Multilayered Liquid Capacitive Micro Inclinometer

• US 20140082954A1
• Filed: 09/27/2013
• Published: 03/27/2014
• Est. Priority Date: 09/27/2012
• Status: Active Grant

• Current Assignee: Sagatek Co., Ltd.
• Original Assignee: Sagatek Co., Ltd.
• Inventors: Chen, Jung-Hsiang, Chen, Cheng-Szu, Chen, Bo-Ting
• Granted Patent: US 9,086,276 B2
• Time in Patent Office: Days
• US Class Current: 33/366.19
• CPC Class Codes: G01C 9/20 the indication being based on the inclination of the surface of a liquid relative to its container

Abstract

The present invention relates to a liquid multilayer capacitive micro inclinometer, comprising at least two pairs of differential electrodes, each pair positioned in a same plane; at least one common electrode with a portion positioned in the plane of each pair of differential electrodes. The differential electrodes and the common electrode are provided in a sealed chamber, in which an immersing liquid is filled. The shape of the differential electrodes forms a sector of a circular plane. The inclinometer may further integrate a reading circuit. The present invention also discloses preparation method for the invented inclinometer.

Claims

1. A liquid capacitive micro inclinometer, comprising:

at least two pairs of differential electrodes, each pair having electrodes positioned in the same plane;

at least one common electrode, with a part thereof positioned in said same plane;

a sealed chamber enclosing said differential electrodes and said common electrode; and

immersing liquid filled in said sealed chamber.

2. The liquid capacitive micro inclinometer of claim 1, wherein each of the differential electrode has a shape of a partial circular plane.

3. The liquid capacitive micro inclinometer of claim 2, wherein the differential electrode has a shape of a sector of a circular plane.

4. The liquid capacitive micro inclinometer of claim 1, wherein a pair of the differential electrodes is prepared in the plane where another pair is provided, with one electrode separated from another in a distance.

5. The liquid capacitive micro inclinometer of claim 1, further comprising a reading circuit to generate reading values of capacitance corresponding to each differential electrode.

6. The liquid capacitive micro inclinometer of claim 1, further comprising a lubrication layer on at least a part of the differential electrodes and the common electrode.

7. The liquid capacitive micro inclinometer of claim 1, wherein the common electrode is provided at internal edges of the differential electrodes.

8. The liquid capacitive micro inclinometer of claim 1, wherein the differential electrodes comprise a plurality of notch at their edge and the common electrode comprises a plurality of extruder extended into said plurality of notch.

9. The liquid capacitive micro inclinometer of claim 8, wherein the shape of the differential electrodes is a sector circular plane and the notches extend to over half radius of the circular plane.

10. The liquid capacitive micro inclinometer of claim 8, wherein the immersing liquid is one selected from the group consisted of a conductive liquid and a dielectric liquid.

11. The liquid capacitive micro inclinometer of claim 1, wherein the plural pairs of differential electrodes and the common electrode are formed on one silicon substrate.

12. The liquid capacitive micro inclinometer of claim 5, wherein the plural pairs of differential electrodes and the common electrode are formed on one silicon substrate and the reading circuit is formed on said silicon substrate.

13. The liquid capacitive micro inclinometer of claim 1, wherein the plural pairs of differential electrodes and the common electrode are formed on a dielectric layer provided on a silicon substrate.

14. The liquid capacitive micro inclinometer of claim 1, wherein the shape and area of each pair of the differential electrodes are identical.

15. A method for preparation of liquid capacitive micro inclinometers, comprising the steps of:

preparing a first substrate;

forming on the first substrate a stack of a plurality of metal layers and a plurality of dielectric layers;

said stack comprising a pattern including at least two pairs of differential electrodes and at least one common electrode, wherein shape of the differential electrodes forms part of a circular plane and wherein electrodes belonging to a pair are in similar shape and have substantially the same area;

releasing the at least two differential electrodes and the at least one common electrode;

preparing a second substrate;

forming a material layer on the second substrate;

forming a recess in the material layer;

adding immersing liquid in the recess;

flipping the first substrate on the second substrate, so that the differential electrodes and the common electrode are positioned in a space defined by the recess; and

combining the first substrate and the second substrate.

16. The method according to claim 15, wherein shape of the differential electrodes forms sector of a circular plane.

17. The method according to claim 15, wherein a pair of the differential electrode is prepared in a layer of the stack other than the layer where another pair is prepared.

18. The method according to claim 15, wherein differential electrodes belonging to one pair have a shape identical to that belonging to another pair.

19. The method according to claim 15, wherein the first substrate is a silicon substrate and the second substrate is a glass substrate.

20. The method according to claim 15, wherein the first substrate is a silicon substrate and the second substrate is a plastic substrate.

21. The method according to claim 15, further comprising the steps of providing notches at an edge of the differential electrodes and providing extruders in the common electrode, such that the extruders extend into respectively corresponding notches.

22. The method according to claim 21, wherein shape of the differential electrodes is a sector circular plane and the notches extend to over half the radius of the circular plane.

23. The method according to claim 15, wherein the immersing liquid is one selected from the group consisted of a conductive liquid and a dielectric liquid.

24. The method according to claim 15, wherein the differential electrodes and the common electrode are formed on a material layer provided on the first substrate and wherein the method further comprises a step of forming a material layer on the first substrate after the first substrate is prepared.

25. The method according to claim 24, wherein the material layer includes at least one dielectric layer.

26. The method according to claim 24, wherein the material layer further comprises at least one metal layer and one additional dielectric layer.

27. The method according to claim 15, further comprising a step of forming a reading circuit, when the differential electrodes and the common electrode are formed.

28. The method according to claim 24, further comprising a step of forming a reading circuit, when the differential electrodes and the common electrode are formed.

29. The method according to claim 15, further comprising a step of forming a reading circuit, when the differential electrodes, the common electrode and the material layer are formed.

30. The method according to claim 15, further comprising a step of applying a lubrication layer on least a partial surface of the differential electrodes and the common electrode, after the differential electrodes and the common electrode are released.

31. The method according to claim 15, wherein releasing the differential electrodes and the common electrode comprises a step of etching, to remove parts of the stack other than the parts forming the pattern of the differential electrodes and the common electrode.