Battery Module Bus Bar Soldering for Automated Assembly

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Solution Overview

Problem

The existing battery module assembly process is hindered by the need for manual clamping of flexible circuit boards, difficulty in detecting welding defects, and the inability to perform the strength evaluation of the welded portion, the time required for the strength of the welded portion, the time required for the strength of the welded portion, and the high material and assembly costs due to the use of sensing plates and complex laser welding processes.

Innovation Solution

A battery module design that eliminates the need for welding sensing plates to circuit boards by using a bus bar frame with inner and terminal bus bars, circuit joints, and wires soldered with aluminum, allowing for automated soldering and non-destructive strength evaluation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sensing plates are welded to the flexible circuit board using laser welding, then electrical connection and voltage measurement are enabled, but the flexible circuit board requires manual clamping which increases assembly time and reduces productivity

Engineering Contradiction:
Improvewelding strengthVSAvoidassembly time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent removes the sensing plate component entirely and replaces the laser welding process with soldering. The flexible circuit board is directly soldered to the bus bar without requiring intermediate sensing plates or manual clamping, thereby eliminating the productivity bottleneck while maintaining electrical connection reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical laser welding process with a soldering process. This substitution eliminates the need for manual clamping operations required by laser welding, enabling automated assembly and significantly improving productivity while maintaining reliable electrical connections

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

2Reliability

If sensing plates are welded to the bus bar using laser welding, then electrical connection is established, but welding defects cannot be easily detected and re-welding is difficult due to narrow unwelded portions

Engineering Contradiction:
Improveelectrical connectionVSAvoidre-welding capability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

By eliminating the sensing plate and laser welding process, the patent removes the root cause of the repair difficulty. The soldering process creates larger, more accessible weld areas that can be easily inspected and re-soldered if defects are detected, significantly improving ease of repair

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The soldering process produces visible solder joints with distinct appearance characteristics that facilitate defect detection. The solder material provides visual cues for inspection, making it easier to identify welding defects and determine whether re-soldering is needed

Inventive Principle:
Principle #32Color changes

3Ease of repair

If the area of the sensing plate is increased to facilitate re-welding, then re-welding becomes easier, but the sensing plate undergoes chemical or thermal deformation during laser welding

Engineering Contradiction:
Improvere-welding capabilityVSAvoidsensing plate integrity
Core Design Contradiction:
Ease of repairVSStability of the object's composition

Solution Approach 1:

The patent replaces laser welding with soldering, which operates at lower temperatures and does not cause the chemical or thermal deformation that affects sensing plates. This substitution maintains sensing plate integrity while still enabling easy repair through re-soldering if needed

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

4Strength

If laser welding is used to join metal parts, then strong electrical connection is achieved, but strength evaluation requires destructive testing which increases time and reduces productivity

Engineering Contradiction:
Improvewelded portion strengthVSAvoidevaluation time
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent replaces laser welding with soldering, which creates joints that can be evaluated through non-destructive testing methods. This substitution eliminates the need for destructive strength evaluation, reducing inspection time and improving productivity while maintaining adequate joint strength

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

5Reliability

If sensing plates are used to connect the flexible circuit board to the bus bar, then electrical connection is enabled, but material cost and assembly cost increase

Engineering Contradiction:
Improveelectrical connectionVSAvoidmaterial cost
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent eliminates the sensing plate component entirely, removing the associated material costs. The flexible circuit board is directly soldered to the bus bar, achieving the same electrical connection function without the additional sensing plate material and reducing overall material costs

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the function of the flexible circuit board directly with the bus bar connection through soldering. By combining these components and eliminating the intermediate sensing plate, the patent reduces material costs while maintaining reliable electrical connection

Inventive Principle:
Principle #5Merging (Combining)

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

Reduces assembly time and costs, enables automated soldering, allows for re-soldering of defects, and provides real-time strength evaluation without chemical or thermal deformation, thereby improving efficiency and reducing material usage.

Implementation Method 1

a wire (170) having a first side soldered to the circuit joint (163) and a second side soldered to the first electrode lead (121) or the joint member (180)

Methodology Applied
Scientific EffectSoldering: Soldering

Data Source

PatentEP4675830A1Battery module
Publication Date: 2026.01.07 LG ENERGY SOLUTION LTD
  • EP4675830A1 patent drawingFigure 1
  • EP4675830A1 patent drawingFigure 2
  • EP4675830A1 patent drawingFigure 3~4

AI summary

A battery module is disclosed. The battery module of the present invention includes: a plurality of inner bus bars disposed in the bus bar frame and connected to a first electrode lead and a second electrode lead; a first terminal bus bar disposed in the bus bar frame and connected to the first electrode lead; a second terminal bus bar disposed in the bus bar frame and connected to the second electrode lead having an polarity opposite to the first terminal bus bar; a circuit board provided with a plurality of circuit joints; a joint member bonded to the second terminal bus bar; and a wire soldered to the first electrode lead and the circuit joint, or soldered to the joint member and the circuit joint.