Multilayer Capacitor Segmented Design for ESL and ESR Balance

Solution Overview

Problem

Existing multilayer capacitors face challenges in achieving a balance between low Equivalent Series Inductance (ESL) and high Equivalent Series Resistance (ESR) while maintaining capacitance, leading to issues like voltage drop and degradation of high-frequency characteristics.

Innovation Solution

A multilayer capacitor design with two distinct capacitor portions, where the first portion has a lower ESL and higher resonant frequency, and the second portion has a higher ESR and lower resonant frequency, allowing for a combined low ESL and high ESR characteristic, enabling flexible resonant frequency adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the ESL is reduced by providing multiple terminals with opposite polarities, then the high-frequency characteristics are improved, but the ESR also decreases causing voltage drop and ringing

Engineering Contradiction:

Improvehigh-frequency characteristicsVSAvoidvoltage drop and ringing

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The capacitor is divided into two distinct capacitor portions: a first capacitor portion with multiple terminals for low ESL and high-frequency characteristics, and a second capacitor portion with fewer terminals for high ESR and resonance suppression. This segmentation allows each portion to independently optimize for its specific function while working together as a unified component.

Inventive Principle:

Principle #1Segmentation

2Reliability

If the ESR is increased by providing only one lead-out portion per internal electrode, then the resonance phenomenon is suppressed, but the ESL increases degrading high-frequency characteristics

Engineering Contradiction:

Improveresonance suppressionVSAvoidhigh-frequency characteristics

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The capacitor is divided into two distinct capacitor portions: a first capacitor portion with multiple terminals for low ESL and high-frequency characteristics, and a second capacitor portion with fewer terminals for high ESR and resonance suppression. This segmentation allows each portion to independently optimize for its specific function while working together as a unified component.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If the material or design of internal electrodes is changed to adjust resonant frequency, then the resonant frequency can be shifted, but the capacitance cannot be maintained at substantially the same level

Engineering Contradiction:

Improveresonant frequency adjustmentVSAvoidcapacitance stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The capacitor is divided into two distinct capacitor portions: a first capacitor portion with multiple terminals for low ESL and high-frequency characteristics, and a second capacitor portion with fewer terminals for high ESR and resonance suppression. This segmentation allows each portion to independently optimize for its specific function while working together as a unified component.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The resonant frequency is adjusted by changing the ESR parameter of the second capacitor portion through terminal configuration, while the capacitance is maintained by keeping the internal electrode design and dielectric layers consistent across both portions. This allows resonant frequency tuning without sacrificing capacitance stability.

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 achieves a balance between low ESL and high ESR, enhancing high-frequency characteristics and allowing for resonant frequency shifting without compromising capacitance.

Implementation Method 1

at least one pair of first and second internal electrodes opposing each other with a predetermined one of the dielectric layers interposed therebetween to define a capacitance

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

at least one pair of third and fourth internal electrodes opposing each other with a predetermined one of the dielectric layers interposed therebetween to define a capacitance

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 3

currents are caused to flow in opposite directions so that magnetic fluxes are canceled, and a reduction of an ESL (equivalent series inductance) is achieved

Methodology Applied

Scientific EffectMagnetic flux cancellation: Magnetic Field

Data Source

PatentUS7508647B2Multilayer capacitor

Publication Date: 2009.03.24 MURATA MFG CO LTD

AI summary

In a multilayer capacitor including a capacitor body, first capacitor portions and a second capacitor portion are arranged in the direction of lamination. While a resonant frequency of the first capacitor portions is set to be greater than a resonant frequency of the second capacitor portion so that the first capacitor portions contribute to low ESL, an ESR per layer of the second capacitor portion is set to be greater than an ESR per layer of the first capacitor portions so that the second capacitor portion contributes to high ESR. Furthermore, a combined ESR of the first capacitor portions is set to be less than or greater than a combined ESR of the second capacitor portion.