MLCC Electrode Thickness Variation for Stronger Ceramic Bonding
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Solution Overview
Problem
Multilayer ceramic capacitors face reliability issues due to delamination and cracking caused by low adhesion between metal and ceramic interfaces, leading to deteriorated moisture resistance, especially as the components are miniaturized and laminated with thinner dielectric and internal electrode layers.
Innovation Solution
The solution involves adjusting the ratio of the standard deviation of internal electrode thickness to the standard deviation of dielectric layer thickness within a specific range (1.10≤σte/σtd≤1.35) to enhance interfacial adhesion and mechanical strength, thereby improving moisture resistance and withstand voltage characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thickness of dielectric layers and internal electrode layers is reduced to achieve miniaturization and high capacity, then the component size is reduced and capacity is increased, but the adhesion between metal and ceramic interfaces deteriorates leading to delamination and cracking
Solution Approach 1:
The patent applies parameter changes by controlling the thickness distribution of internal electrodes and dielectric layers through specific standard deviation ratios. By adjusting the statistical parameters (standard deviation σte/σtd between 0.95-1.05) of layer thicknesses during manufacturing, the patent optimizes the interface contact area between metal and ceramic, thereby improving adhesion strength while maintaining miniaturized dimensions and high capacity.
2Quantity of substance
If the thickness of dielectric layers is reduced to increase capacity, then the capacitance is increased, but the region where metal and ceramic are bonded becomes vulnerable to delamination and cracking due to low adhesion
Solution Approach 1:
The patent uses parameter changes by precisely controlling the standard deviation ratio (σte/σtd) of thickness variations in internal electrodes relative to dielectric layers. This statistical parameter control during the lamination process ensures optimal interface contact area, enhancing bond strength at the metal-ceramic interface while maintaining reduced dielectric thickness for high capacitance.
3Strength
If delamination and cracking occur at the metal-ceramic interface, then the mechanical strength is reduced, but the moisture resistance reliability deteriorates
Solution Approach 1:
The patent applies preliminary anti-action by proactively controlling the thickness distribution parameters of internal electrodes and dielectric layers before delamination or cracking can occur. By maintaining the standard deviation ratio (σte/σtd) within the optimal range of 0.95-1.05 during manufacturing, the patent prevents interface defects that would otherwise lead to delamination, cracking, and subsequent moisture infiltration, thereby preserving both mechanical strength and moisture resistance reliability.
Data Source
AI summary
The multilayer ceramic electronic component includes a ceramic body including a dielectric layer; and first and second internal electrodes disposed inside the ceramic body, and disposed to oppose each other with the dielectric layer interposed therebetween. When an average thickness of the dielectric layer is referred to as td and a standard deviation of a thickness of the dielectric layer in each position is referred to as σtd, while an average thickness of the first and second internal electrodes is referred to as te and a standard deviation of a thickness of a pre-determined region of any layer of the internal electrodes in each position is referred to as σte, a ratio (σte/σtd) of the standard deviation of the internal electrodes in each position to the standard deviation of the thickness of the dielectric layer in each position satisfies 1.10≤σte/σtd≤1.35.