Recently, Epistar, a leading provider of solutions for LED lighting, LED applications and co-activation service, has reached the new milestone of 1000 granted patents.Besides, the company has about another 1,000 patent applications waiting for approval around the world.
 
Since its establishment in 1996, Epistar has firmly believed that technology innovation is the foundation for being a leader in the industry, and that acquisition and strategic deployment of intellectual property rights, such as patents, is a key to success.
 
In Epistar’s extensive patent portfolio, ITO technology is one core technology that Epistar’s founders developed while they were at ITRI (Industrial Technology Research Institute). In the early stages of LED technology development, thin metal was adopted for current spreading, but had the drawback of hindering light extraction. Epistar’s founders realized ITO’s advantages of being transparent and conductive, and developed the implementation of ITO in LEDs to improve current spreading and light extraction. Furthermore, due to its low contact resistance, ITO can be a good ohmic contact layer, and its optical characteristics are suitable for optical field tuning. Epistar’s advancements in this innovative technology can be found in its patents that have been issued in countries around the world, including in China, Japan, Korea, Taiwan, and the United States.
 
Another core technology in which Epistar excels is bonding technology that provides for flexibility in epi structure substrate selection. Epistar’s RD team has developed various bonding techniques with metal, glue, and dielectric materials so that the epi structure is not limited by its growth substrate anymore. Taking GaN-on-Si as an example, after nitride is grown on Si substrate, the epi can be transferred to a transparent or reflective carrier by bonding technology to avoid the light from being absorbed by opaque Si. In other applications, multiple LED structures with different light color can be bonded to one common substrate. With different bonding materials, LED can be disposed on different carriers depending on the application. For example, a widely-adopted low temperature metal bonding process provides robust mechanical support with optional reflector for light extraction enhancement, which makes a vertical blue LED possible at lower cost. Epistar’s innovative glue or dielectric bonding provides a transparent interface that provides the LED with the advantages of having stronger support and transparency, which is expected to be particularly useful in general lighting and LED display applications. Epistar has successfully obtained patents in this technology around the world, including in China, Japan, Korea, Taiwan, and the United States.