This work presents an analytical electro-thermal model for SMD-based printed circuit board (PCB) power converters. Temperature-dependent component losses are derived from analytical models and a 3-D thermal resistance network is employed to characterize the temperatures across components and PCB paths. Furthermore, the work explores the mechanical and thermal interaction within the PCB paths, concurrently analyzing semiconductor switches and the power inductor in synchronous commutation cell configurations. The proposed model undergoes evaluation with two different PCB layouts of a synchronous boost converter, operating at 350 kHz with 50 W and 75 W. Model-generated temperatures are compared with experimental measurements using a thermal imaging camera and with Finite Elements Analysis (FEA) in Ansys Icepak. The acquired results validate the accuracy of the proposed model.