Multilayer Capacitor Curved Edge Radius Chipping

Solution Overview

Problem

The existing electronic components are prone to chipping during manufacturing due to the low strength of their corner portions, and the plating solution can enter the component through the external electrodes, compromising reliability by reducing the thickness of the electrode layers at curved edges and corners.

Innovation Solution

The electronic component design features a curved edge line surface with a radius of curvature smaller than the thickness between the side surface and internal electrode, suppressing the entry of plating solution and enhancing reliability, while also increasing the radius of curvature towards the corner to minimize chipping and expanding the electrode area for increased capacitance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the corner portion and edge line portion of the element body are formed into a curved surface shape to suppress chipping, then the strength and reliability of the element body is improved, but the thickness of the external electrode at these portions decreases, causing plating solution to easily enter and reducing reliability

Engineering Contradiction:

Improvestrength of corner portionVSAvoidreliability against plating solution entry

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent applies different radius of curvature values to different locations: a smaller radius R1 at the edge line surface and a larger radius R2 at the corner portion. This local differentiation allows the edge line area to maintain sufficient electrode thickness to prevent plating solution entry, while the corner area achieves enhanced chipping resistance through greater curvature.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the geometric parameter (radius of curvature) of the curved surfaces at different locations. By setting R1 < T and R2 > T, the patent optimizes the balance between preventing plating solution entry at edge lines and preventing chipping at corners, resolving the contradiction between these two reliability aspects.

Inventive Principle:

Principle #35Parameter changes

2Strength

If the radius of curvature of the edge line surface is increased towards the corner portion to reduce chipping, then the strength is improved, but the electrode layer thickness decreases, allowing plating solution to enter more easily

Engineering Contradiction:

Improvechipping resistanceVSAvoidplating solution entry

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies different radius of curvature values to different locations: a smaller radius R1 at the edge line surface and a larger radius R2 at the corner portion. This local differentiation allows the edge line area to maintain sufficient electrode thickness to prevent plating solution entry, while the corner area achieves enhanced chipping resistance through greater curvature.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the geometric parameter (radius of curvature) of the curved surfaces at different locations. By setting R1 < T and R2 > T, the patent optimizes the balance between preventing plating solution entry at edge lines and preventing chipping at corners, resolving the contradiction between these two reliability aspects.

Inventive Principle:

Principle #35Parameter changes

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 design effectively prevents the entry of plating solution into the component, improving reliability and reducing the likelihood of chipping, while also enhancing capacitance by increasing the electrode area.

Implementation Method 1

When the element body is immersed in a plating solution, the plating solution may enter an interface between the external electrode and the element body through the external electrode due to a pressure difference

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

The plated layer is formed on the electrode layer using a plating method

Methodology Applied

Scientific EffectElectroplating: Electroplating

Data Source

PatentUS11417465B2Electronic component having a plurality of internal electrodes

Publication Date: 2022.08.16 TDK CORP

AI summary

A multilayer capacitor includes an element body, an external electrode, and a plurality of internal electrodes, and a relationship of R1<T is satisfied in a first cross section extending in a direction in which the pair of end surfaces face each other, extending in a lamination direction of the plurality of internal electrodes, and including an electrode portions and a connecting portions when a radius of curvature of an edge line surface is R1 and a thickness between the side surface and the internal electrode at a position at which the side surface and the internal electrode are closest to each other in the lamination direction is T.