Back-Contact Solar Cell Module With Parallel Leads
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Solution Overview
Problem
Existing back-contact solar cell technologies face challenges in efficiently connecting cells in series due to light shielding by gate lines, high production costs, and complexity in the preparation process, particularly for larger silicon wafers, which results in reduced efficiency and increased series resistance.
Innovation Solution
A main-gate-free back-contact solar cell module with P-electrodes and N-electrodes connected to a electrical connection layer via parallel leads, using dotted or linear electrodes made of silver paste, conductive adhesive, or tin solder, with a conductive adhesive layer and anti-oxidation plating, and busbar electrodes arranged on both sides, allowing for multi-point connections and reduced series resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gate lines are placed on the front side of the cell to collect current, then carrier collection efficiency is improved, but light shielding occurs reducing effective light-receiving area
Solution Approach 1:
The patent inverts the conventional electrode placement by moving all electrodes from the front side to the back side of the solar cell. This back-contact configuration eliminates front-side gate lines that shield light, allowing 100% of the front surface to receive sunlight while maintaining effective current collection through the inverted electrode architecture.
2Strength
If thick tin-plated copper band is used for serial connection, then mechanical strength is improved, but cell cracking occurs due to excessive hardness
Solution Approach 1:
The patent replaces the thick, hard tin-plated copper band with a thin, flexible tin-plated copper foil that is softer and more compliant. This thinner connection material, while mechanically weaker individually, provides sufficient strength when combined with the distributed back-contact electrode architecture, and its flexibility prevents cell cracking during installation and operation.
3Reliability
If thin but wide tin-plated copper band is used for serial connection, then cell cracking is avoided, but sunlight shielding increases causing optical loss
Solution Approach 1:
By inverting the electrode configuration to back-contact, the patent eliminates the need for front-side connection bands entirely. The thin tin-plated copper foil is placed only on the back side, making it invisible to incident sunlight and eliminating optical shielding losses while maintaining mechanical reliability through the back-contact architecture.
4Reliability
If conventional conductive backing composite material with laser etching is used, then electrical connection is achieved, but production efficiency is low and cost is high
Solution Approach 1:
The patent extracts and eliminates the complex laser etching and chemical corrosion processes from the conventional conductive backing material preparation. Instead, it uses a simplified screen-printing method to directly form the back-contact electrodes and connection structures in a single step, dramatically improving production efficiency while maintaining electrical connection quality.
Solution Approach 2:
The patent replaces expensive conductive backing composite materials requiring laser etching with inexpensive screen-printed conductive paste structures. This substitution eliminates the need for expensive equipment and complex processing steps, reducing both material costs and production complexity while achieving reliable electrical connections.
5Manufacturing precision
If precise punching of packaging material is performed to penetrate conductive adhesive, then electrical connection precision is improved, but production complexity increases
Solution Approach 1:
The patent extracts and eliminates the precise punching step from the packaging material processing. By using screen-printed conductive paste that forms its own pattern, the method eliminates the need for pre-punched holes in the packaging material, simplifying the production process while maintaining precise electrical connections through the printed conductor geometry.
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 solution enhances efficiency by eliminating light shielding, reduces production costs, and increases the tolerance to hidden-cracks and micro-cracks, resulting in improved power generation and stability of the photovoltaic system.
Implementation Method 1
conductive adhesive layer
Implementation Method 2
conductive adhesive
Implementation Method 3
anti-oxidation plating
Implementation Method 4
solar power generation is a process of power generation in which large-area P-N junction diodes are used to produce photon-generated carries under the radiation of sunlight
Data Source
AI summary
The present invention relates to the field of solar cells, and in particular to a main-gate-free and high-efficiency back-contact solar cell module, a main-gate-free and high-efficiency back-contact solar cell assembly, and a preparation process thereof. The solar cell module, comprising cells and an electrical connection layer, a backlight side of the cells having P-electrodes connected to a P-type doping layer and N-electrodes connected to a N-type doping layer, is characterized in that the electrical connection layer comprises a number of parallel leads each electrically connected to the P-electrodes or the N-electrodes. The present invention has the beneficial effect that a main-gate-free and high-efficiency back-contact solar cell module, a main-gate-free and high-efficiency back-contact solar cell assembly, and a preparation process thereof are provided, which can effectively the short-circuiting of the P-electrodes and the N-electrodes and has the advantages of low cost, high hidden-cracking resistance, high efficiency and high stability.