Processing method of large-light-emitting-angle substrate

Abstract

The invention discloses a method for processing a substrate with a large light-emitting angle, which relates to the technical field of manufacturing of LED (light-emitting diode) photoelectronic devices and comprises the following steps of: preparing a substrate with a manufactured light-emitting epitaxial layer structure and an electrode structure; evaporating a layer of metal film on the back surface of the substrate, performing high-temperature rapid annealing on the metal film to obtain micro-nano spherical metal particles, and randomly distributing the spherical metal particles on the surface layer of the back surface of the substrate; and etching the back surface of the substrate by taking the pattern consisting of the spherical metal particles as a mask, etching pits in an area, which is not covered by the spherical metal particles, of the back surface of the substrate, and after etching is finished, soaking with nitric acid or aqua regia to remove the spherical metal particleson the back surface of the substrate, so as to form a micro-nano-scale randomly distributed pit structure on the back surface of the substrate. The substrate is subjected to process treatment, so thatthe light-emitting angle of the LED is effectively improved.

Description

technical field [0001] The invention relates to the technical field of manufacturing LED optoelectronic devices, in particular to a processing method for a substrate with a large light-emitting angle. Background technique [0002] In the prior art, the LED chip is limited by the total reflection of the substrate and other reasons, so that its light-emitting angle is generally about 120°, which cannot meet the demand for a larger light-emitting angle. [0003] Chinese patent document CN111584692A discloses a flip-chip Mini-LED chip with a large luminous angle and its preparation method. It mainly increases the luminous angle of the LED chip by adding microstructure patterns such as SiO2 and DBR shielding layers on the back of the sapphire substrate. The disadvantages of the solution are: because the shielding layers such as SiO2 and DBR are external materials set on the back of the sapphire, the thermal expansion of the externally processed materials does not match, the relia...

AI Technical Summary

Problems solved by technology

[0002] In the existing technology, the LED chip is limited by the total reflection of the substrate and other reasons, so that its light-emitting angle is generally around 120°, which cannot meet the demand for a larger light-emitting angle.

[0003] Chinese patent document CN111584692A discloses a flip-chip Mini-LED chip with a large luminous angle and its preparation method. It mainly increases the luminous angle of the LED chip by adding microstructure patterns such as SiO2 and DBR shielding layers on the back of the sapphire substrate. The disadvantages of the solution are: because the shielding layers such as SiO2 and DBR are external materials set on the back of the sapphire, the thermal expansion of the externally processed materials does not match, the reliability is not good during operation, and the existence of the shielding layer itself will cause problems. Cause a certain loss of light, in addition, the DBR layer also has the problem of easy desorption