Replication Material Removal via Selective Illumination
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Solution Overview
Problem
In replication processes, unwanted replication material often spreads across substrate surfaces, leading to mechanical stress, warping, delamination, and cosmetic issues, which can impair device functionality and fabrication precision.
Innovation Solution
A method involving imprinting a replication material on a substrate, exposing it to illumination through a masking layer to create a predetermined characteristic, and selectively removing the unexposed portion using a solvent, thereby maintaining the structure and reducing material spread.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If replication material is pressed into substrate surface, then predetermined structure is formed, but material spreads across substrate surface causing mechanical stress and warping
Solution Approach 1:
The patent removes unwanted replication material from portions of the substrate surface after imprinting. This extraction of excess material eliminates the source of mechanical stress and warping while preserving the imprinted structures that provide optical functionality.
Solution Approach 2:
The patent performs selective removal of replication material before dicing the substrate. This preliminary action prevents mechanical stress and warping from affecting subsequent dicing operations and final device performance.
2Manufacturing precision
If replication material is pressed into substrate surface, then predetermined structure is formed, but delamination occurs
Solution Approach 1:
The patent extracts unwanted replication material that causes delamination. By removing material from portions where it would create stress concentrations and adhesion failures, the reliability of the imprinted structures is improved.
3Manufacturing precision
If replication material is pressed into substrate surface, then predetermined structure is formed, but cosmetic issues occur
Solution Approach 1:
The patent removes unwanted replication material that causes cosmetic defects such as excess material visible on the substrate surface. This extraction improves the aesthetic appearance while maintaining the functional imprinted structures.
4Object-affected harmful factors
If unwanted replication material is removed, then mechanical stress and warping are reduced, but additional processing steps are required
Solution Approach 1:
The patent uses a solvent as an intermediary to selectively remove unwanted replication material. The solvent enables easy removal of excess material without requiring complex mechanical or thermal processing steps.
Solution Approach 2:
The patent changes the chemical state of the replication material by applying a solvent, transforming it from a solid polymer network to a dissolved state that can be easily removed. This parameter change enables selective removal with simple processing.
5Manufacturing precision
If illumination is applied through masking layer, then selective modification is achieved, but process complexity increases
Solution Approach 1:
The patent uses a masking layer as an intermediary to control which portions of replication material are exposed to illumination. The masking layer enables precise selective modification without requiring complex direct patterning methods.
Solution Approach 2:
The patent replaces mechanical patterning with optical patterning through illumination through the masking layer. This substitution enables more precise and flexible pattern definition compared to purely mechanical methods.
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 reduces mechanical stress, delamination, and cosmetic issues, enhancing device functionality and precision by ensuring the replication material retains its structure and maintains optical functionality, while allowing for precise light interaction and improved mechanical robustness.
Implementation Method 1
The replication material may include a cross-linked polymer network formed by photopolymerisation upon exposure to ultraviolet illumination
Implementation Method 2
The solvent selectively dissolves the second portion of the replication material that is not exposed to the illumination
Data Source
AI summary
A method includes pressing a face of a stamp into a first portion of a replication material disposed on a substrate, to cause the replication material to have a predetermined characteristic, exposing the first portion of the replication material to illumination, to modify the first portion of the replication material, and subsequently removing a second portion of the replication material that was not exposed to the illumination. An optical device includes a substrate, a portion of replication material disposed on a first surface of the substrate, the portion of replication material forming one or more diffractive optical elements, and a masking layer disposed on a second surface of the substrate, the second surface being opposite the first surface, in which a sidewall of the replication material has a straight profile, and in which the masking layer defines an aperture aligned with the portion of the replication material.