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CN-121983427-A - X5R type high-capacitance multilayer ceramic capacitor and dielectric ceramic powder used for same and preparation method thereof

CN121983427ACN 121983427 ACN121983427 ACN 121983427ACN-121983427-A

Abstract

The invention belongs to the field of ceramic capacitor preparation, and particularly relates to an X5R type high-capacity multilayer ceramic capacitor and dielectric ceramic powder and a preparation method thereof, wherein the dielectric ceramic powder comprises a main component and an auxiliary additive, the molar ratio of the main component to the auxiliary additive is 100:4.35-6.50, the main component is Ba （1‑x） Y x Ti （1‑y） Zr y O 3 powder, wherein X is more than or equal to 0.001 and less than or equal to 0.002,0.05 and y is more than or equal to 0.10, the auxiliary additive comprises 3.5-4.5 parts of MgO, 0.10-0.20 parts of MnCO 3 , 0.05-0.10 parts of V 2 O 5 , 0.35-1.0 parts of SiO 2 and 0.35-0.70 parts of Re 2 O 3 , the average grain size of the dielectric ceramic powder prepared by the invention is less than 250nm, the capacitance temperature change rate in the working temperature range of-55 ℃ to 85 ℃ is more than or equal to +/-15%, the K value is more than 5000 mu F M omega, and the dielectric ceramic powder is suitable for small-sized and high-capacity X5R type multilayer ceramic capacitor.

Inventors

  • LUO PEIFU
  • JIANG RUIYONG
  • HONG ZHICHAO
  • Xiong Yuelong
  • CHEN YONGHONG

Assignees

  • 福建火炬电子科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260331

Claims (8)

  1. 1. The dielectric ceramic powder for the X5R type high-capacity multilayer ceramic capacitor comprises a main component and an auxiliary additive, and is characterized in that the molar ratio of the main component to the auxiliary additive is 100:4.35-6.50, the main component is Ba （1-x） Y x Ti （1-y） Zr y O 3 powder, wherein X is more than or equal to 0.001 and less than or equal to 0.002,0.05 and y is more than or equal to 0.10, the auxiliary additive comprises 3.5-4.5 parts of MgO, 0.10-0.20 part of MnCO 3 , 0.05-0.10 part of V 2 O 5 , 0.35-1.0 part of SiO 2 and 0.35-0.70 part of Re 2 O 3 , and Re is one of Dy and Ho.
  2. 2. The dielectric ceramic powder for the X5R-type high-capacity multilayer ceramic capacitor of claim 1, wherein the Ba （1-x） Y x Ti （1-y） Zr y O 3 is prepared by a hydrothermal synthesis method, and the synthesis steps are as follows: Step S1, adding 0.1-0.2 mole part of Y (NO 3 ) 3 ·6H 2 O, 5-10 mole parts of Zr (NO 3 ） 4 and 90-95 mole parts of TiCl 4 ) into deionized water under ice bath condition, stirring for more than 30 minutes until the Y (NO 3 ) 3 ·6H 2 O and the TiCl 4 are completely dissolved to form a precursor solution, adding 105 mole parts of Ba (OH) 2 ·8H 2 O into the deionized water, adding 0.01 mole part of PEG1000, heating to 60 ℃ and stirring for dissolving to obtain a barium source solution, slowly adding the precursor solution into the barium source solution, stirring for 30 minutes, and slowly adjusting the pH of the solution to 12-13 by using a dilute NaOH solution to obtain the Ba （1-x） Y x Ti （1-y） Zr y O 3 precursor solution; S2, transferring the Ba （1-x） Y x Ti （1-y） Zr y O 3 precursor solution into a polytetrafluoroethylene liner with the filling amount of 70 percent by hydrothermal back pressure, sealing and loading the polytetrafluoroethylene liner into a high-pressure reaction kettle, putting the reaction kettle into a constant-temperature oven, heating to 200-260 ℃ at the heating rate of 2-3 ℃ per minute, carrying out heat preservation treatment for 6-10 hours, and naturally cooling to room temperature; And S3, treating a product, taking out a white suspension in a reaction kettle, pouring the white suspension into a centrifuge tube, centrifuging at a speed of 6000r/min, washing the obtained precipitate with deionized water until the pH value of the washing solution is=7, transferring the precipitate to a stainless steel plate, drying the precipitate at 60 ℃ for 12 hours, and grinding the obtained solid powder with an agate mortar to obtain loose Ba （1-x） Y x Ti （1-y） Zr y O 3 powder.
  3. 3. The dielectric ceramic powder for X5R type high-capacity multilayer ceramic capacitor according to claim 1, wherein the particle size of Ba （1-x） Y x Ti （1-y） Zr y O 3 is smaller than 250nm, and the particle size of the auxiliary additive is smaller than 200nm.
  4. 4. The method for preparing the dielectric ceramic powder for the X5R-type high-capacity multilayer ceramic capacitor, which is disclosed in claim 1, is characterized by comprising the following specific steps: Mixing Ba （1-x） Y x Ti （1-y） Zr y O 3 powder with auxiliary additives, adding a solvent and zirconia balls, mixing, ball milling for 5-6 hours, drying and annealing to obtain the dielectric ceramic powder for the X5R-type high-capacity multilayer ceramic capacitor.
  5. 5. The method for preparing the dielectric ceramic powder for the X5R-type high-capacity multilayer ceramic capacitor according to claim 4, wherein the annealing environment is 600-700 ℃ and the annealing time is 1-3h, and the heating rate is 3 ℃ per minute.
  6. 6. The method for preparing dielectric ceramic powder for X5R type high-capacity multilayer ceramic capacitor as claimed in claim 4, wherein the size of the zirconia balls is 0.3-1.0mm.
  7. 7. An X5R type high-capacity multilayer ceramic capacitor which is characterized by being prepared from the dielectric ceramic powder as set forth in any one of claims 1 to 3.
  8. 8. The method for manufacturing an X5R type high-capacity multilayer ceramic capacitor according to claim 7, wherein the method comprises the following steps: step 1, uniformly mixing dielectric ceramic powder with ethanol, toluene, a dispersing agent, PVB resin and dioctyl phthalate in a ratio of 100:30:30:0.9:9.8:4.2 to obtain casting slurry; step 2, casting the slurry into a dielectric layer thin strip, wherein the thickness of the dielectric layer is 4 mu m, then printing a nickel electrode on the dielectric layer to form a dielectric layer, overlapping the dielectric layer and the dielectric layer in a staggered manner, and manufacturing a blank through water pressure and slicing; Degreasing the green body, sintering the degreased green body into a ceramic body in a reducing atmosphere at 1200-1230 ℃, and then performing reoxidation treatment; and 4, ball milling and chamfering the sintered ceramic body, leading out an electrode, adopting copper electrode slurry for end attachment, drying, and then performing sintering electroplating to obtain the X5R type high-capacity multilayer ceramic capacitor.

Description

X5R type high-capacitance multilayer ceramic capacitor and dielectric ceramic powder used for same and preparation method thereof Technical Field The invention belongs to the field of ceramic capacitor preparation, and particularly relates to an X5R type high-capacitance multilayer ceramic capacitor, dielectric ceramic powder used by the same and a preparation method thereof. Background The development of the multilayer ceramic capacitor (Multilayer Ceramic Capacitor, MLCC) always surrounds the aspects of market demand upgrading, technological breakthrough and domestic replacement, and under the condition of the same size and capacity, the dielectric film thickness of the MLCC with higher K value is higher, the reliability is better, the K value of the traditional ceramic powder is lower than 4000, and the continuous miniaturization of the MLCC is not facilitated. CN106747420A proposes a thin dielectric material for an X5R type multilayer ceramic capacitor and a preparation method thereof, which solve the problem of poor product reliability caused by uneven mixing of an oxide serving as a main additive and a main component in the original dielectric material, wherein the dielectric constant of the multilayer ceramic capacitor prepared by the dielectric material is more than or equal to 3500, the temperature characteristic accords with the X5R characteristic, and the average service life of the multilayer ceramic capacitor is more than 48 hours when a direct current voltage of 50V/um is applied at 150 ℃. CN115206679B proposes a dielectric ceramic composition and application thereof, and the ratio of Ra to Rb is regulated and controlled by regulating the R1 and Gd rare earth components, so that the dielectric ceramic composition has a higher dielectric constant, and the main dielectric constant is in the range of 3000-4500. CN114213120B proposes a main crystal phase pretreatment method for preparing X5R type ceramic dielectric material and capacitor thereof, and the dielectric constant range is 3800-4300. The K value of the above-mentioned patent is greatly improved compared with the K value of the conventional ceramic material, but the dielectric constant is still lower than 4500, so that the dielectric constant of the ceramic material needs to be continuously improved to realize the miniature high-capacity MLCC. With the high-speed development of AI computing power, the X5R type high-capacity MLCC has price advantage and great market potential on the batch deployment of computing power servers, and the high-capacity MLCC mainly develops towards the thinning direction of a dielectric layer in the future, and dielectric ceramic powder with high dielectric constant and high insulation resistance is the key for developing the thin-layer high-capacity MLCC. Therefore, how to improve the main crystal phase of the dielectric ceramic powder to increase the K value and reduce crystal defects, and optimize other component materials at the same time becomes one direction needing to be overcome with emphasis. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides an X5R type high-capacity multilayer ceramic capacitor, dielectric ceramic powder used by the same and a preparation method thereof. The invention adopts the following technical scheme: The dielectric ceramic powder for the X5R type high-capacity multilayer ceramic capacitor comprises a main component and an auxiliary additive, wherein the molar ratio of the main component to the auxiliary additive is 100:4.35-6.50, the main component is Ba （1-x）YxTi（1-y）ZryO3 powder, wherein X is more than or equal to 0.001 and less than or equal to 0.002,0.05 and y is more than or equal to 0.10, the auxiliary additive comprises 3.5-4.5 parts of MgO, 0.10-0.20 parts of MnCO 3, 0.05-0.10 parts of V 2O5, 0.35-1.0 parts of SiO 2 and 0.35-0.70 parts of Re 2O3, and Re is one of Dy and Ho. Further, the Ba （1-x）YxTi（1-y）ZryO3 is prepared by hydrothermal synthesis, and the synthesis steps are as follows: Step S1, adding 0.1-0.2 mole part of Y (NO 3)3·6H2 O, 5-10 mole parts of Zr (NO 3）4 and 90-95 mole parts of TiCl 4) into deionized water under ice bath condition, stirring for more than 30 minutes until the Y (NO 3)3·6H2 O and the TiCl 4 are completely dissolved to form a precursor solution, adding 105 mole parts of Ba (OH) 2·8H2 O into the deionized water, adding 0.01 mole part of PEG1000, heating to 60 ℃ and stirring for dissolving to obtain a barium source solution, slowly adding the precursor solution into the barium source solution, stirring for 30 minutes, and slowly adjusting the pH of the solution to 12-13 by using a dilute NaOH solution to obtain the Ba （1-x）YxTi（1-y）ZryO3 precursor solution; S2, transferring the Ba （1-x）YxTi（1-y）ZryO3 precursor solution into a polytetrafluoroethylene liner with the filling amount of 70 percent by hydrothermal back pressure, sealing and loading the polytetrafluoroethylene liner into a high-pressure r