Definition: MB chip: metal bonded chip; This chip belongs to UEC's patented product.
Features: 1, using high heat dissipation coefficient material-Si as the substrate, easy heat dissipation.
conductivity for heat
GaAs: 46/m-g
Gap: 77 W/m-K
Silicon: 125 ~ 150 W/m-K
Copper: 300~400 W/m-g
Silicon carbide: 490 W/m-g
2. The wafer is bonded to the epitaxial layer and the substrate through the metal layer, and at the same time, photons are reflected to avoid absorption by the substrate.
3. instead of GaAs substrate, conductive silicon substrate has good thermal conductivity (thermal conductivity difference is 3~4 times), which is more suitable for the field of high driving current. 4. The metal reflective layer at the bottom is beneficial to improve luminosity and heat dissipation.
5, the size can be increased, and it can be used in high-power fields, such as: 42mil MB.
GB chip
Definition: GB chip: adhesive chip; This chip belongs to UEC's patented product.
Features: 1: transparent sapphire substrate replaces light-absorbing GaAs substrate, and the optical output power is more than twice that of traditional As (absorbable structure) chip. Sapphire substrate is similar to GaP substrate of TS chip.
2: The chip shines on all sides, and the pattern is excellent.
Light emitting diode chip
3. In terms of brightness, its overall brightness has exceeded the level of ts chip (8.6mil).
4. Dual-electrode structure, its high current resistance is slightly worse than the clarity and characteristics of ts single-electrode TS chip.
Definition: TS chip: transparent structure chip, which belongs to HP's patented product.
Features: 1. Chip technology is complex, much higher than LED.
2. Excellent reliability
3. Transparent GaP substrate, which does not absorb light and has high brightness.
4. Widely used
Definition: AS chip: Absorbable structure chip; After nearly 40 years of development efforts, the R&D and the production and sales of this type of chips in the LED photoelectric industry in Taiwan Province Province are in a mature stage, which is basically at the same level as that of major R&D companies, with little difference. The mainland chip manufacturing industry started late, and there is still a certain gap between brightness and reliability and Taiwan Province industry. What we are discussing here is. As the chip of UEC, especially as the chip of UEC, for example: 7 12Sol-VR, 709sol-VR, 7 12Sym-VR, 709sym-VR, etc.
Features: 1. Four chips, manufactured by MOVPE technology, are brighter than traditional chips.
2. Excellent reliability
3. Widely used
Types of diode chips
1, LPE: liquid phase epitaxy (GaP/GaP)
2.VPE: gas phase epitaxy (gas Xiang Lei crystal method) GaAsP/GaAs.
3.MOVPE: Metal-organic vapor phase epitaxy (organic metal gas Xiang Lei crystallization method) AlGaInP, GaN.
4.SH: GaAlAs/GaAs single heterostructure (single heterostructure) GaAlAs/GaAs.
5.DH: GaAlAs/GaAs double heterostructure, (double heterostructure) GaAlAs/GaAs.
6.DDH: gaalas/gaalas double heterostructure (double heterostructure)
Four important parameters
1, positive working current If
Refers to the forward current value of light-emitting diode when it emits light normally. In fact, IF necessary, if should be lower than 0.6 IFm.
2. Forward working voltage VF
The working voltage given in the parameter table is obtained at a given forward current. Generally measured at IF=20mA. The forward working voltage VF of LED is1.4 ~ 3v.. When the external temperature increases, VF will decrease.
3. Voltammetric characteristics
The relationship between voltage and current of light-emitting diode, when the DC voltage is just below a certain value (called threshold), the current is very small and does not emit light. When the voltage exceeds a certain value, the forward current increases rapidly with the voltage and emits light.
4. Luminous intensity IV
The luminous intensity of light-emitting diodes usually refers to the luminous intensity in the direction of normal line (axis of cylindrical light-emitting tube). If the radiation intensity in this direction is (1/683)W/sr, 1 Candeira (symbol cd) is emitted. Because the light-emitting diode intensity of general LED is relatively small, Candeira (mcd) is usually used to measure the luminous intensity.
5, LED light emitting angle
-90 - +90
6, spectral half width δ λ
It represents the spectral purity of LED.
7. Half-value angle θ 1/2 and viewing angle
θ 1/2 refers to the angle between the light-emitting intensity value and the optical axis (normal direction).
8. Complete shape
The angle converted from the solid angle of LED lamp is also called plane angle.
9. Perspective
Refers to the maximum angle at which LED emits light. Different viewing angles have different applications, also called light intensity angle.
10, hemisphere
Angle between normal 0 and maximum luminous intensity value /2. Strictly speaking, it is the angle between the maximum luminous intensity value and the maximum luminous intensity value /2. The packaging technology of LED leads to that the maximum luminous angle is not the light intensity value of normal 0, and a deviation angle is introduced, which refers to the included angle between the angle corresponding to the maximum luminous intensity and normal 0.
1 1, maximum forward DC current IFm
Maximum allowable forward DC current. Exceeding this value will damage the diode.
12 maximum reverse voltage VRm
The maximum allowable reverse voltage is the breakdown voltage. If this value is exceeded, the LED may be damaged due to breakdown.
13, working environment topm
The ambient temperature range for normal operation of LED. Below or above this temperature range, LED will not work normally, and the efficiency will be greatly reduced.
14, allowed power consumption Pm
The maximum value of the product of the forward DC voltage across the LED and the current flowing through it. If this value is exceeded, the LED will heat up and be damaged. [3]
5 chip size
There are three sizes of high-power LED chips: 38*38mil, 40*40mil and 45*45mil. Of course, the chip size can be customized, which is just a general specification. A mil is a unit of size, and a mil is one thousandth of an inch. 40mil is almost 1 mm, 38mil, 40mil, and 45mil are all commonly used dimensions of 1W high-power chips. Theoretically, the bigger the chip, the greater the current and power it can withstand. However, the material and technology of the chip are also the main factors affecting the power of the chip. For example, CREE 40mil chips can withstand 1W to 3W, and other chips of the same size can withstand 2W at most.
6 Luminous brightness
General brightness: R (red GaAsP 655nm), H (high red GaP 697nm), G (green GAAP 565 nm), Y (yellow GaAsP/GaP 585nm), E (orange GaAsP/ GaP 635nm), etc.
High brightness: VG (bright green GaP 565nm), VY (bright yellow GaAsP/ GaP 585nm), SR (bright red GaA/AS 660nm)；); ;
Ultra-high brightness: UG, UY, UR, UYS, URF, UE, etc.
Binary chips (phosphorus, gallium): H, G, etc.
Ternary chips (phosphorus, gallium, arsenic): SR (bright red GaA/AS 660nm), HR (super bright red GaAlAs 660nm), UR (bright red GaAlAs 660nm), etc.
Quaternary chips (phosphorus, aluminum, gallium, indium): SRF (bright red alga InP), HRF (super bright red alga InP), URF (bright red AlGalnP 630nm), VY (bright yellow GaAsP/GaP 585nm), HY (super bright yellow alga InP 595nm), UY (brightest yellow algainp 550 nm). UYS (brightest yellow AlGalnP 587nm), UE (brightest orange algalnp 620 nm), HE (super bright orange algalnp 620 nm), UG (brightest green algalnp 574 nm) LED, etc.
7 substrate
For the manufacture of LED chips, the choice of substrate materials is the primary consideration. Which suitable substrate should be adopted needs to be selected according to the requirements of equipment and LED devices. Three substrate materials: sapphire (Al2O3), silicon (Si) and silicon carbide (SiC).
Advantages of sapphire: 1. Mature production technology and good device quality; 2. It has good stability and can be used in high temperature growth process; 3. High mechanical strength, easy to handle and clean.
Disadvantages of sapphire: 1. Lattice mismatch and thermal stress mismatch will produce a large number of defects in epitaxial layers; 2. Sapphire is an insulator with two electrodes on the upper surface, which reduces the effective luminous area; 3, photoetching and etching processes are added, and the manufacturing cost is high.
Silicon is a good conductor of heat, which can obviously improve the thermal conductivity of the device, thus prolonging the service life of the device.
In the LED chip with silicon carbide substrate (CREE company specially uses SiC material as the substrate), the electrode is L-shaped, and the current flows longitudinally. The device made of this substrate has very good electrical conductivity and thermal conductivity, which is beneficial to the manufacture of large-area high-power devices. Advantages: The thermal conductivity of silicon carbide is 490 W/m·k, which is more than 10 times higher than that of sapphire substrate. Disadvantages: The manufacturing cost of silicon carbide is high, and the corresponding cost needs to be reduced to realize its commercialization.
8led function
(1) quad chip is manufactured by MOVPE process, and its brightness is brighter than that of conventional chips.
(2) Excellent reliability.
(3) Widely used.
(4) High safety.
(5) Long service life.
9 How to judge
Led chip price: Generally, the price of chips is higher than that of wafers, high-power led chips are definitely higher than low-power led chips, and imported ones are higher than domestic ones. The source prices of imports from Japan, the United States and Taiwan Province Province decreased in turn.
Quality of led chips: The quality of led chips is mainly measured by two main standards: bare crystal brightness and attenuation, and mainly calculated by the yield of led chips in the packaging process.
10 daily use
Red light: 9mil square, (pure red) wavelength: 620-625nm, up and down 60, about 120, brightness as high as1000-1200mcd;
Green light: 12mil square, (pure green) wavelength: 520-525nm, up and down 60, about 120, brightness can reach 2000-3000 MCD；; ;
Performance: it has the characteristics of high brightness, strong antistatic ability, strong attenuation resistance and good consistency, and is the best choice for making led signboards and led luminous characters.
1
1
16 manufacturer introduction
Taiwan Province province LED chip manufacturer
Epistar (abbreviated as ES, (Lianquan, Yuan Kun, Yong Lian, League of Nations), Huga, Genesis Photon, and Arima Photoelectricity (abbreviated as AOC, Tekcore, Qili, Juxin, Hong Guang, Jingfa). Guanglei (ED) and Tyntek are called TK for short, Yaofuzhou Technology TC, Formosa Plastics Extension, Guo Tong, Li Anding, Quanxin Optoelectronics (VPEC), etc.
Huaxing (Ledtech Electronics), Unity Opto Technology, Paraoptoelectronics, Yiguang (Everlight Electronics), Baihong (Bright LED Electronics), Kingbright, Lingsen Precision Industries, Lijite Electronics, Lite-On Technology, HARVATEK, etc.
Domestic LED chip manufacturers
Sanan Optoelectronics (S), Shanghai Epilight (E), Shi Lan Mingxin (SL), Dalian Lu Mei (LM), Yuan Di Optoelectronics, Huacan Optoelectronics, Nanchang Xin Lei, Shanghai Jinqiao Dachen, Hebei Lide, Hebei Huineng, Shenzhen Orende, Shenzhen Century Jingyuan, Guangzhou Puguang, Yangzhou Huaxia Integration, Gansu Xintiandian Company.
International LED chip manufacturer
CREE, Hewlett-Packard (HP), Nichia, Toyota Synthetic, Ocean Ristic Acid, Toshiba, Showa Electric (SDK), Lumileds, Smileds, Genelite, Osram, GeLcore, Seoul Semiconductor, Puri and Epivalley of Korea.
17 anti-theft device
model
reference data
1.Notes for LED chips. . Cob[ reference date 20 13-05-2 1].
2.LED chip classification. LED light [reference date 20 13-04-28].
3. Analysis of important parameters and two structures of 3.LED chip. Semiconductor device application network [reference date: 20 13-07- 10].
4. Classification test of 4.LED chips and devices. Big bit business network [reference date 20 13-05-3].
5. Analysis of common problems in the use of 5.LED chips. Big bit business network [reference date 20 13-05-24].
Led chip price: Generally, the price of chips is higher than that of wafers, high-power led chips are definitely higher than low-power led chips, and imported ones are higher than domestic ones. The source prices of imports from Japan, the United States and Taiwan Province Province decreased in turn.
Quality of led chips: The quality of led chips is mainly measured by two main standards: bare crystal brightness and attenuation, and mainly calculated by the yield of led chips in the packaging process.