作者：Blade

LED production process issues should attach great importance

Currently, LED Lights used as garden lights, tunnel lights, and indoor places used in commercial lighting, office lighting, etc. They are highly desirable. With the advances in LED technology, lower prices at the same time, the phosphor price increases and cost pressures on the traditional lighting. These provide a good opportunity for the led production process to enter the field of interior lighting.

LED production process issues should attach great importance

However, few people concerned that the amount of radiation generated by the LED of each light point is not large, which is far less than the HID (high intensity discharge) light source, but it can make a very small energy concentrated in a certain direction. This also means that, although the LED unlike the laser that the light are strong, yet the local light intensity hazard should also be given special attention.

Insider pointed out that the LED Products are mostly on the sample stage, mainstream or traditional lighting products in the market, but the LED stage of the product will soon be  full arrival. Once the led production process enter into the product stage,  IEC / EN 62471 must be the mandatory implementation. The relevant testing laboratories should have the ability to match, otherwise photo biological safety hazards may occur.

Comment:

Indeed, Once LED enter into the interior lighting, security issues will become more prominent. If LED made of spotlights, table lamps, flashlights, laser lecture pen will cause the child’s interests. Its security has become more important. For example, a small laser lecture pen if exposed directly to the child’s eyes, it will damage the retina of the eye of the child. LED illumination radiation intensity of the harm is an objective reality, and is the most protective part.

Of course, the correct detection LED Flood lighting evaluation of the radiation intensity is very important and difficult. Even if the led production process module to achieve the
requirements of the lighting does not necessarily meet the requirements; lighting should also consider the light distribution, maximum intensity direction than the human eye is very easy to identify, we must seriously look for. These are not just domestic issues, but also the international detection in the field bottleneck.

LED is about to enter the home lighting on the occasion. I hope that the entire industry can be developed as soon as the correct means of detection, and specify a qualified laboratory testing, so in order to minimize the harm from the potential to radically.

Two elements that determine the direction of technological development of LED ligh bulbs

LED lights are the most energy-efficiency green power light source, natural lighting energy saving options, along with the gradual reduction of costs and prices of LED lights, its popularity is also accelerating. In 2020, the market share of LED ligh bulbs is over 50%. What is the influence and determination of led lamp technology development direction?

Two elements that determine the direction of technological development of LED ligh bulbs

Low down the cost of LED light

LED chip occupies the main part of the cost of LED lights, thereby reducing the cost of the LED is to reduce the cost of the LED chip.

The key for LED chip technology development lies in the base material and epitaxial growth techniques. Base material is by the traditional materials of sapphire, silicon and silicon carbide, the development of zinc oxide, gallium nitride and other materials. In a few short years, by means of a series of technical improvements, including chip architecture, surface roughening treatment and multiple quantum structure design, LED light bulbs achieved a great breakthrough on the Light effect.

Low cost silicon substrate technology continue to progress, but the luminous efficiency are still not satisfied, to maintain this pace of development, once they reach a higher level, the silicon substrate as the main technical program has become an inevitable choice. Businesses will also be huge economic returns.

Improving the luminous efficiency of LED lights

Improve the light efficiency can also improve the proportion of the effective light to start. Light thin-film chip technology can reduce the light output of each side of the loss, with the bottom of the reflecting surface of more than 97% of the light from the front output power conversion be mostly light, not only significantly improve the LED light bulbs luminous efficiency, a favorable conditions for the lens design. The thin-film chip technology is the core technology of super bright LED chip production.

Improving the color of the LED Tunnel lights

In the high-brightness white LED, a small portion of blue stokes shift of the longer wavelengths. This is a good thing, because it makes the LED light manufacturers that can use many different colors of the phosphor layer to extend the emission spectrum, effectively enhances LED color rendering index (CRI).

super high power led in low temperature

1, What is the low temperature lighting?
Low temperature lighting refers to the use of artificial light source to light, the ambient temperature below 5 ° C venues, such as refrigerators, freezers, refrigerators, cryogenic plants, outdoor lighting. The low-temperature lighting to fluorescent-based, and now the LED street light (super high power led) source in the low-temperature lighting place.

super high power led in low temperature
2, the fluorescent lamps used in low lighting
Although the fluorescent lamp in a conventional room temperature, the luminous efficiency up to 90lm / W regarded as a high-efficiency light source, but when entering the low illumination environment, whether it is the luminous efficiency, illumination or aesthetic design shows more disadvantages. Even though some manufacturers have introduced a dedicated low temperature fluorescent lamps, to solve the problem of the luminous efficiency, but still can not take into account the illumination and aesthetic requirements. And the price is very expensive. At low temperatures, ordinary fluorescent light-emitting efficiency and even to be halved, and life will be shortened. Even without considering the nonuniform illumination of fluorescent lamps at low temperatures, but also consider the fluorescent light color and color rendering the problem of inadequate, because it can not show the best colors of the goods, can not achieve the purpose of attracting consumers .

3, LED Products used in several major advantages of low temperature lighting
Compared to CCFL fluorescent lamp cold light source, LED  (super high power led) used in low temperature lighting, or has a special advantage. First, LED, even at low temperatures of minus 40 degrees Celsius, can achieve instant start and requires no special circuit or programming. LED luminous efficiency is almost unaffected in the low temperature and may even be better than the normal environment. The three LED is a point light source, with a small, point to the characteristics of the optical arrangement in accordance with the design requirements for refrigerated cabinets, display and other places. And the LED can provide sufficient uniform illumination better to see the product label. Fourth, the LED light color, color temperature, color rendering of the variability can be based on different lighting requirements for different products, select the appropriate LED light source, to achieve the purpose of attracting consumers. Is the difference between LED and CCFL power supply before CCFL must first after a buck DC / DC converter, it will wear out the 10% electricity, wear out 25% of electricity through the Inverter, and finally to Fluorescent tube of power about only 70%. But the LED Lights just after the LED  (super high power led)  Driver will be able to direct transmission of power, so that the efficiency of the transformer circuit to up to 90%, with a larger energy-saving advantage.

super led bulbs in led application

In order to solve the LED Lights heat dissipation problems, the future may be largely vertical structure of the LED structure, promote the technical development of the LED industry. I believe we all are heard, the following only from the technical surface are described, for information on the vertical structure of LED (super led bulbs) technology.

super led bulbs in led application

We know that the LED chip (super led bulbs) has two basic structure of the horizontal structure (Lateral) and the vertical structure (Vertical). The horizontal structure of the LED chip, the two electrodes on the same side of the LED chip, the current limit in the n-and p-type layer in the lateral flow, ranging from distance. The two electrodes of the vertical structure of the LED chips on both sides of the LED epitaxial layer, respectively, due to graphical electrode and the p-type cladding layer as the second electrode, the current almost all vertical flow through the LED epitaxial layer, very little lateral flow current can improve the current distribution of the planar structure the problem, improve the luminous efficiency can also solve P shading to enhance the LED light-emitting area.

 

We start to understand under the vertical structure of the LED manufacturing technology and the basic methods:

Manufacturing vertical structure LED chip technology, there are three main ways:
The growth of GaN films, the use of silicon carbide substrate, the advantage is in the same operating current conditions, the light fades, long life, the shortcomings of the silicon substrate absorbance.
Second, the use of chip bonding and peeling technology manufacturing. The advantage is that the light fades, long life, the deficiencies to be the surface of the LED in order to improve the luminous efficiency.
Is heterogeneous substrates such as silicon substrate GaN LED (super led bulbs)  epitaxial layer, the advantage of good heat dissipation and easy processing.

There are two basic ways: Peel the growth substrate, and stripped the growth substrate to create vertical structure LED chip. Which the growth of GaAs growth substrate on the vertical structure of GaP based LED chips have two structures:
Do not peel the conductive GaAs growth substrate: the stacked conductive DBR reflection layer on the conductive GaAs growth substrate, the growth of GaP based LED epitaxial layer on the reflective layer of conductive DBR.
Stripped GaAs growth substrate: Cascading reflective layer on the GaP based LED epitaxial layer bonded to a conductive support substrate, stripping the GaAs substrate. Conductive support substrate, the substrate of gallium arsenide, gallium phosphide substrate, the silicon substrate, metal and alloy.

In addition, the vertical GaN-based LED Grow Lights grown on silicon, there are two structures:
Stripped silicon growth substrates: metal reflective layer stacked on a conductive silicon growth substrate or conductive DBR reflection layer, the growth of GaN-based LED epitaxial layer on the reflective layer in the metal reflective layer or conductive DBR.
Stripping the silicon growth substrate: cascading metal reflective layer on the GaN-based LED epitaxial layer on the metal reflective layer bonded conductive support substrate, stripping the silicon growth substrate.
A brief description of manufacturing a vertical GaN-based LED process: reflective layer stacked on the reflective layer on the GaN-based LED epitaxial layer bonding the conductive support substrate, stripping the sapphire growth substrate. Conductive support substrate including metal and alloy substrate, the silicon substrate.

The GaP-based LEDs, GaN-based LED and ZnO-based LED of this type of through-hole vertical structure of LED compared to traditional structures LED has a large advantage, in particular in:
1, the vertical structure LEDs of all colors: red LED, green LED, blue LED and ultraviolet light the LED can be made through-hole vertical structure LEDs have great application market.
2, all of the manufacturing process in the chip (wafer) level.
3, no need to play the gold wire with the outside world power is linked through-hole vertical structure LED chip package thickness decreased. Therefore, can be used in the manufacture of ultra-thin devices, such as backlight.

supernova led grow light review in signal lights

LED STREET LIGHT (supernova led grow light review) is a field light source, its light-emitting principle is a PN junction with a positive voltage at both ends of Hole in the P region to the N region. As the minority carrier and majority carrier compound to release energy, part of the energy into heat, the other part of the energy into light.

supernova led grow light review in signal lights

LED Lights (supernova led grow light review)  luminous color in the matrix and the infiltration of miscellaneous materials, in addition to white light are basically pure monochromatic light, light color, easy to control, it can be widely used in traffic lights, hand signal lamp display screen and so on. Traditional railway handheld lights ordinary incandescent bulbs or inflatable incandescent light bulbs as a light source, a red signal, green signal, the yellow signal generated by the red, green, yellow polycarbonate filter, on the one hand, in the polycarbonate added to the molding process, the toner amount is difficult to accurately control, leading to the resulting color is not pure, on the other hand polycarbonate in the long-term use, in particular, will degrade in sunlight yellow, affect the color displayed. And incandescent bulbs are only a dozen hours of service life, change frequently, continuous working time of more than 10 hours not required, the lighting is also heavier to carry the inconvenience.

There are many manufacturers to use red, green, yellow LED signal light, but also there are some manufacturers use multiple ultra bright white LED as white light white light, however due to the low luminous efficiency, low power, enough illumination therefore only be used as a signal can not play the role of task lighting.

LED light  (supernova led grow light review) efficiency with incandescent similar, and increase the scope of the change in color, it has become the basis of the signal light source, while its short response time, low fever, low energy consumption and long life, maintenance costs and low advantage, immediately causes the LED signal lights have a wide range of applications. With the continuous improvement of the optical design, LED luminous efficiency will continue to improve, the number of signal lights use LED tube now down to 100 pieces from the beginning of the four or five hundred, or even dozens of stars.

 

suppliers of led lights with Solar lawn

Solar lawn lamp solar cells energy to carry out the work, when the daytime sunlight on the solar cell, light energy into electrical energy stored in the batteries from the battery at night, as the lawn of LED (light emitting diode ) to provide power. Its advantages for safety, energy, convenience, and environmental protection. Apply to the residential community green beautification lighting decorations, park lawn beautification embellishment.

suppliers of led lights with Solar lawn

LED solar lawn structure:

By the solar modules (photovoltaic panels), ultra-bright LED lights (suppliers of led lights), maintenance-free rechargeable battery, automatic control circuit, lamps and other components.

LED solar lawn lamp system consists of:
Solar lawn boost IC can automatically switch to charge and discharge behavior, when daytime solar charging panel sensor to the sun, the automatic switch to turn off the lights into the state of charge, when darkness fell, the solar charging panels induction less than the sun, and automatically switch open the light to enter the state of battery discharge. Solar lawn boost IC, the output voltage of 1.5 volt rechargeable battery up to 3.6 volts.

LED solar lawn light source advantages:

Most lawn use LED  (suppliers of led lights) as a light source, LED, long life, can reach more than 100,000 hours, low operating voltage, very suitable for application in solar lawn. LED technology has experienced a key breakthrough, and its properties in the past five years has greatly improved its cost performance has greatly improved. In addition, LED  (suppliers of led lights) low voltage DC power supply, the light source control costs low, so that adjustment of light and shade, and frequently switches are possible, and will not have a negative impact on the performance of the LED  (suppliers of led lights). You can also easily control the color, change the distribution of light to generate dynamic mirage, so it is especially suitable for solar lawn.

Unique advantages of solar lawn lamp, solar lawn light and power system design, have developed rapidly in recent years. Lawn small power, mainly decorative purposes, applicable to high mobility, circuit laying difficulty, high water requirements venue. These make many unprecedented advantages of solar powered lawn.

sylvania led flood lights for sports using

The LED screen has become a modern major sports venues, essential facilities, major sporting events with a large number of LED screen (sylvania led flood lights) is indispensable equipment. The Coliseum display system to be able to clear, timely and accurately display the information of the sports competitions, and multimedia technology to show the game live, express and create a tense, warm atmosphere of competition. Require a system with simple and clear, accurate and efficient, easy to operate man-machine interface, support for multi-sport races projects, in line with the requirements of various sports competition rules, easy to maintain and upgrade.

sylvania led flood lights for sports using

The big screen screen is generally divided into the lattice and the timing of two parts, computer network control system for data processing, and control large-screen display, network systems and broadcast television systems to provide real-time data; special Judges access to all kinds of sports competitions basic score information infrastructure.

From their point of view can be divided into two categories, first, full-color LED Lights screen (sylvania led flood lights) for the scene in the game play the game (including the highlights of the stadium), or slow-motion replay and live a wonderful close-up lens, or use 3D animated performance of the tournament and a tournament.

The other is the timing scoring screen, it connected with the game time scoring, player player of the competition results and related information from the sense of the game, timing, scoring screen is more important, some venues may not large video screen, but can not for the timing scoring screen. Timing and scoring screen, the key is real-time accurate and clear, vivid and more expressive (eg, animation, etc.) and as far as possible on this basis. The scoring screen to display text or text plus graphics animation player game scores, data, or other information. Its color to monochrome, multicolor or full color.

It should be noted that the gymnasium electronic display system is a set of game design, and scoring display graphics, banners, video, audio, multimedia player and athlete, sports team background information management as one of the Information Management Centre, in order to be effective to achieve the above, the use of computer network systems as electronic display system hardware and software platforms, electronic screen, the referee seats, game timer, mounted as a network terminal in a LAN, in order to take full advantage of the network platform to reach the information shared management, the control mode is simple, easy system expansion and maintenance. Plus on the Stadium brighter ambient light, viewing distance, viewing angle is relatively large, the specifications of the LED STREET LIGHTs screen (sylvania led flood lights)  brightness according to the situation to be determined.

t12 led tube parameters

1. forward operating current If:
It refers to the normal light of the light emitting diode forward current value. Should be selected in the actual use of IF in 0.6 IFm below.

2. forward operating voltage of the VF (t12 led tube) :
The operating voltage is given in the parameter list in a given forward current. Generally measured at IF = 20mA. Light-emitting diode forward voltage VF 1.4 ~~ 3V. VF will drop in outside temperature.

3. V-I characteristics:
The relationship between voltage and current of the light-emitting diodes, the forward voltage is less than a certain value (called the threshold), the current is very small, non-luminous. When the voltage exceeds a certain value, the forward current with voltage is quickly increased, light.

4. Luminous intensity:
Luminous intensity of light emitting diodes are usually fingering line (cylindrical LED luminous intensity on its axis) direction. In the direction of radiation intensity (1/683) W / sr, the luminous one candela (symbol cd). General LED Lights (t12 led tube) luminous intensity is small, so commonly candlelight luminous intensity (candler mcd) units.

5. LED emitting angle:
-90 ° – +90 °

t12 led tube parameters

6. Spectral half width Δλ:
It indicates that the spectral purity of the light emitting tube.

7. half-value angle θ1 / 2 and perspectives:
θ1 / 2 is the angle between the luminous intensity value of the axial intensity value half of the direction of the light-emitting axial (normal).

8. full shape:
LED light-emitting solid angle conversion point of view, also called the plane angle.

9 perspective:
Refers to the maximum angle of LED light (t12 led tube) , according to the different perspective and different applications, also known as light intensity angle.

10. half-width:
The angle of the method to between 0 ° and the maximum luminous intensity value / 2. Strictly speaking, is the maximum luminous intensity value and the maximum luminous intensity values ​​/ 2 corresponds to the angle. LED Flood light packaging technology lead to the intensity value is not the law of the maximum light-emitting angle to 0 °, the introduction of the deviation angle refers to the point of view and method of the maximum luminous intensity corresponding to the angle between 0 °.

11. Maximum forward DC current IFm:
Allow plus the largest positive DC current. Than this value can damage the diode.

12. maximum reverse voltage VRm:
Allowed plus the maximum reverse voltage. Exceeds this value, the light emitting diode may be breakdown.

13. working environment topm:
The light emitting diode to a working ambient temperature range. Below or above this temperature range, light emitting diodes will not work properly, the efficiency is greatly reduced.

14. allow power Pm:
Allow the addition of the LED at both ends of a positive DC voltage and the flow through the maximum of its current product. Exceeds this value, the LED heat, damage.

 

t4 led tube and led down lights

Although the price factor constraints widely promote the use of high power LED, high reliability, high power LED, significant savings in future maintenance and replacement costs. Colorful, and other sources can not achieve this effect. Easy to control, digital control technology, to achieve dynamic lighting effects. LED Downlight is embedded into the ceiling light shooting style lighting. Its biggest feature is the ability to maintain the overall unity and perfection of the architectural decoration, lighting settings destruction of the perfect unity of the ceiling art. It uses high power LED (t4 led tube) as light source, the visual effects of soft, uniform. LED is the future of green lighting products. Furthermore, LED have the advantages of energy-saving plays an increasingly important role in the development trend of the downlight light.

t4 led tube and led down lights

High-power LED Downlight in the early input costs to be higher than traditional lighting, but after prolonged use, the consumption of the total cost will be lower than traditional lamps. Therefore, using high-power LED Downlight in significantly superior to the traditional incandescent light. And because of the high-power LED constant current drive, no flicker, long working environment eye fatigue. High-power LED is characterized by:

1 less power consumption, high power LED (t4 led tube) : light efficiency 65Lm / W of LED is more than equal to the brightness of incandescent power consumption savings of 80%.

2 long life, high power LED: LED life up to 50000h, 24 hours of continuous light available to seven years.

3 high power LED response speed approaching nanoseconds, the dynamic of brightness and color easy to control, to achieve the dynamic change of the digital control of color.

4 high-power LED design: buildings can be a good match to achieve the effect I saw the light but not light.

5 high-power LED clean and green: no toxic metals mercury, infrared and ultraviolet radiation.

Color: different wavelengths produce different colored light, bright and saturated, no filter, the formation of red, green, and blue control is available in different colors, and can achieve the effect of full-color, gradient, and a variety of colors.

High-power LED  (t4 led tube) to replace the incandescent light source showed the advantages of energy saving and long life incandescent and some other traditional light sources in many technical aspects of room for improvement is very small, the LED lamps to replace or replacement of existing lighting halogen bulbs in the downlights, light bulbs, gas discharge, incandescent light bulbs, luminous efficiency of LED downlights improve the efficiency of traditional lamps, but, due to the higher initial purchase cost, compared with fluorescent lamps, energy saving lamps, the energy saving effect is not very clear.

t5 high bay fixture LED metal package

Common substrate types of rigid printed circuit boards (PCB), high thermal conductivity coefficient of aluminum plate, ceramic substrates, soft printed circuit boards, metal composite materials. Low-power LED Lights package with PCB version of the ordinary for the electronics industry to meet the demand, but more than more than 0.5W LED packaging (t5 high bay fixture) are mostly switched to the metal lines and ceramic high heat dissipation substrate, mainly due to the cooling of the substrate LED life The performance has a direct impact on the package substrate is a very important component in the design of high brightness LED products application.

t5 high bay fixture LED metal package

In the process of the general electricity into light, nearly 80% turn to the heat.  We rely on the heat sink for cooling. In fact, a lot of heat in so small space does not burn particles, but it makes the light more and more weak, which is commonly referred to as the light fades. Only the heat out fast, the light fades before the smaller.

The thermal expansion and dimensional stability of three of the application advantages of LED Tubes components (t5 high bay fixture)  listed below:

1, heat
At present, a lot of double sided, multilayer density, power, heat dissipation is difficult. Conventional PCB substrates such as FR4, CEM3 are poor conductor of heat insulation layer, the heat does not go out. Electronic equipment does not rule out local heating, resulting in the high-temperature failure of electronic components, metal-based printed circuit board can solve this thermal problem.

2, the thermal expansion
Thermal expansion and contraction is the common nature of the material, the different substances CTE (Coefficient of thermal expansion) coefficient of thermal expansion is different. The PCB is resin + reinforced materials (such as fiberglass) + complexes of copper foil. XY axis direction of the board, the PCB coefficient of thermal expansion (CTE) of 13 to 18 PPM / ℃, 80 to 90PPM / ° C in the plate thickness Z-axis direction, the CTE of copper of as 16.8PPM / ℃. Sheet of ceramic chip carrier CTE of as 6PPM / ℃, PCB plated hole wall and connected to the insulated wall in the Z-axis CTE is a big difference, the heat generated can not be immediately removed, thermal expansion and contraction so that the through holes cracking disconnect, such machinery and equipment is not reliable.

SMT (surface mount technology) to make this issue more prominent, the problem must be solved. Surface mount interconnect is achieved through the direct connection of the surface of the solder joint, the CTE of the ceramic chip carrier 6, while the FR4 substrate in the XY CTE of 13 to 18, therefore, mount connector solder joints due to different CTE long  (t5 high bay fixture) withstand the stress can lead to fatigue fracture.

3, the dimensional stability

Metal based PCB, apparently size than the insulating material PCB is much more stable. Printed circuit board of aluminum, aluminum sandwich panel, heated from 30 ℃ to 140 to 150 ° C, the dimensional changes of 2.5 to 3.0%. The metal base circuit board with excellent thermal conductivity, good machining performance and strength, good electromagnetic shielding performance, good magnetic performance. Product design follows the semiconductor conduction mechanism, and therefore not only the thermal conductivity of the metal circuit board (metal PCB): aluminum plate, copper substrate has good thermal conductivity, heat dissipation. And the green environmental protection, both to solve the heat problem to solve environmental problems.