Plastic Encapsulated Microelectronics

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Hygroscopic Swelling: For many years, moisture induced swelling in plastic encapsulant in microelectronic package was ignored. Recently, new techniques of swelling measurements revealed that swelling coefficient is comparable to the coefficient of thermal expansion (CTE), and therefore, swelling mismatches between adjacent components in plastic encapsulated microelectronics must be considered in the design and reliability analysis. Dr. Ardebili's previous reaserch [Ardebili et. al, 2003] involved a pioneering work in new measurement technique for swelling coefficients of common plastic encapsulants (epoxy molding compounds) using a modified thermo-mechanical analyzer (TMA).


Moisture Diffusion Modeling: Moisture in plastic encapsulated electronics (PEMs) can lead to variety of reliability problems including popcorning (cracking during solder reflow), delamination and corrosion. Modeling moisture diffusion allows us to better understand and predict the diffusion process, and more effectively mitigate it. Moisture diffusion can be either Fickian or non-Fickian. Dr. Ardebili's research [Ardebili et. al, 2002] involving experimental observations from moisture sensor placed inside the PEM shows that in many cases, Fickian model is sufficient to predict moisture content at the interface of encapsulant and passivated chip.