A flexible circuit assembly for accommodating a plurality of power electronic devices, including an insulating cover layer having first openings for power electronic devices, a flexible conductive layer arranged under the insulating cover layer and attached with a first adhesive to the insulating cover layer, an intermediate insulating layer arranged under the flexible conductive layer and attached with a second adhesive to the flexible conductive layer, the intermediate insulating layer having second openings, a plurality of heat-conductive elements arranged inside the second openings, a first thin heat sink layer, the heat-conductive elements arranged to be in contact with an upper surface of the thin heat sink layer and the lower surface of the islands via heat-conductive material; and a second thin heat sink layer, upper surfaces of the power electronic devices arranged to be in contact with a lower surface of the thin heat sink layer and the lower surface of the islands via heat-conductive material.