An integrated circuit package includes a support substrate with front connection pads on a front surface thereof and rear connection pads on a rear surface thereof. An integrated circuit device is mounted to the support substrate in flip chip orientation with a front face of the integrated circuit device facing the front surface of the support substrate. A thermally conductive heat spreader is mounted adjacent a rear face of the integrated circuit device. External direct thermal paths thermally couple a top surface of the thermally conductive heat spreader to the rear surface of the support substrate. Each external direct thermal path includes a first portion on and in direct contact with thermally conductive heat spreader, a second portion on and in direct contact with an external side surface of the support substrate and a third portion on and in direct contact with the rear surface of the support substrate.