Solid Electrolytic Capacitor Structure to Prevent Electrolyte Evaporation
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Solution Overview
Problem
Known capacitors deteriorate due to evaporation of electrolytic solution under heat and vibration, leading to instability in capacitor characteristics over time.
Innovation Solution
A solid electrolytic capacitor design using a water-soluble first polymer and a water-dispersible second polymer, combined with a solid-at-normal-temperature substance containing an electrolyte dissolved in a solvent that melts at a specific temperature, to maintain stable capacitor characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a liquid electrolyte is used in an aluminum electrolytic capacitor, then the capacitor can be manufactured with existing technology and processes, but the capacitor has a limited service life and requires periodic maintenance due to electrolyte leakage and drying
Solution Approach 1:
The patent changes the physical state of the electrolyte from liquid to solid polymer form. This fundamental parameter change eliminates electrolyte leakage and drying issues while extending service life, and the solid polymer can be applied using existing coating technologies
Solution Approach 2:
The patent creates a maintenance-free capacitor by using a solid polymer electrolyte that does not require periodic replacement like liquid electrolytes. The solid polymer remains stable throughout the capacitor's entire service life without degradation requiring maintenance
2Reliability
If a solid polymer electrolyte is used to replace liquid electrolyte, then the service life is extended and maintenance is eliminated, but the manufacturing process becomes more complex
Solution Approach 1:
The solid polymer electrolyte forms a self-supporting film that does not require additional containment structures or sealing mechanisms needed for liquid electrolytes. The polymer itself provides both the electrolyte function and the structural integrity
Solution Approach 2:
The patent uses a composite structure combining the solid polymer electrolyte with the aluminum foil and other capacitor components. This composite approach integrates multiple functions into a unified structure that simplifies the overall manufacturing process
3Quantity of substance
If the aluminum foil is etched to increase surface area, then the capacitance is increased, but the mechanical strength of the foil decreases making it more prone to breakage
Solution Approach 1:
The patent employs a porous structure on the aluminum foil surface through etching to dramatically increase the surface area for capacitance. The porous architecture provides both high capacitance and structural reinforcement through the distributed pore network
Solution Approach 2:
The etched aluminum foil is combined with the solid polymer electrolyte to form a composite structure where the polymer fills and reinforces the porous aluminum structure, providing both electrical function and mechanical strength
4Volume of moving object
If the aluminum foil is made thinner to reduce size, then the capacitor volume is reduced, but the foil becomes more fragile and difficult to handle during manufacturing
Solution Approach 1:
The thin aluminum foil is combined with the solid polymer electrolyte to create a composite structure where the polymer provides mechanical support and handling strength while the thin aluminum layer provides the necessary electrical function with minimal volume
Solution Approach 2:
The patent uses thin film aluminum foil supported by the solid polymer matrix, allowing the foil to be extremely thin for miniaturization while the polymer provides the mechanical integrity needed for manufacturing and assembly
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 design ensures stable capacitor characteristics over a long period by preventing electrolyte evaporation and protecting the capacitor element from external forces, while the melting electrolyte repairs oxide film cracks.
Implementation Method 1
a solid polymer electrolyte which has a gel structure formed by incorporating a solvent into the solid polymer electrolyte
Implementation Method 2
a porous coating layer which has an organic-inorganic composite structure and serves to hold the solvent
Data Source
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AI summary
A capacitor element has a water-soluble first polymer disposed on the surfaces of anode and cathode members and a water-dispersible second polymer disposed on the surfaces of the anode and cathode members on which the first polymer is disposed. The second polymer electrically connects together the anode and cathode members. Between the surfaces of the anode and cathode members and between the inner face of a case and the outer face of the capacitor element, a solid-at-normal-temperature substance is disposed that has an electrolyte dissolved in a solvent that is solid at or below a first temperature and that melts when heated to or above a second temperature higher than the first temperature.