White-light LED package structure

Abstract

The invention relates to a white-light LED package structure. The structure comprises a heat radiation substrate 21, an LED lamp chip arranged on the upper surface of the heat radiation substrate 21,a lower silica gel layer 22 arranged on the upper surface of the LED lamp chip, hemispherical silica gel balls 23 arranged on the upper surface of the lower silica gel layer 22, and an upper silica gel layer 24 arranged on the upper surfaces of the lower silica gel layer 22 and the hemispherical silica gel balls 23. The white-light LED package structure solves the problem of reduction of quantum efficiency of fluorescent powders due to high temperature by separating the fluorescent powders from the LED lamp chip.

Description

technical field [0001] The invention relates to the technical field of packaging, in particular to a white light LED packaging structure. Background technique [0002] LED has the characteristics of long life, high luminous efficiency, good color rendering, safe and reliable, rich color and easy maintenance. Under the background of increasingly serious environmental pollution, climate warming and energy shortage, semiconductor lighting technology based on high-power LED has been recognized as one of the most promising high-tech fields in the 21st century. This is a great leap in the history of human lighting since gas lighting, incandescent lamps and fluorescent lamps, and has rapidly improved the lighting quality of human life. [0003] In recent years, LEDs mostly use a GaN-based blue light wick plus yellow fluorescence to generate white light to achieve illumination, which has the following problems. First of all, the light emitted by the LED light source generally has ...

AI Technical Summary

Problems solved by technology

First of all, the light emitted by the LED light source is generally distributed in a divergent manner, that is, the Lambertian distribution, which leads to insufficient illumination brightness of the light source, and generally requires secondary shaping through an external lens to meet the lighting needs of specific occasions, thus increasing production costs; secondly , in the current high-power white LED packaging structure, the phosphor is generally directly coated on the surface of the chip. Since the chip absorbs the backscattered light, this direct coating method will reduce the light extraction of the package. Efficiency. In addition, the high temperature generated by the chip will significantly reduce the quantum efficiency of the phosphor, which seriously affects the lumen efficiency of the package; again, only a part of the energy in the LED input power is converted into light energy, and the rest is converted into heat energy. Therefore, for LED chips, especially LED chips with high power density, how to control their energy is an important issue that LED manufacturing and lamps should focus on solving; then, because high-power LEDs are used in lighting and other occasions, cost control is very important, and The structural size of the external heat sink of high-power LED lamps is not allowed to be too large, and it is impossible to allow active cooling by adding an electric fan. The safe junction temperature of the LED chip should be within 110°C. If the junction temperature is too high, it will cause light A series of problems such as strong reduction, spectral shift, color temperature increase, thermal stress increase, and accelerated aging of the chip greatly reduce the service life of the LED. At the same time, it can also cause accelerated aging of the packaging gel filled on the chip, affecting its Light transmission efficiency; finally, most of the chips are packaged on thin metal heat dissipation substrates. Since the metal heat dissipation substrate is thin, the heat capacity is small, and it is easy to deform, the contact between it and the bottom surface of the heat sink is not close enough to affect the heat dissipation effect.

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