| In this thesis, the phenomena of thermal contact resistance is examined from both an analytical and numerical standpoint. Strong emphasis is made on the differentiation between the macroscopic and microscopic mechanisms and their separate effects on the thermal resistance at the interface of two unbonded materials. Of particular interest is the interface between two dissimilar materials. A full analysis of the macroscopic influence of thermal strains on the deformations at the interface is presented. The dependence of interfacial thermal resistance on the direction of heat flow is explained. The theory of microscopic-based contact resistance is also reviewed. A computer code enabling coupled thermal-mechanical finite element analyses of models was developed to investigate the complex interplay between thermal strains, interface separation, and contact conductance. The program is used to examine past and current methods of experimentally determining thermal contact resistance. A unique procedure, based on observed interfacial phenomena, for experimentally measuring true thermal contact resistance is presented and numerically verified. Finally, the technology developed in this thesis is used to analyze some interface problems in electronic packages. |
