Printed cylinder

Abstract

The present invention provides a printing cylinder that improves transfer performance by suppressing the effects of frictional heat generated between the cylinder and the blade. [Solution] The printing cylinder 10 comprises a core portion 11 having a cylindrical or columnar shape, and a cylindrical surface portion 12 covering the circumferential surface 11a of the core portion 11. The cylindrical surface portion 12 has an inner circumferential surface 12b facing the circumferential surface 11a and an outer circumferential surface 12a located on the opposite side of the inner circumferential surface 12b. Multiple recesses 120 are formed on the outer circumferential surface 12a. Multiple protrusions 210 are formed on the inner circumferential surface 12b.

Description

Technical Field

[0001] The present disclosure relates to a printing cylinder.

Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 2023-140689 (Patent Document 1) discloses a substantially cylindrical printing cylinder having a plurality of concave portions formed on its outer peripheral surface. This printing cylinder is used as a gravure printing plate for printing a paste used for electronic components. For example, in the manufacture of multilayer ceramic capacitors, first, the printing cylinder is immersed in a paste tank storing a paste to be an internal electrode, so that the concave portions of the printing cylinder are filled with the paste. Next, when a blade slidably contacts the outer peripheral surface of the printing cylinder, the excess of the paste filled in the concave portions is scraped off by the blade. Next, an appropriate amount of the paste filled in the concave portions is transferred onto a green sheet.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, when the excess paste is scraped off by the blade as described above, frictional heat is generated on the outer peripheral surface when the blade slidably contacts the outer peripheral surface of the printing cylinder. If the characteristics such as the viscosity of the paste filled in the concave portions change due to this frictional heat, there is a concern that problems such as a decrease in transferability may occur.

[0005] Therefore, the present disclosure has been made to solve the above-described problems, and an object thereof is to provide a printing cylinder in which transferability is improved by suppressing the influence of frictional heat generated between the blade and the printing cylinder.

Means for Solving the Problems

[0006] The printing cylinder according to this disclosure comprises a core portion having a cylindrical or columnar shape and a cylindrical surface portion covering the circumferential surface of the core portion. The cylindrical surface portion has an inner circumferential surface facing the circumferential surface and an outer circumferential surface located on the opposite side of the inner circumferential surface. A plurality of recesses are formed on the outer circumferential surface. A plurality of protrusions are formed on the inner circumferential surface. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a plate cylinder in which the effect of frictional heat generated between the blade and the plate cylinder is suppressed, thereby improving transferability. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing a gravure printing apparatus equipped with a plate cylinder according to an embodiment. [Figure 2] Figure 1 is a perspective view of the printing cylinder. [Figure 3] Figure 1 is a schematic enlarged view of a portion of the printing pattern on the printing cylinder. [Figure 4] Figure 3 is a schematic cross-sectional view of the printed pattern. [Figure 5] Figure 4 is a schematic diagram showing the cylindrical surface portion as viewed from the inner circumferential surface. [Figure 6] Figure 1 is a flowchart illustrating the manufacturing method of a multilayer electronic component using the printing cylinder shown. [Figure 7] This is a schematic cross-sectional view of a portion of the printing cylinder related to the modification. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and their descriptions will not be repeated.

[0010] (Embodiment) <A. Schematic Configuration of Plate Cylinder and Gravure Printing Apparatus> FIG. 1 is a schematic diagram showing a gravure printing apparatus including a plate cylinder according to an embodiment. FIG. 2 is a perspective view of the plate cylinder shown in FIG. 1. First, referring to FIGS. 1 and 2, the schematic configuration of the plate cylinder 10 according to the present embodiment and the gravure printing apparatus 1 including the same will be described.

[0011] As shown in FIGS. 1 and 2, the gravure printing apparatus 1 includes a plate cylinder 10, a backup roll 20, a paste tank 30, and a blade 40.

[0012] The plate cylinder 10 has a cylindrical shape as a whole. The plate cylinder 10 is configured to be rotatable in the direction of arrow AR1 in FIG. 1. A plurality of printing patterns 100 are provided on the outer peripheral surface 12a of the cylindrical surface layer portion 12 of the plate cylinder 10. The cylindrical surface layer portion 12 will be described in detail later. In FIG. 2, two of the plurality of printing patterns 100 appear.

[0013] The backup roll 20 has a cylindrical shape or a cylindrical shape. The backup roll 20 is configured to be rotatable in the direction of arrow AR2 in FIG. 1 (i.e., the direction opposite to the rotation direction of the plate cylinder 10).

[0014] The plate cylinder 10 and the backup roll 20 are arranged to face each other so that a nip portion N is formed. The green sheet 50 passes through the nip portion N such that the dielectric sheet 50a is sandwiched at the nip portion N.

[0015] The paste tank 30 stores a functional paste 31 used for electronic components. A part of the plate cylinder 10 is immersed in the functional paste 31. When performing gravure printing using the plate cylinder 10, as the plate cylinder 10 rotates, the functional paste 31 is filled into a plurality of recesses 120 (see FIG. 3) described later. In the present embodiment, a conductive paste is used as the functional paste 31. Note that a dielectric paste may be used instead of the conductive paste.

[0016] The blade 40 is disposed at a position downstream of the position of the paste tank 30 in the rotational direction of the plate cylinder 10. The blade 40 is in contact with the plate cylinder 10 with a predetermined pressure. The blade 40 scrapes off the excess of the functional paste 31 filled in the recess 120.

[0017] The plate cylinder 10 in a state where an appropriate amount of the functional paste 31 is retained by passing through the blade 40 transfers the functional paste 31 filled in the recess 120 to the green sheet 50 at the nip portion N. Thereby, an electrode pattern 51 corresponding to the printing pattern 100 is printed on the green sheet 50.

[0018] <B. Detailed Configuration of Plate Cylinder> FIG. 3 is a schematic enlarged view showing a part of the printing pattern of the plate cylinder shown in FIG. 1. FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. 3. FIG. 5 is a schematic view of the cylindrical surface layer portion shown in FIG. 4 as viewed from the inner peripheral surface side. Next, with reference to FIGS. 3 to 5 and FIGS. 1 and 2 described above, the detailed configuration of the plate cylinder 10 will be described.

[0019] As shown in FIGS. 1 to 5, the plate cylinder 10 includes a core portion 11 having a cylindrical shape and a cylindrical surface layer portion 12 covering the peripheral surface 11a of the core portion 11. The core portion 11 and the cylindrical surface layer portion 12 are configured separately.

[0020] The core portion 11 is formed of, for example, a metal roll. As the material of the metal roll, iron or aluminum is preferably used. The diameter of the core portion 11 is, for example, 30 mm or more and 200 mm or less. The width dimension parallel to the axial direction of the core portion 11 is, for example, 200 mm or more and 1000 mm or less. Note that the shape of the core portion 11 is not particularly limited to a cylindrical shape, and may be a columnar shape. In this case, the plate cylinder 10 also has a columnar shape as a whole.

[0021] The cylindrical surface layer portion 12 has an inner peripheral surface 12b facing the peripheral surface 11a of the core portion 11 and an outer peripheral surface 12a located on the opposite side of the inner peripheral surface 12b.

[0022] The cylindrical surface layer 12 is fitted onto the core 11 and fixed to the core 11, for example, by screws. However, the method of fixing the cylindrical surface layer 12 to the core 11 is not limited to this, and other fixing methods may be used.

[0023] As shown in Figure 4, the cylindrical surface portion 12 includes a base material 13, a plating layer 14, and a coating layer 15. The base material 13 constitutes the inner circumferential surface 12b of the cylindrical surface portion 12. The plating layer 14 covers the entire main surface of the base material 13 that is located on the opposite side of the pair of main surfaces that face the core portion 11. The coating layer 15 covers the entire main surface of the plating layer 14 that is located on the opposite side of the pair of main surfaces that face the base material 13.

[0024] The base material 13 is formed into a substantially cylindrical shape by, for example, rolling a plate member and welding the ends of the plate member together. While a metal mainly composed of nickel is preferably used as the material for the base material 13, other metals may be used, or materials other than metal may be used. In this embodiment, the base material 13 is composed of a single plate member rolled as described above.

[0025] The thickness of the base material 13 is preferably 0.1 mm or more. This ensures sufficient strength of the cylindrical surface layer 12. On the other hand, the thickness of the base material 13 is preferably 0.15 mm or less. This further improves the heat dissipation efficiency in the gap 220, which will be described later.

[0026] For the plating layer 14, a high-hardness material such as chromium is used. This makes it possible to improve the hardness of the outer surface 12a of the cylindrical surface layer 12.

[0027] The coating layer 15 is preferably made of DLC. DLC refers to a substance mainly composed of carbon that possesses both the carbon-carbon bonds of diamond and graphite. DLC has the properties of being hard and low frictional compared to general materials. For example, the hardness of DLC is higher than that of nickel, which is an example of a material that makes up the base material 13. Also, the coefficient of friction of DLC is lower than that of nickel.

[0028] Therefore, by constructing the coating layer 15 with DLC, the hardness of the outer surface 12a of the cylindrical surface portion 12 can be improved. This suppresses wear of the cylindrical surface portion 12 caused by the blade 40 sliding against the plate cylinder 10. In addition, by constructing the coating layer 15 with DLC, the coefficient of friction of the outer surface 12a of the cylindrical surface portion 12 can be reduced. This suppresses the residue of the functional paste 31 in the recessed area 120 after transfer.

[0029] As shown in Figures 2 to 4, a plurality of recesses 120 are formed on the outer circumferential surface 12a of the cylindrical surface layer 12. As a result, the outer circumferential surface 12a of the cylindrical surface layer 12 is provided with a printed pattern 100 composed of a plurality of ridges 110 and a plurality of recesses 120 separated by these ridges.

[0030] The multiple embankment sections 110 are arranged, for example, in a grid pattern. The multiple embankment sections 110 include vertical embankment sections 111 that extend in the circumferential direction of the printing cylinder 10 and horizontal embankment sections 112 that extend in a direction parallel to the axial direction of the printing cylinder 10.

[0031] The multiple recesses 120 are arranged in a matrix, for example, consisting of rows parallel to the axial direction and columns parallel to the circumferential direction. Adjacent recesses 120 may be connected by providing notches in at least one of the vertical embankment portions 111 and the horizontal embankment portions 112.

[0032] The printed pattern 100 has a roughly rectangular shape. However, the shape of the printed pattern 100 is not particularly limited to a roughly rectangular shape and can be changed as appropriate depending on the shape of the electrode pattern 51.

[0033] As shown in Figure 4, the depth of the recess 120 (more specifically, the depth h from the opening surface OP of the recess 120 to the coating layer 15 of the portion constituting the bottom surface of the recess 120) is, for example, 5 μm or more and 30 μm or less. In this embodiment, the opening surface OP has a rectangular shape when viewed from the normal direction. However, the shape of the opening surface OP when viewed from the normal direction is not particularly limited to a rectangular shape and can be changed as appropriate. The recess 120 is formed, for example, by etching the main surface of the substrate 13.

[0034] As shown in Figures 4 and 5, a plurality of protrusions 210 are formed on the inner circumferential surface 12b of the cylindrical surface layer 12. This configuration makes it possible to suppress the effect of frictional heat generated between the blade 40 and the plate cylinder 10, a point that will be described in detail later.

[0035] In this embodiment, multiple protrusions 210 are formed on the entire inner circumferential surface 12b of the cylindrical surface layer 12. Alternatively, the multiple protrusions 210 may be formed only on the inner circumferential surface 12b of the cylindrical surface layer 12 in the portion where the printed pattern 100 is provided.

[0036] The inner circumferential surface 12b of the cylindrical surface layer 12 is provided with a plurality of protrusions 210 and gaps 220 located between the protrusions 210. In this embodiment, when viewed from the radial direction of the core 11, the gaps 220 are provided in a grid pattern over the entire inner circumferential surface 12b of the cylindrical surface layer 12 (see Figure 5 in particular).

[0037] When viewed from the radial direction of the core part 11, the convex part 210 formed on the inner peripheral surface 12b of the cylindrical surface layer part 12 is arranged at a position overlapping with the concave part 120 formed on the outer peripheral surface 12a of the cylindrical surface layer part 12. In other words, when viewed from the radial direction of the core part 11, the gap part 220 on the inner peripheral surface 12b of the cylindrical surface layer part 12 overlaps with the part where the plurality of concave parts 120 are not located on the outer peripheral surface 12a of the cylindrical surface layer part 12.

[0038] The convex part 210 is in contact with the peripheral surface 11a of the core part 11. Thereby, the strength of the cylindrical surface layer part 12 is ensured, and as a result, it is suppressed that the cylindrical surface layer part 12 is deformed when the blade 40 is in sliding contact with the plate cylinder 10.

[0039] <C. Manufacturing Method of Multilayer Electronic Component> FIG. 6 is a flowchart showing a manufacturing method of a multilayer electronic component using the plate cylinder shown in FIG. 1. Next, an example of a manufacturing method of a multilayer electronic component using the plate cylinder 10 according to the present embodiment will be described with reference to FIG. 6.

[0040] As shown in FIG. 6, first, in step T1, a green sheet 50 and a functional paste 31 are prepared. In the present embodiment, a conductive paste is used as the functional paste 31 for the internal electrode. The green sheet 50 is formed of a dielectric paste obtained by kneading ceramic powder typified by barium titanate, a binder, a dispersant, a plasticizer, and the like. The functional paste 31 is obtained by kneading conductive powder, a solvent, a binder, ceramic powder, and the like. As the green sheet 50 and the functional paste 31, known ones can be used.

[0041] Next, in step T2, using the plate cylinder 10, the functional paste 31 (that is, the conductive paste) is transferred onto the green sheet 50 in a predetermined pattern. Thereby, a dielectric sheet 50a on which an electrode pattern 51 is formed is formed. Note that the plate cylinder 10 may be used for transferring the dielectric paste.

[0042] Next, in step T3, a laminated sheet is manufactured by stacking multiple dielectric sheets. Specifically, first, a predetermined number of dielectric sheets for the outer layer, which do not have electrode patterns printed on them, are stacked. Next, dielectric sheets 50a with electrode patterns 51 printed on them are sequentially stacked on top of these. Then, a predetermined number of the aforementioned dielectric sheets for the outer layer are stacked on top of these.

[0043] Next, in process T4, a laminated block is produced. Specifically, the laminated sheets are pressed in the lamination direction using a press device such as a hydrostatic press.

[0044] Next, in process T5, the laminated chips are manufactured. Specifically, the laminated chips are cut out by cutting the laminated block to a predetermined size with a cutting blade. At this time, the corners and edges of the laminated chips may be rounded by barrel polishing or the like.

[0045] Next, in process T6, the stacked chips are fired. The firing temperature depends on the materials of the dielectric and electrode patterns, but is typically between 900°C and 1300°C.

[0046] Next, in step T7, external electrodes are formed. For example, conductive paste for external electrodes is applied to both end faces of the laminated chip and baked, thereby forming a baked layer on both end faces. At this time, the baking temperature is, for example, 700°C to 900°C.

[0047] Next, a plating layer is applied to the surface of the baked layer as needed. By going through steps T1 to T7 described above, the multilayer electronic component is manufactured.

[0048] In addition, when the above-described multilayer electronic component is a piezoelectric component, the dielectric can be formed of a piezoelectric ceramic. Examples of the piezoelectric ceramic include PZT (lead zirconate titanate) - based ceramics and the like. When the multilayer electronic component is a thermistor, the dielectric can be formed of a semiconductor ceramic. Examples of the semiconductor ceramic include spinel - based ceramics and the like. When the multilayer electronic component is an inductor, the dielectric can be formed of a magnetic ceramic. In this case, the internal electrode becomes a coil - shaped conductor. Examples of the magnetic ceramic include ferrite and the like.

[0049] <D. parenthesis> In the plate cylinder 10 according to the present embodiment, as described above, a plurality of convex portions 210 are formed on the inner peripheral surface 12b of the cylindrical surface layer portion 12. By configuring it in this way, the surface area of the inner peripheral surface 12b can be increased as compared with the case where a plurality of convex portions 210 are not formed on the inner peripheral surface 12b. As a result, it becomes possible to improve the heat dissipation efficiency of the cylindrical surface layer portion 12.

[0050] Also, in the plate cylinder 10 according to the present embodiment, as described above, a gap portion 220 is located between the convex portions 210. Therefore, by allowing a cooling gas or fluid to flow through this gap portion 220, it is possible to further improve the heat dissipation efficiency of the cylindrical surface layer portion 12. In other words, by configuring the gap portion 220 as a flow path for the cooling gas or fluid, it becomes possible to further improve the heat dissipation efficiency of the cylindrical surface layer portion 12.

[0051] By configuring it as in the plate cylinder 10 according to the present embodiment in this way, it becomes possible to improve the heat dissipation efficiency of the cylindrical surface layer portion 12, and thus to improve the heat dissipation efficiency of the plate cylinder 10. As a result, the temperature rise of the plate cylinder 10 due to the frictional heat generated when the blade 40 is in sliding contact with the plate cylinder 10 is suppressed. Therefore, it is effectively suppressed that the transferability deteriorates due to a change in characteristics such as the viscosity of the functional paste 31 filled in the recess 120.

[0052] Therefore, by configuring the plate cylinder 10 according to this embodiment, it is possible to create a plate cylinder in which the effect of frictional heat generated between the blade and the plate cylinder is suppressed, thereby improving transfer performance.

[0053] Furthermore, in the plate cylinder 10 according to this embodiment, as described above, when viewed from the radial direction of the core portion 11, the gap portion 220 on the inner circumferential surface 12b of the cylindrical surface portion 12 overlaps with the portion on the outer circumferential surface 12a of the cylindrical surface portion 12 where the multiple recesses 120 are not located.

[0054] As a result, the gap portion 220, which has particularly high heat dissipation efficiency as described above, is positioned directly below the ridge portion 110, which is a part of the outer circumferential surface 12a of the cylindrical surface portion 12 where frictional heat is particularly concentrated due to the sliding contact of the blade 40. Consequently, the effects of the frictional heat are particularly mitigated, and the decrease in transferability caused by the change in the properties of the functional paste 31 is more effectively suppressed.

[0055] In the embodiment described above, the example shown is that the protrusion 210 formed on the inner circumferential surface 12b of the cylindrical surface layer 12 abuts against the circumferential surface 11a of the core 11. However, the protrusion 210 does not necessarily have to abut against the circumferential surface 11a. In other words, a gap may be provided between the protrusion 210 and the circumferential surface 11a.

[0056] Furthermore, in the embodiment described above, the case in which the plating layer 14 covers the entire main surface of one of the substrates 13 is illustrated, but the plating layer 14 may cover only a part of the main surface of the substrate 13. In this case, it is preferable that the plating layer 14 selectively covers the portion of the main surface of the substrate 13 that constitutes the printed pattern 100. Similarly, in the embodiment described above, the case in which the coating layer 15 covers the entire main surface of one of the plating layers 14 is illustrated, but the coating layer 15 may cover only a part of the main surface of one of the plating layers 14. In this case, it is preferable that the coating layer 15 selectively covers the portion of the main surface of the plating layer 14 that constitutes the printed pattern 100.

[0057] Furthermore, although the above-described embodiment illustrates a case where the substrate 13 is covered by the plating layer 14 and the coating layer 15, the substrate 13 does not necessarily have to be covered by these.

[0058] (modified version) Figure 7 is a schematic cross-sectional view of a modified version of the printing cylinder, enlarged. More specifically, Figure 7 is a schematic cross-sectional view of the modified printing cylinder, corresponding to Figure 4 described above. The modified printing cylinder 10A based on the above-described embodiment will now be described with reference to Figure 7.

[0059] As shown in Figure 7, in the plate cylinder 10A according to this modified example, when viewed from the radial direction of the core portion 11, only a portion of the gap portion 220 on the inner circumferential surface 12b of the cylindrical surface portion 12 overlaps with the portion on the outer circumferential surface 12a of the cylindrical surface portion 12 where the multiple recesses 120 are not located.

[0060] Even with this configuration, effects similar to those described in the above-described embodiment can be obtained, and a plate cylinder can be made in which the effect of frictional heat generated between the blade and the plate cylinder is suppressed, thereby improving transferability.

[0061] (Other forms, etc.) The characteristic configurations shown in the embodiments and modifications of the present disclosure described above can, of course, be combined with each other without departing from the spirit of the present invention.

[0062] The embodiments and their variations disclosed herein are illustrative in all respects and not restrictive. The technical scope of the present invention is defined by the claims and includes all modifications within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0063] 1 Gravure printing apparatus, 10, 10A Plate cylinder, 11 Core, 11a Peripheral surface, 12 Cylindrical surface layer, 12a Outer surface, 12b Inner surface, 13 Substrate, 14 Plating layer, 15 Coating layer, 20 Backup roll, 30 Paste tank, 31 Functional paste, 40 Blade, 50 Green sheet, 50a Dielectric sheet, 51 Electrode pattern, 100 Printing pattern, 110 Embankment, 111 Vertical embankment, 112 Horizontal embankment, 120 Recess, 210 Protrusion, 220 Gap, N Nip, OP Opening surface.

Claims

1. A core having a cylindrical or columnar shape, The cylindrical surface layer covers the circumferential surface of the core and has an inner circumferential surface facing the circumferential surface and an outer circumferential surface located on the opposite side of the inner circumferential surface, Multiple recesses are formed on the outer surface, A printing cylinder having a plurality of protrusions formed on its inner circumferential surface.

2. The printing cylinder according to claim 1, wherein, viewed from the radial direction of the core portion, at least a portion of the gap between the protrusions on the inner circumferential surface overlaps with the portion on the outer circumferential surface where the plurality of recesses are not located.

3. The aforementioned printing cylinder is used for gravure printing to print functional pastes used in electronic components. The printing cylinder according to claim 1, wherein the plurality of recesses on the outer surface constitute a printing pattern.

4. The printing cylinder according to claim 1, wherein the cylindrical surface portion contains at least one of nickel, chromium, and DLC.

5. The cylindrical surface portion includes the base material that constitutes the inner circumferential surface, The printing cylinder according to any one of claims 1 to 4, wherein the base material is composed of a single component.

6. The printing cylinder according to claim 5, wherein the thickness of the base material is 0.1 mm or more and 0.15 mm or less.

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