Micro-LED Panel Light Collection and Color Conversion
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Solution Overview
Problem
Conventional micro-LED panels face challenges in individually controlling small light emitting cells and achieving efficient light collection and color conversion for RGB full-color displays, leading to light loss and interference due to dispersion in the sapphire substrate.
Innovation Solution
The LED panel design includes light emitting cells arrayed below a sapphire substrate with etched portions and corresponding color cells on the substrate, featuring light collecting portions such as reflection planes and lens profiles to effectively collect light from emitting cells on color cells, minimizing interference and increasing light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If light emitting cells are arrayed below a sapphire substrate with color cells formed on the substrate, then color conversion and light transmission are enabled, but light is dispersed in the sapphire substrate causing light loss and interference between adjacent cells
Solution Approach 1:
A light collecting layer is introduced as an intermediary component between the light emitting cells and color cells. This layer actively captures dispersed light photons and redirects them toward the corresponding color cells, preventing energy loss through substrate dispersion and eliminating interference between adjacent cells. The light collecting layer serves as a mediator that transforms the passive sapphire substrate into an active light management system.
2Ease of manufacture
If conventional wire bonding techniques are used to connect micro-LED chips to active matrix substrate, then chip mounting is achieved, but individual control of small light emitting cells (several to several tens of μm) is difficult
Solution Approach 1:
The patent inverts the conventional mounting approach by using flip-chip bonding technology instead of wire bonding. This inversion allows the micro-LED chip to be mounted face-down on the active matrix substrate, with bonding pads directly contacting the substrate contacts. This inverted mounting method enables precise individual control of small light emitting cells (several to several tens of μm) while maintaining ease of manufacture, as the direct contact bonding provides better electrical connection and control capability compared to conventional wire bonding techniques.
3Ease of manufacture
If all light emitting cells emit light of the same wavelength, then manufacturing is simplified, but application to RGB full-color micro-LED displays is difficult
Solution Approach 1:
The patent segments the light emission function into two distinct components: light generating cells and color conversion cells. The light emitting cells are manufactured uniformly to emit light of the same wavelength (simplifying fabrication), while the color conversion cells are segmented into different types (red, green, blue phosphors) that convert the emitted light to different colors. This segmentation allows uniform manufacturing of light emitting cells while achieving RGB full-color display capability through the diversified color conversion layer.
Solution Approach 2:
Color conversion cells serve as intermediaries between the monochromatic light emitting cells and the full-color display requirement. These intermediary cells contain different phosphor materials (red, green, blue) that absorb the emitted light from the light emitting cells and convert it to different wavelengths, thereby enabling RGB full-color display capability while maintaining simplified manufacturing of the light emitting cells.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances light collection and reduces interference between neighboring cells, improving light efficiency and enabling effective color conversion for micro-LED displays.
Implementation Method 1
a plurality of light collecting portions formed corresponding to the plurality of light emitting cells and the plurality of color cells on the bottom surface of the substrate and adapted to collect light from the corresponding light emitting cells on the corresponding color cells
Implementation Method 2
each of the plurality of light collecting portions includes a reflection plane formed in an area of the bottom surface of the overlying sapphire substrate vertically corresponding to the etched portion
Implementation Method 3
a plurality of color cells formed corresponding to the plurality of light emitting cells on the sapphire substrate to change or maintain the color of light from the corresponding light emitting cells
Data Source
AI summary
An LED panel is disclosed. The LED panel includes LED chips and a mount substrate on which the LED chips are mounted by flip bonding. Each of the LED chips includes a sapphire substrate, a plurality of light emitting cells disposed below the sapphire substrate, and an etched portion formed between the plurality of light emitting cells. Each of the LED chips includes a plurality of color cells formed corresponding to the plurality of light emitting cells on the sapphire substrate to change or maintain the color of light from the corresponding light emitting cells and a plurality of light collecting portions formed corresponding to the plurality of light emitting cells and the plurality of color cells on the bottom surface of the substrate and adapted to collect light from the corresponding light emitting cells on the corresponding color cells.