CN-122007399-A - Method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification

Abstract

The invention relates to a method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification, which comprises the following steps of A, synthesizing silver oxalate, B, preparing silver particles, C, preparing silver powder, namely cleaning the silver particles, freeze-drying to form silver blocks, grinding the silver blocks into silver powder, D, preparing silver paste, namely taking the silver powder with the mass ratio of 85% -95%, adding a silane coupling agent, ding Kazhi and terpineol, grinding and then filtering to obtain the high-activity low-resistance nano silver paste.

Inventors

• CHEN JIANLIANG
• HU JUNHUI

Assignees

• 深圳市百柔新材料技术有限公司

Dates

Publication Date

20260512

Application Date

20260403

Claims (10)

1. 1. The method for preparing the silver powder and the silver paste with high activity, high dispersion and low resistance by amino acid modification is characterized by comprising the following steps of: Synthesizing silver oxalate; preparing silver particles, namely obtaining silver particles by means of thermal decomposition of silver oxalate, amino acid, amine and solvent; Preparing silver powder, namely cleaning silver particles, freeze-drying to form silver blocks, and grinding the silver blocks into silver powder; Silver paste is prepared by taking silver powder with the mass ratio of 85% -95%, adding a silane coupling agent, ding Kazhi and terpineol, grinding and filtering to obtain the nano silver paste with high activity and low resistance.
2. 2. The method of preparing silver powder and silver paste with high activity and high dispersion and low resistance according to claim 1, wherein the step A comprises the step of forming silver oxalate by silver nitrate and oxalic acid dihydrate.
3. 3. The method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification according to claim 1, wherein the step A comprises the steps of dissolving oxalic acid dihydrate in water for 30min, dropwise adding silver nitrate dissolved in water for 30min, forming white precipitate, stirring for 30min, stopping, and centrifuging to obtain white solid silver oxalate.
4. 4. The method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification according to any one of claims 1-3, wherein the step A comprises the steps of pouring 63g of oxalic acid dihydrate into a 5L brown three-necked flask, adding 1.5L of deionized water, stirring for 15min to form a clear solution, dissolving 61.2g of silver nitrate into 1.5L of deionized water to form a transparent solution, then dropwise adding the transparent solution into the brown three-necked flask by using a constant pressure funnel for 30min, gradually forming white precipitate in the bottle in the dropwise adding process, reacting for 30min at the rotating speed of 300-800rpm after the dropwise adding is completed, pouring the white solid and the solution into a centrifugal bottle, centrifuging to obtain a white solid, washing with ethanol for 2 times, and washing with acetone for 1 time for later use.
5. 5. The method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification according to claim 1, wherein the step B comprises the steps of uniformly mixing silver oxalate with amino acid, amine and solvent, stirring to form homogeneity, keeping the temperature between 110 ℃ and 120 ℃, heating for a period of time, cooling to obtain silver dispersion liquid, and centrifuging the silver dispersion liquid by using a centrifuge to obtain silver particles.
6. 6. The method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by modifying amino acid according to claim 1, wherein the solvent in the step B is one or more of ethanol, ethylene glycol, n-butanol, isopropanol, amyl alcohol, toluene, xylene and diethylene glycol butyl ether.
7. 7. The method for preparing silver powder and silver paste with high activity and high dispersion and low resistance according to claim 1, wherein the amino acid in the step B comprises one or more of alanine, arginine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, tyrosine and histidine.
8. 8. The method for preparing high activity, high dispersion and low resistance silver powder and paste according to claim 1, wherein said amine in said step B comprises diamine and straight chain amine having a chain length of 3 to 18 carbons.
9. 9. The method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification according to claim 1, wherein in the step D, the mass ratio of the silane coupling agent is less than 0.5%, the mass ratio of Ding Kazhi is 1% -5%, and the mass ratio of terpineol is 1% -5%.
10. 10. The method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification according to claim 1, wherein the step D comprises the steps of taking 93% silver powder by mass, adding 0.1% silane coupling agent, adding 3% Ding Kazhi% terpineol, grinding by using a three-roller grinder, and filtering by using a 400-mesh filter screen to obtain the high-activity low-resistance nano silver paste.

Description

Method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification Technical Field The invention relates to the technical field of silver powder preparation, in particular to a method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by amino acid modification. Background The silver powder with high activity and high dispersion and low resistance is a core foundation for realizing breakthrough of silver-copper interconnection in the field of high-power chips such as chip packaging and the like. Silver powder prepared on the current market in China is difficult to have high activity, high dispersion and low resistance, meanwhile, three points exist, related enterprises in China commonly adopt Japanese wire industry company KM120 products, the products have similar characteristics, the properties of the products cannot completely meet the requirements, the conductivity is still to be improved, the particle size distribution range is limited, and the particle size distribution of 0.15-0.3 mu m can be met. Disclosure of Invention In view of the above, it is necessary to provide a method for preparing high-activity high-dispersion low-resistance silver powder and silver paste by conveniently controlling the particle size distribution range to realize amino acid modification of different submicron silver powders. In order to solve the technical problems, the technical scheme adopted by the invention is that the method for preparing the silver powder and the silver paste with high activity, high dispersion and low resistance by amino acid modification comprises the following steps: A. synthesizing silver oxalate; B. Preparing silver particles, namely obtaining silver particles by means of thermal decomposition of silver oxalate, amino acid, amine and solvent; C. Preparing silver powder, namely cleaning silver particles, freeze-drying to form silver blocks, and grinding the silver blocks into silver powder; D. silver paste is prepared by taking silver powder with the mass ratio of 85% -95%, adding a silane coupling agent, ding Kazhi and terpineol, grinding and filtering to obtain the nano silver paste with high activity and low resistance. Further, step A includes forming silver oxalate with silver nitrate and oxalic acid dihydrate. Further, the step A comprises dissolving oxalic acid dihydrate with water for 30min, dropwise adding silver nitrate dissolved with water for 30min, forming white precipitate, stirring for 30min, stopping, and centrifuging to obtain white solid silver oxalate. The method comprises the steps of A, pouring 63g of oxalic acid dihydrate into a 5L brown three-necked flask, adding 1.5L of deionized water, stirring for 15min to form a clear solution, dissolving 61.2g of silver nitrate into 1.5L of deionized water to form a transparent solution, then dropwise adding the transparent solution into the brown three-necked flask by using a constant pressure funnel for 30min, gradually forming white precipitate in the flask in the dropwise adding process, reacting for 30min at the rotating speed of 300-800rpm after the dropwise adding is finished, pouring the white solid and the solution into a centrifugal bottle, centrifuging to obtain a white solid, washing with ethanol for 2 times, and washing with acetone for 1 time for later use. Further, the step B comprises the steps of uniformly mixing silver oxalate with amino acid, amine and solvent, stirring to form homogeneity, keeping the constant temperature at 110-120 ℃, heating for a period of time, cooling to obtain silver dispersion liquid, and centrifuging the silver dispersion liquid by using a centrifuge to obtain silver particles. Further, the solvent in the step B is one or more of ethanol, ethylene glycol, n-butanol, isopropanol, amyl alcohol, toluene, xylene and diethylene glycol butyl ether. Further, the amino acids in the step B include one or more of alanine, arginine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, tyrosine, and histidine. Further, the amine in step B includes diamine and linear amines having a chain length of 3 to 18 carbons. Further, in the step D, the mass ratio of the silane coupling agent is less than 0.5%, the mass ratio of Ding Kazhi is 1% -5%, and the mass ratio of terpineol is 1% -5%. Further, the step D comprises the steps of taking 93% silver powder by mass, adding 0.1% silane coupling agent, adding 3% Ding Kazhi% terpineol, grinding by using a three-roller grinder, and filtering by using a 400-mesh filter screen to obtain the nano silver paste with high activity and low resistance. The silver paste has the advantages that submicron and high-dispersion silver particles are obtained through the reaction of silver oxalate, amino acid and amine, the amino acid and the amine play roles of a complexing agent, a dispersing agent and a morphology regulating agent, then high-purity silver powder