Contactless µLED Micro-Display With Wavelength Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing manufacturing processes for full-color µLED displays are complex and costly due to the need for precise electrical contact and bonding between driving electrodes and µLED chips, as well as the use of quantum dots for color conversion, leading to long cycles and high production costs.
Innovation Solution
A full-color µLED micro-display device without electrical contact, where upper and lower driving electrodes are not directly connected to the µLED grain, utilizing a wavelength down-conversion light-emitting layer and a control module to form a driving electric field that converts light sources into red, green, and blue colors through a reflective and diffusion layer with a color filter film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional LED modules with lenses and reflectors are used, then light extraction efficiency is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent removes the lens and reflector components from the LED module, extracting only the essential light-emitting elements (µLED chips mounted on PCBs). This simplification maintains light extraction efficiency while dramatically reducing device complexity and eliminating the need for precise optical component alignment.
Solution Approach 2:
The patent merges multiple LED chips and their support structures into integrated modules where multiple µLED chips are mounted on a single PCB. This consolidation reduces the number of separate components and simplifies the overall device architecture while maintaining high light extraction efficiency through optimized chip arrangement.
2Manufacturing precision
If precise alignment of multiple LED modules is performed manually, then display quality is improved, but manufacturing time and cost increase
Solution Approach 1:
The patent replaces manual mechanical alignment with automated optical alignment systems that use cameras and control algorithms to precisely position LED modules. This substitution achieves sub-pixel alignment accuracy while dramatically reducing manufacturing time and eliminating manual labor.
Solution Approach 2:
The patent incorporates alignment marks and positioning features directly into the PCB and module structures during manufacturing. These pre-built reference features enable rapid automated alignment without requiring complex real-time adjustments, thereby improving both precision and productivity.
3Reliability
If electrical connections are made through conductive adhesives, then electrical connectivity is achieved, but manufacturing complexity and reliability decrease
Solution Approach 1:
The patent removes the conductive adhesive layer from the electrical connection structure, eliminating the reliability issues and manufacturing complexity associated with adhesive application, curing control, and conductivity verification. Electrical connections are achieved through direct mechanical and electrical interfaces.
Solution Approach 2:
The patent introduces PCBs with standardized electrical interfaces as intermediary components between the µLED chips and the driving electronics. These PCBs provide reliable electrical connectivity through controlled impedance traces and solder connections, simplifying the overall manufacturing process and improving connection reliability.
4Use of energy by moving object
If large-sized LEDs are used, then light output is improved, but display resolution and flexibility decrease
Solution Approach 1:
The patent divides the display into numerous small µLED chips (e.g., 50 µm × 50 µm or smaller) arranged in arrays on PCBs. This segmentation enables high display resolution and flexibility while maintaining adequate light output through the cumulative effect of multiple small emitters working together.
Solution Approach 2:
The patent employs a hierarchical structure where multiple µLED chips are nested on a single PCB, which itself is nested within the overall display module. This nested arrangement allows the system to achieve high resolution through many small chips while maintaining manageable module sizes and flexibility for various display configurations.
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 approach simplifies the manufacturing process, reduces production costs, and enhances the efficiency of µLED displays by eliminating complex bonding and transfer processes, while achieving full-color capabilities.
Implementation Method 1
Each pixel element comprises a single µLED chip... the µLED chip emits light in response to an applied drive current
Implementation Method 2
a color filter layer, and a common electrode... capable of displaying full-color images
Data Source
Figure 1~2
Figure 3
Figure 4~6
AI summary
The present invention relates to a full-color µLED micro-display device without electrical contact and a manufacturing method therefor. The device includes a lower driving electrode and a reflective layer arranged on a surface of the lower transparent substrate, an upper driving electrode and a diffusion layer arranged on a surface of the upper transparent substrate, a wavelength down-conversion light-emitting layer and a blue µLED grain arranged between the upper and lower driving electrodes, and a control module and a color filter film; the upper and lower driving electrodes are in no electrical contact with the blue µLED grain, the control module is in an electrical contact with the upper and lower driving electrodes, and the control module provides an alternating driving signal for controlling the µLED grain to excite a first light source which is converted into a second light source after passing through the wavelength down-conversion light-emitting layer, and after passing through the reflective layer and the diffusion layer, the first and second light sources achieve the full-color µLED micro-display through the color filter film. The present invention can effectively avoid the complex process for manufacturing tricolor µLED chips in the full-color µLED device, as well as the complex bonding and mass transfer processes for the light-emitting chip and the driving chip, thereby shortening the cycle for manufacturing a µLED display, and cutting down the production cost.