Battery Module Weld Inspection Using Thermal Difference Imaging

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Solution Overview

Problem

Existing methods are inadequate for easily determining whether electrode terminal welds in battery modules are defective, particularly in cases where wire bonding is used for electrical connections, as they often require additional devices or complex processes.

Innovation Solution

A welding inspection apparatus utilizing a thermal imaging camera that moves over the battery module, capturing images during charging and discharging cycles, and employs a difference image algorithm to determine if weld temperatures fall within a normal range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual inspection methods are used to examine weld quality, then the inspection process is simple, but the detection precision is insufficient and cannot detect internal defects

Engineering Contradiction:
Improvedetection precisionVSAvoidinspection method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple inspection functions into a single integrated device: a visual inspection camera captures surface images, a thermal imaging camera detects temperature distribution, and a gas sensor monitors welding fumes. This merging allows the system to achieve high detection precision for both surface and internal defects while maintaining operational simplicity through unified control and processing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inspection device is designed with multi-functionality to detect various types of defects through different physical principles. The visual camera detects surface geometry and external defects, the thermal camera detects internal voids and cracks through temperature anomalies, and the gas sensor detects welding quality through fume analysis. This universal approach enables comprehensive defect detection without requiring multiple separate inspection systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If thermal imaging camera is added to detect internal defects, then the detection precision improves, but the device complexity increases

Engineering Contradiction:
Improveinternal defect detection capabilityVSAvoidinspection device structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the visual inspection camera and thermal imaging camera into a single integrated inspection device with unified control and processing systems. This combining approach enables the device to perform both surface visual inspection and internal thermal defect detection simultaneously, achieving high detection precision while avoiding the complexity of operating separate inspection systems.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If multiple sensors and cameras are integrated for comprehensive inspection, then the detection precision and reliability improve, but the ease of operation deteriorates

Engineering Contradiction:
Improveinspection reliabilityVSAvoiddevice operation convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent integrates multiple sensors and cameras under a single control system that automatically coordinates their operation. The control unit processes data from all sensors simultaneously and generates unified inspection results, which maintains high inspection reliability through comprehensive data collection while preserving ease of operation through automated control and simplified user interface.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inspection device incorporates feedback mechanisms where the control unit receives data from all sensors, processes the information, and adjusts the inspection parameters automatically. This feedback loop ensures reliable detection by continuously optimizing the inspection process while maintaining ease of operation through automated adjustments without requiring manual intervention.

Inventive Principle:
Principle #23Feedback

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

Enables non-destructive inspection of weld quality by identifying temperature deviations, ensuring rapid and accurate detection of defective welds without damaging the battery module.

Implementation Method 1

a thermal imaging camera configured to capture thermal images of the weld area

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP4327975B1Welding inspection apparatus including thermal imaging camera
Publication Date: 2026.04.29 LG ENERGY SOLUTION LTD
  • EP4327975B1 patent drawingFigure 1
  • EP4327975B1 patent drawingFigure 2~3
  • EP4327975B1 patent drawingFigure 4

AI summary

The present invention relates to a welding inspection apparatus including a base unit configured to dispose thereon a battery module, as an object to be inspected, a positive electrode connector and a negative electrode connector connected so as to charge and discharge the battery module, a thermal imaging camera configured to photograph a weld portion of the battery module, and a driving unit configured to move the thermal imaging camera, wherein it is possible to determine whether the weld portion is defective using a nondestructive inspection method.