L.E.W. Techniques Ltd. offers copper tungsten packages for high-power laser diode manufacturers. Copper tungsten can be joined to other metals, such as kovar and alumina, using various solder/braze techniques to form miniature heat sinks and subcarriers. The company says that the packages can be machined to tight tolerances and that the addition of a kovar carrier and metallized ceramics allows laser welding and flexibility for interconnect and test. The devices exhibit thermal expansion of 6.5 to 8.3 ppm/K and thermal conductivity of 175 to 200 W/mK.