熔融锡基合金与铜的润湿性和界面特性
文献类型：学位论文
| 作者 | 张晓瑞 |
| 学位类别 | 硕士 |
| 答辩日期 | 2009-05-25 |
| 授予单位 | 中国科学院过程工程研究所 |
| 授予地点 | 过程工程研究所 |
| 导师 | 袁章福 |
| 关键词 | 润湿性 接触角 滞后性 静滴法 共晶合金 Sn-Bi-Cu合金 |
| 其他题名 | Wettability and Interfacial Characteristics between Molten Sn-based Alloys and Cu |
| 学位专业 | 化学工艺 |
| 中文摘要 | 由于Sn-Pb焊料中的Pb及其化合物有毒，给自然环境和人类健康带来较大的危害，实现全面无铅化，是电子行业今后不可逆转的趋势。良好的润湿性是优质焊料的重要指标。Sn-37Pb焊料在高于其熔点50 K的温度下与铜的接触角为13.3°。绝大多数的无铅锡基合金的润湿性较Sn-37Pb焊料的差，开发润湿性良好和力学性能优良的无铅焊料成为目前主要的研究方向。 本论文选择Sn-9Zn、Sn-3.0Ag-0.5Cu共晶合金和Sn-Bi-Cu合金作为研究对象，通过实验测量、仪器检测与分析探讨，取得了以下创新进展： (1) 采用静滴法测量了三种无铅Sn基合金体系与铜的润湿性，除极易氧化的Sn-9Zn合金外，在相近的外界条件下，Sn-3.0Ag-0.5Cu合金的润湿时间最短，为95 s，熔化温度区间越大润湿时间越长，Sn-30Bi-0.5Cu合金的润湿时间为1070 s。三元合金的润湿性较好，在523 K时，Sn-3.0Ag-0.5Cu合金的接触角为48.9°，Sn-17Bi-0.5Cu的为38.6°，Bi含量增大，润湿性提高，Sn-30Bi-0.5Cu在523 K时接触角为29.1°。除化学反应、表面粗糙度等因素影响外，润湿性随温度的升高而增加。共晶合金的接触角的滞后性小，如Sn-3.0Ag-0.5Cu合金接触角的滞后性可以忽略不计，Bi含量增加也会减小接触角的滞后性，如在523 K时，Sn-17Bi-0.5Cu合金接触角的滞后性为7.9°，而Sn-30Bi-0.5Cu的为3.2°。 (2) 生成IMCs的化学反应有利于熔融合金在铜表面的铺展，界面层厚度是界面反应发生难易程度的一个指标，界面层越厚则界面化学反应越容易进行。Sn-3.0Ag-0.5Cu/Cu的界面层厚度为36 µm，而Sn-9Zn/Cu的界面层最薄，为6 µm，因此Sn-3.0Ag-0.5Cu合金的润湿性较好，但是Sn-9Zn/Cu的界面处几乎没有空洞，机械强度优异，即Zn元素的添加可以提高合金的机械强度。Bi是表面活性元素，在熔融的合金中向界面偏聚，阻止界面反应的进行，在界面处形成空洞，造成焊接失效，所以合金中Bi元素的添加也要适量。 |
| 英文摘要 | Sn-Pb solder alloy endangers environment and human health because of the poisonous Pb and its compounds, thus, realizing Pb-free solder alloys in all electronic products is an irreversible trend in the future. Good wettability is a key factor for excellent solder. At the temperature 50 K higher than its melting temperature(456 K), contact angle between Sn-37Pb solder and Cu is 13.3°. Wettability of the most Pb-free Sn-based alloys is worse than that of Sn-37Pb solder, so developing Pb-free solder alloys with good wettability and excellent mechanical properties is the hot research direction now. In this dissertation, Sn-9Zn, Sn-3.0Ag-0.5Cu eutectic alloys and Sn-Bi-Cu alloys have been investigated. Based on the analysis and discussion on the experimental results as well as the instrumental analysis, the innovative results could be summarized as follows: (1) The wettability of three kinds of lead-free Sn-based alloys on Cu was measured by sessile drop method, except Sn-9Zn alloy which is easy to be oxidized, wetting time of Sn-3.0Ag-0.5Cu alloy is the most shortest—95 s when ambient conditions are similar, the larger melting temperature range the longer wetting time, e.g. wetting time of Sn-30Bi-0.5Cu alloy is 1070 s. Wettability of ternary alloys is better, contact angle between Sn-3.0Ag-0.5Cu alloy and Cu is 48.9° and that of Sn-17Bi-0.5Cu is 38.6° when temperature is 523 K, wettability increases with Bi content increasing, contact angle between Sn-30Bi-0.5Cu alloy and Cu is 29.1° at 523 K. Wettability increases with temperature increasing if there are no influence factors such as chemical reaction, surface roughness etc. Contact angle hysteresis of eutectic alloys is little, increasing Bi content also can decrease contact angle hysteresis, for intance, at 523 K, contact angle hysteresis of Sn-17Bi-0.5Cu alloy is 7.9°, while that of Sn-30Bi-0.5Cu alloy is 3.2°. (2) Chemical reaction which produces intermetallic compounds contributes to molten alloy spread on Cu, interface’s thickness is a surfacial form of interface reaction happened, the thicker interface layer the easier interface chemical reaction takes place. The thick of Sn-3.0Ag-0.5Cu/Cu interface is 36 µm, while the interface of Sn-9Zn/Cu is the least thick—6 µm, hence wettability of Sn-3.0Ag-0.5Cu alloy is better. However, little voids are in Sn-9Zn/Cu interface, mechanical strength is excellent, consequently addition of Zn element can improve mechanical strength of alloy. Bi is surface active agents, liable to segregate at the interface in molten alloy, prevents interface reaction, forms voids at interface and brings about Welding failure, thus, addition of Bi should be appropriate too. |
| 语种 | 中文 |
| 公开日期 | 2013-09-16 |
| 页码 | 71 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1285]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 张晓瑞. 熔融锡基合金与铜的润湿性和界面特性[D]. 过程工程研究所. 中国科学院过程工程研究所. 2009. |
入库方式： OAI收割
来源：过程工程研究所
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