LED Light Absorption Barrier for UV-Safe Laser Liftoff
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor processing methods for LED display devices face challenges in producing high-quality, precisely dimensioned material layers, and the laser liftoff technique used to separate LED substrates from backplane substrates can damage control circuitry due to energetic ultraviolet light escaping through gaps between LED structures.
Innovation Solution
The implementation of a light absorption barrier between LED structures and the substrate, composed of dielectric materials that absorb energetic ultraviolet light during the laser liftoff process, preventing damage to the backplane substrate and enhancing the reflectance of the reflective layer for useful light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser liftoff technique is used to separate LED substrates from backplane substrates, then separation efficiency is improved, but control circuitry is damaged by energetic ultraviolet light
Solution Approach 1:
A light absorption barrier layer is deposited between the LED structures and the backplane substrate. This intermediary layer absorbs the energetic ultraviolet light generated during laser liftoff, preventing it from reaching and damaging the control circuitry on the backplane substrate, while allowing the laser liftoff process to proceed efficiently.
Solution Approach 2:
The light absorption barrier converts the harmful ultraviolet radiation into a useful function by selectively absorbing the damaging wavelengths while transmitting the longer wavelengths needed for LED operation. The barrier transforms the potentially destructive energy into a controlled absorption event that protects the circuitry.
2Object-affected harmful factors
If light absorption barrier is deposited to block ultraviolet light, then protection of backplane substrate is improved, but light extraction efficiency may be reduced
Solution Approach 1:
The light absorption barrier exhibits wavelength-dependent optical properties: it strongly absorbs ultraviolet light below a specific wavelength threshold while being transparent to visible light wavelengths. This local quality in the optical spectrum allows simultaneous protection of the backplane substrate and maintenance of light extraction efficiency for LED operation.
Solution Approach 2:
The barrier layer's optical transmission characteristics are controlled by adjusting its material composition and thickness parameters. By optimizing these parameters, the barrier achieves maximum ultraviolet absorption while maintaining high transparency in the visible range, thus balancing protection and light extraction efficiency.
3Ease of manufacture
If conventional fabrication processes are used to produce patterned material layers, then manufacturing simplicity is maintained, but manufacturing precision of high-quality layers is reduced
Solution Approach 1:
The light absorption barrier is deposited on the substrate before the LED structures are fully formed and before substrate separation. This preliminary action allows the barrier to be in place during subsequent processing steps, ensuring precise positioning and protecting the structures during fabrication while maintaining process simplicity.
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 reduces damage to the backplane substrate and control circuitry, improves light extraction efficiency by blocking damaging short-wavelength radiation, and increases the reflectance of the reflective layer for LED light emission.
Implementation Method 1
A light absorption barrier may be deposited on the patterned LED substrate... The light may be absorbed by surfaces of the LED structures that are in contact with the substrate layer and the light absorption barrier
Implementation Method 2
the light absorption barrier is operable to transmit light emitted from the LED structures... the light absorption barrier prevents the light exposing the patterned LED substrate from reaching the backplane substrate
Implementation Method 3
forming a reflective layer on the light absorption barrier... the light absorption barrier increases a percentage reflectance of the reflective layer for LED light emitted by the LED structure
Implementation Method 4
the group of LED structures may include gallium-and-nitrogen-containing material that generates nitrogen gas (N2) when exposed to the light at the surfaces of the LED structures in contact with the substrate layer
Data Source
AI summary
Exemplary processing methods include forming a group of LED structures on a substrate layer to form a patterned LED substrate. A light absorption barrier may be deposited on the patterned LED substrate. The methods may further include exposing the patterned LED substrate to light. The light may be absorbed by surfaces of the LED structures that are in contact with the substrate layer, and the light absorption barrier. The methods may still further include separating the LED structures for the substrate layer. The bonding between the LED structures and the substrate layer may be weakened by the absorption of the light by the surfaces of the LED structures in contact with the substrate layer.