Photovoltaic Cell String Repair Using Localized Solder-Strip Heating

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Solution Overview

Problem

The existing manual repair methods for photovoltaic cell strings are inefficient, costly, and lack automation, leading to low yield and poor accuracy in replacing defective cells.

Innovation Solution

A device and method that uses a conveying system with a baking device to heat and separate protruding solder strips, allowing for automated desoldering and resoldering of defective cells, incorporating a fixing device for precise alignment and a control system for optimized heat application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual repair methods are used for photovoltaic cell strings, then operators can directly remove defective cells and install new ones, but the repair efficiency is low and productivity is reduced

Engineering Contradiction:
Improverepair efficiencyVSAvoidmanual operation level
Core Design Contradiction:
ProductivityVSExtent of automation

Solution Approach 1:

The patent replaces manual mechanical operations with an automated heating system. The baking device uses thermal energy to melt solder strips, automatically separating defective cells from the string without requiring manual desoldering tools or operations. This substitution of mechanical manual work with thermal automation directly addresses the contradiction by improving repair efficiency while reducing manual operation levels.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes the phase transition of solder from solid to liquid state through heating. The baking device heats the solder strip connecting defective cells to the photovoltaic string, causing it to melt and separate automatically. This phase transition mechanism enables automated cell removal without manual intervention, thereby improving productivity while reducing the extent of manual automation required.

Inventive Principle:
Principle #36Phase transitions

2Reliability

If manual desoldering and resoldering processes are used, then defective cells can be replaced, but the repair cost increases and yield decreases

Engineering Contradiction:
Improverepair yieldVSAvoidrepair process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the heating function into a dedicated baking device that can be integrated into the existing conveyor system. By separating the thermal separation function from manual operations, the device simplifies the overall repair process while improving reliability. The extracted heating mechanism automatically melts and separates defective cells, reducing process complexity and increasing repair yield without requiring complex manual dexterity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If automated heating is used to separate solder strips, then repair efficiency improves, but energy consumption increases

Engineering Contradiction:
Improverepair speedVSAvoidheating energy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial heating action by using the baking device to heat only the specific solder strip regions where defective cells need to be separated, rather than heating the entire photovoltaic string. This localized thermal application improves repair speed by targeting only necessary areas, thereby reducing overall energy consumption while maintaining high productivity. The heating is applied excessively only where needed for separation, not uniformly across the entire string.

Inventive Principle:
Principle #16Partial or excessive action

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 enhances repair efficiency and accuracy, reducing costs and improving yield by automating the process of replacing defective cells in photovoltaic cell strings.

Implementation Method 1

The baking device is configured to heat the photovoltaic cell string located on the second conveying component, so that a protruding solder strip of a solar cell in the photovoltaic cell string is separated or fused at its connecting part

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The press tool is configured to compress the photovoltaic cell string against a non-defective solar cell for replacement at a position of the protruding solder strip and the corresponding back side

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP4113636B1Device and method for repairing photovoltaic cell string
Publication Date: 2024.02.07 JINKO SOLAR CO LTD
  • EP4113636B1 patent drawingFigure 1
  • EP4113636B1 patent drawingFigure 2
  • EP4113636B1 patent drawingFigure 3

AI summary

Provided is a device and method for repairing photovoltaic cell string. The device for repairing photovoltaic cell string includes: a conveying device and a baking device. The conveying device is configured to drive a photovoltaic cell string placed on the conveying device to reciprocate along a first direction. The conveying device includes a first conveying component, a second conveying component and a third conveying component separately arranged. The baking device is arranged toward the second conveying component. The baking device is configured to heat the photovoltaic cell string located on the second conveying component, so that a protruding solder strip of a solar cell on the photovoltaic cell string is separated or fused at its connecting part.