白光led色度的热效应

　　白光led色度的热效应

　　LED制造商竭尽全力确保其高亮度芯片高效运行，持续时间长，并提供美观的照明。然而，固态照明是复杂的，它遵循量子力学的反直观定律，并从现场的产品获得同样的结果，因为在工厂测试的记录是困难的。

　　挑战的主要部分是由于LED对温度变化的敏感性。芯片自然运行热，没有足够的热管理，过热发生，性能迅速下降。然而，即使有合理的措施，以鼓励热量从P - N交界处的设备的核心，它是太容易的温度蠕变在运行过程中。仅仅几十度就足以改变输出光谱，改变色度（颜色），并可能使一个在白炽灯泡或荧光灯管一致发光的情况下长大的消费者感到失望。

　　这篇文章解释了为什么温度的升高改变了白光LED在短期内的光输出，描述了商业芯片的变化幅度，并观察了在颜色变化变得明显之前，温度会上升多远。

　　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.