白光led色度的熱效應

　　LED制造商竭盡全力確保其高亮度芯片高效運行，持續(xù)時間長，并提供美觀的照明。然而，固態(tài)照明是復雜的，它遵循量子力學的反直觀定律，并從現(xiàn)場的產(chǎn)品獲得同樣的結(jié)果，因為在工廠測試的記錄是困難的。

　　挑戰(zhàn)的主要部分是由于LED對溫度變化的敏感性。芯片自然運行熱，沒有足夠的熱管理，過熱發(fā)生，性能迅速下降。然而，即使有合理的措施，以鼓勵熱量從P - N交界處的設備的核心，它是太容易的溫度蠕變在運行過程中。僅僅幾十度就足以改變輸出光譜，改變色度（顏色），并可能使一個在白熾燈泡或熒光燈管一致發(fā)光的情況下長大的消費者感到失望。

　　這篇文章解釋了為什么溫度的升高改變了白光LED在短期內(nèi)的光輸出，描述了商業(yè)芯片的變化幅度，并觀察了在顏色變化變得明顯之前，溫度會上升多遠。

　　Hot running

　　LEDs are cool. Their compact size allows designers to create fashionable lighting fixtures that were previously impractical with bulky and fragile incandescent or compact fluorescent bulbs. However， solid-state lighting， despite its deserved reputation for high efficiency， is only figuratively cool. In operation， the chips generate plenty of heat.

　　Incandescent bulbs also run very hot， but the heat is dissipated as infrared （IR） radiation over a wide area so there are no hotspots. In contrast， LEDs generate heat where all the action takes place， at the junction between the p-type and n-type semiconductors. This junction is tiny， dramatically increasing the power density， as well as making it difficult for the resultant heat to escape.