Other

Fry Metals, Inc.

Norbert J Socolowski

James L Bierschenk

Richard A Howarth

A thermoelectric heat pump which is resistant against thermal stresses incurred during thermal cycling of Thermal Cyclers or the like between cold and hot temperatures of about 0.degree. C. at a ramping rate up to about 1.degree. C. per second has improved joints between the thermoelements and electrical conductors which have low electrical resistance and which substantially reduce fractures during thermal cycling. The joints include a tin-silver-indium solder containing by weight about 95% tin, 3.5% silver, and 1.5% indium, or a tin-silver-cadmium solder containing by weight about 95.5% tin, 3.5% silver, and 1.0% cadmium. A robust nickel diffusion barrier between the joints and thermoelectric elements ends provides additional improvement against joint fracture.

Thermoelectric cooler

A solder preform comprises a body of solder material having at least three legs extending outwardly from a generally central base portion. In a method of use, the preform is disposed between two solderable surfaces (such as the metalized undersurface of a semiconductor die and a support surface therefor), heated above the solder melting point to cause the solder to flow between the surfaces, and then cooled to solidify the solder and effect the bond. The preform configuration is such that the melting solder flows generally outward from the central base portion to expel gases from between the surfaces to be bonded.

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Denville, NJ, United States of America

Norbert J Socolowski