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CN-122025219-A - Conductive paste and preparation method thereof

CN122025219ACN 122025219 ACN122025219 ACN 122025219ACN-122025219-A

Abstract

The invention discloses a conductive paste and a preparation method thereof, wherein the conductive paste comprises the following components, by mass, 3-8% of silver precursor, 0.1-1% of catalyst, 5-20% of silver powder, 30-50% of silver coated metal powder, 8-15% of carrier resin and 20-35% of solvent. According to the invention, the silver carboxylate, the carrier resin, the silver powder and the silver coated metal powder are compounded, so that the use amount of metal silver is reduced, the cost of the paste is greatly reduced, the requirements of thin film silver paste can be met, the requirements of good conductivity, adhesion, oxidation resistance and the like and good bending resistance can be met, the requirements of MB silver paste on bending resistance can be met, the preparation process is simple and convenient, the manufacturing cost is low, and the preparation method has a wide application prospect.

Inventors

  • MEI LE
  • HAO HUADONG
  • WANG SHAN
  • ZHOU XINSHAN

Assignees

  • 苏州晶银新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260311

Claims (10)

  1. 1. The conductive paste is characterized by comprising the following raw materials in percentage by mass: 3-8% of silver precursor Catalyst 0.1-1% Silver powder 5-20% 30-50% Of silver coated metal powder Carrier resin 8-15% 20-35% Of solvent.
  2. 2. The conductive paste according to claim 1, wherein the raw materials for preparing the conductive paste further comprise the following components in percentage by mass: Curing agent 0.5-2% 1 To 5 percent of auxiliary agent 0-2% Of thixotropic agent.
  3. 3. The conductive paste according to claim 2, wherein the curing agent is a blocked isocyanate curing agent, the auxiliary agent comprises one or a combination of several of a dispersing agent, a coupling agent, an adhesion promoter, an antioxidant, a leveling agent and a surfactant, and the thixotropic agent comprises one or a combination of several of a polyamide wax thixotropic agent, gas silicon and carbon black.
  4. 4. The conductive paste according to claim 1, wherein the silver precursor is silver carboxylate R-CO 2 Ag with a carbon chain length of 1-15.
  5. 5. The paste as claimed in any one of claims 1 to 4, wherein the silver carboxylate is synthesized by: Dissolving silver nitrate in a mixed solution of acetonitrile and ethanol to obtain an organic solution of silver nitrate; dissolving organic acid in a mixed solution of triethylamine and ethanol to obtain a mixed solution of the organic acid; And (3) dropwise adding a mixed solution of organic acid into the organic solution of silver nitrate, stirring, fully reacting, standing for precipitation, filtering, and flushing with ethanol and acetone to obtain silver carboxylate.
  6. 6. The electroconductive paste according to claim 1, wherein the catalyst is an amine-based catalyst.
  7. 7. The conductive paste according to claim 1, wherein the silver powder and the silver-coated metal powder are both plate-like powder, the particle size distribution D50 of the silver powder and the silver-coated metal powder is 2-5 μm, and the tap density is 2.5-3.5g/cm 3 .
  8. 8. The paste as claimed in claim 1, wherein the carrier resin is one or more of polyester resin, polyurethane resin, SEBS resin, and modified acrylic.
  9. 9. The conductive paste according to claim 1, wherein the solvent is an ether solvent, and the ether solvent is one or a combination of several selected from diethyl ether, isopropyl ether, methyl ether, dimethyl ether, butyl ether, ethylene glycol dimethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, ethylene glycol butyl ether, diethylene glycol monobutyl ether.
  10. 10. A method for preparing a conductive paste, comprising the steps of: And uniformly mixing the carrier resin with the solvent, adding the catalyst, the curing agent, the auxiliary agent, the thixotropic agent, the silver precursor, the silver powder and the silver coated metal powder, continuously uniformly mixing, and performing dispersion treatment to obtain the conductive paste.

Description

Conductive paste and preparation method thereof Technical Field The invention belongs to the technical field of conductive paste, and particularly relates to a conductive paste and a preparation method thereof. Background The electronics, display and energy industries rely on the use of conductive materials to achieve customized functionality by constructing coatings and patterns on organic and inorganic substrates, and curing to form circuits. Printed electronics offers an attractive alternative to traditional processes by virtue of its low cost, enabling the fabrication of large area flexible devices. In modern electronic devices, highly conductive materials are widely used in the field of fine structures, such as solar cell electrodes, flexible display screens, radio frequency identification tags, antennas, and the like. To reduce the cost of these high-tech devices, the substrates used typically need to have low temperature resistance and to be processed in a low temperature environment to maintain structural integrity. The paste used for printing on various film materials is commonly called MB silver paste, and has the characteristics of good conductivity, low-temperature curing, strong oxidation resistance, good adhesive force and the like. In particular, since the paste is required to be printed on various film materials, and the printed film materials are required to be folded into a specific shape in the subsequent assembly process, there is a strong demand for the bending resistance of the paste. Typically, conventional MB silver pastes typically have a silver content of 50-70%, and thus the cost of the paste is relatively sensitive to fluctuations in silver value. The price of MB silver paste has increased to a different extent due to the dramatic increase in the price of silver. Market due to cost control requirements, there is a need to find a low cost MB slurry. Silver-coated metal powder is a widely used technique for reducing the amount of silver used. Particularly in the photovoltaic field, silver-coated metal powder is a verified technical route for reducing the use amount of silver. Compared with pure silver, the silver-coated metal powder can obviously reduce the use amount of silver, and the difference of conductivity is not obvious. Although the assumption of using silver-coated metal powder to prepare a conventional MB paste has long existed, the use of silver-coated metal powder to prepare an MB paste has the following problems: 1. Compared with 90% of silver content of photovoltaic silver paste, the MB paste has lower silver content, so that the MB paste prepared by using the silver coated metal powder has larger resistance difference from the pure silver paste, and the lower silver content increases the resistance with the pure silver paste; 2. The silver coated metal powder can cause the remarkable reduction of the bending resistance of the slurry, and can not meet the use requirement. The prepared slurry can split as long as being folded in half, resulting in failure of the assembly. The method is characterized in that the metal core is coated with a layer of metal silver by a chemical reduction method, so that compared with flaky silver powder commonly used for preparing MB silver paste, the silver-coated metal powder is relatively large in thickness, so that the prepared paste is relatively brittle and relatively poor in bending resistance, the metal serving as the metal core is usually copper, nickel, tin-lead alloy and other metals, the bending resistance of the metal core is relatively poor compared with that of the metal silver, so that the prepared paste is relatively poor in bending resistance, and the metal core is coated with a layer of metal silver by the chemical plating method, so that the coated silver is relatively easy to fall off, relatively poor in compactness after solidification, and easy to split in the bending process, so that the bending resistance is relatively poor. Disclosure of Invention In order to solve the problems in the prior art, the invention aims to provide a conductive paste and a preparation method thereof. In order to achieve the above purpose and achieve the above technical effects, the invention adopts the following technical scheme: The conductive paste comprises the following raw materials in percentage by mass: 3-8% of silver precursor Catalyst 0.1-1% Silver powder 5-20% 30-50% Of silver coated metal powder Carrier resin 8-15% 20-35% Of solvent. Further, the preparation raw materials of the conductive paste also comprise the following components in percentage by mass: Curing agent 0.5-2% 1 To 5 percent of auxiliary agent 0-2% Of thixotropic agent. The curing agent is a blocked isocyanate curing agent, the auxiliary agent comprises one or a combination of more of a dispersing agent, a coupling agent, an adhesion promoter, an antioxidant, a leveling agent and a surfactant, and the thixotropic agent comprises one or a combination of more of