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Obducat CEO Sees Bright Path for LEDs
September 3, 2008
Will the market for high-brightness light emitting diodes (HB LEDs) add more sparkle to the nanoimprint lithography (NIL) sector? Patrik Lundström, CEO of Obducat AB (Malmo, Sweden) estimates that the LED vendors could buy at least 50 NIL tools in the next three or four years. Many of those LEDs would be used as backlights for LCD-based displays, televisions, and micro projectors. If LEDs become widely used for general lighting, the number of NIL tools sold to LED vendors each year could quickly double.
“We see more consumer electronics products coming with integrated LEDs to replace the current type of backlight in LCD screens. Several companies are pursuing that, while others are looking toward the automotive sector,” he said.
If the LED industry is successful in improving yields, and moving to larger wafers, then “the cost profile definitely is there to move LEDs into general lighting. Then if we look a little further down the road, to nanorods grown on wafers in places defined by imprinting, there is an even bigger opportunity in that space,” Lundström said.
Obducat last month received an order for two of its Sindre 400 NIL systems from Luxtaltek Corp., a Taiwan-based manufacturer of gallium nitride wafers and LEDs. Luxtaltek President C. H. Lin has co-authored research on using NIL to pattern two-dimensional photonic crystals (2DPC) on the top surface of gallium nitride wafers in order to increase the brightness of green LEDs.
Luxtaltek is Obducat’s fourth LED customer to use NIL tools for commercial production, with six tools either in production or on order, Lundström said. After NIL patterns are created on top of the LED, etching is performed on the top nitride layer to allow more photons to find their way out of the chip. Increasing the emission and directionality of photons from the material increases the LED’s brightness.
LED manufacturers tend to use expensive sapphire substrates, with 2-4 in. diameters. Lundström said, “What’s preventing them from moving to larger wafer sizes has been the quality of the epitaxy process.” Cracks tend to develop in the epitaxial layers, causing the costly sapphire substrates to be scrapped. “When they move to larger wafers, they need to make sure not to get cracks in the epi layers. They will lose a lot of money if the substrate yield loss is too high.”
There is a humanitarian aspect to LED lighting. About 1.5 billion people in the world now live in areas that are not connected to the electrical power grid, so the world of bright lights is a limited one. For poor children seeking an education, being able to read after the sun sets is essential. LED-based lights can be combined with solar panels, replacing the fire-prone kerosene lights used in homes and stores. With the rising price of oil, those kerosene-powered lamps are consuming as much as half of the revenues of shop owners in the developing world, according to a World Bank program to develop LED-based lighting for people living off the electric grid.
Posted by David Lammers on September 3, 2008 | Comments (16)
