Laminated coil component

Abstract

To provide a laminated coil component which can prevent breakage or cracking of an element body.SOLUTION: A laminate coil component 1 comprises: an element body 2 which is made up of a plurality of laminated insulator layers; a coil which is disposed inside the element body 2; and an external terminal 3 which is made up of a plurality of laminated conductor layers and is electrically connected to the coil. The element body 2 has: a principal surface 2a; and lateral surfaces 2c, 2e which are adjacent to the principal surface 2a. The external terminal 3 is spaced away from the lateral faces 2c, 2e and is embedded in the element body 2 in a manner exposed from the principal surface 2a. The external terminal 3 has connection surfaces 3c, 3e which are spaced farther away from the lateral faces 2c, 2e as they are spaced farther away from the principal surface 2a.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent Document 1 describes a laminated coil component including an element body, a coil, and external electrodes arranged on the bottom surface of the element body at a distance from the end surfaces. In this laminated coil component, the external electrodes are embedded in the element body so as to be exposed from the bottom surface of the element body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-113299 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the electronic component described above, cracks or chips may occur in the element body near the external electrodes.

[0005] One embodiment of the present disclosure provides a laminated coil component capable of suppressing the occurrence of cracks or chips in an element body. [Means for solving the problem]

[0006] A laminated coil component according to one embodiment of the present disclosure comprises an element body formed by stacking a plurality of insulating layers, a coil disposed within the element body, and an external terminal formed by stacking a plurality of conductor layers and electrically connected to the coil, wherein the element body has a main surface and a first side surface adjacent to the main surface, and the external terminal is embedded in the element body so as to be spaced apart from the first side surface and exposed from the main surface, and has a first spaced apart surface that is spaced apart from the first side surface the further it is from the main surface.

[0007] In this laminated coil component, the external terminal is embedded in the element body so as to be spaced apart from the first side surface and exposed from the main surface. Therefore, the element body has a portion sandwiched between the first side surface and the external terminal. Since such a portion is thinner than other portions, cracks or chips are likely to occur. Therefore, the external terminal has a first separation surface that is further away from the first side surface the further away it is from the main surface. This increases the thickness of the thin portion sandwiched between the first side surface and the external terminal, making it possible to suppress the occurrence of cracks or chips. Furthermore, since the area of ​​the exposed surface of the external terminal used for mounting can be maintained, it is possible to suppress a decrease in mounting strength.

[0008] The ridge portion between the main surface and the first side surface may have a chamfered shape. In this case, the thin portion sandwiched between the first side surface and the external terminal becomes even thinner, making it more likely to crack or chip. Therefore, a configuration in which the external terminal has a first separation surface is more effective.

[0009] The ridge portion may have a rounded chamfered shape, and the thickness of the external terminal may be thicker than the radius of curvature of the ridge portion. In this case, the thin portion sandwiched between the first side surface and the external terminal becomes longer, which makes it more likely to crack or chip. Therefore, a configuration in which the external terminal has a first separation surface is more effective.

[0010] The ridge portion may have a rounded chamfered shape, and the first separating surface may be curved with a radius of curvature larger than the radius of curvature of the ridge portion. In this case, it is easy to increase the thickness of the thin portion sandwiched between the first side surface and the external terminal.

[0011] The external terminals may be disposed outside the ridge portion. In this case, the ridge portion can be formed only from the element body. The ease of polishing varies depending on the material. Thus, a ridge portion formed only from the element body is more likely to be polished to form a chamfered shape than a ridge portion formed from multiple materials.

[0012] The element body may further have a pair of second side surfaces each adjacent to the main surface, the first side surface also adjacent to each of the pair of second side surfaces, the pair of second side surfaces facing each other, and the external terminal may further have a pair of second separated surfaces that are spaced apart from the pair of second side surfaces the further away they are from the main surface. In this case, the element body has three thin portions sandwiched between the first side surface and each of the pair of second side surfaces. It is possible to prevent cracks or chips from occurring in all of these thin portions.

[0013] A laminated coil component according to another embodiment includes an element body formed by stacking a plurality of insulating layers, a coil disposed within the element body, and an external terminal formed by stacking a plurality of conductor layers and electrically connected to the coil, wherein the element body has a rectangular main surface and a pair of side surfaces adjacent to each other and adjacent to the main surface, and the external terminal is embedded in the element body so as to be spaced apart from the pair of side surfaces and exposed from the main surface, and has a second corner portion disposed adjacent to a first corner portion between the pair of side surfaces when viewed from a direction perpendicular to the main surface, and the radius of curvature of the second corner portion is larger than the radius of curvature of the first corner portion.

[0014] In this laminated coil component, the external terminals are embedded in the element body so as to be spaced apart from the pair of side surfaces and exposed from the main surface. Therefore, the element body has a portion sandwiched between the pair of side surfaces and the external terminal. Since such a portion has a smaller volume than other portions, it is prone to cracking or chipping. Therefore, when viewed from a direction perpendicular to the main surface, the radius of curvature of a second corner of the external terminal adjacent to the first corner is made larger than the radius of curvature of a first corner between the pair of side surfaces of the element body. This increases the volume of the portion sandwiched between the pair of side surfaces and the external terminal, making it possible to suppress the occurrence of cracking or chipping. Effect of the Invention

[0015] According to one embodiment of the present invention, there is provided a laminated coil component capable of suppressing the occurrence of cracks or chips in an element body. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view of a laminated coil component according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the laminated coil component of FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the laminated coil component of FIG. [Figure 4] FIG. 4 is a bottom view of the laminated coil component of FIG. [Diagram 5] FIG. 5 is an exploded perspective view of the laminated coil component of FIG. [Figure 6] FIG. 6 is a partially enlarged cross-sectional view of a laminated coil component according to a first modified example. [Figure 7] FIG. 7 is a partially enlarged cross-sectional view of a laminated coil component according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0018] As shown in Fig. 1 to Fig. 5, the laminated coil component 1 includes a rectangular parallelepiped element body 2, a pair of external terminals 3, a coil 10, and connecting conductors 26, 27. 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 laminated coil component 1 is, for example, a laminated high-frequency inductor. Note that the coil 10 and the connecting conductors 26, 27 are not shown in Figs. 1 to 4.

[0019] The element body 2 has main surfaces 2a, 2b facing each other, a pair of side surfaces 2c facing each other, and a pair of side surfaces 2e facing each other. In the following, the direction in which the pair of side surfaces 2e face each other is referred to as a first direction D1, the direction in which the pair of side surfaces 2c face each other is referred to as a second direction D2, and the direction in which the main surfaces 2a, 2b face each other is referred to as a third direction D3. The first direction D1, the second direction D2, and the third direction D3 intersect with each other (here, perpendicularly). In this embodiment, the first direction D1 is the width direction of the element body 2. The second direction D2 is the length direction of the element body 2. The third direction D3 is the height direction of the element body 2.

[0020] The main surfaces 2a, 2b, the pair of side surfaces 2c, and the pair of side surfaces 2e all have a rectangular shape. The long side direction of the main surfaces 2a, 2b coincides with the second direction D2. The short side direction of the main surfaces 2a, 2b coincides with the first direction D1. The main surface 2a is adjacent to each of the side surfaces 2c, 2e. The main surface 2b is adjacent to each of the side surfaces 2c, 2e. Each of the side surfaces 2c is adjacent to each of the side surfaces 2e.

[0021] The ridge portion 2g between the main surface 2a and the side surface 2c has a chamfered shape. The ridge portion 2h between the main surface 2a and the side surface 2e has a chamfered shape. The ridge portion 2i between the side surface 2c and the side surface 2e has a chamfered shape. The ridge portion 2j between the main surface 2b and the side surface 2c has a chamfered shape. The ridge portion 2k between the main surface 2b and the side surface 2e has a chamfered shape. Each of the ridge portions 2g, 2h, 2i, 2j, and 2k has a chamfered shape that has been rounded by, for example, barrel polishing.

[0022] The principal surfaces 2a, 2b extend in the second direction D2 so as to connect the pair of side surfaces 2c. The principal surfaces 2a, 2b also extend in the first direction D1 so as to connect the pair of side surfaces 2e. The pair of side surfaces 2c extend in the third direction D3 so as to connect the principal surfaces 2a, 2b. The pair of side surfaces 2c also extend in the first direction D1 so as to connect the pair of side surfaces 2e. The pair of side surfaces 2e extend in the third direction D3 so as to connect the principal surfaces 2a, 2b. The pair of side surfaces 2e also extend in the second direction D2 so as to connect the pair of side surfaces 2c. The laminated coil component 1 is mounted, for example, by soldering to an electronic device (for example, a circuit board or electronic component). In the laminated coil component 1, the principal surface 2a constitutes a mounting surface facing the electronic device.

[0023] As shown in Fig. 5, the element body 2 is configured by stacking multiple insulator layers 6 in a first direction D1. The element body 2 has multiple insulator layers 6 stacked in the first direction D1. In the element body 2, the stacking direction in which the multiple insulator layers 6 are stacked coincides with the first direction D1. In the actual element body 2, the multiple insulator layers 6 are integrated to the extent that the boundaries between each of the insulator layers 6 are not visible.

[0024] Each insulator layer 6 is formed of a dielectric material containing a glass component. That is, the element body 2 contains a dielectric material containing a glass component as a compound of elements constituting the element body 2. The glass component is, for example, borosilicate glass. The dielectric material is, for example, a dielectric ceramic such as BaTiO3-based, Ba(Ti,Zr)O3-based, or (Ba,Ca)TiO3-based. Each insulator layer 6 is formed of a sintered body of a ceramic green sheet containing a glass ceramic material.

[0025] 2 and 3, a pair of recesses 4 are provided on the main surface 2a. The pair of recesses 4 are spaced apart from each other in the second direction D2. The pair of recesses 4 are spaced apart from the pair of side surfaces 2c and the pair of side surfaces 2e, respectively, when viewed from a direction perpendicular to the main surface 2a (third direction D3). One of the recesses 4 is provided on one of the side surfaces 2c of the element body 2. The other recess 4 is provided on the other side surface 2c of the element body 2.

[0026] As shown in FIGS. 1 to 5, the pair of external terminals 3 are electrically connected to the ends of the coil 10. The pair of external terminals 3 are embedded in the element body 2 so as to be exposed from the main surface 2a. The pair of external terminals 3 are not exposed from the main surface 2b and the side surfaces 2c, 2e. The pair of external terminals 3 are spaced apart from each other in the second direction D2. The pair of external terminals 3 are spaced apart from the pair of side surfaces 2c and the pair of side surfaces 2e, respectively, when viewed from a direction perpendicular to the main surface 2a (third direction D3). One external terminal 3 is provided on one side surface 2c of the element body 2. The other external terminal 3 is provided on the other side surface 2c of the element body 2. The pair of external terminals 3 have the same shape.

[0027] It can also be said that the pair of external terminals 3 are disposed in a pair of recesses 4 provided in the main surface 2a. Each recess 4 is a space recessed from the main surface 2a into the inside of the element body 2. Each recess 4 has a shape corresponding to the shape of the corresponding external terminal 3. Each external terminal 3 is in contact with the entire inner surface of the corresponding recess 4 without any gaps.

[0028] Each external terminal 3 has a rectangular plate shape with the third direction D3 as the thickness direction. The thickness t of the external terminal 3 is larger than the radius of curvature of each edge portion 2g, 2h. The radius of curvature of the edge portion 2g, 2h is, for example, equal to each other. Each external terminal 3 has an exposed surface 3a, a bottom surface 3b, connection surfaces 3c, 3d, and a pair of connection surfaces 3e. The exposed surface 3a and the bottom surface 3b face each other in the thickness direction (third direction D3). The exposed surface 3a faces the outside of the element body 2 and is exposed from the main surface 2a. The exposed surface 3a is located in approximately the same plane as the main surface 2a, but may be located outside the element body 2 from the main surface 2a, or may be located inside the element body 2 from the main surface 2a. That is, each external terminal 3 may protrude from the main surface 2a to the outside of the element body 2, or may be recessed from the main surface 2a to the inside of the element body 2.

[0029] The bottom surface 3b faces the inside of the element body 2 and faces the main surface 2b and the bottom surface 4a of the recess 4, respectively. The exposed surface 3a and the bottom surface 3b are, for example, rectangular flat surfaces. The long side directions of the exposed surface 3a and the bottom surface 3b coincide with the first direction D1. The short side directions of the exposed surface 3a and the bottom surface 3b coincide with the second direction D2.

[0030] Each of the connection surfaces 3c, 3d, and 3e connects the exposed surface 3a and the bottom surface 3b. The connection surface 3c faces the corresponding side surface 2c. The corresponding side surface 2c is the closer side surface 2c of the pair of side surfaces 2c. The connection surfaces 3c and 3d face each other in the second direction D2. The connection surfaces 3c and 3d face opposite sides of the second direction D2. The pair of external terminals 3 are arranged such that the connection surfaces 3d face each other. The pair of connection surfaces 3e face each other in the first direction D1. Each of the connection surfaces 3e faces the corresponding side surface 2e. The corresponding side surface 2e is the closer side surface 2e of the pair of side surfaces 2e.

[0031] The further away the connecting surface 3c is from the main surface 2a, the further away it is from the plane including the corresponding side surface 2c in the second direction D2. The plane including the side surface 2c is a virtual plane. The distance dc between the connecting surface 3c and the plane including the side surface 2c in the second direction D2 becomes longer as the connecting surface 3c is further away from the main surface 2a. Here, the connecting surface 3c may include a portion parallel to the plane including the side surface 2c. In this case, the distance dc is kept constant in the portion parallel to the plane including the side surface 2c. It is sufficient that the connecting surface 3c tends to move away from the plane including the side surface 2c as it moves away from the main surface 2a. It is sufficient that the distance dc simply increases as it moves away from the main surface 2a. A simple increase means that there is no tendency for the distance to decrease.

[0032] The connection surface 3c is curved with a radius of curvature larger than the radius of curvature of the ridge portion 2g. The connection surface 3c is curved so as to bulge toward the inside of the element body 2. In this embodiment, the portion of the connection surface 3c on the exposed surface 3a side is parallel to a plane including the side surface 2c. The plane including the side surface 2e is a virtual plane. The portion of the connection surface 3c on the bottom surface 3b side is curved with a radius of curvature larger than the radius of curvature of the ridge portion 2g. The entire connection surface 3c may be curved with a radius of curvature larger than the radius of curvature of the ridge portion 2g.

[0033] The connecting surface 3d is curved in such a way that the farther it is from the main surface 2a, the closer it is to a plane including the corresponding side surface 2c in the portion on the bottom surface 3b side. The connecting surface 3d is parallel to the plane including the side surface 2c in the portion on the exposed surface 3a side.

[0034] Each connecting surface 3e is spaced apart in the first direction D1 from the plane including the corresponding side surface 2e as it is farther away from the main surface 2a. The distance de by which the planes including the connecting surfaces 3e are spaced apart from each other in the first direction D1 becomes longer as it is farther away from the main surface 2a. Here, the connecting surface 3e may include a portion parallel to the plane including the connecting surface 3e. In this case, the distance de is kept constant in the portion parallel to the plane including the connecting surface 3e. It is sufficient that the connecting surface 3e tends to be farther away from the plane including the connecting surface 3e as it is farther away from the main surface 2a. It is sufficient that the distance de simply increases as it is farther away from the main surface 2a.

[0035] Each connection surface 3e is curved with a radius of curvature larger than the radius of curvature of the ridge portion 2h. The radii of curvature of the connection surfaces 3c, 3d, and 3e are, for example, equal to each other. The connection surfaces 3e are curved so as to bulge toward the inside of the element body 2. In this embodiment, the portion of the connection surface 3e on the exposed surface 3a side is parallel to a plane including the connection surface 3e. The portion of the connection surface 3e on the bottom surface 3b side is curved with a radius of curvature larger than the radius of curvature of the ridge portion 2h. The entire connection surface 3e may be curved with a radius of curvature larger than the radius of curvature of the ridge portion 2h.

[0036] Each external terminal 3 is disposed outside each ridge portion 2g, 2h when viewed from a direction perpendicular to the main surface 2a (third direction D3). That is, each external terminal 3 is disposed within the range of the main surface 2a when viewed from the third direction D3, and is not disposed across the ridge portions 2g, 2h. That is, each external terminal 3 is disposed at a distance from a plane including the corresponding side surface 2c by at least the design value of the curvature radius of the ridge portion 2g or the curvature radius (measured value) of the ridge portions 2i, 2j, 2k. Each external terminal 3 is disposed at a distance from a plane including the corresponding side surface 2e by at least the design value of the curvature radius of the ridge portion 2h or the curvature radius (measured value) of the ridge portions 2i, 2j, 2k. The design values ​​of the ridge portions 2g, 2h, 2i, 2j, 2k are, for example, equal to each other. Since the ridge portions 2g and 2h are adjacent to the main surface 2a on which the external terminal 3 is provided, the radii of curvature of the ridge portions 2g and 2h may be smaller than the design value due to the influence of the external terminal 3. Since the ridge portions 2i, 2j, and 2k are not adjacent to the main surface 2a, the radii of curvature of the ridge portions 2i, 2j, and 2k are not influenced by the external terminal 3 and are close to the design value. Therefore, instead of the design value of the radii of curvature of the ridge portions 2g and 2h, the measured values ​​of the radii of curvature of the ridge portions 2i, 2j, and 2k may be used. Since the ridge portion 2g has a chamfered shape, it is not in contact with either the plane including the side surface 2c or the plane including the main surface 2a. Since the ridge portion 2h has a chamfered shape, it is not in contact with either the plane including the connection surface 3e or the plane including the main surface 2a. The plane including the main surface 2a is a virtual plane.

[0037] When viewed from a direction perpendicular to the main surface 2a (third direction D3), the element body 2 has a corner A1 between the side surfaces 2c and 2e adjacent to each other. The corner A1 is formed by a ridge portion 2i. The element body 2 has four corners A1. When viewed from a direction perpendicular to the main surface 2a (third direction D3), each external terminal 3 has four corners. Of the four corners of the external terminal 3, two corners A2 are arranged adjacent to the corresponding corner A1. In other words, the external terminal 3 has a corner A2 arranged adjacent to the corner A1 between the side surfaces 2c and 2e. Note that adjacent means closest to each other. The radius of curvature of each corner A2 is larger than the radius of curvature of the adjacent corner A1.

[0038] As shown in FIG. 5, the external terminal 3 is configured by stacking a plurality of electrode layers 11 in a first direction D1. The external terminal 3 has a plurality of electrode layers 11 stacked in the first direction D1. The plurality of electrode layers 11 are integrated to such an extent that the boundaries between the electrode layers 11 are not visible. In this embodiment, the number of electrode layers 11 is "6". Each electrode layer 11 is provided in a missing portion formed in the corresponding insulator layer 6. The missing portion constitutes a recess 4. The electrode layer 11 contains a conductive material. The conductive material contains, for example, Ag or Pd. The electrode layer 11 is configured as a sintered body of a conductive paste containing a conductive material powder. The conductive material powder contains, for example, Ag powder or Pd powder.

[0039] The electrode layer 11 may further contain a glass component. That is, the electrode layer 11 may be configured as a sintered body of a conductive paste containing a metal component made of a conductive material powder and a glass component. The glass component is a compound of elements that constitute the element body 2, and is the same component as the glass component contained in the element body 2. The content of the glass component may be set appropriately. Each electrode layer 11 extends along the second direction D2.

[0040] The coil 10 and the connecting conductors 26, 27 are disposed within the element body 2 and are not exposed from the element body 2. The coil 10 has a coil axis along a first direction D1. A pair of ends of the coil 10 are electrically connected to a pair of external terminals 3 (see FIG. 2). One end is electrically connected to one external terminal 3 by a connecting conductor 26. The other end is electrically connected to the other external terminal 3 by a connecting conductor 27.

[0041] The coil 10 has a first coil conductor 22, a second coil conductor 23, a third coil conductor 24, and a fourth coil conductor 25. The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, and the fourth coil conductor 25 are arranged along a first direction D1 in the order of the first coil conductor 22, the second coil conductor 23, the third coil conductor 24, and the fourth coil conductor 25. The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, and the fourth coil conductor 25 each have a shape in which a part of the loop is interrupted, and each has one end and the other end.

[0042] The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, and the fourth coil conductor 25 are formed to have a predetermined width (length in a direction intersecting the first direction D1) and height (length in the first direction). The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, and the fourth coil conductor 25 are formed to have the same width and height as each other.

[0043] The first coil conductor 22 is located in the same layer as the pair of electrode layers 11. The first coil conductor 22 is connected to the other electrode layer 11 located in the same layer via a connection conductor 26. The connection conductor 26 is located in the same layer as the pair of electrode layers 11 and the first coil conductor 22. The connection conductor 26 connects the first coil conductor 22 to the other electrode layer 11. One end of the first coil conductor 22 is connected to the connection conductor 26. The one end of the first coil conductor 22 constitutes the other end of the coil 10. In this embodiment, the first coil conductor 22, the connection conductor 26, and the other electrode layer 11 are integrally formed.

[0044] The second coil conductor 23 is located in the same layer as the pair of electrode layers 11. The second coil conductor 23 is spaced apart from the pair of electrode layers 11 located in the same layer. The other end of the first coil conductor 22 and one end of the second coil conductor 23 are adjacent to each other in the first direction D1 and are in direct contact with each other. When viewed from the first direction D1, the other end of the first coil conductor 22 and one end of the second coil conductor 23 overlap each other.

[0045] The third coil conductor 24 is located in the same layer as the pair of electrode layers 11. The third coil conductor 24 is spaced apart from the pair of electrode layers 11 located in the same layer. The other end of the second coil conductor 23 and one end of the third coil conductor 24 are adjacent to each other in the first direction D1 and are in direct contact with each other. When viewed from the first direction D1, the other end of the second coil conductor 23 and one end of the third coil conductor 24 overlap each other.

[0046] The fourth coil conductor 25 is located in the same layer as the pair of electrode layers 11. The fourth coil conductor 25 is connected to one of the electrode layers 11 located in the same layer via a connection conductor 27. The connection conductor 27 is located in the same layer as the pair of electrode layers 11 and the fourth coil conductor 25. The connection conductor 27 connects the fourth coil conductor 25 to the one of the electrode layers 11. The other end of the fourth coil conductor 25 is connected to the connection conductor 27. The other end of the fourth coil conductor 25 constitutes one end of the coil 10. In this embodiment, the fourth coil conductor 25, the connection conductor 27, and the one of the electrode layers 11 are integrally formed.

[0047] The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, the fourth coil conductor 25, and the connecting conductors 26 and 27 contain a conductive material. The conductive material contains, for example, Ag or Pd. The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, the fourth coil conductor 25, and the connecting conductors 26 and 27 are configured as a sintered body of a conductive paste containing a conductive material powder. The conductive material powder contains, for example, Ag powder or Pd powder.

[0048] In this embodiment, the first coil conductor 22, the second coil conductor 23, the third coil conductor 24, the fourth coil conductor 25, and the connecting conductors 26 and 27 contain the same conductive material as the respective external terminals 3. The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, the fourth coil conductor 25, and the connecting conductors 26 and 27 may contain a conductive material different from that of the respective external terminals 3.

[0049] The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, the fourth coil conductor 25, and the connecting conductors 26 and 27 are provided in the defects formed in the corresponding insulator layers 6. The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, the fourth coil conductor 25, and the connecting conductors 26 and 27 are formed by firing a conductive paste located in the defects formed in the green sheet.

[0050] The defect portion formed in the green sheet is formed, for example, by the following process. First, an element paste containing the constituent material of the insulator layer 6 and a photosensitive material is applied onto a substrate to form a green sheet. The substrate is, for example, a PET film. The photosensitive material contained in the element paste may be either a negative type or a positive type, and a known material can be used. Next, a mask corresponding to the defect portion is used to expose and develop the green sheet by photolithography, thereby forming a defect portion in the green sheet on the substrate. The green sheet with the defect portion formed therein is an element pattern.

[0051] The electrode layer 11, the first coil conductor 22, the second coil conductor 23, the third coil conductor 24, the fourth coil conductor 25, and the connecting conductors 26 and 27 are formed, for example, by the following process.

[0052] First, a conductive paste containing a photosensitive material is applied onto a substrate to form a conductive material layer. The photosensitive material contained in the conductive paste may be either a negative type or a positive type, and a known material may be used. Next, a mask corresponding to the defective portion is used to expose and develop the conductive material layer by a photolithography method, and a conductive pattern corresponding to the shape of the defective portion is formed on the substrate.

[0053] The laminated coil component 1 is obtained, for example, by the following process following the above-mentioned process. A conductive pattern is combined with a missing portion of an element pattern to prepare a sheet in which the element pattern and the conductive pattern are in the same layer. A laminate obtained by stacking a predetermined number of prepared sheets is heat-treated, and then a plurality of green chips are obtained from the laminate. In this process, for example, the green laminate is cut into chips by a cutting machine. As a result, a plurality of green chips having a predetermined size are obtained. Next, the green chips are fired. The laminated coil component 1 is obtained by this firing. A plating layer may be formed on the surface of each external terminal 3. The plating layer is formed, for example, by electroplating or electroless plating. The plating layer contains, for example, Ni, Sn, or Au.

[0054] Since the laminated coil component 1 is formed by utilizing such a photolithography method, the external terminal 3 can be formed in any shape. That is, the connection surfaces 3c, 3d, and 3e can be easily curved with a desired radius of curvature. In the above manufacturing method, a laminate is formed by stacking a predetermined number of sheets prepared after preparing a sheet in which an element pattern and a conductor pattern are formed in the same layer, but the laminate may be formed by other methods. For example, the laminate may be formed while forming an element pattern and a conductor pattern sequentially by a photolithography method on one substrate for lamination. That is, the element 2 may have a plurality of insulating layers 6 having a laminated structure regardless of the manufacturing method. The external terminal 3 may have a plurality of electrode layers 11 having a laminated structure regardless of the manufacturing method.

[0055] As described above, in the laminated coil component 1 according to this embodiment, the external terminals 3 are embedded in the element body 2 so as to be spaced apart from the side surfaces 2c, 2e and exposed from the main surface 2a. Therefore, the element body 2 has a portion sandwiched between the side surface 2c and the external terminals 3, and a portion sandwiched between the side surface 2e and the external terminals 3. These portions are thinner than other portions and are therefore more susceptible to cracking or chipping.

[0056] The connection surface 3c of the external terminal 3 is farther away from the side surface 2c as it is farther away from the main surface 2a. This increases the thickness (length in the second direction D2) of the part of the element 2 sandwiched between the side surface 2c and the external terminal 3, making it possible to suppress the occurrence of cracks or chipping. Also, the connection surface 3e of the external terminal 3 is farther away from the side surface 2e as it is farther away from the main surface 2a. This increases the thickness (length in the first direction D1) of the part of the element 2 sandwiched between the side surface 2e and the external terminal 3, making it possible to suppress the occurrence of cracks or chipping. Since the area of ​​the exposed surface 3a of the external terminal 3 used for mounting can be maintained large, it is possible to suppress a decrease in mounting strength.

[0057] The ridge portion 2g between the main surface 2a and the side surface 2c has a chamfered shape. Therefore, the thin portion sandwiched between the side surface 2c and the external terminal 3 becomes even thinner, so that cracks or chips are more likely to occur. Therefore, it is more effective to have the external terminal 3 have the above-mentioned connection surface 3c. The ridge portion 2h between the main surface 2a and the side surface 2e has a chamfered shape. Therefore, the thin portion sandwiched between the side surface 2e and the external terminal 3 becomes even thinner, so that cracks or chips are more likely to occur. Therefore, it is more effective to have the external terminal 3 have the above-mentioned connection surface 3e.

[0058] The ridges 2g and 2h have a rounded chamfered shape, and the thickness t of the external terminal 3 is thicker than the radius of curvature of the ridges 2g and 2h. Therefore, compared to when the thickness t of the external terminal 3 is equal to or less than the radius of curvature of the ridges 2g, the thin portion sandwiched between the side surface 2c and the external terminal 3 is longer in the thickness direction of the external terminal 3 (third direction D3). Therefore, cracks or chips are more likely to occur, so a configuration in which the external terminal 3 has a connection surface 3c is more effective. Also, compared to when the thickness t of the external terminal 3 is equal to or less than the radius of curvature of the ridges 2h, the thin portion sandwiched between the side surface 2e and the external terminal 3 is longer in the thickness direction of the external terminal 3. Therefore, cracks or chips are more likely to occur, so a configuration in which the external terminal 3 has a connection surface 3e is more effective.

[0059] The ridge portion 2g has a rounded chamfered shape, and the connection surface 3c is curved with a larger radius of curvature than the ridge portion 2g. This allows the thickness of the thin portion sandwiched between the side surface 2c and the external terminal 3 to be increased. The ridge portion 2h has a rounded chamfered shape, and the connection surface 3e is curved with a larger radius of curvature than the ridge portion 2h. This allows the thickness of the thin portion sandwiched between the side surface 2e and the external terminal 3 to be increased.

[0060] The external terminals 3 are disposed outside the ridges 2g, 2h. Therefore, the ridges 2g, 2h can be formed only from the element body 2. The ease of polishing varies depending on the material. Thus, the ridges 2g, 2h formed only from the element body 2 are easier to form a chamfered shape by polishing than ridges formed from multiple materials. This improves the product shape and suppresses cracking or chipping of the element body 2.

[0061] The external terminals 3 are more difficult to polish than, for example, the element body 2 before sintering. Therefore, when the external terminals 3 are also exposed to the side surface 2c and form the ridge line portion 2g, the ridge line portion 2g is difficult to polish and is difficult to form a chamfered shape. Therefore, compared with the other ridge line portions 2h, 2i, 2j, and 2k formed by the element body 2 without the external terminals 3 being exposed, the ridge line portion 2g has a sharp shape and is more likely to become a starting point for cracking or chipping. When the polishing conditions are set according to the external terminals 3, the external terminals 3 are not exposed, and the other ridge line portions 2h, 2i, 2j, and 2k formed by the element body 2 are polished too much, making the element body 2 more likely to roll. Therefore, it becomes difficult to handle the laminated coil component 1. Although the case where the external terminals 3 are exposed to the side surface 2c has been described as an example, the same problem occurs when the external terminals 3 are exposed to the side surface 2e.

[0062] Even when the external terminal 3 is spaced from the plane including the side surface 2c, if the distance of the external terminal 3 from the plane including the side surface 2c is insufficient, specifically, if the distance is shorter than the design value of the curvature radius of the ridge line portions 2g, 2h, 2i, 2j, and 2k, polishing of the ridge line portion 2g is hindered by the external terminal 3, and it is difficult to make the curvature radius of the ridge line portion 2g the design value. For this reason, the ridge line portion 2g is likely to become a starting point for cracking or chipping. If the polishing conditions are matched to the ridge line portion 2g, the curvature radius of the ridge line portion 2g can be made the design value, but the other ridge line portions 2h, 2i, 2j, and 2k are polished too much, and the curvature radius exceeds the design value. Therefore, the element body 2 is likely to roll, and the handling of the laminated coil component 1 becomes difficult. Although the case where the distance of the external terminal 3 from the plane including the side surface 2c is insufficient has been described as an example, the same problem occurs when the distance of the external terminal 3 from the plane including the side surface 2e is insufficient.

[0063] In the laminated coil component 1, the external terminal 3 is embedded in the element body 2 so as to be spaced apart from the adjacent side faces 2c, 2e and exposed from the main surface 2a. Therefore, the element body 2 has a portion sandwiched between the side faces 2c, 2e, and the external terminal 3. Since such a portion has a smaller volume than other portions, it is prone to cracking or chipping. Therefore, when viewed from a direction perpendicular to the main surface 2a (third direction D3), the radius of curvature of the corner A1 between the side faces 2c, 2e of the element body 2 is made larger than the radius of curvature of the corner A1. This increases the volume of the portion sandwiched between the side faces 2c, 2e, and the external terminal 3, making it possible to suppress the occurrence of cracking or chipping.

[0064] The pair of external terminals 3 are exposed only on the main surface 2a, which reduces the mounting area. For example, if the external terminals 3 are exposed on the main surface 2a and the side surface 2c, the solder is also formed on the side surface 2c, which increases the mounting area.

[0065] Although the embodiment of the present invention has been described above, the present invention is not necessarily limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention.

[0066] Fig. 6 is a partially enlarged cross-sectional view of a laminated coil component according to a first modified example. The laminated coil component 1A according to the first modified example shown in Fig. 6 differs from the laminated coil component 1 shown in Figs. 1 to 5 in that it includes an external terminal 3A in which a plurality of electrode layers 31, 32, and 33 are laminated in a third direction D3. The plurality of insulator layers 6 may be laminated in the third direction D3, or may be laminated in the first direction D1 or the second direction D2.

[0067] The multiple electrode layers 31, 32, and 33 are arranged in this order from the principal surface 2b side. That is, the electrode layer 31 is arranged closest to the principal surface 2b, and the electrode layer 33 is arranged closest to the principal surface 2a. The electrode layer 32 is arranged between the electrode layer 31 and the electrode layer 33. The exposed surface 3a is formed by one surface of the electrode layer 33 in the thickness direction (third direction D3). The bottom surface 3b is formed by one surface of the electrode layer 31 in the thickness direction (third direction D3).

[0068] The electrode layers 31, 32, 33 have different lengths in the second direction D2. The electrode layers 31, 32, 33 are arranged, for example, such that the centers in the second direction D2 are aligned with each other. Therefore, in the electrode layers 31, 32, 33, the positions of the end faces on the side surface 2c side and the side surface 2d side are each shifted in a stepped manner. That is, the connection surface 3c and the connection surface 3d each have a stepped shape. Thus, in the laminated coil component 1A as well, the connection surface 3c is spaced farther from the side surface 2c as it is spaced farther from the main surface 2a. Therefore, in the laminated coil component 1A as well, the thickness of the portion sandwiched between the side surface 2c and the external terminal 3 can be increased, and the occurrence of cracks or chipping can be suppressed.

[0069] 7 is a partially enlarged cross-sectional view of a laminated coil component according to a second modified example. A laminated coil component 1B according to a second modified example shown in FIG. 7 differs from the laminated coil component 1A (see FIG. 6) in that it includes an external terminal 3B in which the arrangement of the electrode layers 31, 32, 33 is different from that of the external terminal 3A (see FIG. 6). In the external terminal 3B, the multiple electrode layers 31, 32, 33 are arranged so that the connection surface 3d forms a plane along the third direction D3. The connection surface 3c of the external terminal 3B has a stepped shape, similar to the external terminal 3A. Therefore, in the laminated coil component 1B as well, the thickness of the portion sandwiched between the side surface 2c and the external terminal 3 can be increased to suppress the occurrence of cracks or chipping.

[0070] In the laminated coil component 1, the coil 10 has a coil axis along the first direction D1, and includes a first coil conductor 22, a second coil conductor 23, a third coil conductor 24, and a fourth coil conductor 25. However, the coil axis of the coil 10 does not have to be along the first direction D1. The coil axis of the coil 10 may be along, for example, the second direction D2 or the third direction D3. In addition, the number of coil conductors constituting the coil 10 is not limited to four.

[0071] In the laminated coil component 1, each of the ridge portions 2g, 2h, 2i, 2j, and 2k has a rounded chamfered shape, but each of the ridge portions 2g, 2h, 2i, 2j, and 2k may or may not have a chamfered shape consisting of a flat surface.

[0072] In the laminated coil component 1, the external terminal 3 is composed of six electrode layers 11, but it is sufficient that it is composed of at least two or more electrode layers 11. In the laminated coil components 1A and 1B, the external terminals 3A and 3B are composed of three electrode layers 31, 32, and 33, but it is sufficient that it is composed of at least two or more electrode layers.

[0073] In the laminated coil components 1A and 1B, the connection surface 3c has a stepped shape, but the connection surface 3e may have a stepped shape as well. In this case, the thickness of the portion sandwiched between the side surface 2e and the external terminal 3 is increased, making it possible to suppress the occurrence of cracks or chips. [Explanation of symbols]

[0074] 1, 1A, 1B... laminated coil component, 2... element body, 2a... main surface, 2c, 2e... side surface, 2g, 2h... ridge portion, 3... external terminal, 3c, 3e... connection surface, 6... insulator layer, 10... coil, 11... electrode layer, 31, 32, 33... electrode layer, A1, A2... corner portion, t... thickness.

Claims

1. An element body formed by laminating a plurality of insulating layers; A coil disposed within the body; an external terminal formed by laminating a plurality of conductor layers and electrically connected to the coil; the element body has a main surface and a first side surface adjacent to the main surface, the external terminal is embedded in the element body so as to be spaced apart from the first side surface and exposed from the main surface, the main surface is provided with a recess in which the external terminal is disposed, The inner surface of the recess has a first separation surface facing away from the first side surface and separated from the first side surface as the first separation surface is separated from the main surface. Multilayer coil components.

2. A ridge portion between the main surface and the first side surface has a chamfered shape. The laminated coil component according to claim 1 .

3. The ridge portion has a rounded chamfered shape, The depth of the recess is greater than the radius of curvature of the ridge line. The laminated coil component according to claim 2 .

4. The ridge portion has a rounded chamfered shape, The first separation surface is curved with a radius of curvature larger than the radius of curvature of the ridge line portion. The laminated coil component according to claim 2 .

5. The external terminal is disposed outside the ridge portion. The laminated coil component according to any one of claims 2 to 4.

6. the element body further has a pair of second side surfaces adjacent to the main surface, The first side surface is adjacent to each of the pair of second side surfaces, The pair of second side surfaces face each other, The inner surface of the recess further includes a pair of second separation surfaces facing the opposite side to the pair of second side surfaces and spaced apart from the pair of second side surfaces as the inner surface is spaced apart from the main surface. The laminated coil component according to any one of claims 1 to 5.

7. An element body formed by laminating a plurality of insulating layers; A coil disposed within the body; an external terminal formed by laminating a plurality of conductor layers and electrically connected to the coil; The element body has a rectangular main surface and a pair of side surfaces adjacent to each other and each adjacent to the main surface, the external terminals are embedded in the element body so as to be spaced apart from the pair of side surfaces and exposed from the main surface, the main surface is provided with a recess in which the external terminal is disposed, The recess has a second corner portion disposed adjacent to the first corner portion between the pair of side surfaces when viewed in a direction perpendicular to the main surface, The radius of curvature of the second corner portion is larger than the radius of curvature of the first corner portion, The external terminal has a first remote surface facing a first side surface of the pair of side surfaces and remote from the first side surface as the first remote surface is moved away from the main surface. Multilayer coil components.

Images