Motorola Corporation

Curtis W Mitchell

Howard M Berg

Frank Djennas

Barry C Johnson

Gary L Lewis

A process for flashing a thin layer of silver on metal leadframes using no mask steps and a minimal amount of silver. An unmasked metal leadframe is placed into a cleaning bath that includes silver in solution and has no outside electrical driving force to assist plating. The leadframe is removed from the cleaning bath once a uniform silver layer having a thickness of 100 to 1000 angstroms is plated thereon. The silver layer need not be exact and, therefore, it is not critical that the period of time the leadframe remains in the cleaning bath be exact.

Silver flashing process on semiconductor leadframes

A one step metallization is disclosed for applying a layer of gold or gold alloy to the back of a silicon substrate to facilitate bonding that substrate to a metallized package member. The gold is applied to the substrate, for example by evaporation, while the substrate is maintained at a temperature between about 200.degree. C. and about 360.degree. C. Following the deposition the substrate is quickly cooled to room temperature. The thickness of the gold layer and the deposition temperature are adjusted to insure that the silicon diffusion profile is contained within the gold film during deposition. This insures good adhesion of the gold to the silicon substrate and provides a pure gold surface layer necessary for optimum bonding of the semiconductor substrate to a metallized package portion.

Gold metallization process

A semiconductor package for use in fiber optics systems is disclosed wherein optical performance is enhanced by a lens between a fiber segment and the photoactive area of the semiconductor. The lens is spaced a predetermined distance from the fiber by a layer of elastomer. During assembly of the package, the fiber provides a convenient means for handling the lens.

Fiber optics semiconductor package

A relatively thick ring of polymer or metal encircles the emitting area of a light emitting diode. A spherical lens rests on the ring and is both accurately located with respect to and spaced from the emitting area.

LED having self-aligned lens

A package for fiber optic semiconductor devices is disclosed in which heat is conducted by both a heat spreader and through a plastic enclosure portion of the package.

Growing community of inventors

Phoenix, AZ, United States of America

Curtis W Mitchell