COB 屏幕的技术优势

The packaging technology used in COB screens is different from that of traditional SMD screens.

SMD screen packaging process: this involves fixing LED chips inside a bracket cup, encapsulating them into individual LED beads, and then soldering the beads onto a PCB board.

The surface has a grainy texture; each LED lamp is separate and uneven, feeling rough to the touch.

COB screen packaging process: the LED chip is directly glued to the PCB board and then encapsulated and protected with epoxy resin. The screen surface is smooth and flat.

The main purpose of COB technology is to solve the heat dissipation problem of LED displays. Compared with DIP and SMD, it can save space, simplify the packaging process, and has a highly efficient thermal management method.

 

Next, we will explain the advantages of COB technology from the following six aspects.

(1) LED lamp protection

SMD screens offer only average protection. Its LED lamps  are exposed to the outside, making them susceptible to damage from impacts and moisture corrosion, which may result in the lamps falling off or dying.

COB screens offer high protection, with the chip completely encased in resin, providing impact, moisture, static electricity, and dust protection, virtually eliminating the risk of the light falling off.

(2) Heat dissipation performance

SMD screen has average heat dissipation performance. Heat needs to be conducted to the PCB board through the LED bracket, which is a long path and has high thermal resistance.

COB screen has excellent heat dissipation performance. The chip is in direct contact with the PCB board, resulting in a short heat dissipation path and high efficiency.

(3) Micro-pitch capability

SMD screen has limited pitch size, making it difficult to make the pixel pitch very small ( < P 0.9 is very difficult).

COB screens eliminate the need for LED brackets, allowing pixels to be arranged more densely, making it easier to achieve micro-pitches below P0.9.

(4) Image quality performance

Some components of an SMD screen reflect ambient light. When the screen displays black ( the LEDs are not emitting light), these tiny reflective points make the black appear less pure, resulting in a “grayish-black” color, thus reducing contrast.

The surface of the COB screen is a smooth, uniform black epoxy resin. This “blackboard” absorbs ambient light extremely effectively. When displaying black, the screen reflects almost no light, presenting a very deep, pure black, resulting in extremely high contrast and a stronger visual impact.

(5) Wide viewing angle

The COB screen’s viewing angle can reach >170°, this ensures that everyone, whether seated in the middle or on the sides, sees almost identical content.

It avoids the problem of color cast, darkening, or overexposure seen by viewers on the side.

(6) Maintainability

SMD screens support single-lamp repair, replacing individual faulty LEDs for more precise maintenance at a lower cost.

COB screens are inherently low in failure rate due to their high reliability, and are typically repaired at the module or board level, by replacing the entire unit module. However, the cost of the replacement parts during repair is higher.