Wafer-Level Wavelength Converting Layer Deposition for LED Uniformity
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Solution Overview
Problem
Current wavelength converting material deposition processes, such as chip or package level processing, result in inconsistent CIE coordinates and color temperature (CCT) that are difficult to control, leading to variations in optical properties of light-emitting devices like LEDs.
Innovation Solution
A method for depositing a wavelength converting layer, comprising wavelength converting materials like phosphors mixed with binders like Spin-on-glass, directly onto the light-emitting surface of LEDs using techniques like spin coating, ink-jet printing, or screen printing, allowing for uniform thickness and controlled optical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If chip or package level processing is used for wavelength converting material deposition, then the process is simple and easy to implement, but the CIE coordinates and color temperature become inconsistent and difficult to control
Solution Approach 1:
The patent applies preliminary action by performing wavelength converting material deposition at the wafer level before chip packaging, establishing uniform material distribution early in the manufacturing process. This preliminary deposition on wafers ensures consistent CIE coordinates and color temperature across all chips derived from the same wafer, resolving the inconsistency issue while maintaining manufacturing simplicity.
Solution Approach 2:
The patent changes the deposition parameter scale from chip/package level to wafer level, transforming the process from discrete individual deposition to continuous大面积 deposition. This parameter change enables better control over material thickness and distribution uniformity, directly improving CIE coordinates consistency and color temperature control.
2Ease of manufacture
If chip or package level processing is used for wavelength converting material deposition, then the process is simple, but the fabrication cycle becomes longer
Solution Approach 1:
The patent merges multiple discrete deposition operations into a single wafer-level deposition process. Instead of depositing wavelength converting material on each individual chip or in separate package-level steps, the process deposits material across entire wafers in one operation, significantly reducing fabrication cycle time while maintaining ease of manufacture.
Solution Approach 2:
By performing deposition at the wafer level before packaging, the patent executes the wavelength converting material application in advance during the semiconductor fabrication process. This preliminary action eliminates subsequent deposition steps that would extend the fabrication cycle, thereby improving productivity.
3Ease of manufacture
If chip or package level processing is used for wavelength converting material deposition, then the process is simple, but material loss increases
Solution Approach 1:
The patent changes the deposition area parameter from small chip/package surfaces to large wafer surfaces. This parameter change improves material utilization efficiency by reducing the number of discrete deposition events and associated handling losses, thereby minimizing wavelength converting material loss while keeping the process simple.
Solution Approach 2:
The patent combines multiple small-scale deposition operations into one large-scale wafer-level operation. This merging reduces material loss by eliminating repeated handling, positioning, and deposition setup that occur in chip-level or package-level processing, thereby improving material efficiency.
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 enables consistent and controlled deposition of wavelength converting materials, reducing discrepancies in CIE coordinates and CCT, shortening fabrication cycles, and minimizing material loss, while maintaining high uniformity and thickness precision.
Implementation Method 1
Wavelength-converting regions can absorb light from a light-generating region (e.g., semiconductor region within an LED) and emit light having a different wavelength
Data Source
AI summary
Wavelength converting light-emitting devices and methods of making the same are provided. In some embodiments, the devices include a phosphor material region designed to convert the wavelength of emitted light.