Abstract: A hermetically sealed optoelectronic semiconductor device and package assembly comprises a metallic stud providing an electrical connection to one of the device electrodes, and a heat sink mounting block for the device mounted on and electrically connected to the stud. The device is mounted on the mounting block so that the optical axis of the device is aligned with the stud axis. The mounting block has a substantially annular bottom coaxial with the stud axis so that thermal stress generated between the stud and the mounting block will be substantially balanced and deviation of the optical axis of the device will be minimized. A gap can be provided in the annular bottom to accommodate an electrical lead to which the other of the device electrodes is connected. Alternatively, the annular bottom is continuous and the electrical lead passes through the central passage provided in the stud.

Abstract: A heat dissipating member including a heat sink is placed on a module base board with flip-chips mounted thereon, with metallic plates and first adhesive materials of a good thermal conductivity interposed between the heat dissipating member and the flip-chips in a close contact relation and with a second adhesive material interposed between the heat dissipating member and the base board, wherein the first adhesive material is selected to have a melting point lower than that of the second adhesive material, and then such an assembly is heated so that both the first and second adhesive materials are melted and the metallic plates are mounted onto the flip-chips and the heat dissipating member is mounted onto the base board. A gap is formed between the metallic plates and the heat dissipating member as a result of earlier solidification of the second adhesive material than that of the first adhesive material so as to be precisely controlled such that a heat transferring effect therebetween may not be degraded.