System Thermal Analysis of RF SiP Module in Smartphone

Abstract

The structure of System-in-Package (SiP) in package series has been widely used for many years. A substrate-based platform combines more and more synchronous applied components such as antenna device, RF filter, PA, LNA, RF switch, CMOS, application processor and passives. Its application includes camera module, 5G RF FEM, WiFi module. The main strategies and advantages of SiP are small form factor, flexible design, low cost and time to market. However, the small form factor and high density components will bring more thermal issues.In this work, numerical simulation and experiments in real conditions are applied to compare and evaluate the thermal performance of the system device with SiP module. Compact and detailed models of SiP module will be put into a systemic smartphone and compare their difference. Also, all the passive components, main components, metal frame, gap pad, air and so on will be set into both the simulated model and thermal test. As for heat dissipation, which is directly relative to the thermal performance will also be calculated and considered. The test and simulation results show the main components which SoC and RF modules included, deviation will be lower than 2%.For thermal design, temperature of main components should be first considered. Heat pipe, high thermal pad and some external units, which can dissipate heat, can all be suggested to put into the system as systemic thermal solutions. However, the system thermal solution will induce thermal interaction between SoC and RF module. Thermal co-design for both system and package will be executed for optimizing the thermal performance of all the critical components in a smartphone.