Semiconductor layer pressure switch

• US 5,802,911 A
• Filed: 09/13/1994
• Issued: 09/08/1998
• Est. Priority Date: 09/13/1994
• Status: Expired due to Fees

• Current Assignee: Tokyo Gas Company Limited
• Original Assignee: Tokyo Gas Company Limited
• Inventors: Cahill, Sean Samuel, Neda, Tokudai
• Primary Examiner(s): Oen, William L.
• Application Number:
  US08/305,443
• Time in Patent Office: 1,456 Days
• Field of Search: 200/83 N, 200/83 R, 73/715, 73/716, 73/717, 73/718, 73/719, 73/720, 73/721, 73/722, 73/723, 73/724, 73/725, 73/726, 73/727
• US Class Current: 73/727
• CPC Class Codes: H01H 1/0036 Switches making use of microelectromechanical systems [MEMS] for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009
• CPC Class Codes: H01H 35/2607 Means for adjustment of "ON" or "OFF" operating pressure means for adjustment of "ON" or "OFF" operating temperature of thermally actuated switches by varying bias on the thermal element due to a separate spring H01H37/18
• CPC Class Codes: H01H 59/0009 making use of micromechanics

Abstract

A pressure switch element (1) including a semiconductor layer (3) having a diaphragm portion (5) in its center and a plate (2) having a through hole communicating with the exterior, which are stacked one on another so as to define a gas space (6) between the diaphragm portion of the semiconductor layer and the plate. The element (1) further includes an insulating layer (4) provided on the lower surface of the diaphragm portion (5), a first switch electrode (9) provided on the lower surface of the insulating layer (4), and a second switch electrode (10) behaving as a fixed electrode provided on the plate (2), such that chattering is prevented with a simple structure without using a complex electronic circuit.

Claims

1. A pressure switch element including a semiconductor layer having a diaphragm portion in a center thereof and a plate having a through hole, said semiconductor layer and said plate being stacked one on another and forming a gas space between said diaphragm portion of said semiconductor layer and said plate with said through hole communicating between the interior of said gas space and the exterior of said pressure switch element, said pressure switch element comprising:

an insulating layer on said diaphragm portion of said semiconductor layer and facing said plate;

a first switch electrode on said insulating layer; and

a fixed electrode and a second switch electrode on said plate;

said diaphragm portion on said semiconductor layer, said insulating layer on said diaphragm portion of said semiconductor layer and said fixed electrode on said plate forming a first of a pair of electrostatically attracted contacts; and

said fixed electrode and said second switch electrode on said plate forming a second of said pair of said electrostatically attracted contacts;

said through hole communicating between the interior of said gas space and the exterior of said pressure switch element increasing and decreasing the space between said electrostatically attracted contacts as gas pressure exterior of said pressure switch increase or decrease and is fed to or exhausted from said gas space in said pressure switch element.

2. The pressure switch element according to claim 1 wherein said diaphragm portion and said fixed electrode constitute an electrostatically attractive pair.

3. The pressure switch element according to claim 2 wherein said first switch electrode and said second switch electrode form a switch.

4. The pressure switch element according to claim 1 wherein said first switch electrode and said second switch electrode form a switch.

5. A pressure switch including a pressure switch element comprising:

a semiconductor layer having a diaphragm portion in the center thereof and a plate having a through hole passing through said plate, said semiconductor layer and said plate being stacked one on the other so that said diaphragm portion and said plate form a gas space between said diaphragm portion of said semiconductor layer and said plate and said through hole on said plate communicates said gas chamber with gas pressure exterior to said space;

an insulating layer on a surface of said diaphragm portion facing said plate;

a first switch electrode on said insulating layer; and

a fixed electrode and a second switch on said plate, said diaphragm portion and said fixed electrode being connected to a power source via a switch composed of said first switch electrode and said second switch electrode,

said through hole communicating between the interior of said gas space and the exterior of said pressure switch element increasing and decreasing the space between said switch electrodes as gas pressure exterior of said presssure switch increase or decrease and is fed to or exhausted from said gas space in said pressure switch element.