Widespread method conducted emissions tend to be a result of parasitic capacitances like those of your heatsink and transformer together with the board format, and switching voltage waveform over the change. An unbroken ground plane located to the outer surfaces of the PCB gives the shortest return path for EMI, https://buyacxionfentermina30mg29382.digitollblog.com/31022831/the-definitive-guide-to-fn3270h-200-99