Multilayer electronic components

Abstract

To provide a multilayer electronic component.SOLUTION: A multilayer electronic component includes a body in which internal electrodes including Ni and Sn and dielectric layers are alternately disposed, and external electrodes disposed on a surface of the body, connected to the internal electrodes, and including Cu and Sn, where the internal electrodes include an alloy including Ni, Cu and Sn in a region in contact with the external electrodes to satisfy 1<C2 / C1<13.5, where C1 refers to the content of Sn in the internal electrodes at a central portion of the body, and C2 refers to the content of Sn in the internal electrodes at a point that is 2 μm away from a point at which the internal electrode and the external electrode are in contact with each other in an inward direction of the body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a multilayer electronic component. [Background technology]

[0002] Multi-layered ceramic capacitors (MLCCs), a type of multilayer electronic component, are chip-type capacitors that are mounted on printed circuit boards of various electronic products, such as visual devices like liquid crystal displays (LCDs) and plasma display panels (PDPs), computers, smartphones, and mobile phones, and serve to charge and discharge electricity.

[0003] Such multilayer ceramic capacitors have the advantages of being small in size, yet having high capacitance, and being easy to mount, and therefore can be used as components in various electronic devices. As various electronic devices, such as computers and mobile devices, become smaller and have higher output, there is an increasing demand for multilayer ceramic capacitors that are smaller in size and have higher capacitance.

[0004] Furthermore, in recent years, there has been growing interest in automotive electrical components in the industry, and multilayer ceramic capacitors are also being required to have high reliability and high strength characteristics for use in automobiles or infotainment systems.

[0005] Ni is the main material used for the internal electrodes of multilayer ceramic capacitors. However, if Ni is used exclusively as the internal electrode material, the plating solution that flows in from the external electrode during the plating process can cause corrosion in the area where the internal and external electrodes meet, potentially resulting in chip degradation. Summary of the Invention [Problem to be solved by the invention]

[0006] One of the various objects of the present invention is to provide a multilayer electronic component having excellent moisture resistance reliability.

[0007] One of the various objects of the present invention is to provide a multilayer electronic component in which the occurrence of cracks is suppressed.

[0008] Among various objects of the present invention is to provide a multilayer electronic component with improved capacity.

[0009] However, the scope of the present invention is not limited to the above, and can be more easily understood in the course of describing specific embodiments of the present invention. [Means for solving the problem]

[0010] A multilayer electronic component according to one embodiment of the present invention includes a body in which internal electrodes containing Ni and Sn and dielectric layers are alternately arranged, and external electrodes disposed on the surface of the body and connected to the internal electrodes, the external electrodes containing Cu and Sn. The internal electrodes include an alloy containing Ni, Cu, and Sn in a region in contact with the external electrodes, and when C1 is defined as the Sn content of the internal electrodes at the center of the body and C2 is defined as the Sn content of the internal electrodes at a point 2 μm inward from a point where the internal electrode and the external electrode meet, C2 / C1 is greater than 1 and less than 13.5.

[0011] According to another embodiment of the present invention, there is provided a multilayer electronic component including: a body in which internal electrodes containing Ni and Sn and dielectric layers are alternately arranged; and an external electrode disposed on a surface of the body and connected to the internal electrodes, the external electrode containing Cu and Sn, wherein the internal electrode contains an alloy containing Ni, Cu, and Sn in a region in contact with the external electrode, and the length of a region of the internal electrode in which Sn is 5 at % or more is 5 μm to 10 μm from a point where the internal electrode and the external electrode meet toward the inside of the body. [Effects of the Invention]

[0012] One of the various effects of the present invention is that the internal electrodes include an alloy containing Ni, Cu, and Sn arranged in the area in contact with the external electrodes, thereby improving moisture resistance reliability.

[0013] One of the various effects of the present invention is that it can suppress the occurrence of cracks.

[0014] One of the various effects of the present invention is that it improves capacitance.

[0015] However, the various beneficial advantages and effects of the present invention are not limited to the above, and can be more easily understood in the course of describing specific embodiments of the present invention. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic perspective view of a multilayer electronic component according to an embodiment of the present invention. [Figure 2a] FIG. 2 is a cross-sectional view taken along line II' in FIG. [Figure 2b] FIG. 2b is a diagram for explaining the positions at which the element contents of the internal electrodes are measured in the main body of FIG. 2a. [Figure 3] FIG. 2 is a cross-sectional view taken along line II-II' in FIG. [Figure 4] 1 is an exploded perspective view showing a main body in which dielectric layers and internal electrodes are stacked according to an embodiment of the present invention; [Figure 5] 10A and 10B are photographs of (a) Cu elements and (b) Ni elements observed by SEM-EDX in the region where the internal electrode contacts the external electrode when the external electrode is formed using a conductive paste for external electrodes to which Sn is not added. [Figure 6] Photographs of (a) Cu element, (b) Ni element, and (c) Sn element in the area where the internal electrode contacts the external electrode, when the external electrode is formed using a conductive paste for the external electrode containing 5 wt% Sn, observed using SEM-EDX. [Figure 7]Photographs showing (a) Cu element, (b) Ni element, and (c) Sn element in the area where the internal electrode contacts the external electrode when the external electrode is formed using a conductive paste for the external electrode containing 10 wt% Sn, observed using SEM-EDX. [Figure 8] 1 is a graph showing the atomic weights of Cu, Ni, and Sn elements as a function of the distance from the point where the internal electrode and the external electrode meet toward the inside of the body in the internal electrode of the multilayer electronic component according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, the embodiments of the present invention are provided to more completely explain the present invention to those having average knowledge in the art. Therefore, the shapes and sizes of elements in the drawings may be enlarged or reduced (or highlighted or simplified) for clearer explanation.

[0018] In order to clearly explain the present invention, parts not relevant to the description are omitted in the drawings, thicknesses are exaggerated to clearly show various layers and regions, and components having the same function within the same concept are denoted by the same reference numerals. Furthermore, throughout the specification, the term "comprises" a certain component does not mean that other components are excluded, but that the component may further include other components, unless otherwise specified.

[0019] In the drawings, the X direction can be defined as the second direction, L direction, or length direction, the Y direction can be defined as the third direction, W direction, or width direction, and the Z direction can be defined as the first direction, stacking direction, T direction, or thickness direction.

[0020] Multilayer electronic components FIG. 1 is a schematic perspective view of a multilayer electronic component according to one embodiment of the present invention.

[0021] FIG. 2a is a cross-sectional view taken along line II' in FIG.

[0022] FIG. 2b is a diagram illustrating the position where the element content of the internal electrode is measured in the main body of FIG. 2a.

[0023] FIG. 3 is a cross-sectional view taken along line II-II' in FIG.

[0024] FIG. 4 is an exploded perspective view showing a main body in which dielectric layers and internal electrodes are stacked according to an embodiment of the present invention.

[0025] A multilayer electronic component 100 according to one embodiment of the present invention will now be described with reference to FIGS.

[0026] A multilayer electronic component 100 according to one embodiment of the present invention is a multilayer electronic component including a body 110 in which internal electrodes 121, 122 containing Ni and Sn and dielectric layers 111 are alternately arranged, and external electrodes 131, 132 which are disposed on the surface of the body and connected to the internal electrodes and contain Cu and Sn, wherein the internal electrodes 121, 122 contain an alloy containing Ni, Cu, and Sn in regions in contact with the external electrodes 131, 132, and when the Sn content of the internal electrodes 121, 122 at the center of the body is defined as C1 and the Sn content of the internal electrodes 121, 122 at a point 2 μm inward from the point where the internal electrode and the external electrode meet is defined as C2, C2 / C1 is greater than 1 and less than 13.5.

[0027] The body 110 is formed by alternately laminating dielectric layers 111 and internal electrodes 121 and 122 .

[0028] The specific shape of the body 110 is not particularly limited, but as shown in the drawing, the body 110 may be hexahedral or a similar shape. Furthermore, the body 110 may have a substantially hexahedral shape, although not a hexahedral shape with perfect straight lines, due to shrinkage of the ceramic powder contained in the body 110 during firing.

[0029] The main body 110 may have first and second surfaces 1, 2 facing each other in the thickness direction (Z direction), third and fourth surfaces 3, 4 connected to the first and second surfaces 1, 2 and facing each other in the width direction (Y direction), and fifth and sixth surfaces 5, 6 connected to the first and second surfaces 1, 2 and also connected to the third and fourth surfaces 3, 4 and facing each other in the length direction (X direction).

[0030] The plurality of dielectric layers 111 forming the main body 110 are in a fired state, and the boundaries between adjacent dielectric layers 111 can be integrated to the extent that they are difficult to identify without a scanning electron microscope (SEM).

[0031] According to an embodiment of the present invention, the raw material for forming the dielectric layer 111 is not particularly limited as long as it can obtain a sufficient capacitance. For example, a barium titanate-based material, a lead complex perovskite-based material, or a strontium titanate-based material can be used. The barium titanate-based material can include a BaTiO3-based ceramic powder, and examples of the ceramic powder include BaTiO3, BaTiO3 partially solid-dissolved with Ca (calcium), Zr (zirconium), 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 )O3, etc.

[0032] The material forming the dielectric layer 111 may be a powder of barium titanate (BaTiO3) or the like, to which various ceramic additives, organic solvents, plasticizers, binders, dispersants, etc. may be added depending on the purpose of the present invention.

[0033] On the other hand, the thickness td of the dielectric layer 111 does not need to be particularly limited.

[0034] However, in general, when the dielectric layer is formed to a thickness of less than 0.6 μm, particularly when the thickness of the dielectric layer is 0.41 μm or less, there is a risk that the moisture resistance reliability will decrease.

[0035] As described below, by controlling the Sn content at each position of the internal electrode according to one embodiment of the present invention, it is possible to effectively improve the moisture resistance reliability even when the dielectric layer and the internal electrode are very thin, and therefore it is possible to ensure sufficient moisture resistance reliability even when the thickness of the dielectric layer is 0.41 μm or less.

[0036] Therefore, when the thickness of the dielectric layer 111 is 0.41 μm or less, the effect of improving the moisture resistance reliability according to the present invention can be more significant.

[0037] The thickness td of the dielectric layer 111 may refer to the average thickness of the dielectric layer 111 disposed between the first internal electrode 121 and the second internal electrode 122 .

[0038] The average thickness of the dielectric layer 111 can be measured by scanning an image of a cross section of the body 110 in the length and thickness direction (LT) using a scanning electron microscope (SEM).

[0039] For example, for any dielectric layer extracted from an image obtained by scanning a cross section of the body 110 in the length and thickness direction (LT) cut at the center of the width direction using a scanning electron microscope (SEM), the thickness can be measured at 30 equally spaced points in the length direction and the average value can be calculated.

[0040] The thickness measured at the 30 equally spaced points can be measured at the volume forming section A.

[0041] The main body 110 is arranged inside the main body 110 and includes a first internal electrode 121 and a second internal electrode 122 arranged facing each other with a dielectric layer 111 sandwiched therebetween, and may include a capacitance forming portion A in which capacitance is formed, and cover portions 112 and 113 formed on the upper and lower parts of the capacitance forming portion A.

[0042] The capacitance forming portion A is a portion that contributes to forming the capacitance of the capacitor, and can be formed by repeatedly laminating a plurality of first and second internal electrodes 121 and 122 with the dielectric layer 111 sandwiched therebetween.

[0043] The upper cover part 112 and the lower cover part 113 may be formed by stacking a single dielectric layer or two or more dielectric layers in the thickness direction on the upper and lower surfaces of the capacitance forming part A, respectively, and basically serve to prevent damage to the internal electrodes due to physical or chemical stress.

[0044] The upper cover part 112 and the lower cover part 113 do not include an internal electrode and may include the same material as the dielectric layer 111 .

[0045] That is, the upper cover part 112 and the lower cover part 113 may include a ceramic material, for example, a barium titanate (BaTiO3) based ceramic material.

[0046] On the other hand, there is no need to particularly limit the thickness of the cover portions 112 and 113. However, in order to more easily achieve a smaller size and higher capacity of the multilayer electronic component, the thickness tp of the cover portions 112 and 113 can be 20 μm or less.

[0047] In addition, margin portions 114 and 115 may be arranged on the side surfaces of the capacitance forming portion A.

[0048] The margin portions 114, 115 include a margin portion 114 arranged on the sixth surface 6 of the main body 110 and a margin portion 115 arranged on the fifth surface 5. That is, the margin portions 114, 115 can be arranged on both side surfaces of the ceramic main body 110 in the width direction.

[0049] As shown in FIG. 3, the margins 114 and 115 refer to regions between both ends of the first and second internal electrodes 121 and 122 and the boundary surface of the body 110 in a cross section of the body 110 cut in the width-thickness (WT) direction.

[0050] The margins 114 and 115 essentially serve to prevent damage to the internal electrodes due to physical or chemical stress.

[0051] The margin portions 114 and 115 can be formed by applying a conductive paste to the ceramic green sheet except for the areas where the margin portions are to be formed, thereby forming internal electrodes.

[0052] In addition, in order to reduce the steps caused by the internal electrodes 121, 122, margin portions 114, 115 may be formed by cutting the internal electrodes after lamination so that they are exposed on the fifth and sixth surfaces 5, 6 of the main body, and then laminating a single dielectric layer or two or more dielectric layers in the width direction on both sides of the capacitance forming portion A.

[0053] The internal electrodes 121 and 122 are stacked alternately with the dielectric layers 111 .

[0054] The internal electrodes 121 and 122 may include first and second internal electrodes 121 and 122. The first and second internal electrodes 121 and 122 are alternately arranged to face each other with the dielectric layer 111 constituting the body 110 sandwiched therebetween, and may be exposed to the third and fourth surfaces 3 and 4 of the body 110, respectively.

[0055] Referring to FIG. 2a, the first internal electrode 121 may be spaced apart from the fourth surface 4 and exposed through the third surface 3, and the second internal electrode 122 may be spaced apart from the third surface 3 and exposed through the fourth surface 4.

[0056] In this case, the first and second internal electrodes 121 and 122 may be electrically isolated from each other by the dielectric layer 111 disposed therebetween.

[0057] Referring to FIG. 4, the body 110 can be formed by alternately stacking ceramic green sheets on which the first internal electrodes 121 are printed and ceramic green sheets on which the second internal electrodes 122 are printed, and then firing the stacked ceramic green sheets.

[0058] To achieve a high-capacity multilayer electronic component, the internal electrodes 121, 122 can be stacked in 400 layers or more, but the number is not necessarily limited to this.

[0059] The internal electrodes 121 and 122 of the present invention contain Ni and Sn. The internal electrodes 121 and 122 of the present invention also contain a Ni—Cu—Sn alloy in the regions in contact with the external electrodes 131 and 132.

[0060] Ni is the main material used for the internal electrodes of multilayer ceramic capacitors. However, if Ni is used exclusively as the internal electrode material, the plating solution that flows in from the external electrode during the plating process can cause corrosion in the area where the internal and external electrodes meet, potentially resulting in chip degradation.

[0061] According to an embodiment of the present invention, the internal electrodes 121 and 122 contain a Ni-Cu-Sn alloy in the areas in contact with the external electrodes 131 and 132, thereby preventing Ni corrosion at the ends of the internal electrodes due to penetration of the plating solution during the plating process, thereby improving moisture resistance reliability.

[0062] Furthermore, Sn contained in the internal electrodes 121 and 122 can play a role in suppressing aggregation and breakage of the internal electrodes and improving the capacitance of the multilayer electronic component.

[0063] At this time, the Cu in the Ni-Cu-Sn alloy contained in the internal electrodes 121 and 122 can be the Cu contained in the conductive paste for the external electrodes diffused into the internal electrodes 121 and 122 during the firing process.

[0064] The diffusion coefficient of Cu is approximately 100 times larger than that of Ni at 660 - 730°C, and the diffusion from Cu to Ni is mainly due to the difference in diffusion coefficients. Therefore, during the firing process, the Cu in the external electrodes 131 and 132 moves toward the internal electrodes through the regions in contact with the internal electrodes 121 and 122.

[0065] Also, the internal electrodes 121 and 122 of the present invention contain Sn, and the Sn contained in the conductive paste for the external electrodes also moves toward the internal electrodes through the regions in contact with the internal electrodes during the firing process. Thereby, the Ni-Cu-Sn alloy can be disposed at the ends of the internal electrodes.

[0066] For example, the external electrodes 131 and 132 of the present invention can be formed by a conductive paste for the external electrodes containing Cu and Sn, and the internal electrodes 121 and 122 can be formed by a conductive paste for the internal electrodes containing Ni and Sn.

[0067] When the Sn content of the internal electrodes 121 and 122 in the central part of the main body 110 of the present invention is defined as C1, and the Sn content of the internal electrodes 121 and 122 at a point 2 μm in the inward direction of the main body from the point where the internal electrodes and the external electrodes are in contact is defined as C2, 1 < C2 / C1 < 13.5 is satisfied. Thereby, the occurrence of cracks can be suppressed, and the capacitance and moisture resistance reliability can be improved.

[0068] If C2 / C1 is less than 1, the Sn and Cu contained in the external electrodes may not be sufficiently diffused into the internal electrodes, and an alloy containing Ni, Cu, and Sn may not be sufficiently formed at the ends of the internal electrodes, resulting in insufficient improvement in moisture resistance reliability. Therefore, C2 / C1 is preferably greater than 1, more preferably 1.1 or greater, and even more preferably 1.4 or greater. However, to further improve moisture resistance reliability, C2 / C1 can be controlled to 3.7 or greater, satisfying 3.7≦C2 / C1<13.5. Furthermore, to further improve moisture resistance reliability and capacitance, C2 / C1 can be controlled to 7.0 or greater, satisfying 7.0≦C2 / C1<13.5.

[0069] If C2 / C1 is 13.5 or more, Sn and Cu contained in the external electrodes may diffuse excessively into the internal electrodes, causing the internal electrodes to expand and resulting in radial cracks. Therefore, C2 / C1 is preferably less than 13.5, more preferably 12 or less, and even more preferably 8.9 or less.

[0070] There is no need to particularly limit the contents of C1 and C2. As a specific example, C1 can be 0.1 to 1.0 at %, and C2 can be 1.0 to 20 at %.

[0071] If C1 exceeds 1.0 at%, there is a risk that the connectivity will be reduced due to the aggregation of the internal electrodes caused by Sn, or that Sn will diffuse in the direction of the dielectric, hindering the grain growth of the dielectric.

[0072] If C2 is less than 1.0 at%, the effect of improving moisture resistance reliability due to the alloy containing Ni, Cu, and Sn may be insufficient, and if it exceeds 20.0 at%, radiation cracks may occur.

[0073] The method for controlling C1, C2, and their ratio is not particularly limited. For example, C1, C2, and their ratio can be controlled by adjusting the Sn content, firing temperature, firing time, etc., contained in the conductive paste for external electrodes and the conductive paste for internal electrodes. As a more specific example, by adjusting the Sn content in the conductive paste for external electrodes to a range of 3 wt% to 15 wt%, a multilayer electronic component satisfying the numerical range of C2 / C1 according to the present invention can be manufactured.

[0074] 2b, which is a diagram illustrating the position for measuring the elemental content of the internal electrodes in the main body of FIG. 2a, the point 2 μm toward the inside of the main body 110 from the point where the internal electrodes 121, 122 and the external electrodes 131, 132 contact each other may be a point 2 μm away from the third surface in the case of the first internal electrode, and may be a point 2 μm away from the fourth surface in the case of the second internal electrode. Also, the center of the main body 110 may refer to a 2 μm region in the center of the length direction (X direction) of the main body.

[0075] C1 and C2 can be calculated by dividing the capacitance forming portion A into four equal parts in the Z direction into four regions A1, A2, A3, and A4, calculating the average value of the values ​​measured on the four internal electrodes for each region, and then averaging the average values ​​of each region.

[0076] In this case, when measuring C1 and C2 for each internal electrode, C1 may be a value measured at one point in the center of the thickness direction of the internal electrode, and C2 may be an average value measured over the entire area of ​​the internal electrode corresponding to the central 2 μm region.

[0077] The Cu in the alloy containing Ni, Cu, and Sn contained in the internal electrodes 121, 122 is formed by Cu contained in the conductive paste for the external electrodes being diffused into the internal electrodes 121, 122 during the firing process, and some of the Sn in the Ni-Cu-Sn alloy may also be formed by Sn contained in the conductive paste for the electrodes being diffused into the internal electrodes 121, 122 during the firing process.

[0078] Therefore, the alloy containing Ni, Cu, and Sn contained in the internal electrodes 121 and 122 may have an at% of Sn and Cu gradually decreasing from the contact point between the internal electrode and the external electrode toward the inside of the body, while the at% of Ni gradually increasing from the contact point between the internal electrode and the external electrode toward the inside of the body.

[0079] That is, from the point where the internal electrode and the external electrode meet toward the inside of the body, Cu and Sn may have a concentration gradient in which the concentration gradually decreases, and Ni may have a concentration gradient in which the concentration gradually increases.

[0080] The Sn contained in the internal electrodes may be arranged in a form that gradually decreases from the point where the internal electrode and the external electrode contact toward the inside of the body and maintains a constant content, because the Sn contained in the internal electrodes may include not only Sn that has been diffused from the conductive paste for the external electrodes, but also Sn that was present in the conductive paste for the internal electrodes.

[0081] For example, the Sn content of the internal electrodes 121 and 122 may be gradually decreased from the point where the internal electrode and the external electrode meet toward the inside of the body to a point 5 to 15 μm away, thereby maintaining a constant content.

[0082] In this case, the length of the region of the internal electrodes 121 and 122 where the Sn content is 5 at % or more may be 5 μm to 10 μm from the point where the internal electrode and the external electrode contact each other toward the inside of the body.

[0083] If the length of the region where the Sn content is 5 at % or more is less than 5 μm from the point where the internal electrode and external electrode meet toward the inside of the body, the effect of improving moisture resistance reliability may be insufficient, and if it exceeds 10 μm, radial cracks may occur.

[0084] The Cu contained in the internal electrodes 121 and 122 may be arranged in a form that gradually decreases from the point where the internal electrodes 121 and 122 and the external electrodes 131 and 132 contact each other toward the inside of the body and converges to 0. This is because the Cu contained in the internal electrodes 121 and 122 is diffused Cu contained in the conductive paste for the external electrodes, and the conductive paste for the internal electrodes does not contain Cu.

[0085] As a specific example, the Cu content of the internal electrodes 121 and 122 may gradually decrease from the point where the internal electrode and the external electrode meet toward the inside of the body to a point 5 to 15 μm and then converge to zero.

[0086] In this case, the length of the region of the internal electrodes 121 and 122 where the Cu content is 10 at % or more may be 5 μm to 10 μm from the point where the internal electrode and the external electrode contact each other toward the inside of the body.

[0087] If the length of the region where the Cu content is 10 at% or more is less than 5 μm from the point where the internal electrode and external electrode meet toward the inside of the body, the effect of improving moisture resistance reliability may be insufficient, and if it exceeds 10 μm, radial cracks may occur.

[0088] The internal electrodes 121 and 122 can be formed by printing a conductive paste for internal electrodes containing Ni and Sn onto a ceramic green sheet.

[0089] In addition, the conductive paste for the internal electrodes may further include one or more of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof, and thus the internal electrodes may further include one or more of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof.

[0090] The conductive paste for the internal electrodes may be printed by a screen printing method or a gravure printing method, but the present invention is not limited thereto.

[0091] On the other hand, the thickness te of the internal electrodes 121 and 122 does not need to be particularly limited.

[0092] However, in general, when the internal electrodes 121, 122 are formed thinly with a thickness of less than 0.6 μm, particularly when the thickness of the internal electrodes 121, 122 is 0.41 μm or less, there is a risk that the moisture resistance reliability will decrease.

[0093] As described above, by controlling the Sn content at each position of the internal electrodes according to one embodiment of the present invention, the moisture resistance reliability can be improved by including an alloy containing Ni, Cu, and Sn in the areas where the internal electrodes 121, 122 contact the external electrodes 131, 132, and therefore sufficient moisture resistance reliability can be ensured even when the thickness of the internal electrodes 121, 122 is 0.41 μm or less.

[0094] Therefore, when the thickness of the internal electrodes 121, 122 is 0.41 μm or less, the effect of improving the moisture resistance reliability according to the present invention becomes more significant, and the miniaturization and high capacitance of the capacitor component can be more easily achieved.

[0095] The thickness te of the internal electrodes 121 and 122 may refer to the average thickness of the internal electrodes 121 and 122.

[0096] The average thickness of the internal electrodes 121 and 122 can be measured by scanning an image of a cross section of the body 110 in the length and thickness direction (LT) using a scanning electron microscope (SEM).

[0097] For example, the thickness of any first and second internal electrodes 121, 122 extracted from an image obtained by scanning a cross section of the body 110 in the length and thickness direction (LT) cut at the center of the width (W) direction using a scanning electron microscope (SEM) can be measured at 30 equally spaced points in the length direction, and the average value can be calculated.

[0098] The outer electrodes 131 and 132 are disposed on the body 110 and connected to the inner electrodes 121 and 122 .

[0099] As shown in FIG. 2a, the first and second external electrodes 131 and 132 may be disposed on the third and fourth surfaces 3 and 4 of the body 110, respectively, and connected to the first and second internal electrodes 121 and 122, respectively.

[0100] In this embodiment, the multilayer electronic component 100 has two external electrodes 131 and 132, but the number and shape of the external electrodes 131 and 132 may vary depending on the shape of the internal electrodes 121 and 122 and other purposes.

[0101] The external electrodes 131 and 132 contain Cu and Sn.

[0102] Cu basically serves to ensure electrical connectivity with the internal electrodes, and Sn serves to lower the firing temperature and control the diffusion of Cu.

[0103] On the other hand, the external electrodes 131 and 132 may contain an alloy containing Ni, Cu, and Sn in the areas in contact with the internal electrodes.

[0104] As described above, the diffusion coefficient of Cu is approximately 100 times larger than that of Ni at 660 to 730°C, and the diffusion from Cu to Ni is mainly due to the difference in diffusion coefficient. However, since part of the Ni in the internal electrodes 121 and 122 can also diffuse into the external electrodes, the external electrodes 131 and 132 can also contain an alloy containing Ni, Cu, and Sn in the areas in contact with the internal electrodes 121 and 122.

[0105] The external electrodes 131, 132 may be formed using a conductive paste for external electrodes containing Cu and Sn. The conductive paste for external electrodes may contain glass, and the external electrodes 131, 132 may be fired electrodes. That is, the external electrodes 131, 132 may be formed by applying the conductive paste for external electrodes to the main body 110 and firing it.

[0106] In addition, the conductive paste for the external electrodes may further include one or more of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof, and thus the external electrodes 131, 132 may further include one or more of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof.

[0107] Furthermore, the external electrodes 131, 132 may have a multi-layer structure.

[0108] For example, the external electrodes 131 and 132 may include electrode layers 131a and 132a disposed on the main body 110 and plating layers 131b and 132b formed on the electrode layers 131a and 132a. Here, the electrode layers 131a and 132a may refer to the external electrodes described above.

[0109] In addition, a conductive resin layer containing a conductive metal and a resin may be further disposed between the electrode layers 131a and 132a and the plating layers 131b and 132b.

[0110] The plating layers 131b and 132b serve to improve mounting characteristics. The type of the plating layers 131b and 132b is not particularly limited, and may be a plating layer containing one or more of Ni, Sn, Pd, and alloys thereof, and may be formed of multiple layers.

[0111] As a more specific example of the plating layers 131b, 132b, the plating layers 131b, 132b may be Ni plating layers or Sn plating layers, and may have a form in which a Ni plating layer and a Sn plating layer are formed in this order on the electrode layers 131a, 132a, or a form in which a Sn plating layer, a Ni plating layer, and a Sn plating layer are formed in this order. Also, the plating layers 131b, 132b may include multiple Ni plating layers and / or multiple Sn plating layers.

[0112] The size of the multilayer electronic component 100 does not need to be particularly limited.

[0113] However, in order to achieve both miniaturization and high capacity, it is necessary to reduce the thickness of the dielectric layers and internal electrodes and increase the number of layers. Therefore, the effect of improving reliability and insulation resistance according to the present invention can be more pronounced in multilayer electronic components having a size of 0402 (length x width, 0.4 mm x 0.2 mm) or less.

[0114] Therefore, when the distance between the third and fourth surfaces of the main body is defined as L and the distance between the fifth and sixth surfaces is defined as W, L can be 0.4 mm or less and W can be 0.2 mm or less. In other words, the multilayer electronic component can be 0402 (length x width, 0.4 mm x 0.2 mm) in size or less.

[0115] Hereinafter, a multilayer electronic component according to another embodiment of the present invention will be described in detail. However, since the same drawings and reference numerals as those in the embodiment of the present invention can be applied, the description will be made with reference to FIGS. 1 to 6. Also, to avoid redundant description, the same content as that of the multilayer electronic component according to the embodiment of the present invention will be omitted.

[0116] A multilayer electronic component 100 according to another embodiment of the present invention is a multilayer electronic component including a body in which internal electrodes containing Ni and Sn and dielectric layers are alternately arranged, and external electrodes including Cu and Sn that are disposed on the surface of the body and connected to the internal electrodes, wherein the internal electrodes include an alloy containing Ni, Cu, and Sn in a region in contact with the external electrode, and the length of a region of the internal electrode where the Sn content is 5 at % or more is 5 μm to 10 μm from a point where the internal electrode and the external electrode meet toward the inside of the body.

[0117] If the length of the region where the Sn content is 5 at % or more is less than 5 μm from the point where the internal electrode and external electrode meet toward the inside of the body, the alloy may be insufficiently formed at one end of the internal electrode, resulting in insufficient improvement in moisture resistance reliability.Also, if it exceeds 10 μm, the alloy may be excessively formed at one end of the internal electrode, resulting in an increased thickness, which may cause radial cracks.

[0118] In this case, the internal electrodes 121 and 122 may have a shape in which the Sn content gradually decreases from the point where they contact the external electrodes 131 and 132 to a point where the Sn content is 5 at %. This is because the internal electrodes 121 and 122 may contain Sn diffused from the external electrodes 131 and 132.

[0119] In addition, the length of the region of the internal electrodes 121 and 122 where the Cu content is 10 at % or more may be 5 μm or more and 10 μm or less from the point where the internal electrode and the external electrode meet toward the inside of the body.

[0120] If the length of the region where the Cu content is 10 at% or more is less than 5 μm from the point where the internal electrode and external electrode meet toward the inside of the body, the effect of improving moisture resistance reliability may be insufficient, and if it exceeds 10 μm, radial cracks may occur.

[0121] In this case, the internal electrodes 121 and 122 may have a Cu content that gradually decreases from the point where they contact the external electrodes 131 and 132 to a point where the Cu content is 10 at %. This is because the internal electrodes 121 and 122 may contain Cu diffused from the external electrodes 131 and 132.

[0122] Example 1 Figure 5 shows photographs of (a) Cu element and (b) Ni element observed by SEM-EDX in the area where the internal electrode contacts the external electrode when the external electrode is formed using a conductive paste for external electrodes to which Sn is not added.

[0123] Figure 6 shows photographs of (a) Cu element, (b) Ni element, and (c) Sn element observed by SEM-EDX in the area where the internal electrode contacts the external electrode when the external electrode is formed using a conductive paste for the external electrode containing 5 wt% Sn.

[0124] Figure 7 shows photographs of (a) Cu element, (b) Ni element, and (c) Sn element observed by SEM-EDX in the area where the internal electrode contacts the external electrode when the external electrode is formed using a conductive paste for the external electrode containing 10 wt% Sn.

[0125] The measurement equipment used was a Q-SEM from Zeitz and an EDX from Oxford, and the end of the internal electrode of a cross section (LT cross section) cut in the length and thickness directions at the center of the width direction of the sample chip was observed in ESD mapping mode.

[0126] 5 and 6, it can be seen that Cu diffusion occurs more effectively when Sn is added, but the difference in Cu diffusion is not large.

[0127] In contrast, in FIG. 7, it can be seen that more Sn from the external electrodes is diffused into the internal electrodes, and the diffusion length of Cu is also longer than in FIGS.

[0128] Therefore, it can be seen that the length of the alloy containing Ni, Cu, and Sn disposed at the end of the internal electrode can be controlled by controlling the Sn content contained in the conductive paste for the external electrode.

[0129] Example 2 The Sn content in the conductive paste for external electrodes and the firing conditions were controlled to prepare sample chips that satisfied the Sn content ratios in Table 1 below. Test numbers 1 to 5 used conductive paste for external electrodes containing 5 wt% Sn, and test numbers 6 to 10 used conductive paste for external electrodes containing 10 wt% Sn.

[0130] The Sn content ratio in Table 1 means C2 / C1, where C1 is the Sn content of the internal electrodes 121 and 122 at the center of the body 110, and C2 is the Sn content at a point 2 μm inward from the point where the internal electrode and external electrode meet.

[0131] 2b, the point 2 μm inward from the point where the internal electrodes 121, 122 and the external electrodes 131, 132 meet is a point 2 μm away from the third surface in the case of the first internal electrode, and a point 2 μm away from the fourth surface in the case of the second internal electrode. Also, the center of the body 110 is any point within a 10 μm region in the center of the length direction (X direction) of the body.

[0132] For C1 and C2, the capacitance forming portion A was divided into four equal parts in the Z direction into four regions A1, A2, A3, and A4, and the average values ​​measured on the four internal electrodes for each region were calculated and listed in Table 1 below. The values ​​for the four regions were then averaged and listed in Table 1 below.

[0133] The sample chips with each test number were evaluated for capacitance, the presence or absence of radiation cracks, and moisture resistance reliability, and the results are shown in Table 1 below.

[0134] The radial cracks were observed using an optical microscope (Olympus BX53M x100) to check for the presence or absence of cracks in a cross section in the length and thickness directions cut at the center of the width direction of the body.

[0135] For the moisture resistance reliability, a voltage of 4 V was applied to each sample chip at a temperature of 85°C and a relative humidity of 85%, and the time until the insulation resistance value became 1 / 10 or less of the initial value was measured and described in Table 1 below.

[0136]

Table 1

[0137] In Test Nos. 1 to 7 satisfying 1 < C2 / C1 < 13.5 presented in the present invention, it can be confirmed that no radiation cracks occurred and the moisture resistance reliability was also excellent.

[0138] On the other hand, in Test Nos. 8 to 10 where C2 / C1 is 13.5 or more, radiation cracks were observed, and the moisture resistance reliability was also measured to be 50 hours or less, confirming that it is inferior.

[0139] On the other hand, among Test Nos. 1 to 7, it can be confirmed that Test Nos. 3 to 7 where C2 / C1 is 3.7 or more are more excellent in moisture resistance reliability.

[0140] Also, among Test Nos. 1 to 7, it can be confirmed that Test Nos. 6 and 7 where C2 / C1 is 7.0 or more are even more excellent in moisture resistance reliability and have a higher capacitance.

[0141] FIG. 8 shows the measurement of the atomic ratios of Ni, Cu, and Sn of the internal electrode with respect to Test No. 7 according to the distance from the point where the internal electrode and the external electrode contact toward the inside of the main body.

[0142] It can be confirmed that as the distance from the point where the internal electrode and the external electrode contact toward the inside of the main body increases, the atomic ratios of Cu and Sn of the internal electrode decrease, and the atomic ratio of Ni increases.

[0143] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and the accompanying drawings, but is limited by the appended claims. Therefore, various substitutions, modifications, and changes may be made by those skilled in the art without departing from the technical spirit of the present invention as set forth in the claims, and these also fall within the scope of the present invention. [Explanation of symbols]

[0144] 100 Multilayer electronic components 110 Main Unit 111 Dielectric layer A Capacitance formation part 112, 113 Cover 114, 115 Margin 121, 122 Internal electrode 131, 132 External electrode

Claims

1. a body in which internal electrodes containing Ni and Sn and dielectric layers are alternately arranged; an external electrode disposed on a surface of the body and connected to the internal electrode, the external electrode including Cu and Sn, the internal electrode contains an alloy containing Ni, Cu, and Sn in a region in contact with the external electrode; When the Sn content of the internal electrode at the center of the body is defined as C1 and the Sn content of the internal electrode at a point 2 μm inward from the point where the internal electrode and the external electrode meet is defined as C2, C2 / C1 is greater than 1 and equal to or less than 8.9, The multilayer electronic component, wherein the C1 is 0.1 to 1.0 at %, and the C2 is 1.0 to 20.0 at %.

2. 2. The multilayer electronic component according to claim 1, wherein the C2 / C1 ratio is 1.4 or more and 8.9 or less.

3. 3. The multilayer electronic component according to claim 2, wherein the C2 / C1 ratio is 3.7 or more and 8.9 or less.

4. 4. The multilayer electronic component according to claim 3, wherein the C2 / C1 ratio is 7.0 or more and 8.9 or less.

5. 5. The multilayer electronic component according to claim 1, wherein the alloy containing Ni, Cu, and Sn has an atomic percentage of Sn and Cu that gradually decreases from a point where the internal electrode and the external electrode contact each other toward the inside of the main body.

6. 6. The multilayer electronic component according to claim 1, wherein a length of a region of the internal electrode having an Sn content of 5 at % or more is 5 μm to 10 μm from a point where the internal electrode and the external electrode contact each other toward an inside of the body.

7. 7. The multilayer electronic component according to claim 1, wherein the length of a region of the internal electrode having a Cu content of 10 at % or more is 5 μm to 10 μm from a point where the internal electrode and the external electrode contact each other toward an inside of the body.

8. 8. The multilayer electronic component according to claim 1, wherein the internal electrodes further contain one or more of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof.

9. 9. The multilayer electronic component according to claim 1, wherein the external electrodes contain an alloy containing Ni, Cu, and Sn in regions in contact with the internal electrodes.

10. The multilayer electronic component according to claim 1 , wherein the external electrodes further contain glass.

11. 11. The multilayer electronic component according to claim 1, wherein the external electrodes further contain one or more of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof.

12. 12. The multilayer electronic component according to claim 1, wherein the internal electrodes have an average thickness of 0.41 μm or less.

13. 13. The multilayer electronic component according to claim 1, wherein the dielectric layers have an average thickness of 0.41 μm or less.

14. a body in which internal electrodes containing Ni and Sn and dielectric layers are alternately arranged; an external electrode disposed on a surface of the body and connected to the internal electrode, the external electrode including Cu and Sn, the internal electrode contains an alloy containing Ni, Cu, and Sn in a region in contact with the external electrode; The length of a region of the internal electrode where the Sn content is 5 at % or more is 5 μm or more and 10 μm or less from a point where the internal electrode and the external electrode contact each other toward the inside of the body, wherein C1 is a Sn content of the internal electrode at the center of the body, and C2 is a Sn content of the internal electrode at a point 2 μm inward from a point where the internal electrode and the external electrode meet, and C1 is 0.1 to 1.0 at %, and C2 is 1.0 to 20.0 at %.

15. 15. The multilayer electronic component according to claim 14, wherein the Sn content of the internal electrodes gradually decreases from the point where the internal electrodes contact the external electrodes to a point where the Sn content is 5 at %.

16. 16. The multilayer electronic component according to claim 14, wherein the length of a region of the internal electrode where the Cu content is 10 at % or more is 5 μm to 10 μm from a point where the internal electrode and the external electrode contact each other toward the inside of the body.

17. 17. The multilayer electronic component according to claim 14, wherein the Cu content of the internal electrodes gradually decreases from a point where the internal electrodes contact the external electrodes to a point where the Cu content is 10 at %.

18. 18. The multilayer electronic component according to claim 14, wherein the external electrodes contain an alloy containing Ni, Cu, and Sn in regions in contact with the internal electrodes.

19. A body having internal electrodes containing Ni and Sn and dielectric layers arranged alternately; an external electrode disposed on a surface of the body and connected to the internal electrode, the external electrode including Cu and Sn, the internal electrode contains an alloy containing Ni, Cu, and Sn in a region in contact with the external electrode; When the Sn content of the internal electrode at the center of the body is defined as C1 and the Sn content of the internal electrode at a point 2 μm inward from the point where the internal electrode and the external electrode meet is defined as C2, C2 / C1 is greater than 1 and equal to or less than 8.9, The internal electrode has a region having an Sn content of 5 at % or more, the region having a length of 5 μm to 10 μm from a point where the internal electrode and the external electrode meet toward the inside of the body.

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