Multilayer Ceramic Capacitor Electrode Layout for Warpage Stress Relief

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Solution Overview

Problem

Multilayer ceramic capacitors experience breakage due to stress concentration at the central portion of the external electrode when mounted on a warped insulating substrate, particularly when the end surface of the element body is large.

Innovation Solution

The multilayer ceramic capacitor design includes a first external electrode that extends from the end surface to the main, side, and ridgeline surfaces, with projecting portions to distribute stress more evenly, adhering to specific dimension and projection length ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the end surface of the element body portion is made considerably large, then the electrical connection area is improved, but stress concentration occurs at the central portion of the external electrode causing breakage

Engineering Contradiction:

Improveend surface area of element body portionVSAvoidresistance to breakage

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The external electrode is divided into multiple segments: a first external electrode extending to the end surface, and a second external electrode extending to the outer peripheral surface. This segmentation allows stress to be distributed across different regions rather than concentrating at the central portion, thereby preventing breakage while maintaining large end surface area for electrical connection.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the external electrode are given different extensions and configurations. The first external electrode extends to the end surface for electrical connection, while the second external electrode extends to the outer peripheral surface to distribute stress. This local differentiation optimizes both electrical connection area and stress resistance in respective regions.

Inventive Principle:

Principle #3Local quality

2Area of stationary object

If the external electrode extends to the outer peripheral surface, then the electrical connection area is increased, but stress concentration at the central portion causes breakage

Engineering Contradiction:

Improveexternal electrode coverage areaVSAvoidstrength at central portion

Core Design Contradiction:

Area of stationary objectVSStrength

Solution Approach 1:

The external electrode system is segmented into a first external electrode covering the end surface and a second external electrode covering the outer peripheral surface. This segmentation ensures that the central portion is not overloaded with both electrical connection and stress distribution functions, thereby maintaining strength while maximizing total coverage area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first and second external electrodes have asymmetric extensions: the first extends primarily in the length direction to the end surface, while the second extends to the outer peripheral surface. This asymmetric configuration optimizes stress distribution patterns and prevents concentration at the central portion while maintaining extensive coverage.

Inventive Principle:

Principle #4Asymmetry

3Adaptability or versatility

If the insulating substrate warps under thermal influence, then thermal adaptation is improved, but stress is produced in the external electrode leading to breakage

Engineering Contradiction:

Improveadaptation to substrate warpageVSAvoidresistance to thermal stress

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The external electrode is segmented into multiple portions that can independently accommodate substrate warpage. The first external electrode at the end surface and the second external electrode at the outer peripheral surface can deform differently in response to thermal warping, distributing thermal stress throughout the structure rather than concentrating it at the central portion.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The configuration parameters of the external electrode (extension directions, coverage areas, and geometries) are optimized to accommodate thermal deformation. By carefully designing the extension patterns of the first and second external electrodes, the structure adapts to substrate warpage while maintaining stress distribution that prevents breakage.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250336609A1Multilayer ceramic capacitor

Publication Date: 2025.10.30 MURATA MFG CO LTD

AI summary

A multilayer ceramic capacitor includes an element body portion and an external electrode including an end-surface-side external electrode, a main-surface-side external electrode, a side-surface-side external electrode, and a ridgeline-portion-side external electrode. At least one of the main-surface-side external electrode and the side-surface-side external electrode includes a first projecting portion projecting toward a central portion of the element body portion in a length direction, relative to the ridgeline-portion-side external electrode. T0 is equal to or larger than about 2.5 mm, where T0 denotes a maximum distance between the first and second main surfaces. W0 is equal to or larger than about 2.5 mm, where W0 denotes a maximum distance between first and second side surfaces. 0.01×T0≤P1≤0.06×T0 and 0.01×W0≤P1≤0.06×W0 are satisfied, where P1 denotes a maximum projection length of the first projecting portion.