Multilayer ceramic capacitor

Abstract

This invention provides a multilayer ceramic capacitor, comprising: a body including a dielectric layer and a first inner electrode and a second inner electrode that are point-symmetrical to each other, with the respective dielectric layers disposed between the first inner electrode and the second inner electrode; a first connecting electrode and a second connecting electrode passing through the body in a direction perpendicular to the dielectric layer and connected to the first inner electrode; a third connecting electrode and a fourth connecting electrode passing through the body in a direction perpendicular to the dielectric layer and connected to the second inner electrode; a first outer electrode and a second outer electrode disposed on two outer surfaces of the body and connected to the first connecting electrode and the second connecting electrode; and a third outer electrode and a fourth outer electrode spaced apart from the first outer electrode and the second outer electrode and connected to the third connecting electrode and the fourth connecting electrode. Each of the first inner electrode and the second inner electrode includes an electrode-unformed region.

Description

[0001] This application is a divisional application of the invention patent application "Multilayer Ceramic Capacitor" filed on May 18, 2020, with application number 202010419214.8. Technical Field

[0002] This disclosure relates to a multilayer ceramic capacitor. Background Technology

[0003] Recently, the use of multilayer ceramic capacitors (MLCCs) in electronic devices has increased rapidly. Specifically, with the advent of the fifth-generation (5G) communication era, smartphones require a larger number of capacitors and capacitors with higher capacitance. On the other hand, due to miniaturization technology in assembly products, the mounting area of ​​passive components such as MLCCs and inductors has been reduced, thus requiring further miniaturization and thinning of passive components. Therefore, the following approach has been proposed: multilayer ceramic capacitors and inductors are packaged together with ICs and APs, embedded in the substrate, or mounted on the lower end of the AP in a pad-side capacitor (LSC) manner to improve mounting flexibility.

[0004] In this way, not only can the mounting area be reduced, but the equivalent series inductance (ESL) generated in the substrate can also be reduced. Therefore, the demand for multilayer ceramic capacitors with low thickness is increasing.

[0005] Unlike ordinary MLCCs, via capacitors use a through-hole structure. This is achieved by forming a through-hole in the body where the effective layer forming the capacitor is formed and the capping layers are disposed in the upper and lower parts, and then filling and electrically connecting the through-hole electrodes.

[0006] Unlike typical MLCCs, via capacitors have a structure that uses through-holes. In via capacitors, electrical connections are achieved by forming through-holes in a main body with an effective layer forming the capacitance and capping layers disposed in the upper and lower parts, and filling the through-hole electrodes.

[0007] In this type of via capacitor, the presence of vias may affect the equivalent series inductance (ESL) and equivalent series resistance (ESR), and may reduce the capacitance. Summary of the Invention

[0008] One aspect of this disclosure is to provide a multilayer ceramic capacitor that can improve the equivalent series inductance (ESL) due to the mutual inductance cancellation effect.

[0009] Another aspect of this disclosure is to provide a multilayer ceramic capacitor with improved capacitance compared to a typical internal via structure.

[0010] Another aspect of this disclosure is to provide a multilayer ceramic capacitor with improved breakdown voltage (BDV).

[0011] According to one aspect of this disclosure, a multilayer ceramic capacitor includes: a body including a dielectric layer and a first inner electrode and a second inner electrode that are point-symmetrical to each other, with the respective dielectric layers disposed between the first inner electrode and the second inner electrode; a first connecting electrode and a second connecting electrode that pass through the body in a direction perpendicular to the dielectric layer and are connected to the first inner electrode; a third connecting electrode and a fourth connecting electrode that pass through the body in the direction perpendicular to the dielectric layer and are connected to the second inner electrode; a first outer electrode and a second outer electrode that are disposed on two outer surfaces of the body and connected to the first connecting electrode and the second connecting electrode; and a third outer electrode and a fourth outer electrode that are spaced apart from the first outer electrode and the second outer electrode and connected to the third connecting electrode and the fourth connecting electrode. Each of the first inner electrode and the second inner electrode includes an electrode-unformed region.

[0012] According to one aspect of this disclosure, a multilayer ceramic capacitor includes: a body comprising a dielectric layer and a first inner electrode and a second inner electrode, wherein the respective dielectric layer is disposed between the first inner electrode and the second inner electrode; a first connecting electrode and a second connecting electrode passing through the body in a direction perpendicular to the dielectric layer and connected to the first inner electrode; a third connecting electrode and a fourth connecting electrode passing through the body in the direction perpendicular to the dielectric layer and connected to the second inner electrode; a first outer electrode disposed on an outer surface of the body and connected to the first inner electrode via the first connecting electrode and the second connecting electrode; and a third outer electrode disposed on the outer surface of the body and connected to the second inner electrode via the third connecting electrode and the fourth connecting electrode. The second inner electrode has a first through-hole and a second through-hole, the first connecting electrode is disposed in the first through-hole, the second connecting electrode is disposed in the second through-hole, and the first inner electrode has a third through-hole and a fourth through-hole, the third connecting electrode is disposed in the third through-hole, and the fourth connecting electrode is disposed in the fourth through-hole.

[0013] The ratio of the diameter of one of the first connecting electrode, the second connecting electrode, the third connecting electrode, and the fourth connecting electrode to the distance between the first and third access holes or the distance between the second and fourth access holes is greater than or equal to 0.375 and less than or equal to 0.52.

[0014] The ratio of the distance between the first connecting electrode and the second connecting electrode or the distance between the third connecting electrode and the fourth connecting electrode to the distance between the first through hole and the third through hole or the distance between the second through hole and the fourth through hole is greater than or equal to 2.08 and less than or equal to 4.7.

[0015] According to one aspect of this disclosure, a multilayer ceramic capacitor includes: a body comprising a dielectric layer and a first inner electrode and a second inner electrode, wherein the respective dielectric layer is disposed between the first inner electrode and the second inner electrode; a first connecting electrode and a second connecting electrode passing through the body in a direction perpendicular to the dielectric layer and connected to the first inner electrode; a third connecting electrode and a fourth connecting electrode passing through the body in the direction perpendicular to the dielectric layer and connected to the second inner electrode; a first outer electrode disposed on an outer surface of the body and connected to the first inner electrode via the first connecting electrode and the second connecting electrode; and a third outer electrode disposed on the outer surface of the body and connected to the first inner electrode via the third connecting electrode. The first electrode and the fourth connecting electrode are connected to the second inner electrode, wherein the second inner electrode has a first through hole and a second through hole, the first connecting electrode is disposed in the first through hole, the second connecting electrode is disposed in the second through hole, the first inner electrode has a third through hole and a fourth through hole, the third connecting electrode is disposed in the third through hole, the fourth connecting electrode is disposed in the fourth through hole, and the ratio of the distance between the first connecting electrode and the second connecting electrode or the distance between the third connecting electrode and the fourth connecting electrode to the distance between the first through hole and the third through hole or the distance between the second through hole and the fourth through hole is greater than or equal to 2.08 and less than or equal to 4.7. Attached Figure Description

[0016] The above and other aspects, features, and advantages of this disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0017] Figure 1 This is a schematic perspective view of a multilayer ceramic capacitor according to an embodiment of the present disclosure;

[0018] Figure 2 It is along Figure 1 A cross-sectional view taken from line II-II';

[0019] Figure 3A The first internal electrode is observed within it. Figure 1 Cross-sectional views in the X and Y directions; Figure 3B The second internal electrode is observed within it. Figure 1 Cross-sectional views in the X and Y directions; and

[0020] Figure 4 When viewed in the S1 direction Figure 1 Top view. Detailed Implementation

[0021] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the present disclosure may be exemplified in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. In the drawings, the shape and size of elements may be exaggerated for clarity. Furthermore, in the drawings, elements having the same function within the same scope of the inventive concept will be indicated by the same reference numerals.

[0022] Throughout this specification, unless otherwise specified, when a component is referred to as “comprising” or “including”, it means that the component may also include other components, but does not exclude other components.

[0023] In the accompanying drawings, the X direction can be defined as a first direction, the L direction, or the length direction; the Y direction can be defined as a second direction, the W direction, or the width direction; and the Z direction can be defined as a third direction, the T direction, or the thickness direction.

[0024] In the following text, reference will be made to Figures 1 to 4 A multilayer ceramic capacitor according to an example embodiment of the present disclosure is described in detail.

[0025] According to an embodiment, a multilayer ceramic capacitor 200 includes: a body 210 including a dielectric layer 211 and a first inner electrode 221 and a second inner electrode 222 that are point-symmetrical to each other, with the respective dielectric layer 211 positioned between the first inner electrode 221 and the second inner electrode 222; a first connecting electrode 231 and a second connecting electrode 234 that pass through the body 210 in a direction perpendicular to the dielectric layer 211 to be connected to the first inner electrode 221; a third connecting electrode 232 and a fourth connecting electrode 233 that pass through the body 210 in a direction perpendicular to the dielectric layer 211 to be connected to the second inner electrode 222; a first outer electrode 241 and a second outer electrode 244 disposed on two outer surfaces of the body 210 and connected to the first connecting electrode 231 and the second connecting electrode 234; and a third outer electrode 242 and a fourth outer electrode 243 that are spaced apart from the first outer electrode 241 and the second outer electrode 244 and connected to the third connecting electrode 232 and the fourth connecting electrode 233. The first inner electrode 221 and the second inner electrode 222 may each include electrode-unformed regions 221a and 222a. Each of the electrode-unformed regions 221a and 222a may be a via in a corresponding one of the first inner electrode 221 and the second inner electrode 222. The electrode-unformed regions 221a and 222a may be filled with the material of the dielectric layer 211.

[0026] In the body 210, dielectric layer 211 is alternately stacked with inner electrodes 221 and 222. The specific shape of the body 210 is not limited, but the body 210 may have a hexahedral shape as shown or a hexahedral shape similar to a hexahedron. Although the body 210 is not a perfectly hexahedral shape due to the shrinkage of ceramic powder particles during the sintering process, the body 210 may have a generally hexahedral shape.

[0027] The main body 210 may have a first surface S1 and a second surface S2 opposite to each other in the thickness direction (Z direction), a third surface S3 and a fourth surface S4 connected to the first surface S1 and the second surface S2 and opposite to each other in the width direction (Y direction), and a fifth surface S5 and a sixth surface S6 connected to the first surface S1, the second surface S2, the third surface S3, and the fourth surface S4 and opposite to each other in the length direction (X direction). In this case, the surface selected from the first surface S1, the second surface S2, the third surface S3, and the fourth surface S4 may be a mounting surface. In one example, the first connecting electrode 231 and the second connecting electrode 234 may be arranged along the length direction (X direction), the third connecting electrode 232 and the fourth connecting electrode 233 may be arranged along the length direction (X direction), the first connecting electrode 231 and the third connecting electrode 232 may be arranged along the width direction (Y direction), and the second connecting electrode 234 and the fourth connecting electrode 233 may be arranged along the width direction (Y direction). The length direction (X direction) and the width direction (Y direction) may be perpendicular to each other or substantially perpendicular to each other. The term "generally" reflects consideration of identifiable process errors that may occur during manufacturing or measurement.

[0028] The multiple dielectric layers 211 constituting the main body 210 can be in a sintered state, and adjacent dielectric layers 211 can be integrated with each other, so that the boundaries between them are not easily visible without the use of a scanning electron microscope (SEM).

[0029] According to the example embodiment, the raw materials of dielectric layer 211 are not limited, as long as sufficient capacitance can be obtained. For example, the raw materials of dielectric layer 211 can be barium titanate-based materials, lead-based perovskite composite materials, strontium titanate-based materials, etc. Barium titanate-based materials may include BaTiO3-based ceramic powder particles. The ceramic powder particles can be, for example, BaTiO3-based materials prepared by partially applying calcium (Ca), zirconium (Zr), etc. 1-x Ca x TiO3, Ba(Ti 1-y Ca y O3、(Ba 1-x Ca x (Ti) 1-y Zr y )O3 or Ba(Ti 1-y Zr y For the purposes of this disclosure, various ceramic additives, organic solvents, plasticizers, binders, dispersants, etc., can be added to powder particles such as barium titanate (BaTiO3).

[0030] A first cover portion 212 and a second cover portion 213, each having a predetermined thickness, may be disposed below the lowermost inner electrode and above the uppermost inner electrode of the main body 210, respectively. The first cover portion 212 and the second cover portion 213 may have the same composition as the dielectric layer 211, and may be formed by stacking at least one dielectric layer excluding the inner electrode above the uppermost inner electrode and below the lowermost inner electrode of the main body 210, respectively.

[0031] In the example, the identification part 250 may be disposed on either the first cover 212 or the second cover 213 as needed. The identification part 250 may be formed on one of the first cover 212 and the second cover 213, and may be used to identify the upper and lower parts of the body 210 by utilizing differences in brightness or color. The identification part 250 may be a dielectric layer of a sintered single ceramic green sheet or a stack of multiple ceramic green sheets, and may be included in either the first cover 212 or the second cover 213. For example, the identification part 250 may be formed on only one of the first cover 212 and the second cover 213, thereby identifying the upper and lower parts of the body 210 by utilizing differences in brightness or color.

[0032] The method by which the identification portion 250 has a brightness or color different from that of the first cover portion 212 or the second cover portion 213 is not limited. The identification portion 250 may be formed using ceramic particles having a size different from that of the ceramic particles included in the body 210, or it may be formed by adding an oxide of at least one metal selected from Ni, Mn, Cr, Mg, Y, and V, BaSiO3, or CaSiO3 to the ceramic material. However, the material of the identification portion 250 is not limited to these. When the identification portion 250 is provided, the upper and lower portions of the body 210 can be distinguished from each other, and the protruding direction of the aforementioned connecting electrode can be identified. Therefore, the multilayer ceramic capacitor according to this disclosure can be mounted on a substrate by selecting an orientation with better adhesive strength.

[0033] In the example, the body 210 may have a thickness of 100 μm or less. The thickness of the body 210 may be the vertical distance between the first surface S1 and the second surface S2, and the lower limit of the thickness is not limited, but may be, for example, 5 μm or more. Since the body 210 may have a thickness of 100 μm or less, the multilayer ceramic capacitor according to this disclosure can be applied as a multilayer ceramic capacitor embedded in a substrate and / or a capacitor mounted on the lower end of an AP in an LSC-type manner.

[0034] Figure 3A and Figure 3B This is a cross-sectional view showing the shapes of the first inner electrode 221 and the second inner electrode 222. (Refer to...) Figure 3A and Figure 3BThe first internal electrode 221 and the second internal electrode 222 are point-symmetric to each other. This means that when virtual lines are drawn at the four corners of the internal electrodes 221 and 222, the first internal electrode 221 and the second internal electrode 222 are point-symmetric to each other based on the center lines of the first internal electrode 221 and the second internal electrode 222. As described above, since the first internal electrode 221 and the second internal electrode 222 are point-symmetric to each other, the mutual inductance cancellation effect can be achieved to improve the equivalent series inductance (ESL) of the multilayer ceramic capacitor.

[0035] In the example, the inner electrodes may include a first inner electrode 221 and a second inner electrode 222, both having a rectangular shape. In this case, the first inner electrode 221 may have a third and a fourth through hole, and the second inner electrode 222 may have a first through hole and a second through hole. A through hole may refer to a hole that passes through the first inner electrode 221 and the second inner electrode 222 and is used to connect the first inner electrode 221 and the second inner electrode 222 respectively to an outer electrode having opposite polarities.

[0036] For example, the first connecting electrode 231 and the second connecting electrode 234 can be spaced apart from the second inner electrode 222 through the first and second through holes, and the third connecting electrode 232 and the fourth connecting electrode 233 can be spaced apart from the first inner electrode 221 through the third and fourth through holes, respectively. The first connecting electrode 231 and the second connecting electrode 234 can be configured to pass through the first and second through holes of the second inner electrode 222, such that the first connecting electrode 231 and the second connecting electrode 234 are electrically insulated from the second inner electrode 222. Furthermore, the third connecting electrode 232 and the fourth connecting electrode 233 can be configured to pass through the third and fourth through holes of the first inner electrode 221, such that the third connecting electrode 232 and the fourth connecting electrode 233 are electrically insulated from the first inner electrode 221.

[0037] The first inner electrode 221 can be connected to the first outer electrode 241 and the second outer electrode 244 via the first connecting electrode 231 and the second connecting electrode 234. The second inner electrode 222 can be connected to the third outer electrode 242 and the fourth outer electrode 243 via the third connecting electrode 232 and the fourth connecting electrode 233. In this way, the overlapping area of ​​the first inner electrode 221 and the second inner electrode 222 (with the dielectric layer 211 between them) can be significantly increased. Therefore, the capacitance of the multilayer ceramic capacitor 200 can be significantly increased.

[0038] The first internal electrode 221 and the second internal electrode 222 may contain nickel (Ni) in the highest possible content, but the materials of the first internal electrode 221 and the second internal electrode 222 are not limited thereto. For example, the first internal electrode 221 and the second internal electrode 222 may be formed using a conductive paste comprising at least one of silver (Ag), palladium (Pd), gold (Au), platinum (Pt), nickel (Ni), tin (Sn), copper (Cu), tungsten (W), titanium (Ti), and alloys thereof. The conductive paste may be printed by screen printing or gravure printing, but the printing method of the conductive paste is not limited thereto.

[0039] According to another embodiment, the multilayer ceramic capacitor 200 may include a first connecting electrode 231, a second connecting electrode 234, a third connecting electrode 232, and a fourth connecting electrode 233. Furthermore, the first connecting electrode 231 and the second connecting electrode 234 are electrically connected to a first external electrode 241 and a second external electrode 244, and the third connecting electrode 232 and the fourth connecting electrode 233 are electrically connected to a third external electrode 242 and a fourth external electrode 243.

[0040] As described above, multiple connecting electrodes can be provided to connect the first external electrode 241 and the second external electrode 244 to each other and to connect the third external electrode 242 and the fourth external electrode 243 to each other, so as to improve the adhesion between the external electrodes and the body.

[0041] Figure 4 The distance D1 between the first connecting electrode 231 and the second connecting electrode 234 or the distance D1 between the third connecting electrode 232 and the fourth connecting electrode 233 is shown, as well as the diameter D2 of each of the first connecting electrode 231, the second connecting electrode 234, the third connecting electrode 232, and the fourth connecting electrode 233, and the distance D3 between the first through hole and the third through hole or the second through hole and the fourth through hole.

[0042] The distance D1 between the first connecting electrode 231 and the second connecting electrode 234, or the distance D1 between the third connecting electrode 232 and the fourth connecting electrode 233, can be a value measured based on the center of each connecting electrode. Furthermore, the diameter D2 of each of the first connecting electrode 231, the second connecting electrode 234, the third connecting electrode 232, and the fourth connecting electrode 233 can refer to the maximum diameter of any one of the connecting electrodes. The distance D3 between the first and third via holes, or the distance D3 between the second and fourth via holes, can refer to the shortest distance between the via holes.

[0043] Reference Figure 4The ratio (D1 / D3) of the distance D1 between the first connecting electrode 231 and the second connecting electrode 234, or the distance D1 between the third connecting electrode 232 and the fourth connecting electrode 233, and the distance D3 between the first and third vias, or the distance D3 between the second and fourth vias, can be, for example, 1.90 or greater, 1.94 or greater, 1.98 or greater, 2.02 or greater, 2.06 or greater, 2.08 or greater, or 3.125 or greater. When the ratio D1 / D3 of the distance D1 between the first connecting electrode 231 and the second connecting electrode 234 and the distance D3 between the first and third vias satisfies the above range, the equivalent series inductance (ESL) can be reduced. Specifically, when the ratio D1 / D3 is 3.125 or greater, the ESL reduction effect can be significantly improved.

[0044] In another embodiment, the upper limit of D1 / D3 can be 5.0 or less. D1 / D3 can be 5.0 or less, 4.9 or less, 4.8 or less, 4.700 or less, 4.695 or less, 4.690 or less, or 4.688 or less, but is not limited to these values. When D1 / D3 meets the above ranges, it prevents the reduction in equivalent series inductance (ESL) from becoming less effective.

[0045] In another embodiment, the ratio (D2 / D3) of the diameter D2 of each of the first connecting electrode 231, the second connecting electrode 234, the third connecting electrode 232, and the fourth connecting electrode 233 to the distance D3 between the first and third vias or between the second and fourth vias can be 0.375 or greater. The ratio D2 / D3 can be 0.375 or greater, 0.380 or greater, 0.385 or greater, 0.390 or greater, 0.395 or greater, 0.400 or greater, 0.405 or greater, or 0.410 or greater, but is not limited to these values. When the ratio D2 / D3 meets the above ranges, the equivalent series inductance (ESL) can be reduced. Specifically, when the ratio D2 / D3 is 0.41 or greater, the ESL reduction effect can be significantly improved.

[0046] In another embodiment, the ratio (D2 / D3) of the diameter D2 of each of the first connecting electrode 231, the second connecting electrode 234, the third connecting electrode 232, and the fourth connecting electrode 233 to the distance D3 between the first and third via holes or between the second and fourth via holes can be 0.6 or less. The ratio D2 / D3 can be 0.60 or less, 0.58 or less, 0.56 or less, 0.54 or less, or 0.52 or less, but is not limited thereto. When the ratio D2 / D3 is greater than the above-mentioned numerical range, the capacitance of the multilayer ceramic capacitor will decrease.

[0047] Table 1 shows the ESL characteristics based on the ratio (D1 / D3) of the distance D1 between the first connecting electrode 231 and the second connecting electrode 234, or the distance D1 between the third connecting electrode 232 and the fourth connecting electrode 233, to the distance D3 between the first and third vias, or the distance D3 between the second and fourth vias. Sample capacitors with a length of 890 μm were fabricated, where the distance D3 between the first and third vias, or the distance D3 between the second and fourth vias, was 192 μm, and the average value of 100 sample capacitors was obtained.

[0048] Table 1

[0049] D1(μm) D1 / D3 Capacitance (μF) ESL(PH) ％ 200 1.041667 0.3 53.07 100％ 400 2.083333 0.3 46.78 88％ 600 3.125 0.3 42.74 81％

[0050] As can be seen from Table 1, the ESL characteristics improve as the distance D1 between the connecting electrodes increases. When D1 / D3 is 2.08, a high ESL reduction effect is observed, and when D1 / D3 is 3.125, the ESL reduction effect is further improved.

[0051] Table 2 shows the ESL characteristics based on the ratio (D2 / D3) of the diameter D2 of each of the first connecting electrode 231, the second connecting electrode 234, the third connecting electrode 232, and the fourth connecting electrode 233 to the distance D3 between the first and third via holes or the second and fourth via holes. Sample capacitors with a length of 890 μm were fabricated, wherein the distance D3 between the first and third via holes or the second and fourth via holes was 192 μm, and the distance D1 between the first connecting electrode 231 and the second connecting electrode 234 or the third connecting electrode 232 and the fourth connecting electrode 233 was 600 μm. The average value of 100 sample capacitors was obtained.

[0052] Table 2

[0053] D2(μm) D2 / D3 Capacitance [μF] ESL(PH) ％ 72 0.375 0.31 67.64 100％ 80 0.416667 0.31 36.01 96％ 96 0.5 0.28 34.03 90％

[0054] As can be seen from Table 2, the ESL characteristics improve with the increase of the diameter D2 of the connecting electrode. Since D2 / D3 is greater than 0.375, the ESL is reduced, and the ESL reduction effect is further improved when D2 / D3 is 0.5.

[0055] In the example, connecting electrodes 231, 232, 233, and 234 may contain nickel (Ni) in the highest possible content, but the materials of connecting electrodes 231, 232, 233, and 234 are not limited thereto. For example, connecting electrodes 231, 232, 233, and 234 may be formed using a conductive paste comprising at least one of silver (Ag), palladium (Pd), gold (Au), nickel (Ni), tin (Sn), copper (Cu), tungsten (W), platinum (Pt), titanium (Ti), and alloys thereof. The method of forming connecting electrodes 231, 232, 233, and 234 is not limited. For example, connecting electrodes 231, 232, 233, and 234 may be formed by: forming a laminate having a first inner electrode 221 and a second inner electrode 222 stacked thereon; penetrating the body 210 in a third direction (Z direction) using laser drilling, mechanical pin piercing, etc., to form a through-hole in the body 210; and filling the through-hole in the body 210 with conductive paste.

[0056] In the example, the internal electrodes 221 and 222, as well as the connecting electrodes 231, 232, 233, and 234, may comprise the same metallic material. This same metallic material can be nickel (Ni), but is not limited to it. For example, the same metallic material can be silver (Ag), palladium (Pd), gold (Au), platinum (Pt), nickel (Ni), copper (Cu), tungsten (W), titanium (Ti), and alloys thereof. When the internal electrodes 121 and 122, as well as the connecting electrodes 231, 232, 233, and 234, of the multilayer ceramic capacitor comprise the same metallic material, the initial sintering temperature and / or sintering shrinkage ratio can be matched to prevent cracking, peeling, etc.

[0057] In one embodiment, connecting electrodes 231, 232, 233, and 234 may protrude from the body 210 in the Z direction. (See reference...) Figure 2The first connecting electrode 231 and the second connecting electrode 234 can protrude from the second surface of the body 210. This is because, during the formation of the through-hole, the first connecting electrode 231 and the second connecting electrode 234 are pushed out of the through-hole of the body 210 due to sintering shrinkage, etc. In this case, both the first connecting electrode 231 and the second connecting electrode 234 can have an end that penetrates into the first sintered electrode 241a of the first external electrode, and the second sintered electrode 244a of the second external electrode 244 can fill a portion of the through-hole in the body 210 to contact the other end of the first connecting electrode 231 and the other end of the second connecting electrode 234. Similarly, the third connecting electrode 232 and the fourth connecting electrode 233 can both have an end that penetrates into the third sintered electrode 242a of the third external electrode, and the fourth sintered electrode 243a of the fourth external electrode 243 can fill a portion of the through-hole in the body 210 to contact the other end of the third connecting electrode 232 and the other end of the fourth connecting electrode 233. Since peeling of the connecting electrodes may occur during mounting inside or on the surface of the substrate depending on the size of the protrusion, the adhesive strength of the external electrode may be reduced. In the multilayer ceramic capacitor according to this disclosure, the external electrode may be formed on both the first and second surfaces of the body to prevent the fixing force of the external electrode from being degraded due to the protrusion.

[0058] According to an embodiment, the first external electrode 241, the second external electrode 244, the third external electrode 242, and the fourth external electrode 243 can be disposed on two outer surfaces of the main body 210. For example, the first external electrode 241 and the second external electrode 244 can be disposed on the first surface S1 and the second surface S2 of the main body 210, respectively, and can be electrically connected through the first connecting electrode 231 and the second connecting electrode 234. The third external electrode 242 and the fourth external electrode 243 can be spaced apart from the first external electrode 241 and the second external electrode 244, and can be disposed on the first surface S1 and the second surface S2 of the main body 210, and can be electrically connected to each other through the third connecting electrode 232 and the fourth connecting electrode 233.

[0059] In the following text, reference will be made to Figure 2 The structure of the first external electrode 241 is described. Unless otherwise explicitly described, the description of the structure of the first external electrode 241, including layers 241a, 241b, and 241c, can be applied in the same manner to the second external electrode 244, including layers 244a, 244b, and 244c; the third external electrode 242, including layers 242a, 242b, and 242c; and the fourth external electrode 243, including layers 243a, 243b, and 243c.

[0060] Reference Figure 2The first external electrode 241 may include a first sintered electrode 241a, a first plating layer 241b, and a second plating layer 241c. The first sintered electrode 241a may include at least one of silver (Ag), palladium (Pd), gold (Au), platinum (Pt), nickel (Ni), tin (Sn), copper (Cu), tungsten (W), titanium (Ti), and alloys thereof. For example, the first sintered electrode 241a may be a sintered electrode formed by sintering a conductive paste containing nickel (Ni). Similar to the first sintered electrode 241a, when the external electrode is formed as a sintered electrode, the external electrode can be sintered simultaneously with the body and the internal electrode, and the adhesion strength between the body and the external electrode can be improved.

[0061] In the example, the centerline average roughness Ra of the surfaces of the first external electrode 241, the second external electrode 244, the third external electrode 242, and the fourth external electrode 243 can be in the range of 1 nm to 100 nm. In this specification, "centerline average roughness Ra" can refer to the average value of the distances to a virtual centerline. An external electrode having a centerline average roughness Ra in the range of 1 nm to 100 nm can refer to an external electrode having a surface roughness within the aforementioned range, and can also refer to an external electrode having a surface roughness artificially formed to satisfy the aforementioned range.

[0062] The centerline average roughness Ra is obtained by drawing virtual centerlines for roughness on the surfaces of the first outer electrode 241, the second outer electrode 244, the third outer electrode 242, and the fourth outer electrode 243, measuring the corresponding distances (e.g., r1, r2, r3, ..., and rn) based on the virtual centerlines for roughness, and obtaining the average value as given in Equation 1.

[0063] Formula 1

[0064]

[0065] An external electrode having a centerline average roughness Ra that meets the above-mentioned range can be formed by surface modification using physical or chemical methods. The surface modification method is not limited, as long as it provides the aforementioned roughness. For example, surface modification methods can include surface treatment using acidic or alkaline solutions or physical polishing using abrasives.

[0066] Typically, oxide layers are formed on the surface of sintered electrodes containing nickel or the like during a sintering process. Therefore, it can be difficult to form a plating layer, and the plating layer may easily peel off. When the outer electrode according to the embodiment is surface-modified to meet the centerline average roughness Ra within the aforementioned range, the oxide layer can be removed, or a surface with a predetermined roughness can be formed. Therefore, the adhesion between the outer electrode and the plating layer can be enhanced, and plating peeling can be prevented.

[0067] According to an embodiment, the first plating layer 241b may be a nickel-containing plating layer, and the second plating layer 241c may be a copper- or tin-containing plating layer. The first plating layer 241b may contain nickel to improve adhesion to the first sintered electrode 241a. Furthermore, the second plating layer 241c may contain copper or tin to form an external electrode with improved conductivity, plating adhesion, and solderability.

[0068] In the example, each of the first external electrode 241, the second external electrode 244, the third external electrode 242, and the fourth external electrode 243 may have a thickness ranging from 3 μm to 30 μm. Furthermore, each of the first external electrode 241, the second external electrode 244, the third external electrode 242, and the fourth external electrode 243 may have a thickness ranging from 1 μm to 10 μm. The thickness of each of the first external electrode 241, the second external electrode 244, the third external electrode 242, and the fourth external electrode 243 may refer to the overall thickness of the stacked sintered electrodes, the first plating layer, and the second plating layer, and may also refer to the vertical distance from the body to the surface of the external electrode. The thickness of the external electrodes can be adjusted within the above range to achieve improved mountability without occupying a large space when used for surface mounting or embedding into a substrate.

[0069] The multilayer ceramic capacitor according to this disclosure can be manufactured by the following method. A body comprising a dielectric layer and a first internal electrode and a second internal electrode, wherein the dielectric layer is disposed between the first internal electrode and the second internal electrode, can be prepared by stacking ceramic green sheets and sintering, wherein a paste comprising a conductive metal for forming the internal electrode is printed to a predetermined thickness on one surface of the ceramic green sheet used to form the dielectric layer.

[0070] The first cover portion 212 and the second cover portion 213 can be formed by stacking dielectric layers, neither of which includes internal electrodes, on the upper and lower parts of the main body 210.

[0071] After the cover is formed, through holes are formed in the body 210 using laser drilling or mechanical pin piercing. Then, the first connecting electrode 231, the second connecting electrode 234, the third connecting electrode 232, and the fourth connecting electrode 233 are formed by applying conductive paste to the through holes or by using a conductive filling material such as plating.

[0072] Then, a first external electrode 241 and a second external electrode 244 connected to the first connecting electrode 231 and the second connecting electrode 234, and a third external electrode 242 and a fourth external electrode 243 connected to the third connecting electrode 232 and the fourth connecting electrode 233 can be formed on the surface of the main body 210.

[0073] More specifically, forming the first external electrode 241, the second external electrode 244, the third external electrode 242, and the fourth external electrode 243 may include: forming a first sintered electrode, a second sintered electrode, a third sintered electrode, and a fourth sintered electrode, all comprising nickel, on the body 210; forming a first plating layer on each of the first sintered electrode, the second sintered electrode, the third sintered electrode, and the fourth sintered electrode; and forming a second plating layer on each of the first plating layers.

[0074] A sintered electrode can be formed by coating a conductive paste containing nickel and sintering the paste. The first plating layer may contain nickel and can be formed by electroplating or electroless plating. The second plating layer may contain copper or tin and can be formed by electroplating or electroless plating.

[0075] After forming the sintered electrode, sintering and plasticizing are performed to form the first and second coatings. As a result, the process is complete. Figure 1 The multilayer ceramic capacitor shown.

[0076] As described above, according to the embodiments, the capacitance of the multilayer ceramic capacitor can be increased.

[0077] According to another embodiment, the breakdown voltage (BDV) of a multilayer ceramic capacitor can be increased.

[0078] According to another embodiment, a multilayer ceramic capacitor that can improve the equivalent series inductance (ESL) due to the mutual inductance cancellation effect can be provided.

[0079] Although exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations may be made without departing from the scope of this disclosure as defined by the appended claims.

Claims

1. A multilayer ceramic capacitor, comprising: The main body includes a dielectric layer and a first inner electrode and a second inner electrode that are point-symmetrical to each other, and the corresponding dielectric layer is disposed between the first inner electrode and the second inner electrode. The first connecting electrode and the second connecting electrode pass through the body in a direction perpendicular to the dielectric layer and are connected to the first inner electrode; The third and fourth connecting electrodes pass through the body in the direction perpendicular to the dielectric layer and are connected to the second inner electrode; A first external electrode and a second external electrode are disposed on two outer surfaces of the main body and connected to the first connecting electrode and the second connecting electrode; as well as The third and fourth external electrodes are spaced apart from the first and second external electrodes and connected to the third and fourth connecting electrodes, respectively. The second inner electrode has a first through hole and a second through hole, and the first inner electrode has a third through hole and a fourth through hole. Wherein, the ratio of the distance between the center of the first connecting electrode and the center of the second connecting electrode or the distance between the center of the third connecting electrode and the center of the fourth connecting electrode to the shortest distance between the first passage hole and the third passage hole or the shortest distance between the second passage hole and the fourth passage hole is 1.9 or greater.

2. The multilayer ceramic capacitor of claim 1, wherein, The first connecting electrode and the second connecting electrode respectively pass through the first through hole and the second through hole of the second inner electrode, and The third connecting electrode and the fourth connecting electrode pass through the third passage hole and the fourth passage hole of the first inner electrode, respectively.

3. The multilayer ceramic capacitor of claim 1, wherein, Each of the first inner electrode and the second inner electrode has a rectangular shape.

4. The multilayer ceramic capacitor according to claim 1, wherein, The ratio of the distance between the center of the first connecting electrode and the center of the second connecting electrode, or the distance between the center of the third connecting electrode and the center of the fourth connecting electrode, to the shortest distance between the first and third access holes, or the shortest distance between the second and fourth access holes, is 3.125 or greater.

5. The multilayer ceramic capacitor of claim 1, wherein, The ratio of the distance between the center of the first connecting electrode and the center of the second connecting electrode or the distance between the center of the third connecting electrode and the center of the fourth connecting electrode to the shortest distance between the first and third access holes or the shortest distance between the second and fourth access holes is greater than or equal to 3.125 and less than or equal to 5.

0.

6. The multilayer ceramic capacitor of claim 1, wherein, The ratio of the diameter of one of the first connecting electrode, the second connecting electrode, the third connecting electrode, and the fourth connecting electrode to the shortest distance between the first and third access holes or the shortest distance between the second and fourth access holes is 0.375 or greater.

7. A multilayer ceramic capacitor, comprising: The main body includes a dielectric layer and a first inner electrode and a second inner electrode that are point-symmetrical to each other, and the corresponding dielectric layer is disposed between the first inner electrode and the second inner electrode. The first connecting electrode and the second connecting electrode pass through the body in a direction perpendicular to the dielectric layer and are connected to the first inner electrode; The third and fourth connecting electrodes pass through the body in the direction perpendicular to the dielectric layer and are connected to the second inner electrode; A first external electrode and a second external electrode are disposed on two outer surfaces of the main body and connected to the first connecting electrode and the second connecting electrode; as well as The third and fourth external electrodes are spaced apart from the first and second external electrodes and connected to the third and fourth connecting electrodes, respectively. The second inner electrode has a first through hole and a second through hole, and the first inner electrode has a third through hole and a fourth through hole. Wherein, the ratio of the diameter of one of the first connecting electrode, the second connecting electrode, the third connecting electrode, and the fourth connecting electrode to the shortest distance between the first and third access holes or the shortest distance between the second and fourth access holes is 0.6 or less.

8. The multilayer ceramic capacitor of claim 7, wherein, Each of the first internal electrode and the second internal electrode contains nickel.

9. The multilayer ceramic capacitor of claim 7, wherein, Each of the first external electrode, the second external electrode, the third external electrode, and the fourth external electrode is a sintered electrode containing nickel.

10. The multilayer ceramic capacitor of claim 7, wherein, Each of the first external electrode, the second external electrode, the third external electrode, and the fourth external electrode has a centerline average roughness in the range of 1 nm to 100 nm.

11. The multilayer ceramic capacitor of claim 7, wherein, Each of the first external electrode, the second external electrode, the third external electrode, and the fourth external electrode includes a sintered electrode, and a first plating layer and a second plating layer are sequentially stacked on the sintered electrode.

12. The multilayer ceramic capacitor of claim 7, wherein, Each of the first external electrode, the second external electrode, the third external electrode, and the fourth external electrode has a thickness in the range of 1 μm to 10 μm.

13. The multilayer ceramic capacitor of claim 7, wherein, The body has a thickness of 100 μm or less.

14. A multilayer ceramic capacitor, comprising: The main body includes a dielectric layer and a first inner electrode and a second inner electrode, and the corresponding dielectric layer is disposed between the first inner electrode and the second inner electrode. The first connecting electrode and the second connecting electrode pass through the body in a direction perpendicular to the dielectric layer and are connected to the first inner electrode; The third and fourth connecting electrodes pass through the body in the direction perpendicular to the dielectric layer and are connected to the second inner electrode; A first external electrode is disposed on an outer surface of the main body and connected to the first internal electrode via the first connecting electrode and the second connecting electrode; as well as The third external electrode is disposed on one of the outer surfaces of the main body and connected to the second internal electrode via the third connecting electrode and the fourth connecting electrode. The second inner electrode has a first through-hole and a second through-hole. The first connecting electrode is disposed in the first through-hole, and the second connecting electrode is disposed in the second through-hole. The first inner electrode also has a third through-hole and a fourth through-hole. The third connecting electrode is disposed in the third through-hole, and the fourth connecting electrode is disposed in the fourth through-hole. The ratio of the diameter of one of the first connecting electrode, the second connecting electrode, the third connecting electrode, and the fourth connecting electrode to the shortest distance between the first and third access holes or the shortest distance between the second and fourth access holes is greater than or equal to 0.41 and less than or equal to 0.

52.

15. The multilayer ceramic capacitor according to claim 14, wherein the multilayer ceramic capacitor further comprises: The second external electrode is disposed on another external surface of the main body opposite to the first external surface, and is connected to the first internal electrode through the first connecting electrode and the second connecting electrode; as well as A fourth external electrode is disposed on the other external surface of the main body and is connected to the second internal electrode via the third connecting electrode and the fourth connecting electrode.

16. A multilayer ceramic capacitor, comprising: The main body includes a dielectric layer and a first inner electrode and a second inner electrode, wherein the corresponding dielectric layer is positioned between the first inner electrode and the second inner electrode. The first connecting electrode and the second connecting electrode pass through the body in a direction perpendicular to the dielectric layer and are connected to the first inner electrode; The third and fourth connecting electrodes pass through the body in the direction perpendicular to the dielectric layer and are connected to the second inner electrode; A first external electrode is disposed on an outer surface of the main body and connected to the first internal electrode via the first connecting electrode and the second connecting electrode; as well as The third external electrode is disposed on one of the outer surfaces of the main body and connected to the second internal electrode via the third connecting electrode and the fourth connecting electrode. The second inner electrode has a first through-hole and a second through-hole. The first connecting electrode is disposed in the first through-hole, and the second connecting electrode is disposed in the second through-hole. The first inner electrode also has a third through-hole and a fourth through-hole. The third connecting electrode is disposed in the third through-hole, and the fourth connecting electrode is disposed in the fourth through-hole. The ratio of the distance between the center of the first connecting electrode and the center of the second connecting electrode or the distance between the center of the third connecting electrode and the center of the fourth connecting electrode to the shortest distance between the first and third access holes or the shortest distance between the second and fourth access holes is greater than or equal to 3.125 and less than or equal to 4.

7.

17. The multilayer ceramic capacitor according to claim 16, further comprising: a second external electrode provided on the other external surface of the main body opposite to the one external surface, and connected to the first internal electrode through the first and second connecting electrodes; and a fourth external electrode provided on the other external surface of the main body, and connected to the second internal electrode through the third and fourth connecting electrodes.

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