MEMS SENSOR, METHOD OF MANUFACTURING THEREOF, AND ELECTRONIC APPARATUS

• US 20110120221A1
• Filed: 11/17/2010
• Published: 05/26/2011
• Est. Priority Date: 11/25/2009
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yoda, Mitsuhiro
• Application Number:
  US12/948,055
• Publication Number:
  US 20110120221A1
• Time in Patent Office: Days
• US Class Current: 73/514.32
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2203/0136 Comb structures
• CPC Class Codes: B81B 3/0086 Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage
• CPC Class Codes: G01C 19/5755 the devices having a single sensing mass
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/0814 for translational movement of the mass, e.g. shuttle type
• CPC Class Codes: G01P 2015/082 for two degrees of freedom of movement of a single mass
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.

Abstract

A MEMS sensor includes: a fixed portion; an elastically deformable portion; a movable weight portion coupled to the fixed portion via the elastically deformable portion, the movable weight portion including a coupling portion; a plurality of fixed electrode portions arranged in a first direction and protruding in a second direction perpendicular to the first direction; and a plurality of movable electrode portions protruding from the coupling portion in the second direction, provided to respectively face the plurality of fixed electrode portions, and arranged in the first direction, wherein the movable weight portion has an additional weight portion connected to the coupling portion.

Claims

1. A MEMS sensor comprising:

a fixed portion;

an elastically deformable portion;

a movable weight portion coupled to the fixed portion via the elastically deformable portion, the movable weight portion including a coupling portion;

a plurality of fixed electrode portions arranged in a first direction and protruding in a second direction perpendicular to the first direction; and

a plurality of movable electrode portions protruding from the coupling portion in the second direction, provided to respectively face the plurality of fixed electrode portions, and arranged in the first direction, wherein

the movable weight portion comprises an additional weight portion connected to the coupling portion.

2. The MEMS sensor according to claim 1, further comprising a first connection portion connecting the additional weight portion with the coupling portion.

3. The MEMS sensor according to claim 1, further comprising a second connection portion connecting at least one of the plurality of movable electrode portions with the additional weight portion.

4. The MEMS sensor according to claim 1, wherein

a width of the additional weight portion in a longitudinal section in the second direction is greater than a width of the coupling portion in the longitudinal section in the second direction.

5. The MEMS sensor according to claim 1, wherein

the movable electrode portion protrudes from both edges of the coupling portion in the second direction, and

a width of the additional weight portion in a longitudinal section in the second direction is smaller than a length in the second direction from an end of the movable electrode portion protruding from one edge of the coupling portion to an end of the movable electrode portion protruding from the other edge of the coupling portion.

6. The MEMS sensor according to claim 1, wherein

a height of the additional weight portion in a longitudinal section in the second direction is greater than a height of the coupling portion in the longitudinal section in the second direction.

7. The MEMS sensor according to claim 1, wherein

the elastically deformable portion couples the fixed portion with the additional weight portion.

8. The MEMS sensor according to claim 1, wherein

when a direction perpendicular to the first direction and the second direction is defined as a third direction, one of the fixed electrode portion and the movable electrode portion is longer in the third direction than the other.

9. The MEMS sensor according to claim 8, wherein

one of the plurality of fixed electrode portions and the plurality of movable electrode portions each comprise an upper margin portion and a lower margin portion respectively protruding upward and downward beyond the other in the third direction, and partially comprise a region where a protruding amount of the lower margin portion is greater than a protruding amount of the upper margin portion.

10. An electronic apparatus comprising the MEMS sensor according to claim 1.

11. A method of manufacturing a MEMS sensor, comprising:

preparing a supporting substrate having an intermediate layer and a functional layer stacked on the intermediate layer;

applying etching to the supporting substrate to form a first hollow portion from a surface of the functional layer to a surface of the intermediate layer, to thereby define a fixed portion, a movable weight portion, an elastically deformable portion coupling the fixed portion with the movable weight portion, a fixed electrode portion, and a movable electrode portion facing the fixed electrode portion and protruding from the movable weight portion;

etching the supporting substrate from a surface of the supporting substrate opposite to the surface where the intermediate layer and the functional layer are formed to form a second hollow portion at a position overlapping the first hollow portion as viewed in plan, to thereby define an additional weight portion; and

etching the intermediate layer via at least one of the first hollow portion and the second hollow portion, to thereby form a first connection portion connecting the movable weight portion with the additional weight portion.