Assembly And Measurement Of Semiconductor Lighting Source

With the demand of power saving and the requirement for higher illumination quality, semiconductor lighting sources have been attractive for its excellent characteristics: high efficiency, low power consumption, long source life, color richness and environment friendness etc. As the representative of semiconductor illumination, the performance of high power Light Emitting Diodes (LED) improves quickly resent years and its luminance efficiency has surpassed 50lm/W. Thus high power LED will become the fourth generation lighting source replacing incandescent, fluorescent and high intensity discharge (HID) lamp. Otherwise some key issues should be solved before high power LEDs widely application in general illumination market, such as package heat management and suitable measurement method. This thesis focuses on high power LED lighting sources and researches their assembly and measurement process. Consequently, we analyze and discuss the problems found in this process. Finally the suggestion is proposed to improve thermal dissipation for high power LED.The development of LED package and assembly technology is discussed, especially on the application of multichip package technique for LED lighting sources. Some measured parameters and test methods are introduced. With means of average surface illuminance, luminous flux and efficiency are measured in four LED lighting samples respectively, and compared with traditional incandescent and fluorescent.The measurement data show that the luminous flux of LED lighting samples can reach 184lumen, and luminous efficiency can exceed 40lm/W much higher than incandescent. Comparing with the homogeneous combination of low power high brightness LEDs(HB-LEDs) or high power LEDs, the hybrid combination of HB-LEDs/high power LEDs has higher luminous efficiency, lower cost and better heat dissipation ability, thus it can be applied in fields for home decorate lighting and outdoor illuminance.Finally, for the special LED lighting sample, the heat resistance is computed by formular method and the steady-state heat distribution is simulated by numerical method respectively.