HIGH POWER LIGHT EMITTING DIODES PACKAGE TECHNOLOGY AND FOR ANALYSIS HEAT DISSIPATION

• Main Authors: Wang-Ken Tseng, 曾旺根
• Other Authors: Jin-Shu Wang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/7xd2qm

碩士 === 國立臺北科技大學 === 機電整合研究所 === 100 === The articles presented herein are the research and study of LEDs sealing package technology improvement, by various medium-elements and related parameters affect the critical working conditions, by high temperature environment caused by high-current conjunction.By the technology of PWM (Pulse Width Modulation) pulse bandwidth to control and modulate the timing of power-on, power –off as similar as power input DC power-liked, in order to reduce the thermal generated by power connection constantly. The method is able to prolong the life of LEDs as well as power consumption saving.According to the latest research and tests managed in laboratory, to trigger the LED lighting-on by a kind of power as DC-liked, high frequency as 1000HZ adjust the duty cycle as 80%. The phenomenon of lighting flicker could be eliminated Taking the same LED go through real DC power (pure DC) connect with LED lighting on, and then by the latest development PWM power connection, the LED is able to get 3-4 degree C lower in the same working condition. That is obviously, the way is able to get power saving and prolong the life of LED by thermal dissipation as mentioned above. Except external control to have power saving and LED life prolonging, there is another method by internal modification. That enlarges the pitch between the chips. The surface of substrate is able to get around 6 degree C reduction subject to the pitch of chips enlarge each 1mmx1mm. Heat sink of LED device could be simplified. According to the literature and reports by Mr. Morrisn in 1992 that convection in a nature environment, by a sufficient air circulation space, thin wings correspond a thicker base could be the best design applied for high power LED. The K coefficient Considering the TSP (utilize the characteristics of voltage and temperature change) the K-coefficient should be treated as key-factor That can show the variation of Tj ( temperature on junction) Instruments as Power Supply, Wave Generator , Silicon Heat Plate, Power Transistor, Thermal Meter, Wire of Thermo coupler Multi-meters all are able to measure the K value within a short period. We are able to identify the reflection and influence between the K value and R value ( thermal resistance). That will come to a mathematic formula showing both values are inverse proportion, K value raise up then R value down. This presentation will bring a conclusion to utilize the advantages of mentioned above, as DC-power-liked connection, proper heat sink and modify the pitch of chip (enlarge) then we are able to get power consumption saving by 20% approximately, lower temperature by 3-4 degree C, the same meaning prolong the life of LED and bring cost reduction for all devices.