Thermal Stress Analysis and Strain Energy Release Rate in a Multi-layer Beam

• Main Authors: Chin-Hsien Lin, 林志賢
• Other Authors: 何旭川
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/05811773462538380020

碩士 === 元智大學 === 機械工程學系 === 94 === Multi-layer structures are common in electronic package especially for the micro devices manufactured Via the semi-conductor processes or MEMS processes. As the multi-layer structures subject to uniform temperature change, the thermal stresses are induced due to the mismatch of the coefficients of thermal expansion between the adjacent layers. In this investigation, the longitudinal thermal stresses in the middle region of a bi-layer beam and a tri-layer beam are derived basing on the Euler-Bernoulli beam theory. The strain energy release rate of a bi-layer beam and a tri-layer beam with interfacial crack are derived basing on the theory of fracture mechanics. The analytical expressions of the longitudinal thermal stress and strain energy release rate are validated by the finite element method. The effect of Young’s modulus, coefficients of thermal expansion and thickness between the adjacent layers on the thermal stress and strain energy release rate are presented through parametric study.