Multilayer capacitor and method of manufacturing the same

Abstract

The present disclosure provides a multilayer capacitor and a manufacturing method thereof. The multilayer capacitor includes a capacitor body including first to sixth surfaces and including a plurality of dielectric layers and a plurality of first internal electrodes and a plurality of second internal electrodes, and a first external electrode and a second external electrode. The first internal electrode includes a first capacitance forming portion, a first lead-out portion extending from the first capacitance forming portion toward a third surface of the capacitor body and connected to the first external electrode, and a first dot pattern portion provided at at least one corner of the first capacitance forming portion, and the second internal electrode includes a second capacitance forming portion, a second lead-out portion extending from the second capacitance forming portion toward a fourth surface of the capacitor body and connected to the second external electrode, and a second dot pattern portion provided at at least one corner of the second capacitance forming portion.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2021-0009479, filed with the Korean Intellectual Property Office on January 22, 2021, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates to a multilayer capacitor and a method for manufacturing the same. Background Technology

[0003] A multilayer capacitor (multilayer ceramic capacitor, MLCC) is a passive electronic component that can be used to control electrical signals in a circuit.

[0004] Recently, with the improvement of the performance of electronic devices (such as electronic products and computers), high reliability is also required for multilayer capacitors used in electronic devices.

[0005] To improve the moisture resistance reliability of multilayer capacitors, it may be necessary to reduce the moisture penetration path, and as one method to reduce the moisture penetration path, a bottleneck structure can be applied to the internal electrode.

[0006] However, stepped sections may form at the opposite corners of the bottleneck pattern of the internal electrodes, which could lead to an increased short-circuit rate or reduced reliability. Summary of the Invention

[0007] One aspect of this disclosure is to provide a multilayer capacitor and a method for manufacturing the same, wherein a bottleneck structure is applied to the inner electrode to reduce the moisture penetration path and prevent the formation of stepped portions at the corners of the bottleneck pattern, thereby improving reliability and preventing an increase in short-circuit rate.

[0008] According to one aspect of this disclosure, a multilayer capacitor includes: a capacitor body comprising a first surface and a second surface opposite to each other in a first direction of the capacitor body, a third surface and a fourth surface opposite to each other in a second direction of the capacitor body, and a fifth surface and a sixth surface opposite to each other in a third direction of the capacitor body; the capacitor body includes a plurality of dielectric layers and a first inner electrode and a second inner electrode, the first inner electrode and the second inner electrode being alternately disposed in the first direction, and the dielectric layers being disposed between the first inner electrode and the second inner electrode; and a first outer electrode and a second outer electrode, respectively disposed at both ends of the capacitor body in the second direction. The first inner electrode includes a first capacitance forming portion, a first lead-out portion, and a first dot pattern portion; the first lead-out portion extends from the first capacitance forming portion toward the third surface of the capacitor body and is connected to the first outer electrode; the first dot pattern portion is disposed at at least one corner of the first capacitance forming portion. The second inner electrode includes a second capacitor forming portion, a second lead-out portion, and a second dot pattern portion. The second capacitor forming portion is superimposed on the first capacitor forming portion in the first direction. The second lead-out portion extends from the second capacitor forming portion toward the fourth surface of the capacitor body and is connected to the second outer electrode. The second dot pattern portion is disposed at at least one corner of the second capacitor forming portion.

[0009] The first dot pattern portion and the second dot pattern portion have dot patterns that do not overlap with each other in the first direction.

[0010] The length of the first lead-out portion in the third direction may be less than the length of the first capacitor forming portion in the third direction, and the length of the second lead-out portion in the third direction may be less than the length of the second capacitor forming portion in the third direction.

[0011] In the first dot pattern portion, the first electrode portion and the first interval portion of the dot shape may be alternately arranged in the second direction and alternately arranged in the third direction upward; and in the second dot pattern portion, the second electrode portion and the second interval portion of the dot shape may be alternately arranged in the second direction and alternately arranged in the third direction upward.

[0012] The first electrode portion may be superimposed on the second spacing portion in the first direction, and the second electrode portion may be superimposed on the first spacing portion in the first direction.

[0013] The average thickness of the first electrode portion in the first direction may be 70% to 90% of the average thickness of the first capacitor forming portion in the first direction, and the average thickness of the second electrode portion in the first direction may be 70% to 90% of the average thickness of the second capacitor forming portion in the first direction.

[0014] The capacitor body may include an effective region, an upper cover region, and a lower cover region. In the effective region, the first capacitor forming portion and the second capacitor forming portion are stacked on top of each other in the first direction. The upper cover region and the lower cover region are respectively disposed on the upper surface and the lower surface of the effective region in the first direction.

[0015] The first external electrode may include a first connecting portion disposed on the third surface of the capacitor body and a first strip portion extending from the first connecting portion to a portion of the first surface of the capacitor body, and the second external electrode may include a second connecting portion disposed on the fourth surface of the capacitor body and a second strip portion extending from the second connecting portion to a portion of the first surface of the capacitor body.

[0016] According to one aspect of this disclosure, a mounting plate on which a multilayer capacitor is mounted includes: a plate having a plurality of electrode pads on one surface of the plate; and the multilayer capacitor having an external electrode connected to the electrode pads.

[0017] According to one aspect of this disclosure, a method of manufacturing a multilayer capacitor includes: forming a first internal electrode and a second internal electrode on a first ceramic sheet and a second ceramic sheet, respectively; stacking a plurality of first ceramic sheets on which the first internal electrode is formed and a plurality of second ceramic sheets on which the second internal electrode is formed, such that the first internal electrode and the second internal electrode are opposite to each other and the first ceramic sheet or the second ceramic sheet is between the first internal electrode and the second internal electrode, and pressing the first ceramic sheet and the second ceramic sheet to form a laminate; forming a capacitor body by cutting the laminate and firing it, the capacitor body including a first surface and a second surface opposite to each other in a first direction of the capacitor body, a third surface and a fourth surface opposite to each other in a second direction of the capacitor body, and a fifth surface and a sixth surface opposite to each other in a third direction of the capacitor body, and the capacitor body including a first lead-out portion of the first internal electrode and a second lead-out portion of the second internal electrode exposed through the third surface and the fourth surface, respectively; and forming a first external electrode and a second external electrode electrically connected to the first lead-out portion and the second lead-out portion, respectively, on the capacitor body. The first inner electrode includes a first capacitor forming portion, a first lead-out portion, and a first dot pattern portion. The first lead-out portion extends from the first capacitor forming portion toward the third surface of the capacitor body and is connected to the first outer electrode. The first dot pattern portion is disposed at at least one corner of the first capacitor forming portion. The second inner electrode includes a second capacitor forming portion, a second lead-out portion, and a second dot pattern portion. The second capacitor forming portion overlaps with the first capacitor forming portion in the first direction. The second lead-out portion extends from the second capacitor forming portion toward the fourth surface of the capacitor body and is connected to the second outer electrode. The second dot pattern portion is disposed at at least one corner of the second capacitor forming portion.

[0018] The second electrode portion of the second dot pattern portion may be formed so that it does not overlap with the first electrode portion of the first dot pattern portion in the first direction.

[0019] The first internal electrode can be formed by: providing a printing screen including a screen mesh on the first ceramic sheet; applying conductive paste to the screen mesh at a predetermined thickness; printing a first internal electrode pattern on the screen mesh coated with conductive paste, such that one end in the second direction is formed as a first lead-out portion having a bottleneck shape and a first dot pattern is formed at at least one corner; and developing the exposed conductive paste. The second internal electrode can be formed by: providing a printing screen including a screen mesh on the second ceramic sheet; applying conductive paste to the screen mesh at a predetermined thickness; printing a second internal electrode pattern on the screen mesh coated with conductive paste, such that the other end in the second direction is formed as a second lead-out portion having a bottleneck shape and a second dot pattern is formed at at least one corner; and developing the exposed conductive paste. Attached Figure Description

[0020] The above and other aspects, features and advantages of this disclosure will be more clearly understood by taking into account the accompanying drawings and the following detailed description, in which: Figure 1 This is a perspective view showing a portion of a multilayer capacitor removed according to an exemplary embodiment of the present disclosure; Figure 2A and Figure 2B These are plan views showing the first inner electrode and the second inner electrode according to an exemplary embodiment of the present disclosure; Figure 3 It is along Figure 1 A cross-sectional view taken from line I-I' in the diagram; Figure 4 It is a graph showing how the capacitance of a multilayer capacitor changes with the thickness of the dotted pattern portion; and Figure 5 It shows that it is equipped with Figure 1 A perspective view of the mounting plate for the multilayer capacitor shown. Detailed Implementation

[0021] In the following description, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0022] However, this disclosure may be exemplified in many different forms and should not be construed as being limited to the specific embodiments set forth herein.

[0023] More precisely, these embodiments are provided so that this disclosure will be comprehensive and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0024] For clarity, the shapes and sizes of the elements in the accompanying drawings may be exaggerated, and the elements indicated by the same reference numerals in the drawings are the same elements.

[0025] Furthermore, it should be understood that when a part “includes” an element, it may include other elements, rather than excluding them, unless otherwise stated.

[0026] In the example embodiment, regarding the orientation of the capacitor body, X, Y, and Z shown in the figures can represent the length direction, width direction, and thickness direction of the multilayer capacitor, respectively.

[0027] The thickness direction can be used as the first direction, the length direction can be used as the second direction, and the width direction can be used as the third direction.

[0028] The Z-direction can be the same as the stacking direction of the stacked dielectric layers.

[0029] Figure 1 This is a perspective view showing a portion of a multilayer capacitor removed according to an example embodiment. Figure 2A and Figure 2B These are plan views showing the first inner electrode and the second inner electrode according to the example embodiment. Figure 3 It is along Figure 1 The cross-sectional view taken from line I-I' in the diagram.

[0030] Reference Figures 1 to 3 The multilayer capacitor 100 in the example embodiment may include a capacitor body 110 and a first external electrode 131 and a second external electrode 132.

[0031] The capacitor body 110 may include a plurality of dielectric layers 111 alternately disposed in the Z direction, a plurality of first internal electrodes 121 and a plurality of second internal electrodes 122, wherein the dielectric layers 111 are disposed between the first internal electrodes 121 and the second internal electrodes 122.

[0032] The capacitor body 110 can be formed by stacking multiple dielectric layers 111 in the Z direction and then firing them, and the boundaries between adjacent dielectric layers 111 of the capacitor body 110 can be integrated, making it difficult to identify the boundaries between them without using a scanning electron microscope (SEM).

[0033] The capacitor body 110 may have a generally hexahedral shape, but its exemplary embodiments are not limited thereto. Furthermore, the shape and size of the capacitor body 110 and the number of stacked dielectric layers 111 are not limited to the shapes, sizes, and numbers shown in the figures.

[0034] In an example embodiment, the two surfaces of the capacitor body 110 that are opposite to each other in the Z direction can be defined as a first surface 1 and a second surface 2, the two surfaces connected to the first surface 1 and the second surface 2 and opposite to each other in the X direction can be defined as a third surface 3 and a fourth surface 4, and the two surfaces connected to the first surface 1 and the second surface 2, as well as the third surface 3 and the fourth surface 4 and opposite to each other in the Y direction can be defined as a fifth surface 5 and a sixth surface 6.

[0035] Furthermore, in the example embodiment, the mounting surface of the multilayer capacitor 100 may be the first surface 1 of the capacitor body 110.

[0036] The dielectric layer 111 may include a ceramic material with a high dielectric constant (e.g., barium titanate (BaTiO3) ceramic powder or strontium titanate (SrTiO3) ceramic powder), but its exemplary embodiments are not limited thereto, as long as sufficient capacitance can be obtained.

[0037] In addition to ceramic powder, dielectric layer 111 may also include ceramic additives, organic solvents, plasticizers, binders, and dispersants.

[0038] Transition metal oxides or transition metal carbides, rare earth elements, magnesium (Mg) or aluminum (Al) can be used as ceramic additives.

[0039] The capacitor body 110 may include an effective region and an upper cover 112 and a lower cover 113 (i.e., an upper cover region and a lower cover region). The effective region contributes to the capacitance of the capacitor. The upper cover 112 and the lower cover 113 are formed on the upper and lower surfaces of the effective region in the Z direction as upper and lower edge portions, respectively.

[0040] The upper cover 112 and the lower cover 113 do not include internal electrodes. Otherwise, the upper cover 112 and the lower cover 113 may have the same material and construction as the dielectric layer 111.

[0041] The upper cover 112 and the lower cover 113 can be formed by stacking a single dielectric layer or two or more dielectric layers on the upper and lower surfaces in the Z direction of the effective region, respectively, and can prevent the first inner electrode 121 and the second inner electrode 122 from being damaged due to physical or chemical stress.

[0042] The first inner electrode 121 and the second inner electrode 122 may be applied with different polarities and may be alternately arranged in the Z direction, with the dielectric layer 111 between the first inner electrode 121 and the second inner electrode 122, and one end of the first inner electrode 121 and one end of the second inner electrode 122 may be exposed to the third surface 3 and the fourth surface 4 of the capacitor body 110 respectively (or, respectively contact the third surface 3 and the fourth surface 4 of the capacitor body 110 or extend from the third surface 3 and the fourth surface 4 of the capacitor body 110).

[0043] In this case, the first inner electrode 121 and the second inner electrode 122 can be electrically insulated from each other by the dielectric layer 111 disposed between them.

[0044] Therefore, the ends of the first inner electrode 121 and the second inner electrode 122, which are exposed through the third surface 3 and the fourth surface 4 of the capacitor body 110, can be electrically connected to the first outer electrode 130 and the second outer electrode 140, respectively. The first outer electrode 130 and the second outer electrode 140 are respectively disposed on the third surface 3 and the fourth surface 4 of the capacitor body 110.

[0045] The first internal electrode 121 may include a first capacitor forming portion 121a, a first lead-out portion 121d, and a first dot pattern portion. Reference numerals 121b and 121c indicate portions located between the dot pattern portions and formed to protrude from the first capacitor forming portion 121a.

[0046] The first capacitor forming portion 121a can be spaced apart from the third surface 3, fourth surface 4, fifth surface 5 and sixth surface 6 of the capacitor body 110, and can contribute to the capacitance of the formed capacitor.

[0047] The first lead-out portion 121d can extend from the first capacitor forming portion 121a toward the third surface 3 of the capacitor body 110 to be exposed from the third surface 3 of the capacitor body 110, and can be connected to the first external electrode 131.

[0048] In this case, the length of the first lead-out portion 121d in the Y direction may be less than the length of the first capacitor forming portion 121a in the Y direction. For example, the first internal electrode 121 may have a bottleneck pattern in which the first lead-out portion 121d is in the shape of a bottleneck.

[0049] The first dot pattern portion may be formed at at least one corner of the first capacitor forming portion 121a.

[0050] The first dot pattern portion may include a first electrode portion 121e having a dot shape and a first spacing portion 121f having a dot shape and serving as an edge portion. The first electrode portion 121e and the first spacing portion 121f may be alternately arranged in the X direction and alternately arranged in the Y direction, and may be configured as, for example, a checkerboard shape.

[0051] In this case, the average thickness of the first electrode portion 121e in the Z direction can be 70% to 90% of the average thickness of the first capacitor forming portion 121a.

[0052] When the average thickness of the first electrode portion 121e is less than 70% of the average thickness of the first capacitor forming portion 121a, the electrode connectivity may decrease, which may lead to a reduction in the capacitance of the capacitor. When the average thickness of the first electrode portion 121e exceeds 90% of the average thickness of the first capacitor forming portion 121a, it may not be possible to properly achieve the effect of improving the step difference through the dot pattern portion.

[0053] In an example embodiment, the first dot pattern portion may be formed at all four corners of the first capacitor forming portion 121a, but the first dot pattern portion may also be formed at three or fewer corners of the first capacitor forming portion 121a. Preferably, in order to reduce the step difference, the first dot pattern portion may be formed at all four corners of the first capacitor forming portion 121a.

[0054] The second internal electrode 122 may include a second capacitor forming portion 122a, a second lead-out portion 122d, and a second dot pattern portion. Reference numerals 122b and 122c indicate portions located between the dot pattern portions and formed to protrude from the second capacitor forming portion 122a.

[0055] The second capacitor forming portion 122a may be spaced apart from the third surface 3, fourth surface 4, fifth surface 5 and sixth surface 6 of the capacitor body 110, and may be stacked with the first capacitor forming portion 121a in the Z direction. The second capacitor forming portion 122a may contribute to the capacitance of the formed capacitor.

[0056] The second lead-out portion 122d can extend from the second capacitor forming portion 122a toward the fourth surface 4 of the capacitor body 110 to be exposed from the fourth surface 4 of the capacitor body 110, and can be connected to the second external electrode 132.

[0057] In this case, the length of the second lead-out portion 122d in the Y direction may be less than the length of the second capacitor forming portion 122a in the Y direction. For example, in the second inner electrode 122, the second lead-out portion 122d may have a bottleneck pattern similar to a bottleneck shape.

[0058] The second pattern portion may be formed at at least one corner of the second capacitor forming portion 122a.

[0059] The second dot pattern portion may include a second electrode portion 122e having a dot shape and a second spacing portion 122f having a dot shape and serving as an edge portion. The second electrode portion 122e and the second spacing portion 122f may be alternately arranged in the X direction and alternately arranged in the Y direction, and may be configured as, for example, a checkerboard shape.

[0060] In this case, the average thickness of the second electrode portion 122e in the Z direction can be 70% to 90% of the average thickness of the second capacitor forming portion 122a.

[0061] When the average thickness of the second electrode portion 122e is less than 70% of the average thickness of the second capacitor forming portion 122a, the electrode connectivity may decrease, which may lead to a reduction in the capacitance of the capacitor. When the average thickness of the second electrode portion 122e exceeds 90% of the average thickness of the second capacitor forming portion 122a, it may not be possible to properly achieve the effect of improving the step difference through the dot pattern portion.

[0062] In an example embodiment, the second dot pattern portion may be formed at the four corners of the second capacitor forming portion 122a, but the second dot pattern portion may also be formed at three or fewer corners of the second capacitor forming portion 122a. Preferably, in order to reduce the step difference, the second dot pattern portion may be formed at the four corners of the second capacitor forming portion 122a.

[0063] Furthermore, the first dot pattern portion and the second dot pattern portion may each have dot patterns that do not overlap with each other in the Z direction.

[0064] More specifically, the first electrode portion 121e of the first dot pattern portion may be superimposed on the second spacing portion 122f of the second dot pattern portion in the Z direction, and the first spacing portion 121f of the first dot pattern portion may be superimposed on the second electrode portion 122e of the second dot pattern portion in the Z direction.

[0065] With the above configuration, when a predetermined voltage is applied to the first external electrode 131 and the second external electrode 132, charge can accumulate between the first internal electrode 121 and the second internal electrode 122.

[0066] In this case, the capacitance of the multilayer capacitor 100 can be proportional to the stacking area between the first capacitance forming portion 121a of the first inner electrode 121 and the second capacitance forming portion 122a of the second inner electrode 122, which are stacked on top of each other in the Z direction in the effective region of the capacitor body 110.

[0067] Furthermore, the materials used to form the first internal electrode 121 and the second internal electrode 122 are not limited to any particular material, and conductive pastes including, for example, at least one of noble metal materials (such as platinum (Pt), palladium (Pd), palladium-silver (Pd-Ag) alloys, nickel (Ni), and copper (Cu) can be used.

[0068] In this case, the method for printing conductive paste can be screen printing or gravure printing, but the example embodiments are not limited to these.

[0069] The first external electrode 131 and the second external electrode 132 can be provided with voltages of different polarities, can be disposed at both ends of the capacitor body 110 in the X direction, and can be electrically connected to the exposed portion of the first internal electrode 121 and the exposed portion of the second internal electrode 122, respectively.

[0070] In this case, the first external electrode 131 and the second external electrode 132 may include a conductive layer formed on the capacitor body 110 and a plating layer formed on the conductive layer.

[0071] The coating may include a nickel (Ni) coating formed on a conductive layer and a tin (Sn) coating formed on a nickel (Ni) coating.

[0072] The first external electrode 131 may include a first connecting portion 131a and a first strip portion 131b.

[0073] The first connecting portion 131a may be formed on the third surface 3 of the capacitor body 110 and may be connected to the exposed portion of the first internal electrode 121, and the first strip portion 131b may extend from the first connecting portion 131a to a portion of the first surface 1 of the capacitor body 110.

[0074] In this case, the first strip 131b may also extend to a portion of the fifth surface 5, a portion of the sixth surface 6, and a portion of the second surface 2 of the capacitor body 110 to improve adhesive strength.

[0075] The second external electrode 132 may include a second connecting portion 132a and a second strip portion 132b.

[0076] The second connecting portion 132a may be formed on the fourth surface 4 of the capacitor body 110 and may be connected to the exposed portion of the second inner electrode 122, and the second strip portion 132b may extend from the second connecting portion 132a to a portion of the first surface 1 of the capacitor body 110.

[0077] In this case, the second strip 132b may also extend to a portion of the fifth surface 5, a portion of the sixth surface 6, and a portion of the second surface 2 of the capacitor body 110 to improve adhesive strength.

[0078] In typical multilayer capacitors, a bottleneck structure can be applied to the internal electrode to improve moisture resistance reliability. However, the corner of the internal electrode, which can become a bottleneck pattern, may become an empty part, which may create a significant step difference, potentially increasing the short-circuit rate of the capacitor and causing voltage breakdown.

[0079] In an example embodiment, the first dot pattern portion may be formed at the corner of the first capacitor forming portion of the first inner electrode, and the second dot pattern portion may be formed at the corner of the second capacitor forming portion of the second inner electrode. The dot patterns of the first dot pattern portion and the second dot pattern portion may not overlap with each other in the Z direction, thereby improving the moisture-proof reliability of the inner electrode of the general bottleneck pattern structure and preventing stepped portions.

[0080] Therefore, it can prevent the capacitance of multilayer capacitors from decreasing, improve the short-circuit rate of capacitors, and improve withstand voltage characteristics.

[0081] In the following text, a test can be performed to identify the relationship between the thickness of the first electrode portion of the first dot pattern portion and the second electrode portion of the second dot pattern portion and the capacitance of the capacitor.

[0082] Regarding the average thickness of the dot pattern portion, the 10 inner electrodes are observed by looking at the cross-sectional surface of the central part of the multilayer capacitor in the Z direction, which is parallel to the Z and X directions. The thickness of five points (with equal distance between adjacent points) on the electrode portion of the dot pattern portion of each inner electrode is measured and the average thickness of the five points is calculated. Finally, the average thickness of the 10 inner electrodes is calculated as the average thickness of the dot pattern portion.

[0083] Regarding the average thickness of the capacitor forming part, the 10 inner electrodes are observed by looking at the cross-sectional surface of the central part of the multilayer capacitor in the Z direction, which is parallel to the Z and X directions. The thickness of five points (with equal distance between adjacent points) on the capacitor forming part of each inner electrode is measured and the average thickness of the five points is calculated. Finally, the average thickness of the 10 inner electrodes is calculated as the average thickness of the capacitor forming part.

[0084] Figure 4 It is a graph showing how the capacitance of a multilayer capacitor changes as the thickness of the dot pattern varies.

[0085] Reference Figure 4 When the average thickness of the electrode portion (i.e., the average thickness of the dot pattern portion) is less than 70% of the average thickness of the capacitor forming portion, the capacitance decreases rapidly.

[0086] Therefore, as in the example embodiment, when the average thickness of the electrode portion in the Z direction is 70% or more of the average thickness of the capacitor forming portion in the Z direction, the reduction in capacitance may not be significant.

[0087] Figure 5 It shows that it is equipped with Figure 1 A perspective view of the mounting plate for the multilayer capacitor shown.

[0088] Reference Figure 5 The mounting plate of the multilayer capacitor in the example embodiment may include: a plate 210 on which the multilayer capacitor 100 is mounted; and a first electrode pad 221 and a second electrode pad 222 disposed on the upper surface of the plate 210 and spaced apart from each other.

[0089] The multilayer capacitor 100 can be mounted on the board 210, so that the first external electrode 131 and the second external electrode 132 can contact and connect with the first electrode pad 221 and the second electrode pad 222 respectively.

[0090] In this case, the first external electrode 131 can be electrically connected and physically connected to the first electrode pad 221 and bonded to the first electrode pad 221 via solder 231, and the second external electrode 132 can be electrically connected and physically connected to the second electrode pad 222 and bonded to the second electrode pad 222 via solder 232.

[0091] The multilayer capacitor 100 may be the multilayer capacitor in the above example embodiments, and its detailed description will not be provided to avoid repetition.

[0092] The following describes a method for manufacturing a multilayer capacitor in an example embodiment.

[0093] It can prepare a first ceramic sheet and a second ceramic sheet.

[0094] A first ceramic sheet and a second ceramic sheet can be provided to form the dielectric layer 111 of the capacitor body 110, as well as an upper cover 112 as the upper edge and a lower cover 113 as the lower edge. As for the ceramic sheet, a slurry can be formed by mixing ceramic powder, polymer and solvent. The slurry can be applied to the carrier film by a method such as a doctor blade and the slurry can be dried to form a sheet with a thickness of several μm.

[0095] Subsequently, conductive paste can be printed onto the first and second ceramic sheets to form the first and second internal electrodes.

[0096] Screen printing or gravure printing can be used as a method for printing conductive paste, but exemplary embodiments thereof are not limited thereto.

[0097] In this case, when forming the first internal electrode, a printing screen including a screen can be provided on the first ceramic sheet, and conductive paste can be applied to the screen at a predetermined thickness. The first internal electrode pattern can be printed on the screen with conductive paste applied, such that one end in the length direction can be formed as a lead-out portion with a bottleneck shape and a first dot pattern portion can be formed at at least one corner, and the exposed conductive paste can be developed.

[0098] Therefore, a first inner electrode can be formed, including a first capacitor forming portion, a first lead-out portion, and a first dot pattern portion. The first lead-out portion extends from the first capacitor forming portion toward the third surface of the capacitor body and is connected to the first outer electrode. The first dot pattern portion is formed at at least one corner of the first capacitor forming portion.

[0099] When forming the second inner electrode, a printing screen including a screen can be provided on the second ceramic sheet. Conductive paste can be applied to the screen at a predetermined thickness. The second inner electrode pattern can be printed on the screen with the conductive paste applied, so that the other end in the length direction can be formed as a lead-out portion with a bottleneck shape and a second dot pattern portion that does not overlap with the first dot pattern can be formed at at least one corner. The exposed conductive paste can be developed.

[0100] Therefore, a second inner electrode can be formed, including a second capacitor forming portion, a second lead-out portion, and a second dot pattern portion. The second capacitor forming portion is superimposed on the first capacitor forming portion in a first direction. The second lead-out portion extends from the second capacitor forming portion toward the fourth surface of the capacitor body and is connected to the second outer electrode. The second dot pattern portion is formed at at least one corner of the second capacitor forming portion, and the second electrode portion of the second dot pattern portion is not superimposed on the first electrode portion of the first dot pattern portion in the first direction.

[0101] Subsequently, multiple first ceramic sheets with first internal electrodes and multiple second ceramic sheets with second internal electrodes formed thereon can be stacked, such that the first internal electrodes and the second internal electrodes can be opposite each other and the first ceramic sheet or the second ceramic sheet is between the first internal electrode and the second internal electrode, and the ceramic sheets can be pressed to form a laminate.

[0102] In this case, ceramic sheets without internal electrodes can be stacked first, then multiple first ceramic sheets and multiple second ceramic sheets can be stacked, then ceramic sheets without internal electrodes can be stacked further, and finally the obtained structure can be pressed.

[0103] Subsequently, the laminate can be cut for each region corresponding to a single capacitor, and each cut laminate can be fired to manufacture a capacitor body that includes a first and a second surface opposite to each other in a first direction, a third and a fourth surface opposite to each other in a second direction perpendicular to the first direction, and a fifth and a sixth surface opposite to each other in a third direction perpendicular to the first direction, and the capacitor body includes a first lead-out portion of a first internal electrode and a second lead-out portion of a second internal electrode exposed through the third and fourth surfaces, respectively.

[0104] Subsequently, a multilayer capacitor can be manufactured by forming a first external electrode and a second external electrode, which are respectively electrically connected to the first lead and the second lead, on the capacitor body.

[0105] According to the above example embodiment, the dot pattern portion can be formed at the corner of the capacitance forming portion of the inner electrode, and the dot pattern portions of the vertically stacked inner electrodes can be configured so that they do not overlap with each other, thereby improving the moisture resistance reliability of the multilayer capacitor and achieving the effect of preventing step difference.

[0106] While exemplary embodiments have been shown and described above, it will be readily understood by 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 capacitor, comprising: A capacitor body includes a first surface and a second surface opposite to each other in a first direction, a third surface and a fourth surface opposite to each other in a second direction, and a fifth surface and a sixth surface opposite to each other in a third direction. The capacitor body also includes a plurality of dielectric layers and a first internal electrode and a second internal electrode, the first internal electrode and the second internal electrode being alternately disposed in the first direction, and the dielectric layers being intermediate between the first internal electrode and the second internal electrode. The first external electrode and the second external electrode are respectively disposed at both ends of the capacitor body in the second direction. The first inner electrode includes a first capacitor forming portion, a first lead-out portion, and a first dot pattern portion. The first lead-out portion extends from the first capacitor forming portion toward the third surface of the capacitor body and connects to the first outer electrode. The first dot pattern portion is disposed at at least one corner of the first capacitor forming portion. The second inner electrode includes a second capacitor forming portion, a second lead-out portion, and a second dot pattern portion. The second capacitor forming portion overlaps with the first capacitor forming portion in the first direction. The second lead-out portion extends from the second capacitor forming portion toward the fourth surface of the capacitor body and connects to the second outer electrode. The second dot pattern portion is disposed at at least one corner of the second capacitor forming portion. The first dot pattern portion and the second dot pattern portion are disposed in the region where the first inner electrode and the second inner electrode overlap each other in the first direction.

2. The multilayer capacitor according to claim 1, wherein, The first dot pattern portion and the second dot pattern portion have dot patterns that do not overlap with each other in the first direction.

3. The multilayer capacitor according to claim 1, wherein, The length of the first lead-out portion in the third direction is less than the length of the first capacitor forming portion in the third direction, and the length of the second lead-out portion in the third direction is less than the length of the second capacitor forming portion in the third direction.

4. The multilayer capacitor according to claim 1, in, In the first dot pattern portion, the first electrode portion and the first spacing portion of the dot shape are alternately arranged in the second direction and alternately arranged in the third direction. In the second dot pattern portion, the dot-shaped second electrode portion and the dot-shaped second interval portion are alternately arranged in the second direction and alternately arranged in the third direction.

5. The multilayer capacitor according to claim 4, in, The first electrode portion overlaps with the second spacing portion in the first direction, and The second electrode portion is stacked with the first spacing portion in the first direction.

6. The multilayer capacitor according to claim 4, in, The average thickness of the first electrode portion in the first direction is 70% to 90% of the average thickness of the first capacitor forming portion in the first direction, and The average thickness of the second electrode portion in the first direction is 70% to 90% of the average thickness of the second capacitor forming portion in the first direction.

7. The multilayer capacitor according to claim 1, wherein, The capacitor body includes an effective region, an upper cover region, and a lower cover region. In the effective region, the first capacitor forming portion and the second capacitor forming portion are stacked on top of each other in the first direction. The upper cover region and the lower cover region are respectively disposed on the upper surface and the lower surface of the effective region in the first direction.

8. The multilayer capacitor according to claim 1, in, The first external electrode includes a first connecting portion disposed on the third surface of the capacitor body and a first strip portion extending from the first connecting portion to a portion of the first surface of the capacitor body. The second external electrode includes a second connecting portion disposed on the fourth surface of the capacitor body and a second strip portion extending from the second connecting portion to a portion of the first surface of the capacitor body.

9. A method for manufacturing a multilayer capacitor, comprising: A first internal electrode and a second internal electrode are formed on a first ceramic sheet and a second ceramic sheet, respectively. By stacking a plurality of first ceramic sheets on which the first internal electrode is formed and a plurality of second ceramic sheets on which the second internal electrode is formed, such that the first internal electrode and the second internal electrode are opposite to each other and the first ceramic sheet or the second ceramic sheet is between the first internal electrode and the second internal electrode, and pressing the first ceramic sheet and the second ceramic sheet to form a laminate; The capacitor body is formed by cutting the laminate and firing it. The capacitor body includes a first surface and a second surface that are opposite to each other in a first direction of the capacitor body, a third surface and a fourth surface that are opposite to each other in a second direction of the capacitor body, and a fifth surface and a sixth surface that are opposite to each other in a third direction of the capacitor body. The capacitor body also includes a first lead-out portion of the first internal electrode and a second lead-out portion of the second internal electrode that are exposed through the third surface and the fourth surface, respectively. as well as A first external electrode and a second external electrode are formed on the capacitor body, respectively electrically connected to the first lead and the second lead. The first inner electrode includes a first capacitor forming portion, a first lead-out portion, and a first dot pattern portion. The first lead-out portion extends from the first capacitor forming portion toward the third surface of the capacitor body and connects to the first outer electrode. The first dot pattern portion is formed at at least one corner of the first capacitor forming portion. The second inner electrode includes a second capacitor forming portion, a second lead-out portion, and a second dot pattern portion. The second capacitor forming portion overlaps with the first capacitor forming portion in the first direction. The second lead-out portion extends from the second capacitor forming portion toward the fourth surface of the capacitor body and connects to the second outer electrode. The second dot pattern portion is formed at at least one corner of the second capacitor forming portion. The first dot pattern portion and the second dot pattern portion are disposed in the region where the first inner electrode and the second inner electrode overlap each other in the first direction.

10. The method according to claim 9, wherein, The second electrode portion of the second dot pattern portion is formed such that it does not overlap with the first electrode portion of the first dot pattern portion in the first direction.

11. The method according to claim 9, wherein, The first internal electrode is formed by: providing a printing screen including a screen on the first ceramic sheet; applying conductive paste to the screen at a predetermined thickness; printing a first internal electrode pattern on the screen coated with conductive paste, such that one end in the second direction is formed into a first lead-out portion having a bottleneck shape and the first dot pattern is formed at at least one corner of the first capacitor forming portion; and developing the exposed conductive paste. The second internal electrode is formed by: providing a printing screen including a screen on the second ceramic sheet, applying conductive paste to the screen at a predetermined thickness, printing a second internal electrode pattern on the screen coated with conductive paste, such that the other end in the second direction is formed into a second lead-out portion having a bottleneck shape and a second dot pattern is formed at at least one corner of the second capacitor forming portion, and developing the exposed conductive paste.

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