JP7122121B2 - 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. In recent years, along with the miniaturization and high performance of electronic devices, there is a demand for miniaturization and large capacity of multilayer ceramic capacitors to be mounted.

2. Description of the Related Art A technique of retrofitting a side margin portion in order to reduce the size and increase the capacity of a multilayer ceramic capacitor is known. According to this technique, since the side margin portion can be made thin and uniform, a wide intersection area of the internal electrode portion can be ensured, and miniaturization and large capacity of the multilayer ceramic capacitor can be realized.

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 side margin sheet is arranged.

JP 2012-209539 A

However, with the technique described in Patent Document 1, the side margin sheet may remain on surfaces other than the side surfaces of the laminated chip after being pressed against the elastic body. The remaining side margin sheets may cause a defective appearance of the multilayer ceramic capacitor or contamination of the production equipment.

SUMMARY OF THE INVENTION 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 preventing poor appearance and facility contamination.

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 orthogonal to the first direction, and a cover portion covering the capacitance formation portion from the first direction.
A side margin sheet is punched out from the side surface of the laminate.
The side margin sheets remaining around the laminate are removed.

According to the above configuration, the side margin sheet remaining around the laminate can be removed. This improves the yield of laminated ceramic electronic components. In addition, this makes it possible to prevent contamination of production facilities.

The side margin sheets remaining around the laminate may be removed by pulsed air, adhesive rollers, or ultrasonic waves.
As a result, the side margin sheets remaining around the laminate can be removed without damaging the laminate and the supporting member of the laminate.

As described above, according to the present invention, it is possible to provide a method for manufacturing a multilayer ceramic electronic component that can prevent appearance defects and facility contamination.

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. 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 which looked at the edge surface side of the laminated body which shows the removal method of the side margin sheet which concerns on the said embodiment. It is the figure which looked at the edge surface side of the laminated body which shows the removal method of the side margin sheet which concerns on the said embodiment. It is the figure which looked at the edge surface side of the laminated body which shows the removal method of the side margin sheet 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 invention. FIG. 1 is a perspective view of a laminated ceramic capacitor 10. FIG. 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 8 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 8 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: Formation of Side Margins)
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. An example of a method for providing unfired side margin portions 117 on the side surfaces S of the laminate 116 will be described below.

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.

6, 7, 9 to 11, three laminates 116 are arranged on the tape T, and a plurality of laminates 116 are arranged at regular intervals along the XZ plane. and 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.

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, by moving the laminated body 116 away from the elastic body 200, the side margin portion 117 is formed on the side surface S of the laminated body 116. As shown in FIG.

Subsequently, the tape T holding the laminate 116 is replaced with another tape T. FIG. At this time, as shown in FIG. 6(c), the residual sheet 117r remaining around the laminate 116 in the main surface direction and the end surface direction is adhered to the tape T. As shown in FIG. Therefore, the residual sheet 117r adhered to the tape T is removed together with the tape T. FIG.

As described above, most of the residual sheet 117r remaining after punching is removed when the tape T is reapplied. On the other hand, there is a part of the residual sheet 117r that cannot be removed by replacing the tape T. FIG.

FIGS. 7A and 7B are diagrams showing a case where residual sheets 117r remain around the laminate 116 in the main surface direction and the end surface direction after the side margin sheets 117s are punched out. Although the pressure applied from the elastic body 200 to the side margin sheet 117s is substantially constant, it may partially vary. In addition, it may be difficult for the elastic body 200 to enter between the laminated bodies 116 due to factors such as the size of the laminated body 116 and the elastic modulus of the elastic body 200 . As a result, as shown in FIG. 7A, the unpunched portions of the side margin sheet 117s remain around the laminate 116 in the main surface direction and the end surface direction, and cannot be pushed into the tape T until they are adhered. case arises.

When the laminated body 116 is pulled back from the elastic body 200 in this state, residual sheets 117r may remain around the laminated body 116 in the main surface direction and the end surface direction, as shown in FIG. 7(b). The residual sheet 117r remaining in such a state cannot be removed when the tape T is replaced. Therefore, the residual sheet 117r causes the multilayer ceramic capacitor 10 to have a defective appearance. Moreover, in the subsequent manufacturing process, the residual sheet 117r may come off and contaminate the production equipment.

Therefore, in the present embodiment, after the side margin sheet 117s is punched out on one side surface S, there is a process of removing the remaining residual sheet 117r. As a result, the periphery of the laminated body 116 after punching in the main surface direction and the end surface direction can be kept clean. Therefore, it becomes possible to improve the yield of the multilayer ceramic capacitor 10 . Also, it is possible to prevent contamination of the production equipment.

A method for removing the residual sheet 117r is not particularly limited, but a method that does not damage the tape T and the laminate 116 is preferable. In this embodiment, a method capable of removing the residual sheet 117r without damaging the tape T and the laminate 116 is used. Details of the method will be described later.

After removing the residual sheet 117r, the side margin portion 117 is also formed on the opposite side surface S of the laminate 116 where the side margin portion 117 is not formed in the same manner as described above. After forming the side margin portion 117 on the opposite side surface S, the residual sheet 117r is removed again.

By step S02, unfired ceramic body 111 having side margin portions 117 formed on both side surfaces S of laminate 116 is obtained. FIG. 8 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 .

(Step S03: Firing)
In step S03, the unfired ceramic body 111 obtained in step S02 is fired to fabricate the ceramic body 11 of the multilayer ceramic capacitor 10 shown in FIGS. 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.

[Method for removing residual sheet 117r]
A method for removing the residual sheet 117r remaining around the laminated body 116 in the main surface direction and the end surface direction in step S02 will be described in detail.

As described above, as a method for removing the residual sheet 117r, a method that does not damage the tape T and the laminate 116 is preferable. In this embodiment, pulsed air, a roller, or ultrasonic waves are used as a method for removing the residual sheet 117r. With these, the residual sheet 117r can be removed without damaging the tape T and the laminate 116. FIG.

(Method for removing residual sheet 117r by pulse air)
The residual sheet 117r can be removed by applying vibration, for example. Pulsed air, for example, can be used as a method of applying vibration. FIG. 9 is a diagram showing a method of removing the residual sheet 117r using pulsed air. First, as shown in FIG. 9A, the orientation of the laminate 116 in the Y-axis direction is reversed so that the side surface S on which the side margin portion 117 is formed faces downward in the vertical direction. This makes it easier to remove the remaining sheet 117r that has been peeled off.

Next, the nozzle of the pulse air generator 20 is directed to the surface of the tape T to which the layered body 116 is not attached, and pulse air is generated. Pulsed air may be generated by switching a solenoid valve, or by a nozzle that generates rotational waves. The conditions for generating the pulse air are preferably such that the residual sheet 117r is peeled off and the side margin portion 117 and the laminate 116 are not peeled off from the tape T. FIG.

Specific conditions for generating pulsed air may be, for example, the following conditions.
Air pressure: 0.05MPa to 0.6MPa
Distance between nozzle and tape T: 1mm to 300mm
Frequency: 5-100Hz

The pulse air generated by the pulse air generator 20 causes the tape T to vibrate finely, and the vibration is transmitted to the laminate 116 and the residual sheet 117r. As a result, as shown in FIG. 9B, the residual sheet 117r is peeled off from the laminate 116 and dropped downward in the vertical direction. Thereby, the residual sheet 117r is removed.

In this embodiment, the residual sheet 117r can be removed while preventing the tape T and the laminate 116 from being damaged by applying minute vibrations using pulsed air. A vibration generation method other than pulse air is not particularly limited as long as it is a method that does not damage the tape T and the laminate 116 .

(Method for removing residual sheet 117r by roller)
FIG. 10 is a diagram showing a method of removing the residual sheet 117r using a roller. First, as shown in FIG. 10A, the roller 21 is placed on the surface of the tape T to which the laminated body 116 is attached. The roller 21 has an adhesive surface and is configured to be movable parallel to the Z-axis direction.

Next, by rolling the roller 21 parallel to the Z-axis direction, the residual sheet 117r around the laminate 116 is adhered to the roller 21 as shown in FIG. 10(b). Thereby, the residual sheet 117r is removed.

The residual sheet 117r adhered to the surface of the roller 21 is adhered with a tape or the like having adhesiveness higher than that of the roller 21 and removed. As a result, the roller 21 from which the residual sheet 117r has been removed becomes reusable.

The adhesive strength of the surface of the roller 21 is preferably such that the residual sheet 117r can be adhered and the side margin portion 117 and the laminate 116 are not separated from the tape T.

In this embodiment, the roller 21 as a whole is made of a soft material so that the roller 21 can easily enter the gap between the laminates 116 . The configuration of the roller 21 is not particularly limited as long as it can enter the gap between the laminates 116 and adhere the residual sheet 117r. As another configuration of the roller 21, for example, an elastic material having adhesiveness on the surface may be used.

Further, the roller 21 may be configured by winding a sheet made of a soft material or an elastic material having adhesiveness on the surface. As a result, the roller 21 can be easily put into a reusable state simply by peeling off the portion of the sheet to which the residual sheet 117r is adhered.

(Method for Removing Remaining Sheet 117r Using Ultrasonic Waves)
FIG. 11 is a diagram showing a method of removing the residual sheet 117r using ultrasonic waves. First, the orientation of the laminate 116 in the Y-axis direction is reversed so that the side surface S on which the side margin portion 117 is formed faces downward in the vertical direction.

Next, as shown in FIG. 11(a), the tape T to which the laminate 116 is attached is placed in the ultrasonic cleaning tank 22 filled with water. The ultrasonic cleaning bath 22 is equipped with an ultrasonic wave generating mechanism (not shown).

Subsequently, ultrasonic waves are generated in the ultrasonic cleaning tank 22 . The conditions for generating ultrasonic waves are preferably such that the residual sheet 117r is peeled off and the side margin portion 117 and the laminate 116 are not peeled off from the tape T. FIG.

As a specific condition for generating ultrasonic waves, for example, the frequency can be in the range of 10 kHz to 2 MHz.

Cavitation occurs in the ultrasonic cleaning bath 22 as the ultrasonic waves are generated. A shock wave is generated by repeating cavitation and rupture in the vicinity of the remaining sheet 117r. As a result, the residual sheet 117r is peeled off toward the bottom of the ultrasonic cleaning tank 22, as shown in FIG. 11(b). Thereby, the residual sheet 117r is removed.

[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 117r... Residual sheet 18, 118... Capacitance formation Part 19, 119... Cover part 20... Pulse air generator 21... Roller 22... Ultrasonic cleaning tank 200... Elastic body T... Tape

Claims (4)

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; fabricating a laminate having first and second side surfaces and a cover portion that covers the capacitance forming portion from the first direction;
A side margin sheet is punched out from the second side of the laminate whose first side is held by an adhesive tape, and the residual sheet remaining around the laminate of the side margin sheets is removed by the tape. to the
removing a portion of the residual sheet along with the tape by peeling the tape from the second side;
A method for manufacturing a multilayer ceramic electronic component, wherein a portion of the residual sheet that has not been removed together with the tape is removed. A method for manufacturing a multilayer ceramic electronic component according to claim 1,
A method for manufacturing a multilayer ceramic electronic component, wherein the remaining portion is removed by pulsed air. A method for manufacturing a multilayer ceramic electronic component according to claim 1,
A method for manufacturing a laminated ceramic electronic component, wherein the remaining portion is removed with a roller having adhesiveness. A method for manufacturing a multilayer ceramic electronic component according to claim 1,
A method for manufacturing a multilayer ceramic electronic component, wherein the remaining portion is removed by ultrasonic waves.

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