JP2019160834A - Manufacturing method of multilayer ceramic electronic component - Google Patents

Abstract

To provide a manufacturing method of multilayer ceramic electronic component capable of forming a side margin part stably.SOLUTION: In a manufacturing method of multilayer ceramic electronic component according to an embodiment of the present invention, a laminate is manufactured, having a capacity formation part having multiple ceramic layers laminated in a first direction, and multiple internal electrodes placed between the multiple ceramic layers, a lateral face facing a second direction orthogonal to the first direction, and a cover part covering the capacity formation part from the first direction. A side margin sheet is punched out by pushing the laminate into an elastomer, where the side margin sheet is placed on the surface, two times or more of the thickness of the side margin sheet in the second direction from the lateral face side, and two times or less of the thickness of the laminate in the second direction.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a method for manufacturing a multilayer ceramic electronic component to which a side margin portion is retrofitted.

  A typical multilayer ceramic electronic component is a multilayer ceramic capacitor. In recent years, with the miniaturization and high performance of electronic devices, there has been an increasing demand for higher capacity for multilayer ceramic capacitors.

  In order to increase the capacity of a multilayer ceramic capacitor, a technique of retrofitting a side margin portion is known. According to this technique, since the side margin portion can be made thin, it is possible to secure a large crossing area of the internal electrodes, contributing to an increase in the capacity of the multilayer ceramic capacitor.

  For example, Patent Document 1 describes a method of forming a side margin portion on a side surface of a multilayer chip by pressing the side surface of the multilayer chip against an elastic body on which a ceramic green sheet is arranged.

JP 2012-209539 A

  However, with the technique described in Patent Document 1, when the amount of the laminated chip pushed into the elastic body is small, the ceramic green sheet cannot be punched out. On the other hand, when the pushing amount is large, the stress of the elastic body that has been compressively deformed works strongly in the main surface direction and the end surface direction of the multilayer chip. For this reason, when pulling back the laminated chip from the elastic body, there arises a problem that the adhered ceramic green sheet is peeled off from the laminated chip or the laminated chip is peeled off from the holding member.

  In view of the circumstances as described above, an object of the present invention is to provide a method for manufacturing a multilayer ceramic electronic component capable of stably forming a side margin portion.

In order to achieve the above object, in a method for manufacturing a multilayer ceramic electronic component according to an aspect of the present invention, a plurality of ceramic layers stacked in a first direction and a plurality of internal layers disposed between the plurality of ceramic layers. A laminated body having a capacitor forming portion having an electrode, a side surface facing a second direction orthogonal to the first direction, and a cover portion covering the capacitor forming portion from the first direction is manufactured.
On the elastic body having the side margin sheet disposed on the surface, the laminate is more than twice the thickness of the side margin sheet in the second direction from the side surface, and the thickness of the laminate in the second direction. The side margin sheet is punched out by pushing twice or less.

  According to the manufacturing method described above, when the side margin portion is punched out, the push amount of the stacked body can be set to an appropriate range. As a result, the side margin can be formed stably.

The static shear modulus of the elastic body may be 5 MPa or less.
According to this configuration, a sufficient amount of shearing force for punching can be applied to the side margin sheet, and the laminate can be appropriately pushed into the elastic body.

  As described above, according to the present invention, it is possible to provide a method for manufacturing a multilayer ceramic electronic component capable of stably forming a side margin portion.

1 is a perspective view of a multilayer ceramic capacitor according to an embodiment of the present invention. It is a perspective view along the AA 'line of FIG. 1 of the said multilayer ceramic capacitor. It is sectional drawing along the BB 'line | wire of FIG. 1 of the said multilayer ceramic capacitor. It is a flowchart which shows the manufacturing method of the said multilayer ceramic capacitor. It is a perspective view of the laminated body prepared by step S01 of the said manufacturing method. It is the figure seen from the end surface side of the laminated body which shows step S02 of the said manufacturing method. It is a perspective view of the unfired ceramic body after step S02 of the manufacturing method. It is the figure seen from the end surface side of the laminated body which shows the general punching method. It is the figure seen from the end surface side of the laminated body which shows the punching method which concerns on the said embodiment. It is the figure seen from the end surface side of the laminated body which shows the punching method which concerns on the said embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the drawing, an X axis, a Y axis, and a Z axis that are orthogonal to each other are shown as appropriate. The X axis, Y axis, and Z axis are common in all drawings.

[Overall Configuration of Multilayer Ceramic Capacitor 10]
1 to 3 are views showing a multilayer ceramic capacitor 10 according to an embodiment of the present invention. 2 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along the line AA ′ of FIG. 3 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along line BB ′ of FIG.

  The multilayer ceramic capacitor 10 includes a ceramic body 11, a first external electrode 14, and a second external electrode 15. The ceramic body 11 typically has two end faces that face the X-axis direction, two side faces that face the Y-axis direction, and two main faces that face the Z-axis direction. The shape of the ceramic body 11 is not limited to such a shape. For example, each surface of the ceramic body 11 may be a curved surface, and the ceramic body 11 may have a rounded shape as a whole.

  The external electrodes 14 and 15 cover the end face of the ceramic body 11 and face each other in the X-axis direction with the ceramic body 11 interposed therebetween. The external electrodes 14 and 15 extend from the end surface of the ceramic body 11 to the main surface and side surfaces. Thereby, in the external electrodes 14 and 15, the cross section parallel to the XZ plane and the cross section parallel to the XY plane are both U-shaped. The shape of the external electrodes 14 and 15 is not limited to that shown in FIG.

  The external electrodes 14 and 15 are formed of a good electrical conductor. For example, copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), silver (Ag), gold (Au) can be used as the good electrical conductor for forming the external electrodes 14 and 15. Examples thereof include metals and alloys mainly composed of these.

  The ceramic body 11 is made of dielectric ceramics and includes a laminated body 16 and side margin portions 17. The stacked body 16 has two end surfaces facing the X-axis direction, two side surfaces S facing the Y-axis direction, and two main surfaces facing the Z-axis direction, and is along the XY plane. A plurality of flat ceramic layers extending in the Z-axis direction are stacked. The side margin portion 17 is formed on both side surfaces S of the stacked body 16.

  The stacked body 16 includes a capacity forming portion 18 and a cover portion 19. The capacitance forming unit 18 includes a first internal electrode 12 and a second internal electrode 13 covered with dielectric ceramics, and is covered with a cover unit 19 from the upper and lower sides in the Z-axis direction.

  The internal electrodes 12 and 13 each have a sheet shape extending along the XY plane, and are alternately arranged along the Z-axis direction. That is, the internal electrodes 12 and 13 are opposed to each other in the Z-axis direction with the ceramic layer interposed therebetween. The first internal electrode 12 is drawn out to one end face of the ceramic body 11 and connected to the first external electrode 14. The second internal electrode 13 is drawn out to the other end face of the ceramic body 11 and connected to the second external electrode 15.

  The ceramic layer between the first internal electrodes 12 on one end face side functions as an end margin that ensures insulation between the second internal electrode 13 and the first external electrode 14. Similarly, the ceramic layer between the second internal electrodes 13 on the other end face side functions as an end margin for ensuring insulation between the first internal electrode 12 and the second external electrode 15.

  With such a configuration, in the multilayer ceramic capacitor 10, when a voltage is applied between the first external electrode 14 and the second external electrode 15, a plurality of layers between the first internal electrode 12 and the second internal electrode 13 are provided. A voltage is applied to the ceramic layer. As a result, in the multilayer ceramic capacitor 10, charges corresponding to the voltage between the first external electrode 14 and the second external electrode 15 are stored.

  Further, in the capacitance forming portion 18, the surfaces other than both end surfaces in the X-axis direction where the external electrodes 14 and 15 are provided are covered with the side margin portion 17 and the cover portion 19. Accordingly, in the capacitance forming portion 18, the periphery thereof is protected by the side margin portion 17 and the cover portion 19, and the insulating properties of the internal electrodes 12 and 13 are ensured.

In the ceramic body 11, a dielectric ceramic having a high dielectric constant is used as a main component in order to increase the capacity of each ceramic layer between the internal electrodes 12 and 13. Examples of the dielectric ceramic having a high dielectric constant include a perovskite structure material containing barium (Ba) and titanium (Ti) typified by barium titanate (BaTiO ₃ ).

The main components of the ceramic layer are strontium titanate (SrTiO ₃ ), calcium titanate (CaTiO ₃ ), magnesium titanate (MgTiO ₃ ), calcium zirconate (CaZrO ₃ ), calcium zirconate titanate. (Ca (Zr, Ti) O ₃ ), barium zirconate (BaZrO ₃ ), titanium oxide (TiO ₂ ), or the like may be used.

  The internal electrodes 12 and 13 are formed of a good electrical conductor. Typical examples of good electrical conductors forming the internal electrodes 12 and 13 include nickel (Ni). Besides these, copper (Cu), palladium (Pd), platinum (Pt), silver (Ag), Examples thereof include metals or alloys mainly composed of gold (Au) or the like.

  Note that the multilayer ceramic capacitor 10 according to the present embodiment only needs to include the multilayer body 16 and the side margin portion 17, and other configurations can be appropriately changed. For example, the number of the first and second internal electrodes 12 and 13 can be appropriately determined according to the size and performance required for the multilayer ceramic capacitor 10.

[Method of Manufacturing Multilayer Ceramic Capacitor 10]
FIG. 4 is a flowchart showing a method for manufacturing the multilayer ceramic capacitor 10. 5 to 7 are diagrams illustrating a manufacturing process of the multilayer ceramic capacitor 10. Hereinafter, a method for manufacturing the multilayer ceramic capacitor 10 will be described along FIG. 4 with reference to FIGS.

(Step S01: Laminate preparation)
In step S01, the stacked body 116 is prepared. FIG. 5 is a perspective view of the stacked body 116. The laminate 116 is configured by laminating a plurality of unfired dielectric green sheets in which the internal electrodes 112 and 113 are appropriately patterned. As a result, an unfired capacitance forming portion 118 having a plurality of unfired ceramic layers disposed between the internal electrodes 112 and 113 and a cover portion 119 are formed in the laminate 116.

(Step S02: Side margin portion formation)
In step S02, an unfired ceramic body 111 is produced by providing an unfired side margin portion 117 on the side surface S of the laminate 116 prepared in step S01. A punching method is used to form the side margin portion 117. That is, in the punching method, the side margin portion 117 is formed by punching the side margin sheet 117 s on the side surface of the stacked body 116.

  6A to 6C are diagrams illustrating a method of punching the side margin sheet 117s with the side surface S of the stacked body 116. FIG. First, as shown in FIG. 6A, the other side surface S of the laminate 116 holding one side surface S with an adhesive tape T is placed on a side margin arranged on a flat elastic body 200. It is made to oppose the sheet 117s. In the present embodiment, the elastic body 200 is held by a holding member 300, and the holding member 300 is configured to be movable along the Y-axis direction.

  The side margin sheet 117s is configured as a large dielectric green sheet for forming the unfired side margin portion 117. The thickness of the side margin portion 17 of the multilayer ceramic capacitor 10 shown in FIGS. 2 and 3 can be adjusted by the thickness of the side margin sheet 117s. The side margin sheet 117s can be accurately controlled by forming it into a sheet shape using, for example, a roll coater or a doctor blade.

  Next, as shown in FIG. 6B, the side surface S of the multilayer body 116 is pushed into the side margin sheet 117s, and the multilayer body 116 is sunk into the elastic body 200 together with the side margin sheet 117s. At this time, only the region where the side margin sheet 117s is pressed against the laminated body 116 by the shearing force applied from the elastic body 200 is cut off.

  Then, as illustrated in FIG. 6C, when the stacked body 116 is moved away from the elastic body 200, only the portion attached to the side surface S of the stacked body 116 in the side margin sheet 117 s is removed from the elastic body 200. Separate. Thereby, the side margin portion 117 is formed on the side surface S of the multilayer body 116.

  Subsequently, the direction of the multilayer body 116 in the Y-axis direction is reversed by replacing the tape T holding the multilayer body 116 with another tape T. Then, the side margin portion 117 is formed on the side surface S on the opposite side of the stacked body 116 where the side margin portion 117 is not formed in the same manner as described above. In the present embodiment, the side margin sheet 117s can be stably punched out by adjusting the push amount of the stacked body 116. The detailed method will be described later.

  By step S02, the unfired ceramic body 111 in which the side margin portions 117 are formed on both side surfaces S of the multilayer body 116 is obtained. FIG. 7 is a perspective view of an unfired ceramic body 111. In the unfired ceramic body 111, the side margin S of the multilayer body 116 where the internal electrodes 112 and 113 are exposed is covered with the side margin portion 117.

  6 and 8 to 10, three laminated bodies 116 are arranged on the tape T, but a plurality of laminated bodies 116 are arranged at equal intervals along the XY plane. The interval can be changed as appropriate. Moreover, although the laminated body 116 is typically located in a rectangle on the tape T, the way of arrangement is not limited to this.

(Step S03: Firing)
In step S03, the ceramic body 11 of the multilayer ceramic capacitor 10 shown in FIGS. 1 to 3 is manufactured by firing the unfired ceramic body 111 obtained in step S02. That is, in step S03, the stacked body 116 becomes the stacked body 16, and the side margin portion 117 becomes the side margin portion 17.

The firing temperature in step S03 can be determined based on the sintering temperature of the unfired ceramic body 111. For example, when a barium titanate (BaTiO ₃ ) -based material is used, the firing temperature can be about 1000 to 1300 ° C. The firing can be performed, for example, in a reducing atmosphere or a low oxygen partial pressure atmosphere.

(Step S04: External electrode formation)
In step S04, the external electrodes 14 and 15 are formed at both ends in the X-axis direction of the ceramic body 11 obtained in step S03, so that the multilayer ceramic capacitor 10 shown in FIGS. The formation method of the external electrodes 14 and 15 in step S04 can be arbitrarily selected from known methods.

  Further, the external electrodes 14 and 15 may be simultaneously fired with the unfired ceramic body 111. That is, after step S02, unfired external electrodes are formed on both ends in the X-axis direction of the unfired ceramic body 111, and fired simultaneously with the unfired ceramic body 111 in step S03, whereby the external electrodes 14, 15 are formed. It is also possible to form

  The multilayer ceramic capacitor 10 is manufactured by the above manufacturing method.

[Details of punching method of side margin sheet 117s]
A method for forming the side margin portion 117 on the side surface S of the multilayer body 116 by punching out the side margin sheet 117s on the side surface S of the multilayer body 116 in step S02 will be described in detail. Note that the side margin portion 117 can be formed on the other side surface S of the stacked body 116 as well as the one side surface S.

  Generally, in the method of attaching the side margin part using an elastic body, if the amount of pushing in the laminated body is too small, the side margin sheet is not cut off due to insufficient shearing force by the elastic body, and the side margin sheet is punched appropriately. I can't. Thereby, the punching defect of the side margin sheet occurs. For this reason, it is necessary to increase the pushing amount of the laminated body sufficiently.

  However, problems also occur when the amount of push-in of the laminate is too large. FIG. 8A is a diagram illustrating a state where the amount of pushing of the laminated body 116 into the elastic body 200 is too large. FIG. 8B is a diagram showing a state in which the stacked body 116 is pulled out from the state of FIG.

  If the pushing amount of the laminated body 116 is too large, as shown in FIG. 8A, the stress (restoring force) of the elastic body 200 that is compressively deformed works strongly in the main surface direction and the end surface direction of the laminated body 116. In this state, when the laminated body 116 is pulled out from the elastic body 200, the side margin portion 117 attached to the side surface of the laminated body 116 may be peeled off as shown in FIG. Body 116), the side margin 117 may be displaced (laminated body 116 in the figure), or the laminated body 116 may be peeled off from the tape T (right side laminated body 116 in the figure).

  Therefore, when the punching amount is extreme as described above, defective punching or peeling of the side margin sheet occurs in the manufacturing process, which causes a problem that the yield of the product decreases.

  Therefore, in this embodiment, in step S02, the pushing amount D of the stacked body 116 is set to an appropriate amount with respect to the elastic body 200 on which the side margin sheet 117s is arranged. Hereinafter, a method for punching the side margin sheet 117s of the present embodiment will be described. FIG. 9A is a diagram showing a state just before the laminated body 116 is pushed into the elastic body 200. FIG. 9B is a diagram showing a state where the laminated body 116 is pushed into the elastic body 200 with an appropriate pushing amount.

  In this embodiment, the pushing amount D of the laminated body 116 is the Y axis direction of the laminated body 116 when the laminated body 116 is pushed along the Y axis direction into the elastic body 200 on which the side margin sheet 117s is arranged. Displacement. Specifically, from the state in which the side surface S facing the elastic body 200 side of the laminated body 116 is in contact with the side margin sheet 117s (the state in FIG. 9A) to after being pushed in (the state in FIG. 9B), The displacement of the side surface S in the Y-axis direction is defined as a push-in amount D. That is, the pushing amount D is defined by the distance between the holding member 300 that holds the elastic body 200 and the side surface S.

As shown in FIG. 9A, the side margin sheet 117s and the side surface S on the elastic body 200 side of the laminated body 116 are in contact with each other in a state just before the laminated body 116 is pushed into the elastic body 200. The distance between the holding member 300 and the side surface S at this time is a D _0, the reference value of the pressing amount D. Accordingly, the pushing amount D at this time becomes zero.

Next, as illustrated in FIG. 9B, the side surface S on the elastic body 200 side approaches the holding member 300 in a state where the laminated body 116 is pushed into the elastic body 200. When the distance between the holding member 300 and the side surface S at this time is _{D 1,} the push amount D can be expressed by _{D =} D 0 -D _1.

  In the present embodiment, the push-in amount D is not less than twice the thickness of the side margin sheet 117s in the Y-axis direction and not more than twice the thickness of the stacked body 116 in the Y-axis direction. By setting the pushing amount D to be twice or more the thickness of the side margin sheet 117s in the Y-axis direction, a sufficient amount of shearing force can be applied to the side margin sheet 117s. Thereby, the side margin sheet 117s can be appropriately punched.

  Further, by setting the pushing amount D to be equal to or less than twice the thickness of the laminate 116 in the Y-axis direction, it is possible to reduce the stress caused by the compression-deformed elastic body 200 acting on the main surface and the end face of the laminate 116. . Thereby, peeling of the side margin part 117 and the laminated body 116 can be prevented.

  That is, by satisfying the above conditions, the side margin portion 117 can be stably formed on the side surface S of the stacked body 116.

  In the present embodiment, the static shear modulus of the elastic body 200 is preferably 5 MPa or less. By setting the static shear modulus of the elastic body 200 to 5 MPa or less, the laminate 116 can be appropriately pushed into the elastic body 200.

  Even in the state of FIG. 9B, the stress of the elastic body 200 that has been compressively deformed is acting in the main surface direction and the end surface direction of the laminate 116, but since the elastic body 200 is not greatly compressed and deformed, Power is weakened. For this reason, there is no possibility that the laminated body 116 and the attached side margin sheet 117s are peeled off.

  FIG. 10A is a diagram illustrating a state in which the side margin sheets 117s between the stacked bodies 116 are pushed in until they are in contact with the tape T. FIG. Moreover, FIG.10 (b) is a figure which shows the state which pulled out the laminated body 116 from the state of Fig.10 (a).

  As shown in FIG. 10A, even when the side margin sheet 117s between the stacked bodies 116 is pushed in until it comes into contact with the tape T, the pushing amount D is twice the thickness of the side margin sheet 117s in the Y-axis direction. If the thickness is not more than twice the thickness of the laminate 116 in the Y-axis direction, it can be punched without problems as shown in FIG.

  In FIG. 10B, the side margin sheet 117s adhered to the tape T can be collected when the laminated body 116 is transferred to another tape T. Therefore, according to the punching method of the side margin sheet 117s as described above, the side margin portion 117 can be stably formed, and the remaining side margin sheet 117s after the punching can be prevented.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited only to the above-mentioned embodiment, Of course, a various change can be added.

  For example, in the above embodiment, the multilayer ceramic capacitor 10 has been described as an example of the multilayer ceramic electronic component. However, the present invention is applicable to all multilayer ceramic electronic components. Examples of such multilayer ceramic electronic components include chip varistors, chip thermistors, and multilayer inductors.

DESCRIPTION OF SYMBOLS 10 ... Multilayer ceramic capacitor 11, 111 ... Ceramic body 12, 13, 112, 113 ... Internal electrode 16, 116 ... Laminated body 17,117 ... Side margin part 117s ... Side margin sheet 18, 118 ... Capacitance formation part 19,119 ... Cover part 200 ... Elastic body 300 ... Holding member S ... Side surface T ... Tape

Claims (2)

A capacitor forming portion having a plurality of ceramic layers stacked in a first direction and a plurality of internal electrodes disposed between the plurality of ceramic layers, and facing a second direction orthogonal to the first direction A laminated body having a side surface and a cover portion covering the capacitance forming portion from the first direction;
On the elastic body having the side margin sheet disposed on the surface, the laminated body is more than twice the thickness of the side margin sheet in the second direction from the side surface side, and the thickness of the laminated body in the second direction. A method of manufacturing a multilayer ceramic electronic component in which the side margin sheet is punched out by being pressed twice or less. It is a manufacturing method of the multilayer ceramic electronic component according to claim 1,
A method for producing a multilayer ceramic electronic component, wherein the elastic body has a static shear modulus of 5 MPa or less.

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