Capacitive pressure sensor

US7191661B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Torsten Ohms · Lambach, DE
• Oliver Stoll · Kirchheim unter Teck, DE

Key dates

• Filing date: Apr 15, 2005
• Grant date: Mar 20, 2007
• Expiry date: Jul 10, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L9/0073
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A capacitive pressure sensor made up of two silicon on insulator (SOI) wafers lying opposite of each other and joined to each other in a vacuum-tight manner, a recess being formed between the two wafers. The first wafer exclusively supports the evaluation circuits required for measuring the applied pressure and a capacitive electrode, and the second wafer has a recess formed by surface micromechanics processes, in which the counter electrode to the capacitive electrode of the first wafer is situated. The second wafer at the same time forms a cover for the first wafer.