EVERY THING YOU NEED TO KNOW ABOUT COB LED DISPLAY

What is COB LED Display?

COB (Chip on Board) is a kind of LED display packaging technology. LED light-emitting chips are directly bonded to the module board with high precision and connected to driver components on the module board through special media for overall protection of the light-emitting surface. COB packaging  eliminates  the two key  procedures  of  turning LED chips  into lamp beads and reflow soldering as compared to standard SMD packaging. 
fip-chip cob
COB LED CHIP DISPLAY VISIONPI
cob-led-display-waterproof anti-moisture

Chip-on-Board technology 

The bare IC is mounted directly on the substrate on the back of the PCB, then using a special method of welding using a pure gold wire, a bond is made between the base and silicon chip, then finally the COB is packaged together to form the full-color module.

Micro-led Mass Transfer Technology 

Mass transfer is a technique that can move Micro-LED chips from wafers to display panels.

This is the most challenging part of making MicroLED displays. There are three main challenges in this step “ accuracy, speed, and reliability.

High Accuracy

The transfer process requires high accuracy, as each microLED chip is minuscule and has to align precisely with its designated location. The tolerance for deviation is very low.

High Speed

The transfer process also requires high speed, as contemporary displays have very high resolutions. For instance, a 4K display comprises more than 24 million subpixels. To achieve cost-effectiveness and productivity, the transfer process has to handle multiple microLED chips simultaneously.

High Reliability

The transfer process also requires high reliability, as the display industry expects high standards and low defects. As the displays become larger and finer, the quality becomes more critical. We will elaborate on the microLED quality issue in a subsequent section.

Visionpi’s patented mass transfer technique is a novel approach for transferring millions of micro LED chips accurately. With the mass transfer technology, the UPH of micro & mini LED displays is more than 2.5KK, and the mass production yield rate is more than 99.999%.

Surface treatment technology

Surface treatment is to enhance color uniformity in the different application scenarios.

Flip Chip COB series micro &  mini LED display provides three types of surface treatments, including Brilliant Black, Natural Black, and Matte Black.

cob-led-display-visionpi-painting high contrast ratio copy

Flip chip cob led display production

Advantages of COB LED Display

This new and unique technology has a number of advantages over existing technologies such as SMD and DIP LEDs. Due to the small size of the LED chip, the COB system allows for a much higher packing density than SMD (SMT), the result being a more compact array giving better uniformity and higher intensity even at a close distance and greater heat dissipation for better stability, reliability, and lifespan.: COB chip and pin legs are sealed, resulting in better airtightness, higher resistance to external forces, and a smoother, seamless surface. COB has a much higher level of protection against moisture, electrostatic discharge (ESD), damages, and dust with surface protection rated IP65. COB is an integrated package with even light distribution, and the smooth surface makes images appear softer and friendlier to the human eye.

cob led display production process
  •  Stable technology process.  As shown above, SMD’s need to use reflow soldering. When the soldering paste reaches a temperature of 240°c the epoxy resin weight loss rate is 80% which easily causes the glue to separate from the LED cup, but in the case of COB technology there is not reflow soldering process so is more stable. Solder paste does not need to pass through ROHS approval
  • Finer Pixel Pitch. Pixel pitch is how close pixels are to each other on a display. COB LED technology makes pixel pitch smaller, which means more pixels and better resolution. Smaller pixel pitch also lets viewers see the display clearly even when they are close to it.
cob and smd led display
  • Better Light Effection Good heat dissipation / Low light attenuation, because the COB chip is directly dispensed onto the PCB, the area of heat dissipation is wider than SMD with better attenuation. The heat dissipation of the SMD is emitted through the bottom of its fixing.

cob led wall and smd led wall viewing angle
  •  Larger viewing angle COB small pitch technology has a much wider viewing angle and brightness both indoors and outdoors.
  • cob-led-display-viewing-brightness Superior Durability COB is better at withstanding collisions and the effects of Oil, Damp, Water, Dust, Oxidisation, and dust.

cob led display contrast ratio
  • High Contrast Ratio The contrast ratio of LED displays is an important parameter that determines how clear, vivid, and colorful the image is .COB can reach 15,000 to 20,000 static contrast ratio and up to 100,000 high dynamic contrast ratio.
cob led display ennergy saving
  • Superior Energy-saving COB LED technology delivers higher energy efficiency than SMD. This is important when it comes to the total cost of operation for large format displays that are going to be used all day, every day for months and years to come.

Disadvantages of COB LED Display

  • Difficulty in manufacturing finished products

When an LED display is encapsulated in COB, it must be ensured that the lamp is free of defects before refilling. Unlike an SMD package, a single bulb cannot be replaced, so the packaging process is very demanding. (Visionpi’s patented mass transfer technique is a novel approach for transferring millions of micro LED chips accurately. With the mass transfer technology, the UPH of micro & mini LED displays is more than 2.5KK, and the mass production yield rate is more than 99.999%.)

  • Maintenance inconvenience

if it is a traditional SMD package, you can disassemble the unit board after a single LED soldering repair. However, when it comes to the COB product, maintenance will affect the surrounding lamps, making it very difficult. Although its protection performance is better, we have to admit that there will still be a certain dead light rate. In this case, the only option is to replace the unit board. generally speacking the cost of maintenance is bout the same with SMD.COB panel is more expensive but with much less possibility of failures. as the cob manufacturing cost is decreasing, now the cob led display’price is very clost to SMD’s, in the future the cost will be lower than SMD.

Lateral Chip COB VS A Flip-Chip COB

LC-COB and FC-COB are two types of LED packaging technologies used in Chip-on-Board displays.

LC-COB (wire bonding) has LED chips mounted in parallel on the substrate with electrical connections made from the side of the chip. The chip is attached to the board with an adhesive. Each pad on the device is connected with a fine wire lead that is welded to the pad and to the circuit board. the wire lead would limit the development of finer pixel pitch led display. 

FC-COB, on the other hand, has LED chips mounted upside down on the substrate with electrical contacts facing downwards. flip chip COB eliminates wire bonding and simplifies the production process.

  • Better Thermal performance.

Conductive adhesive bonds the chips to the substrate for better thermal and electrical performance.

  • Higher brightness

A reflective layer on the substrate directs light emitted from the LED chips toward the front of the display, providing high brightness.

  • better visual performance

The flip chip takes a smaller space on the PCB board, providing a larger light-emitting area. The substrate presents a darker black field and higher contrast

flip-chip cob vs lateral chip cob led display

Flip-chip COB is the future.  Compared with the SMD; GOB Packing technology (GOB VS COB), COB  is the next-generation technology advance in COB that improves display quality and durability. It makes the pixels closer, brighter, and more visible from different angles and distances. It also makes the display more reliable, energy-efficient, and resistant to dust, moisture, and collision.COB LED displays are still a popular choice for a wide range of applications such as indoor and outdoor advertising displays, stage backdrops, and event screens, due to their high-quality visuals, energy efficiency, and durability.. In short, COB LED screen technology is a future development trend,the cost will be decreased with the mass transfter technology’s development.

Why Choose Visionpi’s COB LED DISPLAY?

We are a reliable display supplier that offers Mini COB LED displays with three advantages:

  • Technology Innovation: We use COB full flip-chip packaging technology and our patented Mass Transfer Technology to improve the performance and yield of small-pitch LED displays.
  • Excellent Performance: Our Mini COB LED displays have no light stringing, sharp image, vivid color, good heat dissipation, long life, high contrast ratio, wide color gamut, high brightness, and high refresh rate.
  • Cost-effective: Our Mini COB LED displays are energy-saving, easy to install, less maintenance, low maintenance cost, and very cost-effective.
  • Competitive Price.  As a pioneer and leading OEM COB-led panel, we made big progress in mass transfer technology to decrease the cost of cob-led display to the same level price as SMD led display.

Pixel pitch covers P0.4-P1.8 to meet different requirements of users

  •  1,200nits brightness
  •  18Bit grayscale
  •  up to100,000:1 contrast ratio
  •  HDR 10 supported
  •  120% NTSC color gamut
  •  7,680Hz refresh rate
  •  Extremely high protection performance
  • Single Module Calibration Technology
  • onforms to industry standards and specifications
  • Self-developed optical display technology greatly protects the eyes
  • Multi-scene applicability

Pixel pitch covers P0.4-P1.8 to meet different requirements of users

  •  3500 nits brightness
  •  16 Bit grayscale
  •  up to 10000:1 contrast ratio
  •  HDR 10 supported
  •  120% NTSC color gamut
  •  38400Hz refresh rate
  •  Extremely high protection performance
  • Single Module Calibration Technology
  • onforms to industry standards and specifications
  • Self-developed optical display technology greatly protects the eyes
  • Super wide viewing angle 170

Flexible COB LED Display

COB flexible LED modules merge the compact, high-intensity lighting benefits of Chip On Board (COB) technology with the adaptable, bendable nature of flexible LED modules. This innovative combination allows for the creation of highly durable, uniformly lit, and versatile lighting solutions that can be tailored to fit curved and irregular surfaces without compromising on light quality or intensity.

flexible led display die-casting aluminum

Our flexible COB LED display achieves seamless alignment through a CNC die-cast aluminum cabinet, ensuring high precision and uniformity. The die-casting process provides superior dimensional accuracy and stability, crucial for maintaining flatness in fine-pitch displays. It also minimizes pixel misalignment by maintaining consistent cabinet dimensions.

Additionally, aluminum’s excellent thermal conductivity aids in heat dissipation for high-density LED configurations, extending the display’s lifespan. The robust construction of the die-cast aluminum cabinet enhances durability and resistance to physical stress, making it suitable for various installation environments.

COB LED Display Modules

Explore VisionPi’s COB LED Display Module, the pinnacle of cutting-edge technology for OEM applications. As a leading manufacturer, VisionPi offers robust, high-density COB (Chip On Board) LED displays, perfect for creating seamless, high-resolution screens with exceptional durability and performance. Ideal for a wide range of applications from digital signage to sophisticated video walls, discover how our COB LED modules can transform your visual presentations into captivating experiences. Dive into the future of displays with VisionPi’s reliable and innovative solutions

cob led display modules 1.25 1.56 0.9

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