Overlapping Solar Cell String Connectors for Low-Stress Assembly
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Solution Overview
Problem
Existing solar cell string production methods are costly and prone to mechanical stress, leading to increased contact resistance and potential cell breakage due to the use of rigid connectors, which also require a minimum distance between cells, limiting flexibility and efficiency.
Innovation Solution
A method involving a solar cell stack with overlapping cells, where two electrically conductive connecting elements are used to form connections between adjacent cells, allowing for a more flexible and cost-effective series connection with pliant connectors that reduce mechanical loading and enable closer cell spacing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rigid cell connectors are used to electrically conductively connect solar cells, then reliable electrical connection is achieved, but mechanical stress leads to increased contact resistance and cell breakage
Solution Approach 1:
The patent replaces rigid cell connectors with flexible connecting elements made of thin metal foils (aluminum or copper, 5-50 μm thick). These flexible connectors adapt to thermal expansion and mechanical stresses without transmitting excessive forces to the solar cells, thereby preventing contact resistance increases and cell breakage while maintaining reliable electrical connections.
Solution Approach 2:
The patent changes the physical parameters of the connectors from rigid to flexible by using thin metal foils with specific thickness ranges (5-50 μm). This parameter change allows the connectors to deform elastically under mechanical stress, absorbing thermal and mechanical loads without compromising electrical conductivity or damaging the solar cells.
2Stability of the object's composition
If thick rigid cell connectors are used to ensure mechanical stability, then structural stability is improved, but the minimum distance between adjacent solar cells increases
Solution Approach 1:
The patent uses thin flexible metal foils (5-50 μm thick) as connecting elements, which are significantly thinner than traditional rigid connectors. These thin flexible connectors provide sufficient mechanical stability through their flexibility and adaptability, while their reduced thickness allows solar cells to be positioned closer together, decreasing the minimum distance between adjacent cells.
3Reliability
If multiple individual cell connectors are used to connect each pair of solar cells, then reliable electrical connection is achieved, but production complexity and costs increase
Solution Approach 1:
The patent merges multiple individual cell connector functions into a single continuous flexible connecting element that spans multiple solar cells. This single element is divided into multiple connection zones, each providing reliable electrical connection between adjacent cells. This merging approach simplifies the production process by reducing the number of separate components to be handled and assembled.
Solution Approach 2:
The patent employs preliminary action by providing the flexible connecting element in a continuous form before the actual connection process. The connecting element is pre-positioned across multiple solar cells in a stacked arrangement, and then divided into functional segments during the connection process. This preliminary preparation simplifies the overall production workflow and reduces manufacturing complexity.
4Stability of the object's composition
If solar cells are arranged with minimum distance for rigid connector accommodation, then mechanical stability is maintained, but production cost and complexity increase
Solution Approach 1:
The patent uses thin flexible metal foils that require minimal space between solar cells due to their reduced thickness and flexibility. This allows for closer cell spacing while maintaining mechanical stability through the flexible connectors' ability to adapt to thermal and mechanical stresses, thereby reducing production costs and simplifying manufacturing processes.
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 results in a robust, cost-effective solar cell string with reduced contact resistance and increased flexibility, enabling closer cell spacing and improved mechanical stability while maintaining efficient electrical connections.
Implementation Method 1
the electrically conductive connections of the first and the second connecting element to the solar cells are formed by means of laser radiation
Implementation Method 2
the first and the second connecting element are divided and the first and the second connecting element are electrically conductively connected to the solar cells by means of laser radiation
Data Source
AI summary
A method for producing a solar cell string includes:providing a solar cell stack having at least five solar cells which each have a front side and a rear side, the solar cells are arranged in overlapping fashion; andforming electrically conductive connections between the solar cells by:arranging an electrically conductive first connecting element on the solar cell stack and forming electrically conductive connections;dividing the first connecting element into a first group of cell connectors;arranging an electrically conductive second connecting element on the solar cell stack and forming electrically conductive connections; anddividing the second connecting element into a second group of cell connectors.