Battery Fuse Insulating Substrate Heat Accumulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional protection elements for battery packs fail to efficiently transfer heat from a heating resistor to a low-melting-point metal body, leading to ineffective shutdown of the charging/discharging electric current path during abnormal states like overcharging or overdischarging due to the use of low-thermal-conductivity glass insulating layers and high-thermal-conductivity alumina substrates.
Innovation Solution
A protection element structure with a heating resistor on an insulating substrate, a low-melting-point metal body above the resistor, and connection portions with a third insulating layer between the substrate and the metal body, which suppresses heat radiation to the substrate, allowing efficient heat accumulation and quick fusion of the metal body to shut down the current path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If glass insulating layers are used between the heating resistor and low-melting-point metal body, then electrical insulation is provided, but heat transfer efficiency deteriorates due to low thermal conductivity
Solution Approach 1:
The insulating structure is segmented into two distinct layers: a first insulating layer made of glass material providing electrical insulation, and a second insulating layer made of ceramic material providing both insulation and superior heat transfer. This segmentation allows each layer to optimize its material properties for its specific function.
Solution Approach 2:
The patent employs a composite insulating structure combining glass and ceramic materials. The glass-ceramic composite provides both the electrical insulation properties of glass and the high thermal conductivity of ceramic, resolving the contradiction between insulation and heat transfer efficiency.
2Strength
If alumina substrate is used for the insulating substrate, then mechanical strength and electrical insulation are improved, but heat transfer to the metal body deteriorates due to high thermal conductivity causing heat loss
Solution Approach 1:
The patent applies local quality by using alumina substrate only in regions where mechanical strength and electrical insulation are required, while employing ceramic insulating layers specifically in the heat transfer path from the heating resistor to the low-melting-point metal body. This localized material selection optimizes both structural support and thermal efficiency.
Solution Approach 2:
The ceramic insulating layer acts as an intermediary between the alumina substrate and the low-melting-point metal body, providing a thermal bridge that efficiently conducts heat from the heating resistor to the metal body while the alumina substrate provides structural support without directly interfering with the primary heat transfer path.
3Ease of manufacture
If the protection element structure is simplified, then manufacturing cost is reduced, but heat transfer path efficiency deteriorates leading to slower response time
Solution Approach 1:
The patent optimizes the spatial arrangement of insulating layers in the vertical dimension, positioning the high-thermal-conductivity ceramic layer directly in the heat transfer path between the heating resistor and low-melting-point metal body. This dimensional optimization ensures efficient heat transfer without adding horizontal complexity to the manufacturing process.
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 design enables rapid and efficient shutdown of the charging/discharging path by effectively accumulating heat in the low-melting-point metal body, reducing power consumption, and allowing for a smaller, more efficient protection element.
Implementation Method 1
an excessive current flows through the heating resistor 102, the current is controlled by the current control element so as to flow from the battery cell to the heating resistor 102 so that the low-melting-point metal body 104 is fused by heat generated from the heating resistor 102
Implementation Method 2
the low-melting-point metal body 104 is fused by heat generated from the heating resistor 102, thereby shutting down the charging/discharging electric current path
Data Source
AI summary
A protection element, connected onto an electric current path of an electric circuit, is provided with an insulating substrate, a heating resistor formed on one surface of the insulating substrate with a first insulating layer interposed therebetween, a low-melting-point metal body disposed above the heating resistor with a second insulating layer interposed therebetween and that constitutes part of the electric current path, and connection portions connected to both ends of the low-melting-point metal body and that electrically connect the electric current path and the low-melting-point metal body. The connection portions are formed on the surface of the insulating substrate with a first glass layer interposed therebetween.