Delco Electronics Corporation

Delco Electronics Corporatinon

Wayne Anthony Sozansky

Darrel Eugene Peugh

Donald Ray Disney

James M Himelick

James M Rosson

George C Wolf

Susan Acheson Mack

Michael Ray Witty

Richard M Sutherland

Stuart E Longgood

Howard E Harrell

Michael Patrick Meehan

Douglas E Gullion

Michael D Gibson

Robin L Sellers

A method of preventing solder reflow of a SMT component (14) attached with solder (22) to a circuit board (10) that subsequently undergoes a wave soldering operation. The method generally entails the use of a thermal shield (18, 28) that is either part of the support structure (12) for the circuit board (10) during the wave soldering operation, or a temporary mask (28) applied directly to a surface of the circuit board (10). In each case, the thermal shield (18, 28) is configured to contact and completely cover a limited surface region of the circuit board (10) directly opposite the SMT component (14). To provide adequate thermal protection, the covered surface region is preferably as large as or larger than the surface area of the component (14). In a preferred embodiment, the perimeter of the thermal shield (18, 28) has a tapered thickness, e.g., a beveled edge, that enables uninterrupted wave soldering of the surface surrounding the thermal shield (18, 28).

Method of preventing solder reflow of electrical components during wave

A process and combination of materials for underfilling a surface-mount IC device (12), such as a flip chip, for the purpose of increasing the thermal cycle fatigue life of the terminals (14) that attach the device (12) to a thin-laminate organic circuit board (10), such as a printed wiring board (PWB) or printed circuit board (PCB). The process parameters and materials, including the underfill (20), masking (22) and cleaning materials used, exhibit a synergistic effect that increases thermal cycle fatigue resistance to a level at which a flip chip processed in accordance with this invention is capable of reliably withstanding at least 1000 one-hour cycles between -40.degree. C. and 150.degree. C. The materials and the manner in which the device (12) and circuit board (10) are prepared for application of the materials are critical to eliminating tendencies for inconsistent reliability in underfilled SM devices.

Process for producing flip chip circuit board assembly exhibiting

A semiconductor device characterized by a field limiting ring formed by a number of field limiting cells that define wells which are laterally diffused to form a continuous equipotential ring between interior and exterior regions of a semiconductor device. A number of active cells are formed in the interior region, and are therefore delineated from the exterior region of the device. Each of these active cells is a transistor, and preferably a field-effect transistor, whose structure is essentially identical to the field limiting cells, except that their wells are not merged but instead are isolated from each other. The field limiting ring increases the breakdown voltage and the ruggedness of device, and therefore enables the device to sustain high voltages when the device is in the off-state. The process does not require masking, implanting and diffusion steps for the sole purpose of forming the field limiting ring, but is instead fully integrated with the semiconductor process for forming the active cells. The field limiting cells also contribute to forward current conduction when the device is in the on-state, thereby lowering the on-resistance of the device.

Method for making semiconductor device having field limiting ring

Semiconductor device having field limiting ring and a process therefor

A method of suppressing adherence of silicon particles to IC bond pads, and corrosion thereof, during the dicing of silicon wafers by sawing. An anion of an organic acid is added to saw coolant water.

Method of preventing aluminum bond pad corrosion during dicing of

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Greentown, IN, United States of America

Wayne Anthony Sozansky