Electromagnetic and thermal characterisation of PCB planar transformer

A comparison of existing design guidelines for printed circuit board (PCB) planar transformers with 3D finite element analysis simulations is presented. The IPC-2152 standard for determining current carrying capacity of tracks on PCBs was compared with FEA simulated results of the transformer winding temperature rise. Core temperature rise was with manufacturer supplied thermal characteristics for planar E cores. Simulations showed large deviation from the IPC-2152 standard but a good agreement with manufacturer supplied data. Through the simulations the non-uniform distribution of temperature and hotspots in the transformer were observed which cannot be predicted by the well-known design standard for PCB tracks or design guidelines for planar transformer cores.