Delphi-like dynamical compact thermal models using model order reduction

Abstract

Delphi-like Boundary Condition Independent (BCI) Compact Thermal Models (CTMs) are the standard for modelling single die packages. However their extraction, particularly in the transient case, will be time consuming due to complex numerical simulations for a large number of external conditions. Lately, new approaches to extract a BCI Dynamical CTM (DCTM), based on Model Order Reduction (MOR) have been developed. Despite the numerous advantages of this recent method, the lack of numerical tools to integrate reduced-order models (ROM) makes it difficult to use at board level. In this study, a novel process flow for extracting Delphi-inspired BCI DCTMs is investigated. Thus a detailed three-dimensional model is replaced by a BCI-ROM model using FANTASTIC matrix reduction code to generate the data used in the creation of a Delphi-style BCI DCTM. That hybrid reduction method has been applied to an industrial single-chip package, named QFN16. Its derived CTM and DCTM have been compared in term of accuracy and creation time for both approaches: in-house Delphi-inspired and MOR based. The results show that for a similar accuracy, the integration of MOR technique allows minimizing the time-consuming numerical simulations and so to reduce the thermal network creation time by 80%.