Multilayer electronic assembly and method of manufacturing the same

Abstract

The present disclosure provides a multilayer electronic component and a manufacturing method thereof. The multilayer electronic component includes a main body including a dielectric layer and internal electrodes alternately stacked with the dielectric layer, and an external electrode disposed on the main body and connected to the internal electrodes, wherein the internal electrodes include Cu and Ni, and a coefficient of variation (CV) value of Cu / Ni based on a weight ratio in a region of the internal electrodes 5 nm deep from an interface with the dielectric layer is 25.0% or less.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0155482, filed on November 19, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

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

[0003] Multilayer ceramic capacitors (MLCCs, a type of multilayer electronic component) are chip capacitors mounted on printed circuit boards of various electronic products, such as display devices including liquid crystal displays (LCDs) and plasma display panels (PDPs), computers, smartphones, mobile phones, etc., to allow charging and discharging within them.

[0004] MLCCs have a compact structure that ensures high capacitance, are easy to install, and are therefore suitable as components in a wide variety of electronic devices. Recently, as electronic device components have become smaller, the demand for even smaller multilayer ceramic capacitors with higher capacitance has increased.

[0005] However, as the thickness of the internal electrode and dielectric layer has been reduced, the internal electrode connectivity may deteriorate and the internal thickness deviation may increase, thereby reducing reliability.

[0006] However, as the internal electrode and dielectric layer become thinner, high-temperature load reliability and moisture resistance deteriorate. Therefore, a method is needed that can ensure high-temperature load reliability and moisture resistance while reducing the thickness of the internal electrode and dielectric layer. Summary of the Invention

[0007] One aspect of this disclosure provides a multilayer electronic assembly including internal electrodes with improved reliability.

[0008] One aspect of this disclosure also provides a multilayer electronic component in which the high-temperature load reliability of the internal electrodes is improved.

[0009] One aspect of this disclosure also provides a multilayer electronic component in which the moisture-proof reliability of the internal electrodes is improved.

[0010] Another aspect of this disclosure provides a compact, high-capacitance multilayer electronic component with high reliability.

[0011] According to one aspect of this disclosure, a multilayer electronic component may include: a body including a dielectric layer and an inner electrode, the inner electrode being alternately stacked with the dielectric layer; and an outer electrode disposed on the body and connected to the inner electrode, wherein the inner electrode comprises Cu and Ni, and the coefficient of variation (CV) value of Cu / Ni based on weight ratio in a region 5 nm deep from the interface with the dielectric layer of the inner electrode is 25.0% or less.

[0012] According to one aspect of this disclosure, a multilayer electronic component may include internal electrodes stacked alternately with dielectric layers, the internal electrodes comprising a sintered conductive material comprising Cu and Ni, wherein the coefficient of variation of the weight ratio of Cu to Ni at a depth of 5 nm from the interface between the internal electrode and the adjacent dielectric layer of one of the internal electrodes is 25.0% or less.

[0013] According to one aspect of this disclosure, a method for manufacturing a multilayer electronic component as described above includes: stacking a plurality of ceramic green sheets on which conductive paste for internal electrodes is printed; and sintering the ceramic green sheets to form a body, wherein the conductive paste for the internal electrodes comprises Ni powder particles and Cu powder particles, the Cu powder particles having an average diameter of 120 nm or less. Attached Figure Description

[0014] The above and other aspects, features and advantages of this disclosure will be more clearly understood from the following detailed embodiments, taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 This is a schematic perspective view of a multilayer electronic assembly according to exemplary embodiments of the present disclosure;

[0016] Figure 2 It is along Figure 1 A cross-sectional view taken from line I-I';

[0017] Figure 3 It is along Figure 1 A cross-sectional view taken from line II-II';

[0018] Figure 4 This is an exploded perspective view schematically illustrating a body wherein a dielectric layer and an internal electrode are stacked, according to an exemplary embodiment of the present disclosure; and

[0019] Figure 5 yes Figure 2 A magnified view of region K. Detailed Implementation

[0020] Exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. For clarity, the shapes and dimensions of the components in the drawings may be exaggerated or reduced. In the drawings, variations in the shapes shown may be expected, for example, due to manufacturing techniques and / or tolerances. Therefore, embodiments of the present disclosure should not be construed as limited to specific shapes in the areas shown herein, but rather, for example, include, the result of shape variations during manufacturing. The following embodiments may also be implemented by one or a combination thereof.

[0021] 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. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0022] It will be readily understood that although the terms first, second, third, etc., may be used herein to describe various components, assemblies, regions, layers, and / or parts, these components, assemblies, regions, layers, and / or parts should not be limited by these terms. These terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the exemplary embodiments, the first component, first assembly, first region, first layer, or first part discussed below may be referred to as a second component, second assembly, second region, second layer, or second part.

[0023] For ease of description, spatial relative terms such as “above,” “above,” “below,” and “under” are used herein to describe the relationship between one element and another as shown in the figures. It will be understood that, in addition to the orientations depicted in the figures, the spatial relative terms are intended to cover different orientations of the device during use or operation. For example, if the device in the figures is flipped, an element described as “above” or “above” other elements will subsequently be oriented as “below” or “under” other elements or features. Thus, depending on the specific orientation of the figures, the term “above” can encompass both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or in other orientations), and the spatial relative terms used herein may be interpreted accordingly.

[0024] The terminology used herein describes specific embodiments only, and this disclosure is not limited thereto. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as used herein. It will also be understood that when the terms “comprising” and / or “including” are used in this specification, they specify the presence of the stated features, integers, steps, operations, components, elements, and / or groups thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, elements, and / or groups thereof.

[0025] The contents of this disclosure described below may have various configurations, and only the required configurations are presented herein, but are not limited thereto.

[0026] In the accompanying drawings, the X direction can be defined as a second direction, the L direction, or the length direction; the Y direction can be defined as a third direction, the W direction, or the width direction; and the Z direction can be defined as a first direction, the stacking direction, the T direction, or the thickness direction.

[0027] Multilayer electronic assembly

[0028] Figure 1 This is a schematic perspective view of a multilayer electronic assembly according to exemplary embodiments of the present disclosure.

[0029] Figure 2 It is along Figure 1 The cross-sectional view taken from line I-I'.

[0030] Figure 3 It is along Figure 1 The cross-sectional view taken from line II-II'.

[0031] Figure 4 This is an exploded perspective view schematically illustrating a body in which a dielectric layer and an internal electrode are stacked, according to an exemplary embodiment of the present disclosure.

[0032] Figure 5 yes Figure 2 A magnified view of region K.

[0033] In the following text, reference will be made to Figures 1 to 4 A detailed description of a multilayer electronic assembly according to exemplary embodiments of the present disclosure is provided.

[0034] The multilayer electronic assembly 100 may include: a body 110 including a dielectric layer 111 and inner electrodes 121 and 122 alternately disposed with respect to the dielectric layer 111, the inner electrodes 121 and 122 comprising Cu and Ni; and outer electrodes 131 and 132 disposed on the body 110 and connected to the inner electrodes 121 and 122, wherein, in a region 5 nm deep from the interface between the inner electrodes and the dielectric layer, the coefficient of variation (CV) of Cu / Ni (weight percentage) is 25.0% or less.

[0035] Cu / Ni represents the ratio of Cu to Ni content. As an example, the Cu to Ni content ratio can be obtained based on weight percentage.

[0036] Specifically, for example, the coefficient of variation (CV) of the weight percentage Cu to Ni ratio at a depth of 5 nm from the interface between the inner electrode and the adjacent dielectric layer of one of the inner electrodes is 25.0% or less.

[0037] In the body 110, dielectric layer 111 and internal electrodes 121 and 122 are stacked alternately.

[0038] There are no particular restrictions on the specific shape of the body 110, but as shown in the figure, the body 110 may have a hexahedral shape or a shape similar to a hexahedron. Due to the shrinkage (or reduction) of the ceramic powder particles included in the body 110 during the sintering process, the body 110 may have a generally hexahedral shape, and may not have a hexahedral shape containing perfect straight lines.

[0039] The main body 110 may have a first surface 1 and a second surface 2 that are opposite to each other in the thickness direction (Z direction), a third surface 3 and a fourth surface 4 that are connected to the first surface 1 and the second surface 2 and are opposite to each other in the length direction (X direction), and a fifth surface 5 and a sixth surface 6 that are connected to the first surface 1 and the second surface 2, connected to the third surface 3 and the fourth surface 4 and are opposite to each other in the width direction (Y direction).

[0040] The multiple dielectric layers 111 forming the body 110 are in a sintered state, and adjacent dielectric layers 111 can become a single unit, making it difficult to distinguish the boundaries between them without using a scanning electron microscope (SEM).

[0041] According to exemplary embodiments of this disclosure, the raw materials used to form the dielectric layer 111 are not limited, as long as sufficient electrostatic capacitance can be obtained. For example, barium titanate-based materials, lead-based perovskite composite materials, or strontium titanate-based materials can be used. Barium titanate-based materials may include BaTiO3-based ceramic powder particles, and the BaTiO3-based ceramic powder particles may include BaTiO3 and materials obtained by partially dissolving calcium (Ca), zirconium (Zr), etc., in BaTiO3. 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 )O3.

[0042] 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) as materials for forming dielectric layer 111.

[0043] Furthermore, the thickness td of the dielectric layer 111 is not limited.

[0044] However, typically, if the dielectric layer is formed to be as thin as less than 0.6 μm, and in particular, if the thickness of the dielectric layer is 0.41 μm or less, the moisture resistance reliability may be degraded.

[0045] As described below, when Cu is uniformly distributed in the interface between the dielectric layer and the inner electrode according to the exemplary embodiments of the present disclosure, reliability can be improved even when the dielectric layer and the inner electrode are very thin. Therefore, sufficient reliability can be ensured even when the thickness of the dielectric layer is 0.41 μm or less.

[0046] Therefore, when the thickness of dielectric layer 111 is 0.41 μm or less, the effect of improving reliability according to this disclosure can be more significant.

[0047] The thickness td of dielectric layer 111 can refer to the average thickness of dielectric layer 111 disposed between the first inner electrode 121 and the second inner electrode 122.

[0048] The average thickness of dielectric layer 111 can be measured by scanning the length-thickness (LT) cross section of body 110 using a scanning electron microscope (SEM).

[0049] For example, regarding a dielectric layer extracted from an image of a length-thickness (LT) cross-section taken at the central portion of the body 110 in the width direction using SEM, its thickness can be measured at 30 points at equal intervals in the length direction, and the average value of the measured thickness can be calculated.

[0050] The thickness can be measured at 30 equally spaced points at capacitor forming section A, which refers to the area where the first inner electrode 121 and the second inner electrode 122 overlap.

[0051] The main body 110 may include: a capacitor forming portion A, formed inside the main body 110 and forming a capacitor using a first internal electrode 121 and a second internal electrode 122, wherein the first internal electrode 121 and the second internal electrode 122 are arranged facing each other and a dielectric layer 111 is disposed between them; and covering portions 112 and 113, formed above and below the capacitor forming portion A.

[0052] In addition, the capacitor forming part A is the part that contributes to the capacitor forming. The capacitor forming part A can be formed by repeatedly stacking a plurality of first internal electrodes 121 and a plurality of second internal electrodes 122 and placing a dielectric layer 111 between the plurality of first internal electrodes 121 and the plurality of second internal electrodes 122.

[0053] The upper cover portion 112 and the lower cover portion 113 can be formed by stacking a single dielectric layer or two or more dielectric layers on the upper and lower surfaces of the capacitor forming portion A in the thickness direction, respectively, and can be used to prevent damage to the internal electrode due to physical stress or chemical stress.

[0054] The upper cover 112 and the lower cover 113 may not include an inner electrode and may include the same material as the dielectric layer 111.

[0055] In other words, the upper cover 112 and the lower cover 113 may include ceramic materials, such as barium titanate (BaTiO3) based ceramic materials.

[0056] Furthermore, the thickness of the covers 112 and 113 is not limited. However, the thickness tp of the covers 112 and 113 can be 20 μm or less to facilitate the miniaturization and high capacitance of multilayer electronic components.

[0057] Additionally, edge portions 114 and 115 may be provided on the side surface of capacitor forming portion A.

[0058] Edge portions 114 and 115 may include an edge portion 114 provided on the sixth surface 6 of the main body 110 and an edge portion 115 provided on the fifth surface 5 of the main body 110. That is, edge portions 114 and 115 may be provided on two side surfaces of the capacitor forming portion A in the width direction.

[0059] like Figure 3 As shown, the edges 114 and 115 may refer to the region between the two ends of the first inner electrode 121 and the second inner electrode 122 and the boundary surface of the body 110 in a cross section taken along the width-thickness (WT) direction of the body 110.

[0060] Edges 114 and 115 are primarily used to prevent damage to the internal electrodes due to physical or chemical stress.

[0061] Edge portions 114 and 115 can be formed after forming internal electrodes by applying conductive paste to a ceramic green sheet excluding the area where the edge portions are to be formed.

[0062] In addition, in order to suppress the step difference caused by the inner electrodes 121 and 122, the edge portions 114 and 115 can be formed by the following process: after stacking ceramic green sheets printed with conductive paste for the inner electrodes, cutting is performed to expose the inner electrodes to the two side surfaces of the capacitor forming portion A in the width direction, and then a single dielectric layer or two or more dielectric layers are stacked on the two side surfaces of the capacitor forming portion A in the width direction.

[0063] Internal electrodes 121 and 122 are stacked alternately with dielectric layer 111.

[0064] The inner electrodes 121 and 122 may include a first inner electrode 121 and a second inner electrode 122. The first inner electrode 121 and the second inner electrode 122 may be alternately arranged to face each other, and the dielectric layer 111 constituting the body 110 is located between the first inner electrode 121 and the second inner electrode 122, and the first inner electrode 121 and the second inner electrode 122 may be exposed on the third surface 3 and the fourth surface 4 of the body 110, respectively.

[0065] Reference Figure 2 The first inner electrode 121 may be spaced apart from the fourth surface 4 and exposed to the third surface 3, and the second inner electrode 122 may be spaced apart from the third surface 3 and exposed to the fourth surface 4.

[0066] In this case, the first inner electrode 121 and the second inner electrode 122 can be electrically separated from each other by the dielectric layer 111 disposed between them.

[0067] Reference Figure 4 The body 110 can be formed by alternately stacking ceramic green sheets with a first internal electrode 121 printed on them and ceramic green sheets with a second internal electrode 122 printed on them, and then sintering the ceramic green sheets.

[0068] The internal electrodes 121 and 122 may include sintered conductive material.

[0069] In the internal electrodes 121 and 122, the coefficient of variation (CV) value of Cu / Ni (weight percentage) in the region 5 nm deep from the interface with the dielectric layer can be 25.0% or less.

[0070] The work function of Ni is approximately 5.04 to approximately 5.35, and that of Cu is approximately 4.53 to approximately 5.10. Therefore, the work function tends to decrease as the Cu content in the Ni-Cu alloy increases.

[0071] If the Cu content is not uniformly distributed at the interface between the inner electrode and the dielectric layer, reliability may deteriorate due to the non-uniform work function. This is because the work function is lower at locations with relatively higher Cu content, thus increasing the likelihood of current flow. Reliability is improved when Cu is uniformly distributed within the inner electrode, and particularly when Cu is uniformly distributed at the interface between the dielectric layer and the inner electrode.

[0072] According to an exemplary embodiment of this disclosure, by controlling the Cu / Ni (weight percentage) CV value in the region 5 nm deep from the interface between the inner electrode and the dielectric layer 111 to 25.0% or less, the Cu content can be uniformly distributed at the interface between the inner electrodes 121 and 122 and the dielectric layer 111, thereby improving reliability.

[0073] If the Cu / Ni (weight percentage) CV value in the region 5 nm deep from the interface between the inner electrode and the dielectric layer 111 exceeds 25.0%, the high-temperature load reliability and moisture resistance reliability may deteriorate.

[0074] Therefore, the inner electrodes 121 and 122 preferably have a Cu / Ni (weight percentage) CV value of 25.0% or less in a region 5 nm deep from the interface with the dielectric layer 111.

[0075] However, to further improve moisture resistance reliability, the Cu / Ni (weight percentage) CV value in the region 5 nm deep from the interface with the dielectric layer in the inner electrodes 121 and 122 can be 9.2% or less.

[0076] The CV value is the ratio of the standard deviation to the mean, expressed as a percentage.

[0077] In the internal electrodes 121 and 122, when the average value of Cu / Ni (weight percentage) in the region 5 nm deep from the interface with the dielectric layer is x1 and the standard deviation of Cu / Ni (weight percentage) in the region 5 nm deep from the interface with the dielectric layer is s1, the CV value of Cu / Ni (weight percentage) is (s1 / x1)×100%.

[0078] Reference Figure 2 and Figure 5 For an inner electrode located at the center of the thickness direction in a length-thickness (LT) cross-section of the body 110 taken at the center of the width direction, ten points P1, P2, P3, P4, P5, P6, P7, P8, P9, and P10 at a depth of 5 nm from the upper and lower interface regions between the inner electrode and the dielectric layer can be quantitatively analyzed using energy-dispersive X-ray spectroscopy (EDS) to obtain the Cu / Ni (weight percentage) value at each point. Subsequently, the mean x1 and standard deviation s1 of each of the ten Cu / Ni (weight percentage) values ​​can be obtained, and the CV value of Cu / Ni (weight percentage) can be calculated.

[0079] Furthermore, there are no limitations on the methods for controlling the Cu / Ni (weight percentage) CV value. For example, the CV value can be controlled by adjusting the particle size of the conductive powder particles included in the conductive paste used for the internal electrode, the sintering conditions, etc.

[0080] For a specific example, by controlling the average size of Cu powder particles included in the conductive paste used for the internal electrode to 120 nm or less, the CV value of Cu / Ni (weight percentage) can be controlled to 25.0% or less.

[0081] Furthermore, by controlling the average size of Cu powder particles included in the conductive paste for the internal electrode to 50 nm or less, the CV value of Cu / Ni (weight percentage) can be controlled to 9.2% or less.

[0082] Furthermore, the content of Cu in the inner electrode is not limited, but is preferably from 0.4 wt% to 6.0 wt%.

[0083] If the Cu content is less than 0.4 wt%, the effect of improving reliability may be insufficient, and if the Cu content exceeds 6.0 wt%, reliability may deteriorate even if Cu is uniformly distributed in the internal electrode.

[0084] According to exemplary embodiments in this disclosure, the Ni and Cu included in the inner electrodes 121 and 122 may be included in the form of a Ni-Cu alloy.

[0085] Since Ni and Cu are included in the form of a Ni-Cu alloy, the effect of Cu addition can be improved, and the Cu included in the inner electrode can be uniformly distributed in the inner electrode.

[0086] Furthermore, the thickness te of each of the inner electrodes 121 and 122 is not particularly limited.

[0087] However, generally, if each of the inner electrodes 121 and 122 is formed to be thin to have a thickness of less than 0.6 μm, and in particular if the thickness of each of the inner electrodes 121 and 122 is 0.41 μm or less, the moisture-proof reliability may be reduced.

[0088] As described above, when Cu is uniformly distributed in the interface between the dielectric layer and the inner electrode according to the exemplary embodiments of the present disclosure, reliability can be effectively improved even when the dielectric layer and the inner electrode are very thin. Therefore, sufficient moisture-proof reliability can be ensured even when the thickness of each of the inner electrodes 121 and 122 is 0.41 μm or less.

[0089] Therefore, when the thickness of each of the inner electrodes 121 and 122 is 0.41 μm or less, the effect of improving reliability according to this disclosure is more significant, and the miniaturization and high capacitance of the capacitor assembly can be achieved more easily.

[0090] The thickness te of each of the inner electrodes 121 and 122 can refer to the average thickness of the inner electrodes 121 and 122 disposed between adjacent dielectric layers 111.

[0091] The average thickness of the inner electrodes 121 and 122 can be measured by scanning an image of the length-thickness (LT) cross section of the body 110 using SEM.

[0092] For example, in an image obtained by scanning a cross-section of the body 110 in the length-thickness (LT) direction taken at the central portion of the body 110 in the width (W) direction, specific first inner electrode 121 and second inner electrode 122 can be extracted, and their thickness at 30 points at equal intervals in the length direction can be measured, and the average value of the measured thickness can be calculated.

[0093] External electrodes 131 and 132 may be disposed on the main body 110 and may be connected to internal electrodes 121 and 122.

[0094] like Figure 2 As shown, the external electrodes 131 and 132 can be respectively disposed on the third surface 3 and the fourth surface 4 of the main body 110, and can be respectively connected to the first internal electrode 121 and the second internal electrode 122.

[0095] In this exemplary embodiment, a multilayer electronic assembly 100 is described having a structure with two external electrodes 131 and 132, but the number or shape of the external electrodes 131 and 132 may be changed depending on the shape of the internal electrodes 121 and 122 or for other purposes.

[0096] Furthermore, the outer electrodes 131 and 132 can be formed using any material such as metal, as long as the material is conductive, and the specific material can be determined by taking into account electrical properties and structural stability. In addition, the outer electrodes 131 and 132 can have a multilayer structure.

[0097] For example, the external electrodes 131 and 132 may include electrode layers 131a and 132a disposed on the body 110 and plating layers 131b and 132b formed on the electrode layers 131a and 132a.

[0098] For a more specific example of electrode layers 131a and 132a, electrode layers 131a and 132a may be sintered electrodes comprising conductive metal and glass components or resin-based electrodes comprising conductive metal and resin.

[0099] Alternatively, electrode layers 131a and 132a may have a form in which sintered electrodes and resin-based electrodes are sequentially formed on the body 110. Alternatively, electrode layers 131a and 132a may be formed by transferring a sheet including a conductive metal onto the body or by transferring a sheet including a conductive metal onto a sintered electrode.

[0100] Materials with excellent electrical conductivity can be used as conductive metals included in electrode layers 131a and 132a, and there are no particular limitations on the materials. For example, the conductive metal can be one or more of nickel (Ni), copper (Cu), and their alloys.

[0101] Platings 131b and 132b are used to improve mounting characteristics. The types of platings 131b and 132b are not limited and can be platings including at least one of Ni, Sn, Pd, and alloys thereof. Additionally, platings 131b and 132b may comprise multiple layers.

[0102] For a more specific example of plating layers 131b and 132b, plating layers 131b and 132b may include Ni plating layers and / or Sn plating layers, and in the case of including Ni plating layers and Sn plating layers, the Ni plating layers and Sn plating layers may be sequentially formed on electrode layers 131a and 132a, or Sn plating layers, Ni plating layers, and Sn plating layers may be sequentially formed on electrode layers 131a and 132a. Additionally, plating layers 131b and 132b may include multiple Ni plating layers and / or multiple Sn plating layers. Furthermore, plating layers 131b and 132b may have the form of Ni plating layers and Pd plating layers sequentially formed on electrode layers 131a and 132a.

[0103] The size of the multilayer electronic component 100 is not subject to any particular restrictions.

[0104] However, in order to achieve both miniaturization and high capacitance, it is necessary to increase the number of layers by reducing the thickness of the dielectric layer and the internal electrode. Therefore, in multilayer electronic components with a size of 0402 (length × width, 0.4mm × 0.2mm) or smaller, the effect of improving reliability according to this exemplary embodiment can be significant.

[0105] Therefore, when the length of the multilayer electronic component is 0.44 mm or less and the width of the multilayer electronic component is 0.22 mm or less, the reliability improvement effect according to this disclosure can be more significant, taking into account manufacturing errors and the size of the external electrodes.

[0106] Hereinafter, a method for manufacturing a multilayer electronic assembly 100 according to exemplary embodiments of the present disclosure will be described.

[0107] First, multiple ceramic green sheets are prepared.

[0108] Ceramic green sheets are used to form the dielectric layer 111 of the body 110, and a slurry can be prepared by mixing ceramic powder particles, polymer and solvent, and the slurry can be formed into a sheet with a predetermined thickness by methods such as doctor blade method.

[0109] Subsequently, conductive paste for the internal electrode is printed to a predetermined thickness on at least one surface of each ceramic green sheet to form the internal electrode.

[0110] The conductive paste used for the internal electrode includes Ni powder particles and Cu powder particles.

[0111] In this case, the average size of the Cu powder particles can be 120 nm or smaller. By controlling the average size of the Cu powder particles to 120 nm or smaller, the CV value of Cu / Ni (weight percentage) in the region 5 nm deep from the interface between the inner electrode and the dielectric layer can be controlled to 25.0% or smaller.

[0112] Furthermore, the average size of the Cu powder particles can be 50 nm or smaller. By controlling the average size of the Cu powder particles to 50 nm or smaller, the CV value of Cu / Ni (weight percentage) in the region 5 nm deep from the interface between the inner electrode and the dielectric layer can be controlled to 9.2% or smaller.

[0113] As a printing method for conductive paste used for internal electrodes, screen printing or gravure printing can be used.

[0114] Reference Figure 4 The ceramic green sheets with a first internal electrode 121 printed on them and the ceramic green sheets with a second internal electrode 122 printed on them are alternately stacked and pressed in the stacking direction to compress the multiple stacked ceramic green sheets and the internal electrodes formed on the ceramic green sheets, thereby forming a stack.

[0115] Additionally, at least one ceramic green sheet may be stacked above and below the stack to form covers 112 and 113.

[0116] Covers 112 and 113 may have the same composition as dielectric layer 111 located inside the stack body, but differ from dielectric layer 111 in that no internal electrodes are formed on covers 112 and 113.

[0117] Subsequently, each region of the stack corresponding to a multilayer electronic component (e.g., a capacitor) is cut into sheets, and the sheets are fired at high temperature to complete the body 110.

[0118] Subsequently, the exposed portions of the first inner electrode and the second inner electrode exposed on both sides of the body 110 can be covered to form the first outer electrode 131 and the second outer electrode 132, such that the first outer electrode 131 and the second outer electrode 132 are electrically connected to the first inner electrode and the second inner electrode.

[0119] At this point, if necessary, the surfaces of the first external electrode 131 and the second external electrode 132 may be plated with nickel or tin.

[0120] (Example)

[0121] Sample sheets were prepared in which the internal electrode was formed using the following conductive paste for the internal electrode: In the conductive paste for the internal electrode, 6.0 wt% of Cu powder particles having the average size of Table 1 were added based on 100 wt% Ni powder particles.

[0122] The CV value of Cu / Ni (weight percentage) in the region 5 nm deep from the interface between the internal electrode and the dielectric layer was measured, and the high-temperature load reliability and moisture resistance reliability were evaluated.

[0123] Regarding the CV value, for an inner electrode located at the center of the thickness direction in a length-thickness (LT) cross section of the body 110 taken at the center of the width direction, energy dispersive X-ray spectroscopy (EDS) can be used to perform quantitative analysis on ten points P1, P2, P3, P4, P5, P6, P7, P8, P9, and P10 from the upper and lower interface regions between the inner electrode and the dielectric layer toward a depth of 5 nm towards the inner electrode, to obtain the Cu / Ni (weight percentage) value at each point, and the mean x1 and standard deviation s1 of each of the 10 Cu / Ni (weight percentage) values ​​can be obtained, and the CV value of Cu / Ni (weight percentage) can be calculated (CV value = (s1 / x1) × 100%).

[0124] For high-temperature load reliability, 400 samples of each test number were subjected to high-temperature load tests at 125°C and 8V, and the MTTF (Mean Time To Failure) was measured. In this case, the time when the insulation resistance reached 10kΩ or less was defined as the failure time.

[0125] Regarding moisture resistance reliability, at a temperature of 85°C and a relative humidity of 85%, 400 samples of each test number were subjected to an 8V voltage for 60 hours. Samples whose insulation resistance value decreased to less than 1 / 10 of the initial value were evaluated as failures, and the percentage of defective samples was calculated.

[0126] [Table 1]

[0127]

[0128] It can be seen that test numbers 7 to 9, with CV values ​​greater than 25.0%, have short MTTF and high moisture-proof failure rates.

[0129] Furthermore, it can be seen that test numbers 1 to 6 with CV values ​​of 25.0% or less have high-temperature reliability (long MTTF) and excellent moisture-proof reliability.

[0130] Furthermore, it can be seen that test numbers 1 to 3, with CV values ​​of 9.2% or less, have very low moisture-proof failure rates and therefore superior moisture-proof reliability.

[0131] As described above, the reliability of multilayer electronic components can be improved according to exemplary embodiments of the present disclosure.

[0132] Although exemplary embodiments have been shown and described above, it will be readily understood by those skilled in the art that modifications and changes may be made without departing from the scope of this disclosure as defined by the appended claims.

Claims

1. A multilayer electronic component, comprising: The body includes a dielectric layer and an inner electrode, wherein the inner electrode and the dielectric layer are stacked alternately; as well as An external electrode is disposed on the main body and connected to the internal electrode. The internal electrode comprises Cu and Ni, and the coefficient of variation of Cu / Ni based on weight ratio in the region of the internal electrode at a depth of 5 nm from the interface with the dielectric layer is 25.0% or less.

2. The multilayer electronic component according to claim 1, wherein, The internal electrode is formed using a conductive paste containing Ni powder particles and Cu powder particles, with the average size of the Cu powder particles being 120 nm or smaller.

3. The multilayer electronic component according to claim 1, wherein, The coefficient of variation is 9.2% or less.

4. The multilayer electronic component according to claim 2, wherein, The average size of the Cu powder particles is 50 nm or smaller.

5. The multilayer electronic component according to claim 1, wherein, The Cu content in the internal electrode is in the range of 0.4 wt% to 6.0 wt%.

6. The multilayer electronic assembly according to any one of claims 1-5, wherein, The internal electrode comprises a Ni-Cu alloy.

7. The multilayer electronic assembly according to any one of claims 1-5, wherein, The average thickness of the internal electrode is 0.41 μm or less.

8. The multilayer electronic assembly according to any one of claims 1-5, wherein, The average thickness of the dielectric layer is 0.41 μm or less.

9. The multilayer electronic assembly according to any one of claims 1-5, wherein, The multilayer electronic component has a length of 0.44 mm or less and a width of 0.22 mm or less.

10. A multilayer electronic component, comprising: The inner electrodes are stacked alternately with dielectric layers, the inner electrodes comprising a sintered conductive material containing Cu and Ni, wherein the coefficient of variation of the weight ratio of Cu to Ni at a depth of 5 nm from the interface between the inner electrode and the adjacent dielectric layer is 25.0% or less.

11. A method of manufacturing a multilayer electronic component according to claim 1 or 10, the method comprising: Multiple ceramic green sheets stacked thereon, on which conductive paste for internal electrodes is printed; and The multiple ceramic green sheets are sintered to form the main body. The conductive paste used for the internal electrode includes Ni powder particles and Cu powder particles, with the average diameter of the Cu powder particles being 120 nm or less.

12. The method according to claim 11, wherein the average size of the Cu powder particles in the conductive paste used for the internal electrode is 20 nm, 30 nm, 50 nm, 70 nm or 90 nm.

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