Fluid-based switches and methods for producing the same

• US 6,759,611 B1
• Filed: 06/16/2003
• Issued: 07/06/2004
• Est. Priority Date: 06/16/2003
• Status: Expired due to Fees

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Carson, Paul, Wong, Marvin Glenn
• Primary Examiner(s): Friedhofer, Michael A.
• Application Number:
  US10/462,472
• Time in Patent Office: 386 Days
• Field of Search: 200/182, 200/187-189, 200/209-219, 200/233-236, 310/328, 310/331, 310/348, 310/363, 335/4, 335/47, 335/78, 385/19
• US Class Current: 200/182
• CPC Class Codes: H01H 2029/008 using micromechanics, e.g. micromechanical liquid contact switches or [LIMMS]
• CPC Class Codes: H01H 29/28 with level of surface of contact liquid displaced by fluid pressure

Abstract

Fluid-based switches and methods for producing the same are disclosed. In one embodiment, a method for producing a switch comprises depositing a first alignment pad on a first substrate, depositing a second alignment pad on a second substrate, depositing solder on at least one of the alignment pads, depositing a switching fluid on the first substrate, and mating the first substrate to the second substrate by aligning the alignment pads and heating the solder, the substrates defining therebetween a cavity holding the switching fluid, the cavity being sized to allow movement of the switching fluid between first and second states.

Claims

1. A method comprising:

depositing a first alignment pad on a first substrate;

depositing a second alignment pad on a second substrate;

depositing solder on at least one of the first alignment pad and the second alignment pad;

depositing a switching fluid on the first substrate; and

mating the first substrate to the second substrate by aligning the first and second alignment pads and heating the solder, the first substrate and the second substrate defining therebetween a cavity holding the switching fluid, the cavity being sized to allow movement of the switching fluid between first and second states.

2. The method of claim 1, further comprising, after mating, hermetically sealing the first substrate to the second substrate.

3. The method of claim 2, wherein hermetically sealing comprises:

dispensing a solder paste with epoxy flux on at least one of the first and second substrates; and

heating the solder paste.

4. The method of claim 3, wherein the solder has a higher-melting point than the solder paste.

5. The method of claim 1, further comprising:

before mating, depositing a first seal ring on at least a portion of the perimeter of the first substrate and depositing a second seal ring on at least a portion of the perimeter of the second substrate; and

after mating, soldering the first seal ring to the second seal ring.

6. The method of claim 1, further comprising before mating, smoothing a surface of the first substrate that is to be mated to the second substrate, and smoothing a surface of the second substrate that is to be mated to the first substrate.

7. The method of claim 6, wherein smoothing the first substrate and smoothing the second substrate comprises one of lapping, polishing, and chemical mechanical polishing.

8. The method of claim 1, further comprising before depositing the second alignment pad, anodically bonding a first layer of the second substrate to a second layer of the second substrate.

9. The method of claim 1, further comprising before depositing the second alignment pad, fusion bonding a first layer of the second substrate to a second layer of the second substrate.

10. The method of claim 9, wherein the first and second layers comprise glass.

11. The method of claim 1, wherein the first substrate comprises ceramic.

12. A switch comprising:

first and second mated substrates, each substrate including at least one alignment pad, the alignment pads soldered together, the first and second substrates defining therebetween at least portions of a number of cavities;

a plurality of electrodes exposed within one or more of the cavities;

a switching fluid, held within one or more of the cavities, that serves to open and close at least a pair of the plurality of electrodes in response to forces that are applied to the switching fluid; and

an actuating fluid, held within one or more of the cavities, that applies the forces to said switching fluid.

13. The switch of claim 12, wherein the first substrate and the second substrate are hermetically sealed.

14. The switch of claim 12, further comprising a first seal ring deposited on at least a portion of the perimeter of the first substrate, a second seal ring deposited on at least a portion of the perimeter of the second substrate, and solder joining the seal rings.

15. The switch of claim 14, further comprising epoxy flux surrounding at least a portion of the solder.

16. The switch of claim 12, wherein the second substrate comprises a first layer and a second layer, the first and second layers anodically bonded together.

17. The switch of claim 12, wherein the second substrate comprises a first layer and a second layer, the first and second layers fused together.

18. A switch comprising:

first and second mated substrates, each substrate including at least one alignment pad, the alignment pads soldered together, the first and second substrates defining therebetween at least portions of a number of cavities;

a plurality of wettable pads exposed within one or more of the cavities;

a switching fluid, wettable to said pads and held within one or more of the cavities, that serves to open and block light paths through one or more of the cavities in response to forces that are applied to the switching fluid; and

an actuating fluid, held within one or more of the cavities, that applies the forces to said switching fluid.

19. The switch of claim 18, wherein the first substrate and the second substrate are hermetically sealed.

20. The switch of claim 18, further comprising a first seal ring deposited on at least a portion of the perimeter of the first substrate, a second seal ring deposited on at least a portion of the perimeter of the second substrate, and solder joining the seal rings.

21. The switch of claim 20, further comprising epoxy flux surrounding at least a portion of the solder.

22. The switch of claim 18, wherein the second substrate comprises a first layer and a second layer, the first and second layers anodically bonded together.

23. The switch of claim 18, wherein the second substrate comprises a first layer and a second layer, the first and second layers fused together.