Electronic Components

Abstract

To provide an electronic component that can be easily manufactured and has excellent reliability.SOLUTION: An electronic component has an element body 4 with a plurality of side surfaces 5a to 5d along the circumferential direction. The element body 4 has insulating layers 16a to 16d that continuously cover the plurality of side surfaces 5a to 5d along the circumferential direction, and the melting points of the insulating layers 16a to 16d are lower than the melting points of dielectric layers 10 and 11 of the element body 4. The main component of the insulating layer is glass.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present invention relates to electronic components such as multilayer ceramic capacitors. [Background technology]

[0002] For example, in electronic components such as the multilayer ceramic capacitor shown in Patent Document 1, in order to increase the area of ​​the internal electrode layers while miniaturizing the electronic component, a side gap insulating layer made of a dielectric is formed on the side surface of the element body where the side portions of the internal electrode layers are exposed.

[0003] However, in Patent Document 1, only two side surfaces of the multilayer ceramic capacitor are covered with the side gap insulating layer, which makes it easy for moisture to enter through the interface between the end of the side gap insulating layer and the side surface of the element body, posing a reliability issue. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 62-237714 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic component that can be easily manufactured and has excellent reliability. [Means for solving the problem]

[0006] In order to achieve the above object, the electronic component according to the present invention comprises: An electronic component having an element body with a plurality of side surfaces along a circumferential direction, the element body has an insulating layer that continuously covers a plurality of side surfaces along a circumferential direction, The insulating layer has a melting point lower than that of the ceramic layer of the element body.

[0007] The insulating layer in the electronic component of the present invention is an insulating layer that continuously covers multiple side surfaces along the circumferential direction, and is therefore formed with a substantially constant thickness even in areas other than the side gap insulating layer, particularly at corners of the side surfaces of the element body.

[0008] In the electronic component of the present invention, an insulating layer of a uniform thickness is formed near the corners of the side surfaces of the element body compared to other parts, and unlike conventional cases, the edges of the insulating layer with a thin thickness are not formed near the corners, which effectively prevents moisture from entering and improves the moisture resistance and reliability of the electronic component.

[0009] Preferably, the insulating layer has a main component made of glass. Glass-based insulating layers have a high density and excellent moisture resistance compared to ceramic layers made of dielectric layers that emphasize dielectric properties. Therefore, the insulating layer can effectively protect the exposed ends of the internal electrode layers on the side surfaces of the element body, further improving reliability.

[0010] Preferably, the insulating layer covers all of the side surfaces of the element body in a continuous circumferential direction, thereby blocking the intrusion path to the interface between the insulating layer and the element body along the entire periphery of the side surfaces of the element body, thereby further improving the moisture resistance and reliability of the electronic component.

[0011] The insulating layer does not need to completely cover all of the side surfaces of the element body that are continuous along the circumferential direction, and there may be a gap in the insulating layer on one of the side surfaces of the element body. That is, on one of the side surfaces of the element body, an edge of the insulating layer may be located along a direction perpendicular to the circumferential direction near the center of the side surface far from the corners of the element body, and a part of the side surface of the element body may be exposed through the gap between the edges.

[0012] Preferably, the insulating layer has a substantially uniform composition along the circumferential direction. The uniform composition of the insulating layer also makes the moisture resistance uniform along the circumferential direction, reducing the number of starting points that reduce moisture resistance, thereby improving the reliability of the electronic component.

[0013] Preferably, the insulating layer has a thickness of 3 μm to 40 μm. Also, preferably, the insulating layer has a substantially uniform thickness along the circumferential direction. By making the insulating layer have a uniform thickness, the number of starting points that reduce moisture resistance is reduced, improving the moisture resistance of the electronic component and improving its reliability. Because the insulating layer can be formed by a roll transfer method, the insulating layer can easily have a substantially uniform thickness along the circumferential direction.

[0014] Preferably, the thickness of the insulating layer at the corners of the element body is substantially the same as the thickness of the insulating layer at at least one of the two side surfaces of the element body connected to the corners. In particular, by making the thickness of the insulating layer at the corners of the element body the same as that at other parts, the moisture resistance and reliability of the electronic component are improved. Because the insulating layer can be formed by a roll transfer method, the thickness of the insulating layer at the corners of the element body is likely to be substantially uniform compared to other parts.

[0015] The element body may have a laminated structure in which the ceramic layers and internal electrode layers are laminated. Terminal electrodes may be formed on end faces of the element body that intersect with the side faces, connecting to exposed ends of the internal electrode layers. Furthermore, preferably, the edges of the terminal electrodes cover the ends of the insulating layers. This configuration further prevents moisture from penetrating the inside of the element body, improving the moisture resistance and reliability of the electronic component. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. [Figure 2A] FIG. 2A is a cross-sectional view taken along line IIA-IIA shown in FIG. [Figure 2Aa]FIG. 2Aa is a partially enlarged view of the cross-sectional view shown in FIG. 2A. [Figure 2Ab] FIG. 2Ab is a modified example of the partially enlarged view shown in FIG. 2Aa. [Figure 2B] FIG. 2B is a cross-sectional view taken along line IIB-IIB shown in FIG. [Figure 3A] FIG. 3A is a cross-sectional view of a multilayer ceramic capacitor according to another embodiment of the present invention. [Figure 3B] FIG. 3B is a cross-sectional view of a multilayer ceramic capacitor according to still another embodiment of the present invention. [Figure 3C] FIG. 3C is a cross-sectional view of a multilayer ceramic capacitor according to still another embodiment of the present invention. [Figure 4A] 4A is a schematic cross-sectional view parallel to the X-axis and Z-axis showing a lamination step of green sheets in the manufacturing process of the multilayer ceramic capacitor shown in FIG. [Figure 4B] FIG. 4B is a schematic cross-sectional view parallel to the Y-axis and Z-axis showing a lamination process of the green sheets shown in FIG. 4A. [Figure 5A] FIG. 5A is a schematic perspective view of the laminate after the cutting step following the laminating step shown in FIGS. 4A and 4B. [Figure 5B] FIG. 5B is a schematic perspective view of a laminate after a cutting step in the manufacturing process of a multilayer ceramic capacitor according to another embodiment of the present invention. [Figure 6A] FIG. 6A is a schematic perspective view showing a manufacturing process of the multilayer ceramic capacitor of the present invention. [Figure 6B] FIG. 6B is a schematic perspective view showing a continuation of the step shown in FIG. 6A. [Figure 6C] FIG. 6C is a schematic perspective view showing a continuation of the step shown in FIG. 6B. [Figure 6D] FIG. 6D is a schematic perspective view showing a continuation of the step shown in FIG. 6C. [Figure 6E] FIG. 6E is a schematic perspective view showing a continuation of the step shown in FIG. 6D. [Figure 6F] FIG. 6F is a schematic perspective view showing a continuation of the step shown in FIG. 6E. [Figure 6G] FIG. 6G is a schematic perspective view showing a continuation of the step shown in FIG. 6F. [Figure 6H] FIG. 6H is a schematic perspective view of the laminate separated from the sheet after the step shown in FIG. 6G. [Figure 7A] FIG. 7A is a schematic perspective view showing a manufacturing process of a multilayer ceramic capacitor according to a modified example of the present invention. [Figure 7B] FIG. 7B is a schematic perspective view showing a continuation of the step shown in FIG. 7A. [Figure 7C] FIG. 7C is a schematic perspective view showing a continuation of the step shown in FIG. 7B. [Figure 7D] FIG. 7D is a schematic perspective view showing a continuation of the step shown in FIG. 7C. [Figure 7E] FIG. 7E is a schematic perspective view showing a continuation of the step shown in FIG. 7D. [Figure 7F] FIG. 7F is a schematic perspective view showing a continuation of the step shown in FIG. 7E. [Figure 8A] FIG. 8A is a schematic perspective view showing a manufacturing process of a multilayer ceramic capacitor according to another modified example of the present invention. [Figure 8B] FIG. 8B is a schematic perspective view showing a continuation of the step shown in FIG. 8A. [Figure 8C] FIG. 8C is a schematic perspective view showing a continuation of the step shown in FIG. 8B. [Figure 8D] FIG. 8D is a schematic perspective view showing a continuation of the step shown in FIG. 8C. [Figure 8E] FIG. 8E is a schematic perspective view showing a continuation of the step shown in FIG. 8D. [Figure 8F] FIG. 8F is a schematic perspective view showing a continuation of the step shown in FIG. 8E. [Figure 8G] FIG. 8G is a schematic perspective view of the laminate separated from the sheet after the step shown in FIG. 8F. [Figure 9A] FIG. 9A is a schematic perspective view showing a step of cleaning the surface of the laminate. [Figure 9B] FIG. 9B is a schematic perspective view showing a continuation of the step shown in FIG. 9A. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

[0018] First embodiment (Overall structure of a multilayer ceramic capacitor) As an embodiment of the electronic component according to this embodiment, the overall configuration of a multilayer ceramic capacitor will be described.

[0019] As shown in FIG. 1, the multilayer ceramic capacitor 2 according to this embodiment has a multilayer body (element body) 4 made of a ceramic sintered body, a first terminal electrode 6, and a second terminal electrode 8.

[0020] As shown in Fig. 1, the laminate 4 has inner dielectric layers (ceramic layers) 10 and internal electrode layers 12 that are substantially parallel to a plane including the X-axis and Y-axis, and the internal electrode layers 12 are alternately stacked along the Z-axis between the inner dielectric layers 10. Here, "substantially parallel" means that most of the portions are parallel, but there may be some portions that are not parallel, and the internal electrode layers 12 and the inner dielectric layers 10 may have some irregularities or be tilted. In the figure, the X-axis, Y-axis, and Z-axis are approximately perpendicular to each other.

[0021] The portion where the inner dielectric layers 10 and the internal electrode layers 12 are alternately stacked is the interior region 13. The laminate 4 also has exterior regions 11 on both end faces in the stacking direction Z (Z axis). The exterior region 11 is formed by stacking one or more outer dielectric layers. Note that, hereinafter, the "inner dielectric layer 10" and the "outer dielectric layer" may be collectively referred to as the "dielectric layer (ceramic layer)."

[0022] The materials of the dielectric layers constituting the inner dielectric layer 10 and the exterior region 11 may be the same or different and are not particularly limited, but may be composed primarily of, for example, a dielectric material with a perovskite structure such as ABO3 or an alkali niobate ceramic. In ABO3, A is, for example, at least one of Ca, Ba, Sr, etc., and B is at least one of Ti, Zr, etc. The molar ratio of A / B is not particularly limited and is 0.980 to 1.020.

[0023] The number of stacked inner dielectric layers 10 and outer dielectric layers may be determined appropriately depending on the application, etc. The thickness td of the inner dielectric layer 10 shown in Fig. 2A is, for example, 0.1 µm to 40 µm. The ratio of the thickness td of the inner dielectric layer 10 to the thickness te of the internal electrode layer 12 is not particularly limited, but it is preferable that td / te is 2 to 0.5. Furthermore, the ratio of the thickness t0 of the exterior region 11 (see Fig. 1) to the height H0 of the element 3 (see Fig. 2A) is not particularly limited, but it is preferable that t0 / H0 is 0.01 to 0.1.

[0024] The shape and size of the element 3 may be determined appropriately depending on the purpose and application, but it is preferable that the width W0 in the X-axis direction be 0.1 mm to 3.2 mm, the length L0 in the Y-axis direction be 0.2 mm to 3.2 mm, and the height H0 in the Z-axis direction be 0.1 mm to 3.2 mm. Note that it is also preferable that the multilayer ceramic capacitor 2 including the first terminal electrode 6 and the second terminal electrode 8 in the element 3 be within these ranges.

[0025] 1, one of the alternately stacked internal electrode layers 12 has a lead portion 12α electrically connected to the inside of the first terminal electrode 6 formed on one end face 5e in the Y-axis direction of the laminate 4. The other of the alternately stacked internal electrode layers 12 has a lead portion 12β electrically connected to the inside of the second terminal electrode 8 formed on the other end face 5f in the Y-axis direction of the laminate 4.

[0026] The interior region 13 has a capacitance region 14 and lead regions 15A and 15B. The capacitance region 14 is a region where the internal electrode layers 12 are stacked along the stacking direction with the inner dielectric layer 10 sandwiched therebetween. The lead region 15A is a region located between the lead portions 12α of the internal electrode layers 12 connected to the terminal electrode 6. The lead region 15B is a region located between the lead portions 12β of the internal electrode layers 12 connected to the terminal electrode 8.

[0027] The conductive material contained in the internal electrode layer 12 is not particularly limited, and metals such as Ni, Cu, Ag, Pd, Al, Pt, etc., or alloys thereof can be used. As the Ni alloy, an alloy of Ni with one or more elements selected from Mn, Cr, Co, and Al is preferred, and the Ni content in the alloy is preferably 95% by weight or more. Note that the Ni or Ni alloy may contain various trace elements such as P in an amount of approximately 0.1% by weight or less. The internal electrode layer 12 may be formed using a commercially available electrode paste, and the thickness of the internal electrode layer 12 may be appropriately determined depending on the application, etc.

[0028] 2A, in this embodiment, the four side surfaces 5a to 5d of the laminate 4 serving as the element body are continuously covered with insulating layers 16a to 16d that are continuous along the circumferential direction. That is, the insulating layers 16a to 16d are continuously formed along the circumferential direction on the side surfaces 5a and 5c located on both sides along the Z axis of the laminate 4 and the side surfaces 5b and 5d located on both sides along the X axis of the laminate 4, respectively, so as to cover the side surfaces 5a to 5d. In this specification, the direction around the Y axis of the laminate, including the side surfaces 5a to 5d, may be referred to as the circumferential direction or the outer periphery direction.

[0029] In this embodiment, the insulating layers 16a to 16d have substantially the same configuration, and for ease of explanation, unless otherwise specified, the following will describe insulating layers 16a and 16b, and will omit a description of insulating layers 16c and 16d.

[0030] As shown in FIG. 2Aa, the insulating layer 16a formed on the side surface 5a located on the upper side along the Z axis of the laminate 4 has a substantially uniform thickness tz in the Z axis direction. Here, the thickness tz refers to the shortest distance from the outer peripheral surface 16a1 of the insulating layer 16a, which is approximately parallel to the XY plane, to the side surface 5a of the laminate 4. Similarly, the insulating layer 16b formed on the side surface 5b, which is located on one side along the X axis of the laminate 4, has a substantially uniform thickness tx in the X axis direction. Here, the thickness tx refers to the shortest distance from the outer peripheral surface 16b1 of the insulating layer 16b, which is approximately parallel to the YZ plane, to the side surface 5b of the laminate 4. In this embodiment, the thickness tx and the thickness tz are substantially the same.

[0031] In this embodiment, a rounded portion with a predetermined radius of curvature is preferably formed at corner 17 where side surface 5a and side surface 5b intersect, and thickness tp of insulating layer 16p at corner 17 is substantially the same as at least one of thickness tx and thickness tz, preferably both. Note that in this specification, insulating layers 16a to 16d may also be used to mean insulating layer 16p at corner 17.

[0032] Here, corner 17 refers to a corner where side surface 5a and side surface 5b of laminate 4 intersect, when the interface between laminate 4 and insulating layers 16a and 16b is clearly visible. In other words, corner 17 is sandwiched between side surface 5a and side surface 5b of laminate 4. Furthermore, when the interface between laminate 4 and insulating layers 16a and 16b is not clearly visible, corner 17 refers to a corner where outer peripheral surfaces 16a1 of insulating layer 16a and outer peripheral surface 16b1 of insulating layer 16b intersect.

[0033] For example, a corner is defined as a region centered on a line P1 on the outer peripheral surface of the insulating layer that is closest to an intersection P0 between an XY plane formed by an extension of outer peripheral surface 16a1 of insulating layer 16a and a YZ plane formed by an extension of outer peripheral surface 16b1 of insulating layer 16b. The thickness tp of the insulating layer at corner 17 is defined as the shortest distance from P1 to laminate 4.

[0034] The phrase "thickness tp of the insulating layer at corner 17 is substantially the same as at least one of thickness tx and thickness tz, and preferably the same as both" is determined, for example, as follows.

[0035] The thickness tp of the insulating layer at corner 17 is measured at 10 or more points on different cross sections in the Y-axis direction, and the average value tpm and variation σpm are calculated. Furthermore, at the center position of laminate 4 along the X-axis direction, the tz of insulating layer 16a is measured at 10 or more points on different cross sections in the Y-axis direction, and the average value tzm and variation σzm are calculated. Similarly, at the center position of laminate 4 along the Z-axis direction, the tx of insulating layer 16b is measured at 10 or more points on different cross sections in the Y-axis direction, and the average value txm and variation σxm are calculated.

[0036] If the difference between the average value tpm of the insulating layer thickness at corner 17 and the average value tzm of the thickness 16a1 of insulating layer 16a is 1 / 10 μm or less of tzm, they are determined to be substantially the same. The difference between the average value tpm of the insulating layer thickness at corner 17 and the average value txm of the thickness 16b1 of insulating layer 16b can also be determined in a similar manner.

[0037] In this embodiment, insulating layer 16a and insulating layer 16b are smoothly, uniformly, and continuously connected at corner 17, with substantially no gaps from insulating layer 16a to insulating layer 16b and no interface between insulating layer 16a and insulating layer 16b.

[0038] In this embodiment, the thickness of each of the insulating layers 16a to 16d and the thickness (average and variation) of the insulating layer 16p at each corner 17 can be determined in the same manner as above, and all of these thicknesses can be made substantially the same.

[0039] The thickness of the insulating layers 16a to 16d and 16p is preferably within a range of 5 μm to 30 μm, and can be made uniform. This reduces the influence of the thermal expansion coefficient of the insulating layers, and also suppresses structural defects due to the difference in the thermal expansion coefficient between the laminate 4 and the insulating layers. Furthermore, in this embodiment, the insulating layers 16b and 16d function as side gap insulating layers, and can cover the exposed end portions of the internal electrode layers 12 in the X-axis direction with the insulating layers 16b and 16d, providing sufficient protection. Furthermore, in this embodiment, there is little variation in the thickness of each of the insulating layers 16a to 16d and 16p.

[0040] In this embodiment, the outer peripheral surface of insulating layer 16p at corner 17 does not have to be rounded. For example, as shown in FIG. 2Ab, if corner 17 of laminate 4 is chamfered, the outer peripheral surface of insulating layer 16p will be flat along the C-plane of laminate 4. In this case, P1 will be located on the outer peripheral surface of insulating layer 16p, which is a flat surface along the C-plane. In another embodiment of this embodiment, corner 17 may be substantially neither rounded nor chamfered, in which case P0 and P1 will be as close as possible.

[0041] 1, it is preferable that the insulating layers 16a, 16c (the same applies to the insulating layers 16b, 16d, not shown, omitted below) do not substantially cover the end faces 5e, 5f located at both ends in the Y-axis direction of the laminate 4. In other words, it is preferable that the insulating layers 16a, 16c do not cover the connection ends of the lead portions 12α or 12β of the internal electrode layers 12 exposed at the end faces 5e, 5f located at both ends in the Y-axis direction of the laminate 4. This is because the terminal electrodes 6, 8 need to be formed on the outer surfaces 5e, 5f located at both ends in the Y-axis direction of the laminate 4 and connected to the lead portions 12α or 12β of the internal electrode layers 12.

[0042] In this embodiment, the insulating layers 16a to 16d (including 16p / same below) are made of a material having a melting point lower than that of the dielectric layers 10, 11 of the element body 4, and the main component of the insulating layers 16a to 16d is preferably glass containing 25% or more by weight of Si.

[0043] The insulating layers 16a to 16d are primarily made of glass, which enhances the effect of suppressing peeling of the terminal electrodes 6 and 8. This is thought to be because the greater the amount of Si contained in the glass that is the primary component of the insulating layers, the more the insulating layers' resistance to plating improves, and deterioration due to plating can be suppressed. Furthermore, by making the glass that is the primary component of the insulating layers 16a to 16d contain 25% by weight or more of Si, a diffusion layer in which Si is diffused can be formed. This strengthens the bond between the insulating layers 16a to 16d and the terminal electrodes 6 and 8. Therefore, the insulating layers 16a to 16d of this embodiment are preferably made of glass that contains 25% by weight to 70% by weight of Si as the primary component.

[0044] The main component of the insulating layer refers to a component contained in the insulating layer at 40 vol % or more, and preferably refers to a component contained in the insulating layer at 60 vol % or more.

[0045] In addition to Si, the insulating layers 16a to 16d of this embodiment may contain Mg, Ca, Sr, Ba, Li, Na, K, Ti, Zr, B, P, Zn, Al, or the like.

[0046] Furthermore, by forming the insulating layers from a glass component, the adhesive strength between the insulating layers 16a to 16d and the laminate 4 is improved. This is thought to be because a reaction phase is formed at the interface between the glass and the laminate 4, which provides better adhesion between the glass and the laminate 4 than other insulating materials.

[0047] Furthermore, glass has higher insulating properties than ceramic, so compared to when insulating layers 16a-16d are mainly made of ceramic, when insulating layers are mainly made of glass, the incidence of short circuits can be reduced even if the distance between opposing terminal electrodes 6, 8 is shortened.

[0048] The melting point (softening point) of the glass contained in the insulating layers 16a to 16d of this embodiment is preferably 600°C to 950°C. This makes it possible to prevent grain growth of ceramic particles in the dielectric layers when the insulating layers 16a to 16d are fired, thereby suppressing deterioration of properties such as reliability. From the above perspective, the melting point (softening point) of the glass contained in the insulating layers 16a to 16d of this embodiment is more preferably 600°C to 850°C.

[0049] The components other than glass contained in the insulating layers 16a to 16d of this embodiment are not particularly limited, and may include, for example, ceramic filler, BaTiO3, CaTiO3, Al2O3, CaZrO3, MgO, ZrO2, Cr2O3, CoO, etc.

[0050] When the insulating layers 16a to 16d are mainly made of glass, the incidence of short circuits can be reduced even if the terminal electrodes 6, 8 are configured to widely cover the Y-axis direction end portions of the X-axis direction end faces of the laminate 4 and the Y-axis direction end portions of the Z-axis direction end faces, compared to when the insulating layers are made of ceramic.

[0051] In this embodiment, a reaction phase may be formed at the interfaces between the insulating layers 16a-16d and the dielectric layers 10, 11, where at least one of the components of the insulating layers 16a-16d has diffused into the dielectric layers 10, 11. By having a reaction phase at the interfaces between the insulating layers 16a-16d and the inner dielectric layer 10, the side surfaces 5a-5d of the laminate 4 are filled with glass, minimizing the void ratio at the interfaces. This improves the insulation properties of the side surfaces of the laminate 4, and improves the voltage resistance.

[0052] Furthermore, by providing a reactive phase at the interface between the dielectric layer and the insulating layers 16a to 16d, the adhesiveness at the interface between the dielectric layer and the insulating layers 16a to 16d can be improved, thereby suppressing delamination between the laminate 4 and the insulating layers 16a to 16d and increasing the bending strength.

[0053] Regarding the identification of the reaction phase, for example, regarding the interfaces between the dielectric layer of the laminate 4 and the insulating layers 16a to 16d, STEM-EDS analysis of the Si element is performed to obtain mapping data of the Si element, and the locations where the Si element exists can be identified as the reaction phase.

[0054] In the present embodiment, as shown in FIG. 1, both ends of the terminal electrodes 6 and 8 in the Z-axis direction are formed so as to cover both ends of the insulating layers 16a and 16c in the Y-axis direction. Further, as shown in FIG. 2B, both ends of the terminal electrodes 6 and 8 in the X-axis direction are formed so as to cover both ends of the insulating layers 16b and 16d in the Y-axis direction.

[0055] By configuring as described above, at the end faces 5e and 5f of the laminate 4, the terminal electrodes 6 and 8 can completely cover the ends of the interfaces between the insulating layers 16a to 16d and the laminate 4, so that the durability and moisture resistance can be further improved.

[0056] The thickness of the terminal electrodes 6 and 8 may be appropriately determined according to the application and the like.

[0057] In the present embodiment, when the average weight ratio of Si contained in the glass of the insulating layers 16a to 16d is GSi and the average weight ratio of Si contained in the glass of the terminal electrodes 6 and 8 is TSi, it is preferable that GSi / TSi satisfies 1.0 < GSi / TSi ≤ 15.0.

[0058] When GSi / TSi is 1.0 < GSi / TSi ≤ 15.0, a diffusion layer in which Si diffuses can be present. Compared with the case where GSi / TSi is 1.0 or less, the capacitance can be increased and the strength of the terminal electrode can be improved. Further, when GSi / TSi is 1.0 < GSi / TSi ≤ 15.0, compared with the case where GSi / TSi is greater than 15.0, the capacitance can be increased and the results of the limit deflection test can be improved. More preferably, GSi / TSi is 2.0 to 8.0.

[0059] The terminal electrodes 6, 8 of this embodiment are composed of a baked layer (not shown) in contact with the element 3 and a plated layer (not shown) formed thereon. Cu metal, Ni metal, or the like is used as the baked layer. This baked layer is formed so as to cover the end face 5e and a portion of the insulating layers 16a, 16b, 16c, and 16d. Examples of the plated layer include Ni plating, Cu plating, and Sn plating. This embodiment has a terminal structure in which a Ni plated layer is formed on a Cu baked layer, and a Sn plated layer is formed on the Ni plated layer.

[0060] (Manufacturing method of multilayer ceramic capacitors) Next, a method for manufacturing the multilayer ceramic capacitor 2 according to one embodiment of the present invention will be described in detail.

[0061] (Laminate manufacturing process) First, the manufacturing process of the laminate 4 that becomes the element body will be described. An inner green sheet 10a shown in Fig. 4A, which will constitute the inner dielectric layer 10 shown in Fig. 1 after firing, and an outer green sheet 11a shown in Fig. 4A, which will constitute the exterior region 11 shown in Fig. 1, are prepared.

[0062] To form these green sheets 10a and 11a, first, pastes for the inner and outer green sheets are prepared, which are typically organic solvent-based pastes obtained by kneading ceramic powder with an organic vehicle, or water-based pastes.

[0063] The raw material for the ceramic powder can be appropriately selected from composite oxides and various compounds that can be converted into oxides, such as carbonates, nitrates, hydroxides, and organometallic compounds, and can be mixed and used. In this embodiment, the raw material for the ceramic powder is used as a powder having an average particle size of 0.45 μm or less, preferably 0.05 to 0.3 μm. In order to make the inner green sheet extremely thin, it is desirable to use a powder that is finer than the thickness of the green sheet.

[0064] Next, an internal electrode pattern layer 12a shown in FIG. 4A is formed, which will constitute the internal electrode layer 12 shown in FIG. 1 after firing. To this end, a paste for the internal electrode layer is prepared. The paste for the internal electrode layer is prepared by kneading a conductive material made of the various conductive metals and alloys described above with the organic vehicle described above. The metal paste (terminal electrode paste) which will constitute the terminal electrodes 6, 8 shown in FIG. 1 after firing may be prepared in the same manner as the paste for the internal electrode layer described above.

[0065] Using the paste for the inner green sheet and the paste for the internal electrode layer prepared above, the inner green sheets 10a and the internal electrode pattern layers 12a are alternately laminated to produce an inner laminate, as shown in Figures 4A and 4B. After producing the inner laminate, the paste for the outer green sheet is used to form the outer green sheet 11a, which is then pressed in the lamination direction to obtain a green laminate.

[0066] In addition to the above, the green laminate may be produced by alternately stacking a predetermined number of inner green sheets 10a and internal electrode pattern layers 12a directly on the outer green sheet 11a, and then pressing in the stacking direction to obtain the green laminate.

[0067] Next, the green laminate is cut along the C1 and C2 cutting planes in Figures 4A and 4B to obtain green chips 4a. C1 is a cutting plane parallel to the Y-Z axis plane, and C2 is a cutting plane parallel to the Z-X axis plane.

[0068] 4B, the C2 cut surfaces on both sides of the C2 cut surface that cuts the internal electrode pattern layer 12a in the nth layer cut the gaps in the internal electrode pattern layer 12a. Also, the C2 cut surface that cuts the internal electrode pattern layer 12a in the nth layer cuts the gaps in the internal electrode pattern layer 12a in the (n+1)th layer.

[0069] 5A is obtained by this cutting method, so that the nth internal electrode pattern layer 12a of the green chip 4a is exposed at one end face 5e of the green chip 4a in the Y-axis direction, but not at the other end face 5f. Conversely, the (n+1)th internal electrode pattern layer 12a of the green chip 4a is not exposed at one bottom face 5e of the green chip 4a in the Y-axis direction, but is exposed at the other bottom face 5f.

[0070] Furthermore, the internal electrode pattern layers 12a are exposed in all layers on the C1 cut surface of the green chip 4a shown in Fig. 4A, i.e., on the side surfaces 5b and 5d facing the X-axis direction of the green chip 4a shown in Fig. 5A. The method for forming the internal electrode pattern layers 12a is not particularly limited, and they may be formed by a printing method, a transfer method, or a thin film formation method such as vapor deposition or sputtering.

[0071] The green chip 4a is solidified by removing the plasticizer through solidification and drying. The dried green chip 4a is subjected to a binder removal process, a firing process, and an annealing process as needed to obtain the laminate 4 shown in FIG. 2A before the insulating layers 16a to 16d are formed. Furthermore, the terminal electrodes 6 and 8 shown in FIG. 1 are not formed on this laminate 4. A perspective view of the laminate 4 before the insulating layers and terminal electrodes are formed is similar to the perspective view of the green chip 4a, as shown in FIG. 5A.

[0072] In this embodiment, the binder removal step may be performed at a holding temperature of 200°C to 400°C, for example. The firing step may be performed in a reducing atmosphere, and the annealing step may be performed in a neutral or weakly oxidizing atmosphere. Other firing and annealing conditions may include, for example, a firing holding temperature of 1000°C to 1300°C and an annealing holding temperature of 500°C to 1100°C. The binder removal step, firing step, and annealing step may be performed consecutively or independently.

[0073] In the above-described embodiment, the green laminate shown in Figures 4A and 4B is divided into green chips 4a, and then the green chips 4a are fired to form the laminate 4. However, the green laminate shown in Figures 4A and 4B may be fired to form a sintered body, and then the sintered body may be cut to form individual laminates 4.

[0074] The corners of the laminate 4 obtained as described above may be chamfered using a barrel or the like to form an R-surface as shown in Fig. 2Aa or a C-surface as shown in Fig. 2Ab. Furthermore, the end faces 5e and 5f of the laminate 4 may be polished, as necessary, by, for example, barrel polishing or sandblasting.

[0075] (Insulating layer formation process) Next, a process of forming an insulating layer on the outer periphery of the laminate 4 that will become the element body will be described.

[0076] As shown in Fig. 6A, a glass sheet 24 for wrapping is placed on the upper surface of the first rolling member 20, and an adhesive sheet 26 is provided on the lower surface of the second rolling member 22. As shown in Fig. 6B, one or more laminates 4 are sandwiched between the first rolling member 20 and the second rolling member 22, and in this embodiment, the side surface 5a of the laminate 4 is initially attached to the adhesive sheet 26 to form an adhesive layer 26a. Note that Fig. 6A shows the laminate 4 attached to the adhesive sheet 26 on the lower surface of the second rolling member 22, but this is not limiting, and the laminate 4 may initially only be placed on the sheet 24 of the first rolling member 20.

[0077] The first rolling member 20 and the second rolling member 22 may be made of the same material or different materials. These first rolling member 20 and second rolling member 22 may be, for example, plate-like or sheet-like members having a certain degree of rigidity, and the material thereof is not particularly limited and may be any of metal, ceramic, plastic, or the like.

[0078] The wrapping glass sheet 24 is not particularly limited as long as it is a sheet that becomes the insulating layers 16a to 16d shown in FIG. 2A after heat treatment, and examples thereof include a resin sheet in which glass powder is dispersed, or a semi-hardened glass sheet.

[0079] For example, the glass sheet 24 can be formed by kneading the glass powder raw material that constitutes the above-mentioned glass component with a binder and a dispersion medium to make a glass slurry, and then forming the glass slurry into a sheet. The glass sheet 24 is placed on the surface of the first rolling member 20 so that it can be peeled off but does not move laterally.

[0080] Additionally, adhesive layer 26a is disposed on the underside of second rolling member 22 so as to be releasable and prevent lateral movement. Adhesive layer 26 may be formed, for example, from a double-sided adhesive sheet, and preferably has a stronger adhesive strength to laminate 4 than to the underside of second rolling member 22. Adhesive layer 26 is formed from a resin such as synthetic polymers such as polyvinyl butyral, acrylic, polyvinyl alcohol, polyvinyl acetate, and epoxy, or natural polymers such as rosin and terpene.

[0081] As shown in Fig. 6B, second rolling member 22 is lowered relative to first rolling member 20, and second rolling member 22 presses laminate 4 toward first rolling member 20. As a result, part of adhesive layer 26 is transferred to side surface 5a of laminate 4 to become adhesive film 26a. Next, as shown in Fig. 6C, while second rolling member 22 presses laminate 4 relative to first rolling member 20 (the reverse may also be true / same below), second rolling member 22 is moved in a direction (direction of arrow) in which it shifts parallel to first rolling member 20.

[0082] The stack 4 can be rolled on the first rolling member 20 (or second rolling member 22) in the circumferential direction of the side surfaces 5a to 5d in accordance with the movement of the second rolling member 22 relative to the first rolling member 20. When the stack 4 is rolled, the relative distance of the second rolling member 22 to the first rolling member 20 may change along with the change in the rolling radius of rotation of the stack 4. In other words, it is preferable that the stack 4 is always in contact with both the first rolling member and the second rolling member while rolling.

[0083] 6C , as the laminate 4 rolls, the adhesive layer 26a formed on the side surface 5a of the laminate 4 is separated from the underside of the second rolling member 22 and transferred. At the same time, the adhesive sheet 26 is attached to the side surface 5b of the laminate 4, forming an adhesive layer 26b. Note that the winding glass sheet 24 may have a notch 25 formed therein, and the position of the notch 25 preferably coincides with the position of the rolling start point of the side surface 5a of the laminate 4 on the surface of the first rolling member 20.

[0084] 6D, when second rolling member 22 is further moved in the same direction (direction of the arrow), laminate 4 rolls, and adhesive layer 26a formed on side surface 5a of laminate 4 adheres to winding glass sheet 24, forming outer peripheral film 24a that becomes insulating layer 16a. Also, adhesive sheet 26 adheres to side surface 5c of laminate 4, forming adhesive layer 26c.

[0085] 6E, when the second rolling member 22 is further moved in the same direction (direction of the arrow), the glass sheet 24 is separated from the glass sheet 24 located on the surface of the first rolling member 20 at the cuts 25 and transferred to the side surface 5a of the laminate 4, thereby forming the peripheral film 24a. Note that as long as the peripheral film 24a can be transferred to the side surface 5a of the laminate 4, the cuts 25 in the glass sheet 24 are not necessarily required.

[0086] When second rolling member 22 is further moved relatively in the same direction, adhesive layer 26b formed on side surface 5b of laminate 4 adheres to winding glass sheet 24, forming outer peripheral film 24b serving as an insulating layer, as shown in Fig. 6F. Also, adhesive sheet 26 adheres to side surface 5d of laminate 4, forming adhesive layer 26d.

[0087] Similarly, by moving the second rolling member 22 in the same direction and rolling the laminate 4, the winding glass sheet 24 adheres to the adhesive layer 26c on the side surface 5c of the laminate 4, forming a peripheral film 24c that serves as an insulating layer, as shown in Fig. 6G. Furthermore, the winding glass sheet 24 adheres to the adhesive layer 26d on the side surface 5d of the laminate 4, forming a peripheral film 24d that serves as an insulating layer.

[0088] Furthermore, by pressing the laminate 4 toward the first rolling member 20 from above the second rolling member 22 to which the laminate 4 is attached, the outer peripheral film 24d can be separated from the glass sheet 24 located on the first rolling member 20. In this way, the end of the outer peripheral film 24a and the end of the outer peripheral film 24d are joined, and as shown in Fig. 6H, the laminate 4 around which the outer peripheral films 24a to 24d are wound is obtained.

[0089] Next, the laminate 4 with the wound peripheral films 24a-24d is dried and debindered as necessary, and then baked to obtain the laminate 4 with the insulating layers 16a-16d formed thereon, as shown in Fig. 2A. The baking temperature for the peripheral films 24a-24d is preferably 0°C to 150°C, and more preferably 10°C to 50°C higher than the melting point (softening point) of the glass contained in the insulating layers 16a-16d.

[0090] Before the baking treatment, if necessary, the laminate 4 wrapped with the outer peripheral films 24a-24d may be rolled between the first rolling member 20 and the second rolling member 22 as described above, and one or more similar outer peripheral films 24a-24d may be formed on the outer peripheral films 24a-24d. Furthermore, before the baking treatment, if necessary, the laminate 4 wrapped with the outer peripheral films 24a-24d may be deburred by barrel processing or the like.

[0091] After forming the laminate 4 on which the insulating layers 16a to 16d are formed, terminal electrodes 6 and 8 are formed on Y-axis end faces 5e and 5f of the laminate 4, as shown in Fig. 1. To form the terminal electrodes 6 and 8, a metal paste is applied to both end faces in the Y-axis direction of the laminate 4 and baked to form baked metal paste films that serve as electrode films for the terminal electrodes 6 and 8. There are no particular limitations on the method for forming the electrode films for the terminal electrodes 6 and 8, and any appropriate method can be used, such as applying and baking a metal paste, plating, vapor deposition, or sputtering.

[0092] When applying the metal paste by dipping to the end faces of the laminate 4 in the Y-axis direction, it is preferable to apply the metal paste so that it also wets and spreads over the end faces of the laminate 4 in the X-axis direction and the Z-axis direction. The width of the wet spread in the Y-axis direction is preferably 50 μm to 200 μm. The width of the wet spread can be controlled by adjusting the viscosity of the metal paste and the dipping conditions. The baking temperature of the metal paste is preferably 0°C to 50°C higher than the melting point (softening point) of the glass contained in the terminal electrodes 6, 8.

[0093] A coating layer may be formed by plating or sputtering on the surfaces of the electrode films of the terminal electrodes 6 and 8. The terminal electrodes 6 and 8 are formed after the insulating layers 16a to 16d are formed.

[0094] (Summary of the embodiment)

[0095] In this embodiment, the thickness of adhesive sheet 26 shown in Figures 6A to 6G is preferably 0.3 µm to 4 µm, which is about 1 / 5 to 1 / 20 of the thickness of glass sheet 24. Because adhesive sheet 26 of this thickness is sufficiently thin, as shown in Figure 6G, the end of peripheral film 24a and the end of peripheral film 24d made of glass sheet 24 are joined together without being obstructed by adhesive sheet 26, thereby obtaining laminate 4 in which peripheral films 24a to 24d are wound continuously and seamlessly. Therefore, substantially no gaps are formed between insulating layer 16a and insulating layer 16d that are formed, and this prevents cracks from forming.

[0096] As described above, the method for manufacturing the multilayer ceramic capacitor 2 according to this embodiment includes a step (rolling transfer method) of rolling the side surfaces 5a-5d of the laminate 4 on a glass sheet (transfer layer) 24 of a certain thickness so that they come into continuous contact with each other, thereby continuously adhering the outer peripheral films 24a-24d to the side surfaces of the laminate 4. This makes it possible to manufacture the multilayer ceramic capacitor 2 according to this embodiment extremely easily.

[0097] The glass sheet 24 is attached to the side surfaces 5a-5d of the fired laminate 4 and baked to form the insulating layers 16a-16d, a portion of which serves as a side gap insulating layer. The insulating layers 16a-16d are made of a material with a melting point lower than that of the dielectric layers 10, 11 of the laminate 4, and therefore have a baking temperature lower than the baking temperature of the laminate 4. Therefore, the baking temperature for forming the insulating layers 16a-16d has little effect on the laminate 4.

[0098] Furthermore, in this embodiment, the side gap insulating layer is formed by the roll transfer method, and therefore, unlike the coating method, no insulating layer is formed in unnecessary areas. Therefore, the insulating layers 16a-16e are not substantially formed on the end faces 5e, 5f of the laminate 4 where the terminal electrodes 6, 8 are formed and connected to the internal electrode layers 12. As a result, even if the laminate 4 as the element body is miniaturized, the connection reliability between the terminal electrodes 6, 8 and the internal electrode layers 12 is improved. Note that "the insulating layers 16a-16e are not substantially formed on the end faces 5e, 5f of the laminate 4" means that almost no insulating layers are formed compared to the coating method.

[0099] The insulating layers 16a-16d in the multilayer ceramic capacitor 2 of this embodiment are insulating layers that continuously cover the side surfaces 5a-5d in the circumferential direction, and are therefore formed with a substantially uniform thickness even in areas other than the side gap insulating layers. In particular, as shown in FIG. 2Aa or 2Ab, the insulating layers 16p also have a uniform thickness tp at the corners 17 of the side surfaces 5a, 5b of the laminate 4. Furthermore, unlike the edges of insulating layers formed by a coating method, the edges of the insulating layers do not need to be positioned near the corners 17 of the laminate 4 in the multilayer ceramic capacitor 2 of this embodiment.

[0100] In conventional multilayer ceramic capacitors, the edges of the insulating layer formed by a coating method must be positioned near the corners 17 of the laminate 4 so as not to narrow the area of ​​the end faces 5e, 5f of the laminate 4, which serve as the connection end faces with the terminal electrodes 6, 8. In contrast, in the multilayer ceramic capacitor 2 of this embodiment, the insulating layers 16a-16d can be formed by a rolling transfer method, so that the insulating layer 16p is formed to a uniform thickness compared to other parts, even near the corners 17 of the laminate 4, and unlike conventional methods, the edges of the insulating layer with a thin thickness are not formed near the corners 17. This effectively prevents moisture from entering, improving the moisture resistance and reliability of the multilayer ceramic capacitor 2.

[0101] Furthermore, the insulating layers 16a to 16d (including 16p, the same applies hereinafter) have a main component made of glass. The insulating layers 16a to 16d, which are mainly made of glass, have a high density and excellent moisture resistance compared to ceramic layers made of the dielectric layers 10, 11, etc., which emphasize dielectric properties. Therefore, the insulating layers 16a to 16d can effectively protect the exposed ends of the internal electrode layers 12 on the side surfaces of the laminate 4, further improving reliability.

[0102] Furthermore, the insulating layers 16a to 16d cover all of the side surfaces 5a to 5d that are continuous along the circumferential direction of the laminate 4. With this configuration, it is possible to block the penetration paths to the interfaces between the insulating layers 16a to 16d and the laminate 4 all around the side surfaces 5a to 5d of the laminate 4, further improving the moisture resistance and reliability of the multilayer ceramic capacitor 2.

[0103] The insulating layers 16a to 16d do not need to completely cover all of the side surfaces 5a to 5d that are continuous along the circumferential direction of the laminate 4. For example, on one of the side surfaces 5a to 5d, for example, on side surface 5a, there may be a gap in the insulating layer 16a. That is, on one of the side surfaces 5a to 5d (for example, 5a) of the laminate 4, an edge of the insulating layer 16a may be located along a direction perpendicular to the circumferential direction near the center in the X-axis direction of side surface 5a that is far from the corner of the laminate 4, and part of the side surface 5a of the laminate 4 may be exposed through the gap between the edges.

[0104] To form such an insulating layer around the side of the laminate 4, the glass sheet 24 is wound starting from near the center of the X-axis direction on the side 5a of the laminate 4 and ending up winding near the center of the X-axis direction on the side 5a of the same laminate 4.

[0105] In this embodiment, the insulating layers 16a to 16d can have a substantially uniform composition along the circumferential direction. The uniform composition of the insulating layers 16a to 16d also makes the moisture resistance uniform along the circumferential direction, reducing the number of starting points that reduce moisture resistance and improving the reliability of the multilayer ceramic capacitor 2. Note that, by forming the insulating layers 16a to 16d by the roll transfer method, it is easy to form the insulating layers 16a to 16d with a substantially uniform composition along the circumferential direction.

[0106] In this embodiment, the thickness of the insulating layers 16a-16d can be formed by baking one or more layers of the glass sheet 24, and can be, for example, 3 μm-40 μm. Because the insulating layers 16a-16d are formed from glass sheets of uniform thickness, the thickness of the insulating layers 16a-16d is substantially uniform along the circumferential direction. Making the thickness of the insulating layers 16a-16d uniform reduces the number of starting points that reduce moisture resistance, improving the moisture resistance and reliability of the multilayer ceramic capacitor 2. Because the insulating layers 16a-16d can be formed by a rolling transfer method, the thickness of the insulating layers 16a-16d is likely to be substantially uniform along the circumferential direction.

[0107] 2Aa or 2ab, the thickness tp of the insulating layer 16b at the corner 17 of the laminate 4 can be made substantially the same as the thickness tz or tx of the insulating layers 16a, 16b at at least one of the two side surfaces 5a, 5b of the laminate 4 connected to the corner 17. In particular, by making the thickness tp of the insulating layer 16p at the corner 17 of the element 3 the same as the thickness tz or tx of the insulating layer 16p in the other portions, the moisture resistance and reliability of the multilayer ceramic capacitor 2 are improved. Because the insulating layer 16p can be formed by the roll transfer method, the thickness tp of the insulating layer 16p at the corner 17 of the element 3 is likely to be substantially uniform compared to the thickness tz or tx of the other portions.

[0108] In this embodiment, the insulating layers 16a to 16d completely cover the outer periphery of the laminate 4, so that the edges of the interfaces between the insulating layers 16a to 16d and the laminate 4 can be completely covered from the outside air, thereby further improving durability and moisture resistance.

[0109] 1 and 2B, in this embodiment, terminal electrodes 6 and 8 are formed on end faces 5e and 5f of the laminate 4, and the edges of the terminal electrodes 6 and 8 cover parts of the insulating layers 16a to 16d located on the outer faces 5a to 5d of the laminate 4. Therefore, on the end faces 5e and 5f of the laminate 4, the terminal electrodes 6 and 8 can cover the ends of the interfaces between the insulating layers 16a to 16d and the laminate 4, thereby further improving durability and moisture resistance.

[0110] In this embodiment, an insulating layer is formed on the laminate 4 by baking a glass sheet wrapped around the fired laminate 4. By forming an insulating layer in this manner, it is possible to improve the moisture resistance of the electronic component and its durability against external environmental changes such as thermal shock and physical shock.

[0111] The insulating layers 16a to 16d are formed from a single winding glass sheet 24, and each is continuous, with no exposed interface between the insulating layers 16a to 16d and the laminate 4. This makes it difficult for moisture to penetrate the interface, effectively preventing cracks from occurring at the interface.

[0112] In this embodiment, in the cross section shown in FIG. 2A, the variation in the arrangement of the ends of the internal electrode layers 10 of the laminate 4 in the X-axis direction can be kept within 5 μm, for example.

[0113] Second embodiment The multilayer ceramic capacitor according to this embodiment differs from the first embodiment only in the method of forming an insulating layer on the outer periphery of the laminate 4. Therefore, a description of the common parts will be omitted and the following description will mainly focus on the different parts. The parts not described below are the same as those in the first embodiment.

[0114] As shown in FIGS. 7A to 7F, the method for manufacturing the multilayer ceramic capacitor according to this embodiment differs from the method for manufacturing the multilayer ceramic capacitor according to the first embodiment in the step of forming insulating layers 16a to 16d on the outer periphery of the side surfaces 5a to 5d of the laminate 4.

[0115] 7A, a winding glass sheet 24 is laid on the upper surface of the first rolling member 20, and an adhesive sheet 26 is attached to the upper surface of the winding glass sheet 24. In this embodiment, unlike the first embodiment, no adhesive layer is formed on the second rolling member 22, but the second rolling member 22 itself may have adhesiveness.

[0116] The adhesive second rolling member 22 is not particularly limited, and may be a sheet whose surface itself is adhesive, such as a foam sheet, a rubber sheet such as silicone, an acrylic tape, a UV tape (a tape whose adhesive strength weakens when exposed to UV light), etc. Examples of resins that make up the foam sheet include urethane, acrylic, silicone, polyester, and polyurethane.

[0117] 7B, the second rolling member 22 is lowered, and the second rolling member 22 presses the laminate 4 against the first rolling member 20. The side surface 5a of the laminate 4 is attached to the adhesive sheet 26, forming an adhesive layer 26a and an outer film 24a that becomes the insulating layer 16a. The winding glass sheet 24 may have a slit 25 formed therein, the position of which coincides with the edge position of the side surface 5d of the laminate 4.

[0118] As shown in Figure 7C, when the second rolling member 22 presses the laminate 4 against the first rolling member 20 and moves the second rolling member 22 in the direction of the arrow as in the first embodiment, the laminate 4 rolls and the outer film 24a is cut off from the winding glass sheet 24 at the notch 25.

[0119] When the second rolling member 22 is further moved in the same direction as above, the laminate 4 rolls, as shown in FIG. 7D, and the adhesive sheet 26 adheres to the side surface 5b of the laminate together with the sheet 24, forming an adhesive layer 26b and an outer film 24b that becomes the insulating layer 16b.

[0120] When the second rolling member 22 is further moved in the same direction as above, the laminate 4 rolls, as shown in Figure 7E, and the adhesive sheet 26 adheres to the side surface 5c of the laminate together with the sheet 24, forming an adhesive layer 26c and an outer film 24c that becomes the insulating layer 16c.

[0121] By further rolling the laminate 4, as shown in FIG. 7F, the laminate 4 rolls, and the adhesive sheet 26 adheres to the side surface 5d of the laminate, forming an adhesive layer 26d and a peripheral film 24d that becomes an insulating layer 16d.

[0122] Furthermore, as shown in Fig. 7F, by pressing the laminate 4 toward the first rolling member 20 from above the second rolling member 22 to which the laminate 4 is attached, the outer peripheral film 24d can be separated from the winding glass sheet 24. In this way, the end of the outer peripheral film 24a and the outer peripheral film 24d are bonded, and the outer peripheral films 24a to 24d shown in Fig. 6H are wound to obtain the laminate 4. The outer peripheral films 24a to 24d shown in Fig. 6H become the insulating layers 16a to 16d shown in Fig. 2A after baking.

[0123] Third embodiment The multilayer ceramic capacitor according to this embodiment differs from the first or second embodiment only in the method of forming an insulating layer on the outer periphery of the laminate 4. Therefore, a description of the common parts will be omitted and the following description will mainly focus on the different parts. The parts not described below are the same as those described in the above-mentioned embodiments.

[0124] As shown in FIGS. 8A to 8F, the method for manufacturing a multilayer ceramic capacitor according to this embodiment differs from the method for manufacturing a multilayer ceramic capacitor according to the first embodiment in the configuration of the glass sheet in the step of forming an insulating layer on the outer periphery of the laminate 4.

[0125] 8A, an adhesive glass sheet 28 for wrapping is laid on the upper surface of the first rolling member 20. The adhesive glass sheet 28 for wrapping can be manufactured in the same manner as the glass sheet 24 of the first embodiment, and adhesiveness can be imparted to the glass sheet 28 by adjusting the content or composition of the binder and / or dispersion medium or other tackifying components, for example.

[0126] Examples of binders that can be used include ethyl cellulose and polyvinyl butyral, and it is preferable to increase the content of these materials compared to the first embodiment. Examples of dispersion media include terpineol and acetone, and other tackifying components include synthetic polymers such as polyvinyl butyral, acrylic, polyvinyl alcohol, polyvinyl acetate, and epoxy, natural polymers such as rosin and terpene, and plasticizers such as dioctyl phthalate, and it is preferable to increase the content of these materials compared to the first embodiment.

[0127] As shown in Fig. 8B, the second rolling members 22 are lowered, and the second rolling members 22 press the laminate 4 against the first rolling members 20. The side surfaces 5a of the laminate 4 are attached to the adhesive glass sheet 28 for wrapping, forming an outer film 28a that will become the insulating layer 16a. The adhesive glass sheet 28 for wrapping may have cuts 29 formed therein.

[0128] As shown in Figure 8C, when the second rolling member 22 presses the laminate 4 against the first rolling member 20 and moves the second rolling member 22 in the direction of the arrow as in the previously described embodiment, the laminate 4 rolls, and the outer peripheral film 28a adheres to the laminate 4 and is pulled away from the surface of the first rolling member 20.

[0129] When the second rolling member 22 is further moved in the same direction as above, the laminate 4 rolls, and the adhesive glass sheet 28 for wrapping adheres to the side surface 5b of the laminate, forming a peripheral film 28b that will become the insulating layer 16b, as shown in Fig. 8D. When the second rolling member 22 is further moved in the direction of the arrow, the laminate 4 rolls, and the adhesive glass sheet 28 for wrapping adheres to the side surface 5c of the laminate, forming a peripheral film 28c that will become the peripheral layer 16c, as shown in Fig. 8E. When the laminate 4 is further rolled, the laminate 4 rolls, and the adhesive glass sheet 28 for wrapping adheres to the side surface 5d of the laminate, forming a peripheral film 28d that will become the peripheral layer 16d, as shown in Fig. 8F.

[0130] Furthermore, as shown in Fig. 8F, by pressing the laminate 4 toward the first rolling member 20 from above the second rolling member 22 to which the laminate 4 is attached, the outer peripheral film 28d can be separated from the adhesive glass sheet 28 for wrapping. In this way, the end of the outer peripheral film 28a and the outer peripheral film 28d are bonded, and as shown in Fig. 8G, the outer peripheral films 28a to 28d are wound around the laminate 4, thereby obtaining the laminate 4. The outer peripheral films 28a to 28d shown in Fig. 8G become the insulating layers 16a to 16d shown in Fig. 2A after baking.

[0131] In this embodiment, before the outer peripheral films 28a to 28d are wound around the laminate 4 to form the laminate 4, the side surfaces 5a to 5d and / or the end surfaces 5e, 5f of the laminate 4 may be subjected to a cleaning treatment.

[0132] When performing cleaning treatment, it is preferable that the surfaces of the first rolling member 20 and the second rolling member 22 have adhesiveness. The adhesive first rolling member 20 and the adhesive second rolling member 22 may be made of the same material or different materials.

[0133] These first rolling members 20 and second rolling members 22 are not particularly limited and may be sheets whose surface itself is adhesive, such as foam sheets, rubber sheets such as silicone, acrylic tapes, UV tapes (tapes whose adhesive strength weakens when exposed to UV rays), etc. Examples of resins that make up foam sheets include urethane, acrylic, silicone, polyester, and polyurethane.

[0134] First, as shown in Fig. 9A, the second rolling member 22 is lowered and the second rolling member 22 presses the stack 4 against the portion of the first rolling member 20 where the adhesive glass sheet 28 to be wrapped is not placed. Next, as shown in Fig. 9B, the second rolling member 22 is moved in the direction of the arrow in the same manner as in the previously described embodiment, causing the stack 4 to roll, and the side surface 5a of the stack 4 that was attached to the adhesive first rolling member 20 and the side surface 5c of the stack 4 that was attached to the second rolling member 22 are peeled off from the upper surface of the first rolling member 20 and the lower surface of the second rolling member 22. During this process, dirt and other particles are transferred from the surfaces of the side surfaces 5a and 5c of the stack 4 to the contact surfaces of the first rolling member 20 or the second rolling member 22, cleaning the side surfaces 5a and 5c.

[0135] When the second rolling member 22 is further moved in the direction of the arrow, the stack 4 rolls, and the side surface 5b of the stack 4 adheres to the first rolling member 20, and the side surface 5d of the stack 4 adheres to the second rolling member 22. At this time, the position of the side surface 5c of the stack 4 coincides with the position of the end of the adhesive glass sheet 28 for wrapping.

[0136] When second rolling member 22 is further moved in the direction of the arrow, stack 4 rolls, and side surface 5b of stack 4 adhering to first rolling member 20 and side surface 5d of stack 4 adhering to second rolling member 22 peel off from the upper surface of first rolling member 20 and the lower surface of second rolling member 22. At that time, dust and the like are transferred from the surfaces of side surfaces 5b and 5d of stack 4 to the contact surfaces of first rolling member 20 or second rolling member 22, cleaning side surfaces 5b and 5d.

[0137] In other words, in the process of the side surfaces 4a to 4d of the laminate 4 peeling off from the upper surface of the first rolling member 20 and the lower surface of the second rolling member 22, cutting chips and debris (for example, setter chips that adhere during firing) that were attached to the side surfaces 5a to 5d of the laminate 4 can be attached to the upper surface of the first rolling member 20 and the lower surface of the second rolling member 22 and removed.

[0138] 9B, when the second rolling member 22 is further moved in the same direction as above, the laminate 4 rolls, and the side surface 5c of the laminate 4 adheres to the adhesive glass sheet 28 for wrapping, forming an insulating layer 16c. In this state, the laminate 4 in FIG. 8B is turned upside down, and by moving the second rolling member 22 in this state in the direction of the arrow, the step of forming insulating layers 16a-16d on the outer peripheries of the side surfaces 5a-5d of the laminate 4 can be carried out immediately after the cleaning process of the laminate 4.

[0139] Furthermore, by moving the second rolling member 22 in the Y-axis direction from the state of FIG. 9A, the stack 4 is rotated twice, and the end faces 5e and 5f of the stack 4 can also be cleaned.

[0140] In this embodiment, both the first rolling member 20 and the second rolling member 22 are adhesive, but the first rolling member 20 does not have to be adhesive. In that case, by moving the position where the laminate 4 is pressed against the first rolling member 20 away from the end of the adhesive glass sheet 28 for wrapping and increasing the number of times of rolling, it is possible to clean all of the side surfaces 5a to 5d of the laminate 4. Furthermore, by changing the rolling direction, it is possible to clean the end surfaces 5e and 5f of the laminate 4 as well.

[0141] Fourth embodiment 3A, the multilayer ceramic capacitor according to this embodiment differs from the first to third embodiments only in the configuration of the exterior region 11 of the laminate 4, and a description of the common parts will be omitted, and the following description will mainly focus on the different parts. The parts not described below are the same as those described in the above embodiments.

[0142] In this embodiment, the exterior region 11 is made much thinner than the thickness of the exterior region 11 shown in Fig. 2A by providing one or more outer dielectric layers made of the same dielectric as the inner dielectric layer 10. In addition, in this embodiment, the exterior region 11 shown in Fig. 3A does not need to be formed at all.

[0143] That is, in the element body 4, the exterior region 11 in the stacking direction of the layers (Z-axis direction) forms the side surfaces, and insulating layers 16a, 16d are formed on the side surfaces 5a, 5d of the exterior region 11. In this embodiment, the thickness of the exterior region 11 is approximately the same as that of the ceramic layer 10 that forms the interior region 13. The melting points of the insulating layers 16a to 16p are lower than that of the exterior region 11.

[0144] In this embodiment, the exterior region 11 has a thickness similar to that of the inner dielectric layer 10, or even if there is no exterior region 11, the insulating layers 16a to 16d cover the side surfaces 5a to 5d of the laminate 4, so that it has sufficient protective function and strength, improves the durability and moisture resistance of the multilayer ceramic capacitor 2, and makes it possible to improve reliability for long-term use.

[0145] Fifth embodiment 3B, the multilayer ceramic capacitor according to this embodiment differs from the first to fourth embodiments only in the configuration of the inner dielectric layer 10 and the end portions of the internal electrode layers 12. Therefore, a description of the common parts will be omitted and the following description will mainly focus on the different parts. The parts not described below are the same as those described in the above embodiments.

[0146] In this embodiment, dielectric gaps 18b, 18d are formed at both ends in the X-axis direction of the inner dielectric layer 10 and the internal electrode layer 12. That is, the outer sides of the dielectric gaps 18b, 18d in the X-axis direction form the side surfaces 5b, 5d of the laminate 4. By forming the dielectric gaps 18b, 18d in this way, the ends of the internal electrode layers are covered with the dielectric gaps 18b, 18d, which improves the durability and moisture resistance of the multilayer ceramic capacitor 2 and makes it possible to improve reliability in long-term use.

[0147] The laminate 4 of this embodiment is obtained by firing the green chip 4a shown in Fig. 5B and then going through the steps of forming the insulating layers 16a to 16d described above. The green chip 4a shown in Fig. 5B is obtained by changing the pattern shape of the internal electrode pattern layer 12a in the manufacturing process of the laminate described above, so that the internal electrode pattern layer 12a is discontinued at the C1 cross section shown in Fig. 4A.

[0148] 3C, an insulating layer is formed on the outer periphery of the laminate 4, in which the thickness of the exterior region 11 (including the dielectric gaps 18b and 18d) in FIG. 3B is approximately the same as that of the dielectric layer 10 that forms the interior region. This structure is similar to the present embodiment.

[0149] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0150] For example, in the multilayer ceramic capacitor 2 of the first embodiment shown in Fig. 1, at least one of the outer dielectric layers 11, 11 may be omitted. Furthermore, in the above-described embodiment, the main component of the insulating layers 16a to 16d may be composed of a material other than glass, as long as it is composed of a material having a melting point lower than that of the dielectric layers 10, 12 of the laminate 4. For example, the insulating layers 16a to 16d may be composed of ceramic, aluminum, epoxy resin, polyimide resin, etc.

[0151] Furthermore, the electronic component according to the present invention is not limited to a multilayer ceramic capacitor, but can be applied to other electronic components. Examples of other electronic components include all electronic components in which a functional part is formed on the side surface of the element body (an outer surface other than the outer surface on which the terminal electrodes are formed), such as bandpass filters, chip inductors, multilayer three-terminal filters, piezoelectric elements, chip thermistors, chip varistors, chip resistors, and other surface-mounted (SMD) chip-type electronic components. [Explanation of symbols]

[0152] 2. Multilayer ceramic capacitor 3... Element 4... Laminate (element body) 4a... Green Tip 5a~5d… Side 5e,5f… End face 6... 1st terminal electrode 6a... Electrode paste film 8... 2nd terminal electrode 10... Inner dielectric layer (ceramic layer) 10a... Inner green sheet 11... Exterior area (ceramic layer) 11a...Outer green sheet 12… Internal electrode layer 12α,12β…Drawer part 12a... Internal electrode pattern layer 13… Interior area 14… Capacity area 15A,15B…Drawer area 16a, 16b, 16c, 16d, 16p... Insulating layers 16a1,16b1,16c1,16d1...outer surface 17...Corner 18b, 18d... Dielectric gap section 20... First rolling member 22... Second rolling member 24... Glass sheet 24a, 24b, 24c, 24d...Peripheral membrane 25...Notch 26... Adhesive sheet 26a,26b,26c,26d...adhesive film 28...Adhesive glass sheet 28a, 28b, 28c, 28d...Peripheral membrane 29...Notch

Claims

1. An electronic component having an element body with a plurality of side surfaces along a circumferential direction, the element body has an insulating layer that continuously covers a plurality of side surfaces along a circumferential direction, the insulating layer is formed with a constant thickness along the side surfaces of the element body and the chamfered corners where the side surfaces intersect, and along the chamfered corners; An electronic component in which the insulating layer has a melting point lower than the melting point of the ceramic layer of the element body.

2. 2. The electronic component according to claim 1, wherein the insulating layer has a main component made of glass.

3. The electronic component according to claim 1 or 2, wherein the insulating layer covers all of the side surfaces of the element body that are continuous in the circumferential direction.

4. 3. The electronic component according to claim 1, wherein the insulating layer has a gap on one side surface of the element body.

5. 5. The electronic component according to claim 1, wherein the insulating layer has a substantially uniform composition along the circumferential direction.

6. 6. The electronic component according to claim 1, wherein the insulating layer has a thickness of 3 μm to 40 μm.

7. 7. The electronic component according to claim 1, wherein the thickness of the insulating layer is substantially uniform along the circumferential direction.

8. An electronic component according to any one of claims 1 to 7, wherein the thickness of the insulating layer at the corner of the element body is substantially the same as the thickness of the insulating layer at at least one of the two side surfaces of the element body connected to the corner.

9. 9. The electronic component according to claim 1, wherein the element body has a laminated structure in which the ceramic layers and internal electrode layers are laminated.

10. 10. The electronic component according to claim 9, wherein the element body has an exterior region in the stacking direction of the layers forming a side surface, and the insulating layer is formed on the side surface of the exterior region.

11. 11. The electronic component according to claim 10, wherein the exterior region is formed to be thicker than the ceramic layer that forms the interior region.

12. 12. The electronic component according to claim 10, wherein the thickness of the exterior region is approximately the same as that of the ceramic layer that forms the interior region.

13. 13. The electronic component according to claim 10, wherein the exterior region is also formed in a direction perpendicular to the stacking direction of the element body.

14. 14. The electronic component according to claim 10, wherein the ceramic layer forms the exterior region.

15. 15. The electronic component according to claim 10, wherein the insulating layer has a melting point lower than that of the exterior region.

16. 16. The electronic component according to claim 9, wherein terminal electrodes connected to exposed ends of the internal electrode layers are formed on end faces of the element body that intersect with the side faces.

17. 17. The electronic component according to claim 16, wherein an edge of the terminal electrode covers an end of the insulating layer.

18. the ceramic layers and the internal electrode layers are each plural, the insulating layer is formed on the side surface of the element body so as to cover exposed side portions of the plurality of internal electrode layers; 18. The electronic component according to claim 9, wherein the positional variation of the exposed side portions of the plurality of internal electrode layers in contact with the insulating layer is within a predetermined range.

19. The difference between the average thickness (tpm) of the insulating layer at the corner and the average thickness (tzm) of the insulating layer in the Z-axis direction is 1 / 10 or less of (tzm), and a difference between the average thickness (tpm) of the insulating layer at the corner portion and the average thickness (txm) of the insulating layer in the X-axis direction is one-tenth or less of (txm); the thickness (tp) of the insulating layer at the corner portion is substantially equal to at least one of the uniform thickness (tx) in the X-axis direction and the uniform thickness (tz) in the Z-axis direction; The insulating layer has a main component made of glass. The electronic component according to any one of claims 1 to 3.

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