Showa Denko plans GaN LED capacity ramp
Showa Denko (SDK), the huge Japanese company that sells a wide range of chemical products, has revealed details of two new GaN-based LED chips that it plans to produce in large volumes.
SDK says that its proprietary near-ultraviolet and green LED chips are aimed at applications in general lighting and backlighting of large LCD screens.
The company has previously commercialized blue LEDs based on similar structures and has capacity to produce 30 million GaN-based chips per month at its plant in Chiba, Japan.
SDK s blue devices are manufactured using a flip-chip approach, where the chip contacts are fabricated on the epitaxial layer of the structure, before the chip is "flipped" upside down for assembly.
The newly-developed near-UV chips emit at 390 nm, and SDK plans to combine them with a red/green/blue phosphor mix to provide white-light sources. They are said to emit a power of 14 mW at around 400 nm.
SDK also claims that its new green GaN-based LEDs are far brighter than current commercial products, emitting 6.5 mW at 505 nm (blue-green) and around 6 mW at 525 nm.
In addition, the company will market "pure-green" LEDs that emit at 555 nm. SDK says that the use of new crystal-growth conditions has been the key to developing the range of green LED sources.
These green products have been developed for the large LCD screen backlighting market, with SDK estimating that around 14 million LCD televisions are now produced annually.
Now with a complete set of products spanning the color spectrum, SDK is planning to ramp production capacity, while continuing to research new chips. The initial development of the epiwafer technology fundamental to the LED performance took place under the Japanese "Light for the 21st Century" project.
The company will show off its latest products at the Inchem Tokyo 2005 international exhibition, which is being held at the Tokyo Big Sight convention center from November 15-18.
