Stress Analysis for Through Hole Area in Multilayer Alumina Ceramic Substrate

The stress in a through hole area after the firing process was numerically calculated by Finite Element method (FEM) analysis using a 3-dimensional elastic deformation model for Al2O3 multilayer ceramic substrate. The relationship between the property of W conductor material and the stress in the through hole interface was investigated. The stress value is closely related to the mismatch of thermal expansion coefficient between Al2O3 ceramic and W conductor material and the Young's modulus of W conductor material as well, the larger the thermal expansion coefficient difference and Young's modulus, the larger the stress. Similarly, the relationship between the diameter/pitch of the through hole and the stress was investigated, the larger the ratio of the through hole diameter to the through hole pitch, the larger the stress. The maximum stress in the through hole interface was generated near the surface of the Al2O3 ceramic substrate. The numerically computed results were almost coincident with the experimental results.