月份：2012年7月

small led lamps and fire proof

With the rapid development of modern technology, LED lights display screen industry sustained rapid speed of growth, expanding industry, technology innovation, market share since 1993, continued to grow by an annual average growth rate of 40%, however, in 2012 Hong Kong Harbour Grand caught fire incident on April 2, knocked to the entire LED industry a wake-up call: the rapid growth of this industry, LED display screen safe application of technology to the remaining short board, LED products standardization and Standardization was again put on the agenda. In particular, LED display screen fire safety application techniques is the focus of today I would take you to see what factors will affect the display of fire safety issues.

small led lamps and fire proof

Display fire prevention technology is good or bad is closely associated with display fire raw materials, cabinet craft.

The fire main raw materials, including the display of these four aspects of the use of the screen inside the wire, power supply, external protection, structural fire protection materials and plastic kit:

The first point: in most display applications, the unit area of ​​the screen shows the greater the greater the power consumption, higher requirements on the power stability of the wire. Many wire products, in line with GB requirements of the wire to be able to guarantee its security and stability, requires three things: wire core copper conductive carrier, wire core cross-sectional area of ​​tolerance in the value of the standard range, wrapped wire core rubber insulation up to standard and flame retardant, compared to the copper clad aluminum wire core wire core cross-sectional area is small enough level of insulation rubber wire, power performance is more stable, less prone to short-circuit condition;

Second point: UL approved power products also chose the best choice when similar products, the effective conversion rate power load to ensure security and stability in the external ambient temperature of the hot case, can also work;

The third point: display external protective structure material on the market, higher fire rating display products are mostly fire-resistant aluminum composite panel, its fire resistance and excellent fire retardant is also strong, the core material Special Material oxygen aging properties is also very strong, melting temperature 135 ° C, decomposition temperature ≥ 300 ° C, the environmental performance of halogen, in line with SGS, flame retardant B-S1, d0, t0, reference standard the UL94 GB/8624-2006. General outdoor display screen products of the aluminum plate with high temperature, rain and hot and cold impact aging rapidly, season segment in a more humid climate, make it rain easily penetrate inside the screen body leading to electronic components caused by short fire;

The fourth point: the curtain fire raw materials, there is an important part of that is plastic kit, plastic kit modules available for the use of the mask bottom shell materials, the main use of raw materials with a flame retardant PC + fiberglass materials, not only has the resistance burning function better at high temperature and long-term use, no distortion, does not become brittle and crack, combined with the tightness of good glue to use, can effectively block the external environment of the rain in through causing a short circuit within the fire .

In addition to the internal raw materials will affect the fire effect, external configuration and design also very important, but the external configuration is mainly involved to fire prevention, heat in the display screen work at the same time, configure the row of fans and air conditioners cooling the inside of the screen body cooling, recommended every 8-10 square assembly 1P air conditioning to ensure that screen the body temperature is kept constant temperature is not configured in place of air conditioning or exhaust fans can cause uneven heat treatment, easily lead to elevated temperature caused by the screen within the security risks. A lot of LED down lights companies during the cabinet level of protection test simply to simulate the spray water testing in the external environment, pending research on the persistence and strength of the waterproofing effect, with the result in the display products used for some time after there seepage occurred, this is the outdoor display is easy to fire or short service life of the important reasons. In response to a lightning storm, the Screen device arrester is to avoid the lightning assault and burned an essential tool of the screen within the device, the lightning to ground impact without Screen.

Above belong to the display of internal reasons, of course we can not ignore the later maintenance process caused by human factors, in the follow-up maintenance work, for example, the operator did not follow a strict process flow operation (module screws did not matter, wire reverse polarity, conductive objects left over after the operation, etc.), and easily lead to the house on fire.

The exact cause of the fire events of the Hong Kong hotel display there is to be investigated, but not incident on Hong Kong’s LED display product application to hold a negative attitude, while the entire industry standards has not been established, but the industry is doing better LED business or, for example, Chau Ming, Shenzhen City, display products have been the England Test Center BS476 building materials fire retardant test, display products to meet international certification standards within the LED industry leader, we should in line to lead exemplary corporate, high quality, strict specifications required, and guide the healthy development of the industry, thereby enhancing the competitiveness of the industry as a whole in the international arena and globalize.

How to make competent LED power suppliers for high-power LED lighting products

Intelligent control is one of advantages of LED lighting technology. LED power suppliers is a key point of LED intelligent control. Intelligent control have achieved obvious results in LED street lighting and LED tunnel lighting. Central controllers can switch on/off lamps or let them maintain in a certain energy consumption level depending on the density of vehicles on roads or in tunnels. These functions can be realized through all kinds of sensors and embedded systems. Intelligent control in one hand can make LED lighting technology more energy-saving and on the other hand can guarantee the safety of drivers by providing suitable light for drivers within tunnels. Research data demonstrated that tunnels using intelligent LED lighting system can reduce the accident rate by 2%.

 How to make competent LED power suppliers for high-power LED lighting products

Give up high power or supper power, replaced by more stable small-power suppliers. High-power LED circuits will generate more power. High working temperatures are a chief culprit of LED power suppliers’ failure. Relatively, small-power suppliers have been fully developed. They have more advantages in stability and production cost. As a matter of fact, most high-power designs have not been fully tested and verified. In another word, they are still in an immature state before getting to the market. Failures occurred frequently.

 

Cooling and protection is the main external factor for LED power suppliers’ failures. Not only that power suppliers themselves generate heat, lamps body can create heat also. How to conduct this heat into the air was always a big challenge for LED lamp designers. Within such limited space, it is very easy for heat to gather and form “heat island” effect. This will cause huge damages to power suppliers. Isolated circuit is a good solution for this problem.

 

The possibility of maintenance. Power failure is inevitable. The only way is simplifying the structures, making power replacement as easy as lamp body replacement.

 

Protection. Protection is another important aspect for LED lights. The penetration of moisture may cause short circuits. Dust on shells also affects the cooling effect of power suppliers. Exposure to sunlight results high temperature and aging circuits and electronic components. Experiments results show that rotating wiring plug has a higher failure rate, normally caused by moisture penetration.


smd high power led and dlp technology

Strong technology as a new big-screen video, LED lights source DLP splicing products have been one of the industry the focus of industrial innovation. Era light LED technology is not only a simple change of the light source technology, it will fundamentally change the practical performance of the DLP splicing products, or even create many new applications. LED light source DLP Video New in the end they will give industrial customers to bring a new surprise which unexpected?

Lower cost of ownership

smd high power led and dlp technology

The LED high bay light source used in DLP Video Wall product is the first significant change is the user’s cost is significantly reduced. Although the use of LED technology will make the first investment of DLP Video Wall project increased by 30%, but the LED light source to achieve a life of 60,000 hours, is equivalent to about 20 times that of traditional mercury lamps. That is the whole life of the customers in the DLP Video Wall will save at least 20 bulb replacement costs. This fee is not only enough to offset the LED technology resulting from the rising cost of DLP splicing unit can save a lot of money invested.

Another feature of the LED light source technology is the three primary colors of light independently. This makes the DLP projection system to no longer need the splitter device of the color wheel. As a mechanical operation of the product, color wheel maintenance and replacement frequency is caused by the customer an important part of the cost. Although the color wheel components are not DLP Video Wall core supplies, but no color wheel, LED lighting products, the economy still can not be ignored.

The long-life LED light source also makes DLP Video Wall, a significant reduction in maintenance frequency. The annual maintenance number at least a 50% reduction. This will also serve as important “money” node, one of the important added value for customers purchasing LED light source products. In addition, as an efficient light source products, LED down light will also have a higher luminous efficiency, higher light utilization efficiency, which reflects the “low cost” feature of the other part of the conservation of electricity.

Higher system reliability

LED light source of the product itself is a solid cold light source products. Its high efficiency, low heat, solid-state form is not accidental damage. Traditional mercury lamp light source has the vulnerability of ordinary light bulbs, high product temperature in highlighting the work of state, is also easier because of accident damage, burning, or burst. The solid-state light-emitting LED light source features a significant increase in the stability of the light source.

With traditional mercury lamps products, LED light low-voltage DC pulse drive. The power supply section does not contain high-voltage high-current components, the power of life and stability are more controllable. Combination of the three primary colors of natural light-emitting LED light source, and no mechanical color wheel component splitting, making the LED light source part of the power supply, control and spectral three aspects go beyond the traditional mercury lamp stability.

LED light source, the three primary colors independent light-emitting characteristics of the work makes it even a “light bulb” fails, the machine is still in the state of the lack of color display. This is the traditional single-lamp DLP splicing unit once the light bulb burned, in sharp contrast to the situation of not work. The lack of color display characteristics, making the light accidents of LED light source can protect customers’ losses to a minimum or even no loss. LED light source products and a simple single-lamp DLP splicing unit, its reliability is closer to the Lamps backup system.

Green environmentally friendly low-carbon

The LED light source technology is well-known green technology. The characteristics of the semiconductor manufacturing process, to make it easier the control of toxic metals, unlike the traditional mercury lamp, once the damage is likely to cause the leak of the toxic elements of the internal mercury lamp. As semiconductor components, LED light source can also be recycled, one of the important metal elements can re-enter the smelting aspects of regeneration.

In addition, LED light products or high luminous efficiency light source products.

In the same light conditions, with lower power consumption. Moreover, LED light source using digital pulse light, independent of the three primary colors, and only when the DLP light valve chip DMD certain colors of light, LED light source before work. This is very different to work with traditional mercury lamps continued to ignite. LED light source is not continuous, luminous valuable only when needed, to enable them to better meet the needs of the future economic development of low carbon environmental protection.

More gorgeous bright screen

The LED light source is a typical wide-gamut light source, its color effect is far more than the traditional mercury lamp products. Do not need color wheel for additional filtering characteristics, are also better able to protect the entire DLP-ray machine system can accurately restore the excellent color. The giant ocean LED light source DLP splicing products also has 100

smd led lamps, led and oled

The difference between LED lights and OLED

LED TV is the boundary illuminated LCD (liquid crystal display), around the screen a large number of light-emitting diodes, the light transmitted by an independent wire to the center of the screen. It makes the screen thinner, but also brought unpleasant viewing angle.

smd led lamps, led and oled

In contrast OLED (organic light emitting display) screen is able to light-emitting current through organic materials. Because in addition to the backlight, OLED screen performance is more superior than other competing products.

The benefits of OLED led down lights

The OLED TV to be able to provide higher density map and a clearer image, which means that the OLED screen can display three-dimensional images without sacrificing image resolution, as like most other TV. OLED TV to enjoy the natural scenery video like by the window concept, rather than watching a glowing box.

Not talking about color. OLED displays can artificially create all the colors of nature. Looked at the LCD screen and then look at the OLED screen, it feels like “The Wizard of Oz” Dorothy the first time you open the door to the Wonderland.

OLED screen contrast is almost unlimited, so watching the screen does not appear in the Blu-ray Disc “Dark Knight” color aliasing or black spots. OLED also overcomes the problem of motion blur, usually on the LCD device will see a quick flash of the screen characters appear annoying, horrible ghost. Alone, these advantages enough to make OLED screens become the game of choice for display.

OLED screen is not only the TV to become more compact and more thin, it can freely bend. Have not seen any this big screen, but I believe the near future, the TV hanging from the ceiling to.

What are the disadvantages?

OLED TV will be no firm offer, you can imagine that it is approximately twice the price of LCD HDTV. Also, their availability is probably years later, you have to consider replacing the blue OLED life of 14,000 hours (equivalent to eight hours a day to 5 years).

This TV, can not be used outdoors or in a strong light room too light to cover up or play down the television image. Also, long-term exposure to ultraviolet light will be substantial damage to organic diagram, the formation of the necrotic spot caused by the regrettable results equivalent to no longer worth the used car.

May have heard of OLED screens is the power consumption of less environmentally friendly products, but is not the case. OLE screen image blackish power consumption of only 40% of the LCD; image with a white background (the Windows desktop, web, play drama House MD, MD), the OLD power consumption of the screen under normal circumstances three times.

Have yet to become mainstream

We mixed the new OLED TV. Although it unmatched picture quality, OLED TV is not yet universal access. Involved in research and development before the technology immature, Sony only focus on the LED products screen on the LCD.

If the family wants to share a TV as a daily viewing purposes will exclude these expensive types. If a specialized room for watching movies and TV shows every day, not more than five hours, OLED TV is only worth considering.

solar energy led lighting and ppfc design

The development of high-power LED lighting solutions manufacturer currently experiencing the biggest design challenge is the thermal design and thermal overload protection, they must overcome ‘s LED lights source is sensitive to heat problems, and will cause excessive heat or improper application of the performance of the LED light source be discounted.

solar energy led lighting and ppfc design

Theory and practice has proven that LED performance and life expectancy is closely related to the PN junction temperature of the LED. When the LED chip junction temperature rise of 10 ° C, the luminous flux will decay to 1%, 50% reduction in the life of the LED, overcurrent, overvoltage and overheating will significantly reduce the performance and service life of the LED street light. Therefore, in addition to good thermal design, safe and reliable overheating protection must be considered.

Usually on the LED, about 20% of the input power is converted to light, 80% is converted to heat. This depends on many factors, fever may be related to the underlying irregular and phonon emission, seal materials. 90% of the total heat generated by the LED, by conduction transmission. Dissipation of heat from the LED junction, conduction is the thermal conductivity of the main channel, convection and radiation is only about 10% of all heat transfer.

Obviously, LED light source requires accurate power and thermal management systems, as compared with other light sources to provide electricity to the LED most of the conversion to heat. Without proper thermal management, heat will affect the LED life and color output. The same time, due to the LED driver devices are silicon devices, they will soon fail. This must be equipped with fail-safe backup overcurrent protection devices.

So why the success of high-power LED lighting design can not be separated from PPTC? Many people think that the LED driver can provide overcurrent and overtemperature protection is not necessary to add a PPTC device in the external, because it would add additional cost. But this is wrong, many of the LED driver is easy to be damaged due to DC voltage and polarity errors. LED driver outputs will damaged or destroyed due to short circuit. Although most LED drivers contain built-in security features include thermal shutdown, open LED and short circuit detection. However, to protect the integrated circuit (IC) and other sensitive electronic components, and may require additional overcurrent protective device. Therefore, only the PPTC (especially resettable PolySwitch PPTC) is to prevent overheating damage to the most appropriate solutions in the high-power LED down lights.

To illustrate this problem, we first look at a typical LED driver to provide what protection function. The most high-power LED constant current drive to provide the typical protection features include: thermal shutdown protection, overvoltage / overcurrent comparator, high-current MOSFET, the current size of the adjustment, a certain level of ESD protection. However, the thermal shutdown feature is just a self-protection function, it is difficult to be applied to the LED overheat designed to protect. Overvoltage / overcurrent protection characteristics of the need for external overvoltage protection circuit, turn off the power may cause other problems. High-current MOSFET failure modes are usually short-circuit, which is potentially unsafe factors. LED dimming with the current regulation characteristics may cause the LED over-temperature.

But the concept of the the PPTC the protection of high-power LED is different, it has the following four unique advantages:

1) failure mode is a high-impedance, even in the fault state, LED is safe.

2) PPTC can directly measure the temperature of the LED, so you can close protection.

3) PPTC can be achieved over temperature, overcurrent and overvoltage protection. Very easy to use, does not require an external circuit. LED, even in protected state can work.

4) allows designers to lower cost, dimming design, without worrying about security issues. Therefore outside of the LED driver with a PPTC device can achieve stronger security, and meet the most stringent safety standards and to achieve cost reduction.

solar energy street lights and led strips

First, what is LED strips?

Lights with LED lights use a special process of welding copper wire or strip of flexible circuit boards above, and then connect the power light-emitting, because of its light-emitting shape, such as a light band got its name. The first process is welded to the copper above the LED, and then put the PVC pipe or to use the device directly forming both round and flat like its title to distinguish between the number of copper wire and the lamp with the shape of two lines called second-tier, circular preceded round, that is, round the second-tier; flat in front with flat characters, that is flat second-tier. Later developed into a flexible printed circuit board that the FPC to do the carrier, the process easier, the quality is easier to control, longer life, better color and brightness gradually replace the older process, become the trend.

solar energy street lights and led strips

Round second-line conventional three-wire, round, flat line, flat line; colors red, green, blue, yellow, white, colorful. Diameter: 10mm — 16mm widely used in building body contours, bridges, rails, hotels, Lin Yuan, dance halls, advertising decoration places.

Second, what’s  the advantages of  led strips?

1, soft, like a wire, like curling.
2, able to cut and Yanjie.
3, light bulbs and circuit is completely encapsulated in flexible plastic, insulation, waterproof performance is good, safe to use.
4, the weather resistance.
Difficult to break, long service life.
6, easy to create graphics, text and other shapes; has been widely used in buildings, bridges, roads, gardens, courtyards, floors, ceilings, furniture, automotive, ponds, underwater, advertising, signs, signs, decorations and lighting.

how long is the lifespan?

LED constant current component, so different manufacturers to produce LED light with constant-current effect is not the same, of course, life will vary. Of course, if the poor light with the copper or the toughness of the flexible printed circuit board will also affect the life span of LED lights with.

What precautions four LED lights repair?

1, anti-static: LED bulbs is static-sensitive components, if not done in the maintenance of LED lights with anti-static measures, it will burn LED, resulting in waste. It should be noted that the iron must use anti-static soldering iron, maintenance personnel must also make anti-static measures (such as wearing a static ring and anti-static gloves, etc.)
2, the continuous high temperature: LED lights with two important components of the LED and the FPC are not continuous high temperature products. FPC in the sustained high temperatures or exceeds its withstand temperature, it will make the FPC cover film blistering, a direct result of the LED lamp with scrap. Same time, LED can not be sustained tolerance to high temperature, a long time under high temperature and time, its chips will be burned by the high temperature. Therefore, the iron used in the maintenance LED lights with temperature soldering iron to limit the temperature in a range of prohibited to easily change and set. In addition, even so, should also be noted that the residence time of the LED pin in the maintenance of iron not more than 10 seconds, if you exceed this time, it may burn out the LED chip.
3, weak points: a lot of LED lights with a bad pin at the short-circuit, real bad cause must be identified before servicing. Otherwise, the rush to replace the bad LED, once again the power will continue to cause the LED chip breakdown by short-circuit current. So, before the new LED lamps replacement, we must first find out the real causes of bad, the right medicine can do more with less.

Notice points for LED power suppliers

With the improvement of LED packaging and LED cooling technology in recent years, the stability of LED lighting products has reached up and maintained in a high level. An unreasonable cooling section design may cause inevitable lighting attenuation and light shift. Relatively, problems caused by unreasonable drives design are much more serious: such like failure and flickers. Nowadays, LED power suppliers have been the weakness of the entire LED lamps. In another word, according to bucket analogy, the service life of LED power suppliers has become the service life of LED lamps.

With the improvement of LED packaging and LED cooling technology in recent years, the stability of LED lighting products has reached up and maintained in a high level.

Normally, light heads of Street Light are separated from power suppliers. In most cases, it was light heads that failed to work firstly, like Pressure Sodium Lamps. The service life of Pressure Sodium Lamps is around one year.

 

Solving problems of LED power suppliers is rather important, since most LED lamps’ failures are mainly caused by them. Due to lacking of a uniform standard, power suppliers on the market are various in circuit designs, dimensions and other electronic parameters. It is very difficult to replace them once failed. With the emergence of high-power LED lamps, such like high-power LED High Bay Lights, high-power LED Tunnel Lights and high-power LED Flood Lights. Among which LED power suppliers hardly sustained for a long term. Additionally, most of the power suppliers are designed as embedded previously. Maintenance works was beset with difficulties. During a very long period of time, customers had no willing to buy any high-power LED lighting products. “They can be easily damaged. We buy high-power LED lamps since we are looking for a more advanced lighting technology which can help us save more energy, save more money. On contrary, these high-power LED lamps cost us even more.” Complained one of buyers.

 

However, how to make LED drives more reliable? Here we conclude several points:

 

  1. Get rid of multi-output design concepts, develop single output circuits (duplex output tops). Give up high current or supper current, replaced by small current. Multi-output drives will increase the complexity of circuits. Currents on different branches will interfere with each other. Solving this problem will cost manufacturers a large amount of money. Meanwhile, it is current that generate heat (heat is proportional to the square of current). In other words, if current increased to 2 times of original values, the entire system will generate 4 times heat than before. Thus, single output/duplex output will dramatically reduce the failure of LED power suppliers.

Promoting advantages of LED light engine

This article will discuss about promoting advantages of LED lights engine. Before that, let’s figure out what LED light engine means.

 This article will discuss about promoting advantages of LED light engine. Before that, let’s figure out what LED light engine means.

LED light engine is a combination of LED components, LED modules, LED drives and other optical, thermal, mechanical components. This group or engine can be directly connected with branch circuits though a regular connectors which is matching up with the lamp. Thus LED light engine can be considered as a device between LED lamps and LED modules. It has no light head and cannot be directly connected with branch circuits. But similar to LED module, it has lighting matching and cooling function.

 

A uniform standard will make LED light engine more popular. At present, LED lighting industry is enjoying a booming development, especially for indoor lighting. Almost every day, there are a lot of LED companies join into this fierce competition and also a large number of new development LED lighting products emerge on the market. Lacking of a uniform standard made the LED lighting market disordered, which is not conductive to its development. Since LED light engine is a kind of standardized products, different lighting manufacturers can choose suitable products according to their specific requests. This product is more suitable for those new born LED companies. For lacking of experience, it is rather difficult for them to find right LED chips, LED drives and other LED components which match up with their lamps. With the help of LED light engine, they have no need to worry about this, just picking up suitable LED module groups. That will make things much easier for them.

 

Drop the research costs and reduce the production period. Traditional manufacturers for lighting sources need only focus on optical technology and constructer. However, LED lighting is a comprehensive subject which combined optics, electronics, mechanics and thermology. This is so called edge science. It is impossible for small companies to employ specialists in all these areas. LED light engine is a type of high-integrated products, which has already combined electronic technology, optical acknowledge and thermal technology within their products. LED lighting producers only need to consider the lamp structures, secondary heat radiation and secondary lighting matching. Thus, they can dramatically reduce their production costs.

The following development trend of high-brightness LED lightings

How to get the LED lights to support the larger current

In recent years, the industry is very positive for just one to achieve a considerable brightness LED R&D and technology in this regard will fall on. How to make the LED support a larger current. But this result is still far to meet the market expectations. So the goal is more than 10 times and the current conduction to the LED components. So when the LED lightings area size can be expanded to 1m square meters, the following work is how to make the current value reach  350500mA. Because the drive voltage is over 3V, so we can have a 1m square meter of 1W of electricity flowing into the chip area.

The following development trend of high-brightness LED lightings

In the aspect of luminous color rendering, although such a large power input to the GanLED, yet the devoted formation of heat, so the LED products will overheat, which will directly affect into the LED color rendering results. The basic characteristics of the temperature rises, the luminous efficiency will drop and cause CRI bias, so how to effectively release a large number of exothermic heat technology becomes a key, so the LED lightings mounted on the thermal conductivity, heat capacity becomes a very important issue, at present most of the use of divalent metal or ceramic.

Short wavelength to bright high-energy quantitative Reed from the light to enhance the luminous efficiency of phosphors.

From Blu-ray GaNLED has been successfully developed high brightness degree of the green LED start although the long wavelength of the R&D trends, but because InN mixed crystal ratio increased which led to deterioration of the crystalline, and is now gradually being the industry to give up. The other hand, such as laser substitutes new applications R&D also began to consider the industry and the short wavelength of the R&D is actively processing. Recently some Japanese Lab at the University has successfully developed a 250nm of the LED tube, but the practicality is still to be thinking, because the human eye is about 380nm wavelength acceptance, so if the wavelength more than 380nm short-term, which is unable to produce visual LED lightings or low output.

 

 

Introduction of knowledge of the application of led wafer

The production of the wafer production process is very complicated-developed epitaxial wafers, the next at random in each wafer test nice, to met the requirements of good quality and other defective products (a large voltage deviation, the shorter the wavelength Ora longer length, etc.). Yield of the wafer must start doing electrodes(P pole, N pole), followed by epitaxial wafers, laser cutting and hundred percent sorting, depending on the voltage, wavelength, brightness fully automated sorting, which is formed application of led (led panel square pieces). Then visually, put a point defect or electrode wear, sorting out, these are behind the bulk crystal. The blue film is incompatible with normal delivery requirements of the chip, also naturally become edge or hair piece. Bad for the epitaxial wafer(there are some parameters do not meet the requirements), would not have to do film, just as electrode(P,N), also d not divide, it is currently on the market for application of led wafer(there is also some good stuff, such as square piece and so on).

Introduction of knowledge of the application of led wafer

Semiconductor manufacturers mainly use polishing Si(PW) and Si epitaxial film IC as raw material. Nineteen eighties early century starting using epitaxial films, it has a standard PW which does not have the certain electrical properties and eliminates many of the crystal growth and subsequent wafer processing of the surface and the near surface defect.

Historically, epitaxial films by Si manufacturer production and use, in the IC dosage is not big. It needs to be in single crystal Si film  deposited on the surface of a thin layer of single crystal Si. General epitaxial layer thickness is 2~20 μ m, and the Si substrate thickness of 610 μ m (150mm in diameter and 725 μ m (200mm).

LED lights epitaxial film – substrate material

The substrate material is the cornerstone of led lighting industrial technology development. Different substrates require different epitaxial growth techniques, chip processing technology and device packaging technology,  the substrate material determines the development path of application of led lighting technology. The substrate material of choice depends primarily on the following areas:

1, the structural characteristics is well, and the  similar crystal structure of epitaxial materials and substrates, the lattice constant mismatch is small, crystal properties, the defect density.

2. Interface features are well, which is benefit for the epitaxial materials into nuclear and adhesion.

3. cheap price.