Application trend of ultra-high power COB

Application trend of high power COB

LED packaging technology evolution by years

he luminous efficiency of LEDs is soon expected to reach over 80 lumens/W, this is approximately 6 times the efficiency of a conventional incandescent tungsten bulb.

led packaging technology evolution by years

Light-emitting diodes, LEDs, historically have been used for indicators and produced low amounts of heat. The introduction of high brightness LEDs with white light and monochromatic colors have led to a movement towards general illumination. The increased electrical currents used to drive the LEDs have focused more attention on the thermal paths in the developments of LED power packaging.

With the development of chip technology and the market’s need for higher brightness, a large number of packaging products of various forms have been produced, from the early lead-type LED devices, chip printed circuit board (PCB) structure, polyphthalamide ( PPA), polyhexamethylene terephthalate (PCT) and thermosetting epoxy resin (EMC) structure LED devices to today’s aluminum nitride ceramic structure, high-power integrated chip on board packaging (ChipOnBoard, COB), various Flip-chip and other different forms of packaging.

In the future, LED packaging will focus on lighting applications, mainly in the direction of high power, miniaturization, multi-chip integration, high light efficiency and high reliability. In order to improve the lumen cost efficiency of white light LED devices, it will become a new theme to solve the technical problems of heat dissipation under high current and high power working conditions of packaged devices, and to achieve high luminous efficiency and high reliability.

Three major trends in the development of LED packaging technology

increased light efficacy
increased power desnity

Increase the light indensity

increase single COB light efficacy
light engine development

Improve integration density

the development of led packaging
the development of led packaging 2

Improve system cost performance

Improve system cost performance :

Improving the cost-effectiveness of the system is not just a simple increase of lm/$, but for different application solutions, the market will choose the most cost-effective solution for the overall system. Including peripheral supporting costs, assembly costs, equipment replacement costs, and reliability costs. The CSP light source is used for backlighting, and the cost of pure LED packaging will increase, but it may bring about a decrease in the cost of substrates and Lens or an improvement in the performance parameters of the TV set. Car lights have high requirements for reliability, and the improvement of reliability also reduces the cost of the system. The light source products, such as lamp tubes and bulbs, require lower prices and solutions that are more suitable for automated production. Since different applications have different requirements for light sources, multiple packaging forms will still coexist in the future.

The new blue ocean of LED packaging high power COB

The new blue ocean of LED packaging-------Ultra-high power COB: Kilowatt-class COB light source (Kilowatt-class COB), K-COB, a single COB light source with a power greater than 1200W, the highest power can break through the 16KW level, used to replace various traditional light sources with power of 1KW and above.

the development of led packaging3

Why is ultra-high power COB a blue ocean market?

Blank market areas. The maximum power of metal halide lamps can reach 10KW, and some high-altitude lighting or large-space lighting applications require power to reach 2KW. The existing LED replacement effect in these fields is not ideal. The design goal of ultra-high-power COB is to fill the blank area of LED replacement.

HIGH POWER COB LED NEW BLUE OCEAN

The new blue ocean of LED packaging-ultra-high power COB

Why is ultra-high power COB a blue ocean market? Enough technical barriers. Ultra-high-power COB not only increases the packaging area, but also needs to solve a series of problems such as heat dissipation, optics, materials, process and driving caused by power increase, and some of the technologies are not easy to be imitated quickly, and there are enough technologies. Barriers to resist the impact of imitation competition in the market.

Core Technology
%
Core Material
%
Core Parts
%
Core Patent
%
2 22
4 core

Application direction of ultra-high power COB

High luminous flux & small area

sports lighting
large space lighting

Large space lighting

such as Stadium lighting,industry lighting

long-distance lighting
long-distance lighting 2

Long-distance projection lighting-Searchlight

Such as spot lighting, car lights

special lighting 2
special lighting

Special lighting for high reliability requirements

Such as stackyard port lighting, marine lighting

Technical requirements for ultra-high power COB

As the lighting industry, LED must first pay attention to the application of light. From the perspective of application fields, most of the ultra-high-power COBs are used in directional lighting, which requires secondary light distribution for the Lambertian light output of the LED light source. According to the theory of optical expansion of non-imaging systems [Etendue], for the light source, we hope that its optical expansion is as small as possible. In the case that the optical expansion of the optical system is constant, the smaller the optical expansion of the light source, the stronger the optical system's ability to control its light and the higher the effective utilization rate. Therefore, while providing high luminous flux output, the ultra-high power COB must achieve the ultimate in small light-emitting surface.

Technical requirements for high mast application
2

High light efficiency & low thermal resistance :

While ultra-high power COB achieves high luminous flux & small area, both chips and fluorescent materials are facing more severe challenges. Therefore, the ultra-high power COB must maintain a higher luminous efficiency to ensure its energy saving, and at the same time, it can generate less heat and reduce the dependence on the heat dissipation system. The lower thermal resistance can ensure that the heat of the chip and the fluorescent material can be smoothly discharged in the case of kilowatts. The constant goal of all LED products-more light, less heat.

PHOSPHOR CERAMIC advantage

High reliability & long lifespan:

Because the ultra-high power COB is a device with multiple LED chips, and its application environment is mostly high-altitude scenes that are not easy to maintain, once a certain link is neglected, the entire lamp will burn out. Therefore, the reliability and lifetime requirements for ultra-high-power COBs are much higher than general LED application scenarios.

high reliability & long lifespan

The development status of ultra-high power COB

The development status of ultra-high power COB packaging and its application:

1. There are few manufacturers involved, most of the manufacturers’ products have not really been put into the market, and there is still no real leader in the market; 2. The supporting facilities are immature, and the research and development, testing, technology, production, certification and other supporting facilities are immature, and a complete ecosystem cannot be formed; 3. Good and bad products in the market are uneven, failing to guide customers to have a correct understanding of ultra-high power COB; 4. Most products have not been certified by an authority.

led cob certificate

Ultra-high power COB and its application problems

Rely on increasing the light-emitting area to increase the power, the integrated area is larger than the LED array, and the reliability is not as good as the LED array. Even just the chips are put together to reach the theoretical power, and they can't really light up at full load.

smd problem

Regardless of application end use, light source products cannot be truly commercialized. The lamp assembly requirements are not fully considered in the product design: 1. The light-emitting surface accounts for a large proportion. It is easy to be crushed and polluted during the assembly process, which will cause the damage and burn of the entire lamp. 2. Partition control of the light-emitting area. Once a partition fails, uneven heat and cold will easily cause thermal expansion and burn. 3. When the ultra-high-power large-area light source is in normal use, mechanical pressure and thermal stress are prone to interact with each other, and the thermal expansion mismatch between the colloid and the substrate is aggravated, and the intermediate colloid bulges off the substrate and burns instantly.

silicone cob problem

As a cold light source, LED light source, especially ultra-high power COB, must pay attention to the matching and reliability of its heat dissipation system.

heat-sink problem

K-COB relies on the core material technology of the Chinese Academy of Sciences-transparent fluorescent ceramics, combined with a unique packaging design to form a low thermal resistance packaging patent technology, to achieve a kilowatt-level high-power and high-density COB light source module, with completely independent intellectual property rights, breaking through international patent barriers.

K-COB CONTENT KINDLE
K-COB CONTENT KILOWATT
K-COB CONTENT KEEP

The transformation technology of the Institute of Physics and Architecture of the Chinese Academy of Sciences is the only industrialized, large-sized, high-efficiency YAG transparent fluorescent ceramic in China.

Kilowatt-level COB originates from ceramics, not only ceramics. K-COB has created a solid package structure to create a highly reliable kilowatt-level COB light source.

"Unchanging" should be "changing", derived from K-COB's low light attenuation and high reliability characteristics, K-COB modules can easily cope with various harsh environments.

图片1
图片2

Introduction of K-COB technology

Advantages of PHOSPHOR CERAMIC used in LED packaging: 1. The air tightness is good, and it is not easy to be disturbed by the environment. 2. The crystallinity is high, comparable to the molecular structure of single crystal, and the crystal has no refraction and reflection loss caused by excessive gas. 3. The phosphor crystal lattice is complete, the thermal quenching characteristic is good, the thermal light decay is small under high temperature environment, and it will not cause irreversible damage.

Test point Solder joint Luminous surface temperature LED junction temperature
Temperature 91.84℃ 156.19℃ 138.47℃

Traditional COB packaging

Test point Solder joint Luminous surface temperature LED junction temperature
Temperature 91.45℃ 133.58℃ 131.14℃

K-COB LED packaging

ceramic temperature

Micro optics advantage Snell’s Law, K-COB architecture reduces the total reflection of light at the interface through the design of microlenses on the PHOSPHOR CERAMIC surface, thereby increasing the light output rate of the COB package.

K-COB HEAT SINK METHOD

K-COB structure thermal resistance characteristics

high power cob should focus on the horizontal uniformity

300W light source simulation results

From the results, the maximum temperature of the light-emitting surface of the K-COB package architecture is reduced by 22.61°C compared with the traditional packaging architecture, and the junction temperature of the center LED chip is reduced by 7.33°C. With the further increase of area and power, the entire temperature difference will be further enlarged.

300W light source simulation VS actual measurement comparison

https://www.kcobled.com/this-is-k-cob/

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Post time: Dec-31-2021
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