Manufacturing method for multilayer ceramic electronic components

Abstract

In this method for producing a multilayer ceramic electronic component, a base multilayer body is cut at predetermined intervals, a plurality of first rod-like bodies extending in a first direction are formed, a resin is arranged between at least one surface of each of the first rod-like bodies and the first rod-like bodies adjacent thereto, a flat plate-like block in which the plurality of first rod-like bodies are fixed to each other is formed, the flat plate-like block is cut at predetermined intervals in a second direction orthogonal to the first direction, a plurality of second rod-like bodies in which a plurality of element precursors are disposed in a row are thereby formed, the cut surfaces of each of the second rod-like bodies are machined, the plurality of element precursors serve as a plurality of element components, the plurality of element components are fired, the plurality of element components are sintered, and the resin is removed therefrom.

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a multilayer ceramic electronic component, and in particular to a method for producing a multilayer ceramic electronic component, which includes cutting a master laminate obtained by laminating ceramic green sheets and electrode layers, and firing the resulting element component. [Background technology]

[0002] 2. Description of the Related Art A method for manufacturing a multilayer ceramic electronic component, as described in Patent Document 1, for example, is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2006-128285 Summary of the Invention

[0004] A method for producing a multilayer ceramic electronic component according to the present disclosure includes cutting a base laminate in which ceramic green sheets and electrode layers are alternately laminated at predetermined intervals to form a plurality of first rod-shaped bodies extending in a first direction; a resin is disposed on at least one surface of each of the first rod-shaped bodies and between adjacent first rod-shaped bodies to form a flat block in which the first rod-shaped bodies are fixed to each other; cutting the flat block at predetermined intervals in a second direction perpendicular to the first direction to form a plurality of second rod-shaped bodies in which a plurality of element precursors are aligned in a line; processing a cut surface of each of the second rod-shaped bodies to form the plurality of element precursors into a plurality of element components; The plurality of element components are fired to sinter the plurality of element components and remove the resin.

[0005] A method for producing a multilayer ceramic electronic component according to the present disclosure includes cutting a base laminate in which ceramic green sheets and electrode layers are alternately laminated at predetermined intervals to form a plurality of first rod-shaped bodies extending in a first direction, each of which has a first main surface, a second main surface opposite to the first main surface, a first cut surface, and a second cut surface opposite to the first cut surface; aligning the first rod-shaped bodies with a certain gap therebetween, and disposing a resin in the gap to form a flat block in which the first rod-shaped bodies are fixed to one another; cutting the flat block at predetermined intervals in a second direction perpendicular to the first direction to form a plurality of second rod-shaped bodies in which a plurality of element precursors are aligned in a line; processing a cut surface of each of the second rod-shaped bodies to form the plurality of element precursors into a plurality of element components; The plurality of element components are fired to sinter the plurality of element components and remove the resin. [Brief description of the drawings]

[0006] The objects, features and advantages of the present disclosure will become more apparent from the following detailed description and drawings. [Figure 1] FIG. 1 is a perspective view illustrating an example of a multilayer ceramic capacitor. [Diagram 2] FIG. 2 is a perspective view illustrating a schematic diagram of an element part of the multilayer ceramic capacitor of FIG. [Diagram 3] FIG. 3 is a perspective view showing a schematic diagram of a precursor of the element part of FIG. 2. [Figure 4] FIG. 2 is a perspective view showing a schematic diagram of a green sheet on which electrodes are printed. [Diagram 5] FIG. 2 is a perspective view showing a schematic stacking state of green sheets on which electrodes are printed. [Figure 6] 2 is a perspective view showing a schematic diagram of a base laminate for producing the multilayer ceramic capacitor of FIG. 1. FIG. [Figure 7] FIG. 7 is a perspective view that typically shows a first rod-shaped body obtained by cutting the base laminate of FIG. 6. [Figure 8] 1 is a perspective view showing a schematic view of a first rod-shaped body arranged on an adhesive expansion sheet. FIG. [Figure 9] FIG. 4 is a cross-sectional view that illustrates a state in which a first rod-shaped body covered with resin powder is being heated. [Figure 10] FIG. 11 is a cross-sectional view showing a schematic state in which a flat plate placed on resin is being pressed. [Figure 11] FIG. 2 is a perspective view showing a schematic diagram of a flat block. [Figure 12] 12 is a perspective view showing a schematic diagram of a second rod-shaped body obtained by cutting the flat block of FIG. 11. FIG. [Figure 13] 13 is a perspective view showing a state in which the second rod-shaped body in FIG. 12 is rotated about an axis line. FIG. [Figure 14] FIG. 14 is a perspective view showing a schematic diagram of a flat plate-shaped assembly in which the second rod-shaped bodies of FIG. 13 are assembled. [Figure 15] FIG. 2 is a side view showing a state in which the surface of the flat plate-shaped assembly is being polished. [Figure 16] 3 is a cross-sectional view illustrating a first rod-shaped body that is integrated by melt-bonding resin powder particles together. FIG. [Figure 17] FIG. 2 is a perspective view showing a schematic diagram of a flat block. [Figure 18] 18 is a perspective view showing a schematic diagram of a second rod-shaped body obtained by cutting the flat block of FIG. 17. FIG. [Figure 19] 19 is a perspective view showing a state in which the second rod-shaped body in FIG. 18 is rotated about an axis line. FIG. [Figure 20] 20 is a perspective view showing a schematic diagram of a flat plate-shaped assembly in which the second rod-shaped bodies of FIG. 19 are assembled. FIG. [Figure 21] FIG. 2 is a perspective view showing a state in which ceramic green sheets are attached to both sides of a flat plate-like assembly. [Figure 22] FIG. 2 is a perspective view showing a schematic diagram of a flat plate-shaped assembly having ceramic green sheets attached to both sides thereof. [Diagram 23] FIG. 2 is a perspective view showing a schematic diagram of a flat plate-like assembly after firing. [Figure 24] FIG. 2 is a perspective view showing a schematic diagram of a sintered element part that has been barrel polished; [Figure 25A]10 is a cross-sectional view showing a schematic state in which a first rod-shaped body sandwiched between a support sheet and a resin sheet is being heated; FIG. [Figure 25B] FIG. 4 is a cross-sectional view that illustrates a state in which a first rod-shaped body sandwiched between two resin sheets is being heated. [Figure 26] FIG. 4 is a cross-sectional view illustrating a first rod-shaped body fixed by resin. [Figure 27] 5A to 5C are cross-sectional views that diagrammatically show a process of heating a first rod-shaped body having resin powder disposed thereon. [Figure 28] FIG. 11 is a cross-sectional view showing a schematic state in which a flat plate placed on resin is being pressed. [Figure 29] FIG. 2 is a perspective view showing a schematic diagram of a flat block. [Diagram 30] FIG. 30 is a perspective view showing a schematic diagram of a second rod-shaped body obtained by cutting the flat block of FIG. 29. [Diagram 31] 31 is a perspective view showing a state in which the second rod-shaped body in FIG. 30 is rotated about an axis line. FIG. [Figure 32A] 32 is a cross-sectional view showing a state in which a cut surface of the second rod-shaped body in FIG. 31 is dip-coated with a slurry. FIG. [Figure 32B] 32 is a cross-sectional view showing a state in which a cut surface of the second rod-shaped body in FIG. 31 is dip-coated with a slurry. FIG. [Diagram 33] FIG. 13 is a perspective view showing a second rod-shaped body having a slurry applied to its side surface. [Diagram 34] FIG. 4 is a perspective view showing a schematic diagram of a second rod-shaped body after firing. [Diagram 35] FIG. 32 is a perspective view showing a schematic diagram of a flat plate-shaped assembly in which the second rod-shaped bodies of FIG. 31 are assembled. [Diagram 36] FIG. 36 is a perspective view showing a state in which a ceramic green sheet is being transferred onto the surface of the flat plate-like assembly of FIG. 35. [Figure 37] 36 is a perspective view showing a state in which a ceramic green sheet is transferred onto the surface of the flat plate assembly of FIG. 35 and then the base material is peeled off. FIG. [Figure 38] FIG. 2 is a perspective view showing a schematic view of a flat plate-like assembly having a ceramic green sheet applied to the surface thereof as a protective layer. [Figure 39] FIG. 2 is a perspective view showing a schematic diagram of a flat plate-like assembly after firing. [Diagram 40] FIG. 2 is a perspective view showing a state in which a ceramic slurry is transferred onto the surface of a flat plate-like assembly. [Diagram 41] FIG. 2 is a cross-sectional view showing a state in which a flat plate-like assembly is immersed in a ceramic slurry. [Diagram 42] FIG. 2 is a perspective view showing a schematic view of a flat plate-like aggregate during drying. [Diagram 43] FIG. 2 is a perspective view showing a schematic diagram of first rod-shaped bodies arranged in a group with their cut surfaces facing upward. [Diagram 44] 1 is a perspective view showing a schematic view of a first rod-shaped body spaced apart on an adhesive expansion sheet. FIG. [Diagram 45] FIG. 4 is a cross-sectional view illustrating a first rod-shaped body filled with resin powder. [Figure 46] FIG. 11 is a cross-sectional view showing a schematic state in which a flat plate placed on resin is being pressed. [Figure 47] FIG. 2 is a perspective view showing a schematic diagram of a flat block. [Figure 48] FIG. 2 is a perspective view showing a second rod-shaped body obtained by cutting a flat block. [Figure 49] FIG. 11 is a perspective view showing the state of the second rod-shaped bodies assembled after cutting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The configuration on which the method for manufacturing a multilayer ceramic electronic component of the present disclosure is based will be described. In recent years, as electronic devices become smaller and more functional, there is a demand for miniaturization of electronic components mounted in the electronic devices. One example of such an electronic component is a multilayer ceramic capacitor. Multilayer ceramic capacitors with a side length of 1 mm or less are becoming mainstream.

[0008] As described in Patent Document 1, for example, multilayer ceramic electronic components can be manufactured by cutting a master laminate formed by laminating ceramic green sheets and electrode layers into individual element components, firing the element components, and subjecting the fired element components to a specified treatment.

[0009] With the recent trend toward miniaturization of multilayer ceramic electronic components, it has become difficult to handle element components using conventional methods for manufacturing multilayer ceramic electronic components, resulting in problems such as a decrease in product quality and an increase in manufacturing costs.

[0010] Hereinafter, an embodiment of a method for manufacturing a multilayer ceramic electronic component according to the present disclosure will be described with reference to the drawings. Note that, although a method for manufacturing a multilayer ceramic capacitor, which is one example of a multilayer ceramic electronic component, will be described below, the method for manufacturing a multilayer ceramic electronic component according to the present disclosure is not limited to the method for manufacturing a multilayer ceramic capacitor, but can also be applied to methods for manufacturing various other multilayer ceramic electronic components, such as a multilayer piezoelectric element, a multilayer thermistor element, a multilayer chip coil, and a ceramic multilayer substrate.

[0011] First, a multilayer ceramic capacitor, which is an example of a multilayer ceramic electronic component, will be described. FIG. 1 is a perspective view of an example of a multilayer ceramic capacitor. FIG. 2 is a perspective view that typically shows an element component of the multilayer ceramic capacitor of FIG. 1. FIG. 2 is a view showing the element component before firing. Note that although the element component after firing shrinks due to firing, it has the same structure as the element component before firing, so FIG. 2 can also be said to be a view showing the element component after firing. FIG. 3 is a perspective view showing a precursor of the element component of FIG. 2. Hereinafter, the precursor of the element component may be referred to as an element precursor.

[0012] The multilayer ceramic capacitor 1 has an element component 2 and an external electrode 3. As shown in FIG. 2, the element component 2 has a substantially rectangular parallelepiped shape. The element component 2 is made of a dielectric ceramic and has a plurality of internal electrodes 5 connected to the external electrodes 3. The external electrodes 3 are disposed on a pair of end faces of the element component 2 and extend around to other adjacent faces. The multiple internal electrodes 5 extend inward from a pair of end faces of the element component 2 and are alternately stacked without contacting each other.

[0013] The external electrode 3 is configured to have an undercoat layer that connects to the element component 2, and a plated outer layer that facilitates solder mounting of external wiring to the external electrode 3. The undercoat layer may be applied and baked onto the element component 2 after sintering. The undercoat layer may be disposed on the element component 2 before sintering, and may be fired simultaneously with the element component 2. The undercoat layer and plated outer layer may be multiple layers according to the required function. The external electrode 3 may not have a plated outer layer, and may be configured to have an undercoat layer and a conductive resin layer.

[0014] As shown in Figs. 2 and 3, the element part 2 has an element precursor 13 and a protective layer 6. As shown in Fig. 3, the element precursor 13 has a substantially rectangular parallelepiped shape. The element precursor 13 has a first main surface 7a and a second main surface 7b that face each other, a first end surface 8a and a second end surface 8b that face each other, and a first side surface 9a and a second side surface 9b that face each other. Hereinafter, when the first main surface 7a and the second main surface 7b are not distinguished, they will be simply referred to as the main surface 7. Similarly, when the first end surface 8a and the second end surface 8b are not distinguished, they will be simply referred to as the end surface 8, and when the first side surface 9a and the second side surface 9b are not distinguished, they will be simply referred to as the side surface 9.

[0015] The internal electrode 5 is exposed on the end face 8 and the side face 9 of the element precursor 13. The protective layer 6 is disposed on the side face 9 of the element precursor 13. The protective layer 6 prevents the internal electrode 5 exposed on the first end face 8a from being electrically short-circuited with the internal electrode 5 exposed on the second end face 8b. The protective layer 6 also physically protects the part of the internal electrode 5 exposed on the side face 9 of the element precursor 13. The protective layer 6 is attached last in the production of the element component 2. The protective layer 6 protects the internal electrode 5 exposed on the side face 9 of the element precursor 13. The protective layer 6 may be made of a ceramic material. In this case, the protective layer 6 can be made to have insulating properties and high mechanical strength. The ceramic material to become the protective layer 6 is usually disposed on the element precursor 13 before firing. In FIG. 2, the boundary between the element precursor 13 and the protective layer 6 is shown by a two-dot chain line, but the actual boundary is not clearly visible.

[0016] A method for manufacturing the element component 2 in FIG. 2 and the multilayer ceramic capacitor 1 in FIG. 1 will now be described.

[0017] First, a ceramic powder mixture of BaTiO3, a ceramic dielectric material, and additives is wet-milled and mixed in a bead mill. A polyvinyl butyral binder, a plasticizer, and an organic solvent are added to the milled and mixed slurry to produce a ceramic slurry.

[0018] Next, a ceramic green sheet 10 is formed on the carrier film using a die coater. The thickness of the ceramic green sheet 10 may be, for example, about 1 to 10 μm. The thinner the ceramic green sheet 10, the higher the capacitance of the multilayer ceramic capacitor can be. The method for forming the ceramic green sheet 10 is not limited to the die coater, and may be performed using, for example, a doctor blade coater or a gravure coater.

[0019] Next, as shown in FIG. 4, a conductive paste containing a metal material to be the internal electrodes 5 is printed in a predetermined pattern on the ceramic green sheet 10 prepared above by using a screen printing method. The printing of the conductive paste is not limited to the screen printing method, and may be performed by using, for example, a gravure printing method or the like. The conductive paste may contain, for example, a metal such as Ni, Pd, Cu, Ag, or an alloy thereof. Although FIG. 3 shows an example in which the pattern of the internal electrodes 5 is a strip-like pattern of multiple rows, the pattern of the internal electrodes 5 may be, for example, an individual electrode pattern or the like.

[0020] As long as the characteristics of the capacitor can be ensured, the thinner the thickness of the internal electrode 5, the more the internal defects caused by internal stress can be prevented. In the case of a capacitor with a high number of laminations, the thickness of the internal electrode 5 may be, for example, 1.0 μm or less.

[0021] Next, as shown in Fig. 5, a predetermined number of ceramic green sheets 10 with internal electrodes 5 printed thereon are laminated on top of the predetermined number of laminated ceramic green sheets 10, and a predetermined number of ceramic green sheets 10 are further laminated. A predetermined number of ceramic green sheets 10 with internal electrodes 5 printed thereon are laminated while shifting the patterns of the internal electrodes 5. Although omitted in Fig. 5, the ceramic green sheets 10 are laminated on a support sheet. The support sheet may be an adhesive release sheet that can be adhered and released, such as a weak adhesive sheet or a foam release sheet.

[0022] Next, a laminate formed by stacking a plurality of ceramic green sheets 10 is pressed in the stacking direction to obtain an integrated base laminate 11 as shown in FIG. 6. The laminate can be pressed using, for example, a hydrostatic press. Inside the base laminate 11, the internal electrodes 5 are embedded in layers with the ceramic green sheets 10 sandwiched therebetween. When the base laminate 11 is cut lengthwise and crosswise, it becomes the element precursor 13 shown in FIG. 3. The main surface, end surface, and side surface of the base laminate 11 correspond to the main surface 7, end surface 8, and side surface 9 of the element precursor 13, respectively, and therefore will be denoted by the same reference numerals below. Although omitted in FIG. 6, a support sheet used when stacking the ceramic green sheets 10 is located below the base laminate 11.

[0023] Next, as shown in Fig. 7, the base laminate 11 is cut to a predetermined size using a pressure cutting device to obtain a plurality of first rod-shaped bodies 12 extending in a first direction D1. The cut surface of the first rod-shaped body 12 corresponds to the end surface 8 of the element precursor 13, and the internal electrode 5 is exposed on the cut surface of the first rod-shaped body 12. The method of cutting the base laminate 11 is not limited to the method using a pressure cutting device, and a dicing saw device, for example, may be used. In this specification, the cutting of the base laminate 11 to obtain a plurality of first rod-shaped bodies 12 may be referred to as a first cut.

[0024] Next, as shown in FIG. 8, a plurality of first rod-shaped bodies 12 shown in FIG. 7 are placed on an adhesive expansion sheet 14. Furthermore, both ends of the adhesive expansion sheet 14 are expanded in the direction indicated by the arrow A so that the interval between the adjacent first rod-shaped bodies 12 is increased. The gap between the first rod-shaped bodies 12 can be adjusted by adjusting the expansion amount of the adhesive expansion sheet 14. If the gap between the first rod-shaped bodies 12 is too wide, the amount of resin powder used in the subsequent process will increase. The interval between the first rod-shaped bodies 12 may be such that the resin powder can enter the gap between the first rod-shaped bodies 12. Specifically, fine resin powder may be used, and the gap between the first rod-shaped bodies 12 may be more than twice the average particle size of the resin powder.

[0025] As described above, in this embodiment, the gap between the first rod-shaped bodies 12 can be controlled by adjusting the expansion amount of the adhesive expansion sheet 14. This makes it possible to set the amount of resin powder used in the subsequent process to the minimum amount required to fix the first rod-shaped bodies 12 together. As a result, the material cost in manufacturing the multilayer ceramic capacitor can be reduced.

[0026] In cutting involving a cutting width, such as cutting using a dicing saw device, it is not necessary to adjust the gap between the first rod-shaped bodies 12. In cutting using a push-cut cutting device, the cutting groove width is almost zero, but in a later process, the molten resin partially enters the small gap between the first rod-shaped bodies 12 and becomes one with the resin located on the first rod-shaped bodies 12, thereby fixing the first rod-shaped bodies 12 to each other. Depending on the purpose of the later processing, even when cutting using a push-cut blade, the process of forming a gap between adjacent first rod-shaped bodies 12 may not be necessary.

[0027] 4 to 8 are common to the embodiments described below. First, the first embodiment will be described.

[0028] (First embodiment) 9, first, a flat-bottomed dish 17 having a flat bottom surface is prepared, and a plurality of first rods 12 are placed on the bottom surface of the flat-bottomed dish 17 together with a support sheet 18. The plurality of first rods 12 and the support sheet 18 are placed so that the support sheet 18 is in contact with the bottom surface of the flat-bottomed dish 17. Next, resin powder 16 made of a thermoplastic resin is placed on at least one surface of the first rods 12, and then the resin powder 16 is heated to melt.

[0029] After the resin powder 16 is placed, the first rod-shaped bodies 12 may be vibrated before heating. This allows the resin powder 16 to fill the gaps between the adjacent first rod-shaped bodies 12, and increases the degree of filling of the resin powder 16 into the gaps. The average particle size of the resin powder 16 may be half or less of the length of the gaps, and in this case, the degree of filling of the resin powder 16 into the gaps can be effectively increased. The average particle size of the resin powder 16 may be, for example, about 20 to 30 μm. The length of the gaps between the first rod-shaped bodies 12 may be, for example, about 100 μm.

[0030] In this embodiment, after the resin powder 16 is vibration-filled, a parallel partition plate (not shown) is slid along one surface (upper surface) of the first rod-shaped body 12 at a predetermined distance from the one surface (upper surface) of the first rod-shaped body 12 to scrape off excess resin powder 16. Next, the resin powder 16 is heated to a predetermined temperature to melt at least a portion of the resin powder 16. The predetermined temperature can be set appropriately depending on the melting point of the material constituting the resin powder 16, etc. The predetermined temperature may be, for example, about 180°C.

[0031] Resin powder 16 made of a thermoplastic resin melts when heated, and molten resin 15 flows downward and enters the gaps between the first rod-shaped bodies 12. At that time, the air that was present in the gaps escapes to the outside through the voids between the resin powder 16. This pushes the air out of the gaps, and resin 15 fills the gaps from below. The air pushed out to one surface of the first rod-shaped body 12 may cause resin 15 to create a large bubble-like dome, but the bubble-like dome is a surface film and does not affect the filling of the gaps between the first rod-shaped bodies 12 with resin 15.

[0032] The melting point of the thermoplastic resin 15 may be equal to or lower than the decomposition temperature of the binder contained in the ceramic green sheet 10 and the internal electrode 5. This can suppress deterioration of the first rod-shaped body 12 at the stage of melting the resin 15, thereby improving the product quality. The resin 15 may be a resin that does not contain metal, chlorine, fluorine, or the like. This can reduce the risk that substances such as metal, chlorine, or fluorine will remain on the surface of the element component 2 even after the element component 2 is fired, causing deterioration of the characteristics of the product.

[0033] Regarding the wettability of the molten resin 15 to the first rod-shaped body 12, the contact angle of the molten resin 15 to the first rod-shaped body 12 may be 30 degrees or less. If the contact angle is large, the first rod-shaped body 12 will be in a state of repelling the molten resin, and therefore a gap will be formed between the molten resin 15 and the first rod-shaped body 12, and the first rod-shaped bodies 12 may not be firmly fixed to each other with the resin 15. If the contact angle is 30 degrees or less, the wettability of the molten resin 15 to the first rod-shaped body 12 will be increased, and the first rod-shaped bodies 12 can be firmly fixed to each other with the resin 15.

[0034] Resin 15 may be a resin that does not contain an oily material such as wax. Resin 15 is placed in a temperature environment of, for example, 90 to 120°C in a subsequent process, for example, a process in which the ceramic green sheet that will become protective layer 6 is placed on a second rod-shaped body and dried. Oily materials such as wax cannot maintain their shape at such a temperature. Furthermore, molten wax may dissolve the binder in the ceramic green sheet, which may cause problems such as swelling or deformation of element part 2. If resin 15 does not contain an oily material such as wax, such problems can be avoided.

[0035] Resin 15 may be a resin other than a curing reaction type resin. Curing reaction type resins shrink significantly when cured, which may cause deformation of the element part 2. Furthermore, curing reaction type resins generally have a high thermal decomposition temperature, so that when the resin is removed by baking, it is difficult to achieve baking conditions that do not affect the product.

[0036] The resin 15 constituting the resin powder 16, i.e., the resin 15 fixing the first rod-shaped bodies 12 together, is a thermoplastic resin as described above. Examples of the thermoplastic resin 15 include polyethylene, polypropylene, polystyrene, acrylonitrile styrene, methacrylic resin, polyethylene terephthalate, polyvinyl alcohol, polyurethane resin, polyethylene oxide resin, and methacrylic acid ester polymers.

[0037] In this embodiment, as shown in Fig. 10, at the stage where the gaps between the first rod-shaped bodies 12 are filled with molten resin 15, a flat plate 21 is placed on the molten resin 15, and the flat plate 21 is pressed in the direction indicated by arrow B. The flat plate 21 sinks into the molten resin 15 due to the pressing force, but the sinking is stopped by spacers 22 placed around the first rod-shaped bodies 12. By cooling in this state, a layer of resin 15 is formed on the upper part of the first rod-shaped bodies 12. The pressing of the flat plate 21 can be performed using, for example, a press pressure device.

[0038] 11 shows a flat block 23 in which a plurality of first rod-shaped bodies 12 are fixed together with resin to form an integrated body. The plurality of first rod-shaped bodies 12 extend in a first direction D1. In the flat block 23, the resin filled between adjacent first rod-shaped bodies 12 spreads into a resin layer above the first rod-shaped bodies 12, forming a flat resin surface.

[0039] Next, the flat block 23 in FIG. 11 is cut at a predetermined interval in a second direction D2 perpendicular to the first direction D1. FIG. 12 shows a plurality of second rod-shaped bodies 24 obtained by cutting the flat block 23. In this specification, the cutting of the flat block 23 to obtain the plurality of second rod-shaped bodies 24 may be referred to as a second cut. It can also be said that the second cut is performed in a direction perpendicular to the first cut. The cut surface of the second rod-shaped body 24 corresponds to the side surface 9 of the element precursor 13, and the internal electrode 5 is exposed on the cut surface. At this point, each multilayer ceramic electronic component becomes the element precursor 13 shown in FIG. 3.

[0040] If the top surface of the flat block 23 in Fig. 11 is uneven, there is a risk of the accuracy of the second cut being reduced. In this embodiment, as shown in Fig. 10, the top surface of the flat block 23 is flat in order to apply pressure to the resin 15 using the flat plate 21. This makes it possible to improve the accuracy of the second cut, and as a result, the product quality can be improved.

[0041] 13, the second rod-shaped bodies 24 are rotated 90 degrees around their respective axes so that the cut surfaces (surfaces on which the internal electrodes 5 are exposed) resulting from the second cutting face face upward. When the second rod-shaped bodies 24 are rotated, an external force is applied to the second rod-shaped bodies 24. However, since the element body precursors 13 are firmly fixed to each other by the fixing resin, the risk of the element body precursors 13 falling off or the second rod-shaped bodies 24 being deformed is reduced.

[0042] Next, the second rod-shaped bodies 24 are assembled to form a flat plate-shaped assembly 27. When forming the flat plate-shaped assembly 27, the second rod-shaped bodies 24 may be pressed from the sides using two L-shaped frame plates 25 as shown in FIG. 14. In the flat plate-shaped assembly 27, the cut surfaces of the second rod-shaped bodies 24 may be located substantially on the same plane. The cut surfaces (surfaces where the internal electrodes 5 are exposed) resulting from the second cut become the upper and lower surfaces of the flat plate-shaped assembly 27, i.e., the front and back surfaces of the flat plate-shaped assembly. The cut surfaces resulting from the second cut may be referred to as electrode exposed surfaces.

[0043] Although the electrode exposed surface may be processed in the state shown in FIG. 14, in this embodiment, the flat plate-shaped assembly 27 is heated before the processing, and the heating is stopped immediately after the resin starts to melt. As a result, the adjacent second rod-shaped bodies 24 are at least partially bonded with the resin, so that the flat plate-shaped assembly 27 can independently maintain its shape even after the frame plate 25 is removed. As a result, the flat plate-shaped assembly 27 can be easily handled in the subsequent steps. Since the cut surfaces of the second rod-shaped bodies 24 obtained by the second cutting become the upper and lower surfaces of the flat plate-shaped assembly 27, the multiple second rod-shaped bodies 24 can be handled as a single component. As a result, the cut surfaces can be easily processed in the subsequent steps, which in turn can improve the productivity and product quality of the multilayer ceramic electronic component.

[0044] Next, an adhesively removable support sheet 18 is attached and fixed to a first surface (one main surface) 27a of the flat plate-like assembly 27. Then, as shown in Fig. 15, a polishing machine 28 is used to polish a second surface (the other main surface) 27b of the flat plate-like assembly 27 to smooth the surface and remove foreign matter between the exposed electrodes. After polishing of the second surface 27b is completed, the polished surface is fixed with another support sheet 18, and the first surface 27a is polished. The dimensions of the flat plate-like assembly 27 after polishing of the first surface 27a and the second surface 27b are adjusted to the specified dimensions of the product.

[0045] Polishing is performed using multiple grindstones and abrasive powder, progressing from coarse to fine. In the final polishing, abrasive grains with an average grain size of 1 μm or less may be used, or abrasive grains with an average grain size of 0.5 μm or less may be used. This reduces the risk that metal particles released from the internal electrodes 5 by polishing will remain in the abrasive grain scratches and deteriorate the insulation between the internal electrodes 5. The abrasive material may be diamond abrasive grains, which have excellent polishing properties and are unlikely to react with the dielectric material and electrode material during firing.

[0046] In this embodiment, since the plate-like assembly 27 is polished rather than each individual element body precursor 13, it is possible to omit steps such as aligning and fixing the element body precursors 13. Furthermore, since it is possible to suppress variations in the polished surface caused by wobbling of the element body precursors 13 during polishing, it is possible to form a uniform polished surface on all of the element body precursors 13.

[0047] Instead of abrasive polishing, sandpaper tape polishing or cutting with a grinding tool may be performed. In this case, the average particle size of the abrasive particles embedded in the polishing base material used for finishing may be 1 μm or less. This reduces the risk of the insulation between the internal electrodes 5 being deteriorated by metal particles liberated from the internal electrodes 5.

[0048] A ceramic green sheet that will become the protective layer 6 is applied to the polished flat plate assembly 27. The flat plate assembly 27 is then degreased and fired to sinter the element components 2 and to decompose and burn the resin away. The fired flat plate assembly 27 is then cut into individual pieces to produce the element components 2 shown in FIG. 2. Furthermore, external electrodes 3 are attached to the element components 2 to produce the multilayer ceramic capacitor 1 shown in FIG. 1.

[0049] In this embodiment, instead of handling each element part 2, the first rod-shaped body 12 having a plurality of regions that will become element parts 2 and the second rod-shaped body 24 in which a plurality of element precursors 13 are aligned are handled, which facilitates handling of the element parts 2. As a result, it is possible to improve product quality and reduce manufacturing costs.

[0050] In this embodiment, since the resin that fixes the first rod-shaped bodies 12 to each other and the second rod-shaped bodies 24 to each other is a thermoplastic resin, it is possible to melt and bond the resin powders to each other or melt and flow the resin by heating. When heated, the molten resin can enter the gaps between the first rod-shaped bodies 12 and the gaps between the second rod-shaped bodies 24 without substantially applying an external force to the first rod-shaped bodies 12 and the second rod-shaped bodies 24. Furthermore, since the resin has small volumetric shrinkage when cooled, unnecessary stress is not applied to the first rod-shaped bodies 12 and the second rod-shaped bodies 24, and the risk of deformation or damage to the base part 2 can be reduced.

[0051] Second embodiment Next, a description will be given of a second embodiment of the manufacturing method of the present disclosure. The second embodiment of the manufacturing method of the present disclosure is the same as the first embodiment of the manufacturing method of the present disclosure up to the step of producing a plurality of first rod-shaped bodies 12 shown in FIG.

[0052] In this embodiment, first, as shown in FIG. 16, a flat-bottomed dish 17 having a flat bottom surface is prepared, and a plurality of first rod-shaped bodies 12 are placed on the bottom surface of the flat-bottomed dish 17 together with a support sheet 18. The plurality of first rod-shaped bodies 12 and the support sheet 18 are placed so that the support sheet 18 is in contact with the bottom surface of the flat-bottomed dish 17. Next, resin powder 16 is spread over the bottom surface of the flat-bottomed dish 17 from above the plurality of first rod-shaped bodies 12. Next, vibration is applied to the plurality of first rod-shaped bodies 12 to vibrate and fill the resin powder 16 into the gaps between the first rod-shaped bodies 12. Thereafter, a parallel partition plate is slid along one surface (upper surface) of the first rod-shaped bodies 12 at a predetermined interval from the one surface (upper surface) of the first rod-shaped bodies 12, and excess resin powder 16 is scraped off to flatten the upper surface of the powder consisting of the resin powder 16. The average particle size of the resin powder 16 may be half or less of the gaps between the first rod-shaped bodies 12, in which case the degree of filling of the resin powder 16 into the gaps between the first rod-shaped bodies 12 can be increased.

[0053] Thereafter, the resin powder 16 is heated to a temperature just before it is completely melted. This allows the resin powders 16 to be melted and bonded together at the contact points between the resin powders 16, as shown in Fig. 16. As a result, the first rod-shaped bodies 12 are fixed together by at least a portion of the melted resin powder 16, and a flat block 23 in which the first rod-shaped bodies 12 are fixed together and integrated is obtained, as shown in Fig. 17. Note that by appropriately adjusting the heating temperature, it is possible to integrate all of the resin powders 16, in which case the first rod-shaped bodies 12 are firmly fixed together.

[0054] Next, the flat block 23 of FIG. 17 is cut at predetermined intervals in a second direction D2 perpendicular to the first direction D1. FIG. 18 shows a plurality of second rod-shaped bodies 24 obtained by cutting the flat block 23. In other words, FIG. 18 shows a plurality of second rod-shaped bodies 24 obtained by performing a second cut on the flat block 23. The cut surface of the second rod-shaped body 24 corresponds to the side surface 9 of the element body precursor 13, and the internal electrode 5 is exposed on the cut surface. At this point, the individual multilayer ceramic electronic components become the element body precursor 13 shown in FIG. 3.

[0055] 19, the second rod-shaped bodies 24 are rotated 90 degrees around their respective axes so that the cut surfaces (surfaces on which the internal electrodes 5 are exposed) resulting from the second cutting face face upward. When the second rod-shaped bodies 24 are rotated, an external force is applied to the second rod-shaped bodies 24. However, since the element body precursors 13 are firmly fixed to each other with resin, the risk of the element body precursors 13 falling off or the second rod-shaped bodies 24 being deformed is reduced.

[0056] Next, the second rod-shaped bodies 24 are assembled to form a flat plate-shaped assembly 27. When forming the flat plate-shaped assembly 27, as shown in FIG. 20, two L-shaped frame plates 25 may be used to press the second rod-shaped bodies 24 from the lateral periphery. In the flat plate-shaped assembly 27, the cut surfaces of the second rod-shaped bodies 24 may be located substantially on the same plane. The cut surfaces (surfaces where the internal electrodes 5 are exposed) by the second cut are the upper and lower surfaces of the flat plate-shaped assembly 27, i.e., the front and back surfaces of the flat plate-shaped assembly. Next, the flat plate-shaped assembly 27 is heated, and the heating is stopped immediately after the resin attached to the second rod-shaped bodies 24 starts to melt, thereby forming a flat plate-shaped assembly 27 that can independently maintain its shape even after the frame plate 25 is removed. Since the second rod-shaped bodies 24 of the flat plate-shaped assembly 27 are fixed to each other, the L-shaped frame plate 25 can be removed after the flat plate-shaped assembly 27 is formed. Therefore, unnecessary space or equipment is not required in the subsequent steps.

[0057] Next, as shown in FIG. 21, ceramic green sheets 10 that will become the protective layer 6 are arranged and bonded to the upper and lower surfaces of the flat plate-like aggregate 27. The ceramic green sheets 10 that will become the protective layer 6 are made of the same components as the ceramic green sheets used in the element part 2 and have a predetermined thickness required for the protective layer 6. The ceramic green sheets 10 may be attached to both sides of the flat plate-like aggregate 27 at once. If the ceramic green sheets 10 do not have a strength that allows them to be handled individually, the ceramic green sheets 10 may be attached to each side of the flat plate-like aggregate 27 at a time, rather than being attached to both sides at once. This allows the ceramic green sheets 10 and the flat plate-like aggregate 27 to be bonded stably.

[0058] Next, the flat plate assembly 27 with the ceramic green sheets 10 bonded to the upper and lower surfaces is subjected to a hydrostatic press to adhere the ceramic green sheets that will become the protective layers 6 to form the flat plate assembly 27 shown in Fig. 22. In the flat plate assembly 27 of Fig. 22, the excess portions (periphery) of the ceramic green sheets 10 have been cut away. At this point, each multilayer ceramic electronic component becomes the element component 2 of Fig. 2, in which the ceramic green sheets 10 that will become the protective layers 6 are attached to the element precursor 13 shown in Fig. 3.

[0059] Next, the flat plate assembly 27 in FIG. 22 is subjected to a degreasing process and a firing process. First, the flat plate assembly 27 is placed on a zirconia plate, and the plate on which the flat plate assembly 27 is placed is placed in a degreasing furnace to remove the solvent and binder, and then the element components are sintered in a high-temperature firing furnace. The firing temperature can be appropriately set according to the metal material contained in the conductive paste that becomes the internal electrodes 5. The firing temperature may be, for example, 1100 to 1250° C. A conventional method for manufacturing a multilayer ceramic electronic component requires a process of arranging raw chips, which are element components, on a ceramic firing plate before performing a firing process. In this embodiment, it is only necessary to place the flat plate assembly 27, in which multiple element components 2 are integrated, on the firing plate as it is, so that the process of arranging the individual element components 2 on the firing plate is not required.

[0060] FIG. 23 is a schematic diagram of a flat plate-like assembly 27 after sintering. As shown in FIG. 23, the resin surrounding the element components 2 is decomposed and burned away. As a result, gaps 31 are formed between the element components 2, and only the element components 2 consisting of the protective layer 6 and the element precursor 13 remain. Furthermore, separation crack lines 32 are formed in the protective layer 6 at the locations between the element components 2, so that the element components 2 are essentially separated into individual components. The separation crack lines 32 are formed naturally when the element components 2 shrink during the sintering process, widening the gaps between the element components 2, and cracks form in the thinner locations between the element components 2 in the sintered ceramic green sheet 10.

[0061] When the thickness of the ceramic green sheet or the dried ceramic slurry to be the protective layer 6 exceeds 40 μm, the separation crack line 32 may not be generated partially. Therefore, the thickness of the ceramic green sheet or the dried ceramic slurry to be the protective layer 6 may be 40 μm or less.

[0062] Next, the fired element part 2 is subjected to barrel polishing. The barrel polishing is performed for the purpose of removing corners and burrs of the element part 2, and a known barrel polishing method can be used. In this embodiment, the element part 2 and polishing media are placed in a pot containing water and rotated to perform polishing. FIG. 24 shows the element part 2 after barrel polishing. As shown in FIG. 24, in the element part 2 after barrel polishing, the protruding edge of the protective layer 6 is removed, and the corners of the element part 2 are rounded. Note that FIG. 24 shows the element part 2 that is the same as the element part 2 shown in FIG. 2, but is viewed from a different perspective than that of FIG. 2. FIG. 24 is viewed from the same perspective as FIG. 23. In FIG. 24, the boundary between the element precursor 13 and the protective layer 6 is shown by a two-dot chain line, although it does not actually exist.

[0063] In the manner described above, it is possible to produce the element component 2 shown in Fig. 2. Furthermore, by attaching external electrodes 3 to the element component 2, the multilayer ceramic capacitor 1 shown in Fig. 1 can be manufactured.

[0064] Third embodiment Next, a description will be given of a third embodiment of the manufacturing method of the present disclosure. The third embodiment of the manufacturing method of the present disclosure is the same as the first embodiment of the manufacturing method of the present disclosure up to the step of producing a plurality of first rod-shaped bodies 12 shown in FIG.

[0065] In this embodiment, as shown in Fig. 25A, first, a plurality of first rod-shaped bodies 12 are placed on a first flat plate 21a together with a support sheet 18. The plurality of first rod-shaped bodies 12 and the support sheet 18 are placed so that the support sheet 18 is in contact with the upper surface of the first flat plate 21a. Next, the periphery of the plurality of first rod-shaped bodies 12 supported by the support sheet 18 is surrounded by a frame plate 25, a resin sheet 36 is placed on the plurality of first rod-shaped bodies 12, and further, a second flat plate 21b is placed on the resin sheet 36 made of a thermoplastic resin. Thereafter, the resin is heated and melted while pressing the second flat plate 21b with a constant pressure in the direction indicated by the arrow C.

[0066] The molten resin flows downward and enters the gaps between the first rod-shaped bodies 12, and the first rod-shaped bodies 12 are fixed to each other by the resin. In this embodiment, the thermoplastic resin is applied to the first rod-shaped bodies 12 in a sheet shape, which makes it easier to carry out the subsequent steps up to heating. Furthermore, since the first rod-shaped bodies 12 are fixed to each other, the multiple first rod-shaped bodies 12 can be handled as a single part. As a result, processing of the cut surfaces in the subsequent steps is easier. Furthermore, the resin that fixes the first rod-shaped bodies 12 to each other can be removed in the baking step after the processing.

[0067] The upper surface of the frame plate 25 may be at the same height as or higher than the upper surface of the first rod-shaped body 12. This can prevent the molten resin from flowing out to the outside. The height of the upper surface of the first rod-shaped body 12 may be equal to or lower than the height of the upper surface of the first rod-shaped body 12 as long as the resin can be prevented from flowing out to the outside. The thickness of the resin sheet 36 may be about 0.3 mm. The thinner the resin sheet 36 is, the more material can be saved and the manufacturing cost can be reduced. In this embodiment, the thickness of the resin sheet 36 is set to a thickness that can save material and allows the multiple first rod-shaped bodies 12 to be handled as a unit.

[0068] As shown in FIG. 25B, in a state where a plurality of first rod-shaped bodies 12 are sandwiched between two resin sheets 36, the resin of the two resin sheets may be heated and melted. In this case, since a structure is formed in which a plurality of first rod-shaped bodies 12 are sandwiched from above and below, it is possible to firmly fix the first rod-shaped bodies 12 to each other. The resin may be heated in a vacuum device. In this case, since the molten resin easily enters the gaps between the first rod-shaped bodies 12, it is possible to fix the first rod-shaped bodies 12 to each other by the resin with a reduced porosity. As a result, it is possible to fix the first rod-shaped bodies 12 to each other more firmly.

[0069] Fig. 26 is a cross-sectional view showing a schematic state of the first rod-shaped body 12 shown in Fig. 25A after the resin is heated and melted. As shown in Fig. 26, the molten resin 15 flows downward and fills the gaps between the first rod-shaped bodies 12. Note that, as shown in Fig. 26, although voids 31 may exist in the resin 15 located in the gaps, the first rod-shaped bodies 12 are firmly fixed to each other by the resin 15. Fig. 26 corresponds to the state shown in Fig. 17 in the second embodiment. The subsequent steps in the third embodiment are similar to those in the second embodiment, and therefore description thereof will be omitted.

[0070] (Fourth embodiment) Next, a fourth embodiment will be described. The fourth embodiment of the manufacturing method of the present disclosure is the same as the first embodiment of the manufacturing method of the present disclosure up to the step of producing a plurality of first rod-shaped bodies 12 shown in FIG.

[0071] In this embodiment, first, the resin powder 16 is spread on the bottom surface of the flat-bottomed dish 17, and then the resin powder 16 is heated and melted to form a bottom resin 19 as shown in FIG. 27. Next, a plurality of first rod-shaped bodies 12 shown in FIG. 8 are placed on the bottom resin 19, and the resin powder 16 is spread on the plurality of first rod-shaped bodies 12. When the resin powder is spread on the plurality of first rod-shaped bodies 12, the plurality of first rod-shaped bodies 12 are vibrated to densely fill the gaps between the first rod-shaped bodies 12 with the resin powder 16. Furthermore, after the vibration filling, the parallel partition plate is slid along one surface (upper surface) of the first rod-shaped bodies 12 at a predetermined interval from one surface (upper surface) of the first rod-shaped bodies 12, and the layer of the resin powder 16 on the one surface is made to have a uniform thickness. The resin material and the size of the powder are as described in the first embodiment.

[0072] Thereafter, the first rod-shaped bodies 12 in the state shown in FIG. 27 are placed in an oven at a predetermined temperature to heat and melt the resin powder 16. The predetermined temperature can be set appropriately depending on the melting point of the material constituting the resin powder 16, etc. The gaps between the first rod-shaped bodies 12 are filled with the molten resin, and the base resin 19 also melts, so that the molten resin of the resin powder 16 and the base resin 19 become one body. The base resin 19 and the resin powder 16 may be made of the same material. In this case, the base resin 19 and the resin powder 16 show the same melting behavior and have good melt wettability, so that the first rod-shaped bodies 12 can be fixed together more firmly.

[0073] After the resin 15 is filled in the gaps between the first rod-shaped bodies 12, as shown in FIG. 28, a flat plate 21 is placed on the resin 15 and pressed in the direction indicated by the arrow D. The flat plate 21 sinks into the molten resin, but the sinking is stopped by the spacer 22 placed around the first rod-shaped body 12. If the plate is cooled in this state, a resin layer is formed on the upper part of the first rod-shaped body 12. The flat plate 21 can be pressed using, for example, a press pressure device. The flat plate 21 can be pressed at the stage when the resin 15 is melted, and may be pressed inside or outside the oven. In FIG. 28, the spacer 22 is placed on the bottom resin 19, but it may be placed on a flat plate.

[0074] Fig. 29 shows a flat block 23 in which first rod-shaped bodies 12 are fixed together and integrated with resin 15. In the flat block 23 shown in Fig. 29, the resin 15 filled in the gaps between the first rod-shaped bodies 12 spreads into layers of resin 15 located on the upper and lower surfaces of the first rod-shaped bodies 12, forming flat resin surfaces on the upper and lower surfaces of the flat block 23.

[0075] Next, the flat block 23 of FIG. 29 is cut at predetermined intervals in a second direction D2 perpendicular to the first direction D1. FIG. 30 shows a plurality of second rod-shaped bodies 24 obtained by cutting the flat block 23. In other words, FIG. 30 shows a plurality of second rod-shaped bodies 24 obtained by subjecting the flat block 23 to a second cut. The internal electrodes 5 are exposed on the cut surfaces obtained by the second cuts. The cut surfaces obtained by the second cuts correspond to the side surfaces 9 of the element body precursor 13. At this point, each multilayer ceramic electronic component becomes the element body precursor 13 of FIG. 3.

[0076] 31, the second rod-shaped bodies 24 are rotated 90 degrees around their respective axes in the axial direction, so that one of the cut surfaces resulting from the second cut (the surface on which the internal electrode 5 is exposed) faces upward. When the second rod-shaped bodies 24 are rotated, an external force is applied to the second rod-shaped bodies 24. However, since the element body precursors 13 are firmly fixed to each other by the fixing resin, the risk of the element body precursors 13 falling off or the second rod-shaped bodies 24 being deformed is reduced.

[0077] Next, an adhesively removable support sheet 18 is attached to the entire upper surface (cut surface by the second cut) of the plurality of second rod-shaped bodies 24 in FIG. 31, and then the adhesively removable sheet side is attached to a flat plate 21 as shown in FIG. 32A. Then, as shown in FIG. 32B, the exposed electrode surface (the other of the cut surfaces by the second cut) is immersed in ceramic slurry 29 that will become the protective layer 6, and then pulled up, and the ceramic slurry 29 is applied. Then, the applied ceramic slurry 29 is dried at a predetermined temperature. Thereafter, another support sheet is attached to the exposed electrode surface to which the ceramic slurry 29 has been applied, the support sheet 18 used initially is peeled off, and the same process is carried out to apply the ceramic slurry 29 to the exposed electrode surface on the opposite side.

[0078] FIG. 33 shows a state in which the ceramic slurry 29 that will become the protective layer 6 is applied to both electrode exposed surfaces of the second rod-shaped body 24. Focusing on each element precursor 13, the ceramic slurry 29 is applied only to the electrode exposed surface (side surface 9), and the main surface 7 and end surface 8 are covered with resin 15. Conventionally, the application of slurry or ink to the surface of electronic components such as multilayer ceramic electronic components has been performed using a dip method or a screen printing method. In the conventional application method, the slurry or ink can be applied to the application surface, but it is unavoidable that the slurry or ink will spread to other surfaces adjacent to the application surface. In the manufacturing method of the multilayer ceramic electronic component of the present disclosure, the surface adjacent to the application surface is covered with resin, so that the slurry can be effectively prevented from spreading to the adjacent surfaces.

[0079] Next, the second rod-shaped body 24 in FIG. 33 is subjected to a degreasing process and a firing process. First, the second rod-shaped body 24 is placed on a ceramic plate, and the plate on which the second rod-shaped body 24 is placed is placed in a degreasing furnace to remove the solvent and binder, and then fired in a high-temperature firing furnace. FIG. 34 shows a schematic diagram of the state of the second rod-shaped body 24 after firing. As shown in FIG. 34, the resin surrounding the element parts 2 is decomposed and burned away. Therefore, gaps 31 are formed between the element parts 2, and only the element parts 2 composed of the protective layer 6 and the element precursor 13 remain. In addition, separation crack lines 32 are generated in the portions of the protective layer 6 located between the element parts 2, so that the element parts 2 are essentially separated into individual parts. The separation crack lines 32 are naturally formed when the element parts 2 shrink during the sintering process, widening the gaps between the element parts 2, and cracks form in the thin portions of the sintered ceramic slurry 29 located between the element parts 2.

[0080] Next, the fired element part 2 is subjected to barrel polishing. Barrel polishing is performed for the purpose of removing corners and burrs from the element part 2, and a known barrel polishing method can be used. In this embodiment, the element part 2 and polishing media are placed in a pot containing water and rotated for polishing. The element part 2 after barrel polishing is the same as the element part 2 shown in FIG. 24.

[0081] In the manner described above, the element component 2 can be produced. Furthermore, by attaching external electrodes 3 to the element component 2, the multilayer ceramic capacitor 1 shown in FIG.

[0082] Fifth embodiment Next, a fifth embodiment will be described. The fifth embodiment of the manufacturing method of the present disclosure is the same as the third embodiment of the manufacturing method of the present disclosure up to the step of producing the second rod-shaped body 24 of FIG.

[0083] In this embodiment, first, a plurality of second rod-shaped bodies 24 are assembled on a flat plate (not shown) to form a flat plate-shaped assembly 27. When forming the flat plate-shaped assembly 27, two L-shaped frame plates 25 may be used to press the second rod-shaped bodies 24 from the lateral periphery, as shown in Fig. 35. The upper and lower surfaces of the flat plate-shaped assembly 27 are cut surfaces (surfaces where the internal electrodes 5 are exposed) resulting from the second cut.

[0084] Next, as shown in FIG. 36, a ceramic green sheet 10 is formed on the surface (lower surface) of a substrate 35, and the substrate 35 is arranged so that the ceramic green sheet 10 is located on the surface (upper surface) of the flat plate-like aggregate 27. Next, a heater roller 34 whose surface is made of an elastic body is brought into contact with the upper surface of the substrate 35, and the heater roller 34 is rotated while applying pressure to bring the ceramic green sheet 10 into contact with the surface (upper surface) of the flat plate-like aggregate 27. Thereafter, as shown in FIG. 37, the substrate 35 is peeled off by turning it over, so that the ceramic green sheet 10 is transferred to the surface of the flat plate-like aggregate 27. The same process is performed on the back surface (lower surface) of the flat plate-like aggregate 27, so that the ceramic green sheet 10 is transferred. Then, the ceramic green sheet 10 is firmly bonded to the front and back surfaces of the flat plate-like aggregate 27 using a hydrostatic press. The substrate 35 may be a rubber sheet having an elastic body such as silicon, or a resin sheet such as PET (polyethylene terephthalate) or nylon.

[0085] 38 shows a flat plate-like assembly 27 having ceramic green sheets 10 bonded to its upper and lower surfaces. The element part 2 is in a state in which the ceramic green sheets 10 that become the protective layer 6 are provided only on the electrode exposed surfaces, which are the cut surfaces obtained by the second cutting, that is, the element part 2 shown in FIG.

[0086] Next, the flat plate-like assembly 27 of FIG. 38 is subjected to a degreasing process and a firing process. The degreasing process and the firing process can be performed in the same manner as in each of the above-mentioned embodiments. FIG. 39 is a perspective view that shows a schematic state of the flat plate-like assembly 27 shown in FIG. 38 after sintering. The resin surrounding the element parts 2 is decomposed and burned away. Therefore, gaps 31 are formed between the element parts 2, and only the element parts 2 composed of the protective layer 6 and the element precursor 13 remain. In addition, separation crack lines 32 are formed in the portions of the protective layer 6 located between the element parts 2, so that the element parts 2 are essentially separated into individual pieces. The separation crack lines 32 are formed naturally when the element parts 2 shrink during the sintering process, widening the gaps between the element parts 2, and cracks form in the thin portions located between the element parts 2 in the sintered ceramic green sheet 10.

[0087] Next, the fired element part 2 is subjected to barrel polishing. Barrel polishing is performed for the purpose of removing corners and burrs from the element part 2, and a known barrel polishing method can be used. In this embodiment, the element part 2 and polishing media are placed in a pot containing water and rotated for polishing. The element part 2 after barrel polishing is the same as the element part 2 shown in FIG. 24.

[0088] In the manner described above, the element component 2 can be produced. Furthermore, by attaching external electrodes 3 to the element component 2, the multilayer ceramic capacitor 1 shown in FIG.

[0089] In this embodiment, the ceramic green sheet 10 is applied only to the cut surface of the second rod-shaped body 24, and is prevented from spreading to the surfaces adjacent to the cut surface. This makes it possible to prevent burrs from being generated in the fired element part 2, improving product quality. It is also possible to reduce the cost required for barrel polishing to remove burrs.

[0090] Sixth embodiment Next, a description will be given of a sixth embodiment of the manufacturing method of the present disclosure. The sixth embodiment of the manufacturing method of the present disclosure is the same as the fifth embodiment of the manufacturing method of the present disclosure up to the production of the flat plate-shaped assembly 27 of FIG.

[0091] In this embodiment, as shown in Fig. 40, first, ceramic slurry 29 that has been applied in advance to the surface of transfer roller 33, the surface of which is made of an elastic body, is transferred to the surface (upper surface) of flat plate-like assembly 27 in Fig. 35. After the ceramic slurry 29 transferred to the upper surface of flat plate-like assembly 27 is dried, the same treatment is performed on the rear surface (lower surface) of flat plate-like assembly 27.

[0092] The ceramic slurry 29 can be applied to the transfer roller 33 by using, for example, a screen printing device. The roller surface of the transfer roller 33 is used as the surface to be printed, and the transfer roller 33 is rotated in synchronization with printing, so that a predetermined thickness of the ceramic slurry 29 can be applied onto the roller surface.

[0093] According to this embodiment, the ceramic slurry 29 is applied only to the cut surface of the second rod-shaped body 24, and the ceramic slurry 29 is prevented from flowing into the surface adjacent to the cut surface. This makes it possible to prevent burrs from being generated in the sintered element part 2, improving product quality. It also makes it possible to reduce the cost required for barrel polishing to remove burrs.

[0094] The flat plate-like assembly 27 with the ceramic slurry 29 transferred to its front surface (upper surface) and back surface (lower surface) essentially becomes the flat plate-like assembly 27 shown in Fig. 38. Therefore, when the flat plate-like assembly 27 is fired, the fired flat plate-like assembly 27 shown in Fig. 39 is obtained. The subsequent steps in this embodiment are the same as those in the fifth embodiment, and therefore will not be described.

[0095] Seventh embodiment Next, a seventh embodiment will be described. The seventh embodiment of the manufacturing method of the present disclosure is the same as the fifth embodiment of the manufacturing method of the present disclosure up to the production of the flat plate-shaped assembly 27 of FIG.

[0096] In this embodiment, as shown in Fig. 41, first, the flat plate assembly 27 of Fig. 35 is immersed in a container of ceramic slurry 29, and then pulled up vertically. By appropriately adjusting the viscosity and solid content of the ceramic slurry 29, excess ceramic slurry 29 drips off the flat plate assembly 27, and a ceramic slurry 29 layer of a uniform predetermined thickness can be formed. In addition, since the ceramic slurry 29 layer can be simultaneously formed on both of the two electrode exposed surfaces of the flat plate assembly 27, the burden of manufacturing costs can be reduced.

[0097] 42 shows the state of the flat plate-like aggregate 27 during drying. The ceramic slurry 29 may be dried naturally. When drying the ceramic slurry 29, the excess ceramic slurry 29 may be forcibly scraped off using a blade, or the excess ceramic slurry 29 may be blown off using centrifugal force. This makes it possible to shorten the drying time.

[0098] The flat plate assembly 27 is substantially the flat plate assembly 27 shown in Fig. 38. The subsequent steps in the seventh embodiment are similar to those in the fifth embodiment, and therefore the description will be omitted.

[0099] Eighth embodiment In this embodiment, the process up to the first cutting to produce the first rod-shaped body 12 of FIG. 7 from the matrix laminate 11 is the same as the above embodiment, and therefore the description will be omitted. The first rod-shaped body 12 extends in a first direction D1. The first rod-shaped body 12 has a first main surface, a second main surface opposite to the first main surface, a first cut surface, and a second cut surface opposite to the first cut surface. The first rod-shaped body 12 also has a first side surface and a second side surface opposite to the first side surface. The first main surface and the second main surface of the first rod-shaped body 12 correspond to the first main surface 7a and the second main surface 7b of the element precursor 13, respectively, and therefore will be denoted by the same reference numerals below. The first cut surface and the second cut surface of the first rod-shaped body 12 correspond to the first end surface 8a and the second end surface 8b of the element precursor 13, respectively, and therefore will be denoted by the same reference numerals below. The first and second side faces of the first rod-shaped body 12 correspond to the first and second side faces 9a and 9b of the element precursor 13, respectively, and will be denoted by the same reference numerals hereinafter. Hereinafter, when the first main face 7a and the second main face 7b are not differentiated from each other, they will simply be referred to as the main face 7. Similarly, when the first cut face 8a and the second cut face 8b are not differentiated from each other, they will simply be referred to as the cut face 8, and when the first side face 9a and the second side face 9b are not differentiated from each other, they will simply be referred to as the side face 9. The multiple first rod-shaped bodies 12 may include a first rod-shaped body 12 whose first cut face 8a or second cut face 8b is not a face formed by the first cut (i.e., it is an end face 8 of the base laminate 11).

[0100] Next, the first rod-shaped bodies 12 are integrated to form a flat block 23. In the above embodiment, as shown in FIG. 7, the first rod-shaped bodies 12 are aligned so that the first main surfaces 7a are flush with each other and the first cut surface 8a of each first rod-shaped body 12 faces the second cut surface 8b of the first rod-shaped body 12 adjacent to the first rod-shaped body 12. In the present embodiment, as shown in FIG. 43, the first rod-shaped bodies 12 are aligned so that the first cut surfaces 8a are flush with each other and the first main surface 7a of each first rod-shaped body 12 faces the second main surface 7b of the first rod-shaped body 12 adjacent to the first rod-shaped body 12. FIG. 43 shows the first rod-shaped bodies 12 of FIG. 7 rotated 90° around the longitudinal axis and aligned with the main surfaces 7 back to back on the peelable adhesive expansion sheet 14 so that the side surface 9 is an open surface. Regarding the rotation of the first rod-shaped body 12, for example, by utilizing the fact that the internal electrode of the first rod-shaped body 12 is a magnetic metal, it can be rotated 90° around the longitudinal axis by reacting to a magnetic field in the state of FIG. 7. Alternatively, the first rod-shaped body 12 in FIG. 7 may be attached to the adhesive expansion sheet 14, the first rod-shaped bodies 12 may be separated from each other, and the first rod-shaped body 12 may be freed again, and both main surfaces 7 may be sandwiched between elastic plates from above and below, and the elastic plates may be moved in parallel in opposite directions to rotate the first rod-shaped body 12 as if rolling it. After the rotation, the first rod-shaped body 12 may be moved so that the main surfaces 7 are back-to-back with the cut surfaces 8 facing up and down, and the adhesive expansion sheet 14 may be attached from above, and then the first rod-shaped body 12 may be inverted.

[0101] Next, as shown in Fig. 44, both ends of the adhesive expansion sheet 14 are expanded in the direction indicated by the arrow E so as to increase the distance between adjacent first rod-shaped bodies 12. The distance between the first rod-shaped bodies 12 can be adjusted by adjusting the amount of expansion of the adhesive expansion sheet 14. The distance between the first rod-shaped bodies 12 may be such that the resin powder can enter the gap between the first rod-shaped bodies 12, and may be, for example, about 50 µm to 150 µm.

[0102] Next, as shown in FIG. 45, first, a flat-bottomed dish 17 having a flat bottom surface is prepared, and a plurality of first rod-shaped bodies 12 are placed on the bottom surface of the flat-bottomed dish 17 together with a support sheet 18. The plurality of first rod-shaped bodies 12 and the support sheet 18 are placed so that the support sheet 18 is in contact with the bottom surface of the flat-bottomed dish 17. Next, resin powder 16 made of a thermoplastic resin is placed on at least one surface of the first rod-shaped bodies 12, and then vibration is applied to fill the gaps between the first rod-shaped bodies 12 with the resin powder 16. Thereafter, a parallel partition plate (not shown) is slid along one surface of the first rod-shaped bodies 12 at a predetermined interval from one surface (upper surface) of the first rod-shaped bodies 12, and excess resin powder 16 is scraped off. The average particle size of the resin powder 16 may be, for example, about 10 to 50 μm.

[0103] Subsequently, the resin powder 16 is heated to a predetermined temperature to melt at least a portion of the resin powder 16. The predetermined temperature can be appropriately set depending on the melting point of the material constituting the resin powder 16. The predetermined temperature may be, for example, about 150°C to 180°C.

[0104] The resin powder 16 made of a thermoplastic resin melts when heated, and begins to fuse together at the contact surfaces of the resin powder 16. When further heated, the molten resin 15 flows downward and fills the gaps between the first rod-shaped bodies 12.

[0105] The melting point of the thermoplastic resin 15 may be equal to or lower than the decomposition temperature of the binder contained in the ceramic green sheet 10 and the internal electrode 5. This can suppress deterioration of the first rod-shaped body 12 at the stage when the resin 15 is melted. The resin 15 may also be a resin that does not contain metal, chlorine, fluorine, or the like. This can reduce the risk that substances such as metal, chlorine, or fluorine will remain on the surface of the element component 2 even after the element component 2 is fired, causing deterioration of the characteristics of the product.

[0106] 46 shows a state in which, at the stage where the resin 15 has melted in the gaps between the first rod-shaped bodies 12, a flat plate 21 is placed on the molten resin 15 and the flat plate 21 is pressed in the direction indicated by the arrow F. The flat plate 21 sinks into the molten resin 15 due to the pressing force, but the sinking is stopped by the spacer 22 that was placed around the first rod-shaped bodies 12. By cooling in this state, a layer of resin 15 is formed on the top of the first rod-shaped bodies 12. The pressing of the flat plate 21 can be performed using, for example, a press pressure device.

[0107] FIG. 47 shows a flat block 23 in which a plurality of first rod-shaped bodies 12 are fixed together with resin to form an integrated block. The plurality of first rod-shaped bodies 12 extend in a first direction D1. In the flat block 23, the resin filled between adjacent first rod-shaped bodies 12 spreads into a resin layer above the first rod-shaped bodies 12, forming a flat resin surface. In the above description, the resin is filled in the form of powder, but the resin may be filled by placing a thermoplastic resin sheet over the plurality of first rod-shaped bodies 12 aligned at regular intervals and heating and melting the resin while applying a flat press.

[0108] The number of element body precursors 13 included in the flat block 23 in FIG. 47 is greater than the number of element body precursors 13 included in the flat block 23 in FIG. 11 of the first embodiment. This difference is due to the addition of a step of rotating the first rod-shaped body by 90 degrees as shown in FIG. 43. The thickness of the flat block 23 is the longitudinal dimension of the element body precursor 13, not the width dimension, so the number of element body precursors in the same flat block size increases. In other words, according to this embodiment, the element body precursors 13 can be densely arranged in a plan view. In this embodiment, the step of rotating the first rod-shaped body 12 is added, but since the number of element body precursors 13 stored in the flat block 23 is large, the efficiency of the cutting step can be improved. As a result, it is possible to improve the manufacturing efficiency of multilayer ceramic electronic components and reduce the burden of manufacturing costs.

[0109] Next, as shown in Fig. 48, the flat block 23 is cut to a predetermined size to produce a plurality of second rod-shaped bodies 24. The cut surfaces of the second rod-shaped bodies 24 correspond to the side surfaces 9 of the element precursor 13, and the internal electrodes 5 are exposed. At this point, the individual multilayer ceramic electronic components become the element precursors 13 shown in Fig. 3. The flat block 23 may be cut using a press cutter blade 37 as shown in Fig. 48.

[0110] Next, as shown in Fig. 49, the second rod-shaped bodies 24 are rotated 90 degrees around their respective axes so that the cut surfaces (surfaces on which the internal electrodes 5 are exposed) resulting from the second cut face face upward. To face upward, the elongated second rod-shaped bodies can be rotated 90 degrees around the longitudinal axis of the elongated second rod-shaped bodies by using magnetic force or by rolling the second rod-shaped bodies between elastic plates, as in the case of rotating the first rod-shaped bodies described above.

[0111] Next, surface debris from side surface 9, which is the open surface in Fig. 49, is cleaned. As already explained in Fig. 15, this may be done by a polishing method as shown in Fig. 15. Alternatively, other methods such as etching cleaning or blast cleaning may be used. If there is no surface debris on side surface 9, it is possible to skip the cleaning step.

[0112] The subsequent steps are to form a protective layer on the surface of the side surface 9, and the subsequent steps are also similar to the process described in FIG. 21 and subsequent figures of the first embodiment, so a description thereof will be omitted.

[0113] According to the method for manufacturing a multilayer ceramic electronic component of the present disclosure, the handleability of the element component can be improved, which in turn improves product quality and reduces manufacturing costs.

[0114] The methods, devices, materials, etc. used in each embodiment are not limited to the embodiment, and may be used in combination. In the examples, the protective layer is made of the same material as the ceramic green sheet of the dielectric material, but other materials may be used as long as the insulation is ensured. In addition, although omitted in the examples, a release sheet or a release agent may be sandwiched between the flat plate or frame in contact with the resin so as to facilitate release from the resin. In addition, for example, the ceramic green sheet or the flat plate-like assembly to which the ceramic slurry is applied as the protective layer may be cut before firing, or the flat plate-like assembly may be polished and then washed. In this way, changing the processing conditions of each embodiment or adding a new process to each embodiment does not affect the gist of the present disclosure. [Explanation of symbols]

[0115] 1. Multilayer ceramic capacitors 2. Base parts 3 External electrode 5 Internal electrode 6 Protective layer 7 Main Surface 7a 1st principal surface 7b Second main surface 8 End face 8a 1st end face 8b 2nd end face 9. Side 9a 1st side 9b Second side 10 Ceramic green sheet 11 Mother laminate 12 First rod-shaped body 13. Primer 14 Adhesive expansion sheet 15 Resin 16 Resin powder 17 flat bottom plate 18 Support Sheet 19 Resin base 21 flat plate 21a First Plate 21b Second Plate 22 Spacer 23 Flat block 24 Second rod-shaped body 25 Frame board 27 Tabular aggregate 27a 1st page 27b 2nd side 28 Polishing machine 29 Ceramic Slurry 31 void 32 Separation crack line 33 Transfer roller 34 Heater roller 35 Base material 36 Resin sheet 37 Push-cutting blade

Claims

1. cutting a base laminate in which the ceramic green sheets and the electrode layers are alternately laminated at predetermined intervals to form a plurality of first rod-shaped bodies extending in a first direction; disposing a resin on at least one surface of each of the first rod-shaped bodies and between adjacent first rod-shaped bodies to form a flat block in which the first rod-shaped bodies are fixed to each other; cutting the flat block at predetermined intervals in a second direction perpendicular to the first direction to form a plurality of second rod-shaped bodies in which a plurality of element precursors are aligned in a line; performing a processing process on a cut surface of each of the second rod-shaped bodies to convert the plurality of element precursors into a plurality of element parts; a method for manufacturing a multilayer ceramic electronic component, comprising firing the plurality of element components to sinter the plurality of element components and removing the resin, The method for manufacturing a laminated ceramic electronic component includes heating a resin powder disposed on at least one surface of each of the first rod-shaped bodies and between adjacent first rod-shaped bodies, and melting at least a portion of the resin powder, the resin being a thermoplastic resin.

2. 2. The method for producing a multilayer ceramic electronic component according to claim 1, further comprising the steps of: cutting the base laminate; arranging the first rod-shaped bodies on an adhesive expansion sheet; and expanding the adhesive expansion sheet to form gaps between adjacent first rod-shaped bodies in which the resin is disposed.

3. cutting a base laminate in which ceramic green sheets and electrode layers are alternately laminated at predetermined intervals to form a plurality of first rod-shaped bodies extending in a first direction and each of the first rod-shaped bodies having a first main surface, a second main surface opposite to the first main surface, a first cut surface, and a second cut surface opposite to the first cut surface; aligning the first rod-shaped bodies with a certain gap therebetween, and disposing a resin in the gap to form a flat block in which the first rod-shaped bodies are fixed to one another; cutting the flat block at predetermined intervals in a second direction perpendicular to the first direction to form a plurality of second rod-shaped bodies in which a plurality of element precursors are aligned in a line; performing a processing process on a cut surface of each of the second rod-shaped bodies to convert the plurality of element precursors into a plurality of element parts; a method for manufacturing a multilayer ceramic electronic component, comprising firing the plurality of element components to sinter the plurality of element components and removing the resin, The method for manufacturing a laminated ceramic electronic component includes heating a resin powder disposed between adjacent first rod-shaped bodies, and melting at least a portion of the resin powder, the resin being a thermoplastic resin.

4. 4. The method for manufacturing a laminated ceramic electronic component according to claim 3, further comprising aligning the first rod-shaped bodies so that the first main surfaces are flush with each other and the first cut surface of each first rod-shaped body faces the second cut surface of the first rod-shaped body adjacent to the first rod-shaped body, and then disposing a resin in the gaps to form the flat block.

5. 4. The method for manufacturing a laminated ceramic electronic component according to claim 3, further comprising aligning the first rod-shaped bodies so that the first cut surfaces are flush with each other and the first main surface of each first rod-shaped body faces the second main surface of the first rod-shaped body adjacent to the first rod-shaped body, and then disposing a resin in the gaps to form the flat block.

6. 6. The method for producing a multilayer ceramic electronic component according to claim 1, further comprising the steps of: while the resin is at least partially molten, positioning a mold member having a flat surface such that the flat surface faces the flat block, and pressing the mold member against the flat block to flatten a surface of the resin.

7. 7. The method for producing a multilayer ceramic electronic component according to claim 1, wherein the melting point of the resin is equal to or lower than a decomposition temperature of a binder contained in the ceramic green sheets and the electrode layers.

8. The method for manufacturing a multilayer ceramic electronic component according to any one of claims 1 to 7, further comprising the steps of: preparing a flat plate before performing the processing; aligning each of the second rod-shaped bodies on the flat plate so that the cut surface is in contact with a surface of the flat plate; and bringing adjacent second rod-shaped bodies into contact with each other to form a flat plate-shaped assembly in which the plurality of second rod-shaped bodies are integrated.

9. 9. The method for producing a multilayer ceramic electronic component according to claim 8, wherein the plate-like assembly is heated and then cooled, and adjacent second rod-like bodies are bonded to each other with the resin.

10. 10. The method for producing a multilayer ceramic electronic component according to claim 8, wherein the processing step includes polishing or grinding the plate-like assembly.

11. 11. The method for producing a multilayer ceramic electronic component according to claim 8, wherein the processing step includes contacting a ceramic green sheet having a predetermined thickness with a first surface of the flat plate-like assembly.

12. 11. The method for producing a multilayer ceramic electronic component according to claim 8, wherein the processing treatment includes contacting a ceramic green sheet having a predetermined thickness with a first surface of the flat plate-like assembly and a second surface opposite to the first surface.

13. 11. The method for producing a multilayer ceramic electronic component according to claim 8, wherein the processing comprises applying a ceramic slurry to a predetermined thickness on a first surface of the flat plate-like assembly and a second surface opposite to the first surface, and drying the applied ceramic slurry.

14. 11. The method for producing a multilayer ceramic electronic component according to claim 8, wherein the processing step includes immersing the plate-like assembly in a ceramic slurry, then removing the plate-like assembly from the slurry, and drying the plate-like assembly.

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