Sn-Zn系和Sn-Cu系无铅焊锡的研制

【作者】 周甘宇；

【导师】 章四琪；

【作者基本信息】 中南大学 ， 材料学， 2004， 硕士

【摘要】 铅及其合金有毒，随着立法限制和技术要求的提高，研制新型实用的无铅焊锡替代传统的Sn-Pb焊料成为近年来研究的热点。本文以Sn-9Zn、Sn-0.7Cu为基，添加Bi、Al、Ag等合金元素，共研制了15种不同成分的无铅焊锡合金。通过熔点和力学性能的测定及铺展性、抗氧化性和电化学实验，考察了合金元素对研制的合金组织和性能的影响，结果表明： 随Bi含量的增加，Sn-Zn共品合金和Sn-Cu共晶合金的熔点下降，抗拉强度增加、铺展性改善，但是熔化温度区间将逐步增大、塑性降低、耐蚀性和抗氧化性降低；Ag使Sn-Zn-Bi系合金和Sn-Cu-Bi系合金抗拉强度提高，延伸率下降。少量的Ag对合金的熔点影响不明显。Ag的添加能提高Sn-Zn-Bi系合金的抗氧化性和耐蚀性；Al的添加能提高Sn-Zn共晶合金的抗拉强度，抗氧化性，但延伸率略有下降，不过均大于使用要求，即延伸率大于10％。添加Re和Zr不会生成高熔点相。Re的添加对合金耐蚀性的提高效果较好，Zr的作用不太明显；Sn-9Zn-4Bi-0.5Ag、Sn-0.7Cu-5Bi和Sn-8.5Zn-0.878Al-0.122Re实验合金的综合性能较好。更多还原

【Abstract】 Lead-tin(Pb-Sn) solder alloys have been widely used in the modern electronics industry because their low melting points, good wettability, good corrosion resistance and reasonable electrical conductivity. However, due to the toxicity of lead and its alloys, increasing environmental and health concerns and legislation restriction over the use of lead, What’s more, the development of packaging technology need developing solder alloys withstanding good mechanics properties as well as electrical properties. As far now, designing new lead-free solders is a hot spot of recent researches, the effect of adding Bi, Al, Ag on the microstructure and mechanical properties of the Sn-9wt.%Zn and Sn-0.7wt.%Cu based alloy was studied in present paper by using 15 kinds of different component lead-free solders. Many kinds of their properties such as melting points, mechanics properties, wettability, corrosion resistance and electrical conductivity were studied by experiments, the effect of the different elements and composition on the microstructure and properties was provided as follow:Bi is effective for decreasing the melting points, improving the tensile strength and wetting ability of Sn-Zn eutectic and Sn-Cu eutectic alloys. But at the same time, the temperature range between the liquidus and solidus was enlarged, the corrosion resistance was decreased and the elongation becomes worse; Similarly, Ag is effective for improving the tensile strength of Sn-Zn-Bi alloy and Sn-Cu-Bi alloy, and it is also effective for improving the corrosion and oxidation resistance of the Sn-Zn-Bi alloy without a significant increase of their melting points; Al is effective for improving the tensile strength, oxidation resistance of Sn-Zn alloy, their elongation becomes worse when adding Al, but it still above 10% and can meet the requirements; When Re is added, the corrosion resistance of Sn-Zn-Al alloy was improved dramatically, however the effect of Zr id not evident. The comprehensive properties of the Sn-9Zn-4Bi-0.5Ag alloy and Sn-0.7Cu-5Bi alloy are the best among all the alloys studied.更多还原