Wetting-piloted composite solder and preparation method thereof

Abstract

The invention discloses wetting-piloted composite solder which comprises a tin layer and a solder alloy layer, which are compositely rolled, wherein soldering flux layers are sprayed and deposited on the outer surfaces of the tin layer and the solder alloy layer respectively to form a finished composite solder product with a four-layer structure; the thicknesses of the tin layer and the solder alloy layer can be adjusted within 0.01-20 mm according to the clearance filling property of the solder and the size of a clearance; and the thicknesses of the soldering flux layers are adjusted within 0.01-10 mm according to the level of difficulty in removing an oxide film of a workpiece. During preparation of the composite solder, a tin belt and a solder alloy belt are put into a precision rolling machine to be compositely rolled so that the uniform-thickness tin layer is formed on the surface of the solder alloy layer, and then the uniform thickness soldering flux layers are deposited on the outer surfaces of the tin layer and the solder alloy layer in a hot spraying way to form the finished composite solder product with the four-layer structure. A preparation method provided by the invention saves energy and protects the environment, the composite solder is high in tin content and uniform in thickness and beautiful in forming, and since the composite solder has soldering flux, automatic, accurate and quantified addition of the soldering flux is realized during soldering.

Description

technical field [0001] The invention relates to a brazing material, in particular to a wetting pilot composite solder, and also relates to a preparation method of the composite solder. Background technique [0002] Liquid metals are all viscous liquids, and their fluidity can be measured by the viscosity of liquid metals. The greater the viscosity of the liquid metal, the poorer its fluidity, and the viscosity is inversely proportional to the superheat of the liquid metal. Therefore, when the brazing temperature is constant, the lower the melting temperature of the solder, the greater the superheat of the liquid solder, which will cause the viscosity of the liquid solder to decrease and the fluidity to increase. When the melting temperature of the solder increases, the degree of superheat decreases, the viscosity increases, and the fluidity decreases. [0003] Silver-based solder has a moderate melting point, superior brazing process performance, good connection strength, ...

AI Technical Summary

Problems solved by technology

Like silver-based brazing filler metals, traditional CuZnSn brazing filler metals add Sn elements to CuZn alloy brazing filler metals through the batching method, and then use processes such as smelting, casting, rolling, extrusion, and drawing to produce CuZnSn brazing filler metals produced by this method. The Sn content in the solder is low, such as HS221, the tin content is only 1%, otherwise it will also reduce its plasticity, and the solder is difficult to form

Images