JP6497127B2 - Multilayer capacitor - Google Patents

Description

  The present invention relates to a multilayer capacitor.

  It has a rectangular parallelepiped shape, extends in the first direction so as to connect the first and second main surfaces facing each other in the first direction, and is orthogonal to the first direction. A pair of first side surfaces facing each other in the second direction, and a third direction extending in the first direction so as to connect the first and second main surfaces and orthogonal to the first and second directions. An element body having a pair of second side surfaces facing each other, a plurality of internal electrodes alternately arranged in the element body so as to face each other in the first direction, and a pair of element bodies A multilayer capacitor is known that includes a pair of terminal electrodes that are respectively disposed on the second side surface and are connected to a corresponding internal electrode among a plurality of internal electrodes (see, for example, Patent Document 1). ).

JP-A-9-260206

  In recent years, electronic devices such as information terminal devices have been reduced in size and thickness. Along with this, miniaturization is progressing in boards mounted on electronic devices and electronic components mounted on boards, and high-density mounting is also progressing. In order to further reduce the size, electronic component-embedded substrates in which electronic components are embedded in the substrate have been developed. In the electronic component built-in substrate, the electronic component is embedded and mounted inside the substrate. The wiring formed on the substrate and the embedded electronic component must be reliably electrically connected. However, in the multilayer capacitor described in Patent Document 1, no consideration is given to embedding in a substrate (incorporation into the substrate) and electrical connection with wiring formed on the substrate.

  It is an object of the present invention to provide a multilayer capacitor that can be appropriately built in a substrate while ensuring a low profile and ensuring connectivity with wiring formed on the substrate.

  The multilayer capacitor according to the present invention has a rectangular parallelepiped shape, and extends in the first direction so as to connect the first and second main surfaces facing each other in the first direction and the first and second main surfaces. And extending in the first direction so as to connect the first and second main surfaces with the pair of first side surfaces facing each other in the second direction orthogonal to the first direction and the first and second A plurality of interiors alternately arranged in the element body so as to oppose each other in the first direction, and an element body having a pair of second side surfaces facing each other in a third direction orthogonal to the direction An electrode and a pair of terminal electrodes respectively disposed on a pair of second side surfaces of the element body and connected to a corresponding internal electrode among the plurality of internal electrodes, and in the first direction of the element body The length is smaller than the length of the element body in the second direction and the length of the element body in the third direction. When the electrodes are divided in the second direction into a pair of end regions and a central region located between the pair of end regions, the region where each terminal electrode of the element body is arranged is A first region located, and a pair of second regions where the end regions are located, each terminal electrode being disposed on the first major surface and the first electrode portion disposed on the first major surface The second main surface is a plane perpendicular to the first direction across the first region and the pair of second regions, and the second region of the first region in the first direction of the first region. The element body thickness is smaller than the second element body thickness in the first direction of each second region, and from the second main surface of the first region to the surface of the portion located in the first region of the first electrode portion. The first distance in the first direction is the second distance in the first direction from the second main surface of the second region to the surface of the portion of the first electrode portion located in each second region. The difference between the first element thickness and the second element thickness is smaller than the difference between the first distance and the second distance, and the first electrode thickness of the portion located in the first region of the second electrode portion Is larger than the second electrode thickness of the portion of the second electrode portion located in each second region.

  In the multilayer capacitor according to the present invention, the length of the element body in the first direction is smaller than the length of the element body in the second direction and the length of the element body in the third direction. As a result, the multilayer capacitor can be reduced in height, and a multilayer capacitor suitable for incorporation in a substrate can be realized. Each terminal electrode has a first electrode portion arranged on the first main surface and a second electrode portion arranged on the second main surface. Therefore, the multilayer capacitor according to the present invention can be electrically connected to the wiring formed on the substrate on at least one main surface side of the first and second main surfaces, and can be easily incorporated in the substrate.

  After the multilayer capacitor is disposed in the housing portion of the substrate, the housing portion is filled with a resin, thereby being built in the substrate. When the multilayer capacitor in accordance with the present invention is disposed in the housing portion such that the second main surface of the element body faces the bottom portion of the housing portion, the first of the portions located in the first region of the second electrode portion. Since the electrode thickness is larger than the second electrode thickness of the second electrode portion located in each second region, the resin wraps around each terminal electrode when the resin is filled around the multilayer capacitor. easy. As a result, the multilayer capacitor can be appropriately embedded in the substrate.

  The first element body thickness in the first direction of the first region is smaller than the second element body thickness in the first direction of each second region. The first distance in the first direction from the second main surface of the first region to the surface of the portion of the first electrode portion located in the first region is the first distance from the second main surface of the second region to the first electrode portion. It is smaller than the second distance in the first direction to the surface of the portion located in each second region. That is, a depression is formed on the surface of the multilayer capacitor according to the present invention on the first main surface side. Therefore, when the multilayer capacitor according to the present invention is disposed in the housing portion so that the first main surface of the element body faces the bottom portion of the housing portion, the posture of the multilayer capacitor in the housing portion is stabilized. As a result, since the multilayer capacitor is built into the substrate in a stable posture, the multilayer capacitor can be appropriately built into the substrate.

  After the multilayer capacitor is built in the substrate, via holes reaching each terminal electrode are formed in the substrate by laser processing. The via hole formed by laser processing is formed in a tapered shape having a diameter reduced from the surface side of the substrate toward the terminal electrode side. Accordingly, the farther the distance from the surface of the substrate is, the smaller the inner diameter of the via hole. That is, as the distance from the surface of the substrate increases, the area of the conductor disposed in the via hole decreases. When the area of the conductor is small, the connection area between the terminal electrode and the conductor is also small.

  After the multilayer capacitor according to the present invention is built in the substrate, when the via hole is formed from the first main surface side by laser processing and the conductor is disposed in the via hole, the first element thickness and the second element thickness Is larger than the difference between the first distance and the second distance, so that the difference between the first element thickness and the second element thickness is less than or equal to the difference between the first distance and the second distance. The distance from the surface of the substrate to the surface of the terminal electrode is small. Therefore, the connection area between the terminal electrode and the conductor is large, and the connectivity between the terminal electrode and the conductor is ensured.

  After the multilayer capacitor according to the present invention is built in the substrate, when a via hole is formed from the second main surface side by laser processing and a conductor is disposed in the via hole, the via hole is positioned in the first region of the second electrode portion. Since the first electrode thickness of the portion to be performed is larger than the second electrode thickness of the portion located in each second region of the second electrode portion, the first electrode thickness of the portion located in the first region of the second electrode portion Compared with the structure which is below the 2nd electrode thickness of the part located in each 2nd area | region among 2nd electrode parts, the distance from the surface of a board | substrate to the surface of a terminal electrode is small. Therefore, the connection area between the terminal electrode and the conductor is large, and the connectivity between the terminal electrode and the conductor is ensured.

  The interval between the end regions adjacent in the first direction may be larger than the interval between the central regions adjacent in the first direction. The electric field distribution tends to concentrate on the end region of the internal electrode. When the electric field distribution is concentrated in the end region, the electric field strength becomes extremely high, and a discharge is generated between the end regions adjacent in the first direction, so that the insulating state may be destroyed. In the configuration in which the interval between the end regions adjacent in the first direction is larger than the interval between the central regions adjacent in the first direction, the interval between the end regions adjacent in the first direction is adjacent in the first direction. Compared to a configuration where the distance between the central regions is equal to or less than the distance between the central regions, even when the electric field distribution is concentrated on the end regions of the internal electrodes, the electric field strength is less likely to increase, and discharge occurs between the adjacent end regions in the first direction. Can be suppressed. In the configuration in which the interval between the central regions adjacent in the first direction is smaller than the interval between the end regions adjacent in the first direction, the interval between the central regions adjacent in the first direction is adjacent in the first direction. Capacitance is high as compared with a configuration equivalent to the interval between the end regions. Therefore, it is possible to suppress the occurrence of dielectric breakdown while securing the electrical characteristics of the multilayer capacitor to a desired value.

  The region exposed from the pair of terminal electrodes of the element body has a third region in which the central region is located and a pair of fourth regions in which the end regions are located. A plane perpendicular to the first direction spans one region, a pair of second regions, a third region, and a pair of fourth regions, and the element body thickness in the first direction of the third region is It may be smaller than the element thickness in one direction. In this case, since the depression is formed in the first main surface of the element body, when the multilayer capacitor is disposed in the housing portion so that the first main surface of the element body faces the bottom portion of the housing portion, A space is formed between the bottom of the housing part and the first main surface of the element body. The space functions as a resin reservoir when the resin is filled around the multilayer capacitor, and the multilayer capacitor can be appropriately embedded in the substrate.

  The region where each terminal electrode of the element body is disposed further includes a pair of outer regions located outside each second region in the second direction, and the thickness of each outer region in the first direction and the first electrode The sum of the thickness in the first direction of the portion located in each outer region of the portion and the thickness in the first direction of the portion located in each outer region of the second electrode portion is the first distance and the first electrode It may be smaller than the total value with the thickness. When the multilayer capacitor is disposed in the housing portion so that the second main surface of the element body faces the bottom portion of the housing portion, the resin is filled around each terminal electrode when the resin is filled around the multilayer capacitor. Is easier to wrap around.

  According to the present invention, it is possible to provide a multilayer capacitor that can be reduced in height and can be appropriately embedded in a substrate while ensuring connectivity with wiring formed on the substrate.

1 is a perspective view showing a multilayer capacitor according to an embodiment of the present invention. It is a perspective view which shows the multilayer capacitor which concerns on this embodiment. It is a top view which shows the multilayer capacitor which concerns on this embodiment. It is a figure for demonstrating the cross-sectional structure along the IV-IV line in FIG. It is a figure for demonstrating the cross-sectional structure along the VV line in FIG. It is a figure for demonstrating the cross-sectional structure along the VI-VI line in FIG. It is a figure for demonstrating the cross-sectional structure along the VII-VII line in FIG. It is a top view which shows the 1st and 2nd internal electrode. It is a schematic diagram for demonstrating the various dimensions of the multilayer capacitor which concerns on this embodiment. It is a schematic diagram for demonstrating the various dimensions of the multilayer capacitor which concerns on this embodiment. It is a figure for demonstrating the mounting structure of the multilayer capacitor concerning this embodiment. It is a figure for demonstrating the mounting structure of the multilayer capacitor concerning this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  With reference to FIGS. 1-7, the structure of the multilayer capacitor C1 which concerns on this embodiment is demonstrated. 1 and 2 are perspective views showing the multilayer capacitor according to the present embodiment. FIG. 3 is a plan view showing the multilayer capacitor in accordance with the present embodiment. FIG. 4 is a diagram for explaining a cross-sectional configuration along the line IV-IV in FIG. 3. FIG. 5 is a diagram for explaining a cross-sectional configuration along the line V-V in FIG. 3. FIG. 6 is a view for explaining a cross-sectional configuration along the line VI-VI in FIG. 3. FIG. 7 is a diagram for explaining a cross-sectional configuration along the line VII-VII in FIG. 3.

  As shown in FIGS. 1 to 7, the multilayer capacitor C1 includes an element body 2 having a rectangular parallelepiped shape, a first terminal electrode 5 and a second terminal electrode 7 disposed on the outer surface of the element body 2, and It has. The first terminal electrode 5 and the second terminal electrode 7 are separated from each other. The rectangular parallelepiped shape includes a rectangular parallelepiped shape in which corners and ridge lines are chamfered and a rectangular parallelepiped shape in which corners and ridge lines are rounded.

  The element body 2 has, as its outer surface, substantially rectangular first and second main surfaces 2a, 2b facing each other and a pair of first side surfaces 2c, 2d facing each other. And a pair of second side surfaces 2e and 2f. The direction in which the first main surface 2a and the second main surface 2b are opposed is the first direction D1, the direction in which the pair of first side surfaces 2c and 2d are opposed is the second direction D2, and a pair of The direction in which the second side surfaces 2e and 2f face each other is the third direction D3. In the present embodiment, the first direction D <b> 1 is the height direction of the element body 2. The second direction D2 is the width direction of the element body 2 and is orthogonal to the first direction D1. The third direction D3 is the longitudinal direction of the element body 2, and is orthogonal to the first direction D1 and the second direction D2.

  The length of the element body 2 in the first direction D1 is smaller than the length of the element body 2 in the third direction D3 and the length of the element body 2 in the second direction D2. The length of the element body 2 in the third direction D3 is larger than the length of the element body 2 in the second direction D2. The length of the element body 2 in the third direction D3 is set to 0.4 to 1.6 mm, for example. The length of the element body 2 in the second direction D2 is set to 0.2 to 0.8 mm, for example. The length of the element body 2 in the first direction D1 is set to 0.1 to 0.35 mm, for example. The multilayer capacitor C1 is an ultra-low profile multilayer capacitor. The length of the element body 2 in the second direction D2 may be equal to the length of the element body 2 in the third direction D3, and the length of the element body 2 in the second direction D2 is It may be larger than the length in the third direction D3.

  “Equivalent” may be equivalent to a value including a slight difference or a manufacturing error in a preset range in addition to being equal. For example, if a plurality of values are included in a range of ± 5% of the average value of the plurality of values, the plurality of values are defined to be equivalent.

  The pair of first side surfaces 2c, 2d extends in the first direction D1 so as to connect the first main surface 2a and the second main surface 2b. The pair of first side surfaces 2c, 2d also extend in the third direction D3 (the long side direction of the first and second main surfaces 2a, 2b). The pair of second side surfaces 2e and 2f extends in the first direction D1 so as to connect the first main surface 2a and the second main surface 2b. The pair of second side surfaces 2e and 2f also extend in the second direction D2 (the short side direction of the first and second main surfaces 2a and 2b).

The element body 2 is configured by laminating a plurality of dielectric layers in a direction (first direction D1) in which the first main surface 2a and the second main surface 2b face each other. In the element body 2, the stacking direction of the plurality of dielectric layers (hereinafter simply referred to as “stacking direction”) coincides with the first direction D <b> 1. Each dielectric layer is formed of a ceramic green sheet (hereinafter simply referred to as “dielectric ceramic such as BaTiO ₃ series, Ba (Ti, Zr) O ₃ series, or (Ba, Ca) TiO ₃ series)”. This is called a “green sheet”). In the actual element body 2, the dielectric layers are integrated to such an extent that the boundary between the dielectric layers is not visible.

  As shown in FIGS. 4 to 7, the multilayer capacitor C <b> 1 includes a plurality of first internal electrodes 11 and a plurality of second internal electrodes 13. The first and second internal electrodes 11 and 13 are made of a conductive material (for example, Ni or Cu) that is usually used as an internal electrode of a laminated electric element. The 1st and 2nd internal electrodes 11 and 13 are comprised as a sintered compact of the electrically conductive paste containing the said electrically conductive material.

  The first internal electrode 11 and the second internal electrode 13 are arranged at different positions (layers) in the first direction D1. That is, the first internal electrodes 11 and the second internal electrodes 13 are alternately arranged in the element body 2 so as to face each other with a gap in the first direction D1. The first internal electrode 11 and the second internal electrode 13 have different polarities.

  As shown in FIG. 8A, each first internal electrode 11 includes a main electrode portion 11a and a connection portion 11b. The connection portion 11b extends from one side (one short side) of the main electrode portion 11a and is exposed to the first side surface 2c. The first internal electrode 11 is exposed at the second side surface 2e, and is not exposed at the first and second main surfaces 2a, 2b, the pair of first side surfaces 2c, 2d, and the second side surface 2f. The main electrode part 11a and the connection part 11b are integrally formed.

  The main electrode portion 11a has a rectangular shape in which the third direction D3 is a long side direction and the second direction D2 is a short side direction. That is, the main electrode portion 11a of each first internal electrode 11 has a length in the third direction D3 that is greater than a length in the second direction D2. The connecting portion 11b extends from the end portion on the second side surface 2e side of the main electrode portion 11a to the second side surface 2e. The length of the connection part 11b in the third direction D3 is smaller than the length of the main electrode part 11a in the third direction D3. The length of the connection part 11b in the second direction D2 is equal to the length of the main electrode part 11a in the second direction D2. The connecting part 11b is connected to the first terminal electrode 5 at the end exposed at the second side face 2e. The length of the connection part 11b in the second direction D2 may be smaller than the length of the main electrode part 11a in the second direction D2.

  As shown in FIG. 8B, each second internal electrode 13 includes a main electrode portion 13a and a connection portion 13b. The main electrode portion 13a is opposed to the main electrode portion 11a in the first direction D1 via a part (dielectric layer) of the element body 2. The connection portion 13b extends from one side (one short side) of the main electrode portion 13a and is exposed to the second side surface 2f. The second internal electrode 13 is exposed on the second side surface 2f, and is not exposed on the first and second main surfaces 2a and 2b, the pair of first side surfaces 2c and 2d, and the second side surface 2e. The main electrode portion 13a and the connection portion 13b are integrally formed.

  The main electrode portion 13a has a rectangular shape in which the third direction D3 is a long side direction and the second direction D2 is a short side direction. That is, the main electrode portion 13a of each second internal electrode 13 has a length in the third direction D3 that is greater than a length in the second direction D2. The connection portion 13b extends from the end portion on the second side surface 2f side of the main electrode portion 13a to the second side surface 2f. The length of the connecting portion 13b in the third direction D3 is smaller than the length of the main electrode portion 13a in the third direction D3. The length of the connecting portion 13b in the second direction D2 is equal to the length of the main electrode portion 13a in the second direction D2. The connection portion 13b is connected to the second terminal electrode 7 at the end exposed at the second side surface 2f. The length of the connection part 13b in the second direction D2 may be smaller than the length of the main electrode part 13a in the second direction D2.

  The first terminal electrode 5 is located at the end of the element body 2 on the second side surface 2e side when viewed in the third direction D3. The first terminal electrode 5 includes an electrode portion 5a disposed on the first major surface 2a, an electrode portion 5b disposed on the second major surface 2b, an electrode portion 5c disposed on the second side surface 2e, and It has the electrode part 5d arrange | positioned at a pair of 1st side surface 2c, 2d. That is, the first terminal electrode 5 is formed on the five surfaces 2a, 2b, 2c, 2d, and 2e. The electrode portions 5a, 5b, 5c, and 5d adjacent to each other are connected at the ridge line portion of the element body 2 and are electrically connected.

  The electrode portion 5a and the electrode portion 5c are connected at a ridge line portion between the first main surface 2a and the second side surface 2e. The electrode portion 5a and the electrode portion 5d are connected at a ridge line portion between the first main surface 2a and the first side surfaces 2c and 2d. The electrode portion 5b and the electrode portion 5c are connected at a ridge line portion between the second main surface 2b and the second side surface 2e. The electrode portion 5b and the electrode portion 5d are connected at a ridge line portion between the second main surface 2b and the first side surfaces 2c and 2d. The electrode portion 5c and the electrode portion 5d are connected at a ridge line portion between the second side surface 2e and the first side surfaces 2c and 2d.

  The electrode portion 5c is disposed so as to cover all the portions exposed to the second side surface 2e of each connection portion 11b, and the connection portion 11b is directly connected to the first terminal electrode 5. That is, the connection part 11b connects the main electrode part 11a and the electrode part 5c. Thereby, each first internal electrode 11 is electrically connected to the first terminal electrode 5.

  The second terminal electrode 7 is located at the end of the element body 2 on the second side face 2f side when viewed in the third direction D3. The second terminal electrode 7 includes an electrode portion 7a disposed on the first main surface 2a, an electrode portion 7b disposed on the second main surface 2b, an electrode portion 7c disposed on the second side surface 2f, and It has the electrode part 7d arrange | positioned at a pair of 1st side surface 2c, 2d. That is, the second terminal electrode 7 is formed on the five surfaces 2a, 2b, 2c, 2d, and 2f. The electrode portions 7a, 7b, 7c, and 7d adjacent to each other are connected at the ridge line portion of the element body 2 and are electrically connected.

  The electrode portion 7a and the electrode portion 7c are connected at a ridge line portion between the first main surface 2a and the second side surface 2f. The electrode portion 7a and the electrode portion 7d are connected at a ridge line portion between the first main surface 2a and the first side surfaces 2c and 2d. The electrode portion 7b and the electrode portion 7c are connected at a ridge line portion between the second main surface 2b and the second side surface 2f. The electrode portion 7b and the electrode portion 7d are connected at a ridge line portion between the second main surface 2b and the first side surfaces 2c and 2d. The electrode portion 7c and the electrode portion 7d are connected at a ridge line portion between the second side surface 2f and the first side surfaces 2c and 2d.

  The electrode portion 7 c is arranged so as to cover all the portions exposed to the second side surface 2 f of each connection portion 13 b, and the connection portion 13 b is directly connected to the second terminal electrode 7. That is, the connection part 13b connects the main electrode part 13a and the electrode part 7c. Thereby, each second internal electrode 13 is electrically connected to the second terminal electrode 7.

  The first terminal electrode 5 and the second terminal electrode 7 are separated from each other in the third direction D3. That is, the element body 2 is exposed between the first terminal electrode 5 and the second terminal electrode 7. The electrode portion 5a and the electrode portion 7a disposed on the first main surface 2a are separated from each other in the third direction D3 on the first main surface 2a. The electrode portion 5b and the electrode portion 7b arranged on the second main surface 2b are separated from each other in the third direction D3 on the second main surface 2b. The electrode portion 5d and the electrode portion 7d disposed on the first side surface 2c are separated from each other in the third direction D3 on the first side surface 2c. The electrode portion 5d and the electrode portion 7d disposed on the first side surface 2d are separated from each other in the third direction D3 on the first side surface 2d.

  The first and second terminal electrodes 5 and 7 have a first electrode layer 21, a second electrode layer 23, and a third electrode layer 25, respectively. That is, the electrode portions 5a, 5b, 5c, and 5d and the electrode portions 7a, 7b, 7c, and 7d include the first electrode layer 21, the second electrode layer 23, and the third electrode layer 25, respectively. The third electrode layer 25 constitutes the outermost layer of the first and second terminal electrodes 5 and 7.

  The first electrode layer 21 is formed by applying and baking a conductive paste on the surface of the element body 2. That is, the first electrode layer 21 is a baked conductor layer. In the present embodiment, the first electrode layer 21 is a baked conductor layer made of Cu. The first electrode layer 21 may be a baked conductor layer made of Ni. Thus, the first electrode layer 21 contains Cu or Ni. As the conductive paste, a powder made of Cu or Ni mixed with a glass component, an organic binder, and an organic solvent is used. The thickness of the first electrode layer 21 is, for example, a maximum of 20 μm and a minimum of 5 μm.

  The second electrode layer 23 is formed on the first electrode layer 21 by a plating method. In the present embodiment, the second electrode layer 23 is a Ni plating layer formed on the first electrode layer 21 by Ni plating. The second electrode layer 23 may be a Sn plating layer. Thus, the 2nd electrode layer 23 contains Ni or Sn. The thickness of the second electrode layer 23 is, for example, 1 to 5 μm.

  The third electrode layer 25 is formed on the second electrode layer 23 by a plating method. In the present embodiment, the third electrode layer 25 is a Cu plating layer formed on the second electrode layer 23 by Cu plating. The second electrode layer 23 may be an Au plating layer. Thus, the third electrode layer 25 contains Cu or Au. The thickness of the third electrode layer 25 is, for example, 1 to 15 μm.

  Next, various dimensions in the multilayer capacitor C1 (element body 2) will be described in more detail with reference to FIGS. 9 and 10 are schematic views for explaining various dimensions of the multilayer capacitor in accordance with the present embodiment.

  As shown in FIGS. 5 to 8, the first and second internal electrodes 11 and 13 are positioned between the pair of end regions IE1 and the pair of end regions IE1 when viewed in the second direction D2. It is divided into a central area IE2. As shown in FIG. 5, the region where the first terminal electrode 5 of the element body 2 is disposed includes a first region 3A where the central region IE2 is located and a pair of second regions where the end region IE1 is located. 3B and a pair of outer regions 3C. Each outer region 3C is a region where the first and second inner electrodes 11 and 13 are not disposed, and is located outside each second region 3B in the second direction D2. The region where the second terminal electrode 7 of the element body 2 is disposed also includes a first region 3A, a pair of second regions 3B, and a pair of outer regions 3C, as shown in FIG. Yes.

  As shown in FIG. 7, the regions exposed from the first and second terminal electrodes 5 and 7 of the element body 2 include the third region 4 </ b> A in which the central region IE <b> 2 is positioned and the end region IE <b> 1. It has a pair of fourth regions 4B and a pair of outer regions 4C. Each outer region 4C is a region where the first and second inner electrodes 11 and 13 are not disposed, and is located outside each fourth region 4B in the second direction D2.

  The second main surface 2b of the element body 2 is a plane substantially orthogonal to the first direction D1 across the first region 3A, the pair of second regions 3B, the third region 4A, and the pair of fourth regions 4B. Has been. As described above, the element body 2 is obtained by firing a laminate of a plurality of green sheets. The laminated body is generally pressed by an isostatic pressing method before firing. Thereby, the green sheets are in close contact with each other.

  In the isostatic pressing method, the laminate is disposed on a substrate made of stainless steel or the like, and the laminate and the substrate are vacuum-sealed with a vacuum film. The laminated body sealed in vacuum is put in a pressure vessel in which a pressure medium (for example, water) is stored, and is pressurized by the pressure medium. Since the laminate is disposed on the substrate, the surface of the laminate that faces the substrate is a flat surface. For this reason, the element | base_body 2 obtained from a laminated body has a plane (2nd main surface 2b). Here, the plane means a plane physically formed with the plane as a target, and does not need to be a geometrically perfect plane. Therefore, the 2nd main surface 2b may have a micro unevenness | corrugation, for example.

As shown in FIG. 9, the element thickness T _{3A in} the first direction D1 of the first region 3A is smaller than the element thickness T _{3B in} the first direction D1 of each second region 3B. That is, in the first region 3A, the distance between the first main surface 2a and the second main surface 2b in the first direction D1 is the first distance between the first main surface 2a and the second main surface 2b in the second region 3B. It is smaller than the interval in one direction D1. As shown in FIG. 10, the element thickness T _{4A in} the first direction D1 of the third region 4A is smaller than the element thickness T _{4B in} the first direction D1 of each fourth region 4B. That is, the distance in the first direction D1 between the first main surface 2a and the second main surface 2b in the third region 4A is the same as the distance between the first main surface 2a and the second main surface 2b in the fourth region 4B. It is smaller than the interval in one direction D1.

  The first and second internal electrodes 11 and 13 are obtained by firing a paste layer formed by applying a conductive paste to a green sheet together with the green sheet. When forming the paste layer on the green sheet, a step is formed between the green sheet and the paste layer. The level difference between the green sheet and the paste layer may cause an internal structural defect of the element body 2. For this reason, the level | step difference absorption layer for absorbing the level | step difference formed with a green sheet and a paste layer is formed in the area | region in which the paste layer on a green sheet is not formed. The step absorption layer is formed, for example, by applying a slurry containing a dielectric material.

  In general, the step absorption layer is formed so as to overlap with the outer edge of the paste layer in consideration of a deviation in manufacturing. That is, the step absorption layer is disposed not only in the region where the paste layer on the green sheet is not formed, but also on the paste layer. For this reason, in the laminated body obtained by laminating | stacking a green sheet and carrying out an isostatic pressing, the thickness in the position corresponding to the said outer edge of a paste layer becomes thicker than the thickness in another position. In the element body 2 obtained after firing, the thickness of the element body 2 at the positions corresponding to the outer edges of the first and second inner electrodes 11 and 13 is the outer edge of the first and second inner electrodes 11 and 13 of the element body 2. It is larger than the thickness at the corresponding position.

  Since the step absorption layer is formed so as to overlap the outer edge of the paste layer, as shown in FIG. 4, the gap G1 between the end regions IE1 adjacent in the first direction D1 is adjacent in the first direction D1. It is larger than the gap G2 between the central regions IE2. In the present embodiment, positions corresponding to the outer edges of the first and second internal electrodes 11 and 13 of the element body 2 correspond to the second region 3B and the fourth region 4B, and the first and second inner electrodes of the element body 2 Positions other than the outer edges of the electrodes 11 and 13 correspond to the first region 3A and the third region 4A.

  Since the surface of the laminate that faces the substrate is made flat by the substrate, the opposite surface of the surface of the laminate that faces the substrate is on the inner side of the outer edge of the paste layer due to the above-described thickness relationship. A depression is formed in a region corresponding to the region. Therefore, a depression reflecting the depression formed in the laminated body is also formed on the first main surface 2a of the element body 2.

  As shown in FIG. 9, the surface of the electrode portions 5 a and 7 a arranged on the first main surface 2 a of the element body 2 is formed with a recess corresponding to the recess of the first main surface 2 a of the element body 2. Has been. Accordingly, the first distance L1 in the first direction D1 from the second main surface 2b of the first region 3A to the surface of the portion of the electrode portions 5a and 7a located in the first region 3A is the second distance 3B of the second region 3B. It is smaller than the second distance L2 in the first direction D1 from the two principal surfaces 2b to the surface of the portion of the electrode portions 5a, 7a located in the second region 3B. In the present embodiment, the first distance L1 from the second main surface 2b to the surface of the electrode portion 5a is equal to the first distance L1 from the second main surface 2b to the surface of the electrode portion 7a. The second distance L2 from 2b to the surface of the electrode portion 5a is equal to the second distance L2 from the second main surface 2b to the surface of the electrode portion 7a.

  About the thickness of the 1st electrode layer 21 of each electrode part 5a, 5b, the thickness of the center part is the maximum seeing from the 1st direction D1, and the thickness of the part located in a ridgeline part is the minimum. The thickness of the second electrode layer 23 is the same throughout the electrode portions 5a, 5b, 5c and 5d. The thickness of the third electrode layer 25 is also the same throughout the electrode portions 5a, 5b, 5c, and 5d. Regarding the thickness of the first electrode layer 21 of each of the electrode portions 7a and 7b, the thickness of the central portion is the maximum when viewed from the first direction D1, and the thickness of the portion located at the ridge line portion is the minimum. The thickness of the second electrode layer 23 is the same throughout the electrode portions 7a, 7b, 7c, and 7d. The thickness of the third electrode layer 25 is also the same throughout the electrode portions 7a, 7b, 7c, and 7d.

The shapes of the surfaces of the first and second terminal electrodes 5 and 7 are affected by the shape of the first electrode layer 21. Therefore, the difference between the element thickness T _3A and the element thickness T _3B is larger than the difference between the first distance L1 and the second distance L2. Electrode portion 5b, electrode thickness _{T E1} of the portion located in the first region 3A of 7b, the electrode portions 5b, larger than the electrode thickness _{T E2} of the portion located at each second region 3B of 7b. In the present embodiment, are equivalent to the electrode thickness _{T E1} electrode thickness _{T E1} and the electrode portion 7b of the electrode portion 5b, it is equivalent to the electrode thickness _{T E2} of the electrode thickness _{T E2} and the electrode portion 7b of the electrode portions 5b .

A body thickness _{T 3C} of the first direction D1 of the outer region 3C, the electrode portions 5a, the electrode thickness _{T E3} of the first direction D1 of the portion located at each outer region 3C of 7a, the electrode portions 5b, 7b of Among these, the total value of the electrode thickness _{TE4 in} the first direction D1 of the portion located in each outer region 3C is smaller than the total value of the first distance L1 and the electrode thickness _TE1 . In the present embodiment, it is equivalent to the electrode thickness _{T E3} electrode thickness _{T E3} and the electrode portion 7a of the electrode portion 5a, which is equivalent to the electrode thickness _{T E4} electrode thickness _{T E4} and the electrode portion 7b of the electrode portions 5b .

  As described above, in the present embodiment, the length of the element body 2 in the first direction D1 is smaller than the length of the element body 2 in the second direction D2 and the length of the element body 2 in the third direction D3. As a result, the multilayer capacitor C1 can be reduced in height, and a multilayer capacitor suitable for incorporation in a substrate can be realized. The 1st terminal electrode 5 has the electrode part 5a arrange | positioned at the 1st main surface 2a, and has the electrode part 5b arrange | positioned at the 2nd main surface 2b. The 2nd terminal electrode 7 has the electrode part 7a arrange | positioned at the 1st main surface 2a, and has the electrode part 7b arrange | positioned at the 2nd main surface 2b. Therefore, the multilayer capacitor C1 is a wiring formed on the substrate on the first main surface 2a side of the element body 2, the second main surface 2b side of the element body 2, or both main surfaces 2a and 2b side of the element body 2. Can be electrically connected to each other and can be easily built into the board.

The multilayer capacitor C1 is built in the substrate by being placed in the housing portion of the substrate and then being filled with resin. When the multilayer capacitor C1 is disposed in the housing portion so that the second main surface 2b of the element body 2 is opposed to the bottom portion of the housing portion, the electrode thickness _TE1 of the electrode portions 5b and 7b is set to the electrode portions 5b and 7b. since the electrode thickness T _E2 greater than when the resin is filled around the multilayer capacitor C1, the resin wraparound easily around the first and second terminal electrodes 5 and 7. Thereby, the multilayer capacitor C1 can be appropriately built in the substrate.

The element body thickness T _3A is smaller than the element body thickness T _3B , and the first distance L1 is smaller than the second distance L2. That is, a depression is formed on the surface of the multilayer capacitor C1 on the first main surface 2a side. Therefore, when the multilayer capacitor C1 is disposed in the housing portion so that the first main surface 2a of the element body 2 faces the bottom portion of the housing portion, the posture of the multilayer capacitor C1 in the housing portion is stabilized. As a result, since the multilayer capacitor C1 is built into the substrate in a stable posture, the multilayer capacitor C1 can be appropriately built into the substrate.

  After the multilayer capacitor C1 is built in the substrate, via holes reaching the first and second terminal electrodes 5 and 7 are formed in the substrate by laser processing. The via hole formed by laser processing is formed in a tapered shape having a diameter reduced from the surface side of the substrate toward the first and second terminal electrodes 5 and 7. Accordingly, the farther the distance from the surface of the substrate is, the smaller the inner diameter of the via hole. That is, as the distance from the surface of the substrate increases, the area of the conductor disposed in the via hole decreases. When the area of the conductor is small, the connection area between the first and second terminal electrodes 5, 7 and the conductor is also small.

After the multilayer capacitor C1 is built in the substrate, when the via hole is formed from the first main surface 2a side by laser processing and the conductor is disposed in the via hole, the element thickness T _3A and the element thickness T _3B are Since the difference is larger than the difference between the first distance L1 and the second distance L2, the difference between the element thickness T _3A and the element thickness T _3B is equal to or less than the difference between the first distance L1 and the second distance L2. The distance from the surface of the substrate to the surfaces of the first and second terminal electrodes 5 and 7 is small. Therefore, the connection area between the first and second terminal electrodes 5, 7 and the conductor is large, and the connectivity between the first and second terminal electrodes 5, 7 and the conductor is ensured.

After the multilayer capacitor C1 is incorporated into the substrate, the via hole from the second principal surface 2b side is formed by laser processing, if the conductor in the via hole is disposed, the electrode portions 5b, electrode thickness T _E1 and 7b are electrode portions 5b, is greater than the electrode thickness _{T E2} of 7b, the electrode portions 5b, 7b of electrode thickness _{T E1} is the electrode portions 5b, as compared with the electrode thickness is _{T E2} less construction of 7b, the first and from the surface of the substrate The distance to the surface of the second terminal electrodes 5 and 7 is small. Therefore, the connection area between the first and second terminal electrodes 5, 7 and the conductor is large, and the connectivity between the first and second terminal electrodes 5, 7 and the conductor is ensured.

  The electric field distribution tends to concentrate on the end region IE1 of the first and second internal electrodes 11, 13. When the electric field distribution is concentrated on the end region IE1, the electric field strength becomes extremely high, and a discharge is generated between the end regions IE1 adjacent in the first direction D1, and the insulating state may be destroyed.

  In the multilayer capacitor C1 in which the interval G1 between the end regions IE1 adjacent in the first direction D1 is larger than the interval G2 between the central regions IE2 adjacent in the first direction D1, the multilayer capacitor C1 is equal to or less than the interval G2. In contrast, even when the electric field distribution is concentrated in the end region IE1, the electric field strength is unlikely to increase, and the occurrence of discharge between the end regions IE1 adjacent in the first direction D1 can be suppressed. The multilayer capacitor C1 in which the gap G2 is smaller than the gap G1 has a higher capacitance than the multilayer capacitor in which the gap G2 is equal to the gap G1. Therefore, it is possible to suppress the occurrence of dielectric breakdown while securing the electrical characteristics of the multilayer capacitor C1 to a desired value.

The region exposed from the first and second terminal electrodes 5 and 7 of the element body 2 has a third region 4A and a pair of fourth regions 4B. The second main surface 2b is a plane orthogonal to the first direction D1 across the first region 3A, the pair of second regions 3B, the third region 4A, and the pair of fourth regions 4B. Body thickness _{T 4A} of the first direction D1 of the third region 4A is smaller than the body thickness _{T 4B} of the first direction D1 of the fourth region 4B. That is, since a depression is formed in the first main surface 2a of the element body 2, the multilayer capacitor C1 is arranged in the accommodating portion so that the first main surface 2a of the element body 2 faces the bottom portion of the accommodating portion. In this case, a space is formed between the bottom of the housing part and the first main surface 2 a of the element body 2. The space functions as a resin reservoir when the resin is filled around the multilayer capacitor C1, and the multilayer capacitor C1 can be appropriately embedded in the substrate.

The region in which the first and second terminal electrodes 5 and 7 of the element body 2 are disposed further includes a pair of outer regions 3C. A body thickness _{T 3C} of each outer region 3C, the electrode portions 5a, the electrode thickness _{T E3} of 7a, the electrode portion 5b, the total value of the electrode thickness _{T E4} and 7b has a first distance L1 and the electrode thickness _{T E1} Less than the sum of For this reason, when the multilayer capacitor C1 is disposed in the housing portion so that the second main surface 2b of the element body 2 faces the bottom portion of the housing portion, when the resin is filled around the multilayer capacitor C1, The resin is more likely to go around the first and second terminal electrodes 5 and 7.

  The multilayer capacitor C1 is embedded and mounted in the substrate 31, as shown in FIGS. That is, the multilayer capacitor C1 is built in the substrate 31. 11 and 12 are views for explaining the multilayer capacitor mounting structure according to the present embodiment.

  The substrate 31 is configured by laminating a plurality of insulating layers 33. The insulating layer 33 is made of an insulating material such as ceramic or resin, and is integrated with each other by bonding or the like.

  The multilayer capacitor C1 is disposed in a housing portion 31a formed on the substrate 31, and is fixed to the substrate 31 by a resin 34 filled in the housing portion 31a. As a result, the multilayer capacitor C1 is embedded in the substrate 31. In the mounting structure shown in FIG. 11, the multilayer capacitor C1 is arranged in the housing part 31a so that the second main surface 2b of the element body 2 faces the bottom of the housing part 31a. In the mounting structure shown in FIG. 12, the multilayer capacitor C1 is disposed in the housing portion 31a so that the first main surface 2a of the element body 2 faces the bottom of the housing portion 31a.

  The multilayer capacitor C <b> 1 is electrically connected through electrodes 35 and 37 disposed on the surface of the substrate 31 and via conductors 45 and 47. In the mounting structure shown in FIG. 11, the electrode portion 5 a of the first terminal electrode 5 is electrically connected to the electrode 35 through the via conductor 45, and the electrode portion 7 a of the second terminal electrode 7 is connected to the electrode through the via conductor 47. 37 is electrically connected. In the mounting structure shown in FIG. 12, the electrode portion 5 b of the first terminal electrode 5 is electrically connected to the electrode 35 through the via conductor 45, and the electrode portion 7 b of the second terminal electrode 7 is connected to the electrode through the via conductor 47. 37 is electrically connected.

  The via conductors 45 and 47 are formed by growing a conductive metal (such as Cu or Au) in the via hole formed in the substrate 31 by electroless plating or the like. The via holes are formed by laser processing so as to reach the electrode portions 5a, 5b, 7a, 7b of the first and second terminal electrodes 5, 7 of the multilayer capacitor C1 from the surface side of the substrate 31.

  In the multilayer capacitor C1, the electrode portions 5a, 5b, 7a, and 7b have a third electrode layer 25 as a plating layer. Therefore, the via conductors 45, 47 formed in the via hole and the electrode portions 5a, 5b, 7a, 7b can be reliably connected. In particular, when the via conductors 45 and 47 are formed by plating, the via conductors 45 and 47 and the electrode portions 5a, 5b, 7a, and 7b are more reliably connected.

  As mentioned above, although embodiment of this invention has been described, this invention is not necessarily limited to embodiment mentioned above, A various change is possible in the range which does not deviate from the summary.

  The 1st and 2nd terminal electrodes 5 and 7 do not need to have the electrode parts 5d and 7d. That is, the first terminal electrode 5 may be formed on the three surfaces 2a, 2b, and 2c, and the second terminal electrode 7 may be formed on the three surfaces 2a, 2b, and 2d.

2 ... Element body, 2a ... First main surface, 2b ... Second main surface, 2c, 2d ... First side surface, 2e, 2f ... Second side surface, 3A ... First region, 3B ... Second region, 3C ... Outer side Region 4A ... Third region 4B ... Fourth region 5 ... First terminal electrode 5a, 5b, 5c, 5d ... Electrode part, 7 ... Second terminal electrode, 7a, 7b, 7c, 7d ... Electrode part, DESCRIPTION OF SYMBOLS 11 ... 1st internal electrode, 13 ... 2nd internal electrode, C1 ... Multilayer capacitor, D1 ... 1st direction, D2 ... 2nd direction, D3 ... 3rd direction, G1 ... Space | interval of edge region, G2 ... Center part Space between regions, IE1... End region, IE2... Center region, L1... First distance, L2... Second distance, T _3A , T _3B , T _3C , T _4A , T _4B ... element thickness, T _E1 , T _E2 , T _E3 , T _E4 ... Electrode thickness.

Claims (4)

The first and second main surfaces that have a rectangular parallelepiped shape and face each other in the first direction, and extend in the first direction so as to connect the first and second main surfaces, and the first A pair of first side surfaces facing each other in a second direction orthogonal to the direction, and extending in the first direction so as to connect the first and second main surfaces and in the first and second directions An element body having a pair of second side surfaces facing each other in a third direction perpendicular to each other;
A plurality of internal electrodes alternately arranged in the element body so as to face each other in the first direction;
A pair of terminal electrodes disposed on the pair of second side surfaces of the element body and connected to a corresponding internal electrode among the plurality of internal electrodes,
The length of the element body in the first direction is smaller than the length of the element body in the second direction and the length of the element body in the third direction,
When each of the internal electrodes is divided into a pair of end regions and a central region located between the pair of end regions in the second direction, the terminal electrodes of the element body are disposed. The region has a first region where the central region is located, and a pair of second regions where the end regions are located,
Each of the terminal electrodes has a first electrode portion disposed on the first main surface, and a second electrode portion disposed on the second main surface,
The second main surface is a plane orthogonal to the first direction across the first region and the pair of second regions,
The first element thickness in the first direction of the first region is smaller than the second element thickness in the first direction of each second region,
The first distance in the first direction from the second main surface of the first region to the surface of the first electrode portion located in the first region is the second main surface of the second region. Less than the second distance in the first direction from the first electrode portion to the surface of the portion located in each second region,
The difference between the first element thickness and the second element thickness is greater than the difference between the first distance and the second distance,
A multilayer capacitor in which a first electrode thickness of a portion located in the first region of the second electrode portion is larger than a second electrode thickness of a portion located in each of the second regions of the second electrode portion.   The multilayer capacitor according to claim 1, wherein an interval between the end regions adjacent in the first direction is larger than an interval between the central regions adjacent in the first direction. The region exposed from the pair of terminal electrodes of the element body includes a third region in which the central region is located, and a pair of fourth regions in which the end region is located,
The second main surface is a plane orthogonal to the first direction across the first region, the pair of second regions, the third region, and the pair of fourth regions,
3. The multilayer capacitor according to claim 1, wherein an element thickness in the first direction of the third region is smaller than an element thickness in the first direction of each of the fourth regions. The region where the terminal electrodes of the element body are arranged further includes a pair of outer regions located outside the second region in the second direction,
The thickness of each outer region in the first direction, the thickness of the first electrode portion located in each outer region, the thickness in the first direction, and the second electrode portion located in each outer region The multilayer capacitor according to any one of claims 1 to 3, wherein a total value of the thicknesses of the portions in the first direction is smaller than a total value of the first distance and the first electrode thickness.

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