Capacitive pressure sensor

• US 6,595,064 B2
• Filed: 05/24/2001
• Issued: 07/22/2003
• Est. Priority Date: 07/26/2000
• Status: Expired due to Fees

• Current Assignee: Endress+Hauser GmbH+Co (ENDRESS)
• Original Assignee: Endress+Hauser GmbH+Co (ENDRESS)
• Inventors: Velten, Thomas, Hegner, Frank, Rossberg, Andreas, Drewes, Ulfert, Breme, Jürgen, Schmidt, Elke Maria
• Primary Examiner(s): Hirschfeld, Andrew H.
• Assistant Examiner(s): FERGUSON SAMRETH, MARISSA LIANA
• Application Number:
  US09/863,271
• Publication Number:
  US 20020014124A1
• Time in Patent Office: 789 Days
• Field of Search: 737/18, 737/24, 737/15, 361/283, 361/283.1, 361/283.4, 361/521, 338/2, 338/5
• US Class Current: 73/718
• CPC Class Codes: G01L 9/0048 Details about the mounting of the diaphragm to its support or about the diaphragm edges, e.g. notches, round shapes for stress relief
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm
• CPC Class Codes: G01L 9/0075 using a ceramic diaphragm, e.g. alumina, fused quartz, glass

Abstract

A diaphragm 30 and basic body 20 of a pressure sensor 10 are interconnected via a joint F. A groove 26 is provided in the basic body 20 in order to reduce the stress concentration in the region of the joint F.

Claims

1. A pressure sensor, comprising:

a basic body having a diaphragm bed;

a diaphragm connected to said diaphragm bed; and

a measuring capacitor for generating a measuring signal, said measuring capacitor having a first electrode and a second electrode applied opposite one another on said basic body and on the underside of said diaphragm, wherein a groove is formed in said diaphragm bed, at the end of a joint formed by said diaphragm and said basic body, said groove adjoining said measuring capacitor and serving for stress concentration relief.

2. The pressure sensor as defined in claim 1, wherein said grove has a bulging cross section.

3. The pressure sensor as defined in claim 1, wherein said groove has an elongated cross section.

4. The pressure sensor as defined in claim 1, wherein said groove has a circular cross section.

5. The pressure sensor as defined in claim 1, wherein said basic body is made from one of:

a ceramic and monocrystalline material.

6. The pressure sensor as defined in claim 2, wherein said basic body is made from one of:

a ceramic and monocrystalline material.

7. The pressure sensor as defined in claim 3, wherein said basic body is made from one of:

a ceramic and monocrystalline material.

8. The pressure sensor as defined in claim 4, wherein said basic body is made from one of:

a ceramic and monocrystalline material.

9. The pressure sensor as defined in claim 1, wherein said groove includes a curved surface.