We propose an advanced thermal-moisture analogy scheme to cope with the inherent limitations of the existing analogy schemes. The new scheme is based on the experimentally observed unique hygroscopic behavior of polymeric materials used in microelectronics; i.e., the saturated concentration is only a function of relative humidity regardless of temperature. A new analogy formulation based on the modified solubility is presented and the scheme is implemented to investigate its accuracy and applicability. The results from a simple case study corroborate that the advanced scheme can be used effectively for package assemblies subjected to general anisothermal loading conditions.
Thermal-moisture analogy schemes for a moisture diffusion analysis are reviewed. Two schemes for practical applications are described using the governing equations of heat and mass diffusions: (1) direct analogy and (2) normalized analogy. The schemes are implemented to define valid domains of application. The results corroborate that the direct analogy is valid only for single-material systems, but the normalized analogy can be extended to multimaterial systems if thermal loading conditions are isothermal, spatially as well as temporally.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.