High luminance sources those with high light intensity from a small source size can contribute to the DOEs goals of continual energy savings and efficient utilization of light by improving the performance of lighting in new ways and reducing negative impacts through the control of intensity and reduction of glare. However, heat produced within these sources is not efficiently removed, and leads to degradation and catastrophic failure. To avoid this, the power is often limited and the full capabilities not realized. Improving the thermal stability and conductivity of encapsulant materials for phosphors can extend the LED operating range and offer improved optical efficiencies. In addition, manufacturing approaches for phosphor and encapsulant deposition can be improved to increase throughout, speed, and efficiency. Through wafer-scale packaging of the down-converter and encapsulant directly on the LED die. This problem is being address through the development of a robust phosphor en- capsulant and processing method to withstand high temperatures and power densities for high luminance LEDs. This will extend the LED operating range to allow for higher power operating conditions and longer phosphor and device lifetimes, while also exploring cost-effective wafer-scale packaging. Our solution is based upon glass encapsulation of multiple phosphors for high color- quality, high luminance devices. This solution will offer a high temperature encapsulant solution that can be implemented into the current LED manufacturing process. Deposition of the phosphor and encapsulant on the wafer-level can offer improved manufacturing throughput, increased speed, and higher efficiency, eliminating unnecessary and repetitive steps. The overall goal of this Phase I project is to determine the technical feasibility of glass encapsulated phosphor materials for use with LEDs and to lay the groundwork for full wafer-scale deposition of the phosphor and glass encapsulant during the Phase II project. Key technical objectives include: thermal and optical property studies via modeling to quantify the expected improvement in glass encapsulation of phosphors compared to silicone; development of glass encapsulated phosphor technology and performance testing; thermal, optical, mechanical, and chemical stability testing; and development of a feasible concept and plan for wafer-scale deposition of the phosphor and encapsulant. This work will establish and quantify the anticipated benefits of this innovation, and set the stage for successful commercial implementation of glass encapsulated phosphor deposition on the LED wafer-level. This project has a number of commercial, societal, environmental, and educational impacts. Market entry is planned in automotive lighting, followed by projection, flash, horticulture, back lighting, and general illumination. Deployment of this technology will create employment opportunities throughout the value chain by manufacturing in-house. This technology will impact energy used for lighting, helping to reduce global energy consumption and preserve our environment. Educational outreach by project personnel impacts the local community, nearby institutions, and visitors through seminars and workshops, materials research, and entrepreneurship. The technical results may also inform future materials research in the development of robust materials, components, and devices to advance other areas of lighting research.
