Thermal Stress in Encapsulated Electronic Packages

The paper represents stress assessment of electronic packages with complete compound encapsulation subjected to thermal impacts. The stress calculation scheme for the joint of electronic component and surrounding layer of compound is brought to axially symmetric problem of two joined thick-walled cylinders and described by using Lame-Gadolin theory. The mathematical model was obtained by solving statically indeterminate problem. Formulas for radial and tangential stress and contact pressure calculation were obtained for stationary thermal condition. Non-stationary problem of thermal conduction in the sealed package was solved. The problem of non-stationary radial distribution of temperature in electronic component and compound was solved. Calculation formulas were optimized for the ultimate thermal impact on the encapsulated package.