In recent years, while the small-pitch LED display products have grown rapidly, the small-pitch LED display technology is also making continuous progress. Recently, a new type of packaging——COB (chip-on-board) packaging products has gradually become a hot packaging situation due to its unique process and product characteristics…
COB (Chip On Board), that is, packaging RGB chips on a circuit board, is a new full-color LED technology developed based on the plane technology of solid crystal and precise glue dispensing technology. In the COB product process, the PCB board is first mounted with an IC, and then the chip is fixed on the surface of the substrate, and then an electrical connection is established between the chip and the substrate by wire bonding, and after passing the test, it is glued and sealed to become A Indoor Flexible LED Mesh full-color module. It has the following advantages:
Process stability
Compared with the traditional surface-mounted LED display, the COB technology display is more stable and simpler.
During the reflow soldering process of the traditional surface-mounted LED display, due to the different expansion coefficients of the SMD lamp bead bracket and the epoxy resin at high temperature, it is easy to cause the bracket and the epoxy resin package to fall off, and gaps appear. It is prone to dead lights, resulting in a high defect rate. The COB technology display screen is more stable, because there is no need to go through reflow soldering in the processing technology, which avoids the problem of gaps between the lamp bead bracket and the epoxy resin caused by high-temperature soldering in the welding machine, so COB products are not easy to install after leaving the factory. A dead light phenomenon occurs. In addition, COB’s unique packaging method also effectively protects the light-emitting diodes and enhances their resistance.
glow effect
COB products package the light on the PCB board, so the heat dissipation is directly through the PCB board, the heat is easily dissipated, and it hardly causes serious light attenuation, so there are few dead lights, which greatly prolongs the life of the display. The chip of traditional surface-mounted LED products is fixed in the bowl and does not directly contact the PCB board. It mainly dissipates heat through the colloid and four pads. The heat dissipation area is small, and the heat will be concentrated on the chip, which will cause serious light attenuation for a long time. Even the dead light phenomenon reduces the service life and quality of the display screen.
durability
The COB process small-pitch LED display has the properties of anti-impact, waterproof, moisture-proof, dust-proof, oil-proof, oxidation-proof, anti-static, etc., so it has the characteristics of wear resistance and easy cleaning. The surface of the lamp point is raised into a spherical surface, which is smooth and hard, and is resistant to impact and wear; if there is a bad point, it can be repaired point by point. Since there is no mask, the surface is smooth and smooth, and the surface dirt can be cleaned with water or cloth.
energy saving
The COB display adopts large-chip light-emitting diodes, which can effectively increase the brightness, and the heat dissipation is even, the brightness attenuation coefficient is small, and it can maintain good consistency after long-term use. The technician uses a 480*480mm cabinet, and when the brightness is 1000nit, the energy consumption of COB-P2.5 and SMD-P2.5 is compared, among which COB consumes 80.57W and SMD consumes 165.7W. It can be concluded that the premise of emitting the same brightness Next, the COB has smaller heat dissipation and is more energy-efficient.
COB packaging technology has significant advantages in stability, luminous effect, durability, power consumption, etc., and has emerged in the LED display market, especially in the field of outdoor small-pitch LED packaging. The excellent effect of COB has been gradually recognized by the market.