TSV三维射频微系统跨尺度热-结构失效机理研究

TSV 3D-Integration is considered to be an attractive system-level integration method, which could be used to realize miniaturization and high integration of RF system. High power of active devices and multi-layer stacks increase the power density of the RF microsystem rapidly, furthermore, there exists quite a lot thermal mismatch and discontinuous interfaces, therefore, thermal-structural reliability is a serious threat to the 3D TSV RF micro system. The project will focus on the interface delamination and structural failure of the TSV 3D RF micro system. First, the electric load temperature cycling test is used to accelerate the interface cracking. Then, the scanning acoustic microscope (C-sam), X-ray fluoroscopy microscopy and SEM scanning electron microscope are employed to track the interface crack initiation and propagation. Finally, the thermal-structural failure mechanism of the TSV RF micro system will be systematically investigated according to the theory of interface mechanics. In this research, the dynamic thermal response and temperature distribution under periodic thermal loading system will be investigated for the TSV 3D system. A numerical model with considering the microstructure parameters will be proposed based on interface mechanics, and it is then used to predict the interface crack propagation of the TSV RF micro system subjected to non-uniform temperature distribution. The effect of the micro-crack, IMC microstructure and interface morphology on the bonding strength and failure modes will be investigated. The dominant cracking mechanism under non-uniform temperature load will be discussed, and the robustness and adaptability of the failure criterion and prediction method for multi-scale dimensions will also be revealed. The research will explore a new area for the reliability evaluation of TSV 3D micro system, and can provide guidance and direction for the optimization of the structural design and material selection for 3D RF integration. The research has high academic research and practical application value.

TSV三维集成是实现小型化及多功能化的系统级架构方法。由于射频有源器件功耗较大，加之三维堆叠使得功耗密度上升迅速，且大量存在材料热失配及结构界面不连续，严重威胁三维射频微系统的可靠性。本项目将围绕热载荷下系统结构界面开裂失效问题，通过电加载温度循环试验加速界面开裂，采用超声波扫描显微镜、X-RAY透视显微镜和SEM扫描电子显微镜追踪界面裂纹的萌生与扩展，依据界面力学评价体系进行跨尺度热-结构破坏机理的研究。探明周期性热载荷作用下系统的热响应及温度分布；建立包含微观结构特征的非均布温度场下界面裂纹扩展预测的数值模型，研究微裂纹、IMC微结构及界面几何形貌对结合强度和破坏模式的影响，弄清非均布温度载荷下主导开裂机制；揭示不同界面失效准则及评价方法的多尺度适应性。本课题将为TSV射频微系统的可靠性评估拓展新的领域，并为结构设计优化和材料选择提供指导和依据，具有较高的学术研究价值和实际应用价值。

TSV三维集成是实现小型化及多功能化的系统级架构方法。由于射频有源器件功耗较大， .加之三维堆叠使得功耗密度上升迅速，且大量存在材料热失配及结构界面不连续，严重威胁三维射频微系统的可靠性。本研究围绕热载荷下系统结构界面开裂失效问题，研究界面裂纹的萌生与扩展，并依据界面力学评价体系进行跨尺度热-结构破坏机理的研究。设计了结构尺寸27mm×7.8mm×0.2mm的TSV硅转接板，上下两层转接板间通过AuSn围框进行键合。对Si-Si键合与AuSn键合两种方案进行了界面韧性测试。完成了TSV三维微系统结构中硅片、微凸点、塑封料等材料基础热力学性能测试、微观尺度纳米压痕和界面破坏试样的加工制备；完成基于纳米压痕进行了微系统互连焊料微纳尺度硬度及模量等力学参数提取，完成了基于微观压痕测试的焊料蠕变本构方程参数提取；完成基于构建拉伸、剪切、裂劈受力特征的Si/AuSn/Si界面韧性参数提取；利用焊料的微观纳米压痕测试数据，进行三维射频微系统微凸点寿命预测评估，研究尺度效应对微系统寿命的影响。本课题能够保证小型化高集成高功率密度异质异构集成三维射频微系统的高效可靠性设计，对进一步提高交变非均布温度载荷下的循环可靠性具有很好的指导意义，同时也可以应用到5G通讯的高集成射频单元的设计中，对5G通讯、射频先进系统级封装设计及产业化具有很好的指导作用。将为TSV射频微系统的可靠性评估拓展新的领域，并为结构设计优化和材料选择提供指导和依据，具有较高的学术研究价值和实际应用价值。