Patent attributes
A pressure sensing device includes a support structure, an isolated diaphragm, a working oil, and a MEMS die sensing element. The support structure defines a portion of a sealed cavity. The isolated diaphragm is mounted to the support structure. The isolated diaphragm has in inner side that defines an end of the sealed cavity and an outer side opposite the inner side. The working oil is contained within the sealed cavity. The MEMS die sensing element is enclosed within the support structure. The MEMS die sensing element is exposed to the working oil within the sealed cavity. A pressure exerted on the outer side of the isolated diaphragm by a fluid medium is transferred via the working oil to the MEMS die sensing element to measure the pressure of the fluid medium. The working oil has a low vapor pressure and a low volatility content.
