Pressure sensor, and sensor unit provided with same

Patent metadata

Field	Value
Publication number	US-9733142-B2
Application number	US-201314436280-A
Country	US
Kind code	B2
Filing date	Oct 15, 2013
Priority date	Oct 17, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

When a main body of a sensor chip ( 1 ) is in a grounded state, a shield layer ( 71 ) constituting a shield electrode formed on a circuit layer ( 72 ) is grounded through a resistor ( 46 ).

First claim

The invention claimed is:

1. A pressure sensor comprising:
a sensor chip comprising:
a main body comprising:
a movable portion provided with a plurality of pressure detection elements, the movable portion being adapted to displace in response to a pressure acting thereon; and
a fixed portion that is continuous with the movable portion;

a circuit formed in a first layer laminated on the main body, the circuit being connected to the pressure detection elements through a conductive element; and
a shield layer formed in a second layer laminated on the first layer, the shield layer having an opening extending therethrough directly above the movable portion, the shield layer formed continuously around the opening;
a capacitor formed between the shield layer and an output voltage line; and
a resistor connected between the shield layer and a ground line, the resistor having a resistance value greater than or equal to 10Ω and less than or equal to 1 MΩ.

2. The pressure sensor according to claim 1 , wherein a shield layer made of aluminum and connected to the resistor is formed in the second layer and above the circuit formed in the first layer.

3. The pressure sensor according to claim 2 , wherein a shield layer made of aluminum and connected to the resistor is formed in the second layer at a position immediately above a plurality of semiconductor elements in the circuit to be formed in the first layer.

4. The pressure sensor according to claim 1 , wherein the shield layer in the second layer is made of polysilicon, and covers a predetermined region located immediately above the plurality of pressure detection elements.

5. A sensor unit comprising:
the pressure sensor according to claim 1 ;
a housing configured to accommodate the pressure sensor through use of a sealing material;
a diaphragm configured to isolate an inner peripheral portion of the housing from a pressure chamber of which a pressure is to be detected;
a pressure transmission medium filled between the diaphragm and the sensor chip of the pressure sensor; and
a terminal group to be electrically connected to the circuit in the sensor chip of the pressure sensor.

6. A sensor unit comprising:
the pressure sensor according to claim 1 ;
a housing configured to accommodate the pressure sensor through use of a sealing material;
a diaphragm configured to isolate an inner peripheral portion of the housing from a pressure chamber of which a pressure is to be detected;
a pressure transmission medium filled between the diaphragm and the sensor chip of the pressure sensor;
a terminal group to be electrically connected to the circuit in the sensor chip of the pressure sensor, and
wherein the shield layer is made of aluminum and is connected to the resistor, wherein the shield layer is formed in the second layer and above the circuit formed in the first layer.

7. A sensor unit comprising:
the pressure sensor according to claim 1 ;
a housing configured to accommodate the pressure sensor through use of a sealing material;
a diaphragm configured to isolate an inner peripheral portion of the housing from a pressure chamber of which a pressure is to be detected;
a pressure transmission medium filled between the diaphragm and the sensor chip of the pressure sensor;
a terminal group to be electrically connected to the circuit in the sensor chip of the pressure sensor, and
wherein the shield layer in the second layer is made of polysilicon, and covers a predetermined region located immediately above the plurality of pressure detection elements.

8. A pressure sensor comprising:
a sensor chip comprising:
a main body comprising:
a movable portion provided with a plurality of pressure detection elements, the movable portion being adapted to displace in response to a pressure acting thereon; and
a fixed portion that is continuous with the movable portion;

a circuit formed in a first layer laminated on the main body, the circuit being connected to the pressure detection elements through a conductive element;
a shield layer formed in a second layer laminated on the first layer, the shield layer having an opening extending therethrough directly above the movable portion, the shield layer formed continuously around the opening;
a capacitor formed between the shield layer and a ground line; and
a resistor connected between the shield layer and an input voltage line, the resistor having a resistance value greater than or equal to 10Ω and less than or equal to 1 MΩ.

9. A sensor unit comprising:
the pressure sensor according to claim 8 ;
a housing configured to accommodate the pressure sensor through use of a sealing material;
a diaphragm configured to isolate an inner peripheral portion of the housing from a pressure chamber of which a pressure is to be detected;
a pressure transmission medium filled between the diaphragm and the sensor chip of the pressure sensor; and
a terminal group to be electrically connected to the circuit in the sensor chip of the pressure sensor.

10. The pressure sensor according to claim 8 , wherein a shield layer made of aluminum and connected to the resistor is formed in the second layer and above the circuit formed in the first layer.

11. The pressure sensor according to claim 10 , wherein a shield layer made of aluminum and connected to the resistor is formed in the second layer at a position immediately above a plurality of semiconductor elements in the circuit to be formed in the first layer.

12. The pressure sensor according to claim 8 , wherein the shield layer in the second layer is made of polysilicon, and covers a predetermined region located immediately above the plurality of pressure detection elements.

13. A sensor unit comprising:
the pressure sensor according to claim 8 ;
a housing configured to accommodate the pressure sensor through use of a sealing material;
a diaphragm configured to isolate an inner peripheral portion of the housing from a pressure chamber of which a pressure is to be detected;
a pressure transmission medium filled between the diaphragm and the sensor chip of the pressure sensor;
a terminal group to be electrically connected to the circuit in the sensor chip of the pressure sensor, and
wherein the shield layer is made of aluminum and is connected to the resistor, wherein the shield layer is formed in the second layer and above the circuit formed in the first layer.

14. A sensor unit comprising:
the pressure sensor according to claim 8 ;
a housing configured to accommodate the pressure sensor through use of a sealing material;
a diaphragm configured to isolate an inner peripheral portion of the housing from a pressure chamber of which a pressure is to be detected;
a pressure transmission medium filled between the diaphragm and the sensor chip of the pressure sensor;
a terminal group to be electrically connected to the circuit in the sensor chip of the pressure sensor, and
wherein the shield layer in the second layer is made of polysilicon, and covers a predetermined region located immediately above the plurality of pressure detection elements.

15. A pressure sensor comprising:
a sensor chip comprising:
a main body comprising:
a fixed portion formed on a glass layer;
a movable portion integrally formed with the fixed portion, the movable portion being displaceable in response to pressure acting thereon; and
a plurality of pressure detection elements positioned on the main body;

a circuit layer laminated on the main body, the circuit layer having a circuit formed therein that is electrically connected to the pressure detection elements through a co

Assignees

• Kk saginomiya seisakusho
• Fuji Electric Co Ltd

Inventors

• Ishikawa Takuro
• Kanai Yuji
• Matsunami Kazuhiro

Classifications

• G01L19/142

  Multiple part housings · CPC title

• G01L19/0645

  using isolation membranes, specially adapted for protection · CPC title

• G01L9/0054

  integral with a semiconducting diaphragm · CPC title

• G01L19/069 Primary

  Protection against electromagnetic or electrostatic interferences · CPC title

• H01L2924/10253

  Electricity · mapped topic