γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.) was added and adjusted to have the following composition ratio to obtain a copper oxide ink for inkjet (2).
Cu ₂ O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/6 / 37.7 / 0.3 (unit: mass%).

  The copper oxide ink (2) for inkjet was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 32 nm. The amount of hydrazine was 2800 ppm. The dispersant content was 6 g.

  In Example 2, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass was 0.014, the dispersing agent mass / copper oxide mass was 0.3, and the dispersion stability was B.

  Using the obtained copper oxide ink for ink jet (2), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 25 μΩcm.

Example 3
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  As a dispersant, 68.5 g of BYK145 and 490 g of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) were added to 390 g of the resulting precipitate, and the mixture was dispersed using a homogenizer under a nitrogen atmosphere.

Subsequently, concentration with a UF membrane module and dilution with diethylene glycol were repeated to obtain a cuprous oxide dispersion (copper oxide ink). To the obtained cuprous oxide dispersion, γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.) was added and adjusted to have the following composition ratio to obtain a copper oxide ink for inkjet (3).
Cu ₂ O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/5 / 38.7 / 0.3 (unit: mass%).

  The copper oxide ink (3) for inkjet was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 25 nm. The amount of hydrazine was 2700 ppm. Further, the dispersant content was 5 g.

  In Example 3, the acid value of the dispersant was 76. The reducing agent mass / copper oxide mass was 0.014, the dispersing agent mass / copper oxide mass was 0.25, and the dispersion stability was A.

  Inkjet printing was performed under the same conditions as in Example 1 using the obtained copper oxide ink for inkjet (3), and the mixture was heated and fired under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 21 μΩcm.

(Example 4)
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  1.37 g of BYK145 and 490 g of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) were added as a dispersant to 390 g of the resulting precipitate, and dispersed using a homogenizer under a nitrogen atmosphere.

Subsequently, concentration with a UF membrane module and dilution with diethylene glycol were repeated to obtain a cuprous oxide dispersion (copper oxide ink). To the obtained cuprous oxide dispersion, γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.) was added and adjusted so as to have the following composition ratio to obtain a copper oxide ink for inkjet (4).
Cu2O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36 / 0.1 / 43.6 / 0.3 (unit: mass%).

  The copper oxide ink (4) for inkjet was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 32 nm. The amount of hydrazine was 2800 ppm. The dispersant content was 0.1 g.

  In Example 4, the acid value of the dispersant was 76. The reducing agent mass / copper oxide mass was 0.014, the dispersing agent mass / copper oxide mass was 0.005, and the dispersion stability was B.

  Using the obtained copper oxide ink for ink jet (4), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 19 μΩcm.

(Example 5)
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  13.7 g of BYK145 and 490 g of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) were added as a dispersant to 390 g of the obtained precipitate, and dispersed using a homogenizer under a nitrogen atmosphere.

Subsequently, concentration with a UF membrane module and dilution with diethylene glycol were repeated to obtain a cuprous oxide dispersion (copper oxide ink). To the obtained cuprous oxide dispersion, γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.) was added and adjusted to have the following composition ratio to obtain a copper oxide ink for inkjet (5).
Cu2O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/1 / 42.7 / 0.3 (unit: mass%).

  The copper oxide ink for inkjet (5) was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 26 nm. The amount of hydrazine was 2800 ppm. The dispersant content was 1 g.

  In Example 5, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass was 0.014, the dispersing agent mass / copper oxide mass was 0.05, and the dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (5), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 19 μΩcm.

(Example 6)
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  27.4 g of BYK145 and 490 g of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) were added as a dispersant to 390 g of the resulting precipitate, and dispersed using a homogenizer under a nitrogen atmosphere.

Subsequently, concentration with a UF membrane module and dilution with diethylene glycol were repeated to obtain a cuprous oxide dispersion (copper oxide ink). To the obtained cuprous oxide dispersion, γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.) was added and adjusted to have the following composition ratio to obtain a copper oxide ink for inkjet (6).
Cu2O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/2 / 41.7 / 0.3 (unit: mass%).

  The copper oxide ink for inkjet (6) was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 22 nm. The amount of hydrazine was 2800 ppm. The dispersant content was 2 g.

  In Example 6, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass was 0.014, the dispersing agent mass / copper oxide mass was 0.10, and the dispersion stability was A.

  Inkjet printing was performed under the same conditions as in Example 1 using the obtained copper oxide ink for inkjet (6), and the mixture was heated and baked under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 18 μΩcm.

(Example 7)
Hydrazine (1.5 g) was added to 98.5 g of the inkjet copper oxide ink (1) obtained in Example 1 to obtain an inkjet copper oxide ink (7).

  The copper oxide ink for inkjet (7) was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 30 nm. The amount of hydrazine was 18000 ppm. The dispersant content was 4 g.

  In Example 7, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass was 0.090, the dispersing agent mass / copper oxide mass was 0.20, and the dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (7), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 20 μΩcm.

(Example 8)
Hydrazine 0.80g was put into 99.2g of the copper oxide ink for inkjet (1) obtained in Example 1, and the copper oxide ink (8) for inkjet was obtained.

  The copper oxide ink for inkjet (8) was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 27 nm. The amount of hydrazine was 11000 ppm. The dispersant content was 4 g.

  In Example 8, the acid value of the dispersant was 76. The reducing agent mass / copper oxide mass was 0.055, the dispersing agent mass / copper oxide mass was 0.20, and the dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (8), ink jet printing was performed under the same conditions as in Example 1, and then heat-fired and reduced under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 21 μΩcm.

Example 9
Hydrazine 0.30g was put into 99.7g of the inkjet copper oxide ink (1) obtained in Example 1 to obtain an inkjet copper oxide ink (9).

  The ink-jet copper oxide ink (9) was well dispersed. The content of cuprous oxide in 100 g was 20 g, and the particle size was 22 nm. The amount of hydrazine was 5900 ppm. The dispersant content was 4 g.

  In Example 9, the acid value of the dispersant was 76. The reducing agent mass / copper oxide mass was 0.030, the dispersing agent mass / copper oxide mass was 0.20, and the dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (9), ink jet printing was performed under the same conditions as in Example 1, heat-fired and reduced under the same conditions as in Example 1, and a copper film was produced. Inkjet printability was B. The volume resistivity of the conductive film was 18 μΩcm.

(Example 10)
100 g of the copper oxide ink for inkjet (1) obtained in Example 1 is 1.0 g of MegaFac (registered trademark) F-477 (manufactured by DIC Corporation, number average molecular weight 6700) which is a fluorine-containing organic compound as an inkjet regulator. Was added to obtain a copper oxide ink for inkjet (10).

  The ink-jet copper oxide ink (10) was well dispersed. The content of cuprous oxide in 101 g was 20 g, and the particle size was 22 nm. The amount of hydrazine was 2800 ppm. The dispersant content was 4 g.

  In Example 10, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.010. The dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (10), ink jet printing was carried out under the same conditions as in Example 1, and heat baked and reduced under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 21 μΩcm.

(Example 11)
Into 100 g of the copper oxide ink for ink-jet (1) obtained in Example 1, 66.6 g of Megafac F-477 was added as an ink jet adjusting agent to obtain a copper oxide ink for ink-jet (11).

  The ink-jet copper oxide ink (11) was well dispersed. The content of cuprous oxide in 167 g was 20 g, and the particle size was 24 nm. The amount of hydrazine was 1700 ppm. The dispersant content was 4 g.

  In Example 11, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.40. The dispersion stability was B.

  Using the obtained copper oxide ink for ink jet (11), ink jet printing was performed under the same conditions as in Example 1, heat-fired and reduced under the same conditions as in Example 1, and a copper film was produced. Inkjet printability was B. The volume resistivity of the conductive film was 35 μΩcm.

(Example 12)
Into 100 g of the copper oxide ink for ink jet (1) obtained in Example 1, 2.0 g of Megafac F-477 was added as an ink jet adjusting agent to obtain a copper oxide ink for ink jet (12).

  The ink-jet copper oxide ink (12) was well dispersed. The content of cuprous oxide in 102 g was 20 g, and the particle size was 24 nm. The amount of hydrazine was 2700 ppm. The dispersant content was 4 g.

In Example 12, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.020. The dispersion stability was A.
Using the obtained copper oxide ink for ink jet (12), ink jet printing was performed under the same conditions as in Example 1, heat-fired and reduced under the same conditions as in Example 1, and a copper film was produced. Inkjet printability was A. The volume resistivity of the conductive film was 22 μΩcm.

(Example 13)
42 g of Megafax F-477 was added as an inkjet adjusting agent to 100 g of the copper oxide ink for inkjet (1) obtained in Example 1, to obtain a copper oxide ink for inkjet (13).

  The ink-jet copper oxide ink (13) was well dispersed. The content of cuprous oxide in 142 g was 20 g, and the particle size was 28 nm. The amount of hydrazine was 1900 ppm. The dispersant content was 4 g.

  In Example 13, the acid value of the dispersant was 76. The reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.30. The dispersion stability was B.

  Using the obtained copper oxide ink for ink jet (13), ink jet printing was performed under the same conditions as in Example 1, and heat baked and reduced under the same conditions as in Example 1 to produce a copper film. Inkjet printability was A. The volume resistivity of the conductive film was 30 μΩcm.

(Example 14)
100 g of the copper oxide ink for ink-jet (1) obtained in Example 1 was charged with 5 g of Megafac F-477 as an ink jet adjusting agent to obtain a copper oxide ink for ink-jet (14).

  The copper oxide ink for inkjet (14) was well dispersed. The content of cuprous oxide in 105 g was 20 g, and the particle size was 22 nm. The amount of hydrazine was 2600 ppm. The dispersant content was 4 g.

  In Example 14, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the ink jet adjusting agent mass / ink jet copper oxide ink mass is 0.048. The dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (14), ink jet printing was performed under the same conditions as in Example 1, heat-fired and reduced under the same conditions as in Example 1, and a copper film was produced. Inkjet printability was S. The volume resistivity of the conductive film was 24 μΩcm.

(Example 15)
100 g of the copper oxide ink for ink jet (1) obtained in Example 1 was charged with 25 g of Megafac F-477 as an ink jet adjusting agent to obtain a copper oxide ink for ink jet (15).

  The copper oxide ink for inkjet (15) was well dispersed. The content of cuprous oxide in 125 g was 20 g, and the particle size was 24 nm. The amount of hydrazine was 2200 ppm. The dispersant content was 4 g.

  In Example 15, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.20. The dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (15), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was S. The volume resistivity of the conductive film was 28 μΩcm.

(Example 16)
100 g of the copper oxide ink for inkjet (1) obtained in Example 1 was charged with 1.0 g of Surflon S611 (manufactured by Seimi Chemical Co., Ltd., number average molecular weight 11000) as an inkjet regulator to obtain an inkjet copper oxide ink (16). .

  The ink-jet copper oxide ink (16) was well dispersed. The content of cuprous oxide in 101 g was 20 g, and the particle size was 22 nm. The amount of hydrazine was 2800 ppm. The dispersant content was 4 g.

  In Example 16, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.010. The dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (16), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 22 μΩcm.

(Example 17)
66.6 g of Surflon S611 as an inkjet adjusting agent was added to 100 g of the inkjet copper ink (1) obtained in Example 1 to obtain an inkjet copper oxide ink (17).

  The ink-jet copper oxide ink (17) was well dispersed. The content of cuprous oxide in 167 g was 20 g, and the particle size was 24 nm. The amount of hydrazine was 1800 ppm. The dispersant content was 4 g.

  In Example 17, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.40. The dispersion stability was B.

  Using the obtained copper oxide ink for ink jet (17), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 38 μΩcm.

(Example 18)
Into 100 g of the copper oxide ink for ink jet (1) obtained in Example 1, 1.0 g of PEG400 (manufactured by Kanto Chemical Co., Ltd., number average molecular weight 400) was added as an ink jet adjusting agent to obtain a copper oxide ink for ink jet (18).

  The copper oxide ink for inkjet (18) was well dispersed. The content of cuprous oxide in 101 g was 20 g, and the particle size was 24 nm. The amount of hydrazine was 2800 ppm. The dispersant content was 4 g.

  In Example 18, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.010. The dispersion stability was A.

  Using the obtained copper oxide ink for ink jet (18), ink jet printing was performed under the same conditions as in Example 1, heat-fired and reduced under the same conditions as in Example 1, and a copper film was produced. Inkjet printability was B. The volume resistivity of the conductive film was 25 μΩcm.

(Example 19)
66.6 g of PEG400 was added as an ink jet adjusting agent to 100 g of the copper oxide ink for ink jet (1) obtained in Example 1 to obtain a copper oxide ink for ink jet (19).

  The copper oxide ink for inkjet (19) was well dispersed. The content of cuprous oxide in 167 g was 20 g, and the particle size was 28 nm. The amount of hydrazine was 1800 ppm. The dispersant content was 4 g.

  In Example 19, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersing agent mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink jet copper oxide ink mass is 0.40. The dispersion stability was B.

  Using the obtained copper oxide ink for ink jet (19), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 30 μΩcm.

(Example 20)
100 g of MegaFuck F-477 as an ink jet adjusting agent was added to 100 g of the copper oxide ink for ink jet (1) obtained in Example 1, to obtain a copper oxide ink for ink jet (20).

  The copper oxide ink (20) for inkjet was dispersed. The content of cuprous oxide in 200 g was 20 g, and the particle size was 50 nm. The amount of hydrazine was 1400 ppm. The dispersant content was 4 g.

  In Example 20, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass is 0.014, the dispersant mass / copper oxide mass is 0.20, and the inkjet modifier mass / ink oxide copper oxide mass is 0.50. The dispersion stability was C.

  Using the obtained copper oxide ink for ink jet (19), ink jet printing was performed under the same conditions as in Example 1, and heating and baking were performed under the same conditions as in Example 1 to produce a copper film. Inkjet printability was B. The volume resistivity of the conductive film was 70 μΩcm.

(Comparative Example 1)
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  BYK145 54.8g and ethanol (Kanto Chemical Co., Ltd.) 920g were added to the obtained precipitate 390g, and it disperse | distributed using the homogenizer in nitrogen atmosphere, and obtained 1365g of cuprous oxide dispersion liquids.

  In Comparative Example 1, ethanol (boiling point is about 79 ° C.) is contained as a solvent in the cuprous oxide dispersion.

  In Comparative Example 1, the content of cuprous oxide in 100 g was 20 g, and the particle size was 21 nm. The amount of hydrazine was 2900 ppm. In Comparative Example 1, the acid value of the dispersant was 76. The reducing agent mass / copper oxide mass was 0.015, the dispersing agent mass / copper oxide mass was 0.2, and the dispersion stability was A.

  The obtained copper oxide ink DMC-11601 cartridge (manufactured by FUJIFILM) was filled and ink jet printing was performed using a Dimatrix material printer (manufactured by FUJIFILM) under the conditions of line: 20 μm and space: 20 μm. In this case, discontinuity or fading occurred, or the liquid droplets landed at a place that was not a line, and the line could not be formed. The ink jet printability was C.

(Comparative Example 2)
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation. Dispersor BYK-170 (manufactured by Big Chemie) 13.7 g (dispersant content 4 g) and ethanol (manufactured by Kanto Chemical Co., Inc.) 961 g are added to the obtained precipitate 390 g, and dispersed and oxidized using a homogenizer in a nitrogen atmosphere. 1365 g of cuprous dispersion was obtained.

  In Comparative Example 2, ethanol (boiling point is about 79 ° C.) is contained as a solvent in the cuprous oxide dispersion.

  The content of cuprous oxide in 100 g was 20 g. The solubility was poor and the copper oxide particles were agglomerated and could not be made into ink. The amount of hydrazine was 2900 ppm. The acid value of the dispersant was 11. The reducing agent mass / copper oxide mass was 0.015, the dispersing agent mass / copper oxide mass was 0.2, and the dispersion stability was C. Further, since ink could not be formed, ink jet printing could not be performed (ink jet printability was C).

(Comparative Example 3)
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  110 g of BYK145 and 490 g of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) were added as a dispersant to 390 g of the obtained precipitate, and the mixture was dispersed using a homogenizer under a nitrogen atmosphere.

Subsequently, concentration with a UF membrane module and dilution with diethylene glycol were repeated to obtain a cuprous oxide dispersion (copper oxide ink). To the obtained cuprous oxide dispersion, γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.) was added and adjusted so as to have the following composition ratio, but the copper oxide particles aggregated and could not be made into an ink.
Cu2O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/8 / 35.7 / 0.3 (unit: mass%).

  The content of cuprous oxide in 100 g was 20 g, and the amount of hydrazine was 2800 ppm. The dispersant content was 8 g.

  In Comparative Example 3, the acid value of the dispersant was 76. Further, the reducing agent mass / copper oxide mass was 0.014, the dispersing agent mass / copper oxide mass was 0.40, and the dispersion stability was C. Further, since ink could not be formed, ink jet printing could not be performed (ink jet printability was C).

(Comparative Example 4)
In a mixed solvent of 7560 g of water and 3494 g of 1,2-propylene glycol (manufactured by Wako Pure Chemical Industries), 806 g of copper (II) acetate monohydrate (manufactured by Wako Pure Chemical Industries) is dissolved, and hydrazine monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved. ) 235 g was added and stirred. Then, it isolate | separated into the supernatant liquid and the precipitate by centrifugation.

  490 g of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) was added to 390 g of the resulting precipitate, and dispersed using a homogenizer under a nitrogen atmosphere.

Subsequently, concentration with a UF membrane module and dilution with diethylene glycol were repeated to obtain a cuprous oxide dispersion (copper oxide ink). To the obtained cuprous oxide dispersion, γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.) was added and adjusted so as to have the following composition ratio, but the copper oxide particles aggregated and could not be made into an ink.
Cu2O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/0 / 43.7 / 0.3 (unit: mass%).

  The content of cuprous oxide in 100 g was 20 g, and the amount of hydrazine was 2800 ppm. In Comparative Example 4, the reducing agent mass / copper oxide mass was 0.014, the dispersing agent mass / copper oxide mass was 0.0, and the dispersion stability was C. Further, since ink could not be formed, ink jet printing could not be performed (ink jet printability was C).

(Comparative Example 5)
To 97 g of the copper oxide ink for ink jet (1) obtained in Example 1, 3.0 g of hydrazine was added.
Copper oxide particles aggregated and could not be made into ink.
Cu2O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/4/36/4 (unit: mass%).

  The content of cuprous oxide in 100 g was 20 g, and the amount of hydrazine was 33000 ppm. In Comparative Example 5, the reducing agent mass / copper oxide mass was 0.20, the dispersing agent mass / copper oxide mass was 0.20, and the dispersion stability was C. Further, since ink could not be formed, ink jet printing could not be performed (ink jet printability was C).

(Comparative Example 6)
To 36 g of diethylene glycol and 40 g of γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.), 20 g of cuprous oxide (MP-CU2O-25 manufactured by EM Japan) and 4.0 g of DisperBYK-145 (manufactured by Big Chemie) are added, and a homogenizer is added under a nitrogen atmosphere. Although dispersed, the copper oxide particles were agglomerated and could not be inked.
Cu2O / DEG / BYK145 / γ-butyrolactone / hydrazine = 20/36/4/40/0 (unit: mass%).

  The content of cuprous oxide in 100 g was 20 g, and the amount of hydrazine was 0.0 ppm. The particle size of cupric oxide was 190 nm. In Comparative Example 6, the reducing agent mass / copper oxide mass was 0.0, the dispersing agent mass / copper oxide mass was 0.20, and the dispersion stability was C. Further, since ink could not be formed, ink jet printing could not be performed (ink jet printability was C).

  The experimental results of Examples 1 to 20 and Comparative Examples 1 to 6 are shown in Table 1 below. In addition, the amount of “hydrazine” shown in Table 1 is a value rounded off to the second decimal place.

  In Examples 1 to 20, the value of (reducing agent mass / copper oxide mass) is from 0.0001 to 0.10, and the value of (dispersing agent mass / copper oxide mass) is from 0.0050 to 0.00. It contained at least two types of solvents having a boiling point of 100 ° C. or higher. Thereby, in Example 1- Example 20, it can be printed by the inkjet method, and it is thought that the reduction | restoration of copper oxide was accelerated | stimulated by using hydrazine as a reducing agent, and can produce a copper film with low resistance. done.

  Further, in Examples 1 to 20, in addition to the above, the acid value of the dispersant is 20 or more and 130 or less, which can improve the dispersion stability and enables high-definition inkjet printing. The resistance reduction of the wiring can be improved.

  On the other hand, in Comparative Examples 1 to 6 using ethanol, it was difficult to produce a copper wiring by an inkjet method in the dispersion. Further, in Comparative Example 2 in which ethanol was used and the acid value of the dispersant was less than 20, the copper oxide ink was agglomerated, so that inkjet printing and resistance measurement could not be performed.

  With the copper oxide ink of the present invention, wiring can be produced using an ink jet method, and a conductive film with little disconnection or breakage can be obtained by plasma, heat, or light baking treatment. Therefore, the copper oxide ink of the present invention is suitably used for the production of RFID, antennas, printed wiring boards, electronic devices, transparent conductive films, electromagnetic wave shields, antistatic films and the like.

DESCRIPTION OF SYMBOLS 1 Copper oxide ink for inkjet 2 Copper oxide 3 Phosphate ester salt 10 Conductive substrate 11 Substrate 12 Insulation region 13 Conductive pattern

Claims (7)

The solvent contains copper or copper oxide, a dispersant, and a reducing agent,
The content of the reducing agent is in the range of the following formula (1),
The content of the dispersant is in the range of the following formula (2),
Containing at least two kinds of the solvents having boiling points of 100 ° C. or higher,
A copper oxide ink for ink jet printing.
0.0001 ≦ (reducing agent mass / copper oxide mass) ≦ 0.10 (1)
0.0050 ≦ (dispersant mass / copper oxide mass) ≦ 0.30 (2)   The copper oxide ink for inkjet according to claim 1, wherein the copper oxide is cuprous oxide.   The reducing agent is hydrazine, hydrazine hydrate, sodium, carbon, potassium iodide, oxalic acid, iron (II) sulfide, sodium thiosulfate, ascorbic acid, tin (II) chloride, diisobutylaluminum hydride, formic acid, hydrogen The copper oxide ink for inkjet according to claim 1, comprising at least one selected from the group consisting of sodium borohydride and sulfite.   The copper oxide ink for inkjet according to any one of claims 1 to 3, wherein an acid value of the dispersant is 20 or more and 130 or less. The inkjet copper ink includes an inkjet modifier, and the number average molecular weight of the inkjet modifier is 350 or more and 30000 or less, and falls within the range of the following formula (3). The copper oxide ink for inkjet according to any one of the above.
0.010 ≦ (Mass of inkjet adjusting agent / Mass of copper oxide ink for inkjet) ≦ 0.40 (3)   A copper oxide ink according to any one of claims 1 to 5, wherein a pattern is formed on a substrate using an ink jet apparatus, a plasma is generated in an atmosphere containing a reducing gas, and the pattern is baked. A process for producing a conductive substrate, characterized by performing a treatment.   A pattern is formed on a substrate using an ink jet apparatus using the copper oxide ink according to any one of claims 1 to 5, and then heat or light irradiation treatment is performed on the pattern. A method for manufacturing a conductive substrate.

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