Polymeric Monolithic Capacitor High-Temperature Stability
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Solution Overview
Problem
Current capacitors, such as metallized film capacitors and ceramic multilayer capacitors, face limitations in high temperature, high ripple current, and high voltage applications due to size, weight, and reliability issues, with existing technologies unable to efficiently reduce size while maintaining performance and extending operating temperature beyond 105°C.
Innovation Solution
The development of polymer monolithic capacitors with self-healing properties, achieved through specific polymer dielectric materials with high glass transition temperatures and optimized electrode resistivity, combined with advanced processing techniques like plasma ashing and arc spraying, to enhance stability and energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If polymer film thickness is reduced to decrease capacitor size, then volumetric efficiency improves, but film strength and manufacturing feasibility deteriorate
Solution Approach 1:
The patent employs a composite structure consisting of multiple thin polymer dielectric layers (each 0.1-10 micrometers thick) combined with metallized electrode layers. This composite approach allows the use of extremely thin individual layers that would be too weak if used alone, while the cumulative structure provides both the required strength and the reduced volume for high energy density.
Solution Approach 2:
The patent divides the dielectric into thousands of thin individual polymer layers rather than using a single thick layer. Each thin layer is individually manufacturable and sufficiently strong, and when stacked together they create a monolithic structure with overall strength comparable to or exceeding traditional thick films, while achieving much higher volumetric efficiency.
2Volume of moving object
If polymer film thickness is reduced to decrease capacitor size, then volumetric efficiency improves, but manufacturing precision requirements worsen
Solution Approach 1:
The patent changes the manufacturing parameters by operating in a vacuum environment and using atomic layer deposition or similar precision techniques to control film thickness at the nanometer scale. This allows consistent production of ultra-thin layers (0.1-10 micrometers) with precise thickness control, something difficult to achieve with conventional atmospheric manufacturing processes.
Solution Approach 2:
The patent replaces conventional mechanical film handling and winding processes with a vacuum-based sequential deposition process. This substitution eliminates the need for mechanical manipulation of extremely thin films, avoiding damage and maintaining precision throughout manufacturing. The monolithic structure is built layer-by-layer in situ without mechanical assembly.
3Adaptability or versatility
If operating temperature is extended beyond 105°C to serve automotive applications, then application range improves, but capacitor reliability and lifetime deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the polymer dielectric materials to select polymers with higher thermal stability and higher glass transition temperatures. This allows the capacitor to operate reliably at temperatures exceeding 105°C (up to 125°C or higher in some embodiments) while maintaining acceptable lifetime and performance characteristics.
Solution Approach 2:
The patent uses composite material systems combining specific polymer dielectrics with metallized electrodes and protective coatings designed for high-temperature operation. This composite approach enhances overall thermal stability and reliability at elevated temperatures compared to conventional polymer films.
4Reliability
If electrode thickness is reduced to increase self-healing properties, then self-healing capability improves, but electrical conductivity and current carrying capacity worsen
Solution Approach 1:
The patent optimizes the electrode layer parameters by controlling metal thickness, composition, and density to achieve a balance where thin electrodes (providing good self-healing) maintain sufficient conductivity. The metallization process parameters are precisely controlled to create electrodes with optimal properties for both self-healing and electrical performance.
Solution Approach 2:
The patent employs composite electrode structures combining metal layers with conductive polymers or other materials to enhance conductivity while maintaining thin thickness. This composite approach allows thin electrodes to achieve the necessary electrical conductivity without compromising self-healing properties.
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 resulting capacitors exhibit stable operation at elevated temperatures, reduced size and weight, and increased energy density, effectively addressing the limitations of existing technologies in automotive and pulse power applications.
Implementation Method 1
polymer dielectric materials with high glass transition temperatures
Implementation Method 2
advanced processing techniques like plasma ashing
Implementation Method 3
advanced processing techniques like plasma ashing and arc spraying
Implementation Method 4
polymer dielectric and metallized electrodes
Data Source
AI summary
Prismatic polymer monolithic capacitor structure including multiple interleaving radiation-cured polymer dielectric layers and metal layers. Method for fabrication of same. The chemical composition of polymer dielectric and the electrode resistivity parameters are chosen to maximize the capacitor self-healing properties and energy density, and to assure the stability of the capacitance and dissipation factor over the operating temperature range. The glass transition temperature of the polymer dielectric is specifically chosen to avoid mechanical relaxation from occurring in the operating temperature range, which prevents high moisture permeation into the structure (which can lead to higher dissipation factor and electrode corrosion). The geometry and shape of the capacitor are appropriately controlled to minimize losses when the capacitor is exposed to pulse and alternating currents.