- 學位論文
高功率發光二極體封裝技術與散熱分析
HIGH POWER LIGHT EMITTING DIODES PACKAGE TECHNOLOGY AND FOR ANALYSIS HEAT DISSIPATION
摘要
本文對於現有LEDs封裝製程以及封裝時變異因素之控制與掌握、對於熱阻路徑、散熱鰭片中間介質材料均有提出說明、高功率高耗能高熱量是一體共生，本文以PWM( Pulse Width Modulation) 脈波頻寬控制以下統稱為(類直流定功率加熱)，以該模式來調節電源的開啟與停頓、藉以減少連續通電產生熱聚集、佐以人眼視覺暫停現象、吾人由實驗得知: 類直流定功率加熱模式、以開啟與停止時序來點滅發光二極體、當高頻控制1000Hzs、外控制turn on 工作周期比80%.點亮光模組、可以消弭光源閃動現象、並與一般純直流電控方式做一比較。相較之下、可降溫3~4度C、 另 加大晶粒與晶粒間擺置空間、也可以減少兩晶粒相互熱干擾.實驗得知 ：每加大1mm x 1mm 晶粒與晶粒間擺置空間，基板表面溫度可降溫6℃。 散熱鰭片設計宜簡單、文獻回顧1992年Morrisn發現、於自然對流情況下、氣流通道空間要足夠、底座要厚,鰭片要薄。文獻研究指出當鰭片越高、鰭片要越密集，而利用溫升與電壓變化特性下的TSP (溫度感應參數)中K FACTOR 相當關鍵、可反映 Tj (接面溫度) 的溫升狀態，文中以一般測試儀器如電源供應器：信號產生器、矽熱板片、功率晶體、溫度計、熱偶線、多功能電表、可以於短時間下測到K FACTOR值該K VALUE 可以反推到熱阻(R值)相互關係、當K值增加則熱阻下降、Tj(Junction Temperature)降低。同時以”類直流定功率之加熱"方式搭配人眼的視覺暫留效應、於人眼觀察光強度且無差異狀態下、可以有效節省20%電力消耗、降低溫度約3~4℃發熱.、也等同於產品性能提升.品質更好、使用壽命更久。
並列摘要
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.