The EIP Suite of Electrical Package Analysis Tools: A Description, Brief History of Related Work at IBM and Discussion of Electrical Issues and Interesting Package Effects

Event Date: April 10, 2008
Speaker: Dr. Barry J. Rubin
Speaker Affiliation: IBM
Time: 9:00 AM
Location: MSEE 239
Contact Name: Host: Prof Dan Jiao
Open To: Acceptable for ECE694A


The EIP Suite of Tools is a rich set of tools for comprehensive package analysis.  It includes tools for two-dimensional capacitance and inductance analysis; three-dimensional capacitance and inductance analysis;DC resistance calculation; and full-wave, three-dimensional analysis. Also included is a set of tools for generating standard formats and converting industry standard physical descriptions to the EIP physical format (.modla) and converting back.

These tools can be traced back to early work on capacitance and inductance calculation within IBM.  Some of the kernels of these tools were updated with more advanced mathematical approaches, tied to a graphical user interface, and interfaced with advanced automatic gridding algorithms. Others were developed using the latest hierarchical algorithms, advanced iterative, FFT, and other techniques.  These tools were designed to handle complicated structures, such as single- and multi-chip modules, and in their present or earlier forms have been used to design many generations of IBM computer server products.

The tools provide highly-predictable results, allowing a skilled user to obtain results of high resolution and accuracy.   Anyone with a basic knowledge of simple circuits should feel comfortable using these tools because the required boundary conditions are entered using lumped resistances, capacitances, and inductances and voltage or current sources.   Microwave engineers, however, can also use these tools to design antennas, and EMC engineers can use the tools for calculating electromagnetic effects related to interference and other issues. 

In this talk, we describe the EIP tools and the developments at IBM that preceded them.  We review the fundamental issues that designers need to address in computer design, namely signal reflection and transmission, coupled and delta-I noises, electromagnetic interference and compatibility, and DC power distribution, and point out where special care is needed in their calculation.  We then describe a number of structures and effects observed based upon use of the EIP tools, and these include: common errors associated with ignoring signal return currents; noncausal effects caused by insufficient gridding; errors associated with too coarse modeling of resistive and inductive spreading effects; errors caused by failure to consider all the segments that form inductive loops; how adding small decoupling capacitances can worsen, rather than improve switching noises; and why negative inductances are often both physical and expected.


Barry J. Rubin, Ph.D., is a research staff member at IBM's T. J. Watson Research Center, N.Y. He formerly worked on the circuit design of CMOS and charge-coupled devices and then in electrical package analysis, doing pioneering work on the understanding and calculation of signal propagation and delta-I noise in single and multi-chip ceramic modules. Dr. Rubin later focused on electromagnetic techniques: He developed the first rigorous technique for calculating the propagation parameters for signal lines and other features situated in a mesh plane environment; he developed the approach for using two-dimensional rooftop functions to model volume polarization effects; he developed comprehensive techniques using physically-based gridding to automatically refine meshes for conductor proximity effects; and he co-invented a robust technique for handling inhomogeneous structures. More recently, he developed reduced-coupling and other advanced techniques for handling large problems. He has worked on nearly all aspects of the electrical analysis of packages and been personally involved in the analysis of many generations of IBM server products.  Dr. Rubin's work appears in numerous conference and journal articles. He has mentored dozens of engineers and interns, and he holds an IBM Fifth Plateau Invention Achievement Award.