A, LED history

Fifty years ago, people have about semiconductor material can produce the basic knowledge of light, 1962, general electric company, HeLun grams of NickHolonyakJr (j) ratnayake developed the first kind of practical application of visible light emitting diode. LED emitting diode (one English is the abbreviation of emitting diode), it is the basic structure of a electroluminescent materials, in a semiconductor, then fuses shelf round sealed with epoxy resin, namely, so can have solid encapsulated inside the core wire, so the aseismatic performance. LED Initially the instructions for instrument LED light source, then all the traffic lights, LED in large letters shown in the screen shows and widely used with good economic benefit and social benefit. 12 inches of red traffic light, for example, in the United States was using long life and low efficiency of 140 watts incandescent lamp illuminant, it produces a white light of 2000 lumens. The red filter, light loss, only 200 lumens 90% of the red light. But in the new design of the lamp, Lumileds company adopted 18 red LED light source, including loss of power circuit, and can produce the same efficacy. Automotive lights is an important field of application LED light source.

Second, the LED chip principle:

Leds (LightEmittingDiode), light emitting diode, is a solid, it can directly semiconductor devices DianZhuan into the light. The heart is a LED semiconductor wafer, chip attach a stent in the end, the end is negative, the other end of the positive power connection, make whole chips are epoxy encapsulation. Semiconductor wafer consists of two parts, the part is P type semiconductor, in its dominant inside hole, the other side is n-type semiconductor, here basically is electricity. But these two kinds of semiconductor connected between them, to form a "P -" N. When the current through the wire to the chip, electronic would be to P area, in P area with cavitation compound, and electronic in the form of photon energy, which is LED the principle. But the wavelength of light is light color, is formed by the material and P - N.

Third, the LED chip classification:

1 MB chip definition and characteristics definition: MetalBonding (metal adhesive) chip, This chip UEC belongs to the patent products. Features: (1) adopting high heat coefficient of the material - Si substrate, heat as easily. ThermalConductivity GaAs: 46W/m - K GaP: 77W/m - K, Si: 125 ~ 150W/m - K w/Cupper: 300 K m - 490W/m - SiC: K (2) through the metal layer to joints (waferbonding epitaxial layer and substrate), at the same time, avoid the reflection photon absorb. (3) the Si substrate instead of conductive GaAs substrate, good thermal conductivity of heat capacity difference (3 ~ 4 times more comfortable in) and high drive current fields. (4) bottom, the metal reflection spectrophotometry and heat. (5) size can increase, applied field, eg: 42milMB Highpower.

2 GB chip definition and feature definition: GlueBonding (adhesive) chip, This chip UEC belongs to the patent products. Features: (1) the sapphire substrates replace absorb light GaAs underlay, its optical power is a traditional AS (Absorbable benefit) more than two times, the chip sapphire substrates similar TS chip GaP substrate. (2) chip has excellent luminescence, all Pattern. (3), its overall brightness brightness already more than TS chip level (8.6 mil). (4), the double electrode structure of high current aspect to slightly bad in TS electrode chip.

3 TS chip definition and feature definition: transparentstructure (transparent substrate) chip, this chip belongs to the patent products. HP Features: (1) the chip production process complex, far higher than ASLED. (2) reliability of excellence. (3) transparent substrate, no GaP absorbing light, high brightness. (4) wide application.

4 AS chip definition and characteristics Absorbablestructure definition: absorbing substrate) chip (, After nearly four years of development efforts, Taiwan LED light electric field for this type of chip r&d, production, sales in mature stage, each big companies in the aspects of basic research, the gap at the same level. Mainland chip manufacturing startting evening, its brightness and reliability and Taiwan of industry, here we are talking of the chip, especially UEC of chips, eg: 712SOL - VR, 709SOL - VR, 712SYM - VR, 709SYM - VR, etc. Features: (1) the fabrication process, USES MOVPE chip, relative to conventional chip bright brightness. (2) good trust. (3) wide application.

Four, light emitting diode chip material epitaxy types

1: LiquidPhaseEpitaxy (LPE) phase epitaxy GaP/GaP
2 VaporPhaseEpitaxy VPE: (gas phase epitaxy GaAsP/GaAs method)
3 MOVPE: MetalOrganicVaporPhaseEpitaxy (organic metal gas phase epitaxy AlGaInP, GaN method)
SH: 4) GaAlAs/GaAsSingleHeterostructure (single structure) GaAlAs/GaAs
5 GaAlAs/DH: GaAsDoubleHeterostructure (double structure) GaAlAs/GaAs
6 DDH: GaAlAs/GaAlAsDoubleHeterostructure (double structure) GaAlAs/GaAlAs

Five, LED chips and shine

LED chip composition: mainly arsenic (AS) aluminum (AL) gallium (Ga) indium (IN) phosphorus (P) nitrogen (N) strontium (Si) this several elements of several kinds of composition.

LED chip classification: 1, according to the luminous intensity points: A, general brightness: R, h., and y., e. g., B, high brightness: VG VY, SR, such C, brightness: UG, UR, UYS UY, URF, etc, D UE, visible (infrared) : R, SIR, VIR HIR, infrared receiver E, F, PT: count: PD

2, according to the element points: A, dual wafer (p, gallium) : H, G, etc, the ternary wafer (B), phosphorus, arsenic, SR, HR, such C, four yuan UR wafer (p, aluminum, gallium, indium) : SRF HRF, URF, VY, UYS UY, and HY, wash., UE, and UG

3 LED chip features list:

LED chips type emitting light colors elements wavelength (nm)
LnGaN/SBI blue sic 430

HY ultra bright yellow AlGalnP 595

SBK lighter blue lnGaN/sic 3093

SE GaoLiangJie color GaAsP/GaP 610

DBK Gan/lighter blue GaunN 470

HE ultra bright orange AlGalnP 620

SGL green lnGaN/sic 502

The most bright orange UE AlGalnP 620

A DGL relatively bright green LnGaN/GaN 505

URF most bright red AlGalnP 630

A bright green DGM lnGaN 871

E orange GaAsP/GaP 635

PG pure green GaP 555

R red GAaAsP 665

SG standard green GaP 560

SR is bright red GaA/AS 660

G green GaP

HR ultra bright red GaAlAs 660

VG relatively bright green GaP

The bright red UR GaAlAs 660

UG most bright green AIGalnP 574

H, GaP 697

Y yellow GaAsP / 585 GaP

HIR infrared GaAlAs 850

A bright yellow GaAsP/VY 585 GaP

SIR infrared GaAlAs 880

UYS most bright yellow AlGalnP 587

VIR infrared GaAlAs 940

The bright yellow UY AlGalnP 595

IR infrared GaAs 940