Silver-copper-tin alloy, silver-copper-tin alloy filamentary solder and preparation method thereof

Abstract

The invention provides silver-copper-tin alloy, a silver-copper-tin alloy brazing wire prepared by using the silver-copper-tin alloy and a preparation method for the silver-copper-tin alloy brazing wire. The silver-copper-tin alloy consists of the following ingredients in percent by weight: 25-35wt% of copper, 5-18wt% of tin and the balance silver. The silver-copper-tin alloy brazing wire is excellent in welding performance, and is an important intermediate-temperature brazing wire for an electric vacuum device; and the problem that an electronic device is failed due to over high brazing temperature is effectively solved. The preparation method comprises the following steps of selecting high-purity silver, oxygen-free copper and high-purity tin; calculating the required quantities of the high-purity silver, the oxygen-free copper and the high-purity tin according to a matching range; preparing materials; placing matched furnace materials in a crucible of a double-vacuum continuous casting machine; refining the furnace materials after the furnace materials are totally melted; regulating the temperature to 730-760 DEG C; beginning to perform casting at the speed of 1.5mm / s after standing for a moment; stopping 2 seconds after performing casting for 1 second; performing multi-pass rotary swaging and online annealing on cast ingots; enabling the diameters of the cast ingots to be reduced to 3.4 mm from 8mm by rotary swaging; and performing wiredrawing, vacuum annealing, peeling treatment and cleaning so as to obtain a threadlike finished product with the diameter of 0.5mm. The preparation method is simple; and the problem that the silver-copper-tin alloy is quite easy to oxidize in a machining and forming process is solved.

Description

technical field [0001] The invention relates to a brazing material, in particular to a silver-copper-tin alloy, a wire-shaped solder made from the silver-copper-tin alloy and a preparation method thereof. Background technique [0002] During the brazing process of electronic devices, heat-sensitive semiconductors and other components are easily damaged due to excessive brazing temperature. In order to prevent this from happening and reduce premature failure of electronic devices caused by thermal stress, the brazing temperature should be lowered as much as possible. . At present, most of the brazing materials used at home and abroad have melting temperatures above 650°C and below 500°C, while there are very few types of medium-temperature brazing materials with melting temperatures between 500 and 650°C. [0003] Among them, the melting point of silver-copper-tin solder is basically between 500 and 650°C, which can effectively avoid the failure of electronic devices due to ...

AI Technical Summary

Problems solved by technology

[0004] Therefore, at present, the melting point is basically between 500-650°C, and there are few varieties of medium-temperature solder, and the preparation and molding process is relatively complicated.

It is necessary to develop an easy-to-prepare silver-copper-tin alloy to meet the current urgent demand for medium-temperature solder, especially the demand for solder with a melting point between 500 and 650°C for electric vacuum devices. At the same time, it is also necessary to explore the processing and Heat treatment process to solve the problem of easy oxidation during processing and molding