Robust Phosphor Encapsulation for Wafer Scale Packaging of LEDs Topic: 8d

High luminance sources – those with high light intensity from a small source size cancontributetotheDOE’sgoalsofcontinualenergysavingsandefficientutilizationoflightby improving the performance of lighting in new ways and reducing negative impacts through the control of intensity and reduction of glare. However, heat produced withinthesesourcesisnot efficiently removed,andleadstodegradationandcatastrophicfailure.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 op-tical efficiencies.Inaddition,manufacturingapproachesforphosphorandencapsulantdeposition canbeimprovedtoincreasethroughout,speed,andefficiency. 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 baseduponglassencapsulationofmultiplephosphorsforhighcolor- quality,highluminancedevices.Thissolutionwillofferahightemperatureencapsulantsolution thatcanbeimplementedintothecurrentLEDmanufacturingprocess.Deposition of the phosphorand 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 duringthePhaseIIproject.Key technical objectives include: thermal and optical property studies viamodelingtoquantifythe expected improvementinglassencapsulationofphosphorscomparedtosilicone;developmentof glassencapsulatedphosphortechnologyandperformancetesting;thermal,optical,mechanical, and chemical stability testing; and development of a feasible concept and planforwafer-scale deposition of the phosphor and encapsulant. This work will establish and quantify theanticipated 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,anded- ucational impacts. Market entry is planned in automotive lighting, followed by projection, flash, horticulture, backlighting, and general illumination. Deployment of this technology will create em- ployment opportunitiesthroughoutthevaluechainbymanufacturingin-house.Thistechnology willimpactenergyusedforlighting,helpingtoreduceglobalenergyconsumptionandpreserve our environment. Educational outreach by project personnel impacts the local community, nearby institutions, andvisitorsthroughseminarsandworkshops,materialsresearch,andentrepreneur- ship. 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.