Multilayer Capacitor Electrode Chemistry to Suppress A/C Cracking
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Solution Overview
Problem
Multilayer ceramic capacitors face issues with A/C cracking between the capacitance formation portion and the cover portion due to mismatched shrinkage behavior and bonding forces, leading to potential short circuits and reduced breakdown voltage, which compromises reliability.
Innovation Solution
The solution involves a multilayer electronic component with internal electrodes closest to the cover portion having a controlled ratio of Ni(OH)2 to NiO, optimized through surface treatment in an oxygen atmosphere, to enhance hydrogen bonding and improve bonding forces between the capacitance formation and cover portions, thereby suppressing A/C cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thickness of internal electrode is reduced to increase the number of stacked layers, then the size of multilayer ceramic capacitor decreases and capacity increases, but sintering shrinkage initiation temperature is lowered and mismatch in shrinkage behavior with dielectric layer is increased, causing defects such as delamination
Solution Approach 1:
The patent changes the chemical composition parameters of the internal electrode by controlling the ratio of Ni(OH)2 to NiO (maintaining Ni(OH)2 at 5-20 mass% and NiO at 80-95 mass%). This parameter adjustment optimizes the sintering characteristics and bonding strength, allowing thin internal electrodes to maintain adequate bonding reliability with dielectric layers despite reduced thickness.
2Ease of manufacture
If the bonding force between capacitance formation portion and cover portion is insufficient, then manufacturing is easier, but A/C cracking between capacitance formation portion and cover portion occurs, causing short circuit or reduced breakdown voltage
Solution Approach 1:
The patent modifies the chemical composition of the internal electrode by precisely controlling the Ni(OH)2 content (5-20 mass%) alongside NiO (80-95 mass%). This compositional parameter change enhances the bonding force between the capacitance formation portion and cover portion, preventing A/C cracking while maintaining ease of manufacture.
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 approach effectively reduces A/C cracking and enhances the reliability of multilayer ceramic capacitors by improving the bonding force between the capacitance formation and cover portions, even at thinner layer thicknesses, ensuring high breakdown voltage and reduced short circuit rates.
Implementation Method 1
a surface treatment on a metal particle in an oxygen atmosphere
Implementation Method 2
enhance hydrogen bonding and improve bonding forces between the capacitance formation and cover portions
Implementation Method 3
forming a body including a dielectric layer and an internal electrode by sintering the stack body
Data Source
AI summary
A multilayer electronic component includes a body including a plurality of dielectric layers, a plurality of internal electrodes, a capacitance formation portion in which the plurality of dielectric layers and the plurality of internal electrodes are alternately disposed in a first direction, a first cover portion disposed on one surface of the capacitance formation portion in the first direction and including a dielectric layer, and a second cover portion disposed on the other surface of the capacitance formation portion in the first direction and including a dielectric layer; and an external electrode disposed on the body, wherein, if an internal electrode disposed closest to the first cover portion, among the plurality of internal electrodes, is referred to as IE1, a ratio of Ni(OH)2 mass to NiO mass in IE1 is 4.5 or more and 7.5 or less.