Solar Cell Module Wrinkle Prevention via Back-Side Sheet Elongation

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Solution Overview

Problem

The use of a front-side transparent protective member with non-planar surfaces of different surface areas in solar cell module manufacturing often results in wrinkles on the back-side protective sheet member due to thermal contraction and breaking elongation issues.

Innovation Solution

The method involves using a back-side protective sheet member with a thermal contraction rate of 1% or more and a breaking elongation of 300% or more, which is not preheated or pre-thermally contracted, to prevent wrinkles by allowing it to contract and elongate during the lamination process, respectively, while using a front-side transparent protective member with a surface area larger than its projected area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a front-side transparent protective member with non-planar shape and larger surface area is used, then the protective member can provide better protection and aesthetic appearance, but wrinkles are likely to occur on the back-side protective sheet member

Engineering Contradiction:

Improvenon-planar shape of front-side transparent protective memberVSAvoidwrinkle occurrence on back-side protective sheet member

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The patent changes the thermal contraction rate parameter of the back-side protective sheet member to 1% or more, which allows the material to accommodate the non-planar shape of the front-side transparent protective member during lamination without generating wrinkles. This parameter change transforms the material's thermal response to match the geometric requirements.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary thermal action by heating the back-side protective sheet member before lamination to promote thermal contraction. This preliminary heating action prepares the material in advance to contract and conform to the non-planar shape, preventing wrinkle formation during the subsequent lamination process.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If the back-side protective sheet member has high thermal contraction rate, then wrinkles can be inhibited, but the material may become too rigid or difficult to process

Engineering Contradiction:

Improvewrinkle inhibition on back-side protective sheet memberVSAvoidprocessability of back-side protective sheet member

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent introduces dynamic control by applying heat temporarily during the lamination process to activate thermal contraction only when needed. The back-side protective sheet member maintains its high thermal contraction rate capability but remains flexible during processing, contracting dynamically in response to localized heating at the lamination interface rather than being permanently rigid.

Inventive Principle:

Principle #15Dynamics

3Manufacturing precision

If the back-side protective sheet member has high breaking elongation, then it can accommodate shape variations without wrinkling, but the material may require more energy to process or control

Engineering Contradiction:

Improvewrinkle prevention through elongation capabilityVSAvoidenergy consumption during lamination process

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces mechanical stretching or forcing methods with thermal energy substitution. Instead of applying mechanical force to stretch the back-side protective sheet member to match the non-planar shape, the process uses thermal energy to induce controlled contraction, leveraging the material's high breaking elongation property through temperature-dependent dimensional changes rather than mechanical work.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach effectively inhibits the occurrence of wrinkles on the back-side protective sheet member, ensuring a smooth and wrinkle-free solar cell module manufacturing process.

Implementation Method 1

the back-side protective sheet member has a thermal contraction rate of 1% or more

Methodology Applied

Scientific EffectThermal contraction: Thermal Contraction

Implementation Method 2

sealing the solar cell in a bonding layer

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS9666740B2Solar cell module manufacturing method

Publication Date: 2017.05.30 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A solar cell module manufacturing method includes: preparing a front-side transparent protective member and a back-side protective sheet member, the front-side transparent protective member including a first principal surface and a second principal surface, a surface area of at least the first principal surface being larger than a projected area of the first principal surface, the back-side protective sheet member including a third principal surface and a fourth principal surface; and disposing a solar cell between the second principal surface of the front-side transparent protective member and the third principal surface of the back-side protective sheet member, and sealing the solar cell with a bonding layer therebetween. A breaking elongation of the back-side protective sheet member is 300% or more.