Intaglio printing device

Abstract

The present invention provides a gravure printing device that can print ink in a pattern with good precision on a long sheet member. The gravure printing device (1A) of the present invention includes: a gravure roll (71) having a plurality of ink holding portions (73) formed in a pattern on the outer circumferential surface of a cylindrical body, which rotates about an axis and contacts one surface of a long sheet member (2) being conveyed at a given speed, thereby transferring ink held in the ink holding portions (73) to the sheet member (2) and printing the ink in a pattern on the one surface of the sheet member (2); and a speed changing portion (41, 77) that can change the relative speed between the conveying speed of the sheet member (2) and the circumferential speed of the gravure roll (71) at the contact portion of the sheet member (2) and the gravure roll (71).

Description

Technical Field

[0001] This invention relates to gravure printing apparatus. Background Technology

[0002] For example, in manufacturing a multilayer ceramic capacitor, an internal electrode pattern is printed on a ceramic green sheet. Then, a master block is manufactured by stacking the ceramic green sheets with the internal electrode pattern printed on them, and this master block is divided to manufacture individual multilayer sheets. Furthermore, external electrodes are formed on the end faces of these multilayer sheets, thereby manufacturing the multilayer ceramic capacitor. Here, the internal electrode pattern is printed by gravure printing, which involves conveying the ceramic green sheet at a given speed between a rotating gravure roller and a pressing roller (see Patent Document 1).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-297667 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, when printing patterns such as internal electrode patterns on long sheet components such as ceramic raw sheets using gravure printing, it is not easy to print the patterns with good accuracy because the state of the sheet components varies with temperature, humidity and tension.

[0008] The purpose of this invention is to provide a gravure printing apparatus that can print ink into patterns with good precision on long strip-shaped sheet components.

[0009] Technical solutions for solving the problem

[0010] To solve the above problems, a gravure printing apparatus is provided, comprising: a gravure roller having a cylindrical outer peripheral surface with a plurality of ink holding portions formed in a pattern, which rotates about an axis and contacts one side of an elongated sheet member being conveyed at a given speed, thereby transferring ink held in the ink holding portions to the sheet member and printing the ink into a pattern on the side of the sheet member; and a speed changing unit capable of changing the relative speed between the conveying speed of the sheet member and the circumferential speed of the gravure roller at the contact portion between the sheet member and the gravure roller.

[0011] Invention Effects

[0012] According to the present invention, a gravure printing apparatus is provided that can print ink into a pattern with good precision on a long strip-shaped sheet component. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of a multilayer ceramic capacitor 100 manufactured by gravure printing apparatus 1A.

[0014] Figure 2 This is a three-dimensional view of a multilayer ceramic capacitor 100.

[0015] Figure 3 This is a diagram illustrating the gravure printing apparatus 1A of the first embodiment of printing the internal electrode pattern 21 on the ceramic green sheet 2.

[0016] Figure 4 This is an example of an internal electrode pattern 21 printed on a ceramic green sheet 2.

[0017] Figure 5 This is a diagram illustrating the gravure printing apparatus 1B according to the second embodiment. Detailed Implementation

[0018] (First Embodiment)

[0019] The gravure printing apparatus 1A according to the first embodiment of the present invention will be described below. The gravure printing apparatus 1A is used, for example, in manufacturing processes such as… Figure 1 and Figure 2 The multilayer ceramic capacitor 100 shown is used.

[0020] Figure 1 This is a cross-sectional view of a multilayer ceramic capacitor 100 manufactured by the gravure printing apparatus 1A according to the embodiment. Figure 2 This is a perspective view of a multilayer ceramic capacitor 100. The multilayer ceramic capacitor 100 includes: a multilayer body 110 having a dielectric layer 111 made of ceramic dielectric material and a plurality of internal electrodes 112 stacked through the dielectric layer 111; and a pair of external electrodes 113 configured to be in contact with a pair of opposing end faces 110a of the internal electrodes 112 alternately led out to the multilayer body 110.

[0021] Regarding the multilayer ceramic capacitor 100, generally speaking, a master block is made by stacking ceramic green sheets 2 with internal electrode patterns 21 printed on them (described later). After the master block is divided into individual multilayer pieces, it is manufactured through processes such as forming external electrodes 113 and plating the external electrodes 113.

[0022] (Gravure printing apparatus 1A)

[0023] Figure 3 This is a diagram illustrating the gravure printing apparatus 1A of the first embodiment of printing the internal electrode pattern 21 on the ceramic green sheet 2.

[0024] (Ceramic shard 2)

[0025] Ceramic raw sheet 2 is a long strip-shaped sheet component formed by using a ceramic slurry containing ceramic powder, binder and solvent on a carrier film and forming it into a sheet shape using a die coating machine, gravure coating machine or micro gravure coating machine.

[0026] (Gravure printing apparatus 1A)

[0027] The gravure printing apparatus 1A includes a supply roller 3 disposed on the upstream side of the conveying direction of the ceramic green sheet 2 and a winding roller 4 disposed on the downstream side. In addition, a tension adjustment unit 5, a tension measuring unit 6, a gravure printing machine 7, a drying oven 8, and a spacing detection unit 9 are disposed between the supply roller 3 and the winding roller 4. Furthermore, a control unit 10 for controlling the entire gravure printing apparatus 1A is disposed thereon.

[0028] (Supply roller 3)

[0029] The supply roller 3 is positioned at the upstream end of the gravure printing apparatus 1A and has rolled up a ceramic green sheet 2 in a state where the internal electrode pattern 21 has not been printed.

[0030] (Winding roller 4)

[0031] The winding roller 4 is located at the downstream end of the gravure printing apparatus 1A and winds the ceramic green sheet 2 that has been supplied from the supply roller 3 and printed with the internal electrode pattern 21. The winding roller 4 is connected to the winding roller drive unit 41 that drives the winding roller 4 to rotate.

[0032] In this embodiment, the winding roller drive unit 41 is also a speed change unit capable of changing the conveying speed of the ceramic green sheet 2. However, the change of the conveying speed of the ceramic green sheet 2 is not limited to the winding roller drive unit 41, and conveying rollers or the like can also be provided in the conveying path of the ceramic green sheet 2.

[0033] (Tension Adjustment Section 5)

[0034] The tension adjustment unit 5 is located downstream of the supply roller 3. The tension adjustment unit 5 includes: guide rollers 51 and 52, which change the conveying direction of the ceramic green sheet 2; and a tension adjusting roller 53, disposed between the guide rollers 51 and 52, which, in this embodiment, adjusts the tension of the ceramic green sheet 2 by displacement in the vertical direction. Furthermore, the tension adjustment unit 5 includes a tension adjusting roller drive unit 54 that drives the tension adjusting roller 53 in the vertical direction. Alternatively, the tension adjustment unit 5 can be either a swing-type tension adjusting roller that adjusts the tension of the ceramic green sheet 2 by displacement in the horizontal direction, or a linear horizontal tension adjusting roller that moves linearly in the horizontal direction.

[0035] (Tension Measurement Section 6)

[0036] Downstream of the tension adjustment unit 5, a tension measuring unit 6 is provided for measuring the tension of the ceramic green sheet 2.

[0037] (Gravure printing press 7)

[0038] Downstream of the tension measuring unit 6, a gravure printing machine 7 is arranged. The gravure printing machine 7 includes a gravure roller 71, a paste supply unit 75, a doctor blade 76, a gravure roller drive unit 77, a first pressing roller 72A and a second pressing roller 72B, and a pressing roller drive unit 78.

[0039] (Gravure Roll 71)

[0040] The gravure roller 71 is a cylindrical or cylindrical component capable of rotating about a horizontally extending axis. The gravure roller 71 has multiple recesses 73 formed on its outer peripheral surface, corresponding to the shape of the internal electrode pattern 21 transferred onto the ceramic green sheet 2, serving as ink holding portions. The recesses 73 are arranged axially and circumferentially on the outer peripheral surface of the gravure roller 71.

[0041] (Ointment Supply Department 75)

[0042] The paste supply section 75 stores conductive paste 74, which serves as ink. The lower portion of the gravure roller 71 is immersed in the conductive paste 74. When the gravure roller 71 rotates and the recess 73 on its outer circumference is immersed in the conductive paste 74 in the paste supply section 75, the conductive paste 74 remains in the recess 73.

[0043] (Scraper 76)

[0044] The scraper 76 is configured to abut against the outer peripheral surface of the gravure roller 71 after the conductive paste 74 is held in the recess 73. The scraper 76 presses against the outer peripheral surface of the gravure roller 71 and scrapes off excess conductive paste 74 adhering to the portion of the outer peripheral surface of the gravure roller 71 other than the recess 73.

[0045] (Gravure roller drive unit 77)

[0046] The gravure roller drive unit 77 can change the circumferential speed of the outer peripheral surface of the gravure roller 71 by changing the rotational speed of the gravure roller 71. The gravure roller drive unit 77, together with the winding roller drive unit 41 described above, is a speed change unit that can change the relative speed between the conveying speed of the ceramic green sheet 2 at the contact portion between the ceramic green sheet 2 and the gravure roller 71 and the circumferential speed of the gravure roller 71.

[0047] (First pressing roller 72A and second pressing roller 72B)

[0048] The first pressing roller 72A and the second pressing roller 72B are respectively positioned on the upstream and downstream sides, sandwiching the gravure roller 71 in the conveying direction of the ceramic green sheet 2. The first pressing roller 72A and the second pressing roller 72B press the ceramic green sheet 2 from the other side and wrap it around the outer circumference of the gravure roller 71.

[0049] The first pressing roller 72A and the second pressing roller 72B are cylindrical or cylindrical components that rotate around an axis substantially parallel to the axis of the gravure roller 71. The outer peripheral surfaces of the first pressing roller 72A and the second pressing roller 72B may or may not be covered by elastic components. The elastic components are made of rubber components or resin materials such as nitrile rubber, polyurethane rubber, silicone rubber, styrene rubber, and ethylene rubber, but are not limited to these; they may also be made of other elastic materials.

[0050] (Press the pressure roller drive section 78)

[0051] The press roller drive unit 78 can change the circumferential speed of the outer peripheral surfaces of the first press roller 72A and the second press roller 72B by changing the rotational speed of the first press roller 72A and the second press roller 72B. The gravure roller drive unit 77 and the press roller drive unit 78 can drive each other independently. That is, the first press roller 72A and the second press roller 72B can rotate at different circumferential speeds without following the rotation of the gravure roller 71.

[0052] (Drying Oven 8)

[0053] Downstream of the gravure printing press 7, there is a drying oven 8 for drying the printed internal electrode pattern 21.

[0054] (Gap Detection Unit 9)

[0055] On the outlet side of the drying oven 8, a spacing detection unit 9 is provided to detect the spacing of the internal electrode pattern 21 printed on the ceramic green sheet 2.

[0056] (Control Unit 10)

[0057] The tension adjustment roller drive unit 54, tension measuring unit 6, gravure roller drive unit 77, pressing roller drive unit 78, spacing detection unit 9, and winding roller drive unit 41 are connected to the control unit 10.

[0058] The control unit 10, in conjunction with the operation of the gravure roller drive unit 77, causes the winding roller drive unit 41 to operate, thereby driving the winding roller 4 to rotate. Thus, the ceramic green sheets 2 are successively released starting from the supply roller 3. Alternatively, a drive unit can be provided on the supply roller 3 to successively release the ceramic green sheets 2. By suppressing tension as much as possible between the winding roller 4, the supply roller 3, and the gravure plate 71, deformation of the printed pattern can be prevented.

[0059] The tension measuring unit 6 measures the tension of the continuously released ceramic green sheets 2. The measured tension value is sent to the control unit 10.

[0060] After the tension of the ceramic green sheet 2 is measured by the tension measuring unit 6, it is conveyed to the gravure printing machine 7. The control unit 10 drives the gravure roller 71 and the first pressing roller 72A and the second pressing roller 72B via the gravure roller drive unit 77 and the pressing roller drive unit 78 of the gravure printing machine 7. In the gravure printing machine 7, the ceramic green sheet 2 is pressed towards the gravure roller 71 by the first pressing roller 72A and the second pressing roller 72B.

[0061] If the gravure roller 71 rotates, the conductive paste 74 accumulated in the paste supply section 75 is held in the recess 73 of the gravure roller 71 and is transported to the contact section with the ceramic green sheet 2.

[0062] During this process, the scraper 76 presses against the surface of the gravure roller 71 and scrapes off the conductive paste 74 adhering to the surface of the gravure roller 71, except for the recess 73.

[0063] The ceramic sheet 2 is conveyed and passes over the gravure roller 71. At this time, the ceramic sheet 2 is pressed against the outer peripheral surface of the gravure roller 71 by the first pressing roller 72A and the second pressing roller 72B, and the conductive paste 74 filling the recess 73 of the gravure roller 71 is transferred to the ceramic sheet 2, thereby printing the internal electrode pattern 21 on the ceramic sheet 2.

[0064] The internal electrode pattern 21 printed on the ceramic green sheet 2 is dried in the drying oven 8.

[0065] Then, the spacing PX in the transport direction and the spacing PY in the width direction of the internal electrode pattern 21 formed on the ceramic green sheet 2 are detected by the spacing detection unit 9. Figure 4 This is an example of an internal electrode pattern 21 printed on a ceramic green sheet 2. The arrows in the figure indicate the transport direction of the ceramic green sheet 2. Figure 4 The diagram shows the spacing PX in the conveying direction and the spacing PY in the width direction of the internal electrode pattern 21. Alternatively, multiple positioning marks printed in the conveying direction and width direction can be arranged near the internal electrode pattern, and these positioning marks can be used to represent the spacings PX and PY.

[0066] The values ​​of the spacing PX in the conveying direction and the spacing PY in the width direction of the internal electrode pattern 21, detected by the spacing detection unit 9, are sent to the control unit 10. Alternatively, a monitor or similar device can be installed on the control unit 10, allowing the operator to measure the spacing PX and the width direction spacing PY via images.

[0067] Then, the ceramic green sheet 2 is wound onto the winding roller 55.

[0068] The control unit 10 compares the tension value of the incoming ceramic green sheet 2 with the target values ​​for the spacing PX in the conveying direction and the spacing PY in the width direction of the internal electrode pattern 21. Furthermore, if the spacing PX and spacing PY differ from the target values, the control unit 10 provides feedback on the result, causing the tension adjustment roller drive unit 54, the gravure roller drive unit 77, the pressing roller drive unit 78, and the winding roller drive unit 41 to operate.

[0069] (1) For example, when the spacing PX is different from the target value, the control unit 10 can change the rotation speed of the gravure roller 71, that is, the circumferential speed of the outer peripheral surface of the gravure roller 71, by means of the conveying speed of the gravure roller drive unit 77 relative to the ceramic green sheet 2.

[0070] Furthermore, if the control unit 10 slows down the circumferential speed of the gravure roller 71 relative to the conveying speed of the ceramic green sheet 2 by means of the gravure roller drive unit 77, the spacing PX in the conveying direction of the internal electrode pattern 21 becomes longer.

[0071] Conversely, if the control unit 10 increases the circumferential speed of the gravure roller 71 relative to the conveying speed of the ceramic green sheet 2 by the gravure roller drive unit 77, the spacing PX in the conveying direction of the internal electrode pattern 21 becomes shorter.

[0072] In this way, by changing the circumferential speed of the gravure roller 71 relative to the conveying speed of the ceramic green sheet 2, the spacing PX of the conveying direction of the internal electrode pattern 21 can be adjusted.

[0073] (2) In addition, the control unit 10 can also work with the operation of the gravure roller drive unit 77 to make the winding roller drive unit 41 work and change the rotation speed of the winding roller 4 while the circumferential speed of the gravure roller 71 is constant, thereby changing the conveying speed of the ceramic green sheet 2.

[0074] For example, if the conveying speed of the ceramic green sheet 2 is increased relative to the circumferential speed of the gravure roller 71, the spacing PX of the internal electrode patterns 21 in the conveying direction becomes longer. Conversely, if the conveying speed of the ceramic green sheet 2 is decreased relative to the circumferential speed of the gravure roller 71, the spacing PX of the internal electrode patterns 21 in the conveying direction becomes shorter.

[0075] In this way, by changing the circumferential speed of the ceramic green sheet 2 relative to the gravure roller 71, the spacing PX of the conveying direction of the internal electrode pattern 21 can be adjusted.

[0076] Furthermore, the gravure roller 71, the first pressing roller 72A, and the second pressing roller 72B can be driven independently. The first pressing roller 72A and the second pressing roller 72B rotate at essentially the same speed as the winding roller 4 and the supply roller 3 to prevent deformation of the pattern due to tension.

[0077] (3) Furthermore, the control unit 10 can move the tension adjustment roller 53 up and down via the tension adjustment roller drive unit 54 of the tension adjustment unit 5 to change the tension of the ceramic green sheet 2.

[0078] For example, if the tension adjusting roller 53 is moved downward by the tension adjusting roller drive 54, the tension of the ceramic green sheet 2 increases. As a result, the ceramic green sheet 2 extends in the conveying direction and its width narrows. If ink is transferred from the recess 73 to the ceramic green sheet 2, which extends in the conveying direction and has a narrower width, then when the tension is released, compared with the case of printing under low tension, the spacing PX of the transferred ink in the conveying direction is narrower and the spacing PY in the width direction is thicker.

[0079] Conversely, if the tension adjusting roller 53 is moved upward by the tension adjusting roller drive 54, the tension of the ceramic green sheet 2 decreases. As a result, the ceramic green sheet 2 narrows and widens in the conveying direction. If ink is transferred from the recess 73 onto the ceramic green sheet 2, which has narrowed and widened in the conveying direction, the spacing PX of the transferred ink extends and the spacing PY in the width direction narrows compared to printing under high tension.

[0080] According to this embodiment, a speed changing unit (gravure roller drive unit 77 and winding roller drive unit 41) is provided, which is capable of changing the relative speed between the conveying speed of the ceramic green sheet 2 and the circumferential speed of the gravure roller 71 at the contact portion between the ceramic green sheet 2, which is a sheet component, and the gravure roller 71.

[0081] Therefore, the relative speed between the conveying speed of the ceramic green sheet 2 and the circumferential speed of the gravure roller 71 can be changed by the speed change unit (gravure roller drive unit 77 and winding roller drive unit 41), so the spacing of the internal electrode pattern 21 can be finely adjusted, and the internal electrode pattern 21 can be printed with good accuracy.

[0082] Furthermore, according to this embodiment, a tension adjustment section 5 is provided, which is capable of adjusting the tension of the ceramic green sheet 2, which is a sheet component.

[0083] The tension of the ceramic sheet 2 can be changed by moving the tension adjustment roller 53 up and down via the tension adjustment roller drive 54 of the tension adjustment section 5. Therefore, the spacing of the internal electrode pattern 21 can be finely adjusted, and the internal electrode pattern 21 can be printed with good accuracy.

[0084] Furthermore, in the first embodiment, by changing the rotational speed of the first pressing roller 72A and the second pressing roller 72B, the tension when the ceramic green sheet 2 contacts the gravure roller 71 can be adjusted, and the first pressing roller 72A and the second pressing roller 72B can also function as tension adjustment units. Additionally, the first pressing roller 72A and the second pressing roller 72B may not be connected to the drive mechanism, or they may rotate only in conjunction with the conveying speed of the winding roller.

[0085] Therefore, the tension of the ceramic green sheet 2 can be changed, and the spacing of the internal electrode pattern 21 can be finely adjusted, so that the internal electrode pattern 21 can be printed with good precision.

[0086] (Second Implementation)

[0087] Next, the gravure printing apparatus 1B according to the second embodiment of the present invention will be described. Figure 5 This is a diagram illustrating the gravure printing apparatus 1B according to the second embodiment of the present invention.

[0088] The gravure printing apparatus 1B of the second embodiment includes a pressing roller 72 instead of the first pressing roller 72A and the second pressing roller 72B of the first embodiment. The pressing roller 72 is disposed opposite to the gravure roller 71, and holds the ceramic green sheet 2 between the pressing roller 72 and the gravure roller 71. The pressing roller 72 is a cylindrical or cylindrical member that rotates about an axis substantially parallel to the axis of the gravure roller 71. The outer peripheral surface of the pressing roller 72 is covered by an elastic member in the same way as the first pressing roller 72A and the second pressing roller 72B.

[0089] In the second embodiment, a speed changing unit (gravure roller drive unit 77 and winding roller drive unit 41) is also provided, which can change the relative speed of the conveying speed of the ceramic green sheet 2 and the circumferential speed of the gravure roller 71 at the contact portion between the ceramic green sheet 2, which is a sheet component, and the gravure roller 71.

[0090] Therefore, the relative speed between the conveying speed of the ceramic green sheet 2 and the circumferential speed of the gravure roller 71 can be changed by the speed changing unit (gravure roller drive unit 77 and winding roller drive unit 41). Thus, the spacing of the internal electrode pattern 21 can be finely adjusted, and the internal electrode pattern 21 can be printed with good accuracy.

[0091] In addition, it has a tension adjustment unit 5 that can adjust the tension of the ceramic green sheet 2, which is a sheet component.

[0092] The tension adjustment roller 53 can be moved up and down by the tension adjustment roller drive 54 of the tension adjustment unit 5, thereby changing the tension of the ceramic green sheet 2. Therefore, the spacing of the internal electrode pattern 21 can be finely adjusted, and the internal electrode pattern 21 can be printed with good accuracy.

[0093] The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments and various applications and modifications can be applied within the scope of the invention.

[0094] Explanation of reference numerals in the attached figures

[0095] 1A, 1B: Gravure printing apparatus;

[0096] 2: Ceramic green sheets (sheet components);

[0097] 3: Supply roller;

[0098] 4: Winding roller;

[0099] 5: Tension adjustment section;

[0100] 6: Tension measuring section;

[0101] 7: Gravure printing press;

[0102] 9: Spacing detection unit;

[0103] 10: Control Department;

[0104] 21: Internal electrode pattern;

[0105] 41: Winding roller drive unit (speed change unit);

[0106] 51: Guide roller;

[0107] 52: Guide roller;

[0108] 53: Tension adjusting roller;

[0109] 54: Tension adjustment roller drive unit;

[0110] 55: Winding roller;

[0111] 71: Gravure roller;

[0112] 72: Pressing roller;

[0113] 72A: First pressing roller;

[0114] 72B: Second pressing roller;

[0115] 73: Recess (ink holding area);

[0116] 74: Conductive paste;

[0117] 77: Gravure roller drive unit (speed change unit);

[0118] 78: Press roller drive unit.

Claims

1. A gravure printing apparatus for printing patterns for laminated ceramic capacitors, wherein, The gravure printing apparatus includes: A gravure roller has a cylindrical outer peripheral surface with multiple ink holding portions formed in a pattern. By rotating about an axis, the outer peripheral surface contacts one side of a strip-shaped sheet member being conveyed at a given speed, thereby transferring the ink held in the ink holding portions to the sheet member, and printing the ink in a pattern on the side of the sheet member. The speed change unit is capable of changing the relative speed between the conveying speed of the sheet component and the circumferential speed of the gravure roller at the contact portion between the sheet component and the gravure roller. The tension adjustment section is capable of adjusting the tension of the sheet component; and The control unit compares the spacing of the ink printed in a pattern with a target value. If the spacing differs from the target value, it feeds back the result to the speed change unit or the tension adjustment unit. The speed changing unit can change the circumferential speed of the gravure roller. The spacing includes the spacing of the patterned ink in the conveying direction of the sheet member, and the spacing of the patterned ink in the width direction perpendicular to the conveying direction.

2. The gravure printing apparatus according to claim 1, wherein, The tension adjustment section includes a tension adjustment roller.

3. The gravure printing apparatus according to claim 1 or 2, wherein, have: The gravure roller drive unit rotates and drives the gravure roller. The pressing roller clamps the sheet component between itself and the gravure roller, pressing the sheet component toward the gravure roller side; and The pressing roller drive unit is capable of rotating the pressing roller at a different circumferential speed than the gravure roller.

4. The gravure printing apparatus according to claim 1 or 2, wherein, It includes: a first pressing roller and a second pressing roller, which are respectively disposed on the upstream and downstream sides, clamping the gravure roller in the conveying direction of the sheet member, pressing the sheet member from the other side and winding it around the outer peripheral surface of the gravure roller.

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