Under the premise of not changing the material, LED within the limits of, and means of increasing the brightness is current, as the current increases, LED heat expected to soar. Use LED portable projector, or micro-cast of friends, must have deep experience, LED projector light, very hot, and generally had obvious noise. These products, small body is on the one hand, the key is its own heat due to large.
With the increase in power, LED heat sink becomes more and more prominent, a wealth of practical application shows that LED cannot increase the input power of the underlying cause, is due to the LED will emit a lot of heat during the work process, the die junction temperature increased rapidly, thermal resistance increases. Input power, the higher the heating effect is. Temperature increases will result in the device properties change and decay, increase in Nonradiative recombination, the leakage current of the device increases, semiconductor materials growth and electromigration of metal electrode, encapsulated with epoxy yellow, severe effects LED photoelectric parameters. Even the power LED failed. Therefore, for LED devices, thermal resistance and junction temperature, studies on thermal properties of light emitting diodes have become increasingly important.