Advantages of COB packaging over traditional SMD packaging

With the continuous advancement of solid-state lighting technology, COB (chip-on-board) packaging technology has received more and more attention. Due to the characteristics of COB light sources such as low thermal resistance, high luminous flux density, less glare, and uniform light emission, they have been widely used in indoor and outdoor lighting fixtures, such as downlights, bulbs, fluorescent tubes, street lights, and mining lamps.

This article describes the advantages of COB packaging over traditional LED packaging, mainly comparing it from five aspects: production efficiency advantage, low thermal resistance advantage, light quality advantage, application advantage, and cost advantage, to illustrate the dominant position of COB packaging in the future development of LED lighting.

1. Advantages in production efficiency

The production process of OB packaging is basically the same as that of traditional SMD. The efficiency of die bonding and wire bonding is basically the same as that of SMD packaging. However, in terms of dispensing, separation, spectroscopy and packaging, the efficiency of COB packaging is much higher than that of SMD products. The labor and manufacturing costs of traditional SMD packaging account for about 15% of the material cost, and the labor and manufacturing costs of COB packaging account for about 10% of the material cost. By using COB packaging, labor and manufacturing costs can be saved by 5%.

2. Low thermal resistance advantage

The system thermal resistance of traditional SMD packaging applications is: chip-bonding adhesive-solder joint-tin paste-copper foil-insulating layer-aluminum. The system thermal resistance of COB packaging is: chip-bonding adhesive-aluminum. The system thermal resistance of COB packaging is much lower than that of traditional SMD packaging, which greatly increases the life of LEDs.

3. Light quality advantage

Traditional SMD packaging uses multiple discrete devices to attach to the PCB board in the form of patches to form a light source component for LED applications. This approach has problems such as point light, glare and ghosting. COB packaging, on the other hand, is an integrated package and a surface light source with a large viewing angle and easy adjustment, which reduces the loss of light refraction.

4. Application advantages (taking fluorescent tube COB as an example)

From the above figure, we can see that COB light source eliminates the process of patch and reflow soldering at the application end, greatly reducing the production and manufacturing process at the application end. At the same time, it can save the corresponding equipment, the investment cost of production and manufacturing equipment is lower, and the production efficiency is higher.

Taking the current manufacturing of 1.2m 2000LM fluorescent tube as an example, about 288pcs 3528 light sources are needed, and the mounting cost is about RMB 0.01/pcs. The mounting cost of a 1.2m fluorescent tube is

288*0.01=2.88 yuan. This cost can be saved if COB light source is used.

5. Cost advantage

(1) Take 1.2m fluorescent tube as an example (light source part)

From the above table, we can see that by using COB light sources, the cost of a 1600lm lamp can be reduced by 24.44%, the cost of a 1800lm lamp can be reduced by 29%, and the cost of a 2000lm lamp can be reduced by 32.37%.

(2) Take the production of 7W bulb/downlight as an example (light source is 6W)

From the above, we can see that the cost of using COB can be reduced by 19% to 32% compared with the traditional SMD light source. This can greatly reduce the cost of LED finished products, which will be conducive to the popularization of LED lighting as soon as possible.

Summarize:

The use of COB light sources has five major advantages over the use of traditional SMD packaged light sources. It has great advantages in light source production efficiency, thermal resistance, light quality, application, and cost. The overall cost can be reduced by about 25%. In addition, the devices are simple and convenient to use, and the process flow is simple.

in conclusion:

With the increasing application of LED in the lighting field, from the perspective of cost and application, integrated COB packaging is more suitable for the new generation of LED lighting structure. The development of COB packaging is the main way to solve the problems of high thermal resistance and high cost in the existing SMD packaging structure. The number of COB packaging will gradually increase due to its excellent performance, especially the increase in the proportion of output value, which will further promote the popularization of LED lighting.