Physical quantity sensor, electronic device, and mobile body

• US 9,857,390 B2
• Filed: 08/06/2015
• Issued: 01/02/2018
• Est. Priority Date: 08/27/2014
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Takizawa, Teruo
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US14/819,756
• Publication Number:
  US 20160061853A1
• Time in Patent Office: 880 Days
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81B 7/02 containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] B81B7/04 takes precedence
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: B81C 2203/0145 Hermetically sealing an opening in the lid
• CPC Class Codes: B81C 2203/031 Anodic bondings
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: G01C 19/5783 Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
• CPC Class Codes: G01D 11/245 Housings for sensors
• CPC Class Codes: G01P 1/02 Housings
• CPC Class Codes: G01P 1/023 for acceleration measuring devices

Abstract

A physical quantity sensor has a package, which is provided with a substrate and a lid and has an internal space inside, and a functional element which is accommodated in the internal space, the lid is formed on a partition wall section which is provided on the periphery of the internal space in planar view and has a communication hole which causes a lower surface at the substrate side to communicate with an upper surface at the opposite side to the substrate, and the communication hole communicates with the internal space via a groove which is formed in the substrate.

Claims

1. A physical quantity sensor comprising:

a substrate having a first concavity and a substrate ledge, the substrate ledge being provided at a periphery of the substrate;

a lid having a second concavity facing the first concavity, the lid having a lid ledge at a periphery of the lid, the lid ledge being fixed to the substrate ledge;

a cavity which is from configured by the first concavity and the second concavity;

a functional element which is accommodated in the cavity;

a communication through hole which is formed in the lid ledge, the communication through hole being spaced apart from the first and second concavities in a plan view; and

a groove which is formed in the substrate ledge and communicates with the first concavity, the groove extending along a top substrate surface of the substrate ledge from the communication through hole to an edge of the first concavity,

wherein the communication through hole spatially communicates with the cavity via the groove.

2. The physical quantity sensor according to claim 1,

wherein a sealing material is disposed inside the communication through hole so that the cavity is sealed from outside atmosphere.

3. The physical quantity sensor according to claim 1,

wherein the lid ledge has a lid ledge top surface and a lid ledge bottom surface, the lid ledge top surface is closer to a bottom of the second concavity than the lid ledge bottom surface, and

an inner surface of the communication through hole inclines from the lid ledge top surface toward the lid ledge bottom surface with respect to a normal line of the lid ledge bottom surface.

4. The physical quantity sensor according to claim 1,

wherein an overlapping substrate ledge area of the substrate ledge overlaps the second concavity in the plan view, and

the groove is formed in an area located outside of the overlapping substrate ledge area in the plan view.

5. The physical quantity sensor according to claim 4,

wherein the groove is formed in the overlapping substrate ledge area.

6. The physical quantity sensor according to claim 4,

wherein the groove is open at the lid ledge top surface.

7. The physical quantity sensor according to claim 4,

wherein a depth of the groove is shallower than a depth of the first concavity.

8. The physical quantity sensor according to claim 1,

wherein the lid ledge has a lid ledge top surface and a lid ledge bottom surface, the lid ledge top surface is closer to a bottom of the second concavity than the lid ledge bottom surface, and

a width of the groove is wider than an opening of the communication through hole located on the lid ledge bottom surface.

9. The physical quantity sensor according to claim 1,

wherein the groove includes one of a bent section and a curved section between the communication through hole and the cavity in the plan view.

10. The physical quantity sensor according to claim 1,

wherein a position in the groove spaced apart from an edge of the groove is connected to the communication through hole.

11. The physical quantity sensor according to claim 1,

wherein the groove is a liquid reservoir.

14. An electronic device comprising:

the physical quantity sensor according to claim 1; and

a display that displays an image,

wherein the physical quantity sensor is configured to detect a physical quantity of the electronic device.

15. An electronic device comprising:

the physical quantity sensor according to claim 2; and

a display that displays an image,

wherein the physical quantity sensor is configured to detect a physical quantity of the electronic device.

16. An electronic device comprising:

the physical quantity sensor according to claim 3; and

a display that displays an image,

wherein the physical quantity sensor is configured to detect a physical quantity of the electronic device.

17. An electronic device comprising:

the physical quantity sensor according to claim 4; and

a display that displays an image,

wherein the physical quantity sensor is configured to detect a physical quantity of the electronic device.

18. An electronic device comprising:

the physical quantity sensor according to claim 5; and

a display that displays an image,

wherein the physical quantity sensor is configured to detect a physical quantity of the electronic device.

19. An electronic device comprising:

the physical quantity sensor according to claim 6; and

a display that displays an image,

wherein the physical quantity sensor is configured to detect a physical quantity of the electronic device.

20. A mobile body comprising:

the physical quantity sensor according to claim 1; and

a movable housing that accommodates the physical quantity sensor,

wherein the physical quantity sensor is configured to detect a physical quantity of the mobile body.

12. A physical quantity sensor comprising:

a substrate having a first concavity, a second concavity, a substrate center ledge, and a substrate peripheral ledge, the substrate center ledge being provided between the first and second concavities in a plan view, the substrate peripheral ledge being provided at a periphery of the substrate;

a lid having a third concavity facing the first concavity, the lid having a fourth concavity facing the second concavity, the lid having a lid center ledge provided between the third and fourth concavities in the plan view, the lid having a lid peripheral ledge at a periphery of the lid, the lid peripheral ledge being fixed to the substrate peripheral ledge;

a first cavity which is configured by the first concavity and the third concavity;

a second cavity which is configured by the second concavity and the fourth concavity;

a first functional element which is accommodated in the first cavity;

a second functional element which is accommodated in the second cavity;

a first communication through hole which is formed in the lid center ledge, the first communication through hole being spaced apart from the first, second, third, and fourth concavities in the plan view;

a second communication through hole which is formed next to the first communication through hole in the lid center ledge, the second communication through hole being spaced apart from the first, second, third, and fourth concavities in the plan view;

a first groove which is formed in the substrate center ledge and communicates with the first concavity, the first groove extending along a top substrate surface of the substrate center ledge from the first communication through hole to an edge of the first concavity; and

a second groove which is formed in the substrate center ledge and communicates with the second concavity, the second groove extending along the top substrate surface of the substrate center ledge from the second communication through hole to an edge of the second concavity,

wherein the lid center ledge is fixed to the substrate center ledge so as to become a partition wall between the first and second cavities, and

the first and second communication through holes spatially communicate with the first and second cavities via the first and second grooves, respectively.

13. The physical quantity sensor according to claim 12,

wherein the first functional element is an acceleration detection element, and

the second functional element is an angular velocity detection element.