Patent Publication Number: US-2023154680-A1

Title: Electronic component, circuit board, and method of mounting electronic component on circuit board

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to Japanese Patent Application No. 2018-189163 filed on Oct. 4, 2018. The entire contents of this application are hereby incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electronic component, a circuit board on which the electronic component is mounted, and a method of mounting the electronic component on the circuit board. 
     2. Description of the Related Art 
     Conventionally, when power supply voltage supplied to an IC fluctuates, circuit operation of the IC becomes unstable. Therefore, there has been known a method of stabilizing the circuit operation of the IC by inserting a capacitor between a power supply pin of the IC and the ground. 
     As one of such capacitors, JP 2004-342846 A describes a multilayer ceramic capacitor, including a laminate in which a plurality of first internal electrodes and a plurality of second internal electrodes are alternately laminated with dielectric layers interposed therebetween, a first external electrode formed on a first end surface of the laminate and electrically connected to the first internal electrodes, and a second external electrode formed on a second end surface of the laminate and electrically connected to the second internal electrodes. 
     Here, as a capacitor having high frequency characteristics, there has been known a temperature compensating capacitor in which titanium oxide, calcium zirconate, and the like are included in a dielectric layer. However, the temperature compensating capacitor has a problem that the capacitance per volume is small. 
     SUMMARY OF THE INVENTION 
     Preferred embodiments of the present invention provide electronic components which are each able to significantly improve high frequency characteristics and electronic component characteristics including, for example, capacitance per volume. 
     According to a preferred embodiment of the present invention, an electronic component includes a laminate in which first internal electrodes and second internal electrodes are alternately laminated in a lamination direction with dielectric layers interposed between the first internal electrodes and the second internal electrodes, the laminate including: a first main surface and a second main surface opposite to each other in the lamination direction; a first side surface and a second side surface opposite to each other in a width direction orthogonal or substantially orthogonal to the lamination direction; and a first end surface and a second end surface opposite to each other in a length direction orthogonal or substantially orthogonal to the lamination direction and the width direction; a first external electrode provided on a surface of the laminate and electrically connected to the first internal electrodes; and a second external electrode provided on a surface of the laminate and electrically connected to the second internal electrodes, in which, when a cross section including the length direction and the width direction of the laminate is viewed from the lamination direction, side margin portions each include a dielectric including Ca, Zr, and Ti, each of the side margin portions being a region in which none of the first internal electrodes and the second internal electrodes are disposed. 
     Each of the dielectric layers between each of the first internal electrodes and the second internal electrodes may include a dielectric material including Ba and Ti as main components. 
     A dimension of each of the side margin portions in the width direction may be about 5 μm or more and about 30 μm or less. 
     The number of laminated internal electrodes including the first internal electrodes and the second internal electrodes may be about 10 or more and about 500 or less. A distance between the first main surface and the internal electrode at a position closest to the first main surface among the first internal electrodes and the second internal electrodes may be about 5 μm or more and about 30 μm or less. A distance between the second main surface and the internal electrode at a position closest to the second main surface among the first internal electrodes and the second internal electrodes may be about 5 μm or more and about 30 μm or less. 
     The first internal electrodes and the second internal electrodes may each include Cu. 
     The electronic component may have a dimension in the length direction of about 0.2 mm or more and about 3.2 mm or less, a dimension in the width direction of about 0.1 mm or more and about 1.6 mm or less, and a dimension in the lamination direction of about 0.1 mm or more and about 1.6 mm or less. 
     A circuit board according to a preferred embodiment of the present invention is a circuit board on which the electronic component described above is mounted, and the electronic component is mounted so that the side margin portions thereof face a mounting surface of the circuit board. 
     A distance between an end portion of the electronic component on the circuit board side and the mounting surface of the circuit board may be about 20 μm or more and about 50 μm or less. 
     A method of mounting an electronic component of according to a preferred embodiment the present invention on the circuit board is a method of mounting the electronic component described above on a circuit board, and includes mounting the electronic component so that the side margin portions of the electronic component face the mounting surface of the circuit board. 
     According to the electronic components of preferred embodiments of the present invention, for example, when current flows in a state in which the electronic component is mounted so that the side margin portions face the mounting surface of the circuit board, in a high frequency band, due to surface effects, the current flows in the vicinity of the surface of the internal electrode closest to the mounting surface of the circuit board. Since the side margin portion includes a dielectric with Ca, Zr, and Ti, current loss is small, and the high frequency characteristics are able to be significantly improved. Further, for example, with a configuration in which the electronic component is a capacitor and the dielectric layer between the first internal electrode and the second internal electrode includes Ba and Ti, the capacitance per volume of the capacitor is able to be increased. 
     The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an example of a multilayer ceramic capacitor according to a preferred embodiment of the present invention. 
         FIG.  2    is a cross-sectional view of a multilayer ceramic capacitor illustrated in  FIG.  1    along the line II-II. 
         FIG.  3    is a cross-sectional view of the multilayer ceramic capacitor illustrated in  FIG.  1    taken along the line III-III. 
         FIG.  4    is a view of a state in which the multilayer ceramic capacitor is mounted on a circuit board. 
         FIGS.  5 A and  5 B  are views of an example of a method of manufacturing the multilayer ceramic capacitor according to the preferred embodiment of the present invention, in which  FIG.  5 A  is a schematic view of a ceramic green sheet on which conductive films are provided, and  FIG.  5 B  is a schematic view of a state in which the ceramic green sheets on which the conductive films are provided are being laminated. 
         FIG.  6    is a perspective view of an example of the appearance of a laminate chip prepared in the middle of the manufacture of the multilayer ceramic capacitor  10 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the features of the present invention will be specifically described by describing preferred embodiments of the present invention. In the following, a multilayer ceramic capacitor is described as an example of an electronic component of the present invention. However, the electronic component is not limited to the multilayer ceramic capacitor, and may be another electronic component such as, for example, an inductor or an LC filter. 
       FIG.  1    is a perspective view of an example of a multilayer ceramic capacitor  10  according to a preferred embodiment of the present invention.  FIG.  2    is a cross-sectional view of the multilayer ceramic capacitor  10  illustrated in  FIG.  1    along the line II-II.  FIG.  3    is a cross-sectional view of the multilayer ceramic capacitor  10  illustrated in  FIG.  1    taken along the line III-III. 
     As illustrated in  FIGS.  1  to  3   , the multilayer ceramic capacitor  10  preferably has a rectangular parallelepiped shape or a substantially rectangular parallelepiped shape as a whole, and includes a laminate  11  and a pair of external electrodes  14  ( 14   a  and  14   b ). The pair of external electrodes  14  ( 14   a  and  14   b ) face each other as illustrated in  FIG.  1   . 
     Here, the direction in which the pair of external electrodes  14  face each other is defined as a length direction L of the multilayer ceramic capacitor  10 , the lamination direction of internal electrodes  13  ( 13   a ,  13   b ) described later is defined as a lamination direction T, and the direction orthogonal or substantially orthogonal to either of the length direction L and the lamination direction T is defined as a width direction W. 
     The size of the multilayer ceramic capacitor  10  is preferably, for example, about 0.2 mm to about 3.2 mm (inclusive) in dimension in the length direction L, about 0.1 mm to about 1.6 mm (inclusive) in dimension in the width direction W, and about 0.1 mm to about 1.6 mm (inclusive) in dimension in the lamination direction T. 
     The laminate  11  includes a first end surface  15   a  and a second end surface  15   b  opposite to each other in the length direction L, a first main surface  16   a  and a second main surface  16   b  opposite to each other in the lamination direction T, and a first side surface  17   a  and second side surface  17   b  opposite to each other in the width direction W. 
     The first end surface  15   a  and the second end surface  15   b  extend along the width direction W and the lamination direction T. The first main surface  16   a  and the second main surface  16   b  extend along the length direction L and the width direction W. The first side surface  17   a  and the second side surface  17   b  extend along the length direction L and the lamination direction T. 
     The laminate  11  preferably has rounded corner portions and ridge line portions. Here, the corner portion is a portion at which the three surfaces of the laminate  11  intersect, and the ridge line portion is a portion at which the two surfaces of the laminate  11  intersect. 
     As illustrated in  FIGS.  2  and  3   , the laminate  11  includes an inner layer portion  21 , outer layer portions  22 , and side margin portions  23 . 
     The inner layer portion  21  includes dielectric layers  12 , first internal electrodes  13   a , and second internal electrodes  13   b . The dielectric layer  12  is sandwiched between the first internal electrode  13   a  and the second internal electrode  13   b . The inner layer portion  21  is provided by alternately laminating the plurality of first internal electrodes  13   a  and the plurality of second internal electrodes  13   b  with the dielectric layers  12  interposed therebetween. 
     The dielectric layer  12  preferably includes a dielectric material including Ba and Ti as main components, and for example, includes about 90 mol % or more of Ba and Ti in combination. More specifically, the dielectric layer  12  preferably includes a perovskite compound with Ba and Ti as main components, and includes dielectric ceramic particles having a perovskite structure. At least one of Si, Mg, and Ba, for example, may be included in these main components as an additive. The dielectric layers  12  may also include rare earth elements, for example, Dy, Y and Ho. However, the dielectric layer  12  does not include Ca and Zr. The thickness of the dielectric layers  12  is preferably, for example, about 0.3 μm or more and about 0.8 μm or less. 
     The first internal electrode  13   a  and the second internal electrode  13   b  face each other in the lamination direction T with the dielectric layer  12  interposed therebetween. Capacitance is generated in a portion where the first internal electrode  13   a  and the second internal electrode  13   b  face each other with the dielectric layer  12  interposed therebetween. 
     The dielectric layer  12  extends in the width direction W and the length direction L. The first internal electrode  13   a  extends flatly along the dielectric layer  12  and is drawn to the first end surface  15   a  of the laminate  11 . The second internal electrode  13   b  extends flatly along the dielectric layer  12  and is drawn to the second end surface  15   b  of the laminate  11 . 
     The first internal electrode  13   a  and the second internal electrode  13   b  preferably include, for example, Cu. The first internal electrode  13   a  and the second internal electrode  13   b  may include, in addition to Cu, other metal(s), for example, Ni, Ag, Pd, an Ag—Pd alloy, or Au. The first internal electrode  13   a  and the second internal electrode  13   b  may include the same dielectric particles or similar dielectric particles as the dielectric layer  12 . 
     The number of laminated internal electrodes  13  including the first internal electrodes  13   a  and the second internal electrodes  13   b  is preferably, for example, about 10 or more and about 500 or less. The thickness of the first internal electrode  13   a  and the second internal electrode  13   b  is preferably, for example, about 0.3 μm or more and about 0.8 μm or less. 
     When the cross section including the width direction W and the lamination direction T of the multilayer ceramic capacitor  10  is viewed from the length direction L, the positions of the end portions of the internal electrodes  13  are aligned in the lamination direction T, or may have such a positional relationship that the central portion in the lamination direction bulges outward compared to the outer sides in the lamination direction. In other words, the dimensions in the width direction W of the internal electrodes  13  located at the central portion in the lamination direction T are equal to or larger than the dimensions in the width direction W of the internal electrodes  13  located on the outer side in the lamination direction T. 
     The outer layer portions  22  are provided on both outer sides in the lamination direction T of the inner layer portion  21 . That is, the inner layer portion  21  is sandwiched between the two outer layer portions  22  provided on both the outer sides in the lamination direction T. The outer layer portions  22  each correspond to a region in which none of the first internal electrode  13   a  and the second internal electrode  13   b  exist except for the side margin portions  23  described later when a freely-selected cross section including the lamination direction T and the width direction W of the laminate  11  is viewed from the length direction L. The outer layer portions  22  are each preferably a dielectric including the same material or a similar material as the dielectric layer  12 . 
     The dimensions in the lamination direction T of the outer layer portions  22 , that is, a distance between the internal electrode at a position closest to the first main surface  16   a  among the first internal electrodes  13   a  and the second internal electrodes  13   b , and the first main surface  16   a  and a distance between the internal electrode at a position closest to the second main surface  16   b  among the first internal electrodes  13   a  and the second internal electrodes  13   b  and the second main surface  16   b  are each preferably, for example, about 5 μm or more and about 30 μm or less. 
     The side margin portions  23  each correspond to a region in which none of the first internal electrode  13   a  and the second internal electrode  13   b  exists when a freely-selected cross section including the length direction L and the width direction W of the laminate  11  is viewed from the lamination direction T. As illustrated in  FIG.  3   , the side margin portions  23  are located on both outer sides in the width direction W. That is, the two side margin portions  23  are provided to sandwich the inner layer portion  21  and the outer layer portions  22  in the width direction W. 
     In the present preferred embodiment, the side margin portion  23  includes a plurality of side margin layers laminated in the width direction W. Specifically, the side margin portion  23  includes an outer side margin layer  23   a  and an inner side margin layer  23   b . The outer side margin layers  23   a  are located on the first side surface  17   a  side and the second side surface  17   b  side of the laminate  11 . Further, the inner side margin layers  23   b  are located on the inner layer portion  21  side. 
     It should be noted that the side margin portion  23  includes the plurality of side margin layers  23   a  and  23   b , and the boundary is able to be easily confirmed by observation with an optical microscope due to the difference in the sinterability between the outer side margin layer  23   a  and the inner side margin layer  23   b . That is, the boundary exists between the outer side margin layer  23   a  and the inner side margin layer  23   b.    
     The dimension in the width direction W of the side margin portion  23  is preferably, for example, about 5 μm or more and about 30 μm or less. In the present preferred embodiment, the dimension in the width direction W of the outer side margin layer  23   a  is larger than the dimension in the width direction W of the inner side margin layer  23   b.    
     The dimension in the width direction W of the side margin portion  23  is an average dimension obtained by measuring dimensions of the side margin portion  23  at a plurality of locations along the lamination direction T and calculating an average based on the measurement results. The measuring method of the dimension in the width direction W of the side margin portion  23  is as follows. 
     First, a surface including the width direction W and the lamination direction T of the multilayer ceramic capacitor  10  is exposed. This surface is hereinafter referred to as a “WT cross section”. Next, an image is taken with an optical microscope so that the end portions in the width direction W of the first internal electrodes  13   a  and the second internal electrodes  13   b  in the WT cross section and any one of the two side margin portions  23  located on both the outer sides in the width direction W are captured within the same field of view or substantially the same field of view. There are three imaging locations of an upper portion, a central portion, and a lower portion in the lamination direction T. Then, in the upper portion, the central portion, and the lower portion, a plurality of line segments parallel or substantially parallel to the width direction W are drawn from the end portions in the width direction W of the first internal electrodes  13   a  and the second internal electrodes  13   b  toward the first side surface  17   a  or the second side surface  17   b , and the lengths of the line segments are measured. The average value of the lengths of the line segments measured, as described above, at each of the upper portion, the central portion, and the lower portion is calculated. Further, the average values are further averaged to obtain a dimension in the width direction W of the side margin portion  23 . 
     The side margin portion  23  preferably includes a dielectric with Ca, Zr, and Ti, for example. That is, the side margin portion  23  includes a dielectric ceramic material with Ca, Zr, and Ti as main components. The side margin portion  23  preferably further includes Si, for example, as an additive. Each component is able to be observed by WDX or TEM. 
     The outer side margin layer  23   a  includes a larger content of Si than the inner side margin layer  23   b . That is, the molar ratio of Si/Ti of the outer side margin layer  23   a  is higher than the molar ratio of Si/Ti of the inner side margin layer  23   b . Since Si functions as a sintering aid, the outer side margin layer  23   a  provided by firing in manufacturing the multilayer ceramic capacitor  10  includes a denser structure than the inner side margin layer  23   b . With this, the strength of the side margin portion  23  is able to be significantly improved, so that the side margin portion  23  is unlikely to be cracked or chipped, thus being able to significantly reduce or prevent the entry of moisture into the inside. Each component can be observed by WDX or TEM. 
     A first external electrode  14   a  is provided on the entire or substantially the entire first end surface  15   a  of the laminate  11 , and wraps around the first main surface  16   a , the second main surface  16   b , the first side surface  17   a , and the second side surface  17   b , from the first end surface  15   a . The first external electrode  14   a  is electrically connected to the first internal electrodes  13   a.    
     A second external electrode  14   b  is provided on the entire or substantially the entire second end surface  15   b  of the laminate  11 , and wraps around the first main surface  16   a , the second main surface  16   b , the first side surface  17   a , and the second side surface  17   b , from the second end surface  15   b . The second external electrode  14   b  is electrically connected to the second internal electrodes  13   b.    
     In the present preferred embodiment, as illustrated in  FIG.  2   , the first external electrode  14   a  includes a three-layer structure including a first base electrode layer  141   a , a first lower plating layer  141   b  provided on the surface of the first base electrode layer  141   a , and a first upper plating layer  141   c  provided on the surface of the first lower plating layer  141   b.    
     The first base electrode layer  141   a  covers the entire or substantially the entire first end surface  15   a  of the laminate  11 , and covers a portion of each of the first side surface  17   a  and the second side surface  17   b  and a portion of each of the first main surface  16   a  and the second main surface  16   b , from the portion covering the first end surface  15   a.    
     Further, in the present preferred embodiment, as illustrated in  FIG.  2   , the second external electrode  14   b  includes a three-layer structure including a second base electrode layer  142   a , a second lower plating layer  142   b  provided on the surface of the second base electrode layer  142   a , and a second upper plating layer  142   c  provided on the surface of the second lower plating layer  142   b.    
     The second base electrode layer  142   a  covers the entire or substantially the entire second end surface  15   b  of the laminate  11 , and covers a portion of each of the first side surface  17   a  and the second side surface  17   b  and a portion of each of the first main surface  16   a  and the second main surface  16   b , from the portion covering the second end surface  15   b.    
     The first base electrode layer  141   a  and the second base electrode layer  142   a  preferably include, for example, metal(s) such as Ni, Cu, Ag, Pd, an Ag—Pd alloy, or Au. The first base electrode layer  141   a  and the second base electrode layer  142   a  may be a plurality of layers. 
     The first base electrode layer  141   a  and the second base electrode layer  142   a  may be formed by co-firing in which the first base electrode layer  141   a  and the second base electrode layer  142   a  are fired with the first internal electrodes  13   a  and the second internal electrodes  13   b  at the same time, or may be formed by post-fire in which conductive paste is applied on the laminate  11  and the first base electrode layer  141   a  and the second base electrode layer  142   a  are fired. In the case of formation by co-firing, for example, the first internal electrode  13   a  and the second internal electrode  13   b  may include Ni, and the first base electrode layer  141   a  and the second base electrode layer  142   a  may also include Ni. In the case of formation by the co-firing, the first base electrode layer  141   a  and the second base electrode layer  142   a  include a common material made of a dielectric material shared with the dielectric layer (note that the common material is a dielectric material which is commonly used (i.e. shared) in the electrode layer and the dielectric layer). The first base electrode layer  141   a  and the second base electrode layer  142   a  preferably include three or more times by weight of the common material as compared with the common material included in the internal electrode. The first base electrode layer  141   a  and the second base electrode layer  142   a  may be formed by direct plating, or may be formed by curing a resin layer including conductive particles and thermosetting resin. 
     It is preferable that the first lower plating layer  141   b  and the second lower plating layer  142   b  include Ni, for example, in order to prevent solder breakage. However, the first lower plating layer  141   b  and the second lower plating layer  142   b  may include, for example, metal(s) such as Cu, Ag, Pd, an Ag—Pd alloy, or Au in addition to Ni. 
     It is preferable that the first upper plating layer  141   c  and the second upper plating layer  142   c  include Sn, for example, in order to significantly improve the mountability. However, the first upper plating layer  141   c  and the second upper plating layer  142   c  may include, for example, metal(s) such as Cu, Ag, Pd, an Ag—Pd alloy, or Au, in addition to Sn. 
     The configurations of the first external electrode  14   a  and the second external electrode  14   b  are not limited to the configurations described above. For example, by directly plating the laminate  11 , the first external electrode  14   a  and the second external electrode  14   b  may be formed by plating. 
     (Circuit Board on which Multilayer Ceramic Capacitor is Mounted) 
     The multilayer ceramic capacitor  10  described above is able to be mounted on a circuit board so that the side margin portion  23  faces the mounting surface of the circuit board. 
       FIG.  4    is a view of a state in which the multilayer ceramic capacitor  10  is mounted on a circuit board  40 . The multilayer ceramic capacitor  10  is mounted so that the side margin portion  23  faces a mounting surface  40   a  of the circuit board  40 . More specifically, the first external electrode  14   a  and the second external electrode  14   b  of the multilayer ceramic capacitor  10  are mounted by each being joined to a land electrode provided on the mounting surface  40   a  of the circuit board  40  by solder  45 . 
     In the example illustrated in  FIG.  4   , the side margin portion  23  located on the first side surface  17   a  side is mounted to face the mounting surface  40   a  of the circuit board  40 , but the side margin portion  23  located on the second side surface  17   b  side may be mounted to face the mounting surface  40   a  of the circuit board  40 . 
     In the mounted state illustrated in  FIG.  4   , the lamination direction of the first internal electrodes  13   a  and the second internal electrodes  13   b  are parallel or substantially parallel to the extending direction of the mounting surface  40   a  of the circuit board  40 . 
     A distance L 1  between the end portion of the multilayer ceramic capacitor  10  on the circuit board  40  side and the mounting surface  40   a  of the circuit board  40  is preferably, for example, about 20 μm or more and about 50 μm or less. 
     In a high frequency band, a skin effect concentrates current on the surface of a conductor. Therefore, the current flowing in the multilayer ceramic capacitor  10  mounted on the circuit board  40  flows in the vicinity of the surface of the internal electrode  13  closest to the mounting surface  40   a  of the circuit board  40  as indicated by the arrow in  FIG.  4   . In this case, the configuration of the side margin portion  23  on the side close to the mounting surface  40   a  of the substrate  40  greatly affects a current loss, but in the present preferred embodiment, the side margin portion  23  preferably includes Ca, Zr, and Ti, for example, as main components. That is, since the side margin portion  23  includes Ca, Zr and Ti as main components included in a dielectric of a temperature compensating capacitor which is able to provide good high frequency characteristics, the current loss is able to be reduced, and the high frequency characteristics are able to be significantly improved. 
     In addition, since the multilayer ceramic capacitor  10  in the present preferred embodiment is manufactured by bonding, later, ceramic green sheets defining the side margin portions  23  as described later, the dimension in the width direction W of the side margin portions  23  is able to be shortened. With this, the distance between the circuit board  40  and the position where the current flows in the multilayer ceramic capacitor  10  is able to be shortened, so that a current path is able to be shortened, and an equivalent series inductance (ESL) is able to be reduced. 
     Furthermore, the dielectric layers  12  of the inner layer portion  21  each include Ba and Ti but do not include Ca and Zr, so that the capacitance per volume of the multilayer ceramic capacitor  10  is able to be increased. 
     The advantageous effects described above are advantageous effects of the circuit board  40  on which the multilayer ceramic capacitor  10  is mounted, and also advantageous effects of the multilayer ceramic capacitor  10  itself. 
     (Method of Manufacturing Multilayer Ceramic Capacitor) 
     Hereinafter, an example of the method of manufacturing the multilayer ceramic capacitor  10  which includes the structure described above is described.  FIGS.  5 A and  5 B  are views of an example of the method of manufacturing the multilayer ceramic capacitor  10  according to a preferred embodiment of the present invention, in which  FIG.  5 A  is a schematic view of a ceramic green sheet on which conductive films are provided, and  FIG.  5 B  is a schematic view of a state in which the ceramic green sheets on which conductive films are provided are being laminated.  FIG.  6    is a perspective view of an example of the appearance of a laminate chip prepared in the middle of the manufacture of the multilayer ceramic capacitor  10 . 
     First, a perovskite compound including Ba and Ti is prepared as a dielectric material. A ceramic slurry is prepared by mixing, as additives, at least one of Si, Mg, and Ba, an organic binder, an organic solvent, a plasticizer, and a dispersant in a predetermined ratio with dielectric powder obtained from the dielectric material. 
     Then, ceramic green sheets  50   a  and  50   b  are prepared by applying the prepared ceramic slurry on the surfaces of a plurality of resin films (not shown). The ceramic green sheets  50   b  are alternately laminated with the ceramic green sheets  50   a . The ceramic green sheets  50   a  and  50   b  may preferably be prepared, for example, by a die coater, a gravure coater, a microgravure coater, or the like. 
     Next, as illustrated in  FIG.  5 A , conductive paste that defines internal electrodes is printed in stripes on the surfaces of the ceramic green sheets  50   a  and  50   b , and dried. The conductive paste that defines the internal electrodes includes Cu. Here, the direction in which the conductive paste that defines the internal electrodes extends in stripes is defined as an X direction, and the direction orthogonal or substantially orthogonal to the X direction on the ceramic green sheet is defined as a Y direction. Thus, conductive films  52   a  ( 52   b ) to be the first internal electrodes  13   a  (second internal electrodes  13   b ) are formed. As the printing method, various methods, including screen printing, ink jet printing, gravure printing, and the like, may preferably be used. 
     Next, the prepared ceramic green sheets are laminated. Specifically, after a predetermined number of ceramic green sheets on which conductive films are not formed to be the outer layer portion  22  are laminated, the plurality of ceramic green sheets  50   a  and  50   b  on which the conductive films  52   a  and  52   b  are formed are laminated while being mutually shifted in the Y direction, as illustrated in  FIG.  5 B . Then, a predetermined number of ceramic green sheets on which conductive films are not formed to be the outer layer portion  22  are laminated thereon to obtain a mother laminate. 
     Subsequently, the mother laminate is pressed by, for example, a method such as rigid press or isostatic press. Then, the pressed mother laminate is cut into a chip shape, so that a laminate chip  60  illustrated in  FIG.  6    is provided. 
     As illustrated in  FIG.  6   , only the conductive films  52   a  of the ceramic green sheets  50   a  are exposed at one end surface of the laminate chip  60 , and only the conductive films  52   b  of the ceramic green sheets  50   b  are exposed at the other end surface. Further, on both side surfaces of the laminate chip  60 , the conductive films  52   a  of the ceramic green sheets  50   a  and the conductive films  52   b  of the ceramic green sheets  50   b  are exposed. 
     Subsequently, ceramic green sheets that define side margin portions to be the side margin portions  23  are prepared. A compound including Ca, Zr, and Ti is prepared as a dielectric material for preparing a ceramic green sheet that defines a side margin portion. A ceramic slurry is prepared by mixing an additive including at least Si, an organic binder, an organic solvent, a plasticizer, and a dispersant in a predetermined ratio with dielectric powder obtained from the dielectric material. Subsequently, the ceramic green sheets that define the side margin portions are prepared with the prepared ceramic slurry. 
     Here, when the ceramic slurry is to be prepared, the content of Si included in the ceramic slurry that defines the outer side margin layer  23   a  is adjusted to be larger than the content of Si included in the ceramic slurry that defines the inner side margin layer  23   b . Further, the ceramic slurry is applied so that the thickness of the ceramic green sheet that defines the outer side margin layer  23   a  is larger than the thickness of the ceramic green sheet that defines the inner side margin layer  23   b.    
     Subsequently, the ceramic green sheet that defines an inner side margin layer is laminated and bonded onto the ceramic green sheet that defines an outer side margin layer to provide a ceramic green sheet that defines a side margin portion with a two-layer structure. 
     Subsequently, of the ceramic green sheets that defines a side margin portion, the ceramic green sheet that defines an inner side margin layer, and the side surface of the laminate chip  60  to which the conductive films  52   a  and  52   b  are exposed face each other, and pressing and punching are preformed, to thus form a layer to be the side margin portion  23 . A layer to be the side margin portion  23  is formed on the side surface on the opposite side by the same method or a similar method. 
     Subsequently, barrel polishing of the laminate chip on which the layer to be the side margin portion  23  is provided is performed. Then, the laminate chip is subjected to degreasing treatment under a predetermined condition in a nitrogen atmosphere, and then firing treatment is performed at a predetermined temperature in a nitrogen-hydrogen-steam mixed atmosphere. With this, a sintered laminate is provided. 
     Next, external electrode paste including Cu as a main component is applied and baked on each end surface of the sintered laminate to form the first base electrode layer  141   a  connected to the first internal electrodes  13   a  and the second base electrode layer  142   a  connected to the second internal electrodes  13   b . Subsequently, the first lower plating layer  141   b  is formed by Ni plating on the surface of the first base electrode layer  141   a , and the first upper plating layer  141   c  is formed by Sn plating on the surface of the first lower plating layer  141   b . Accordingly, the first external electrode  14   a  is formed. The second external electrode  14   b  is formed by the same method or a similar method. 
     However, the laminate chip and the external electrode paste may be fired at the same time. 
     The multilayer ceramic capacitor  10  is prepared by the method described above. However, the manufacturing method described above is an example, and the method of manufacturing multilayer ceramic capacitor  10  is not limited to the manufacturing method described above. 
     The present invention is not limited to the preferred embodiment described above, and various applications and modifications may be applied within the scope of the present invention. 
     For example, although the side margin portion  23  is described as including the two side margin layers  23   a  and  23   b  laminated in the width direction W in the preferred embodiment described above, the side margin portion  23  may include one side margin layer or may include three or more side margin layers. 
     While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.