Packaging and interconnect design and analysis using FDTD

This paper presents information about the development of a versatile FDTD solver and explores design issues relevant to the packaging and interconnect design engineers. The EM analysis development is called "LC". It consists of a GUI interface with the ability to auto-mesh a graphically defined user geometry. A number of different excitations are possible, and the outputs can yield not only field data, but also voltages, currents, impedances, inductances, capacitances and fluxes. Further, both time and frequency-domain data are available on output. It also allows for 2-D visual simulations of the full 3-D problem being simulated during time-stepping. This is very useful in identifying problem areas with a particular design. Another very important and relevant feature of the LC tool is an interface to SPICE which will analyze a circuit based on FDTD field values linked to SPICE at each time step. The SPICE interface also generates output voltages and/or currents that modify the FDTD field values which are then used during the next FDTD time-step. Essentially LC is an integrated EM model editor, simulator, and analysis tool. It is composed of 100,000 lines of C and Fortran, uses OSF/Motif, and is portable to all commercial Unix platforms. Its companion batch simulator, FDTD, and plotting program, LCPlot, are also included in the executable distribution.