Apparatus and method for anchoring micromachined structures

• US 20050262942A1
• Filed: 05/16/2005
• Published: 12/01/2005
• Est. Priority Date: 07/19/2002
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Samuels, Howard R., Judy, Michael W.
• Granted Patent: US 7,134,340 B2
• Time in Patent Office: Days
• US Class Current: 73/514.10
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2203/051 Translation according to an axis parallel to the substrate
• CPC Class Codes: B81B 2203/055 Translation in a plane parallel to the substrate, i.e. enabling movement along any direction in the plane
• CPC Class Codes: B81B 3/0072 For controlling internal stress or strain in moving or flexible elements, e.g. stress compensating layers
• 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 29/49007 Indicating transducer
• CPC Class Codes: Y10T 74/1293 Flexure hinges for gyros

Abstract

Micromachined structures, such as fixed drive or sensing fingers of an inertial sensor, are anchored to a substrate using multiple anchors or elongated anchors in order to reduce the bending or twisting of the micromachined structure about the anchor point.

Claims

1. A micromachined apparatus comprising:

a substrate; and

at least one micromachined structure anchored to the substrate, wherein the at least one micromachined structure is subject to bending or twisting about the anchor point, and wherein the at least one micromachined structure is anchored to the substrate using one of an elongated anchor and multiple anchors in order to reduce the bending or twisting of the at least one micromachined structure about the anchor point.

2. A micromachined apparatus according to claim 1, wherein the at least one micromachined structure comprises a fixed finger structure.

3. A micromachined apparatus according to claim 2, wherein the fixed finger structure is interdigitated with a movable finger structure.

4. A micromachined apparatus according to claim 3, wherein the fixed finger structure is operable to sense movement of the movable finger structure.

5. A micromachined apparatus according to claim 3, wherein the fixed finger structure is operable to drive movement of the movable finger structure.

6. A micromachined apparatus according to claim 1, wherein the apparatus is a micromachined inertial sensor.

7. A micromachined apparatus according to claim 6, wherein the apparatus is a micromachined accelerometer.

8. A micromachined apparatus according to claim 6, wherein the apparatus is a micromachined gyroscope.

9. A micromachined apparatus according to claim 6, wherein the inertial sensor includes a movable frame, and wherein the at least one micromachined structure is operable to sense movement of the frame.

10. A method for anchoring a micromachined structure to a substrate, the micromachined structure subject to bending or twisting about an anchor point, the method comprising:

providing a substrate;

providing a micromachined structure; and

anchoring the micromachined structure to the substrate using one of an elongated anchor and multiple anchors in order to reduce the bending or twisting of the micromachined structure about the anchor point.

11. A micromachined apparatus according to claim 10, wherein the at least one micromachined structure comprises a fixed finger structure.

12. A micromachined apparatus according to claim 11, wherein the fixed finger structure is interdigitated with a movable finger structure.

13. A micromachined apparatus according to claim 12, wherein the fixed finger structure is operable to sense movement of the movable finger structure.

14. A micromachined apparatus according to claim 12, wherein the fixed finger structure is operable to drive movement of the movable finger structure.

15. A micromachined apparatus according to claim 10, wherein the apparatus is a micromachined inertial sensor.

16. A micromachined apparatus according to claim 15, wherein the apparatus is a micromachined accelerometer.

17. A micromachined apparatus according to claim 15, wherein the apparatus is a micromachined gyroscope.

18. A micromachined apparatus according to claim 15, wherein the inertial sensor includes a movable frame, and wherein the at least one micromachined structure is operable to sense movement of the frame.