JP7688528B2 - Manufacturing method for multilayer ceramic electronic components - Google Patents

Description

The present invention relates to a method for manufacturing a multilayer ceramic electronic component that includes a side margin.

There is a known technology for retrofitting side margins during the manufacturing process of multilayer ceramic capacitors (see, for example, Patent Document 1). This technology is advantageous for miniaturizing multilayer ceramic capacitors and increasing their capacitance, because the thin side margins can reliably protect the side surfaces of the laminate where the internal electrodes are exposed.

As an example, in the method for manufacturing a multilayer ceramic capacitor described in Patent Document 1, a laminate sheet made by stacking ceramic sheets on which internal electrodes are printed is cut to produce multiple laminates with the cut surfaces where the internal electrodes are exposed as sides. Then, the ceramic sheets are punched out at the sides of the laminate to form side margins on both sides of the laminate.

JP 2012-209539 A

In the method described in Patent Document 1, in order to increase the adhesion of the side margins to the sides of the laminate, the ceramic sheet is heated and punched on the sides of the laminate. However, even with this method, the adhesion of the side margins is still insufficient, and the side margins may peel off from the sides of the laminate in a later process.

In view of the above circumstances, the object of the present invention is to provide a technology that improves the adhesion of the side margin portion to the side surface of the laminate.

In order to achieve the above object, a manufacturing method for a multilayer ceramic electronic component according to one embodiment of the present invention includes providing a laminate having a plurality of ceramic layers stacked in a uniaxial direction, a plurality of internal electrodes located between the plurality of ceramic layers, and side surfaces on which the plurality of internal electrodes are exposed, and a side margin sheet.
At least one of the side surface and the side margin sheet is made hydrophilic by a discharge treatment, thereby forming a hydrophilic surface.
The side surface and the side margin sheet are bonded together using the hydrophilic surface as an adhesive surface.
In this configuration, by providing a hydrophilic surface as the adhesive surface between the side surface of the laminate and the side margin sheet, high adhesion can be obtained between the side surface of the laminate and the side margin sheet.

In the manufacturing method, the side surface and the side margin sheet may be bonded via an adhesive having a larger amount of liquid component than the plurality of ceramic layers and the side margin sheet.
In this case, it is preferable to form the hydrophilic surface on both the side surface and the side margin sheet.
It is also preferable that the adhesive contains moisture of 0.1 wt % or more.

In the above manufacturing method, the side surface and the side margin sheet may be directly bonded to each other.
In this case, the hydrophilic surface may be provided on the side surface, but the side margin sheet need not be provided with the hydrophilic surface.
It is also preferable that the amount of liquid component in the side margin sheet is greater than that in the ceramic sheet.
Furthermore, it is preferable that the side margin sheet contains moisture of 0.05 wt % or more.

As described above, the present invention provides a technology that improves the adhesion of the side margin portion to the side surface of the laminate.

1 is a perspective view of a multilayer ceramic capacitor according to an embodiment of the present invention; 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line AA' in FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line BB' in FIG. 1. 4 is a flowchart showing a method for manufacturing the multilayer ceramic capacitor. 2 is a plan view of a ceramic sheet prepared in step S01 of the manufacturing method. FIG. FIG. 2 is a perspective view showing step S02 of the manufacturing method. FIG. 4 is a plan view showing step S03 of the manufacturing method. FIG. 11 is a partial cross-sectional view showing step S03. FIG. 4 is a cross-sectional view showing step S04 of the manufacturing method. FIG. 4 is a cross-sectional view showing step S05 of the manufacturing method. FIG. 11 is a cross-sectional view showing step S05. FIG. 4 is a cross-sectional view showing step S06 of the manufacturing method. FIG. 11 is a cross-sectional view showing step S07 of the manufacturing method. FIG. 11 is a cross-sectional view showing step S07. FIG. 2 is a perspective view of an unfired ceramic body obtained in step S07. FIG. 11 is a cross-sectional view showing another embodiment of step S05.

The multilayer ceramic capacitor 10 according to an embodiment of the present invention will be described below with reference to the drawings. In addition, the drawings appropriately show an X-axis, a Y-axis, and a Z-axis that are mutually orthogonal. The X-axis, the Y-axis, and the Z-axis define a fixed coordinate system that is fixed with respect to the multilayer ceramic capacitor 10.

The drawings also show, where appropriate, x-, y-, and z-axes which are mutually orthogonal. Unlike the X-, Y-, and Z-axes described above, the x-, y-, and z-axes define a real space coordinate system that is fixed relative to real space. The x- and y-axes extend horizontally, meaning that the x-y plane is the horizontal plane. The z-axis extends vertically, up and down.

[Configuration of Multilayer Ceramic Capacitor 10]
1 to 3 are diagrams showing a multilayer ceramic capacitor 10 according to an embodiment of the present invention. Fig. 1 is a perspective view of the multilayer ceramic capacitor 10. Fig. 2 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along line AA' in Fig. 1. Fig. 3 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along line BB' in Fig. 1.

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 is configured as a hexahedron having first and second end faces perpendicular to the X-axis, first and second side faces perpendicular to the Y-axis, and first and second main faces perpendicular to the Z-axis.

The first and second end faces, the first and second side faces, and the first and second main faces of the ceramic body 11 are all configured as flat surfaces. In this embodiment, the flat surface does not have to be a strictly flat surface as long as it is recognized as flat when viewed overall, and includes, for example, a surface having minute irregularities or a gently curved shape that exists within a specified range.

The external electrodes 14, 15 cover both end faces of the ceramic body 11 and face each other in the X-axis direction with the ceramic body 11 in between. The external electrodes 14, 15 extend from each end face of the ceramic body 11 to the main surface and side surfaces. As a result, the cross sections of the external electrodes 14, 15 parallel to the X-Z plane and the cross sections parallel to the X-Y plane are both U-shaped.

The shape of the external electrodes 14, 15 is not limited to that shown in FIG. 1. For example, the external electrodes 14, 15 may extend from both end faces of the ceramic body 11 to only one of the main surfaces, and may have an L-shaped cross section parallel to the X-Z plane. Furthermore, the external electrodes 14, 15 do not have to extend to any of the main surfaces or side surfaces.

The external electrodes 14, 15 are formed from a good electrical conductor. Examples of good electrical conductors that form the external electrodes 14, 15 include metals or alloys whose main component is copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), silver (Ag), gold (Au), etc. In this embodiment, the main component refers to the component with the highest content ratio.

The ceramic body 11 is made of dielectric ceramics and has a laminate 16 and first and second side margins 17a, 17b. The laminate 16 has first and second side surfaces S1, S2 that face each other in the Y-axis direction, first and second end faces that face each other in the X-axis direction, and first and second main surfaces that face each other in the Z-axis direction.

The laminate 16 has a configuration in which multiple flat ceramic layers extending along the X-Y plane are stacked in the Z-axis direction. The laminate 16 has a capacitance forming portion 18 and a cover portion 19. The cover portion 19 covers the capacitance forming portion 18 from above and below in the Z-axis direction, and constitutes the first and second main surfaces of the laminate 16.

The capacitance forming portion 18 is disposed between multiple ceramic layers and has multiple sheet-like first and second internal electrodes 12, 13 extending along the X-Y plane. The internal electrodes 12, 13 are alternately disposed along the Z-axis direction. In other words, the internal electrodes 12, 13 face each other in the Z-axis direction with the ceramic layers in between.

The first internal electrode 12 is extended to the end surface covered by the first external electrode 14. On the other hand, the second internal electrode 13 is extended to the end surface covered by the second external electrode 15. As a result, the first internal electrode 12 is connected only to the first external electrode 14, and the second internal electrode 13 is connected only to the second external electrode 15.

The internal electrodes 12, 13 are formed across the entire width of the capacitance forming portion 18 in the Y-axis direction and are exposed on both side surfaces S1, S2 of the laminate 16. In other words, in the ceramic body 11, both ends of each internal electrode 12, 13 in the Y-axis direction are aligned along the Z-axis direction on both side surfaces S1, S2 of the laminate 16.

In the ceramic body 11, the first side margin 17a covers the first side surface S1 of the laminate 16, and the second side margin 17b covers the second side surface S2 of the laminate 16. This ensures that the ceramic body 11 has sufficient insulation between the internal electrodes 12, 13 on both side surfaces S1, S2 of the laminate 16.

With this configuration, when a voltage is applied between the first external electrode 14 and the second external electrode 15 in the multilayer ceramic capacitor 10, the voltage is applied to the multiple ceramic layers between the first internal electrode 12 and the second internal electrode 13. As a result, a charge corresponding to the voltage between the first external electrode 14 and the second external electrode 15 is stored in the multilayer ceramic capacitor 10.

In the ceramic body 11, a dielectric ceramic having a high dielectric constant is used to increase the capacitance of each ceramic layer between the internal electrodes 12 and 13. An example of a dielectric ceramic having a high dielectric constant is a material having a perovskite structure containing barium (Ba) and titanium (Ti), such as barium titanate ( _BaTiO3 ).

The ceramic layer may be composed of a composition such as strontium titanate ( _SrTiO3 ), calcium titanate ( _CaTiO3 ), magnesium titanate ( _MgTiO3 ), calcium zirconate ( _CaZrO3 ), calcium zirconate titanate (Ca(Zr, _Ti ) _O3 ), barium zirconate (BaZrO3), titanium oxide ( _TiO2 ), etc.

The internal electrodes 12, 13 are formed from a good electrical conductor. Typical examples of good electrical conductors forming the internal electrodes 12, 13 include nickel (Ni), as well as metals or alloys whose main components are copper (Cu), palladium (Pd), platinum (Pt), silver (Ag), gold (Au), etc.

[Method of Manufacturing Multilayer Ceramic Capacitor 10]
Fig. 4 is a flowchart showing a method for manufacturing the multilayer ceramic capacitor 10 according to this embodiment. Figs. 5 to 15 are views showing the manufacturing process of the multilayer ceramic capacitor 10. The method for manufacturing the multilayer ceramic capacitor 10 will be described below along with Fig. 4 with appropriate reference to Figs. 5 to 15.

(Step S01: Prepare ceramic sheet)
In step S01, a first ceramic sheet 101 and a second ceramic sheet 102 for forming the capacitance forming portion 18, and a third ceramic sheet 103 for forming the cover portion 19 are prepared. The ceramic sheets 101, 102, and 103 are configured as unfired dielectric green sheets whose main component is dielectric ceramics.

The ceramic sheets 101, 102, and 103 are formed into sheets using, for example, a roll coater or a doctor blade. The thickness of the ceramic sheets 101 and 102 is adjusted according to the thickness of the ceramic layer in the capacitance forming portion 18 after firing. The thickness of the third ceramic sheet 103 can be adjusted as appropriate.

Figure 5 is a plan view of the ceramic sheets 101, 102, and 103. At this stage, the ceramic sheets 101, 102, and 103 are configured as large sheets that have not been singulated. Figure 5 shows the cutting lines Lx and Ly used when singulating each multilayer ceramic capacitor 10. The cutting line Lx is parallel to the X-axis, and the cutting line Ly is parallel to the Y-axis.

As shown in FIG. 5, an unfired first internal electrode 112 corresponding to the first internal electrode 12 is formed on the first ceramic sheet 101, and an unfired second internal electrode 113 corresponding to the second internal electrode 13 is formed on the second ceramic sheet 102. No internal electrode is formed on the third ceramic sheet 103 corresponding to the cover portion 19.

The internal electrodes 112, 113 can be formed by applying any conductive paste to the ceramic sheets 101, 102. The method for applying the conductive paste can be selected from any known technique. For example, the conductive paste can be applied by screen printing or gravure printing.

Gaps in the X-axis direction along the cutting lines Ly are formed in the internal electrodes 112 and 113, one for every other cutting line Ly. The gaps in the first internal electrode 112 and the gaps in the second internal electrode 113 are arranged alternately in the X-axis direction. In other words, the cutting lines Ly passing through the gaps in the first internal electrode 112 and the cutting lines Ly passing through the gaps in the second internal electrode 113 are arranged alternately.

(Step S02: Lamination)
In step S02, the ceramic sheets 101, 102, and 103 prepared in step S01 are laminated as shown in Fig. 6 to produce a laminated sheet 104. In the laminated sheet 104, the first ceramic sheet 101 and the second ceramic sheet 102 corresponding to the capacitance forming portion 18 are laminated alternately in the Z-axis direction.

In the laminated sheet 104, third ceramic sheets 103 corresponding to the cover portion 19 are laminated on the upper and lower surfaces in the Z-axis direction of the alternately laminated ceramic sheets 101 and 102. In the example shown in FIG. 6, three third ceramic sheets 103 are laminated on each side, but the number of third ceramic sheets 103 can be changed as appropriate.

The laminated sheet 104 is integrated by pressing the ceramic sheets 101, 102, and 103 together. For example, hydrostatic pressure or uniaxial pressure is preferably used to press the ceramic sheets 101, 102, and 103 together. This makes it possible to densify the laminated sheet 104.

(Step S03: Disconnect)
In step S03, the laminate sheet 104 obtained in step S02 is cut along the cutting lines Lx and Ly to produce an unfired laminate 116. The laminate 116 corresponds to the fired laminate 16. For example, a press blade or a rotary blade can be used to cut the laminate sheet 104.

Figures 7 and 8 are schematic diagrams for explaining an example of step S03. Figure 7 is a plan view of the laminated sheet 104. Figure 8 is a cross-sectional view of the laminated sheet 104 along the Y-Z plane. The laminated sheet 104 is cut by the push cutter blade BL along the cutting lines Lx and Ly while being held by an adhesive cut sheet C, such as a foam release sheet.

First, as shown in FIG. 8(A), the push-cutting blade BL is positioned above the laminated sheet 104 in the Z-axis direction, with its tip pointing toward the laminated sheet 104 below in the Z-axis direction. Next, as shown in FIG. 8(B), the push-cutting blade BL is moved downward in the Z-axis direction until it reaches the cut sheet C, penetrating the laminated sheet 104.

Then, as shown in FIG. 8(C), the cutting blade BL is moved upward in the Z-axis direction to pull it out of the laminated sheet 104. This cuts the laminated sheet 104 in the X-axis and Y-axis directions, forming a laminate 116 having first and second side surfaces S1, S2 that expose the internal electrodes 112, 113 in the Y-axis direction.

(Step S04: Discharge process 1)
In this embodiment, a discharge treatment is performed as a pretreatment for forming the side margins 117a and 117b. For the discharge treatment, a discharge device P that generates a discharge by a high voltage is used. The purpose of the discharge treatment is to impart hydrophilicity to the treated surface, and examples of the discharge treatment include nitrogen plasma treatment, argon plasma treatment, oxygen plasma treatment, and corona discharge treatment.

In step S04, a discharge treatment is performed to properly form the first side margin portion 117a. Specifically, the discharge treatment is performed on the first side surface S1 of the multiple laminates 116 and one surface of the first side margin sheet 117s1. The first side margin sheet 117s1 is an insulating ceramic sheet prepared to form the first side margin portion 117a.

The first side margin sheet 117s1 is configured as an unfired dielectric green sheet whose main component is dielectric ceramics, similar to the above-mentioned ceramic sheets 101, 102, and 103. The first side margin sheet 117s1 is formed into a sheet shape using, for example, a roll coater or a doctor blade.

In step S04, the orientation of the multiple laminates 116 after step S03 is changed in order to collectively perform discharge processing on the first side surfaces S1 of the multiple laminates 116. In other words, the multiple laminates 116 immediately after step S03 shown in FIG. 8(C) are changed from a state in which the sides S1 and S2 are close to each other in the Y-axis direction to a state in which the sides S1 and S2 face up and down in the vertical direction.

The orientation of the side surfaces S1, S2 of the multiple laminates 116 can be changed by a known method such as a rolling method. In the rolling method, the laminates 116 are first attached from the cut sheet C to a first adhesive sheet F1 having extensibility, and the first adhesive sheet F1 is stretched to increase the spacing between the laminates 116.

Then, the multiple laminates 116 are rolled on the first adhesive sheet F1. At this time, all of the laminates 116 can be rolled at once, for example, by using a rolling plate or the like. This rotates the laminates 116 by 90 degrees, and as shown in FIG. 9(A), the sides S1 and S2 can be oriented upward and downward in the z-axis direction, respectively.

In other words, after rolling, the second side S2 of each of the multiple laminates 116 facing downward in the z-axis direction is held by the first adhesive sheet F1, and the first side S1 faces upward in the z-axis direction. This makes it possible to simultaneously perform a discharge treatment on the first side S1 of all of the laminates 116 facing upward in the z-axis direction.

In the discharge process of step S04, as shown in FIG. 9(A), discharge irradiation is performed by a discharge device P facing the first side surface S1 of the multiple laminates 116. The first side surface S1 of the multiple laminates 116 that has been subjected to discharge irradiation is given hydrophilicity as the number of hydrophilic groups increases. As a result, the first side surface S1 of the multiple laminates 116 becomes a hydrophilic surface T.

Similarly, as shown in FIG. 9(B), discharge irradiation is performed by a discharge device P facing the first side margin sheet 117s1. The irradiated surface of the first side margin sheet 117s1 that has been subjected to discharge irradiation is rendered hydrophilic as the number of hydrophilic groups increases. As a result, one surface of the first side margin sheet 117s1 becomes a hydrophilic surface T.

In this embodiment, the hydrophilicity of the target surface before and after the discharge treatment is understood based on the wettability of water, and specifically, is evaluated based on the contact angle of dropped water with the surface. In other words, in this embodiment, the contact angle of water on the hydrophilic surface T that has been subjected to the discharge treatment is smaller than the contact angle of water on the surface before the discharge treatment.

(Step S05: Side margin formation 1)
In step S05, an unfired first side margin portion 117a is provided on the laminate 116. The first side margin portion 117a is formed by punching out a first side margin sheet 117s1 on the first side surface S1 of each laminate 116. In step S05, an adhesive D is used to improve adhesion between each laminate 116 and the first side margin portion 117a.

The adhesive D used in step S05 contains a larger amount of liquid components, such as binder and solvent, than the ceramic sheets 101, 102, and 103 that constitute the multiple ceramic layers of the laminate 116 and the first side margin sheet 117s1 that constitutes the first side margin portion 117a. This allows the adhesive D to have high wettability with respect to the hydrophilic surface T.

In the adhesive D used in step S05, the amount of liquid components such as binders and solvents is preferably 1.0 wt % or more in order to obtain higher wettability to the hydrophilic surface T. Furthermore, in order to obtain even higher wettability to the hydrophilic surface T, it is even more preferable that the adhesive D contains water of 0.1 wt % or more as a liquid component.

As shown in FIG. 10, adhesive D is placed on the first side S1 of each laminate 116. To place adhesive D on the first side S1 of each laminate 116, for example, a dispenser capable of dispensing a fixed amount of adhesive D can be used. Alternatively, adhesive D may be applied to the first side S1 of each laminate 116 using any other application device.

Next, the first side margin sheet 117s1 is punched out at the first side surface S1 of the multiple laminates 116 on which the adhesive D is disposed. First, as shown in FIG. 11(A), the hydrophilic surface T of the first side margin sheet 117s1 is placed opposite the z-axis direction above the first side surface S1 of the multiple laminates 116 on which the adhesive D is disposed.

Then, as shown in FIG. 11B, while the lower surface of the first adhesive sheet F1 in the z-axis direction is held by the holding member H, the first side margin sheet 117s1 is pressed downward in the z-axis direction toward the holding member H by the elastic member E arranged above in the z-axis direction. This causes the elastic member E to bite into the spaces between the multiple laminates 116.

At this time, the first side margin sheet 117s1 is pressed against the first side surface S1 of the multiple laminates 116 via the adhesive D by the elastic member E. This causes the adhesive D, which has a large amount of liquid components, to wet and spread without gaps on both the first side surface S1, which is the hydrophilic surface T of the multiple laminates 116, and the hydrophilic surface T of the first side margin sheet 117s1.

At the same time, the first side margin sheet 117s1 is pressed downward in the z-axis direction by the elastic member E around the first side surface S1 of the laminate 116. As a result, the first side margin sheet 117s1 is cut along the contour of the first side surface S1 of each laminate 116 by the shear force applied in the z-axis direction, and is divided into individual pieces.

The individualized first side margin sheet 117s1 remains on the first side surface S1 of each laminate 116, forming the first side margin portion 117a. In this manner, each laminate 116 and the first side margin portion 117a bonded together via adhesive D can achieve high adhesion due to the action of adhesive D, which adheres tightly to the hydrophilic surfaces T of both laminates.

Then, as shown in FIG. 11(C), the elastic member E is moved upward in the z-axis direction to separate the elastic member E from the first side margin sheet 117s1. The first side margin sheet 117s1 remaining in the space between the multiple laminates 116 in which the first side margin portion 117a is formed is removed.

(Step S06: Discharge process 2)
In step S06, a discharge treatment is performed to satisfactorily form the second side margin portion 117b. Specifically, the discharge treatment is performed on the second side surfaces S2 of the multiple laminates 116 and one surface of the second side margin sheet 117s2. The second side margin sheet 117s2 is an insulating ceramic sheet prepared to form the second side margin portion 117b.

The second side margin sheet 117s2, like the first side margin sheet 117s1, is constructed as an unsintered dielectric green sheet whose main component is dielectric ceramics. The second side margin sheet 117s2 may have the same configuration as the first side margin sheet 117s1 or a different configuration.

In step S06, the multiple laminates 116 on which the first side margins 117a were formed in step S05 are transferred from the first adhesive sheet F1 to the second adhesive sheet F2. Specifically, starting from the state after step S05, the second adhesive sheet F2 is first attached to the first side margins 117a formed on the first side surfaces S1 of the multiple laminates 116.

Next, the multiple laminates 116 with the first side margin portion 117a formed and sandwiched between the first and second adhesive sheets F1 and F2 are inverted up and down in the z-axis direction. Then, the first adhesive sheet F1 is peeled off from the second side surface S2 of the multiple laminates 116. As a result, the second side surface S2 of each of the multiple laminates 116 faces upward in the z-axis direction (see FIG. 12(A)).

In the discharge process of step S06, as shown in FIG. 12(A), discharge irradiation is performed by a discharge device P facing the second side surface S2 of the multiple laminates 116. The second side surface S2 of the multiple laminates 116 that has been subjected to discharge irradiation is given hydrophilicity as the hydrophilic groups increase. As a result, the second side surface S2 of the multiple laminates 116 becomes a hydrophilic surface T.

Similarly, as shown in FIG. 12(B), discharge irradiation is performed by a discharge device P facing the second side margin sheet 117s2. The irradiated surface of the second side margin sheet 117s2 that has been subjected to discharge irradiation is made hydrophilic as the number of hydrophilic groups increases. As a result, one surface of the second side margin sheet 117s2 becomes a hydrophilic surface T.

(Step S07: Formation of side margin portion 2)
In step S07, an unfired second side margin portion 117b is provided on the laminate 116. The second side margin portion 117b is formed by punching out a second side margin sheet 117s2 on the second side surface S2 of each laminate 116. In step S07, an adhesive D is used to improve adhesion between each laminate 116 and the second side margin portion 117b.

As shown in FIG. 13, adhesive D is placed on the second side S2 of each laminate 116. The placement of adhesive D in step S07 can be performed using a dispenser or the like, similar to step S05. Note that the composition of adhesive D used in step S07 may be the same as that in step S05, or may be different from that in step S05.

The adhesive D used in step S07 contains a larger amount of liquid components, such as binder and solvent, than the ceramic sheets 101, 102, and 103 constituting the multiple ceramic layers of the laminate 116 and the second side margin sheet 117s2 constituting the second side margin portion 117b. This allows the adhesive D to have high wettability with respect to the hydrophilic surface T.

In the adhesive D used in step S07, the amount of liquid components such as binders and solvents is preferably 1.0 wt % or more in order to obtain higher wettability to the hydrophilic surface T. Furthermore, in order to obtain even higher wettability to the hydrophilic surface T, it is even more preferable that the adhesive D contains 0.1 wt % or more of water as a liquid component.

Next, the second side margin sheet 117s2 is punched out at the second side surface S2 of the multiple laminates 116 on which the adhesive D is disposed. First, as shown in FIG. 14(A), the hydrophilic surface T of the second side margin sheet 117s2 is placed opposite the z-axis direction above the second side surface S2 of the multiple laminates 116 on which the adhesive D is disposed.

Then, as shown in FIG. 14B, while the lower surface of the second adhesive sheet F2 in the z-axis direction is held by the holding member H, the second side margin sheet 117s2 is pressed downward in the z-axis direction toward the holding member H by the elastic member E arranged above in the z-axis direction. This causes the elastic member E to bite into the spaces between the multiple laminates 116.

At this time, the second side margin sheet 117s2 is pressed against the second side surface S2 of the multiple laminates 116 via the adhesive D by the elastic member E. As a result, the adhesive D, which has a large amount of liquid components, spreads without any gaps on both the second side surface S2, which is the hydrophilic surface T of the multiple laminates 116, and the hydrophilic surface T of the second side margin sheet 117s2.

At the same time, the second side margin sheet 117s2 is pressed downward in the z-axis direction by the elastic member E around the second side surface S2 of the laminate 116. As a result, the second side margin sheet 117s2 is cut along the contour of the second side surface S2 of each laminate 116 by the shear force applied in the z-axis direction, and is divided into individual pieces.

The individualized second side margin sheet 117s2 remains on the second side surface S2 of each laminate 116, forming the second side margin portion 117b. In this manner, each laminate 116 and the second side margin portion 117b bonded together via the adhesive D can obtain high adhesion due to the action of the adhesive D, which adheres closely to the hydrophilic surfaces T of both laminates without any gaps.

Then, as shown in FIG. 14(C), the elastic member E is moved upward in the z-axis direction to separate the elastic member E from the second side margin sheet 117s2. The second side margin sheet 117s2 remaining in the space between the multiple laminates 116 in which the second side margin portion 117b is formed is removed.

This results in the unsintered ceramic body 111 shown in FIG. 15. In the ceramic body 111, the side margins 117a, 117b have high adhesion to the side surfaces S1, S2 of the laminate 116, making the side margins 117a, 117b less likely to peel off from the side surfaces S1, S2 of the laminate 116.

(Step S08: Firing)
In step S08, the ceramic body 111 obtained in step S07 and shown in Fig. 15 is fired to produce the ceramic body 11 of the multilayer ceramic capacitor 10 shown in Figs. 1 to 3. That is, in step S08, the laminate 116 becomes the laminate 16, and the side margin portions 117a, 117b become the side margin portions 17a, 17b.

The firing temperature in step S08 can be determined based on the sintering temperature of the 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. Furthermore, the firing can be performed, for example, in a reducing atmosphere or a low oxygen partial pressure atmosphere.

(Step S09: Forming external electrodes)
In step S09, external electrodes 14, 15 are formed on both ends in the X-axis direction of the ceramic body 11 obtained in step S08, thereby producing the multilayer ceramic capacitor 10 shown in Figures 1 to 3. The method for forming the external electrodes 14, 15 in step S06 can be arbitrarily selected from known methods.

The multilayer ceramic capacitor 10 is thus completed. In this manufacturing method, side margins 117a, 117b are formed on the side surfaces S1, S2 of the laminate 116 where the internal electrodes 112, 113 are exposed, so that the positions of the ends of the multiple internal electrodes 12, 13 in the ceramic body 11 in the Y-axis direction are aligned to within 0.5 μm.

[Other embodiments]
Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made thereto.

For example, the discharge treatment in steps S04 and S06 is preferably performed on both the multiple laminates 116 and the side margin sheets 117s1 and 117s2, but may be performed on only one of them. In addition, the discharge treatment in steps S04 and S06 may include two or more discharge irradiations, and may further include different types of discharge treatments.

In addition, in steps S05 and S07, the adhesive D may be applied to the side margin sheets 117s1 and 117s2 instead of the side surfaces S1 and S2 of the multiple laminates 116. In this case, the adhesive D may be applied to the entire surface of the side margin sheets 117s1 and 117s2, or the adhesive D may be placed only at the positions facing the multiple laminates 116.

Furthermore, steps S05 and S07 are not limited to punching out the side margin sheets 117s1 and 117s2 at the sides S1 and S2 of the multiple laminates 116. For example, the side margin sheets 117s1 and 117s2 may be cut in advance to separate the side margin portions 117a and 117b, which may be attached to the sides S1 and S2 of the multiple laminates 116.

In addition, in steps S05 and S07, the adhesive D may not be used, that is, the side margins 117a and 117b may be directly bonded to the side surfaces S1 and S2 of the multiple laminates 116. In this case, too, the hydrophilic surface T acts to ensure good adhesion between the side surfaces S1 and S2 of the multiple laminates 116 and the side margins 117a and 117b.

Figure 16 shows a configuration in which the first side margin portion 117a is directly bonded to the first side surface S1 of the multiple laminates 116 in step S05. In this configuration, the first side margin portion 117a is directly formed on the first side surface S1 of each laminate 116 by punching out the first side margin sheet 117s1 on the first side surface S1 of the multiple laminates 116.

In this case, as shown in FIG. 16, a hydrophilic surface T can be provided only on the first side surface S1 of the multiple laminates 116, and the first side margin sheet 117s1 can be configured not to have a hydrophilic surface T. In this configuration, it is preferable to make the amount of liquid component in the first side margin sheet 117s1 greater than that of the multiple ceramic layers that make up the laminate 116.

This allows the first side margin sheet 117s1 to have high wettability with respect to the hydrophilic surface T. Therefore, the first side margin sheet 117s1 spreads without gaps over the first side surface S1, which is the hydrophilic surface T of the multiple laminates 116, and the first side margin portion 117a has high adhesion to the first side surface S1 of the laminate 116.

Similarly, in step S07, a hydrophilic surface T is provided only on the second side surface S2 of the multiple laminates 116, and the amount of liquid component in the second side margin sheet 117s2 is made greater than that of the multiple ceramic layers that make up the laminate 116, thereby obtaining high adhesion of the second side margin portion 117b to the second side surface S2 of the laminate 116.

In the above configuration, in the side margin sheets 117s1 and 117s2, the amount of liquid components such as binders and solvents is preferably 1.0 wt % or more in order to obtain higher wettability to the hydrophilic surface T. Furthermore, in order to obtain even higher wettability to the hydrophilic surface T, it is even more preferable that the side margin sheets 117s1 and 117s2 contain 0.05 wt % or more of moisture as a liquid component.

In the above embodiment, the manufacturing method of the multilayer ceramic capacitor 10 has been described as an example of a multilayer ceramic electronic component, but the manufacturing method of the present invention can be applied to multilayer ceramic electronic components in general. Examples of such multilayer ceramic electronic components include chip varistors, chip thermistors, and multilayer inductors.

10... Multilayer ceramic capacitor 11... Ceramic body 12, 13... Internal electrodes 14, 15... External electrodes 16... Laminates 17a, 17b... Side margin portion 18... Capacitor forming portion 19... Cover portion 111... Ceramic body 112, 113... Internal electrode 116... Laminates 117a, 117b... Side margin portions 117s1, 117s2... Side margin sheet D... Adhesives S1, S2... Side surface

Claims (2)

A laminate having a plurality of ceramic layers laminated in one axial direction, a plurality of internal electrodes positioned between the plurality of ceramic layers, and a side surface to which the plurality of internal electrodes are exposed; and a side margin sheet are prepared;
forming a hydrophilic surface by imparting hydrophilicity to both the side surface and the side margin sheet through a discharge treatment;
a step of adhering the side surface and the side margin sheet using the hydrophilic surface as an adhesive surface;
The side surface and the side margin sheet are bonded to each other via an adhesive having a larger amount of liquid component than the plurality of ceramic layers and the side margin sheet;
The adhesive contains 0.1 wt % or more of moisture.
A method for manufacturing multilayer ceramic electronic components. A laminate having a plurality of ceramic layers laminated in one axial direction, a plurality of internal electrodes positioned between the plurality of ceramic layers, and a side surface to which the plurality of internal electrodes are exposed; and a side margin sheet are prepared;
The side surface is provided with a hydrophilic surface by a discharge treatment, and the side margin sheet is not provided with a hydrophilic surface,
a step of directly bonding the side surface and the side margin sheet using the hydrophilic surface as an adhesive surface,
the amount of liquid component in the side margin sheet is greater than that in the ceramic sheet forming the ceramic layer;
The side margin sheet contains 0.05 wt % or more of moisture.
A method for manufacturing multilayer ceramic electronic components.

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