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KR-20220081259-A - Hydrothermal method of Barium Titanate doped metal atom, and Barium Titanate Nano Rods for multi layer ceramic capacitor and manufacturing method Thereof, and Multi Layer Ceramic Capacitor

KR20220081259AKR 20220081259 AKR20220081259 AKR 20220081259AKR-20220081259-A

Abstract

The present invention relates to a method for hydrothermal synthesis of barium titanate doped with a metal element, a barium titanate nanorod for a multilayer ceramic capacitor, a method for manufacturing the same, and a multilayer ceramic capacitor, comprising: 3(TiO 2 )·H 2 O precursor doped with a metal element We propose a method for hydrothermal synthesis with a barium compound based on the hydrothermal synthesis method, manufacturing barium titanate nanorods for multilayer ceramic capacitors using this hydrothermal synthesis method, and applying the barium titanate nanorods prepared in this way as dielectric material for multilayer ceramic capacitors. characterized. According to the present invention, particle size, shape, and degree of crystallinity can be controlled through a hydrothermal synthesis process based on 3(TiO 2 )·H 2 O precursor and doping with metal elements, and without additional firing or pulverization processes A single-phase barium titanate nanorod can be manufactured, and through this, it can be applied to X7R-class or X8R-class multilayer ceramic capacitors to ensure reliable operation according to temperature characteristics and exhibit excellent characteristics. Not only can it be manufactured, but it can also provide advantages of increasing mass productivity while lowering the production cost.

Inventors

  • KIM DONG WAN
  • KIM JAE CHAN
  • CHOI CHANGHOON
  • PARK JONG CHEL
  • KIM WOONG JU
  • PARK JUNG BEEN

Assignees

  • UNIV KOREA RES & BUS FOUND

Dates

Publication Date
20220615
Application Date
20210928
Priority Date
20201207

Claims (20)

  1. Titanic acid doped with a metal element, characterized in that by hydrothermal synthesis of a metal element-doped 3(TiO 2 )·H 2 O precursor with an aqueous Ba(OH) 2 ·8H 2 O solution to obtain barium titanate doped with a metallic element. Barium hydrothermal synthesis method.
  2. (A) 3(TiO 2 ).H 2 O preparing a precursor; (B) synthesizing a 3(TiO 2 )·H 2 O precursor doped with a metal element by adding a metal element to the 3(TiO 2 )·H 2 O precursor; (C) hydrothermal synthesis of the metal element-doped 3(TiO 2 )·H 2 O precursor with a Ba(OH) 2 ·8H 2 O aqueous solution to obtain barium titanate; A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that it consists of
  3. 3. The method of claim 1 or 2, The metal element is At least one of Mn, Fe, Ni, Co, Mg, Sn, Ge, Si, Bi, Pb, Ca, Cu, Zn, Nb, Al, V, Eu, Y, Dy, Gd, and La is used. A method for hydrothermal synthesis of barium titanate doped with a metallic element,
  4. 3. The method of claim 1 or 2, The metal element is A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that it is added within the range of 0.5 mol% to 60 mol%.
  5. 3. The method of claim 1 or 2, The barium titanate obtained by the hydrothermal synthesis has a structure of [Ba 1-x M' x Ti 1-y M" y O 3 ]. A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that
  6. 6. The method of claim 5, In the structure of [Ba 1-x M' x Ti 1-y M" y O 3 ], M' is Ca, and M" is any one of Mn, Mg, and Si. A method for hydrothermal synthesis of barium titanate doped with a metal element,
  7. 7. The method of claim 6, A method for hydrothermal synthesis of barium titanate doped with a metallic element, characterized in that the Mn content is within 2 mol%, the Mg content is within 0.6 mol%, the Si content is within 1 mol%, and the Ca content is within 50 mol%,
  8. 7. The method of claim 6, In the structure of [Ba 1-x M' x Ti 1-y M" y O 3 ], At least one of Fe, Ni, Co, Sn, Ge, Bi, Pb, Cu, Zn, Nb, Al, V, Eu, Y, Dy, Gd, La is replaced by M' or M" A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that it is added or synthesized.
  9. 3. The method of claim 2, The step (A) is, (a) a process of dissolving the TiO 2 raw material in a NaOH solvent and then stirring and ultrasonically dispersing for 1 hour; (b) putting the solution obtained in step (a) into a hydrothermal synthesis reactor and reacting at 160° C. to 200° C. for 24 hours to 48 hours; (c) washing the solution obtained through (b) with demineralized water and then ion-exchanging the solution in HCl; (d) washing the solution obtained through the process (c) with demineralized water and then using a centrifuge to obtain a 3(TiO 2 )·H 2 O precursor; A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that it comprises a.
  10. 10. The method of claim 9, The step (B) is, (1) a process of dissolving an additive containing a metal element in demineralized water; (2) 3(TiO 2 )·H 2 O precursor obtained in step (A) is immersed in the solution obtained in step (1) for 10 to 16 hours and 3(TiO 2 )·H doped with a metal element the process of synthesizing 2 O precursors; (3) the process of washing the solution obtained through the process (2) with demineralized water and then freeze-drying it into a powder; A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that it comprises a.
  11. 11. The method of claim 10, The additive is Mg(CH 3 COO) 2 , Mn(NO 3 ) 2 , Zn(NO 3 ) 2 A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that it is one selected from the group consisting of Mg(CH 3 COO) 2 .
  12. 10. The method of claim 9, The step (B) is, (1) After preparing a mixed solution by mixing Tetraethyl orthosilicate solution and demineralized water, Fe, Ni, Co, Sn, Ge, Si, Bi, Pb, Ca, Cu, Nb, Al, a process of dissolving at least one of V, Eu, Y, Dy, Gd, and La; (2) 3(TiO 2 )·H 2 O precursor obtained in step (A) is immersed in the solution obtained in step (1) for 10 to 16 hours and 3(TiO 2 )·H doped with a metal element the process of synthesizing 2 O precursors; (3) washing the solution obtained through the process (2) with demineralized water or ethanol, then freeze-drying to powder; A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that it comprises a.
  13. 13. The method of claim 10 or 12, The step (C) is, ① The process of dissolving Ba(OH) 2 ·8H 2 O in demineralized water; ② Put the 3(TiO 2 )·H 2 O precursor powder doped with the metal element obtained in step (B) into the Ba(OH) 2 ·8H 2 O aqueous solution obtained through the step ①, and for 20 to 40 minutes agitation and ultrasonic dispersion; ③ The process of obtaining an aqueous solution having barium titanate crystals by putting the solution obtained in the above ② process into a hydrothermal synthesis reactor and reacting at 100° C. to 250° C. for 1 hour to 5 hours; ④ The process of washing the aqueous solution having barium titanate crystals obtained through the above step ③ with an HCl solution, further washing with demineralized water, and then drying at 80°C to 100°C; A method for hydrothermal synthesis of barium titanate doped with a metal element, characterized in that it comprises a.
  14. 14. The method of claim 13, The molar ratio (Ba/Ti) of barium (Ba) and titanium (Ti) reacting with each other in the process ② is 1.0 to 2.0.
  15. 15. A barium titanate nanorod for a multilayer ceramic capacitor, characterized in that it is obtained by the hydrothermal synthesis method of barium titanate doped with a metal element according to any one of claims 1 to 14.
  16. barium titanate compounds; a metal element doped with the barium titanate compound; Barium titanate nanorods for multilayer ceramic capacitors, comprising:
  17. 17. The method of claim 16, The metal element is Mn, Fe, Ni, Co, Mg, Sn, Ge, Si, Bi, Pb, Ca, Cu, Zn, Nb, Al, V, Eu, Y, Dy, Gd, characterized in that at least one or more of La Barium titanate nanorods for multilayer ceramic capacitors.
  18. 17. The method of claim 16, The barium titanate nanorods, Barium titanate nanorods for multilayer ceramic capacitors, characterized in that they are crystal grains or quantum dots.
  19. 17. The method of claim 16, The barium titanate nanorods, Barium titanate nanorods for multilayer ceramic capacitors, characterized in that the average length is 2 μm to 10 μm and the average diameter is 100 nm to 500 nm.
  20. 17. The method of claim 16, The barium titanate nanorods, [Ba 1-x M' x Ti 1-y M" y O 3 ] Barium titanate nanorods for multilayer ceramic capacitors, characterized in that they have a structure.

Description

BACKGROUND OF THE INVENTION Field of the Invention manufacturing method Thereof, and Multi Layer Ceramic Capacitor} The present invention relates to a method for hydrothermal synthesis of barium titanate doped with a metal element, a barium titanate nanorod for a multilayer ceramic capacitor using the same, a method for manufacturing the same, and a multilayer ceramic capacitor, and more particularly, through a hydrothermal synthesis process of doping a metal element Barium titanate sequence doped with metal elements to synthesize barium titanate and use it as a dielectric material for multilayer ceramic capacitors, as well as to increase the sinterability between the internal electrode layer and the dielectric layer, and to realize X7R class or X8R class multilayer ceramic capacitors The present invention relates to a synthesis method, a barium titanate nanorod for a multilayer ceramic capacitor using the same, a manufacturing method therefor, and a multilayer ceramic capacitor. In general, a multi-layer ceramic capacitor (hereinafter referred to as 'MLCC') is a C (Capacitor) that occupies the largest portion of the circuit passive components (R, L, C) of electronic products, and constitutes the circuit. It is an essential component that temporarily stores and discharges electric charges. These MLCCs maintain a constant flow of current for stable circuit operation and prevent electromagnetic interference. BaTiO 3 (BT; barium titanate) is used to form a thick film and laminate It is manufactured by simultaneous sintering with the electrode. The BaTiO 3 is a core material occupying about 65% of various materials constituting the MLCC, and is used as a dielectric material for the MLCC. As shown in FIG. 1 , the MLCC has a stacked structure including a dielectric layer 1 , an internal electrode layer 2 , and an external electrode layer 3 , and a plating layer may be formed on the external electrode layer 3 . On the other hand, MLCC can be broadly divided into IT equipment and electronic equipment. Compared to IT MLCC, electric vehicle MLCC is 3 to 10 times more expensive and is in the spotlight as a high value-added industry. Research for use in electric vehicles is actively underway, and electric vehicles require about 12 times more MLCC than smartphones and 4 times more than general vehicles. For example, about 1,000 MLCCs are required for one smartphone, and about 12,000 MLCCs are required for one electric vehicle. Specifically, MLCCs for electric vehicles have high-temperature durability required for engine room applications, flexural strength characteristics that can withstand vibrations of automobiles, high-capacity/high-voltage durability and power required for MLCCs for electric vehicle/HEV (hybrid vehicle) power conversion circuits. High-capacity/high-reliability characteristics such as small/high-capacity characteristics required for supply management circuits are simultaneously required. Here, among the high reliability characteristics of MLCC, characteristics such as flexural strength characteristics and high pressure durability are guaranteed through AEC-Q200 international certification, and in the case of high temperature durability, the guaranteed temperature is classified according to temperature characteristics by methods such as X7R and X8R. Currently, X7R-class or X7S-class MLCCs are mainly being used as MLCCs for battlefield use. However, it is pointed out that X7R-class or X7S-class MLCCs for electric vehicles currently used as MLCCs for electric use have disadvantages in securing reliability of MLCC devices such as withstand voltage characteristics. is in reality. In addition, conventionally, a solid-phase method or a subcritical hydrothermal synthesis method is mainly used in manufacturing MLCC, which is a new technology because the production cost is high and there is a difficulty in controlling the shape of the BaTiO 3 (sometimes abbreviated as 'BTO') material. There is a need for development. 1 is a view showing the structure of a general multilayer ceramic capacitor. 2 is a process flow diagram illustrating a method for hydrothermal synthesis of barium titanate doped with a metal element according to an embodiment of the present invention. 3 is a flowchart illustrating a method of manufacturing barium titanate nanorods for multilayer ceramic capacitors according to an embodiment of the present invention. Figure 4 shows each embodiment according to metal element (eg, Mn, Mg, Si, Ca) doping of barium titanate nanorods in the present invention, pattern analysis results using X-ray diffraction analyzer (XRD) is data representing Figure 5 shows each embodiment according to the metal element (eg, Mn, Mg, Si, Ca) doping of barium titanate nanorods in the present invention, showing the analysis results using a scanning electron microscope (SEM) It is an image. Figure 6 shows each embodiment according to the metal element (eg, Mn, Mg, Si, Ca) doping of barium titanate nanorods in the present i