LED chipmakers are developing new substrates based on copper-tungsten, ceramic or diamond thin-film to replace sapphire substrates to improve heat dissipation amid the surging demand for high-power LEDs used in LED lighting and TV backlighting, according to market sources.
Besides improving product stability, effective heat dissipation further enhances brightness since a LED chip loses 5% of its brightness when it reaches 80-degrees Celsius. For high-power LED applications such as projectors, new substrate technologies that enable higher brightness without sacrificing reliability are critical to future developments.
LED chipmaker Formosa Epitaxy has been one of the most active players thus far in copper-tungsten substrate adoption. The Taiwan-based company has started small volume production using copper-tungsten substrates for pico projectors and expects the new substrate technology to account for 20-30% of its high-power LED chip shipments in 2011, the company said.
Formosa Epitaxy began making pico projector LED chips in May, and the segment should represent 10% of monthly revenues at the end of 2010 with shipments of NT$70-80 million US$2.18-2.49 million and over one million units in volume.
Fellow LED chipmaker Epistar, however, is considering other materials, pointing out that metals are susceptible to expansion and contraction from temperature changes. Tekcore is currently developing metal substrate production but has not reached the manufacturing stage.
