Faraday Box Plasma Etching for Depth-Graded Grating Patterns
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Solution Overview
Problem
The challenge in manufacturing diffraction grating light guide plates is the formation of needle-like structures during the plasma etching process, which hinders precise pattern formation in the mold creation.
Innovation Solution
A plasma etching method using a Faraday cage with a mesh part and a shutter that gradually changes the etching depth by moving the shutter from the outer to the central portion of the cage, inhibiting the formation of needle-like structures and enabling precise pattern formation on the etching base.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If plasma etching is performed on an etching base to form a diffraction grating pattern, then the mold for diffraction grating light guide plate can be manufactured, but needle-like structures (grass) are formed in the pattern portion section, making it difficult to precisely form the desired pattern
Solution Approach 1:
The invention divides the Faraday cage into multiple segments: a main body portion and a mesh portion that can be independently adjusted. By segmenting the Faraday cage structure, the patent enables independent optimization of the mesh portion to control plasma distribution, thereby preventing needle-like structure formation while maintaining pattern formation precision
Solution Approach 2:
The invention introduces a movable shutter that can dynamically adjust the plasma distribution across the etching base during the etching process. By moving the shutter to shield different regions, the patent dynamically controls the plasma flux to prevent grass formation in pattern portions while maintaining etching precision
2Manufacturing precision
If a Faraday cage with mesh part is used for plasma etching, then needle-like structure formation is inhibited, but the device complexity increases due to the need for shutter mechanism and mesh structure
Solution Approach 1:
The Faraday cage design integrates multiple functions into a single structure: the mesh portion simultaneously serves as a plasma distribution controller and a structural component, while the shutter mechanism provides both plasma shielding and pattern definition capabilities. This multi-functionality reduces the need for separate components, thereby managing device complexity while achieving precise pattern formation
Solution Approach 2:
The invention changes the physical parameters of the Faraday cage, specifically introducing a mesh structure with specific aperture sizes and a shutter mechanism with controllable positioning. By optimizing these parameters, the patent achieves precise plasma control to prevent needle-like structures without requiring excessive structural complexity
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 effectively prevents the formation of needle-like structures and allows for the easy creation of pattern portions with depth gradients on the etching base, enhancing the precision and efficiency of the plasma etching process.
Implementation Method 1
performing plasma etching on the etching base
Implementation Method 2
providing an etching base in a Faraday cage having a mesh part provided on an upper side thereof
Data Source
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AI summary
The present application relates to a plasma etching method using a faraday box, comprising the steps of: providing a base material for etching in the faraday box having a mesh part provided on the upper surface thereof; shielding at least a portion of the mesh part with a shutter, and then performing plasma etching on the base material for etching; and forming a pattern part on the base material for etching by performing plasma etching while moving the shutter in the direction from the outer part of the faraday box to the center part thereof, wherein the depth of the pattern part gradually changes in the direction from one side of the base material for etching to the other side thereof.