JP5881613B2 - Conductive composition and method for forming conductive film - Google Patents

Description

  The present invention relates to a conductive composition that can be used, for example, for forming a conductive film of an electronic component, and a method for forming a conductive film using the conductive composition.

  As a method for forming a conductive circuit of various electronic components, a subtractive method, an additive method, and the like are known. In the additive method, a conductive composition is applied onto a substrate using a technique such as screen printing to form a pattern, and the conductive composition (conductive circuit) is formed by firing the conductive composition at a predetermined temperature. It is formed.

  Patent Document 1 discloses copper powder, a solvent composed of a polyhydric alcohol having two or more OH groups such as ethylene glycol and diethylene glycol, two or more COOH groups such as malic acid and citric acid, and one OH group. An electrically conductive composition containing an additive composed of the above compound is disclosed. This conductive composition can be fired at a low temperature not only in an inert atmosphere but also in an air atmosphere. Moreover, according to this electroconductive composition, it is possible to prevent the copper particle which is a filler from oxidizing, and to form the electrically conductive film which has favorable electroconductivity.

JP 2007-258123 A

  However, the conductive composition disclosed in Patent Document 1 has an extremely limited temperature range of 150 ° C. to 200 ° C. that can be fired in the air atmosphere. For this reason, the conductive composition disclosed in Patent Document 1 has a problem that it is difficult to control the firing temperature and it is difficult to put it to practical use.

  This invention is made | formed in view of the above situations, Comprising: It aims at providing the formation method of the electrically conductive composition which can be baked in air | atmosphere, and its electrically conductive film.

  The present inventors have studied to solve the above problems. As a result, it was discovered that a conductive composition that can be fired in an air atmosphere can be obtained by adding a specific carboxylic acid and a specific amine compound to a metal powder mainly composed of a base metal such as copper.

That is, the conductive composition of the present invention is
(A) metal powder mainly composed of base metal;
(B) an amine compound represented by the following general formula (1), or an aliphatic amine having two or more amino groups;
(C) an aliphatic hydroxy acid;
It is characterized by containing.

R ₂ —HN—R ₁ —O—R ₃ (1)
(In the formula, R ₁ represents an alkylene group having 2 to 8 carbon atoms, and R ₂ and R ₃ each represents an H atom or an alkyl group having 1 to 4 carbon atoms.)

  In the conductive composition of the present invention, the component (B) is preferably an aliphatic amine having an OH group.

  The component (B) is preferably at least one selected from 3-amino-1-propanol, 3-methoxypropylamine, N-methylethanolamine, and 1,3-diaminopropane, Particularly preferred is 1-propanol.

  In the conductive composition of the present invention, the component (C) is preferably at least one selected from glycolic acid, lactic acid, and citric acid, and particularly preferably glycolic acid.

  The conductive composition of the present invention preferably further contains a linear epoxy resin having one or more OH groups in the molecule.

  The component (A) is preferably at least one selected from copper, nickel, zinc, tin, and solder.

  Moreover, this invention provides the electrically conductive film obtained by apply | coating the above-mentioned electroconductive composition on a board | substrate, and heating at 70 degreeC or more and 500 degrees C or less.

  Furthermore, this invention provides the formation method of the electrically conductive film which has the heat processing process heated at 70 degreeC or more and 500 degrees C or less, after apply | coating one of above-described electrically conductive compositions on a board | substrate. In this method, the heat treatment step is preferably performed in an air atmosphere.

  ADVANTAGE OF THE INVENTION According to this invention, the formation method of the electrically conductive composition which can be baked in an atmospheric condition, and the electrically conductive film using the same can be provided.

Hereinafter, embodiments for carrying out the present invention will be described in detail.
The conductive composition according to this embodiment includes (A) a metal powder mainly composed of a base metal, and (B) an amine compound represented by the following general formula (1), or a fat having two or more amino groups. A group amine and (C) an aliphatic hydroxy acid.

R ₂ —HN—R ₁ —O—R ₃ (1)
(In the formula, R ₁ represents an alkylene group having 2 to 8 carbon atoms, and R ₂ and R ₃ each represents an H atom or an alkyl group having 1 to 4 carbon atoms.)

  The “metal powder mainly composed of a base metal” as the component (A) means a metal powder containing a base metal in an amount of 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more. Therefore, if not only metal powder consisting of only a base metal but also metal powder consisting of a mixture of a base metal and another metal contains 50% by weight or more of the base metal, the “metal mainly composed of base metal” is used here. Included in "powder". Further, if the metal powder made of an alloy of a base metal and another metal (for example, solder which is an alloy of tin and another metal) also contains 50% by weight or more of tin which is a base metal, here It is included in the “metal powder mainly composed of base metals”.

The term “base metal” is generally used as a synonym for “precious metal”. The “base metal” may mean all metals other than gold and silver. Further, “base metal” chemically means a metal having a relatively high tendency to ionize and having a property of being easily oxidized in a high temperature atmosphere.
Examples of the “base metal” that can be used in the present invention include iron, cobalt, nickel, copper, zinc, molybdenum, tungsten, cadmium, indium, tin, and antimony. Among these, it is most preferable to use copper. This is because copper has low electrical resistivity and high conductivity, and is less susceptible to electromigration when used for forming a conductive circuit on a printed wiring board.

  The average particle diameter of the “metal powder mainly composed of base metal” of the component (A) is not particularly limited, but is preferably 1 nm or more and 100 μm or less, and more preferably 100 nm or more and 10 μm or less. When the average particle diameter is within this range, the conductive composition can be suitably used as a conductive paste for circuit pattern printing. In addition, the average particle diameter in this specification means the average particle diameter based on the number standard by laser diffraction scattering type particle size distribution measurement. The metal powder mainly composed of a base metal can be produced by a known method such as an electrolysis method, a reduction method, or an atomization method.

  Examples of the amine compound represented by the above formula (1) include 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, 3-methoxypropylamine, N-methylethanolamine, and N-methyl. Specific examples include propanolamine and the like.

As the compound represented by the above formula (1), an aliphatic amine having an OH group is preferably used. That is, it is preferable that both R ₂ and R ₃ in the above formula (1) are H atoms.

  Most preferably, 3-amino-1-propanol is used as the compound represented by the above formula (1).

The “aliphatic amine having two or more amino groups (—NH ₂ )” as the component (B) means that the H atom of a linear or branched saturated hydrocarbon is substituted by two or more amino groups. It means the compound made. That is, taking a diamine in which the H atom of a linear or branched saturated hydrocarbon is substituted by two amino groups, it means a compound represented by the following general formula (2).

H ₂ N—R ₄ —NH ₂ Formula (2)
(In the formula, R ₄ represents an alkylene group.)

In the above formula (2), R ₄ is preferably an alkylene group having 2 to 12 carbon atoms, and more preferably an alkylene group having 2 to 8 carbon atoms.

  Examples of the compound represented by the above formula (2) include 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,8-diaminooctane, 1,10-diaminodecane, and the like. Specific examples can be given. Of these, it is most preferable to use 1,3-diaminopropane.

  The “aliphatic hydroxy acid” of the component (C) is an aliphatic carboxylic acid having an OH group, and glycolic acid, lactic acid, glyceric acid, hydroxybutyric acid, malic acid, tartaric acid, citric acid, 3-hydroxy Specific examples include propionic acid and the like. Among these, it is preferable to use at least one selected from glycolic acid, lactic acid, and citric acid, and it is most preferable to use glycolic acid.

  Moreover, it is preferable that the electrically conductive composition of this invention contains the linear epoxy resin which has 1 or more of OH groups in (D) molecule | numerator. The term “linear” as used herein means that the molecule does not have a benzene ring and has a linear structure in which at least 3 carbons are continuous in the portion excluding the terminal epoxy group. To do. Such an epoxy resin that can be used in the present invention is not particularly limited. For example, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, etc. Can be used. Each of these has a structure of the following formulas (3) to (7) (in the formula (4), n is 1 to 10).

  To improve the applicability and adhesion of the conductive composition to the substrate by adding the component (D) “linear epoxy resin having an OH group” to the components (A) to (C). Can do. On the other hand, when “epoxy resin having no OH group” is added to the components (A) to (C), the compatibility of the epoxy resin with the components (B) and (C) is not good. Therefore, such an effect cannot be obtained sufficiently.

  In addition, when the component (D) “linear epoxy resin having an OH group” is added to the components (A) to (C), the surface of the base metal particles is blocked by the epoxy resin blocking oxygen. Can be prevented from oxidizing. As a result, the conductive composition can be fired at a higher temperature, and a conductive film having higher conductivity can be formed.

By adding and mixing the above components (A) to (C) and, if necessary, the component (D), a paste-like conductive composition can be obtained.
In addition, the order which mixes above-mentioned (A)-(C) component is arbitrary, For example, you may mix the component of (A)-(C) simultaneously, (B) component and (C) component (A) component may be added later and mixed.

The mixing ratio of the components (A) to (C) in the conductive composition of the present invention is not particularly limited, but the component (B) is 1 to 50 weights per 100 parts by weight of the component (A). Part, (C) component 1-50 parts by weight is preferred. More preferably, they are 5-25 weight part of (B) component and 5-25 weight part of (C) component with respect to 100 weight part of (A) component. Most preferably, they are 5-10 weight part of (B) component and 5-10 weight part of (C) component with respect to 100 weight part of (A) component.
When the mixing ratio of the components (B) and (C) is less than the above, a conductive film having high conductivity may not be obtained. Moreover, when there are more mixing ratios of (B) and (C) component than the above, there exists a possibility that the viscosity of an electroconductive composition may become low too much and may have a bad influence on the application | coating performance to the board | substrate at the time of screen printing.

  In addition to the components (A) to (D), a solvent or an organic binder for adjusting the viscosity to be suitable for printing on the substrate is added to the conductive composition of the present invention, if necessary. be able to. As the solvent and the organic binder, for example, known ones disclosed in JP 2007-258123 A can be used. As a solvent for diluting the conductive composition to lower the viscosity, for example, water, methanol, ethanol, 1,3-propanediol, ethylene glycol monoacetate, ethyl hydroxyacetate, or the like can be used.

Next, a method for forming a conductive film on a substrate using the conductive composition obtained as described above will be described.
The components (A) to (C) and, if necessary, the component (D) are mixed to prepare a paste-like conductive composition, and then the conductive composition is applied onto a substrate. As a coating method, for example, a known method such as a screen printing method can be used.

  After applying the paste-like conductive composition on the substrate, the conductive composition is fired at a temperature of 70 ° C. or higher and 500 ° C. or lower (heat treatment step). When the firing temperature is lower than this range, the volatilization or thermal decomposition of the organic matter in the conductive composition becomes insufficient, and the conductivity of the conductive film may be hindered by the organic matter residue. On the other hand, when the firing temperature is higher than this range, the surface of the base metal particles in the conductive composition is easily oxidized, so that a conductive film having high conductivity may not be obtained. A more preferable range of the firing temperature is 150 ° C. or more and 500 ° C. or less.

The preferable range of the firing temperature varies depending on the type of the base metal of the component (A). Further, it varies depending on whether or not the component (D) is contained in the conductive composition.
For example, when copper is used as the base metal of the component (A) and does not contain the component (D), it is preferably fired at 150 to 400 ° C, and fired at 200 to 350 ° C. More preferably. When copper is used as the base metal of the component (A) and the component (D) is contained, it is preferably fired at 250 to 500 ° C, and fired at 350 to 500 ° C. Is more preferable. When nickel is used as the base metal of the component (A) and does not contain the component (D), it is preferably fired at 150 to 400 ° C, and fired at 200 to 350 ° C. Is more preferable. When nickel is used as the base metal of the component (A) and contains the component (D), it is preferably fired at 250 to 500 ° C., and fired at 350 to 500 ° C. Is more preferable. When solder is used as the base metal of the component (A) and the component (D) is not contained, the conductive composition is preferably fired at 80 to 300 ° C. More preferably, baking is performed at a temperature of 0 ° C. When tin is used as the base metal of the component (A) and does not contain the component (D), firing is preferably performed at 80 to 230 ° C., and is performed at 80 to 150 ° C. Is more preferable.

  Further, depending on the type of the base metal of the component (A), it is possible to form a conductive film simply by drying the conductive composition at around room temperature (20 ° C.). For example, when zinc is used as the base metal of the component (A), it is possible to form a conductive film by simply drying the conductive composition near room temperature.

  When zinc is used as the base metal of the component (A) and does not contain the component (D), the conductive composition is dried near room temperature or a temperature of 300 ° C. or lower. Is preferably fired at 80 to 150 ° C. When zinc is used as the base metal of the component (A) and the component (D) is contained, it is preferably fired at 100 to 300 ° C, and fired at 150 to 300 ° C. Is more preferable.

  Note that the step of heating and baking the conductive composition at 70 ° C. or higher and 500 ° C. or lower may be performed in an air atmosphere in which air (oxygen) exists around the conductive composition, and oxygen is excluded from the air. May be performed in a nitrogen atmosphere. The step of drying the conductive composition near room temperature may also be performed in an air atmosphere in which air (oxygen) exists around the conductive composition, or may be performed in a nitrogen atmosphere excluding oxygen from the air. .

  The conductive film thus obtained has high conductivity because particles made of a base metal are present in the film. In particular, when copper powder is used as the component (A), copper is a material that has a low resistivity and is not easily affected by electromigration, so that a conductive film having high conductivity and migration resistance is obtained. Can do.

  The electrically conductive film obtained by baking the electrically conductive composition of this invention can be used for formation of the circuit pattern in a conductive circuit of various electronic components, for example, a printed circuit board.

  The conductive composition of the present invention can be fired in an air atmosphere in which oxygen is present. Therefore, a large facility for making the inside of the firing furnace a nitrogen atmosphere is unnecessary, and the conductive composition can be fired at a low cost.

  According to the conductive composition of the present invention, a conductive film having high conductivity can be formed. The reason why such an effect can be obtained by the conductive composition of the present invention is considered as follows.

That is, when the component (C) is contained in the conductive composition, the thin oxide layer on the particle surface made of a base metal is removed by the organic acid flux effect.
It is considered that the components (B) and (C) form a kind of complex on the particle surface from which the oxide layer has been removed. And when an electroconductive composition is heated in an atmospheric condition, this complex becomes a protective layer, and it is thought that it thermally decomposes, suppressing the oxidation of the surface of the particle | grains which consist of a base metal. Thereby, even if it is a case where a conductive composition is baked in air | atmosphere atmosphere, it is thought that the electrically conductive film which has high electroconductivity can be formed.

  The reason why the above-described effects of the present invention are obtained is the inventors' estimation based on the present knowledge, and does not limit the scope of the present invention.

  Examples 1 to 12 of the present invention will be described below, but the present invention is not limited thereto.

Example 1
A conductive composition is prepared by mixing 100 parts by weight of copper powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C). did. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 200 degreeC for 10 minute (s), and the electrically conductive film was formed. Moreover, after apply | coating the composition prepared similarly on a board | substrate, it heated at 300 degreeC for 5 minute (s), and formed the electrically conductive film. When the specific resistance values of the two conductive films thus obtained were measured, the results of 0.8 × 10 ⁻⁴ [Ω · cm] and 0.5 × 10 ⁻⁴ [Ω · cm] were obtained. It was.

(Example 2)
A conductive composition was prepared by mixing 100 parts by weight of copper powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of lactic acid as the component (C). . As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 300 degreeC for 5 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 2.5 × 10 ⁻⁴ [Ω · cm] was obtained.

(Example 3)
A conductive composition is prepared by mixing 100 parts by weight of copper powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of citric acid as the component (C). did. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 300 degreeC for 5 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 1.5 × 10 ⁻⁴ [Ω · cm] was obtained.

Example 4
A conductive composition was prepared by mixing 100 parts by weight of copper powder as the component (A), 5 parts by weight of 1,3-diaminopropane as the component (B), and 10 parts by weight of glycolic acid as the component (C). . As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 300 degreeC for 5 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 1.0 × 10 ⁻⁴ [Ω · cm] was obtained.

(Example 5)
A conductive composition was prepared by mixing 100 parts by weight of copper powder as the component (A), 10 parts by weight of 3-methoxypropylamine as the component (B), and 10 parts by weight of glycolic acid as the component (C). As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 300 degreeC for 5 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.9 × 10 ⁻⁴ [Ω · cm] was obtained.

(Example 6)
A conductive composition was prepared by mixing 100 parts by weight of copper powder as the component (A), 10 parts by weight of N-methylethanolamine as the component (B), and 10 parts by weight of glycolic acid as the component (C). As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 300 degreeC for 5 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 1.1 × 10 ⁻⁴ [Ω · cm] was obtained.

(Example 7)
100 parts by weight of copper powder as the component (A), 2 parts by weight of 3-amino-1-propanol as the component (B), 5 parts by weight of glycolic acid as the component (C), and sorbitol as the component (D) A conductive composition was prepared by mixing 10 parts by weight of polyglycidyl ether. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 500 degreeC for 10 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.2 × 10 ⁻⁴ [Ω · cm] was obtained.

(Example 8)
A conductive composition is prepared by mixing 100 parts by weight of nickel powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C). did. As the nickel powder, a spherical powder having an average particle diameter of 1 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 150 degreeC for 5 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 5.0 × 10 ⁻⁴ [Ω · cm] was obtained.

Example 9
A conductive composition is prepared by mixing 100 parts by weight of zinc powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C). did. As the zinc powder, a spherical powder having an average particle diameter of 4 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 150 degreeC for 5 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.2 × 10 ⁻⁴ [Ω · cm] was obtained.

(Example 10)
A conductive composition is prepared by mixing 100 parts by weight of solder powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C). did. As the solder powder, a spherical powder having an average particle diameter of 4 μm made of an alloy of Sn: Ag: Cu = 96.5: 3: 0.5 by weight ratio was used. After apply | coating the obtained composition on a board | substrate, it heated at 150 degreeC for 10 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.6 × 10 ⁻⁴ [Ω · cm] was obtained.

(Example 11)
A conductive composition is prepared by mixing 100 parts by weight of zinc powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C). did. As the zinc powder, a spherical powder having an average particle diameter of 4 μm was used. After apply | coating the obtained composition on a board | substrate, it was left to dry at room temperature (20 degreeC) for 24 hours, and the electrically conductive film was formed. When the specific resistance value of the conductive film thus obtained was measured, a result of 2.0 × 10 ⁻⁴ [Ω · cm] was obtained.

(Example 12)
A conductive composition is prepared by mixing 100 parts by weight of tin powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C). did. As the tin powder, a spherical powder having an average particle diameter of 5 μm was used. After apply | coating the obtained composition on a board | substrate, it heated at 150 degreeC for 10 minute (s), and formed the electrically conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.6 × 10 ⁻⁴ [Ω · cm] was obtained.

  Hereinafter, Comparative Examples 1 to 4 of the present invention will be described.

(Comparative Example 1)
A composition was prepared by mixing 100 parts by weight of copper powder, 10 parts by weight of 3-amino-1-propanol, and 10 parts by weight of propionic acid. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was applied on a substrate, it was heated at 200 ° C. for 10 minutes to form a film. The film thus obtained was not conductive and could not be called a “conductive film”.

(Comparative Example 2)
A composition was prepared by mixing 100 parts by weight of copper powder, 10 parts by weight of 3-amino-1-propanol, and 10 parts by weight of p-hydroxybenzoic acid. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was applied on a substrate, it was heated at 200 ° C. for 10 minutes to form a film. The film thus obtained was not conductive and could not be called a “conductive film”.

(Comparative Example 3)
A composition was prepared by mixing 100 parts by weight of copper powder, 10 parts by weight of 1-aminopropane, and 10 parts by weight of glycolic acid. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was applied on a substrate, it was heated at 200 ° C. for 10 minutes to form a film. The film thus obtained was not conductive and could not be called a “conductive film”.

(Comparative Example 4)
A composition was prepared by mixing 100 parts by weight of copper powder and 10 parts by weight of lactic acid. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. The obtained composition was applied onto a substrate and then heated at 300 ° C. for 5 minutes to form a film. The film thus obtained was not conductive and could not be called a “conductive film”.

  The results of Examples 1 to 12 and Comparative Examples 1 to 4 are summarized in Tables 1 and 2 below.

  As can be seen from the results of Examples 1 to 12, it has been found that according to the conductive composition of the present invention, a conductive film having a low specific resistance value (that is, a high conductivity) can be obtained.

  As can be seen by comparing the results of Examples 1, 2, and 3, the conductive composition using glycolic acid as the component (C) is higher than the case of using other hydroxy acids (lactic acid and citric acid). It has been found that a conductive film having conductivity can be obtained.

  As can be seen from the comparison of the results of Examples 1, 4, 5, and 6, the conductive composition using 3-amino-1-propanol as the component (B) was obtained by using other amine compounds (1,3-diamino). It has been found that a conductive film having higher conductivity than that obtained using propane, 3-methoxypropylamine, N-methylethanolamine) can be obtained.

  As can be seen from the comparison of the results of Examples 1 and 7, the conductive composition (Example 7) containing the above component (D) in addition to the above components (A) to (C) is composed of the above component (D). It has been found that a conductive film that can be fired at a higher temperature than a conductive composition containing no hydrogen (Example 1) and that has high conductivity can be obtained.

  As can be seen by comparing the results of Example 1 and Comparative Example 1, when an aliphatic carboxylic acid having no OH group is added instead of the component (C), a conductive film having high conductivity is obtained. Not found out.

  As can be seen by comparing the results of Example 1 and Comparative Example 2, it was found that when an aromatic hydroxy acid was added instead of the component (C), a conductive film having high conductivity could not be obtained. .

  As can be seen by comparing the results of Example 1 and Comparative Example 3, when an amine compound having one amino group and no OH group is added in place of the component (B), it has high conductivity. It was found that a conductive film could not be obtained.

  As can be seen from the results of Comparative Example 4, it was found that when a composition containing only the components (A) and (C) was baked, a conductive film having high conductivity could not be obtained.

Claims (6)

(A) metal powder mainly composed of base metal;
(B) an amine compound represented by the following general formula (1), or an aliphatic amine having two or more amino groups;
(C) an aliphatic hydroxy acid ,
The component (B) is at least one selected from 3-amino-1-propanol, 3-methoxypropylamine, N-methylethanolamine, and 1,3-diaminopropane. object.
R ₂ —HN—R ₁ —O—R ₃ (1)
(In the formula, R ₁ represents an alkylene group having 2 to 8 carbon atoms, and R ₂ and R ₃ each represents an H atom or an alkyl group having 1 to 4 carbon atoms.) The conductive composition according to claim 1 , wherein the component (C) is at least one selected from glycolic acid, lactic acid, and citric acid. The conductive composition according to claim 1 or 2 , further comprising a linear epoxy resin having at least one OH group in the molecule. The electrically conductive composition according to any one of claims 1 to 3 , wherein the component (A) is at least one selected from copper, nickel, zinc, tin, and solder. After applying the conductive composition according to the substrate to any one of claims 1 to claim 4, the conductive pattern forming method comprising a heat treatment step of heating at 70 ° C. or higher 500 ° C. or less. The method for forming a conductive film according to claim 5 , wherein the heat treatment step is performed in an air atmosphere.