LED Phosphor Deposition for White Light Color Correction
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Solution Overview
Problem
Conventional methods for producing white light using LEDs often result in off-white emissions due to variances in InGaN LED wavelengths, leading to reduced color fidelity in electronic devices.
Innovation Solution
A microelectronic workpiece processing system that measures and maps emission characteristics of InGaN LEDs, develops a recipe for converter materials based on these measurements, and adjusts the application of converter materials to match the emission wavelengths, ensuring accurate color correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single converter material is deposited on InGaN base material, then the manufacturing process is simple, but the color fidelity is reduced due to off-white emissions
Solution Approach 1:
The patent applies different converter materials to different regions or layers of the LED structure. Specifically, it uses a first converter material (yellow-emitting phosphor) and a second converter material (red-emitting phosphor) in different configurations, where each material is selectively applied to achieve optimal color correction in its respective region, thereby improving overall color fidelity while maintaining manufacturing feasibility
Solution Approach 2:
The patent employs composite phosphor structures by combining multiple converter materials with different emission characteristics. The composite structure includes both yellow-emitting and red-emitting phosphors that work together to correct the blue emission from InGaN, producing a more accurate white light output than single-material converters could achieve alone
2Manufacturing precision
If converter material is applied to correct color, then color fidelity improves, but the device complexity increases due to multiple material applications
Solution Approach 1:
The patent incorporates color correction measures during the initial LED manufacturing process rather than as a separate post-processing step. The converter materials are deposited on the InGaN base material during the same fabrication sequence, performing the color correction action in advance and integrating it into the base manufacturing flow, which reduces overall system complexity
Solution Approach 2:
The patent merges the color correction function with the existing LED structure by integrating converter materials directly into the LED device architecture. The phosphors are incorporated into the same package and optical path as the InGaN chip, combining the light emission and color correction functions into a single integrated device rather than requiring separate correction components
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
The system effectively reduces off-white color production by selectively applying converter materials, achieving closer alignment with true white light emissions and improving color fidelity.
Implementation Method 1
the InGaN base material emits a blue light that stimulates the converter material to emit a yellow, green, orange, amber, or red light
Data Source
AI summary
Several embodiments of semiconductor systems and associated methods of color corrections are disclosed herein. In one embodiment, a method for producing a light emitting diode (LED) includes forming an (LED) on a substrate, measuring a base emission characteristic of the formed LED, and selecting a phosphor based on the measured base emission characteristic of the formed LED such that a combined emission from the LED and the phosphor at least approximates white light. The method further includes introducing the selected phosphor onto the LED via, for example, inkjet printing.