New products vie for high-power LED market

14 Jul 2006

Amid fierce competition in the high-power LED market, manufacturers are lining up to introduce new products that deliver greater efficiency and more light output.

As high-power LEDs start to deliver the light output needed to enable a whole new range of applications, a number of companies are launching new modules and chips that push the performance envelope still further. As a example, LedEngin emerged from stealth mode this week to reveal 24 new high-power LED products, including what the company claims are the world's first ultra-small 10 W and 15 W LED emitters.

The emitters, which measure just 7.0x7.0x0.9 mm, are each made up of four high-power LED chips. When driven at 700 mA, the 10 W white emitter produces a maximum luminous flux of in white, while the 15 W version can be driven at up to 1050 mA, although the luminous flux figure has not yet been released. According to LedEngin, the brigtness of the emitters make them ideal for use in large-screen projection TVs, spot lighting and architectural lighting.

However, the quest for maximum light output has led to relatively low luminous efficacy, at around 25 lm/W for the 10 W version. The packages therefore feature a very low coefficient of thermal resistance, at around 3 deg C/W, to ensure that excess heat generated during operation is dissipated effectively.

LedEngin's product family also includes single-chip 1 W, 3 W and 5 W light sources measuring 4.4x4.4x1.05 mm. The 1 W version operates at 350 mA to deliver between 35 and 65 lm in white, while the 5 W version operates at 350 mA to deliver 90-130 lm in white.

This news follows the announcement by BridgeLux last week that it has introduced the only 60-mil (1.5 mm) chip available in production volumes today. Most high-power chips are limited in size to 1 mm on each side because the efficiency of extracting light from the chip falls as the chip area increases, but BridgeLux claims to have solved this problem with its KO series of blue-emitting chips.

"The development objective with the KO series was to reduce the input voltage while increasing overall light extraction," said Robert Walker, BridgeLux CEO. "The net result is a fully scalable family of LED chips that yields a 10-30% increase in its light output efficiency."

The blue-emitting chip, which is one in a family of KO blue devices, can support a drive current of up to 1200 mA. When combined with phosphors to generate white light, the chip can produce a luminous flux of 140 lm.