Method for coating fluorescent powder for high-power white light-emitting diode

Abstract

High power white light LED phosphor coating method, involving a phosphor powder coating method. In two stainless steel tablets square hole A and B is engraved respectively , the two square holes are bond together after aligning their centers to form a mould; flip chip soldered to the substrate; take silicone resin A and B, weigh phosphor powder and nano-SiO2, first mix silicone resin and phosphorpowder, then add SiO2 grinding, mixing evenly to obtain the colloid flour; nest the mould in the chip and substrate, making the square hole B nesting substrate, square hole nesting the peripheral of the chip, put the colloid powder on the surface of the mould, use scraper to quickly scrape over and take off the mould by uniform speed lifting device, so that phosphous powder coating is completed. Finally chip is put in drying box for solidification.

Description

technical field [0001] The invention relates to a phosphor coating method, in particular to a phosphor coating method for a high-power white light emitting diode. Background technique [0002] Lighting Emitting Diod (Lighting Emitting Diod) has the advantages of long life, energy saving, fast response, high reliability, environmental protection and safety (Zhang Guoyi, Chen Zhiguo. The cornerstone of solid-state lighting source - gallium nitride-based white light diode, physics and high-tech Technology, 2004, 34(11)). With the advancement of science and technology, the light efficiency of LED has been greatly improved, and the application level of white light LED has also been gradually developed, which has been hailed as the main lighting source in the 21st century. In recent years, high-power white light LEDs have developed rapidly, and there is a tendency to enter the field of lighting. Many scientific research and production departments around the world are actively inv...

AI Technical Summary

Problems solved by technology

Due to the small size of the low-power chip, the method of dispensing powder has little effect on the luminous effect; and now that LEDs have developed to high-power, the coating method of phosphor powder has not been greatly improved.

However, chips for high-power LEDs occupy a large area, and some have reached 1.00mm×1.00mm. The way of dispensing powder will cause uneven distribution of phosphor powder. The middle part of the surface is relatively large, which often causes blue light to appear from the sides and edges during the lighting process, and emits the color of the phosphor (yellow, red, green) above the chip, which will cause LED lights to be distributed in space. Inhomogeneity, inconsistent color temperature, phenomena such as yellow or blue circles appear, which affect lighting effects and color rendering (1, Cao X A, Stokes E B, Sandvik P. Optimization of current spreading metal layer for GaN / InGaN-based light emitting diodes [J]. SolidState Electronics, 2002, 46: 1235-1239; 2. Guo X, Schubert E F. Current crowding in GaN / InGaN light emitting diodes on insulating substrates [J]. J. Appl. Phys, 2000, 90 (8 ): 4191-4195)

[0003] Some manufacturers in Japan and the United States are now using electrophoresis, spraying, sputtering and other methods to improve the coating uniformity of phosphor powder. Although the effect is good, the process is complicated and the cost is too high, which is not suitable for low-cost mass production.

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