E.i. Dupont De Nemours and Company

Delco Electronics Corporation

Christopher R Needes

Kenneth Warren Hang

Carl Baasun Wang

Yueli Wang

Patricia J Ollivier

Kumaran M Nair

Dwadasi H Sarma

Joseph R Rellick

Christine Ann Paszkiet

Mark Frederick McCombs

James Catlin Orem

Methods of forming a multilayer circuit comprising:

Thick film conductor case compositions for LTCC tape

The present invention is directed to the use of a thick film paste composition comprising, in weight percent total paste composition, materials selected from mixtures of lead iron tungstate niobate solid solutions 30 to 80%, calcined mixtures of barium titanate, lead oxide and fused silica 20 to 70%, barium titanate 30 to 50%, calcined mixtures of barium titanate 30 to 50%, barium titanate and calcined mixtures of barium titanate 30 to 50%, lead oxide and fused silica 50-80%, and a lead germanate glass 3-20%, as a thick film paste via fill composition for use in the formation of multilayer low temperature cofired ceramic circuits.

Thick film paste via fill composition for use in LTCC applications

A thick film composition consisting essentially of:

This invention relates to a process which produces flat, distortion-free, zero-shrink, low-temperature co-fired ceramic (LTCC) bodies, composites, modules or packages from precursor green (unfired) laminates of three or more different dielectric tape chemistries that are configured in an uniquely or pseudo-symmetrical arrangement in the z-axis of the laminate.

Process for the constrained sintering of a pseudo-symmetrically configured low temperature cofired ceramic structure

A method to produce a distortion-free asymmetrical low-temperature co-fired ceramic structure comprising at least one layer of glass-containing internal constraining tape and at least one layer of glass-containing primary tape wherein the internal constraining tape and the primary tape are laminated to form an asymmetrical laminate and wherein a release layer is deposited on at least one surface of the laminate forming an assembly, wherein the surface is opposite the position of greatest asymmetry of the laminated layers and wherein the assembly is thermally processed producing a structure exhibiting an interactive suppression of x,y shrinkage.

Process for the constrained sintering of asymmetrically configured dielectric layers

A thick film hybrid multilayer circuit characterized by circuit components that are electrically interconnected with a multilayer structure composed of multiple layers of conductors interlaid with layers of a dielectric material in order to achieve high component density. The circuit components of the hybrid circuit are bonded to the multilayer structure with a novel soldering technique employing multiple solder compositions, which reduces the occurrence of dielectric fatigue cracking from thermal cycling. As a result, the multilayer structure exhibits significantly enhanced thermal fatigue resistance.

Solder process for enhancing reliability of multilayer hybrid circuits

Air-fireable thick film conductor compositions are provided. The conductor composition is a paste containing (1) an inorganic powder made from an intermetallic phase copper-aluminum powder, aluminum powder and a glass frit and (2) an inert organic liquid vehicle.

Air-fireable conductor composition

An improved electrode having a surface mixture of nickel and porous nickel produced by applying a paste mixture of NiAl.sub.2 and Ni.sub.3 B together with a vehicle to a substrate. After burning off the vehicle and firing in air at a temperature of 450.degree. to 650.degree. C. and thereafter sintering at a temperature of 800.degree. to 900.degree. C. in nitrogen, the coating on the substrate contains Ni.sub.2 Al.sub.3, NiAl.sub.2 B and nickel together with a thin overlayer of B.sub.2 O.sub.3. After removing the intermetallic aluminum, boron and boron oxide by dissolution with sodium hydroxide, the surface of the substrate contains Raney nickel supported on a structure of nickel. The resulting electrodes can be used as cathodes in water or brine electrolysis cells.

Porous nickel coated electrodes

Thick film conductor compositions containing silver powder and lead bismuthate glass frit powder and an organic vehicle/solvent system are presented for use as grid metallizations to the n-type layers of n- on p- silicon solar cells.

Thick film silver metallizations for silicon solar cells

A process for making an electrode having a Raney nickel surface layer of thickness greater than 75 microns and an average porosity of at least 11%, comprising interdiffusing aluminum and nickel on a conductive metal core at a temperature of at least 660.degree. C. to form a nickel-aluminum alloy layer on the core from which layer aluminum is selectively dissolved. When used as a cathode in an electrolytic cell for producing hydrogen, chlorine and caustic from brine, the electrode exhibits low hydrogen overvoltage.

Process for making catalytically active Raney nickel electrodes

An improved electrode having a porous nickel surface layer of greater than 75 microns in thickness and at least 11% in porosity is produced by a process which includes interdiffusing aluminum and nickel at a temperature of at least 660.degree. C. to form a nickel-aluminum alloy layer from which aluminum is subsequently selectively dissolved. When used as a cathode in an electrolytic cell for producing hydrogen, chlorine and caustic from brine, the improved electrode exhibits exceptionally low hydrogen overvoltage.

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Chapel Hill, NC, United States of America

Christopher R Needes