Abstract: This method comprises the following steps, which are compatible with thin-film technology: forming a bottom electrode (2) on an insulating substrate (1), depositing a humidity-sensitive polymer layer (5) of uniform thickness on the bottom electrode (2) leaving contact areas (3a, 3b) uncovered, activating surface bonds of the polymer layer (5), applying a colloidal dispersion of SiO.sub.2 or Al.sub.2 O.sub.3 particles (6) of uniform grain size as a thin layer to the polymer layer (5) and subsequently drying it, depositing a cover electrode (7) on the particles (6) still evenly distributed on the polymer layer (5) after the drying of the dispersion, and removing the particles (6) together with the portions of the cover electrode (7) overlying them.

Abstract: A mechanically heavily loadable and high-vacuum-tight feedthrough connection through a hole (2) of a high-temperature-resistant and vacuum-proof insulating part (1), particularly of ceramic, glass, or a single crystal, is disclosed which can be produced in a single high-temperature step and is thus inexpensive. It is designed as a terminal lead (4) covered with active solder and soldered into the hole, the terminal lead having a coefficient of thermal expansion less than that of the insulating part (1). The feedthrough connection is preferably used in a capacitive pressure sensor (10) having a diaphragm (11) and a substrate (12) which have spaced-apart, flat inner surfaces which are provided with at least one conductive layer (14, 15) for forming at least one capacitor and are electrically connected to the respective rear side via the feedthrough connection.

Abstract: The pressure sensor consists of a substrate and a diaphragm joined together around the periphery so as to form a chamber. The surface of the diaphragm facing away from the substrate is exposed to a medium whose pressure is to be measured. To protect the diaphragm against corrosion or abrasion, the diaphragm surface exposed to the medium is covered with a layer of silicon carbide, preferably by chemical vapor deposition.

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.

Abstract: The substrate (12) and/or the diaphragm (11) of the pressure sensor (10) are made of ceramic, glass, or a single-crystal material. The side of the diaphragm (11) facing the substrate (12) is covered with a layer of silicon carbide, niobium, or tantalum which, in turn, is covered with a protective layer (21) and serves as one capacitor electrode (14). The side of the substrate (12) facing the diaphragm (11) is covered with at least one additional layer of any one of said materials which, in turn, is covered with an additional protective layer (22) and serves as the second capacitor electrode (15). Substrate (12) and diaphragm (11) are soldered together by a formed part of active solder (20) which also serves as a spacer.This pressure sensor can be manufactured in a single soldering step. The maximum load capacity of the diaphragm is determined not by the strength of the joint, but only by the strength of the diaphragm material.

Abstract: The pressure sensor comprises a base body and diaphragm which are assembled at a defined distance apart parallel to each other to form a chamber, at least one of the two assembled parts consisting of ceramic, glass, metal or a monocrystalline material. In dependence upon the external pressure acting on the pressure sensor the distance between said parts and thus the capacitance between two electrodes carried by said parts changes. The base body and the diaphragm are firmly connected together by a shaped part of metal serving at the same time as spacer. If at least one of the two parts consists of ceramic, glass, metal or a monocrystalline material, the two joined parts can be soldered together by a shaped part of active solder. If the two assembled parts consist of oxide ceramic or sapphire they can be connected together by the direct copper bonding method. In this case the shaped part consists of copper which is connected to the two parts by a eutectic melt forming at the surface.

Abstract: The capacitive pressure sensor (10) has two disks (11, 12) of alumina which are joined together around the periphery in a defined spaced relationship and parallel to each other, forming a chamber (14). At least one of the two disks (11) is designed as an elastic diaphragm. A pure nickel coating (16, 18) is applied to the surface of each disk by electroless deposition from an aqueous solution, and on the surfaces of the two disks facing each other, capacitor electrodes (17, 20, 21) are formed by patterning the nickel coating. The capacitor electrodes are connected to an electronic circuit disposed outside the chamber (14) by additional nickel coatings which are formed in plated-through holes (30, 31, 32) simultaneously with the deposition of the pure nickel coating.

Abstract: A thin-film humidity sensor for measuring the absolute humidity having a base electrode, a moisture-sensitive dielectric layer and a top electrode is formed at the end face of an electrically insulating bushing body by the thin-film technique. The connecting conductors are led through the bushing body and terminate in contact areas which are ground plane and polished together with the end face of the bushing body. The metal layers forming the electrodes are so shaped on application, preferably by means of perforated masks, that they each cover the contact area of the associated connecting conductor and are electrically connected thereto. The bushing body is inserted into a sleeve of a highly alloyed nickel-molybdenum compound and connected thereto in pressure-resistant manner.

Abstract: A thin-film humidity sensor for measuring the absolute humidity having a base electrode, a moisture-sensitive dielectric layer and a top electrode is formed at the end face of an electrically insulating bushing body by the thin-film technique. The connecting conductors are led through the bushing body and terminate in contact areas which are ground plane and polished together with the end face of the bushing body. The metal layers forming the electrodes are so shaped on application, preferably by means of perforated masks, that they each cover the contact area of the associated connecting conductor and are electrically connected thereto. The bushing body is inserted into a sleeve of a highly alloyed nickel-molybdenum compound and connected thereto in pressure-resistant manner.