Solar Module Laminated Back Sheet With Elastic Buffer Layer

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Solution Overview

Problem

Conventional solar power generation devices experience gaps and delamination between the fiber-containing sheet and the back sheet due to differing thermal expansion coefficients, leading to instability and reduced power generation efficiency, especially when flexible materials are used.

Innovation Solution

A laminated body comprising an installation surface, an elastic body, and a back sheet, where the elastic body is placed between the fiber-containing sheet and the back sheet, allowing for three-dimensional deformation to accommodate thermal expansion, thereby reducing shear stress and preventing gaps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If flexible resin materials are used for the back sheet to ensure flexibility and portability, then the solar power generation device becomes lighter and more portable, but thermal expansion/contraction causes greater deformation and delamination due to high linear expansion coefficient

Engineering Contradiction:
ImproveflexibilityVSAvoidstability
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

An elastic body is introduced as an intermediary layer between the back sheet and the fiber-containing sheet. This elastic body has a linear expansion coefficient between those of the back sheet and the fiber-containing sheet, acting as a buffer that reduces thermal stress and prevents delamination while allowing the back sheet to maintain its flexibility

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The linear expansion coefficient of the elastic body is specifically selected to be between the linear expansion coefficients of the back sheet and the fiber-containing sheet. This parameter optimization creates a gradient structure that gradually transitions thermal expansion properties, reducing stress concentration and preventing delamination

Inventive Principle:
Principle #35Parameter changes

2Strength

If the solar power generation device is fixed to the fiber-containing sheet using adhesive, then the device is secured in place, but large shear stress from thermal expansion difference causes delamination and gap formation

Engineering Contradiction:
Improvefixation strengthVSAvoidlong-term stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The elastic body serves as a mediator between the back sheet and the fiber-containing sheet, reducing the thermal stress transmitted to the adhesive layer. This intermediary structure allows the adhesive to maintain strong fixation without experiencing damaging shear stress from thermal expansion differences

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastic body provides beforehand cushioning by absorbing and distributing thermal stress before it reaches the adhesive layer. This pre-cushioning effect prevents the adhesive from failing due to thermal cycling, ensuring long-term stability of the fixation

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

3Strength

If fixing means such as piles are used to secure the device, then mechanical fixation is achieved, but wind enters gaps to cause vibration and damage to power generation cells and wiring

Engineering Contradiction:
Improvemechanical fixationVSAvoidwind-induced vibration
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The elastic body acts as a sealing intermediary that fills and seals the gap between the back sheet and the fiber-containing sheet. This elastic sealing layer prevents wind from entering the gap and causing vibration, while still allowing the fixing means to provide mechanical fixation

Inventive Principle:
Principle #24Intermediary (Mediator)

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 laminated structure stabilizes the solar power generation device by minimizing gaps and delamination, ensuring long-term fixation and maintaining power generation efficiency.

Implementation Method 1

the elastic body having a longitudinal elastic modulus of 0.1 MPa or greater and 1000 MPa or less

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the back sheet and the installation surface have different linear expansion coefficients

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4580041A1Laminated body and solar power generation system
Publication Date: 2025.07.02 SEKISUI CHEMICAL CO LTD
  • EP4580041A1 patent drawingFigure 1~3
  • EP4580041A1 patent drawingFigure 4
  • EP4580041A1 patent drawingFigure 5(A)~5(C)

AI summary

Provided is a laminated body that includes an installation surface and a back sheet constituting a bottom section of a solar power generation device and in which a gap is unlikely to occur between the installation surface and the back sheet. A laminated body 1 of the present invention includes an installation surface 3, an elastic body 4, and a back sheet 6 constituting a bottom section of a solar power generation device 5. The elastic body 4 is fixed in a state placed on the installation surface 3. The back sheet 6 is fixed in a state placed on an upper surface of the elastic body 4.