JP2009246102A - Method for manufacturing laminated electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminated electronic component capable of obtaining a laminated body having a little deformation or the like. <P>SOLUTION: When a laminated capacitor is manufactured, a green laminated body with a ceramic green sheet and an inner conductor laminated is manufactured. The green laminated body is held by a fixing tool so that the whole side surfaces of the green laminated body are surrounded by a frame body. The green laminated body is put into a flexible pouch together with the fixing tool and vacuum-packed, then hydrotatic-pressed in this state. After that, the green laminated body is removed from the fixing tool, and pressed in a laminated direction by the pressure lower than that in the hydrostatic pressing with the side surfaces of the green laminated body opened. Then, the green laminated body is cut and burned, and a terminal electrode is formed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a multilayer electronic component such as a multilayer capacitor.

As a conventional method for manufacturing a laminated electronic component, for example, as described in Patent Document 1, a ceramic laminate is placed in a recess formed by a base and a frame, and an upper punch is placed on the ceramic laminate. In a state in which the ceramic laminate is positioned, hydrostatic pressure is applied to the ceramic laminate via the base and the upper punch to compress the ceramic laminate.
JP-A-2-161713

  However, when the ceramic laminate is hydrostatically pressed in a state in which the ceramic laminate (laminate) is surrounded by a frame as in the prior art described above, the deformation and warpage of the ceramic laminate are caused by the stress generated from the inside of the ceramic laminate. As a result, bending or the like may occur, which may affect the characteristics of the laminated electronic component.

  An object of the present invention is to provide a method for manufacturing a laminated electronic component capable of obtaining a laminated body with little deformation or the like.

  The present invention relates to a method for manufacturing a laminated electronic component in which an element body layer and an internal electrode layer are laminated, in which a ceramic green sheet forming an element body layer and an internal conductor forming an internal electrode layer are laminated. After carrying out a preparatory step for preparing a laminate, a first press step for surrounding the side surface of the laminate with a frame, and pressing the laminate in the lamination direction with a first pressure in that state, and a first press step, And a second pressing step of pressing the laminated body in the laminating direction at a second pressure lower than the first pressure with the side surface of the laminated body being opened.

  In the method for manufacturing a multilayer electronic component according to the present invention, first, the side surface of the multilayer body is surrounded by a frame, and in that state, the multilayer body is pressed in the stacking direction with a first pressure. Here, when the laminated body is pressed in the laminating direction, the laminated body tends to extend in the lateral direction due to the stress generated in the laminated body, but the lateral extension of the laminated body is suppressed by the frame body. However, when the pressing of the laminated body is finished and the pressure is reduced, the laminated body is deformed by the stress accumulated in the laminated body. Therefore, in order to flatten such a laminated body, the laminated body is pressed in the lamination direction with a second pressure. At this time, since the laminate is first pressed with the first pressure, the laminate is hardened to some extent, and the laminate is difficult to extend in the lateral direction. For this reason, in this press process, the laminated body is pressed in the laminating direction at a second pressure lower than the first pressure with the side surface of the laminated body being opened. As described above, since the pressing process in the stacking direction of the stacked body is performed twice, a stacked body with less deformation or the like can be obtained.

  Preferably, in the first pressing step, the laminated body is pressed in the laminating direction with a first pressure so that a region in the laminated body where the internal conductor is not formed is recessed in the laminating direction. Thus, by denting the region where the inner conductor is not formed in the multilayer body in the laminating direction, minute voids or delaminations are less likely to occur in the region. Here, by forming such a dent in the laminate, when the frame is removed after the laminate is pressed, the laminate is likely to be deformed due to stress accumulated in the laminate. Become. Therefore, the effect by performing the press processing of a laminated body twice comes to appear more notably. Further, in the second press treatment, the laminate is pressed at a second pressure lower than the first pressure, so that it is possible to prevent deformation or crushing of the dent formed in the laminate during the first press treatment. it can.

  Preferably, in the first pressing step, the laminate is hydrostatically pressed with a first pressure. In this case, the first pressing step can be performed with simple equipment.

  According to the present invention, it is possible to obtain a laminated body with less deformation and the like. This makes it possible to ensure good characteristics of the multilayer electronic component.

  Preferred embodiments of a method for manufacturing a laminated electronic component according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a multilayer capacitor as a multilayer electronic component manufactured by an embodiment of a method for manufacturing a multilayer electronic component according to the present invention. In the figure, the multilayer capacitor 1 includes a substantially rectangular parallelepiped multilayer body 2 and terminal electrodes 3A and 3B which are formed at both ends of the multilayer body 2 and function as input / output terminal electrodes.

The multilayer body 2 includes a plurality of dielectric layers 4, a plurality (two in this case) of internal electrode layers 5A, and a plurality (two in this case) of internal electrode layers 5B. The stacked body 2 has a structure in which internal electrode layers 5A and internal electrode layers 5B are alternately stacked with a plurality of dielectric layers 4 interposed therebetween. Some of the internal electrode layers 5A and 5B overlap each other when viewed from the stacking direction. And the function as a capacitor | condenser will be exhibited by the part which internal electrode layer 5A, 5B mutually overlaps, and the dielectric material layer 4 located in between. The dielectric layer 4 is made of a dielectric material such as BaTiO ₃ ceramic. The internal electrode layers 5A and 5B are made of, for example, Ni or Ni alloy.

  The internal electrode layer 5A extends to one end surface of the multilayer body 2 and is electrically connected to the terminal electrode 3A. The internal electrode layer 5B extends to the other end surface of the multilayer body 2 and is electrically connected to the terminal electrode 3B. The terminal electrodes 3A and 3B are formed by sequentially forming a Ni plating layer and a Sn plating layer on a baking electrode layer such as Cu or Ag.

  FIG. 2 is a flowchart showing a procedure for manufacturing the multilayer capacitor 1 described above. Hereinafter, a method of manufacturing the multilayer capacitor 1 will be described with reference to FIG.

  First, a green laminated body is produced in which the ceramic green sheet for forming the dielectric layer 4 and the internal conductor for forming the internal electrode layers 5A and 5B are laminated (step S51).

Specifically, for example, a dielectric material such as BaTiO ₃ , CaTiO ₃ , SrTiO _{3, and the} like, and rare earth oxide, magnesium oxide, manganese oxide, and the like, which are subcomponents, are mixed at a predetermined ratio to make a dielectric slurry. In addition, for example, a co-material, an organic binder, a dispersant, an organic solvent, and the like are mixed with Ni powder, and dispersed in a ball mill or a roll mill to form a conductive paste.

  And a ceramic green sheet is formed by apply | coating dielectric slurry on a PET film by the doctor blade method etc., and drying. Also, a plurality of conductor patterns (internal conductors) are formed by applying a conductive paste on a ceramic green sheet by screen printing and drying. These conductor patterns are arranged in a matrix on a ceramic green sheet, for example.

  Subsequently, a green laminate 10 as shown in FIG. 3A is obtained by laminating a ceramic green sheet on which no conductor pattern is formed and a ceramic green sheet on which a conductor pattern is formed. The green laminated body 10 has a conductor forming region P in which the internal conductor 11 is formed in the stacking direction and a conductor non-formed region Q in which the internal conductor 11 is not formed in the stacking direction. In the conductor formation region P, the inner conductors 11 that are adjacent to each other in the vertical direction are formed so as to be shifted from each other in the front and back direction in FIG.

  Next, as shown in FIG. 3B, the green laminate 10 is held by the fixing jig 12 (step S52). The fixing jig 12 includes a base 13 on which the green laminated body 10 is placed, a frame 14 disposed on the base 13 and surrounding the entire side surface of the green laminated body 10, and the green laminated body 10 with respect to the base 13. And a pressing plate 15 that presses and holds. A protrusion 13 a for positioning the frame body 14 with respect to the base 13 is provided on the upper surface of the base 13. The thickness (height) of the frame body 14 is configured to be larger than the thickness of the green laminated body 10. In addition, as a material of the base 13, the frame body 14, and the pressing plate 15, for example, a highly rigid material such as a metal such as aluminum or stainless steel, alumina, reinforced plastic, or the like is used.

  When the green laminate 10 is held by such a fixing jig 12, the green laminate 10 is placed on the protrusion 13 a of the base 13 via the elastic sheet 16, and the green laminate 10 is surrounded by the frame 14. State. Then, the pressing plate 15 is disposed on the green laminate 10 via the elastic sheet 17.

  Next, as shown in FIG. 3 (c), the green laminate 10 held by the fixing jig 12 is put into the flexible bag 18 as it is, and the green laminate 10 is put in the flexible bag 18 in this state. Vacuum packaging is performed (step S53). As the flexible bag 18, for example, a bag made of a flexible material having excellent water resistance such as vinyl or rubber is used.

Next, the green laminated body 10 vacuum-packed with the flexible bag 18 is placed in, for example, water stored in a water tank, and the green laminated body 10 is hydrostatically pressed (step S54). At this time, the pressure applied to the green laminated body 10 is, for example, about 1000 to 2000 kg / cm ² . Moreover, the temperature of water is about 60-70 degreeC, for example.

  At the time of hydrostatic pressure pressing of the green laminate 10, since pressure is applied to the green laminate 10 from above and below the green laminate 10, as shown in FIG. A stress is generated, and the green laminate 10 tends to extend in the lateral direction due to the stress. At this time, since the green laminated body 10 is surrounded by the frame body 14, the lateral extension of the green laminated body 10 is suppressed by the frame body 14, and stress is accumulated in the green laminated body 10. .

  Further, by performing the hydrostatic press, the adhesion of the conductor non-formation region Q of the green laminate 10 is increased, and the dent 19 is generated in the conductor non-formation region Q on the upper and lower surfaces of the green laminate 10. (See FIG. 4 (b)). This prevents the occurrence of pores (minute gaps), delamination (delamination), and the like in the conductor unformed region Q of the green laminate 10.

  After the hydrostatic pressure pressing of the green laminate 10 is finished, the green laminate 10 held by the fixing jig 12 is taken out from the flexible bag 18 (step S55), and the green laminate 10 is further fixed to the fixing jig 12. Is removed (step S56).

  At this time, when the green laminated body 10 is removed from the frame body 14, the side surface of the green laminated body 10 is released from the frame body 14, so that it was stored inside the green laminated body 10 by the frame body 14 during hydrostatic pressing. The stress in the lateral direction is free. As a result, as shown in FIG. 4B, the green laminate 10 is deformed or warped.

Next, in order to flatten the green laminated body 10 in which such deformation or warpage has occurred, as shown in FIG. 5A, a press machine 22 having an upper press portion 20 and a lower press portion 21 is used. Then, the green laminated body 10 is pressed in the laminating direction with the side surface of the green laminated body 10 being opened (step S57). At this time, the green laminated body 10 is pressed at a pressure lower than the hydrostatic pressure pressing process performed in the above step S54, for example, about 750 kg / cm ² . Thereby, as shown in FIG.5 (b), the upper surface and lower surface of the green laminated body 10 can be made flat.

  Here, since the green laminated body 10 is hardened to some extent by the isostatic pressing performed in the above step S54, the force that the green laminated body 10 tends to extend in the lateral direction is small. For this reason, even if it performs this press process in the state which opened the side surface of the green laminated body 10, there is no trouble in particular. In addition, the green laminate 10 is pressed at a pressure lower than the hydrostatic press performed in the above step S54, thereby preventing the recess 19 formed in the upper and lower surfaces of the green laminate 10 from being deformed or crushed. Can do.

  The pressing method employed in this step may be any of a die press, a calender roll, an isostatic press, etc., as long as the green laminate 10 is pressed with the side surface of the green laminate 10 open. May be.

  After the second pressing process of the green laminated body 10 is completed and the green laminated body 10 is taken out from the press machine 22, the green laminated body 10 is cut into each conductor forming region P along the vertical and horizontal directions. Thus, a plurality of chip-like green laminates 10 are obtained (step S58). At this time, the green laminated body 10 is cut so that the inner conductors 11 that are vertically adjacent to each other are exposed on the opposite sides.

  Next, after the binder removal of the chip-like green laminate 10 is performed, the chip-like green laminate 10 is baked to laminate the dielectric layer 4 and the internal electrode layers 5A and 5B. Is obtained (step S59).

  Next, terminal electrodes 3A and 3B are formed on both end faces of the laminate 2 (step S60). At this time, terminal electrodes 3A and 3B are obtained by transferring and baking an electrode paste mainly composed of Ag, Cu or Ni on both end faces of the laminate 2, and further performing, for example, electroplating of Cu, Ni and Sn. It is done.

  As described above, in the present embodiment, when the green laminated body 10 is fixed to the fixing jig 12 having the frame body 14 surrounding the side surface of the green laminated body 10, the green laminated body 10 is hydrostatically pressed. Since the force to extend in the lateral direction of the green laminated body 10 is accumulated in the green laminated body 10, the green laminated body 10 is deformed or warped when the hydrostatic press of the green laminated body 10 is finished and the pressure is reduced. Etc. occur. However, after that, the green laminate 10 is pressed at a pressure lower than that of the above hydrostatic pressure pressing process with the side surface of the green laminate 10 opened, so that the state of the recess 19 formed in the green laminate 10 is changed. While maintaining, the green laminated body 10 can be flattened by eliminating deformation, warpage, and the like generated in the green laminated body 10. Thereby, since the deformation | transformation, curvature, etc. of the multilayer capacitor 1 as a finished product can be prevented, the characteristics of the multilayer capacitor 1 can be improved.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the side surface of the green laminate 10 is first surrounded by the frame 14, and the green laminate 10 is hydrostatically pressed in that state. If it carries out in the state which enclosed the side surface of this with the frame, it will not be restricted especially to an isostatic press.

  Moreover, although the said embodiment is about the manufacturing method of a multilayer capacitor, the manufacturing method of the multilayer electronic component concerning this invention is applicable also to other multilayer electronic components, for example, a multilayer inductor.

It is sectional drawing which shows a multilayer capacitor as a multilayer electronic component manufactured by one Embodiment of the manufacturing method of the multilayer electronic component concerning this invention. It is a flowchart which shows the procedure which manufactures the multilayer capacitor shown in FIG. FIG. 2 is a cross-sectional view showing a process for manufacturing the multilayer capacitor shown in FIG. 1. It is sectional drawing which shows the state of a green laminated body when the hydrostatic pressure press process shown in FIG. 2 is implemented. FIG. 2 is a cross-sectional view showing a process for manufacturing the multilayer capacitor shown in FIG. 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Multilayer capacitor (laminated electronic component), 3A, 3B ... Terminal electrode, 4 ... Dielectric layer (element body layer), 5A, 5B ... Internal electrode layer, 10 ... Green laminated body, 11 ... Internal conductor, 14 ... Frame body.

Claims (3)

A method for producing a laminated electronic component in which an element body layer and an internal electrode layer are laminated,
A preparation step of preparing a laminated body in which a ceramic green sheet forming the element body layer and an internal conductor forming the internal electrode layer are laminated;
A first pressing step in which a side surface of the laminated body is surrounded by a frame body and the laminated body is pressed in a laminating direction with a first pressure in the state;
A second pressing step of pressing the laminated body in a laminating direction at a second pressure lower than the first pressure in a state where the side surface of the laminated body is opened after the first pressing step is performed. A method for manufacturing a laminated electronic component.   The first pressing step is characterized in that the laminated body is pressed in the laminating direction with a first pressure so as to dent a region in the laminated body where the inner conductor is not formed in the laminating direction. 2. A method for producing a laminated electronic component according to 1.   3. The method for manufacturing a laminated electronic component according to claim 1, wherein in the first pressing step, the laminated body is hydrostatically pressed with a first pressure. 4.

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