Tab Lead Capacitor

Abstract

Differential thermal expansion between a monolithic chip capacitor and the common hybrid substrate materials gives rise to significant stresses in the chip. For conventional attach techniques and conventional chips, these stresses may exceed the strength of one or more of the components, chip, termination, substrate metallization, or solder, in the assembly with disastrous effects. Further, common choices of materials aggravate the basic problem by "building-in" opportunities for delayed failure due to slow formation of brittle intermetallies in the assembly. We have examined this problem in detail, and we offer a solution that incorporates material, process, and design innovations which essentially eliminate these problems as sources of device failure.