At the Light + Building 2014 tradefair in Frankfurt, Germany (30 March - 4 April), Lextar Electronics Corp of Hsinchu Science Park, Taiwan – founded in 2008 as a subsidiary of display panel maker AU Optronics (AUO) – has debuted its packaging-free White Chip LED, exhibited in various LED lighting applications including a 50-Watt halogen-equivalent GU10 LED spot lamp, a point-light candle lamp, and an omni-directional LED tube with ultra-high efficiency (demonstrating the synergy of the firm's vertical integration of LED epiwafer, chip and package operations, as well as lighting products.).
Lextar's new White Chip technology involves a substrate-free flip-chip and phosphor molding process, and can be fabricated using existing surface-mount technology (SMT) equipment (features that can significantly simplify the manufacturing process, says the firm). White Chip is a chip-scale die without a packaging process, featuring high lumen densities, high lumen output, wide beam angle. Also, it can be packaged closer, simplifying optical lens design, claims Lextar. White Chip can be applied to lighting products, especially small sized lamps such as spot or candle lamps. It can also be applied to backlighting, helping to reduce the thickness of direct-lit backlight modules.
Lextar says that, when used in GU10 spot lamps, the White Chip can achieve high lumen output and high lumen intensity, reaching up to 2500cd at 25° with a high color rendering index (CRI) of 90, making it a suitable replacement for a 50-watt halogen lamp. The White Chip also gives the firm's point-light candle lamp identically glowing effects to starlight, claims Lextar. Moreover, the firm's light tube - equipped with the White Chip and chip-on-glass (COG) technology - enables 360° illumination, reaching luminous efficiency of 200 lumens per watt.
Since LED companies have been eager in the last few years to develop simplified manufacturing process with reduced costs, flip-chip and several packaging-free LED products are becoming more popular, says Dr Reg Tsai, director of Lextar's Technology R&D Division. The firm says that, due to its vertical integration, Lextar can provide products and services through various stages from upstream chips to finished lighting products. The firm expects to transition its new White Chip technology into the market in second-quarter 2014.
