JP2006051651A - Gravure printer and method for manufacturing laminated ceramic electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gravure printer which can form a conductive paste film with excellent smoothness by gravure printing. <P>SOLUTION: In this gravure printer, a plurality of cells 17 partitioned by a bank 15 in a printing direction and a bank 16 in an intersecting direction, are formed in an image line part 13 formed on the peripheral surface of a gravure roll 2, and a notch 19 is formed in the bank 16 in the intersecting direction so that the adjacent cells 17 can communicate with each other in the printing direction. The bank 16 in the intersecting direction located in the center of the image line part 13, has the notch 19 formed in a position coming into contact with the bank 15 in the printing direction. Consequently, the bank 16 in the intersecting direction is positioned independently of the bank 15 in the printing direction. Also, the method for manufacturing a laminated ceramic electronic component is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gravure printing machine and a method for manufacturing a multilayer ceramic electronic component implemented using the gravure printing machine, and in particular, improves the smoothness of transfer of a printing paste to a printing sheet during gravure printing and gravure printing. The present invention relates to a technique for improving the smoothness of a paste film formed by.

  In order to manufacture a multilayer ceramic electronic component such as a multilayer ceramic capacitor, for example, a step of forming a conductive paste film serving as an internal electrode on a ceramic green sheet is performed. The internal electrode provided by the conductive paste film is required to have high pattern accuracy. Gravure printing has attracted attention as a technique that can satisfy this requirement (see, for example, Patent Document 1).

  In patent document 1, in order to equalize the thickness in the outer peripheral part of the paste film formed by the gravure printing, it forms in the image line part to which the printing paste is provided, which is formed on the peripheral surface of the gravure roll. For a plurality of cells, the cell opening area in the outer peripheral portion is made smaller than the cell opening area in the central portion, and the cell depth in the outer peripheral portion is made shallower than the cell depth in the central portion. Things are listed.

  However, since the cells described in Patent Document 1 are independent of each other in the image area, the ratio of the area of the cell portion to the area of the entire image area is relatively low. In some cases, the flow of printing paste between adjacent cells cannot occur, so that it is particularly unsuitable for printing to form a paste film having a relatively large area, and uneven printing tends to occur.

  As what can solve the above-mentioned problem, although it is not intended to be applied in the field of electronic components, for example, there are those described in Patent Document 2 or Patent Document 3.

  In Patent Document 2, a bank defining a plurality of cells formed in an image line portion is disposed so as to extend obliquely with respect to the printing direction, and each cell is in a communicating state between adjacent ones. Proposals have been proposed in which the banks that divide the cells are finely divided and notches are provided at the intersections of the banks.

  According to the technique described in Patent Document 2 described above, the ratio of the area of the area (that is, the cell and the notch) that can hold the printing paste to the area of the entire image portion can be increased, and through the notch. The flow of printing paste can be expected.

  However, in the technique described in Patent Document 2, since it is an essential requirement that the notch interval be smaller than the width of the bank, a printing paste having a relatively high viscosity such as a conductive paste is used. If this occurs, the flow of the printing paste between adjacent cells is limited. As a result, traces of cells may remain in the printed paste film, or a smooth paste film may not be formed.

  Further, in the technique described in Patent Document 2, a bank defining a plurality of cells formed in an image line portion is finely divided while being arranged so as to extend obliquely with respect to the printing direction. Since notches are provided at the intersections of the banks, when using a printing paste having a relatively high viscosity such as a conductive paste, the so-called stringing of the printing paste when the printing sheet leaves the gravure roll is prevented. It does not occur stably, and stringing tends to occur frequently. This also causes the formation of a smooth paste film.

  On the other hand, in Patent Document 3, the cells are in communication with each other at the intersection of the printing direction bank defining a plurality of cells formed in the image line portion and the vertical direction bank extending in a direction perpendicular thereto. Some have been removed by etching.

  According to the technique described in Patent Document 3 described above, since the printing paste is filled also at the intersections of the banks, it is possible to expect improvement in the uniformity or smoothness of the thickness of the paste film.

  However, in the technique described in Patent Document 3, since the path for the printing paste caused by the etching removal at the crossing portion of the bank is relatively shallow and thin, the flow resistance of the printing paste passing therethrough is large. Therefore, for example, when a printing paste having a relatively high viscosity, such as a conductive paste, is used, the flow of the printing paste between adjacent cells cannot substantially occur, and as a result, a smooth paste film cannot be formed. There is.

Further, even in the technique described in Patent Document 3, when a printing paste having a relatively high viscosity such as a conductive paste is used, stringing does not occur stably, and stringing is likely to be frequently cut. The formation of a smooth paste film may be hindered.
JP-A-9-76459 Japanese Utility Model Publication No. 5-41015 JP 59-232347 A

  Accordingly, an object of the present invention is to provide a gravure printing machine and a method for manufacturing a multilayer ceramic electronic component implemented using the gravure printing machine, which can solve the above-described problems.

  The present invention is first directed to a gravure printing machine for forming a paste film on a printing sheet by gravure printing.

  This gravure printing machine includes a gravure roll that forms an image line portion to which a printing paste for providing a paste film is applied on its peripheral surface.

  The image line portion is provided with a printing direction bank extending substantially in the printing direction and a cross direction bank extending in a direction intersecting the printing direction bank, and a plurality of sections divided by the printing direction bank and the cross direction bank. Cells are formed. Further, in order to make the cells adjacent in the printing direction communicate with each other, a notch is provided in the crossing bank.

  The gravure printing machine having such a configuration is characterized by having the following configuration in order to solve the technical problems described above.

  That is, at least a part of the cross-direction banks is characterized in that the above-mentioned notch is provided at a position in contact with the printing-direction bank, and is thereby positioned independently of the printing-direction bank. .

  Note that the direction in which the bank in the printing direction extends is the substantially printing direction because there is an allowable range of about ± 5 degrees with respect to the printing direction.

  As described above, it is preferable that the cross direction bank located independently of the printing direction bank is distributed in at least the central portion of the image line portion. In this case, it is more preferable that more than half of the cross-direction banks distributed in the central portion of the image line portion are located independently of the print-direction banks, and most preferably distributed in the central portion of the image line portion. That is, all cross-direction banks are located independently of the printing-direction banks.

  For at least some of the cross-direction banks, a notch may be further provided at an intermediate position between adjacent printing-direction banks.

  As described above, the crossing direction bank extends in a direction intersecting the printing direction bank, but most typically, it extends in a direction perpendicular to the printing direction bank.

  The opening width of the notch is preferably larger than the width of the crossing bank.

  It is preferable that the printing direction bank is provided so as to extend substantially continuously from the printing start end to the printing end in the image line portion. The fact that the printing direction bank extends substantially continuously means that the printing direction bank may be interrupted at several points in the middle, and for example, grooves may be formed at the start and end of printing. ing.

  The gravure printing machine according to the present invention is particularly preferably used for producing a multilayer ceramic electronic component. In this case, the patterned layer forming a part of the multilayer structure provided in the multilayer ceramic electronic component becomes a paste film formed by the gravure printing machine. Therefore, the present invention is also directed to a method for manufacturing a multilayer ceramic electronic component that is carried out using the gravure printing machine as described above.

  In the method for manufacturing a multilayer ceramic electronic component according to the present invention, it is preferable that gravure printing is used to form a conductive paste film that becomes an internal electrode. That is, a conductive paste is used as the above-described printing paste, and the paste film formed by the printing paste is preferably a conductive paste film serving as an internal electrode.

  In the method of manufacturing a multilayer ceramic electronic component according to the present invention, gravure printing is to form a step-absorbing ceramic layer formed in a region where the internal electrode is not formed in order to absorb the step due to the thickness of the internal electrode. It is also preferable that it is used for. That is, it is preferable that a ceramic slurry is used as the above-described printing paste, and the paste film formed by the printing paste is a step absorbing ceramic layer.

  As described above, according to the gravure printing machine according to the present invention, the image line portion formed on the peripheral surface of the gravure roll is provided with the printing direction bank and the cross direction bank and intersects with the printing direction bank. In order to establish a communication state between adjacent cells divided by a directional bank, a notch is provided in the cross direction bank, and at least a part of the cross direction bank has the above-described notch. Conductive paste provided at a position in contact with the printing direction bank and thereby independent of the printing direction bank, for example, a relatively high content of inorganic powder, and thus a relatively high viscosity Or even if something like a ceramic slurry is used as a printing paste, the printing paste flows smoothly through notches between cells adjacent in the printing direction. Can, and the stringing of the printing paste can be produced stably, so that it is possible to improve the smoothness of the paste film formed by gravure printing.

  The effects as described above are as follows: (1) When cross-direction banks located independently of the printing-direction banks are distributed at least in the center of the image line portion, (2) distributed in the center of the image line portion. When more than half of the cross-direction banks are located independently from the print-direction bank, (3) all cross-direction banks distributed in the center of the image line are located independently from the print-direction bank. It is more prominent in the order of

  In addition, the effect as described above is that when at least a part of the cross-direction banks is further provided with a notch at an intermediate position between adjacent printing-direction banks, the opening width of the notch is determined to be the width of the cross-direction bank. Even when the size is increased, or when the printing direction bank is provided so as to extend substantially continuously from the printing start end to the printing end in the image line portion, it is more remarkably exhibited.

  When the crossing direction bank extends in a direction perpendicular to the printing direction bank, the movement of the printing paste in each cell during printing occurs in a well-balanced manner. This also contributes to improving the smoothness of the paste film.

  From the above, the gravure printing machine according to the present invention can exhibit more remarkable effects when applied to the production of multilayer ceramic electronic components. This is because, in the production of a multilayer ceramic electronic component, for example, a conductive paste or ceramic slurry having a relatively high viscosity is used as a printing paste. That is, if applied to the production of multilayer ceramic electronic components using the gravure printing machine according to the present invention, the characteristics of the obtained multilayer ceramic electronic components can be stabilized, and the occurrence of defective products can be suppressed, The manufacturing yield can be improved.

  In particular, if a conductive paste film or a step absorbing ceramic layer serving as an internal electrode provided in a multilayer ceramic electronic component is formed by the gravure printing machine according to the present invention, the conductive paste film or the step absorbing ceramic layer Since the thickness can be made uniform, it is possible to prevent a short circuit failure or an insulation resistance failure in the obtained multilayer ceramic electronic component.

  FIG. 1 is a front view schematically showing a gravure printing machine 1 according to a first embodiment of the present invention.

  The gravure printing machine 1 includes a gravure roll 2 and an impression cylinder 4 opposed to the gravure roll 2 with a printing sheet 3 interposed therebetween. The gravure roll 2 and the impression cylinder 4 rotate in the directions of arrows 5 and 6, respectively, so that the printing sheet 3 is conveyed in the direction of arrow 7. There may be a gravure printing machine that does not include an impression cylinder as in the case of a gravure lithographic printing machine.

  The gravure printer 1 is used for manufacturing a multilayer ceramic electronic component such as a multilayer ceramic capacitor. More specifically, the gravure printing machine 1 is used to form a paste film to be a patterned layer that forms a part of a multilayer structure provided in a multilayer ceramic electronic component on the printing sheet 3 by gravure printing. It is done. More specifically, as shown in FIG. 2, a conductive paste film 9 to be a patterned internal electrode is formed on the ceramic green sheet 8 by gravure printing.

  The ceramic green sheet 8 is backed by a carrier film 10 as shown in FIG. Therefore, the printing sheet 3 shown in FIG. 1 is the ceramic green sheet 8 backed by the carrier film 10 in this way.

  As shown in FIG. 1, the gravure roll 2 is immersed in a conductive paste 12 accommodated in a tank 11, whereby a plurality of image line portions 13 (formed on the peripheral surface of the gravure roll 2 ( A part of the conductive paste 12 is schematically shown). Details of the image line unit 13 will be described later. The conductive paste 12 may be supplied to the gravure roll 2 by a method such as injecting the conductive paste 12 toward the gravure roll 2. Excess conductive paste 12 on the peripheral surface of the gravure roll 2 is scraped off by a doctor blade 14.

  The image line portion 13 has a pattern corresponding to the pattern of the conductive paste film 9 shown in FIG. 2, as only a representative one is schematically shown in FIG. In this embodiment, the longitudinal direction of the image line portion 13 is directed to the circumferential direction of the gravure roll 2.

  FIG. 4 is a development view of the peripheral surface of the gravure roll 2, showing one image portion 13 in an enlarged manner. In FIG. 4, the printing direction is indicated by an arrow, and this printing direction corresponds to the arrow 5 shown in FIG. More specifically, the upper end side in FIG. 4 of the image line unit 13 is the printing start end side, and the lower end side is the printing end side. Therefore, in the printing process, the region of the image line portion 13 that contacts the printing sheet 3 changes its position from the upper end side to the lower end side in FIG.

  The image line portion 13 includes a plurality of printing direction banks 15 extending in the printing direction and a plurality of cross direction banks 16 extending in the direction intersecting the printing direction bank 15, in the illustrated embodiment, in the vertical direction. Provided. Then, a plurality of cells 17 partitioned by the printing direction bank 15 and the cross direction bank 16 are formed.

  Looking at the opening area of each of the plurality of cells 17, the cell 17 (A) positioned at the side edge of the image line portion 13 is the cell 17 (B) positioned at the center of the image line portion 13. It is smaller than Further, the cell 17 (C) positioned on the printing end side of the image line unit 13 is made smaller than the cell 17 (D) positioned on the printing start end side of the image line unit 13. By adopting such a configuration, the so-called “saddle phenomenon” described below can be made difficult to occur.

  In general, when a paste film is formed by applying gravure printing, a so-called “saddle phenomenon” in which the peripheral portion of the paste film becomes thicker than the central portion tends to occur. When a multilayer ceramic electronic component is manufactured using a conductive paste film in which such a “saddle phenomenon” has occurred, a short circuit failure or a structural defect may be caused. The configuration as described above is effective in suppressing such a “saddle phenomenon”.

  From the opposite viewpoint, the cell 17 (D) located on the printing start end side of the image line portion 13 is made larger than the cell 17 (C) located on the printing end side of the image line portion 13. Will be. This is for preventing printing fading and insufficient transfer of the conductive paste 12.

  In addition, neither the printing direction bank 15 nor the cross direction bank 16 is allowed to reach the peripheral edge of the image line unit 13, thereby forming a groove 18 having a predetermined width. This is for improving the linearity of the contour of the printed conductive paste film 9.

  In order to make the cells 17 adjacent in the printing direction communicate with each other, a notch 19 is provided in the cross bank 16. The notch 19 located at the side edge of the image line portion 13 forms part of the groove 18 described above.

  Further, at least a part of the crossing direction bank 16, that is, in this embodiment, the crossing direction bank 16 distributed in the central portion of the image line part 13 is a position where the above-described notch 19 is in contact with the printing direction bank 15. Thereby being positioned independently of the printing direction bank 15. Thus, it is preferable that the cross direction bank 16 positioned independently of the printing direction bank 15 is more than half of the cross direction bank 16 distributed in the center of the image line portion, and more preferably, As in the embodiment, all of the cross-directional banks 16 distributed in the center of the image line unit 13 are used.

  The opening width W1 of the notch 19 is preferably made larger than the width W2 of the crossing bank 16. For example, the width W2 of the cross bank 16 is 5 to 20 μm, whereas the opening width W1 of the notch 19 is 20 to 40 μm.

  Further, each printing direction bank 15 extends substantially continuously from the printing start end to the printing end in the image line unit 13.

  By adopting such a configuration, even if the conductive paste 12 having a higher viscosity of, for example, 1 to 100 Pa · s than the general gravure ink is used as the printing paste, the ink in the general gravure printing is also used. Even when a paste film having a thickness larger than the thickness of the film, for example, 0.5 to 2 μm, is formed, an entirely smooth paste film can be advantageously formed.

  More specifically, the conductive paste 12 can smoothly flow through the notch 19 between the cells 17 adjacent in the printing direction, and stringing of the conductive paste 12 can be stably generated. . As a result, the smoothness of the formed conductive paste film 9 can be improved. Further, the linearity of the contour of the outer periphery of the conductive paste film 9 can be made excellent.

  As described above, after the ceramic green sheet 8 on which the conductive paste 9 as shown in FIG. 2 is formed is obtained using the gravure printing machine 1, a plurality of ceramic green sheets 8 are laminated and pressure-bonded, and necessary. Are cut and then fired to obtain a laminated structure that becomes a component body for the multilayer ceramic electronic component. In this laminated structure, the conductive paste film 9 described above constitutes an internal electrode. Next, if necessary, external electrodes and the like are formed on the outer surface of the multilayer structure, thereby completing a desired multilayer ceramic electronic component.

  In such a multilayer ceramic electronic component, as described above, since the conductive paste film 9 is formed smoothly over the entire surface, stress is not concentrated locally in the crimping process. It is possible to prevent a short-circuit failure such as contact through the electrode, or a local decrease in the thickness of the ceramic layer to cause an insulation resistance failure.

  5, FIG. 6, FIG. 7 and FIG. 8 are views corresponding to a part of FIG. 4 for explaining the second, third, fourth and fifth embodiments of the present invention, respectively. 5 to 8, elements corresponding to those shown in FIG. 4 are denoted by the same reference numerals, and redundant description is omitted.

  The second to fourth embodiments shown in FIG. 5 to FIG. 7 particularly provide a modification of the shape of the cross-direction bank 16, and none of the cross-direction banks 16 extends linearly. .

  In the second embodiment shown in FIG. 5, the cross bank 16 has an inverted V shape. In the third embodiment shown in FIG. 6, the crossing direction bank 16 has a V shape. In the fourth embodiment shown in FIG. 7, the crossing direction bank 16 has a wave shape.

  These changes in the shape of the cross-direction bank 16 allow a fine adjustment of the resistance to the flow of the conductive paste 12 in the image portion 13 when the gravure printing is performed. Therefore, the amount of the conductive paste 12 flowing between the cells 17 adjacent in the printing direction can be adjusted, and the smoothness of the surface of the conductive paste film 9 can be further improved depending on the viscosity of the conductive paste 12 used. It becomes possible.

  For example, if the second embodiment shown in FIG. 5 is compared with the third embodiment shown in FIG. 6, the second embodiment is more conductive than the third embodiment. 12 flows are likely to occur. Therefore, when the viscosity of the conductive paste 12 is relatively high, it is desirable to apply the second embodiment shown in FIG. 5, while when the viscosity of the conductive paste 12 is low, it is shown in FIG. It is desirable to apply the third embodiment shown.

  The fifth embodiment shown in FIG. 8 is characterized in that an intermediate notch 20 is further provided in an intermediate position between adjacent printing direction banks 15 in the cross direction bank 16. Such an intermediate notch 20 makes it easier for the conductive paste 12 to flow between the cells 17 adjacent in the printing direction. Therefore, the presence / absence of the intermediate notch 20, the opening width of the intermediate notch 20, the number and positions of the intermediate notches 20, and the like may be determined according to the fluidity required for the conductive paste 12.

  While the present invention has been described with reference to the illustrated embodiment, various other modifications are possible within the scope of the present invention.

  For example, in the illustrated embodiment, the image portion 13 is rectangular, but the shape of the image portion is arbitrarily changed according to the pattern of the conductive paste film 9 to be formed by gravure printing. can do.

  In the illustrated embodiment, the printing sheet 3 is a ceramic green sheet 8 backed by a carrier film 10, and the conductive paste film 9 is formed on the ceramic green sheet 8. Only such a resin sheet may be used as the printing sheet 3, and the conductive paste film 9 may be formed on the resin sheet. In this case, the conductive paste film 9 formed on the resin sheet is transferred onto the ceramic green sheet 8 in a subsequent process.

  In the illustrated embodiment, the paste film formed by gravure printing is the conductive paste film 9, but may be a film made of a paste like ceramic slurry, for example. More specifically, for example, in a multilayer ceramic capacitor or the like, in order to absorb a step due to the thickness of the internal electrode, a step absorbing ceramic layer may be formed in a region where the internal electrode is not formed. The present invention can also be applied to a case where a paste film made of a ceramic slurry to be a layer is to be formed.

1 is a front view schematically showing a gravure printing machine 1 according to a first embodiment of the present invention. It is sectional drawing which shows the state by which the conductive paste film | membrane 9 was formed on the ceramic green sheet 8 backed by the carrier film 10 as the to-be-printed sheet 3 with the gravure printing machine 1 shown in FIG. It is a perspective view which shows independently the gravure roll 2 shown in FIG. FIG. 4 is a development view of the peripheral surface of the gravure roll 2, showing an enlargement of one image line portion 13 shown in FIG. 3. It is a figure equivalent to a part of FIG. 4 for describing 2nd Embodiment of this invention. It is a figure equivalent to a part of FIG. 4 for demonstrating the 3rd Embodiment of this invention. It is a figure equivalent to a part of FIG. 4 for demonstrating 4th Embodiment of this invention. It is a figure equivalent to a part of FIG. 4 for demonstrating 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gravure printing machine 2 Gravure roll 3 Sheet to be printed 8 Ceramic green sheet 9 Conductive paste film 12 Conductive paste 13 Image line 15 Print direction bank 16 Cross direction bank 17 Cell 19, 20 Notch

Claims (12)

A gravure printing machine for forming a paste film on a printing sheet by gravure printing,
A gravure roll forming an image line portion to which a printing paste giving the paste film is applied on its peripheral surface,
The image line portion is provided with a printing direction bank extending substantially in the printing direction and a cross direction bank extending in a direction intersecting the printing direction bank, and is partitioned by the printing direction bank and the cross direction bank. A plurality of cells are formed,
In order to establish a communication state between the cells adjacent in the printing direction, the crossing bank is provided with a notch,
At least a part of the cross-direction bank is provided at a position where the notch is in contact with the printing-direction bank, thereby being positioned independently of the printing-direction bank.
Gravure printing machine.   The gravure printing press according to claim 1, wherein the cross-direction bank positioned independently of the printing-direction bank is distributed at least in a central portion of the image line portion.   The gravure printing press according to claim 2, wherein more than half of the cross-direction banks distributed in the center of the image line portion are located independently of the printing-direction banks.   The gravure printing machine according to claim 3, wherein all of the cross-direction banks distributed in a central portion of the image line portion are located independently of the printing-direction banks.   The gravure printing machine according to any one of claims 1 to 4, wherein at least a part of the cross-direction bank is further provided with the notch at an intermediate position between the adjacent printing-direction banks.   The gravure printing machine according to any one of claims 1 to 5, wherein the cross-direction bank extends in a direction perpendicular to the printing-direction bank.   The gravure printing machine according to any one of claims 1 to 6, wherein an opening width of the notch is larger than a width of the bank in the cross direction.   The gravure printing machine according to any one of claims 1 to 7, wherein the printing direction bank is provided so as to extend substantially continuously from a printing start end to a printing end in the image line portion.   9. The multilayer ceramic electronic component is used for manufacturing, and the paste film is to be a patterned layer forming a part of a multilayer structure provided in the multilayer ceramic electronic component. A gravure printing machine according to any one of the above.   The manufacturing method of a multilayer ceramic electronic component implemented using the gravure printing machine of Claim 9.   The method for producing a multilayer ceramic electronic component according to claim 10, wherein a conductive paste is used as the printing paste, and the paste film is a conductive paste film that serves as an internal electrode.   The ceramic slurry is used as the printing paste, and the paste film is a step-absorbing ceramic layer formed in a region where the internal electrode is not formed in order to absorb a step due to the thickness of the internal electrode. Manufacturing method for multilayer ceramic electronic parts.

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