COB LED Display Screen Advantages and Disadvantages

29 Apr.,2024

 

COB LED Display Screen Advantages and Disadvantages

COB LED Definition:

What does COB stand for? According to Wikipedia, COB is the abbreviation of the chip on board. It is a kind of manufacturing where integrated circuits are wired and bonded directly to a printed circuit board, with LED lamps in the front and drive ICs at the back to make up a COB LED module. Then such LED module COB composes an LED display.

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The COB LED encapsulation gathers the upstream of LED chip technology, midstream of encapsulation technology and downstream of display technology. As a result, COB LED display could be applied widely based on the upstream, midstream and downstream close cooperation.

Here are some advantages of COB LED:

R&D: There is no diameter of per single LED, and it could be made even more micro in theory.

Technical craftsmanship: COB LED holder cost is reduced, the production process is simplified, the LED chip thermal resistance is lowered, high-density packaging is achieved.

Project installation: It is much more convenient and faster to install of COB LED module.

6 Features as follows:

  1. Ultra slim: PCB boards with 0.4mm ~ 1.2mm thickness could be adopted according to clients’ requirements. This makes the weight lighter than about 1/3 compared with traditional LED displays. As a result, it could help to lower down the cost of transportation and project steel structure.
  2. Anticollision and crush resistance: For the COB LED, it is to encapsulate the LED chip on the PCB board, then solidify with an epoxy resin glue. The surface would convex as a sphere, making it anticollision.
  3. Big view angle: The view angle is about 180°.
  4. Good heat dissipation: The COB LED is to encapsulate the LED lamp on the PCB board. It could dissipate the heat easily with the copper foil on the PCB. Besides, the thickness of the PCB copper foil is strictly demanded. Adding immersion gold technology, there is no severe luminance attenuation. So it could prolong the life span of the LED display.
  5. Easy to clean: It is enough to use water and cloth to clean the COB LED if there is dust.
  6. It is waterproof, damp proof, anticorrosion, dustproof, anti-static, anti-oxidation. Besides, it could work perfectly even it is under -30℃ or above +80℃.

Although COB LED has the above advantages, there are some technical problems need to be solved:

☛ The passing rate is low for one-time encapsulation. And the maintenance cost is high.

☛ The homogeneity of the COB LED display is not as good as that of the SMD LED display.

☛ The COB LED at the moment still needs solid crystal and wire solder craftsmanship, which brings many problems during this process.

☛ The production cost is much higher than the SMD type due to a high failure rate.

Conclusion:

Although COB LED technology has achieved many breakthroughs, SMD LED is still widely applied in P1 or above types. We could say the COB LED display is made only for P1 or below pixel pitch types. And the COB LED could be applied more in the future.

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What are the pros and cons of COB LED Screen?

COB LED Screen packaging technology has great advantages compared with SMD packaging technology.

Its pros: smaller space of LED beads, better protection performance, long service life, and low dead light rate.

Its cons: difficulty in manufacturing finished products, maintenance inconvenience.

The so-called COB package, that is, the chip-on-board package, is actually a kind of LED chip pasted on the PCB substrate, is a new packaging technology different from SMD packaging technology, this packaging technology simplifies the entire packaging process of the chip, but also eliminates the original support and reflow process so that the entire LED is more stable, the point spacing is also smaller, directly improve the resolution of the LED display.

Advantage Analysis

  • The distance between points can be smaller

The most important feature of COB packaging technology is that it can reduce the spacing of LED beads. The original package of SMD in the LED display of the small point spacing can only be P1.2, that is, 1.2mm, difficult to achieve, and can not guarantee a certain dead light rate. However, because the encapsulated COB changes the layout and composition of the LED beads, it can essentially reduce the reverse dot pitch, and the resolution is close to the level of the LCD splicing screen.

  • Better protection performance

For LED display with small space, during transportation and installation, as long as it is subjected to external force, some light beads will fall off, resulting in dead lights of individual pixels, not emitting light or only showing monochrome, which has some reason with the encapsulation technology. As the encapsulation COB is the LED chip directly encapsulated in the recess of the PCB lamp, and then fixed with epoxy resin, so the whole lamp ball is a raised sphere, both smooth and hard, with better protection.

  • Long service life and low dead light rate

COB package product is to encapsulate the lamp on the PCB board, through the PCB board copper foil to quickly transfer the heat of the wick, and the thickness of the PCB board copper foil on the process has strict requirements, coupled with the gold plating process, almost will not cause serious light attenuation. Thus greatly extending the service life of the LED display.

Disadvantage Analysis

  • Difficulty in manufacturing finished products

When the LED display is encapsulated in COB, it has to ensure the lamp with no problem before refilling. It cannot replace a single bulb as an SMD package, so it is very demanding throughout the packaging process.

  • Maintenance inconvenience

If it’s a traditional LED light package SMD, you can disassemble the unit board after a single bulb soldering repair. When it comes to the COB product, the maintenance will affect the surrounding lamps, maintenance is very difficult, and although its protection performance is better, there still will be a certain dead light rate, in this case, can only replace the unit board.

With the introduction of any packaging technology, there are reasons for its existence and space, of course, there will be imperfections. In the future, the development and promotion of technology will also reduce this impact. In short, COB LED screen technology is a future development trend, especially since its LED packaging space is small, for many users, the resolution is a very important technology.

For more information, please visit led display company.