Capacitive accelerometer sensor and method for its manufacture

US5569852A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Jiri Marek · Reutlingen, DE
• Frank Bantien · Ditzingen, DE
• Horst Muenzel · Reutlingen, DE
• Michael Offenberg · Lörrach, DE

Key dates

• Filing date: Dec 14, 1994
• Grant date: Oct 29, 1996
• Expiry date: Dec 14, 2014

Classification

• Technology area (CPC G): Physics
• CPC primary: G01P2015/0814
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A contacting of a capacitive accelerometer sensor of monocrystalline material is achieved by a capacitive accelerometer sensor having a structure etched out of a monocrystalline layer arranged on a substrate, including a seismic mass that is only joined to the substrate by suspension segments and executing a movement in its longitudinal direction in response to the occurrence of an acceleration of parallel, plate-like first fingers extending out from this mass at right angles to their longitudinal direction and of plate-like second fingers running parallel to the first fingers and anchored to the substrate. The first and second fingers form a capacitor arrangement. The suspension segments, which are anchored with their end region that is distant from the seismic mass to the substrate, and second fingers are electrically isolated, by an isolation strip, from the other remaining layer of monocrystalline material. A passivation layer extends over the isolation strip, and at least partially over the remaining layer. Conductors arranged on the passivation layer and serving as connecting leads for the capacitor arrangement extend across the isolation strip up to the connections of the ca…