Prospects for LED lighting
U.S. Department of Energy (DOE) of the LED to make this evaluation: no other lighting technology such as LED Floodlight 80W energy-saving potential and upgrade the quality of our built environment.
For LED packaging, the 2010 annual growth rate of more than 50 percent, more than 80 billion U.S. dollars, 2014, the compound annual growth rate of the LED market will exceed 30%, amounting to over 20 billion dollars. 2014 LED lighting applications, according to DisplaySearch's latest report shows that, due to the LED chip power-up and cost reduction, each LCD TV backlight LED devices will be a corresponding reduction in expected to become the mainstream of LED application will replace the LCD TV backlight applications.
Four elements of the LED quality
Evaluated the quality of the LED has many parameters, mainly the following four aspects, LED service life, luminous efficiency, color rendering index, the relative color temperature. To improve the quality of LED, we must proceed from the above four areas, this article from the angle of the LED device packages, focusing on package thermal management to enhance the LED quality and reduce the cost of unit lumen.
led driver 120w is a semiconductor device electro-optic conversion, only 10 to 40 percent of the energy into electrical energy in the course of their work, and other electricity is almost entirely transformed into heat, resulting in LED temperature, LED temperature rise of LED failure and performance degradation the main reason. LED overheating will affect the performance of LED short-term and long-term, short-term will affect the LED luminous efficiency and color offset; long-term will lead to the deterioration of chip defects and packaging materials, seriously affecting the life and reliability of the LED. With the increase of the operating current of a single device, the device heating will increase, leading to the LED junction temperature rise, decreased luminous efficiency. Therefore, the thermal management of LED devices is to reduce the focus of the unit lumen cost.
Reduce the cost of units of lumens from the package point of view
Mainstream manufacturers 1W high power LED Flood light 10W chip prices is still high, at current prices, even if the price is then reduced by 50% is still high, short term, high-power chip diving prices unlikely. From the package point of view, the price of a single device continued to decline in the limited space, chip price cuts or price in a single device to reduce the cost of road unit lumen is difficult to go on. The following two aspects may be a viable method to reduce the cost of units of lumens:
From the chips, the need to improve the current density of single-chip 1W chip to work under 700mA or 1000mA, and the luminous efficiency only slightly lower.
From the package point of view, to minimize the size of the device, while reducing the thermal resistance of the entire device, so a single device to support a larger current, the power of a single device to achieve 3-5W, thereby reducing the cost of the entire package.
The ultimate goal is to: enhance and maintain the luminous efficiency, and enhanced thermal capacity of the entire LED Spotlight 30W devices, in a small, light, thin package devices to achieve high efficiency, high current, high power. The number of vendors based on the structure of ceramic heat 3535 (T1901PW) size SMD high power devices can already 700mA work, the luminous flux of 220lm above. Early 2012 will increase to 1050mA, the luminous flux of 300lm.
You can also use different packaging technology, performance can be seen that the measured thermal resistance of the 3535 devices, flip-eutectic mode devices, thermal resistance as low as 2.5 ° C / W, so that devices 1050mA conditions in the lamp good heat dissipation case, the device junction temperature and temperature difference between the bottom of the device still does not exceed 10 ℃.
Power devices to improve device current density, but also reduce the unit lumen cost effective way to size of SMD in power LED products, for example to sferics photoelectric new high thermal conductivity material 3020 (T3400SW), T3400SW with low heat resistance, excellent heat resistance heat resistance, high current conditions remain high light efficiency. Typical luminous flux of 20lm @ 60mA, the beginning of 2012, up to 50lm @ 150mA, the current level, the cost of unit of luminous flux equivalent to approximately half of 20mA devices. Has obvious cost advantages.