Planar Disc Fuse Layout for Compact Battery Cell Isolation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing circuit protection devices for battery packs, such as PTC devices and fuse devices, have limitations including low hold currents, inability to permanently disable faulty cells, and increased size, which are not effectively addressed in addressing overcurrent conditions in battery cells.

Innovation Solution

A disc fuse design featuring an electrically insulating substrate with conductive terminals and fusible elements that provide overcurrent protection by allowing high hold currents during normal operation and permanently disabling faulty cells, while maintaining a compact size by using an electrically insulating substrate and conductive vias for connection, with a conformal coating for protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If larger protection devices are used to handle high currents, then overcurrent protection capability is improved, but battery pack size increases

Engineering Contradiction:
Improveovercurrent protection capabilityVSAvoidbattery pack size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The invention replaces bulky mechanical fuse structures with a compact planar design using thin-film or laminated fusible elements on an insulating substrate. This substitution of the mechanical system with a more integrated structure dramatically reduces the volume required for high-current protection while maintaining the necessary protection capability.

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

Solution Approach 2:

The fuse device transitions from a three-dimensional bulky structure to a two-dimensional planar configuration. The fusible elements are arranged in a flat layout on the insulating substrate, allowing high-current handling capability to be achieved through increased surface area rather than increased volume, thus reducing the overall space required in the battery pack.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If conventional fuse structures are used, then current interruption is achieved, but the device complexity and space requirements increase

Engineering Contradiction:
Improvecurrent interruption capabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple functional elements are merged into a single integrated structure. The insulating substrate simultaneously provides mechanical support, electrical insulation, and structural stability. The fusible elements are directly connected to terminals without requiring separate mounting hardware or complex assembly, simplifying the overall device structure while maintaining effective current interruption capability.

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

The disc fuse effectively arrests excessive current and permanently disables faulty battery cells, providing robust overcurrent protection without increasing the size of the battery pack, ensuring device safety and efficiency.

Implementation Method 1

a fuse portion extending from the inner edge, the fuse portion comprising a fusible element

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

the via provides an electrical connection between the first terminal and the contact pad

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3588622B1Disc fuse
Publication Date: 2023.10.18 LITTELFUSE INC
  • EP3588622B1 patent drawingFigure 1A~1B
  • EP3588622B1 patent drawingFigure 1C
  • EP3588622B1 patent drawingFigure 2

AI summary

A disc fuse including an electrically insulating substrate having a via formed therethrough extending between a first surface and a second surface of the substrate, an electrically conductive first terminal disposed on the first surface of the substrate, and an electrically conductive second terminal disposed on the second surface of the substrate, the second terminal including an outer portion having an inner edge defining a through-hole in the second terminal, the second terminal further including a fuse portion extending from the inner edge, the fuse portion comprising a fusible element terminating in a contact pad, wherein the substrate provides an electrically insulating barrier between the first terminal and the second terminal and wherein the via provides an electrical connection between the first terminal and the contact pad.