Micromechanical sensor

• US 20140352433A1
• Filed: 08/20/2014
• Published: 12/04/2014
• Est. Priority Date: 04/28/2009
• Status: Active Grant

• Current Assignee: Hanking Electronics Hongkong Company Limited
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Hammer, Hanno
• Granted Patent: US 9,778,038 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0888 for indicating angular acceleration

Abstract

A micromechanical sensor comprising a substrate (5) and at least one mass (6) which is situated on the substrate (5) and which moves relative to the substrate (5) is used to detect motions of the sensor due to an acceleration force and/or Coriolis force which occur(s). The mass (6) and the substrate (5) and/or two masses (5, 7) which move toward one another are connected by at least one bending spring device (6). The bending spring device (6) has a spring bar (9) and a meander (10), provided thereon, having a circle of curvature (K1; K6; K8; K9; K11) whose midpoint (MP1; MP6; MP8; MP9; MP11) and radius of curvature (r1; r6; r8; r9; r11) are inside the meander (10). For reducing stresses that occur, in addition to the radius of curvature (r1; r6; r8; r9; r11) having the inner midpoint (MP1; MP6; MP8; MP9; MP11), the meander (10) has at least one further radius of curvature (r2; r3; r4; r5; r7; r10) having a midpoint (MP2; MP3; MP4; MP5; MP7; MP10) outside the meander (10). The at least one further radius of curvature (r2; r3; r4; r5; r7; r10) is situated between the meander (10) and the spring bar (9).

Claims

1. A gyroscope comprising:

a substrate;

a first mass within a plurality of masses located above the substrate, the first mass radially oscillates from a first location on the substrate; and

a first bending spring within a plurality of bending springs, the first bending spring coupled to the first mass to cause radial oscillation of the first mass, the first bending spring comprising;

a first spring bar coupled to the first mass;

a first meander extending essentially at a right angle to the first spring bar, the first meander extending along a first axis in a first direct; and

a second meander extending essentially at a right angle to the first spring bar, the second meander extending along the first axis in a second direction.

2. The gyroscope of claim 1 wherein a first recess couples the first bending spring to a fixed location in the gyroscope.

3. The gyroscope of claim 1 wherein the first meander has a squared end.

4. The gyroscope of claim 1 wherein the first meander has a rounded end.

5. The gyroscope of claim 1 wherein the first meander has a circle of curvature that has an inner midpoint and a radius of curvature inside the first meander.

6. The gyroscope of claim 1 wherein first bending spring has a non-constant radius of curvature.

7. The gyroscope of claim 1 wherein the first meander and the spring bar have a convex curvature.

8. The gyroscope of claim 1 wherein the first meander and the spring bar have an elliptical bend.

9. A gyroscope comprising:

a substrate;

a first mass within a plurality of masses located above the substrate, the first mass radially oscillates from a first location on the substrate along a first axis;

a second mass within the plurality of masses, the second mass radially oscillates from the first location on the substrate along the first axis; and

a first bending spring within a plurality of bending springs, the first bending spring coupled to the first mass to cause radial oscillation of the first mass, the first bending spring comprising;

a first spring bar coupled to the first mass;

a first meander extending essentially at a right angle to the first spring bar, the first meander extending along a first axis; and

a second meander extending essentially at a right angle to the first spring bar, the second meander extending along the first axis;

a second bending spring within a plurality of bending springs, the second bending spring coupled to the second mass to cause radial oscillation of the second mass, the second bending spring comprising;

a second spring bar coupled to the second mass;

a third meander extending essentially at a right angle to the second spring bar, the third meander extending along a second axis; and

a second meander extending essentially at a right angle to the second spring bar, the second meander extending along the second axis.

10. The gyroscope of claim 9 further comprising a central anchor that is the first location from which the first and second masses radially oscillate.

11. The gyroscope of claim 10 wherein the central anchor is rectangular.

12. The gyroscope of claim 11 wherein the central anchor is circular.

13. The gyroscope of claim 9 further comprising:

a third bending spring within a plurality of bending springs, the third bending spring coupled to the first mass to further cause radial oscillation of the first mass, the third bending spring comprising;

a third spring bar coupled to the first mass;

a fifth meander extending essentially at a right angle to the third spring bar, the fifth meander extending along a third axis; and

a sixth meander extending essentially at a right angle to the third spring bar, the sixth meander extending along the third axis;

a fourth bending spring within a plurality of bending springs, the fourth bending spring coupled to the second mass to further cause radial oscillation of the second mass, the fourth bending spring comprising;

a fourth spring bar coupled to the second mass;

a seventh meander extending essentially at a right angle to the fourth spring bar, the seventh meander extending along a fourth axis; and

an eighth meander extending essentially at a right angle to the fourth spring bar, the eighth meander extending along the fourth axis.

14. The gyroscope of claim 9 wherein the first and second masses radially oscillate along an x-axis.

15. The gyroscope of claim 9 wherein the first and second masses radially oscillate along a y-axis.

16. The gyroscope of claim 9 wherein the first, second, third, fourth, fifth, sixth, seventh and eighth meanders have a squared end.

17. The gyroscope of claim 9 wherein the first, second, third, fourth, fifth, sixth, seventh and eighth meanders have a rounded end.

18. The gyroscope of claim 9 wherein the first meander has a circle of curvature that has an inner midpoint and a radius of curvature inside the first meander.

19. The gyroscope of claim 9 wherein first, second, third and fourth bending spring have non-constant radii of curvatures.