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

Abstract

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 evaluating deformation of the free-standing layer by capacitative or resistance change, to obtain pressure sensors, vibration sensors, acceleration sensors, and the like, of minute construction. A typical dimension of the thick-film layer is in the order of tens of micrometers, with the free space after removal of the filler (2) being also about in the order of tens of micrometers.

Inventors

• 👤 Gunther Stecher
• 👤 Herbert Zimmermann

Bibliographic Details