Modeling the Electrical Parasitics for Large I/O Ball Grid Array Packages for RF Applications

This publication describes a computer program that can rapidly generate RF models of the electrical parasitics for either two layer low cost BGA packages or for multi-layer high performance BGA packages. The user enters simple dimensional information for the geometry's of the package from the package drawings. There are two files generated as outputs of the program. One file is a table containing all of the leads with each of the lead's parasitics listed along with the input data and some of the calculated dimensions. The other file generated -is a “SPICE deck.” This file contains all the leads' parasitics in the form of a circuit topology that can be used as input for a SPICE simulation. The Package Parasitic Model Program is helpful in integrated circuit package design and analysis by delivering a complete model of package parasitics within a few minutes. Also presented in this paper is a technique of measuring large I/O BGA packages to 2 GHz and a comparison of sample measurements to simulated models generated by the program.