【 Weak current College 】 LED dictionary 】

SMDLED　surface-mountdeviceLED。 Surface adhesion-LED.

Surface adhesion-LED is beginning in 1980, was more small package and factory automation. Initially the main factors discouraging manufacturers is surface adhesion LED the first problem is unable to complete the high-temperature solder reflow under infrared rays. LED low specific heat of a IC, temperatures not only leads to decline and more brightness temperatures up to 100 degrees will accelerate the deterioration of the component. Led packaging using resin will absorb the moisture, the rapid vaporization of water molecules, causes cracks in the original packaging resin, affect the product efficiency. In the early 1990s, HP and SiemensComponentGroup cooperative development long molecular bond adhesion of polymer as a surface-LED with handling the machine's design, surface adhesion type LED to this is the official debut.

LED　LightEmittingDiode。 Light emitting diode.

LED for power electronic components can be luminous, and is made of semiconductor material, material use glow III-V family of chemical elements (such as gallium phosphide (GaP), gallium arsenide (GaAs), etc.), light emitting principle is to convert light energy, namely to bring current compound semiconductors, electronic and electric tunnel, the combination of excess energy in the form of a light release, reaching a glow effect that belong to cold glow, the life up to 100 hours. LED most major characteristic is: no warm light time (idlingtime), response is very fast (about 10 ^-9 seconds), the volume small, the electricity, polluting low, suitable for mass production, high reliability, easy to meet application needs made into very small, or array type, scope of application is wide, such as motor vehicles, communications industries, computer, traffic signal, monitor, etc.

LED and can be divided into upper, middle and lower reaches. From upstream to downstream, the gap between the appearance of products. Upstream is formedby Lei chip, the chip looks probably Lei a diameter of six to eight centimeters wide, round, thickness quite thin, like a flat metal. Led color and brightness of the decision by the epitaxial materials and Epitaxial LED manufacturing costs accounted for 70% of the led industry is extremely important. Upstream Epitaxial wafers in order to: single chip (III-V family substrate), structural design, crystal growth, material/thickness measurements.

River manufacturers is the chip to be cut, formed to tens of thousands of grain. According to the size of the chip, you can cut to 20 000 to 40 000 grain. These crystal looks like sand on the beach, usually with special adhesive tape fixed, then sent to downstream manufacturers for package deal. River grain processing order is: Lei chip, metal film evaporation, mask, etching, heat treatment, cutting, cracks, measure. Whereas, in order to lower package: grain, solid Crystal, adhesive, hitting line, resin encapsulated, long to bake, tinned, shear pin, test.

Domestic main LED manufacturers: Dingyuan, light Lei, League of Nations, light etc. billion

Infrared emitting diode IR LightEmittingDiode.

Mainly in GaAs series material development, usually to LPE liquid phase Epitaxial method method, luminous wavelength from 850 ~ 940.

GaP gallium phosphide.

Gallium phosphide, III-Ⅴ family (35 people) element chemical compounds. GaP is an indirect transfer-type semiconductor, low current, high-efficiency light-emitting characteristics, scope of cover red glow to yellow-green, LED one of the main materials used.

GaN Gan.

Gan, III-Ⅴ group elements in the chemical compounds. GaN to fabrication, MOVPE make high brightness LED pure blue and pure green LED can be applied to the Blu-ray laser diodes, Green's production. MOVPE though is a mature technology of Epitaxial production, but this technique produced GaN blue LED which still have considerable expertise, experience and skills

AlInGaP Indium gallium phosphide.

AlInGaP this material is in recent years used in the manufacture of high-brightness LED the newer material on, use MOVPE Epitaxial method. The world's only three manufacturers to supply the products of the company, the United States Japan HP, Toshiba, Taiwan's photo.

AlGaAs aluminum gallium arsenide.

AlAs for GaAs and mixed grain of. AlGaAs suitable for manufacturing high-brightness red light and infrared LED mainly to LPE Epitaxial method of production, but due to the required production AlGaAs substrate, technical difficulty.

Reverse adhesive-type thin chip LED reversemountingtype thin chip LED.

This kind of chip you can tack in wear-printed circuit board, reducing the thickness of the LED. Primary keys can be used as a portable phone's backlight.

Side emitting angle LED

This kind of LED chip is from top level glow, but may be a light-emitting surface of the rotating surface of the weld. Side emitting angle LED with ultra small form factor and high brightness is of two kinds, ultra small form factor for LCD backlight, pagers, mobile phones; high brightness type is used for steam, locomotive headlights of the third moment and outdoor displays.

Right angle surface adhesion type LED bulb SIDELED.

Right angle surface adhesion type LED bulb does not require additional optical parts or reflector, the light of acts after soldering line parallel to the PCB with the engineering staff at design time with greater flexibility, enabling the design of the posterior segment plus this product without prior consideration. Products can be applied in the auto power off switch, security lighting and light-tube, used as a phone and data processing system of indicators.

Visible light LED lightLightEmittingDiode。

LED (light emitting diode), depending on the shine wavelength roughly divided into visible and non visible light. Visible LED products mainly include traditional LED, high brightness AlGaInP (gallium Indium phosphide) red, yellow, orange and light LED InGaN (Indium Gallium Nitride) blue, green, LED, white led. Its products to display purposes, and to the brightness of a candle (1cd) as a General LED and high brightness LED of the demarcation point. General LED is widely used in various indoor display applications; high-brightness LED which is suitable for outdoor displays, such as car headlights Myers III, outdoor information board and the traffic signal, etc.

Not visible LED not visible LightEmittingDiode.

LED (light emitting diode), depending on the shine wavelength roughly divided into visible and non visible light. Not visible wavelength LED, 850-1550 Nano, its short wavelength, infrared light can be used as the infrared wireless communication, such as infrared led application in photocopying paper size detection, appliances remote control, factory automatic detection, automatic doors and automatic flushing device control; long-wavelength infrared, used in medium and short fibre communications, as the light source for optical communication.

GaNLED Gan LEDs.

GaNLED belong to direct energy gap of semiconductor material, to its energy gap and AlN-3.4ev 6.3ev, InN, for 2.0ev several materials made of mixed grain, you can set the energy gap from continuous change to 6.3ev 2.0ev, so you can get from the ultraviolet, violet, blue, green to yellow light and color.

The most successful GaN component has high brightness green LED Blu-ray and because GaN high brightness green LED Blu-ray, successful development, makes the outdoor full color LED display and led traffic signal, a variety of LED applications are more widely. To stimulate high-brightness LED fluorescent substances Blu (phospher) can produce white light, low power and high life, the future is likely to replace the General lighting of incandescent, GaNLED very strong market potential.

OLED　OELD。 OrganicElectro-LuminescenceDisplay。 Organicwavelengths.

Through the current driving organic thin film to light, the light can be a separate of red, blue, green, or even a full-color. Because OLED organic materials used by will self-luminous, unlike LCD Panel rear need plus backlight, you can dramatically reduce power consumption, simplify the process, the panel thickness thinner. OLED feature with self-luminous, wide angle, response speed, low power consumption, high contrast, brightness, the thickness of thin, full-color, and animate, etc., is considered a great potential of flat display technology. China currently has rhenium Po, light Lei, TECO laser, optical and other manufacturers into the hanli.

Indoor LED display board

LED display board regardless of size, are LED by a single component to Assembly, LED by a single component, from the point of downstream packaged LED matrix, or unit of the module, and the Cluster display board manufacturers will these single components, in accordance with a variety of different needs, assembled into a variety of large, kanban, plus the control circuit, and then to the construction site installation testing.

Indoor LED displays used for KANBAN close watched, so require, in General, higher resolution is to use the point matrix module for indoor environment more stable, so they don't need to do, and heat-proof protective devices, construction area easier.

Outdoor LED display board

LED display board regardless of size, are LED by a single component to Assembly, LED by a single component, from the point of downstream packaged, or matrix of LED units, display module Cluster board manufacturers will these single components, in accordance with the needs of a variety not, assembled into a variety of large, kanban, plus the control circuit, and then to the construction site installation testing.

Outdoor LED kanban, viewing distance, the resolution requirements relative lower, but the brightness, visibility and weatherability of requirements are quite high, so in the outdoor construction on the need to consider issues such as thermal and waterproof.

Large led display

Large led display requires a combination of different element component and technology, a manufacturer is difficult to fully-produced and self-contained, and therefore the Division of external industry is very important. Large led display required element components include: DriverIC, LEDCluster, PowerSupply, Cable and mechanical frameworks; the technical aspects of needs including: antistatic design, power and distribution planning, driving circuit design, driven software design, the design of mechanical structure (thermal, Visual, support, Sun, moisture, and other considerations), and brightness and color of test technology.

UVLED UV diode

UVLED (ultraviolet light-emitting diode) lighting not only clean air, energy conservation, and is expected to replace the incandescent lamp fluorescent lamps and lighting fittings, and past only 405nm wavelength band has recently expanded to 200nm, expected application scope will be greatly expanded to sterilization, wastewater treatment, deodorant, medical care, dermatology, identification of counterfeit banknotes and environmental Sensor, etc.

Luminous flux (Luminousflux, Φ) units: lumens (lumen, lm) consists of a light source emits and eye perception of all the radiant energy called flux. Light intensity (luminousintensity, I) light source in a direction of the solid angle of the light flux size. Units: candela(Candela, cd) illumination (Illuminance, E) unit: Lux (Lux, lx) illumination is the luminous flux and the ratio of the illuminated. 1lux of illuminance for 1lumen light flux evenly distributed in the area of a square meters of area. Luminance (Luminance, L) units: candela per square meter (cd/m2) to a light source or an illuminated brilliance of its unit surface in one direction of the light intensity density, it is the human eyes perceive the light or the degree of bright illuminated.

Light-emitting diode (LED LightEmittingDiode, hereinafter referred to as)?

Is a kind of excited by applied voltage and shine optical electronics (electric energy → light) of optoelectronic Semiconductor components. Luminous phenomena in the case of direct light emitting Semiconductors (no intervening third particle). The luminous phenomena can be divided into three procedures (direct lighting):

Price of electricity with e-mail from external energy (clockwise bias), excited to conductive belt and, at the price of electricity in a power hole left by the band to form e-hole pair. Stimulated by e-mail to the conductive strips, and other particle collisions (scattering), part of the energy loss, but close to the edge of conductive tape. Once the conductive belt edge e to find electro band price electric hole, e from the conductive belt edge through trap Center (free energy) or luminescent Center (free energy), back to the price of electricity and electric tunnel complex, electronic-electric hole to disappear.

Because the LED mainly through emitting Centre and electronic electric tunnel complex and glow, so it is a solid state light sources of micro-, small size, long life, driving voltage is low, the reaction rate, earthquake resistance is very high, and can be combined with light, thin and miniaturization of the application of the equipment needs to be very common in everyday life.

Use a variety of compound semiconductor materials and components structure changed to design different LED. Depending on the shine wavelength is divided into visible light, not the visible light (IR, UV).

Visible light: red, Orange, yellow, green, blue, purple, etc. all kinds of colors, mainly to display purposes. 1 candlelight and luminance (cd) as the General brightness and high brightness of the demarcation point. General brightness LED is widely used in various indoor display applications; high-brightness LEDis suitable for outdoor displays, such as: car headlights Myers III, outdoor information board and the traffic signal, etc. Not visible: short wavelength infrared light can be used as the infrared wireless communication; long-wavelength infrared is used in short fibre communications, as the light source for optical communication.

Use of materials is basically has largely determined the release LED wavelength, which is suitable for making 1000mcd above high-brightness LED material composed of long wavelength short wavelength, AlGaAs (aluminum gallium arsenide), AlGaInP (Indium gallium phosphide) and GaInN (Indium Gallium Nitride), etc.

AlGaAs (aluminum gallium arsenide) suitable for the manufacture of high-brightness red light and infrared LED, primarily in the liquid phase Epitaxial (LPE) method for mass production, the use of double-hetero-interface structure (DH), but because of the need to make AlGaAs substrate, technical difficulty is very high, therefore the investment and development of small firms. AlGaInP (Indium gallium phosphide) suitable for high-brightness red, Orange, yellow and green LED light, mainly in metal-organic vapor phase Epitaxial (MOVPE) method for mass production, the use of double-heterojunction interface (DH) and quantum well (QW) structure, increase efficiency even more. And because AlGaInP red LED at high temperatures and high humidity environment, its life test results superior to AlGaAs red light LED, the future has become the red light LED mainstream trend.

GaInN (Indium Gallium Nitride) for high brightness of dark green, blue, violet and UV LED to high-temperature metal organic vapor phase Epitaxial (MOVPE) method for mass production, also double heterojunction interface (DH) and quantum well (QW) structure, more efficient than the aforesaid AlGaAs, AlGaInP higher. Global manufacturers have been actively involved in related materials component technology research and development, and a breakthrough.

Whiteled, but Japan, Asia-Pacific companies use Blu-ray LED plus yellow fluorescent material, its photoelectric conversion efficiency in April 1998, has been raised to 15 lumens/Watt, slightly higher than traditional light bulbs, to the development of common lighting course, white led most the opportunity to become the future in the lighting industry's star product.

LED design, mainly used in electric appliances product display, advertising Board or decorative. But because it has a fixed wavelength and user-friendly features that have been used to study on plant production. 1987 some scholars use fixed wavelength characteristics, application of the plant to the ground, patterns change and research on the disease. In ancient Japan Chiba University (Kozai) Professor, applied at the Organization of production of bottles. Expected future in light of the tremendous value. Of course, currently LED brightness and the price has yet to reach practical phase, however, because of the tremendous market potential, in all aspects of the expanded rapidly, the LED will become available for plant growth emerging light source.

Wafer growth fundamentals of epitaxial growth is, in a heated to proper temperature of the substrate substrate (there are two Ruby and SiC), gaseous substances In, Ga, Al, P controlled transportation to the substrate surface, a specific single crystal thin film growth. Current LED wafer growth technology is mainly made of metal organic chemical vapor deposition.
MOCVD metal organic chemical vapor deposition (MOCVD Metal-OrganicChemicalVaporDeposition, for short), 1968, by the United States to Locke will companies in a single product preparation compound semiconductor thin films by new technology. The equipment set precision machinery, semiconductors, vacuum electronics, fluid mechanics, optics, chemistry, computer, multidisciplinary, is a high degree of automation, which is very expensive, technology integration and sophisticated electronic equipment, mainly for GaN (Gan) Semiconductor epitaxy and blue, green or UV LED chip manufacturing, photonics industry the most promising one of special equipment.