Capacitor Film Composition for High-Temperature Breakdown and Winding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitors, particularly those for automotive applications, face challenges with safety function operability and dielectric breakdown strength at high temperatures, and thin films used in these capacitors suffer from winding misalignment issues during manufacturing.
Innovation Solution
A film comprising syndiotactic polystyrene resin and polyphenylene ether resin with titanium oxide particles, where the syndiotactic polystyrene content is 50% or higher and polyphenylene ether content is 10% or higher, and titanium oxide particles are present in a specific concentration range, or the film has a reduced peak height of 0.05 μm to 0.30 μm, enhancing safety function operability and dielectric breakdown strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the film surface is roughened to improve safety function operability, then the safety function operability is improved, but the dielectric breakdown strength decreases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the reduced peak height Spk within the range of 0.05 μm to 0.30 μm. This optimized parameter range creates surface roughness that improves safety function operability while avoiding excessive roughness that would reduce dielectric breakdown strength. The specific quantitative control of surface morphology parameters resolves the contradiction between safety and dielectric strength.
Solution Approach 2:
The patent uses a composite resin system combining syndiotactic polystyrene (50-85 mass%) with polyphenylene ether (10-45 mass%). This composite material structure provides both the mechanical properties needed for surface roughness control and the dielectric properties needed to maintain high breakdown strength despite surface roughening. The synergistic combination of these two polymers resolves the contradiction between safety function and dielectric strength.
2Volume of moving object
If the film thickness is reduced to meet smaller size requirements, then the capacitor size is reduced, but the element-winding suitability deteriorates with winding misalignment
Solution Approach 1:
The patent applies parameter changes by optimizing the reduced peak height Spk to 0.05-0.30 μm, which creates controlled surface roughness that improves winding alignment. This surface morphology control compensates for the reduced thickness, allowing thin films to maintain good element-winding suitability during the winding process while achieving compact capacitor sizes.
Solution Approach 2:
The patent applies local quality by creating specific surface roughness characteristics (controlled Spk) only at the film surface while maintaining uniform thickness and composition throughout. This localized surface modification improves winding suitability without affecting the overall film thickness, enabling compact capacitors with good manufacturing precision.
3Temperature
If higher heat resistance is required for automotive capacitor applications, then the heat resistance is improved, but the safety function operability and dielectric breakdown strength at high temperatures are compromised
Solution Approach 1:
The patent uses a composite material system of syndiotactic polystyrene and polyphenylene ether that maintains thermal stability while ensuring safety function operability at high temperatures. The specific composition range (50-85 mass% syndiotactic polystyrene, 10-45 mass% polyphenylene ether) provides both heat resistance and reliable safety function operation in automotive temperature conditions.
Solution Approach 2:
The patent applies parameter changes by optimizing the surface morphology (Spk: 0.05-0.30 μm) and composition ratios to ensure that safety function operability is maintained at high temperatures. The controlled surface roughness and specific polymer composition work together to provide both thermal stability and reliable safety function operation in high-temperature automotive environments.
Data Source
AI summary
An object is to provide a film that provides a capacitor excellent in safety function operability, and that has a high level of dielectric breakdown strength at high temperatures and good element-winding suitability. The object is achieved by a film containing a syndiotactic polystyrene resin and a polyphenylene ether resin, the content of the syndiotactic polystyrene resin in the film being 50 mass % or higher, the content of the polyphenylene ether resin in the film being 10 mass % or higher, wherein (A) the film contains titanium oxide particles as inorganic particles, and the content of the titanium oxide particles in the film is 0.55 mass % or higher and 3 mass % or lower, and/or (B) at least one surface of the film has a reduced peak height Spk of 0.05 μm or more and 0.30 μm or less.