Ceramic Electronic Component Terminals With Concave-Convex Ends

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Solution Overview

Problem

Ceramic electronic components face cracking issues due to stress applied during mounting and use, particularly in reduced-size devices, where existing terminal electrode designs fail to distribute stress effectively, leading to reduced fixation forces and reliability in connection with wiring boards.

Innovation Solution

The design features external terminal electrodes with a concave-convex shape on the mounting surface, increasing the contact area and stress distribution, and includes internal electrodes and via-hole conductors to enhance electrical connectivity and mounting efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the ceramic electronic component size and thickness are reduced, then the component can be used in high-pitch electronic devices, but the strength of the ceramic electronic component lowers and cracking risk increases

Engineering Contradiction:
Improvecomponent sizeVSAvoidcomponent strength
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The terminal electrode ends are formed with a curved surface instead of a flat surface. This curvature increases the contact area between the terminal electrode and the ceramic body, distributing stress more evenly and preventing stress concentration that would lead to cracking in reduced-size components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the geometric parameters of the terminal electrode, specifically forming a curved surface at the end of the terminal electrode. This parameter change increases the contact area and modifies the stress distribution pattern, allowing smaller components to maintain sufficient strength.

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If the terminal electrode area on the mounting surface is reduced, then the component size can be reduced, but the fixation force and connection reliability deteriorate

Engineering Contradiction:
Improvecomponent sizeVSAvoidconnection reliability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

By forming a curved surface at the terminal electrode end, the contact area with the mounting surface is increased without increasing the overall component footprint. This curvature allows the terminal electrode to maintain adequate fixation force and connection reliability even in reduced-size components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The curved surface is applied locally at the end of the terminal electrode rather than across the entire electrode. This localized quality change increases contact area precisely where it is needed for fixation and connection, without increasing the overall component size.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If the terminal electrode area on the mounting surface is reduced, then the component size can be reduced, but the laser beam irradiation accuracy during embedding becomes difficult to achieve

Engineering Contradiction:
Improvecomponent sizeVSAvoidlaser beam irradiation accuracy
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The curved surface at the terminal electrode end provides a distinct geometric feature that improves laser beam irradiation accuracy. The curvature creates a well-defined target area for laser embedding, making it easier to achieve precise irradiation even when the overall component size is reduced.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP2187411B1Ceramic electronic component terminals
Publication Date: 2019.02.27 MURATA MFG CO LTD
  • EP2187411B1 patent drawingFigure 1
  • EP2187411B1 patent drawingFigure 2
  • EP2187411B1 patent drawingFigure 3

AI summary

In a ceramic electronic component having a thin structure, particularly, the occurrence of cracks is prevented which are possibly caused due to stress applied when the ceramic component is mounted or in a mounted state. Each of first and second external terminal electrodes (23 and 24) has a substantially rectangular region on a principal surface of a ceramic element body, the principal surface being directed to the mounting surface side. An end of the first external terminal electrode, which is positioned in contact with a gap region (34), and each ends of the second external terminal electrodes (37,38), which are positioned in contact with the gap region, are each formed in a concave-convex shape on the principal surface.