An ECU, a control box, and a CMF using the ECU are provided. The control box includes a heat sink and the ECU. The ECU include a support bracket mounted on the heat sink, a power supply board supported by the support bracket, and a signal board stacked over the power supply board and electrically connecting with the power supply board. The support bracket is made of an insulation material. The power supply board carries a plurality of power devices which are in contact with the heat sink for heat dissipation multiple power devices.