Measuring Package and Interconnect Model Parameters Using Distributed Impedance

Abstract

The method developed here employs time domain reflectometry (TDR) techniques to measure model parameters of a lead in an interconnect or a package. TDR techniques have been broadly used in testing interconnect networks, since reflected waveforms provide excellent visualization of the signal path and waveform features can be readily associated with physical features of the device. What has not been widely appreciated is that quantitative values of network model parameters can be as easily extracted with TDR, in a manner that can make lumped model generation for an interconnect an easy job. The technique described here will be usefbl when a device already exists, for model pnmmeter geiieration from measurements, or, in cases where theoretical models also exist, for model parameter venficatioii. Although it can be used for a large variety of distributed impedance function carries the information about the local inductance and capacitance of the lead. Thus, lumped element LCZ models can be derived knowing this function. All the necessary calculations can easily be performed in time domain, thus avoiding artifacts that can arise with time-frequency domain transformations.