Impact of Chipset Configuration on Thermal Performance of Smartphones

Smartphone features are dependent on design and performance of IC chipsets hosted within it. Many times, thermal performance of a chipset varies in one device vs. another due to differences in IC placement, PCB configuration, and system-level thermal design. This paper reports a comprehensive study on how architecture of chipset placement and PCB shape impacts thermal performance of a given chipset. In addition, it explores how implementation of Thermal Interface Materials (TIMs) impacts junction and skin temperatures. A phone model reflecting thermal and mechanical characteristics of a high-tier smartphone is utilized as the platform to drive the study. Thermal performance of a same chipset is evaluated based on two PCB shapes (L-shape and H-shape) and two placement architectures (single-side and double-side). Junction temperature of IC packages and skin temperature of the phone are monitored to highlight the thermal performance of each configuration. It is found that double-side placement thermally outperforms single-side placement as it can utilize more heat sinking features within smartphone. Further, the H-shape PCB thermally outperforms the L-shape PCB as the former facilitates more in-plane heat spreading. Findings highlight the importance of striking a balance between junction and skin temperatures in smartphones.