Clonal Growth of Single-Crystal Copper Foil via Annealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current industrial copper foils are typically polycrystalline, with high defect densities and limited electrical and thermal conductivity, hindering the full utilization of copper's superior performance.
Innovation Solution
A method for clonal growth of single-crystal copper foil involves placing a small single-crystal copper foil on a larger polycrystal copper foil and subjecting them to an annealing process in a controlled atmosphere, transforming the polycrystal foil into a large-sized single-crystal foil with the same surface index.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polycrystal copper foil is used for industrial applications, then production cost and ease of manufacture are improved, but electrical and thermal conductivity are reduced due to high defect density and grain boundaries
Solution Approach 1:
The invention changes the crystal structure parameter from polycrystalline to single-crystalline by controlling the annealing process. By heating the polycrystal copper foil to high temperature (above recrystallization temperature) and maintaining it for a specific time, the material transforms from a polycrystalline state with many grain boundaries to a single-crystal state with no grain boundaries, thereby improving electrical and thermal conductivity while maintaining ease of manufacture through a relatively simple heat treatment process
Solution Approach 2:
The invention utilizes the phase transition of copper from polycrystalline structure to single-crystal structure during annealing. By controlling the temperature and time parameters, the material undergoes a structural phase transition where multiple small crystals merge into one large single crystal, eliminating grain boundaries and defects that hinder conductivity, thus resolving the contradiction between ease of manufacture and electrical/thermal performance
2Reliability
If single-crystal copper foil is produced to eliminate grain boundaries and defects, then electrical and thermal conductivity are improved, but production complexity and cost increase
Solution Approach 1:
The invention applies preliminary action by using a seed crystal or template with the desired single-crystal orientation before the actual growth process. The seed crystal is placed on the polycrystal copper foil, and during annealing, the single-crystal structure propagates from the seed, guiding the transformation and ensuring the final product has the required single-crystal structure with high conductivity, while keeping the process relatively simple
Solution Approach 2:
The invention uses an intermediary approach by introducing a seed crystal or orientation template as a mediator during the annealing process. This intermediary element guides the crystal growth and ensures the formation of a large-area single crystal from polycrystal material, simplifying the production process while achieving high conductivity without requiring complex equipment or multiple processing steps
3Area of stationary object
If large-area single-crystal copper foil is produced directly, then area and performance are improved, but manufacturing difficulty and cost increase significantly
Solution Approach 1:
The invention applies segmentation by dividing the large-area single-crystal production into two stages: first, creating a small single-crystal seed or template; second, using this seed to guide the transformation of the entire large-area polycrystal foil into a single crystal. This segmentation allows the complex task of producing large-area single crystal to be broken down into manageable steps, maintaining ease of manufacture while achieving large area and high performance
Solution Approach 2:
The invention uses copying by creating a small single-crystal template or seed that serves as a model, then copying this crystal structure across the entire large-area foil during annealing. The seed crystal's atomic arrangement is replicated throughout the material, producing a large-area single crystal with the desired orientation and properties, thereby simplifying manufacturing while achieving large area and superior performance
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 produces large-area single-crystal copper foils with reduced defects and superior performance, expanding the area by approximately 3000 times while reducing preparation costs and simplifying the process.
Implementation Method 1
annealing to transform the first polycrystal copper foil into a large-sized second single-crystal copper foil having the same surface index as the first single-crystal copper foil by cloning with the small-sized first single-crystal copper foil as a clone matrix
Data Source
AI summary
A method for clonal-growth of a single-crystal metal, including: using copper as an example, placing an existing small-sized single-crystal copper foil with a plane of any index on a copper foil that needs to be single-crystallized, and performing annealing to obtain, by cloning, a large-area (in meters) single-crystal copper foil with the same surface index as that of the parent facet. The method solves the difficult problem of large-area single-crystal copper foil preparation. By performing annealing, a parent single-crystal copper foil with a very small size (˜0.25 cm2) can be cloned to produce a large-area (˜700 cm2) single-crystal copper foil, which is an increase in area of about 3000 times.