Serious thermal environment stress has a bad influence on the normal operation of most electronic components, leading to the quick failure of electronic components that will push the failure of the whole product. In recent years, with the application of large-scale and hyper-scale integrated circuits (ICs) and surface mount technology (SMT), electronic products embrace the features of miniature, high density and high reliability. Electronic products in aerospace field are the most susceptible to the features of high integrity, high accuracy, high complexity and miniature, which results in the increasing requirement of thermal design of electronic system. Heat problem has been an important element in influencing the performance and reliability of electronic system.

As a significant part of electronic devices, whether PCBs have a reasonable design is directly related to the performance of the devices. If PCB design fails to meet the thermal design requirement, electronic devices will possibly be damaged. The growing circuit module integrity and massive application of ICs and multi-chip module (MCM) contribute to the improvement of assembly density, leading to the big density of heat flow on PCBs. A PCB with excellent performance not only has correct connection in terms of layout and routing, but also can ensure its thermal reliability for safe operation. Therefore, it's of great significance to implement thermal design and analysis for PCBs.