JP2014182913A - Composition for conductive film formation, and method for producing conductive film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for conductive film formation that enables the formation of a conductive film that can be in excellent contact with a base material.SOLUTION: The composition for conductive film formation contains: copper nanoparticles having an average aggregated particle size of 50 to 200 nm; a copper filler having an average aggregated particle size of 1 to 10 μm; and a copper formate complex formed with copper formate in which amine is arranged.

Description

  The present invention relates to a conductive film forming composition. In more detail, this invention relates to the composition for electrically conductive film formation containing a copper nanoparticle, a copper filler, and the copper formate copper complex which an amine coordinates to copper formate.

As a method for forming a metal film on a base material, a dispersion of metal particles or metal oxide particles is applied to the base material by a printing method, and heat treatment is performed to sinter the metal film or wiring on a circuit board. A technique for forming an electrical copper passage is known.
Since the above method is simple, energy-saving, and resource-saving compared to the conventional high-heat / vacuum process (sputtering) or plating process, it is highly anticipated in the development of next-generation electronics.

More specifically, in Patent Document 1, copper filler having an average aggregate particle diameter of 0.5 to 20 μm, copper nanoparticles having an average aggregate particle diameter of 50 to 200 nm, an aliphatic carboxylic acid, and a resin A method of forming a metal film by applying and baking a conductive paste containing a binder on a substrate is disclosed.
Moreover, in patent document 2, the surface of the copper filler whose average particle diameter is 0.5-20 micrometers is covered with the copper nanoparticle covering copper filler with which the average particle diameter is 50-100 nm, and resin A method of forming a metal film by applying and baking a copper paste containing a binder on a substrate is disclosed.

International Publication No. 2010/032841 International Publication No. 2009/116349

On the other hand, in recent years, in order to meet the demand for miniaturization and high functionality of electronic devices, wirings are further miniaturized and highly integrated. In connection with it, the further improvement of the adhesiveness of a base material and an electrically conductive film is requested | required.
When the present inventors tried to produce a conductive film using the composition for forming a conductive film described in Patent Document 1 and Patent Document 2, in any case, the obtained conductive film was not in contact with the substrate. Adhesion did not reach the level required recently, and further improvements were necessary.

Then, an object of this invention is to provide the composition for electrically conductive film formation which can form the electrically conductive film excellent in adhesiveness with a base material in view of the said situation.
Another object of the present invention is to provide a method for producing a conductive film using the composition for forming a conductive film.

As a result of intensive studies on the problems of the prior art, the present inventors have found that copper nanoparticles having an average aggregate particle diameter of 50 to 200 nm, a copper filler having an average aggregate particle diameter of 1 to 10 μm, copper formate and amine The present inventors have found that the above-described problems can be solved by using a copper formate complex (in this specification, sometimes simply referred to as “copper formate complex”) formed by coordination.
That is, it has been found that the above object can be achieved by the following configuration.

(1) A conductive film comprising copper nanoparticles having an average aggregate particle diameter of 50 to 200 nm, a copper filler having an average aggregate particle diameter of 1 to 10 μm, and a copper formate complex in which an amine is coordinated to copper formate. Forming composition.
(2) The composition for electrically conductive film formation as described in (1) with which the surface of a copper filler is coat | covered with the copper nanoparticle.
(3) The composition for electrically conductive film formation as described in (1) or (2) whose content of a copper formate complex is 1-50 mass% with respect to the total mass of a copper filler.
(4) Conductivity as described in any one of (1)-(3) whose content of a copper filler is 45-80 mass% with respect to the total mass of a copper filler, a copper nanoparticle, and a copper formate complex. Film forming composition.
(5) The composition for forming a conductive film according to any one of (1) to (4), further including a polymer binder.
(6) The composition for electrically conductive film formation as described in (4) whose content of a polymer binder is 2-8 mass% with respect to the total mass of a copper filler, a copper nanoparticle, and a copper formate complex.
(7) The composition for electrically conductive film formation as described in any one of (1)-(6) in which an amine contains the tertiary amine represented by Formula (1).

Wherein R ¹ and R ² are each independently selected from the group consisting of a methyl group, an ethyl group, a 2-hydroxyethyl group and a 2-methoxyethyl group, and R ³ and R ⁴ are each independently R ⁵ is selected from the group consisting of a hydrogen atom, a methyl group and a hydroxy group, and R ⁵ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or 3 to 6 carbon atoms. Selected from the group consisting of a cyclic alkyl group, 2-hydroxyethyl group, 2-methoxyethyl group and 2-ethoxyethyl group, and X is selected from the group consisting of a methylene group, an ethylene group and a propylene group. ]
(8) The composition for forming a conductive film according to any one of (1) to (7), further comprising a low-molecular amine.
(9) The composition for electrically conductive film formation as described in (8) whose content of a low molecular amine is 1-15 mass% with respect to the total mass of a copper filler and a copper nanoparticle.
(10) The composition for forming a conductive film according to any one of (1) to (9), further comprising a carboxylic acid.
(11) The composition for forming a conductive film according to (10), wherein the content of carboxylic acid is 1 to 15% by mass with respect to the total mass of the copper filler and the copper nanoparticles.
(12) A coating film forming step of applying the composition for forming a conductive film according to any one of (1) to (11) on a substrate to form a coating film, and heating the coating film The manufacturing method of an electrically conductive film provided with the electrically conductive film formation process of performing a process and / or a light irradiation process, and forming an electrically conductive film.

ADVANTAGE OF THE INVENTION According to this invention, the composition for electrically conductive film formation which can form the electrically conductive film excellent in adhesiveness with a base material can be provided.
Moreover, according to this invention, the manufacturing method of the electrically conductive film using this composition for electrically conductive film formation can also be provided.

First, the features of the present invention compared with the prior art will be described.
One of the characteristics of the present invention is a copper formate complex in which an amine is coordinated to copper formate in addition to copper nanoparticles having a specific average aggregate particle diameter and copper particles having a specific average aggregate particle diameter. (In this specification, the composition is simply a “copper formate complex”).

By using a copper formate complex in which an amine is coordinated to copper formate, the conductive film-forming composition of the present invention can be sintered at a relatively low temperature, and the central metal of the copper formate complex can be sintered at the time of sintering. Cu produced by reduction of Cu ²⁺ works as a conductive adhesive, and has an effect of promoting fusion between copper fillers and between copper nanoparticles / copper fillers. Thereby, the film | membrane quality of the copper film formed improves and adhesiveness with a board | substrate improves.

  Below, the composition for electrically conductive film formation of this invention and the manufacturing method of an electrically conductive film using the same are demonstrated in detail.

[Composition for forming conductive film]
The composition for forming a conductive film of the present invention is formed by coordinating an amine to copper filler having an average aggregate particle diameter of 1 to 10 μm, copper nanoparticles having an average aggregate particle diameter of 50 to 200 nm, and copper formate. And a copper formate complex.

  The composition for forming a conductive film of the present invention may contain a solvent and / or a dispersion medium described later. When a solvent and / or a dispersion medium are contained, the composition for forming a conductive film of the present invention may be called a solvent conductive paste or a copper paste.

In the present invention, the average aggregate particle diameter refers to an average aggregate particle diameter (number average aggregate particle diameter) measured by a scanning electron microscope (hereinafter referred to as “SEM”).
The average agglomerated particle diameter of the copper filler or copper nanoparticles can be determined by measuring the agglomerated particle diameter of 100 copper nanoparticles or copper fillers randomly selected from the SEM image and taking the average. it can.
Hereafter, each component contained in the composition for electrically conductive film formation is explained in full detail.

<Copper filler>
As a copper filler, the well-known metal copper particle used for the composition for electrically conductive film formation is mentioned.

  The average aggregate particle diameter of the copper filler is 1 to 10 μm, preferably 3 to 10 μm. By including a copper filler having an average aggregate particle diameter of 1 μm or more, the flow characteristics of the conductive film forming composition are improved. By including a copper filler having an average aggregate particle diameter of 10 μm or less, it becomes easy to produce fine wiring. If the average aggregate particle diameter of the copper filler obtained by mixing two or more types of copper fillers is within the above range, the mixture of the two or more types of copper fillers can be used without particular limitation.

  The content of the copper filler may be appropriately selected according to the ratio of the volume of the copper filler and the voids present between them, and is not particularly limited, but the total of the copper filler, the copper nanoparticles, and the copper formate complex The mass percentage of the copper filler with respect to the mass is preferably 45 to 80 mass%, and more preferably 45 to 70 mass%. By making content of a copper filler into 45 mass% or more, the electroconductivity of the copper film formed can be made more favorable. By making content of a copper filler into 80 mass% or less, the applicability | paintability of the electrically conductive paste with respect to a base material can be made more favorable.

<Copper nanoparticles>
As the copper nanoparticles, metal copper nanoparticles or copper hydride nanoparticles are preferred from the viewpoint of forming an electrically conductive film having excellent conductivity and excellent adhesion to the substrate. Copper hydride is a compound containing hydrogen in addition to copper as an element. The copper atom exists in a state of being bonded to a hydrogen atom and has a property of decomposing into metallic copper and hydrogen at 60 to 100 ° C.

  The average aggregate particle diameter of the copper nanoparticles is 50 to 200 nm, and preferably 70 to 150 nm. By including copper nanoparticles having an average aggregate particle diameter of 50 nm or more, cracks generated in the conductive film due to volume shrinkage accompanying the fusion and growth of copper nanoparticles are unlikely to occur. By including copper nanoparticles having an average aggregate particle size of 200 nm or less, the surface melting temperature is lowered, so that surface melting is likely to occur, and a dense conductive film can be formed, so that improvement in conductivity can be expected. If the average aggregate particle diameter of the copper nanoparticles obtained by mixing two or more types of copper nanoparticles is within the above range, the mixture of the two or more types of copper nanoparticles should be used without particular limitation. Can do.

  In the present invention, metallic copper nanoparticles and copper hydride nanoparticles are used as aggregated particles. These aggregated particles are obtained by aggregating primary particles having an average primary particle diameter of approximately 10 to 100 nm, preferably 20 to 50 nm. The average primary particle size of the nanoparticles was measured by measuring the primary particle size of 100 nanoparticles randomly selected from a transmission electron microscope (hereinafter referred to as “TEM”) image and taking the average. Can be sought.

  In the composition for forming a conductive film of the present invention, the content of the copper nanoparticles is not particularly limited, but is preferably 5 to 50% by mass and more preferably 10 to 35% by mass with respect to the total mass of the copper filler. By making content of a copper nanoparticle 5 mass% or more, the electroconductive path between copper fillers can be increased further and the volume resistivity of the electrically conductive film formed can be suppressed lower. Moreover, the fluidity | liquidity of an electrically conductive paste can be made higher by making content of a copper nanoparticle into 50 mass% or less.

(Method 1 for producing copper nanoparticles)
Although the manufacturing method in particular of a copper hydride nanoparticle is not restrict | limited, For example, as mentioned later, it can manufacture through the following process (a)-(d). Moreover, the metal copper nanoparticle formed by thermally decomposing a copper hydride nanoparticle can be manufactured through the following process (e) further.

(A) A step of preparing an aqueous solution containing copper ions by dissolving a water-soluble copper compound in water.
(B) A step of adjusting the pH to 3 or less by adding an acid to the prepared aqueous solution.
(C) A step of adding a reducing agent to the aqueous solution while stirring the aqueous solution whose pH is adjusted to 3 or less to reduce copper ions to produce copper hydride nanoparticles having an average aggregate particle size of 50 to 200 nm. .
(D) A step of purifying the produced copper hydride nanoparticles with a mixed dispersion medium of water and methanol, if desired.
(E) A step of thermally decomposing the obtained copper hydride nanoparticles to produce metallic copper nanoparticles.

Step (a):
Examples of the water-soluble copper compound include copper sulfate, copper nitrate, copper formate, copper acetate, copper chloride, copper bromide, copper iodide and the like. As for the density | concentration of a water-soluble copper compound, 0.1-30 mass% is preferable in 100 mass% of aqueous solution, and 1-20 mass% is more preferable. If the density | concentration of the water-soluble copper compound in aqueous solution is 0.1 mass% or more, the quantity of water will be restrained and the production efficiency of a copper hydride nanoparticle will become favorable. If the density | concentration of the water-soluble copper compound in aqueous solution is 30 mass% or less, the fall of the yield of a copper hydride nanoparticle will be suppressed.

Step (b):
By adjusting the pH of the aqueous solution to 3 or less, copper ions in the aqueous solution are easily reduced by the reducing agent, and copper hydride nanoparticles are easily generated. When pH of aqueous solution exceeds 3, there exists a possibility that a metal copper nanoparticle may produce | generate, without producing | generating a copper hydride nanoparticle. The pH of the aqueous solution is preferably 0.5 to 2.0, and more preferably 0.7 to 1.5, from the viewpoint that copper hydride nanoparticles can be generated in a short time.
In addition, you may perform a process (a) and a process (b) simultaneously.

  Examples of the acid used in the step (b) include formic acid, citric acid, maleic acid, malonic acid, acetic acid, propionic acid, sulfuric acid, nitric acid, hydrochloric acid, etc. Among them, formic acid is preferable. These acids are used to adjust the pH of an aqueous solution containing copper ions, but it is considered that the surface of the copper nanoparticles may be covered and the conductivity of the copper nanoparticles may be affected. Formic acid is an acid having a reducing action, and by using formic acid in step (b), there is an effect of suppressing oxidation of the surface of the obtained copper nanoparticles.

Step (c):
Copper ions are reduced by a reducing agent under acidic conditions, and copper hydride nanoparticles gradually grow to produce copper hydride nanoparticles having an average aggregate particle diameter of 50 to 200 nm.
When formic acid is used as the acid in the step (b), the produced copper hydride nanoparticles are immediately covered with the formic acid present together and stabilized.

  As the reducing agent, metal hydride or hypophosphorous acid is preferable because of its large reducing action. Examples of the metal hydride include lithium aluminum hydride, lithium borohydride, sodium borohydride, lithium hydride, potassium hydride, calcium hydride, etc., and include lithium aluminum hydride, lithium borohydride or borohydride. Sodium is preferred.

  The addition amount of the reducing agent is preferably 1.5 to 10 times the number of equivalents of copper ions, more preferably 22 to 5 times the number of equivalents. If the addition amount of the reducing agent is 1.5 times the number of equivalents or more with respect to copper ions, the reducing action is sufficient. When the addition amount of the reducing agent is 10 times the number of equivalents or less with respect to copper ions, the amount of impurities (sodium, boron, phosphorus, etc.) contained in the copper hydride nanoparticles can be suppressed. 5-60 degreeC is preferable and, as for the temperature of the aqueous solution at the time of adding a reducing agent, 20-50 degreeC is more preferable. If the temperature of aqueous solution is 60 degrees C or less, decomposition | disassembly of a copper hydride nanoparticle will be suppressed.

Step (d):
When the suspension containing copper hydride nanoparticles is allowed to stand, the copper hydride nanoparticles aggregate and precipitate. The precipitate is separated and then re-dispersed in a dispersion medium, and then purified by a method in which the copper hydride nanoparticles are agglomerated again and precipitated to obtain highly purified copper hydride nanoparticles.

  The dispersion medium used for purification is preferably a water / methanol mixed dispersion medium or a water / ethanol mixed dispersion medium. With water alone, the surface tension of water is large, so water cannot enter the pores of the aggregates of copper hydride nanoparticles, and the effect of purification is small. On the other hand, with methanol alone, the dielectric constant of methanol is small, so that the impurity sodium cannot be released into the dispersion medium as ions, and the purification effect is small. The proportion of water in the mixed dispersion medium is preferably 40 to 90 mass%, more preferably 50 to 85 mass%, based on the entire mixed dispersion medium. The amount of sodium contained in the copper hydride nanoparticles is preferably 800 ppm or less, and more preferably 100 ppm or less.

Step (e):
Thermal decomposition is performed under an inert atmosphere. The oxygen concentration in the atmosphere is preferably 1000 ppm or less. When it exceeds 1000 ppm, cuprous oxide will be produced by oxidation. The temperature of thermal decomposition is preferably 60 to 100 ° C, more preferably 70 to 90 ° C. If temperature is 60 degreeC or more, thermal decomposition will advance smoothly. If temperature is 100 degrees C or less, fusion | melting of copper nanoparticles will be suppressed.

(Method 2 for producing copper nanoparticles)
Copper nanoparticles can also be produced through the following steps (a ′) to (d ′).
(A ′) A step of dissolving a water-soluble copper compound in water to prepare an aqueous solution containing copper ions.
(B ′) A step of heating the prepared aqueous solution to 30 ° C. or more and reducing copper ions with hypophosphorous acid to produce copper hydride nanoparticles or, in some cases, metal copper nanoparticles.
(C ′) a step of thermally decomposing the copper hydride nanoparticles to produce metal copper nanoparticles, if desired.
(D ′) A step of purifying the obtained copper nanoparticles as desired.

Step (a ′):
It is the same as the said process (a).

Step (b ′):
Copper ions are reduced under acidic conditions by hypophosphorous acid at a temperature of 30 ° C. or higher, and copper hydride nanoparticles are gradually grown to produce copper hydride nanoparticles having an average aggregate particle size of 50 to 200 nm. . Further, when the reaction is allowed to proceed for a certain time or more, metallic copper is generated by the decomposition of copper hydride. 30-80 degreeC is preferable and, as for the temperature of the aqueous solution in a process (b), 35-60 degreeC is more preferable. If the temperature of aqueous solution is 80 degrees C or less, the change of the reaction system by water evaporation can be suppressed.
Hypophosphorous acid is preferably added as an aqueous solution. The concentration of hypophosphorous acid is preferably 30 to 80% by mass and more preferably 40 to 60% by mass in 100% by mass of the aqueous solution. If the concentration of hypophosphorous acid in the aqueous solution is 30% by mass or more, the amount of water can be suppressed. If the concentration of hypophosphorous acid in the aqueous solution is 80% by mass or less, a rapid reaction can be suppressed.

  The addition amount of hypophosphorous acid is preferably 1.5 to 10 times the number of equivalents to copper ions. When the amount of hypophosphorous acid added is 1.5 times the number of equivalents or more with respect to copper ions, the reducing action is sufficient. If the addition amount of the reducing agent is 10 times the number of equivalents or less with respect to copper ions, the adverse effect of the remaining phosphorus can be suppressed.

Step (c ′):
It is the same as the said process (e).

Step (d ′):
If desired, the obtained copper nanoparticles may be purified. Examples of the purification method include a method of dispersing the obtained copper nanoparticles in water.

<Copper filler coated with copper nanoparticles>
In the composition for forming a conductive film of the present invention, the copper filler and the copper nanoparticles may be used as a copper nanoparticle-coated copper filler obtained by coating a copper filler with copper nanoparticles.
The copper nanoparticle-coated copper filler is a copper nanoparticle-coated copper filler in which the surface of a copper filler having an average aggregate particle diameter of 1 to 10 μm is coated with copper nanoparticles having an average aggregate particle diameter of 50 to 200 nm. .

In the composition for forming a conductive film of the present invention, the content of the copper nanoparticles covering the copper filler is not particularly limited, but the copper nanoparticles covering the copper filler and the copper nanoparticles not covering the copper filler 5-50 mass% is preferable with respect to the total mass of a copper filler, and 10-35 mass% is more preferable. By making content of a copper nanoparticle 5 mass% or more, the electroconductive path between copper fillers can be increased further and the volume resistivity of the electrically conductive film formed can be suppressed lower. Moreover, the fluidity | liquidity of an electrically conductive paste can be made higher by making content of a copper nanoparticle into 50 mass% or less.
Moreover, among the copper nanoparticles contained in the composition for forming a conductive film, the mass ratio of the copper nanoparticles covering the copper filler is preferably as large as possible, and preferably 50% by mass or more based on the total mass of the copper nanoparticles. 70 mass% or more is more preferable, and 90 mass% or more is further more preferable.

(Method for producing copper filler coated with copper nanoparticles)
Although the manufacturing method of a copper nanoparticle covering copper filler is not specifically limited, For example, the manufacturing method which has the following process (I) and (II) is mentioned.
(I) The process of obtaining the copper hydride nanoparticle covering copper filler by making the surface of the copper filler whose average aggregated particle diameter is 1-10 micrometers coat | cover with the copper hydride nanoparticle whose average aggregated particle diameter is 20-100 nm.
(II) The copper hydride nanoparticle-coated copper filler is fired at 50 to 100 ° C. in an inert gas atmosphere, and the surface of the copper filler is coated with copper nanoparticles having an average aggregate particle diameter of 50 to 200 nm. Obtaining a copper filler coated with copper nanoparticles.

Step (I):
The step (1) preferably comprises the following steps (I-1) to (I-2).
(I-1) A step of obtaining a dispersion by dispersing copper filler having an average aggregate particle diameter of 1 to 10 μm and copper hydride nanoparticles having an average aggregate particle diameter of 20 to 100 nm in a dispersion medium.
(I-2) A step of volatilizing and removing the dispersion medium from the obtained dispersion to coat the surface of the copper filler with copper hydride nanoparticles to obtain a copper hydride nanoparticle-coated copper filler.

Step (I-1):
The relative dielectric constant of the dispersion medium is preferably 4 to 40, and more preferably 10 to 30. If the relative dielectric constant of the dispersion medium is 4 or more, the dispersibility of the copper hydride nanoparticles will be good. If the relative dielectric constant of the dispersion medium is 40 or less, the dispersibility of the copper filler will be good.
Examples of the dispersion medium include methyl alcohol (33.0 (20 ° C.)), ethyl alcohol (25.3 (20 ° C.)), 1-propanol (20.8 (20 ° C.)), 2-propanol (20. 2 (20 ° C)), 1-butanol (17.8 (2O ° C)), 2-butanol (17.3 (20 ° C)), isobutyl alcohol (17.9 (20 ° C)), 1-pentanol ( 15.1 (25 ° C)), isopentyl alcohol (14.7 (20 ° C)), 1-hexanol (13.3 (20 ° C)), 1-octanol (10.3 (20 ° C)), cyclohexanol (16.4 (20 ° C)), cyclohexanone (16.1 (20 ° C)), acetone (21.0 (20 ° C)), octyl alcohol (10.3 (20 ° C)) and ethyl acetate (6.1) (20 ° C)) It is. The relative dielectric constant is shown in parentheses.
As the dispersion medium, 1-propanol (20.8 (20 ° C.)) or 2-propanol (20.2 (20 ° C.)) is preferable because both the copper filler and the copper hydride nanoparticles are excellent in dispersibility.

  The amount of the dispersion medium in the step (I-1) is preferably 250 to 1250% by mass and more preferably 300 to 750% by mass with respect to 100% by mass in total of the copper filler and the copper hydride nanoparticles. When the amount of the dispersion medium is 250% by mass or more, the copper hydride nanoparticles and the copper filler can be uniformly dispersed in the dispersion medium. When the amount of the dispersion medium is 1250% by mass or less, the time required for volatilizing the dispersion medium is short, and the manufacturing cost can be suppressed.

  Copper hydride nanoparticles exist in a state where copper atoms are bonded to hydrogen atoms, and have a property of decomposing into metal copper and hydrogen at 50 to 100 ° C. As a copper hydride nanoparticle, what is obtained with the manufacturing method of an above-described copper hydride nanoparticle is mentioned, for example.

  The average aggregate particle diameter of the copper hydride nanoparticles is 20 to 100 nm, and preferably 25 to 80 nm. If the average agglomerated particle diameter of the copper hydride nanoparticles is 20 nm or more, aggregation of the copper hydride nanoparticles during firing can be suppressed. If the average aggregate particle diameter of the copper hydride nanoparticles is 100 nm or less, copper hydride nanoparticles having a sufficiently high surface activity can be obtained.

Step (I-2):
The volatilization of the dispersion medium is preferably performed gradually under a reduced pressure of 450 to 600 mmHg. When the pressure is 450 mmHg or more, the copper hydride nanoparticles and the copper filler can be uniformly dispersed until immediately before the dispersion medium is completely volatilized. If the pressure is 600 mmHg or less, the time required to volatilize the dispersion medium is short, and the manufacturing cost can be reduced.
The fact that the surface of the copper filler is coated with copper hydride nanoparticles can be confirmed by observing the SEM image and confirming that a plurality of copper hydride nanoparticles are attached to at least a part of the surface of the copper filler.

Step (II):
By firing the copper hydride nanoparticle-coated copper filler at 50 to 100 ° C. in an inert gas atmosphere, the copper hydride nanoparticles on the surface of the copper filler are decomposed into metallic copper and hydrogen, and at the same time the nanoparticles are bonded to each other. It sinters and the copper nanoparticle whose average aggregated particle diameter is 50-200 nm is obtained.

  Examples of the inert gas include nitrogen gas, helium, neon, argon, krypton, xenon, and radon, and nitrogen gas or argon is preferable. A calcination temperature is 50-100 degreeC, and 60-80 degreeC is preferable. If a calcination temperature is 50 degreeC or more, the copper nanoparticle covering copper filler which can suppress generation | occurrence | production of the crack which arises in a metal film will be obtained. If a calcination temperature is 100 degrees C or less, the copper nanoparticle covering copper filler in which the activity of the copper nanoparticle surface is not lost is obtained.

<Copper formate complex in which amine is coordinated to copper formate>
A copper formate complex in which an amine is coordinated to copper formate (also referred to simply as “copper formate complex” in this specification) can be synthesized by mixing copper formate and an amine.
Copper formate and amine may be mixed as they are, or may be mixed as an aqueous solution, an organic solvent solution or an organic solvent suspension. The mixing of copper formate and amine is preferably performed using a suitable stirrer or mixer at a temperature of about 0 to 100 ° C.
Moreover, it is preferable that copper formate and an amine add 2-4 equivalents of amine with respect to 1 equivalent of copper formate.
When the amount of amine added when synthesizing the copper formate complex is too small, the storage stability of the resulting copper formate complex is lowered, and the complex may precipitate. However, even in this case, it can be used by heating and dissolving the complex.

In the composition obtained by mixing copper formate and amine, a copper formate complex having a formate anion and an amine as a ligand as main components is formed. In a preferred copper formate complex, it is preferable that formate anion and amine each coordinate two molecules to Cu ²⁺ which is a central metal. The two amines may be of the same type or different types.

  Depending on the mixing conditions, the composition formed by mixing copper formate and amine may contain a solvent and unreacted amine in addition to the above copper formate complex. When mixing at an equivalent ratio of 1: 2, a composition consisting essentially of only the copper formate complex is obtained.

  In the composition for forming a conductive film of the present invention, the content of the copper formate complex is not particularly limited, but is preferably 1 to 70% by mass, and 1 to 50% by mass with respect to the total mass of the copper filler. % Is more preferable, and 10 to 30% by mass is further preferable. By containing 1% by mass or more of the copper formate complex, the adhesion of the conductive film formed using the composition for forming a conductive film of the present invention is further improved, and by containing 70% by mass or less, The volume shrinkage of the conductive film formed using the composition for forming a conductive film is small, and it is easy to form a thick film.

(Copper formate)
As said copper formate, anhydrous copper formate (II), copper (II) formate, dihydrate, copper formate (II), tetrahydrate, etc. can be used.

(Amine)
As the amine, primary to tertiary amines can be used.
Of these, tertiary amines are preferred from the viewpoint of low boiling point of amines.
Further, from the viewpoint of increasing the hydrophilicity of the obtained copper formate complex, an amine having one or more hydroxy groups in the molecule is preferable.

  Examples of the primary amine include a monoalkylamine in which one or more hydrogen atoms of an alkyl group may be substituted with a substituent, and one or more hydrogen atoms in an aryl group are substituted with a substituent. A monoarylamine, a mono (heteroaryl) amine in which one or more hydrogen atoms of the heteroaryl group may be substituted with a substituent, and one or more hydrogen atoms of an alkylene group or an arylene group are substituted. Examples of the diamine may be substituted.

  The alkyl group constituting the monoalkylamine may be a linear, branched, or cyclic alkyl group, a linear alkyl group having 1 to 19 carbon atoms, or a branched alkyl group having 3 to 19 carbon atoms. Or a cyclic alkyl group having 3 to 7 carbon atoms is preferred.

  Examples of the linear or branched alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group. Group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylbutyl group, 2-methylbutyl group, n-hexyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl Group, 1,1-dimethylbutyl group, 2,2-dimethylbutyl group, 3,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 3-ethylbutyl group, 1 -Ethyl-1-methylpropyl group, n-heptyl group, 1-methylhexyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group Ruhexyl group, 5-methylhexyl group, 1,1-dimethylpentyl group, 2,2-dimethylpentyl group, 2,3-dimethylpentyl group, 2,4-dimethylpentyl group, 3,3-dimethylpentyl group, 4 , 4-dimethylpentyl group, 1-ethylpentyl group, 2-ethylpentyl group, 3-ethylpentyl group, 4-ethylpentyl group, 2,2,3-trimethylbutyl group, 1-propylbutyl group, n-octyl Group, isooctyl group, 1-methylheptyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 1-ethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 4-ethylhexyl group, 5-ethylhexyl group, 1,1-dimethylhexyl group, 2,2-dimethylhexyl group, 3,3-di Tylhexyl, 4,4-dimethylhexyl, 5,5-dimethylhexyl, 1-propylpentyl, 2-propylpentyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl Group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group and icosyl group.

  Examples of the cyclic alkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, an isobornyl group, a 1-adamantyl group, and a 2-adamantyl group. Group and tricyclodecyl group can be exemplified.

  Specific examples of preferable monoalkylamines include n-propylamine, 2-ethylhexylamine, tert-butylamine, n-octadecylamine (stearylamine), and cyclohexylamine.

  The aryl group constituting the monoarylamine is preferably a phenyl group, a 1-naphthyl group or a 2-naphthyl group.

  Examples of the secondary amine include dialkylamines in which one or more hydrogen atoms of an alkyl group may be substituted with a substituent, and one or more hydrogen atoms in an aryl group may be substituted with a substituent. Examples include good diarylamines, and di (heteroaryl) amines in which one or more hydrogen atoms of the heteroaryl group may be substituted with a substituent.

  The alkyl group constituting the dialkylamine is the same as the alkyl group constituting the monoalkylamine, a linear alkyl group having 1 to 9 carbon atoms, a branched alkyl group having 3 to 9 carbon atoms, or A cyclic alkyl group having 3 to 7 carbon atoms is preferred. Further, the two alkyl groups of the dialkylamine may be the same or different.

  Specific examples of preferred dialkylamines include N-methylethanolamine, N-ethylethanolamine, diethylamine and morpholine.

  Examples of the tertiary amine include a trialkylamine in which one or more hydrogen atoms of an alkyl group may be substituted with a substituent, and one or more hydrogen atoms in an alkyl group and / or aryl group are substituted. And dialkylmonoarylamine which may be substituted with a group.

  The alkyl group constituting the trialkylamine is the same as the alkyl group constituting the monoalkylamine, a linear alkyl group having 1 to 19 carbon atoms, a branched alkyl group having 3 to 19 carbon atoms, Or a C3-C7 cyclic alkyl group is preferable. Moreover, the types of the three alkyl groups of the trialkylamine may be the same, two may be the same, or three may be different from each other. That is, all of the three alkyl groups may be the same, all may be different, or only a part may be different.

  Examples of the trialkylamine include triethylamine, N, N-dimethyl-n-octadecylamine, N, N-dimethylcyclohexylamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, and N-methyldiethanolamine. N-methylmorpholine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tricyclohexylamine, trioctylamine, trilaurylamine, tristearylamine, trioleylamine, tribenzylamine, dioleyl monoethanolamine, di Lauryl monopropanolamine, dioctyl monoethanolamine, dihexyl monopropanolamine, dibutyl monopropanolamine, oleyl diethanolamine, stearyl Propanolamine, lauryl diethanolamine, octyl dipropanolamine, butyl diethanolamine, benzyl diethanolamine, phenyl diethanolamine, tolyl dipropanolamine, xylyl diethanolamine, triethanolamine, and tri propanolamine.

Particularly preferred tertiary amines include tertiary amines represented by the following formula (1).

Wherein R ¹ and R ² are each independently selected from the group consisting of a methyl group, an ethyl group, a 2-hydroxyethyl group and a 2-methoxyethyl group, and R ³ and R ⁴ are each independently R ⁵ is selected from the group consisting of a hydrogen atom, a methyl group and a hydroxy group, and R ⁵ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or 3 to 6 carbon atoms. Selected from the group consisting of a cyclic alkyl group, 2-hydroxyethyl group, 2-methoxyethyl group and 2-ethoxyethyl group, and X is selected from the group consisting of a methylene group, an ethylene group and a propylene group. R ³ and R ⁴ are preferably not hydroxy groups at the same time. ]

  Examples of the tertiary amine represented by the above formula (1) include N, N-dimethylethanolamine, N, N-dimethyl-2-methoxyethylamine, N, N-dimethyl-2-ethoxyethylamine, N, N-dimethyl-2-n-propoxyethylamine, N, N-dimethyl-2-isopropoxyethylamine, N, N-dimethyl-2-n-butoxyethylamine, N, N-dimethyl-2- (2-hydroxyethyloxy) ) Ethylamine, N, N-dimethyl-2- (2-methoxyethyloxy) ethylamine, N, N-dimethyl-2- (2-ethoxyethyloxy) ethylamine, N, N-dimethyl-1,1-dimethyl-2 -Hydroxyethylamine, N, N-dimethyl-1,1-dimethyl-2-methoxyethylamine, N, N-dimethyl-1,1 Dimethyl-2-ethoxyethylamine, N, N-dimethyl-3-hydroxypropylamine, N, N-dimethyl-3-methoxypropylamine, N, N-dimethyl-3-ethoxypropylamine, N, N-dimethyl-3 -Isopropoxypropylamine, N, N-dimethyl-3-n-butoxypropylamine and N, N-dimethyl-2-hydroxyethanolamine (N, N-dimethyl-1,2-dihydroxyethylamine).

Among these, N, N-dimethyl-2-hydroxyethanolamine (N, N-dimethyl-1,2-dihydroxyethylamine) represented by the following formula (2) is particularly preferable.

<Polymer binder>
The composition for forming a conductive film of the present invention may further contain a polymer binder. As the polymer binder, one type or two or more types of polymer compounds can be used. The polymer binder serves as a primer that assists the adhesion between the metallic copper and the base material in the conductive film to be formed.

  Preferred examples of the polymer binder include cellulose resin, acrylic resin, polyester resin, polyolefin resin, polyurethane resin, epoxy resin, rosin compound, and vinyl polymer. Examples of the vinyl polymer include polyvinyl pyrrolidone and polyvinyl alcohol.

  The content of the polymer binder in the composition for forming a conductive film can serve as a primer that assists the adhesion between the metallic copper and the base material, and does not deteriorate the conductivity of the formed conductive film. If there is, it will not be specifically limited. Specifically, the content of the polymer binder is preferably 2 to 8% by mass and more preferably 2 to 6% by mass with respect to the total mass of the copper filler, copper nanoparticles, and copper formate complex. Since the polymer binder and the metallic copper are likely to form a phase separation state, when an excessive amount of the polymeric binder is contained, the metallic copper tends to form domains (regions) independent of each other, and the conductivity may be deteriorated.

<Low molecular amine>
The resin composition for forming a conductive film of the present invention may further contain a low molecular amine. Copper (II) oxide does not dissolve in water, but in the presence of water and a low-molecular amine, a copper-amine complex in which four molecules of amine are coordinated to one copper (II) ion is formed and water-solubilized. By this reaction, the copper filler and the copper oxide on the surface of the copper nanoparticles are water-solubilized and removed from the particle surface. As a result, the conductivity and adhesion of the resulting conductive film are improved.

  If the low molecular amine remains in the formed conductive film, the conductivity and adhesion may be reduced. Therefore, it is preferable that the low molecular amine volatilizes or decomposes during firing and does not remain in the formed conductive film. For this reason, it is preferable that the boiling point or decomposition temperature of a low molecular amine is below a calcination temperature. Moreover, it is preferable that it is a gas or a liquid at normal temperature, and it is more preferable that it is a liquid from a viewpoint that manufacture of an electrically conductive paste becomes easier.

  The boiling point or decomposition temperature of the low molecular amine is preferably 250 ° C. or lower, more preferably 200 ° C. or lower, and further preferably 150 ° C. or lower. Further, it may be a gas or a liquid at normal temperature (20 ± 15 ° C., JIS Z 8703: 1983).

  The low molecular amine may be any of primary amine, secondary amine, or tertiary amine, and an amine that can be a ligand of the above-described copper formate complex can also be used. Specific examples of the low molecular amine include, for example, ethylamine, dimethylamine, diethylamine, dipropylamine, trimethylamine, triethylamine, tripropylamine, N, N-dimethyl-ethanolamine, N, N-diethyl-ethanolamine, Examples include 2-dimethylamino-2-methyl-1-propanol.

  The low molecular amine may be the same type of amine as the amine contained in the copper formate complex as a ligand, or may be a different type of amine, but is preferably a different type of amine. It is more preferable that the amine has a boiling point or a decomposition temperature lower than that of the amine coordinated with the copper complex. This is because when the composition for forming a conductive film of the present invention is baked, it is preferably volatilized or decomposed so as not to remain as much as possible in the formed conductive film.

  Although content in the composition for electrically conductive film formation of a low molecular amine is not specifically limited, 1-15 mass% is preferable with respect to the total mass of a copper filler and a copper nanoparticle, and 1-10 mass% is more preferable. Within this range, the effect of dissolving the copper nanoparticles on the surface of the copper nanoparticles and the copper filler by the low molecular amine is sufficiently exerted to improve the conductivity, and the adhesion of the formed conductive film is deteriorated. I won't let you.

<carboxylic acid>
The composition for forming a conductive film of the present invention may further contain a carboxylic acid. As the carboxylic acid, either monocarboxylic acid or polycarboxylic acid can be used. As the polycarboxylic acid, dicarboxylic acid or tricarboxylic acid is preferable.

  Examples of the monocarboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearin, Examples include oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, lactic acid, and pyruvic acid. Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, malic acid, and the like. Examples of the tricarboxylic acid include propane-1,2,3-tricarboxylic acid, citric acid (2-hydroxypropane-1,2,3-tricarboxylic acid), and isocitric acid (1-hydroxypropane-1,2). -3-tricarboxylic acid) and the like. Carboxylic acid can be used individually by 1 type or in combination of 2 or more types.

  The carboxylic acid is preferably at least one selected from the group consisting of formic acid, maleic acid and citric acid, and more preferably any one selected from formic acid, maleic acid and citric acid.

  When the composition for electrically conductive film formation of this invention contains carboxylic acid, the composition for electrically conductive film formation which is excellent in oxidation resistance and is easy to sinter can be obtained. Carboxylic acid is considered to decompose and remove the oxide film on the surface of the copper filler and copper nanoparticles. For this reason, in the composition for electrically conductive film formation of this invention, the volume resistivity of the electrically conductive film formed can further be reduced by containing carboxylic acid.

  Although content in the composition for electrically conductive film formation of carboxylic acid is not specifically limited, 1-15 mass% is preferable with respect to the total mass of a copper filler and a copper nanoparticle, 3-15 mass% is more preferable, 3 More preferably, it is 10 mass%. Within this range, the effect of removing the oxide film on the surface of the copper nanoparticles and copper filler by the carboxylic acid is sufficiently exerted to improve the conductivity, and the adhesion of the formed conductive film is deteriorated. I won't let you.

In the present invention, carboxylic acid may be used also in the step of producing copper hydride nanoparticles (the step (b)). In this case, the carboxylic acid used in the step (b) is a conductive material. You may serve as the carboxylic acid used when manufacturing the film forming composition.
The carboxylic acid is required to be water-soluble in the step (b), and contributes to the suppression of oxidation of the copper nanoparticles and the copper filler and the improvement of the dispersibility in the polymer binder in the manufacturing process of the conductive film forming composition. It is considered a thing. If the carboxylic acid satisfies both of these characteristics, the composition for forming a conductive film of the present invention containing the carboxylic acid used in the step (b) is mixed with a polymer binder without mixing another carboxylic acid. Then, the composition for forming a conductive film of the present invention may be prepared.
However, in general, it is preferable to select different carboxylic acid used in the step (b) and carboxylic acid used in the manufacturing process of the conductive film forming composition. Specifically, it is preferable to use formic acid having a reducing action in the step (b), and to use an aliphatic carboxylic acid having a hydrocarbon group having 4 to 20 carbon atoms in the production process of the conductive film forming composition.

<Solvent / Dispersion medium>
The composition for forming a conductive film of the present invention may contain a solvent or a dispersion medium (hereinafter simply referred to as “solvent”) to form a conductive paste or a copper paste.
A solvent will not be restrict | limited especially if it functions as a dispersion medium of a copper filler and copper nanoparticle, or a copper nanoparticle covering copper filler, and melt | dissolves a copper formate complex.
As the solvent, for example, water, organic solvents such as alcohols, ethers, and esters can be used. Among these, water, aliphatic alcohols having a monovalent hydroxy group, alkyl ethers derived from these aliphatic alcohols, aliphatics, from the point of better compatibility with copper formate complexes, copper fillers and copper nanoparticles. Alkyl esters derived from alcohols or mixtures thereof are preferably used.

When water is used as the solvent, one having a level of purity of ion-exchanged water is preferable.
Examples of aliphatic alcohols having 1 to 3 hydroxy groups include methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, cyclohexanol, 1-heptanol, 1-octanol and 1-nonanol. 1-decanol, glycidol, methylcyclohexanol, 2-methyl-1-butanol, 3-methyl-2-butanol, 4-methyl-2-pentanol, isopropyl alcohol, 2-ethylbutanol, 2-ethylhexanol, 2 -Octanol, terpineol, dihydroterpineol, 2-methoxyethanol, 2-ethoxyethanol, 2-n-butoxyethanol, carbitol, ethyl carbitol, n-butyl carbitol, diacetone alcohol, ethylene glycol Diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, trimethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, pentamethylene glycol, Examples include hexylene glycol and glycerin.
Among these, C1-C6 aliphatic alcohols having 1 to 3 valent hydroxy groups are preferable because their boiling points are not too high and hardly remain after formation of the conductive film. Specifically, methanol, ethylene glycol, glycerin 2-methoxyethanol, diethylene glycol, and isopropyl alcohol are more preferable.

  Examples of ethers include alkyl ethers derived from the above alcohols, such as diethyl ether, diisobutyl ether, dibutyl ether, methyl-t-butyl ether, methyl cyclohexyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl. Examples include ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane and the like. Especially, the C2-C8 alkyl ether derived from a C1-C4 aliphatic alcohol which has a 1-3 valent hydroxy group is preferable, and specifically, diethyl ether, diethylene glycol dimethyl ether, and tetrahydrofuran are more preferable.

  Examples of the esters include alkyl esters derived from the above alcohols, such as methyl formate, ethyl formate, butyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate, butyl propionate, and γ-butyrolactone. Illustrated. Especially, the C2-C8 alkyl ester derived from a C1-C4 aliphatic alcohol which has a 1-3 valent hydroxy group is preferable, and, specifically, methyl formate, ethyl formate, and methyl acetate are more preferable. .

  Among these solvents, it is particularly preferable to use water as the main solvent because the boiling point is not too high. The main solvent is a solvent having the highest content in the solvent.

<Other ingredients>
The composition for forming a conductive film of the present invention may contain other components in addition to those described above.
For example, the composition for forming a conductive film may contain a surfactant. The surfactant plays a role of improving the dispersibility of the copper oxide particles. The type of the surfactant is not particularly limited, and examples thereof include an anionic surfactant, a cationic surfactant, a nonionic surfactant, a fluorine surfactant, and an amphoteric surfactant. These surfactants can be used alone or in combination of two or more.

[Method for producing conductive film-forming composition]
The manufacturing method in particular of the composition for electrically conductive film formation of this invention is not restrict | limited, A well-known method is employable. For example, after adding a copper filler and a copper nanoparticle, or a copper nanoparticle-coated copper filler, a copper formate complex, and a low molecular amine, a polymer binder, an aliphatic carboxylic acid, etc. in a solvent, an ultrasonic method ( For example, the composition can be obtained by dispersing the components by known means such as an ultrasonic homogenizer, a mixer method, a three-roll method, or a ball mill method.

[Method for producing conductive film]
The manufacturing method of the electrically conductive film of this invention provides the coating film formation process which provides the composition for electrically conductive film formation mentioned above on a base material, and forms a coating film, and heat processing and / or light with respect to the said coating film A conductive film forming step of performing irradiation treatment and forming a conductive film. Below, each process is explained in full detail.

(Coating film formation process)
This step is a step of forming a coating film by applying the above-described composition for forming a conductive film on a substrate. The precursor film before the reduction treatment is obtained in this step.
The conductive film forming composition used is as described above.

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

The method for applying the conductive film forming composition onto the substrate is not particularly limited, and a known method can be adopted. For example, coating methods such as a screen printing method, a dip coating method, a spray coating method, a spin coating method, and an ink jet method can be used.
The shape of application is not particularly limited, and may be a surface covering the entire surface of the substrate or a pattern (for example, a wiring or a dot).
The coating amount of the composition for forming a conductive film on the substrate may be adjusted as appropriate according to the desired film thickness of the conductive film, but usually the coating film thickness is preferably 0.01 to 5000 μm, 0.1-1000 micrometers is more preferable.

In this step, if necessary, the conductive film-forming composition may be applied to the substrate and then dried to remove the solvent. By removing the remaining solvent, it is possible to suppress the generation of minute cracks and voids due to the vaporization and expansion of the solvent in the conductive film forming step described later. It is preferable in terms of adhesion.
As a method for the drying treatment, a hot air dryer or the like can be used, and the temperature is preferably 40 to 200 ° C., more preferably 50 to 150 ° C. More preferably, the heat treatment is performed at 70 ° C. to 120 ° C. Since metal copper is used in the present invention, conditions that suppress oxidation are preferable, for example, an inert gas atmosphere such as nitrogen or argon is more preferable, and drying is preferably performed in a reducing gas atmosphere such as hydrogen.

(Conductive film formation process)
This step is a step of forming a conductive film containing metallic copper by performing heat treatment and / or light irradiation treatment on the coating film formed in the coating film forming step.
By performing the heat treatment and / or the light irradiation treatment, copper (II) in the copper formate complex is reduced to copper (0).
More specifically, for example, by performing the above-described treatment, the copper metal produced from the copper formate complex and the copper filler and / or the copper nanoparticles are fused together to form grains, and the grains are bonded to each other. -Form a thin film by fusing.

As the conditions for the heat treatment, optimum conditions are appropriately selected according to the type of the copper formate complex and the solvent used. Among them, the heating temperature is preferably 100 to 400 ° C, more preferably 250 to 400 ° C, and the heating time is 5 to 120 minutes in that a conductive film that is more excellent in conductivity can be formed in a short time. Preferably, 5 to 60 minutes is more preferable.
The heating means is not particularly limited, and known heating means such as an oven and a hot plate can be used.
In the present invention, the conductive film can be formed by heat treatment at a relatively low temperature, and therefore, the process cost is low.

  Unlike the heat treatment described above, the light irradiation treatment can reduce and sinter to metallic copper by irradiating light on the portion to which the coating film is applied at room temperature for a short time, and heating for a long time. The base material is not deteriorated by, and the adhesion of the conductive film to the base material becomes better.

The light source used in the light irradiation treatment is not particularly limited, and examples thereof include a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, and a carbon arc lamp. Examples of radiation include electron beams, X-rays, ion beams, and far infrared rays. Further, g-line, i-line, deep-UV light, and high-density energy beam (laser beam) are also used.
Specific examples of preferred embodiments include scanning exposure with an infrared laser, high-illuminance flash exposure such as a xenon discharge lamp, and infrared lamp exposure.

The light irradiation is preferably light irradiation with a flash lamp, and more preferably pulsed light irradiation with a flash lamp. Irradiation with high-energy pulsed light can concentrate and heat the surface of the portion to which the coating film has been applied in a very short time, so that the influence of heat on the substrate can be extremely reduced.
The irradiation energy of the pulse light is preferably 1~100J / cm ^2, more preferably 1~30J / cm ^2, preferably 1μ seconds ~100m sec as a pulse width, and more preferably 10μ sec ~10m seconds. The irradiation time of the pulsed light is preferably 1 to 100 milliseconds, more preferably 1 to 50 milliseconds, and further preferably 1 to 20 milliseconds.

  The heat treatment and the light irradiation treatment may be performed alone or both may be performed simultaneously. Moreover, after performing one process, you may perform the other process further.

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

(Conductive film)
By carrying out the above steps, a conductive film (copper film) containing metallic copper is obtained.
The film thickness of the conductive film is not particularly limited, and an optimum film thickness is appropriately adjusted according to the intended use. Especially, from the point of a printed wiring board use, 0.01-1000 micrometers is preferable and 0.1-100 micrometers is more preferable.
The film thickness is a value (average value) obtained by measuring three or more thicknesses at arbitrary points on the conductive film and arithmetically averaging the values.

  The adhesion of the conductive film can be evaluated by a conventionally known method. For example, using a H pencil, the load is 750 g ± 10 g, and JIS K 5600-5-4: 1999 “scratch hardness (pencil method). It is preferable to carry out in accordance with the test method. In this case, the scratching test is repeated 10 times, and scratching at the time of scratching is preferably 6 times or less, more preferably 5 times or less, and more preferably 2 times or less. preferable.

The volume resistance value of the conductive film is preferably 1.0 × 10 ⁻¹ Ωcm or less, more preferably 1.0 × 10 ⁻³ Ωcm or less, and even more preferably 5.0 × 10 ⁻⁴ Ωcm or less from the viewpoint of conductive properties. preferable.
The volume resistance value can be calculated by multiplying the obtained surface resistance value by the film thickness after measuring the surface resistance value of the conductive film by the four-probe method.

The conductive film may be provided on the entire surface of the base material or in a pattern. The patterned conductive film is useful as a conductor wiring (wiring) such as a printed wiring board.
As a method of obtaining a patterned conductive film, the above-mentioned composition for forming a conductive film was applied to a substrate in a pattern, and the above heat treatment and / or light irradiation treatment was performed, or the entire surface of the substrate was provided. For example, a method of etching the conductive film in a pattern may be used.
The etching method is not particularly limited, and a known subtractive method, semi-additive method, or the like can be employed.

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

The material of the insulating film is not particularly limited. For example, epoxy resin, glass epoxy resin, aramid resin, crystalline polyolefin resin, amorphous polyolefin resin, fluorine-containing resin (polytetrafluoroethylene, perfluorinated polyimide, perfluorinated) Amorphous resin), polyimide resin, polyether sulfone resin, polyphenylene sulfide resin, polyether ether ketone resin, liquid crystal resin, and the like.
Among these, from the viewpoints of adhesion, dimensional stability, heat resistance, electrical insulation, and the like, it is preferable to contain an epoxy resin, a polyimide resin, or a liquid crystal resin, and more preferably an epoxy resin. Specifically, ABF TECH-13, ABF GX-13, etc. are mentioned.

  Further, a solder resist, which is a kind of insulating layer material used for wiring protection, is described in detail in, for example, JP-A-10-204150, JP-A-2003-222993, and the like. These materials can also be applied to the present invention if desired. A commercially available solder resist may be used, and specific examples include PFR800 manufactured by Taiyo Ink Manufacturing Co., Ltd., PSR4000 (trade name), SR7200G manufactured by Hitachi Chemical Co., Ltd., and the like.

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

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these.

(Synthesis Example 1: Synthesis of copper formate complex 1)
To a 1 L eggplant flask, methanol (100 mL) and copper (II) formate tetrahydrate (11.3 g; 0.05 mol) were added to prepare a suspension. To the suspension was added N, N-dimethyl-1,2-dihydroxyethylamine (see the following formula, hereinafter may be referred to as “amine A”) (11.9 g; 0.11 mol), and 1 hour at room temperature. Stir. The obtained solution was distilled off under reduced pressure to obtain a copper formate complex (22 g). This copper formate complex is referred to as “copper formate complex 1”.

(Synthesis Example 2: Synthesis of copper formate complex 2)
A copper formate complex (17.5 g) was obtained in the same manner as in Synthesis Example 1 except that the amount of amine A added was changed from 11.9 g (0.11 mol) to 6.0 g (0.057 mol). This copper formate complex is referred to as “copper formate complex 2”.

(Synthesis Example 3: Synthesis of Copper Formate Complex 3)
A copper formate complex (20.4 g) was obtained in the same manner as in Synthesis Example 1 except that the amount of amine A added was changed from 11.9 g (0.11 mol) to 9.0 g (0.086 mol). This copper formate complex is referred to as “copper formate complex 3”.

(Synthesis Example 4: Synthesis of Copper Formate Complex 4)
A copper formate complex (25.8 g) was obtained in the same manner as in Synthesis Example 1 except that the amount of amine A added was changed from 11.9 g (0.11 mol) to 15.0 g (0.14 mol). This copper formate complex is referred to as “copper formate complex 4”.

(Synthesis Example 5: Synthesis of copper formate complex 5)
Example except that hexylamine (refer to the following formula, hereinafter sometimes referred to as “amine B”) (10.1 g; 0.1 mol) was used instead of amine A (11.9 g; 0.11 mol) In the same manner as in Example 1, a copper formate complex (21 g) was obtained. This copper formate complex is referred to as “copper formate complex 5”.

(Production Example 1: Production of copper hydride nanoparticles 1)
Copper (II) sulfate pentahydrate (5.2 g), distilled water (30 g), and formic acid (3 g) were dissolved in a 100 mL three-necked flask to prepare an aqueous solution containing copper ions. While the prepared aqueous solution was vigorously stirred, a 4 mass% aqueous sodium borohydride solution (23 g) was slowly added dropwise to the aqueous solution at 20 ° C. After completion of the dropwise addition, stirring was continued for 10 minutes to obtain a suspension. Aggregates in the suspension were precipitated by centrifugation, and the precipitates were separated. After the separated precipitate was redispersed in 2-propanol (30 g), the aggregate was precipitated by centrifugal separation, and the precipitate was separated to obtain copper hydride nanoparticles (copper hydride nanoparticles 1). .

(Production Example 2: Production of copper nanoparticle-coated copper filler 1)
Copper hydride nanoparticle 1 (1 g) and copper filler (Mitsui Metal Mining Co., Ltd., 1400 YP; average aggregated particle diameter 7 μm, aggregated particle diameter range = 3 to 10 μm) (hereinafter referred to as “copper filler 1”) (3 g Was added to 2-propanol (20 g) and stirred to obtain a dispersion. The obtained dispersion was heated to 80 ° C. under a reduced pressure of −35 kPa, and 2-propanol was volatilized and gradually removed from the dispersion. At this time, the copper hydride nanoparticles were decomposed (reduced) into metal copper nanoparticles, and a conductive filler (copper nanoparticle-coated copper filler 1) in which the surface of the copper filler was coated with copper nanoparticles was obtained. The average aggregate particle diameter measured by SEM of the copper nanoparticles covering the surface of the copper filler (hereinafter referred to as “copper nanoparticles 1”) was 100 nm.

(Production Example 3: Production of Copper Nanoparticle-Coated Copper Filler 2)
Copper hydride nanoparticles 1 (1 g) and copper filler (Mitsui Metals Mining Co., Ltd., MA-CJF; average aggregated particle diameter 18 μm) (hereinafter referred to as “copper filler 2”) (3 g) were combined with 20g) and stirred to obtain a dispersion. The obtained dispersion was heated to 80 ° C. under a reduced pressure of −35 kPa, and 2-propanol was volatilized and gradually removed from the dispersion. At this time, the copper hydride nanoparticles were decomposed (reduced) into metallic copper nanoparticles, and a conductive filler (copper nanoparticle-coated copper filler 2) in which the surface of the copper filler was coated with copper nanoparticles was obtained. The average aggregate particle diameter measured by SEM of the copper nanoparticles (hereinafter referred to as “copper nanoparticles 2”) covering the surface of the copper filler was 100 nm.

Example 1
Copper nanoparticle-coated copper filler 1 (1.0 g; including copper filler 1 (0.75 g) and copper nanoparticle 1 (0.25 g)), copper formate complex 1 (0.25 g), and polyvinylpyrrolidone ( Wako Pure Chemical Industries, Ltd., K-60) (0.04 g) and water (0.64 g) were mixed and treated with an ultrasonic homogenizer for 30 minutes to prepare a copper paste (copper paste 1).
Copper paste 1 is applied to a 2 cm × 2 cm surface of a roughened glass epoxy substrate to a thickness of 20 μm, dried in a glove box (oxygen concentration <100 ppm) on a hot plate at 100 ° C. for 10 minutes, and then in an argon atmosphere. A copper film was formed by sintering at 300 ° C. for 20 minutes. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Example 2)
Instead of the copper nanoparticle-coated copper filler 1 (1.0 g), the copper filler 1 (0.75 g) and the copper nanoparticle 3 (manufactured by Iox, Cu-001; average aggregate particle diameter 70 nm: copper nanoparticle 3) (0 .30 g) was used, and a copper paste was prepared in the same manner as in Example 1 to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Example 3)
A copper paste was prepared and a copper film was formed in the same manner as in Example 1 except that the copper formate complex 5 was used instead of the copper formate complex 1. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

Example 4
A copper paste was prepared in the same manner as in Example 1 except that the blending amount of the copper formate complex 1 was changed from 0.25 g to 0.04 g to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Example 5)
A copper paste was prepared in the same manner as in Example 1 except that the amount of the copper formate complex 1 was changed from 0.25 g to 0.07 g to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Example 6)
A copper paste was prepared in the same manner as in Example 1 except that the blending amount of the copper formate complex 1 was changed from 0.25 g to 0.12 g to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Example 7)
A copper paste was prepared in the same manner as in Example 1 except that the amount of the copper formate complex 1 was changed from 0.25 g to 0.50 g, and a copper film was formed. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Example 8)
A copper paste was prepared in the same manner as in Example 1 except that a copper formate complex 2 was used in place of the copper formate complex 1 to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.
In addition, when the prepared copper paste was preserve | saved for one day by refrigeration (4 degreeC) and precipitation of the complex was observed, precipitation was observed. Precipitation was re-dissolved by heating the copper paste to 60 ° C., and a copper film could be formed.

Example 9
A copper paste was prepared in the same manner as in Example 1 except that the copper formate complex 3 was used in place of the copper formate complex 1 to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.
In addition, when the prepared copper paste was preserve | saved for one day by refrigeration (4 degreeC) and precipitation of the complex was observed, precipitation was observed. Precipitation was re-dissolved by heating the copper paste to 60 ° C., and a copper film could be formed.

(Example 10)
A copper paste was prepared in the same manner as in Example 1 except that the copper formate complex 4 was used in place of the copper formate complex 1 to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.
In addition, when the prepared copper paste was preserve | saved for one day by refrigeration (4 degreeC) and the precipitation condition of the complex was observed, precipitation was not observed.

(Example 11)
A copper paste was prepared in the same manner as in Example 1 except that the content of polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K-60) was changed from 0.04 g to 0.02 g. . The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.
In addition, the strength of the coating film was low, and chipping was observed during the formation of the copper film.

(Example 12)
A copper paste was prepared in the same manner as in Example 1 except that the content of polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K-60) was changed from 0.04 g to 0.12 g. . The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.
In addition, since there was much content of a polymer, the nonuniformity was recognized by the obtained copper film.

(Example 13)
A copper paste was prepared and a copper film was formed in the same manner as in Example 1 except that diethylamine (see the following formula, hereinafter sometimes referred to as “amine C”) (0.13 g) was contained. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Example 14)
A copper paste was prepared in the same manner as in Example 1 except that citric acid (0.15 g) was contained, and a copper film was formed. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Comparative Example 1)
A copper paste was prepared in the same manner as in Example 1 except that the copper formate complex 1 was not used, and a copper film was formed. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Comparative Example 2)
In place of copper nanoparticle-coated copper filler 1 (1.0 g), copper nanoparticle-coated copper filler 2 (1.0 g; including copper filler 2 (0.75 g) and copper nanoparticle 2 (0.25 g)). Except for the points used, a copper paste was prepared in the same manner as in Example 1 to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Comparative Example 3)
A copper paste was prepared in the same manner as in Example 1 except that the copper filler 1 (1.0 g) was used instead of the copper nanoparticle-coated copper filler 1 (1.0 g) to form a copper film. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Comparative Example 4)
A point in which acetylacetone copper (hereinafter sometimes referred to as “copper complex A”) (0.20 g) was used in place of copper formate complex 1 (0.25 g), and N, N-dimethyl-2,3-dihydroxypropyl A copper paste was prepared in the same manner as in Example 1 except that an amine (hereinafter sometimes referred to as “amine D”) (see formula below) (0.50 g) was contained, and a copper film was formed. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Comparative Example 5)
Example 1 was repeated except that copper acetate (0.20 g; 0.01 mol) was used instead of copper formate complex 1 (0.25 g), and amine D (0.50 g) was contained. A copper paste was prepared and a copper film was formed. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Comparative Example 6)
A copper paste was prepared in the same manner as in Example 1 except that the copper formate complex 1 (0.25 g) was not contained and citric acid (0.20 g) was contained, and a copper film was formed. The following adhesion evaluation was implemented with respect to the formed copper film. The results are shown in Table 1.

(Adhesion evaluation)
About the formed copper film, adhesiveness was evaluated by the scratch test. The scratch test was repeated 10 times, and the adhesion of the copper film was graded and evaluated according to the following criteria. Practically, it is preferably A to C.
A: The occurrence of scratches during scratching is 2 or less of 10 times.
B: Scratches occurring at the time of scratching are 3 to 4 times out of 10 times.
C: The occurrence of scratches during scratching is 5 to 6 out of 10 times.
D: The occurrence of scratches during scratching is 7 or more out of 10 times.
The evaluation (grade) is shown in Table 1.
The scratch test was performed using a H pencil (manufactured by Mitsubishi Pencil Co., Ltd.) and a pencil scratch tester (manufactured by Cortec Co., Ltd.) under a load of 750 g ± 10 g and JIS K 5600-5-4: 1999 “scratch hardness (pencil method). ) "In accordance with the test method. Here, the hardness H of the pencil core is defined by JIS S 6006: 2007 “Pencils, colored pencils and shin used for them”.

(Conductivity evaluation)
Among the formed copper films, the volume resistivity (unit: 10 ⁻⁵ Ω · cm) was measured for those having an adhesion evaluation (grade) of A or B. Volume resistivity measurement is performed using a four-point probe resistivity meter (Mitsubishi Chemical Co., Ltd., Loresta-GP), and the arithmetic average of the values obtained by measuring the volume resistivity at any four locations of the copper film. The value was defined as the volume resistivity of the copper film. The obtained volume resistivity is shown in Table 1.

In Table 1, the copper fillers and copper nanoparticles of Examples 1, 3 to 14 and Comparative Examples 1 and 4 to 6 are blended with the copper nanoparticle-coated copper filler 1 produced in Production Example 2, and are Comparative Examples. The copper filler 2 and the copper nanoparticles 2 are blended with the copper nanoparticle-coated copper filler 2 produced in Production Example 3. In addition, Table 1 shows the average aggregate particle diameter of the copper filler and the copper nanoparticles.
In Table 1, “ratio [mass%]” in the column of copper formate complex is a mass percentage of the copper formate complex relative to the total mass of the copper filler, and “ratio [mass%]” in the column of polymer binder is The mass percentage of the polymer binder with respect to the total mass of the copper filler, the copper nanoparticles and the copper formate complex, and the “ratio [mass%]” in the amine column is the mass percentage of the amine with respect to the total mass of the copper filler and the copper nanoparticles. Yes, “ratio [mass%]” in the column of carboxylic acid is a mass percentage of the carboxylic acid relative to the total mass of the copper filler and the copper nanoparticles.
In Table 1, “copper complex A” means acetylacetone copper, “PVP” means polyvinylpyrrolidone, “amine A” means N, N-dimethyl-1,2-dihydroxyethylamine, “amine C”. "Means diethylamine and" amine D "means N, N-dimethyl-1,2-dihydroxypropylamine.
Moreover, in Table 1, “unapplicable” means that the copper filler in the copper paste was heavily settled and could not be applied.

When Examples 1-14 are compared with Comparative Examples 1-6, in Examples 1-14 using the composition for electrically conductive film formation (copper paste) of this invention, the copper film which has the outstanding adhesiveness is obtained. I was able to.
When Example 1 is compared with Example 2, Example 1 using a copper nanoparticle-coated copper filler in which a copper filler is coated with copper nanoparticles does not coat the copper filler with copper nanoparticles. Compared to Example 2 in which nanoparticles were mixed separately, adhesion and conductivity were excellent.
Moreover, when Example 1 and Example 3 were contrasted, the direction of Example 1 whose amine compound used as the ligand of a copper formate complex is a tertiary amine was excellent in adhesiveness and electroconductivity.
Moreover, even if it is a case where content of the copper formate complex with respect to the copper filler in the composition for electrically conductive film is changed so that it may show from the comparison of Example 1, 4-7, copper which has the outstanding adhesiveness A membrane could be obtained. Furthermore, Example 1, 4-7 whose content of a copper formate complex is 1-50 mass% is more excellent in adhesiveness compared with Example 7 whose content of a copper formate complex exceeds 50 mass%. It was.
Moreover, even if it is a case where the number of moles of the amine used as the ligand of a copper formate complex differs from the comparison of Example 1 and 8-10, the copper film which has the outstanding adhesiveness can be obtained. It was.
Further, when Example 1 is compared with Examples 12 and 13, Example 1 in which the content of PVP as a polymer binder is 3.2% by mass of the total mass of the copper filler, the copper nanoparticles, and the copper formate complex is Adhesiveness was more excellent than Example 12 of less than 2% by mass and Example 13 of more than 8% by mass of the total mass.
Moreover, when Example 1 was compared with Example 14, the direction of Example 14 containing a citric acid was excellent in electroconductivity compared with Example 1 which does not contain.

  In Comparative Example 2 using the composition for forming a conductive film containing a copper filler having an average particle diameter exceeding a predetermined range, the copper filler was heavily settled, and the composition could not be applied on the substrate. A copper film could not be formed.

Claims (12)

  A conductive film-forming composition comprising copper nanoparticles having an average aggregate particle diameter of 50 to 200 nm, a copper filler having an average aggregate particle diameter of 1 to 10 μm, and a copper formate complex in which an amine is coordinated to copper formate. object.   The composition for electrically conductive film formation of Claim 1 with which the surface of the said copper filler is coat | covered with the said copper nanoparticle.   The composition for electrically conductive film formation of Claim 1 or 2 whose content of the said copper formate complex is 1-50 mass% with respect to the total mass of the said copper filler.   The electrically conductive film of any one of Claims 1-3 whose content of the said copper filler is 45-80 mass% with respect to the total mass of the said copper filler, the said copper nanoparticle, and the said copper formate complex. Forming composition.   Furthermore, the composition for electrically conductive film formation of any one of Claims 1-4 containing a polymer binder.   The composition for electrically conductive film formation of Claim 4 whose content of the said polymer binder is 2-8 mass% with respect to the total mass of the said copper filler, the said copper nanoparticle, and the said copper formate complex. The composition for electrically conductive film formation of any one of Claims 1-6 in which the said amine contains the tertiary amine represented by following formula (1).

Wherein R ¹ and R ² are each independently selected from the group consisting of a methyl group, an ethyl group, a 2-hydroxyethyl group and a 2-methoxyethyl group, and R ³ and R ⁴ are each independently R ⁵ is selected from the group consisting of a hydrogen atom, a methyl group and a hydroxy group, and R ⁵ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or 3 to 6 carbon atoms. Selected from the group consisting of a cyclic alkyl group, 2-hydroxyethyl group, 2-methoxyethyl group and 2-ethoxyethyl group, and X is selected from the group consisting of a methylene group, an ethylene group and a propylene group. ]   Furthermore, the composition for electrically conductive film formation of any one of Claims 1-7 containing a low molecular amine.   The composition for electrically conductive film formation of Claim 8 whose content of the said low molecular amine is 1-15 mass% with respect to the total mass of the said copper filler and the said copper nanoparticle.   Furthermore, the composition for electrically conductive film formation of any one of Claims 1-9 containing carboxylic acid.   The composition for electrically conductive film formation of Claim 10 whose content of the said carboxylic acid is 1-15 mass% with respect to the total mass of the said copper filler and the said copper nanoparticle. The coating film formation process which provides the composition for electrically conductive film formation of any one of Claims 1-11 on a base material, and forms a coating film,
The manufacturing method of an electrically conductive film provided with the electrically conductive film formation process which heat-processes and / or light-irradiates with respect to the said coating film, and forms an electrically conductive film.