LED display encapsulation process plays an important role in ensuring its stability and preventing light drop. Among them, COB and GOB are common encapsulation processes. So, what is the difference between COB and GOB? What are their respective advantages and disadvantages? Let's explore together.

1. Different processing methods and protection objects
COB display is used to attach the light-emitting chip directly to the PCB substrate, and then use the brush epoxy resin covered in the surface layer of the way for encapsulation. Its main purpose is to protect the light-emitting chips. The GOB display uses a transparent gel to fill the bead surface to form a protective layer of the encapsulation process, mainly to protect the LED beads.

2. Different application areas
COB display by eliminating the physical spacing between the LED lamp beads, can realize the LED display below 1mm, mainly used for small pitch display. While GOB display enhances the overall protection ability of conventional display. Conventional LED displays are susceptible to interference from harsh environments, while GOB displays have the ability to be waterproof, moisture-proof, anti-collision and anti-static, expanding the application areas of LED displays.

Advantages of GOB display

1. High protection
After GOB encapsulation treatment, GOB display module has the ability of waterproof, moisture-proof, anti-collision and so on.

2. Better Optics and Stability
GOB encapsulation technology transforms the original particle pixels on the surface of the light board into an overall flat light board, realizing the conversion from point light source to surface light source. This makes the product luminescence more uniform, the stability of the screen body is higher, and the service life is longer. In addition, the GOB display avoids the impact of blue light to a certain extent, relieves visual fatigue, and enhances color contrast, and the viewing angle is also increased.

Disadvantages of GOB display

1. Crosstalk interference
As the GOB display is encapsulated with transparent material on the module by means of adhesive filling, the principle is to protect the point light source. This will form a transparent light path on the surface of the module, and the surface of the module is not processed for concentrating or diffusing light. Therefore, there is a translucent transparent body between the point light sources inside the module, which to a certain extent is easy to lead to string light interference between the light sources.

2. Process differences
There are differences in the level of GOB display processing technology of different manufacturers, which may lead to inconsistencies in GOB mounting flatness in the display industry. The different gel thickness of the encapsulation method may lead to the existence of optical range difference between modules, which in turn affects the display effect of the whole screen. Especially for small-pitch high-definition display, the visual difference is more obvious.

Advantages of COB display

1. Small-pitch package
The most important feature of COB packaging technology is to reduce the spacing between the LED chips. In the past, SMD package LED display can only achieve P1.2 small pitch, that is, 1.2mm, it is difficult to realize a tighter pixel arrangement. However, by changing the layout and connection of LED chips, COB package essentially realizes a smaller dot pitch, and the market has widely recognized its maturity and stability, and can achieve ultra-high resolution below P1.

2. Excellent protection performance
For the smaller size of the LED display, in the transportation and installation process, even if subjected to light ** hit, the LED lamp beads may fall off, resulting in a single pixel failure. COB encapsulation technology directly encapsulates the LED chip in the PCB module groove, and firmly fixed with epoxy resin, so that the entire lamp bead to form a raised sphere, the surface is smooth and sturdy, with better protection performance.
3.Long service life and low dead light rate.COB packaging products will be LED lamp beads encapsulated in the PCB board, and through the PCB board of copper foil quickly conduct the heat generated by the lamp beads, and the thickness of the copper foil on the PCB board of the process requirements are extremely high, coupled with the application of gold-plating process, almost does not lead to serious light attenuation. As a result, the service life of COB display is greatly extended, while the dead light rate is greatly reduced.

Disadvantages of COB display

1. Higher manufacturing costs
COB display encapsulation process is more complex, requiring each lamp bead in the refill before there is no problem, can not replace individual lamp beads like SMD encapsulation technology. Therefore, the entire COB packaging process is more demanding.

2. Inconvenient maintenance
Compared with the traditional SMD packaging technology, if the COB packaging technology fails, maintenance will affect the surrounding lamp beads, maintenance work is more difficult. Although the COB display has good protection performance, but there is still a certain rate of dead lights. In the event of a dead lamp, only the entire module board can be replaced, so the product yield requirements are higher.