Mass flow sensor having an improved membrane stability

US6820481B1 · kind B1 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Heribert Weber · Leverkusen, DE
• Werner Steiner · Schrobenhausen, DE

Key dates

• Filing date: Oct 30, 2000
• Grant date: Nov 23, 2004
• Expiry date: Oct 30, 2020

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F1/6845
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A mass flow sensor is described. To improve the membrane stability of the known mass flow sensor, in particular the reoxide layer which is present in the known mass flow sensor is replaced by a thicker PECVD silicon oxide layer. The thickness of the silicon oxide layer deposited on the platinum layer is increased, and the known mass flow sensor is also provided with a cover layer of PECVD silicon nitride forming a moisture barrier.