Gravure cylinder and method for manufacturing ceramic electronic component

Abstract

This gravure cylinder has a cylindrical or columnar shape, and is provided with a plurality of recessed parts on the outer peripheral surface, the recessed parts holding paste to be transferred to a sheet on which the paste is to be transferred. The plurality of recessed parts each have an electrode cell defining the corresponding recessed part. Let that, on the outer peripheral surface, the rotating direction is defined as Y direction and the direction orthogonal to Y direction is defined as X direction, and that the length in X direction of an outermost electrode cell located outermost on both sides in X direction is defined as Ax and the length in X direction of an inside electrode cell located inside of the outermost electrode cell in X direction is defined as Bx, then the relation of Ax>Bx holds.　

Description

Gravure plate and method for manufacturing ceramic electronic components

[0001] The present invention relates to a gravure plate and a method for manufacturing a ceramic electronic component.

[0002] In manufacturing methods for ceramic electronic components such as multilayer ceramic capacitors, screen printing and gravure printing are generally used. In the latter, in order to transfer the internal electrode material to the dielectric material, a pattern to be printed is formed on a gravure plate for intaglio printing, and processing using the pattern is performed to improve printability (see, for example, Patent Documents 1 and 2).

[0003] JP 2022-128283 A JP 2019-006126 A

[0004] During printing, saddle formation occurs in screen printing, making it difficult to maintain the smoothness and rectangularity of the printed film. Gravure printing improves the smoothness and rectangularity of the printed film to a certain extent, but the smaller the printed shape, the more likely it is that the rectangularity of the printed film will decrease, resulting in a decrease in the cross-sectional area occupation rate of the electrode portion.

[0005] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a gravure plate capable of improving the cross-sectional area occupation rate of the electrode portion, and a method for manufacturing a ceramic electronic component.

[0006] The gravure plate according to the present invention has a cylindrical or columnar shape and is provided on its outer peripheral surface with a plurality of recesses for holding paste to be transferred to a receiving sheet, and a plurality of electrode cells each forming a recess are formed in the recesses. On the outer peripheral surface, the rotation direction is defined as the Y direction, the direction perpendicular to the Y direction is defined as the X direction, and the length in the X direction of the outermost outer electrode cells on both sides in the X direction is defined as A. ｘ and the length in the X direction of the inner electrode cell that is more inward than the outer electrode cell in the X direction is B ｘ In this case, A ｘ >B ｘ The following relationship is established.

[0007] In the above gravure version, A ｘ / Bｘ may be 1.1 or greater.

[0008] In the above gravure version, A ｘ / B ｘ may be 2.0 or less.

[0009] In the gravure plate, the length of the outer electrode cell in the Y direction is A ｙ and the length of the inner electrode cell in the Y direction is B ｙ In this case, A ｙ >B ｙ The following relationship may be established.

[0010] In the above gravure version, A ｙ / B ｙ may be 1.0 or greater.

[0011] In the above gravure version, A ｙ / B ｙ may be 2.0 or less.

[0012] In the XY plane of the gravure plate, the area of ​​the outer electrode cell is S Ａ is the area of ​​the inner electrode cell S Ｂ It may be larger than

[0013] In the above gravure version, S Ａ / S Ｂ may be 1.1 or greater.

[0014] In the above gravure version, S Ａ / S Ｂ may be 4.0 or less.

[0015] In the gravure plate, the depth A of the outer electrode cell ｚ is the depth B of the inner electrode cell ｚ It may be larger than

[0016] In the above gravure version, A ｚ / B ｚ may be 1.0 or greater.

[0017] In the above gravure version, A ｚ / B ｚ may be equal to or less than 3.33.

[0018] In the gravure plate, the recesses may have a size of 1.0 mm or less in the Y direction and 0.5 mm or less in the X direction.

[0019] Another gravure plate according to the present invention is a gravure plate having a cylindrical or columnar shape, and having a plurality of recesses formed on its outer peripheral surface for holding paste to be transferred to a receiving sheet, and a plurality of electrode cells each forming a recess are formed in the recesses, and when the rotation direction on the outer peripheral surface is defined as the Y direction and the direction perpendicular to the Y direction is defined as the X direction, the plurality of electrode cells arranged in the Y direction form two rows, a first row and a second row, and in the X direction, the tip ends of the electrode cells in the first row facing the electrode cells of the second row are positioned closer to the electrode cells of the second row than the tip ends of the electrode cells in the second row facing the electrode cells of the first row, and the tip ends of the electrode cells in the second row facing the electrode cells of the first row are positioned closer to the electrode cells of the first row than the tip ends of the electrode cells in the first row facing the electrode cells of the second row.

[0020] In the gravure plate, the recesses may have a size of 1.0 mm or less in the Y direction and 0.5 mm or less in the X direction.

[0021] The method for manufacturing a ceramic electronic component according to the present invention uses a gravure printing machine including any of the gravure plates described above, a paste supply unit in which the paste is stored, and an impression cylinder that sandwiches the recipient sheet between the gravure plate and the impression cylinder, inserting the recipient sheet between the rotating gravure plate and the impression cylinder, and pressing the recipient sheet toward the gravure plate using the impression cylinder to transfer the paste held in the recesses to the recipient sheet, and stacking the recipient sheets to which the paste has been transferred to obtain a laminate.

[0022] According to the present invention, it is possible to provide a gravure plate capable of improving the cross-sectional area occupation rate of the electrode portion, and a method for manufacturing a ceramic electronic component.

[0023] 1 is a partial cross-sectional perspective view of a multilayer ceramic capacitor; a cross-sectional view taken along line A-A in FIG. 1; a cross-sectional view taken along line B-B in FIG. 1; an enlarged cross-sectional view of the vicinity of an external electrode; a diagram illustrating a flow of a manufacturing method of a multilayer ceramic capacitor; (a) and (b) are diagrams illustrating a lamination step; a schematic diagram showing a gravure printing machine; a perspective view of a gravure plate; an enlarged plan view of one recess; (a) is a diagram illustrating a printing result in 316 size, (b) is a diagram illustrating a printing result in 107 size, (c) is a diagram illustrating a printing result in 105 size, and (d) is a diagram illustrating a printing result in 063 size; a diagram illustrating an XZ cross section; a diagram for explaining the dimensions of each part in each electrode cell of the recess; a diagram for explaining other shapes of each electrode cell; a diagram illustrating the depth of an electrode cell; a schematic plan view of a recess according to a second embodiment; a diagram illustrating Example 1; a diagram illustrating Example 2; a diagram illustrating Example 3; and a diagram illustrating a comparative example.

[0024] Hereinafter, embodiments will be described with reference to the drawings.

[0025] First, an overview of the structure of a multilayer ceramic capacitor 100 manufactured using a gravure printing machine according to an embodiment will be described. FIG. 1 is a partial cross-sectional perspective view of the multilayer ceramic capacitor 100. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1. As illustrated in FIGS. 1 to 3, the multilayer ceramic capacitor 100 includes a laminated chip 10 having a substantially rectangular parallelepiped shape and external electrodes 20a, 20b provided on two opposing end surfaces of the laminated chip 10. Of the four surfaces of the laminated chip 10 other than the two end surfaces, the two surfaces other than the top and bottom surfaces in the stacking direction are referred to as side surfaces. The external electrodes 20a, 20b extend on the top, bottom, and two side surfaces of the laminated chip 10 in the stacking direction. However, the external electrodes 20a, 20b are spaced apart from each other.

[0026] The multilayer chip 10 has a configuration in which dielectric layers 11 containing a ceramic material that functions as a dielectric and internal electrode layers 12 are alternately stacked. The edges of each internal electrode layer 12 are alternately extended to the end face of the multilayer chip 10 on which the external electrode 20a is provided and the end face on which the external electrode 20b is provided. As a result, each internal electrode layer 12 is alternately electrically connected to the external electrode 20a and the external electrode 20b. As a result, the multilayer ceramic capacitor 100 has a configuration in which multiple dielectric layers 11 are stacked with the internal electrode layers 12 interposed therebetween. In addition, in the stacking of the dielectric layers 11 and the internal electrode layers 12, internal electrode layers 12 are arranged on both outermost layers in the stacking direction, and the outermost internal electrode layers 12 are covered by cover layers 13. The cover layers 13 are primarily composed of a ceramic material. For example, the cover layers 13 may have the same or different composition as the dielectric layers 11.

[0027] The size of the multilayer ceramic capacitor 100 is, for example, 0.25 mm in length, 0.125 mm in width, and 0.125 mm in height, or 0.4 mm in length, 0.2 mm in width, and 0.2 mm in height, or 0.6 mm in length, 0.3 mm in width, and 0.3 mm in height, or 1.0 mm in length, 0.5 mm in width, and 0.5 mm in height, or 1.6 mm in length, 0.8 mm in width, and 0.8 mm in height, or 3.2 mm in length, 1.6 mm in width, and 1.6 mm in height, or 4.5 mm in length, 3.2 mm in width, and 2.5 mm in height, but is not limited to these sizes.

[0028] The internal electrode layers 12 are primarily composed of base metals such as nickel (Ni), copper (Cu), and tin (Sn), or alloys thereof. Precious metals such as platinum (Pt), palladium (Pd), silver (Ag), and gold (Au), or alloys containing these metals, may also be used as the primary component of the internal electrode layers 12. The internal electrode layers 12 may also contain ceramic particles, such as co-materials. The average thickness of each internal electrode layer 12 is, for example, 0.5 μm or less, and preferably 0.4 μm or less. The average thickness of each internal electrode layer 12 can be measured by observing the cross section of the multilayer ceramic capacitor 100 with a scanning electron microscope (SEM), measuring the thickness at 10 points for each of 10 different internal electrode layers 12, and deriving the average value of all the measurement points.

[0029] The dielectric layer 11 is, for example, a compound represented by the general formula ABO ３ The main phase is a ceramic material having a perovskite structure represented by the formula: ３－α For example, the ceramic material includes barium titanate (BaTiO ３ ), calcium zirconate (CaZrO ３ ), calcium titanate (CaTiO ３ ), strontium titanate (SrTiO ３ ), magnesium titanate (MgTiO ３ ), Ba that forms a perovskite structure １-ｘ－ｙ Ca ｘ Sr ｙ Ti １－ｚ Zr ｚ O ３ (0≦x≦1, 0≦y≦1, 0≦z≦1) and the like. １-ｘ－ｙ Ca ｘ Sr ｙ Ti １－ｚ Zr ｚ O ３Examples of the ceramic materials include barium strontium titanate, barium calcium titanate, barium zirconate, barium titanate zirconate, calcium titanate zirconate, and barium calcium titanate zirconate. For example, the dielectric layers 11 contain 90 at% or more of the main component ceramic. The average thickness of each dielectric layer 11 is, for example, 1.0 μm or less, and preferably 0.8 μm or less. The average thickness of each internal electrode layer 12 can be measured by observing the cross section of the multilayer ceramic capacitor 100 with a scanning electron microscope (SEM), measuring the thickness at 10 points on each of 10 different dielectric layers 11, and deriving the average value of all the measurement points.

[0030] An additive may be added to the dielectric layer 11. Examples of the additive to the dielectric layer 11 include oxides of zirconium (Zr), hafnium (Hf), magnesium (Mg), manganese (Mn), molybdenum (Mo), vanadium (V), chromium (Cr), rare earth elements (yttrium (Y), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), and ytterbium (Yb)), oxides containing cobalt (Co), nickel (Ni), lithium (Li), boron (B), sodium (Na), potassium (K), or silicon (Si), or glasses containing cobalt, nickel, lithium, boron, sodium, potassium, or silicon.

[0031] 2 , the region where the internal electrode layer 12 connected to the external electrode 20a and the internal electrode layer 12 connected to the external electrode 20b face each other is a region where capacitance is generated in the multilayer ceramic capacitor 100. Therefore, this region where capacitance is generated is referred to as a capacitance portion 14. In other words, the capacitance portion 14 is a region where adjacent internal electrode layers 12 connected to different external electrodes face each other.

[0032] The region where the internal electrode layers 12 connected to the external electrode 20a face each other without an internal electrode layer 12 connected to the external electrode 20b interposed therebetween is called the end margin 15. The region where the internal electrode layers 12 connected to the external electrode 20b face each other without an internal electrode layer 12 connected to the external electrode 20a interposed therebetween is also the end margin 15. In other words, the end margin 15 is the region where the internal electrode layers 12 connected to the same external electrode face each other without an internal electrode layer 12 connected to a different external electrode interposed therebetween. The end margin 15 is a region where no electrical capacitance is generated.

[0033] 3, in the laminated chip 10, the side margins 16 are regions provided so as to cover the ends of the dielectric layers 11 and the internal electrode layers 12 on two side surfaces. In other words, the side margins 16 are regions provided outside the capacitive portions 14 in the width direction of the internal electrode layers 12. The side margins 16 are also regions that do not generate electrical capacitance.

[0034] FIG. 4 is an enlarged cross-sectional view of the vicinity of the external electrode 20a. Hatching is omitted in FIG. 4 . As illustrated in FIG. 4 , a plating layer 22 may be provided on the outer surface of the external electrode 20a, with the external electrode 20a serving as a base layer. The external electrode 20a is primarily composed of Ni or Cu. The external electrode 20a may also contain a glass component. The plating layer 22 is primarily composed of a metal such as Cu, Ni, aluminum (Al), zinc (Zn), or Sn, or an alloy of two or more of these metals. The plating layer 22 may be a plating layer of a single metal component, or may be a plurality of plating layers of different metal components. For example, the plating layer 22 has a structure in which a first plating layer 23, a second plating layer 24, and a third plating layer 25 are formed in this order from the external electrode 20a side. The first plating layer 23 is, for example, a Cu plating layer. The second plating layer 24 is, for example, a Ni plating layer. The third plating layer 25 is, for example, a Sn plating layer. Although FIG. 4 illustrates the external electrode 20a as an example, the plating layer 22 may also be provided on the outer surface of the external electrode 20b in the same manner.

[0035] Next, a description will be given of a method for manufacturing the multilayer ceramic capacitor 100. FIG.

[0036] (Step of Preparing Raw Material Powder) First, a dielectric material is prepared for forming the dielectric layer 11. The A-site elements and B-site elements contained in the dielectric layer 11 are usually ABO ３ The dielectric layer 11 contains a sintered body of BaTiO particles. ３ is a tetragonal compound with a perovskite structure and exhibits a high dielectric constant. ３ Generally, barium titanate can be obtained by reacting a titanium raw material such as titanium dioxide with a barium raw material such as barium carbonate to synthesize barium titanate. Various methods have been known for synthesizing the dielectric powder of the dielectric layer 11, such as a solid-phase method, a sol-gel method, and a hydrothermal method. Any of these methods can be used in this embodiment.

[0037] A predetermined additive compound is added to the obtained dielectric powder depending on the purpose. Examples of the additive compound include oxides of Mo, Nb, Ta, W, Mg, Mn, V, Cr, rare earth elements (Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb), oxides containing Co, Ni, Li, B, Na, K, or Si, and glasses containing Co, Ni, Li, B, Na, K, or Si. Of these, SiO is mainly used. ２ functions as a sintering aid.

[0038] For example, the dielectric powder and the additive compound are wet mixed, dried, and pulverized to prepare the ceramic material. For example, the ceramic material obtained as described above may be pulverized as necessary to adjust the particle size, or may be combined with a classification process to adjust the particle size. The dielectric material is obtained by the above steps.

[0039] (Lamination Process) Next, a binder such as polyvinyl butyral (PVB) resin, an organic solvent such as ethanol or toluene, and a plasticizer are added to the obtained dielectric material and wet mixed. Using the obtained slurry, a dielectric green sheet 52 is coated on a substrate 51 by, for example, a die coater method or a doctor blade method, and then dried. The substrate 51 is, for example, a polyethylene terephthalate (PET) film.

[0040] Next, as illustrated in FIG. 6( a), internal electrode patterns 53 are printed on a dielectric green sheet 52. In FIG. 6( a), as an example, four layers of internal electrode patterns 53 are printed at predetermined intervals on the dielectric green sheet 52. The dielectric green sheet 52 on which the internal electrode patterns 53 are printed is used as a lamination unit. An organometallic complex solution containing an additive metal element or a fine powder containing the additive metal element is added to each internal electrode pattern 53. The additive metal element may be in the form of a single metal, an alloy, an oxide, or the like. Alternatively, the additive metal element may be introduced by coating the surface of the main component metal of the internal electrode pattern 53 with the additive metal element. The additive metal element may be one or more selected from Au, Sn, Cr, Fe, Y, In, As, Co, Cu, Ir, Mg, Os, Pd, Pt, Re, Rh, Ru, Se, Te, W, Zn, Ag, Mo, and Ge.

[0041] Next, while peeling the dielectric green sheet 52 from the substrate 51, the lamination units are stacked as shown in FIG. 6(b). Next, a predetermined number of cover sheets 54 (e.g., 2 to 10 layers) are stacked on top and bottom of the laminate obtained by stacking the lamination units, and are thermocompression bonded, and then cut to a predetermined chip size. In the example of FIG. 6(b), cutting is performed along the dotted lines. The cover sheet 54 may have the same components as the dielectric green sheet 52, or may contain a different additive compound.

[0042] (Firing step) The ceramic laminate thus obtained is ２ After the binder removal treatment in an atmosphere, a metal paste that will become the base layer of the external electrodes 20a, 20b is applied by dipping, and the metal paste is then applied in an atmosphere with an oxygen partial pressure of 10 －５ ~10 －８The mixture is fired in a reducing atmosphere at 1100 to 1300° C. at 1 atm. In this manner, the multilayer ceramic capacitor 100 is obtained.

[0043] (Reoxidation treatment step) Then, N ２ A reoxidation treatment may be carried out in a gas atmosphere at 600° C. to 1000° C.

[0044] (Plating Process) Thereafter, the external electrodes 20a, 20b may be coated with a metal such as Cu, Ni, or Sn by plating.

[0045] Next, the gravure printing machine 200 according to this embodiment will be described. Fig. 7 is a schematic diagram showing the gravure printing machine 200. The gravure printing machine 200 is a device for printing the internal electrode pattern 53 exemplified in Fig. 6(a) on the dielectric green sheet 52.

[0046] The gravure printing machine 200 includes a cylindrical gravure plate 202 on which recesses 201 in the shape of the internal electrode pattern 53 are formed, a paste supply unit 204 in which conductive paste 203 for the internal electrode pattern 53 is stored, an impression cylinder 205 that holds the dielectric green sheet 52 between the gravure plate 202 and the impression cylinder 205, and a doctor blade 206 arranged on the side of the gravure plate 202. Hereinafter, the side on which the paste supply unit 204 is arranged with respect to the gravure plate 202 will be referred to as the bottom. The impression cylinder 205 is arranged above the gravure plate 202. The gravure plate 202 and the impression cylinder 205 each rotate in the direction of the arrow.

[0047] Fig. 8 is a perspective view of the gravure plate 202. The gravure plate 202 is rotatable about a horizontally extending axis 202a and has a cylindrical or columnar member. The gravure plate 202 has a plurality of recesses 201 formed on its outer peripheral surface, which correspond to the shape of the internal electrode pattern 53 to be transferred to the dielectric green sheet 52. Although Fig. 8 shows only two recesses 201, the recesses 201 are aligned and arranged at approximately equal intervals on the outer peripheral surface of the gravure plate 202 in the axial direction X and the transfer direction Y (circumferential direction, rotational direction).

[0048] In this embodiment, the recess 201 is formed so that the longitudinal direction of the recess 201 coincides with the transfer direction Y of the gravure plate 202 and the lateral direction of the recess 201 coincides with the axial direction X parallel to the axis 202 a of the gravure plate 202 .

[0049] 7 again. The paste supply unit 204 is a reservoir tank for the conductive paste 203, which is disposed below the gravure plate 202. The conductive paste 203 is stored in the paste supply unit 204, and the lower portion of the gravure plate 202 is immersed in the conductive paste 203. This causes the conductive paste 203 to be held in the recesses 201 on the outer peripheral surface of the gravure plate 202.

[0050] A doctor blade 206 is disposed on the side of the gravure plate 202. The conductive paste 203 enters the recesses 201 of the gravure plate 202 in the paste supply section 204, and is carried by the rotation of the gravure plate 202 to the contact portion with the dielectric green sheet 52. During this process, the doctor blade 206 is pressed against the surface of the gravure plate 202, and the doctor blade 206 scrapes off the conductive paste 203 adhering to the portion of the surface of the gravure plate 202 other than the recesses 201.

[0051] The impression cylinder 205 is a cylindrical or columnar member that is disposed above the gravure plate 202 and rotates around an impression cylinder axis 205a that is substantially parallel to the axis 202a. The outer peripheral surface of the impression cylinder 205 is covered with an elastic member. The elastic member is made of a rubber material such as silicone rubber or urethane rubber, or a resin material, but is not limited to these and may be made of other elastic materials.

[0052] The impression cylinder 205 sandwiches the dielectric green sheet 52 between itself and the gravure plate 202, and presses the dielectric green sheet 52 toward the gravure plate 202. Here, the impression cylinder 205 is an elastic body and therefore elastically deforms, and the contact portion between the gravure plate 202 and the impression cylinder 205 has a predetermined nip width N. The conductive paste 203 held in the recesses 201 of the gravure plate 202 is transferred to the dielectric green sheet 52 within the range of this nip width N. For example, the longitudinal dimension L of the recesses 201 of the gravure plate 202, which is the transfer direction Y, is smaller than the nip width N.

[0053] 9 is an enlarged plan view of one recess 201. The recess 201 is formed by etching or engraving using a photomask master, and has a structure in which a plurality of electrode cells are regularly arranged. Each electrode cell has a recess shape that is filled with conductive paste 203. Therefore, the recess 201 is an aggregate of a plurality of recess-shaped electrode cells.

[0054] As illustrated in FIG. 9 , the outermost electrode cells on both sides in the X direction are referred to as outer electrode cells 211. Furthermore, the inner electrode cells in the X direction are referred to as inner electrode cells 212. In the recess 201, a plurality of outer electrode cells 211 are arranged along the Y direction at the outermost positions in the X direction. Furthermore, in the recess 201, a plurality of inner electrode cells 212 are arranged along the Y direction at positions more inward in the X direction than the outer electrode cells 211. While two rows of inner electrode cells 212 are formed along the Y direction in FIG. 9 , there may be one row, or three or more rows. The conductive paste 203 filled in each electrode cell is transferred to the dielectric green sheet 52, thereby printing the internal electrode pattern 53.

[0055] When printing the internal electrode pattern 53, saddles occur in screen printing, making it difficult to maintain the smoothness and rectangularity of the printed film. Gravure printing improves this to some extent, but one of the problems with gravure printing is that the smaller the printed shape, the greater the width of the electrode in the X-axis direction (L Ｘ ) the proportion of the shoulder shape at the printing edge becomes larger, and the occupation ratio of the electrode area in the cross section in the X-axis direction (the proportion contributing to the electrode) tends to decrease.

[0056] FIG. 10(a) is a diagram illustrating the printing result (shape of the internal electrode pattern 53) for a 316 size (length 3.2 mm, width 1.6 mm, height 1.6 mm). The horizontal axis represents the X direction, and the vertical axis represents the thickness (height) of the conductive paste 203 in the internal electrode pattern 53. As illustrated in FIG. 10(a), it can be seen that a sufficient amount of conductive paste 203 is printed even at the end of the recess 201 in the X direction. This is because, for large-sized products, when the gravure printing method is applied to an item production method, the length L in the X direction of the recess 201 is Ｘ This is thought to be because the ratio of the electrode cross-sectional area to the electrode surface area becomes larger and a certain amount or more of the electrode cross-sectional area can be obtained without taking into consideration the occupancy rate of the electrode cross-sectional area.

[0057] 10B is a diagram illustrating the printing results for the 107 size (length 1.6 mm, width 0.8 mm, height 0.8 mm). It can be seen that even for the 107 size, a sufficient amount of conductive paste 203 is printed even at the end in the X direction. As such, for the large size, a sufficient amount of conductive paste 203 is printed even at the end in the X direction.

[0058] In contrast, FIG. 10(c) illustrates the printing results for a 105 size (length 1.0 mm, width 0.5 mm, height 0.5 mm), and FIG. 10(d) illustrates the printing results for a 063 size (length 0.6 mm, width 0.3 mm, height 0.3 mm). As illustrated in FIGS. 10(c) and 10(d), it can be seen that in the small sizes, a sufficient amount of conductive paste 203 is not printed at the end in the X direction. Therefore, as the gravure printing method is increasingly used for small-sized products (e.g., 105 size or smaller), the decrease in the occupancy rate of the electrode cross-sectional area becomes significant, and improvements are required.

[0059] Here, the definition of the electrode cross-sectional area occupancy rate will be explained. First, the Z direction is defined as a direction perpendicular to both the X direction and the Y direction. In other words, the Z direction is defined as the depth direction of the recess 201. In this case, the electrode cross-sectional area occupancy rate is defined as the ratio of the length L of the recess 201 in the X-direction to the length L of the recess 201 in the X-Z cross section, as exemplified in FIG. ｘThe thickness T is the maximum thickness of the conductive paste 203 in the Z direction. ｚ 10( a ) is defined as the ratio of the area occupied by the conductive paste 203 to the area of ​​a rectangle when the height is 1 / 2. Therefore, the electrode cross-sectional area occupation ratio becomes higher as the shape of the conductive paste 203 becomes closer to a rectangle in the XZ cross section, and becomes lower as the shape of the conductive paste 203 deviates from a rectangle. According to this definition, the electrode cross-sectional area occupation ratio in Figure 10( a ) is 95% to close to 100%, the electrode cross-sectional area occupation ratio in Figure 10( b ) is 90% to close to 98%, and the electrode cross-sectional area occupation ratios in Figures 10( c ) and 10( d ) are less than 95%.

[0060] The gravure printing machine 200 according to this embodiment has a configuration that can improve the printing quality while maintaining the rectangular shape of the printing film even for small-sized products, and can increase the cross-sectional area occupation rate of the electrode portion. Details will be described below.

[0061] 12 is a diagram for explaining the dimensions of each part of each electrode cell of the recess 201. As illustrated in FIG. 12, the maximum length of the outer electrode cell 211 in the X direction is defined as length A ｘ The maximum length in the Y direction is called length A ｙ The maximum length of the inner electrode cell 212 in the X direction is referred to as length B ｘ The maximum length in the Y direction is called length B ｙ In this case, A ｘ >B ｘ Each electrode cell is formed so that the following relationship holds:

[0062] With this configuration, a sufficient amount of conductive paste is transferred to the electrode cells in locations where the printing thickness tends to be small in the X direction, which increases the rectangularity of the printed film shape in the XZ cross section, and the electrode cross-sectional area occupancy rate approaches 100%.

[0063] The shape of the electrode cells is not limited to the shape shown in FIG. 12 . FIG. 13 is a diagram for explaining other shapes of the electrode cells. For example, the outer electrode cell 211 may have another shape such as a pentagon. The inner electrode cell 212 may have a shape such as a rhombus or a hexagon to match the shape of the outer electrode cell 211. Even in this case, the maximum length of the outer electrode cell 211 in the X direction is defined as length A. ｘ The maximum length in the Y direction is length A ｙ The maximum length of the inner electrode cell 212 in the X direction is length B ｘ The maximum length in the Y direction is length B ｙ Let's say.

[0064] Length A ｘ is length B ｘ Since it is preferable that A is sufficiently larger than ｘ / B ｘ In this embodiment, it is preferable to set a lower limit to A ｘ / B ｘ is preferably 1.1 or more, more preferably 1.4 or more, and even more preferably 1.6 or more.

[0065] On the other hand, length A ｘ is length B ｘ If it is too large, the transfer state may change during printing, and the electrodes may not be printed properly, for example, being cut off. ｘ / B ｘ In this embodiment, it is preferable to set an upper limit to A ｘ / B ｘ is preferably 2.0 or less, more preferably 1.9 or less, and even more preferably 1.8 or less.

[0066] From the viewpoint of printability, length A ｙ is the length B ｙ If the length Ay is smaller than the length By, the filling state of the conductive paste may change, and the rectangularity may be reduced. ｙ is length B ｙ Since it is preferable that A is sufficiently larger than ｙ / B ｙIn this embodiment, it is preferable to set a lower limit to A ｙ / B ｙ is preferably 1.0 or more, more preferably 1.1 or more, and even more preferably 1.2 or more.

[0067] On the other hand, length A ｙ is length B ｙ If the thickness is too large, the printability may be reduced and unintended transfer may occur on the electrode surface. For example, streaks may appear on the electrode surface. ｙ / B ｙ In this embodiment, it is preferable to set an upper limit to A ｙ / B ｙ is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.3 or less.

[0068] Length A ｘ is length B ｘ and the length A ｙ is length B ｙ Therefore, in the XY plane, the area S of the outer electrode cell 211 is preferably larger than Ａ is the area S of the inner electrode cell 212 Ｂ It is preferable that the area S Ａ is the area S Ｂ Since it is preferable that S Ａ / S Ｂ In this embodiment, it is preferable to set a lower limit for S Ａ / S Ｂ is preferably 1.1 or more, more preferably 1.54 or more, and even more preferably 1.92 or more.

[0069] On the other hand, the area S Ａ is the area S Ｂ If it is too large, the filling state of the conductive paste may change and the rectangularity may decrease. Ａ / S Ｂ In this embodiment, it is preferable to set an upper limit to S Ａ / S Ｂis preferably 4.0 or less, more preferably 2.85 or less, and even more preferably 2.34 or less.

[0070] In addition, since it is preferable that a sufficient amount of conductive paste 203 can be transferred from the outer electrode cell 211, as illustrated in FIG. 14, the depth A of the outer electrode cell 211 in the Z direction is ｚ is the depth B of the inner electrode cell 212 in the Z direction. ｚ It is preferable that the depth A is greater than ｚ is depth B ｚ Since it is preferable that A ｚ / B ｚ In this embodiment, it is preferable to set a lower limit to A ｚ / B ｚ is preferably 1.0 or more, more preferably 1.25 or more, and even more preferably 1.67 or more.

[0071] On the other hand, depth A ｚ is depth B ｚ If it is too large, the transfer state of the paste may differ, and there is a risk of paste missing after printing. ｚ / B ｚ In this embodiment, it is preferable to set an upper limit to A ｚ / B ｚ is preferably 3.33 or less, more preferably 2.5 or less, and even more preferably 2.0 or less.

[0072] As an example, the length A ｘ is 0.022 mm or more and 0.22 mm or less, and length B ｘ is 0.02 mm or more and 0.2 mm or less, and length A ｙ is 0.015 mm or more and 0.15 mm or less, and length B ｙ is 0.015 mm or more and 0.15 mm or less, and the depth A ｚ is 0.0111 mm or more and 0.0333 mm or less, and the depth B ｚ is 0.01 mm or more and 0.03 mm or less, and the area S Ａ is 0.275 mm ２ 275mm or more ２ and the area SＢ is 0.225 mm ２ 225mm or more ２ The following is the result.

[0073] The size of the recess 201 is not particularly limited, but may be, for example, 0.25 mm or less in the Y direction and 0.125 mm or less in the X direction, 0.4 mm or less in the Y direction and 0.2 mm or less in the X direction, 0.6 mm or less in the Y direction and 0.3 mm or less in the X direction, 1.0 mm or less in the Y direction and 0.5 mm or less in the X direction, 1.6 mm or less in the X direction and 0.8 mm or less in the X direction, 3.2 mm or less in the X direction and 1.6 mm or less in the X direction, or 4.5 mm or less in the Y direction and 3.2 mm or less in the X direction.

[0074] Second Embodiment In the second embodiment, a case will be described in which a plurality of electrode cells arranged in the Y direction in the recess 201 form two columns. Fig. 15 is a schematic plan view of the recess 201 according to the second embodiment. As illustrated in Fig. 15, a plurality of electrode cells arranged in the Y direction form two columns. The column on the left side in Fig. 15 is referred to as the first column, and the column on the right side in Fig. 15 is referred to as the second column. The electrode cells in the first column are referred to as first electrode cells 213. The electrode cells in the second column are referred to as second electrode cells 214.

[0075] In the X direction, the tip of the first electrode cell 213 on the second electrode cell 214 side is located closer to the second electrode cell 214 than the tip of the second electrode cell 214 on the first electrode cell 213 side. In addition, in the X direction, the tip of the second electrode cell 214 on the first electrode cell 213 side is located closer to the first electrode cell 213 than the tip of the first electrode cell 213 on the second electrode cell 214 side. According to this configuration, a region that is elongated in the X direction is provided in the first electrode cell 213, and a region that is elongated in the X direction is also provided in the second electrode cell 214. As a result, the conductive paste 203 is supplied to the outside in the X direction, and the cross-sectional area occupation rate of the electrode portion increases.

[0076] The multilayer ceramic capacitor according to the first embodiment was fabricated and its characteristics were examined.

[0077] In Example 1, as illustrated in Fig. 16, gravure printing was performed using a gravure plate 202 having recesses 201 in which a plurality of inner electrode cells 212 were arranged in a row in the Y direction. The recesses 201 corresponded to the 0402 size (length 0.4 mm, width 0.2 mm, height 0.2 mm). Length A ｘ is 0.044 mm, and the length A ｙ is 0.035 mm, and the depth A ｚ is 0.0154 mm, and length B ｘ is 0.04 mm, and length B ｙ is 0.03 mm, and the depth B ｚ When the conductive paste was transferred onto the dielectric green sheet using this gravure plate 202, the cross-sectional area occupation rate of the electrode portion was 84.7%.

[0078] In Example 2, as illustrated in Fig. 17, gravure printing was performed using a gravure plate 202 having recesses 201 in which a plurality of inner electrode cells 212 were arranged in two rows in the Y direction. The recesses 201 corresponded to the 0603 size (length 0.6 mm, width 0.3 mm, height 0.3 mm). Length A ｘ is 0.077 mm, and the length A ｙ is 0.055 mm, and the depth A ｚ is 0.0154 mm, and length B ｘ is 0.07 mm, and length B ｙ is 0.05 mm, and the depth B ｚ When the conductive paste was transferred onto the dielectric green sheet using this gravure plate 202, the cross-sectional area occupation rate of the electrode portion was 86.6%.

[0079] In Example 3, as illustrated in Fig. 18, gravure printing was performed using a gravure plate 202 having recesses 201 in which a plurality of inner electrode cells 212 were arranged in three rows in the Y direction. The recesses 201 corresponded to the 0402 size (length 0.4 mm, width 0.2 mm, height 0.2 mm). Length A ｘ is 0.044 mm, and the length A ｙ is 0.035 mm, and the depth A ｚ is 0.0154 mm, and length B ｘis 0.04 mm, and length B ｙ is 0.03 mm, and the depth B ｚ When the conductive paste was transferred onto the dielectric green sheet using this gravure plate 202, the cross-sectional area occupation rate of the electrode portion was 86.4%.

[0080] Comparative Example In the comparative example, as illustrated in Fig. 19, gravure printing was performed using a gravure plate 202 having recesses 201 in which a plurality of inner electrode cells 212 were arranged in two rows in the Y direction. The recesses 201 corresponded to the 0402 size (length 0.4 mm, width 0.2 mm, height 0.2 mm). Length A ｘ is 0.01 mm, and length A ｙ is 0.035 mm, and the depth A ｚ is 0.0154 mm, and length B ｘ is 0.04 mm, and length B ｙ is 0.03 mm, and the depth B ｚ When the conductive paste was transferred onto the dielectric green sheet using this gravure plate 202, the electrode cross-sectional area occupation rate was 79.0%.

[0081] From the above results, the electrode cross-sectional area occupancy rate was low in the comparative example. ｘ is length B ｘ This is thought to be because, since the length A was smaller than , a sufficient amount of conductive paste was not transferred to the outer region in the X direction, so the paste was horizontalized from the inner region to the outer region, resulting in a decrease in rectangularity. In contrast, in Examples 1 to 3, the electrode cross-sectional area occupation ratio was high. This is because the length A ｘ is length B ｘ This is thought to be because the width of the conductive paste was larger than 1 / 2, and as a result, a sufficient amount of conductive paste was transferred to the outer region in the X direction, thereby maintaining the rectangular shape.

[0082] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims.

[0083] REFERENCE SIGNS LIST 10 laminated chip 11 dielectric layer 12 internal electrode layer 13 cover layer 14 capacitance section 15 end margin 16 side margin 20a, 20b external electrode 22 plating layer 23 first plating layer 24 second plating layer 25 third plating layer 51 substrate 52 dielectric green sheet 53 internal electrode pattern 100 multilayer ceramic capacitor 200 gravure printing machine 201 recess 202 gravure plate 203 conductive paste 204 paste supply section 205 impression cylinder 206 doctor blade 211 outer electrode cell 212 inner electrode cell 213 first electrode cell 214 second electrode cell

Claims

1. A gravure plate having a cylindrical or columnar shape and having a plurality of recesses on its outer surface for holding paste to be transferred to a receiving sheet, wherein a plurality of electrode cells each forming a recess are formed in the recesses, and on the outer surface, the rotation direction is the Y direction, the direction perpendicular to the Y direction is the X direction, and the length in the X direction of the outermost outer electrode cells on both sides of the X direction is A. ｘ and the length in the X direction of the inner electrode cell that is more inward than the outer electrode cell in the X direction is B ｘ In this case, A ｘ >B ｘ A gravure version in which the relationship between the two is established.

2. A ｘ / B ｘ The gravure plate according to claim 1 , wherein is 1.1 or greater.

3. A ｘ / B ｘ 2. The gravure plate according to claim 1, wherein the σ is 2.0 or less.

4. The length of the outer electrode cell in the Y direction is A ｙ and the length of the inner electrode cell in the Y direction is B ｙ In this case, A ｙ >B ｙ 2. The gravure plate according to claim 1, wherein the following relationship holds:

5. A ｙ / B ｙ The gravure plate according to claim 4, wherein is 1.0 or greater.

6. A ｙ / B ｙ 5. The gravure plate according to claim 4, wherein the σ is 2.0 or less.

7. In the XY plane, the area of ​​the outer electrode cell is S Ａ is the area of ​​the inner electrode cell S Ｂ 10. The gravure plate of claim 1, wherein the gravure plate is greater than 8. S Ａ / S Ｂ The gravure plate according to claim 7, wherein is 1.1 or greater.

9. S Ａ / S Ｂ 8. The gravure plate according to claim 7, wherein the σ is 4.0 or less.

10. Depth A of the outer electrode cell ｚ is the depth B of the inner electrode cell ｚ 10. The gravure plate of claim 1, wherein the gravure plate is greater than 11. A ｚ / B ｚ The gravure plate of claim 10, wherein is 1.0 or greater.

12. A ｚ / B ｚ 11. The gravure plate of claim 10, wherein is 3.33 or less.

13. The gravure plate according to claim 1, wherein the recesses have a size of 1.0 mm or less in the Y direction and 0.5 mm or less in the X direction.

14. A gravure plate having a cylindrical or columnar shape and provided on its outer peripheral surface with a plurality of recesses for holding paste to be transferred to a receiving sheet, wherein a plurality of electrode cells each forming a recess are formed in the recesses, and when the rotation direction on the outer peripheral surface is the Y direction and the direction perpendicular to the Y direction is the X direction, the plurality of electrode cells arranged in the Y direction form two rows, a first row and a second row, and in the X direction, the tips of the electrode cells in the first row facing the electrode cells of the second row are positioned closer to the electrode cells of the second row than the tips of the electrode cells in the second row facing the electrode cells of the first row, and the tips of the electrode cells in the second row facing the electrode cells of the first row are positioned closer to the electrode cells of the first row than the tips of the electrode cells in the first row facing the electrode cells of the second row.

15. The gravure plate according to claim 13, wherein the recesses have a size of 1.0 mm or less in the Y direction and 0.5 mm or less in the X direction.

16. A method for manufacturing ceramic electronic components, using a gravure printing machine equipped with a gravure plate according to any one of claims 1 to 15, a paste supply unit in which the paste is stored, and an impression cylinder that holds the recipient sheet between the gravure plate and the impression cylinder, inserting the recipient sheet between the rotating gravure plate and the impression cylinder, pressing the recipient sheet against the gravure plate with the impression cylinder to transfer the paste held in the recesses to the recipient sheet, and stacking the recipient sheets to which the paste has been transferred to obtain a laminate.

Images