JP2017063166A - Multilayer capacitor and mounting structure therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer capacitor suppressing propagation of vibration to a board, while enhancing the mounting stability, when mounted on the board.SOLUTION: In a multilayer capacitor, first external terminal 7a is connected with a first external electrode 3a, and a second external terminal 7b is connected with a second external electrode 3b. The first external terminal 7a includes a first body part 7a1 located separately from the lower surface 4b of the multilayer capacitor body 10, and a first connection 7a2 provided on the first side face 4e in the longitudinal central part of the first body part 7a1, and bonded to the lower surface extension 3a3 of the first external electrode 3a. The second external terminal 7b includes a second body part 7b1 located remotely from the lower surface 4b of the multilayer capacitor body 10, and a second connection 7b2 provided on the second side face 4f in the longitudinal central part of the second body part 7b1, and bonded to the lower surface extension 3b3 of the second external electrode 3b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a multilayer capacitor in which a pair of external electrodes is provided on a multilayer body in which a plurality of dielectric layers and internal electrode layers are alternately stacked, and a mounting structure thereof.

  In multilayer capacitors, dielectric layers and internal electrode layers are alternately stacked, and a ferroelectric material such as barium titanate with a relatively high dielectric constant is generally used as the ceramic material for the dielectric layer. It is used for. For example, when a DC voltage on which an AC component is superimposed is applied to such a multilayer capacitor, the dielectric layer is distorted due to the electrostrictive effect of the voltage, and the multilayer capacitor itself vibrates. The multilayer capacitor is mounted on the substrate via solder or the like. The vibration of the multilayer capacitor itself propagates to the substrate, and the vibration propagated to the substrate resonates and amplifies the vibration. Sound is generated. When the substrate resonates at an audible resonance frequency, an audible sound is generated from the substrate, and a so-called sounding phenomenon occurs. Specifically, in a multilayer capacitor, a pair of external electrodes and a substrate are mounted via solder, and the vibration of the multilayer capacitor deforms the substrate via a solder joint formed on the external electrode. A vibration sound is generated in the substrate.

  The multilayer capacitor is provided with a pair of external electrodes at the center of a pair of side surfaces of the multilayer body in order to reduce noise. An example of such a multilayer capacitor is disclosed in Patent Document 1.

JP 2007-194312 A

  However, the structure of the multilayer capacitor described above has a problem that the pair of external electrodes has a small length along the longitudinal direction of the multilayer body, and the mounting stability tends to be lowered.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a multilayer capacitor and a mounting structure that can suppress noise and improve mounting stability.

The multilayer capacitor in accordance with one aspect of the present invention is a rectangular capacitor, in which dielectric layers and internal electrode layers are alternately stacked, positioned in the stacking direction of the dielectric layers and the internal electrode layers and facing each other. An upper surface and a lower surface; a first side surface and a second side surface adjacent to the long side of the upper surface and the lower surface; a first end surface and a second end surface adjacent to the short side of the upper surface and the lower surface; And a multilayer capacitor body having a first external electrode and a second external electrode which are provided on the pair of side surfaces and are electrically connected to the different internal electrode layers. A multilayer capacitor including a first external terminal and a second external terminal joined to the first external electrode and the second external electrode, wherein the first external electrode and the second external terminal The electrode is the center of the side Including a side surface portion provided on the side surface, an upper surface extending portion extending from the side surface portion to the upper surface, and a lower surface extending portion extending from the side surface portion to the lower surface, The first external terminal includes a first body portion of a plate-like body disposed away from the lower surface so as to face the lower surface in the longitudinal direction of the multilayer capacitor body, and a longitudinal direction of the first body portion Provided on the side portion on the first side surface side of the central portion, and extends from the side portion toward the first side surface side so as to overlap the lower surface extending portion of the first external electrode, A first connection portion joined to a lower surface extension portion of the first external electrode, and the second external terminal is opposed to the lower surface in the longitudinal direction of the multilayer capacitor body. The second main body portion of the plate-like body arranged away from the lower surface and the longitudinal direction of the second main body portion Provided on the side portion on the second side surface side of the central portion, and extends from the side portion toward the first side surface so as to overlap the lower surface extending portion of the second external electrode, And a second connection portion joined to a lower surface extension portion of the second external electrode, and the first connection portion is directed toward the lower surface extension portion side of the first external electrode. The first main body portion protrudes so that the upper portion is higher than the main surface on the lower surface side, and a space portion is formed below, and the second connection portion is a lower surface of the second external electrode. It protrudes so that an upper part may become higher than the main surface of the said lower surface side of a said 2nd main body part toward the extension part side, and a space part is formed below, It is characterized by the above-mentioned.

  In the multilayer capacitor mounting structure according to one aspect of the present invention, the multilayer capacitor and the substrate provided with the substrate electrode on which the multilayer capacitor is mounted include the lower surface and the mounting surface of the substrate. Are arranged so as to face each other, and the first connection portion and the substrate electrode are joined via solder provided in the space portion, and the second connection portion and the substrate electrode are connected to the space portion. It is characterized in that it is joined via solder provided on.

  According to the multilayer capacitor of the present invention, it is possible to suppress the propagation of vibration to the substrate when mounted on the substrate and improve the mounting stability.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic perspective view which shows the multilayer capacitor | condenser which concerns on embodiment, Comprising: (a) is the schematic perspective view seen from the upper surface side, (b) is the schematic perspective view seen from the lower surface side. is there. (A) is the schematic side view seen from the direction perpendicular | vertical to the longitudinal direction of a multilayer capacitor main body in the state which mounted the multilayer capacitor shown in FIG. 1 on a board | substrate, (b) is shown in FIG. FIG. 5 is a schematic side view of the multilayer capacitor body viewed from a direction perpendicular to the short direction of the multilayer capacitor body in a state where the multilayer capacitor is mounted on a substrate. (A) is a cross-sectional view taken along line AA of the multilayer capacitor shown in FIG. 1, and (b) is a cross section taken along line BB of the multilayer capacitor shown in FIG. It is a figure and (c) is sectional drawing cut | disconnected by CC line of the multilayer capacitor | condenser shown in FIG. (A)-(c) is a top view for demonstrating an internal electrode layer. It is the schematic perspective view seen from the lower surface side of other examples of the multilayer capacitor concerning an embodiment. (A) is a schematic perspective view showing a state in which the multilayer capacitor shown in FIG. 1 is mounted on a substrate, and (b) is a cross section taken along line DD of the multilayer capacitor shown in (a). FIG. (A) is explanatory drawing for demonstrating the state which mounted the multilayer capacitor shown in FIG. 1 on the board | substrate, (b) demonstrated the state which mounted the multilayer capacitor | condenser shown in FIG. 5 on the board | substrate. It is explanatory drawing for doing. (A) And (b) is the schematic perspective view seen from the lower surface side of the other example of the multilayer capacitor | condenser which concerns on embodiment. (A)-(d) is explanatory drawing for demonstrating the manufacturing method of the multilayer capacitor | condenser shown in FIG.

<Embodiment>
Hereinafter, a multilayer capacitor 10A according to an embodiment of the present invention will be described with reference to the drawings. In addition, for convenience, the multilayer capacitor 10A defines an orthogonal coordinate system XYZ, and uses the terms of the upper surface or the lower surface with the positive side in the Z direction as the upper side. In the present embodiment, one of the pair of main surfaces is the upper surface 4a and the other is the lower surface 4b. In addition, in each drawing, the same code | symbol is used about the same member and the same part, and the overlapping description is abbreviate | omitted.

  FIG. 1A is a schematic perspective view showing a state in which the upper surface of the multilayer capacitor 10A according to the embodiment of the present invention is on the upper side, and FIG. 1B is a lower surface of the multilayer capacitor 10A. It is a schematic perspective view which shows the state which turned up. The multilayer capacitor 10A includes a multilayer capacitor main body 10 and a pair of external terminals 7 (first external electrodes 3a) joined to the pair of external electrodes 3 (first external electrode 3a and second external electrode 3b) of the multilayer capacitor main body 10. 1 external terminal 7a and second external terminal 7b).

  The multilayer capacitor body 10 includes a rectangular parallelepiped laminated body 1 in which dielectric layers 1a and internal electrode layers 2 (first internal electrode layer 2a and second internal electrode layer 2b) are alternately laminated, and a laminated body. A pair of external electrodes 3 (first external electrode 3a and second external electrode 3b) provided on one pair of side surfaces 4e and 4f and electrically connected to different internal electrode layers 2 respectively. Yes. The laminated body 1 has a rectangular parallelepiped shape in which first internal electrode layers 2a and second internal electrode layers 2b are alternately laminated via dielectric layers 1a.

  The multilayer body 1 includes a rectangular upper surface 4a and a lower surface 4b that are positioned in the stacking direction of the dielectric layer 1a and the internal electrode layer 2 (the first internal electrode layer 2a and the second internal electrode layer 2b) and face each other. A pair of side surfaces (a first side surface 4e and a second side surface 4f) facing each other and positioned between the upper surface 4a and the lower surface 4b and adjacent to the long sides of the upper surface 4a and the lower surface 4b, and an upper surface 4a A pair of end faces (first end face 4c and second end face 4d) facing each other and located between the lower face 4b and adjacent to the short sides of the upper face 4a and the lower face 4b are provided. In addition, a pair of side surfaces (first side surface 4e and second side surface 4f) are located along the longitudinal direction (X direction) of the laminate 1, and a pair of end surfaces (first end surface 4c and second end surface 4d). ) Is located along the short direction (Y direction) of the laminate 1.

  As described above, in the laminate 1, the pair of end faces 4c and 4d are located between the upper surface 4a and the lower surface 4b, and are orthogonal to the upper surface 4a and the lower surface 4b, and the pair of side surfaces 4e and 4f are the upper surface 4a and the lower surface. 4b and orthogonal to the upper surface 4a and the lower surface 4b, and the pair of end surfaces 4c and 4d and the pair of side surfaces 4e and 4f are orthogonal to each other. The rectangular parallelepiped shape includes not only a cubic shape or a rectangular parallelepiped shape, but also includes, for example, a shape in which a ridge line portion of a cube or a rectangular parallelepiped is chamfered and the ridge line portion has an R shape.

  The laminated body 1 is a sintered body obtained by laminating and firing a plurality of ceramic green sheets in which the internal electrode layer 2 is formed on the surface of the dielectric layer 1a. Thus, the multilayer body 1 is formed in a rectangular parallelepiped shape, and a plane that is a cross section (XY plane) in a direction orthogonal to the stacking direction (Z direction) of the dielectric layer 1a and the internal electrode layer 2 is rectangular. It has become.

  As shown in FIG. 1, the pair of external electrodes 3 is provided on the first side surface 4e and the second side surface 4f, and includes a first external electrode 3a and a second external electrode 3b. As shown in FIGS. 2 and 3, the first external electrode 3a has a side surface portion 3a1, an upper surface extension portion 3a2, and a lower surface extension portion 3a3, and the side surface portion 3a1 is the first side surface 4e. Provided on the first side surface 4e so as to include the central portion, the upper surface extending portion 3a2 extends on the upper surface 4a from the side surface portion 3a1 toward the central portion in the lateral direction (Y direction) of the stacked body 1, The lower surface extending portion 3a3 extends on the lower surface 4b from the side surface portion 3a1 toward the central portion in the lateral direction (Y direction) of the stacked body 1.

  As shown in FIGS. 2 and 3, the second external electrode 3b has a side surface portion 3b1, an upper surface extension portion 3b2, and a lower surface extension portion 3b3, and the side surface portion 3b1 is the second side surface. 4f is provided on the second side surface 4f so as to include the central portion, and the upper surface extending portion 3b2 extends on the upper surface 4a from the side surface portion 3b1 toward the central portion in the lateral direction (Y direction) of the stacked body 1. And the lower surface extension part 3b3 is extended on the lower surface 4b toward the center part of the transversal direction (Y direction) of the laminated body 1 from the side surface part 3b1.

  As shown in FIG. 1, the upper surface extension portion 3a2 (upper surface extension portion 3b2) and the lower surface extension portion 3a3 (lower surface extension portion 3b3) are curved in a convex shape toward the central portions of the upper surface 4a and the lower surface 4b. For example, it is curved in an arc shape toward the center. Thus, the upper surface extending portion 3a2 and the lower surface extending portion 3a3 have a curved portion that curves in a convex shape toward the central portion, and the curved portion is, for example, an arc shape that curves in a convex shape, Similarly, the upper surface extended portion 3b2 and the lower surface extended portion 3b3 have a curved portion that curves in a convex shape toward the central portion side, and the curved portion is For example, an arc shape, a semicircular shape, or a semi-elliptical shape that curves in a convex shape.

  In the multilayer capacitor main body 10, the upper surface extending portion 3a2 (upper surface extending portion 3b2) and the lower surface extending portion 3a3 (lower surface extending portion 3b3) are curved in a convex shape toward the central portions of the upper surface 1a and the lower surface 1b. Since it extends, the pair of external electrodes 3 are difficult to peel from the laminate 1.

  As shown in FIG. 3, the internal electrode layer 2 includes a first internal electrode layer 2a and a second internal electrode layer 2b. The first internal electrode layer 2a and the second internal electrode layer 2b are Are opposed to each other at a predetermined interval, and are alternately arranged at a predetermined interval in the stacking direction via a plurality of dielectric layers 1a in the stacked body 1. The internal electrode layer 2 is provided so as to be substantially parallel to the upper surface 4 a and the lower surface 4 b of the multilayer body 1.

  As shown in FIG. 2, the first external electrode 3a is provided such that the side surface portion 3a1 includes the central portion of the first side surface 4e, and the first internal electrode layer 2a led out to the first side surface 4e. Is electrically connected. Similarly, the second external electrode 3b is provided so that the side surface portion 3b1 includes the center portion of the second side surface 4f, and the second external electrode 3b is electrically connected to the second internal electrode layer 2b drawn out to the second side surface 4f. Connected.

  As shown in FIG. 4B, the first internal electrode layer 2a has a lead portion 2aa to the first side surface 4e at the center portion on the first side surface 4e side. The first side surface 4e is pulled out and is exposed to the first side surface 4e.

  Further, as shown in FIG. 4C, the second internal electrode layer 2b has a lead portion 2ba to the second side surface 4f at the center portion on the second side surface 4f side, and the lead portion 2ba. Is pulled out to the second side surface 4f opposite to the first side surface 4e and is arranged to be exposed to the second side surface 4f. The first internal electrode layer 2a and the second internal electrode layer 2b are not exposed on the first end surface 4d and the second end surface 4d. In FIG. 4A, the first internal electrode layer 2a exposed on the first side face 4e is indicated by a solid line, and the second internal electrode layer 2b exposed on the second side face 4f is indicated by a broken line.

As described above, in the multilayer capacitor body 10, the first external electrode 3a is provided at the center of the first side face 4e, and the second external electrode 3b is provided at the center of the second side face 4f. . As shown in FIG. 4B, the first external electrode 3a is provided so that the side surface portion 3a1 covers the extraction portion 2aa of the first internal electrode layer 2a extracted to the first side surface 4e. Are electrically connected to the first internal electrode layer 2a. Further, as shown in FIG. 4C, the second external electrode 3b includes a lead portion 2ba of the second internal electrode layer 2b in which the side surface portion 3b1 is drawn to the second side surface 4f.
And is electrically connected to the second internal electrode layer 2b.

  The central portion of the first side surface 4e is a region including a bisector that bisects the first side surface 4e vertically, and the first external electrode 3a is provided so that the side surface portion 3a1 includes this region. It has been. The central portion of the second side surface 4f is a region including a bisector that bisects the second side surface 4f vertically, and the side portion 3b1 of the second external electrode 3b includes this region. Is provided. In FIG. 4A, the bisector L is indicated by a long chain line.

  Thus, the internal electrode layer 2 is electrically connected to different external electrodes 3 for each layer, and a pair of external electrodes 3 connected to a pair of external electrodes 3 by applying a voltage to the pair of external electrodes 3. A capacitance is generated in the dielectric layer 1a sandwiched between the internal electrode layers 2 (the first internal electrode layer 2a and the second internal electrode layer 2b).

  The dimension of the multilayer capacitor body 10 having such a configuration is such that the length in the longitudinal direction (X direction) is, for example, 0.6 (mm) to 2.2 (mm), and the length in the short direction (Y direction). For example, the length in the height direction (Z direction) is, for example, 0.3 (mm) to 1.5 (mm).

  The dielectric layer 1a has a rectangular shape in plan view from the stacking direction (Z direction). The structure of the dielectric layer 1a and the internal electrode layer 2 shown in FIG. 3 is a schematic structure. In reality, there are many layers in which several to several hundred dielectric layers 1a and the internal electrode layer 2 are laminated. The thickness per layer is, for example, 0.2 (μm) to 3 (μm). In the laminate 1, for example, a plurality of dielectric layers 1 a composed of 10 (layers) to 1000 (layers) and an internal electrode layer 2 are laminated in the Z direction. Further, the number of internal electrode layers 2 in the multilayer body 1 is appropriately set according to the characteristics of the multilayer capacitor body 10.

The dielectric layer 1a is, for example, barium titanate (BaTiO ₃ ), calcium titanate (CaTiO ₃ ), strontium titanate (SrTiO ₃ ), or calcium zirconate (CaZrO ₃ ). In addition, it is preferable that the dielectric layer 1a uses barium titanate as a ferroelectric material having a high dielectric constant from the viewpoint of a high dielectric constant.

  As shown in FIG. 4, the lead-out portion 2aa and the lead-out portion 2ba are provided so that the lengths along the longitudinal direction (X direction) of the stacked body 1 are substantially the same. Not only this but the drawer part 2aa and the drawer part 2ba may mutually differ in the length along the longitudinal direction (X direction) of the laminated body 1. FIG.

  The lead portion 2aa (drawer portion 2ba) maintains the symmetry of vibration, and can reduce the elements that vibrate the substrate when the multilayer capacitor 10A is mounted. Therefore, the lead side surface 4e (second side surface) The exposed portion in 4f) is preferably provided so as to include the bisector L of the first side face 4e (second side face 4f).

  The conductive material of the internal electrode layer 2 (the first internal electrode layer 2a and the second internal electrode layer 2b) is, for example, nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), or gold ( A metal material such as Au) or an alloy material such as an Ag-Pd alloy including one or more of these metal materials. The first internal electrode layer 2a and the second internal electrode layer 2b have an electrode thickness of, for example, 0.2 (μm) to 2 (μm), and the thickness is appropriately set according to the application. That's fine. The first internal electrode layer 2a and the second internal electrode layer 2b are preferably formed of the same metal material or alloy material.

The pair of external electrodes 3 includes a first external electrode 3a and a second external electrode 3b, and the first external electrode 3a and the second external electrode 3b are disposed so as to face each other. One external electrode 3a is disposed on the first side surface 4e, is electrically connected to the first internal electrode 2a drawn out to the first side surface 4e, and the second external electrode 3b is It is arranged on the second side surface 4e and is electrically connected to the second internal electrode 2b drawn out to the second side surface 4f.

  The pair of external electrodes 3 (first external electrode 3a and second external electrode 3b) includes a base electrode 5 and a plating layer 6 as shown in FIG. The base electrode 5 is electrically connected to the internal electrode 2 drawn out to the first side face 4 e or the second side face 4 f, and the plating layer 6 is on the surface of the base electrode 5 so as to cover the base electrode 5. Is formed. The plating layer 6 is provided to protect the base electrode 5 or to improve the bonding property between the pair of external electrodes 3 and the pair of external terminals 7 in the case of fusion bonding. The pair of external electrodes 3 is not limited to the plating layer 6, and any metal layer that can be melt bonded to the base electrode 5 may be provided.

  The conductive material of the base electrode 5 includes, for example, a metal material such as nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), or gold (Au), or one or more of these metal materials. For example, an alloy material such as an Ag—Pd alloy. The pair of base electrodes 5 is preferably formed of the same metal material or alloy material.

  The thickness of the base electrode 5 on the upper surface 4a and the lower surface 4b is, for example, 4 (μm) to 10 (μm), and the thickness on the first side surface 4e and the second side surface 4f is, for example, 10 (μm) to 25 (μm).

  In addition, one of the pair of base electrodes 5 is provided so as to extend from the first side surface 4e to the upper surface 4a and the lower surface 4b, and the other extends from the second side surface 4f to the upper surface 4a and the lower surface 4b. It is provided to exist. The plating layer 6 is formed on the surface of the base electrode 5 so as to cover the base electrode 5 formed on the surface of the multilayer body 1.

  Thus, as shown in FIG. 3, the first external electrode 3a and the second external electrode 3b have the plating layer 6 formed on the surface of the base electrode 5. For example, the plating layer 6 includes the first external electrode 3a and the second external electrode 3b. A laminate composed of the plating layer 6a and the second plating layer 6b formed on the surface of the first plating layer 6a is formed on the surface. The plating layer 6 is, for example, a nickel (Ni) plating layer, a copper (Cu) plating layer, a gold (Au) plating layer, a tin (Sn) plating layer, or the like.

  When the plating layer 6 is composed of a laminate, for example, the first external electrode 3a and the second external electrode 3b form a Ni plating layer (first plating layer 6a) on the surface of the base electrode 5, An Sn plating layer (second plating layer 6b) may be formed on the surface of the Ni plating layer, and the plating layer 6 may be formed of a laminate of the Ni plating layer and the Sn plating layer. The first plating layer 6a has a thickness of, for example, 5 (μm) to 10 (μm), and the second plating layer 6b has a thickness of, for example, 3 (μm) to 5 (μm). The first external electrode 3 a and the second external electrode 3 b may be formed of a single plating layer 6.

  Here, the pair of external terminals 7 (first external terminal 74a and second external terminal 4b) will be described below with reference to the drawings.

  As shown in FIGS. 1 and 2, the pair of external terminals 7 includes a first external terminal 7 a and a second external terminal 7 b, and the first external terminal 7 a is the first external terminal of the multilayer capacitor body 10. The second external terminal 7b is joined to the lower surface extension portion 3b3 of the second external electrode 3b, and is joined to the lower surface extension portion 3a3 of the electrode 3a.

  The first external terminal 7 a includes a first main body portion 7 a 1 and a first connection portion 7 a 2 so that the first main body portion 7 a 1 faces the lower surface 4 b in the longitudinal direction of the multilayer capacitor main body 10. It is a rectangular plate-like body disposed away from the lower surface 4b, and the first connection portion 7a2 is provided on the side portion on the first side surface 4e side of the central portion in the longitudinal direction of the first main body portion 7a1, Extending from the side portion toward the first side surface 4e so as to overlap the lower surface extension portion 3a3 of the first external electrode 3a, and joined to the lower surface extension portion 3a3 of the first external electrode 3a. . The first external terminal 7a is provided with a first connection portion 7a2 at a central portion in a side view from a direction perpendicular to the first side surface 4e, and the first external terminal 7a has a first connection portion 7a2 as a center. Main body portions 7a1 are provided in the left-right direction.

  The second external terminal 7 b includes a second main body portion 7 b 1 and a second connection portion 7 b 2, and the second main body portion 7 b 1 faces the lower surface 4 b in the longitudinal direction of the multilayer capacitor main body 10. In this way, the second connecting portion 7b2 is provided on the side portion on the second side surface 4f side of the central portion in the longitudinal direction of the second main body portion 7b1. Extending from the side toward the second side face 4f so as to overlap the lower surface extension 3b3 of the second external electrode 3b and joined to the lower surface extension 3b3 of the second external electrode 3b. ing. The second external terminal 7b is provided with a second connection portion 7b2 at the central portion when viewed from the side perpendicular to the second side surface 4f, and the second connection portion 7b2 is the second connection center. Main body portions 7a1 are provided in the left-right direction.

  As shown in FIGS. 1 and 2, the first connection portion 7a2 is located above the main surface on the lower surface 4a side of the first main body portion 7a1 toward the lower surface extension portion 3a3 side of the first external electrode 3a. And the space 7a3 is formed in the lower portion. Similarly, the second connection portion 7b2 is second toward the lower surface extension portion 3b3 side of the second external electrode 3b. The main body portion 7b1 protrudes so that the upper portion is higher than the main surface on the lower surface 4b side, and a space portion 7b3 is formed below.

  In the multilayer capacitor 10A, the first external terminal 7a is joined to the lower surface extension 3a3, and the second external terminal 7b is joined to the lower surface extension 3b3. When viewed from above, the pair of external terminals 7 are provided on the inner side of the pair of external electrodes 3. Even when the pair of external terminals 7 are provided, the size of the multilayer capacitor body 10 in the short direction is reduced. Will not be affected. That is, when the multilayer capacitor 10A is provided with a pair of external terminals 7, the multilayer capacitor body 10 is viewed from above (when viewed in plan) compared to the case where the multilayer capacitor body 10 is alone (when the pair of external terminals 7 is not provided). The size of does not change and does not affect the size.

  The first external terminal 7a is provided with solder in the space 7a3 below the first connection portion 7a2, and is electrically connected to the substrate electrode 9a of the substrate 9 via the solder. 7b is provided with solder in the space 7b3 below the second connecting portion 7b2, and is electrically connected to the substrate electrode 9b of the substrate 9 via this solder.

  The first external terminal 7a is joined to the lower surface extending portion 3a3 of the first external electrode 3a at the first connection portion 7a2 by using, for example, solder joining or fusion joining. Similarly, the second external terminal 7b is joined to the lower surface extending portion 3b3 of the second external electrode 3b at the second connection portion 7b2 by using, for example, solder joining or fusion joining. In the present embodiment, the first external terminal 7a and the second external terminal 7b are joined to the first external electrode 3a and the second external electrode 3b by fusion bonding.

Specifically, as shown in FIG. 1, the first external terminal 7a is formed by melting and bonding the first external electrode 3a and the first connecting portion 7a2 to form a circular molten portion 7a4. The first external electrode 3a and the first connection portion 7a2 are melt-bonded at the circular melting portion 7a4. Further, the first external terminal 7a is joined to the first external electrode 3a only by the melting portion 7a4. Similarly, as shown in FIG. 1, the second external terminal 7b is formed by melting and joining the second external electrode 3b and the second connection portion 7b2 to form a circular molten portion 7b4. The second external electrode 3b and the second connection portion 7b2 are melt-bonded at the circular melting portion 7b4. The second external terminal 7b is joined to the second external electrode 3b only by the melting part 7b4. In this way, the melting part 7a4 and the melting part 7b4 become circular joints, and the pair of external electrodes 3 and the pair of external terminals 7 are joined.

  In the multilayer capacitor 10A, as shown in FIG. 1, two melting portions 7a4 are provided in the first connection portion 7a2, and two melting portions 7b4 are provided in the second connection portion 7b2. The number of the melting parts 7a4 and the melting parts 7b4 is not limited to these numbers, and may be one or three or more according to the size or bonding strength of the multilayer capacitor body 10.

  As shown in FIG. 1, in the first external terminal 7a, the first main body portion 7a1 is a rectangular plate-like body, is disposed to face the lower surface 4b, and is substantially parallel to the lower surface 4b. The first connecting portion 7a2 is joined to the first external electrode 3a by fusion bonding, and is connected to the substrate electrode 9a via the solder 11 provided in the space portion 7a3 below the first connecting portion 7a2. Will be. The shape of the first main body portion 7a1 is not limited to a rectangular plate-like body, and is appropriately set. As shown in FIG. 2, the first main body portion 7 a 1 faces the substrate 9 and is disposed away from the substrate 9. Since the first main body portion 7 a 1 is disposed away from the substrate 9, vibration is difficult to propagate to the substrate 9.

  Further, as shown in FIG. 1, the second external terminal 7b has a second main body portion 7b1 that is a rectangular plate-like body, is disposed to face the lower surface 4b, and is substantially parallel to the lower surface 4b. The second connection portion 7b2 is joined to the second external electrode 3b by fusion bonding, and is connected to the substrate electrode 9b via the solder 11 provided in the space portion 7b3 of the second connection portion 7b2. Will be. The shape of the second main body portion 7b1 is not limited to the rectangular plate-like body, and is appropriately set. The second main body portion 7b1 faces the substrate 9 and is arranged away from the substrate 9. Since the second main body portion 7 b 1 is disposed away from the substrate 9, vibration is not easily propagated to the substrate 9.

  In the multilayer capacitor 10A, when the pair of external electrodes 3 and the pair of external terminals 7 are bonded using fusion bonding, the bonding portion between the first external terminal 7a and the first external electrode 3a is Point contact occurs, and the joint between the second external terminal 7b and the second external electrode 3b becomes point contact, and vibration of the multilayer capacitor body 10 is difficult to propagate. Here, the point contact means a circular joint having a diameter of 30 (μm) to 50 (μm).

  In this way, in the multilayer capacitor 10A, the first external terminal 7a and the first external electrode 3a are melt-bonded by point contact, so the first external terminal 7a is restrained by the first external electrode 3a. In addition, since the second external terminal 7b and the second external electrode 3b are melt-bonded by point contact, the second external terminal 7b is not easily restrained by the second external electrode 3b. Therefore, in the multilayer capacitor 10A, vibration due to distortion of the multilayer capacitor body 10 is easily absorbed by the first external terminal 7a and the second external terminal 7b.

In addition, the first external terminal 7a is melt-bonded to the first external electrode 3a, so that the joining region of the melted portion 7a4 with the first external electrode 3a can be reduced, and the second external terminal 7b is The second external electrode 3b is melt-bonded, and the bonding region of the melted portion 7b4 with the second external electrode 3b can be reduced. Therefore, in the multilayer capacitor 10A, the first external terminal 7a is not easily restrained by the first external electrode 3a, and the first external terminal 7b is hardly restrained by the second external electrode 3b. Vibration due to distortion of the capacitor body 10 is easily absorbed. For example, in the case of laser spot welding, the size of the joining region can be adjusted by the beam diameter of the irradiated laser beam or the emission output.

  The pair of external terminals 7 (second external terminal 7a and second external terminal 7b) are, for example, iron (Fe), nickel (Ni), chromium (Cr), copper (Cu), silver (Ag), or cobalt. It is a metal material such as (Co), or an alloy material such as a stainless alloy or a copper alloy containing one or more of these metal materials. The first external terminal 7a and the second external terminal 7b are preferably formed of the same metal material or alloy material.

  The pair of external terminals 7 (the first external terminal 7a and the second external terminal 7b) have a plating layer formed on the surface so as to be solder-bonded to the substrate electrode 9a and the substrate electrode 9b. Including a plating layer. The plating layer is formed, for example, by performing a masking process or the like on a region of the pair of external terminals 7 where the plating layer is not formed. The plating layer is formed in a region including the first connection portion 7a2 and the second connection portion 7b2 by using, for example, an electrolytic plating method, and the first connection portion 7a2 and the second connection portion 7b2 are A plating layer is formed on the pair of external electrodes 3 and the substrate electrodes 9a and 9b. The plating layer may be formed not only on both main surfaces of the pair of external terminals 7 but also on the side surface located between both main surfaces.

  Further, for example, the plating layer is composed of a first plating layer and a second plating layer formed on the surface of the first plating layer, and the first plating layer includes the first external terminals 7a and The surface of the second external terminal 7b is covered, and the second plating layer is formed on the surface of the first plating layer and covers the surface of the first plating layer. Each of the first plating layer and the second plating layer may be composed of a plurality of plating layers.

  The first plating layer is, for example, a metal material such as nickel (Ni), silver (Ag), or tin (Sn), or an alloy material such as an Sn—Ag alloy including one or more of these metal materials. It is. For example, the first plating layer is made of a metal material of nickel (Ni) or an alloy material containing nickel (Ni) as a main component, and has a thickness of, for example, 1 (μm) to 2 (μm).

  In addition, the second plating layer is, for example, a metal material such as nickel (Ni), silver (Ag), or tin (Sn), or an alloy of, for example, Sn—Ag alloy containing one or more of these metal materials. Material. For example, the second plating layer is made of a metal material of tin (Sn) or an alloy material containing tin (Sn) as a main component, and has a thickness of, for example, 1 (μm) to 2 (μm).

  Further, the pair of external terminals 7A (the first external terminal 7a and the second external terminal 7b) may have a shape as shown in FIG. Specifically, in the first external terminal 7a, the size of the formation region of the first connection portion 7a21 is larger than that of the first connection portion 7a2, and the second external terminal 7b is The size of the region where the second connection portion 7b21 is formed is larger than that of the second connection portion 7b2. As described above, the first connection portion 7a2 (first connection portion 7a21) and the second connection portion 7b2 (second connection portion 7b21) have the size of the formation region between the substrate electrode 9a and the substrate electrode 9b. It can be set as appropriate according to the bonding strength.

  The first connection portion 7a2 (first connection portion 7a21) also when the length of the multilayer body 1 of the first external electrode 3a and the second external electrode 3b along the longitudinal direction (X direction) is small. ) And the second connection portion 7 b 2 (second connection portion 7 b 21), the size of the formation region can be appropriately set according to the bonding strength between the pair of external electrodes 3 and the pair of external terminals 7.

  The first external terminal 7a and the second external terminal 7b have a thickness of, for example, 0.1 (mm) to 0.15 (mm), and are suitable for the size or use of the multilayer capacitor body 10. Accordingly, the thickness may be set appropriately so as to obtain an effect of suppressing vibration noise.

  For example, the first external terminal 7a and the second external terminal 7b are less rigid when the thickness is less than 0.1 (mm), and thus absorb vibration due to distortion generated in the multilayer capacitor body 10. Although it becomes easy, when mounted on the substrate 9, the mounting stability is deteriorated. The first external terminal 7a and the second external terminal 7b are not joined to the first external electrode 3a and the second external terminal 3b, that is, the first main body portion 7a1 and the second main body. The part 7b2 absorbs vibration due to distortion.

  On the other hand, the first external terminal 7a and the second external terminal 7b increase in rigidity when the thickness is greater than 0.15 (mm), and thus absorb vibration due to distortion generated in the multilayer capacitor body 10. It becomes difficult to do. As described above, in the multilayer capacitor 10A, the thicknesses of the first external terminal 7a and the second external terminal 7b are set in consideration of the vibration noise suppression effect and the mounting stability.

  The lengths of the first external terminal 7a and the second external terminal 7b may be set as appropriate so that the effect of suppressing vibration noise can be obtained according to the size or use of the multilayer capacitor body 10. For example, the first external terminal 7a and the second external terminal 7b are generated in the multilayer capacitor body 10 because the rigidity decreases as the length of the first body portion 7a1 and the second body portion 7b2 increases. It becomes easy to absorb the vibration due to the strain.

  On the other hand, the first external terminal 4a and the second external terminal 4b have increased rigidity when the lengths of the first main body portion 7a2 and the second main body portion 7b2 are shortened. It becomes difficult to absorb the vibration caused by the generated distortion. As described above, in the multilayer capacitor 10A, the lengths of the first main body portion 7a2 and the second main body portion 7b2 are set in consideration of the vibration noise suppressing effect and the mounting stability. The size of the multilayer capacitor 10A is such that the first body portion 7a2 and the second body portion 7b2 are long enough to be positioned on the inner side of the multilayer capacitor body 10 when viewed from above (plan view). From this point, it is preferable.

  Further, as shown in FIG. 8A, in the multilayer capacitor 10A, the first main body portion 7a1 (second main body portion 7b1) is outside the first connection portion 7a2 (second connection portion 7b2). May have a through hole 8 penetrating the upper and lower main surfaces. In the multilayer capacitor 10AA, as shown in FIG. 8B, the first main body portion 7a1 (second main body portion 7b1) is outside the first connection portion 7a2 (second connection portion 7b2). May have a through hole 8 penetrating the upper and lower main surfaces. As described above, the first external terminal 7a and the second external terminal 7b are reduced in rigidity by providing through holes in the first main body portion 7a1 and the second main body portion 7b1. It becomes easier to absorb the vibration caused by the distortion generated in 10. The through-hole 8 can be appropriately provided according to the size of the first external terminal 7a and the second external terminal 7b.

  Here, the mounting structure of the multilayer capacitor 10A according to the present embodiment will be described below.

6A shows a state in which the multilayer capacitor 10A is mounted on the substrate 9, and FIG. 6B shows a state in which the multilayer capacitor 10A is mounted on the substrate 9, and FIG. It is sectional drawing cut | disconnected by the DD line | wire. FIG. 7A shows a state in which the multilayer capacitor 10 </ b> A is mounted on the substrate 9, and schematically shows a part of the multilayer capacitor body 10 cut out. FIG. 7B shows a state in which the multilayer capacitor 10AA shown in FIG. 5 is mounted on the substrate 9, and schematically shows a part of the multilayer capacitor main body 10 cut out. The multilayer capacitor 10A will be described below.

  The multilayer capacitor 10 </ b> A is mounted on a circuit board (hereinafter referred to as a board 9) via the solder 11, for example. The substrate 9 is used for, for example, a notebook personal computer, a smartphone, a mobile phone, or the like. For example, an electric circuit to which the multilayer capacitor 10A is electrically connected is formed on the surface. In the substrate 9, the insulating layer on the surface is omitted.

  Further, as shown in FIG. 6, for example, the substrate 9 is provided with a substrate electrode 9a and a substrate electrode 9b on the surface on which the multilayer capacitor 10A is mounted, and wiring (not shown) extends from the substrate electrode 9a. In addition, wiring (not shown) extends from the substrate electrode 9b.

  In the multilayer capacitor 10A, the first external terminal 7a and the substrate electrode 9a are solder-bonded via, for example, solder 11, and the second external terminal 7b and substrate electrode 9b are connected to, for example, the solder 11. Soldered through. The multilayer capacitor 10 </ b> A is disposed such that the lower surface 4 b faces the mounting surface of the substrate 9. Solder joining is performed by, for example, solder printed on the substrate electrode 9a and the substrate electrode 9b.

  As shown in FIG. 6, the first external terminal 7a and the substrate electrode 9a are joined via the solder 11 disposed in the space 7a3 below the first connecting portion 7a2, and the second external terminal The terminal 7b and the substrate electrode 9b are joined via the solder 11 arranged in the space 7b3 below the second connection portion 7b2. The pair of external terminals 7, the substrate electrode 9a, and the substrate electrode 9b are joined via the solder 11 provided in the space portion 7a3 and the space portion 7b3, and are connected to the first side portion 3a1 and the second side portion 3b1. The solder fillet is hardly formed, and the vibration of the multilayer capacitor body 10 is hardly transmitted through the solder fillet. In addition, the solder 11 is provided in the space portion 7a3 (space portion 7b4), and the pair of external terminals 7, the substrate electrode 9a, and the substrate electrode 9b are joined, so that the multilayer capacitor 10A on the substrate 9 is formed. The mounting area can be reduced.

  The solder material to be used is not particularly limited as long as it has good wettability with the pair of external terminals 7. As the solder material, for example, Sn-Ag-Cu-based or Sn-Sb-based solder can be used.

For example, in the multilayer capacitor, when the multilayer capacitor main body is composed mainly of barium titanate (BaTiO ₃ ), etc. as a dielectric layer, when an AC voltage is applied to the multilayer capacitor main body, Due to the electrostrictive effect, distortion occurs in the dielectric layer in accordance with the magnitude of the AC voltage. In the multilayer capacitor, the distortion causes vibration in the multilayer capacitor body itself, and the vibration propagates to the substrate and the substrate vibrates. When this vibration is in an audible frequency band, the vibration of the substrate appears as vibration sound.

  In such a multilayer capacitor, a pair of external electrodes is provided at the center of a pair of side surfaces of the multilayer body in order to improve the effect of suppressing vibration noise, but the pair of external electrodes is arranged in the longitudinal direction of the multilayer body. The length along the line becomes small, and the mounting stability tends to be lowered.

For example, when the length of the laminated body 1 of the first external electrode 3a and the second external electrode 3b along the longitudinal direction is small, the laminated type is used by the surface tension of the molten solder at the time of reflow for solder joining. The capacitor floats up, and one end of both ends in the longitudinal direction of the multilayer body 1 is inclined toward the substrate 9, and the pair of external electrodes 3 and the substrate electrode 9 a may be solder-bonded in a state where the end is in contact with the substrate. There is. As described above, when the multilayer capacitor and the substrate 9 are soldered and brought into contact with each other, the vibration of the multilayer capacitor is directly transmitted to the substrate 9 and the noise suppressing effect is likely to be lowered.

  However, in the multilayer capacitor 10, the first external electrode 3a is joined at the first connection portion 7a2 of the first external terminal 7a, and the second external electrode 3b is the second connection of the second external terminal 7b. The joint portion is connected by the portion 7b2, and the reflow for joining the first connecting portion 7a2 and the substrate electrode 9a and joining the second connecting portion 7b2 and the substrate electrode 9b is performed by the surface tension of the molten solder. However, the first body portion 7a1 is disposed away from the lower surface 4b so as to face the lower surface 4b in the longitudinal direction of the multilayer capacitor body 10, and the second body portion 7b1 is disposed in the multilayer capacitor body. 10 is disposed away from the lower surface 4b so as to be opposed to the lower surface 4b in the longitudinal direction, so that one end of both ends in the longitudinal direction of the multilayer capacitor body 10 is in contact with the substrate and a pair of external ends 7 and the substrate electrode 9a and the substrate electrode 9b is hardly soldered. That is, in the multilayer capacitor 10A, the end portion in the longitudinal direction is difficult to contact the substrate, and the vibration of the multilayer capacitor body 10 is not easily transmitted directly to the substrate 9.

  Further, in the multilayer capacitor 10A, the first main body portion 7a1 and the second main body portion 7b2 are arranged apart from the lower surface 4b, so that the vibration of the multilayer capacitor main body 10 is affected by the first main body portion 7a1 and the second main body portion 7b2. Difficult to be transmitted to the main body 7b2.

  Here, an example of a manufacturing method of the multilayer capacitor body 10A shown in FIG. 1 will be described below.

  First, a method for manufacturing the multilayer capacitor body 10 will be described below.

  A plurality of first and second ceramic green sheets are prepared. The first ceramic green sheet is to form the first internal electrode layer 2a, and the second ceramic green sheet is to form the second internal electrode layer 2b.

  In order to form the first internal electrode layer 2a, the conductive paste layer of the first internal electrode layer 2a is formed on the plurality of first ceramic green sheets using the conductive paste for the first internal electrode layer 2a. It is formed. In the first ceramic green sheet, a plurality of first internal electrode layers 2 a are formed in one ceramic green sheet in order to obtain a large number of multilayer capacitor bodies 10.

  Further, in order to form the second internal electrode layer 2b, the conductive paste layer for the second internal electrode layer 2b is replaced with the conductive paste for the second internal electrode layer 2b on the plurality of second ceramic green sheets. Formed using. In the second ceramic green sheet, a plurality of second internal electrode layers 2b are formed in one ceramic green sheet in order to obtain a large number of multilayer capacitor bodies 10.

  The conductive paste layers of the first internal electrode layer 2a and the second internal electrode layer 2b described above are printed on each ceramic green sheet in a predetermined pattern using, for example, a screen printing method. Formed.

  The first and second ceramic green sheets are the dielectric layer 1a, the conductive paste layer of the first internal electrode 2a is the first internal electrode 2a, and the conductive paste layer of the second internal electrode layer 2b is the first 2 internal electrode layers 2b.

As a material of the ceramic green sheet used as the dielectric layer 1a, for example, a dielectric ceramic such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ or CaZrO ₃ is mainly used. For example, a Mn compound, Fe compound, Cr compound, Co compound, or Ni compound may be added as a subcomponent.

  The first and second ceramic green sheets are prepared by adding a suitable organic solvent to the dielectric ceramic raw material powder and the organic binder, and mixing them to produce a slurry ceramic slurry. Obtained by molding.

  The conductive paste for the first internal electrode layer 2a and the conductive paste for the second internal electrode layer 2b are additives (dielectric materials) added to the above-mentioned powder of the conductive material (metal material) of the internal electrode layer 2. It is prepared by adding a binder, a solvent, a dispersant and the like and kneading. The conductive material of each internal electrode layer includes, for example, a metal material such as nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), or gold (Au), or one or more of these metal materials. For example, alloy materials, such as an Ag-Pd alloy, are mentioned. The first internal electrode layer 2a and the second internal electrode layer 2b are preferably formed of the same metal material or alloy material.

  First ceramic green sheets and second ceramic green sheets are alternately laminated. And the ceramic green sheet which does not form the internal electrode layer 2 is each laminated | stacked on the outermost layer of a Z direction, and it is set as a laminated body.

  The laminated body composed of the plurality of first and second ceramic green sheets thus laminated becomes a large-sized raw laminated body including a large number of raw laminated bodies 1 by pressing and integrating them. By cutting this large green laminate, the green laminate 1 to be the laminate 1 of the multilayer capacitor body 10 shown in FIG. 1 can be obtained. The large green laminate can be cut using, for example, a dicing blade.

  And the laminated body 1 can be obtained by baking the raw laminated body 1 at 800 (degreeC) -1300 (degreeC), for example. By this step, the plurality of first and second ceramic green sheets become the dielectric layer 1a, the conductor paste layer of the first internal electrode layer 2a becomes the first internal electrode layer 2a, and the second internal electrode layer 2b. The conductive paste layer becomes the second internal electrode layer 2b. Further, the laminated body 1 is rounded at the corners or sides using a polishing means such as barrel polishing. The laminated body 1 becomes a thing by which a corner | angular part or a side part is hard to be missing by rounding a corner | angular part or a side part.

  Here, an example of a method for forming the pair of external electrodes 3 (the first external electrode 3a and the second external electrode 3b) will be described below.

  The pair of base electrodes 5 are each provided with a conductive paste to be the base electrode 5 on the first side surface 4e (second side surface 4f), the upper surface 4a, and the lower surface 4b by using a roller transfer method.

  The conductive paste to be the base electrode 5 is transferred to the first side surface 4e and the second side surface 4f of the multilayer body 1. Thus, the conductive paste 17 to be the base electrode 5 is provided on the first side surface 4e (second side surface 4f), and the conductive paste 17 to be the base electrode 5 extends to the upper surface 4a and the lower surface 4b. Provided. Note that the shape of the transferred base electrode 5 is reflected in the upper surface extension portion 3a2 (upper surface extension portion 3b2) and the lower surface extension portion 3b2 (lower surface extension portion 3b3) of the pair of external electrodes 3. .

After the transferred conductive paste is sintered to form the base electrode 5, a plating layer 6 is provided so as to cover the surface of the base electrode 5 to form a pair of external electrodes 3. The conductive paste for the base electrode 5 is produced by adding a binder, a solvent, a dispersant, and the like to the metal material powder constituting the base electrode 5 described above and kneading. The conductive material of the base electrode is, for example, a metal material such as nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), or gold (Au), or
For example, an alloy material such as an Ag—Pd alloy including one or more of these metal materials.

  The plating layer 6 is formed on the surface of the base electrode 5 so as to cover the base electrode 5. The plating layer 6 is formed on the surface of the base electrode 5 using, for example, an electrolytic plating method. The plating layer 6 is, for example, a nickel (Ni) plating layer, a copper (Cu) plating layer, a gold (Au) plating layer, a tin (Sn) plating layer, or the like. Although the plating layer 6 may be formed from a single plating layer, the multilayer capacitor main body 10 includes the first plating layer 6a and the second plating layer 6b. The body is formed on the surface. For example, in the multilayer capacitor body 10, the first plating layer 6 a is made of a nickel (Ni) plating layer, the second plating layer 6 a is made of a tin (Sn) plating layer, and the second plating layer 6 b has tin ( The Sn) plating layer is formed so as to cover the nickel (Ni) plating layer of the first plating layer 6a.

  Next, an example of a method for manufacturing the multilayer capacitor 10A will be described below with reference to FIG.

  First, an example of a manufacturing method of the pair of external terminals 7 (first external terminal 7a and second external terminal 7b) will be described. One strip-shaped metal plate is prepared. The strip-shaped metal plate has, for example, a thickness of 0.1 (mm) to 0.15 (mm), a length of 100 (mm) to 250 (mm), and is made of, for example, a stainless alloy.

  For example, as shown in FIG. 9A, the first external terminal 7aa that becomes the first external terminal 7a and the second external terminal 7bb that becomes the second external terminal 7b face each other. The metal plate is punched using, for example, a press punching method in accordance with the pattern shapes of the first external terminal 7aa and the second external terminal 7bb. In addition, the first connection portion 7a2 and the second connection portion 7b2 are deep-drawn with respect to the regions to be the first connection portion 7a2 and the second connection portion 7b2, for example, by pressing, so that the first connection portion 7a2 and the second connection portion 7b2 are formed. The first connecting portion 7a2 and the second connecting portion 7b2 are formed by projecting.

  In this way, as shown in FIG. 9A, a plurality of external terminal pairs 12a each including the first external terminal 7aa and the second external terminal 7bb are provided on the band-shaped metal plate. In the following description, a lead frame 12 having a plurality of external terminal bodies 12a formed on a strip-shaped metal plate is used. As described above, the plurality of multilayer capacitors 10 </ b> A can be efficiently manufactured by using the lead frame 12.

  In the lead frame 12, for example, a plating layer is formed by plating the plurality of external terminal pairs 12a. In the lead frame 12, the plating process is performed on the non-formed region of the plating layer by masking. The external terminal pair 12a (the first external terminal 7aa and the second external terminal 7bb) includes a region including the first connection portion 7a2 of the first external terminal 7aa and a second of the second external terminal 7bb. A plating layer is formed in the region including the connection portion 7b2 by using, for example, an electrolytic plating method. The masking can be performed using, for example, a low hardness rubber sheet or the like.

  In the above description, the lead frame 12 is plated after the punching process. However, the lead frame 12 may be punched after the plating process, and the shape of the pair of external terminals 7 may be changed. Considering the processing order, the processing order is set appropriately.

  Next, as shown in FIG. 9B, the multilayer capacitor body 10 is mounted on the first external terminal 4aa and the second external terminal 4bb using, for example, an automatic mounting machine equipped with a suction nozzle. .

  Then, after mounting the multilayer capacitor body 10, as shown in FIG. 9C, the first connection portion 7 b 2 and the second connection portion 7 b 2 are subjected to, for example, laser spot welding. The external terminal 7aa and the first external electrode 3a are melt-bonded, and the second external terminal 7bb and the second external electrode 3b are melt-bonded. Thus, by using melt bonding for bonding the pair of external electrodes 3 and the pair of external terminals 7, the bonding process is greatly simplified, and the process is excellent in mass productivity.

  Further, since the pair of external electrodes 3 and the pair of external terminals 7 are melt-bonded, solder bonding is unnecessary, and the multilayer capacitor 10A is soldered when the multilayer capacitor 10A is mounted on the substrate 9 via solder. Since it becomes difficult to be affected by the attachment temperature, deterioration of reliability is suppressed.

  In addition, in the multilayer capacitor, for example, when the peripheral portions of the first connection portion 7b2 and the second connection portion 7b2 and the pair of external electrodes 3 are joined via solder, the solder easily flows downward. Therefore, the bondability tends to be lowered. On the other hand, the multilayer capacitor 10A has a pair of external electrodes by using fusion bonding to the first connection portion 7a2 and the first external electrode 3a and the second connection portion 7b2 and the second external electrode 3b. 3 and the pair of external terminals 7 can be enhanced.

  The fusion bonding is spot welding such as arc spot welding or laser spot welding. In laser spot welding, for example, an energy beam such as a YAG laser is spot-irradiated to the first connection portion 7a2 and the second connection portion 7b2, and the first connection portion 7b2 and the first external electrode 3a are irradiated. And the first connection portion 7b2 and the first external electrode 3b are melt-bonded. By irradiating the first connecting portion 7a2 and the second connecting portion 7b2 with an energy beam in a spot manner, the first connecting portion 7a2 and the second connecting portion 7b2 are locally heated, for example, When the melting temperature of the stainless alloy of the pair of external terminals 7 reaches 1400 (° C.) to 1450 (° C.), the first connection portion 7a2 and the second connection portion 7b23 are melted to melt with the pair of external electrodes 3. Will be joined.

  Further, in the multilayer capacitor 10A, when a nickel (Ni) plating layer using an electrolytic plating method is used as the plating layer 6 of the pair of external electrodes 3 and a stainless alloy is used for the pair of external terminals 7, nickel (Ni ) The melting temperatures of the plating layer and the stainless alloy are similar, and the bondability between the pair of external terminals 7 and the pair of external electrodes 3 can be improved. As described above, the multilayer capacitor 10A has a melting temperature with respect to the plating layer 6 and the pair of external terminals 7 of the pair of external electrodes 3 in the fusion bonding of the pair of external electrodes 3 and the pair of external terminals 7. It is more preferable to use a similar material because the joining region of the melting part 7a4 and the melting part 7b4 can be easily controlled.

  In this way, the multilayer capacitor body 10 has the first external terminal 4aa attached to the first external electrode 3a and the second external terminal 4bb as the second external electrode by using fusion bonding. It will be attached to 3b.

  Next, as shown in FIG. 9C, the lead frame 12 sets the first cutting line S1 and the second cutting line S2 to the first cutting line S1 and the second cutting line S2. On the other hand, a cutting process is performed. For example, in the lead frame 12, the external terminal pair 12a on which the multilayer capacitor main body 10 is mounted is cut using a cutting die. As a result, a plurality of multilayer capacitors 10A are obtained from the lead frame 12 as shown in FIG. The first cutting line S1 and the second cutting line S2 are indicated by dotted lines in FIG. 9C.

As described above, by using the lead frame 12, the multilayer capacitor 10A shown in FIG. 1 can be efficiently manufactured. In the multilayer capacitor 10A, the pair of external terminals 7 are joined to the pair of external electrodes 3 using fusion bonding, and the pair of external terminals is heated by soldering the multilayer capacitor 10A onto the substrate 9. 7 can be prevented from detaching.

  The present invention is not limited to the multilayer capacitor 10A of the above-described embodiment, and various changes and improvements can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Laminated body 1a Dielectric layer 2 Internal electrode layer 2a 1st internal electrode layer 2b 2nd internal electrode layer 3 External electrode 3a 1st external electrode 3b 2nd external electrode 4a Upper surface 4b Lower surface 4c 1st end surface 4d Second end face 4e First side face 4f Second side face 5 Underlying electrode 6 Plating layer 6a First plating layer 6b Second plating layer 7, 7A External terminal 7a First external terminal 7a1 First main body 7a2 First connection portion 7a3 Space portion 7a4 Melting portion 7b Second external terminal 7b1 First body portion 7b2 First connection portion 7b3 Space portion 7b4 Melting portion 8 Through hole 9 Substrate 9a, 9b Substrate electrode 10 Multilayer capacitor body 10A, 10AA Multilayer capacitor 11 Solder 12 Lead frame 12a External terminal pair S1, S2 Cutting line

Claims (4)

Dielectric layers and internal electrode layers are alternately stacked, and are positioned in the stacking direction of the dielectric layers and the internal electrode layers. A rectangular parallelepiped laminate having a first side surface and a second side surface adjacent to the side, and a first end surface and a second end surface adjacent to the short side of the upper surface and the lower surface, and
A multilayer capacitor body having a first external electrode and a second external electrode provided on the pair of side surfaces and electrically connected to the different internal electrode layers;
A multilayer capacitor comprising a first external terminal and a second external terminal joined to the first external electrode and the second external electrode,
The first external electrode and the second external electrode include a side surface portion provided on the side surface so as to include a central portion of the side surface, an upper surface extending portion extending from the side surface portion to the upper surface, and the side surface portion. Each having a lower surface extending portion extending from the lower surface to the lower surface,
The first external terminal includes a first body portion of a plate-like body disposed away from the lower surface so as to face the lower surface in the longitudinal direction of the multilayer capacitor body, and a longitudinal direction of the first body portion. Provided on the side portion on the first side surface side of the central portion in the direction and extending from the side portion toward the first side surface side so as to overlap the lower surface extending portion of the first external electrode. A first connection portion joined to the lower surface extension portion of the first external electrode,
The second external terminal includes a second body portion of a plate-like body disposed away from the lower surface so as to face the lower surface in the longitudinal direction of the multilayer capacitor body, and a longitudinal direction of the second body portion. Provided in the side portion on the second side surface side of the central portion in the direction and extending from the side portion toward the first side surface side so as to overlap the lower surface extending portion of the second external electrode. A second connecting portion joined to the lower surface extending portion of the second external electrode,
The first connection portion protrudes downwardly toward the lower surface extension portion side of the first external electrode so that the upper portion is higher than the main surface on the lower surface side of the first main body portion. A space is formed, and the second connecting portion has an upper portion higher than the main surface on the lower surface side of the second main body portion toward the lower surface extending portion side of the second external electrode. And a space is formed below the multilayer capacitor.   The first main body has a through-hole penetrating the upper and lower main surfaces in a region located outside the first connecting portion, and the second main body has the second connection 2. The multilayer capacitor according to claim 1, further comprising a through-hole penetrating the upper and lower main surfaces in a region located outside the portion.   The first connection portion is melt bonded to the lower surface extension portion of the first external electrode, and the second connection portion is melt bonded to the lower surface extension portion of the second external electrode. The multilayer capacitor according to claim 1, wherein the multilayer capacitor is provided. 4. The multilayer capacitor according to claim 1 and a substrate provided with a substrate electrode on which the multilayer capacitor is mounted are disposed so that the lower surface and the mounting surface of the substrate face each other. In addition, the first connecting portion and the substrate electrode are joined via solder provided in the space portion, and the second connecting portion and the substrate electrode are connected via solder provided in the space portion. Mounting structure characterized by being bonded together.

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