Prospects for LED light
United States Energy Department (DOE) LED to make such evaluation: no other such as LED lighting technologies can have a lot of energy-saving potential and improve the quality of our built environment.
For LED package, 2010 growth rate of more than 50%, more than $ 8 billion by 2014, LED marketing compound annual growth rate of more than 30%, more than 20 billion dollars. According to DisplaySearch’s latest report showed that because of the LED chip power increase and cost reduction, each LCD TV backlight LED devices used by the corresponding decrease by 2014 LED lighting applications will replace the application become the mainstream LED backlight for LCD TV.
Four elements LED quality
Quality evaluation of current for LED lamp many parameters, mainly in the following 4 aspects, namely LED service life, efficiency, color index, relative temperature. To enhance the quality of LED must be from the four areas mentioned above, this article from the viewpoint of LED device package, focused through heat management in packaging, to achieve the way to improve the quality LED lumens and reduce unit costs.
LED is one of electro-optic conversion in semiconductor devices, in the course of their work only 10~40% of electrical energy into light energy, almost all of electrical energy into heat energy, led LED temperature, LED temperature rise is causing major causes of failure and poor performance LED lamp. LED overheating can affect the performance LED both the short and long term, short term impact of LED luminous efficiency and color offset; long-term raises chip defects and deterioration of packaging material, seriously affecting LED service life and reliability. As a single device operating current increases, device heating will increase and cause the LED junction temperature rise, luminous efficiency decline. Thermal management is to reduce the units lumen LED devices cost focus.
From the perspective of packaging method for reducing the cost of units of lumens
1W high-power LED chip prices now mainstream manufacturers remained relatively high, at current prices still high even if prices down 50%, the short term, high power chips appear unlikely diving price cuts. From the perspective of encapsulation, a decline in the price of the device space is limited, by means of a chip price or the price of single devices lumens to reduce unit costs of the road is hard to go on. Both of the following may be feasible method to reduce the cost of units of lumens:
1, from the chip side, must improve the current density of single-chip, enables 1W chips to work under 700mA and 1000mA, and only minor reduce light efficiency.
2, from the perspective of encapsulation, reducing device size as possible, while reducing the overall thermal resistance of the device, enable support for larger currents of single devices, individual devices power up to 3-5W, so as to reduce overall packaging costs.