Organic LED Patterning via Visible Laser Irradiation
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Solution Overview
Problem
Existing methods for patterning organic LED devices, such as those described in US 2004/0119028 and WO 02/07235, have limitations in efficiency and cost-effectiveness, particularly in creating customer-specific designs and maintaining the integrity of the device without visible damage.
Innovation Solution
A method involving irradiation of the organic light emitting layer with laser light in the visible spectrum, below the ablation threshold of the anode and cathode layers, to reduce light emitting properties and enable precise patterning without ablation, allowing for customer-specific designs and quick production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If infrared laser beam treatment is used to pattern organic LEDs, then patterning can be achieved, but visible damage remains on the device in the off-state
Solution Approach 1:
The patent changes the wavelength parameter from infrared to visible spectrum (400-700 nm), and adjusts the intensity parameter to remain below the ablation threshold. This parameter change allows the laser to selectively reduce light emitting properties without causing visible damage or ablation to the organic LED device structure.
2Manufacturing precision
If photolithography masks are used for patterning, then precise patterns can be created, but the process becomes expensive and complex
Solution Approach 1:
The patent extracts and eliminates the photolithography mask component from the patterning process. By using direct laser irradiation with visible light, the method achieves precise patterning without requiring masks, thereby simplifying the overall device structure and reducing manufacturing complexity while maintaining pattern precision.
Solution Approach 2:
The patent replaces the mechanical photolithography mask system with an optical laser irradiation system. This substitution eliminates the need for physical masks and their associated alignment and handling complexities, while achieving comparable or superior patterning precision through optical control.
3Adaptability or versatility
If standard patterning methods are used, then device patterning is achieved, but customer-specific designs require expensive retooling
Solution Approach 1:
The patent introduces dynamic flexibility to the patterning process by using laser irradiation parameters (wavelength, intensity, duration, scan patterns) that can be easily adjusted for different designs. This dynamic control allows customer-specific designs to be implemented without expensive retooling, as the laser parameters can be reprogrammed to create different patterns on the same device structure.
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 method allows for efficient and cost-effective patterning of organic LED devices with precise control over light emission, enabling greyscale images and customer-specific designs without visible damage in the off-state, reducing the need for expensive photolithography masks and enabling rapid response to customer demands.
Implementation Method 1
irradiating with a laser light in the visible light spectrum, the laser light having a wavelength in an absorption band of the organic light emitting layer
Data Source
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AI summary
It is presented an organic LED device 101 with, when in use, a predetermined pattern on its light emitting parts. The organic LED device 101 comprises an anode 105, a cathode 103, and an organic light emitting layer 107. The organic light emitting layer 107 is configured to emit light, wherein the organic light emitting layer 107 comprises portion with reduced light emitting properties, the portions of the organic light emitting layer 107 having been irradiated by light with a wavelength in the absorption band of the organic light emitting layer 107, the light intensity being below an ablation threshold of the cathode layer 103, the anode layer 105 and the organic light emitting layer 107 of the organic LED device 101, reducing the light emitting properties of the irradiated portions of the organic light emitting layer 107. It is also presented a method for reducing the light emitting properties of the organic LED device 101.