KR101156966B1 - metal paste of low metalizing temperature for conductive pattern - Google Patents

Abstract

The present invention relates to a low-temperature calcined conductive metal paste, which comprises a reaction precipitate settled on a slurry containing a fatty acid metal; Metal powder; bookbinder; And it provides a low-temperature baking type conductive metal paste consisting of the remaining amount of the solvent for viscosity adjustment.

The metal paste of the present invention can be calcined at low temperature by the low metallization temperature of the fatty acid metal and is fused at a high speed to realize low surface resistance. In addition, in the present invention, by using the slurry reaction mixture as it is in the paste, the process of separating fatty acids and milling them into a paste reduces energy saving and processes to achieve economics of paste manufacturing.

Fatty acid silver, silver formic acid, slurry, low temperature calcining type

Description

Metallic paste of low metalizing temperature for conductive pattern

The present invention relates to a low temperature calcined conductive metal paste, and more particularly to a metal paste comprising a metal powder and a fatty acid metal slurry.

Many studies have been made to form a pattern by a printing method using an ink containing a MOD material.

Since Best, RW has tested the feasibility of inks using MOD materials (IEEE Transactions on Components, Hybrids and Mamufacturing Technology, 12 (4), 545-549, 1987). Much research has been done on inks.

Here, the metallo-organic decompositon (MOD) material is an organometallic compound that is decomposed and metallized at a temperature lower than the metal melting temperature.

Kobio, Inc U. S. Patent 6878184 discloses a technique for forming an ink on nanoparticles using MOD and a reducing agent (e.g., aldehyde). The reaction conditions are difficult and expensive MOD materials must be used in large quantities.

Combining the advantages of MOD capable of low-temperature metallization with the high electrical conductivity of bulk metals, Kid international publication WO98-37133 discloses the use of a composite composition of MOD material and particulate metal as an ink for screen printing.

In addition, the applicant of the present invention for a solution ink containing aliphatic or aromatic silver that can be metallized at a low temperature Patent registration 616361 (August 21, 2006), Patent registration 0587404 (August 30, 2006), Patent registration 0587402 (Published May 30, 2006), 2007-0081546 (published 2007.08.17) and 2007-0058816 (published 2007.06.11). Further, a paste material containing a metal powder and a MOD material has been disclosed in Korean Patent Registration No. 0705824 (date of April 13, 2007) and Patent Registration No. 0711505 (date of April 19, 2007).

The above techniques basically explain the possibility that MOD materials, which are precursors of metals, are essential and can be used as inks, but because they are expensive, they have economic problems in the use of the material, and thus, the low-temperature metallization which is economically commercially manufacturable is possible. Provision of a metal paste is required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a metal paste for forming a conductive film which can be economically manufactured and capable of low temperature metallization.

According to the present invention, a metal powder; A slurry obtained by filtering the reaction precipitate mixture in a solvent containing 1 to 3 carbon atoms having 1 to 3 carboxyl groups and a metal ion in a solvent, followed by washing and filtering with an aliphatic alcohol having 1 to 4 carbon atoms having 1 to 3 hydroxy groups; bookbinder; And the low-temperature baking conductive paste which consists of a solvent residual amount for viscosity adjustment is provided. In some cases, the low-temperature calcined conductive paste may further include a reactive organic solvent having a hetero atom P, S, O or N and forming a complex or chelating compound with respect to the fatty acid metal on the slurry.

In the calcined conductive paste, the metal powder is preferably 1 to 95% by weight, most preferably 20 to 70% by weight, and the slurry is preferably 0.1 to 90% by weight, most preferably 10 ˜50 wt.% And the binder is preferably 0.1-15 wt.% By weight.

The fatty acid is, for example, maleic acid, malonic acid, succinic acid, acetic acid, dried acid, methacrylic acid, propionic acid, sorbic acid, citric acid, undecylenic acid, neo-decanoic acid, oleic acid, oxalic acid, formic acid, gluconic acid. Preferably citric acid, oxalic acid, formic acid, maleic acid.

The filtering and washing of the reaction settled mixture is intended to remove unreacted substances and organic solvents, and the washing is again to remove the organic detergents, for example, ethylene glycol, acetone, and the like. The aliphatic alcohol having 1 to 4 carbon atoms having a hydroxy group is preferably methanol or ethanol.

The filtration washed reaction precipitate mixture on the slurry is a mixed slurry of the resulting fatty acid metal and alcohol cleaner. The reaction precipitate is obtained by adding ethylene glycol solution of sodium chloride to methanol solution of fatty acid to form sodium fatty acid, followed by precipitation by adding ethylene glycol solution of metal ions.

 The metal powder is not particularly limited. For example, silver, iron, zinc, tin, nickel, indium, gold, platinum, palladium, lead, antimony, copper or alloys thereof. The metal ion may be a different metal from the metal powder, but is preferably the same metal. The metal of the metal powder and the metal ion is preferably copper or silver.

The viscosity adjusting solvent is preferably an aliphatic alcohol having 1 to 4 carbon atoms having 1 to 3 hydroxy groups, an alkyl ether having 2 to 8 carbon atoms or an alkyl ester having 2 to 8 carbon atoms, for example, butyl carbitol acetate, Butyl carbitol, ethyl carbitol, ethyl carbitol acetate, terpineol, texanol, mentanol, isoamyl acetate, methanol, ethanol and mixtures thereof.

The binder can be variously selected depending on the heat resistance temperature and the purpose. For example, it is an acrylic binder, an epoxy binder, a polyester binder, a polyurethane binder, or a binder which has a polyamic acid or a polyamic acid derivative as a main component.

The reactive organic solvent is an organic solvent having a ketone group, a mercapto group, a carboxyl group, an aniline group, an ether group or a sulfite group as a solvent having hetero atoms P, S, O and N. The reactive organic solvent is preferably an amine substituted with at least one aliphatic having an aliphatic or hydroxy group having 1 to 6 carbon atoms and a linear or branched aliphatic thiol having 1 to 16 carbon atoms, for example methylamine, ethylamine, Isopropylamine, monoethanolamine, diethanolamine, triethanolamine and most preferably ethylamine. The addition of the reactive organic solvent may increase the solubility of the fatty acid metal to increase the fluidity and homogeneity of the paste.

The fatty acid metal slurry used in the paste of the present invention fills the pores between the metal powder particles or connects the metal particles to provide an effect of increasing the metal density in the paste. In addition, the smaller the size of the metal particles, the higher the surface energy, which allows to have a low surface resistance even at a low firing temperature, the metal particles produced by the metallization of fatty acid metal satisfies this.

The metal paste of the present invention is capable of low-temperature firing by the low metallization temperature of the fatty acid metal, thereby fusion at a high speed to realize low surface resistance. In addition, in the present invention, by using the slurry reaction mixture as it is in the paste, the process of separating fatty acids and milling them into a paste reduces energy saving and processes to achieve economics of paste manufacturing.

Hereinafter, the present invention will be described in detail by examples. These examples are intended to illustrate the invention and should not be construed as limiting the protection scope of the invention.

Comparative Example 1

105 g of a plate-shaped silver powder (D ₅₀ = 1.97 μm), 22.5 g of KER828 epoxy binder from Kumho P & B Chemistry, and 150 g of a paste composition consisting of a residual amount of solvent consisting of normal terpineol and butyl celusolve (weight 4: 4) The paste was prepared by mixing. After the paste was aged for a certain period of time, the paste was coated on PET to be used as a base material, and then heat-treated at 110, 120, and 150 ° C. to measure the surface resistance at 4-probe point.

Example 1

Slurry  Produce

46 g of formic acid are dissociated in excess methanol. To this solution being stirred is added 40 g of sodium hydroxide dissociated with ethylene glycol to form sodium formate. Adding 170 g of silver nitrate dissociated with ethylene glycol to form a white precipitate of silver formate. The precipitate is washed well with acetone and then filtered, followed by filtration with plenty of methanol to obtain silver formic acid in the form of a 70 wt.% Slurry containing methanol.

Silver paste manufacturer

2.1 g of the silver formic acid slurry prepared above; 104 g of plate-shaped silver powder having an average particle size of 1.97 μm; 26.25 g of KER828 epoxy binder from Kumho P & B Chemical; The silver formic acid slurry-added paste was prepared by completely mixing the 150 g paste composition consisting of a solvent residue consisting of normal terpineol and butyl cellussolve (weight ratio 4: 6). The compositional component ratios used in preparing the pastes used in the examples are shown in Table 1.

The paste was screen printed on a PET substrate and heat-treated at 110, 120, and 150 ° C., respectively, and the surface resistance was measured at 4-probe point.

Example 2

It was carried out as in Example 1 except that 4.2 g of formic acid slurry phase and 103 g of plate-shaped silver powder were used.

Example 3

It was carried out as in Example 1 except that 6.4 g of silver formic acid slurry and 102 g of plate-shaped silver powder were used.

Example 4

It was carried out as in Example 1 except that 9.1 g of formic acid slurry phase and 98 g of plate-shaped silver powder were used.

Example 5

The same procedure was followed as in Example 1 except that 12 g of silver formic acid slurry and 97 g of plate-shaped silver powder were used.

Example 6

It was carried out as in Example 1 except that 15 g of silver formic acid slurry phase and 95 g of plate-shaped silver powder were used.

Example 7

It was carried out as in Example 1 except that 15 g of silver formic acid slurry and 90 g of plate-shaped silver powder were used.

Example 8

It was carried out as in Example 1 except that 18 g of silver formic acid slurry phase and 88 g of plate-shaped silver powder were used.

Example 9

It was carried out as in Example 1, except that 21 g of silver formic acid slurry phase and 87 g of plate-shaped silver powder were used.

Table 1

Silver formic acid slurry (g) Silver powder (g) Binder (g) Paste total weight (g) Comparative Example 1 - 105 22.5 150 Example 1 2.1 104 26.5 150 Example 2 4.2 103 26.5 150 Example 3 6.4 102 26.5 150 Example 4 9.1  98 26.5 150 Example 5 12  97 26.5 150 Example 6 15  95 26.5 150 Example 7 15  90 26.5 150 Example 8 18  88 26.5 150 Example 9 21  87 26.5 150

Table 2

Heat treatment temperature 110 ℃ 120 DEG C 150 ℃ materials Surface resistance (mΩ / □) Adhesive strength (/ 100) Hardness Surface resistance (mΩ / □) Adhesion
(/ 100) Hardness Surface resistance (mΩ / □) Adhesion
(/ 100) Hardness Comparative Example 1 PET 44.27 100 5H 44.76 100 5H 36.79 100 5H Example 1 PET 39.06 100 5H 34.09 100 5H 26.89 100 5H Example 2 PET 30.33 100 5H 28.16 100 5H 25.22 100 5H Example 3 PET 25.15 100 5H 25.45 100 5H 22.56 100 5H Example 4 PET 30.41 100 5H 29.49 100 5H 29.09 100 5H Example 5 PET 33.01 100 5H 32.59 100 5H 30.00 100 5H Example 6 PET 29.95 100 5H 25.95 100 5H 20.57 100 5H Example 7 PET 37.25 100 5H 41.46 100 5H 31.25 100 5H Example 8 PET 37.96 100 5H 36.18 100 5H 31.38 100 5H Example 9 PET 32.42 100 5H 33.74 100 5H 27.05 100 5H

1 is a SEM image (X 5,000) of a cross section of Comparative Example 1 paste printed on a glass substrate and heat-treated at 150 ° C.

Figure 2 is a SEM image of the cross-section of the paste using the silver formic acid slurry in Example 3 after printing on a glass substrate and heat-treated at 150 ℃

Claims (5)

20-70 wt% metal powder; Ethylene glycol solution of sodium chloride was added to methanol solution of C1-C12 fatty acid having 1 to 3 carboxyl groups to form sodium fatty acid, and then the precipitated mixture precipitated by addition of ethylene glycol solution of metal ion was filtered and washed. 10 to 50% by weight of a slurry washed with aliphatic alcohols having 1 to 4 carbon atoms having 1 to 3 hydroxyl groups; 0.1-15% by weight of the binder; And a low-temperature calcined conductive metal paste comprising a residual amount of solvent for viscosity adjustment, wherein the metal powder is silver, iron, zinc, tin, nickel, indium, gold, platinum, palladium, lead, antimony, copper and alloys thereof. Low-temperature calcined conductive metal paste which is a powder of a metal selected from and the binder is an acrylic binder, an epoxy binder, a polyester binder, a polyurethane binder, a polyamic acid or a binder containing polyamic acid as an active ingredient. delete The low temperature calcined conductive metal paste according to claim 1, further comprising a reactive organic solvent having a hetero atom P, S, O or N and dissolving the reaction precipitate mixture. The method of claim 3, wherein the fatty acid is maleic acid, malonic acid, succinic acid, acetic acid, dried acid, methacrylic acid, propionic acid, sorbic acid, citric acid, undecylenic acid, neo-decanoic acid, oleic acid, oxalic acid, formic acid or gluconic acid ego; The reaction precipitate mixture is obtained by adding sodium ethylene glycol solution to fatty acid methanol solution to form fatty acid sodium, followed by precipitation by adding ethylene glycol solution of metal ions, and final washing is performed using methanol or ethanol; The metal of the metal powder and the metal ion is silver The viscosity adjusting solvent is selected from the group consisting of butyl carbitol acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, terpineol, texanol, mentanol, isoamyl acetate, methanol, ethanol and mixtures thereof Become; The reactive organic solvent is a low temperature calcined conductive metal paste which is methylamine, ethylamine, isopropylamine, monoethanolamine, diethanolamine or triethanolamine. delete

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