Multilayer Ceramic Capacitor Applications Research Articles

CaTiO3 nanoparticles as functional additives for the BaTiO3-based X8R type dielectric ceramics

This research investigates the potential of Calcium titanate (CaTiO3 or CT) nanoparticles as functional additives to enhance the dielectric properties of Barium titanate (BaTiO3 or BT)-based ceramic dielectrics. To address the need for high-temperature stability in MLCC (multilayer ceramic capacitor) applications, especially within the automotive and aerospace sectors, we have explored BT-based complex perovskite solid solutions comprising various cation substitutions, including Ca2+ and Yb3+, into barium titanate (BT) as a method to suppress the dielectric property anomaly near the Curie temperature effectively. The focus is on the impact of the application of CT nanoparticles as additive materials on phase formation, microstructure development, and dielectric behavior of the resulting ceramics to align with the Extended 'Temperature Coefficient of Capacitance (TCC)' criteria defined by the EIA X8R specification. When the hydrothermally synthesized CT nanopowder was applied in the Ca-doped BT ceramics fabrications as source material of the Ca dopants, it was beneficial to achieve both temperature stability and high dielectric constant. The CT nanoparticles are believed to play multiple roles during the solid-state reaction with BT and rare earth dopant (Yb). Since the Yb3+ ions can be more easily dissolved into the CT lattice than BT with their amphoteric character, the CT nanoparticles in the BT-CT-Yb2O3 mixture can act as an intermediary, dissolving the Yb3+ first in its A- or B-site before the final solid-solution formation with the BT. The sequential substitutions of the Yb3+ and Ca2+ into BT via CT nanoparticles could affect the site occupancy of Ca2+ in the BT lattice, which is very important in determining the dielectric properties of the Ca-doped BT processed in reducing atmospheres. Through a comprehensive experimental approach, including phase composition analysis via X-ray diffraction (XRD) and microstructural examination using Field Emission Scanning Electron Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM), this work reveals the significance of synthetic methodology and dopant incorporation strategy on achieving a desired core-shell microstructure and improved dielectric performance. This research underscores the efficacy of CT nanoparticles as a promising route towards the development of BT-based dielectric ceramics with superior temperature stability, offering valuable insights for the advancement of MLCC technology to cater to high-temperature applications.

Structural, relaxor behavior, and energy storage performance of BaTiO3–Bi (Mg2/3Nb1/3)O3 solid solutions for potential MLCC application

In the discussed work, (1-x) BaTiO3 (BT)-x Bi(Mg2/3Nb1/3)O3 (BMN) solid-combinations have been synthesized via the solid-state process; and both corresponding dielectric and ferroelectric behavior have been learned for possible Multilayer Ceramic Capacitor (MLCC) applications. The phase confirmation has been identified utilizing X-ray diffraction; and Rietveld refinement technique has been used for structural analysis that unveils the formation of pure perovskite structure of the prepared ceramics. Rietveld refinement results reveal the structural changeover from tetragonal to pseudo-cubic for x≥0.125. Raman spectroscopy measurements confirm the structural phase changes and lattice modifications due to the chemical substitutions. Microstructural analysis has been done with the help of electron micrograph. Dielectric performance of the synthesized (1-x)BaTiO3(BT)-xBi(Mg2/3Nb1/3)O3(BMN) solid solutions has been examined within a temperature range of 173K–473K at different applied frequencies. A broad phase transition and relaxor character is detected from dielectric investigation. The relaxor behavior has been quantified by the Vogel-Fulcher fitting. The thermal stability of the prepared samples was calculated by means of standard formula of Temperature Coefficient of Capacitance (TCC). Hysteresis loop was undertaken to identify the ferroelectric properties and energy storage capacity. Among all the compositions, x = 0.10 shows good thermal stability, an elevated recoverable energy density; and a remarkable efficiency that makes it suitable for MLCC applications.

Investigation of moisture-induced crack propagation in the soft-termination multi-layer ceramic capacitor during thermal reflow process

Purpose This study aims to investigate crack propagation in a moisture-preconditioned soft-termination multi-layer ceramic capacitor (MLCC) during thermal reflow process. Design/methodology/approach Experimental and extended finite element method (X-FEM) numerical analyses were used to analyse the soft-termination MLCC during thermal reflow. A cross-sectional field emission scanning electron microscope image of an actual MLCC’s crack was used to validate the accuracy of the simulation results generated in the study. Findings At 270°C, micro-voids between the copper-electrode and copper-epoxy layers absorbed 284.2 mm/mg3 of moisture, which generated 6.29 MPa of vapour pressure and caused a crack to propagate. Moisture that rapidly vaporises during reflow can cause stresses that exceed the adhesive/substrate interface’s adhesion strength of 6 MPa. Higher vapour pressure reduces crack development resistance. Thus, the maximum crack propagation between the copper-electrode and copper-epoxy layers at high reflow temperature was 0.077 mm. The numerical model was well-validated, as the maximum crack propagation discrepancy was 2.6%. Practical implications This research holds significant implications for the industry by providing valuable insights into the moisture-induced crack propagation mechanisms in soft-termination MLCCs during the reflow process. The findings can be used to optimise the design, manufacturing and assembly processes, ultimately leading to enhanced product quality, improved performance and increased reliability in various electronic applications. Moreover, while the study focused on a specific type of soft-termination MLCC in the reflow process, the methodologies and principles used in this research can be extended to other types of MLCC packages. The fundamental understanding gained from this study can be extrapolated to similar structures, enabling manufacturers to implement effective strategies for crack reduction across a wider range of MLCC applications. Originality/value The moisture-induced crack propagation in the soft-termination MLCC during thermal reflow process has not been reported to date. X-FEM numerical analysis on crack propagation have never been researched on the soft-termination MLCC.

Dielectric and anti-reduction properties of BaTiO3-based ceramics for MLCC application

BaTiO3 ceramics doped with different contents of Co2O3(abbreviated as (1-x) BT-xCo2O3) and (1-x) BaTiO3-xBiCoO3(abbreviated as (1-x) BT-xBC) ceramics were prepared via conventional solid-state process and sintered in reducing atmosphere. The main crystal phase of both ceramic samples was characterized by X-ray diffraction (XRD), which was perovskite structure. Compared with (1-x) BT-xCo2O3, (1-x) BT-xBC ceramic samples were dense with uniform microstructure confirmed by scanning electron microscopy (SEM). The 0.95BT-0.05BC ceramics had good dielectric properties, with ε25°C = 2670, tanδ = 0.012, and resistivity was 1.71 × 1011 Ω cm at 25°C, meeting the X7S standard for multilayer ceramic capacitor (MLCC) applications. The mechanism of improved anti-reduction property of (1-x) BT-xBC ceramics was studied by X-ray photoelectron spectroscopy (XPS) and thermally stimulated depolarization current (TSDC) techniques. The XPS results showed that there were two valence states of Co in 0.95BT-0.05BC and 0.95BT-0.05Co2O3 ceramics, indicating that the introduction of Co can improve anti-reduction property of BT-based ceramics. The TSDC revealed the formation of defect dipoles [2CoTi’−Vo▪▪], which was considered to be the cause for the improvement in anti-reduction property.

Investigation of Dielectric and Energy Storage Performance of (1-x)BaTiO3-xBi(Zn2/3Nb1/3)O3 Ceramic for Possible MLCC Application

The dielectric and energy-storage performance of (1-x)BaTiO3(BT)-xBi(Zn2/3Nb1/3)O3(BZN) [0 ≤ x ≤ 0.15] materials are presented in this manuscript for potential multilayer ceramic capacitor application. The solid-state reaction method is adapted for the preparation of the ceramics. X-ray diffraction patterns of the ceramics reveal the formation of pure perovskite pseudo-cubic structure with space group P m −3 m. Temperature and frequency-dependent dielectric behavior are analyzed to understand the change in dielectric performance with the rise in BZN concentration. The degree of diffuseness in the phase transition has been analyzed by using the modified Curie-Weiss Law. The temperature Coefficient of Capacitance (TCC) has been calculated to analyze the thermal stability of the material. The P-E hysteresis loop measurement has been carried out at different applied fields and found that 0.15 mol% of BT-BZN can withstand maximum electric field exposure without undergoing any electrical breakdown. The energy storage efficiency is calculated for all the compositions and maximum efficiency is obtained for x = 0.15. The frequency-dependent P-E hysteresis is carried out and frequency stability of polarization is obtained for 0.85BT-0.15 BZN ceramic.

Investigation into the crystal structure-dielectric property correlation in barium titanate nanocrystals of different sizes.

For high capacitance multilayer ceramic capacitors, high dielectric constant and lead-free ceramic nanoparticles are highly desired. However, as the particle size decreases to a few tens of nanometers, their dielectric constant significantly decreases, and the underlying mechanism has yet to be fully elucidated. Herein, we report a systematic investigation into the crystal structure-dielectric property relationship of combustion-made BaTiO3 (BTO) nanocrystals. When the nanocrystal size was 100 nm and below, a metastable paraelectric cubic phase was found in the as-received BTO (denoted as arBTO) nanocrystals based on an X-ray diffraction (XRD) study. A stable ferroelectric tetragonal phase was present when the nanocrystal size was above 200 nm. Notably, the cubic arBTO (particle size ≤100 nm) exhibited tetragonal fluctuations as revealed by Raman spectroscopy, whereas the tetragonal arBTO (particle size ≥200 nm) contained ∼10% cubic fraction according to the Rietveld fitting of the XRD profiles. Thermal annealing of the multi-grain tetragonal arBTO at 950 °C yielded single crystals of annealed BTO (denoted as anBTO), whose dielectric constants were higher than those of arBTO. However, the single crystalline anBTO prevented the formation of 90° domains; therefore, they exhibited a low dielectric constant of ∼300. Although X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy could not identify the exact structural defects, our study revealed that surface and bulk defects formed during synthesis affect the final crystal structures and thus the dielectric properties of BTO nanocrystals with different sizes. The understanding obtained from this study will help us design high dielectric constant perovskite nanocrystals for next-generation multilayer ceramic capacitor applications.

Influence of MnO2 addition on the dielectric properties of 0.95MgTiO3-0.05CaTiO3 ceramics sintered in a reducing atmosphere

The increasing cost of palladium has demonstrated the significant value of using inexpensive base metals as inner electrodes for RF/microwave multilayer ceramic capacitors. However, solving the co-sintering problem of dielectric ceramics with base metals such as copper is highly challenging, as sintering in a reducing atmosphere is required to prevent the oxidation of the base metals. In this work, the feasibility of sintering nonreducible MnO2-doped 0.95MgTiO3-0.05CaTiO3 (95MCT) ceramics in a reducing atmosphere (H2-N2, pO2=1×10−10∼1×10−11MPa) at 1000 °C was investigated. The effects of the MnO2 additive (1.6–2.4 mol%) on the phase structures, dielectric properties, and thermal stability were studied. Thermally stimulated depolarization current (TSDC) analysis and X-ray photoelectron spectroscopy (XPS) were conducted to characterize the oxygen vacancies and Mn ion valence state in MnO2-doped ceramics, indicating that Mn plays an important role in the dielectric properties, especially the extrinsic dielectric loss. With the optimized addition of 2.0 mol% MnO2, due to the decrease in oxygen vacancy concentration, the samples with εr=20.22 exhibited the attractive properties of a high insulation resistivity of IR =3.65×1014 Ω∙cm and a low dielectric loss of tanδ=0.036%, meeting the C0G specifications. The results show that the 2.0 mol% MnO2-doped 0.95MgTiO3-0.05CaTiO3 ceramic is an outstanding nonreducible dielectric material for base-metal electrode RF/microwave multilayer ceramic capacitor applications with low cost, excellent dielectric properties, and high reliability.

Microstructural, mechanical and electrical properties of BT, BZT-BCT, and BNT-BT-BKT ferroelectrics synthesized by mechanochemical route

BaTiO3 (BT), 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT), 85.4(Bi0.5Na0.5)TiO3-2.6(BaTiO3)-12(Bi0.5K0.5)TiO3 (BNT-BT-BKT) lead free ferroelectric ceramics were synthesized by high energy ball milling (HEBM) assisted solid-state reaction route. The Crystallite size of the HEBM powders was found to be in the nano-range. XRD, SEM, dielectric, polarization vs. electric field (P-E) loop and mechanical characterizations and analysis of these sintered ceramics were carried out. Lower calcination and sintering temperatures along with better densification with the lower average grain size of these ceramics were optimized and obtained compared to the same systems synthesized by the solid-state reaction route. Enhanced values at room temperature (RT) of εr~2875, 5133, and 1701 and lower values of tanδ~0.013, 0.015, and 0.058 were obtained for BT, BZT-BCT, and BNT-BT-BKT sintered ceramics, respectively. Well saturated P-E loops were obtained for all the ceramics, which confirmed their ferroelectric behaviour. Hardness value ~7.23 GPa, 5.53 GPa, and 5.16 GPa were found for BT, BZT-BCT, and BNT-BT-BKT sintered ceramics, respectively. The temperature coefficient of capacitance, TCC, was obtained within ±15% in the temperature range from RT tõ135 °C for BT ceramics with high εr and low value of tanδ, which suggested its usefulness for multilayer ceramic capacitor (MLCC) applications.

Fabrication of high quality factor cold sintered MgTiO3–NaCl microwave ceramic composites

Magnesium titanate is a well-known low loss dielectric ceramic, widely used in dielectric resonator and multilayer ceramic capacitor applications. But its high sintering temperature (1400°C) results in high energy consumption and thereby increases the environmental pollution and production cost. Furthermore, traditional sintering methods restrict co-sintering of ceramics with low melting metals and polymers. Cold Sintering Process (CSP) which provides a simple, effective and energy saving strategy for ceramic fabrication has not yet been reported for the fabrication of magnesium titanate based microwave dielectric ceramics. In the present work, dense samples of xMgTiO3-(1-x)NaCl (x = 0–0.5) ceramic composites were successfully prepared by cold sintering process (CSP) for the first time, at < 250°C, in 30 min,under a uniaxial pressure of 450 MPa. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) reveal that both MgTiO3 and NaCl co-exist in all the composites without any chemical reaction between the two phases. Raman spectra and scanning electron micrograph of MgTiO3 confirm the presence of MgTi2O5 as indicated by XRD. Relative permittivity (εr) of xMgTiO3- (1-x)NaCl composite increases and temperature coefficient of resonant frequency (TCF) decreases with increasing x; Qxf shows a non-linear variation with a maximum value of 29,500 GHz at x = 0.2. Results indicate that density, grain size and homogeneity of the particles influence the Qxf value of the composites. This study highlights the potential of cold sintering for the fabrication of MgTiO3 based composites with competitive microwave dielectric properties.

High permittivity and excellent high‐temperature energy storage properties of X9R BaTiO3–(Bi0.5Na0.5)TiO3 ceramics

AbstractWe fabricated x(Bi0.5Na0.5)TiO3–(1−x)[BaTiO3–(Bi0.5Na0.5)TiO3–Nb] (BNT‐doped BTBNT‐Nb) dielectric materials with high permittivity and excellent high‐temperature energy storage properties. The initial powder of Nb‐modified BTBNT was first calcined and then modified with different stoichiometric ratios of (Bi0.5Na0.5)TiO3 (BNT). Variable‐temperature X‐ray diffraction (XRD) results showed that the ceramics with a small amount of BNT doping consisted of coexisting tetragonal and pseudocubic phases, which transformed into the pseudocubic phase as the test temperature increased. The results of transmission electron microscopy (TEM) showed that the ceramic grain was the core‐shell structure. The permittivity of the 5 mol% BNT‐doped BTBNT‐Nb ceramic reached up to 2343, meeting the X9R specification. The discharge energy densities of all samples were 1.70‐1.91 J/cm3 at room temperature. The discharge energy densities of all samples fluctuated by only ±5% over the wide temperature range from 25°C to 175°C and ±8% from 25°C to 200°C. The discharge energy density of the 50 mol% BNT‐doped BTBNT‐Nb ceramic was 2.01 J/cm3 at 210 kV/cm and 175°C. The maximum energy efficiencies of all ceramics were up to ~91% at high temperatures and were much better than those at room temperature. The stable dielectric properties within a wide temperature window and excellent high‐temperature energy storage properties of this BNT‐doped BTBNT‐Nb system make it promising to provide candidate materials for multilayer ceramic capacitor applications.

Anti-reductive characteristics and dielectric loss mechanisms of Ba2ZnSi2O7 microwave dielectric ceramic

Abstract Ba2ZnSi2O7 ceramic was prepared by conventional solid-state method and sintering under four different atmospheres (air, O2, N2, and N2–1 vol% H2). The Ba2ZnSi2O7 ceramic exhibited a single phase under air, O2, and, N2, whereas two phases (including BaSiO3 impurity) were observed under the N2–1 vol% H2 atmosphere due to Zn2+ evaporation. Dielectric loss was proportional to oxygen partial pressure due to the conduction mechanism of dominant holes. The Ba2ZnSi2O7 ceramic exhibited good microwave dielectric properties (er = 8.3, Q × f = 27200 GHz, τf = −41.5 ppm/°C) under the N2–1 vol% H2 atmosphere, making it a novel candidate with good anti-reductive characteristics for base metal electrode–multilayer ceramic capacitor applications.

Superior energy storage properties and excellent stability of novel NaNbO3-based lead-free ceramics with A-site vacancy obtained via a Bi2O3 substitution strategy

Novel environment-friendly NaNbO3-based lead-free ceramics with ultrahigh energy storage density and power density for multilayer ceramic capacitor applications.

Superior Reliability Via Two‐Step Sintering: Barium Titanate Ceramics

Two‐step sintering (TSS) in a reducing atmosphere has been employed to obtain fine‐grain BaTiO3 ceramics with a core‐shell microstructure, a more uniform grain‐size distribution, and superior reliability for multilayer ceramic capacitor applications. Compared to ceramics of the same composition conventionally sintered for about the same time, TSS ceramics feature a thinner shell thickness thus a stronger dopant localization, which leads to a lower concentration, higher internal resistance and more dopant‐ association. Improved reliability is manifest in a 50% higher breakdown strength at ambient temperature and a 400% longer endurance time to withstand DC stress at 185°C, in addition to a less field‐and‐temperature‐dependent capacitance. A scaling analysis of the redistribution and endurance dynamics identifies transmission across the shell‐grain‐boundary region as the critical element beneficially impacted by core‐shell structure and two‐step sintering.

Microstructure and dielectric properties of (K0.5Na0.5)NbO3–Bi(Zn2/3Nb1/3)O3 − xmol%CeO2 lead-free ceramics for high temperature capacitor applications

(K0.5Na0.5)NbO3–Bi(Zn2/3Nb1/3)O3 − xmol%CeO2 [0.97KNN–0.03BZN − xCeO2] lead-free ceramics were synthesized and the phase structure, microstructure and dielectric properties were investigated. Dielectric studies reveal that the 0.97KNN–0.03BZN − 1.0CeO2 ceramics show excellent dielectric properties at a broad usage temperature range (150–350 °C): the dielectric permittivity is near 1900 (at 10 kHz) with the capacitance variation (ΔC/C150 °C) no more than ±10 %; the temperature coefficient of permittivity (TCe) is as low as −162 ppm/°C; the corresponding dielectric loss is less than 2.5 %. These results indicate that the 0.97KNN–0.03BZN − 1.0CeO2 ceramics are promising candidates for high temperature multilayer ceramic capacitor applications.

Electrical and reliability characteristics of Mn-doped nano BaTiO3-based ceramics for ultrathin multilayer ceramic capacitor application

Nano BaTiO3-based dielectric ceramics were prepared by chemical coating approach, which are promising for ultrathin multilayer ceramic capacitor (MLCC) applications. The doping effects of Mn element on the microstructures and dielectric properties of the ceramics were investigated. The degradation test and impedance spectroscopy were employed to study the resistance degradation and the conduction mechanism of Mn-doped nano-BaTiO3 ceramic samples. It has been found that the reliability characteristics greatly depended on the Mn-doped content. Moreover, the BaTiO3 ceramic with grain size in nanoscale is more sensitive to the Mn-doped content than that in sub-micron scale. The addition of 0.3 mol. % Mn is beneficial for improving the reliability of the nano BaTiO3-based ceramics, which is an important parameter for MLCC applications. However, further increasing the addition amount will deteriorate the performance of the ceramic samples.

Fabrication of BaTiO3-Based Dielectrics for Ultrathin-Layer Multilayer Ceramic Capacitor Application by a Modified Coating Approach

The development of multilayer ceramic capacitor (MLCC) with base metal electrode (BME) requires precise controlling of the microstructure in a very thin dielectric layer (<1 µm). In this paper, a modified coating approach for high coverage of BaTiO3 powder for further MLCC application has been developed. The well dispersed and coated BaTiO3 powders are prepared and the relative mechanism has been discussed. Furthermore, the ultrafine grained X7R dielectric ceramics were produced by both conventional mixing and modified coating methods. Compared with the conventional mixing method, the ceramics prepared by the coating approach exhibited better TCC (the temperature coefficient of capacitance) performance, with dielectric constant over 2000 and grain size below 150 nm. In addition, it is found through the coating method the content of additives can be reduced to a relatively smaller amount than that required in conventional mixing method.

Fabrication of BaTiO3-Based Dielectrics for Ultrathin-Layer Multilayer Ceramic Capacitor Application by a Modified Coating Approach

The development of multilayer ceramic capacitor (MLCC) with base metal electrode (BME) requires precise controlling of the microstructure in a very thin dielectric layer (<1 µm). In this paper, a modified coating approach for high coverage of BaTiO3 powder for further MLCC application has been developed. The well dispersed and coated BaTiO3 powders are prepared and the relative mechanism has been discussed. Furthermore, the ultrafine grained X7R dielectric ceramics were produced by both conventional mixing and modified coating methods. Compared with the conventional mixing method, the ceramics prepared by the coating approach exhibited better TCC (the temperature coefficient of capacitance) performance, with dielectric constant over 2000 and grain size below 150 nm. In addition, it is found through the coating method the content of additives can be reduced to a relatively smaller amount than that required in conventional mixing method.

Synthesis and Characterization of Nano-Barium Titanate Prepared by Hydrothermal Process

Capacitors are the most convenient and economical devices for storage of electrical energy. Performance of a capacitor is primarily governed by solid-state characteristics of its dielectric material and the explicit value of the dielectric constant. Titanate ceramics such as Barium Titanate are popular capacitor dielectric materials because of their high dielectric constant and ferroelectric properties. In recent years, extensive research work has been done on Barium Titanate for multilayer ceramic capacitor application. Barium Titanate has been synthesized from high energy ball-milling process and sol-gel process or a thermo-chemical process. However, because of contamination from the grinding media, relatively wide particle size distribution and abnormal grain growth during the sintering, other novel synthesis processes have been developed. Nano-technology based hydrothermal synthesis is one such new process. In this paper, an effort has been made to synthesize nanocrystalline Barium Titanate through hydrothermal process. Characterization of the synthesized Barium Titanate is carried out by using X-ray diffraction for crystalline structure, scanning electron microscopy for microstructure and electron dispersive spectroscopy for chemical composition. Electric properties such as dielectric constant, dielectric dissipation factor and electrical resistivity have been measured. It has been observed that dielectric constant of about 4000 and dielectric dissipation factor of below 0.3 are obtained over a wide range of frequencies. The crystallite size of the optimized material is less than 50 nm.

Formation of Core‐Shell Structure in Ultrafine‐Grained BaTiO3‐Based Ceramics Through Nanodopant Method

The formation of core‐shell structure is the key issue of temperature stable barium titanate‐based dielectric ceramic for multilayer ceramic capacitor application. It is difficult to obtain and observe the core‐shell structure in ceramic grains when the grain size becomes smaller, especially to sizes &lt;200 nm. A nanodopant method has been developed for the preparation of ultrafine‐grained barium titanate‐based ceramics with grain size below 200 nm. The existence of core‐shell structure was proved by transmission electron microscopy observation and energy‐dispersive spectroscopy analysis. High‐performance X7R dielectric ceramics were produced in a reducing atmosphere by normal sintering and two‐step sintering method. The dielectric constant at room temperature could reach over 2000, with a low dielectric loss at about 1.0% and high insulation resistivity ∼1012Ω·cm.

Preparation of Nano BaTiO3‐Based Ceramics for Multilayer Ceramic Capacitor Application by Chemical Coating Method

The base‐metal‐electrode multilayer ceramic capacitors (BME MLCCs) for future application require much thinner dielectric layers (&lt;1 μm). Therefore, the grain size and uniformity of BME MLCC powders should be effectively controlled. In this paper, the nanosized BME MLCC powders were prepared by chemical coating method. The well‐coated BaTiO3 particles were obtained by adjusting an appropriate pH value. Transmission electron microscopy, energy‐dispersive spectroscopy, X‐ray photoelectron spectrum were utilized for the study of microstructures and element analysis. The high‐performance X7R dielectric ceramics were produced in reducing atmosphere by “two‐step” sintering method at a low temperature of 950°C. The dielectric constant at room temperature could reach ∼2400, with low dielectric loss below 1.0% and high insulation resistivity ∼1012Ω·cm. The ceramic grains were very homogenous with the average size below 150 nm.