Shenzhen Lianchengfa Technology Co., Ltd.

With the gradual development of LED display technology at any time, there are also LED display products in SMD package and COB package on the market, so what are the advantages and disadvantages of COB package LED display and the development difficulties? Next, LCF sent the editor to take everyone to take a look!

Chip on Board is a structure in which multiple LED chips are directly mounted on a heat dissipation PCB substrate to conduct heat directly. COB packaging integrates upstream chip technology, midstream packaging technology and downstream display technology. Therefore, according to Lianchengfa, COB packaging requires the close cooperation of upstream, midstream and downstream enterprises to promote the large-scale application of COB LED displays.

COB integrated packaging LED display module, the front is the LED light module to form the pixel, the bottom is the IC drive element, and finally the COB display modules are spliced into the design size of the LED display.

Theoretical advantages of COB:

1. Design and development: Without the diameter of a single lamp body, it can be made smaller in theory;

2. Technical process: reduce the cost of the bracket and simplify the manufacturing process, reduce the thermal resistance of the chip, and achieve high-density packaging;

3. Engineering installation: From the perspective of the application side, COB LED display modules can provide easier and faster installation efficiency for manufacturers of display screen applications.

4. Product characteristics:

(1) Ultra-thin: According to the actual needs of customers, PCB boards with a thickness of 0.4-1.2mm can be used to reduce the weight to at least 1/3 of the original traditional products, which can significantly reduce the structure, transportation and engineering costs for customers.

(2) Anti-collision and anti-pressure: COB products directly encapsulate the LED chip in the concave lamp position of the PCB board, and then encapsulate and cure with epoxy resin glue. The surface of the lamp point is convex into a spherical surface, smooth and hard, and resistant to impact grind.

(3) Large viewing angle: the viewing angle is greater than 175 degrees, close to 180 degrees, and has a better optical diffuse color blur effect.

(4) Strong heat dissipation ability: COB products package the lamp on the PCB board, and quickly transmit the heat of the wick through the copper foil on the PCB board, and the thickness of the copper foil on the PCB board has strict process requirements, plus the sinking Gold process, hardly cause serious light attenuation. So there are few dead lights, which greatly prolongs the life of the LED display.

(5) Wear-resistant and easy to clean: the surface is smooth and hard, impact-resistant and wear-resistant; without a mask, it can be cleaned with water or cloth if there is dust.

(6) All-weather excellent features: triple protection treatment, waterproof, damp, rot, dust, static electricity, oxidation, and ultraviolet effects are outstanding; it meets all-weather working conditions, and can still be used normally in a temperature difference environment of minus 30 degrees to minus 80 degrees.

It is for these reasons that COB packaging technology has been pushed to the foreground in the display field.

Current technical problems of COB:

At present, the accumulation of COB in the industry and the details of the process need to be improved, and some technical difficulties are also faced.

1. The one-time pass rate of the package is not high, the contrast is low, and the maintenance cost is high;

2. The uniformity of its color rendering is far inferior to that of the display screen after the SMD device with spectroscopic and color separation is used.

3. The existing COB packaging still adopts front-mounted chips, which require die bonding and wire bonding processes. Therefore, there are many problems in the wire bonding process and the difficulty of the process is inversely proportional to the pad area.

4. Manufacturing cost: Due to the high defect rate, the manufacturing cost is far higher than that of SMD with small spacing.

Based on the above reasons, although the current COB technology has made some breakthroughs in the display field, it does not mean that the SMD technology has completely withdrawn and declined. In the field of dot pitches above 1.0mm, SMD packaging technology, with its mature and stable product performance, is widely used. The leading market practice and perfect installation and maintenance guarantee system are still the leading role, and it is also the most suitable selection direction for users and the market.

With the gradual improvement of COB product technology and the further evolution of market demand, the large-scale application of COB packaging technology will reflect its technical advantages and value in the range of 0.5mm~1.0mm dot pitch. : "The COB package is tailor-made for 1.0mm and below dot pitches."

The above is the relevant knowledge about the advantages, disadvantages and development difficulties of COB-packaged LED display screens compiled by LCF Xiaobian. I hope it will be helpful to everyone. At the same time, you are welcome to correct or supplement. LCF is a national-level professional and new "little giant" enterprise, a LED display application and solution provider integrating "hardware + software + content + interaction". The main business covers four major sections: "Smart City", "Cultural Tourism Commercial Performance", "Commercial Display Engineering", and "Content Technology". It has the world's leading automated production equipment, modern post-doctoral research laboratories and comprehensive sales and services. team. Friends who need to buy LED display，pleas contact us. LCF LED display manufacturer, a big country brand, trustworthy!