Since the emergence of external lighting, we have divided lighting into three eras: the era of filament bulbs (incandescent lamps), the era of gas bulbs (fluorescent lamps), and the era of semiconductor light-emitting (LED). Among them, the incandescent lamp with the longest history and the mainstream LED in the future are the most important inspection points. No matter how the times develop, the production process of the lighting industry is surprisingly similar, but China is in the downstream of the industry. The core technologies are basically owned by countries and regions such as Europe, America and Japan.

1. The light-emitting principle of LED is that when electrons pass through a layer of semiconductor material, the semiconductor material is excited to convert electrical energy into light energy. However, the light-emitting ability of single-layer semiconductors is very weak, so many layers of single-layer materials should be stacked and pressed into a composite material like a thousand-layer cake, which is an "epitaxial wafer".

Therefore, the luminous efficiency of LED depends on how many layers can be pressed into the same thickness. The thinner the single-layer material, the more layers that can be stacked, and the higher the luminous efficiency. Now the thickness of each layer is generally only 2-20 microns, which also determines that the production of epitaxial wafers is the most difficult part of the entire LED production process.

2. Cutting - LED core: It is equivalent to extracting the filament from the tungsten filament material. The difference is that the epitaxial wafer after cutting is a square shape.

Due to the special structure of the epitaxial wafer, it is very difficult to cut out the light-emitting core intact. Not only a vacuum environment, but also a professional cutting machine is required. There are currently only two manufacturers in the world that produce this type of cutting machine.

3. Put the core into the LED chip: the chip is to the LED, just like the lamp holder is to the light bulb, it is the power supply part. "Chip" is a very important equipment to achieve the desired effect of LED, because LED has very high requirements on current.

4. Encapsulate the LED chip into a luminous body: encapsulate the LED chip into a luminous body, just like adding a lampshade to a filament lamp holder to make a light bulb. The shape of the shade can vary depending on the needs, but the packaging technology determines the lifetime of the luminaire.

5. Lighting application: Just like using incandescent light bulbs, it can be assembled into different LED products according to different functions and needs.

For LED lighting, the first three steps of epitaxial wafers, dicing and chips are upstream, the fourth step is packaging, and the fifth step is downstream. These problems require us to use more energy to break through.