Modeling the Power and Ground Effects of BGA Packages

Ground bounce noise and power supply noise are the major concerns in the electrical design of ball grid array (BGA) packages, therefore accurate models of the package's ground and power structures are needed for circuit simulators. This innovative new software is targeted for the engineer who, at his laptop PC, can rapidly generate accurate power and ground electrical models of an entire BGA package. Using the accepted approximation equations of Grover and Walker [4], [5], the program was designed to be fast and portable contrasting other methods of modeling in which such attributes were sacrificed for greater accuracy. Operation consists of entering the available data, and in just minutes retrieving a parameter listing and two sub-circuit models simultaneously, one circuit for power and one for the ground of the package. The values of inductance and capacitance generated by the program closelymatch those generated by Grover, Walker, and Caggiano [4]??-??[6]. The listing can be used as an evaluation tool for a specific package (e.g., during a design review when critical information is needed quickly) while the circuit models can be used in a simulation program with integrated circuit emphasis (SPICE) circuit simulation of the integrated circuit (IC). These separate models, designed with as few components as possible in order to reduce the complexity of the SPICE topology while still maintaining accuracy, can be either incorporated with signal package models or can be simulated alone.