Busbar Solder Pin Connection for Reworkable Battery Modules

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Solution Overview

Problem

Existing battery modules face challenges in efficiently and cost-effectively connecting bus bars and voltage sensing members, particularly in terms of quality control and the inability to rework or replace defective components without discarding the entire battery cell.

Innovation Solution

The battery module employs a solder pin connection method, where a solder pin with a base portion and a hole insert portion is inserted into a pin hole on the bus bar, allowing for easy connection and disconnection without welding, thereby facilitating quality control and rework.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laser welding is used to connect the sensing member to the bus bar, then electrical connection is achieved, but quality control becomes difficult and rework is impossible

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidrework capability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The connection structure is segmented into modular components: a sensing member, a bus bar with a through-hole, and a fastening element. This segmentation allows the sensing member to be independently installed, inspected, and replaced without affecting the bus bar or requiring welding operations, thereby enabling rework while maintaining reliable electrical connection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the laser welding process (thermal/mechanical system) with a mechanical fastening system using a fastening element inserted through a hole. This substitution eliminates the quality control difficulties and irreversibility of welding while providing reliable electrical connection through direct mechanical and electrical contact.

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

2Reliability

If laser welding is used to connect the sensing member to the bus bar, then electrical connection is achieved, but manufacturing cost and quality control difficulty increase

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidquality control ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the complex laser welding process with a simple mechanical insertion process. The fastening element is inserted through a pre-formed hole in the bus bar, creating both mechanical and electrical connection. This dramatically simplifies manufacturing, eliminates the need for expensive laser equipment and skilled operators, and enables straightforward quality inspection through visual confirmation of insertion.

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

Solution Approach 2:

The fastening element serves as a simple, inexpensive component that can be easily replaced if defective. This approach trades the high cost and complexity of laser welding for a low-cost mechanical solution that prioritizes ease of manufacture and quality control.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Adaptability or versatility

If the sensing member is defective, then replacement is needed, but the entire battery cell must be discarded with conventional welding methods

Engineering Contradiction:
Improvecomponent replaceabilityVSAvoidbattery cell waste
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The connection structure is designed as separable modules: the sensing member can be independently removed from the bus bar by extracting the fastening element. This segmentation enables replacement of only the defective sensing member while preserving the battery cell and bus bar, eliminating the waste associated with conventional welding methods where the entire assembly must be discarded.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent enables recovery and reuse of the bus bar and other components when the sensing member is defective. By using a non-permanent mechanical connection instead of welding, the system allows selective replacement of only the faulty component, thereby reducing material waste and improving sustainability.

Inventive Principle:
Principle #34Discarding and recovering

4Reliability

If conventional welding methods are used to connect bus bars and sensing members, then electrical connection is established, but the connection process is time-consuming and complex

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidassembly speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the time-consuming laser welding process with a rapid mechanical insertion process. The fastening element is simply inserted through a pre-formed hole in the bus bar to establish both mechanical and electrical connection with the sensing member. This eliminates the heating, cooling, and quality inspection time required for welding, dramatically increasing assembly speed while maintaining reliable electrical connection.

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 connection method enables rapid and easy assembly of bus bars and voltage sensing members, enhances quality control by simplifying the connection process, and allows for rework and replacement of defective components without discarding the entire battery cell.

Implementation Method 1

a solder pin 60 configured to be inserted into the pin hole 32 of the bus bar 30

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4135114B1Battery module comprising solder pin for connection to busbar and battery pack including same
Publication Date: 2025.06.11 LG ENERGY SOLUTION LTD
  • EP4135114B1 patent drawingFigure 1
  • EP4135114B1 patent drawingFigure 2~3
  • EP4135114B1 patent drawingFigure 4~5

AI summary

Disclosed is a battery module, which includes battery cells connected in series or connected in series and in parallel; a plurality of bus bars connected to corresponding electrode leads of the battery cells; and a voltage sensing member having sensing parts respectively connected to the bus bars, wherein each of the plurality of bus bars has a pin hole perforated therethrough in a thickness direction, and each of the sensing parts has a solder pin configured to be inserted into and released from the pin hole.