Electrical characterization of ball grid array packages from S-parameter measurements below 500 MHz

Abstract

Ball grid array (BGA) packages have been characterized from one port S-parameter measurements by shorting and opening the connection on the ball side of BGA packages. Transmission line parameters (resistance, inductance and capacitance) using the /spl Gamma/ equivalent circuit model are extracted from the measured S/sub 11/ parameter. Extracted resistances are strongly dependent on frequency, but extracted inductances and capacitances are nearly constant up to 500 MHz. Extracted capacitances are well matched to those measured from an LCR meter and calculated from a three-dimensional (3-D) simulator, Capacitance in a transmission line plays an important role in electrical performance for packages so that we may model a transmission line as a single capacitor. Extracted capacitances using the single capacitor model also well represent the measured S/sub 11/. These results suggest that the single capacitor model can be efficiently used for the transmission line model in BGA packages up to 500 MHz.