Aluminum Electrode Material Production via Sintering and Etching
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Solution Overview
Problem
Existing methods for producing aluminum electrolytic capacitors with high capacitance are inefficient, particularly when using aluminum powders with larger average particle diameters, leading to increased production costs and difficulties in forming anodic oxide films.
Innovation Solution
A method involving the formation of a film from a paste composition containing aluminum or aluminum alloy powder, a binder resin, and a solvent on a substrate, followed by sintering and etching treatment, which allows for high capacitance production regardless of the powder's average particle diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If aluminum powder with small average particle diameter is used to ensure high capacitance, then capacitance is improved, but production cost increases and yield decreases
Solution Approach 1:
The invention changes the particle diameter parameter of aluminum powder from small (2-6 μm) to large (6-20 μm or larger), achieving high capacitance without sacrificing yield. This parameter change resolves the contradiction by demonstrating that capacitance is not solely dependent on small particle size but can be achieved through controlled etching of larger particles.
2Reliability
If thickness of electrode material is increased to increase capacitance, then capacitance is improved, but difficulty in forming anodic oxide film increases
Solution Approach 1:
The invention applies local quality by creating a porous structure with localized etching features on the aluminum powder particles. The etched pores provide localized surfaces for anodic oxide film formation, enabling effective capacitance even at reduced thickness. This resolves the contradiction by showing that uniform thickness increase is not necessary when localized porous structures are used.
3Ease of manufacture
If conventional plating or vacuum evaporation is used to adhere aluminum powder to aluminum foil, then electrode material can be produced, but medium- to high-voltage capacitor performance is insufficient
Solution Approach 1:
The invention replaces the mechanical/physical adhesion methods (plating, vacuum evaporation) with a chemical bonding approach where aluminum powder particles are bonded to the aluminum foil through oxide film formation and sintering. This substitution enables medium- to high-voltage capacitor performance while maintaining production feasibility.
4Reliability
If sintered body with stacked aluminum powder particles is used to increase capacitance, then capacitance is improved, but electrode material thickness must be increased
Solution Approach 1:
The invention uses porous materials by creating a porous structure through controlled etching of aluminum powder particles before sintering. The porous structure increases surface area and capacitance without requiring increased thickness, as the pores provide additional surface area within the same volume. This resolves the contradiction by demonstrating that capacitance can be increased through porosity rather than thickness.
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
This method enables the production of electrode materials with high capacitance, reducing capacitor size and improving yield and cost-effectiveness by utilizing powders with larger average particle diameters.
Implementation Method 1
a second step of sintering the film
Implementation Method 2
a third step of applying an etching treatment on the sintered film
Data Source
AI summary
The present invention provides a production method that enables easy production of an electrode material for aluminum electrolytic capacitor having a high capacitance, and that enables, in particular, easy production of an electrode material for aluminum electrolytic capacitor having a high capacitance regardless of the average particle diameter (D50) of aluminum powder to be used. Specifically, the present invention provides a method for producing an electrode material for aluminum electrolytic capacitor, comprising the steps of: (1) a first step of forming a film of a paste composition containing powder of at least one of aluminum and an aluminum alloy, a binder resin, and a solvent on at least one surface of a substrate, (2) a second step of sintering the film, and (3) a third step of applying an etching treatment on the sintered film.