Electrolytic Capacitor Element Structure for Low-ESR Stacking

Solution Overview

Problem

Electrolytic capacitors face increased equivalent series resistance (ESR) and reduced strength when multiple capacitor elements are stacked due to void formation during welding, leading to potential deterioration of the solid electrolyte layer and decreased electrostatic capacity.

Innovation Solution

A capacitor element design featuring a thin-thickness region formed by compressing or removing parts of the porous anode body, with a denser metal substrate stacked on this region to reduce voids and enhance strength, and a cathode layer formed on the cathode formation part to suppress oxygen penetration and electrical resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple capacitor elements are stacked to increase capacitance, then the electrostatic capacity is improved, but the equivalent series resistance increases due to void formation during welding

Engineering Contradiction:

Improveelectrostatic capacityVSAvoidequivalent series resistance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The anode body is designed with different thicknesses in different regions: a thin-thickness region for welding purposes and a thick-thickness region for maintaining capacitance. This local differentiation allows the welding area to have minimal void formation while the capacitance area maintains sufficient porous structure, thereby resolving the contradiction between increasing capacity and reducing ESR.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The anode body is segmented into functionally distinct regions: a thin-thickness region specifically for welding and a thick-thickness region for capacitance storage. This segmentation enables each region to optimize its performance for its specific function, allowing multiple elements to be stacked with reduced ESR while maintaining high capacitance.

Inventive Principle:

Principle #1Segmentation

2Quantity of substance

If multiple capacitor elements are stacked to increase capacitance, then the electrostatic capacity is improved, but the strength decreases due to void formation during welding

Engineering Contradiction:

Improveelectrostatic capacityVSAvoidstrength of capacitor elements

Core Design Contradiction:

Quantity of substanceVSStrength

Solution Approach 1:

The anode body is designed with different thicknesses in different regions: a thin-thickness region for welding purposes and a thick-thickness region for maintaining capacitance. This local differentiation allows the welding area to have minimal void formation while the capacitance area maintains sufficient porous structure, thereby resolving the contradiction between increasing capacity and reducing ESR.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The anode body is segmented into functionally distinct regions: a thin-thickness region specifically for welding and a thick-thickness region for capacitance storage. This segmentation enables each region to optimize its performance for its specific function, allowing multiple elements to be stacked with reduced ESR while maintaining high capacitance.

Inventive Principle:

Principle #1Segmentation

3Reliability

If the porous region thickness is reduced to minimize voids during welding, then the ESR is reduced, but the electrostatic capacity decreases

Engineering Contradiction:

Improveequivalent series resistanceVSAvoidelectrostatic capacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The anode body is designed with different thicknesses in different regions: a thin-thickness region for welding purposes and a thick-thickness region for maintaining capacitance. This local differentiation allows the welding area to have minimal void formation while the capacitance area maintains sufficient porous structure, thereby resolving the contradiction between increasing capacity and reducing ESR.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The anode body is segmented into functionally distinct regions: a thin-thickness region specifically for welding and a thick-thickness region for capacitance storage. This segmentation enables each region to optimize its performance for its specific function, allowing multiple elements to be stacked with reduced ESR while maintaining high capacitance.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12154728B2Capacitor element, electrolytic capacitor, and methods for manufacturing same

Publication Date: 2024.11.26 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A capacitor element includes an anode body including a porous region located at a surface of the anode body, a dielectric layer that covers at least a part of the anode body, and a cathode layer that covers at least a part of the dielectric layer. The anode body includes an anode part and a cathode formation part on which the cathode layer is disposed, the cathode formation part being adjacent to the anode part. At least a part of the porous region of the anode part includes a thin-thickness region that is thinner than the porous region in the cathode formation part, and a metal substrate is stacked on at least a part of the thin-thickness region. The metal substrate is denser than the porous region in the cathode formation part.