Reliability and contact resistance of polysilicon beam leads for use in a high-density connector

A study was conducted to measure and characterize the reliability of polysilicon cantilever beams with electroplated gold pads for use in a high-density connector. Beam leads of various lengths and widths with electroplated gold contact pads on their ends were tested over 1000 cycles to determine their mechanical reliability, and to measure their contact resistance with gold bumps on a separate substrate. The optimum length and width of polysilicon beams, insulated on top and bottom with CVD oxide and nitrides, were determined to be 400 /spl mu/m and 125 /spl mu/m, respectively. The contact resistance was measured to be about 1.22/spl plusmn/0.68 /spl Omega/ after 1000 cycles. These results indicate very high-density connectors with high mechanical reliability and low contact resistance can be fabricated.