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With the rise of small-pitch LED, the upper limit of ultra-high-definition display is being broken through again and again, and in the process, often accompanied by technological innovation. There is no greater contribution to this than COB technology. With 5G+8K on the national agenda, small-pitch LEDs began to break through the upper limit of ultra-high-definition display, and the various limitations of SMD, in the field of micro-pitch, COB technology has contributed more and more to this, COB is still an emerging term a few years ago, but in the rapid development of the LED industry, COB has now become the mainstream direction, COB to help ultra-high-definition display has become the display industry’s Development direction, LED display products into the era of tiny pitch. In view of the increasing demand for COB small pitch, muchHUB takes stock of the key COB packaging technologies to help you understand the industry situation of COB packaging, further familiarize yourself with the industry landscape and understand the market.

1.COB’s flip-flop and front loading technology

COB technology itself has long been the focus of the market, however, flip-flop COB and COB technology to a new height, COB itself is a multi-bead integration without bracket packaging technology, direct packaging of light-emitting chips on the PCB board, eliminating the tedious table paste process, no bracket welding feet, each pixel of the LED chip and welding wire are tightly epoxy resin colloid Tightly encapsulated in the gel, without any exposed elements, providing protection for the LED chip, can solve the problem of damage caused by external factors to the pixel, flip-chip COB can significantly increase the current density, improve the stability of the lamp beads and luminous efficiency, flip-chip structure can well meet such needs, simplify the production process, better display effect, can achieve chip-level pitch, has reached Micro LED level.

2. Co-cathode and co-anode technology

Conventional LED display adopts the common anode (positive) power supply method, the current flows from the PCB board to the lamp beads, using the common anode lamp beads and the corresponding driver IC, RGB lamp beads unified power supply. “Common cathode” refers to the common cathode (negative) power supply method, using common cathode lamp beads and special common cathode driver IC program, RGB separate power supply, the current through the lamp beads and then to the negative IC. After using common cathode, there is no need to configure voltage divider resistor to reduce this part of energy consumption, while the display brightness and display effect is not affected, and energy saving is increased by 25%~40%.

3. Good heat dissipation

COB packaging process is to fix the LED bare chip directly to the pad, so the heat dissipation area is relatively large compared to the traditional packaging process, the material comprehensive thermal conductivity is also high, good heat dissipation. The traditional package is to fix the LED bare chip on the pad inside the bracket, and the pad needs to transfer the heat to the PCB board indirectly through the metal pin of the bracket.

4. Smaller size

Using COB technology, it is possible to bind and mount on both sides of the PCB, which reduces the size of COB application modules accordingly and expands the application space of COB modules.

5. Reduces moiré

COB package micro-pitch LED display adopts high fill factor optical design, luminous uniformity, similar to “surface light source”, effectively reduce moiré. Its matte coating technology also significantly improves contrast, reduces glare and blinding sensation, and effectively resists blue light damage, which not only reduces visual fatigue of human eyes, but also produces high-definition video or photos under camera or camcorder shooting, especially suitable for applications that require long-term viewing and shooting of the screen (such as lecture halls, studios, etc.).

6.High reliability and low maintenance costs

COB packaging technology encapsulates the pixel dots on the PCB board, realizing the comprehensive sealing of the PCB board, crystal particles, solder pins and leads, etc. The surface is smooth without exposed components, and the protection ability is very strong. The surface of pixel dots is smooth and hard, with anti-knock, anti-impact, anti-vibration, anti-pressure, water-proof, moisture-proof, dust-proof, oil-proof, anti-oxidation, anti-static and other properties, high stability and easy maintenance. The adoption of COB packaging process makes the bad dot rate and the loss of control rate of the whole screen below one in a million, and the fanless design not only reduces noise but also reduces the failure point, which ensures that the screen hardly generates any maintenance cost during the use.