Dielectric composition for multilayer ceramic capacitor, multilayer ceramic capacitor containing the same, and method for manufacturing the same

Abstract

The present invention provides a dielectric composition for a multilayer ceramic capacitor, a multilayer ceramic capacitor including the same, and a method for manufacturing the same. The dielectric composition for a multilayer ceramic capacitor of the present invention includes a barium-based compound, gadolinium oxide (Gd2O3), manganese oxide (Mn3O4), and magnesium carbonate (MgCO3). This has excellent reliability and performance.

Description

[Technical field]

[0001] The present invention relates to a dielectric composition for a multilayer ceramic capacitor, a multilayer ceramic capacitor including the same, and a method for manufacturing the same, and more particularly to a dielectric composition for a multilayer ceramic capacitor having excellent reliability and performance, a multilayer ceramic capacitor including the same, and a method for manufacturing the same. [Background technology]

[0002] An electronic component using a ceramic material, such as a capacitor, an inductor, a piezoelectric element, a varistor, or a thermistor, includes a ceramic body made of a ceramic material, an internal electrode formed inside the body, and an external electrode disposed on a surface of the ceramic body so as to be connected to the internal electrode.

[0003] Among ceramic electronic components, a multilayer ceramic capacitor is a device that consists of multiple laminated dielectric layers, internal electrodes that are arranged facing each other with one dielectric layer between them, and a capacitor that is electrically connected to the internal electrodes. and an external electrode connected to the external electrode.

[0004] A multilayer ceramic capacitor is usually manufactured by laminating an internal electrode paste and a dielectric layer paste by a sheet method, a printing method or the like, and then co-firing the laminated layers.

[0005] The dielectric material used in conventional multilayer ceramic high-capacity capacitors is a ferroelectric material based on barium titanate (BaTiO3), which has a high dielectric constant at room temperature, a relatively small dissipation factor, and excellent insulation resistance characteristics.

[0006] However, with the evolution of electronic control in automobiles, the demands for performance and reliability of electronic components using ceramic materials are increasing, and the problem with the previously used dielectric materials based on barium titanate (BaTiO3) is that they not only do not guarantee the reliability of the evolving electronic components, but they also do not guarantee excellent performance.

[0007] In addition, the existing methods for manufacturing general multilayer ceramic high-capacity capacitors have the problem that they do not guarantee the reliability of evolving electronic components, nor do they guarantee excellent performance. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a dielectric composition for a multilayer ceramic capacitor having excellent reliability over a life span, a multilayer ceramic capacitor including the same, and a method for manufacturing the same.

[0009] Another object of the present invention is to provide a dielectric composition for a multilayer ceramic capacitor having not only low equivalent series resistance and leakage current but also high quality factor and DC insulation resistance, a multilayer ceramic capacitor including the same, and a method for manufacturing the same. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a compound semiconductor material containing a barium-based compound, gadolinium oxide (Gd2O3), manganese oxide (Mn3O4) and magnesium carbonate (MgCO3). A dielectric composition for a layered ceramic capacitor is provided.

[0011] Barium-based compounds may also include barium zirconate (BaZrO3) and barium titanate (BaTiO3).

[0012] The barium-based compound may also contain barium zirconate (BaZrO3) and barium titanate (BaTiO3) in a molar ratio of 1:2-6.

[0013] The dielectric composition may contain 2 to 6 molar parts of gadolinium oxide (Gd2O3), 0.01 to 1 molar part of manganese oxide (Mn3O4) powder, and 2 to 6 molar parts of magnesium carbonate (MgCO3) relative to 100 molar parts of the barium-based compound.

[0014] In addition, the dielectric composition can satisfy the following conditions (1) to (3). (1) D10≦60nm (2) 150 nm ≤ D50 ≤ 350 nm (3) D90≦2,000 nm

[0015] In the above conditions (1) to (3), D10, D50 and D90 refer to particle sizes that correspond to 10%, 50% and 90% of the maximum value in the cumulative volume distribution of the particle size of the dielectric composition, respectively.

[0016] The present invention also provides a multilayer ceramic capacitor including a capacitor body in which ceramic bodies and internal electrodes are alternately laminated, and external electrodes formed on an outer surface of the capacitor body and electrically connected to the internal electrodes.

[0017] The ceramic body may also be one in which the dielectric composition of the present invention is sintered.

[0018] The present invention further provides a method for manufacturing a multilayer ceramic capacitor, including a first step of preparing a dielectric composition for a multilayer ceramic capacitor; a second step of mixing the dielectric composition with a binder and an organic solvent to prepare a ceramic slurry; a third step of casting the ceramic slurry to form a ceramic green sheet; a fourth step of printing internal electrodes on one side of the ceramic green sheet and laminating a plurality of such sheets to prepare a green chip; a fifth step of performing a degreasing process and a sintering process on the green chip to prepare a capacitor body; and a sixth step of printing external electrodes, which are electrically connected to the internal electrodes, on the outer surface of the capacitor body to prepare a multilayer ceramic capacitor.

[0019] The dielectric composition for a multilayer ceramic capacitor may be a mixture of a barium compound, gadolinium oxide (Gd2O3), manganese oxide (Mn3O4) and magnesium carbonate (MgCO3).

[0020] The barium-based compound may be a mixture of barium zirconate (BaZrO3) and barium titanate (BaTiO3) in a molar ratio of 1:2-6.

[0021] The dielectric composition may be a mixture of 100 molar parts of a barium-based compound, 2 to 6 molar parts of gadolinium oxide (Gd2O3), 0.01 to 1 molar part of manganese oxide (Mn3O4) powder, and 2 to 6 molar parts of magnesium carbonate (MgCO3).

[0022] In the second step of the method for producing a multilayer ceramic capacitor, a binder and an organic solvent are mixed with the dielectric composition, the mixture is pulverized, and then degassing and aging steps are performed to produce a ceramic slurry that satisfies the following conditions (1) to (3) and has a viscosity of 100 to 500 cps: It is possible to manufacture lees. (1) D10≦60nm (2) 150 nm ≤ D50 ≤ 350 nm (3) D90≦2,000 nm

[0023] In the above conditions (1) to (3), D10, D50 and D90 refer to particle sizes that correspond to 10%, 50% and 90% of the maximum value in the cumulative volume distribution of the ceramic slurry particle sizes, respectively.

[0024] The binder may also include one or more selected from the group consisting of polyvinyl butyral, ethyl cellulose, polyvinyl alcohol, and acrylic. Effect of the Invention

[0025] The dielectric composition for a multilayer ceramic capacitor, the multilayer ceramic capacitor containing the same, and the manufacturing method thereof according to the present invention not only have excellent reliability with respect to life, but also have low equivalent series resistance and leakage current, and high quality factor and DC insulation resistance. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a graph showing the temperature versus ripple current at frequencies of 30 kHz, 100 kHz, and 300 kHz for the multilayer ceramic capacitor manufactured in Example 1 and a Murata multilayer ceramic capacitor X7R. [Diagram 2] FIG. 2 is a graph showing the equivalent series resistance versus frequency for the multilayer ceramic capacitor produced in Example 1 and for the X7R multilayer ceramic capacitor manufactured by Murata Corporation. [Diagram 3] FIG. 3 is a graph showing the quality factor versus frequency of the multilayer ceramic capacitor produced in Example 1 and the X7R multilayer ceramic capacitor manufactured by Murata Corporation. [Figure 4] FIG. 4 is a graph showing the DC insulation resistance versus time at a high temperature of 150° C. for the multilayer ceramic capacitor produced in Example 1 and for the X7R multilayer ceramic capacitor manufactured by Murata Corporation. [Diagram 5] FIG. 5 is a graph showing the leakage current versus voltage at a high temperature of 150° C. for the multilayer ceramic capacitor produced in Example 1 and the multilayer ceramic capacitor X7R manufactured by Murata Corporation. [Figure 6] FIG. 6 is a graph showing the change in terminal self-generated capacitance with respect to an increase in DC bias voltage for the multilayer ceramic capacitor manufactured in Example 1 and the X7R multilayer ceramic capacitor manufactured by Murata Corporation. [Figure 7] FIG. 7 is an end view showing a detailed configuration of a multilayer ceramic capacitor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily carry out the embodiments. The present invention may be embodied in various different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0028] As shown in FIG. 7, the multilayer ceramic capacitor according to an embodiment of the present invention includes a capacitor body 110 in which a ceramic body 111 and internal electrodes 121 and 122 are alternately laminated. and external electrodes 131, 132 electrically connected to the internal electrodes 121, 122. In other words, the first and second external electrodes 131, 132 may be formed on an outer surface or both ends of the capacitor body 110, which are conductive, in other words, electrically connected, to the first and second internal electrodes 121, 122 alternately arranged inside the capacitor body 110.

[0029] The shape of the capacitor body 110 is not particularly limited, but may generally be a hexahedron. The dimensions are also not particularly limited, and may be designed to be appropriate for the application. For example, the capacitor body may be designed to have dimensions of 0.5 to 8.0 mm in length, 0.5 to 8.0 mm in width, and 0.2 to 5.0 mm in thickness.

[0030] The thickness of the ceramic body 111 can be arbitrarily changed according to the capacitance design of the multilayer ceramic capacitor, and in one embodiment of the present invention, the thickness of each ceramic body 111 may be 5 to 100 μm, preferably 15 to 50 μm. If the ceramic body 111 is too thin, the number of crystal grains in one ceramic body is small, which adversely affects reliability, so the thickness of the ceramic body 111 may be 5 μm or more.

[0031] The internal electrodes 121 and 122 may be laminated such that the end faces are exposed at both opposing ends of the capacitor body 110, respectively.

[0032] The external electrodes 131 and 132 are formed on both ends of the capacitor body 110 and are electrically connected to the exposed end surfaces of the internal electrodes 121 and 122 to form a capacitor circuit.

[0033] The conductive material contained in the internal electrodes 121, 122 is not particularly limited, but may preferably contain nickel (Ni) as a main component.

[0034] The thickness of the internal electrodes 121, 122 can be appropriately designed depending on the application, and in one embodiment of the present invention, the thickness of the internal electrodes 121, 122 may be 0.1 to 50 μm, preferably 0.1 to 10 μm.

[0035] The conductive material contained in the external electrodes 131, 132 is not particularly limited, but may contain nickel (Ni), copper (Cu), or an alloy thereof as a main component.

[0036] The ceramic body 111 may be made by sintering a dielectric composition for a multilayer ceramic capacitor according to the present invention, which will be described later.

[0037] The dielectric composition for a multilayer ceramic capacitor according to one embodiment of the present invention may contain one or more selected from a barium-based compound, gadolinium oxide (Gd2O3), manganese oxide (Mn3O4), and magnesium carbonate (MgCO3), and preferably may contain a barium-based compound, gadolinium oxide (Gd2O3), manganese oxide (Mn3O4), and magnesium carbonate (MgCO3).

[0038] Specifically, the dielectric composition for multilayer ceramic capacitors of the present invention may contain 2 to 6 molar parts, preferably 3 to 5 molar parts, and more preferably 3.5 to 4.5 molar parts of gadolinium oxide relative to 100 molar parts of the barium-based compound. If the gadolinium oxide is contained in an amount less than 2 molar parts, there may be a problem that the characteristics such as temperature and DC bias are deteriorated, and if the gadolinium oxide is contained in an amount more than 6 molar parts, there may be a problem that the dielectric composition is not sintered.

[0039] The dielectric composition for a multilayer ceramic capacitor of the present invention contains 0.01 to 1 molar part, preferably 0.05 to 0.5 molar parts of manganese oxide per 100 molar parts of a barium-based compound. If the manganese oxide is contained in an amount of less than 0.01 part by mol, there may be a problem of reduced reliability, and if it is contained in an amount of more than 1 part by mol, there may be a problem of reduced characteristics.

[0040] Furthermore, the dielectric composition for multilayer ceramic capacitors of the present invention may contain 2 to 6 molar parts, preferably 3 to 5 molar parts, and more preferably 3.5 to 4.5 molar parts of magnesium carbonate relative to 100 molar parts of the barium-based compound. If the magnesium carbonate is contained in an amount less than 2 molar parts, there may be a problem that the temperature characteristics are not satisfied, whereas if it is contained in an amount exceeding 6 molar parts, there may be a problem that the dielectric constant of the element is reduced.

[0041] The barium-based compound may include one or more selected from barium zirconate (BaZrO3) and barium titanate (BaTiO3), and preferably includes barium zirconate (BaZrO3) and barium titanate (BaTiO3).

[0042] In this case, the barium-based compound may contain barium zirconate (BaZrO3) and barium titanate (BaTiO3) in a molar ratio of 1:2 to 6, preferably 1:3 to 5, and more preferably 1:3.5 to 4.5. If the molar ratio is less than 1:2, there may be a problem that the element does not sinter, and if it exceeds 1:6, there may be a problem that the characteristics such as temperature and DC bias are deteriorated.

[0043] Furthermore, the dielectric composition for a multilayer ceramic capacitor of the present invention can satisfy the following conditions (1) to (3). If the following conditions (1) to (3) are not satisfied, there may be a problem that it is difficult to ensure a uniform grain size after sintering. (1) D10≦60 nm, preferably 1 nm≦D10≦50 nm, more preferably 3 nm≦D10≦50 nm (2) 150 nm≦D50≦350 nm, preferably 200 nm≦D50≦300 nm, more preferably 220 nm≦D50≦280 nm (3) D90≦2,000 nm, preferably 500 nm≦D90≦1,500 nm, more preferably 700 nm≦D90≦1,000 nm

[0044] In the above conditions (1) to (3), D10, D50 and D90 respectively refer to particle sizes that correspond to 10%, 50% and 90% of the maximum value in the cumulative volume distribution of particle sizes of the dielectric composition for multilayer ceramic capacitors of the present invention.

[0045] A method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention includes first to sixth steps.

[0046] First, in the first step of the method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention, a dielectric composition for a multilayer ceramic capacitor may be prepared. The prepared dielectric composition for a multilayer ceramic capacitor may be a mixture of one or more selected from a barium-based compound, gadolinium oxide (Gd2O3), manganese oxide (Mn3O4), and magnesium carbonate (MgCO3), and may be a mixture of a barium-based compound, gadolinium oxide (Gd2O3), manganese oxide (Mn3O4), and magnesium carbonate (MgCO3). Specifically, the dielectric composition for multilayer ceramic capacitors of the present invention may be a mixture of 0.01 to 1 molar part, preferably 0.05 to 0.5 molar parts, more preferably 0.07 to 0.13 molar parts of manganese oxide, 2 to 6 molar parts, preferably 3 to 5 molar parts, more preferably 3.5 to 4.5 molar parts of magnesium carbonate, and 2 to 6 molar parts, preferably 3 to 5 molar parts, more preferably 3.5 to 4.5 molar parts of gadolinium oxide, relative to 100 molar parts of barium-based compound. The barium-based compound may be a mixture of barium zirconate (BaZrO3) and barium titanate (BaTiO3), preferably a mixture of barium zirconate (BaZrO3) and barium titanate (BaTiO3) in a molar ratio of 1:2 to 6, preferably a molar ratio of 1:3 to 5, more preferably a molar ratio of 1:3.5 to 4.5.

[0047] Next, in the second step of the method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention, a binder and an organic solvent may be mixed with the dielectric composition for a multilayer ceramic capacitor prepared in the first step to prepare a ceramic slurry.

[0048] Specifically, in the second step of the method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention, the dielectric composition for a multilayer ceramic capacitor prepared in the first step is mixed with a binder and an organic solvent, pulverized, and then defoamed and aged to produce a ceramic slurry that satisfies the following conditions (1) to (3) and has a viscosity of 100 to 500 cps, preferably 200 to 400 cps. If the viscosity is less than 100 cps or exceeds 500 cps, there may be a problem that makes it difficult to manufacture a sheet. (1) D10≦60 nm, preferably 1 nm≦D10≦50 nm, more preferably 3 nm≦D10≦50 nm (2) 150 nm≦D50≦350 nm, preferably 200 nm≦D50≦300 nm, more preferably 220 nm≦D50≦280 nm (3) D90≦2,000 nm, preferably 500 nm≦D90≦1,500 nm, more preferably 700 nm≦D90≦1,000 nm

[0049] In the above conditions (1) to (3), D10, D50 and D90 refer to particle sizes that correspond to 10%, 50% and 90% of the maximum value in the cumulative volume distribution of the ceramic slurry particle sizes.

[0050] The binder used in the second step may include at least one selected from polyvinyl butyral, ethyl cellulose, polyvinyl alcohol, and acryl, preferably at least one selected from polyvinyl butyral and acryl, more preferably polyvinyl butyral. Also, the binder used in the second step may be mixed in an amount of 3 to 20 parts by weight, preferably 6 to 11 parts by weight, more preferably 7 to 10 parts by weight, with respect to 100 parts by weight of the dielectric composition for multilayer ceramic capacitor prepared in the first step.

[0051] The organic solvent used in the second step may include any organic solvent used in the art, and may preferably include one or more selected from ethanol, toluene, methyl ethyl ketone, and xylene. The organic solvent used in the second step may be mixed in an amount of 45 to 95 parts by weight, preferably 55 to 85 parts by weight, and more preferably 65 to 75 parts by weight, based on 100 parts by weight of the dielectric composition for multilayer ceramic capacitors prepared in the first step.

[0052] In addition, the pulverization in the second step can be performed by any pulverization process that can be generally performed in the art. For example, the pulverization can be performed by ball milling, and the balls used can be zirconia beads of 0.1 to 0.5 mm.

[0053] In addition, the defoaming and aging process in the second stage can be any defoaming and aging process that is commonly performed in the art. Next, in the third step of the method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention, the ceramic slurry prepared in the second step is cast to form a ceramic green sheet. Specifically, the casting may be performed by any casting process that is generally performed in the art, and for example, the ceramic slurry may be dropped onto a PET film and a comma roll type casting device may be used to form a ceramic green sheet.

[0054] Next, in the fourth step of the method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention, an internal electrode is printed on one side of the ceramic green sheet formed in the third step, and a plurality of sheets are laminated to manufacture a green chip. In this case, a conductive paste containing Ni as a main component can be used as the internal electrode, and any printing process that can be generally performed in the art can be used for printing, for example, a screen printing method can be used for printing. In addition, the ceramic green sheet may be laminated in 5 to 200 layers, preferably 10 to 100 layers, more preferably 10 to 60 layers, even more preferably 20 to 50 layers, and even more preferably 30 to 40 layers.

[0055] Furthermore, after stacking multiple sheets, they can be hot isostatically pressed at a temperature of 40 to 120°C, preferably 60 to 100°C, and then cut to a specified size to produce a green chip.

[0056] Next, in the fifth step of the method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention, a capacitor body can be manufactured by carrying out a debinding process and a sintering process on the green chip manufactured in the fourth step. Specifically, in the fourth step, two debinding processes and one sintering process can be sequentially carried out to manufacture the capacitor body. For example, the green chip is subjected to a first debinding process at a temperature of 200 to 400°C, preferably 250 to 350°C, and an oxidizing atmosphere for 60 to 300 minutes, preferably 120 to 240 minutes, and a second debinding process at a temperature of 800 to 1000°C, preferably 850 to 950°C, and a nitrogen atmosphere for 30 to 120 minutes, preferably 45 to 90 minutes, and the green chip subjected to the debinding process is sintered at a temperature of 1000 to 1400°C, preferably 1100 to 1300°C, and a nitrogen-hydrogen mixed gas atmosphere for 60 to 300 minutes, preferably 120 to 240 minutes, to manufacture the capacitor body. The degreasing can be performed by any degreasing process that can be generally performed in the industry, and as an example, it can be performed by using an atmospheric degreasing furnace.

[0057] The sintering may be carried out by any sintering process that is generally available in the art, and may be carried out using a continuous furnace, for example.

[0058] Finally, in the sixth step of the method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention, a multilayer ceramic capacitor may be manufactured by printing external electrodes electrically connected to the internal electrodes on the outer surface or both end surfaces of the capacitor body manufactured in the fifth step. In this case, a conductive paste containing Cu as a main component may be used as the external electrodes, and the printing may be performed by any printing process commonly performed in the art, for example, by a dipping method.

[0059] Example 1: Manufacture of multilayer ceramic capacitor (1) A dielectric composition for multilayer ceramic capacitors was manufactured by mixing 100 mol parts of barium-based compound powder with 4 mol parts of gadolinium oxide (Gd2O3) powder, 0.1 mol parts of manganese oxide (Mn3O4) powder, and 4 mol parts of magnesium carbonate (MgCO3). At this time, a mixture of barium zirconate (BaZrO3) powder and barium titanate (BaTiO3) powder in a molar ratio of 1:4 was used as the barium-based compound powder. (2) The dielectric composition for multilayer ceramic capacitor thus prepared was mixed with a binder and an organic solvent, and pulverized by ball milling using 0.2 mm zirconia beads, followed by defoamation and aging processes to prepare a ceramic slurry having particle sizes of D10 45 nm, D50 250 nm, and D90 900 nm and a viscosity of 300 cps. Polyvinyl butyral was used as the binder, toluene was used as the organic solvent, and D10, D50, and D90 refer to particle sizes that correspond to 10%, 50%, and 90% of the maximum value in the volume cumulative distribution of the particle size of the ceramic slurry, respectively. (3) The produced ceramic slurry was dropped onto a PET film and formed into a sheet using a comma roll type casting device to produce a ceramic green sheet having a thickness of 30 μm. (4) A conductive paste containing Ni as a main component to be used as an internal electrode was printed on one side of the produced ceramic green sheet by screen printing, and then multiple sheets were stacked. Specifically, the ceramic green sheets were stacked alternately so that the conductive paste region containing Ni as a main component formed the counter electrode, and then hot isostatically pressed at a temperature of 80°C, and then cut to a specified size to produce a green chip. In this case, the ceramic green sheets were stacked in 33 layers, and the area of ​​the counter electrode was 20 mm 2 It was. (5) The manufactured green chip was subjected to a primary debinding process at a temperature of 300°C in an oxidizing atmosphere for 120 minutes, and a secondary debinding process at a temperature of 900°C in a nitrogen atmosphere for 60 minutes. The green chip that had undergone the debinding process was sintered at a temperature of 1200°C in a nitrogen-hydrogen mixed gas atmosphere for 120 minutes to manufacture a capacitor body. (6) A conductive paste containing Cu as its main component was used as external electrodes on both end surfaces of the manufactured capacitor body by dipping and then baked to manufacture a multilayer ceramic capacitor having external electrodes electrically connected to the internal electrodes and external dimensions of 5.7 mm in length, 5.0 mm in width, and 2.0 mm in thickness.

[0060] Experimental example: Measurement of the physical properties of multilayer ceramic capacitors The multilayer ceramic capacitor manufactured in Example 1, namely, Murata's multilayer ceramic capacitor X7R, was measured for physical properties under the following measurement conditions. (1) Input: Function generator (2) Amplifier: DC~1MHz, approx. 3~4A, CV Type (3) Output: Oscilloscope, current probes (4) Other: Thermocouples, temperature measurement programs

[0061] Experimental example 1: Measuring temperature versus ripple current at frequencies of 30kHz, 100kHz, and 300kHz The multilayer ceramic capacitor (=X7T) manufactured in Example 1 and X7R, a multilayer ceramic capacitor manufactured by Murata Corporation (=having a composition including 3.9-9.0 molar parts of magnesium (Mg), 11.3-14.7 molar parts of gadolinium (Gd), 10.3-14.1 molar parts of zirconium (Zr), 1.5-2.8 molar parts of manganese (Mn), 29.3-32.3 molar parts of calcium (Ca), and 4.4-8.2 molar parts of silicon (Si) relative to 100 molar parts of barium titanate (BaTiO3)) were measured for temperature versus ripple current at frequencies of 30 kHz, 100 kHz, and 300 kHz, and the measured values ​​are shown in Table 1, and the measurement graph is shown in FIG. 1. Referring to Table 1 and FIG. 1, it was confirmed that the multilayer ceramic capacitor manufactured in Example 1 exhibited a lower temperature than X7R, a multilayer ceramic capacitor manufactured by Murata Corporation, and had excellent reliability with respect to life.

[0062] [Table 1]

[0063] Experimental example 2: Measurement of equivalent series resistance (ESR) versus frequency The equivalent series resistance versus frequency of the multilayer ceramic capacitor manufactured in Example 1 (=AMO) and Murata's multilayer ceramic capacitor X7R (=MURATA) was measured, and the measurement graph is shown in Figure 2. Referring to Figure 2, it was confirmed that the multilayer ceramic capacitor manufactured in Example 1 has a lower equivalent series resistance than Murata's multilayer ceramic capacitor X7R.

[0064] Experimental example 3: Measurement of quality factor (Q) versus frequency The quality factors of the multilayer ceramic capacitor manufactured in Example 1 (=AMO) and Murata's multilayer ceramic capacitor X7R (=MURATA) were measured, and the measurement graph is shown in Figure 3. Referring to Figure 3, it was confirmed that the multilayer ceramic capacitor manufactured in Example 1 has a higher quality factor value than Murata's multilayer ceramic capacitor X7R.

[0065] Experimental Example 4: Measurement of DC insulation resistance (hot-IR) versus time at high temperature The multilayer ceramic capacitor manufactured in Example 1 (=AMO) and Murata's multilayer ceramic capacitor X7R (=MURATA) were measured for DC insulation resistance at a high temperature of 150°C versus time, and the measurement graph is shown in Figure 4. Referring to Figure 4, it was confirmed that the multilayer ceramic capacitor manufactured in Example 1 exhibited higher DC insulation resistance than Murata's multilayer ceramic capacitor X7R, and thus had excellent reliability.

[0066] Experimental Example 5: Measurement of leakage current (IL) versus voltage at high temperature The multilayer ceramic capacitor manufactured in Example 1 (=AMO) and Murata's multilayer ceramic capacitor X7R (=MURATA) were measured for leakage current versus voltage at a high temperature of 150°C, and the measurement graph is shown in Figure 5. Referring to Figure 5, it was confirmed that the multilayer ceramic capacitor manufactured in Example 1 exhibited a lower leakage current than Murata's multilayer ceramic capacitor X7R, and thus had excellent reliability.

[0067] Experimental example 6: Measurement of terminal self-generated capacitance change (△Cp) against DC bias The amount of change in terminal self-generated capacitance with respect to an increase in DC bias voltage was measured for the multilayer ceramic capacitor (=X7T) manufactured in Example 1 and the multilayer ceramic capacitor X7R manufactured by Murata, and the measurement graph is shown in Figure 6. Referring to Figure 6, it was confirmed that the multilayer ceramic capacitor manufactured in Example 1 has better DC bias characteristics than the multilayer ceramic capacitor X7R manufactured by Murata.

[0068] Although one embodiment of the present invention has been described above, the concept of the present invention is not limited to the embodiment presented in this specification, and a person skilled in the art who understands the concept of the present invention can easily propose other embodiments by adding, changing, deleting, or adding components within the scope of the same concept, which can also be said to fall within the scope of the concept of the present invention. [Industrial Applicability]

[0069] The present invention relates to a dielectric composition for a multilayer ceramic capacitor, a multilayer ceramic capacitor including the same, and a method for manufacturing the same, and more particularly to a dielectric composition for a multilayer ceramic capacitor having excellent reliability and performance, a multilayer ceramic capacitor including the same, and a method for manufacturing the same.

Claims

1. Barium compounds, gadolinium oxide (Gd ２ O ３ ), manganese oxide (Mn ３ O ４ ) and magnesium carbonate (MgCO ３ ), The barium-based compound is barium zirconate (BaZrO ３ ) and barium titanate (BaTiO ３ ) . A dielectric composition for a multilayer ceramic capacitor.

2. The barium-based compound is barium zirconate (BaZrO ３ ) and barium titanate (BaTiO ３ 2. The dielectric composition for a multilayer ceramic capacitor according to claim 1, wherein the molar ratio of the compound is 1:2 to 6.

3. The dielectric composition contains, relative to 100 parts by mole of a barium-based compound, Gadolinium oxide (Gd ２ O ３ ) 2 to 6 mole parts, manganese oxide (Mn ３ O ４ ) powder 0.01 to 1 mol parts and magnesium carbonate (MgCO ３ 2. The dielectric composition for a multilayer ceramic capacitor according to claim 1, wherein the dielectric composition contains 2 to 6 parts by mole of the aromatic hydrocarbon.

4. The dielectric composition for a multilayer ceramic capacitor according to claim 1, which satisfies the following conditions (1) to (3): (1) D10≦60 nm (2) 150 nm≦D50≦350 nm (3) D90≦2,000nm In the above conditions (1) to (3), D10, D50 and D90 refer to particle sizes that correspond to 10%, 50% and 90% of the maximum value in the cumulative volume distribution of the particle size of the dielectric composition, respectively.

5. A capacitor body in which a ceramic body on which the dielectric composition according to claim 1 is sintered and internal electrodes are alternately laminated; and external electrodes formed on an outer surface of the capacitor body and electrically connected to the internal electrodes.

6. A first step of preparing a dielectric composition for a multilayer ceramic capacitor; A second step of mixing the dielectric composition with a binder and an organic solvent to prepare a ceramic slurry; a third step of casting the ceramic slurry to form a ceramic green sheet; a fourth step of printing an internal electrode on one side of the ceramic green sheet and stacking a plurality of the sheets to manufacture a green chip; a fifth step of manufacturing a capacitor body by performing a debinding process and a sintering process on the green chip; and a sixth step of printing external electrodes electrically connected to the internal electrodes on an external surface of the capacitor body to manufacture a multilayer ceramic capacitor. The dielectric composition for multilayer ceramic capacitors contains a barium-based compound, gadolinium oxide (Gd ２ O ３ ), manganese oxide (Mn ３ O ４ ) and magnesium carbonate (MgCO ３ ) is mixed.

7. The barium-based compound is barium zirconate (BaZrO ３ ) and barium titanate (BaTiO ３ 7. The method for producing a multilayer ceramic capacitor according to claim 6, wherein the above-mentioned components are mixed in a molar ratio of 1:2 to 1:

6.

8. The dielectric composition contains, relative to 100 parts by mole of a barium-based compound, Gadolinium oxide (Gd ２ O ３ ) 2 to 6 mole parts, manganese oxide (Mn ３ O ４ ) powder 0.01 to 1 mol parts and magnesium carbonate (MgCO ３ 7. The method for producing a multilayer ceramic capacitor according to claim 6, wherein the amount of the mixed material is 2 to 6 parts by mole.

9. 7. The method for manufacturing a multilayer ceramic capacitor according to claim 6, wherein the second step comprises mixing a binder and an organic solvent with the dielectric composition, pulverizing the mixture, and then performing a degassing and aging process to prepare a ceramic slurry that satisfies the following conditions (1) to (3) and has a viscosity of 100 to 500 cps. (1) D10≦60 nm (2) 150 nm≦D50≦350 nm (3) D90≦2,000nm In the above conditions (1) to (3), D10, D50 and D90 refer to particle sizes that correspond to 10%, 50% and 90% of the maximum value in the cumulative volume distribution of the ceramic slurry particle sizes, respectively.

10. 7. The method of claim 6, wherein the binder comprises at least one selected from the group consisting of polyvinyl butyral, ethyl cellulose, polyvinyl alcohol, and acrylic.

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