Silicon Wafer Texturization Reduces Fragmentation
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Solution Overview
Problem
Existing methods for texturizing silicon wafers result in high fragmentation rates and inefficiencies during the separation of laminated wafers, leading to waste of etching solutions and increased processing costs due to the need for double-sided texturization and subsequent removal of nano-textured surfaces.
Innovation Solution
A method involving the superimposition of two silicon wafers, where nano-textured surface etching is performed on one side and a nano-textured surface etched strip is created on the edge of the attached surface, allowing for easier separation with reduced fragmentation rates by controlling the etching rate and solution composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If double-sided texturization is performed on silicon wafers, then the photoelectric conversion efficiency is improved, but the etching solution consumption increases and the processing complexity increases
Solution Approach 1:
The patent segments the texturization process by performing nano-textured surface etching only on the exposed surface of the silicon wafer, while the attached surface receives only micro-textured surface etching. This segmentation allows the etching solution to be used selectively where needed for photoelectric conversion, reducing overall solution consumption while maintaining efficiency.
Solution Approach 2:
The patent applies different etching qualities to different surfaces: the exposed surface receives comprehensive nano-textured etching for optimal light absorption, while the attached surface receives only micro-textured etching. This local differentiation maintains photoelectric conversion efficiency where required while reducing unnecessary etching solution usage on the attached surface.
2Reliability
If double-sided texturization is performed on silicon wafers, then the photoelectric conversion efficiency is improved, but the processing steps increase
Solution Approach 1:
The patent merges the texturization process by performing both micro-textured surface etching and nano-textured surface etching in an integrated workflow. The micro-textured etching is performed on both surfaces, and the nano-textured etching is selectively applied to the exposed surface, combining multiple functions into a unified process that reduces overall processing steps.
Solution Approach 2:
The patent performs micro-textured surface etching on both surfaces as a preliminary action before performing nano-textured surface etching only on the exposed surface. This preliminary action prepares both surfaces uniformly, and then the selective nano-texturing is applied only where needed, reducing the total number of processing steps compared to traditional double-sided nano-texturing.
3Loss of substance
If laminated wafers are separated after single-sided texturization, then the etching solution is saved, but the fragmentation rate increases due to strong binding
Solution Approach 1:
The patent applies different surface treatments to different locations: the exposed surface receives full nano-textured etching, while the attached surface receives only micro-textured etching. This creates a local quality difference where the attached surface has reduced binding strength due to the absence of nano-texturing, allowing easy separation while the exposed surface maintains optimal photoelectric conversion efficiency.
Solution Approach 2:
The patent segments the surface treatment by applying micro-textured etching to the attached surface and nano-textured etching to the exposed surface. This segmentation creates a functional differentiation where the attached surface is optimized for easy separation (reduced binding) while the exposed surface is optimized for photoelectric conversion, resolving the contradiction between solution savings and wafer integrity.
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 the binding potential energy between wafers, simplifies the texturization process, and decreases the fragmentation rate during separation, while optimizing the use of etching solutions and improving the efficiency of solar cell production.
Implementation Method 1
performing nano-textured surface etching on the first silicon wafer superimposition structure; providing each silicon wafer with nano-textured surface on the exposed surface thereof and a nano-textured surface etched strip on the edge of the attached surface thereof
Data Source
AI summary
The present disclosure relates to a method for preparing nano-textured surface on single side of a silicon wafer, including the following steps: (1) superimposing two silicon wafers to obtain a first silicon wafer superimposition structure; the side on which the silicon wafers is superimposed is recorded as an attached surface, and the side exposed outside is recorded as an exposed surface; and (2) performing nano-textured surface etching on the first silicon wafer superimposition structure; and providing each silicon wafer with nano-textured surface on the exposed surface and a nano-textured surface etched strip on the edge of the attached surface. In the present disclosure, while the nano-textured surface etching is performed, the edge of the attached surface is etched with nano-textured surface by selecting a specific etching rate, which reduces the pulling force for detaching the wafers and reduces the fragmentation rate during the detaching process.