Capacitive magnetic field sensor

US6765394B1 · kind B1 · utility

Assignee

• Micronas GmbH · DE

Inventors

• Gunter Igel · Teningen, DE
• Ulrich Sieben · Meßkirch, DE
• Jürgen Giehl · Kirchzarten, DE

Key dates

• Filing date: Nov 26, 2001
• Grant date: Jul 20, 2004
• Expiry date: Nov 26, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/038
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a capacitive magnetic field sensor. This sensor has a first electrode (2) and a second electrode (3), which are spaced apart from one another and which form a measurement capacitance. The first electrode (2) is situated on a first substrate body (4), and the second electrode (3) on a second substrate body (5). The second substrate body (5) is designed as a deformable membrane in the vicinity of the second electrode (3). A magnetic body (6) is situated in the vicinity of the second electrode (3) and the membrane, and is rigidly connected to the membrane and to the second electrode (3). As a result of this rigid connection, the influence of an external magnetic field on the magnetic body causes not only the magnetic body (6) to change its position but also causes the membrane and the second electrode (3) to change their position, since they are rigidly connected to said magnetic body. Because the second electrode (3) changes its position, its distance from the first electrode (2) changes, and thus the measurement capacitance, which acts as a measure of the externally applied magnetic field. This capacitive magnetic field sensor is distinguished by very small …