An Overview -Advanced Packaging for Solid State Light Emitting Diode(SSLED) Lighting

摘要

Implementation of advanced packaging concepts inrnSSLED lighting has the potential to make a significantrnimpact on worldwide energy and environmentalrnconcerns. In US Department of Energy studies (ref 1),rnit has been estimated that, on average, 2.1 quads ofrnenergy (the equivalent to 55 million tons of oil) couldrnbe saved annually by the implementation of Solid-rnState Lighting (SSL) nationwide. SSL uses solid-staternLight Emitting Diodes (SSLEDs) for generalrnillumination instead of traditional incandescent orrnfluorescent lighting sources. This paper will present anrnoverview of the issues for current SSLED lightingrntechnologies, and how advanced packaging andrnintegration concepts can address these concerns.rnIn traditional lighting sources, the majority ofrnelectrical power is converted to radiant energy-visiblernlight, IR and UV radiation and only a small fraction isrnconverted to heat (～ 8 to 42%). However in SSLEDs,rnthe electrical power is converted to visible lightrn(～20%) and heat (～80%). Heat generated in LightrnEmitting Diodes (LEDs) has to be conducted awayrnfrom the source or else the device junctionrntemperature will rise. Without adequate thermalrnmanagement, both the device performance andrnlifetime will be adversely affected by higher junctionrntemperature.rnHigh cost of SSLED-based lamps is another majorrnfactor preventing the widespread use of SSLEDrnlighting. Currently LED lamps cost 50 to 100 timesrnmore than traditional lights. Despite the considerablyrnlonger lifetime of an LED light, the average consumerrnis not willing to pay the higher upfront cost.rnThe key to addressing these concerns is having arnpackaging solution that will provide adequate thermalrnmanagement at a lower price. In this paper, therncurrent and advanced packaging solutions arernpresented.