Photovoltaic Module Assembly for Back-Contact Cell Warpage Control

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Solution Overview

Problem

Back-contact cells experience warping and cracking due to stress from single-side welding of solder strips on the back side, leading to reduced yield and increased manufacturing costs.

Innovation Solution

A method involving pre-curing an adhesive layer between a front plate and cells before connecting them with solder strips, followed by applying a second adhesive layer and a back plate to form a photovoltaic module, thereby preventing warping and cracking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If single-side welding of solder strips is used on back-contact cells, then manufacturing process is simplified, but cell warping and cracking occur due to stress

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidcell structural integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The adhesive layer is applied and cured on the front side of the cell before the solder strip welding process. This preliminary action provides stress compensation that prevents warping and cracking during subsequent single-side welding operations on the back side.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

An adhesive layer is introduced as an intermediary element between the cell structure and the welding process. This adhesive layer acts as a stress buffer that compensates for the thermal and mechanical stress generated during single-side solder strip welding, preventing cell damage while maintaining manufacturing simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If adhesive layer is applied before welding, then cell warping and cracking are prevented, but manufacturing process complexity increases

Engineering Contradiction:
Improvecell structural integrityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The adhesive layer application process is merged with the existing front side processing steps. The adhesive is applied and cured during the same manufacturing sequence as other front side operations, before the cells are flipped for back side welding, thereby integrating the stress compensation function without adding separate process steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The curing parameters of the adhesive layer (temperature, time, humidity) are optimized to match the existing manufacturing process parameters. By adjusting the adhesive curing conditions to align with standard production parameters, the process complexity is minimized while maintaining effective stress compensation.

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

The method effectively prevents cell warping and cracking, improving the yield and reducing manufacturing costs by stabilizing the cells during the assembly process.

Implementation Method 1

pre-curing the first adhesive layer between the front plate and the plurality of cells

Methodology Applied
Scientific EffectCuring:

Implementation Method 2

curing the second adhesive layer between the back plate and the plurality of cell strings

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP4376101B1Method for manufacturing photovoltaic module
Publication Date: 2026.03.04 JINKO SOLAR (HAINING) CO LTS
  • EP4376101B1 patent drawingFigure 1
  • EP4376101B1 patent drawingFigure 2
  • EP4376101B1 patent drawingFigure 3

AI summary

A method for manufacturing a photovoltaic module and a photovoltaic module are provided. The method includes: laying a front plate, a first adhesive layer on the front plate, and a plurality of cells on the first adhesive layer, and pre-curing the first adhesive layer between the front plate and the plurality of cells; forming a plurality of cell strings by connecting the plurality of cells through a plurality of solder strips after the first adhesive layer is pre-cured; and laying a second adhesive layer on the plurality of cell strings, laying a back plate on the second adhesive layer, and curing the second adhesive layer between the back plate and the plurality of cell strings, to form the photovoltaic module.