What Are the Factors That Affect AC -free LED Light Efficiency

1. The heat dissipation technology For the light -emitting diode composed of PN, when the forward current flows from the PN, the PN knot has heating loss. These calories are radiated into the air through bonding glue, irrigation material, heat sinking, etc., and radiated into the air. In this process, each part of the material has heat resistance to prevent heat flow, that is, heat resistance, AC -free LED thermal resistance is the fixed value determined by the device's size, structure and material. The thermal resistance of the light diode is RTH (/w), and the heat dissipation power is PD (W). At this time, the PN knot temperature caused by the heat loss of the current rises to: t () = Rth PD. PN knot temperature is: TJ = TARTH PD, where TA is the ambient temperature. As the rising temperature of the knot will reduce the chance of compounding the PN, the brightness of the glowing diodes will decrease. At the same time, due to the increased temperature increase caused by thermal loss, the brightness of the light -emitting diode will no longer continue to increase with the current proportion, that is, the phenomenon of thermal saturation. In addition, with the rise of the knot temperature, the peak wavelength of glowing will also drift in the direction of the long wave, about 0.2-0.3nm/, which is for the white AC-free LED by the white AC-free LED by coating the YAG fluorescent powder by the Blu-ray chip. The drift of the Blu -ray wavelength will cause the losing match with the fluorescent powder to stimulate the wavelength, thereby reducing the overall lighting efficiency of the white light LED, and the change in the white light color temperature. For power emitting diode, the driving current is generally more than hundreds of millimeters. The current density of the PN knot is very high, so the temperature rise of the PN knot is very obvious. For packaging and applications, how to reduce the thermal resistance of the product, so that the heat generated by the PN knot can be emitted as soon as possible, which can not only improve the saturation current of the product, improve the light efficiency of the product, but also improve the reliability and life of the product. In order to reduce the thermal resistance of the product, the choice of packaging materials is particularly important, including heat sinking, adhesive, etc. The heat resistance of each material should be low, that is, the heat conduction performance is good. Secondly, the structure design should be reasonable. The thermal conductivity between each material is continuously matched, and the thermal conductivity between the materials is good to avoid generating heat dissipation bottlenecks in the thermal conductivity. At the same time, it is necessary to ensure from the craftsmanship, the heat is emitted in time according to the pre -designed heat dissipation channel. 2. The choice of filling glue According to the law of refraction, when the light is incident from the light media to the light sparse medium, when the incident angle reaches a certain value, that is, when the critical angle is greater than the critical angle, the full launch will occur. In terms of GAN blue chip, the refractive index of GAN materials is 2.3. When the light is shot from the crystal to the air, according to the law of refraction, the critical angle 0 = sin-(n2/n1) is The refractive index, N1 is the refractive index of GAN, thereby calculating the critical angle 0 about 25.8 degrees. In this case, only the incident angle 25.8 degrees in the three-dimensional corner of the space in the three-dimensional corner of the space is reported. At present, the external quantum efficiency of the GAN chip is about 30%-40%. Therefore, due to the internal absorption of the chip crystal absorption , The proportion of lighting to the outside of the crystal is very small. According to reports, the external quantum efficiency of the GAN chip is currently around 30%-40%. Similarly, the light emitted by the chip must be transmitted to the space through the packaging material, and the effect of the material on the lighting efficiency of the material must be considered. Therefore, in order to improve the lighting efficiency of AC -free LED products packaging, the value of N2 must be increased, that is, the refractive index of the packaging material to improve the critical angle of the product, thereby improving the product packaging lighting efficiency. At the same time, the absorption of lighting materials for packaging materials should be small. In order to increase the proportion of light out of light, the shape of the packaging is arched or hemispherical. In this way, when the light is shot from the packaging material to the air, it is almost vertically shot to the interface, so no full reflection will be generated. 3. There are two main aspects of the reflection treatment reflection treatment. One is the reflection treatment inside the chip, and the other is the reflection of the packaging materials to the light. Through the reflection of the inside and outside, it will increase the proportion of the optical pass from the internal of the chip, reduce The internal absorption of the chip, improve the power AC -free LED finished product lighting efficiency. In terms of packaging, power -type LEDs usually assemble the power -type chip on a metal bracket or substrate with a reflective cavity. The bracket -type reflex cavity generally uses an electroplating to improve the reflection effect. Methods, electroplating treatment is also performed, but the above two methods are affected by mold accuracy and process. At present, the domestic reflex cavity of a sheet -type type, due to insufficient polishing accuracy or the oxidation of the metal coating, the reflex effect is poor, which has caused many light to be absorbed after the reflection area is ejected, and it cannot be reflected to the light surface at the expected target, which leads to reaching to reaching to reaching the expected target, which leads to reaching reaching to reaching the expected target, which leads to reaching reaching to reaching to reaching to reaching the expected target, which leads to reaching to reaching to reaching to reaching the expected target, which leads to reaching to reaching to reaching to reaching the expected target, which leads to reaching to reaching to reaching the expected target, which leads to reaching to reaching to reaching to reaching the expected target, it will lead to reaching reaching to reaching to reach The lighting efficiency after the packaging is low. We have developed a reflex treatment process with an organic material coating with independent intellectual property rights with independent intellectual property after many research and experiments. The light shot above it reflects to the out of light. The processing efficiency of the product after processing can be increased by 30%-50%compared to processing. The light effect of our current 1W white light power LED can reach 40-50LM/W (test results on the distance PMS-50 spectrum analysis test instrument), and have obtained a good packaging effect. 4. In terms of white power AC -free LED, the improvement of light power AC is also related to the selection and process processing of fluorescent powder. In order to improve the efficiency of fluorescent powder to stimulate the blue chip, first of all, the choice of fluorescent powder should be appropriate, including stimulating wavelength, particle size, and inspiration efficiency. Secondly, the coating of fluorescent powder should be evenly coated, and the thickness of each luminous chip with a relatively luminous chip is evenly thick, so as not to cause the local light cannot be shot due to uneven thickness. Good heat dissipation design plays a significant effect on improving the power -free LED product lighting efficiency, and it is also the prerequisite for ensuring product life and reliability. And the well -designed lighting channel, here to refer to the structural design, material selection and process processing of reflection cavity, filling glue, etc., which can effectively improve the lighting efficiency of the power -type LED. For the power -based white light LED, the choice and process design of fluorescent powder is also very important to improve the improvement of light spots and the improvement of lighting efficiency.