Conductive silver paste with low resistance used for touch screen and preparation method thereof

Abstract

The invention provides a preparation method of a conductive sliver paste with a low resistance used for a touch screen. The conductive silver paste comprises 60-70 percent of flake silver powder, 24-38 percent of macromolecular resin carrier and 2-4 percent of additive; the macromolecular resin carrier is formed by mixing vinylchloride-vinylacetate copolymer, polyester resin and solvent, wherein the macromolecular resin carrier comprises, 15-35 percent of vinylchloride-vinylacetate copolymer and 65-85 percent of solvent; 30-40 percent of polyester resin and 60-70 percent of solvent. The preparation method comprises the following steps of firstly mixing the vinylchloride-vinylacetate copolymer with the solvent, and then heating and dissolving the resin and the solvent at a constant temperature, filtering the mixture on a piece of 300-500-mesh screen cloth for removing impurities to obtain the carrier; and then fully mixing the flake silver powder, the additive and the prepared macromolecular resin carrier in a mixer uniformly, dispersing the mixture at a high speed with a high-speed dispersion machine to obtain uniform paste; and then grinding the obtained paste in a three-high mill to obtain the conductive silver paste material; finally, synchronously pouring the conductive silver paste material into a vacuum defoaming device which is in a vacuumizing state, vacuumizing the paste material and agitating the paste material synchronously by the vacuum defomaing device, and obtaining the conductive silver paste with low resistance used for the touch screen.

Description

technical field [0001] The invention belongs to the technical field of conductive material composites, and relates to a conductive silver paste, in particular to a method for preparing a low-resistance conductive silver paste for a touch screen. Background technique [0002] With the rapid development of science and technology, touch screen technology has also been widely used in different electronic products such as computers, televisions, mobile phones and digital cameras. The conductive silver paste, the key material printed on the touch screen by screen printing, plays a very important role in the performance parameters of the touch screen made of tin-doped indium oxide (Indium Tin Oxide, referred to as ITO). At present, the conductive silver paste used in resistive and capacitive touch screens usually uses metal flake silver powder as the main raw material. In order to ensure the conductivity of the conductive silver paste for screen printing circuits, the silver conten...

AI Technical Summary

Problems solved by technology

At present, the conductive silver paste used in resistive and capacitive touch screens usually uses metal flake silver powder as the main raw material. In order to ensure the conductivity of the conductive silver paste for screen printing circuits, the silver content of foreign conductive silver paste is mostly 72%. Above, due to the high silver content of the conductive silver paste, the cost is relatively high; while the silver content of the domestic conductive silver paste is relatively low, generally below 60%, and the bonding between the conductive silver paste and the touch screen is poor , The printed circuit printed with conductive silver paste is also prone to air holes, resulting in a higher resistance value of the printed circuit circuit on the touch screen, which also affects the sensitivity of the touch screen