Lead-free alloy solder containing rare-earth and more alloy components

A lead-free solder, multi-alloy technology, used in metal processing equipment, welding/cutting media/materials, welding media, etc. The effect of crystallizing and improving performance

Inactive Publication Date: 2002-05-01
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

U.S. Patent US 6176947 B1 reports lead-free solder alloy containing Sn, Cu, Ag, Bi, In, Sb, although the melting point of solder alloy in this invention can be reduced to below 200 ℃, the wettability of solder alloy of this invention still no improvement

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach

[0018] Sn-Ag-Cu-Bi-In-Sb-RE lead-free solder containing rare earth elements basically has the following chemical composition:

[0019] 0.1 to 5% by weight of Ag;

[0020] 0.1-1% by weight of Cu;

[0021] 0.1-8% by weight of Bi;

[0022] 0.1 to 7.5% by weight of In;

[0023] 0-8% by weight of Sb;

[0024] 0.01-2% by weight of La and Ce mixed rare earth or La and Ce

[0025] Mixed rare earth plus one or both of Pr and Nd;

[0026] The balance is composed of Sn and unavoidable impurities.

[0027] First, the mixed rare earth elements and Sn are smelted in a vacuum furnace at a temperature of 550° C. to form an alloy containing 2.5% by weight of rare earth elements in Sn. Then add other alloying elements in proportion, smelt in a vacuum furnace at 550-600°C, and keep warm for 1-2 hours. Finally, the solder alloy can be obtained by casting. The obt...

Embodiment

[0030] Examples of rare earth-containing multicomponent lead-free solder alloys are described in detail below and compared.

[0031] Table 1 is the chemical composition list of four kinds of multi-element lead-free solder alloys. Among them, the first three lead-free solder alloys contain rare earth elements, and for comparison, the last lead-free solder alloy does not contain rare earth elements.

[0032] Table 2 shows the liquidus temperature, solidus temperature, tensile strength, yield strength, elongation and reduction of area of ​​four multicomponent lead-free solder alloys.

[0033] In combination with Table 1 and Table 2, the following describes the embodiments of the present invention in detail. First, the mixed rare earth elements and Sn are smelted in a vacuum furnace at a temperature of 550° C. to form an alloy containing 2.5% by weight of rare earth elements in Sn. Three kinds of rare earth-containing Sn-Ag-Cu-Bi-In-Sb-RE alloys as shown in Table 1 were added in...

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Abstract

A lead-free alloy solder containing rare-earth elements and multiple other elements for electronic package contains Ag (0.1-5 wt.%), Cu (0.1-1 wt.%), Bi (0.1-8 wt.%), In (0.1-7.5 wt.%), Sb (0-8 wt.%), the mixture of La and Ce or the mixture of La, Ce and one or both of Pr and Nd (0.01-2 wt.%) and Sn (the balance). It has liquidus temp less than 210 deg.c (even 190 deg.C or lower), less than 15 deg.c for liquidus and solidus temp difference, at least 60 MPa of yield strength, at least 18% of elongation percentage, excellent wetting ability, and high soldering quality.

Description

technical field [0001] The invention belongs to the technical field of new materials, and in particular relates to a lead-free solder alloy for electronic packaging and assembly brazing, which is mainly used to replace the use of Sn-Pb solder in the field of electronic assembly and packaging. The lead-free solder alloy can meet the requirement of high-performance solder in the electronic industry. Background technique [0002] At present, Sn-Pb alloy (especially Sn-37Pb), because of its low cost, good electrical conductivity and excellent mechanical and brazing properties, has become the most important brazing material for electronic packaging and assembly in the electronics industry. However, Pb and substances containing Pb are poisonous and harmful substances that endanger human health and pollute the environment. Sn-Pb solder will directly harm the human body during production and use; in addition, the solder containing Pb in electronic component waste will be oxidized t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K35/26C22C13/00
Inventor 王来黄明亮赵杰于大全韩双起
Owner DALIAN UNIV OF TECH
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