Capacitive pressure sensor and method of manufacturing same

US5050035A · kind A · utility

Assignee

• Endress u Hauser GmbH u Co. · DE

Inventors

• Frank Hegner · Bad Kötzting, DE
• Manfred Frank · Auckland, NZ

Key dates

• Filing date: Mar 20, 1990
• Grant date: Sep 17, 1991
• Expiry date: Mar 20, 2010

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/435
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

This rugged, temperature-shock-insensitive, and low-cost pressure sensor (1) has a diaphragm (2) and a substrate (3) which are alumina-ceramic parts, preferably with a purity of 96%, are joined together in a defined spaced relationship and parallel to each other by means of an intermediate layer, forming a, preferably closed, chamber, and have flat inner surfaces which are provided with at least one conductive layer for forming at least one capacitor and are electrically connected to the respective rear side of the diaphragm or substrate via through-hole coatings. For the conductive layers (6, 7, 8), the through-hole coatings (12, 13, 14), and the intermediate layer (5), use is made of a conductive paste or a resistive paste with a sheet resistivity not higher than 1 ohm/square, which are applied using silk-screening techniques.