Delco Electronics Corporation

Delphi Technologies, Inc.

Paratek Microwave Incorporated

Marion Edmond Ellis

Lewis Henry Little

Philip Harbaugh Bowles

Washington Morris Mobley

Raymond O Butler, Jr

Frans Peter Lautzenhiser

Ronald J Kiess

Anthony John Stankavich

Luna H Chiu

Douglas Ray Sparks

Joel Franklin Downey

Richard Dixon Parker

Christine Ann Paszkiet

Andres Deogracias Viduya

Dwadasi Hare Rama Sarma

Dwadasi Hare Sarma

Steven Wesley Winn

Tunable dielectric materials including an electronically tunable dielectric ceramic and a low loss glass additive are disclosed. The tunable dielectric may comprise a ferroelectric perskovite material such as barium strontium titanate. The glass additive may comprise boron, barium, calcium, lithium, manganese, silicon, zinc and/or aluminum-containing glasses having dielectric losses of less than 0.003 at 2 GHz. The materials may further include other additives such as non-tunable metal oxides and silicates. The low loss glass additive enables the materials to be sintered at relatively low temperatures while providing improved properties such as low microwave losses and high breakdown strengths.

Tunable dielectric compositions including low loss glass

A thick film resistor strain gauge is applied to a stainless steel shell portion of a spark plug. There are two preferable ways of applying a thick film resistor to the metal shell. In a first embodiment, the thick film resistor may be directly printed on to the shell portion with special screen printing equipment. In a second embodiment, the thick film resistor is printed and applied as a decal to the shell portion. The thick film resistors may be included in a quarter, a half, or a full wheatstone bridge strain gauge circuit. One of two embodiments of an automatic drift compensating circuit is used to determine the change in resistance experienced by the thick film resistors affixed to the spark plug. Either one of the automatic drift compensation circuits output a voltage signal which is proportional to the pressure changes occurring inside the engine cylinder into which the spark plug is threaded.

Spark plug mounted thick film strain gauge

A process for forming stable integrated resistors ( ) and capacitors ( ) on organic substrates ( ). The resistors ( ) and capacitors ( ) are capable of a wide range of resistance and capacitance values, yet can be processed in a manner that does not detrimentally effect the organic substrate ( ) or entail complicated processing. The method generally entails the use of thick-film materials usually of the types used to form resistors and capacitors on ceramic substrates. The thick-film materials are applied to an electrically-conductive foil ( ) and then heated to bond the thick-film material to the foil ( ) and form a solid resistive or capacitive mass ( ). The foil ( ) is then laminated to an organic substrate ( ), such that the resistive/capacitive mass ( ) is attached to and preferably embedded in the organic substrate ( ). Finally, the foil ( ) is etched to form at least one of two terminals that contact the resistive/capacitive mass ( ) and thereby complete the passive electrical component ( ). Resistors ( ) can also be formed of polymer thick-film (PTF) inks, in which case the PTF ink is cured on the foil ( ) for an extended period at a temperature sufficient to completely cure the ink prior to laminating the foil ( ) to the organic substrate ( ).

Method of forming integral passive electrical components on organic circuit board substrates

A hybrid circuit structure that includes a metal substrate, an inorganic electrical insulator layer and at least one inorganic thick-film passive circuit element, such as a thick-film resistor, capacitor or conductor. An interface layer is provided between the insulator layer and the circuit element to prevent the detrimental effects of interlayer diffusion. The composition of the interface layer is selected to prevent the diffusion of constituents from the inorganic insulator layer, and to have a CTE near that of the circuit element to reduce thermal fatigue. As a result, the passive circuit element can be formed of essentially any one of a number of conventional inorganic thick-film materials that are widely used on alumina substrates.

Method of forming thick-film hybrid circuit on a metal circuit board

A method for forming a ruthenium-based thick-film resistor having copper terminations, in which the thick-film resistor is fired in a non-oxidizing atmosphere so as not to oxidize the copper terminations yet without reducing the thick-film resistor to metallic ruthenium. A ruthenium-based thick-film resistor ink having a matrix material and an organic vehicle is deposited on a copper layer that will form the terminations for the thick-film resistor formed by firing the ink. The organic vehicle of the ink is then burned out at a temperature of less than 350&deg; C. in an oxidizing atmosphere, such as air. Thereafter, the ink is fired in a non-oxidizing atmosphere (e.g., nitrogen) at a temperature sufficient to sinter the matrix material and yield a ruthenium-based thick-film resistor with copper terminations formed by the copper layer.

Method of forming ruthenium-based thick-film resistors

16 A thick-film circuit (10) includes an electrically conductive substrate (12), such as stainless steel, and a first layer of a gold-rich conductor (15) applied directly thereon. The gold layer is fired in a non-oxidizing atmosphere, such as nitrogen, to ensure a solid mechanical and electrical connection between the gold and the substrate. A next layer of a silver composition (20) containing a first proportion of silver to a conductive metal is directly applied to the gold layer (15). Preferably, the composition (20) includes palladium in equal parts with the silver to achieve a secure mechanical and electrical contact with the gold layer with a minimum resistivity. A silver-rich layer (23) is then applied directly onto the intermediate layer. This silver-rich layer (23) is a composition of silver and the conductive metal in a second proportion greater than the first proportion. In one embodiment, this second proportion is three parts silver to one part palladium by weight. The thick-film stack-up (10) provides a minimum resistance conductive path between electrical components mounted on the silver-rich layer (23) and the conductive substrate (12).

Thick-film circuits and metallization process

A sensor (10) having polysilicon strain-sensing elements (20) on a metal diaphragm (16). A thick-film insulating layer (18) covers the metal diaphragm (16), and thin-film polysilicon resistive elements (20) are formed on the thick-film insulating layer (18). Thick-film conductors (22) are formed on the thick-film insulating layer (18) and contact the thin-film polysilicon resistive elements (20) to form electrical interconnects to the resistive elements (20). The thick-film conductors (22) preferably contain silicon in order to reduce diffusion of silicon from the polysilicon resistive elements (20). The thick-film insulating layer (18) may be made up of a number of individual thick-film layers, the uppermost of which is stable and nonreactive with the thin-film polysilicon resistive elements (20) and the thick-film conductors (22) at temperatures of at least 600.degree. C. A passivation layer (24) overlies the thin-film polysilicon resistive elements (20) and the thick-film conductors (22). The sensor (10) can be made sufficiently rugged to be used as a structural member of a fluid-containing vessel.

Metal diaphragm sensor with polysilicon sensing elements and methods

A thick-film strain-sensing structure for a media-compatible, high-pressure sensor. The strain-sensing structure generally includes a metal diaphragm, at least one electrical-insulating layer on the diaphragm, an interface layer on the electrical-insulating layer, and at least one thick-film piezoresistor on the interface layer for sensing deflection of the diaphragm. The interface layer and the electrical-insulating layers are preferably formed by thick-film processing, as done for the piezoresistors. For compatibility with the metal diaphragm, the electrical-insulating layer has a CTE near that of the diaphragm. The interface layer is formulated to inhibit and control diffusion of the electrical-insulating layers into the piezoresistors. For this purpose, the interface layer is formed from a composition that contains, in addition to a suitable organic media, alumina, zinc oxide, and at least one glass frit mixture comprising lead oxide, a source of boron oxide such as boric acid, silica and alumina. Additional constituents of the interface layer preferably include titania, cupric oxide, manganese carbonate as a source for manganese monoxide, and cobalt carbonate as a source of cobalt oxide.

Diffusion-barrier materials for thick-film piezoresistors and sensors

A high temperature thick-film hybrid circuit is characterized by a surface-mount circuit component that is electrically interconnected with a conductor. The surface-mount circuit component of the thick-film hybrid circuit is bonded to the conductor with a soldering technique employing dual-solder layers. The dual-solder layers enable component attachment to the conductor at a temperature below the maximum processing temperature of the component, while forming a solder joint that exhibits suitable adhesion properties at temperatures in excess of 165.degree. C. The dual-solder layers can be chosen to inhibit tin diffusion from the solder, silver leaching from the conductor, and the formation of a brittle intermetallic at the solder-conductor interface.

Dual-solder process for enhancing reliability of thick-film hybrid

A novel thick film resistor configuration and a method for fabricating thick film resistors, by which such resistors can be processed to achieve targeted electrical properties in an as-fired condition. The configuration and method of this invention involve creating a thick film resistor in the form of a series of short resistors whose combined resistance values approximately equal the predetermined resistance value required of the thick film resistor by its hybrid electronic circuit, yet with the use of minimal post-firing trimming. Such a configuration and method enable the production of thick film resistors from the same ink composition but with significantly different aspect ratios, yet which exhibit minimal differences between TCR values. Consequently, thick film resistors configured and fabricated in accordance with this invention are characterized by enhanced production throughput, repeatability, and reliability.

Segmented thick film resistors

Thick film resistor ink compositions and a method for formulating and processing such inks are provided for producing thick film resistors having highly repeatable and stable resistance characteristics. The inks are specifically formulated to produce resistors whose resistivities are determined in part by the sintering temperature employed in the processing of the resistors. The processing of the inks involves using infrared radiation techniques to rapidly sinter the inks at highly controllable temperatures, so as to enable the resistance of a resistor to be predictably altered by the sintering operation, such that in-process adjustments can be made to the processing method. Thick film resistors produced in accordance with this invention are characterized by high stability to environmental influences and low TCR values on the order of about .+-.50 ppm/.degree.C.

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Kokomo, IN, United States of America

Marion Edmond Ellis