No abstract

The effects of thermal stress resulting from thermal cooling in copper/diamond/copper heat spreader is investigated using finite element method. A similar model of diamond/SiC heat spreader is compared without addition of interlayer. The effect of carbide interlayer in reduction of interfacial thermal stress is investigated. The results show that the carbide interlayer film thickness is critical in stress reduction for a copper/diamond/copper heat spreader device. Diamond/SiC device has lower interfacial stress without interlayer. The study of mechanical and thermal property of diamond heat spreader is useful for optimal designs of efficient heat spreader for electronic components.

No abstract

The effect of thermoelastic damping as a main dissipation mechanism in single crystalline silicon, GaAs, diamond, SiC and SiO2 micromechanical resonators are studied. Numerical simulation is performed to compare quality factors of the given materials. Results using Zener’s well-known approximation and recent developments of Lifshitz and Roukes models were used to model thermoelasticity effects. In the later model, the effect of thermal diffusion length is taken into account for determination of thermoelastic damping. Our results show that larger discrepancy is obtained between the two models for SiO2. The difference is pronounced when beam aspect ratio (L/w) is smaller. Such progresses will find potential applications in optimal design of high quality factor micrometer- and nanometer-scale electromechanical systems.