PTC Device Direct Connection on Protection Circuit Board
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Solution Overview
Problem
The existing protection circuit boards with PTC devices have low heat transfer efficiency due to indirect connection with the battery cell, leading to performance deterioration and increased internal resistance, and require multi-layered circuit boards for pattern formation, increasing production costs.
Innovation Solution
A protection circuit board with a PTC device directly connected to the electrode terminal of the battery cell via first and second leads, using spot-welding or reflow soldering methods, eliminating the need for an additional electrode lead and enhancing heat transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the PTC device is installed as a single component on the protection circuit board (indirect connection), then the manufacturing process is simplified, but the heat transfer efficiency is low resulting in performance deterioration
Solution Approach 1:
The patent merges the PTC device with the protection circuit board by directly installing the PTC device on the circuit board and electrically connecting it to the battery cell terminals. This integration eliminates the need for separate indirect connection components while maintaining direct thermal and electrical contact with the battery cell, thereby resolving the contradiction between manufacturing simplicity and heat transfer efficiency.
2Area of stationary object
If the protection circuit board uses a multi-layered structure to ensure pattern-forming area, then the pattern design area is sufficient, but the production cost increases
Solution Approach 1:
The patent utilizes the vertical dimension by installing the PTC device upright on the circuit board surface, allowing electrical connection to battery terminals through leads extending from the PTC device. This three-dimensional arrangement enables sufficient pattern design area on a single-layer board, eliminating the need for costly multi-layered structures while maintaining adequate space for circuit patterns.
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
Improved safety performance and reduced internal resistance with increased pattern-forming area on the circuit board, allowing for cost-effective production using fewer layers, thus enhancing the overall efficiency and safety of the battery system.
Implementation Method 1
A PTC device, which has been primarily used as the secondary protection device, is now installed in the form of a single component on the protection circuit board
Implementation Method 2
using spot-welding or reflow soldering methods
Implementation Method 3
using spot-welding or reflow soldering methods
Data Source
AI summary
A protection circuit board, a secondary battery with the protection circuit board, and a battery pack comprising the secondary battery.A PTC device which is a secondary protection device is provided on the protection circuit board, and is installed in electrical connection with an electrode terminal of a bare cell of the secondary battery. According to a structural configuration where the PTC device is electrically connected to the bare cell while being installed on the protection circuit board, the PTC device sensitively responds to temperature changes of the bare cell to thereby cut off a flow of electric current. Due to such a structural configuration of the PTC device, formation of an electrode lead is excluded for electrical connection with the bare cell on the protection circuit board. Consequently, a pattern-forming area which is designed on the protection circuit board increases.