Effect of insulating material and structure on the reliability of silicon through hole under thermal stress

Through Silicon Via (TSV) technology has the advantages of reducing package size, reducing transmission delay, and reducing chip power consumption, which is the key technology for the integrated circuit industry to continue to develop into the post-Moore era. The advantages of TSV technology make it widely used in the field of high-density integrated circuit packaging. High-density integrated circuit (IC) aerospace applications face the test of extreme service environments and long-term service requirements. TSV has reliability problems under the action of temperature stress, which affects the practical application of aerospace devices. In this paper, the structural design and thermal stress simulation analysis of TSV is carried out by ANSYS finite element simulation technology, and the influence of the insulating material and structure of TSV on the reliability of TSV is studied. High-temperature storage test and temperature cycle test were carried out on the actual TSV structure. By comparing the simulation results with the reliability test results, the failure mechanism was analyzed and the failure law was obtained. The results show that the thermal expansion coefficient difference is the main reason for the failure of TSV under thermal stress. The thermal stress is concentrated at the interface with the largest difference in thermal expansion coefficients. Under the same temperature condition, the anisotropic stress of the PI insulation layer is less than that of the SiO2 insulation layer, so it has better reliability under the action of thermal stress. The failure modes of insulating layers of different materials are different. The TSV failure mode of the silica insulator is Cu expansion. The TSV failure mode of the PI insulation layer is PI bulging.