Delco Electronics Corporation

Delphi Technologies, Inc.

Casantra Acquisition III LLC

Philip Harbaugh Bowles

Marion Edmond Ellis

Washington Morris Mobley

Michael Livingston Shipman

Frans Peter Lautzenhiser

Richard Dixon Parker

Dwadasi Hare Rama Sarma

Anthony John Stankavich

Marion Edmund Ellis

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

A method and encapsulation material for encapsulating the solder joints of an IC device mounted on the substrate of an electronic circuit assembly. The encapsulation material is formulated to be sufficiently opaque to x-radiation to enable the use of x-radiation imaging techniques to detect air pockets and voids in the encapsulation material that might degrade the fatigue life properties of the solder joints encapsulated by the encapsulation material. For the purpose of enhancing the fatigue life properties of the solder joints, the encapsulation material contains a filler material dispersed in a polymeric material, such as an epoxy, such that the encapsulation material is characterized by a coefficient of thermal expansion approximately equal to that of the solder joints. The filler material contains a sufficient amount of an element to render the encapsulation material opaque to x-radiation. Generally, suitable elements are those having an atomic number of at least about 35, such as lead, barium, zirconium, mercury, bismuth, tantalum, tin and tungsten. The element may be present as an oxide, particularly if the filler material is glass microspheres.

X-ray detectable encapsulation material and method for its use

Method of inspecting integrated circuit solder joints with x-ray

Growing community of inventors

Carmel, IN, United States of America

Philip Harbaugh Bowles