Cutting method and method for manufacturing a multilayer ceramic component

Abstract

In the present invention, a mother laminate is cut by arranging the mother laminate on a pedestal and moving a cutting blade having a linear cutting edge through the mother laminate in a parallel direction along the arrangement surface of the pedestal, where the cutting edge is tilted relative to the travel direction thereof.

Description

Technical Field

[0001] The present disclosure relates to a cutting method and a method for manufacturing a multilayer ceramic component.

Background Art

[0002] An example of the prior art is described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The cutting method for a multilayer component of the present disclosure arranges a mother laminate in which a ceramic green sheet and an electrode layer are alternately laminated on a pedestal, and moves a cutting blade having a linear cutting edge in a parallel direction along the placement surface of the pedestal in a state where the cutting edge is inclined with respect to the traveling direction to cut the mother laminate.

[0005] The manufacturing method for a multilayer ceramic component of the present disclosure includes the above cutting method, After forming a protective layer on the surface of the green component obtained by cutting, the green component is fired.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0007] The object, features, and advantages of the present disclosure will become clearer from the following detailed description and drawings.

[0008] An example of the configuration on which the present disclosure is based is described in Patent Document 1. In recent years, with the miniaturization and high functionality of electronic devices, miniaturization of electronic components mounted on electronic devices has been demanded. As an example of such an electronic component, a multilayer ceramic capacitor can be mentioned. In multilayer ceramic capacitors, products with a side length of 1 mm or less have become mainstream. In multilayer ceramic capacitors, in order to improve the capacitance per unit volume, it is important to thin the dielectric between the internal electrode layers, reduce the margin portion for protecting the inside, and increase the area ratio of the internal electrode layers.

[0009] In the manufacturing method described in Patent Document 1, a mother laminate formed by laminating a ceramic green sheet and a conductive film is cut, and individual laminates with the conductive film exposed on the cut surface are cut out. A ceramic paste is applied to the cut surface of the cut-out laminate to provide a thin protective portion as a margin portion.

[0010] In the die cutting, which is the manufacturing method described in Patent Document 1, in the final stage of cutting where the cutting blade approaches the lower surface, cracks occur toward the lower surface of the laminate, generating microcracks on the cut surface. Also, when trying to reduce the influence of the cutting blade by thinning the thickness of the cutting blade, the cutting blade escapes outward during cutting, and the cut surface is curved irregularly and cut obliquely.

[0011] Hereinafter, embodiments of the cutting method of the present disclosure and the manufacturing method of the multilayer ceramic component will be described with reference to the drawings. In the following, a multilayer ceramic capacitor will be described as an example of the multilayer ceramic component. However, the multilayer ceramic component targeted by the present disclosure is not limited to the multilayer ceramic capacitor, and can also be applied to various multilayer ceramic components such as multilayer piezoelectric elements, multilayer thermistor elements, multilayer chip coils, and ceramic multilayer substrates.

[0012] First, a multilayer ceramic capacitor, which is an example of the multilayer ceramic component, will be described. FIG. 1 is a perspective view of an example of the multilayer ceramic capacitor. FIG. 2 is a perspective view schematically showing the body component of the multilayer ceramic capacitor in FIG. 1. FIG. 2 shows the body component before firing. Note that although the body component after firing has shrunk due to firing, since it has the same structure as the body component before firing, it can also be said that FIG. 2 shows the body component after firing. FIG. 3 is a perspective view showing the precursor of the body component in FIG. 2. Hereinafter, the precursor of the body component may be referred to as the body precursor.

[0013] The multilayer ceramic capacitor 1 has a body component 2 and an external electrode 3. As shown in FIG. 2, the body component 2 has a substantially rectangular parallelepiped shape. The body component 2 is made of dielectric ceramics 4 and has a plurality of internal electrode layers 5 connected to the external electrode 3. The external electrode 3 is disposed on a pair of end faces of the body component 2 and wraps around to other adjacent faces. The plurality of internal electrode layers 5 extend inward from a pair of end faces of the body component 2 and are alternately laminated without contacting each other.

[0014] The external electrode 3 is composed of an underlayer connected to the body component 2 and a plating outer layer that facilitates soldering of the external wiring to the external electrode 3. The underlayer may be applied and baked on the body component 2 after firing. The underlayer may be disposed on the body component 2 before firing and fired simultaneously with the body component 2. The underlayer and the plating outer layer may be multiple layers according to the required functions. The external electrode 3 may be composed of an underlayer and a conductive resin layer without having a plating outer layer.

[0015] As shown in FIGS. 2 and 3, the body component 2 has a body precursor 13 and a protective layer 6. As shown in FIG. 3, the body precursor 13 has a substantially rectangular parallelepiped shape. The body precursor 13 has main surfaces 7 facing each other, end surfaces 8 facing each other, and side surfaces 9 facing each other.

[0016] The internal electrode layer 5 is exposed on the end surfaces 8 and side surfaces 9 of the body precursor 13. The protective layer 6 is disposed on the side surface 9 of the body precursor 13. The protective layer 6 suppresses the electrical short - circuit between the internal electrode layer 5 exposed on one end surface 8 and the internal electrode layer 5 exposed on the other end surface 8. Also, the protective layer 6 physically protects the portion of the internal electrode layer 5 exposed on the side surface 9 of the body precursor 13. The protective layer 6 is attached last in manufacturing the body component 2. The protective layer 6 protects the internal electrode layer 5 exposed on the side surface 9 of the body 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 insulation and high mechanical strength. The ceramic material that becomes the protective layer 6 is usually disposed on the body precursor 13 before firing. In FIG. 2, the boundary between the body precursor 13 and the protective layer 6 is shown by a two - dot chain line, but the actual boundary is not clearly shown.

[0017] In the above, in addition to the body component 2, the body precursor 13 which is its precursor is also described. In the present disclosure, the “laminated component” includes both the body component 2 and the body precursor 13.

[0018] Hereinafter, the manufacturing method of the body component 2 and the multilayer ceramic capacitor 1 in FIG. 2 will be described. First, a ceramic mixed powder obtained by adding an additive to BaTiO3, which is a ceramic dielectric material, is wet - pulverized and mixed with a bead mill. A polyvinyl butyral - based binder, a plasticizer, and an organic solvent are added to and mixed with this pulverized and mixed slurry to produce a ceramic slurry.

[0019] Next, using a die coater, the ceramic green sheet 10 is formed on the carrier film. The thickness of the ceramic green sheet 10 may be, for example, about 1 to 10 μm. The thinner the thickness of the ceramic green sheet 10, the higher the capacitance of the multilayer ceramic capacitor can be. The formation of 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.

[0020] Next, as shown in FIG. 4, a conductive paste to be the internal electrode layer 5 is printed in a predetermined pattern on the ceramic green sheet 10 created above using the screen printing method. The printing of the conductive paste is not limited to the screen printing method, and may be performed using, for example, a gravure printing method. The conductive paste may contain, for example, metals such as Ni, Pd, Cu, Ag, or alloys thereof. In the figure, an example in which the pattern of the internal electrode layer 5 is a multi-row strip pattern is shown, but the pattern of the internal electrode layer 5 may be, for example, a pattern such as an individual electrode pattern.

[0021] After printing, the conductive paste is dried. Since mainly the solvent component volatilizes by drying, the internal electrode layer 5 after drying is in a state where nickel particles are dispersed in the organic binder. As long as the characteristics as a capacitor can be ensured, the thinner the thickness of the internal electrode layer 5, the more internal defects due to internal stress can be prevented. For a capacitor with a high number of stacked layers, the thickness of the internal electrode layer 5 may be, for example, 2.0 μm or less.

[0022] Next, as shown in FIG. 5, a predetermined number of ceramic green sheets 10 with the internal electrode layer 5 printed thereon are stacked on top of a predetermined number of stacked ceramic green sheets 10, and further, a predetermined number of ceramic green sheets 10 are stacked. The ceramic green sheets 10 with the internal electrode layer 5 printed thereon are stacked in a predetermined number while shifting the pattern of the internal electrode layer 5. Although omitted in FIG. 5, the stacking of the ceramic green sheets 10 is performed on a support sheet. The support sheet may be an adhesive release sheet capable of adhesion and release, such as a weakly adhesive sheet or a foamed release sheet.

[0023] Next, a laminate formed by stacking a plurality of ceramic green sheets 10 is pressed in the stacking direction to obtain an integrated mother laminate 11 as shown in FIG. 6. The pressing of the laminate can be performed, for example, using a hydrostatic press device. Inside the mother laminate 11, the internal electrode layer 5 is embedded in layers with the ceramic green sheet 10 sandwiched therebetween. When the mother laminate 11 is cut longitudinally and transversely, it becomes the green body precursor 13 shown in FIG. 3. Since the main surface, end surface, and side surface of the mother laminate 11 respectively correspond to the main surface 7, end surface 8, and side surface 9 of the green body precursor 13, the same reference numerals will be used hereinafter. The dashed lines shown in FIG. 6 are cutting lines indicating the positions where cutting is planned. The mother laminate 11 is cut along each cutting line using a cutting blade 14. The mother laminate 11 is handled while being disposed on the support sheet 18, and the cutting is also performed on the support sheet 18.

[0024] The mother laminate 11 is cut at regular intervals using a shearing cut method. FIG. 7 is a schematic diagram showing the state of cutting along the cutting line shown by VII-VII in FIG. 6. In the present embodiment, the mother laminate 11 is placed on the pedestal 19, and the cutting blade 14 having a linear cutting edge 14a is moved through the mother laminate 11 with the cutting edge 14a inclined with respect to the traveling direction to cut the mother laminate 11. The traveling direction of the cutting blade 14 is indicated by an arrow A in FIG. 7. In the cutting method of the present embodiment, the mother laminate 11 is cut by moving the cutting blade 14 along a direction parallel to the placement surface of the pedestal 19 on which the mother laminate 11 is placed. The traveling direction of the cutting blade 14 is along the direction of the placement surface of the pedestal 19. When the pedestal 19 is installed such that the placement surface is parallel to the horizontal direction, the traveling direction of the cutting blade 14 is the horizontal direction. Thus, the cutting method of the present embodiment is not a conventional pressing cut method in which the cutting blade is moved toward the placement surface of the pedestal 19, but a shearing cut method in which the cutting blade 14 is moved along the placement surface of the pedestal 19. Since the mother laminate 11 is usually flat, when the cutting edge 14a is inclined with respect to the traveling direction, the cutting edge 14a of the cutting blade 14 cuts the mother laminate 11 in a state inclined with respect to the main surface 7 of the mother laminate 11. The cutting edge 14a of the cutting blade 14 is inclined such that the upper side is located in front of the traveling direction of the cutting blade 14 and the lower side is located behind the traveling direction.

[0025] According to the cutting method of the present embodiment, the mother laminate 11 can be cut with a relatively weak force, and the stress on the cut surface can be reduced. As a result, deformation due to cutting and short-circuiting of the internal electrode layer 5 on the cut surface are reduced.

[0026] In the mother laminate 11, the ceramic green sheet 10 is composed of a resin binder that can be cut by the cutting blade 14 and ceramic particles dispersed therein that cannot be cut by the cutting blade 14. Similarly, the internal electrode layer 5 is also composed of a resin binder that can be cut and metal particles that cannot be cut. In the case of conventional pushing cutting, the cutting edge 14a of the cutting blade 14 is perpendicular to the advancing direction. In the uncut portion located in front of the cutting edge 14a advancing within the ceramic green sheet 10, there is a sparse region where the resin binder expanded by the thickness of the cutting blade 14 extends and the ceramic particles are sparse. When the cutting edge 14a hits the ceramic particles, the ceramic particles are pushed in the advancing direction by the cutting blade 14 without being cut. The pushed ceramic particles are pushed into the uncut portion in front, and the repulsive force thereof becomes the resistance to cutting. In the cutting method of the present embodiment, the cutting edge 14a of the cutting blade 14 is inclined with respect to the advancing direction, and the sparse region where the particles are sparse is also inclined along the cutting edge 14a. When the cutting edge 14a hits the ceramic particles, the ceramic particles are pushed by the cutting blade 14 without being cut. At this time, since the ceramic particles have room to move in an oblique direction along the sparse region, they can escape from the approaching cutting edge, the repulsive force by the ceramic particles is dispersed, and the resistance to cutting becomes small. The internal electrode layer 5 is the same as or similar to the ceramic green sheet 10. By such a mechanism, the cutting method of the present embodiment can cut the mother laminate 11 with a weaker force compared to conventional pushing cutting.

[0027] As the material of the cutting blade 14, for example, silicon, carbon steel containing manganese, or cemented carbide obtained by mixing tungsten carbide and cobalt and sintering them can be used. Further, other components may be included in order to increase the hardness, flexural strength, and fracture toughness.

[0028] In the present embodiment, for example, the mother laminate 11 is cut along one cutting line by the cutting blade 14, then cut along the adjacent cutting line, and this is repeated until cutting is completed at all the cutting lines.

[0029] The tip (cutting edge) of the cutting blade 14 may slide on the placement surface of the pedestal 19, but moving through the support sheet 18 as in this embodiment can reduce damage to the placement surface of the pedestal 19 or wear of the tip of the cutting blade 14.

[0030] In the cutting method of this embodiment, the angle (inclination angle) b formed between the cutting edge 14a of the cutting blade 14 and the advancing direction is, for example, 15° to 80°. The inclination angle b may be appropriately set according to the thickness, material, etc. of the mother laminate 11.

[0031] The tip of the cutting blade 14 may be, for example, a pointed shape. The angle a of the tip when the cutting blade 14 is viewed from the side is, for example, 30° to 75°. If the tip angle of the cutting blade 14 is less than 30°, the cutting blade 14 becomes thin and the thickness has to be increased to ensure rigidity. If the tip angle of the cutting blade 14 is greater than 75°, the contact area between the cutting surface and the blade surface becomes large during cutting, and the frictional force with the cutting surface becomes large. The shape on the peak side of the cutting blade 14 is not particularly limited and may be a curved shape or a shape that forms part of a polygon.

[0032] The thickness of the cutting blade 14 is preferably thin, and the longer the length of the cutting edge 14a, the better. In the case of shearing, it can be cut with a relatively weak force, so the thickness of the cutting blade 14 can be, for example, 100 μm or less. The cutting blade 14 may be a single-edge blade or a double-edge blade, but a double-edge blade is desirable. In the case of a single-edge blade, the contact area where the flat side contacts the cutting surface becomes large, so the frictional force with the cutting surface becomes large. Also, in the case of a double-edge blade, it is preferably a so-called clam blade in which the cross-section of the cutting edge bulges outward. By doing so, the contact area with the cutting surface is small and the rigidity is improved.

[0033] Also, the pedestal 19 may incorporate a heater 20. The mother laminate 11 arranged on the pedestal 19 is heated by the heater 20, so that the resin binder in the mother laminate 11 softens, making it easier to cut and also enabling adaptation to deformation during cutting, so a smooth cutting surface can be obtained.

[0034] FIG. 8 is a schematic view of the cutting state as seen from the moving direction side of the cutting blade 14. At the time of cutting, the uncut portion of the mother laminate 11 may be sandwiched and fixed between the pedestal 19 and the pressing plate 21. When the uncut portion is fixed, even if stress is applied by the cutting blade 14 during cutting, the uncut portion does not move, and it is possible to prevent the cut surface from becoming irregular. Further, the surface of the pressing plate 21 that contacts the mother laminate 11 may be a concavo-convex surface with a surface roughness Ra of 5 μm or more. Such a concavo-convex surface can surely fix the uncut portion.

[0035] Furthermore, a magnet may be provided on the pedestal 19. The magnet may be, for example, an electromagnet. When the material of the cutting blade 14 is a magnetic material such as carbon steel containing silicon and manganese, the tip of the cutting blade 14 is magnetically attracted to the pedestal 19, and it is possible to prevent the cutting blade 14 from deflecting during cutting. When the internal electrode layer 5 of the mother laminate 11 is a ferromagnetic material such as nickel-containing substances, the mother laminate 11 during cutting can be magnetically attracted and fixed to the pedestal 19.

[0036] Another embodiment will be described. The above-described embodiment is a cutting method in which a plurality of cuts are repeated using one cutting blade 14 to cut along all the cutting lines of the mother laminate 11. In this embodiment, as shown in FIG. 9, a plurality of cutting blades 14 are arranged at regular intervals in a direction perpendicular to the moving direction and held by a holding member, and cutting is performed by moving the holding member. Thereby, a plurality of cuts can be made simultaneously in one cutting operation.

[0037] Furthermore, the plurality of arranged cutting blades 14 may be held by a holder 16, which is a holding member, at positions shifted in the moving direction. When cutting simultaneously with a plurality of cutting blades 14, if the cutting blades 14 are at the same position in the moving direction, the portion of the mother laminate 11 to be cut is compressed by forces applied in opposite directions by the two cutting blades 14 during cutting. If the interval between the cutting blades 14 held by the holder 16 is small, it will be greatly deformed by the compression. By setting the cutting blades 14 at positions shifted in the moving direction, only the force by one cutting blade 14 is applied during cutting, and deformation due to compression can be suppressed. In the example shown in FIG. 9, the cutting blades 14 held by the holder 16 are all held at shifted positions. As another example, the cutting blades 14 may be arranged in a staggered pattern with a shift every other one as long as the positions of adjacent cutting blades 14 are shifted in the moving direction since the cutting blades 14 held by the holder 16 only need to be shifted in the moving direction relative to each other.

[0038] As shown in FIG. 10, by cutting the mother laminate 11 by the cutting method of the present embodiment, a plurality of first rod-shaped bodies 12 are obtained. The cut surface of the first rod-shaped body 12 is a surface corresponding to the side surface 9 of the base precursor 13, and the internal electrode layer 5 is exposed. In the present disclosure, the cutting of the mother laminate 11 for obtaining a plurality of first rod-shaped bodies 12 may be referred to as the first cutting.

[0039] After the cutting is completed, as shown in FIG. 11, the plurality of first rod-shaped bodies 12 are each rotated 90 degrees around the axis in the longitudinal direction so that the cut surfaces where the internal electrode layer 5 is exposed are aligned upward.

[0040] Since the directions of the cut surfaces of the respective first rod-shaped bodies 12 are aligned upward, a ceramic slurry can be uniformly applied to the cut surfaces of the plurality of first rod-shaped bodies 12. After the ceramic slurry is dried, the ceramic slurry is further uniformly applied to the cut surfaces on the opposite sides of the first rod-shaped bodies 12 as well. As shown in FIG. 12, a protective layer 6 can be formed by applying the ceramic slurry to the cut surfaces of the respective first rod-shaped bodies 12. The ceramic slurry that becomes the protective layer 6 may be of the same composition as the ceramic green sheet 10 constituting the mother laminate 11.

[0041] After forming the protective layer 6, each first rod-shaped body 12 is cut in a direction orthogonal to the first cutting to obtain a body part 2 as shown in FIG. 13. After firing the body part 2 thus obtained, an external electrode 3 can be formed to manufacture the multilayer ceramic capacitor 1. The firing temperature can be appropriately set according to the ceramic material contained in the ceramic green sheet 10 that becomes the dielectric ceramics 4 and the metal material contained in the conductive paste that becomes the internal electrode layer 5. The firing temperature may be, for example, 1100 to 1250°C.

[0042] As described above, in the cutting of the mother laminate 11, deformation due to cutting and short-circuiting of the electrode layer on the cut surface are reduced, so the yield in the manufacture of the multilayer ceramic capacitor 1 is improved.

[0043] Next, another manufacturing method of the body part 2 and the multilayer ceramic capacitor 1 will be described. Since the procedure for producing the mother laminate 11 is the same as the above-described manufacturing method, the description is omitted. The mother laminate 11 is cut by the first cutting using a cutting machine to obtain a plurality of first rod-shaped bodies 12. The cutting here may use the cutting method according to each of the above-described embodiments, or may be other cutting methods such as dicing cutting or pushing cutting. As shown in FIG. 14, in the manufacturing method of this example, the cutting direction in the first cutting is different by 90° from that of the first rod-shaped body 12 described above, and the cut surface of the first rod-shaped body 12 in this example is a surface corresponding to the end face 8 of the body precursor 13. After cutting, a certain interval is provided between adjacent first rod-shaped bodies 12.

[0044] As shown in FIG. 15, a thermoplastic resin sheet 36 and a flat plate 22 are placed so as to cover the upper surfaces of the plurality of first rod-shaped bodies 12 and heated under pressure. The resin sheet 36 melts by heating and flows into the gaps between the first rod-shaped bodies 12. Note that frame-shaped or columnar spacers 25 are arranged on the surface of the pedestal 19 to define the interval between the pedestal 19 and the flat plate 22. By arranging the spacers 25, it is possible to prevent the melted resin sheet 36 from being extruded more than necessary by the flat plate 22, and a part of the melted resin sheet 36 remains on the upper surface of the first rod-shaped body 12.

[0045] After melting the resin sheet 36 and then cooling it, the gaps between the first rod-shaped bodies 12 are filled with the thermoplastic resin 15, and a flat laminated body block 23 in which the upper surfaces of the first rod-shaped bodies 12 are covered with the thermoplastic resin 15 is obtained. FIG. 16 is a cross-sectional view of the flat laminated body block 23, and FIG. 17 is a perspective view of the flat laminated body block 23. The flat laminated body block 23 is a flat block in which a plurality of first rod-shaped bodies 12 that are laminated bodies are aligned in direction and fixed with resin.

[0046] Next, the flat laminated body block 23 is cut using the cutting method of the present embodiment. The cutting here is performed in a direction perpendicular to the first cutting, and the cutting surface becomes a surface corresponding to the side surface 9 of the base precursor 13. As shown in FIG. 18, similar to or the same as the aforementioned cutting method, the cutting edge 14a of the cutting blade 14 used is linear, and the cutting blade 14 is moved in a state where the cutting edge 14a is inclined at an inclination angle b with respect to the traveling direction. The traveling direction of the cutting blade 14 is indicated by an arrow A in FIG. 18. When the cutting edge 14a is inclined with respect to the traveling direction, the cutting edge 14a of the cutting blade 14 cuts the flat laminated body block 23 in a state inclined with respect to the main surface. The inclination angle b is, for example, 15° to 80°.

[0047] FIG. 19 is a schematic view of the cutting state as viewed from the moving direction side of the cutting blade 14. The upper and lower end portions of the cutting blade 14 are fixed to holders 16 that are fixing members in a state where the cutting edge 14a is inclined, and both holders 16 move synchronously. When the holders 16 move to cut the flat laminated body block 23, the cutting blade 14 is returned to the position before cutting, and the flat laminated body block 23 is fed out toward the holders 16 by a predetermined distance by a pusher 17, and the next cutting is performed.

[0048] Since the flat laminate block 23 is a block fixed with the thermoplastic resin 15, the force required for cutting is greater than when cutting the mother laminate 11. Since both the upper and lower ends of the cutting blade 14 in the vertical direction are fixed to the holder 16, even in a cutting that requires a relatively large force, there is no vibration of the cutting blade 14, there is little deformation, and a smooth cut surface can be obtained. Further, at the time of cutting, the uncut portion of the flat laminate block 23 may be sandwiched and fixed between the pedestal 19 and the pressing plate 21. The pedestal 19 may incorporate a heater 20.

[0049] As shown in FIG. 20, by cutting the flat laminate block 23 by the cutting method of the present embodiment, a plurality of second rod-shaped bodies 24 are obtained. The cut surface of the second rod-shaped body 24 corresponds to the side surface 9 of the elementary body precursor 13. The second rod-shaped body 24 has a structure in which the elementary body precursor 13 is connected with the thermoplastic resin 15.

[0050] After the cutting is completed, the plurality of second rod-shaped bodies 24 are each rotated 90 degrees around the longitudinal axis so that the cut surfaces where the internal electrode layers 5 are exposed face upward. After the orientations of the second rod-shaped bodies 24 are aligned, the plurality of second rod-shaped bodies 24 are assembled to form a component assembly 27. For example, the jig 26 is horizontally moved from the outer sides in the left-right direction of the gap toward the center. As shown in the perspective view of FIG. 21, the jig 26 is an L-shaped mold, and by the two jigs 26, the plurality of second rod-shaped bodies 24 are respectively positioned in the longitudinal direction and the direction perpendicular to the longitudinal direction to form a plate-shaped component assembly 27.

[0051] Next, as shown in FIG. 22, a ceramic green sheet 10 serving as the protective layer 6 is disposed on the upper and lower surfaces of the component assembly 27. The ceramic green sheet 10 may be disposed on the upper and lower surfaces of the component assembly 27 at once. When the ceramic green sheet 10 does not have a strength that allows it to be handled alone, the ceramic green sheet 10 may be disposed on each side of the component assembly 27 one by one instead of disposing it on both sides at once.

[0052] Next, a hydrostatic press is applied to the component assembly 27 with the ceramic green sheet 10 disposed on the upper and lower surfaces to closely adhere the ceramic green sheet 10 that becomes the protective layer 6. In the component assembly 27 shown in Fig. 23, the extra portion (outer peripheral portion) of the ceramic green sheet 10 has been cut off. At this point, the individual multilayer ceramic components have the same or similar configuration as the green body component 2 with the ceramic green sheet 10 that becomes the protective layer 6 disposed on the green body precursor 13 shown in Fig. 3.

[0053] Next, the component assembly 27 with the ceramic green sheet 10 is subjected to a debinding process and a firing process. First, the component assembly 27 is placed on a zirconia plate, and the plate on which the component assembly 27 is placed is put into a debinding furnace to remove the solvent and the binder, and then fired in a high-temperature firing furnace. The firing temperature can be appropriately set according to the ceramic material contained in the ceramic green sheet 10 that becomes the dielectric ceramics 4 and the metal material contained in the conductive paste that becomes the internal electrode layer 5. The firing temperature may be, for example, 1100 to 1250 °C.

[0054] Fig. 24 is a perspective view schematically showing the component assembly 27 after firing. As shown in Fig. 24, the thermoplastic resin 15 that surrounded the green body component 2 decomposes and burns away. Therefore, the space between the green body components 2 where the thermoplastic resin 15 was filled becomes a void 31, and the green body component 2 composed of the protective layer 6 and the green body precursor 13 is in a connected state. Also, in the protective layer 6, a split line 32 occurs at the portion located in the void 31 between the green body components 2. As a result, the green body components 2 are substantially individually divided. As the green body components 2 shrink during the sintering process and the space between the green body components 2 expands, cracks occur in the thin portion of the sintered protective layer 6 between the green body components 2, and the split line 32 is formed.

[0055] For the fired green body part 2, barrel polishing is performed. The barrel polishing is performed for the purpose of removing the corners and burrs of the green body part 2, and a known barrel polishing method can be used. In this embodiment, for example, the green body part 2 divided by the dividing line 32 and the abrasive are placed in a pot filled with water and rotated for polishing. FIG. 25 is a perspective view showing the green body part 2 after barrel polishing. As shown in FIG. 25, in the green body part 2 after barrel polishing, the burrs of the protective layer 6 are removed and the corners of the green body part 2 are rounded off.

[0056] As described above, the green body part 2 can be manufactured. Further, an external electrode 3 can be formed on the green body part 2 to manufacture the multilayer ceramic capacitor 1.

[0057] As described above, in the cutting of the flat laminated body block 23, deformation due to cutting and short-circuiting of the electrode layer on the cut surface are reduced, so the yield in the manufacture of the multilayer ceramic capacitor 1 is improved.

[0058] The following embodiments are possible for the present disclosure.

[0059] The method for cutting a laminated component of the present disclosure arranges a mother laminate in which a ceramic green sheet and an electrode layer are alternately laminated on a pedestal, and moves a cutting blade having a linear cutting edge in a state where the cutting edge is inclined with respect to the traveling direction in the mother laminate in a parallel direction along the placement surface of the pedestal to cut the mother laminate.

[0060] The method for manufacturing a multilayer ceramic component of the present disclosure includes the above cutting method, and after forming a protective layer on the surface of the green body part obtained by cutting, the green body part is fired.

[0061] According to the cutting method of the present disclosure, the mother laminate can be cut with a relatively weak force, and the stress on the cut surface can be reduced. As a result, deformation due to cutting and short-circuiting of the electrode layer on the cut surface are reduced.

[0062] According to the method for manufacturing a multilayer ceramic component of the present disclosure, the yield is improved.

[0063] The methods, apparatuses, materials, etc. used in each embodiment are not limited to that specific embodiment and may be used in combination. Also, for example, a flat aggregate provided with a ceramic green sheet or ceramic slurry serving as a protective layer may be cut before firing, or may be washed after polishing the flat aggregate. Thus, changing the processing conditions of each embodiment or adding new steps to each embodiment does not affect the gist of the present disclosure in any way.

Explanation of Reference Numerals

[0064] 1 Multilayer ceramic capacitor 2 Body component 3 External electrode 4 Dielectric ceramics 5 Internal electrode layer 6 Protective layer 7 Main surface 8 End face 9 Side surface 10 Ceramic green sheet 11 Mother laminate 12 First rod-shaped body 13 Body precursor 14 Cutting blade 14a Blade tip 15 Thermoplastic resin 16 Holder 17 Pusher 18 Pedestal 18 Support sheet 19 Pedestal 20 Heater 21 Plate 22 Flat plate 23 Flat laminate block 24 Second rod-shaped body 25 Spacer 26 Jig 27 Component assembly 31 Void 32 Division line 36 Resin sheet

Claims

1. A mother laminate in which a ceramic green sheet and electrode layers are alternately laminated is placed on a pedestal, and a cutting blade having a linear cutting edge with a tip angle of 30° to 75° when viewed from the side is used. The cutting method for cutting the mother laminate by moving the cutting blade in a parallel direction along the placement surface of the pedestal in a state where the cutting edge is inclined at an angle of 15° to 80° with respect to the advancing direction, wherein a plurality of the cutting blades are arranged at regular intervals in a direction orthogonal to the moving direction and are located on a holding member and the holding member is moved to perform cutting.

2. The method according to claim 1, wherein the uncut portion of the mother laminate is sandwiched between the pedestal and a pressing plate and cutting is performed.

1.

3. The method according to claim 1 or 2, wherein cutting is performed while the mother laminate is heated.

4. The method according to claim 1 or 2, wherein the pedestal has a magnet.

5. The method according to claim 1 or 2, wherein the plurality of arranged cutting blades are located on the holding member at positions shifted in the moving direction.

6. The method according to claim 1 or 2, wherein upper and lower ends of the cutting blade are respectively fixed to fixing members, and both fixing members move synchronously.

7. The method according to claim 1 or 2, wherein the mother laminate is in a flat plate shape in which a plurality of laminates are aligned in the same direction and fixed with resin.

8. Including the cutting method according to claim 1 or 2, a method for manufacturing a laminated ceramic component, in which a protective layer is formed on the surface of the elementary component obtained by cutting, and then the elementary component is fired. ​

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