低银无铅焊点在力、热、电耦合作用下失效机理的研究

项目名称： 低银无铅焊点在力、热、电耦合作用下失效机理的研究

项目编号： No.51301007

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 马立民

作者单位： 北京工业大学

项目金额： 25万元

中文摘要： Sn基共晶/近共晶钎料已广泛用于表面组装技术。但较高的Ag含量也成为众多研究机构和工业界研发新一代低银钎料的动力。此外，虽然Sn基钎料焊点在单一严峻载荷（如蠕变、热疲劳、电迁移等）作用下的失效机理已得到充分认识，但在多种严峻载荷耦合作用下失效机理的研究却没有得到足够的重视。多种严峻载荷耦合作用并不是多个单一严峻载荷效应简单的叠加。力、热、电在焊点服役过程中对焊料损伤的各自作用及其导致的焊点失效机制尚需研究。本项目以低银无铅焊点为研究对象，选择Co、Ni、及具有纳米结构的笼形硅氧烷齐聚物(POSS)作为增强颗粒提高低银钎料在复杂服役条件下的可靠性。同时阐明Sn晶粒及金属间化合物在不同类型的力、热、电严峻载荷耦合作用下的显微形貌演变、晶体取向演变、元素分布演变过程。项目的开展可建立材料显微组织（元素分布、晶体取向）与材料性能（电导率）之间的关联，进而阐明焊点在多种严峻载荷耦合作用下的失效机理。

中文关键词： 低银焊料；电迁移；蠕变；热疲劳；多场耦合

英文摘要： Eutectic/near-eutectic Sn based solders have been widely used in surface mount technology. However, many institutions and industry dedicate to develop new solder alloys due to the high content of Ag element in current solders. Besides, the typical reliability issues of Pb-free solder joints such as electromigration (EM)， Creep， and thermomechanical fatigue (TMF) have been investigated and comprehended individually with the effort of a flurry of activities in electronic community. The failure mechanisms of micro-electronic devices under the real service environment which commonly includes a fluctuated temperature, electrical current and mechanical loading are still not understood. That is, EM, creep, and TMF may intertwine with each other and none of the solitary models can be used to explain the failure of the joint. Therefore, the study of these coupling effects on solder joints is a note worthy matter. In order to improve the reliabilities of low-silver solder joint, the Co, Ni as well as the nano-structured cage-type polyhedral oligomeric silsesquioxane (POSS) will be used as the reinforcement particles in this study. The microstructure evolution, grain orientation change, and element redistribution process of Sn grains and intermetallic compound (IMC) under the coupling effect of mechanical, thermal, and ele

英文关键词： low-silver solder；electromigration；creep；thermomechanical fatigue；multifield coupling