LED lighting prospects
The US Department of Energy (DOE) has made such an assessment of LEDs: no other lighting technology can have the same energy-saving potential as LEDs and improve the quality of our built environment.
For LED packaging , the growth rate in 2010 exceeded 50%, exceeding 8 billion US dollars. By 2014, the compound annual growth rate of the LED market will exceed 30%, and the amount will exceed 20 billion US dollars. According to the latest report from DisplaySearch, LED devices used in LCD backlights will be reduced due to the increase in power and cost reduction of LED chips . It is expected that LED lighting applications will replace LCD TV backlight applications as the mainstream of LED applications in 2014.
LED quality four elements
At present, there are many parameters for the evaluation of LED quality, mainly the following four aspects, namely LED service life, luminous efficiency, color rendering index, relative color temperature and so on. In order to improve the quality of LEDs, we must start from the above four aspects. From the perspective of LED device packaging, this paper focuses on the thermal management of packaging to improve the quality of LEDs and reduce the cost per unit of lumens.
LED is an electro-optical conversion semiconductor device. In the working process, only 10~40% of the electrical energy is converted into light energy, and almost all other electrical energy is converted into thermal energy, which causes the LED temperature to rise. LED temperature rise is the LED failure and performance degradation. main reason. LED overheating will affect the short-term and long-term performance of LEDs. Short-term effects will affect the LED's luminous efficiency and color shift. Long-term LED chip defects and packaging materials will be degraded, seriously affecting the service life and reliability of LEDs. As the operating current of a single device increases, the device heat increases, causing the LED junction temperature to rise and the luminous efficiency to decrease. Therefore, thermal management of LED devices is the focus of reducing unit lumen costs.
Method for reducing unit lumen cost from a packaging perspective
At present, the price of 1W high-power LED chips of mainstream manufacturers is still high. According to the current price, even if the price is reduced by 50%, it is still high. In the short term, the possibility of high-power chips exploding in water is small. From the perspective of packaging, the price of a single device continues to decline, so the road to lowering the cost per unit lumen through chip price reduction or single device price reduction is difficult to go. The following two aspects may be a viable way to reduce the cost per unit of lumens:
1. From the chip point of view, it is necessary to increase the current density of a single chip, so that the 1W chip can work at 700 mA or 1000 mA, and the light effect is only slightly reduced.
2. From the packaging point of view, the device size is reduced as much as possible, and the thermal resistance of the entire device is reduced, so that a single device supports a larger current, and the power of a single device reaches 3-5 W, thereby reducing the overall package cost.
Shenzhen Ever-smart Sensor Technology Co., LTD , https://www.fluhandy.com