Capacitance type accelerometer

• US 5,095,752 A
• Filed: 10/31/1989
• Issued: 03/17/1992
• Est. Priority Date: 11/15/1988
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Matsumoto, Masahiro, Miki, Masayuki, Suzuki, Seiko, Tsuchitani, Shigeki
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): DOMBROSKE, GEORGE M
• Application Number:
  US07/429,546
• Time in Patent Office: 868 Days
• Field of Search: 73/517 R, 73/517 B, 437/61, 437/67, 437/187, 437/195, 437/915, 437/980
• US Class Current: 73/514.32
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2207/095 through the lid
• CPC Class Codes: B81B 2207/096 through the substrate
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/131 with electrostatic counterbalancing means
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends

Abstract

A capacitance type accelerometer, having a fist silicon plate formed a movable electrode which is moved according to acceleration, two second silicon plates which are disposed on both sides of the first silicon plate with a certain separation distance, and thermal oxide films which are respectively disposed between the first silicon plate except the movable electrode and the two second silicon plates and stick the first silicon plate except the movable electrode and the two second silicon plates together. And further, a capacitance type accelerometer, having, a silicon plate forming a movable electrode which is moved according to acceleration, glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are connected to both sides of the silicon plate except the movable electrode and lead wires which are respectively connected to the conductive layers through a groove formed between the silicon plate and the glass plates.

Claims

1. A capacitance type accelerometer, having:

a silicon plate including a portion formed as a movable electrode which is moved according to acceleration;

glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are connected to both sides of the silicon plate except the movable electrode; and

lead wires which are respectively connected to the conductive layers through at least one preformed groove provided in at least one of the silicon plate and the glass plates.

2. A capacitance type accelerometer as defined in claim 1, wherein;

the groove is formed on the silicon plate.

3. A capacitance type accelerometer as defined in claim 1, wherein;

the groove is formed on the glass plates.

4. A capacitance type accelerometer as defined in claim 1, wherein;

the groove is filled with a non-conductive material.

5. A capacitive type accelerometer having:

a silicon plate including a portion formed as a movable electrode which is moved according to acceleration;

glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are connected to both sides of the silicon plate except the movable electrode;

lead wires which are respectively connected to the conductive layers through at least one groove formed in at least one of the silicon plate and the glass plates; and

silicon plates respectively covering each outside surface of the glass plates.

6. A capacitance type accelerometer as defined in claim 5, further having;

conductive paste electrically connecting one of the lead wires to a connecting terminal.

7. A capacitance type accelerometer, having:

a silicon plate including a portion formed as a movable electrode which is moved according to accelerating force;

glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are anodic-bonded to both sides of the silicon plate except the movable electrode; and

lead wires which are respectively connected to the conductive layer and are respectively fed out of the glass plate through a hole formed thereon.

8. A capacitance type accelerometer, having:

a silicon plate including a portion formed as a movable electrode which is moved according to acceleration;

thermal oxide films which are respectively formed on the silicon plate except the movable electrode;

polycrystal silicon layer formed on the thermal oxide films;

glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are connected to both sides of the silicon plate through the thermal oxide films and the polycrystal silicon layer except the movable electrode; and

thin lead wires which respectively connect lead out terminals to the conductive layers through portions between the thermal oxide films and the glass plates and are connected to the polycrystal silicon layer.

9. A capacitance type accelerometer comprising:

a silicon plate including a portion formed as a movable electrode which is moved in response to acceleration;

first and second plate members disposed on opposite sides of the silicon plate and being spaced at least from the movable electrode portion of the silicon plate, the plate members being connected to the silicon plate other than in the region of the movable electrode portion;

wherein the first and second plate members are glass plate members, each glass plate member having a conductive layer mounted thereon and disposed in opposition to the movable electrode portion of the silicon plate; and

lead wires respectively connected to the conductive layers through at least one preformed groove provided in at least one of the silicon plate and the glass plate members.

10. A capacitance type accelerometer according to claim 9, further comprising silicon plates respectively covering each outside surface of the glass plates.

11. A capacitance type accelerometer according to claim 9, wherein the groove is filled with a non-conductive material.