With the advancement of epitaxial chip technology, the cost of chips has rapidly declined. The discrete chip back-end process and traditional packaging process have become the main bottlenecks for cost reduction. Wang Xiwei, general manager of Jingyuan Optoelectronics Co., Ltd. and lighting application host, said that when the package lumen efficiency reaches 500lm/$, the price of LED replacement lamp for 60W incandescent lamp can be reduced to 10 dollars, and the lighting market can enter the promotion stage. Moreover, the packaging process is not without technical content. How to solve the problem of LED heat dissipation? How to increase the efficiency of LED light output? How to improve the reliability of LED? It is an urgent problem to be solved. In addition, the larger the package size, the better? The design and structure of the traditional LED package has a new development direction? It is also a problem that enterprises need to consider. At the China International Semiconductor Lighting Exhibition and Forum, the three chapters of "Japan's SSL Packaging New Technology Discussion", "Advanced Packaging and Module Technology Branch", and "Heat Management and Reliability Technology" are from different perspectives. The "blocking tiger" on the road of industrial development has been discussed in depth. At present, the reasons for restricting the development of the LED packaging industry mainly include three aspects: First, the key packaging materials, such as solid crystal materials, silica gel, epoxy resin, phosphors, etc., need to be improved; second, high-power LED packaging The heat dissipation problem of the technology has not been completely solved; the third is the lack of innovation in the packaging structure for different applications. Solve the problems of cost, reliability and color rendering from the material link In addition to chip manufacturing technology, phosphor manufacturing technology and heat dissipation technology, the performance of LED packaging materials (filling or bonding materials) has a significant impact on the luminous efficiency, brightness and lifetime of LEDs. The use of UV-resistant, heat-resistant aging, high refractive index, low stress packaging materials can significantly improve the light output power and service life of the lighting device. As we all know, epoxy resin will have aging problems under the influence of ultraviolet light and temperature. A.Okuno, chairman of Japan SANYU REC Resin Co., Ltd., said that the new resin material has good thermal stability and radiation resistance, and is very strong. Attachment, and high light transmittance, the resin's aging rate is reduced by 70%, can be used in the unique vacuum printing packaging system technology, the product's thermal stability and light aging resistance are improved, and for white LED bias The blue phenomenon has also improved. For wire bonding, Liu Sheng, director of the Wuhan Institute of Optoelectronics and the Microsystems Research Center of Huazhong University of Science and Technology, pointed out that gold wire is widely used at present, but the price of gold wire is expensive, resulting in higher LED cost and lower copper wire price. It has great application potential in reducing costs. In the phosphor chain, Yin Mei Optoelectronics executive vice president and technical director Yi-Qun Li confirmed through experiments that the aluminate green phosphor and the nitride red phosphor R630 can be combined to achieve warm white LED for general illumination. YAG, OG450, silicate yellow phosphor, etc., can realize cold white LED for general illumination. Lu Pengzhi, an assistant researcher at the Institute of Semiconductors of the Chinese Academy of Sciences, pointed out that the color index of the warm white light produced by the blue LED is relatively low. Efficiency will decrease. The substrate is the basis for solving the heat dissipation problem of high-power LED The main heat dissipation path of high-power LEDs is thermal contact conduction. The solution of heat dissipation problem should be perfectly matched by the good LED package design and materials and LED module design, but the basis of heat dissipation lies in the substrate. There are generally four types of common substrates: conventional and very mature PCBs, developing metal core substrates (MCPCB), ceramic materials based on ceramic materials, and copper-clad ceramic substrates (DBC). Ceramic substrates based on insulating materials such as AlN, SiC, and BeO are the most respected directions in the industry. Y. Kanechika, manager of Deshan, Japan, believes that AlN materials, especially sintered AlN ceramics, have high heat and thermal expansion coefficients, high strength and electrical insulation, and good transparency. AlN heat-dissipating substrates can be used for high performance. High-power device packaging field. Thermal management is a key factor in the efficiency, reliability, and long-term stability of LED systems. Although the industry has done a lot of simulation and simulation work, measuring the true temperature of LED devices is still a problem without affecting the system. Rafael Jordan, Ph.D., of the Fraunhofer Institute for Reliability and Microintegration in Germany, said that time-analyzed high-resolution thermal imaging can be used to analyze the thermal parameters in high-power LED packages, which provides an in-depth study of the thermal issues of LEDs. A good test method. Explore new package structures In the semiconductor industry, with the advancement of chip technology, packaging technology has changed, and technologies such as WLP (Wafer Level Packaging) and SIP (System in Package) have emerged. The core technology of the middle and upper reaches gradually covers or even spans the traditional packaging technology, which greatly reduces the packaging process and cost. Many experts at home and abroad said that the LED industry is also in or about to be in this period of change. When the luminous efficiency of the chip reaches 150 lm/W or more, the traditional packaging technology is in need of change. Xiao Guowei, Managing Director of Jingke Electronics (Guangzhou) Co., Ltd. believes that the cost of a single chip packaging model has become closer to the limit. The high-end LED lighting market will increasingly use high-power LED chips and light sources with integrated circuit technology. The trend of technology and modular chips will become the mainstream direction in the future, because this is the only way to solve the problem that the cost of separating devices in the packaging process is getting higher and higher and it is difficult to fall again. Some experts have proposed that COB (chip on board) is the mainstream direction of future lighting design from the perspective of cost and application. The LED module of the COB package has a plurality of LED chips mounted on the substrate. The use of multiple chips not only improves the brightness, but also facilitates the rational configuration of the LED chips and reduces the input current of the individual LED chips to ensure high efficiency. Moreover, the surface light source can greatly expand the heat dissipation area of ​​the package, so that heat can be more easily conducted to the outer casing. In addition, COB packaging has once again led to the battle between high-power LEDs and low-power LEDs. Chairman of Fujian Zhongke Wanbang He Wenming believes that the integration of low-power LEDs will be the mainstream of the future. China is a big LED packaging country, and 80% of global LED device packaging is concentrated in China. In 2009, the output value of China's LED packaging reached 20.4 billion yuan. It is expected that the growth rate will exceed 10% in 2010. The development of high-power and SMD products has become a target for many enterprises to expand production. The gap between the packaging technology of Chinese enterprises and the world's top technology is gradually narrowing, and it is at the forefront of the world in local products. However, the core patents such as white LED packaging technology and high-power LED package cooling technology are in the hands of foreign big manufacturers. If large-scale packaging production and large-scale export, it is bound to encounter patent war. Designing low-cost, high-performance new packaging structures with innovative ideas will be the key to China's packaging companies in an invincible position in the new round of competition. Cross flow fans are mainly used for air conditioners, air curtain equipment, dryers, dry-type transformers, household appliances and equipment on grain combine harvesters Cross Flow Cooling Fan,Copper Cross Flow Fan,Transformer Cooling Fan,Top Blowing Series Cooling Fan Henan New Electric Power Co.,Ltd. , https://www.newelectricpower.com
Service conditions of transformer cooling fan:
1. The ambient temperature shall be+75 ℃ ≥ - 40 ℃.
2. The industrial gas passing through the cooling fan is not allowed to have strong acid, strong alkali and various solutions.
3.Sand and dust and other sundries are not allowed to fall into the fan, so as to avoid fan burning and fan blade breakage.
Working principle
When GF series cooling fan is used for dry-type transformer, the fan is placed on both sides of the coil, and the cold air is directly blown into the high and low pressure cooling air passages of the dry-type transformer coil, which has obvious heat dissipation effect, ensuring the normal operation of the dry-type transformer and prolonging its service life. Fan start stop, transformer overtemperature alarm, overtemperature trip and other functions are provided by the temperature control device.
Maintenance and use
1. Before the fan is used, the insulation resistance shall be tested to be greater than 2 megohms. When the fan is hot or humid, the insulation resistance shall not be less than 0.5 megohms.
2. Before starting the fan, please check whether the appearance is intact, whether the connection is reliable, and whether the wind wheel rotates flexibly without blocking.
3. Clean the dust in the fan regularly to prevent affecting the air volume.