Analysis of electrical resistance monitoring of PCMCIA interconnection failures

Abstract

High resolution electrical resistance measurements were used to monitor interconnection failures on PCMCIA test cards. The cards were clamped at the connector end by a fixture which was attached to a shaker. The shaker was excited at the card's first resonant mode to induce interconnect failures. During the vibration, electrical resistance of the interconnects was monitored with sufficient resolution to measure the strain induced resistance change. Three daisy-chained modules on the PCMCIA test card were studied. These modules were: a 176 lead QFP, a 40 lead Type II TSOP, and a 40 lead Type I TSOP. The resistance measuring technique used has been called resistance spectroscopy and had a resolution of better than 1 /spl mu//spl Omega/. Resistance measurements were made on nine test cards, and partial measurements were made on another eleven. A finite element analysis of the surface strain on the card was used to estimate the relative contributions to the measured resistance from the solder joints, leads, and card traces.