JP7122129B2 - Manufacturing method for multilayer ceramic electronic component - Google Patents

Description

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

A typical laminated ceramic electronic component is a laminated ceramic capacitor. 2. Description of the Related Art In recent years, with the miniaturization and high performance of electronic devices, the demand for higher capacity multilayer ceramic capacitors has become stronger.

In order to increase the capacity of a multilayer ceramic capacitor, a technique of retrofitting a side margin portion is known. According to this technology, since the side margin portion can be made thin, a wide intersecting area of the internal electrodes can be ensured, which contributes to increasing the capacity of the multilayer ceramic capacitor.

For example, Patent Literature 1 describes a method of forming a side margin portion on the side surface of a laminated chip by pressing the side surface of the laminated 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, the ceramic green sheet cannot be punched out when the amount of pressing of the laminated chip into the elastic body is small. On the other hand, when the amount of pushing is large, the stress of the compressively deformed elastic body acts strongly in the main surface direction and the end surface direction of the laminated chip. Therefore, when the laminated chip is pulled back from the elastic body, there arises a problem that the attached ceramic green sheet is peeled off from the laminated chip or the laminated chip is peeled off from the holding member.

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

To achieve the above object, a method for manufacturing a multilayer ceramic electronic component according to one aspect of the present invention includes: a plurality of ceramic layers laminated in a first direction; electrodes, a side surface facing a second direction perpendicular to the first direction, and a cover portion covering the capacitance formation portion from the first direction.
The laminated body is applied from the side surface side to the elastic body having the side margin sheet disposed on the surface thereof, and is at least twice the thickness of the side margin sheet in the second direction and the thickness of the laminated body in the second direction. The side margin sheet is punched out by pushing down twice or less.

According to the manufacturing method described above, when punching out the side margin portions, the pressing amount of the laminate can be set within an appropriate range. This makes it possible to stably form the side margin portions.

A static shear elastic 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 that can stably form side margin portions.

1 is a perspective view of a laminated ceramic capacitor according to one embodiment of the present invention; FIG. FIG. 2 is a perspective view of the multilayer ceramic capacitor taken along line AA' in FIG. 1; 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line BB' of FIG. 1; FIG. 4 is a flow chart showing a method for manufacturing the laminated 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. FIG. 4 is a perspective view of an unfired ceramic body after step S02 of the manufacturing method; It is the figure seen from the end face side of the laminated body which shows the general punching method. It is the figure which looked at the end surface side of the laminated body which shows the punching method which concerns on the said embodiment. It is the figure which looked at 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.
The drawings show mutually orthogonal X, Y and Z axes where 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 diagrams showing a multilayer ceramic capacitor 10 according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along line AA' in FIG. FIG. 3 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along line BB' of FIG.

A laminated ceramic capacitor 10 includes a ceramic element body 11 , a first external electrode 14 and a second external electrode 15 . The ceramic body 11 typically has two end faces facing the X-axis direction, two side faces facing the Y-axis direction, and two principal faces facing the Z-axis direction. Note that 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 curved, and the ceramic body 11 may have a rounded shape as a whole.

The external electrodes 14 and 15 cover the end faces 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 surfaces of the ceramic body 11 to the main surface and side surfaces. As a result, the external electrodes 14 and 15 have a U-shaped cross section parallel to the XZ plane and a cross section parallel to the XY plane. The shape of the external electrodes 14 and 15 is not limited to that shown in FIG.

The external electrodes 14 and 15 are made of a good electrical conductor. Good electrical conductors forming the external electrodes 14 and 15 include, for example, copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), silver (Ag), and gold (Au). and the like as a main component.

The ceramic body 11 is made of dielectric ceramics and has a laminate 16 and side margin portions 17 . The laminate 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 along the XY plane It has a configuration in which a plurality of plate-like ceramic layers extending in the direction of the Z-axis are laminated. The side margin portions 17 are formed on both side surfaces S of the laminate 16 .

The laminate 16 has a capacitance forming portion 18 and a cover portion 19 . The capacitance forming portion 18 has a first internal electrode 12 and a second internal electrode 13 covered with dielectric ceramics, and is covered with a cover portion 19 from above and below in the Z-axis direction.

The internal electrodes 12 and 13 are sheet-shaped and extend along the XY plane, and are alternately arranged along the Z-axis direction. That is, the internal electrodes 12 and 13 face each other in the Z-axis direction with the ceramic layer interposed therebetween. The first internal electrode 12 is drawn out to one end surface 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 surface 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 electrodes 13 and the first external electrodes 14 . Similarly, the ceramic layer between the second internal electrodes 13 on the other end face side functions as an end margin that ensures 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, the plurality of voltages between the first internal electrode 12 and the second internal electrode 13 A voltage is applied to the ceramic layer of As a result, in the multilayer ceramic capacitor 10 , electric 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 the X-axis direction end surfaces on which the external electrodes 14 and 15 are provided are covered with the side margin portion 17 and the cover portion 19 . Therefore, the periphery of the capacitance forming portion 18 is protected by the side margin portion 17 and the cover portion 19, and the insulation of the internal electrodes 12 and 13 is ensured.

In order to increase the capacity of each ceramic layer between the internal electrodes 12 and 13, the ceramic body 11 uses dielectric ceramics with a high dielectric constant as the main component. Dielectric ceramics with a high dielectric constant include, for example, perovskite structure materials containing barium (Ba) and titanium (Ti), represented 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 ), and calcium zirconate titanate. (Ca(Zr, Ti)O ₃ ) system, barium zirconate (BaZrO ₃ ) system, titanium oxide (TiO ₂ ) system, or the like may be used.

The internal electrodes 12 and 13 are made of a good electrical conductor. Nickel (Ni) is typically used as a good electrical conductor forming the internal electrodes 12 and 13. In addition, copper (Cu), palladium (Pd), platinum (Pt), silver (Ag), A metal or alloy containing gold (Au) or the like as a main component can be used.

The laminated ceramic capacitor 10 according to the present embodiment only needs to include the laminated body 16 and the side margin portions 17, and other configurations can be changed as appropriate. For example, the numbers of the first and second internal electrodes 12 and 13 can be appropriately determined according to the size and performance required of the multilayer ceramic capacitor 10 .

[Manufacturing Method of Multilayer Ceramic Capacitor 10]
FIG. 4 is a flow chart showing the manufacturing method of the multilayer ceramic capacitor 10. As shown in FIG. 5 to 7 are diagrams showing the manufacturing process of the multilayer ceramic capacitor 10. FIG. Hereinafter, a method for manufacturing the laminated ceramic capacitor 10 will be described along FIG. 4 with reference to FIGS. 5 to 7 as appropriate.

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

(Step S02: Side Margin Formation)
In step S02, an unfired ceramic body 111 is manufactured 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 portions 117 . That is, in the punching method, the side margin portions 117 are formed by punching the side margin sheets 117 s from the side surfaces of the laminate 116 .

FIGS. 6A to 6C are diagrams showing a method of punching out the side margin sheet 117s on the side surface S of the laminate 116. FIG. First, as shown in FIG. 6( a ), the other side S of the laminated body 116 having one side S held by an adhesive tape T is placed on a flat elastic body 200 at a side margin. It is made to face the sheet 117s. In this 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 117 s is configured as a large dielectric green sheet for forming the unfired side margin portion 117 . The thickness of the side margin sheet 117s in the Y-axis direction of the side margin portion 17 of the multilayer ceramic capacitor 10 shown in FIGS. 2 and 3 can be adjusted. The thickness of 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 laminated body 116 is pushed into the side margin sheet 117s, and the laminated body 116 sinks into the elastic body 200 together with the side margin sheet 117s. At this time, only the region of the side margin sheet 117s pressed against the laminate 116 is cut off by the shearing force applied from the elastic body 200 .

Then, as shown in FIG. 6C, when the laminate 116 is moved away from the elastic body 200, only the portion of the side margin sheet 117s stuck to the side surface S of the laminate 116 is separated from the elastic body 200. Separate. As a result, side margin portions 117 are formed on the side surfaces S of the laminate 116 .

Subsequently, by replacing the tape T holding the laminate 116 with another tape T, the orientation of the laminate 116 in the Y-axis direction is reversed. Side margin portions 117 are formed in the same manner as described above on the opposite side surface S of the laminate 116 where the side margin portions 117 are not formed. In this embodiment, the side margin sheet 117s can be stably punched out by adjusting the pushing amount of the laminate 116. FIG. The detailed method will be described later.

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

In FIGS. 6 and 8 to 10, three laminates 116 are arranged on the tape T, and a plurality of laminates 116 are arranged at regular intervals along the XY plane. The interval can be changed as appropriate. Moreover, although the laminates 116 are typically arranged in a rectangular shape on the tape T, the 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 produced by firing the unfired ceramic body 111 obtained in step S02. That is, by step S<b>03 , the layered body 116 becomes the layered body 16 and the side margin portion 117 becomes the side margin portion 17 .

The sintering temperature in step S<b>03 can be determined based on the sintering temperature of the unsintered 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. Also, the firing can be performed, for example, in a reducing atmosphere or in a low oxygen partial pressure atmosphere.

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

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

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

[Details of punching method for side margin sheet 117s]
A method of forming side margin portions 117 on side surfaces S of laminate 116 by punching side margin sheets 117s from side surfaces S of laminate 116 in step S02 will be described in detail. It should be noted that the side margin portion 117 can be formed on the other side surface S of the laminate 116 as well as on the one side surface S.

In general, in the method of post-attaching the side margins using an elastic body, if the amount of pushing into the laminate is too small, the side margin sheets will not be cut off due to the insufficient shearing force of the elastic body, and the side margin sheets will be punched out appropriately. I can't. As a result, defective punching of the side margin sheet occurs. Therefore, it is necessary to sufficiently increase the pushing amount of the laminate.

However, problems also occur when the amount of pressing of the laminate is too large. FIG. 8A is a diagram showing a state in which the amount of pressing of the laminate 116 into the elastic body 200 is too large. FIG. 8(b) is a diagram showing a state in which the laminated body 116 is pulled out from the state shown in FIG. 8(a).

If the amount of pressing of the laminated body 116 is too large, the stress (restoring force) of the compressively deformed elastic body 200 acts strongly in the main surface direction and the end surface direction of the laminated body 116, as shown in FIG. 8(a). 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 peel off as shown in FIG. 116), the side margin portion 117 may be displaced (laminated body 116 in the center of the drawing), or the laminated body 116 may be peeled off from the tape T (laminated body 116 on the right in the drawing).

Therefore, when the amount of punching is extremely large as described above, defective punching or peeling of the side margin sheet occurs in the manufacturing process, resulting in a problem of reduced product yield.

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

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 sheets 117s are arranged. is the displacement of Specifically, from the state in which the side surface S of the laminate 116 facing the elastic body 200 side is in contact with the side margin sheet 117s (the state in FIG. 9A) to the state 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 pushing amount D. As shown in FIG. That is, the pushing amount D is defined by the distance between the holding member 300 holding the elastic body 200 and the side surface S.

As shown in FIG. 9A, just before the laminated body 116 is pushed into the elastic body 200, the side margin sheet 117s and the side surface S of the laminated body 116 on the elastic body 200 side are in contact with each other. The distance between the holding member 300 and the side surface S at this time is D0, which is the reference value for the pushing amount _D. FIG. Therefore, the pushing amount D at this time is zero.

Next, as shown in FIG. 9B , in a state in which the laminated body 116 is pushed into the elastic body 200 , the side surface S on the elastic body 200 side approaches the holding member 300 . Assuming that the distance between the holding member 300 and the side surface S at this time is D ₁ , the pushing amount D can be expressed as D=D ₀ -D ₁ .

In this embodiment, the pushing amount D is twice or more the thickness of the side margin sheet 117s in the Y-axis direction and is twice or less than the thickness of the laminate 116 in the Y-axis direction. A sufficient amount of shearing force for punching can be applied to the side margin sheet 117s by setting the pressing amount D to be at least twice the thickness of the side margin sheet 117s in the Y-axis direction. Thereby, the side margin sheet 117s can be punched out appropriately.

In addition, 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 due to the compressively deformed elastic body 200 acting on the main surfaces and end surfaces of the laminate 116 . . As a result, peeling of the side margin portion 117 and the laminate 116 can be prevented.

That is, by satisfying each of the above conditions, it is possible to stably form the side margin portion 117 on the side surface S of the stacked body 116 .

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

In the state shown in FIG. 9(b), the stress of the elastic body 200 that has undergone compressive deformation acts in the main surface direction and the end surface direction of the laminate 116. power becomes weaker. Therefore, there is no possibility that the laminated body 116 and the attached side margin sheet 117s are peeled off.

FIG. 10(a) shows a state in which the side margin sheet 117s between the laminates 116 is pushed in until it comes into contact with the tape T. FIG. 10(b) is a diagram showing a state in which the laminated body 116 is pulled out from the state shown in FIG. 10(a).

As shown in FIG. 10A, even when the side margin sheets 117s between the stacks 116 are pushed in until they come into contact with the tape T, the pushing amount D is twice the thickness of the side margin sheets 117s in the Y-axis direction. As long as the thickness is equal to or less than twice the thickness of the laminate 116 in the Y-axis direction, punching can be performed without problems as shown in FIG. 10(b).

10(b), the side margin sheet 117s adhered to the tape T can be recovered when the laminate 116 is transferred to another tape T. In FIG. 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 side margin sheet 117s after punching can be prevented from remaining.

[Other embodiments]
Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments and can be modified in various ways.

For example, in the above embodiments, the laminated ceramic capacitor 10 was explained as an example of the laminated ceramic electronic component, but the present invention is applicable to all laminated ceramic electronic components. Examples of such multilayer ceramic electronic components include chip varistors, chip thermistors, and multilayer inductors.

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

Claims (3)

a capacitance forming portion having a plurality of ceramic layers laminated in a first direction and a plurality of internal electrodes arranged between the plurality of ceramic layers; producing a laminate having a side surface and a cover portion covering the capacitance forming portion from the first direction;
The side margin sheet is pushed into the elastic body on which the side margin sheet is arranged on the surface by pressing the laminate from the side surface side to 1 to 2 times the thickness of the laminate in the second direction. A method for manufacturing a laminated ceramic electronic component by punching. A method for manufacturing a multilayer ceramic electronic component according to claim 1,
A method for manufacturing a multilayer ceramic electronic component, wherein the elastic body has a static shear elastic modulus of 5 MPa or less. A method for manufacturing a multilayer ceramic electronic component according to claim 1 or 2,
The laminate has first and second side surfaces facing the second direction,
The side margin sheet is punched out by pressing the laminated body, the first side surface of which is held by an adhesive tape, into the elastic body from the second side surface side, and the punched side margin sheet is attached to the tape. glue,
The punched side margin sheet is collected together with the tape by peeling the tape from the second side surface.
A method for manufacturing a multilayer ceramic electronic component.

Images