PHYSICAL QUANTITY SENSOR ELEMENT, PHYSICAL QUANTITY SENSOR, ELECTRONIC EQUIPMENT, AND MOVABLE BODY

• US 20160069683A1
• Filed: 09/03/2015
• Published: 03/10/2016
• Est. Priority Date: 09/05/2014
• Status: Active Grant

• Current Assignee: Columbia Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: FURUHATA, Makoto
• Granted Patent: US 9,939,268 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion

Abstract

A physical quantity sensor element is formed into a plane-shape which extends along an XY plane, and is provided with a driving portion which vibrates in a Z-axis direction, a detecting portion which vibrates in an X-axis direction due to Coriolis effect acting on the driving portion, a beam portion which connects the driving portion and the detecting portion, a fixing portion, and a beam portion which connects the detecting portion and the fixing portion, in which a spring constant of the beam portion in the Z-axis direction is smaller than a spring constant of the beam portion in the Z-axis direction, and a spring constant of the beam portion in the Z-axis direction is greater than a spring constant of the beam portion in the X-axis direction.

Claims

1. A physical quantity sensor element comprising:

a driving portion which vibrates in a first direction along a first axis orthogonal to a reference surface;

a detecting portion which vibrates in a second direction along a second axis in the reference surface due to an inertial force acting on the driving portion;

a first beam portion which connects the driving portion and the detecting portion with each other;

a fixing portion; and

a second beam portion which connects the detecting portion and the fixing portion,

wherein a spring constant of the first beam portion in the first direction is smaller than a spring constant of the second beam portion in the first direction, and

wherein a spring constant of the second beam portion in the first direction is greater than a spring constant of the second beam portion in the second direction.

2. The physical quantity sensor element according to claim 1,

wherein when the spring constant of the first beam portion in the first direction is set to be k1z, and the spring constant of the second beam portion in the first direction is set to be k2z, a relationship expressed by k1z/k2z≦

1/10 is established.

3. The physical quantity sensor element according to claim 1,

wherein a length of the first beam portion is longer than a length of the second beam portion.

4. The physical quantity sensor element according to claim 1,

wherein the first beam portion includes a portion which is formed into a meandering shape in planar view when seen from the first direction.

5. The physical quantity sensor element according to claim 4,

wherein the first beam portion includes a first portion which extends along the second axis, and a second portion which extends along a third axis orthogonal to the second axis in the reference surface, and

wherein a length of the first portion is longer than a length of the second portion.

6. The physical quantity sensor element according to claim 1,

wherein a thickness of the first beam portion is smaller than a thickness of the second beam portion.

7. The physical quantity sensor element according to claim 1,

wherein a width of the second beam portion is smaller than a thickness of the second beam portion.

8. A physical quantity sensor comprising:

the physical quantity sensor element according to claim 1; and

a package which stores the physical quantity sensor element.

9. Electronic equipment comprising the physical quantity sensor element according to claim 1.

10. A movable body comprising the physical quantity sensor element according to claim 1.