MLCC Internal Electrode Paste Using Ni3C to Prevent Sintering Cracks

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The sintering process for manufacturing multilayer ceramic capacitors can lead to cracking and reduced connectivity between the dielectric and internal electrode layers due to carbon dioxide formation from binder components, affecting capacitance and moisture resistance reliability.

Innovation Solution

Incorporating nickel carbide (Ni3C) powder particles in the conductive paste for the internal electrode layer, with a concentration of 0.5 wt% to 0.8 wt% relative to nickel powder, to reduce carbon emission and enhance connectivity and reliability during sintering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional conductive paste containing carbon-based binder is used in sintering process, then the manufacturing process is simple, but carbon dioxide formation causes cracking at the interface between dielectric layer and internal electrode layer

Engineering Contradiction:

Improvesimplicity of sintering processVSAvoidconnectivity between dielectric layer and internal electrode layer

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent converts the harmful carbon dioxide gas generated during sintering into beneficial nickel carbide particles. By adding nickel powder to the conductive paste, the carbon from the binder reacts with nickel to form nickel carbide (Ni3C) particles that remain in the internal electrode layer, preventing cracking while maintaining electrical conductivity. This transforms the harmful carbon emission into a protective element.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent modifies the chemical composition parameters of the conductive paste by adding nickel powder at a specific ratio (0.5-5.0 wt% relative to carbon-based binder). This parameter change alters the sintering reaction products from harmful carbon dioxide to beneficial nickel carbide, resolving the cracking issue while maintaining process simplicity.

Inventive Principle:

Principle #35Parameter changes

2Strength

If carbon-based binder is used in conductive paste, then the paste has good binding properties, but carbon emission reduces connectivity and increases voids in internal electrode layer

Engineering Contradiction:

Improvebinding properties of conductive pasteVSAvoidconnectivity of internal electrode layer

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The carbon from the binder, which normally causes harm by forming carbon dioxide and creating voids, is converted into beneficial nickel carbide particles through reaction with added nickel powder. These nickel carbide particles fill voids and improve connectivity rather than creating defects.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Nickel powder acts as an intermediary substance that mediates between the carbon-based binder and the final electrode structure. It reacts with carbon to form nickel carbide, which serves as a bridge maintaining both binding properties and electrical connectivity in the sintered electrode layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If conventional conductive paste is used, then the manufacturing cost is low, but moisture resistance reliability is poor due to cracking and reduced connectivity

Engineering Contradiction:

Improvecost of conductive pasteVSAvoidmoisture resistance reliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent modifies the compositional parameters of the conductive paste by incorporating nickel powder at optimized ratios. This parameter change prevents cracking and improves connectivity, thereby enhancing moisture resistance reliability while maintaining cost-effectiveness through a relatively simple formulation adjustment.

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

Improved connectivity and increased capacitance, along with enhanced moisture resistance reliability of the capacitor component, as demonstrated by increased connectivity and stable insulation resistance under testing conditions.

Implementation Method 1

In a sintering process for manufacturing an MLCC, carbon of a binder, or the like, included in the conductive paste may react with oxygen to form carbon dioxide. Such carbon dioxide may cause cracking to occur in an interface between a dielectric layer and an internal electrode layer.

Methodology Applied

Scientific EffectCarbon emission reduction through nickel carbide decomposition: Thermolysis

Implementation Method 2

an MLCC is manufactured by screen-printing a conductive paste for forming an internal electrode layer on a dielectric green sheet, laminating a plurality of dielectric green sheets on which the conductive paste is printed, and sintering the plurality of dielectric green sheets

Methodology Applied

Scientific EffectSintering: Sintering

Data Source

PatentUS11990280B2Capacitor component having nickel and carbon between internal electrode and dielectric layers

Publication Date: 2024.05.21 SAMSUNG ELECTRO MECHANICS CO LTD

AI summary

A capacitor component includes a body, including a dielectric layer and an internal electrode layer, and an external electrode disposed on the body and connected to the internal electrode layer. A region, containing nickel (Ni) and carbon (C), is present between the internal electrode layer and the dielectric layer.