System-Level Thermal-Electromagnetic-Circuit Coupling Analysis and Heat-Dissipation Design for an FOWLP-Based RF Module

Thermal effects pose a significant challenge to the electromagnetic transmission and circuit-level performance of compact radio-frequency (RF) modules based on advanced packaging technology. To address the limitations of conventional thermal-electrical coupling analysis methods and thermal-management approaches for RF integrated modules, this paper presents an algorithm-assisted modeling (AAM)-based thermal-electromagnetic-circuit coupling analysis method and package-level heat-dissipation layout designs for a fan-out wafer-level packaging (FOWLP)-based frequency-modulated continuous-wave (FMCW) RF module. First, an FOWLP-based FMCW RF module is developed as the analysis platform. Then, the proposed AAM-based method introduces the nonuniform temperature distribution into the electromagnetic and circuit-level analysis of the RF module. The results show that, as the ambient temperature increases, the S-parameter curves exhibit more pronounced fluctuations, and the reduction in intermediate-frequency signal-to-noise ratio (SNR) calculated by the AAM-based method relative to the uniform-temperature model also increases. Finally, three horizontal heat-dissipation layouts based on through-mold via (TMV) chips and solder-ball arrays are designed and evaluated. Without changing the original package dimensions, the proposed layouts improve both thermal and system-level RF performance. The hybrid layout reduces the maximum temperature and the area exceeding 40° C by 6.0% and 52.2%, respectively. The uniform layout provides the largest improvements in transmit power and intermediate-frequency SNR, with increases of 2.93,dB and 1.51 dB, respectively.