Fluoropolymer Thick-Film PTC Resistor Composition for High Voltage Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing PTC circuits face issues such as resistance shift stability, powered on/off cycling inconsistency, sensitivity to adhesives, and inadequate performance under high voltages, which hinder their functionality in applications like electric vehicle battery heating films.
Innovation Solution
A polymer thick film PTC carbon resistor composition comprising a fluoropolymer resin, organic solvent, and oxidized carbon black is developed, with specific properties to achieve a resistivity of at least 65,000 ohm/sq/25 μm, suitable for high voltage applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional PTC circuits are used, then basic functionality is achieved, but sensitivity to adhesive increases
Solution Approach 1:
The patent modifies the chemical parameters of the composition by incorporating fluoropolymer resin with specific properties that reduce adhesive sensitivity. The organic solvent system and oxidized carbon black formulation create a matrix that is less sensitive to adhesive variations, thereby improving ease of operation without compromising reliability.
2Power
If conventional PTC circuits are used, then standard voltage operation is achieved, but high voltage performance deteriorates
Solution Approach 1:
The patent changes the electrical parameters of the composition by using oxidized carbon black with controlled surface area and oxygen content, which improves charge distribution and reduces electrical breakdown. This enables the PTC circuit to operate reliably under high voltage conditions (exceeding 300V) while maintaining standard voltage functionality.
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 composition ensures stable resistivity and consistent performance under high voltages, addressing the limitations of existing PTC circuits and enabling their use in high voltage applications.
Implementation Method 1
The composition exhibits a resistivity of at least 65,000 ohm/sq/25 μm when dried for a time of about 1 minute to about 24 hours at a temperature of about 90° C. to about 210° C.
Implementation Method 2
The composition exhibits a resistivity of at least 65,000 ohm/sq/25 μm when dried for a time of about 1 minute to about 24 hours at a temperature of about 90° C. to about 210° C.
Data Source
AI summary
A polymer thick film positive temperature coefficient carbon resistor composition is provided. The composition includes an organic medium including a fluoropolymer resin and an organic solvent The composition includes a conductive carbon powder. The composition exhibits a resistivity of at least 65,000 ohm/sq/25 μm when dried for a time of about 1 minute to about 24 hours at a temperature of about 90° C. to about 210° C. Methods for forming a positive temperature coefficient circuit are also provided.