Deep analysis LED technology

First, the introduction of LED

LED is the abbreviation of English Light Emitting Diode, which is a new type of high-efficiency solid light source that emits light with weak electric energy. The most important component of an LED is a semiconductor crystal whose basic structure is an electroluminescent semiconductor crystal placed on a leaded shelf and then sealed with epoxy resin to protect the inner core. If a current passes, the crystal will illuminate, and different semiconductor crystals will emit light of different colors. The quality of LEDs depends not only on the quality of the materials used, but also on the level of packaging technology.

The main advantages of LED are: environmental protection, energy saving and long life. It does not produce environmentally polluting gases, generating much less heat than traditional incandescent lamps. More than 90% of the energy of incandescent lamps is dissipated as heat, and the power consumption of LEDs is the same. It is only 1/10 of the average incandescent lamp, but its life can be extended by nearly 100 times.

Second, the current status of LED

With the success of LEDs of various colors, LEDs have only been used as indicator lights for instrumentation, to traffic lights, high-position brake lights (third brake lights on cars), displays (monochrome, two-color, Full-color, indoor and outdoor all-weather), mobile phones, lanterns (contour lights, coconut lights, fireworks lights), and now widely used in urban lighting engineering lighting, showing a good development space and broad Market prospects.

At present, the color of the LED light source mainly includes red, yellow, blue, green, white and full color (RGB three colors, composed of three primary colors of red, green and yellow), and the illumination angle is also expanded from the original 60 degrees to 120 degrees. Manufacturers at home and abroad have used LEDs to produce floodlights, buried lights, lawn lights, guardrail lights, aquarium lights, etc., which are widely used in various scenic spots or urban lighting projects.

At the 2003 Guangzhou International Lighting Exhibition (held November 18-21), a foreign company exhibited a new type of LED light source. Its remarkable feature is the installation of LEDs on flexible substrates. On the board (similar to the “wire” in a folding phone), the entire light source is small, can be bent, and can emit different colors depending on the value of the passing current.

Third, the application of LED in the advertising industry

In traditional light sources, incandescent lamps, fluorescent lamps, neon lights have been everywhere, people may have turned a blind eye to their existence, especially in the advertising industry, the application of neon lights has become very popular. Most advertising engineering developers will immediately think of neon lights when creating signs, such as logos, but they are not familiar with LEDs. In fact, as a new type of electric light source, LED has obvious advantages in the production of large-scale luminous three-dimensional characters and logos, especially after the high-brightness LED is successfully developed and put into use.

In the application of signage projects such as large-scale illuminated three-dimensional characters and logos using LEDs as light sources, LED light sources are mounted on small integrated circuit boards, which are generally small squares and long squares, and also have circular shapes. Oval shape, connect these boards with special connection lines, connect a dedicated transformer (generally choose DC12V, 24V), and then turn on the general lighting power supply.

At present, the three-dimensional luminous characters (or logos) using LEDs as light sources are mostly copper characters or metal groove characters (sprayed with various colors of paint), acrylic characters (organic sheets or acrylic sheets of various colors are attached to the bottom or surface) , FRP word. By adding an LED light source to the groove word, the acrylic sheet or the cover of the organic sheet is provided with a special aluminum-plastic edge strip, so that the three-dimensional luminous word is completed. Such a three-dimensional luminous word is not only bright and novel, but also easily solves the problems that the original three-dimensional characters are easy to fade, the light is dim, the material life is short, and maintenance is often required.

The LED light source can also be used in a light box, which can make the light box thinner, make the light box more compact and exquisite, and emit beautiful and charming colors.

Fourth, the outlook of LED

At present, LED products and related supporting products are high in price, and there are still insufficient brightness, which adds great difficulty to promotion and application. If the production scale of LEDs and ultra-high-brightness LEDs is further expanded and the cost is further reduced, the advantages in performance, energy saving and service life can make up for the temporary disadvantage of high price and cost. LED and ultra-high brightness LED will become a kind of Very competitive new electric light source. At that time, LEDs, which are small in size, light in weight, good in direction, and resistant to various harsh conditions, will definitely have a strong impact on the traditional light source market.

In terms of urban lighting, the government departments have fully played a guiding role in grasping new opportunities in new industries. On June 19, 2003, the “National Semiconductor Lighting Project” Coordination Leading Group was established across departments and regions. This leading group composed of relevant government departments such as the Ministry of Science and Technology, the Ministry of Information Industry, the Ministry of Construction, the Ministry of Education, the Chinese Academy of Sciences, and the China Light Industry Federation has already done a top-level design, established a public platform, and submitted a special report to the State Council. Among the four recommendations put forward in the special report, the second suggestion is: It is recommended to use the 2008 Beijing Olympic Games and the 2010 Shanghai World Expo as an opportunity to promote the application of semiconductor lamps in urban landscape lighting. Considering the cost performance, it is best to start with special lighting (special lighting including urban landscape lighting, automotive lighting, road traffic lighting and military lighting, etc.). At present, the most realistic market is the lighting project such as urban landscape lighting, which can best exert the advantages of less energy consumption, long life, maintenance-free, impact resistance and vibration, and environmental protection.

LED lighting is one of the most promising high-tech fields in the 21st century. Faced with the huge temptation of the lighting market, the international lighting industry giants have cooperated with semiconductor companies to invest millions of dollars in the development of LED lighting and related system equipment, and the scale of investment will continue to increase.

China has a certain technical and industrial base in this field, and it is one of the few high-tech industries that have little gap with the developed countries. In this sunrise industry, we hope to see domestic research institutes and enterprises can develop and produce LED light sources with leading technology, mature products, stable quality and low price, so that LED light sources can be widely used in various fields.