Motorola Corporation

William L Hunter

Michael B McShane

Israel A Lesk

George W Hawkins

James J Casto

Ronald E Thomas

Paul R Theobald

A molded semiconductor package having a flagless leadframe wherein a semiconductor die is disposed in or above a die opening of a leadframe. This allows for thin, symmetrical packages and packages having a minimum number of material interfaces to be manufactured because no leadframe flags and minimal die bond material are employed. The present invention further includes guard rings to protect high stress areas of the semiconductor die from damage and heat spreaders to more effectively spread heat dissipated by the semiconductor die.

Flagless semiconductor package

A heat spreader which is self-positioning into a mold cavity prior to encapsulation in plastic is provided. To minimize capacitance between the spreader and a metal lead frame having a semiconductor die mounted thereon, the heat spreader has a frame with notches in the opposite ends which define bifurcated limbs. Lateral standoffs extend from each of the sides thereof and feet extend from the bottom surface thereof. A central portion extends a predetermined distance from the top surface thereof for intimate positioning with the lead frame. The standoffs, limbs and feet are sized to firmly position the heat spreader upon insertion into the mold cavity. To maintain substantially constant capacitance between the spreader and the lead frame from part to part, each bifurcated limb has an inner edge which complements or conforms to the portion of the lead frame which will overlay the limb in the encapsulated plastic.

Self-positioning heat spreader

Growing community of inventors

Scottsdale, AZ, United States of America

William L Hunter