Manufacturing method of substrate for Mini-LED chip with large light-emitting angle

Abstract

The invention discloses a manufacturing method of a substrate for a Mini- LED chip with a large light-emitting angle, which relates to the technical field of photoelectron manufacturing, and comprisesthe following steps: preparing a substrate with a manufactured light-emitting epitaxial layer structure and an electrode structure; coating the back surface of the substrate with a saturated salt solution of chloride, and baking the back surface of the substrate until moisture is completely evaporated to form micro-nano-scale chloride particles which are randomly distributed on the surface layerof the back surface of the substrate; and performing plasma etching on the back surface of the substrate by taking the pattern formed by the chloride particles as a mask, cleaning the chloride particles on the back surface of the substrate after etching is finished, and forming a micro-nano scale and randomly distributed pit structure on the back surface of the substrate. The substrate is subjected to process treatment, so that the light-emitting angle of the Mini LED is effectively improved.

Description

technical field [0001] The invention relates to the technical field of optoelectronic manufacturing, in particular to a method for manufacturing a substrate for a Mini-LED chip with a large light emitting angle. Background technique [0002] Mini LED generally refers to LEDs with a size of 75-200 μm, also known as sub-millimeter light-emitting diodes. Mini LED is the main force in the development of LED technology in recent years, and it is widely used in liquid crystal display backlight, Mini RGB display, small-pitch display and other fields. However, the traditional sapphire light-emitting surface chip has a small light-emitting angle, and requires high-density arrangement to achieve uniform light mixing. The small number of chips will lead to a large optical distance of the backlight display, and the high-density arrangement will lead to higher costs. Decrease in process yield. [0003] Chinese patent document CN111584692A discloses a flip-chip Mini-LED chip with a larg...

AI Technical Summary

Problems solved by technology

However, the traditional sapphire light-emitting surface chip has a small light-emitting angle, and requires high-density arrangement to achieve uniform light mixing. The small number of chips will lead to a large optical distance of the backlight display, and the high-density arrangement will lead to higher costs. Process yield decline

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