sn-ag-cu lead-free solder with nd, se and ga

Abstract

The invention relates to a Sn-Ag-Cu lead-free solder containing Nd, Se and Ga, and belongs to a brazing material in the fields of metal materials and metallurgy. The Sn-Ag-Cu lead-free solder comprises the following components in percentage by mass: 0.01 to 0.5 percent of Ag, 0.02 to 1.0 percent of Cu, 0.001 to 0.5 percent of Nd, 0.001 to 0.5 percent of Se, 0.003 to 1.5 percent of Ga and the balance of Sn. Noble metal silver which belongs to a strategic resource can be saved; silver content can be reduced to be ultralow, and the wettability of the solder can be improved; when the Sn-Ag-Cu lead-free solder is matched with a commercially available RMA brazing flux, the mechanical property of a brazing seam is 75 to 85MPa, and the tensile strength is 76 to 88MPa, so that the Sn-Ag-Cu lead-free solder can be suitable for wave soldering, reflow soldering and manual welding in electronic industry; and environment-friendly, lead-free and cadmium-free requirements in manufacturing industry can be met.

Description

technical field [0001] The invention relates to a Sn-Ag-Cu lead-free solder containing Nd, Se and Ga, belonging to metal materials and brazing materials in the field of metallurgy. It is mainly used for the assembly and packaging of components in the electronic industry. It is a new type of green and environmentally friendly lead-free solder with good brazing performance (such as wetting performance) and excellent mechanical properties of solder joints (brazing seams). . Background technique [0002] With the entry into force of the RoHS (The Restriction of the Use of certain Hazardous Substance in Electrical and Electronic Equipment) directive, the replacement of tin-lead solder has always been a hot research topic for technicians in the electronics industry. At present, representative lead-free solders include Sn-Ag-Cu, Sn-Cu, Sn-Cu-Ni and other alloy systems, each with its own strengths, but compared with tin-lead solders, the cost of solder and solder There is still ...

AI Technical Summary

Problems solved by technology

At present, the representative lead-free solders include Sn-Ag-Cu, Sn-Cu, Sn-Cu-Ni and other alloy systems, each has its own strengths, but compared with tin-lead solders, the cost of solder and solder There is still a certain gap in terms of melting point, etc.

Sn-Zn solder melting point and raw material cost are lower than Sn-Ag-Cu, Sn-Cu, Sn-Cu-Ni solder, especially Sn-Zn solder melting point is very close to tin-lead solder, but due to Sn -Zn series solder has poor wettability, so it is still difficult to apply to industrial production, and still needs research and improvement

[0003] In recent years, "Sn-Ag-Cu lead-free solder containing Pr, Ni, and Ga" has been developed on the basis of Sn-Ag-Cu at home and abroad (China Invention patent application publication number, CN101537546A), "Sn-Ag-Cu lead-free solder containing Nd, Li, As, In" (Chinese invention patent application publication number, CN101579790A), "Sn-Ag-Cu containing Pr, Zr, Co Ag-Cu lead-free solder" (Chinese invention patent application publication number, CN101579789A) and "Sn-Ag-Cu lead-free solder containing Nd, Ni, Co" (Chinese invention patent application publication number, CN101537547A), etc. "Multiple alloy system" Sn-Ag-Cu solders, compared with ternary Sn-Ag-Cu alloys, have improved many properties, but they all have an obvious "weakness", that is, their silver content Both are 0.5% to 4.5%, no matter compared with Sn-Cu, Sn-Cu-Ni and Sn-Zn solder, or compared with traditional Sn-Pb solder, the cost of raw materials is much higher

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