Multi-Layer FFC Cable Assembly for Lightweight High-Current Links

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Solution Overview

Problem

Conventional bus bars used for high voltage and high current applications are heavy and costly, leading to increased weight and material costs in battery packs.

Innovation Solution

A FFC cable assembly comprising a multi-layered FFC cable with insulation and high current terminals, which is lighter and more economical than traditional bus bars while capable of handling high voltage and high current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If bus bars are used for high voltage and high current electrical connections, then sufficient energization capability is achieved, but weight and material cost increase significantly

Engineering Contradiction:
Improveenergization capabilityVSAvoidweight
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The invention divides the electrical connection system into modular FFC cables with integrated conductor wires, insulation layers, and terminal portions. This segmentation allows for optimized material usage and reduced weight compared to traditional solid bus bars, while maintaining the required power transmission capability through multiple parallel conductors.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The FFC cable employs composite material construction with copper or aluminum conductor wires, plastic insulation layers, and protective sheath members. This composite structure provides both the electrical conductivity needed for high power transmission and the mechanical properties for reduced weight and flexibility, resolving the contradiction between power capability and weight.

Inventive Principle:
Principle #40Composite materials

2Power

If bus bars are used for high voltage and high current electrical connections, then sufficient energization capability is achieved, but material cost becomes a considerable burden

Engineering Contradiction:
Improveenergization capabilityVSAvoidmaterial cost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The modular FFC cable structure with standardized insulation layers and terminal portions enables efficient manufacturing processes and material utilization. This segmentation allows for cost-effective production compared to custom-fabricated bus bars, reducing material cost while maintaining high power transmission capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the structural parameters from solid bus bar geometry to multi-conductor FFC cable configuration. This parameter change optimizes the balance between electrical performance and material cost, allowing sufficient energization capability at lower material expense through efficient material distribution and standardized manufacturing.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If multiple bus bars are used in battery pack to provide electrical connections, then adequate electrical connectivity is achieved, but total weight of battery pack increases

Engineering Contradiction:
Improveelectrical connectivityVSAvoidtotal weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention merges multiple conductor wires into a single integrated FFC cable assembly with unified insulation and protective sheath. This merging reduces the total number of separate components needed for electrical connections, thereby reducing total weight while maintaining adequate electrical connectivity through the combined conductor capacity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The composite material construction of FFC cables provides both mechanical strength for reliable connectivity and reduced weight. The plastic insulation and sheath materials offer protection and structural integrity, allowing multiple cables to be used for adequate connectivity without proportionally increasing total weight compared to traditional bus bar assemblies.

Inventive Principle:
Principle #40Composite materials

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 FFC cable assembly effectively reduces the weight and material costs of battery packs while maintaining the ability to handle high voltage and high current, making it a more economical and lightweight alternative to conventional bus bars.

Implementation Method 1

a compression member elastically deformed inside the opening to compress a portion of the conductor wire holder

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The insulation tube may be a thermally shrinkable tube

Methodology Applied
Scientific EffectThermal shrinkage: Thermal Contraction

Data Source

PatentEP3951804B1FFC cable assembly
Publication Date: 2025.01.22 LG ENERGY SOLUTION LTD
  • EP3951804B1 patent drawingFigure 1
  • EP3951804B1 patent drawingFigure 2~3
  • EP3951804B1 patent drawingFigure 4~5

AI summary

Disclosed is a FFC cable assembly, which includes a multi FFC cable having a plurality of FFC films arranged in a layered form and an insulation tube for surrounding the plurality of FFC films; and high current terminals mounted to both ends of the multi FFC cable.