JP4347858B2 - Method and apparatus for pressing ceramic green sheet laminate - Google Patents

Description

  The present invention relates to a pressing method and a pressing apparatus for a ceramic green sheet laminate.

The manufacturing process of the multilayer electronic component includes a process of pressing a laminated body in which a plurality of ceramic sheets are laminated in a predetermined order by pressing. As a technique related to such a press, for example, there is a method of manufacturing a multilayer ceramic electronic component described in Patent Document 1. In this conventional method for manufacturing a multilayer ceramic electronic component, a release material layer made of, for example, polytetrafluoroethylene resin is bonded to the surface of a mold used for pressing, and the laminate is pressed through this release material layer. .
JP-A-10-214747

  Like the mold release material layer described above, the technology of interposing a highly peelable film between the laminate and the mold during pressing ensures the peelability between the pressed laminate and the mold, to the mold. This is a significant technique in that it can suppress the peeling and deformation of the laminated body due to the adhesion. However, when a film having an area substantially equal to that of the multilayer body is used as in the conventional method for manufacturing a multilayer ceramic electronic component described above, there has been a problem that misalignment easily occurs between the multilayer body and the film. When such a positional shift occurs, the uniformity of the pressure applied from the mold to the laminated body during pressing is impaired, and there is a risk of increasing the dimensional variation of the laminated body after pressing.

  The present invention has been made to solve the above problems, and is a press of a ceramic green sheet laminate that can suppress the dimensional variation of the laminate after pressing while ensuring the peelability between the laminate and the press die. It is an object to provide a method and a pressing device.

  In order to solve the above problems, a method for pressing a ceramic green sheet laminate according to the present invention is a laminate in which a plurality of ceramic green sheets are laminated by an upper die and a lower die that are arranged so that their press surfaces face each other. A method for pressing a ceramic green sheet laminate, wherein the first flexible film and the second flexible film are formed so as to be opposed to the upper mold press surface and the lower mold press surface. A step of transporting each of the adhesive films, a step of disposing the laminate between the first flexible film and the second flexible film between the upper mold press surface and the lower mold press surface; At least one of the upper die and the lower die is advanced toward the other so that the press surfaces are relatively close to each other, and the laminate is ceramic through the first flexible film and the second flexible film. Glee It is characterized in that a step of pressing the stacking direction of the sheet.

  In this method of pressing a ceramic green sheet laminate, a first flexible film and a second flexible film having a long shape are interposed between an upper mold and a lower mold, and the first flexible film And the laminated body of the ceramic green sheet is pressed through the second flexible film. Thus, by using a flexible film having a long shape, tolerance of positioning of the laminate with respect to the longitudinal direction of the flexible film is eased, and positioning of the flexible film and the laminate is easy. It becomes. Therefore, the pressure applied to the laminated body from the pressing mold during pressing can be made uniform, and the dimensional variation of the laminated body after pressing can be suppressed while ensuring the peelability between the upper mold and the lower mold and the laminated body.

  Moreover, it is preferable to further include a step of arranging an annular frame body between the first flexible film and the second flexible film so as to surround the side surface of the laminate. In this case, the deformation of the laminated body during pressing can be regulated by the annular frame.

  Moreover, it is preferable to further include a step of turning back the conveying direction of the first flexible film or the second flexible film by the edge portion on the downstream side of the arrangement position of the upper mold and the lower mold. If it carries out like this, the peeling defect at the time of peeling a flexible film from the laminated body after a press can be prevented.

  The press device according to the present invention is a press device that presses a laminated body in which a plurality of ceramic green sheets are laminated by an upper die and a lower die arranged so that the press surfaces face each other. The first film conveying means and the second film for conveying the first flexible film and the second flexible film, respectively, which are long so as to face the pressing surface of the lower mold and the pressing surface of the lower mold At least one of the upper mold and the lower mold is advanced toward the other so that the press means and the pressing surface are relatively close to each other, and the first flexible film and the second flexible film are interposed. And a mold control means for pressing the laminate in the laminating direction of the ceramic green sheets.

  In this press apparatus, the first flexible film and the second flexible film having a long shape are interposed between the upper mold and the lower mold, and the first flexible film and the second flexible film are interposed. The laminated body of ceramic green sheets can be pressed through the conductive film. Thus, by using a flexible film having a long shape, tolerance of positioning of the laminate with respect to the longitudinal direction of the flexible film is eased, and positioning of the flexible film and the laminate is easy. It becomes. Therefore, the pressure applied to the laminated body from the pressing mold during pressing can be made uniform, and the dimensional variation of the laminated body after pressing can be suppressed while ensuring the peelability between the upper mold and the lower mold and the laminated body.

  Moreover, it is preferable to further include a frame arrangement means for arranging an annular frame body between the first flexible film and the second flexible film so as to surround the side surface of the laminate. In this case, the deformation of the laminated body during pressing can be regulated by the annular frame.

  It is preferable to further include an edge portion that turns back the transport direction of the first flexible film or the second flexible film on the downstream side of the arrangement position of the upper mold and the lower mold. If it carries out like this, the peeling defect at the time of peeling a flexible film from the laminated body after a press can be prevented.

  As described above, according to the method and apparatus for pressing a ceramic green sheet laminate according to the present invention, the dimensional variation of the laminate after pressing is suppressed while ensuring the peelability between the laminate and the press die. it can.

  Hereinafter, preferred embodiments of a method for pressing a ceramic green sheet laminate and a press apparatus according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a configuration of a ceramic capacitor manufactured by using a method for pressing a ceramic green sheet laminate according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG. As shown in FIGS. 1 and 2, the ceramic capacitor 1 includes an element portion 2 having a substantially rectangular parallelepiped shape, and a pair of terminal electrodes 3 and 3 formed at both ends in the longitudinal direction of the element portion 2. Yes.

  As shown in FIG. 2, the element portion 2 is configured by alternately laminating dielectric layers 4 and internal electrode layers 5. As shown in FIG. 3, such an element portion 2 is formed by sequentially laminating dielectric layers 4 on which rectangular internal electrode layers 5 are formed. Further, dielectric layers 6 in which the internal electrode layer 5 is not formed are laminated as protective layers at both ends of the element unit 2 in the lamination direction. Although simplified in FIG. 2, in practice, about 300 dielectric layers 4 are laminated.

  The internal electrode layers 5 and 5 adjacent to each other in the upper and lower sides face each other with a certain area and are electrically insulated from each other by the dielectric layer 4. The internal electrode layers 5 and 5 extend to the end of the dielectric layer 4 and are electrically connected to one terminal electrodes 3 and 3 different from each other. Therefore, when a predetermined voltage is applied to the terminal electrodes 3, 3, charges proportional to the facing area are stored between the internal electrode layers 5, 5 facing vertically.

  Then, the manufacturing method of the ceramic capacitor 1 mentioned above is demonstrated.

First, a plurality of layers of ceramic green sheets 7 and 8 are manufactured using a dielectric material mainly composed of BaTiO ₃ . Next, for example, a conductive paste mainly composed of Ag is screen-printed, and a predetermined drying process is performed to form rectangular conductive patterns 6 in a matrix on the ceramic green sheet 7. After a predetermined number of ceramic green sheets 7 are formed and sequentially stacked, two ceramic green sheets 8 not having the conductive pattern 6 are stacked on both end surfaces in the stacking direction of the ceramic green sheets 7 as shown in FIG. Then, the laminate 30 is formed. At this time, the green sheets 7 and 8 are temporarily pressure-bonded to such an extent that they can be handled as a laminated body 30.

  After the laminated body 30 is formed, a crimping process for pressing and laminating the laminated body 30 is performed. FIG. 5 is a diagram showing a device configuration of the press device 10 used in the crimping process. As shown in FIG. 5, the press apparatus 10 includes a press mold 11 including an upper mold 11a and a lower mold 11b, a vacuum suction plate 12, an upper film transport mechanism (first film transport means) 13, and a lower film. A transport mechanism (second film transport unit) 14, an annular frame 15, and an operation control unit (mold control unit, frame body arrangement unit) 16 are provided.

  The upper mold 11a and the lower mold 11b are arranged in a pair at the press position P so that the press surfaces 20a and 20b face each other. The upper die 11a is lowered to the lower die 11b side in synchronization with the laminate 30 and the flexible film 24 described later being conveyed to the press position P under the control of the operation control unit 16, and after the press, Ascend to the original position. Moreover, the vacuum suction plate 12 conveys the laminated body 30 to the press position P, and mounts the laminated body 30 on the lower mold | type 11b via the lower film 24b mentioned later. After the press is completed, the vacuum suction plate 12 conveys the stacked body 30 to a predetermined take-out position (not shown).

  The upper film transport mechanism 13 includes a feeding roller 21, a winding roller 22, and auxiliary rollers 23 and 23 arranged between the feeding roller 21 and the winding roller 22. From the supply roller 21, a long flexible film 24 (first flexible film, hereinafter referred to as “upper film 24a”) made of, for example, PET (polyethylene terephthalate) is supplied. The upper film 24a has a width that is slightly smaller than the width of the laminate 30 (see FIG. 10). The fed upper film 24a is guided by the auxiliary rollers 23 and 23, conveyed to the press position P so as to face the press surface 20a of the upper mold 11a, and then taken up by the take-up roller 22.

  Similarly to the upper film transport mechanism 13, the lower film transport mechanism 14 includes a feeding roller 25, a winding roller 26, auxiliary rollers 27 and 27 disposed between the feeding roller 25 and the winding roller 26, and a press position. And auxiliary rollers 28 and 28 arranged on the downstream side of P. A long flexible film 24 (second flexible film, hereinafter referred to as “lower film 24 b”) similar to the upper film 24 a is fed from the feeding roller 25. The lower film 24b has a larger width than the upper film 24a (see FIG. 10). The drawn-out lower film 24b is guided by auxiliary rollers 27 and 27 and conveyed to the press position P so as to face the press surface 20b of the lower mold 11b in a state where the center is aligned with the upper film 24a.

  In the lower film transport mechanism 14, an edge portion 29 that folds the lower film 24 b is provided on the downstream side of the press position P. Then, the lower film 24 b is folded back at an acute angle along the tip of the edge portion 29, and is then wound around the winding roller 26 via the auxiliary rollers 28 and 28.

  As shown in FIG. 6, the annular frame 15 is formed in a substantially square shape with, for example, metal. As shown in FIG. 5, the annular frame 15 is supported between the upper film 24a and the lower film 24b at the press position P by, for example, a support arm (not shown). The annular frame 15 is lowered to the lower mold 11 b side when the stacked body 30 is conveyed to the press position P by the vacuum suction plate 12 by the control of the support arm by the operation control unit 16, and the side surface of the stacked body 30. Is placed on the lower film 24b. After pressing, the annular frame 15 is raised to the original position.

  As shown in FIG. 7, the press-bonding process using the press device 10 includes a film transport process (step S01), a laminate transport process (step S02), a frame body placement process (step S03), and a pressurizing process. Five steps of (Step S04) and a peeling step (Step S05) are included.

  First, in the film transport process, the upper film transport mechanism 13 and the lower film transport mechanism 14 cause the upper film 24a and the lower film 24b to face the press surface 20a of the upper mold 11a and the press surface 20b of the lower mold 11b, respectively. It is conveyed to the press position P. Next, in a laminated body conveyance process, as shown to Fig.8 (a), the laminated body 30 is conveyed toward the press position P by the vacuum suction plate 12. FIG. And as shown in FIG.8 (b), after the laminated body 30 has been arrange | positioned on the press surface 20b of the lower mold | type 11b in the state pinched | interposed into the upper film 24a and the lower film 24b, the vacuum suction plate 12 is a press. Retreat to the downstream side of the position P.

  Further, in the frame body arranging step, as shown in FIG. 9A, the annular frame body 15 is lowered toward the lower mold 11b by a support arm (not shown). Accordingly, as shown in FIGS. 9A and 10, the upper film 24 a and the lower film 24 b are respectively arranged above and below the laminated body 30 placed on the lower mold 11 b at the press position P. The frame body 15 is placed on the upper surface of the lower mold 11b through the lower film 24b so as to surround the side surface of the laminated body 30.

After the arrangement of the laminate 30, the upper film 24a, the lower film 24b, and the annular frame 15 is finished, in the pressurizing step, as shown in FIG. 9B, the upper mold 11a faces the lower mold 11b. Descend. Thus, the laminate 30 is sandwiched between the press surface 20a of the upper mold 11a and the press surface 20b of the lower mold 11b via the upper film 24a and the lower film 24b, and is press-bonded with a certain pressure in the stacking direction. The temperature of the upper die 11a and the lower die 11b during press bonding is preferably in the range of about 50 ° C. to about 70 ° C., and the press pressure is in the range of about 600 kg / cm ² to about 800 kg / cm ² . It is preferable to do. This is because when the temperature range and the pressure range are lower than the lower limit, poor press bonding is likely to occur, and when the temperature range and the pressure range are higher than the upper limit, the laminate 30 is likely to be deformed.

  After press-bonding, as shown in FIG. 11A, when the upper mold 11a and the annular frame 15 are raised to their original positions, the vacuum suction plate 12 retracted downstream is conveyed to the press position P. Is done. As shown in FIG. 11B, the vacuum suction plate 12 sucks the laminated body 30 after pressing, and conveys the laminated body 30 to the downstream side of the press position P together with the lower film 24b.

  In the peeling process, as shown in FIG. 12, the laminated body 30 is conveyed by the vacuum suction plate 12 while following the conveyance of the lower film 24b by the take-up roller 26 until it passes through the edge portion 29 from the press position P. And the lower film 24b is peeled from the lower surface of the laminated body 30 by turning back the conveyance direction of the lower film 24b along the front-end | tip of the edge part 29 at an acute angle. After the lower film 24b is peeled off, the vacuum suction plate 12 transports the laminate 30 to a predetermined take-out position (not shown), and the crimping process is completed.

  After the crimping step is completed, the laminated body 30 is cut into a predetermined shape and size by dicing and fired at a predetermined temperature, whereby the element portion 2 is completed. Thereafter, a conductor paste is applied and baked on both ends of the element portion 2 to form the terminal electrodes 3 and 3, and a plating layer (not shown) is formed on the terminal electrodes 3 and 3, as shown in FIGS. The ceramic capacitor 1 is completed.

  As described above, in this ceramic green sheet laminate pressing method and pressing apparatus 10, the upper film 24a and the lower film 24b, which are long, are used as the pressing surface 20a of the upper mold 11a and the pressing surface 20b of the lower mold 11b. The laminated body 30 is pressed via the upper film 24a and the lower film 24b by arrange | positioning so that it may oppose. Thus, the tolerance of positioning of the laminated body 30 with respect to the longitudinal direction of each film 24a, 24b is eased by using the long upper film 24a and the lower film 24b, and the respective films 24a, 24b and the laminated body 30 are relaxed. It becomes easy to position. Therefore, the pressure applied to the laminate 30 from the upper die 11a and the lower die 11b during pressing can be made uniform, and the peelability of the laminate 30 after pressing can be secured while ensuring the peelability between the upper die 11a and the lower die 11b and the laminate 30. Dimensional variation can be suppressed.

  Moreover, in this ceramic green sheet laminate pressing method and press apparatus 10, the annular frame 15 is disposed so as to surround the side surface of the laminate 30 conveyed to the press position P. The deformation of the body 30 can be regulated by the annular frame 15. Furthermore, when peeling the laminated body 30 and the lower film 24b after pressing, the conveying direction of the lower film 24b is turned back to an acute angle by the edge portion 29 on the downstream side of the pressing position P, and the edge portion is moved from the pressing position P to the edge portion. The laminated body 30 is conveyed by following the lower film 24 b until it passes 29. With such a configuration, the lower film 24b can be suitably peeled off from the laminated body 30 after pressing, and deformation or breakage of the laminated body 30 due to poor peeling of the lower film 24b can be suppressed.

  Next, an experiment conducted for verifying the effect of suppressing the dimensional variation of the laminate when the above-described method for pressing the ceramic green sheet laminate is used will be described.

  In this experiment, the laminated body was pressed through a flexible film (cut film) cut according to the size of the laminated body when the laminated body was press-bonded through a long flexible film. It was investigated how the dimension of each side of the laminated body after the press was changed in the case of performing the press-bonding. Samples of the laminate were prepared with thicknesses of 0.5 mm and 0.3 mm, and the changes in the dimensions of the sides a to d shown in FIG. 13A were measured for each sample. .

  FIG.13 (b) is a figure which shows the experimental result. As shown in FIG. 13 (b), when a cut film is used, in a sample having a thickness of 0.5 mm, the amount of change in each side a to d after pressing is 0.062% to 0.145%. The dimensional difference between the sides a to d is about 0.08%. In the sample having a thickness of 0.3 mm, the amount of change in each side a to d after pressing is 0.098% to 0.280%, and the dimensional difference between the sides a to d is about 0. 18%.

  On the other hand, when a long film is used, in a sample having a thickness of 0.5 mm, the amount of change of each side a to d after pressing is 0.020% to 0.053%, and each side a to The dimensional difference between d is about 0.03%. Further, in the sample having a thickness of 0.3 mm, the amount of change in each side a to d after pressing is 0.008% to 0.028%, and the dimensional difference between each side a to d is about 0. 0.02%.

  Thus, when a long flexible film is used, the dimensional difference of each side of the laminated body after a press is suppressed low compared with the case where a cut film is used. This is because when a long flexible film is used, positioning of the laminate and the film is facilitated, and the pressure applied to the laminate from the pressing mold during pressing can be made uniform. The effectiveness of the present invention was confirmed.

  The present invention is not limited to the above embodiment. For example, in the embodiment described above, the width of the lower film 24b is larger than the width of the upper film 24a and is substantially equal to the annular frame 15 (see FIG. 10), but the width of the lower film 24b is It may be the same width as the film 24a. Further, as shown in FIG. 14, instead of providing the annular frame 15, a rectangular recess 40 having a size corresponding to the annular frame 15 is provided on the upper surface side of the lower mold 11 b, and the bottom surface of the recess 40 is provided. It is good also as the press surface 20b of the lower mold | type 11b. In this case, if the lower film 24b is conveyed along the recessed part 40 and the laminated body 30 is fitted in the recessed part 40, then the upper mold 11a is lowered toward the lower mold 11b. It is possible to obtain the same effect as the above-described embodiment.

It is a perspective view of the ceramic capacitor manufactured using the press method of the ceramic green sheet laminated body which concerns on one Embodiment of this invention. It is the II-II sectional view taken on the line in FIG. It is a figure which shows the structure of the internal electrode layer formed in each dielectric material layer. It is a disassembled perspective view of a laminated body. It is a figure which shows the structure of a press apparatus. It is a perspective view of an annular frame type. It is a flowchart of the crimping | compression-bonding process performed using the press apparatus shown in FIG. It is a figure which shows the crimping | compression-bonding process of the laminated body shown in FIG. FIG. 9 is a diagram showing a step subsequent to that in FIG. 8. It is a top view which shows the state of the laminated body in the case of a press. FIG. 10 is a diagram showing a step subsequent to FIG. 9. It is a figure which expands and shows the structure of the vicinity of an edge part. It is a figure which shows the experimental result of the experiment which verified the difference of the dimensional dispersion after the press of the laminated body press-bonded using a long flexible film, and the laminated body press-pressed using a cut film. is there. It is a figure which shows the structure of the press apparatus which concerns on a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ceramic capacitor, 7, 8 ... Ceramic green sheet, 10 ... Press apparatus, 11a ... Upper mold | type, 11b ... Lower mold | type, 13 ... Upper film conveyance mechanism (1st film conveyance means), 14 ... Lower film conveyance mechanism ( (Second film conveying means), 15 ... annular frame, 16 ... operation control section (mold control means, frame body arranging means), 20a ... upper press surface, 20b ... lower die press surface, 24a ... upper Film (first flexible film), 24b ... lower film (second flexible film), 29 ... edge portion, 30 ... laminate.

Claims (4)

A method for pressing a ceramic green sheet laminate, in which a laminate in which a plurality of ceramic green sheets are laminated is pressed by an upper die and a lower die that are arranged so that the respective press surfaces face each other,
A step of conveying the first flexible film and the second flexible film having a long shape so as to face the press surface of the upper mold and the press surface of the lower mold, and
Disposing the laminate between the first flexible film and the second flexible film between the upper mold press surface and the lower mold press surface;
Disposing an annular frame between the first flexible film and the second flexible film so as to surround a side surface of the laminate;
At least one of the upper mold and the lower mold is advanced toward the other so that the press surfaces are relatively close to each other, and the first flexible film and the second flexible film are interposed therebetween. And a step of pressing the laminated body in the laminating direction of the ceramic green sheet. The method further comprises a step of turning back the conveying direction of the first flexible film or the second flexible film by an edge portion on the downstream side of the arrangement position of the upper mold and the lower mold. The method for pressing a ceramic green sheet laminate according to claim 1 . A pressing device that presses a laminated body in which a plurality of ceramic green sheets are laminated by an upper die and a lower die that are arranged so that their press surfaces face each other,
A first film transporting means for transporting a first flexible film and a second flexible film, which are elongated, so as to face the press surface of the upper mold and the press surface of the lower mold, and A second film conveying means;
Frame body arrangement means for arranging an annular frame body between the first flexible film and the second flexible film so as to surround a side surface of the laminate;
At least one of the upper mold and the lower mold is advanced toward the other so that the press surfaces are relatively close to each other, and the first flexible film and the second flexible film are interposed therebetween. And a die control means for pressing the laminate in the laminating direction of the ceramic green sheets. The apparatus further comprises an edge portion that turns back a conveying direction of the first flexible film or the second flexible film on a downstream side of the arrangement position of the upper mold and the lower mold. Item 4. The pressing device according to item 3 .

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