JP6520604B2 - Laminated coil parts - Google Patents

Description

  The present invention relates to a laminated coil component.

  As described in Patent Document 1, an entire body including a magnetic material, a coil including a plurality of internal conductors disposed apart from each other in a first direction in the body, and a coil DESCRIPTION OF RELATED ART The laminated coil component provided with the stress relaxation part currently formed so that it may surround is known.

  In the laminated coil component described in Patent Document 1, a stress relaxation portion is formed so as to surround the entire coil. In this case, since the stress relieving portion is made of powder, there is a problem that the strength of the element decreases. Therefore, there is also known a laminated coil component in which a stress relaxation portion is formed so as to surround each of the inner conductors constituting the coil instead of the entire coil, as in the laminated coil component described in Patent Document 2.

JP, 2006-253322, A Japanese Patent Application Laid-Open No. 6-96953

  In the laminated coil component described in Patent Document 2, the element body has an element region located between the adjacent internal conductors in the first direction. The thickness in the first direction of the element region (hereinafter, also simply referred to as “the thickness of the element region”) is narrower than the distance between the adjacent internal conductors in the first direction. Therefore, when the stress relaxation portion becomes thick, it becomes difficult to secure the thickness of the element region. In this case, for example, if it is attempted to secure the thickness of the element region by reducing the cross-sectional area of each internal conductor without changing the magnetic path length, there is a problem that the DC resistance of each internal conductor becomes large. . In addition, if it is attempted to secure the thickness of the element region by increasing the magnetic path length without changing the cross sectional area of each internal conductor, the whole element becomes thick and the laminated coil component can not be miniaturized. There is.

  If the thickness of the element region can not be sufficiently secured, a crack may occur between the adjacent internal conductors in the first direction, which may result in an interlayer short circuit between the internal conductors. Therefore, a laminated coil component capable of alleviating the internal stress of the element body while securing a sufficient thickness of the element region is required.

  Then, an object of this invention is to provide the laminated coil components which can relieve | moderate the internal stress of an element body, fully ensuring the thickness of an element body area | region.

  A laminated coil component according to the present invention comprises an element body including a magnetic material, and a coil including a plurality of internal conductors spaced apart from each other in a first direction in the element body and electrically connected to each other. And a plurality of stress relaxation spaces in contact with the surface of each inner conductor and in which powder is present, wherein the element is located between adjacent inner conductors in the first direction. Each stress relaxation space has a first interface with each inner conductor and a second interface with the element area; and the first interface and the second interface are It faces in one direction, and the distance from the first boundary surface to the second boundary surface is smaller than the thickness in the first direction of the element region.

  In the laminated coil component according to the present invention, each stress relieving space where powder exists is in contact with the surface of each internal conductor, and therefore, the adjacent internal conductors in the first direction and the element positioned therebetween Each stress relaxation space intervenes between the region. Thereby, it is possible to relieve the internal stress generated in the element body due to the difference in the thermal contraction rate between each internal conductor and the element body. The distance from the first boundary surface to the second boundary surface of the stress relaxation space is a thickness in the first direction of the stress relaxation space (hereinafter, also simply referred to as “a thickness of stress relaxation”). The thickness of this stress relaxation is smaller than the thickness in the first direction of the element region located between the respective internal conductors adjacent in the first direction (hereinafter, also simply referred to as the “thickness of the element region”) . That is, the thickness of the element region is at least larger than the thickness of the stress relaxation space. Therefore, even in the case where the stress relaxation space is interposed between each inner conductor adjacent in the first direction and the element region located therebetween, compared with the stress relaxation space which is interposed, A sufficient thickness of the element region can be secured. As mentioned above, the internal stress of an element body can be relieved, securing the thickness of an element body field enough.

  In the laminated coil component according to the present invention, each internal conductor has a first surface facing one side in the first direction and a second surface facing the other side in the first direction, and each stress The surface with which the relaxation space is in contact may be the first surface. In this case, each stress relaxation space is in contact with the first surface of the first surface and the second surface of each inner conductor. That is, each stress relaxation space is formed on the first surface of each inner conductor. Therefore, each stress relaxation space can be formed more easily than when each stress relaxation space is formed on both the first surface and the second surface, and the thickness of the element region can be easily secured. .

  In the laminated coil component according to the present invention, the first surface may be planar. In this case, each stress relaxation space is in contact with the planar first surface. That is, since the first surface on which each stress relaxation space is formed is flat, each stress relaxation space can be easily formed.

  In the laminated coil component according to the present invention, the first surface includes a first surface portion extending in a direction orthogonal to the first direction, and a second surface inclined with respect to the first direction and the first surface portion. The stress relaxation space may be in contact with the first surface portion and the second surface portion. In this case, even if the first surface of each internal conductor has the first surface portion and the second surface portion, each stress relaxation space is in contact with the first surface portion and the second surface portion. As a result, the internal stress of the element can be reliably relieved.

  In the laminated coil component according to the present invention, the average particle diameter of the powder may be 0.1 μm or less. In this case, since the powder has good flowability, the powder can flexibly follow the behavior according to the difference in thermal contraction rate between the body and the internal conductor, and the internal stress of the body can be more reliably relaxed. can do.

In the laminated coil component according to the present invention, the powder material may be ZrO ₂ . In this case, ZrO ₂ is preferable because it hardly affects the magnetic material contained in the element, for example, the ferrite material. Furthermore, since the melting point of ZrO ₂ is considerably higher than the sintering temperature of the magnetic material contained in the element, for example, the ferrite material, it can surely exist as a powder.

  In the laminated coil component according to the present invention, each internal conductor may contain a metal oxide. In this case, since the contraction rate at the time of firing of the conductive paste constituting each internal conductor can be reduced, the cross-sectional area of each internal conductor can be increased. And also when the cross-sectional area of each internal conductor is enlarged in this way, the internal stress of the element can be relaxed by the stress relaxation space.

  According to the present invention, there is provided a laminated coil component capable of alleviating the internal stress of the element body while sufficiently securing the thickness of the element region.

FIG. 1 is a perspective view showing a laminated coil component according to a first embodiment of the present invention. It is a disassembled perspective view of the laminated coil components shown in FIG. It is a top view which shows each coil conductor. It is a top view which shows each coil conductor. It is a top view which shows each coil conductor. FIG. 6 is a cross-sectional view of the element along the line VI-VI in FIG. 1; It is a figure which expands and shows a part of FIG. It is an exploded perspective view of a lamination coil part concerning a 2nd embodiment. It is a top view which shows each lead-out conductor. It is sectional drawing of the laminated coil components which concern on 2nd Embodiment. It is an exploded perspective view of a lamination coil part concerning a 3rd embodiment. It is a top view which shows each coil conductor. It is a top view which shows each coil conductor. It is a top view which shows each coil conductor. It is sectional drawing of the laminated coil components which concern on 3rd Embodiment. It is a figure which expands and shows a part of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same elements or elements having the same function will be denoted by the same reference symbols, without redundant description.

First Embodiment
A laminated coil component according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG. 1 is a perspective view showing a laminated coil component according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the laminated coil component shown in FIG. 3 to 5 are plan views showing each coil conductor. 6 is a cross-sectional view of the element along the line VI-VI in FIG. FIG. 7 is an enlarged view of a part of FIG. In the exploded perspective view of FIG. 2, the illustration of the plurality of magnetic layers forming the element body and the external electrodes disposed at both ends of the element body is omitted. Further, in the cross-sectional view of FIG. 6, the illustration of the external electrodes disposed at both ends of the element body is omitted.

  As shown in FIG. 1, the laminated coil component 1 includes an element body 2 and a pair of external electrodes 4 and 5 disposed at both ends of the element body 2.

  The element body 2 has a rectangular parallelepiped shape. The element body 2 has, as its outer surface, four side surfaces 2c, 2d, which extend in the opposing direction of the pair of end surfaces 2a, 2b so as to connect the pair of end surfaces 2a, 2b facing each other 2e and 2f. The side surface 2 d is defined as, for example, a surface facing the other electronic device when the laminated coil component 1 is mounted on another electronic device (for example, a circuit board or an electronic component) which is not illustrated.

  The opposing direction of the end faces 2a and 2b, the opposing direction of the side faces 2c and 2d, and the opposing direction of the side faces 2e and 2f are substantially orthogonal to each other. Note that the rectangular parallelepiped shape includes the shape of a rectangular parallelepiped in which the corner portion and the ridge portion are chamfered, and the shape of a rectangular parallelepiped in which the corner portion and the ridge portion are rounded.

  The element body 2 is configured by laminating a plurality of magnetic layers 11 (see FIGS. 3 to 6). The magnetic layers 11 are stacked in the opposing direction of the side surfaces 2 c and 2 d of the element body 2. That is, the stacking direction of the magnetic layers 11 coincides with the facing direction of the side surfaces 2 c and 2 d of the element body 2. Hereinafter, the opposing direction of the side surfaces 2c and 2d is also referred to as a “stacking direction”. Each magnetic layer 11 has a substantially rectangular shape. In the present embodiment, the side surface 2 d side of the element body 2 will be described as one side in the stacking direction, and the side surface 2 e side of the element body 2 will be described as the other side in the stacking direction.

  Each magnetic layer 11 is made of, for example, a sintered body of a ceramic green sheet containing a magnetic material (Ni-Cu-Zn ferrite material, Ni-Cu-Zn-Mg ferrite material, Ni-Cu ferrite material, etc.) Configured In the actual element body 2, each magnetic layer 11 is integrated to such an extent that the boundary between the layers can not be visually recognized (see FIG. 6). The magnetic material of the ceramic green sheet constituting each magnetic layer 11 may contain an Fe alloy or the like.

  The external electrode 4 is disposed on the end face 2 a of the element body 2, and the external electrode 5 is disposed on the end face 2 b of the element body 2. That is, the external electrodes 4 and 5 are spaced apart from each other in the opposing direction of the pair of end surfaces 2a and 2b. Each of the external electrodes 4 and 5 has a substantially rectangular shape in a plan view, and its corner is rounded. Each of the outer electrodes 4 and 5 contains a conductive material (for example, Ag or Pd). Each of the external electrodes 4 and 5 is configured as a sintered body of a conductive paste containing a conductive metal powder (for example, an Ag powder or a Pd powder) and a glass frit. Each of the external electrodes 4 and 5 is electroplated to form a plating layer on its surface. For example, Ni, Sn or the like is used for electroplating.

  The external electrode 4 includes an electrode portion 4a located on the end surface 2a, an electrode portion 4b located on the side surface 2d, an electrode portion 4c located on the side surface 2c, an electrode portion 4d located on the side surface 2e, and a side surface And an electrode portion 4e located on 2f. The electrode portion 4a covers the entire surface of the end face 2a. The electrode portion 4 b covers a part of the side surface 2 d. The electrode portion 4c covers a part of the side surface 2c. The electrode portion 4d covers a part of the side surface 2e. The electrode portion 4e covers a part of the side surface 2f. The five electrode portions 4a, 4b, 4c, 4d and 4e are integrally formed.

  The external electrode 5 includes an electrode portion 5a located on the end surface 2b, an electrode portion 5b located on the side surface 2d, an electrode portion 5c located on the side surface 2c, an electrode portion 5d located on the side surface 2e, and a side surface And an electrode portion 5e located on 2f. The electrode portion 5a covers the entire surface of the end face 2b. The electrode portion 5b covers a part of the side surface 2d. The electrode portion 5c covers a part of the side surface 2c. The electrode portion 5d covers a part of the side surface 2e. The electrode portion 5e covers a part of the side surface 2f. The five electrode portions 5a, 5b, 5c, 5d, 5e are integrally formed.

  As shown in FIGS. 2 to 6, the laminated coil component 1 includes a plurality of coil conductors 21, 22 and 23 (a plurality of inner conductors), a plurality of lead conductors 24 and 25, and a plurality of stress relaxation spaces 31, 32 and 33 are provided in the element body 2. In addition, in FIG. 2, each stress relaxation space 31-33 is shown with the dashed-dotted line.

  The coil conductors 21 to 23 and the lead conductors 24 and 25 are spaced apart from each other in the stacking direction (first direction). The coil conductors 21 to 23 and the lead conductors 24 and 25 have substantially the same thickness in the stacking direction (see FIG. 6). The end portions of the coil conductors 21 to 23 are connected to each other by the through hole conductors 12 b and 12 c. Specifically, the end T1 of the coil conductor 21 and the end T2 of the coil conductor 22 are connected by the through hole conductor 12b. The end T3 of the coil conductor 22 and the end T4 of the coil conductor 23 are connected by the through hole conductor 12c. Thus, the coil 20 is comprised in the element | base_body 2 by each end part T1-T4 of each coil conductor 21-23 being connected via through-hole conductor 12b, 12c. That is, the laminated coil component 1 includes the coil 20 in the element body 2. The coil 20 includes a plurality of coil conductors 21 to 23 which are mutually separated in the stacking direction and electrically connected to each other. The coil 20 has an axial center along the stacking direction.

  The coil conductor 21 is disposed at a position closest to the side surface 2 c of the element body 2 in the stacking direction among the coil conductors 21 to 23. The end E1 of the coil conductor 21 constitutes one end E1 of the coil 20. The coil conductor 23 is disposed at a position closest to the side surface 2 d of the element body 2 in the stacking direction among the coil conductors 21 to 23. The end E2 of the coil conductor 23 constitutes the other end E2 of the coil 20. Each coil conductor 21 to 23 has a substantially trapezoidal cross section (see FIG. 6). The details of the cross-sectional shape of each of the coil conductors 21 to 23 will be described later with reference to FIG.

  The lead conductor 24 is disposed closer to the side surface 2 c of the element body 2 in the stacking direction than the coil conductor 21. The lead conductor 24 and the coil conductor 21 are adjacent in the stacking direction. The end T5 of the lead conductor 24 is connected to the end E1 of the coil conductor 21 by the through hole conductor 12a. That is, the lead conductor 24 and the end E1 of the coil 20 are connected by the through hole conductor 12a.

  The end 24 a of the lead conductor 24 is exposed to the end face 2 b of the element body 2 and is connected to the electrode portion 5 a of the external electrode 5 covering the end face 2 b. That is, the lead conductor 24 and the external electrode 5 are connected. Therefore, the end E1 of the coil 20 and the external electrode 5 are electrically connected via the lead conductor 24 and the through hole conductor 12a.

  The lead conductor 25 is disposed closer to the side surface 2 d of the element body 2 in the stacking direction than the coil conductor 23. The lead conductor 25 and the coil conductor 23 are adjacent in the stacking direction. The end T6 of the lead conductor 25 is connected to the end E2 of the coil conductor 23 by the through hole conductor 12d. That is, the lead conductor 25 and the end E2 of the coil 20 are connected by the through hole conductor 12d.

  The end 25a of the lead conductor 25 is exposed to the end face 2a of the element body 2 and is connected to the electrode portion 4a of the external electrode 4 covering the end face 2a. That is, the lead conductor 25 and the external electrode 4 are connected. Therefore, the end E2 of the coil 20 and the external electrode 4 are electrically connected via the lead conductor 25 and the through hole conductor 12d.

Each coil conductor 21-23, each lead conductor 24, 25 and each through-hole conductor 12a-12d contain a conductive material (for example, Ag or Pd etc.), for example. Each coil conductor 21-23, each lead conductor 24, 25 and each through-hole conductor 12a-12d are formed as a sintered body of a conductive paste containing conductive metal powder (for example, Ag powder or Pd powder etc.) Ru. For example, metal oxides (TiO ₂ , Al ₂ O ₃ , ZrO _{2, and the} like) may be contained in the coil conductors 21 to 23, the lead conductors 24 and 24, and the through hole conductors 12 a and 12 d, for example. In this case, the coil conductors 21 to 23, the lead conductors 24 and 24, and the through hole conductors 12a and 12d are formed as sintered bodies of the conductive paste containing the metal oxide. According to this case, the shrinkage factor at the time of firing of the conductive paste can be reduced.

Each stress relaxation space 31, 32, 33 is in contact with each coil conductor 21-23. The stress relaxation spaces 31 to 33 are spaces in which the powders 31c, 32c, and 33c exist, and are interposed between the element region in the element 2 and the coil conductors 21 to 23. , Relieve the internal stress generated in the element body 2. The material of each powder 31c, 32c, 33c is, for example, ZrO ₂ or the like. The melting point of ZrO ₂ is, for example, about 2700 ° C. or more, which is considerably higher than the firing temperature of the ferrite material. The average particle diameter of each powder 31c, 32c, 33c is, for example, 0.1 μm or less.

  The stress relaxation space 31 is located between the coil conductor 21 and the coil conductor 22 in the stacking direction. As shown in FIG. 3, the stress relaxation space 31 is formed on the surface 21 d (see FIG. 7) on the lower side (side 2 d side of the element body 2) of the coil conductor 21 in the stacking direction. The stress relaxation space 31 is along a portion other than the end T 1 of the coil conductor 21. That is, the stress relaxation space 31 does not cover the end T1 which is a connection portion of the coil conductor 21 with the through hole conductor 12b. The stress relaxation space 31 is formed so as not to protrude from the coil conductor 21 when viewed in the stacking direction.

  The stress relaxation space 32 is located between the coil conductor 22 and the coil conductor 23 in the stacking direction. As shown in FIG. 4, the stress relaxation space 32 is formed on the surface 22 d (see FIG. 7) on the lower side (side 2 d side of the element body 2) of the coil conductor 22 in the stacking direction. The stress relaxation space 32 is along a portion other than the end portion T3 of the coil conductor 22. That is, the stress relaxation space 32 does not cover the end portion T3 which is a connection portion of the coil conductor 22 with the through hole conductor 12c. The stress relaxation space 32 is formed so as not to protrude from the coil conductor 22 when viewed in the stacking direction.

  The stress relaxation space 33 is located between the coil conductor 23 and the lead conductor 25 in the stacking direction. As shown in FIG. 5, the stress relaxation space 33 is formed on the surface 23d (see FIG. 7) on the lower side (side 2d side of the element body 2) of the coil conductor 23 in the stacking direction. The stress relaxation space 33 is along a portion other than the end E2 of the coil conductor 23. That is, the stress relaxation space 33 is configured not to cover the end E2 which is a connection portion of the coil conductor 23 with the through hole conductor 12d. The stress relaxation space 33 is formed so as not to protrude from the coil conductor 23 when viewed in the stacking direction.

  As shown in FIG. 6, the element body 2 has element regions 11 a to 11 d between the coil conductors 21 to 23 and the lead conductors 24 and 25 adjacent to each other in the stacking direction. The element region 11 a is located between the coil conductor 21 and the coil conductor 22. The element region 11 a is sandwiched between the stress relaxation space 31 and the coil conductor 22. The element region 11 b is located between the coil conductor 22 and the coil conductor 23. The element region 11 b is sandwiched between the stress relaxation space 32 and the coil conductor 23. The element region 11 c is located between the coil conductor 23 and the lead conductor 25. The element region 11 c is sandwiched between the stress relaxation space 33 and the lead conductor 25. The element region 11 d is located between the coil conductor 21 and the lead conductor 24. The element region 11 d is sandwiched between the coil conductor 21 and the lead conductor 24.

  Next, with reference to FIG. 7, the cross-sectional configurations of the coil conductors 21 to 23 and the stress relaxation spaces 31 to 33 will be described in detail. FIG. 7 is an enlarged view of a region including a part (portion on the end face 2 a side of the element body 2) of each of the coil conductors 21 to 23 in the cross-sectional view of FIG. 6. In addition, since it is the same as that of FIG. 7, the area | region containing the part by the side of the end surface 2b of the element body 2 of each coil conductor 21-23 in sectional drawing of FIG.

  As shown in FIG. 7, the coil conductor 21 has a surface 21 d and a surface 21 e. The surface 21 d faces the side surface 2 d side of the element body 2, and the surface 21 e faces the side surface 2 c side of the element body 2. That is, in the present embodiment, the surface 21 d is a first surface facing one side in the stacking direction, and the surface 21 e is a second surface facing the other side in the stacking direction. The surface 21d is planar and substantially orthogonal to the stacking direction. The surface 21e has a flat portion 21a (first surface portion) and two inclined portions 21b and 21c (second surface portion).

  The flat portion 21a is flat and substantially parallel to the surface 21d. That is, the flat portion 21a extends in the direction orthogonal to the stacking direction. The flat portion 21a has an area smaller than that of the surface 21d. Each of the inclined portions 21b and 21c is inclined and inclined with respect to the stacking direction and the surface 21d. The inclined portion 21b and the inclined portion 21c are opposed to each other, and are formed to connect the surface 21d and the flat portion 21a, respectively. The inclined portion 21b is inclined from the end face 2a of the element body 2 to the end face 2b as it goes from the side 2d to the side 2c in the stacking direction. The inclined portion 21c is inclined from the end face 2b side of the element body 2 to the end face 2a side from the side face 2d side of the element body 2 to the side face 2c side in the stacking direction. That is, the inclined portion 21b and the inclined portion 21c are inclined so as to approach each other from the side 2d to the side 2c in the stacking direction.

  The coil conductor 22 has a surface 22d and a surface 22e. The surface 22 d faces the side surface 2 d side of the element body 2, and the surface 22 e faces the side surface 2 c side of the element body 2. That is, in the present embodiment, the surface 22 d is a first surface facing one side in the stacking direction, and the surface 22 e is a second surface facing the other side in the stacking direction. The surface 22d is planar and substantially orthogonal to the stacking direction. The surface 22e has a flat portion 22a (first surface portion) and two inclined portions 22b and 22c (second surface portion).

  The flat portion 22a is flat and substantially parallel to the surface 22d. That is, the flat portion 22a extends in the direction orthogonal to the stacking direction. The flat portion 22a has an area smaller than that of the surface 22d. Each of the inclined portions 22b and 22c is inclined and inclined with respect to the stacking direction and the surface 22d. The inclined portion 22b and the inclined portion 22c are opposed to each other, and are formed to connect the surface 22d and the flat portion 22a, respectively. The inclined portion 22b is inclined from the end face 2a side of the element body 2 to the end face 2b side from the side face 2d side of the element body 2 to the side face 2c side in the stacking direction. The inclined portion 22c is inclined from the end face 2b side of the element body 2 to the end face 2a side from the side face 2d side of the element body 2 to the side face 2c side in the stacking direction. That is, the inclined portions 22b and the inclined portions 22c are inclined so as to approach each other from the side 2d to the side 2c in the stacking direction.

  The coil conductor 23 has a surface 23 d and a surface 23 e. The surface 23 d faces the side surface 2 d side of the element body 2, and the surface 23 e faces the side surface 2 c side of the element body 2. That is, in the present embodiment, the surface 23 d is a first surface facing one side in the stacking direction, and the surface 23 e is a second surface facing the other side in the stacking direction. The surface 23d is planar and substantially orthogonal to the stacking direction. The surface 23e has a flat portion 23a (first surface portion) and two inclined portions 23b and 23c (second surface portion).

  The flat portion 23a is flat and substantially parallel to the surface 23d. That is, the flat portion 23a extends in the direction orthogonal to the stacking direction. The flat portion 23a has an area smaller than that of the surface 23d. Each of the inclined portions 23b and 23c is inclined and inclined with respect to the stacking direction and the surface 23d. The inclined portion 23 b and the inclined portion 23 c face each other, and are formed to connect the surface 23 d and the flat portion 23 a, respectively. The inclined portion 22b is inclined from the end face 2a side of the element body 2 to the end face 2b side from the side face 2d side of the element body 2 to the side face 2c side in the stacking direction. The inclined portion 22c is inclined from the end face 2b side of the element body 2 to the end face 2a side from the side face 2d side of the element body 2 to the side face 2c side in the stacking direction. That is, the inclined portion 23b and the inclined portion 23c are inclined so as to approach each other from the side 2d side to the side 2c in the stacking direction.

  The stress relaxation space 31 has a first interface 31a with the coil conductor 21 and a second interface 31b with the element region 11a. The first boundary surface 31 a is in contact with the surface 21 d of the coil conductor 21. The second boundary surface 31b is in contact with the element region 11a. The first boundary surface 31a and the second boundary surface 31b are opposed in the stacking direction.

  The stress relaxation space 32 has a first interface 32 a with the coil conductor 22 and a second interface 32 b with the element region 11 b. The first boundary surface 32 a is in contact with the surface 22 d of the coil conductor 22. The second boundary surface 31b is in contact with the element region 11b. The first boundary surface 32a and the second boundary surface 32b face each other in the stacking direction.

  The stress relaxation space 33 has a first interface 33a with the coil conductor 23 and a second interface 33b with the element region 11c. The first boundary surface 33 a is in contact with the surface 23 d of the coil conductor 23. The second boundary surface 32b is in contact with the element region 11c. The first boundary surface 33a and the second boundary surface 33b face each other in the stacking direction.

  The thickness (hereinafter, also simply referred to as "thickness La") of the stress relaxation spaces 31 to 33 in the stacking direction is between the first boundary surfaces 31a to 33a and the second boundary surfaces 31b to 33b facing each other. It is defined as a distance. In the present embodiment, the thickness La of the stress relaxation space 31 is a distance from the first boundary surface 31 a to the second boundary surface 31 b. The thickness La of the stress relaxation space 32 is a distance from the first boundary surface 32 a to the second boundary surface 32 b. The thickness La of the stress relaxation space 33 is a distance from the first boundary surface 33a to the second boundary surface 33b. The thicknesses La of the stress relaxation spaces 31 to 33 are all substantially equal.

  The thickness in the stacking direction of each element region 11a, 11b (hereinafter, also simply referred to as "thickness Lb") is defined as the shortest distance in the stacking direction of the element regions 11a, 11b. In the present embodiment, the thickness Lb of the element region 11a is the distance from the second boundary surface 31b to the flat portion 22a. The thickness Lb of the element region 11b is the distance from the second boundary surface 32b to the flat portion 23a. The thicknesses Lb of the element regions 11a and 11b are substantially equal to each other.

  The thickness La of each of the stress relaxation spaces 31 to 33 is smaller than the thickness Lb of each of the element regions 11a and 11b. That is, thickness Lb of element regions 11a and 11b is at least larger than thickness La of stress relaxation spaces 31-33. Accordingly, a sufficient thickness Lb of the element region 11 a can be secured between the coil conductors 21 and 22 compared to the stress relaxation space 31. A sufficient thickness Lb of the element region 11 b can be secured between the coil conductors 22 and 23 compared to the stress relaxation space 32. Specifically, the thickness La of each of the stress relaxation spaces 31 to 33 is, for example, about 1 to 2 μm. On the other hand, the thickness Lb of each element region 11a, 11b is, for example, about 3 to 30 μm. The difference between the thickness Lb of each of the element regions 11a and 11b and the thickness La of each of the stress relaxation spaces 31 to 33 is preferably, for example, 5 to 20 or more.

  The thickness of the element region 11c in the stacking direction is defined as the shortest distance in the stacking direction of the element region 11c, similarly to the thicknesses Lb of the element regions 11a and 11b, although not shown. The thickness of the element region 11c in the stacking direction is substantially the same as the thickness Lb of the element regions 11a and 11b. Hereinafter, the thickness of the element region 11c in the stacking direction is also simply referred to as "thickness Lb". The thickness La of the stress relaxation space 33 is smaller than the thickness Lb of the element region 11c. That is, the thickness Lb of the element region 11 c is at least larger than the thickness La of the stress relaxation space 33. Thus, a sufficient thickness Lb of the element region 11 c can be secured between the coil conductor 23 and the lead conductor 25 as compared to the stress relaxation space 33.

  Here, each of the stress relaxation spaces 31 to 33 may be entirely filled with the respective powders 31c to 33c, and a void or the like may be formed between the respective powders 31c to 33c. That is, each powder 31c to 33c may be densely present in each stress relaxation space 31 to 33 so as to be in contact with each coil conductor 21 to 23 and each element region 11a to 11c. There may be an air gap between the conductors 21 to 23 and at least one of the element regions 11a to 11c. The voids and the like are formed, for example, due to the disappearance of the organic solvent and the like contained in the material for forming the stress relaxation spaces 31 to 33 at the time of firing.

  Even when such a void is formed, the thickness La of each of the stress relaxation spaces 31 to 33 is, as described above, the first boundary surfaces 31a to 33a with the respective coil conductors 21 to 23, and It is defined as a distance between each of the second boundary surfaces 31b to 33b with the element regions 11a to 11c. That is, the thickness La of each of the stress relaxation spaces 31 to 33 is not only the thickness of the region where each powder 31 c to 33 c excluding the void exists but the thickness La of each stress relaxation space 31 to 33 including the void. It is prescribed.

  In the element body 2, for example, the difference in thermal contraction rate between the material for forming the element body 2 and the material for forming the coil conductors 21 to 23 and the lead conductors 24 and 25, etc. An air gap or the like may be formed between the element region and each of the coil conductors 21 to 23 and the lead conductors 24 and 25. That is, the element regions 11a to 11c may have gaps or the like not in contact with the coil conductors 21 to 23 and the lead conductors 24 and 25. Even when such a void is formed, the thickness Lb of the element regions 11a to 11c is defined as the shortest distance in the stacking direction of the element regions 11a to 11c as described above. When a void is formed, the shortest distance in the stacking direction of the element regions 11a to 11c is smaller than when no void is formed. For example, when no air gap is formed, the thickness Lb of the element region 11a is the distance from the second boundary surface 31b to the flat portion 22a, but for example, between the element region 11a and the flat portion 22a. In the case where a void is formed, the thickness Lb of the element region 11a is the distance from the second boundary surface 31b to the boundary surface with the void. Further, when no air gap is formed, the thickness Lb of the element region 11b is the distance from the second boundary surface 32b to the flat portion 23a, and for example, between the element region 11b and the flat portion 23a. When a void is formed, the distance is the distance from the second boundary surface 32 b to the boundary surface with the void.

  Next, on the unfired ceramic green sheet to be the magnetic layer 11, a method of forming conductor patterns corresponding to the coil conductors 21 to 23 and powder patterns corresponding to the stress relaxation spaces 31 to 33 explain.

First, a paste such as ZrO ₂ is applied on the ceramic green sheet by screen printing or the like to form powder patterns that become stress relaxation spaces 31 to 33 after firing. The paste such as ZrO ₂ is produced by mixing ZrO ₂ powder with an organic solvent, an organic binder and the like. Subsequently, the conductive paste described above is applied by screen printing or the like on each powder pattern formed on the ceramic green sheet to form each conductor pattern to be each coil conductor 21 to 23 after firing. . The conductive paste is produced by mixing a conductor powder, an organic solvent, an organic binder and the like. Each conductor pattern is sintered by firing to become each coil conductor 21-23. Each powder pattern becomes stress relaxation space 31-33 in which each powder 31c-33c exists by baking. The powders 31c to 33c present in the stress relaxation spaces 31 to 33 are substantially the same as the average particle diameter of the ZrO ₂ powder used to form each powder pattern before firing.

  The respective lead conductors 24 and 25 correspond to the respective lead conductors 24 and 25 by applying the above-described conductive paste by screen printing or the like onto the ceramic green sheet that constitutes the magnetic layer 11. A conductor pattern is formed, and each conductor pattern is sintered and formed. Each of the through-hole conductors 12 a to 12 d is formed by sintering the conductive paste filled in each through-hole formed on the ceramic green sheet that is to constitute the magnetic layer 11. Each conductor pattern formed on the ceramic green sheet and each conductive paste filled in the through holes are integrated, and are integrally and simultaneously formed by firing.

  As described above, according to the laminated coil component 1 according to the present embodiment, the stress relaxation spaces 31 to 33 in which the powders 31 c to 33 c are present are in contact with the surfaces 21 d to 23 d of the coil conductors 21 to 23. The stress relaxation spaces 31 and 32 intervene between the coil conductors 21 to 23 adjacent to each other in the stacking direction and the element regions 11a and 11b. Thereby, it is possible to relieve the internal stress generated in the element body due to the difference between the thermal contraction rates of the coil conductors 21 to 23 and the element body 2 or the like. The thickness La of each of the stress relaxation spaces 31 to 33 is smaller than the thickness Lb of each of the element regions 11a and 11b. That is, the thickness Lb of each element region 11 a, 11 b is at least larger than the thickness La of each stress relaxation space 31, 32. Therefore, even when the stress relaxation spaces 31 and 32 intervene between the coil conductors 21 to 23 and the element regions 11a and 11b adjacent in the stacking direction, the stress relaxation spaces interposed. It is possible to secure a sufficient thickness Lb of the element regions 11a and 11b as compared with 31 and 32. As described above, the internal stress of the element body 2 can be relaxed while securing the thickness Lb of the element regions 11a and 11b sufficiently.

  According to the laminated coil component 1, the stress relaxation spaces 31 to 33 are in contact with the surfaces 21 d to 23 d among the surfaces 21 d to 23 d and the surfaces 21 e to 23 e of the coil conductors 21 to 23. That is, each stress relaxation space 31-33 is formed in the surfaces 21d-23d of each coil conductor 21-23. For this reason, while each stress relaxation space 31-33 can be easily formed compared with the case where each stress relaxation space 31-33 is formed in both the surfaces 21d-23d and the surface 21e23e, the element region 11a , 11b are easier to secure. Furthermore, since surfaces 21e to 23e in which the stress relaxation spaces 31 to 33 are not formed are coupled to the element body 2 without interposing the stress relaxation spaces 31 to 33, the surfaces 21e to 23e and the element body 2 are coupled The strength can be increased.

  According to the laminated coil component 1, the stress relaxation spaces 31 to 33 are in contact with the planar surfaces 21 d to 23 d. That is, since the surfaces 21 d to 23 d in which the stress relaxation spaces 31 to 33 are formed are planar, the stress relaxation spaces 31 to 33 can be easily formed.

  According to the laminated coil component 1, the average particle diameter of the powders 31c to 33c is 0.1 μm or less and the flowability of the powders 31c to 33c is good, so the thermal contraction of the element body 2 and the coil conductors 21 to 23 The powders 31c to 33c can flexibly follow the behavior according to the rate difference, and the internal stress of the element body 2 can be relaxed more reliably.

According to the laminated coil component 1, the powder material is ZrO ₂ , and ZrO ₂ is preferable because it has less influence on the ferrite material and the like contained in the element body 2. Furthermore, since the melting point of ZrO ₂ is considerably higher than the firing temperature of the ferrite material and the like contained in the element body 2, it can surely exist as a powder.

  According to the laminated coil component 1, since each coil conductor 21 to 23 contains a metal oxide, and the shrinkage factor at the time of firing of the conductive paste constituting each coil conductor 21 to 23 can be reduced, The cross-sectional area of each coil conductor can be enlarged. And also when the cross-sectional area of each coil conductor 21-23 is enlarged in this way, the internal stress of the element | base body 2 can be relieve | moderated by the stress relaxation space 31-33.

  Note that according to the laminated coil component 1, each stress relaxation space is not formed in each of the lead conductors 24, 25. Therefore, the adhesion between the lead conductors 24 and 25 and the magnetic layer 11 is good, and the end portions 24a and 25a of the lead conductors 24 and 25 (that is, exposed on the end faces 2a and 2b of the element body 2) It is possible to suppress the infiltration of the plating solution from the existing portion).

Second Embodiment
Next, a laminated coil component according to a second embodiment will be described with reference to FIGS. FIG. 8 is an exploded perspective view of the laminated coil component according to the second embodiment. FIG. 9 is a plan view showing each lead conductor. FIG. 10 is a cross-sectional view of the laminated coil component according to the second embodiment. FIG. 9 corresponds to FIG. Note that, in the exploded perspective view of FIG. 8, the illustration of the plurality of magnetic layers forming the element body and the external electrodes disposed at both ends of the element body is omitted. Further, in the cross-sectional view of FIG. 10, the illustration of the external electrodes disposed at both ends of the element body is omitted. Moreover, since it is a perspective view of the laminated coil component which concerns on this embodiment, and the figure corresponding to FIG. 1 is the same as that of FIG. 1, illustration is abbreviate | omitted.

As shown in FIGS. 8 to 10, the laminated coil component 1A according to the second embodiment is disposed at both ends of the element body 2 and the element body 2 similarly to the laminated coil component 1 according to the first embodiment. A pair of external electrodes 4 and 5 (see FIG. 1), a plurality of coil conductors 21 to 23, a plurality of lead conductors 24 and 25, and a plurality of stress relaxation spaces 31 to 33 are provided. The layered coil component 1A according to the second embodiment is different from the layered coil component 1 described above in that it further includes stress relaxation spaces 34 and 35 in contact with the respective lead conductors 24 and 25. The stress relaxation spaces 34, 35 are spaces in which the respective powders 34c, 35c (see FIG. 8) exist, and are interposed between the element region in the element 2 and the lead conductors 24, 25. Thus, the internal stress generated in the element body 2 is relieved. The material of each powder 34c, 35c is, for example, ZrO ₂ or the like. The average particle diameter of each powder 34c, 35c is, for example, 0.1 μm or less.

  As shown in FIG. 8, the stress relaxation space 34 is located between the lead conductor 24 and the coil conductor 21 in the stacking direction. As shown in FIG. 9A, the stress relaxation space 34 is formed on the surface 24d (see FIG. 10) on the lower side (the side surface 2d side of the element body 2) of the lead conductor 24 in the stacking direction. The stress relaxation space 34 is along a portion other than the end T5 of the lead conductor 24 and the end 24a. That is, the stress relaxation space 34 does not cover the end portion T5 which is a connection portion with the through hole conductor 12a and the end portion 24a which is a connection portion with the external electrode 4. The stress relaxation space 34 is formed so as not to protrude from the lead conductor 24 when viewed in the stacking direction.

  The stress relaxation space 35 is located between the lead conductor 25 and the coil conductor 23 in the stacking direction. As shown in FIG. 9B, the stress relaxation space 35 is formed on the surface 25d (see FIG. 10) on the lower side (the side surface 2d side of the element body 2) of the lead conductor 25 in the stacking direction. The stress relaxation space 35 is along a portion other than the end T6 and the end 25a of the lead conductor 25. That is, the stress relaxation space 35 does not cover the end portion T6 which is a connection portion with the through hole conductor 12d and the end portion 25a which is a connection portion with the external electrode 4. The stress relaxation space 35 is formed so as not to protrude from the lead conductor 25 when viewed in the stacking direction.

  As shown in FIG. 10, the stress relaxation space 34 has a first interface 34a with the lead conductor 24 and a second interface 34b with the element region 11d. The first boundary surface 34 a is in contact with the surface 24 d of the lead conductor 24. The second boundary surface 34b is in contact with the element region 11d. In the above embodiment, the element region 11 d is sandwiched between the coil conductor 21 and the lead conductor 24, but in the present embodiment, the element region 11 d includes the coil conductor 21 and the stress relaxation space 34. In between. The first boundary surface 34a and the second boundary surface 34b face each other in the stacking direction.

  The stress relaxation space 35 has a first boundary surface 35 a with the lead conductor 25 and a second boundary surface 35 b with the element region between the lead conductor 25 and the side surface 2 d in the element body 2. The first boundary surface 35 a is in contact with the surface 25 d of the lead conductor 25. The second boundary surface 35 b is in contact with the element region between the lead conductor 25 and the side surface 2 d of the element 2. The first boundary surface 35a and the second boundary surface 35b face each other in the stacking direction.

  The thickness of each stress relaxation space 34, 35 in the stacking direction is not shown, but, like the thickness La of each stress relaxation space 34, 35, the first boundary surface 34a, 35a and the second boundary face each other. It is defined as the distance between the faces 34b, 35b. Hereinafter, the thickness in the stacking direction of each of the stress relaxation spaces 34 and 35 is also simply referred to as “thickness La”. The thickness La of the stress relaxation space 34 is a distance from the first boundary surface 34 a to the second boundary surface 34 b. The thickness La of the stress relaxation space 35 is a distance from the first boundary surface 35a to the second boundary surface 35b. The thickness La of each of the stress relaxation spaces 34 and 35 is substantially equal to the thickness La of each of the stress relaxation spaces 31 to 33.

  The thickness of the body region 11d in the stacking direction is defined as the shortest distance in the stacking direction of the body region 11d as in the case of the thickness Lb of the body regions 11a to 11c, although not shown. The thickness of the element region 11d in the stacking direction is substantially the same as the thickness Lb of the element regions 11a to 11c. Hereinafter, the thickness of the element region 11d in the stacking direction is also simply referred to as "thickness Lb". The thickness La of the stress relaxation space 34 is smaller than the thickness Lb of the element region 11 d. That is, the thickness Lb of the element region 11 d is at least larger than the thickness La of the stress relaxation space 34. Accordingly, a sufficient thickness Lb of the element region 11 d can be secured between the coil conductor 21 and the lead conductor 24 as compared to the stress relaxation space 34.

  As in the above embodiment, the respective stress relaxation spaces 34 and 35 may be entirely filled with the respective powders 34c and 35c, and a void or the like is formed between the respective powders 34c and 35c. It is also good. Even when such an air gap is formed, the thickness La of each of the stress relaxation spaces 34 and 35 is defined as described above. That is, the thickness La of each stress relaxation space 34, 35 is not only the thickness of the region where each powder 34c, 35c excluding the void exists but the thickness of each stress relaxation space 34, 35 including the void. It is prescribed.

  As described above, also in the present embodiment, as in the first embodiment, the internal stress of the element body 2 can be relaxed while sufficiently securing the thickness Lb of the element regions 11a and 11b.

  Furthermore, according to the present embodiment, since the stress relaxation spaces 34 and 35 are also formed in the lead conductors 24 and 25, the internal stress of the element body 2 can be further relieved. The thickness Lb of the element region 11 d is at least larger than the stress relaxation space 34. Therefore, even when the stress relaxation space 34 is interposed between the lead conductor 24 and the coil conductor 21 adjacent in the stacking direction, the element region 11 d is sufficient compared to the stress relaxation space 34 interposed. Thickness Lb can be secured.

  Furthermore, according to the present embodiment, the stress relaxation spaces do not cover the end portions 24a and 25a of the lead conductors 24 and 25 (that is, the portions exposed to the end surfaces 2a and 2b of the element body 2). 34, 35 are formed. Therefore, the end portions 24a and 25a are joined to the element body 2 without interposing the stress relaxation spaces 34 and 35, and the adhesion between the end portions 24a and 25a and the element body 2 is good, and the end portions 24a, It can suppress that a plating solution infiltrates from 25a.

Third Embodiment
Next, a laminated coil component according to a third embodiment will be described with reference to FIGS. 11 to 16. FIG. 11 is an exploded perspective view of the laminated coil component according to the third embodiment. 12 to 14 are plan views showing each coil conductor. FIG. 15 is a cross-sectional view of the laminated coil component according to the third embodiment. FIG. 15 corresponds to FIG. FIG. 16 is a diagram showing a part of FIG. 15 in an enlarged manner. In the exploded perspective view of FIG. 11, the illustration of the plurality of magnetic layers forming the element body and the external electrodes disposed at both ends of the element body is omitted. Further, in the cross-sectional view of FIG. 15, the illustration of the external electrodes disposed at both ends of the element body is omitted. Moreover, since it is a perspective view of the laminated coil component which concerns on this embodiment, and the figure corresponding to FIG. 1 is the same as that of FIG. 1, illustration is abbreviate | omitted.

  As shown in FIGS. 11 to 16, the laminated coil component 1 </ b> B according to the third embodiment is disposed at both ends of the element body 2 and the element body 2 as in the laminated coil component 1 according to the first embodiment. A pair of outer electrodes 4 and 5 (see FIG. 1), a plurality of coil conductors 21 to 23, and a plurality of lead conductors 24 and 25 are provided. The layered coil component 1B according to the third embodiment is different from the layered coil component 1 described above in that each of the stress relaxation spaces 41 to 43 is provided instead of the stress relaxation spaces 31 to 33.

Each stress relaxation space 41-43 is in contact with each coil conductor 21-23. The stress relaxation spaces 41 to 43 are spaces in which the powders 41 c, 42 c, and 43 c exist, and are interposed between the element region in the element 2 and the coil conductors 21 to 23. , Relieve the internal stress generated in the element body 2. The material of each powder 41c, 42c, 43c is, for example, ZrO ₂ or the like. The average particle diameter of each powder 41c, 42c, 43c is, for example, 0.1 μm or less.

  As shown in FIG. 11, the stress relaxation space 41 is located between the lead conductor 24 and the coil conductor 21 in the stacking direction. As shown in FIG. 12, the stress relaxation space 41 is formed on the surface 21 e (see FIG. 16) on the upper side (side surface 2 c side of the element body 2) of the coil conductor 21 in the stacking direction. The stress relaxation space 41 is along a portion other than the end E1 of the coil conductor 21. That is, the stress relaxation space 41 does not cover the end E1 which is a connection portion of the coil conductor 21 with the through hole conductor 12a. The stress relaxation space 41 is formed so as not to protrude from the coil conductor 21 when viewed in the stacking direction.

  The stress relaxation space 42 is located between the coil conductor 21 and the coil conductor 22 in the stacking direction. As shown in FIG. 13, the stress relaxation space 42 is formed on the surface 22 e (see FIG. 16) on the upper side (the side surface 2 c side of the element body 2) of the coil conductor 22 in the stacking direction. The stress relaxation space 42 is along a portion other than the end portion T2 of the coil conductor 22. That is, the stress relaxation space 42 does not cover the end portion T2 which is a connection portion of the coil conductor 22 with the through hole conductor 12b. The stress relaxation space 42 is formed so as not to protrude from the coil conductor 22 as viewed in the stacking direction.

  The stress relaxation space 43 is located between the coil conductor 22 and the coil conductor 23 in the stacking direction. As shown in FIG. 14, the stress relaxation space 43 is formed on the surface 23 e (see FIG. 16) on the upper side (side surface 2 c side of the element body 2) of the coil conductor 23 in the stacking direction. The stress relaxation space 43 is along a portion other than the end portion T4 of the coil conductor 23. That is, the stress relieving space 43 does not cover the end portion T4 which is a connection portion of the coil conductor 23 with the through hole conductor 12c. The stress relaxation space 43 is formed so as not to protrude from the coil conductor 23 as viewed in the stacking direction.

  As shown in FIG. 15, in the present embodiment, the element region 11 a is sandwiched between the coil conductor 21 and the stress relaxation space 42. The element region 11 b is sandwiched between the coil conductor 22 and the stress relaxation space 43. The element region 11 c is sandwiched between the coil conductor 23 and the lead conductor 25. The element region 11 d is sandwiched between the lead conductor 24 and the stress relaxation space 41.

  Next, with reference to FIG. 16, the cross-sectional configurations of the coil conductors 21 to 23 and the stress relaxation spaces 41 to 43 will be described in detail. FIG. 16 is an enlarged view of a region including a part (portion on the end face 2 b side of the element body 2) of each of the coil conductors 21 to 23 in the cross-sectional view of FIG. 15. The area including the portion on the end face 2a side of the element body 2 of each of the coil conductors 21 to 23 in the cross-sectional view of FIG. 15 is the same as that of FIG. In the present embodiment, the side surface 2e of the element body 2 will be described as one side in the stacking direction, and the side surface 2d of the element body 2 will be described as the other side in the stacking direction. That is, in this embodiment, each surface 21e, 22e, 23e of each coil conductor 21-23 is a first surface facing one side in the stacking direction, and each surface 21d, 22d, each surface of each coil conductor 21-23. 23 d is a second surface facing the other side in the stacking direction.

  As shown in FIG. 16, the stress relaxation space 41 has a first interface 41 b with the coil conductor 21 and a second interface 41 a with the element region 11 d. The first boundary surface 41 b is in contact with the surface 21 e of the coil conductor 21. That is, the first boundary surface 41b is in contact with the flat portion 21a and the inclined portions 21b and 21c. In the present embodiment, the first boundary surface 41b is in continuous contact with the flat portion 21a and the inclined portions 21b and 21c. Thereby, the stress relaxation space 41 integrally covers the flat portion 21a and the inclined portions 21b and 21c. The second boundary surface 41a is in contact with the element region 11d. The first boundary surface 41 b and the second boundary surface 41 a face each other in the stacking direction.

  The stress relaxation space 42 has a first interface 42 b with the coil conductor 22 and a second interface 42 a with the element region 11 a. The first boundary surface 42 b is in contact with the surface 22 e of the coil conductor 22. That is, the first boundary surface 42b is in contact with the flat portion 22a and the inclined portions 22b and 22c. In the present embodiment, the first boundary surface 42b is in continuous contact with the flat portion 22a and the inclined portions 22b and 22c. Thereby, the stress relaxation space 42 integrally covers the flat portion 22a and the inclined portions 22b and 22c. The second boundary surface 42a is in contact with the element region 11a. The first boundary surface 42 b and the second boundary surface 42 a face each other in the stacking direction.

  The stress relaxation space 43 has a first boundary surface 43b with the coil conductor 23 and a second boundary surface 43a with the element region 11b. The first boundary surface 43 b is in contact with the surface 23 e of the coil conductor 23. That is, the first boundary surface 43b is in contact with the flat portion 23a and the inclined portions 23b and 23c. In the present embodiment, the first boundary surface 43b is in continuous contact with the flat portion 23a and the inclined portions 23b and 23c. Thus, the stress relaxation space 43 integrally covers the flat portion 23a and the inclined portions 23b and 23c. The second boundary surface 43a is in contact with the element region 11b. The first boundary surface 43 b and the second boundary surface 43 a are opposed in the stacking direction.

  The thickness (hereinafter, also simply referred to as "thickness Lc") of the stress relaxation spaces 41 to 43 in the stacking direction is between the first boundary surfaces 41b to 43b and the second boundary surfaces 41a to 43a facing each other. It is defined as a distance. In the present embodiment, the thickness Lc of the stress relaxation space 41 is a distance from the first boundary surface 41 b to the second boundary surface 41 a. The thickness Lc of the stress relaxation space 42 is a distance from the first boundary surface 42 b to the second boundary surface 42 a. The thickness Lc of the stress relaxation space 43 is a distance from the first boundary surface 43 b to the second boundary surface 43 a. The thicknesses Lc of the stress relaxation spaces 41 to 43 are all substantially equal.

  The thickness in the stacking direction of each element region 11a, 11b (hereinafter, also simply referred to as "thickness Ld") is defined as the shortest distance in the stacking direction of the element regions 11a, 11b. In the present embodiment, the thickness Ld of the element region 11a is the distance from the second boundary surface 42a to the surface 21d. The thickness Ld of the element region 11b is the distance from the second boundary surface 43a to the surface 22d. The thicknesses Ld of the element regions 11a and 11b are substantially equal to each other.

  The thicknesses Lc of the stress relaxation spaces 41 to 43 are smaller than the thicknesses Ld of the element regions 11a and 11b. That is, thickness Ld of element regions 11a and 11b is at least larger than thickness Lc of stress relaxation spaces 41-43. Therefore, a sufficient thickness Ld of the element region 11 a can be secured between the coil conductors 21 and 22 compared to the stress relaxation space 41. A sufficient thickness Ld of the element region 11 b can be secured between the coil conductors 22 and 23 compared to the stress relaxation space 42. Specifically, the thickness Lc of each of the stress relaxation spaces 41 to 43 is, for example, about 1 to 2 μm. On the other hand, the thickness Ld of each element region 11a, 11b is, for example, about 3 to 30 μm. The difference between the thickness Lc of each element region 11a, 11b and the thickness Ld of each stress relaxation space 41 to 43 is preferably, for example, 5 to 20 or more.

  The thickness of the element region 11d in the stacking direction is defined as the shortest distance in the stacking direction of the element region 11d, similarly to the thicknesses Lc of the element regions 11a and 11b, although not shown. The thickness of the element region 11d in the stacking direction is substantially the same as the thickness Lc of the element regions 11a and 11b. Hereinafter, the thickness of the element region 11d in the stacking direction is also simply referred to as "thickness Lc". The thickness La of the stress relaxation space 41 is smaller than the thickness Ld of the element region 11 d. That is, the thickness Ld of the element region 11 d is at least larger than the thickness Lc of the stress relaxation space 41. Therefore, a sufficient thickness Ld of the element region 11 d can be secured between the coil conductor 21 and the lead conductor 24 compared to the stress relaxation space 41.

  As in the above embodiment, the respective stress relaxation spaces 41 to 43 may be entirely filled with the respective powders 41c to 43c, and a void or the like may be formed between the respective powders 41c to 43c. . Even in the case where such a void is formed, the thickness Lc of each of the stress relaxation spaces 41 to 43 is defined as described above. That is, the thickness Lc of each stress relaxation space 41 to 43 is not the thickness of only the region where each powder 41 c to 43 c excluding the void exists but the thickness L of each stress relaxation space 41 to 43 including the void. It is prescribed.

  Element regions 11a, 11b, and 11d may have gaps or the like not in contact with coil conductors 21 to 23 and lead conductors 24 and 25, respectively. Even when such a void is formed, thickness Ld of element regions 11a, 11b and 11d is defined as the shortest distance in the stacking direction of element regions 11a, 11b and 11d as described above. Be done. When a void is formed, the shortest distance in the stacking direction of the element regions 11a, 11b, and 11d is smaller than when the void is not formed. For example, when no void is formed, the thickness Ld of the element region 11a is the distance from the second boundary surface 42a to the surface 21d, but a void is formed between the element region 11a and the surface 21d. In this case, the thickness Ld of the element region 11a is the distance from the second boundary surface 42a to the boundary surface with the air gap. When no void is formed, thickness Ld of element region 11b is the distance from second boundary surface 43a to surface 22d, but a void is formed between element region 11b and flat portion 23a. In the case where the distance between the second boundary surface 43a and the gap is the distance between the second boundary surface 43a and the void.

  Next, on the unfired ceramic green sheet to be the magnetic layer 11, a method of forming conductor patterns corresponding to the coil conductors 21 to 23 and powder patterns corresponding to the stress relaxation spaces 41 to 43 explain. In addition, the formation method of each lead-out conductor 24 and 25 and each through-hole conductor 12a-12d is the same as that of 1st Embodiment.

First, each conductive pattern which becomes each coil conductor 21-23 after baking is formed by applying said conductive paste by screen printing etc. on a ceramic green sheet. The conductive paste is produced by mixing a conductor powder, an organic solvent, an organic binder and the like. Subsequently, a paste such as ZrO ₂ is applied by screen printing or the like on each conductor pattern formed on the ceramic green sheet to form powder patterns to be stress relaxation spaces 41 to 43 after firing. Ru. The paste such as ZrO ₂ is produced by mixing ZrO ₂ powder with an organic solvent, an organic binder and the like. Each conductor pattern is sintered by firing to become each coil conductor 21-23. Each powder pattern becomes stress relaxation space 41-43 in which each powder 41c-43c exists by baking. The powders 41c to 43c present in the stress relaxation spaces 41 to 43 are substantially the same as the average particle diameter of the ZrO ₂ powder used to form each powder pattern before firing.

  As described above, according to the laminated coil component 1B according to the present embodiment, the stress relaxation spaces 41 to 43 in which the powders 41c to 43c are present are in contact with the surfaces 21e to 23e of the coil conductors 21 to 23, respectively. The stress relaxation spaces 42 and 43 intervene between the coil conductors 21 to 23 adjacent to each other in the stacking direction and the element regions 11a and 11b. Thereby, it is possible to relieve the internal stress generated in the element body due to the difference between the thermal contraction rates of the coil conductors 21 to 23 and the element body 2 or the like. The thickness Lc of each of the stress relaxation spaces 41 to 43 is smaller than the thickness Ld of each of the element regions 11a and 11b. That is, the thickness Ld of each element region 11a, 11b is at least larger than the thickness Lc of each stress relaxation space 41-43. Therefore, even if the stress relaxation spaces 42 and 43 intervene between the coil conductors 21 to 23 and the element regions 11a and 11b adjacent in the stacking direction, the stress relaxation spaces 42 interposed therebetween. , 43, and sufficient thickness Ld of element regions 11a and 11b can be secured. As described above, the internal stress of the element body 2 can be relaxed while the thickness Ld of the element regions 11a and 11b is sufficiently secured.

  Furthermore, according to the laminated coil component 1B, the stress relaxation spaces 41 to 43 are in contact with the flat portions 21a to 23a and the inclined portions 21b to 23b and 21c to 23c, respectively, so that the internal stress of the element is reliably achieved. Can be relaxed.

  As mentioned above, although various embodiment of this invention was described, this invention is not limited to the said embodiment, You may deform | transform in the range which does not change the summary described in each claim, or may apply to others.

  In the said embodiment, although each stress relaxation space 31-33, 41-43 was formed in the surface of one side in the lamination direction in each coil conductor 21-23, it is not restricted to this. For example, the coil conductors 21 to 23 may be formed on both the surface on one side and the surface on the other side in the stacking direction. Each stress relaxation space 31-33, 41-43 may be in contact with part of the surface of each coil conductor 21-23 or may be in contact with the entire surface of each coil conductor 21-23. Each stress relieving space 31-33, 41-43 may be formed to surround the surface of each coil conductor 21-23. Further, in the above embodiment, the stress relaxation spaces 31 to 33, 41 to 43 are formed so as not to protrude from the coil conductors 21 to 23 when viewed in the stacking direction, but the invention is not limited thereto. When viewed from the direction, it may be formed to protrude from the coil conductors 21 to 23. In the above embodiment, the stress relaxation spaces 34 and 35 are formed so as not to protrude from the lead conductors 24 and 25 when viewed in the stacking direction, but the present invention is not limited thereto. , And may be formed to protrude from the lead conductors 24 and 25.

  In the said embodiment, although each coil conductor 21-23 presupposed that it is a trapezoid shape in cross section, it is not restricted to this. For example, each of the coil conductors 21 to 23 may have a substantially rectangular cross section or the like.

  Although the coil conductors 21 to 23 and the lead conductors 24 and 25 have substantially the same thickness in the stacking direction in the above embodiment, the present invention is not limited to this. For example, the thickness in the stacking direction of each lead conductor 24, 25 may be smaller than the thickness of each coil conductor 21-23. In this case, the stress generated inside the element body 2 due to the respective lead conductors 24 and 25 can be suppressed. When the thickness of each of the lead conductors 24 and 25 in the stacking direction is reduced as described above, the resistance is increased. Therefore, two lead conductors 24 and 25 may be arranged two by two in the stacking direction.

In the above embodiment, each powder 31C～35c, the material of 41C～43c, for example, was to be ZrO ₂ or the like, not limited to this. For example, the material of each of the powders 31c to 35c and 41c to 43c may be a ferrite material whose firing temperature is higher than that of the ferrite material constituting the element body 2. In this case, the stress relaxation spaces 31 to 35 and 41 to 43 in which the respective powders 31c to 35c and 41c to 43c exist can also function as magnetic materials. Moreover, the material of the powder which comprises each stress relaxation space 31-33, 41-43 may be a material whose dielectric constant is higher than that of the element body 2. In this case, the capacitance between the coil conductors 21 to 23 can be reduced.

  In the third embodiment, the stress relaxation space may be formed in the lead conductors 24 and 25.

  1, 1A, 1B: laminated coil component, 2: element body, 20: coil, 21-23: coil conductor, 21d, 22d, 23d, 21e, 22e, 23e: surface, 21a, 22a, 23a: flat portion, 21b , 22b, 23b, 21c, 22c, 23c: inclined portion, 31 to 33: stress relaxation space, 31a, 32a, 33a: first boundary surface, 31b, 32b, 33b: second boundary surface, 41 to 43: stress relaxation Space, 41b, 42b, 43b: first interface, 41a, 42a, 43a: second interface, La, Lb, Lc, Ld: thickness.

Claims (4)

An element containing a magnetic material,
A coil comprising a plurality of inner conductors spaced apart in a first direction and electrically connected to each other in said body;
A plurality of stress relaxation spaces in contact with the surface of each of the inner conductors and in which powder is present;
Equipped with
The element body has an element region located between the internal conductors adjacent in the first direction,
Each of the stress relaxation spaces has a first interface with the inner conductor and a second interface with the element region,
The first boundary surface and the second boundary surface face each other in the first direction,
Distance from the first boundary surface to the second boundary surface, rather smaller than the thickness at the first direction of the element body region,
Each of the inner conductors has a first surface facing one side of the first direction and a second surface facing the other side of the first direction,
The first surface has a first surface portion extending in a direction orthogonal to the first direction, and a second surface portion inclined with respect to the first direction and the first surface portion. And
Each of the stress relaxation spaces is in contact with the first surface portion and the second surface portion . The laminated coil component according to claim 1 , wherein an average particle diameter of the powder is 0.1 μm or less. Material of the powder is ZrO _2, a laminated coil component according to claim 1 or 2. The laminated coil component according to any one of claims 1 to 3 , wherein each of the inner conductors contains a metal oxide.

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