SnAgCu leadless brazing filler metal with antioxygenic performance

Abstract

The invention relates to Sn-Ag-Cu lead-free solder with oxidation resisting performance, and belongs to the manufacture technical field of lead-free solder for electronic assembly in microelectronics. The solder comprises the following components (mass percent): 0.1 percent to 5 percent is Ag, 0.1 percent to 1.5 percent is Cu, 0.01 percent to 1 percent is Ce, 0.01 percent to 0.5 percent is Ni, 0.0001 percent to 0.2 percent is P, or at the same time, 0.001 percent to 0.5 percent of Ge is added and the rest comprises Sn. The invention provides a method that microelements such as Ni, rare earth element CE, P, or at the same time Ge are added into the Sn-Ag-Cu solder alloy, the wet ability and the mechanical property of the alloy solder are further improved, and especially the oxidation resisting performance is greatly improved. The organism of the alloy solder of the invention is refined and uniform, no toxic element such as PB is included, the pollution to environment does not exist, the smelting is convenient, the invention can be processed into a great variety of production forms, the WEEE and RoHS instruction issued can be met, and the invention is the good low temperature lead-free solder.

Description

technical field [0001] The invention relates to a lead-free solder alloy in the welding field, in particular to a SnAgCu lead-free solder alloy with oxidation resistance, and belongs to the technical field of lead-free solder manufacturing for electronic assembly in the microelectronics industry. Background technique [0002] With the implementation of WEEE and RoHS directives, due to the great pressure of commercial competition and the enhancement of people's environmental protection awareness, relevant enterprises and scientific research institutions in various countries have further strengthened the research work on lead-free solder. At present, the internationally recognized lead-free solders are alloys such as SnAg, SnCu, SnBi, SnZn and SnAgCu. SnAg solder has different cooling rates in different cooling regions, so it is easy to produce silver phase transition problems, and Cu in the matrix is ​​easy to diffuse into the solder, resulting in a decrease in the reliabilit...

AI Technical Summary

Problems solved by technology

[0005] The overall performance of SnAgCu solder is relatively good, but its wetting performance and oxidation resistance need to be further improved

Since SnAgCu solder contains a large amount of tin, it requires a higher soldering temperature than tin-lead solder, and the oxidation of the alloy is very sensitive to temperature, so the oxidation rate of the alloy will increase accordingly. Studies have shown that a large amount of tin produced by oxidation Slag not only consumes raw materials and increases the cost of the alloy, but also has a great impact on the reliability of welded joints