A light emitting diode package structure comprising: - at least one LED die; a submount having electrodes (32, 34), wherein the at least one LED die is mounted on the submount; a molded package body formed of an electrically insulating plastic material; a metal slug (44, 140) extending through the body and molded into the body, a top and bottom surface of the slug being exposed through the body, the submount being mounted on the top surface of the slug such that the at least one LED die is electrically insulated from the slug and thermally coupled to the slug; male metal connector terminals (36, 38) molded into the body, the connector terminals being electrically coupled to the submount electrodes for supplying power to the at least one LED die, the male connector terminals being configured for connection to a power supply by means of corresponding female connectors; clamping screw openings (52, 54) formed by the package structure configured to allow the body and slug to be firmly clamped to a thermally conductive mounting structure by clamping screws such that there is a thermal coupling between the bottom surface of the slug and the mounting structure, the clamping screw openings being at least along two opposite edges of the molded package body with the slug between the clamping screw openings; a metal plate molded into the bottom of the body; and metal tabs on the metal plate extending into the clamping screw openings such that a downward movement of the clamping screws presses down on the tabs, wherein the metal plate being mechanically coupled with the slug such that thermal contact between the exposed slug and the mounting structure can be increased by means of the metal tabs during mounting the package structure on the mounting structure. - at least one LED die; a submount having electrodes (32, 34), wherein the at least one LED die is mounted on the submount; a molded package body formed of an electrically insulating plastic material; a metal slug (44, 140) extending through the body and molded into the body, a top and bottom surface of the slug being exposed through the body, the submount being mounted on the top surface of the slug such that the at least one LED die is electrically insulated from the slug and thermally coupled to the slug; male metal connector terminals (36, 38) molded into the body, the connector terminals being electrically coupled to the submount electrodes for supplying power to the at least one LED die, the male connector terminals being configured for connection to a power supply by means of corresponding female connectors; clamping screw openings (52, 54) formed by the package structure configured to allow the body and slug to be firmly clamped to a thermally conductive mounting structure by clamping screws such that there is a thermal coupling between the bottom surface of the slug and the mounting structure, the clamping screw openings being at least along two opposite edges of the molded package body with the slug between the clamping screw openings; a metal plate molded into the bottom of the body; and metal tabs on the metal plate extending into the clamping screw openings such that a downward movement of the clamping screws presses down on the tabs, wherein the metal plate being mechanically coupled with the slug such that thermal contact between the exposed slug and the mounting structure can be increased by means of the metal tabs during mounting the package structure on the mounting structure. a submount having electrodes (32, 34), wherein the at least one LED die is mounted on the submount; a molded package body formed of an electrically insulating plastic material; a metal slug (44, 140) extending through the body and molded into the body, a top and bottom surface of the slug being exposed through the body, the submount being mounted on the top surface of the slug such that the at least one LED die is electrically insulated from the slug and thermally coupled to the slug; male metal connector terminals (36, 38) molded into the body, the connector terminals being electrically coupled to the submount electrodes for supplying power to the at least one LED die, the male connector terminals being configured for connection to a power supply by means of corresponding female connectors; clamping screw openings (52, 54) formed by the package structure configured to allow the body and slug to be firmly clamped to a thermally conductive mounting structure by clamping screws such that there is a thermal coupling between the bottom surface of the slug and the mounting structure, the clamping screw openings being at least along two opposite edges of the molded package body with the slug between the clamping screw openings; a metal plate molded into the bottom of the body; and metal tabs on the metal plate extending into the clamping screw openings such that a downward movement of the clamping screws presses down on the tabs, wherein the metal plate being mechanically coupled with the slug such that thermal contact between the exposed slug and the mounting structure can be increased by means of the metal tabs during mounting the package structure on the mounting structure.