Ceramic Component Ni Plating Composition for Crack-Resistant Soldering

Solution Overview

Problem

The generation of stress, such as thermal expansion and contraction stress, in the Ni plating layer of electronic components during soldering can lead to cracks, while adding sulfur to the Ni plating layer reduces internal stress but facilitates oxidation and deteriorates solder wettability.

Innovation Solution

A ceramic electronic component with a nickel plating layer containing sulfur in both compound and atomic states, with a specific ratio of sulfur, to balance stress reduction and oxidation prevention, accompanied by a tin plating layer to enhance solderability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If S is added to the Ni plating layer, then internal stress is reduced and cracks are prevented, but oxidation is facilitated and solder wettability deteriorates

Engineering Contradiction:

Improvecrack resistanceVSAvoidsolder wettability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The outer electrode is divided into multiple functional layers: a Ni plating layer containing S in specific amounts (0.03-5 ppm) to reduce internal stress and prevent cracks, and a separate Sn plating layer applied on top to provide good solder wettability. This segmentation allows each layer to perform its specialized function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

S is added locally to the Ni plating layer at controlled concentrations (0.03-5 ppm) to specifically address crack resistance in the Ni layer, while the Sn plating layer is applied locally on top to provide the soldering interface with excellent wettability. Each layer has locally optimized composition for its specific function.

Inventive Principle:

Principle #3Local quality

2Reliability

If a Ni plating layer with low S concentration is formed to maintain wettability, then soldering is improved, but internal stress remains and cracks may occur

Engineering Contradiction:

Improvesolder wettabilityVSAvoidcrack resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The outer electrode is divided into multiple functional layers: a Ni plating layer containing S in specific amounts (0.03-5 ppm) to reduce internal stress and prevent cracks, and a separate Sn plating layer applied on top to provide good solder wettability. This segmentation allows each layer to perform its specialized function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The outer electrode uses a composite structure combining Ni and Sn plating layers, where the Ni layer provides mechanical strength and stress control with optimized S content, and the Sn layer provides soldering compatibility. The composite structure achieves properties that neither layer could achieve alone.

Inventive Principle:

Principle #40Composite materials

3Stress or pressure

If S is added to the Ni plating layer, then internal stress is reduced, but oxidation of the Ni layer is facilitated

Engineering Contradiction:

Improveinternal stressVSAvoidoxidation

Core Design Contradiction:

Stress or pressureVSObject-generated harmful factors

Solution Approach 1:

The outer electrode is divided into multiple functional layers: a Ni plating layer containing S in specific amounts (0.03-5 ppm) to reduce internal stress and prevent cracks, and a separate Sn plating layer applied on top to provide good solder wettability. This segmentation allows each layer to perform its specialized function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The Sn plating layer acts as an intermediary protective layer between the Ni plating layer and the external environment. It prevents direct exposure of the Ni layer to oxidizing conditions while allowing the Ni layer to maintain its optimized S content for stress reduction.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The proposed configuration reduces internal stress and oxidation of the nickel plating layer, improving the strength and solder mountability of ceramic electronic components.

Implementation Method 1

When S is added to the Ni plating layer, internal stress is prevented from being generated during fixing by soldering

Methodology Applied

Scientific EffectInternal stress reduction:

Implementation Method 2

when S is added to the Ni plating layer, oxidation of the Ni layer is facilitated

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS20250329498A1Electronic component

Publication Date: 2025.10.23 MURATA MFG CO LTD

AI summary

A ceramic electronic component includes a main body portion and an outer electrode on a surface of the main body portion. The outer electrode includes a nickel plating layer including sulfur in a compound state and an atomic state. A ratio of an amount of sulfur included in the compound state to all sulfur included in the compound state and the atomic state in the nickel plating layer is about 25% or more and less than about 100%.