Liquid metal MEMS switch

Patent metadata

Field	Value
Publication number	US-12046430-B2
Application number	US-202318213296-A
Country	US
Kind code	B2
Filing date	Jun 23, 2023
Priority date	Dec 27, 2018
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

A switch that includes a droplet capable of spreading between two conductors to allow them to be coupled when a voltage is applied. The droplet can be enclosed by a cap that is bonded to a wafer that the droplet is placed upon, and include metallic properties. The cap can create a cavity that may be filled by a fluid, gas, or vapor. The cavity can have multiple conductors that extend partially or fully through it. The droplet can couple the conductors when specific voltages, or frequencies are applied to them. At the specific voltage and frequency, the droplet can spread, allowing at least two conductors to be coupled.

First claim

What is claimed is:

1. A method of fabricating a switch, comprising:
depositing an oxide layer on a substrate;
patterning a biasing structure on the oxide layer;
growing the oxide layer through the biasing structure;
planarizing the oxide layer to form a planarized surface;
depositing a metal layer on the planarized surface;
selectively depositing a dielectric layer on the metal layer to form a wafer;
dispensing a droplet on the wafer;
providing a dielectric cap; and
bonding the dielectric cap to the wafer to enclose the droplet.

2. The method of claim 1 , further comprising applying a voltage to force the droplet to a first side of the metal layer.

3. The method of claim 1 , wherein growing the oxide layer includes depositing additional oxide layer materials.

4. The method of claim 1 , wherein the metal layer is comprised of a metallic material.

5. The method of claim 1 , wherein providing the dielectric cap includes printing the dielectric cap on a frame.

6. The method of claim 1 , wherein providing the dielectric cap includes filling the dielectric cap with a fluid.

7. The method of claim 1 , wherein the droplet is configurable to flow as a liquid in response to having a voltage applied to the droplet.

8. The method of claim 7 , wherein the droplet is configurable to respond to particular voltages.

9. The method of claim 7 , wherein the droplet is configurable to respond to particular frequencies.

10. The method of claim 7 , wherein the droplet is configurable to return to an original state in response to having the voltage removed from the droplet.

11. The method of claim 1 , wherein the biasing structure is a conductive material.

12. The method of claim 1 , wherein the oxide layer is grown through a patterned biasing structure from the substrate.

13. The method of claim 2 , wherein the droplet is forced to the first side by an attractive force.

14. The method of claim 2 , wherein the droplet is forced to the first side by a repulsive force.

15. The method of claim 1 , wherein the biasing structure has a high resistivity.

Assignees

• Texas Instruments Inc

Inventors

• Fruehling Adam Joseph
• Parekh Dishit Paresh
• Revier Daniel Lee
• Cook Benjamin Stassen

Classifications

• H01H1/0036

  Switches making use of microelectromechanical systems [MEMS] (for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009) · CPC title

• H01H11/00

  Apparatus or processes specially adapted for the manufacture of electric switches (processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88) · CPC title

• H01H2029/008

  using micromechanics, e.g. micromechanical liquid contact switches or [LIMMS] · CPC title

• H01H29/28 Primary

  with level of surface of contact liquid displaced by fluid pressure · CPC title

• H01H29/00 Primary

  Switches having at least one liquid contact (solid contacts wetted or soaked with mercury H01H1/08) · CPC title