Delco Electronics Corporation

Aparna Vaidyanthan

Robert K Constable

Shailendra Verma

Ralph Edward Cornell

Curt A Erickson

A surface mount circuit device (,), such as a flip chip, of the type which is attached to a conductor pattern (,) with solder bump connections (,). The solder bump connections (,) are formed by reflowing solder on shaped input/output pads (,) on the device (,), with the shape of the pads (,) being tailored to favorably affect optimal distribution, shape and height of the solder bump connections (,) following reflow soldering of the device (,) to the conductor pattern (,). The solder bump connections (,) are preferably characterized by a shape that increases the stand-off height of the device (,). The shaped solder bump connections (,) also promote stress relief during thermal cycling, improve mechanical bonding, allow better penetration of cleaning solutions, and improve flow of encapsulation materials between the device (,) and its substrate (,).

Solder bump input/output pad for a surface mount circuit device

A strain gauge has a stainless steel substrate with a dielectric coating comprising two dielectric layers. A circuit comprising conductors, resistors and piezoresistors in a Wheatstone bridge configuration is formed on the dielectric. One dielectric layer is to adhere to the steel and a second is to form a barrier against diffusion of the first layer into the piezoresistor material. An amplification and signal conditioning circuit is applied adjacent the bridge. The steel substrate is to be welded or bolted at its marginal portions to a structure subject to strain.

Growing community of inventors

Carmel, IN, United States of America

Aparna Vaidyanthan