Electrical thick-film, free-standing, self-supporting structure, and method of its manufacture, particularly for sensors used with internal combustion engines

US4410872A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gunther Stecher · Ludwigsburg, DE
• Herbert Zimmermann · Freiberg am Neckar, DE

Key dates

• Filing date: Aug 27, 1980
• Grant date: Oct 18, 1983
• Expiry date: Aug 27, 2000

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N33/0009
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A free-standing, self-supporting layer of glass-ceramic or crystallized glass is applied by thick-film technology over a presintered layer made of a vaporizable or etchable material which, after sintering the thick-film glass-ceramic or crystallized glass layer (3) to a substrate (1), is removed by heating or etching. The layer (2) to be removed is preferably applied in past form with the glass-ceramic thick-film layer (3) thereover either in form of a crossing bridge, as a partially covering cantilever, or entirely surrounding the layer 2, in which latter case the thick-vaporizable film layer (3) is of porous construction so that the volatile or components of the underlying layer (2) can escape through the thick-film layer (3). A typical layer which is volatile or vaporizable includes carbon black, a resin binder and a solvent, applied to a substrate, for example of ceramic or enameled metal, over which the glass-ceramic layer is applied. Electrically conductive tracks can be applied directly on the substrate beneath the layer (2) to be removed, and to the thick-film layer, or in the form of strain or temperature-sensitive resistors, for connection to an external circuit evaluatin…