Photovoltaic Module Encapsulation for Low-Temperature Welding Contact

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Solution Overview

Problem

The arrangement and welding of electrodes and welding strips in photovoltaic modules affect the efficiency and yield of photovoltaic cells, with conventional high-temperature welding causing warpage and deformation, and low-temperature welding leading to poor contact due to adhesive flow during lamination.

Innovation Solution

A photovoltaic module design using secondary grid lines and low-temperature welding strips, with encapsulation layers having varying flowability to prevent adhesive flow and ensure proper contact, and a method involving lamination at specific temperatures to fix the cells with encapsulation layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If low-temperature welding strips are used, then manufacturing costs are reduced and photoelectric conversion efficiency is improved, but poor contact occurs between the welding strips and electrodes due to adhesive flow during lamination

Engineering Contradiction:
Improvemanufacturing costVSAvoidcontact quality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The encapsulation layer is divided into two sub-layers with different flowability characteristics. The first sub-layer has lower flowability to prevent adhesive from flowing between welding strips and electrodes during lamination, while the second sub-layer has higher flowability to ensure proper bonding. This segmentation resolves the contradiction by allowing low-temperature welding strips to be used without compromising contact quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the flowability parameter of the encapsulation layer by using different materials or formulations for the two sub-layers. The first sub-layer uses material with lower flowability (higher viscosity) to prevent adhesive flow, while the second sub-layer uses material with higher flowability for better bonding, thus resolving the contact quality issue while maintaining low-temperature welding benefits.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional high-temperature welding is used, then reliable contact between welding strips and electrodes is achieved, but warpage and deformation of solar cells occur

Engineering Contradiction:
Improvecontact qualityVSAvoidcell deformation
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent changes the temperature parameter of the welding process by using low-temperature welding strips instead of conventional high-temperature welding. This prevents thermal damage and deformation of solar cells while achieving reliable contact through the specially designed encapsulation layer that prevents adhesive flow during lamination.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a single encapsulation layer is used, then manufacturing process is simple, but adhesive flow causes poor contact between welding strips and electrodes

Engineering Contradiction:
Improveencapsulation structureVSAvoidcontact quality
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The encapsulation layer is segmented into two sub-layers with different flowability characteristics. The first sub-layer has lower flowability to prevent adhesive flow during lamination, ensuring good contact between welding strips and electrodes. The second sub-layer has higher flowability for proper bonding. This segmentation resolves the contradiction between structural complexity and contact quality.

Inventive Principle:
Principle #1Segmentation

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 design reduces manufacturing costs, improves photoelectric conversion efficiency, and enhances the yield and service life of photovoltaic modules by preventing poor contact and ensuring strong bonding.

Implementation Method 1

Each encapsulation layer of the at least one encapsulation layer includes a first encapsulation sub-layer and a second encapsulation sub-layer, the first encapsulation sub-layer is adjacent to the plurality of connection members and portions of the plurality of solar cells not covered by the plurality of connection members, and the second encapsulation sub-layer is on a surface of the first encapsulation sub-layer facing away from the plurality of solar cells, where flowability of the first encapsulation sub-layer is smaller than flowability of the second encapsulation sub-layer

Methodology Applied
Scientific EffectFlowability control:

Implementation Method 2

a method involving lamination at specific temperatures to fix the cells with encapsulation layers

Methodology Applied
Scientific EffectLamination: Lamination

Implementation Method 3

electrodes are used to collect and export electrons generated by the photovoltaic effect

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4401151B1Method for manufacturing a photovoltaic module
Publication Date: 2025.07.09 ZHEJIANG JINKO SOLAR CO LTD
  • EP4401151B1 patent drawingFigure 1A~2
  • EP4401151B1 patent drawingFigure 3~4B
  • EP4401151B1 patent drawingFigure 5~8A

AI summary

A photovoltaic module and a method for manufacturing the photovoltaic module are provided. A respective solar cell has a front surface and a rear surface opposite to the front surface, each of which has a plurality of electrodes formed thereon. Each connection member of the plurality of connection members is configured to connect two adjacent solar cells of the plurality of solar cells and has a first end portion disposed over the front surface of a first solar cell of the two adjacent solar cells and a second end portion disposed over the rear surface of a second solar cell of the two adjacent solar cells. Each encapsulation layer includes a first encapsulation sub-layer and a second encapsulation sub-layer, where flowability of the first encapsulation sub-layer is smaller than flowability of the second encapsulation sub-layer.