Angular velocity sensor for suppressing fluctuation of detection sensitivity

• US 9,632,105 B2
• Filed: 09/28/2012
• Issued: 04/25/2017
• Est. Priority Date: 09/30/2011
• Status: Expired due to Fees

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Yoshiuchi, Shigehiro, Ohuchi, Satoshi, Fujii, Tsuyoshi, Yamamoto, Kensaku, Ohkoshi, Hideo
• Primary Examiner(s): Patel, Harshad R
• Assistant Examiner(s): Singer, David L
• Application Number:
  US14/347,867
• Publication Number:
  US 20140238131A1
• Time in Patent Office: 1,670 Days
• Field of Search: 7351416, 7351436, 7351438, 7351402, 7350401, 7350402
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81B 2201/025 Inertial sensors not provided for in B81B2201/0235 - B81B2201/0242
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 7/0048 between the MEMS die and the substrate
• CPC Class Codes: B81C 1/0023 Packaging together an electronic processing unit die and a micromechanical structure die MEMS packages B81B7/0032; MEMS packaging processes B81C1/00261
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: G01C 19/5769 Manufacturing; Mounting; Housings
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2225/06506 Wire or wire-like electrical connections between devices
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H10N 30/302 : Sensors

Abstract

An inertial force sensor that can suppress fluctuation of detection sensitivity even if an external stress is applied to the inertial force sensor. Angular velocity sensor (1), that is, an inertial force sensor includes ceramic substrate (6), lower lid (4) adhering to ceramic substrate (6) with adhesives (11a and 11b) (first adhesives), and sensor element (2) adhering to lower lid (4) with adhesives (10a and 10b) (second adhesives). The elastic moduli of adhesives (11a and 11b) are smaller than those of adhesives (10a and 10b).

Claims

1. An angular velocity sensor comprising:

a first substrate having a lower surface on which an output terminal is provided and an upper surface on which an electrode is provided;

a second substrate disposed on the first substrate, having a circuit carrying out at least one of a signal process selected from a synchronous detection process, a filter process or a correction process, outputting a signal to the output terminal;

a third substrate disposed on the second substrate;

a fourth substrate disposed on the third substrate, having a frame part, a beam part connected to the frame part, a weight part connected to the beam part, an electrode pad disposed on the frame part, and a drive part to cause a vibration in the weight part, the electrode pad electrically connected to the circuit;

a bonding wire electrically connecting the electrode pad to the electrode on the upper surface of the first substrate;

a first connection layer disposed between the second substrate and the third substrate, and connecting the second substrate and the third substrate, comprising a silicon material; and

a second connection layer disposed between the third substrate and the fourth substrate, and connecting the third substrate and the fourth substrate;

wherein the first substrate, the second substrate, the third substrate, and the fourth substrate are stacked in this order, and

wherein an elastic modulus of the first connection layer is smaller than an elastic modulus of the second connection layer.

2. The angular velocity sensor of claim 1, wherein the electrode pad is disposed on an upper surface of the fourth substrate.

3. The angular velocity sensor of claim 1,

wherein the weight part includes a first weight part, a second weight part, a third weight part and a fourth weight part, and

wherein the third substrate is provided with through-holes at positions corresponding to the first weight part, the second weight part, the third weight part and the fourth weight part.

4. The angular velocity sensor of claim 1, wherein the second connection layer is not provided between the weight part and the third substrate, and the third substrate is recessed relative to the weight part at a portion where the second connection layer is not provided.

5. The angular velocity sensor of claim 1, wherein

the weight part includes a first weight part, a second weight part, a third weight part and a fourth weight part;

the beam part includes a first beam part, a second beam part, a third beam part and a fourth beam part connected to respective one of the first weight part, the second weight part, the third weight part and the fourth weight part;

the fourth substrate includes a center beam part connected to the first beam part, the second beam part, the third beam part and the fourth beam part, and

a third layer is disposed between the center beam part and the third substrate.

6. The angular velocity sensor of claim 5, wherein the third layer is disposed below a center of the fourth substrate.

7. The angular velocity sensor of claim 1, wherein the electrode pad is disposed at an outer peripheral part of the fourth substrate.

8. The angular velocity sensor of claim 7, wherein the second connection layer is disposed under the outer peripheral part of the fourth substrate.

9. The angular velocity sensor of claim 1, wherein the first substrate includes a cavity to accommodate the second substrate, the third substrate and the fourth substrate.

10. The angular velocity sensor of claim 1, wherein the first substrate comprises a ceramic material.

11. The angular velocity sensor of claim 1, wherein each of the third substrate and the fourth substrate comprise a silicon material.

12. The angular velocity sensor of claim 1, wherein the fourth substrate includes a detector part to detect a Coriolis force caused by an angular velocity applied to the angular velocity sensor.