LCD TV 側入式LED 光源模組之熱傳分析

Abstract

液晶電視LCD (Liquid Crystal Display) TV所使用之背光源技術，已幾乎由CCFL (Cold-Cathode Fluorescent Lamps)轉移至LED (Light Emitting Diode)； LED背光源又可分為側入式及直下式，其中因TV產品趨勢已走向薄型化設計，故側入式LED背光源已被廣泛地應用於 LCD TV。然而散熱問題仍是LED背光源需克服及注意的問題，若在進行LCD TV LED背光模組設計時，先針對LED散熱模組，利用模擬方式進行設計考量，於產品試作前分析及預測LED之溫度分佈，可降低產品製作試誤風險，縮短開發期限，故本研究以側入式背光32”LCD TV 為例，針對LED光源模組散熱進行熱分析及模擬。然而有諸多影響因子與LED發熱有關，本文研究方向將以散熱片大小及LED電流大小進行熱分析及模擬，繼而提出較佳之散熱片大小及電流。

Modern LCD (Liquid Crystal Display) technology, whether it is large, medium and small size, is still need a backlight. Nowadays, the mainstream of backlight source is LED backlighting instead of the cold cathode fluorescent (CCFL) backlighting, and used by most other LCDs for the benefit of light weight, thin, power-saving. Two main models of LED backlighting may be used: Edge-lit LEDs and LED backlighting (Full array). Edge-lit LEDs has the advantage of better light weight, thin and narrow border design, so the edge-type LED backlight has been widely used in LCD TV. However, heat dissipation problem is still the LED backlight design to be overcome and should be paid attention. The general design methodology of the LED cooling modules uses simulation and experiments to test for product analysis and forecasting the temperature distribution of the LED module can reduce the risk of product production error. This study focuses on the 32 "LCD TV backlit design to the LED light source cooling module thermal analysis and simulation. The simulation and experimental results shown that the influencing factors of LED heat dissipation related to the size of the heat sink and the LED input power. This study provides thermal analysis and simulation process for LED-backlit LCD and proposes a better heat sink size and input power consideration.