Pressure sensor having semiconductor sensor chip
AssigneeDenso Corporation
InventorsMasahito Imai, Takeshi Shinoda, Yasutoshi Suzuki, Hiroaki Tanaka
Life of this patent
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Abstract
A semiconductor sensor chip mounted on a thin diaphragm of a cylindrical metallic stem via an insulation layer is hermetically contained in a housing of a pressure sensor. The sensor chip includes a strain gage for outputting an electrical signal according to distortion of the diaphragm caused by pressure to be measured. A shield layer is interposed between the insulation layer and the sensor chip, and the shield layer is grounded. Influence of outside noises on the sensor outputs is eliminated or suppressed by the grounded shield layer even if the outside noises are in a high frequency region.
Claims5
A pressure sensor comprising:
- a metallic stem having a diaphragm for sensing a pressure applied thereto, the metallic stem being contained in a housing;
- a semiconductor sensor chip mounted on a front surface of the diaphragm with an insulation layer interposed therebetween;
- a strain gage for converting distortion of the diaphragm caused by the pressure applied thereto into an electrical signal, the strain gage being formed on the semiconductor sensor chip;
- and
- a grounded shield layer for electrically interrupting the strain gage from the metallic stem that is interposed between the strain gage and insulation layer, wherein:
- the semiconductor sensor chip comprises a silicon semiconductor chip having a first-type conduction layer contacting the insulation layer and a second-type conduction layer formed on the first-type conduction layer;
- the first-type conduction layer functions as the grounded shield layer;
- and
- the strain gage is formed by a first-type conduction region formed in the second-type conduction layer and separated from the first-type conduction layer.
Dependencies are inferred from the claim text.