Higher temperature, shorter lifespan of the chip LED
As a new generation of LED light source, gradually applied to general lighting in the past, namely its most basic optical requirements flux, currently there are two ways to improve the LED luminous flux, respectively, increase chip brightness and more dense arrangement of particles, etc., these methods require input energy higher power, while the input LED's energy, only a small portion is converted into light, most of them turn into heat within the single package into doubling current heat will naturally doubled, so in such a small cooling By area, the heat problem will gradually deteriorate.
Like traditional light sources, LED will generate heat during operation, their number depending on the overall luminous efficiency. In the role of applied electrical energy, radiative recombination of electrons and holes occur electroluminescence, in the vicinity of the PN junction light radiated from the LED chip itself need to go through a semiconductor media and packaging media to reach the outside world. Integrated current injection efficiency, luminescent quantum efficiency, chip external light efficiency, and ultimately only about 30% to 40% of the input electrical energy into light, the remaining 60% to 70% of the energy mainly in the non-radiative recombination occurring lattice vibrations The forms can be converted into heat. The LED chip temperature rises, it will enhance the non-radiative recombination, further weaken the luminous efficiency, and shorten life. LED lights are used in cooling technology must be able to effectively reduce the light-emitting diode PN junction to ambient thermal resistance, in order to reduce the LED PN junction temperature as to improve the life of LED lights.
In the operating current constant conditions, Lumidleds1W LED light failure and junction temperature curve, showing higher junction temperature, the faster the flux decay, life expectancy is shorter.