Electrical shield structure for pressure sensor

• US 7,171,856 B2
• Filed: 03/08/2005
• Issued: 02/06/2007
• Est. Priority Date: 03/12/2004
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Baba, Hironobu, Koike, Haruhisa, Segawa, Nobuo
• Primary Examiner(s): Lefkowitz; Edward
• Assistant Examiner(s): ALLEN, ANDRE J
• Application Number:
  US11/073,631
• Publication Number:
  US 20050199070A1
• Time in Patent Office: 700 Days
• Field of Search: 737/18, 737/24, 737/00, 361/283.1, 361/283.4
• US Class Current: 73/718
• CPC Class Codes: G01L 13/026 involving double diaphragm
• CPC Class Codes: G01L 19/0645 using isolation membranes, specially adapted for protection

Abstract

A pressure sensor includes a case having a concave portion, a sensing portion disposed in the concave portion to output an electrical signal proportional to an applied pressure, a circuit portion disposed in the concave portion and connected to the sensing portion and a conductive diaphragm fixed to the case to cover the concave portion. A conductive member surrounds the sensing portion and the circuit portion to provide an electrical shield. The diaphragm is used as a part of the conductive member.

Claims

1. A pressure sensor comprising:

a case having a concave portion;

a sensing portion disposed in the concave portion, the sensor portion including a diaphragm part deformable in accordance with an applied pressure, the sensing portion outputting an electrical signal proportional to the applied pressure;

a circuit portion disposed in the concave portion and connected to the sensing portion; and

a conductive diaphragm fixed to the case to cover the concave portion,

wherein a conductive member surrounds the sensing portion and the circuit portion to provide an electrical shield, wherein the conductive diaphragm is used as a part of the conductive member

wherein the sensing portion is electrically insulated from the conductive member and the conductive diaphragm.

2. The pressure sensor of claim 1, wherein the conductive member comprises the conductive diaphragm and a metal board fixed on the case.

3. The pressure sensor of claim 1, wherein the circuit portion includes a terminal disposed in the concave portion, wherein a first end of the terminal is exposed in the concave portion, wherein a wire electrically connects the sensing portion with the terminal.

4. The pressure sensor of claim 3, wherein the terminal has a second end that protrudes from the conductive member to provide an external electrical connection.

5. The pressure sensor according to claim 1, wherein the conductive diaphragm is located at two opposite sides of the sensing portion.

6. The pressure sensor according to claim 1, further comprising a housing for receiving at least a part of the case, the housing having a pressure introduction hole for introducing a pressure to be applied, wherein the conductive diaphragm is inserted between the case and the housing.

7. The pressure sensor according to claim 2, wherein the metal board has a side plate extending on a surface of the case in a direction approximately perpendicular to an extending direction of the conductive diaphragm.

8. The pressure sensor according to claim 2, wherein the metal board is bent at a corner of the case.