Dual-pattern LED patterned substrate and LED chip

Abstract

The invention discloses a dual-pattern LED patterned substrate. Patterns on the substrate include the hemispherical pattern and the conical pattern. The radius r1 of the bottom circle of the hemispherical pattern is not equal to the radius r2 of the bottom circle of the conical pattern. The invention further discloses an LED chip comprising the dual-pattern LED patterned substrate. The light emitting efficiency of an LED is improved through the combination with the effect of the conical surface of the conical pattern and the spherical surface of the hemispherical pattern on optimizing the LED light emitting efficiency; the patterns on the substrate are dense, and therefore more light rays can be emitted out of the LED chip, especially, more light rays can be emitted out of the top and the bottom of the chip, and the LED light extraction ratio is greatly increased.

Description

technical field [0001] The invention relates to an LED patterned substrate, in particular to a double-pattern LED patterned substrate and an LED chip. Background technique [0002] In recent years, GaN-based LEDs have been widely used in traffic lights, LCD backlights, full-color displays, and general lighting due to their advantages such as high brightness, low energy consumption, and long life. However, there is a huge difference between the refractive index of GaN material (n=2.45) and air (n=1.0), and the critical angle of total reflection is only about 24°, which leads to the significant total reflection of light inside the chip and cannot be emitted. LED, which greatly reduces the light extraction rate of the LED. Later, improvement schemes were proposed for this problem, such as introducing Bragg reflection layer, photonic crystal, surface roughening and substrate patterning, etc. Among them, the patterned substrate technology can not only improve the light extracti...

AI Technical Summary

Problems solved by technology

However, due to the limitations of the development of pattern etching technology, the pattern design of graphic substrate technology has been limited to the regular arrangement of a single pattern, such as the rectangular or hexagonal arrangement of a single pattern such as cones, hexagonal pyramids, triangular pyramids, and hemispheres.

In these traditional substrate pattern designs, the pattern spacing cannot be reduced infinitely. Even in the most densely arranged patterns, there are still many gaps between adjacent patterns, and this part of the gap will be greatly reduced. Small room for improving the light extraction rate of the graphics substrate LED

Moreover, an overly dense substrate pattern is not conducive to the nucleation and growth of epitaxial GaN crystals, so the design and arrangement of patterned substrate patterns is a major problem in optimizing the light extraction efficiency of LEDs.

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