Epistar recently was granted its 1000th patent. This number will continue to grow as there are about another 1,000 applications pending worldwide.

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.

For applications requiring high power, a larger size chip is normally preferred because it endures high current injection with high power efficiency. Epistar has acquired a portfolio of patents from a Swiss company directed to technology including the design of extension electrodes that can avoid the high cost associated with the process and at the same time improve electrical efficiency by alleviating problems of light trapped or lost in an LED chip.

As the first company to commercialize high-voltage chips (HV), Epistar has also developed several arrangements of multiple cells/junctions on one common substrate that can be driven by high voltage. With its delicate interconnection design, HV chips have excellent electrical properties and flexibility for diversified lighting applications. In addition to such unique structure, Epistar is known as the only chip maker that can provide full-spectrum products. As a result, Epistar can help customers by using its excellent red and blue chips with one or more cells/junctions for warm white applications. Design patents and utility patents related to this technology have been granted to Epistar in countries around the world including China, Japan, Korea, Taiwan, and the United States.

Epistar’s RD team is full of energy and has a vision for the future. There are already several ready-to-go technologies in the patent portfolio that can embrace the LED lighting era to come. One representative work is to connect chips on one transparent base to form a filament-like structure for retrofit light bulbs or lamps. In addition, Epistar also obtained exclusive rights in remote phosphor field that contains an optical device in-between a wavelength converting device and an illumination source. With these patented technologies, Epistar can work with its customers to develop more competitive products and speed up the adoption of LEDs in lighting.

Epistar not only respects others’ IP but also protects its proprietary technologies by filing its own patents or by acquisition to strengthen its patent portfolio. This is a demonstration of Epistar’s engineering efforts and capabilities. It also provides Epistar’s customers and partners freedom and a secured position in LED industry.