LED Color Tuning via Selective Phosphor Deposition
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Solution Overview
Problem
Conventional light emitting diodes (LEDs) cannot produce true white light as they typically emit light at a single wavelength, leading to off-white colors and reduced color fidelity when the base material and light conversion material are not matched appropriately.
Innovation Solution
The method involves selectively applying light conversion materials, such as phosphors, onto LEDs in specific patterns to compensate for color variances across a microelectronic workpiece, allowing precise tuning of colors and achieving desired light emission, including white light, by combining blue light with yellow and red emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light conversion material is deposited on a base material to emulate white light, then the LED can produce white light appearance, but the color fidelity deteriorates when the base material and light conversion material are not matched appropriately
Solution Approach 1:
The patent applies different light conversion materials to different regions of the LED chip surface. By dividing the chip into multiple zones and applying specific phosphor materials (e.g., yellow phosphor in some regions, red phosphor in others) with controlled concentrations, the invention achieves precise color tuning across the entire LED, resolving the contradiction between white light emission and color fidelity
Solution Approach 2:
The invention varies the concentration and composition of light conversion materials across different regions of the LED chip. By adjusting phosphor concentration gradients and material compositions, the patent optimizes the spectral output to maintain high color fidelity while achieving true white light emission, thereby resolving the mismatch problem between base material and light conversion material
2Ease of manufacture
If light conversion materials are applied uniformly across the LED, then the manufacturing process is simplified, but color variances occur across the microelectronic workpiece
Solution Approach 1:
Instead of uniform application, the patent implements region-specific light conversion material deposition with varying concentrations and compositions. This localized approach compensates for manufacturing variations across the workpiece while maintaining color consistency, resolving the contradiction between manufacturing simplicity and color uniformity
Solution Approach 2:
The patent employs preliminary characterization of each LED chip's color properties before light conversion material application. By pre-measuring the base material emission characteristics and then selectively applying compensating phosphor materials, the invention achieves color consistency across the workpiece without requiring complex real-time adjustment during manufacturing
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 ensures consistent and accurate color reproduction across LEDs, addressing the issue of off-white emissions and enhancing color fidelity in electronic devices by tailoring the composition and arrangement of light conversion materials for individual LEDs.
Implementation Method 1
In operation, the InGaN base material emits a blue light that stimulates the light conversion material to emit a yellow light
Implementation Method 2
the blue light stimulates the light conversion material to emit a yellow light
Data Source
AI summary
Light emitting diodes and methods for manufacturing light emitting diodes are disclosed herein. In one embodiment, a method for manufacturing a light emitting diode (LED) comprises applying a first light conversion material to a first region on the LED and applying a second light conversion material to a second, different region on the LED. A portion of the LED is exposed after applying the first and second light conversion materials.