Deflection behavior of several encapsulant materials under uniform pressure
was studied to determine the best encapsulant for MEMS device. Encapsulation is
needed to protect movable parts of MEMS devices during high pressure transfer
molded packaging process. The selected encapsulant material has to have surface
deflection of less than 5 ?m under 100 atm vertical loading. Deflection was
simulated using CoventorWare ver.2005 software and verified with calculation
results obtained using shell bending theory. Screening design was used to
construct a systematic approach for selecting the best encapsulant material and
thickness under uniform pressure up to 100 atm. Materials considered for this
study were polyimide, parylene C and carbon based epoxy resin. It was observed
that carbon based epoxy resin has deflection of less than 5 ?m for all
thickness and pressure variations. Parylene C is acceptable and polyimide is
unsuitable as high strength encapsulant. Carbon based epoxy resin is considered
the best encapsulation material for MEMS under high pressure packaging process
due to its high strength.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
