Use of micro-structured plate for controlling capacitance of mechanical capacitor switches

Patent metadata

Field	Value
Publication number	US-9641174-B2
Application number	US-201213444753-A
Country	US
Kind code	B2
Filing date	Apr 11, 2012
Priority date	Apr 11, 2011
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

Micro capacitive switches and methods of manufacturing micro capacitive switches at variable nominal capacitance value using micro-structures on the contact plates of the same dimension. In a preferred embodiment, a separately manufactured contact plate can be mounted to a movable magnet in order to be actuated to “on” and “off” state of the capacitive switch. Depending on the contact plate's surface condition, variable contact capacitance at “on” state can be precisely specified by geometrical properties of the micro-structures on the surface, such as the density, size and depth.

First claim

What is claimed is:

1. A capacitance switch comprising
a first plate including a magnet,
a second plate, and
a plurality of micro-posts extending from the first plate and having uniform dimensions,
the plurality of micro-posts having a dielectric coating deposited thereon,
wherein during an “off” state the plurality of micro-posts are in spaced relation with the second plate, and
wherein radio frequency power is transmitted between the first and second plates through the plurality of micro-posts when in an “on state”, and wherein during the “on” state the plurality of micro-posts contact the second plate creating a homogeneous capacitive contact with the second plate across the plurality of micro-posts and capacitively coupling the first plate with the second plate,
wherein a capacitive value of the homogeneous capacitive contact is a function of the number of individual micro-posts in contact with the second plate.

2. The capacitance switch of claim 1 wherein the dielectric is silicon nitride.

3. The capacitance switch of claim 1 wherein the plurality of micro-posts have a rectangular shape.

4. The capacitance switch of claim 1 wherein the plurality of micro-posts have a circular shape.

5. The capacitance switch of claim 1 wherein the plurality of micro-posts have an octagonal shape.

6. The capacitance switch of claim 1 wherein the capacitive value of the homogeneous capacitive contact is a function of a contact area between the plurality of micro-posts and the second plate.

7. The capacitance switch of claim 1 wherein the capacitive value of the homogeneous capacitive contact is a function of the height of a micro-post of the plurality of micro-posts.

8. A capacitance switch comprising
a first plate including a magnet,
a second plate, and
a plurality of micro-posts extending from the first plate and having uniform dimensions, the plurality of micro-posts having a dielectric coating deposited thereon, wherein during an “off” state the plurality of micro-posts are in spaced relation with the second plate, and wherein radio frequency power is transmitted between the first and second plates through the plurality of micro-posts when in an “on state”, and wherein during the and during an “on” state the plurality of micro-posts contact the second plate creating a homogeneous capacitive contact with the second plate across the plurality of micro-posts and capacitively coupling the first plate with the second plate, wherein a capacitive value of the homogeneous capacitive contact is a function of a periodic pattern of the plurality of micro-posts.

9. A micro-post capacitance switch comprising
a top plate including a magnet,
a plurality of micro-posts coupled to the top plate and having uniform dimensions, the plurality of micro-posts having a dielectric coating deposited thereon, and
a pair of parallel bottom plates, the bottom plates being laterally spaced from one another,
wherein radio frequency power is transmitted between the top and bottom plates through the plurality of micro-posts when in an “on” state, wherein the plurality of micro-posts capacitively and homogeneously couple the top and bottom plates in the “on” state, wherein during an “off” state the plurality of micro-posts are in spaced relation with the bottom plates.

10. The micro-post circuit of claim 9 wherein the dielectric is silicon nitride.

11. The micro-post circuit of claim 9 wherein the capacitance of the homogeneous capacitive coupling has a value that is a function of the number of individual micro-posts in contact with the bottom plates.

12. The micro-post circuit of claim 9 wherein the plurality of micro-posts have a rectangular shape.

13. The micro-post circuit of claim 9 wherein the plurality of micro-posts have a circular shape.

14. The micro-post circuit of claim 9 wherein the plurality of micro-posts have an octagonal shape.

15. The micro-post circuit of claim 9 wherein the capacitance of the homogeneous capacitive coupling has a value that is a function of a contact area between the plurality of micro-posts and the second plate.

16. The micro-post circuit of claim 9 wherein the capacitance of the capacitive coupling has a value that is a function of the height of a micro-post of the plurality of micro-posts.

17. A micro-post capacitance switch comprising
a top plate including a magnet,
a plurality of micro-posts coupled to the top plate and having uniform dimensions, the plurality of micro-posts having a dielectric coating deposited thereon, and
a pair of parallel bottom plates, the bottom plates being laterally spaced from one another,
wherein radio frequency power is transmitted between the top and bottom plates through the plurality of micro-posts when in an “on” state, wherein the plurality of micro-posts capacitively and homogeneously couple the top and bottom plates in the “on” state, wherein during an “off” state the plurality of micro-posts are in spaced relation with the bottom plates, and wherein the capacitance of the capacitive coupling has a value that is a function of a periodic pattern of the plurality of micro-posts.

Assignees

• Bachman Mark
• Li Guann-Pyng
• Zhang Yang
• Chang Ruisheng
• Wang Minfeng
• Kim Sungjun
• Univ California

Inventors

• Bachman Mark
• Li Guann-Pyng
• Zhang Yang
• Chang Ruisheng
• Wang Minfeng
• Kim Sungjun

Classifications

• H03K17/975 Primary

  using a capacitive movable element · CPC title