A high anti-oxidation lead-free solder

Abstract

The invention discloses a Sn Ag Cu base high-anti-oxidation lead-free solder. The component and mass percent of the solder are 0.3 to 3.0 of silver, 0.1 to 1.5 of copper and the rest of tin. On the basis, 0 to 1.0 of gallium, 0 to 1.0 of germanium, 0 to 0.7 of antimony, 0 to 0.2 nickel and a trace of cerium and neodymium are added to the solder. Metal elements of different proportions are added to the Sn Ag Cu base solder through an intermediate alloy mode, the oxidative stability of the solder is greatly improved, and meanwhile the high-anti-oxidation lead-free solder has good wettability, creep properties and strength of extension, and is good in mechanical behavior, and can be widely applied to electronic packaging soldered joint.

Description

technical field [0001] The invention relates to a lead-free solder alloy used for soldering in the electronic industry, and furthermore, it is a SnAgCu lead-free alloy with high oxidation resistance and excellent mechanical properties that can be used in a relatively high temperature working environment. solder alloy. Background technique [0002] Tin-lead solder has the characteristics of low cost, low melting point, and excellent mechanical properties. However, due to the toxicity of lead, it has brought inevitable pollution and damage in the process of solder production and human use. Since the EU RoHS directive in 2006 Since the implementation of the regulations on the maximum limit values ​​of six harmful substances, more and more lead-free solders have replaced tin-lead solders in the field of electronic packaging technology, and SnAgCu solders have become widely recognized in the field of soldering due to their good mechanical properties. The first choice for tin-lea...

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Problems solved by technology

[0003] However, the cost of SnAgCu lead-free solder is high, and the strength of its oxidation resistance will affect the mechanical strength of the solder joint, the electrical conductivity and the generation of tin slag. In order to change this phenomenon, the method of adding antioxidants is usually used Lead Solder Modified

[0004] The invention patent with the Chinese publication number CN102039496A discloses an anti-oxidation low-silver lead-free solder and its production method. The oxidation resistance of the solder is improved by adding a certain amount of Ga and P, but since P is not easy to disperse in the alloy, And it will form a dense skin layer on the surface of metal separation, which will bring difficulties to further processing. At the same time, it has high requirements for flux, which will affect the subsequent welding effect

[0005] The invention patent with the Chinese publication number CN101992362A discloses a lead-free solder alloy suitable for powder making with oxidation resistance. Adding Ge can inhibit the further oxidation of the solder and refine the crystal grains at the same time, but its oxidation resistance cannot be obtained. High protection, and at the same time, the wettability is improved to a certain extent by adding Sb

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