Sensor having particle barrier

• US 10,267,822 B2
• Filed: 01/31/2013
• Issued: 04/23/2019
• Est. Priority Date: 01/31/2013
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Wu, Jennifer, Alley, Rodney L., Walmsley, Robert G., Milligan, Donald J.
• Primary Examiner(s): Raevis, Robert R
• Application Number:
  US14/763,511
• Publication Number:
  US 20150355223A1
• Time in Patent Office: 2,273 Days
• Field of Search: 7351401-51438
• CPC Class Codes: B81B 2201/0221 Variable capacitors
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 7/0029 Protection against environmental influences not provided for in groups B81B7/0012 - B81B7/0025
• CPC Class Codes: G01C 19/5769 Manufacturing; Mounting; Housings
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

A sensor having a particle barrier is described. In an example, a sensor includes: first and second electrode sets respectively disposed upon a planar support surface and a proof mass that is compliantly displaceable along a first axis substantially parallel to the planar support surface; and a first barrier disposed on the planar support around the first electrode set having a height less than a gap between the planar support and the proof mass to mitigate particle migration into the first or second electrode set.

Claims

1. A sensor, comprising:

first and second electrode sets respectively disposed upon a planar support surface of a planar support and a proof mass that is compliantly displaceable along a first axis substantially parallel to the planar support surface; and

a first barrier disposed on the planar support surface around the first electrode set having a height less than a gap between the planar support and the proof mass to mitigate particle migration into the first or second electrode sets, wherein the first barrier comprises

a first elongated segment set disposed on the planar support surrounding the first electrode set; and

a second elongated segment set disposed on the planar support and spaced apart from and surrounding the first elongated segment set.

2. The sensor of claim 1, further comprising:

a trench formed in the planar support around the first barrier.

3. The sensor of claim 1, further comprising:

a second barrier disposed on the proof mass outside of the second electrode set having a height less than the gap between the planar support and the proof mass.

4. The sensor of claim 3, further comprising:

a trench formed in the proof mass around the second barrier.

5. The sensor of claim 1, wherein at least one of the first or second elongated segment set includes at least one break between segments.

6. The sensor of claim 1, wherein the first barrier surrounds a plurality of sides of the first electrode set, the first electrode set comprising electrodes.

7. The sensor of claim 6, wherein the first barrier has a plurality of segments arranged along respective sides of the plurality of sides of the first electrode set.

8. The sensor of claim 7, wherein the plurality of segments of the first barrier extend continuously completely around the first electrode set.

9. The sensor of claim 7, wherein breaks are provided between the plurality of segments of the first barrier.

10. A method of making a sensor, comprising:

forming a substrate having a first electrode set disposed thereon, the first electrode set comprising a plurality of electrodes;

forming a proof mass having a second electrode set, the second electrode set comprising a plurality of electrodes, the proof mass being moveable along a first axis relative to the substrate; and

forming a first barrier on the substrate that surrounds the first electrode set, the first barrier having a height less than a gap between the substrate and the proof mass to mitigate particle migration into the first or second electrode sets, wherein the first barrier comprises;

a first elongated segment set disposed on the substrate surrounding the first electrode set; and

a second elongated segment set disposed on the substrate spaced apart from and surrounding the first elongated segment set.

11. The method of claim 10, further comprising:

forming at least one trench in the substrate around the first barrier.

12. The method of claim 10, further comprising:

forming a second barrier on the proof mass outside of the second electrode set having a height less than the gap between the substrate and the proof mass.

13. The method of claim 12, further comprising:

forming at least one trench in the proof mass around the second barrier.

14. The method of claim 10, wherein at least one of the first elongated segment set or the second elongated segment set includes a break between segments.

15. The method of claim 10, wherein forming the first barrier comprises forming the first barrier that surrounds a plurality of sides of the first electrode set.

16. The method of claim 15, wherein forming the first barrier comprises forming the first barrier that includes a plurality of segments that extend along respective sides of the plurality of sides of the first electrode set.

17. A sensor comprising:

a substrate;

a proof mass that is moveable along an axis relative to a surface of the substrate;

first and second electrode sets respectively disposed upon the substrate and the proof mass, the first electrode set comprising a plurality of electrodes, and the second electrode set comprising a plurality of electrodes;

a barrier disposed on the surface of the substrate and surrounding a plurality of sides of the first electrode set, the barrier having a height less than a gap between the substrate and the proof mass to mitigate particle migration into the first electrode set or second electrode set; and

a trench formed in the substrate around the barrier, the trench extending into the substrate below the surface of the substrate.

18. The sensor of claim 17, wherein the barrier comprises a plurality of segments arranged along respective sides of the plurality of sides of the first electrode set.