LED Wafer Cutting with Variable Beam Water-Jet Laser
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Solution Overview
Problem
Existing light-emitting diode (LED) manufacturing methods do not effectively create a light-emitting element with a shaped side surface that enhances light extraction and structural integrity, limiting the efficiency and durability of LED devices.
Innovation Solution
A method involving a wafer-level process where a water-jet laser with varying beam sizes is used to cut a wafer, forming a light-emitting element with a side surface comprising first and second arc portions and a transition portion, allowing for the creation of light-emitting dies with specific curvature profiles that enhance light extraction and structural support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional LED manufacturing methods are used, then production is simpler and faster, but light extraction efficiency and structural integrity are insufficient
Solution Approach 1:
The patent applies curvature to the side surface of the LED device by forming arc portions (first and second arcs) with specific radii of curvature. This curved geometry improves light extraction efficiency by reducing total internal reflection at the side surfaces, while the specific design parameters (arc radii, transition portions) maintain structural integrity during the wafer-level manufacturing process
2Reliability
If conventional flat side surfaces are used, then manufacturing is easier, but light extraction efficiency is limited
Solution Approach 1:
The patent implements curved side surfaces with specific geometric parameters (first arc portion with radius R1, second arc portion with radius R2, and transition portions connecting them). This curvature design enhances light extraction by modifying the escape cone angle and reducing total internal reflection, while the precise geometric control is achieved through wafer-level processing techniques
Solution Approach 2:
The patent optimizes specific geometric parameters including the radii of curvature (R1, R2) of the arc portions, the angles of the transition portions, and the depth of the curved structures. These parameter variations allow tuning of light extraction efficiency while maintaining compatibility with standard manufacturing processes
3Manufacturing precision
If wafer-level cutting is performed with single beam size, then process is simpler, but shaped side surfaces with specific curvature cannot be formed
Solution Approach 1:
The patent uses a water jet laser system with variable beam size to create precisely controlled arc portions on the wafer. By adjusting the beam size during cutting, the system forms the first and second arc portions with specific radii of curvature, enabling accurate reproduction of the desired curved side surface geometry in the final LED devices
Solution Approach 2:
The patent employs dynamic parameter changes during the cutting process, specifically varying the water jet laser beam size to create different curvature radii. The beam size is adjusted to form the first arc portion with radius R1, then modified to create the second arc portion with radius R2, allowing precise control over the side surface geometry
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 method enables the production of light-emitting elements with improved light extraction and structural integrity, leading to enhanced performance and reliability in LED devices.
Implementation Method 1
cutting the wafer from one of the bottom surface or the top surface of the wafer by a water-jet laser having a first beam size; cutting the wafer from the other one of the bottom surface or the upper surface of the wafer by the water-jet laser having a second beam size
Data Source
AI summary
A method for manufacturing a light-emitting element, including steps of: providing a wafer-level element including a wafer and a light-emitting stack on the wafer, wherein the wafer including an upper surface and a bottom surface, and light-emitting stack is formed on the upper surface of the wafer; forming a light-emitting stack on the upper surface of the wafer; cutting the wafer from one of the bottom surface or the top surface of the wafer by a water-jet laser having a first beam size; cutting the wafer from the other one of the bottom surface or the upper surface of the wafer by the water-jet laser having a second beam size; and dividing the wafer-level element wafer and the light-emitting stack into a plurality of light-emitting dies.