Solid Electrolytic Capacitor Insulating Layer Configuration

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Solution Overview

Problem

Conventional solid electrolytic capacitors face challenges with increased stress and positional discrepancies between laminated capacitor elements due to thick insulating layers, leading to increased leakage current and reduced capacitance, especially as electronic devices require higher capacitance in smaller spaces.

Innovation Solution

The solution involves laminating capacitor elements with a first insulating layer on one main surface and no insulating layer on the opposing surface, allowing for closer stacking and reduced stress, while a thinner second insulating layer on the other surface further enhances positional alignment and prevents short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If thick insulating layers are used between capacitor elements, then electrical insulation is improved, but stress and positional discrepancies between laminated elements increase

Engineering Contradiction:

Improveelectrical insulationVSAvoidstress between laminated elements

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The patent applies different insulating layer configurations to different regions: a first insulating layer is formed on the first main surface of the separation section, while the second main surface has no insulating layer or a thinner second insulating layer. This local differentiation reduces overall stress while maintaining necessary electrical insulation at critical interfaces.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The insulating structure is segmented into multiple layers with different thicknesses and positions. The first insulating layer provides insulation where needed, while the absence or reduced thickness of insulation on the second surface reduces stress accumulation, creating a balanced configuration.

Inventive Principle:

Principle #1Segmentation

2Reliability

If thick insulating layers are used between capacitor elements, then electrical insulation is improved, but leakage current increases

Engineering Contradiction:

Improveelectrical insulationVSAvoidleakage current

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

By providing insulating layers only on specific surfaces (first main surface) or with different thicknesses on opposite surfaces, the patent maintains adequate electrical insulation to prevent leakage current while avoiding excessive insulation that would increase stress and contribute to positional discrepancies.

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If more capacitor elements are laminated to increase capacitance, then capacitance is improved, but thickness of the capacitor increases

Engineering Contradiction:

ImprovecapacitanceVSAvoidthickness of capacitor

Core Design Contradiction:

Quantity of substanceVSLength of stationary object

Solution Approach 1:

The patent changes the insulating layer parameters (thickness distribution, presence on specific surfaces) to reduce the overall thickness contribution of insulation materials, enabling closer stacking of capacitor elements and increasing capacitance without proportionally increasing total thickness.

Inventive Principle:

Principle #35Parameter changes

4Stress or pressure

If insulating layers are reduced to decrease stress, then stress is reduced, but risk of short circuits increases

Engineering Contradiction:

Improvestress between laminated elementsVSAvoidshort circuit prevention

Core Design Contradiction:

Stress or pressureVSReliability

Solution Approach 1:

The patent strategically places insulating layers on specific surfaces (first main surface of separation section) where electrical insulation is most critical for preventing short circuits, while reducing or eliminating insulation on other surfaces where stress reduction is the priority, achieving a balanced configuration.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The first insulating layer acts as an intermediary that provides necessary electrical insulation between adjacent capacitor elements while the reduced insulation on the second surface minimizes stress, creating a mediator structure that balances insulation and stress requirements.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11443903B2Solid electrolytic capacitor having an insulating layer between exposed anode portions

Publication Date: 2022.09.13 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A solid electrolytic capacitor includes a plurality of capacitor elements that are laminated with each other. The plurality of capacitor elements each include an anode body, a solid electrolyte layer, and a cathode lead-out layer. The anode body is a foil-shaped electric conductor having a first main surface and a second main surface opposite to the first main surface. The anode body includes an anode section, a cathode formation section, and a separation section interposed between the anode section and the cathode formation section. The solid electrolyte layer and the cathode lead-out layer are disposed on both the first and the second main surfaces of the cathode formation section. A first insulating layer is disposed on the first main surface of the separation section. A first capacitor element and a second capacitor element that are adjacent to each other among the plurality of the capacitor elements are stacked so that the first insulating layer in the first capacitor element faces the second main surface of the separation section in the second capacitor element.