Sn-Ag-Cu-Dy Lead-free solder alloy

Abstract

The present invention discloses one kind of no-Pb Sn-Ag-Cu-Dy soldering alloy. The no-Pb Sn-Ag-Cu-Dy soldering alloy consists of Dy 0.01-4.0 wt%, Ag 0.1-5.0 wt%, Cu 0.01-2.0 wt%, P, Mg and / or Al 0.001-0.1 wt%, and Sn and evitable impurities for the rest. It has relatively low smelting point, low Ag consumption, low cost, high wettability, high antioxidant capacity, and capacity of form soldering spot with high mechanical performance and high electric performance. It may be applied in SMT of IC's.

Description

technical field [0001] The invention relates to a solder alloy, in particular to a Sn-Ag-Cu-Dy lead-free solder alloy. Background technique [0002] With the rapid development of the electronics industry and human requirements for environmental protection, countries around the world are gradually prohibiting the use of lead-containing materials, including lead-containing solder. The United States, Japan, and Europe have all restricted the use of lead-containing solder in legislation. Among them, the WEEE Act of the European Union clearly stipulates that the use of lead-containing solder in electronic products sold in the EU after July 1, 2006 is prohibited. It is the general trend that lead-free solder will replace lead-containing solder in the near future. [0003] All countries and regions in the world have invested a lot of manpower and material resources in the development and research of new lead-free electronic assembly solders. As a new type of lead-free electronic ...

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Problems solved by technology

However, judging from the current situation, the above two main alloys have their inherent shortcomings: the currently used Sn-Ag-Cu systems mainly include Sn3.0Ag0.5Cu and Sn3.0Ag0.5Cu held by Japan Sensuke and Iowa State University Sn3.8Ag0.7Cu patented product and quaternary alloy solder developed on its basis: Sn-Ag-Cu-Sb (Castin alloy), Sn-Ag-Cu-Bi (USP4879096 and CAP1299471), Sn-Ag-Cu- Ni (USP4758407) and Sn-Ag-Cu-Zn recommended by NCMS, the main disadvantage of Sn-Ag-Cu is that the cost of the alloy is very high because it contains 3-4% silver, and there are problems such as alloy melting and assembly temperature window , the anti-oxidation and corrosion performance is also unsatisfactory. These quaternary solders have improved the Sn-Ag-Cu ternary solder to a certain extent, but there are still deficiencies in some aspects; It is easy to form slag, and the high melting temperature causes certain problems in welding reliability and process yield

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