Solid Electrolyte Capacitor Manufacturing with Multi-Layer Conductive Polymer
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Solution Overview
Problem
Existing methods for manufacturing solid aluminum electrolytic capacitors face challenges in achieving uniform conductive polymer layers, leading to insufficient capacitance, high ESR, and leakage current issues due to difficulties in impregnating large particles and forming dense film layers, which result in low yield rates and increased costs.
Innovation Solution
A method involving four conductive polymer layers is employed, where the first layer is prepared by chemical polymerization, the second and third layers by impregnation with small and larger particle dispersions respectively, and the fourth layer by electrochemical polymerization, to achieve uniformity and density, reducing the capacitor thickness and improving capacitance and ESR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single composition soluble conductive polymer solution or conductive polymer dispersion is used for impregnation, then the impregnation process is simple, but large particles cannot enter surface pores sufficiently, resulting in insufficient capacitance extraction
Solution Approach 1:
The patent divides the impregnation process into multiple sequential stages, each using conductive polymer solutions with different particle size distributions. The first stage uses a solution with smaller particles (0.1-10 μm) to penetrate deep into pores, while subsequent stages use solutions with progressively larger particles (10-50 μm, then 50-200 μm) to build up the film layer. This segmentation allows both sufficient pore penetration and effective capacitance extraction.
2Reliability
If impregnation time in oxidizing agent solution is extended to improve polymer layer formation, then more complete polymerization occurs, but ESR increases and manufacturing cost increases
Solution Approach 1:
The patent applies preliminary action by first forming a base conductive polymer layer through chemical polymerization before the impregnation process. This pre-formed layer provides a foundation that reduces the required impregnation time in oxidizing agent solution, as the subsequent impregnation only needs to complete the polymerization and form the outer film layers, not create the entire conductive structure from scratch.
3Shape
If the capacitor component is impregnated and dried to form a film layer, then a conductive polymer film is formed, but a dense chemically-bonded film layer is not formed at the outermost layer, resulting in thin film at corners and leakage current
Solution Approach 1:
The patent implements continuity of useful action by performing multiple sequential impregnation cycles rather than a single impregnation step. Each cycle deposits additional conductive polymer material and forms chemical bonds, creating a progressively denser and more continuous film structure. This multi-stage continuous process ensures complete coverage including corner areas and eliminates defects that would cause leakage current.
4Quantity of substance
If multiple conductive polymer layers with different particle sizes are used, then capacitance extraction and film density are improved, but the manufacturing process complexity increases
Solution Approach 1:
The patent applies parameter changes by systematically varying the particle size distribution parameter across different impregnation stages. The first stage uses particles of 0.1-10 μm, the second stage uses 10-50 μm, and the third stage uses 50-200 μm. This controlled parameter variation optimizes both capacitance extraction and film density while maintaining a manageable manufacturing process through standardized procedural steps.
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 approach enhances capacitance extraction, reduces ESR, and minimizes leakage current, resulting in a more efficient and cost-effective solid aluminum electrolytic capacitor with improved performance and yield.
Implementation Method 1
preparing a first conductive polymer layer on the formed anode aluminum foil by chemical polymerization, wherein the chemical polymerization comprises: impregnating the anode aluminum foil in a reducing solution for 0.3-3 min and drying the anode aluminum foil; impregnating the anode aluminum foil in an oxidizing solution for 0.3-3 min and drying the anode aluminum foil
Implementation Method 2
preparing a second conductive polymer layer by impregnation in a dispersion of small-size particles; preparing a third conductive polymer layer by impregnation in a dispersion of particles larger than those for the preparation of the second conductive layer
Implementation Method 3
preparing a fourth conductive polymer layer by electrochemical polymerization
Implementation Method 4
impregnating the anode aluminum foil in a reducing solution for 0.3-3 min and drying the anode aluminum foil; impregnating the anode aluminum foil in an oxidizing solution for 0.3-3 min and drying the anode aluminum foil
Data Source
AI summary
The present invention relates to capacitor manufacturing, and particularly to a method for manufacturing a solid aluminum electrolytic capacitor, including: cutting an anode aluminum foil to a desired width; welding the cut anode aluminum foil to a stainless steel strip, and coating an insulating adhesive to partition an anode zone from a cathode zone; forming the cut anode aluminum foil; preparing a first conductive polymer layer on the anode aluminum foil by chemical polymerization; preparing a second conductive polymer layer by impregnation; preparing a third conductive polymer layer by impregnation; preparing a forth conductive polymer layer by electrochemical polymerization; preparing a carbon paste layer and a silver paste layer on the anode aluminum foil; and subjecting the resulting product to stacking, packaging, aging and sorting.