Photovoltaic Module Solder Strip Layout for Micro-Crack Reduction

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Solution Overview

Problem

Photovoltaic modules face issues with micro-cracks due to the mismatched thickness of solder strips and adhesive layers, leading to power attenuation and increased production costs, as well as inefficiencies in space utilization and crack prevention during lamination.

Innovation Solution

The implementation of a photovoltaic module design that limits the thickness ratio range of the adhesive layer to match the solder strip size, using thinner solder strips with a flat section to reduce pressure on solar cells and incorporate a reflective section for efficient light utilization, thereby minimizing micro-cracks and power loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the thickness of the protective adhesive layer is increased to prevent micro-cracks, then the reliability of the solar cell is improved, but the manufacturing cost increases and the power generation efficiency decreases due to thicker non-active layers

Engineering Contradiction:
Improvemicro-crack preventionVSAvoidpower generation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies parameter changes by precisely controlling the thickness of the protective adhesive layer within a specific range (0.3mm to 0.6mm) and matching it with corresponding solder strip thickness parameters (0.2mm to 0.4mm). This optimized parameter combination ensures adequate crack prevention while minimizing the impact on power generation efficiency, resolving the contradiction between reliability and productivity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the thickness of the protective adhesive layer is decreased to improve power generation efficiency, then the productivity is improved, but the reliability decreases due to increased risk of micro-cracks

Engineering Contradiction:
Improvepower generation efficiencyVSAvoidmicro-crack prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent establishes specific parameter ranges for the protective adhesive layer thickness (0.3mm to 0.6mm) and solder strip thickness (0.2mm to 0.4mm), creating an optimized parameter combination that balances power generation efficiency with micro-crack prevention, thereby resolving the contradiction between productivity and reliability.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the solder strip thickness is increased to strengthen the connection between solar cells, then the strength is improved, but the harmful factors increase due to greater pressure on the solar cell surface causing micro-cracks

Engineering Contradiction:
Improveconnection strengthVSAvoidmicro-crack risk
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent optimizes the solder strip thickness parameter within the range of 0.2mm to 0.4mm, balancing the connection strength between solar cells with the pressure exerted on the solar cell surface. This parameter optimization ensures adequate mechanical strength while minimizing micro-crack risk, resolving the contradiction between strength and harmful factors.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces the protective adhesive layer as a cushioning element between the solder strip and the solar cell surface. This layer absorbs and distributes the pressure from the solder strip before it reaches the solar cell, providing beforehand cushioning that prevents micro-cracks while maintaining connection strength, thereby resolving the contradiction between strength and harmful factors.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Reliability

If the thickness of the protective adhesive layer is increased to ensure adequate protection, then the reliability is improved, but the device complexity increases due to stricter thickness matching requirements

Engineering Contradiction:
Improvecrack protectionVSAvoidthickness matching complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent defines specific parameter ranges for the protective adhesive layer thickness (0.3mm to 0.6mm) and solder strip thickness (0.2mm to 0.4mm), creating a standardized parameter system that simplifies the thickness matching process. These defined ranges reduce the complexity of design and manufacturing while ensuring adequate crack protection, resolving the contradiction between reliability and device complexity.

Inventive Principle:
Principle #35Parameter changes

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 effectively reduces micro-crack rates and power attenuation, enhances space utilization, and lowers production costs by ensuring a reasonable match between adhesive layer thickness and solder strip size, while maintaining high power output and reliability.

Implementation Method 1

a reflective section and a flat section, the reflective section is arranged on a surface of the solar cell... the reflective section can efficiently reflect light incident on its surface to the front surface of the solar cell

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

A protective adhesive layer is respectively arranged between the solar cell string and the transparent plate and between the solar cell string and the back plate... the protective adhesive layer can prevent micro-cracks caused by lamination pressure directly transferred through the solder strip

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP4120368B1Photovoltaic module
Publication Date: 2023.11.29 SHANGHAI JINKO GREEN ENERGY ENTERPRISE MANAGEMENT CO LTD
  • EP4120368B1 patent drawingFigure 1
  • EP4120368B1 patent drawingFigure 2~3
  • EP4120368B1 patent drawingFigure 4~5

AI summary

Provided are a photovoltaic module, comprising a solar cell string, the solar cell string comprising a plurality of solar cells arranged in sequence, adjacent solar cells being connected by solder strips, the solder strip being connected to a front surface of one solar cell and to a back surface of the other solar cell, a long-side dimension of the solar cell being within a range of 150mm to 220mm; two protective adhesive layers respectively covering front and back surfaces of the solar cell string, a dimensional difference between a thickness of one protective adhesive layer and a thickness of the solder strip being defined as a first thickness, a ratio of the first thickness to the thickness of one protective adhesive layer being not less than 0 and not greater than 20%; a transparent plate covering a surface of the protective adhesive layer on the front surface of the solar cell string; and a back plate covering a surface of the protective adhesive layer on the back surface of the solar cell string. The present disclosure can match the thickness of the adhesive layer with the size of the solder strip reasonably, thereby improving the protective effect of the protective adhesive layer.