An electronic module containing a heat sink member, a flexible printed circuit board with electrical components mounted on both sides, and a protective cover. The heat sink member has an external surface containing a plurality of protruding fins. Its internal surface contains a raised grid of ribs with cavities present between the ribs. The cavities contain ceramic-filled silicone for improved heat transfer between the electrical components present on the circuit board, and the heat sink member. High heat-producing components are mounted on one side of the circuit board and are thermally coupled with the heat sink member by means of copper-plated through-holes in the circuit board. The protective cover is mounted to the internal surface of the heat sink and encloses the printed circuit board. A connector assembly serves to connect the electronic module to external circuitry.