High-conductivity low-temperature sliver paste and preparation method thereof

Abstract

The invention discloses a high-conductivity low-temperature sliver paste and a preparation method thereof. The preparation method comprises the steps of successively mixing a high-toughness resin, a thickening agent, a flexibilizer and an organic solvent; successively adding a low-melting-point alloy, a soldering flux and conductive silver powder, and performing high-speed mixing for obtaining paste; and grinding the paste to the paste with fineness of 5-10 mu m, and obtaining the conductive sliver paste. The conductive silver paste prepared by the invention has advantages of high conductivity and high mechanical property. After the low-melting-point alloy is added, conductivity performance and hardness performance are greatly improved. Through adding appropriate amount of thickening agent and flexibilizer, diffusion performance and bending performance of a sliver strip can be effectively controlled. The low-temperature sliver paste prepared by the invention has advantages of effectively reducing silver content, improving conductivity and mechanical performance and greatly saving cost. The high-conductivity low-temperature sliver paste can be widely applied in the industries of a thin-film switch, a capacitive electrode, a touch screen, etc.

Description

technical field [0001] The invention relates to the technical field of silver paste, in particular to a low-temperature silver paste with high conductivity, which can be used for membrane switches, capacitor electrodes and touch screens. Background technique [0002] As a functional printing material, conductive paste has been widely used in electronic information products due to its good physical properties. With the development of electronic products to be lighter, thinner, more functional and more environmentally friendly, its Performance also puts forward higher requirements. Among them, the low-temperature halogen-free conductive silver paste is widely used in membrane switches, capacitive electrodes, touch screens, etc. because of its excellent electrical conductivity, thermal conductivity, and practicability. Low-temperature conductive silver paste is a uniform paste made by stirring and dispersing conductive silver powder as a conductive filler with high polymer res...

AI Technical Summary

Problems solved by technology

Conductive silver powder is a metal powder with relatively high hardness, but the hardness of high polymers such as resin is generally poor

However, when the demand for high hardness is met by increasing the filling amount of silver powder, a relatively small amount of resin cannot fully and effectively cover the silver powder, resulting in poor adsorption of the silver powder on the surface and falling off.

[0005] Low-melting-point alloys are lead-free alloy compounds that have been gradually introduced to scientists after lead and its compounds were banned. The eutectic point is low, and the preparation of low-melting point alloy powders by aqueous solution can effectively control their particle size and particle size. distribution, which makes it possible to introduce low-melting-point alloy powder into the conductive ink system; The application of melting point alloys, currently few researchers have introduced low melting point alloys into the low temperature conductive silver paste system

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