极端温度梯度下IMC微焊点快速形成机制及其失效机理研究

Harsh Service Conditions impose higher requirements on the packaging technology and reliability of electronic products. It is imperative to address the issue of the reliability of the solder/intermetallic compound (IMC) interface and mismatches of material performance during service in micro solder joints. The IMC interconnection structure with no defect, continuous and single phase has good high temperature stability and resistance to electromigration. However, we need to investigated its rapid formation mechanism, long-term reliability and other issues. In this project, two kinds of pad materials including cobalt-based thin film and pure copper were selected to systematically study the growth and evolution of interfacial CoSn3 and Cu6Sn5 IMC at the harsh temperature gradient with pure tin to form flip-chip structure solder joints. The growth kinetic parameters and mechanism of IMCs were clarified. The identification of key control factors for the formation of defects-free during growth, combined with the reliability results under temperature field and impact loading based on numerical simulation, reveals the rapid formation and failure mechanism of IMC micro solder joints under harsh temperature gradients. The key data and manufacturing process of the IMC interconnect structure in the package were obtain. Such a systematic study is expected to be able to yield fruitful results, which will enrich the material system used in high performance packaging technology with low cost and lay the theoretical foundation for the manufacture of IMC micro joint under harsh condition.

极端环境服役条件对电子终端产品的封装技术及其可靠性提出了更高的要求，封装微焊点中焊料/金属间化合物(IMC)界面和材料性能匹配在服役过程中产生的可靠性问题亟待解决。无缺陷、连续、单相的IMC互连结构具有良好的高温稳定性和抗电迁移能力，但需要解决其快速形成机制与长久可靠性等问题。.本项目选用钴基薄膜和纯铜两种焊盘材料，系统研究其与纯锡形成倒装结构焊点在极端温度梯度下界面CoSn3 和Cu6Sn5 IMC的生长演变规律，获得生长动力学参数，阐明IMC生长的微观机制，探明生长中无缺陷形成的关键控制因素，并结合基于数值模拟的温度场和冲击载荷下的可靠性结果，揭示极端温度梯度下IMC微焊点的快速形成机制及其失效机理，获得IMC互连结构在封装中的关键基础数据和制造工艺。.本项目的顺利实施不仅可丰富高性能封装技术的材料体系，还可为极端条件下高可靠IMC微焊点的制造奠定理论基础。

极端环境服役条件对电子终端产品的封装技术及其可靠性提出了更高的要求，封装微焊点中焊料/金属间化合物(IMC)界面和材料性能匹配在服役过程中产生的可靠性问题亟待解决。.本项目选用钴基薄膜和纯铜两种焊盘材料，系统研究了焊点在极端温度梯度下界面反应和IMC生长演变规律，主要成果如下：1）阐明了CoSn3等IMC的生长机制，利用Co-P薄膜和温度梯度调控IMC焊点生长取向的方法，实现对IMC焊点特定取向生长和调控；2）明确了IMC焊点在温度梯度下通过元素调控改变原子迁移和IMC生长的演变规律，获得了Co原子在温度梯度下迁移的驱动力，探明IMC生长过程中无缺陷形成的关键控制因素，揭示极端温度梯度下IMC微焊点的生长形成机制；3）系统归纳了SAC/Co-xat.%P结构焊点在快速热疲劳等极端条件下的微裂纹演变，揭示极端温度梯度下IMC微焊点的失效机理，初步获得IMC互连结构在封装中的基础数据和制造工艺。上述研究成果丰富了高性能封装技术的材料体系，可为解决先进封装IMC可靠性问题提供不同技术路径和工程参考。共发表学术论文8篇，在ICEPT等国际学术会议上发表论文6篇，申请中国发明专利12项，授权中国发明专利6项，做邀请报告和分会报告8次，培养硕士研究生毕业3名。