Bent Welding Strip Layout for Crack-Resistant Photovoltaic Modules
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Solution Overview
Problem
Current photovoltaic modules are prone to cracking and fragmentation of solar cell sheets, leading to low yield and high manufacturing costs due to stress issues during the electrical contact process.
Innovation Solution
The use of welding strips with continuous bending portions that act as buffer joints to align with bus bars and bonding pads on the solar cell sheets, releasing stress and improving connection reliability, while ensuring proper electrical contact and reducing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding strips are used to connect solar cell sheets, then electrical contact is achieved, but stress causes cracking and fragmentation of solar cell sheets
Solution Approach 1:
The welding strip is divided into multiple straight portions and multiple bending portions alternately arranged along the width direction. The bending portions are further divided into first bending portions and second bending portions. This segmentation allows the welding strip to flex and release stress during welding, preventing cracking and fragmentation of the solar cell sheets while maintaining reliable electrical contact.
2Reliability
If welding strips with bending portions are used, then stress is released, but manufacturing complexity increases
Solution Approach 1:
The welding strip incorporates bending portions with curved shapes (first bending portions and second bending portions) that allow stress release during welding. These curved portions are strategically positioned between straight portions to provide flexibility while maintaining a relatively simple overall structure that can be manufactured using standard processes.
3Reliability
If welding strips are aligned with bus bars, then electrical contact is improved, but positioning precision requirements increase
Solution Approach 1:
The welding strip features straight portions that are specifically positioned to align with bus bars for optimal electrical contact, while bending portions are located in regions where precise alignment is less critical. This local differentiation allows the welding strip to achieve good electrical contact at key interfaces while tolerating manufacturing variations in other areas.
Data Source
AI summary
The photovoltaic module includes at least one cell string, including multiple solar cell sheets, and adjacent solar cell sheets in the multiple solar cell sheets are connected to each other by multiple welding strips. In some embodiments, the photovoltaic module further includes multiple welding strips, where each of the multiple welding strips is in electrical contact with a corresponding bus bar, each of the multiple welding strips includes multiple bending portions arranged continuously along a second direction. In addition, along the second direction, an orthographic projection of a central line of each of the multiple welding strips on a back surface of the solar cell sheet coincides with an orthographic projection of a central line of the corresponding bus bar and/or an orthographic projection of a central line of each of the multiple bonding pads on the corresponding bus bar on the back surface of the solar cell sheet.