G. Hanreich, L. Musiejovsky, J. Nicolics, K. Riedling:
"Development and Application of an Efficient Algorithm for Thermal Simulation of High-Lead Count Packages";
Talk: International Spring Seminar on Electronics Technology (ISSE), Freital-Dresden, Germany; 05-18-1999 - 05-20-1999; in: "Conference Proceedings ISSE '99 - Technology Drivers in Electronics", W. Sauer, K.-J. Wolter (ed.); Verlag Dr. Markus A. Detert, (1999), 16 - 22.

Reliability and lifetime of electronic components are mainly influenced by thermomechanically induced stress and thermal load. These factors can be minimized by optimizing the component's design using thermal simulation methods. However, rising complexity of electronic components requires new simulation tools capable of features like economic model creation allowing to use very high node numbers, and efficient calculation methods. As a new approach a simulation tool, based on an alternating-direction implicit algorithm (ADI-method) has been developed for transient thermal simulation. While conventional explicit algorithms require an uneconomically large number of time steps and are not applicable in case of large node numbers, and implicit procedures require the solution of large sets of simultaneous equations at each time step, the ADI-method needs only a line-by-line solution of small equation systems. A further advantage is the tridiagonal form of these equation systems which can be solved by a simple direct method. This method is applied for thermal characterization of a 176 lead QFP-package. For this purpose a model with 320.000 nodal points has been created. Steady-state and transient thermal qualities of the package under various boundary conditions as specified by the Joint Electronic Device Engineering Council (JEDEC) are investigated by comparing results of simulations and experimental procedures.