Electrostatic capacitance type transducer and method for producing the same

• US 5,917,264 A
• Filed: 09/03/1997
• Issued: 06/29/1999
• Est. Priority Date: 09/05/1996
• Status: Expired due to Term

• Current Assignee: Nagano Keiki Company Limited
• Original Assignee: Nagano Keiki Company Limited
• Inventors: Maruno, Naohiko, Yokoyama, Seiichi, Ito, Hiroji, Sekimori, Yukimitsu, Kaise, Fumio
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US08/922,507
• Time in Patent Office: 664 Days
• Field of Search: 310/309, 73/718, 73/724, 73/514.32, 361/283, 361/284
• US Class Current: 310/309
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

The present invention provides an electrostatic capacitance type transducer and a method for producing the same, with the ensured sufficient connecting strength and insulation between a movable electrode and a fixed electrode and smooth production. In the electrostatic capacitance type transducer having: a substrate; a movable electrode placed on the opposite side of a space from the substrate and having displacement in relation to the substrate; and a fixed electrode formed on a detecting face of the substrate which is opposite to the movable electrode, an insulation film is formed on the approximately whole surface, including the fixed electrode, of the detecting face of the substrate, in which the substrate and the movable electrode are connected through the insulation film to each other by means of the anode-contact.

Claims

1. An electrostatic capacitance type transducer comprising:

a non-conductive substrate having a detecting face;

a fixed electrode formed on said detecting face;

an insulating film disposed over said detecting face of said substrate, wherein said insulating film covers said fixed electrode and has a thickness between 100 Å and

10,000 Å

;

a movable electrode mounted over said detecting face of said substrate, wherein said movable electrode forms a diaphragm that extends over and is spaced from said fixed electrode wherein, said movable electrode is anode bonded to said insulating film so that said substrate and said movable electrode are anode-bonded together.

2. The electrostatic capacitance type transducer according to claim 1, wherein said insulating film comprises silicon dioxide (SiO₂) as the main component.

3. The electrostatic capacitance type transducer of claim 2, wherein the movable electrode has a conductive signal receiving portion that extends from a side face of the substrate to the movable electrode.

4. The electrostatic capacitance type transducer according to claim 1, wherein:

at least two fixed electrodes are formed on said detecting face of said substrate and at least at first one of said fixed electrodes is formed to surround a second one of said fixed electrodes;

said substrate has an upper face opposite said detecting face, conductive signal receiving portions are formed on said upper face, each said signal receiving portion being connected to one of said fixed electrodes, and an anodic bonding electrode is formed on said upper face, said anodic bonding electrode being formed to define a gap; and

one of said signal receiving portions that is connected to either said first or said second fixed electrode has a leading portion that extends through the gap defined by said anodic bonding electrode.

5. The electrostatic capacitance type transducer according to claim 4, wherein said first fixed electrode includes plural electrode elements including an outer electrode element that surrounds both the remaining electrode elements forming said first fixed electrode and said second fixed electrode, wherein one of said electrode elements of said first fixed electrode is provided with said leading portion that extends through the gap defined by said anodic bonding electrode.

6. The electrostatic capacitance type transducer according to claim 5, wherein said outermost electrode element of said first fixed electrode is the electrode element provided with said leading portion that extends through the gap defined by said anodic bonding electrode.

7. The electrostatic capacitance type transducer according to claim 4, wherein a side face of said substrate is formed with a signal receiving portion that is connected to said movable electrode.

8. The electrostatic capacitance type transducer of claim 4, wherein either said first or said second fixed electrode has plural electrode elements.

9. The electrostatic capacitance type transducer of claim 1, wherein the movable electrode has a conductive signal receiving portion that extends from a side face of the substrate to the movable electrode.