MICRO-ELECTRO-MECHANICAL DEVICE HAVING LOW THERMAL EXPANSION DIFFERENCE

• US 20140144234A1
• Filed: 10/23/2013
• Published: 05/29/2014
• Est. Priority Date: 11/26/2012
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Tsai, Ming-Han, Liu, Yu-Chia, Fang, Wei-Leun
• Granted Patent: US 9,944,513 B2
• Time in Patent Office: Days
• US Class Current: 73/514.32
• CPC Class Codes: B81B 3/0081 Thermal properties

Abstract

The invention provides a micro-electro-mechanical device which is manufactured by a CMOS manufacturing process. The micro-electro-mechanical device includes a stationary unit, a movable unit, and a connecting member. The stationary unit includes a first capacitive sensing region and a fixed structure region. The movable unit includes a second capacitive sensing region and a proof mass, wherein the first capacitive sensing region and the second capacitive sensing region form a capacitor, and the proof mass region consists of a single material. The connecting member is for connecting the movable unit in a way to allow a relative movement of the movable unit with respect to the stationary unit.

Claims

1. A micro-electro-mechanical device having low thermal expansion difference, comprising:

a stationary unit, including a first capacitive sensing region and a fixed structure region;

a movable unit, including a second capacitive sensing region and a proof mass, wherein the first capacitive sensing region and the second capacitive sensing region form a capacitor, and the proof mass consists of a single material; and

a connecting member for connecting the movable unit while allowing a relative movement of the movable unit with respect to the stationary unit.

2. The micro-electro-mechanical device having low thermal expansion difference of claim 1, wherein the proof mass includes a plurality of through holes.

3. The micro-electro-mechanical device having low thermal expansion difference of claim 1, wherein the single material of the proof mass is an insulating material.

4. The micro-electro-mechanical device having low thermal expansion difference of claim 3, wherein the single material consists of silicon dioxide.

5. The micro-electro-mechanical device having low thermal expansion difference of claim 1, wherein the fixed structure region consists of a single material.

6. The micro-electro-mechanical device having low thermal expansion difference of claim 1, wherein from top view, more than 50% of the total area of the movable unit is formed by the single material from top surface through bottom surface.

9. The micro-electro-mechanical device having low thermal expansion difference of claim 6, wherein the single material is an insulating material.

11. The micro-electro-mechanical device having low thermal expansion difference of claim 6, wherein the fixed structure region consists of a single material.

12. The micro-electro-mechanical device having low thermal expansion difference of claim 11, wherein from top view, more than 50% of the total area of the stationary unit is formed by the single material from top surface through bottom surface.

7. A micro-electro-mechanical device having low thermal expansion difference, wherein the micro-electro-mechanical device comprising:

a stationary unit, including a first capacitive sensing region and a fixed structure region;

a movable unit, including a second capacitive sensing region, wherein the first capacitive sensing region and the second capacitive sensing region form a capacitor, and from top view, more than 50% of the total area of the movable unit is formed by a single material from top surface through bottom surface; and

a connecting member, connecting the movable unit while allowing a relative movement of the movable unit with respect to the stationary unit.

8. The micro-electro-mechanical device having low thermal expansion difference of claim 7, wherein the movable unit includes a plurality of through holes, and the total area of the movable unit includes areas of the through holes.

10. The micro-electro-mechanical device having low thermal expansion difference of claim 8, wherein the single material consists of silicon dioxide.