Multilayer Ceramic Capacitor Electrode Segmentation for Low ESL

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Solution Overview

Problem

Existing multilayer ceramic capacitors face challenges in achieving sufficient heat dissipation and low equivalent series inductance (ESL) while reducing capacitance and preventing an increase in direct-current (DC) resistance.

Innovation Solution

A multilayer ceramic capacitor design with a specific internal electrode layer configuration and external electrode arrangement, where the second internal electrode layer is located within one-third of the multilayer body in the stacking direction, and external electrodes are positioned to minimize coverage and maximize heat dissipation, along with a mounting structure that shortens the current path to the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the total number of internal electrodes is reduced to decrease capacitance, then the capacitance is reduced, but the DC resistance increases

Engineering Contradiction:

ImprovecapacitanceVSAvoidDC resistance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The internal electrodes are segmented into two distinct groups: first internal electrodes extending in the stacking direction and second internal electrodes extending in the width direction. This segmentation allows for optimized current paths while maintaining reduced capacitance, as each group contributes differently to the electrical characteristics of the capacitor.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimensional arrangement by having second internal electrodes extend in the width direction perpendicular to the stacking direction, rather than only in the stacking direction. This dimensional change creates additional current path options that reduce DC resistance without increasing capacitance.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Quantity of substance

If capacitance portions are disposed on the upper and lower sides, then the capacitance structure is formed, but the external electrodes on the side surfaces are connected to capacitance portions located far from the mounting surface, increasing the coverage area and reducing heat dissipation effect

Engineering Contradiction:

Improvecapacitance structureVSAvoidheat dissipation effect

Core Design Contradiction:

Quantity of substanceVSTemperature

Solution Approach 1:

The patent applies local quality by positioning the second internal electrodes within a specific region (within one-third of the multilayer body thickness from the first main surface). This localized arrangement ensures that the external electrodes on side surfaces connect to capacitance portions closer to the mounting surface, improving heat dissipation in the critical region near the mounting surface.

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If capacitance portions are disposed on the upper and lower sides, then the capacitance structure is formed, but the current path to the mounting substrate is increased in length, reducing the low ESL effect

Engineering Contradiction:

Improvecapacitance structureVSAvoidcurrent path length

Core Design Contradiction:

Quantity of substanceVSLength of moving object

Solution Approach 1:

The second internal electrodes are positioned within a specific local region (within one-third of the multilayer body thickness from the first main surface), creating optimized current paths that are shorter and more direct to the mounting substrate, thereby reducing ESL.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

By introducing second internal electrodes that extend in the width direction and positioning them within the upper portion of the multilayer body, the patent creates a three-dimensional current path structure that shortens the effective current path length to the mounting substrate compared to conventional arrangements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Reliability

If the external electrodes on the side surfaces cover a larger area of the multilayer body, then the electrode connection is improved, but the heat dissipation effect is reduced

Engineering Contradiction:

Improveelectrode connectionVSAvoidheat dissipation effect

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent optimizes the coverage area of external electrodes by positioning second internal electrodes within a specific region (within one-third of the multilayer body thickness). This creates a balanced design where external electrodes maintain sufficient connection area while exposing more of the multilayer body surface for heat dissipation.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20230343521A1Multilayer ceramic capacitor and mounting structure of multilayer ceramic capacitor

Publication Date: 2023.10.26 MURATA MFG CO LTD

AI summary

A multilayer ceramic capacitor includes a multilayer body including dielectric layers and internal electrode layers, first and second main surfaces facing each other in a stacking direction, first and second side surfaces facing each other in a width direction perpendicular or substantially perpendicular to the stacking direction, and first and second end surfaces facing each other in a length direction perpendicular or substantially perpendicular to the stacking and width directions, a first external electrode on the first end surface, a second external electrode on the second end surface, a third external electrode on the first side surface, and a fourth external electrode on the second side surface. A first internal electrode layer is exposed at the first and second end surfaces, and a second internal electrode layer is exposed at the first and second side surfaces and is within a range from the second main surface to ⅓ of the multilayer body in the stacking direction.