A kind of preparation method of conductive silver paste based on silver-coated graphite conductive agent

Abstract

The invention relates to a conductive material synthesis technology, and aims to provide a preparation method of conductive silver paste based on a silver-coated graphite conductive agent. The preparation method comprises the following steps: adding a carbon conductive agent into a sodium polysulfide solution, carrying out supersonic vibration and then, carrying out dipping, filtering and drying to obtain a sodium polysulfide modified carbon material; dispersing the sodium polysulfide modified carbon material in a silver ammonia solution, and stirring for reaction to obtain a silver sulfide loaded carbon material; adding NaCl to reduce silver sulfide into metal silver, and carrying out filtering, washing and drying to obtain a silver-loaded carbon material; adding pyrrole into a cyclodextrin solution, and carrying out ultrasonic treatment to obtain a pyrrole cyclodextrin inclusion compound solution; dropwise adding hydrogen peroxide, then adding the silver-loaded carbon material, and uniformly stirring, and heating to remove water to obtain the conductive silver paste. The silver-loaded carbon material obtained by the invention has the characteristics of low density and low silverconsumption, but maintaining the same conductivity. The use amount of silver can be effectively reduced, the cost is reduced, and the maximum exertion of the electrical conductivity and the thermal conductivity of the silver is facilitated by using the least silver.

Description

technical field [0001] The invention relates to a synthesis technology of conductive materials, more specifically, relates to a new type of conductive agent and a preparation method thereof which uses silver-coated nano-graphite to reduce the contact resistance between graphite conductors and reduce the cost of conductive silver paste. Background technique [0002] Printed circuit boards, solar cell panels, and anti-radiation coatings all require highly conductive materials as the main components of conductive paste. Silver powder has good corrosion resistance and high conductivity and is widely used, such as PET-based membrane switch and low-temperature silver paste for flexible circuit boards, paste for single-board ceramic capacitors, silver paste for varistors and thermistors, Silver paste for piezoelectric ceramics, silver electrode paste for carbon film potentiometer, etc. Silver powder is classified according to particle size, the average particle size <0.1μm (100...

AI Technical Summary

Problems solved by technology

However, carbon materials are usually hydrophobic, and the affinity between silver and carbon is poor. It is difficult to achieve uniform coverage of silver on the surface of carbon particles by simple electroless plating, and it is difficult to control the thickness of the silver plating layer, and it is difficult to ensure the uniformity of conductivity.