Substrate-Free Optical Filter Structure for Flatness and Strength
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Solution Overview
Problem
Traditional optical filters using dielectric materials face issues with warping due to stress between the dielectric stack layer and substrate, leading to reduced yield and incompatibility with miniaturization and automated production, especially when bonded to miniaturized optical elements.
Innovation Solution
A method involving a substrate with trenches is used to form a solidified structure by depositing a sacrificial layer and dielectric stack layers, followed by removing the substrate, enhancing structural strength and flatness while reducing volume, suitable for miniaturized elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a substrate is used to support the dielectric stack layer, then structural strength is improved, but the optical filter warps due to stress between different materials
Solution Approach 1:
The patent removes the substrate entirely from the optical filter structure, extracting only the essential dielectric stack layer to form a standalone optical filter. This eliminates the stress-induced warping problem caused by material incompatibility between substrate and dielectric layer, while the edges of the dielectric stack layer are solidified to provide necessary structural strength.
Solution Approach 2:
The patent applies solidified structure specifically at the edges of the dielectric stack layer rather than using a uniform substrate throughout. This local reinforcement provides structural strength where needed (at the edges for handling and mounting) while maintaining overall flatness and eliminating substrate-related stress in the central optical area.
2Shape
If the substrate thickness is increased to maintain flatness, then flatness is improved, but the volume of the optical filter increases
Solution Approach 1:
By removing the substrate entirely and relying on the solidified edge structure to provide necessary mechanical support, the patent eliminates the need for thick substrates. This reduces the optical filter volume to only the essential dielectric stack layer thickness, enabling bonding with miniaturized optical elements while maintaining adequate flatness through the solidified edge configuration.
3Adaptability or versatility
If the area of the optical filter is reduced for miniaturized elements, then adaptability is improved, but the cut portion becomes easy to damage
Solution Approach 1:
The patent pre-solidifies the edges of the dielectric stack layer during the deposition process itself, creating a reinforced edge structure before any cutting or miniaturization operations. This preliminary reinforcement ensures that even when the optical filter is cut to small sizes for miniaturized elements, the edges remain structurally strong and resistant to damage.
4Productivity
If traditional cutting method is used to reduce optical filter area, then productivity is improved, but the cut portion is easy to be damaged
Solution Approach 1:
The solidified edge structure is created during the deposition process before cutting operations. This preliminary reinforcement allows subsequent cutting and miniaturization to proceed with high productivity while maintaining structural integrity, as the edges are already strengthened and resistant to damage during handling and processing.
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 produces a substrate-free optical filter with improved structural strength, flatness, and reduced volume, enabling automated production and bonding to miniaturized elements through transfer printing.
Implementation Method 1
The sacrificial layer is removed with a solvent to separate the at least one prototype optical filter from the substrate
Implementation Method 2
The fixed layer is irradiated with light to separate the optical filter from the fixed layer
Implementation Method 3
A thermal evaporation deposition process is performed on the substrate to deposit a sacrificial layer on the at least two regions
Data Source
AI summary
The present disclosure relates to an optical filter and a method of producing the same. In the producing method, a thermal evaporation deposition process of a sacrificial layer, and depositions process of a base layer and a dielectric stack layer are sequentially performed on a substrate having a trench with a specific width, so that the base layer and the dielectric stack layer extend outward to form a solidified structure with a specific length. Next, a fixed layer is affixed to the dielectric stack layer, and the sacrificial layer is removed using a solvent to remove the substrate. As such, structural strength and flatness of the produced optical filter are enhanced, and a volume thereof is reduced, such that the optical filter can be applied to automated processes of miniaturized elements.