Delco Electronics Corporation

Susan Acheson Mack

Darrel Eugene Peugh

William David Higdon

Wayne Anthony Sozansky

James M Rosson

Ralph Edward Cornell

Michael Ray Witty

Robin L Sellers

Michael Patrick Meehan

Michael D Gibson

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 flip chip integrated circuit device (110) is provided having a surface, a perimeter, and solder bumps (112) located on the surface. At least one solder bump (112), and preferably a plurality of solder bumps (112), are spaced apart from the perimeter of the device (110). Electrically conductive runners (118) extend from the perimeter of the device (110) to each of those solder bumps (112) that are spaced apart from the perimeter, so as to electrically interconnect the solder bumps (112) to a point, such as a pad (116), at the perimeter. As a result, not all of the solder bumps (112) employed by the device (110) need be accommodated at the perimeter of the device (110), such that the size and number of the solder bumps (112) does not dictate the size of the device (110).

Solderable contacts for flip chip integrated circuit devices

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Kokomo, IN, United States of America

Susan Acheson Mack