Conductive silver paste for laser cutting, low-temperature curing superfine spherical silver powder and preparation method of conductive silver paste and the low-temperature curing superfine spherical silver powder

Abstract

The invention relates to conductive silver paste for laser cutting, low-temperature curing superfine spherical silver powder and a preparation method of the conductive silver paste and the low-temperature curing superfine spherical silver powder. The conductive silver paste for laser cutting is characterized by comprising the following components in parts by weight: 10-40 parts of a resin material, 0.5-5 parts of blocked isocyanate or amino resin, 20-80 parts of a solvent, 0.1-1 part of a fluorine-containing chlorine compound conductive additive, 0-2 parts of a dispersing agent and 55-60 partsof low-temperature cured superfine spherical silver powder. The conductivity of the conductive silver paste for laser cutting is greatly improved, and then the conductive silver paste can be appliedto laser cutting.

Description

technical field [0001] The invention relates to an electronic paste, in particular to a preparation method for laser cutting conductive silver paste, low-temperature curing ultrafine spherical silver powder and each other. Background technique [0002] Low-temperature curing silver paste is used for various substrates that can only withstand low-temperature baking. The substrate is generally plastic film (board) or paper film (board), and the material of plastic film (board) is generally PET, PI, PC, etc.; low-temperature curing silver paste can be used in computer keyboards, membrane switches, touch screens and other electronic products. Strict requirements; the existing low-temperature curing silver paste for screen printing can generally only print lines with a width of 60 microns and a line spacing of 60 microns (commonly known as 60 / 60 lines), which cannot meet the current market requirements for electronic products ( Thin lines with a width of 20-25 microns can meet t...

AI Technical Summary

Problems solved by technology

[0002] Low-temperature curing silver paste is used for various substrates that can only withstand low-temperature baking. The substrate is generally plastic film (board) or paper film (board), and the material of plastic film (board) is generally PET, PI, PC, etc.; low-temperature curing silver paste can be used in computer keyboards, membrane switches, touch screens and other electronic products. Strict requirements; the existing low-temperature curing silver paste for screen printing can generally only print lines with a width of 60 microns and a line spacing of 60 microns (commonly known as 60 / 60 lines), which cannot meet the current market requirements for electronic products ( Thin lines with a width of 20-25 microns can meet the requirements); while screen printing technology can print lines with a width of 25 microns and a line spacing of 25 microns (commonly known as 25 / 25 lines), but using the existing low-temperature curing silver When the paste is printed, the line spacing cannot reach 25 microns, because the two lines may be connected due to the diffusion of the silver paste, and the two lines will be turned on and short-circuited after curing, so the existing low-level cured silver paste cannot be used for electronic components that are grouped and wired. middle

[0003] In order to solve the above problems, laser cutting is generally used in the industry to cut ultra-fine silver lines of 25 / 25 microns or even 20 / 20 microns; that is, silver lines of 1 mm or even wider can be printed first during printing, and then cut by laser after curing Cutting ultra-fine silver lines of 25 / 25 microns, 20 / 20 microns (width / line spacing) or above, reaching the yellow light process (the so-called yellow light process is the method of exposing ultra-fine lines by exposure and chemical etching Line production, which has the disadvantages of complex process, large equipment investment, low efficiency, etc.) in the fineness requirements of the line; mature laser cutting can even replace the yellow light process, and can be widely used in the touch screen line production process

In addition, the conductivity of the existing low-temperature cured silver paste is poor. This is because the surface of the spherical silver powder has not been treated (such as physical polishing, grinding, etc.) after the reduction of the spherical silver powder. Connect and conduct electricity together, but because the contact surface between the spherical silver powder is the contact between the arc surface and the arc surface, the contact area is small, so the conductivity of the low-temperature curing silver paste is poor, which directly affects the quality of electronic products