Integrated Temperature and Stress Sensors in Fan-Out Wafer-Level Packaging to Better Achieve the Third-Generation Reliability of Electronic Systems

To satisfy the developmental requirements of applications, such as autonomous driving, high-performance computing, and the Internet of Things (IoT), the integration density, performance, and reliability tradeoff of electronic systems are posing numerous challenges. Prognostics and health management (PHM) using multiple types of sensors can address reliability problems and enhance the functional safety of electronic systems. However, the limited integration density of conventional electronic packaging indicates that functional chips can only replace sensor chips for physical quantity monitoring, without simultaneous functional degradation monitoring and fault identification. This study proposed an integration method that is compatible with front and rear processes to integrate temperature and stress sensors into the power-driven module, that is, fan-out wafer-level packaging technology. First, the temperature and stress sensors are calibrated using a microloading platform and sensitivity consistency is ensured. Second, the temperature inside the module under various working conditions is evaluated using the data obtained by temperature sensors. The stress data inside the micromodule under mechanical loading are obtained through stress sensors. The proposed method can realize in situ monitoring inside advanced packaging and provide considerable data for PHM research.