Multilayer coil component

Abstract

To provide a multilayer coil component that relieves stress acting on the mounting surface.SOLUTION: A multilayer coil component 1 includes an element body 2, a coil 5 disposed within the element body, and external electrodes 3 and 4 exposed on the element body. The external electrodes are electrically connected to the coil. The element body includes a stress relief layer 21 located between the coil and the external electrodes.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a laminated coil component. [Background technology]

[0002] A multilayer coil component is known that includes an element body, a coil disposed within the element body, and external electrodes that are electrically connected to the coil and exposed on the element body (see, for example, Patent Document 1). The surfaces of the external electrodes form a mounting surface that faces an electronic device in which the multilayer coil component is mounted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-009391 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one aspect of the present invention is to provide a laminated coil component that relieves stress acting on a mounting surface. [Means for solving the problem]

[0005] A laminated coil component according to one aspect of the present invention includes an element body, a coil disposed within the element body, and external electrodes exposed on the element body. The external electrodes are electrically connected to the coil. The element body includes a stress relief layer located between the coil and the external electrodes. [Effects of the Invention]

[0006] One aspect of the present invention provides a laminated coil component that relieves stress acting on a mounting surface. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a laminated coil component according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of the coil according to the first embodiment. [Figure 3] FIG. 3 is an exploded view showing the configuration of the laminated coil component according to the first embodiment. [Figure 4] FIG. 4 is a view showing a cross-sectional configuration of the laminated coil component according to the first embodiment. [Figure 5] FIG. 5 is a view showing a cross-sectional configuration of the laminated coil component according to the second embodiment. [Figure 6] FIG. 6 is a diagram showing a cross-sectional configuration of the laminated coil component according to the third embodiment. [Figure 7] FIG. 7 is a diagram showing a cross-sectional configuration of the laminated coil component according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and redundant description will be omitted as appropriate.

[0009] (First embodiment) A laminated coil component 1 according to a first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a perspective view of the laminated coil component according to the first embodiment. FIG. 2 is a perspective view of a coil according to the first embodiment. FIG. 3 is an exploded view showing the configuration of the laminated coil component according to the first embodiment. FIG. 4 is a view showing the cross-sectional configuration of the laminated coil component according to the first embodiment. As shown in FIGS. 1 and 2, the laminated coil component 1 includes an element body 2, external electrodes 3 and 4, a coil 5, first connecting conductors 6 and second connecting conductors 7.

[0010] The element body 2 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. The element body 2 has, as its outer surfaces, a pair of end faces 2a and 2b, a pair of main faces 2c and 2d, and a pair of side faces 2e and 2f. The end faces 2a and 2b face each other. The main faces 2c and 2d face each other. The side faces 2e and 2f face each other. Hereinafter, the facing direction of the main faces 2c and 2d is referred to as a first direction D1, the facing direction of the end faces 2a and 2b is referred to as a second direction D2, and the facing direction of the side faces 2e and 2f is referred to as a third direction D3. The first direction D1, the second direction D2, and the third direction D3 are approximately perpendicular to each other.

[0011] The end faces 2a, 2b extend in the first direction D1 to connect the principal faces 2c, 2d. The end faces 2a, 2b also extend in the third direction D3 to connect the side faces 2e, 2f. The principal faces 2c, 2d extend in the second direction D2 to connect the end faces 2a, 2b. The principal faces 2c, 2d also extend in the third direction D3 to connect the side faces 2e, 2f. The side faces 2e, 2f extend in the first direction D1 to connect the principal faces 2c, 2d. The side faces 2e, 2f also extend in the second direction D2 to connect the end faces 2a, 2b.

[0012] The main surface 2d is included in the mounting surface and is the surface that faces another electronic device (not shown) when the laminated coil component 1 is mounted on the other electronic device (for example, a circuit board or a laminated electronic component). The end surfaces 2a and 2b and the side surfaces 2e and 2f are surfaces that are continuous with the mounting surface (i.e., the main surface 2d).

[0013] The length of the element body 2 in the second direction D2 is longer than the length of the element body 2 in the first direction D1 and the length of the element body 2 in the third direction D3. The length of the element body 2 in the third direction D3 is longer than the length of the element body 2 in the first direction D1. That is, in this embodiment, the end faces 2a, 2b, main faces 2c, 2d, and side faces 2e, 2f have a rectangular shape. The length of the element body 2 in the first direction D1 may be equal to or shorter than the length of the element body 2 in the third direction D3.

[0014] In this embodiment, "equivalent" does not only mean equal, but also may mean values that include slight differences or manufacturing errors within a preset range. For example, if multiple values are within a range of ±20% of the average value of the multiple values, the multiple values are defined as equivalent.

[0015] The element body 2 includes a metal component and a resin component. The metal component is, for example, composed of a plurality of metal particles. In one example, the metal particles are made of a soft magnetic alloy. The soft magnetic alloy is, for example, an Fe-Si alloy. The soft magnetic alloy may be, for example, an Fe-Ni-Si-M alloy. "M" includes one or more elements selected from Co, Cr, Mn, P, Ti, Zr, Hf, Nb, Ta, Mo, Mg, Ca, Sr, Ba, Zn, B, Al, and rare earth elements. In the element body 2, the metal particles are bonded together. The bonding between the metal particles is achieved, for example, by bonding between oxide films formed on the surfaces of the metal particles. The average particle diameter of the metal particles is 0.5 to 15 μm. In this embodiment, the average particle diameter of the metal particles is 5 μm. The "average particle diameter" is calculated, for example, from at least one cross section of the element body 2. In one example, it means the particle size at an integrated value of 50% in the particle size distribution obtained by image processing an image of at least one cross section of the element body 2.

[0016] The resin component may be, for example, a resin interposed between the plurality of metal magnetic particles. The resin may be impregnated into the gaps between the plurality of adjacent metal magnetic particles. In one example, the resin is an insulating resin having electrical insulating properties. The resin may include, for example, a silicone resin, a phenolic resin, an acrylic resin, or an epoxy resin.

[0017] The external electrodes 3 and 4 are electrically connected to the coil 5. The external electrodes 3 and 4 are exposed on the element body 2. The external electrodes 3 and 4 are exposed in the same direction as the main surface 2d. The external electrodes 3 and 4 are arranged so that they are exposed only in the same direction as the main surface 2d on the surface of the element body 2. The mounting surface of the element body 2 is composed of the surfaces of the external electrodes 3 and 4 and the main surface 2d. The external electrodes 3 and 4 are spaced apart in the second direction D2. The external electrode 3 is located near the end surface 2a of the element body 2. The external electrode 4 is located near the end surface 2b of the element body 2. When viewed from the first direction D1, the external electrodes 3 and 4 are located away from the ridges between the main surface 2d and each of the end surfaces 2a and 2b and the side surfaces 2e and 2f. When viewed from the first direction D1, the external electrodes 3 and 4 are rectangular. The long sides of the external electrodes 3 and 4 extend along the third direction D3, and the short sides extend along the second direction D2.

[0018] The external electrodes 3, 4 contain a conductive material. The conductive material is, for example, Ag or Pd. The external electrodes 3, 4 are configured as a sintered body of a conductive paste. The conductive paste contains a conductive metal powder and glass frit. The conductive metal powder is, for example, Ag powder or Pd powder. A plating layer is formed on the surface of the external electrodes 3, 4. The plating layer is formed, for example, by electroplating. The electroplating is, for example, Ni electroplating or Sn electroplating. The external electrodes 3, 4 may protrude from the main surface 2d.

[0019] The coil 5 is composed of a plurality of coil conductors 51, 52, and 53 and a plurality of through-hole conductors 54 and 55. The plurality of coil conductors 51, 52, and 53 are arranged in that order along the first direction D1. The coil conductors 51 and 52 are electrically connected to each other via the through-hole conductor 54. The coil conductors 52 and 53 are electrically connected to each other via the through-hole conductor 55. The coil conductor 53 is located closest to the principal surface 2d and includes one end of the coil 5 in the first direction D1. The coil conductor 51 is located closest to the principal surface 2c and includes the other end of the coil 5 in the first direction D1. Each of the coil conductors 51 to 53 forms a part of a circular track in the coil 5. The coil 5 includes a conductive material. The conductive material is, for example, Ag, Pd, Cu, Al, or Ni. The plurality of coil conductors 51 to 53 may be plated conductors.

[0020] The first connecting conductor 6 is disposed within the element body 2. The first connecting conductor 6 connects the external electrode 3 and the coil 5. The first connecting conductor 6 is a through-hole conductor. The first connecting conductor 6 extends in the first direction D1 and is connected to the external electrode 3 and one end of the coil 5. The second connecting conductor 7 is disposed within the element body 2. The second connecting conductor 7 connects the external electrode 4 and the coil 5. The second connecting conductor 7 is a through-hole conductor. The second connecting conductor 7 extends in the first direction D1 and is connected to the external electrode 4 and the other end of the coil 5. The first connecting conductor 6 and the second connecting conductor 7 have a rectangular column shape with the first direction D1 as the longitudinal direction.

[0021] As shown in FIG. 3 , the laminated coil component 1 includes a layer La, a layer Lb, a layer Lc, a layer Lc, a layer Ld, a layer Le, a layer Le, a layer Lf, a layer Lg, a layer Lh, a layer Lg, a layer Lg, and a layer Lj, stacked in this order. The layer La includes a main surface 2c, and the layer Lj includes a main surface 2d. The layers La to Lj have the same thickness. In one example, the thickness of each of the layers La to Lj is not less than 1 μm and not more than 500 μm. In the laminated coil component 1, the direction defining the thickness is along a first direction D1.

[0022] In the laminated coil component 1, the element body 2 includes a layer 20a, a layer 20b, a layer 20c, a layer 20c, a layer 20d, a layer 20e, a layer 20e, a layer 20f, a layer 20g, a layer 20h, a layer 20g, a layer 20j, which are stacked in this order. The layer 20h is defined as a stress relief layer 21. The layers 20a to 20j are integrated to the extent that the boundaries between the layers are not visible.

[0023] The coil 5 includes a coil conductor layer 50a, a plurality of through-hole conductor layers 50d, a coil conductor layer 50b, a plurality of through-hole conductor layers 50e, and a coil conductor layer 50c, which are stacked in this order. In the multilayer coil component 1, the number of each of the through-hole conductor layers 50d and 50e is "2." The coil conductor layer 50a constitutes the coil conductor 51, the coil conductor layer 50b constitutes the coil conductor 52, and the coil conductor layer 50c constitutes the coil conductor 53. The plurality of through-hole conductor layers 50d constitute the through-hole conductor 54, and the plurality of through-hole conductor layers 50e constitute the through-hole conductor 55. The coil conductor layers 50a to 50c and the through-hole conductor layers 50d and 50e are integrated to the extent that the boundaries between the layers are not visible.

[0024] The first connecting conductor 6 includes a plurality of stacked first connecting conductor layers 60a. In the laminated coil component 1, the number of the plurality of first connecting conductor layers 60a is "4." The plurality of first connecting conductor layers 60a are integrated to an extent that the boundaries between the layers are not visible. The second connecting conductor 7 includes a plurality of stacked second connecting conductor layers 70a. In the laminated coil component 1, the number of the plurality of second connecting conductor layers 70a is "10." The plurality of second connecting conductor layers 70a are integrated to an extent that the boundaries between the layers are not visible. The external electrode 3 includes an external electrode layer 30. The external electrode 4 includes an external electrode layer 40.

[0025] The layer La is composed of a layer 20a. The layer 20a includes a main surface 2c. The layer Lb is composed of the layer 20b and a coil conductor layer 50a. The coil conductor layer 50a is provided in a defect portion formed in the layer 20b. The layer Lc is composed of the layer 20c, a through-hole conductor layer 50d, and a second connecting conductor layer 70a. The through-hole conductor layer 50d and the second connecting conductor layer 70a are provided in a recess formed in the layer 20c. The layer Ld is composed of a layer 20d, a coil conductor layer 50b, and a second connecting conductor layer 70a. The coil conductor layer 50b and the second connecting conductor layer 70a are provided in a cutout portion formed in the layer 20d. The layer Le is composed of a layer 20e, a through-hole conductor layer 50e, and a second connecting conductor layer 70a. The through-hole conductor layer 50e and the second connecting conductor layer 70a are provided in a recess formed in the layer 20e. The layer Lf is composed of a layer 20f, a coil conductor layer 50c, and a second connecting conductor layer 70a. The coil conductor layer 50c and the second connecting conductor layer 70a are provided in a cutout portion formed in the layer 20f. The layer Lg is composed of a layer 20g, a first connecting conductor layer 60a, and a second connecting conductor layer 70a. The first connecting conductor layer 60a and the second connecting conductor layer 70a are provided in a recess formed in the layer 20g. The layer Lh is composed of a layer 20h, a first connecting conductor layer 60a, and a second connecting conductor layer 70a. The first connecting conductor layer 60a and the second connecting conductor layer 70a are provided in a recess formed in the layer 20h. The layer Lj is composed of a layer 20j and external electrode layers 30 and 40. The external electrode layers 30 and 40 are provided in recesses formed in the layer Lj. The layer 20j includes a main surface 2d.

[0026] As shown in FIG. 4 , the stress relaxation layer 21 is located between the coil 5 and the external electrodes 3 and 4. In the first direction D1, portions of the element body 2 other than the stress relaxation layer 21 are interposed between the stress relaxation layer 21 and the coil 5. In the first direction D1, portions of the element body 2 other than the stress relaxation layer 21 are interposed between the stress relaxation layer 21 and the external electrodes 3 and 4. The stress relaxation layer 21 extends along a second direction D2 and a third direction D3 that intersect with the first direction D1. The end faces of the stress relaxation layer 21 in the second direction D2 may be included in the end faces 2a and 2b. The end faces of the stress relaxation layer 21 in the third direction D3 may be included in the side faces 2e and 2f. In one example, the thickness of the stress relaxation layer 21 is 1 μm or more and 300 μm or less.

[0027] The stress relaxation layer 21 and the portion of the element body 2 other than the stress relaxation layer 21 each contain a metal component and a resin component. The ratio of the resin component to the metal component in the stress relaxation layer 21 is higher than the ratio of the resin component to the metal component in the portion of the element body 2 other than the stress relaxation layer 21. The volume content of the resin component in the stress relaxation layer 21 may be higher than the volume content of the resin component in the portion of the element body 2 other than the stress relaxation layer 21. The volume content of the resin component is calculated, for example, from each cross section of the stress relaxation layer 21 and the portion of the element body 2 other than the stress relaxation layer 21. In one example, the volume content of the resin component in the stress relaxation layer 21 is at least 1% higher than the volume content of the resin component in the portion of the element body 2 other than the stress relaxation layer 21. The mass content of the resin component in the stress relaxation layer 21 may be higher than the mass content of the resin component in the portion of the element body 2 other than the stress relaxation layer 21. In one example, the mass content of the resin component in the stress relaxation layer 21 is at least 1% higher than the mass content of the resin component in the portion of the element body 2 other than the stress relaxation layer 21 .

[0028] The ratio of the resin component to the metal component in the stress relaxation layer 21 may vary depending on the position in the stress relaxation layer 21 between the coil 5 and the external electrodes 3 and 4. The position between the coil 5 and the external electrodes 3 and 4 includes the position in the first direction D1. For example, the ratio of the resin component to the metal component in the portion of the stress relaxation layer 21 located closer to the external electrodes 3 and 4 may be greater than the ratio of the resin component to the metal component in the portion of the stress relaxation layer 21 located closer to the coil 5.

[0029] The volume content of voids existing between adjacent metal magnetic particles in the stress relaxation layer 21 may be greater than the volume content of voids existing between adjacent metal magnetic particles in the portion of the element body 2 other than the stress relaxation layer 21. The voids may be filled with resin. In one example, the volume content of voids existing between adjacent metal magnetic particles in the stress relaxation layer 21 is at least 1% greater than the volume content of voids existing between adjacent metal magnetic particles in the portion of the element body 2 other than the stress relaxation layer 21. The density of the stress relaxation layer 21 may be less than the density of the portion of the element body 2 other than the stress relaxation layer 21. In one example, the density of the stress relaxation layer 21 is at least 1% less than the density of the portion of the element body 2 other than the stress relaxation layer 21.

[0030] As described above, the external electrodes 3 and 4 exposed on the element body 2 are connected to other electronic devices via solder. An external force applied to the mounted laminated coil component 1 acts as stress on the mounting surface formed by the main surface 2d and the external electrodes 3 and 4. If the stress acting on the mounting surface exceeds the mounting strength, the laminated coil component 1 may peel off from the other electronic device. In the laminated coil component 1, the element body 2 includes a stress relaxation layer 21 located between the coil 5 and the external electrodes 3 and 4. An external force applied to the laminated coil component 1 acts on the mounting surface via the stress relaxation layer 21. Because the stress relaxation layer 21 absorbs changes in stress due to impacts and the like, changes in stress occurring in the element body 2 are unlikely to act on the mounting surface. Therefore, the laminated coil component 1 relaxes the stress acting on the mounting surface.

[0031] In the element body 2, the stress relaxation layer 21 and the portion other than the stress relaxation layer 21 each contain a metal component and a resin component. The ratio of the resin component to the metal component in the stress relaxation layer 21 is greater than the ratio of the resin component to the metal component in the portion of the element body 2 other than the stress relaxation layer 21. The resin component absorbs stress changes more easily than the metal component, and as a result, the multilayer coil component 1 further reduces the stress acting on the mounting surface.

[0032] The ratio of the resin component to the metal component of the stress relaxation layer 21 may vary depending on the position on the stress relaxation layer 21 between the coil 5 and the external electrodes 3, 4. Vibrations applied to the mounted laminated coil component 1 act as stress on the element body 2. The vibrations applied to the laminated coil component 1 act on the mounting surface via the stress relaxation layer 21. In a configuration in which the ratio of resin components to metal components in the stress relaxation layer 21 varies depending on the position on the stress relaxation layer 21 between the coil 5 and the external electrodes 3 and 4, the frequency of vibrations absorbed by the stress relaxation layer 21 varies depending on the ratio of resin components to metal components. As a result, in a configuration in which the ratio of resin components to metal components in the stress relaxation layer 21 varies depending on the position on the stress relaxation layer 21 between the coil 5 and the external electrodes 3 and 4, the range of vibration frequencies absorbed by the stress relaxation layer 21 is wider than in a configuration in which the ratio of resin components to metal components in the stress relaxation layer 21 is constant. The ratio of resin components to metal components in the portion of the stress relaxation layer 21 located closer to the external electrodes 3, 4 may be greater than the ratio of resin components to metal components in the portion of the stress relaxation layer 21 located closer to the coil 5. Since the portion of the stress relaxation layer 21 containing a larger amount of resin component is located closer to the mounting surface, the stress acting on the mounting surface can be further relaxed.

[0033] A laminated coil component 1A according to the second embodiment will be described below with reference to Fig. 5. Fig. 5 is a diagram showing the cross-sectional configuration of the laminated coil component according to the second embodiment. Differences between the laminated coil component 1 according to the first embodiment and the laminated coil component 1A according to the second embodiment will be mainly described below.

[0034] In the laminated coil component 1A, the stress relaxation layer 21 overlaps the external electrodes 3, 4. In the element body 2, the stress relaxation layer 21 is located on the external electrodes 3, 4. In the first direction D1, no part of the element body 2 other than the stress relaxation layer 21 is interposed between the stress relaxation layer 21 and the external electrodes 3, 4. In the first direction D1, the stress relaxation layer 21 and the external electrodes 3, 4 are adjacent to each other.

[0035] Deflection of another electronic device in which the laminated coil component 1A is mounted acts as a bending moment on the laminated coil component 1A. When a bending moment acts on the laminated coil component 1A, cracks may occur between the element body 2 and the external electrodes 3 and 4 due to the difference in bending deformation between the element body 2 and the external electrodes 3 and 4. In the laminated coil component 1A, the stress relaxation layers 21 overlap the external electrodes 3 and 4, and therefore the element body 2 is more likely to follow the bending deformation of the external electrodes 3 and 4 than in a configuration in which portions of the element body 2 other than the stress relaxation layers 21 overlap the external electrodes 3 and 4. Therefore, the laminated coil component 1A is resistant to bending of other electronic devices in which the laminated coil component 1A is mounted.

[0036] A laminated coil component 1B according to the third embodiment will be described below with reference to Fig. 6. Fig. 6 is a view showing the cross-sectional configuration of the laminated coil component according to the third embodiment. The following mainly describes the differences between the laminated coil component 1A according to the second embodiment and the laminated coil component 1B according to the third embodiment.

[0037] In the laminated coil component 1B, the element body 2 further includes a stress relaxation layer 22 separate from the stress relaxation layer 21. The stress relaxation layer 21 is defined as a first stress relaxation layer, and the stress relaxation layer 22 is defined as a second stress relaxation layer. The stress relaxation layer 22 is located between the stress relaxation layer 21 and the coil 5. The stress relaxation layer 22 extends along a second direction D2 and a third direction D3 that intersect with the first direction D1. The end faces of the stress relaxation layer 22 in the second direction D2 may be included in the end faces 2a and 2b. The end faces of the stress relaxation layer 22 in the third direction D3 may be included in the side faces 2e and 2f.

[0038] The stress relaxation layer 22 is arranged to overlap the coil conductor 53. In the element body 2, the coil conductor 53 is located on the stress relaxation layer 22. In the first direction D1, a portion of the element body 2 other than the stress relaxation layer 21 is interposed between the stress relaxation layer 21 and the stress relaxation layer 22.

[0039] The stress relaxation layer 22 has a ratio of resin component to metal component that is different from the ratio of resin component to metal component of the stress relaxation layer 21. The ratio of resin component to metal component in the stress relaxation layer 22 may be smaller than the ratio of resin component to metal component in the stress relaxation layer 21.

[0040] In the laminated coil component 1B, the element body 2 includes a stress relaxation layer 21 and a stress relaxation layer 22 located between the stress relaxation layer 21 and the coil 5. Changes in stress occurring in the element body 2 are absorbed by both the stress relaxation layer 21 and the stress relaxation layer 22. Therefore, the laminated coil component 1B further relaxes the stress acting on the mounting surface. The stress relaxation layer 22 has a ratio of resin component to metal component that is different from the ratio of resin component to metal component of the stress relaxation layer 21. Compared to a configuration in which the ratio of resin component to metal component of the stress relaxation layer 21 is the same as the ratio of resin component to metal component of the stress relaxation layer 22, the stress relaxation layer 21 and the stress relaxation layer 22 absorb a wider range of vibration frequencies in the laminated coil component 1B. The ratio of the resin component to the metal component of the stress relaxation layer 21 may be greater than the ratio of the resin component to the metal component of the stress relaxation layer 22 . The stress relaxation layer 21, which contains more resin components than the stress relaxation layer 22, is located closer to the mounting surface than the stress relaxation layer 22, and can therefore further relax the stress acting on the mounting surface. The stress relaxation layer 21, which contains more resin components than the stress relaxation layer 22, overlaps the external electrodes 3 and 4, and therefore the laminated coil component 1B is more resistant to bending of another electronic device in which the laminated coil component 1B is mounted.

[0041] A laminated coil component 1C according to a fourth embodiment will be described below with reference to Fig. 7. Fig. 7 is a view showing the cross-sectional configuration of the laminated coil component according to the fourth embodiment. The following mainly describes the differences between the laminated coil component 1A according to the second embodiment and the laminated coil component 1C according to the third embodiment.

[0042] In the laminated coil component 1C, the element body 2 includes a stress relaxation layer 23 instead of the stress relaxation layer 21. The stress relaxation layer 23 has a thickness greater than that of the external electrodes 3 and 4. The stress relaxation layer 23 may have a thickness, for example, twice or more the thickness of the external electrodes 3 and 4. The stress relaxation layer 23 may be composed of a plurality of layers 20h. In one example, the thickness of the stress relaxation layer 23 is 1 μm or more and 300 μm or less. The stress relaxation layer 23 extends along a second direction D2 and a third direction D3 that intersect with the first direction D1. The end faces of the stress relaxation layer 23 in the second direction D2 may be included in the end faces 2a and 2b. The end faces of the stress relaxation layer 23 in the third direction D3 may be included in the side faces 2e and 2f.

[0043] In the laminated coil component 1C, a portion of the element body 2 closer to one end in the first direction D1 than the coil 5 is made up of a stress relaxation layer 23. The stress relaxation layer 23 includes the main surface 2d. The thickness of the stress relaxation layer 23 is the distance between the coil 5 and the main surface 2d. At least a portion of the stress relaxation layer 23 is located in the same layer as the external electrodes 3, 4. The stress relaxation layer 23 overlaps the external electrodes 3, 4. The stress relaxation layer 23 is arranged so as to overlap the coil conductor 53.

[0044] The stress relaxation layer 23 has a thickness greater than that of the external electrodes 3, 4. An external force applied to the laminated coil component 1C acts on the mounting surface via the stress relaxation layer 23. Therefore, in the laminated coil component 1C, changes in stress generated in the element body 2 are less likely to act on the mounting surface, compared to a configuration in which the stress relaxation layer has a thickness smaller than that of the external electrodes 3, 4.

[0045] The present invention has been described in detail above based on the embodiments. However, the present invention is not limited to the above embodiments. The present invention can be modified in various ways without departing from the gist of the present invention. The first, second, third, and fourth embodiments can be combined as appropriate.

[0046] As can be understood from the above description of the embodiments and modifications, the present specification includes disclosure of the following aspects. (Appendix 1) The base body and a coil disposed within the element body; an external electrode electrically connected to the coil and exposed on the element body, the element body includes a stress relaxation layer located between the coil and the external electrode; Multilayer coil components. (Appendix 2) the stress relaxation layer and a portion of the element body other than the stress relaxation layer each contain a metal component and a resin component, 2. The laminated coil component according to claim 1, wherein a ratio of the resin component to the metal component in the stress relaxation layer is greater than a ratio of the resin component to the metal component in a portion of the element body other than the stress relaxation layer. (Appendix 3) 3. The laminated coil component according to claim 1, wherein the stress relaxation layer overlaps the external electrode. (Appendix 4) the stress relief layer includes a first stress relief layer, the element body further includes a second stress relief layer separate from the first stress relief layer, 4. The laminated coil component according to any one of claims 1 to 3, wherein the second stress relaxation layer is located between the first stress relaxation layer and the coil. (Appendix 5) the first stress relief layer and the second stress relief layer each contain a metal component and a resin component, 5. The laminated coil component according to claim 4, wherein the second stress relaxation layer has a ratio of the resin component to the metal component that is different from a ratio of the resin component to the metal component of the first stress relaxation layer. (Appendix 6) 3. The laminated coil component according to claim 1, wherein the stress relaxation layer has a thickness greater than a thickness of the external electrodes. (Appendix 7) the stress relaxation layer contains a metal component and a resin component, 3. The laminated coil component according to claim 1, wherein a ratio of the resin component to the metal component in the stress relaxation layer varies depending on a position in the stress relaxation layer between the coil and the external electrode. [Explanation of symbols]

[0047] 1, 1A, 1B, 1C... multilayer coil component, 2... element body, 2d... main surface, 3, 4... external electrode, 5... coil, 21, 22, 23... stress relaxation layer.

Claims

1. The base body and a coil disposed within the element body; an external electrode electrically connected to the coil and exposed on the element body, the element body includes a stress relaxation layer located between the coil and the external electrode; Multilayer coil components.

2. the stress relaxation layer and a portion of the element body other than the stress relaxation layer each contain a metal component and a resin component, 2. The laminated coil component according to claim 1, wherein a ratio of the resin component to the metal component in the stress relaxation layer is greater than a ratio of the resin component to the metal component in a portion of the element body other than the stress relaxation layer.

3. The laminated coil component according to claim 1 , wherein the stress relaxation layer overlaps the external electrode.

4. the stress relief layer includes a first stress relief layer, the element body further includes a second stress relief layer separate from the first stress relief layer, The laminated coil component according to claim 1 , wherein the second stress relaxation layer is located between the first stress relaxation layer and the coil.

5. the first stress relief layer and the second stress relief layer each contain a metal component and a resin component, 5. The laminated coil component according to claim 4, wherein the second stress relaxation layer has a ratio of the resin component to the metal component that is different from a ratio of the resin component to the metal component of the first stress relaxation layer.

6. The laminated coil component according to claim 1 , wherein the stress relaxation layer has a thickness greater than a thickness of the external electrodes.

7. the stress relaxation layer contains a metal component and a resin component, 3. The laminated coil component according to claim 1, wherein a ratio of the resin component to the metal component in the stress relaxation layer varies depending on a position in the stress relaxation layer between the coil and the external electrode.

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