Pressure transducer and manufacturing method thereof
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMasaharu Ikeda, Masayoshi Esashi
Life of this patent
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Abstract
A pressure transducer designed to transform static pressure or dynamic pressure applied to a diaphragm into a corresponding electrical signal and a method of manufacturing the same are provided. The transducer includes a fixed electrode formed in an upper surface of a substrate and a moving electrode provided in the diaphragm disposed above the fixed electrode through a cavity. The substrate has formed in the bottom thereof at least one hole which is used in a manufacturing process for removing a sacrificial layer formed between the diaphragm and the upper surface of the substrate in dry etching to form the cavity.
Claims10
A pressure transducer comprising:
- a substrate having a first surface and a second surface opposed to the first surface;
- a fixed electrode formed in the first surface of said substrate;
- a diaphragm attached at a peripheral portion thereof to the first surface of said substrate and extending above said first surface so as to form a cavity between a central portion thereof and said fixed electrode above said first surface, said diaphragm having a moving electrode opposed to said fixed electrode through the cavity and being deformed in response to an applied pressure to change a distance between the moving electrode and said fixed electrode as a function of the applied pressure;
- a hole formed in said substrate which extends from the second surface to the cavity;
- and
- at least one radial groove which is formed in the first surface of said substrate within the cavity and which communicates at a first end thereof with said hole.
Dependencies are inferred from the claim text.