摘要
The thermoelastic strains are induced by through silicon vias due to the difference of thermal expansion coefficients between the copper (similar to 18 ppm/degrees C) and silicon (similar to 2.8 ppm/degrees C) when the structures are exposed to a thermal ramp in the process flow. A compact analytic model (Bessel function) of the strain field is obtained using Kane-Mindlin theory, and has a good agreement with the finite-element simulations. The elastic strains in the silicon in the radial direction and angular direction are tensile and compressive, respectively. The linear superposition of the analytic model of a single via can be used in the multi-via configuration. Due to the interaction of vias, the slightly larger errors of strain occur between the two close vias when the linear superposition is used.
- 出版日期2012-3
- 单位中国科学院电工研究所