ANGULAR VELOCITY SENSOR AND METHOD OF MANUFACTURING THE SAME

• US 20100000322A1
• Filed: 06/25/2009
• Published: 01/07/2010
• Est. Priority Date: 07/04/2008
• Status: Active Grant

• Current Assignee: Sony Semiconductor Solutions Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Shibayama, Tetsuya, Honda, Junichi, Inaguma, Teruo
• Granted Patent: US 8,516,888 B2
• Time in Patent Office: Days
• US Class Current: 73/504.16
• CPC Class Codes: G01C 19/5621 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5628 Manufacturing; Trimming; Mounting; Housings
• CPC Class Codes: Y10T 29/49126 Assembling bases

Abstract

Disclosed is an angular velocity sensor. The angular velocity sensor includes a first layer, a piezoelectric layer, and a second layer. The first layer has a first main surface and a second main surface, and includes a vibrator portion and a base portion that supports the vibrator portion. The piezoelectric layer is formed on the first main surface of the first layer. The second layer is integrally bonded to the base portion on a side of the second main surface of the first layer.

Claims

1. An angular velocity sensor, comprising:

a first layer having a first main surface and a second main surface, the first layer including a vibrator portion and a base portion that supports the vibrator portion;

a piezoelectric layer formed on the first main surface of the first layer; and

a second layer integrally bonded to the base portion on a side of the second main surface of the first layer.

2. The angular velocity sensor according to claim 1,

wherein the second layer is thicker than the first layer.

3. The angular velocity sensor according to claim 2,

wherein the first layer has the same thickness as the vibrator portion.

4. The angular velocity sensor according to claim 3,

wherein the first layer and the second layer each are made of a silicon substrate,

the angular velocity sensor further comprising:

a bonding layer made of a silicon oxide layer between the first layer and the second layer.

5. The angular velocity sensor according to claim 4, further comprising:

a plurality of terminal portions that are formed on the base portion on a side of the first main surface and connected to an external circuit,

wherein the second layer is bonded to the second main surface over an area corresponding to formation positions of the plurality of terminal portions.

6. The angular velocity sensor according to claim 5,

wherein the vibrator portion includes three arm portions that extend in parallel to one another.

7. The angular velocity sensor according to claim 5,

wherein the second layer includes a shielding portion that shields the vibrator portion, and

wherein the shielding portion includes, on a surface opposed to the vibrator portion, a concave part in which a vibration space of the vibrator portion is formed.

12. The angular velocity sensor manufacturing method according to claim 1, further comprising:

forming, in the first substrate, a through hole through which the vibrator portion is exposed to outside from the opening.

13. The angular velocity sensor manufacturing method according to claim 12,

wherein the step of forming the through hole includes forming, in the first substrate, an etching groove that corresponds to an outline of the opening by the dry etching process.

8. An angular velocity sensor manufacturing method, comprising.

forming an insulation layer on a first substrate;

forming, on the insulation layer, an opening from which the first substrate is exposed;

bonding a second substrate to the first substrate with the insulation layer being sandwiched;

forming a piezoelectric layer on a main surface of one of the first substrate and the second substrate;

forming a vibrator portion in an area on the main surface which corresponds to a formation position of the opening, and

forming an outline of a base portion that supports the vibrator portion by dicing the first substrate and the second substrate.

9. The angular velocity sensor manufacturing method according to claim 8,

wherein the second substrate is thinner than the first substrate, and

wherein the main surface is a main surface of the second substrate.

10. The angular velocity sensor manufacturing method according to claim 9,

wherein the step of forming the insulation layer includes forming a silicon oxide layer on the first substrate by performing a heating process on the first substrate as a silicon substrate in an oxygen atmosphere.

11. The angular velocity sensor manufacturing method according to claim 10,

wherein the step of forming the vibrator portion includes forming, in the second substrate, an etching groove that corresponds to an outline of the vibrator portion by a dry etching process.

14. The angular velocity sensor manufacturing method according to claim 9, further comprising:

forming a concave part on a surface of the first substrate that is exposed from the opening after the opening is formed.

15. The angular velocity sensor manufacturing method according to claim 9, further comprising:

polishing the main surface by a predetermined amount before the piezoelectric layer is formed.