MB chip
Definition: MB chip: Metal Bonding (metal bonding) chip; This chip is a patented product of UEC
Features: 1. High heat dissipation Coefficient of material---Si as substrate, easy to dissipate heat.
Thermal Conductivity
GaAs: 46 W/m-K
GaP: 77 W/m-K
Si: 125 ~ 150 W/m-K
Cupper: 300~400 W/m-k
SiC: 490 W/m-K
2 , wafer bonding the epitaxial layer and the substrate through the metal layer, while reflecting photons to avoid absorption by the substrate.
3. The conductive Si substrate replaces the GaAs substrate and has good thermal conductivity capability (the thermal conductivity differs by 3 to 4 times), and is more suitable for high drive current fields. 4. The bottom metal reflective layer is conducive to the improvement of brightness and heat dissipation
5. The size can be increased and used in high power fields, eg: 42mil MB
GB chip
Definition: GB chip: Glue Bonding chip; this chip is a patented product of UEC
Features: 1: Transparent sapphire substrate replaces the light-absorbing GaAs substrate, and its light output power It is more than 2 times that of traditional AS (Absorbable structure) chips. The sapphire substrate is similar to the GaP substrate of TS chips.
2: The chip emits light from all sides and has excellent Pattern
LED chip
3: In terms of brightness, its overall brightness has exceeded the level of TS chips (8.6mil)
4: Dual-electrode structure, its high current resistance is slightly worse than TS single-electrode TS chip definition and characteristics
Definition: TS chip: transparent structure (transparent substrate) chip, this chip is HP's patented product.
Features: 1. The chip process is complex, much higher than AS LED
2. Excellent reliability
3. Transparent GaP substrate, does not absorb Light, high brightness
4. Wide application
Definition: AS chip: Absorbable structure (absorbent substrate) chip; After nearly forty years of development efforts, Taiwan’s LED optoelectronics industry has The research and development, production and sales of this type of chip are at a mature stage. The research and development levels of major companies in this area are basically at the same level, with little difference. Mainland China's chip manufacturing industry started late, and its brightness and reliability are still far behind those of the Taiwan industry. There is a certain gap. The AS chip we are talking about here refers specifically to the AS chip of UEC, eg: 712SOL-VR, 709SOL-VR, 712SYM-VR, 709SYM-VR, etc.
Features: 1. Four The meta-chip is manufactured using the MOVPE process and is brighter than conventional chips
2. Excellent reliability
3. Widely used
Types of diode chips
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1. LPE: Liquid Phase Epitaxy (liquid phase epitaxy) GaP/GaP
2. VPE: Vapor Phase Epitaxy (vapor phase epitaxy) GaAsP/GaAs
3. MOVPE: Metal Organic Vapor Phase Epitaxy (organic metal vapor phase epitaxy) 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) GaAlAs/GaAlAs[2]
4 Important parameters
1. Forward operating current If
It refers to the forward current value when the light-emitting diode emits light normally. In actual use, IF should be selected below 0.6·IFm according to needs.
2. Forward operating voltage VF
The operating voltage given in the parameter table is obtained at a given forward current. Generally it is measured when IF=20mA. The forward working voltage VF of the light-emitting diode is 1.4~3V. When the outside temperature increases, VF will decrease.
3. V-I characteristics
The relationship between the voltage and current of a light-emitting diode. When the forward voltage is less than a certain value (called the threshold), the current is extremely small and no light is emitted. . 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 a light-emitting diode usually refers to the luminous intensity in the direction of the normal (for a cylindrical light-emitting tube, its axis). If the radiation intensity in this direction is (1/683) W/sr, it emits 1 candela (symbol is cd). Since the intensity of general LED light-emitting diodes is small, the unit of luminous intensity is often candelas (mcd).
5. LED light-emitting angle
-90°- 90°
6. Spectral half-width Δλ
It represents the light-emitting tube spectral purity.
7. Half value angle θ1/2 and viewing angle
θ1/2 refers to the angle between the direction where the luminous intensity value is half of the axial intensity value and the luminous axis (normal direction) horn.
8. Full shape
The angle calculated based on the LED lighting solid angle is also called the plane angle.
9. Viewing angle
Refers to the maximum angle at which the LED emits light. Depending on the viewing angle, the application is also different, also called the light intensity angle.
10. Half-shape
The angle between the normal direction 0° and the maximum luminous intensity value/2. Strictly speaking, it is the angle corresponding to the maximum luminous intensity value and the maximum luminous intensity value/2. The LED packaging technology causes the maximum luminous angle to be different from the light intensity value of 0° in the normal direction, and introduces a deviation angle, which refers to the angle between the angle corresponding to the maximum luminous intensity and 0° in the normal direction.
11. Maximum forward DC current IFm
The maximum forward DC current allowed. Exceeding this value may damage the diode.
12. Maximum reverse voltage VRm
The maximum reverse voltage allowed is the breakdown voltage. Exceeding this value, the LED may be damaged by breakdown.
13. Working environment topm
The ambient temperature range in which the light-emitting diode can work normally. Below or above this temperature range, the light-emitting diode will not work properly and its efficiency will be greatly reduced.
14. Allowable power consumption Pm
The maximum value allowed to be applied to the product of the forward DC voltage at both ends of the LED and the current flowing through it. If this value is exceeded, the LED will become hot and damaged. [3]
5 chip sizes
High-power LED chips have three sizes: 38*38mil, 40*40mil, 45*45mil. Of course, the chip size can be customized. These are just generally common specifications. Mil is a unit of size, and a mil is one thousandth of an inch. 40mil is almost 1mm. 38mil, 40mil, and 45mil are all common size specifications for 1W high-power chips. Theoretically, the larger the chip, the greater the current and power it can withstand. However, the chip material and manufacturing process are also the main factors affecting the chip power. For example, CREE's 40mil chip can withstand power from 1W to 3W, while other brands' chips of the same size can withstand up to 2W.
6 Luminous brightness
General brightness: R (red GaAsP 655nm), H (high red GaP 697nm), G (green GaP 565nm), Y (yellow GaAsP/GaP 585nm) , E (orange GaAsP/ GaP 635nm), etc.;
High brightness: VG (brighter green GaP 565nm), VY (brighter yellow GaAsP/ GaP 585nm), SR (brighter red GaA/AS 660nm);
Ultra-high brightness: UG, UY, UR, UYS, URF, UE, etc.
Binary wafer (phosphorus, gallium): H, G, etc.;
Ternary wafer (phosphorus, gallium, arsenic): SR (brighter red GaA/AS 660nm), HR (super bright red GaAlAs 660nm), UR (brightest red GaAlAs 660nm), etc.;
Quaternary wafer (phosphorus, aluminum, gallium, indium): SRF (brighter red AlGalnP), HRF (super Bright red AlGalnP), URF (brightest red AlGalnP 630nm), VY (brighter yellow GaAsP/GaP 585nm), HY (ultra-bright yellow AlGalnP 595nm), UY (brightest yellow AlGalnP 595nm), UYS (brightest yellow AlGalnP 587nm) ), UE (brightest orange AlGalnP 620nm), HE (super bright orange AlGalnP 620nm), UG (brightest green AIGalnP 574nm) LED, etc.
7 Substrate
For the production of LED chips, the selection of substrate materials is the primary consideration. Which suitable substrate should be used needs to be selected based on the requirements of the equipment and LED device. Three substrate materials: sapphire (Al2O3), silicon (Si), and silicon carbide (SiC).
The advantages of sapphire: 1. Mature production technology and good device quality; 2. Very stable and can be used in high-temperature growth processes; 3. High mechanical strength and easy to handle and clean.
Disadvantages of sapphire: 1. Lattice mismatch and thermal stress mismatch will produce a large number of defects in the epitaxial layer; 2. Sapphire is an insulator, and two electrodes are made on the upper surface, causing The effective light-emitting area is reduced; 3. The photolithography and etching process is increased, and the production cost is high.
Silicon is a good conductor of heat, so the thermal conductivity of the device can be significantly improved, thereby extending the life of the device.
The LED chip of the silicon carbide substrate (CREE company specifically uses SiC material as the substrate) has an L-shaped electrode and the current flows longitudinally. Devices made using this substrate have very good electrical and thermal conductivity, which is conducive to making large-area high-power devices. Advantages: The thermal conductivity of silicon carbide is 490W/m·K, which is more than 10 times higher than that of sapphire substrate. Disadvantages: The manufacturing cost of silicon carbide is high, and its commercialization needs to reduce the corresponding costs.
Features of 8led
(1) Quaternary chip, prepared using MOVPE process, is brighter than conventional chips.
(2) Excellent reliability.
(3) Widely used.
(4) High safety.
(5) Long life.
9 How to judge
The price of LED chips: Generally speaking, the price of wafers is higher than that of wafers, and high-power LED chips are definitely higher than low-power LED chips. Imported products are higher than domestic products, and the price of imported products decreases in order from Japan, the United States, and Taiwan.
Quality of LED chips: The quality of LED chips is mainly measured by the two main criteria of bare crystal brightness and attenuation. In the packaging process, it is mainly calculated from the yield rate of LED chip packaging.
10 Daily use
Red light: 9mil regular square chip, (pure red) wavelength: 620-625nm, 60° up and down, 120° left and right, brightness up to 1000-1200mcd;
Green light: 12mil regular square chip, (pure green) wavelength: 520-525nm, 60° up and down, 120° left and right, brightness up to 2000-3000mcd;
Performance: high brightness, It has strong anti-static ability, strong anti-attenuation ability, and good consistency. It is the best choice for making LED signboards and LED luminous characters.
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16 Manufacturer Introduction
Taiwanese LED chip manufacturers
Epistar Abbreviation: ES, (Lianquan, Yuankun, Lianyong, Guolian), Huga, Genesis Photonics, Arima Optoelectronics Abbreviation: AOC, Tekcore, Qili , Juxin, Guanghong, Jingfa, Shichuang, Zhoulei, Lian Sheng (HPO), Hanguang (HL), Guanglei (ED), Dingyuan (Tyntek) abbreviation: TK, Yaofuzhou Technology TC, Canyuan (Formosa Epitaxy), Guotong, Lianding, VPEC, etc.
Huaxing (Ledtech Electronics), Dongbei (Unity Opto Technology), Para Light Electronics, Everlight Electronics, Bright LED Electronics, Kingbright, Lingsen Precision Industries, Ligitek Electronics, Lite-On Technology, HARVATEK, etc.
Domestic LED chip manufacturers
Sanan Optoelectronics (S), Shanghai Epilight (E), Silan Mingxin (SL), Dalian Lumei (LM) ), Diyuan Optoelectronics, Huacan Optoelectronics, Nanchang Xinlei, Shanghai Jinqiao Dachen, Hebei Lide, Hebei Huineng, Shenzhen Orunde, Shenzhen Century Jingyuan, Guangzhou Puguang, Yangzhou Huaxia Integrated, Gansu Xintian Electric Company, Dongguan Fudi Electronic Materials, Qingxin Optoelectronics, Jingneng Optoelectronics, Zhongwei Optoelectronics, Qianzhao Optoelectronics, Jingda Optoelectronics, Shenzhen Fangda, Shandong Huaguang, Shanghai Sapphire, etc.
International LED chip manufacturers
CREE, Hewlett-Packard (HP), Nichia, Toyoda Gosei, Dayang Nippon Sanso, Toshiba, Showa Denko (SDK), Lumileds, Asahi Smileds, Genelite, Osram, GeLcore, Seoul Semiconductor, etc., Bridgelux, Korea's Epivalley, etc.
17 anti-theft device
Model number
Reference materials
1. LED chip precautions． cob [cited date 2013-05-21]．
2． LED chip classification． LED.lights [reference date 2013-04-28]．
3． Analysis of important parameters and two structures of LED chips. Semiconductor Device Application Network [Citation date 2013-07-10].
4. Sorting and testing of LED chips and devices. Big Bit Business Network [cited date 2013-05-3]．
5. Analysis of common problems encountered in the use of LED chips． Big Bit Business Network [Citation date 2013-05-24]．
The price of LED chips: Generally speaking, the price of wafers is higher than that of wafers. High-power LED chips are definitely higher than low-power LED chips. Imported ones are higher than domestic ones. Imported ones are higher. Source prices decrease in order from Japan, the United States, and Taiwan.
Quality of LED chips: The quality of LED chips is mainly measured by the two main criteria of bare crystal brightness and attenuation. In the packaging process, it is mainly calculated from the yield rate of LED chip packaging.