MULTI-AXIS MEMS RATE SENSOR DEVICE

• US 20140311247A1
• Filed: 01/24/2014
• Published: 10/23/2014
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: mCube, Inc.
• Original Assignee: mCube, Inc.
• Inventors: ZHANG, WENHUA, Yoneoka, Shingo, Sridharamurthy, Sudheer, Lee, Terrence
• Granted Patent: US 10,036,635 B2
• Time in Patent Office: Days
• US Class Current: 73/652
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion

Abstract

A MEMS rate sensor device. In an embodiment, the sensor device includes a MEMS rate sensor configured overlying a CMOS substrate. The MEMS rate sensor can include a driver set, with four driver elements, and a sensor set, with six sensing elements, configured for 3-axis rotational sensing. This sensor architecture allows low damping in driving masses and high damping in sensing masses, which is ideal for a MEMS rate sensor design. Low driver damping is beneficial to MEMS rate power consumption and performance, with low driving electrical potential to achieve high oscillation amplitude.

Claims

1. An MEMS rate sensor device, the device comprising:

a driver set, the driver set including a plurality of driving elements and being configured for 3-axis rotational sensing, and

a sensor set, the sensor set including a plurality of sensing elements and a plurality of sensing masses, wherein the sensor set is electrically coupled to the driver set.

2. The device of claim 1 further comprising a single crystal silicon substrate, wherein the driver set and the sensor set are formed overlying the substrate.

3. The device of claim 1 wherein the plurality of driving elements are mechanically coupled to each other

4. The device of claim 3 wherein the plurality of driving elements includes a first x-driving element, a second x-driving element, a first y-driving element, and a second y-driving element.

5. The device of claim 3 wherein the plurality of driving elements includes a first x-driving element and a second y-driving element.

6. The device of claim 1 wherein the plurality of sensing masses comprise a first x-sensing mass, a second x-sensing mass, a first y-sensing mass, and a second y-sensing mass.

7. The device of claim 6 wherein the first and second x-sensing masses are mechanically coupled to each other and the first and second y-sensing masses are mechanically coupled to each other.

8. The device of claim 6 further comprising a first z-sensing mass and a second z-sensing mass, each of the z-sensing masses coupled to a first z-sensing element and a second z-sensing element.

9. An MEMS rate sensor device, the device comprising:

a substrate member having a surface region;

a CMOS IC layer overlying the surface region, the CMOS IC layer having a CMOS surface region; and

a MEMS rate sensor overlying the CMOS surface region, the MEMS rate sensor including

a driver set, the driver set including

a first driving element,

a second driving element,

a third driving element, and

a fourth driving element,

wherein all of the driving elements are mechanically coupled to each other, the driver set being configured for 3-axis rotational sensing, and

a sensor set, the sensor set including

a first sensing element,

a second sensing element,

a first sensing mass mechanically coupled to the first and second sensing element,

a third sensing element,

a fourth sensing element,

a second sensing mass mechanically coupled to the third and fourth

sensing element,

a fifth sensing element,

a sixth sensing element, and

a third sensing mass mechanically coupled to the fifth and sixth sensing element,

wherein the sensor set is electrically coupled to the driver set.

10. The device of claim 9 wherein the substrate member comprises a single crystal silicon material.

11. A MEMS device comprising:

a layer of silicon crystal material comprising;

an x-axis rotational proof mass portion;

an x-axis drive portion;

an x-axis rotational physical data portion;

a y-axis rotational proof mass portion;

a y-axis drive portion;

a y-axis rotational physical data portion;

a z-axis rotational proof mass portion, wherein the z-axis rotational proof mass portion includes the x-axis rotational proof mass portion and the y-axis rotational proof mass portion; and

a z-axis rotational physical data portion.

12. The device of claim 11 further comprising:

a substrate coupled to the layer of silicon crystal material comprising;

an x-axis rotation electronic feedback portion configured to convert physical data from the x-axis rotation physical data portion into x-axis rotation electrical data;

a y-axis rotation electronic feedback portion configured to convert physical data from the y-axis rotation physical data portion into y-axis rotation electrical data; and

a z-axis rotation electronic feedback portion configured to convert physical data from the z-axis rotation physical data portion to z-axis rotation electrical data.

13. The device of claim 12 wherein the x-axis rotation electrical data comprises an x-axis rotation capacitance value.

14. The device of claim 12 wherein the x-axis rotation physical data portion comprises a first capacitor plate.

15. The device of claim 14

wherein the x-axis rotation electronic data portion comprises a second capacitor place;

and

wherein the physical data comprises movement of the first capacitor plate relative to the second capacitor plate.

16. The device of claim 11 wherein the x-axis rotation proof mass portion comprises a first proof mass and a second proof mass;

wherein the x-axis drive portion comprises a first driver and a second driver; and

wherein the first driver drives the first proof mass;

wherein the second driver drives the second proof mass; and

wherein the first driver and second driver have a phase relation selected from a group consisting of;

in-phase, 180 degrees out-of-phase.

17. The device of claim 11 wherein the y-axis rotation proof mass portion comprises a first proof mass and a second proof mass;

wherein the y-axis drive portion comprises a first driver and a second driver; and

wherein the first driver drives the first proof mass;

wherein the second driver drives the second proof mass; and

wherein the first driver and second driver have a phase relation selected from a group consisting of;

in-phase, 180 degrees out-of-phase.

18. The device of claim 11 wherein the x-axis rotation proof mass portion comprises a first proof mass and a second proof mass;

wherein the x-axis drive portion comprises a driver; and

wherein the driver drives the first and second proof mass;

wherein driver is configured to drive the first and second proof masses with a phase relation selected from a group consisting of;

in-phase, 180 degrees out-of-phase.

19. The device of claim 11 wherein the y-axis rotation proof mass portion comprises a first proof mass and a second proof mass;

wherein the y-axis drive portion comprises a driver; and

wherein the driver drives the first and second proof mass;

wherein driver is configured to drive the first and second proof masses with a phase relation selected from a group consisting of;

in-phase, 180 degrees out-of-phase.

20. The device of claim 11 wherein the single layer of silicon crystal material comprises single crystal silicon.