Advantages, disadvantages and characteristics of COB packaging
In this article, we will discuss the advantages and disadvantages of COB packaging. COB packaging, or Chips on Board, is a technology used to solve LED heat dissipation issues. Compared to through-hole and SMD packages, COB packaging is characterized by space-saving, simplified packaging operations, and efficient heat management.
COB packaging involves attaching bare chips to a substrate using conductive or non-conductive adhesive and then wire bonding to achieve electrical connection. If the bare chip is exposed to air, it is susceptible to contamination or damage, which can affect or destroy the chip's function. Therefore, the chip and wire bonding are encapsulated with adhesive. This packaging form is also called soft-packaging.
Advantages of COB Packaging:
1. Ultra-light and thin: Depending on the customer's actual needs, PCB boards with thicknesses ranging from 0.4-1.2mm can be used, reducing weight to one-third of traditional products, which can significantly reduce structural, transportation, and engineering costs.
2. Anti-collision and pressure-resistant: COB products directly encapsulate the LED chip in the concave lamp position of the PCB board, and then encapsulate it with epoxy resin glue. The surface of the lamp point protrudes into a spherical shape, which is smooth and hard, and resistant to collision and wear.
3. Wide viewing angle: COB packaging uses shallow spherical surface emission, with a viewing angle greater than 175 degrees, close to 180 degrees, and has a more excellent optical diffusion and color rendering effect.
4. Bendable: The ability to bend is a unique feature of COB packaging. The bending of the PCB will not damage the encapsulated LED chip, so using COB modules can easily produce LED curved screens, circular screens, and wave-shaped screens. It is an ideal substrate for personalized screens in bars and nightclubs. It can achieve seamless splicing, simple structure, and the price is much lower than that of LED-shaped screens made by flexible circuit boards and traditional display module production.
5. Strong heat dissipation ability: COB products encapsulate the lamp on the PCB board and quickly transfer the heat generated by the lamp core through the copper foil on the PCB board. Moreover, the thickness of the copper foil on the PCB board has strict process requirements, plus immersion gold technology, which almost does not cause serious light attenuation. Therefore, there are few dead lights, greatly extending the life of the LED display.
6. Wear-resistant and easy to clean: The surface of the lamp point protrudes into a spherical shape, which is smooth and hard, and resistant to collision and wear. If there are bad points, they can be repaired point by point. There is no mask, and dust can be cleaned with water or cloth.
7. All-weather excellent features: Adopting triple protection treatment, waterproof, moisture-proof, anti-corrosion, dust-proof, anti-static, oxidation, and UV effects are outstanding; it can work in all-weather conditions, and can still be used normally in a temperature difference environment of minus 30 degrees to plus 80 degrees.
Disadvantages of COB Packaging:
1. The packaging density is slightly smaller than TAB and inverted chip welding technology.
2. It requires a separate welding machine and packaging machine, and the production technology requirements are extremely strict. If the speed cannot keep up, or the PCB patch has more stringent environmental requirements and cannot be repaired, it may cause problems.
These are the advantages and disadvantages of COB packaging. We hope this article is helpful to you.
Watt Smith
Collaborator & Editor
Hello! My name is Watt Smith working on Chipdatas. I write and share relevant articles on electronic components category.
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