Monofunctional Amine Primer for Capacitor Polymer Adhesion

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Solution Overview

Problem

Existing processes for producing solid electrolytic capacitors face challenges in achieving uniform surface coverage with polymeric outer layers, leading to high residual current and insufficient thermal stability, particularly at edges and corners, due to inhomogeneous layer formation and mechanical stress during encapsulation.

Innovation Solution

A process involving a primer solution with a monofunctional amine and carboxylic acid is applied to the capacitor body, followed by a conjugated polymer solution, to enhance the coverage and stability of the polymeric outer layer, ensuring better edge and corner coverage and thermal stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If in situ polymerization is used to form the polymeric outer layer, then the layer can be formed directly on the capacitor body, but the layer becomes inhomogeneous and edges/corners are insufficiently covered

Engineering Contradiction:
Improvedirect layer formationVSAvoidlayer homogeneity and edge coverage
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

A primer layer is applied to the capacitor body surface before applying the polymeric outer layer. This preliminary action prepares the surface to ensure uniform coverage and proper adhesion, particularly at edges and corners, resolving the inhomogeneity issue while maintaining the direct formation advantage.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The primer layer acts as an intermediary between the capacitor body and the polymeric outer layer. This intermediate layer improves adhesion and ensures uniform distribution of the outer layer, particularly addressing the edge coverage problem while preserving the simplicity of direct formation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the polymeric outer layer is used as a mechanical buffer, then residual current is reduced, but thermal stability at high temperatures remains insufficient

Engineering Contradiction:
Improveresidual current reductionVSAvoidthermal stability
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

A composite structure is created with a primer layer and a polymeric outer layer. The primer layer provides thermal stability and adhesion, while the polymeric outer layer provides mechanical buffering and reduces residual current. This composite approach resolves both requirements simultaneously.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different layers are assigned different functional properties: the primer layer is optimized for thermal stability and adhesion, while the polymeric outer layer is optimized for mechanical buffering. This local differentiation of material properties resolves the contradiction between residual current reduction and thermal stability.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If multiple coating cycles are used to achieve uniform coverage, then edge coverage improves, but the production process becomes more complex and prone to faults

Engineering Contradiction:
Improveedge coverageVSAvoidproduction process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The primer layer is applied as a preliminary step before the polymeric outer layer, creating a prepared surface that ensures uniform coverage in a single或少量 coating cycles. This eliminates the need for multiple repetitive coating cycles while maintaining excellent edge coverage.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The primer layer serves as an intermediary that facilitates uniform application of the polymeric outer layer, reducing the number of coating cycles needed. This intermediate step simplifies the overall production process while ensuring precise edge coverage.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 process results in solid electrolytic capacitors with low residual current, low equivalent series resistance, and high thermal stability, improving their performance and reliability in electronic circuits.

Implementation Method 1

a primer solution e) which comprises at least one monofunctional amine and at least one carboxylic acid is applied to the capacitor body

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

a solution or dispersion a) which comprises a conjugated polymer b) and a solvent or dispersant d) is then applied and the solvent or dispersant d) is then at least partially removed

Methodology Applied
Scientific EffectDeposition: Deposition (physical)

Data Source

PatentEP2950316B1Monofunctional amines as adhesion primers for conductive polymers
Publication Date: 2019.11.06 HERAEUS DEUTSCHLAND GMBH & CO KG
  • EP2950316B1 patent drawingFigure 1
  • EP2950316B1 patent drawingFigure 2
  • EP2950316B1 patent drawing

AI summary

The present invention relates to a process for producing an electrolytic capacitor, the process comprising process steps i) ii): i) providing a capacitor body (1) that comprises - an electrode body (2) of an electrode material, - a dielectric (3) which at least partially covers the surface of this electrode material, and - a solid electrolyte (4) at least comprising an electrically conductive material which at least partially covers the dielectric surface; ii) applying a primer solution e) to the capacitor body (1), followed by an application of a solution or dispersion a) comprising a conjugated polymer b) and a solvent or dispersant d), followed by an at least partial removal of the solvent or dispersant d) for the formation of the polymeric outer layer (5) that is formed onto the capacitor body (1); wherein the primer solution e) comprises at least one monofunctional amine and at least one carboxylic acid.