Sensata Technologies, Inc.

Stephen P Greene

Andrew F Willner

Eric J Giasson

Alan G Amore

Douglas B Strott

Vanvisa Attaset

James I Ogilvie

Mark P McNeal

David J Field

A pressure sensing element includes a sensing sub-element disposed on a diaphragm, the element including a shield disposed over the sub-element and configured to substantially eliminate influence of external charge on the sub-element during operation. A method of fabrication and a pressure sensor making use of the pressure sensing element are disclosed.

MEMS pressure sensor field shield layout for surface charge immunity in oil filled packaging

A pressure sensing device () is shown having a ceramic capacitive sensing element () received in a chamber formed in a hexport housing (). The hexport housing has a fluid passageway () communicating with a recessed chamber () formed in a bottom wall circumscribed by an annular platform shoulder (). A thin flexible metal diaphragm () is hermetically attached to the bottom wall along the platform shoulder. A curable adhesive resin having a thermal coefficient of expansion and modulus of elasticity appropriately matching that of sensing element (), such as polyurethane, is cast between the sensing element () and the metal diaphragm () forming, when cured, a layer bonded to both members resulting in a sensor that is effective in monitoring negative as well as positive fluid pressures. In one embodiment a ring is used to define layerlaterally and in a second embodiment an insulator sleeve () and shield sleeve () which receives pressure sensing element () each have an open end with an inwardly extending lip () that define layerlaterally.

Hermetic pressure sensing device

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Scituate, RI, United States of America

Stephen P Greene