1. The luminescence principle of the led is to stimulate the semiconductor material to convert electrical energy into light energy through a layer of semiconductor materials. However, single-layer semiconductor has weak luminous ability, so it is necessary to superposition many layers of single layer material into a composite material like a thousand layer cake, which is called "epitaxial slice".

Therefore, the luminous efficiency of the led depends on how many layers can be pressed in the same thickness. The thinner the single-layer material, the more layers you can add, the higher the luminous efficiency. Currently, the average thickness of each layer is only 2 to 20 microns, which determines that the production of epitaxial wafer is the most difficult part of the whole led production process.

2. Cutting -- led core: it is equivalent to drawing the filament from the tungsten wire. The difference is that the epitaxial slice after cutting is the square shape.

Because of the special structure of the epitaxial slice, it is very difficult to cut off the core of the light intact. Not only need the vacuum environment, but also professional cutting machine. Only two manufacturers in the world produce this kind of cutter.

3. Put the core into the led chip: the chip is to the led, just as the lamp holder is to the light bulb, which is the power supply part. "Chip" is an important device to realize the ideal effect of the led, because the led has a high demand for current.

4. Encapsulate led chip into a luminous body: the led chip is packaged into a luminous body, just as the lamp holder is made into a light bulb. The shape of the lampshade can vary according to the requirements, but the packaging technology determines the life of the luminescent body.

5. Lighting application: as with incandescent light bulbs, different led products are assembled according to different functions and needs.

For led line lamps, the first three steps of epitaxial wafer, cutting and chip are upstream, the fourth step encapsulation is middle reaches, and the fifth step is downstream. These problems require us to use more energy to break through.

Led lamp line to identify the good or bad, need to check the flatness, no bubbles, inclusions, quality defects such as scratch, lanes and fog, such defects of glass, in use will happen deformation, lower the opacity of the glass, mechanical strength and thermal stability of the glass.

1. Brightness check. Test product illumination at a meter from the product, and whether it is consistent with the supplier's data.

2. Light failure detection, daily check the illumination value with the illuminometer, and whether the illuminance is in normal attenuation range.

3, the temperature examination, integrated with a thermometer to check the LED light source near 1 cm, test temperature is within the scope of the 80 degrees, with a thermometer testing LED floodlight table surface temperature, whether under 60 degrees. Remember to attend the exhibition before 2008, customers always touch the product. The temperature is not high enough to think the product is good. After 2008, more and more professional customers will take the illuminometer to test the temperature near the light source. Because they know that surface stability doesn't mean the product is good, maybe this product is very bad, because it doesn't even have heat.

4. Whether there are scratches, deformations and fingerprints on the glass surface. The handprint can reflect the strict management of the factory and the strict quality requirements.