NiAl Intermetallic Electrodes for MLCC Shrinkage Control
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Solution Overview
Problem
In multilayer ceramic capacitors, the low melting point of nickel particles leads to over-sintering and electrode cuttings during firing, which hinders the formation of thin internal electrode layers necessary for high-capacity and compact devices, and existing methods for sintering inhibition are either costly or ineffective at high temperatures.
Innovation Solution
Incorporating intermetallic compounds such as NiAl and Ni3Al into the internal electrode layers, which raises the sintering temperature and inhibits shrinkage, thereby preventing electrode cuttings and ensuring good conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nickel particles are used as conducting particle materials, then good conductivity is achieved, but over-sintering occurs at sintering temperature range of dielectric powders
Solution Approach 1:
The patent changes the material parameter from pure nickel particles to nickel-aluminum alloy particles, which fundamentally alters the sintering behavior. The alloy particles maintain good conductivity while exhibiting suppressed sintering at high temperatures, resolving the contradiction between conductivity and sintering control.
Solution Approach 2:
The patent uses composite nickel-aluminum alloy particles as conducting particle materials. This composite approach combines the beneficial properties of nickel (conductivity) and aluminum (high melting point, sintering suppression), achieving both good conductivity and resistance to over-sintering.
2Volume of moving object
If internal electrode layers are made thinner to achieve high capacity and compact size, then capacity increases, but electrode cuttings occur during firing
Solution Approach 1:
The patent changes the material composition parameter from pure nickel to nickel-aluminum alloy, which fundamentally alters the thermal behavior of the internal electrode layers. This material parameter change enables thin electrode layers to maintain structural integrity during firing by suppressing sintering, thus achieving both compact size and electrode reliability.
3Manufacturing precision
If high melting point metals are added to alloy nickel particles to raise sintering temperature, then sintering inhibition is achieved, but cost increases and productivity decreases
Solution Approach 1:
The patent uses aluminum, which is a low-cost and abundant metal, instead of expensive high melting point metals. The nickel-aluminum alloy achieves effective sintering inhibition at high temperatures while maintaining cost-effectiveness and high productivity, replacing the need for costly alternative materials.
Solution Approach 2:
The patent changes the alloying element parameter from expensive high melting point metals to aluminum, which provides comparable or superior sintering inhibition effects at lower cost. This parameter change in material composition resolves the contradiction between sintering control and productivity.
4Quantity of substance
If nickel particles are microparticulated to fill sufficient particles in thinned internal electrode sheets, then electrode layer density increases, but over-sintering accelerates and electrode cuttings increase
Solution Approach 1:
The patent uses composite nickel-aluminum alloy particles with microparticulated structure. The aluminum component in the alloy suppresses sintering even at fine particle sizes, allowing high particle density in thin electrode layers without accelerating over-sintering. This composite material approach resolves the contradiction between particle density and sintering control.
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 use of NiAl and Ni3Al intermetallic compounds in internal electrode layers effectively suppresses shrinkage and maintains high conductivity, enhancing capacitor capacity and reducing structural defects like delamination and cracks, while avoiding the limitations of existing sintering inhibition methods.
Implementation Method 1
nickel particles become over-sintered at sintering temperature range of dielectric powders
Implementation Method 2
Incorporating intermetallic compounds such as NiAl and Ni3Al into the internal electrode layers, which raises the sintering temperature and inhibits shrinkage
Data Source
AI summary
An object of the present invention is to provide an electrode sintered body wherein shrinkage is prohibited and conductivity is good. An electrode sintered body including intermetallic compound comprising nickel and aluminum is provided. And then an internal electrode paste, which can inhibit shrinkage of an internal electrode layer, is manufactured by raising sintering temperature of conducting particle materials constituting internal electrode sheet to be internal electrode layers after firing. Further, a high-function multilayer electronic device using electrode paste for internal electrodes is manufactured.