Abstract

The solder joints that connect the integrated circuit (IC) to the printed circuit board (PCB) are subject to failure due to mechanical stresses during thermal cycling caused primarily by thermal mismatch. When we started doing this class of simulations at MicroConsult, a typical simulation would take weeks to conclude. Over the years, with the help of software enhancements and new hardware capabilities, these runtimes could be reduced down to a few hours. All improvements combined, we could achieve a speedup of more than 300 running exactly the same simulation models from just a decade ago. We will report on results from actual real world simulations that have been performed on MicroConsult’s HPC cluster. That includes a comparison of hardware improvements for Intel Xeon CPUs going back to the Broadwell generation from 2015 up to the Ice Lake generation from 2021. In addition, we will show the complementing improvements implemented in the Ansys Mechanical code. The key to achieving optimal performance is to do better than just use more cores and hope for the best, but to set up a balanced system by utilizing modern CPUs with advanced instruction sets (AVX 512), enough RAM, a fast mass storage system and the best performing interconnect. Beyond using optimal hardware, it is imperative that a user has some understanding of the scaling limitations of their FEA software. For Ansys Mechanical, the largest accelerations are typically achieved running models consisting only of solids. Adding contacts generally degrades performance and scaling. However, by utilizing features such as small sliding contact and contact splitting, that became available during the latest release cycles, those limitations could be largely overcome, especially at high core counts. Our recommendation is to use HPC for your daily simulations: it is not only an enabler for solving large finite element models but will also dramatically improve productivity. Instead of waiting overnight to get to the critical point, HPC can help do the same amount of work over an extended coffee break. Background: MicroConsult is a high performance computing partner to Ansys and works closely together with the Ansys Mechanical solver team in Canonsburg.