Physical quantity sensor and electronic apparatus

• US 9,429,589 B2
• Filed: 02/27/2013
• Issued: 08/30/2016
• Est. Priority Date: 03/02/2012
• Status: Active Grant

• Current Assignee: Crystal Leap Zrt
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Tanaka, Satoru
• Primary Examiner(s): Patel, Harshad R
• Assistant Examiner(s): Hopkins, Brandi N
• Application Number:
  US13/778,568
• Publication Number:
  US 20130228013A1
• Time in Patent Office: 1,280 Days
• US Class Current: 1/1
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0831 the mass being of the paddle type having the pivot axis between the longitudinal ends of the mass, e.g. see-saw configuration
• CPC Class Codes: G01P 2015/0837 the mass being suspended so as to only allow movement perpendicular to the plane of the substrate, i.e. z-axis sensor

Abstract

A physical quantity sensor includes a base section, a movable body having a movable electrode section, pivot sections connected to the movable body, and forming a pivot axis of the movable body, a fixation section fixed to the substrate, and adapted to support the movable body via the pivot sections, and a fixed electrode section disposed on the substrate so as to be opposed to the movable electrode section, and the fixation section is provided with opening sections disposed on a line of the pivot axis.

Claims

1. A physical quantity sensor comprising:

a substrate haying a recess and a periphery surrounding the recess;

a movable body having a movable electrode;

a pivot connected to the movable body, the pivot forming a pivot axis of the movable body;

a fixation section fixed on the periphery of the substrate, the pivot interconnecting the fixation section and the movable body such that the movable body is laterally spaced apart from the fixation section via a gap except at the pivot and is suspended above a bottom surface of the recess;

an opening that is provided in the fixation section directly adjacent to the pivot; and

a fixed electrode disposed on the bottom surface of the recess so as to be opposed to the movable electrode,

wherein the opening intersects the pivot axis,

the movable body, the pivot, the fixation section and the opening are coplanar in a cross sectional view,

the opening is a through hole penetrating entirely through the fixation section and is different from the gap, and

the movable body, the pivot and the fixation section is made from a single continuous member.

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

the substrate is formed of an insulating material, and

the movable body is formed of a semiconductor material.

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

the opening extends in a direction intersecting with the pivot axis in a plan view.

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

the movable body has a mass difference between a first region located at one side with respect to the pivot axis and a second region located at an opposite side with respect to the pivot axis.

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

the fixed electrode includes

a first detection electrode disposed at a position opposed to the first region, and

a second detection electrode disposed at a position opposed to the second region.

6. An electronic apparatus comprising:

a display;

the physical quantity sensor according to claim 1; and

a case that houses the display and the physical quantity sensor.

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

the fixation section includes a connection section,

the pivot is fixed to the fixation section at the connection section,

the connection section is separated from the substrate such that the connection section does not contact the substrate.

8. A physical quantity sensor comprising:

a substrate having a recess and a periphery surrounding the recess;

a movable body having a movable electrode;

a pivot connected to the movable body, the pivot forming a pivot axis of the movable body;

a fixed electrode disposed on a bottom surface of the recess so as to be opposed to the movable electrode;

a center fixation section provided as part of the movable body, the center fixation section fixedly connecting a lower surface of the movable body to the substrate such that the movable body is suspended above the recess except at the center fixation section;

a connection section interconnecting the center fixation section and first and second parts of the pivot; and

first and second body openings formed through the connection section between the center fixation section and the first and second parts of the pivot, the first and second body openings intersecting the pivot axis, wherein

the movable body, the pivot, the center fixation section and the first and second body openings are coplanar in a cross sectional view, and

the first and second body openings are through holes penetrating entirely through the center fixation section.