Heraeus Electro-Nite International N.v.

Heraeus Sensor Technology Gmbh

Karlheinz Ullrich

Karlheinz Wienand

Matthias Muziol

Karl-Heinz Wienand

Stefan Dietmann

Gerhard Damaschke

Tim Asmus

Margit Sander

Armin Lotz

Angela Maier

A sensor, particularly an impedance sensor, for example a soot sensor, is provided which has two mutually electrically insulated electrodes, wherein at least one external electrode is formed from a composite of metal and inorganic oxide as a film pattern having a film thickness of 0.5 to 20 &#x3bc;m. The trace width of the film pattern and the spacing between the traces is 5 to 70 &#x3bc;m and the border region around the conductor trace edge varies less than 10 &#x3bc;m. Both electrodes can be arranged adjacent to each other as a film pattern in a plane. Preferably, the sensor has a heater. For mass production, electrodes are produced as a film pattern having a film thickness of 0.5 to 20 &#x3bc;m on electrically insulating oxide bases and, following full-surface imprinting of a metal powder and oxide-containing paste, the electrodes are structured particularly accurately as traces from the printed film. In particular, the film thickness of the printed film is reduced.

Photolithographic structured thick layer sensor

A high temperature-stable sensor is provided in which electrodes on a substrate or an insulation layer are in contact with a sensitive layer, wherein the electrodes have platinum, rhodium, or iridium or an electrically conductive oxide layer. For this purpose, an intermediate product is provided as a platform chip, which has a deposited layer made of platinum, rhodium, or iridium or an alloy of platinum, rhodium, or iridium and is covered by an electrically conductive oxide. From the deposited layer, a conductive structure is formed and thus a platform chip is created with an electrically conductive structure subject to external influences. This structure has an electrically conductive oxide and/or its parts have long-term, stable characteristic resistance curves under high-temperature loading above about 500&#xb0; C., especially between about 600&#xb0; C. and 950&#xb0; C. A sensor with a gas-sensitive layer formed as a gas-sensitive sensor is preferred.

High temperature-stable sensor

A flow sensor element and a method for self-cleaning of the flow sensor element are provided, in which a temperature-measuring element and a heating element are arranged on a carrier element, and these elements can form a multiple-part ceramic component. The temperature-measuring element has a platinum thin-film resistor on a ceramic substrate for the temperature measurement and is heated with an additional platinum thin-film resistor. A measurement device, in particular an anemometric measurement device of a flow sensor, contains film resistors mounted in at least one opening of a cover or a hollow body. Two of the film resistors have resistance values differing by one to three orders of magnitude. The anemometric measurement device has a temperature sensor and a heat output sensor set in a carrier element. The temperature sensor has a temperature-measuring resistor and a heat conductor, as platinum thin-film or thick-film resistors, on a ceramic substrate.

Flow sensor element and its self-cleaning

A flow sensor element is provided having at least one temperature-measuring element and at least one heating element each having at least one platinum thin film resistor, the at least one temperature-measuring element and the at least one heating element each being arranged on a carrier element which is formed from a ceramic foil laminate or a multi-part ceramic component. The carrier elements have electrical conductor paths and junction surfaces for electrically contacting the at least one temperature-measuring element and the at least one heating element. The at least one temperature-measuring element and the at least one heating element each have a metallic carrier foil with an electrically insulating coating, on which the platinum thin film resistors are arranged. The flow sensor element may be used for mass through-flow measurements of gaseous or liquid media in pipe ducts, for example in an exhaust gas pipe of an internal combustion engine.

Flow sensor element and method of using same

A semiconductor component with an integrated circuit has a cooling body as a heat sink and a temperature sensor thermally connected thereto, whose resistance is dependent on temperature. The temperature sensor contains a thin film measuring resistor, which is applied to an electrically insulating surface of a foil-like substrate, and the total thickness of the temperature sensor lies in a range of about 10 &mgr;m to 100 &mgr;m. The thin film measuring resistor is formed as a planar component, with the temperature sensor being arranged between the integrated circuit and the cooling body. The thin film measuring resistor is provided on one side with a thermal coupling layer bordering on the cooling body, while on the other side the resistor has a substrate bordering on a heat distributor, which at least partially surrounds the integrated circuit.

Semiconductor component with integrated circuit, cooling body, and temperature sensor

A temperature-dependent measuring resistance with low mass and thereby rapid response time has a conductor path provided with at least two connection contact pads. The conductor path is applied to a metal substrate with an insulation layer (membrane) situated thereon. A portion of the conductor path spans a recess of the substrate in a bridge-like manner. The conductor path is selectively covered by a passivation layer up to its connection contact pads.

Process for manufacturing an electrical resistor with at least two connection contact pads on a substrate with at least one recess

For reduction of toxic components in exhaust gases of internal combustion engines, particularly of nitrogen oxides in motor vehicles, a portion of the exhaust gases, essentially operating as inert gases, are recirculated into the combustion chamber of the engine for the purpose of reducing the peak combustion temperature. In the air intake region the engine is fed an adjustable mixture of partially recirculated exhaust gas and air, wherein the mass of in-flowing air and the mass of exhaust gas recirculated from the engine following its cleaning and cooling are fed respectively to its own flow rate sensor. From the determined mass flow amounts of in-flowing air and recirculated exhaust gas, an actual value signal is formed and compared with a target value signal dependent upon the respective performance specification. A regulation deviation of the actual value signal leads to an adjustment signal, which intervenes into the exhaust gas recirculation for the purpose of adjusting the amount recirculated.

Device for exhaust gas recirculation into the air intake region of motor vehicle internal combustion engines

For reductions of toxic components in exhaust gases of internal combustion engines, particularly of nitrogen oxides in motor vehicles, a portion of the exhaust gases, essentially operating as inert gases, are recirculated into the combustion chamber of the engine for the purpose of reducing the peak combustion temperature. In the air intake region the engine is fed an adjustable mixture of partially recirculated exhaust gas and air, wherein the mass of in-flowing air and the mass of exhaust gas recirculated from the engine following its cleaning and cooling are fed respectively to its own flow rate sensor. From the determined mass flow amounts of in-flowing air and recirculated exhaust gas, an actual value signal is formed and compared with a target value signal dependent upon the respective performance specification. A regulation deviation of the actual value signal leads to an adjustment signal, which intervenes into the exhaust gas recirculation for the purpose of adjusting the amount recirculated.

Process for exhaust gas recirculation into the air intake region of motor vehicle internal combustion engines and device therefor

In order to connect contact surfaces of electric component blanks for layer resistors to at least two elongated, metallic connection leads, elongated, slot-shaped openings are made, e.g., by etching, in a continuous metal sheet to manufacture a connection lead blank. The openings border on later connection leads of the connection blank and cross-struts yet to be removed. In a second step, the connection lead blank is brought into a cassette and seized, whereby one of the cross-struts projects out of the cassette and is separated in a third step, such that the free ends of the parallel-running connection leads project out of the cassette. In a fourth step, the cassette is brought into a bonding or welding device, so that the free ends of the connection leads cover the contact surfaces of a component blank or a multi-component blank and are connected together by a bonding or welding operation. In case a multi-component blank (multi-unit plate) is used, it is then separated into individual components. Proving to be advantageous are a high corrosion resistance (up to 750&deg; C.) and the possibility of largely automated manufacturing and further processing.

Method for connecting contact surfaces of electrical component blanks and device therefor

A temperature-dependent measuring resistance with rapid response time is at least partially arranged on an electrically insulating surface of a ceramic substrate, wherein a portion of the conductor path spans a recess situated in the substrate in a bridge-like manner, and the remaining portion of the conductor path in the edge area of the substrate adjacent to the recess is provided with connection contact fields. The conductor path comprises a platinum or gold layer, wherein the conductor path is partially provided with a cover layer of glass, and wherein the connection contact fields are exposed. In a further embodiment, the conductor path is arranged together with the connection contact fields either on a screen-printed glass membrane or on a thin film membrane applied in a PVD process, which covers the surface of the ceramic substrate and spans the recess. The cover layer is likewise selectively applied by screen printing in case there is a glass membrane. In the case of a thin film membrane, the cover layer is also applied selectively by a PVD process and can be the same material as the thin film membrane. The ceramic substrate preferably comprises aluminum oxide.

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Gross-Umstadt, Germany

Karlheinz Ullrich