BOTTOM PORTED MEMS MICROPHONE WITH ADDITIONAL PORT FOR VERIFICATION OF ENVIRONMENTAL SEAL

摘要

Methods and systems for verification of an environmental seal provided by an encapsulant coating of a bottom-ported MEMS microphone package. A purposeful acoustic leak is provided on an upper surface of a package housing (in the form of an additional acoustic port) and a sealing material is applied to an outer surface of the package housing. A properly applied encapsulant coating will completely seal the additional acoustic port on the upper surface of the package housing. However, the placement of the additional acoustic port on the upper surface of the package housing will have a significant, detectable effect on the frequency response of the microphone if it is not completely sealed by the encapsulant coating. Accordingly, the environmental seal provided by the encapsulant coating is verified by confirming, based on the acoustic frequency response testing, that the encapsulant coating has effectively sealed the additional acoustic port on the upper surface of the package housing.