Multilayer Capacitor ESR Control via Lead Conductor Width Segmentation

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Solution Overview

Problem

Multilayer capacitors face challenges in increasing Equivalent Series Resistance (ESR) and decreasing Equivalent Series Inductance (ESL) while preventing open failure during polishing, which affects product yield.

Innovation Solution

A multilayer capacitor design with internal electrodes connected through lead conductors to terminal and external electrodes in a specific configuration, where the ESR control section has narrower lead conductors and a unique layout to enhance ESR and prevent open failure, and the ESL is reduced by alternating current directions in the capacitance section.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the width of lead conductors is decreased to increase ESR, then ESR is improved, but open failure becomes likely during polishing

Engineering Contradiction:
ImproveESR (Equivalent Series Resistance)VSAvoidopen failure prevention
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies local quality by differentiating the width of lead conductors based on their functional location. Lead conductors in the ESR control section have a first width (narrower) to increase resistance, while lead conductors in the capacitance section have a second width (wider) to prevent open failure during polishing. This localized differentiation allows each region to optimize for its specific function without compromising overall reliability.

Inventive Principle:
Principle #3Local quality

2Reliability

If the width of lead conductors is increased to prevent open failure, then reliability is improved, but ESR cannot be increased sufficiently

Engineering Contradiction:
Improveopen failure preventionVSAvoidESR (Equivalent Series Resistance)
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent segments the lead conductors into two distinct groups based on their location and function. The first lead conductors in the ESR control section are designed with a narrower width to provide higher resistance for ESR control, while the second lead conductors in the capacitance section are designed with a wider width to ensure mechanical robustness and prevent open failure. This segmentation allows independent optimization of each conductor group for its specific purpose.

Inventive Principle:
Principle #1Segmentation

3Speed

If internal electrodes are connected in parallel to external electrodes, then ESL is reduced, but ESR cannot be increased

Engineering Contradiction:
ImproveESL (Equivalent Series Inductance)VSAvoidESR (Equivalent Series Resistance)
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The patent introduces a new dimensional aspect to the electrode connection topology by creating a hybrid connection structure. The ESR control section uses series connection between terminal conductors (increasing ESR), while the capacitance section uses parallel connection between internal electrodes and external electrodes (reducing ESL). This multi-dimensional connection approach allows simultaneous optimization of both ESR and ESL parameters that cannot be achieved with a single connection topology.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP2101337B1Multilayer capacitor and mounted structure thereof
Publication Date: 2013.11.27 TDK CORP
  • EP2101337B1 patent drawingFigure 1
  • EP2101337B1 patent drawingFigure 2
  • EP2101337B1 patent drawingFigure 3

AI summary

In a multilayer capacitor 1, widths L3, L4 of lead conductors 14C, 14D of internal electrode 7C and widths L5, L6 of lead conductors 14E, 14F of internal electrode 7D in an ESR control section 12 are smaller than any one of widths W1, T1 of internal electrode 7A and widths W2, T2 of internal electrode 7B in a capacitance section 11. This narrows cross sections of the conductor portions connecting between the internal electrodes 7 and the external electrodes 3, so as to further increase ESR. The widths L3-L6 of the respective lead conductors 14C-14F in the ESR control section 12 are wider than widths L1, L2 of respective lead conductors 14A, 14B in the capacitance section 11. This effectively prevents open failure and improves a yield of products.