Capacitive ceramic pressure measuring cell and pressure sensor with such a pressure measuring cell

US8966989B2 · kind B2 · utility

Assignee

• ENDRESS+HAUSER GMBH+CO.KG · DE

Inventors

• Ulfert Drewes · Bad Hersfeld, DE
• Thomas Uehlin · Schopfheim, DE
• Elke Schmidt · Bad Säckingen, DE
• Andreas Rossberg · Bad Säckingen, DE

Key dates

• Filing date: Jun 22, 2010
• Grant date: Mar 3, 2015
• Expiry date: Jun 29, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L9/0075
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A capacitive pressure measuring cell, including a ceramic platform and a ceramic measuring membrane, which are connected pressure tightly along a joint to form a reference pressure chamber between them. The measuring membrane has a first electrode facing the platform, and the platform has at least a second electrode facing the measuring membrane. The capacitance between the first and second electrodes depends on the difference between a pressure externally acting on the measuring membrane and a pressure reigning in the reference pressure chamber, wherein the joint has a thickness d, which defines an equilibrium distance between the measuring membrane and the front side of the platform. On the front side of the platform, a support layer is arranged, which comprises an inorganic insulator, wherein the support layer has a thickness of at least 0.2, and wherein the second electrode is arranged on the support layer.