Delco Electronics Corporation

Delphi Technologies, Inc.

Christine Redder Coapman

Bruce Alan Myers

John Karl Isenberg

Christine Ann Paszkiet

James A Blanton

Anthony John Stankavich

Ralph Edward Cornell

A thick-film conductor, a method for forming the conductor, and a method for attaching a surface-mount circuit device to the conductor with a solder connection. The conductor is formed of a thick-film conductive ink that would normally produce a solderable conductor, but is rendered unsolderable by additions of a fine inorganic particulate material. A solderable region, preferably a pillar, is then selectively formed on the unsolderable conductor to determine the distribution and height of the solder connection on the conductor. In order to suitably affect the solderability of the conductor, the particulate material is present as a fine dispersion and in a sufficient quantity, but not in quantities that significantly affect the electrical, mechanical and processing characteristics of the conductor.

Method for controlling solderability of a conductor and conductor formed thereby

A conductor (112) and method for attaching a surface mount device to the conductor (112), in which solder bumps (16) formed by the method are characterized as being accurately located on the conductor (112) and having a bump height and shape that provides stress relief during thermal cycles, minimizes bridging between adjacent bumps (16), allows penetration of cleaning solutions for removing undesirable residues, and enables the penetration of mechanical bonding and encapsulation materials between the chip and its substrate (10). Such benefits are achieved by forming the conductor (112) of a nonsolderable material, on which a solderable pillar (114) is formed. The pillar (114) is selectively formed to have a shape that determines the distribution and height of the solder bump (16) on the conductor (112).

Method for controlling solder bump shape and stand-off height

A method of forming solder stops on a thick film, comprising a conductive metal and an inorganic oxide, including the step of directing a laser beam onto the film to form a surface consisting essentially of fused inorganic oxides which acts as a solder stop.

Electrical connector having energy-formed solder stops and methods of

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Kokomo, IN, United States of America

Christine Redder Coapman