NeoPac Lighting Inc., a Taiwanese LED-packaging startup, has come up with a patented solution to the technological bottleneck that has kept most of its peers from boosting LED-lamp illumination by any significant amount.

The core of the innovative solution is an efficient heat-dissipation technology called a "heat pipe," which NeoPac claims can maintain the junction temperature of the positive and negative electrodes of LED chips within a low range. This is a vital consideration. "Heat is the major killer of LED illumination," explains Jeffery Chen, the company`s chairman and CEO. "The higher the heat is, the faster the brightness decays."



The heat pipe is not a new concept in the PC industry, which uses it to dissipate heat from personal computers. However, Chen stresses, "We`re the first LED packager to apply the concept to LED lamps, and to have succeeded in reducing the junction temperature."

Previous experience with various organizations specializing in PC heat-dissipation technology, optoelectronics devices, and chip packaging have taught Chen, better than his peers, how to incorporate heat-dissipation technology into LED modules. In 1985 he went to work as an optoelectrnics-semiconductor specialist at the government-backed Industrial Technology Research Institute; 17 years later he became president of Yeh-Chiang Technology Corp. (YC Tech), Taiwan`s largest supplier of PC-thermal solutions (including heat pipes); shortly after that, he joined an IC packager.

"During my stay at YC Tech," Chen boasts, "I boosted the company`s heat-pipe output to from 500,000 to eight million units a month, unseating the Japanese as the world`s largest supplier of those products." He set up NeoPac two years ago.

NeoPac`s heat pipe consists of an aluminum tube surrounded by stacked aluminum heat-dissipation fins. The pipe measures 50mm to 120mm in length, making it adaptable to various kinds of lighting fixtures. The company mounts its patented NeoPac Emitter LED module onto a pipe with its own "system-in-a-package" technology to make its patented "light engine." Encased in a housing, the engine becomes a "NeoBulb" lamp which, the company says, is a universal platform for a variety of lighting applications.



Less Heat, More Light

Its highly effective heat-dissipation technology allows the company to mount a cluster of high-power chips on its "Emitter" module. A recently introduced 135-watt LED streetlight has an output of 5,000 lumens, which the company claims is the best performance in the industry for general lighting purposes.

The streetlight`s module contains eight chips with a total of 18 NeoBulb lamps; nevertheless, the temperature at the positive-negative electrode junction stays under 60 degrees Celsius and the ambient temperature of the emitter remains at about 25 degrees. Measuring 720mm long by 450mm wide by 205mm high, the light can be used with most standard outdoor lighting fixtures currently available. It has an Ingress Protection (IP) dust-proof rating and waterproof rating of 6 and 5, respectively.

Chen says that he plans to boost the efficiency of his company`s 135W streetlight to 75 lumens per watt next year, up from 37 lumens now, to bring total illumination to 10,000 lumens. "By doing that," Chen stresses, "we will break the Haitz Law and boost total lumens without any restriction."

The Haitz Law was established by Roland Haitz, a scientist now retired from Agilent Technology, who predicted in 2003 that based on the previous record-a doubling of illumination every 18 to 24 months--the lumens of a single LED would increase 20 fold while the price of the diode would fall to one-tenth of the 2003 level by 2013. "Our achievement has caught Mr. Heitz`s attention," Chen says, showing an e-mail from the scientist on his computer screen.

Its achievement has made NeoPac a topic of discussion at industry symposiums, both domestic and international. According to Chen, heavyweight LED-lamp manufacturers such as Philips have approached the company in search of cooperation.

The Taiwanese company has opened a headquarters in Hong Kong to facilitate the raising of funds for future expansion on capital markets; but, while valuing mainland China for the competitive production costs available there, Taiwan remains its main base for research and development.

NeoPac has won at least 50 patents for its LED lighting technology. The company recently introduced the 75W, 2,500-lumen "Lotus Lantern" aimed at the huge mainland Chinese market, which is now being boosted by the demand from the upcoming 2008 Olympic Games in Beijing, for energy-conserving lighting equipment.

"We`re revolutionizing the world of lighting," Chen claims. "With our technology, we are bridging the gap between the solid lighting and traditional lighting industries."
(by Ken Liu)