Decoupling and Reconstruction of Low-Quality Temperature Fields of Printed Circuit Boards

The increasing integration of electronic components and the complexity of printed circuit boards (PCBs) necessitate more efficient, accurate, and safe PCB inspection requirements. Using infrared thermography (IRT) instruments to measure temperature fields to identify PCB faults has the advantage of nonintrusive detection compared with the traditional electrical measurement method. This article establishes a thermal model of PCBs to overcome the mutual interference of heating components and enhance the quality of thermal images. A method for solving the power of heating components and decoupling the PCB temperature field using Green's functions is proposed. Furthermore, a robust and accuracy-optimized reconstruction (RAOR) method is proposed to reconstruct low-quality temperature fields, including denoising temperature fields with high-level noise and recovering incomplete temperature fields. The study validates the proposed temperature field decoupling method by analyzing a buck dc/dc converter, demonstrating its ability to accurately determine the thermal power of components and separate the temperature fields of different components. The proposed method uses partial temperature measurement points to estimate temperature fields, effectively suppressing the high-level Gaussian and salt-and-pepper noise in thermal images and restoring incomplete thermal images. The research results promise to expand the practical applications of online PCB testing technology and improve fault diagnosis.