Three-Layer Co-Extruded Solar Backplate for Heat and Strength

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Solution Overview

Problem

Existing solar cell module backboards have poor heat conduction efficiency, low reflective rate, low UV resistance, high water vapor permeation, and are expensive, leading to reduced power generation efficiency and difficulty in repair.

Innovation Solution

A three-layer co-extruded solar cell module backboard using dynamic crosslinking extrusion technology, with a crosslinked polymer alloy core layer and co-extruded crosslinked polymer alloy outer and inner layers, enhancing heat resistance, mechanical strength, and environmental protection performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a backboard is made thicker to improve mechanical strength, then strength is improved, but heat conduction efficiency deteriorates and heat resistance becomes poorer

Engineering Contradiction:
Improvemechanical strengthVSAvoidheat resistance
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent employs a three-layer composite structure consisting of a fluorine-containing film layer, a PET base layer, and a polyamide surface layer. Each layer contributes specific properties: the fluorine-containing film provides heat resistance and low friction, the PET layer provides mechanical strength and dimensional stability, and the polyamide layer provides UV resistance and surface durability. This composite structure achieves both high mechanical strength and good heat resistance without requiring increased thickness.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If the backboard uses conventional materials and structure, then manufacturing is simpler, but reflective rate is low affecting power generation efficiency

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidpower generation efficiency
Core Design Contradiction:
Ease of manufactureVSPower

Solution Approach 1:

The patent applies local quality enhancement by incorporating a fluorine-containing film layer specifically on the rear surface of the backboard. This layer provides high reflective rate (80% or more) in specific wavelength ranges, directly improving light reflection to the solar cells and thereby enhancing power generation efficiency. The fluorine-containing film is applied only where needed for reflection, while other layers handle structural and protective functions.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If conventional surface materials are used, then manufacturing cost is lower, but UV resistance is low causing material to pulverize, yellow, crack and age early

Engineering Contradiction:
Improvemanufacturing costVSAvoidUV resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses a polyamide resin as the surface layer material, which inherently provides excellent UV resistance, hydrolysis resistance, and weatherability. The polyamide layer is specifically designed to protect the backboard from environmental degradation including UV-induced pulverization, yellowing, and cracking. This material selection balances durability requirements with manufacturing feasibility.

Inventive Principle:
Principle #40Composite materials

4Ease of manufacture

If conventional film materials are used, then manufacturing is easier, but water vapor permeation rate is high causing PID phenomenon

Engineering Contradiction:
Improvemanufacturing easeVSAvoidwater resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent employs a multi-layer composite structure where the fluorine-containing film layer and polyamide surface layer both contribute to low water vapor permeation. The fluorine-containing film provides a hydrophobic barrier, while the polyamide layer provides molecular-level water vapor resistance. This composite approach achieves water vapor permeation rates below 50 g·mm/m²·day, preventing PID phenomenon while maintaining manufacturing feasibility through established lamination processes.

Inventive Principle:
Principle #40Composite materials

5Device complexity

If conventional adhesive bonding is used to composite three layers, then manufacturing process is simpler, but the backboard becomes expensive and repair is difficult

Engineering Contradiction:
Improvemanufacturing process complexityVSAvoidrepairability
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The patent integrates the three layers (fluorine-containing film, PET base layer, and polyamide surface layer) into a single composite backboard structure that functions as one unified component. This integration improves repairability compared to separate adhesive-bonded layers, as the co-extruded or co-laminated structure creates stronger inter-layer bonding without requiring additional adhesive materials that can fail over time. The unified structure eliminates adhesive degradation issues and simplifies replacement rather than repair scenarios.

Inventive Principle:
Principle #5Merging (Combining)

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

The solution provides improved water resistance, higher reflective rate, better long-term aging resistance, and environmental protection performance, along with lower costs and enhanced mechanical strength, compared to prior art.

Implementation Method 1

the fluorine-containing film has a reflective rate of 80% or more in specific wavelength ranges

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

the UV resistance is low, so the material of the surface layer of the cell piece is pulverized too early, yellows, cracks, ages and fails

Methodology Applied
Scientific EffectUV absorption: Absorption (EM radiation)

Implementation Method 3

the water vapor permeation rate is high, so a Potential Induced Degradation (PID) phenomenon is caused

Methodology Applied
Scientific EffectWater vapor permeation resistance: Permeation

Data Source

PatentEP3252832B1Co-extruded one-time formed backplate having three-layer structure for solar cell module
Publication Date: 2022.05.11 CYBRID TECHNOLOGIES INC
  • EP3252832B1 patent drawingFigure 1
  • EP3252832B1 patent drawingFigure 2
  • EP3252832B1 patent drawing

AI summary

The present invention discloses a co-extruded one-time-formed solar cell module backboard in a three-layer structure. The backboard is formed by co-extruding three layers: a middle layer located in the middle as well as an outer layer and an inner layer located at two sides of the middle layer, and has high water resisting capability, high reflective rate, good long-term aging resistance performances of hydrolysis resistance, UV resistance and heat resistance and good recoverability and environmental protection performance. Compared with the prior art, the backboard has better water resisting ability, higher reflectivity, better long-term aging resistance performances of hydrolysis resistance, UV resistance and heat resistance, better recoverability and environmental protection performance and lower cost. Compared with a backboard in a co-extruded structure in the prior art, the backboard of the present invention has better heat resistance, better dimensional stability and higher mechanical breaking strength.