Laminated coil component

Abstract

The present application provides a laminated coil component including a body, a coil, and an external terminal. The body is formed by laminating a plurality of insulator layers. The coil is disposed in the body. The external terminal is formed by laminating a plurality of conductor layers and is electrically connected to the coil. The body has a main surface and a first side surface adjacent to the main surface. The external terminal is embedded in the body in a manner that the external terminal is separated from the first side surface and exposed from the main surface. The external terminal has a first separation surface that is separated from the first side surface as the external terminal is separated from the main surface.

Description

Technical Field

[0001] This invention relates to laminated coil components. Background Technology

[0002] Japanese Patent Application Publication No. 2018-113299 discloses a laminated coil component comprising a substrate, a coil, and external electrodes disposed separately on the bottom and end faces of the substrate. In this laminated coil component, the external electrodes are embedded in the substrate such that they protrude from the bottom surface of the substrate. Summary of the Invention

[0003] In the aforementioned electronic components, there are cases where cracks or gaps are generated in the substrate near the external electrodes.

[0004] One aspect of the present invention provides a laminated coil component capable of suppressing the formation of cracks or gaps in the substrate.

[0005] According to one aspect of the present invention, a laminated coil component includes a body, a coil, and external terminals. The body is formed by stacking multiple insulating layers. The coil is disposed within the body. The external terminals are formed by stacking multiple conductor layers and are electrically connected to the coil. The body has a main surface and a first side surface adjacent to the main surface. The external terminals are embedded in the body in a manner that separates them from the first side surface and exposes them from the main surface. The external terminals have a first separation surface that separates them further from the first side surface the further they are from the main surface.

[0006] In this laminated coil assembly, the external terminal is embedded in the substrate in a manner that separates it from the first side surface and exposes it from the main surface. Therefore, the substrate has a portion sandwiched between the first side surface and the external terminal. Since this portion is thinner than other portions, it is prone to cracking or gaps. Therefore, the external terminal has a first separation surface that separates further from the first side surface as it moves from the main surface. This increases the thickness of the thin portion sandwiched between the first side surface and the external terminal, suppressing the formation of cracks or gaps. The area of ​​the exposed surface of the external terminal for mounting is maintained. This suppresses a decrease in mounting strength.

[0007] The edge between the main surface and the first side surface can also have a chamfered shape. In this case, since the thin portion sandwiched between the first side surface and the outer terminal becomes thinner, it is more prone to cracks or gaps. Therefore, the structure with a first separation surface on the outer terminal is more effective.

[0008] The ridge portion can also have a rounded chamfered shape. The thickness of the outer terminal can also be greater than the radius of curvature of the ridge portion. In this case, since the thin portion sandwiched between the first side and the outer terminal becomes longer, it is more prone to cracks or gaps. Therefore, the structure with a first separation surface on the outer terminal is more effective.

[0009] The ridge portion can also have a rounded chamfered shape. The first separation surface can also be bent with a radius of curvature larger than that 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 outer terminal.

[0010] External terminals can also be disposed on the outside of the ridge portion. In this case, the ridge portion can be constructed solely from the base material. The ease of grinding varies depending on the material. Therefore, in a ridge portion constructed solely from the base material, it is easier to form a chamfered shape through grinding compared to a ridge portion constructed from multiple materials.

[0011] The substrate may further have a pair of second side surfaces, each adjacent to the main surface. The first side surface may also be adjacent to each of the pair of second side surfaces. The pair of second side surfaces may also be opposite each other. The external terminals may further have a pair of second separation surfaces that separate further from the main surface and further from the pair of second side surfaces. In this case, the substrate has three thin portions sandwiched between the first side surface and each of the pair of second side surfaces. The generation of cracks or notches can be completely suppressed in all of these thin portions.

[0012] Another type of laminated coil component includes a body, a coil, and external terminals. The body is formed by stacking multiple insulating layers. The coil is disposed within the body. The external terminals are formed by stacking multiple conductor layers and are electrically connected to the coil. The body has a rectangular main surface and a pair of adjacent side surfaces, each adjacent to the main surface. The external terminals are embedded in the body in a manner separated from the pair of side surfaces and exposed from the main surface. The external terminals have a second corner portion arranged adjacent to a first corner portion between the pair of side surfaces when viewed from a direction orthogonal 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.

[0013] In this laminated coil assembly, the external terminals are embedded in the substrate in a manner separated from a pair of side surfaces and exposed from the main surface. Therefore, the substrate has a portion sandwiched between the pair of side surfaces and the external terminals. Since this portion is relatively small compared to other portions, it is prone to cracking or gaps. Therefore, when viewed from a direction orthogonal to the main surface, the radius of curvature of the second corner of the external terminal adjacent to the first corner is increased relative to the radius of curvature of the first corner between the pair of side surfaces of the substrate. This increases the volume of the portion sandwiched between the pair of side surfaces and the external terminals, suppressing the formation of cracks or gaps. Attached Figure Description

[0014] Figure 1 This is a perspective view of the stacked coil component according to the embodiment.

[0015] Figure 2 yes Figure 1 A cross-sectional view of the stacked coil component.

[0016] Figure 3 yes Figure 1 A cross-sectional view of the stacked coil component.

[0017] Figure 4 yes Figure 1 A bottom view of the stacked coil components.

[0018] Figure 5 yes Figure 1 An exploded perspective view of the stacked coil components.

[0019] Figure 6 This is a partially enlarged cross-sectional view of the stacked coil component in the first modified example.

[0020] Figure 7 This is a partially enlarged cross-sectional view of the stacked coil component in the second variation. Detailed Implementation

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in the description of the drawings, the same or equivalent elements are labeled with the same symbols, and repeated descriptions are omitted.

[0022] like Figures 1-5 As shown, the laminated coil component 1 includes a rectangular parallelepiped body 2, a pair of external terminals 3, a coil 10, and connecting conductors 26 and 27. The rectangular parallelepiped shape includes a cuboid shape with chamfered corners and edges, and a cuboid shape with rounded corners and edges. The laminated coil component 1 is, for example, a laminated high-frequency inductor. Furthermore, in... Figures 1-4 The diagrams of coil 10 and connecting conductors 26 and 27 are omitted.

[0023] The base body 2 has two opposing main faces 2a and 2b, a pair of opposing side faces 2c, and a pair of opposing side faces 2e. In the following description, the direction in which the pair of side faces 2e are opposite is designated as the first direction D1, the direction in which the pair of side faces 2c are opposite is designated as the second direction D2, and the direction in which the main faces 2a and 2b are opposite is designated as the third direction D3. The first direction D1, the second direction D2, and the third direction D3 intersect each other (here, they are orthogonal). In this embodiment, the first direction D1 is the width direction of the base body 2. The second direction D2 is the length direction of the base body 2. The third direction D3 is the height direction of the base body 2.

[0024] Main faces 2a and 2b, as well as a pair of side faces 2c and a pair of side faces 2e, are all rectangular in shape. The long sides of main faces 2a and 2b align with the second direction D2. The short sides of main faces 2a and 2b align with the first direction D1. Main face 2a is adjacent to each of the side faces 2c and 2e. Main face 2b is adjacent to each of the side faces 2c and 2e. Each of the side faces 2c is adjacent to each of the side faces 2e.

[0025] The edge portion 2g between the main surface 2a and the side surface 2c has a chamfered shape. The edge portion 2h between the main surface 2a and the side surface 2e has a chamfered shape. The edge portion 2i between the side surface 2c and the side surface 2e has a chamfered shape. The edge portion 2j between the main surface 2b and the side surface 2c has a chamfered shape. The edge portion 2k between the main surface 2b and the side surface 2e has a chamfered shape. Each edge portion 2g, 2h, 2i, 2j, and 2k has a rounded chamfered shape, for example, by tumbling.

[0026] Main surfaces 2a and 2b extend along a second direction D2, connecting a pair of side surfaces 2c. Main surfaces 2a and 2b also extend along a first direction D1, connecting a pair of side surfaces 2e. A pair of side surfaces 2c extend along a third direction D3, connecting the main surfaces 2a and 2b. A pair of side surfaces 2c also extend along the first direction D1, connecting a pair of side surfaces 2e. A pair of side surfaces 2e extend along a third direction D3, connecting the main surfaces 2a and 2b. A pair of side surfaces 2e also extend along the second direction D2, connecting a pair of side surfaces 2c. The laminated coil component 1 is soldered to an electronic device (e.g., a circuit board or electronic component). In the laminated coil component 1, the main surface 2a constitutes a mounting surface opposite to the electronic device.

[0027] like Figure 5 As shown, the substrate 2 is constructed by stacking multiple insulating layers 6 in the first direction D1. The substrate 2 has multiple insulating layers 6 stacked in the first direction D1. In the substrate 2, the stacking direction of the multiple insulating layers 6 is consistent with the first direction D1. In the actual substrate 2, the multiple insulating layers 6 are integrated to the point that the boundaries between the individual insulating layers 6 are indistinguishable.

[0028] Each insulating layer 6 is formed of a dielectric material containing a glass component. That is, the base material 2, as a compound of the elements constituting the base material 2, contains a dielectric material containing a glass component. The glass component is, for example, borosilicate glass. The dielectric material is, for example, a dielectric ceramic of the BaTiO3 type, Ba(Ti,Zr)O3 type, or (Ba,Ca)TiO3 type. Each insulating layer 6 is composed of a sintered body of ceramic green sheets containing glass ceramic material.

[0029] like Figure 2 and Figure 3 As shown, a pair of recesses 4 are provided on the main surface 2a. The pair of recesses 4 are separated from each other in the second direction D2. When viewed from a direction orthogonal to the main surface 2a (the third direction D3), the pair of recesses 4 are separated from a pair of side surfaces 2c and a pair of side surfaces 2e, respectively. One recess 4 is provided on one side surface 2c of the body 2. The other recess 4 is provided on the other side surface 2c of the body 2.

[0030] like Figures 1-5As shown, a pair of external terminals 3 are electrically connected to the ends of coil 10. The pair of external terminals 3 are embedded in the body 2, protruding from the main surface 2a. The pair of external terminals 3 are not exposed on the main surface 2b or the sides 2c and 2e. The pair of external terminals 3 are separated from each other in the second direction D2. Viewed from a direction orthogonal to the main surface 2a (third direction D3), the pair of external terminals 3 are separated from the pair of sides 2c and the pair of sides 2e, respectively. One external terminal 3 is located on one side 2c of the body 2. The other external terminal 3 is located on the other side 2c of the body 2. The pair of external terminals 3 have the same shape.

[0031] The pair of external terminals 3 can also be described as being disposed within a pair of recesses 4 located on the main surface 2a. Each recess 4 is a space recessed from the main surface 2a toward the inside of the body 2. Each recess 4 has a shape corresponding to the shape of the corresponding external terminal 3. Each external terminal 3 is in complete, seamless contact with the inner surface of the corresponding recess 4.

[0032] Each external terminal 3 is a rectangular plate with its thickness along the third direction D3. The thickness t of the external terminal 3 is larger than the radius of curvature of each edge portion 2g, 2h. The radii of curvature of the edge portions 2g, 2h are, for example, equal to each other. Each external terminal 3 has an exposed surface 3a, a bottom surface 3b, connecting surfaces 3c, 3d, and a pair of connecting surfaces 3e. The exposed surface 3a and the bottom surface 3b are opposite each other in the thickness direction (third direction D3). The exposed surface 3a faces outward from the main surface 2a. The exposed surface 3a is located in approximately the same plane as the main surface 2a, but it can be located either further outward from the main surface 2a or further inward from the main surface 2a. That is, each external terminal 3 can protrude outward from the main surface 2a towards the outside of the main body 2, or it can be recessed inward from the main surface 2a towards the inside of the main body 2.

[0033] The bottom surface 3b faces the inside of the body 2 and is opposite to 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 planes. The long side direction of the exposed surface 3a and the bottom surface 3b is consistent with the first direction D1. The short side direction of the exposed surface 3a and the bottom surface 3b is consistent with the second direction D2.

[0034] Each connecting surface 3c, 3d, and 3e connects the exposed surface 3a to the bottom surface 3b. Connecting surface 3c faces its corresponding side surface 2c. A corresponding side surface 2c refers to the closer side surface 2c of a pair of side surfaces 2c. Connecting surfaces 3c and 3d face each other in the second direction D2. Connecting surfaces 3c and 3d face opposite sides of the second direction D2. A pair of external terminals 3 are arranged with connecting surfaces 3d facing each other. A pair of connecting surfaces 3e face each other in the first direction D1. Each connecting surface 3e faces its corresponding side surface 2e. A corresponding side surface 2e refers to the closer side surface 2e of a pair of side surfaces 2e.

[0035] The more the connecting surface 3c separates from the main surface 2a, the more it separates from the plane containing the corresponding side surface 2c in the second direction D2. The plane containing side surface 2c is an imaginary plane. The distance dc between the planes containing the connecting surface 3c and the side surface 2c in the second direction D2 becomes longer as they separate from the main surface 2a. Here, the connecting surface 3c may also include a portion parallel to the plane containing side surface 2c. In this case, the distance dc remains constant in the portion parallel to the plane containing side surface 2c. The connecting surface 3c should tend to separate from the plane containing side surface 2c as it separates from the main surface 2a. The distance dc should increase monotonically as it separates from the main surface 2a. Monotonically increasing means there is no tendency to decrease.

[0036] The connecting surface 3c is curved with a radius of curvature larger than that of the ridge portion 2g. The connecting surface 3c is curved in a manner that bulges inward toward the body 2. In this embodiment, the portion of the connecting surface 3c exposed on the side 3a is parallel to the plane including the side surface 2c. The plane including the side surface 2e is an imaginary plane. The portion of the connecting surface 3c on the bottom surface 3b is curved with a radius of curvature larger than that of the ridge portion 2g. Alternatively, the entire connecting surface 3c may be curved with a radius of curvature larger than that of the ridge portion 2g.

[0037] The connecting surface 3d curves such that the portion on the bottom surface 3b is closer to the plane containing the corresponding side surface 2c the further it separates from the main surface 2a. The portion of the connecting surface 3d on the exposed surface 3a side is parallel to the plane containing the side surface 2c.

[0038] The more each connecting surface 3e separates from the main surface 2a, the more it separates from the plane containing the corresponding side surface 2e in the first direction D1. The distance de between the planes containing the connecting surface 3e and the side surface 2e in the first direction D1 becomes longer as they separate from the main surface 2a. Here, the connecting surface 3e may also include a portion parallel to the plane containing the side surface 2e. In this case, the distance de remains constant in the portion parallel to the plane containing the side surface 2e. The connecting surface 3e should tend to separate from the plane containing the side surface 2e as it separates from the main surface 2a. The distance de should increase monotonically as it separates from the main surface 2a.

[0039] Each connecting surface 3e is curved with a radius of curvature larger than that of the ridge portion 2h. The radii of curvature of connecting surfaces 3c, 3d, and 3e are, for example, equal to each other. The connecting surface 3e is curved in a manner that bulges inward toward the base body 2. In this embodiment, the portion of the connecting surface 3e on the exposed surface 3a side is parallel to the plane containing the connecting surface 3e. The portion of the connecting surface 3e on the bottom surface 3b side is curved with a radius of curvature larger than that of the ridge portion 2h. The entire connecting surface 3e may also be curved with a radius of curvature larger than that of the ridge portion 2h.

[0040] Each external terminal 3, viewed from a direction orthogonal to the main surface 2a (third direction D3), is positioned outside each ridge portion 2g, 2h. That is, each external terminal 3, viewed from the third direction D3, is positioned within the area of ​​the main surface 2a and does not cross the ridge portions 2g, 2h. Specifically, the external terminal 3 is positioned separately from the plane containing the corresponding side surface 2c, at a distance greater than or equal to the design value of the radius of curvature of the ridge portion 2g or the measured radius of curvature of the ridge portions 2i, 2j, 2k. Similarly, the external terminal 3 is positioned separately from the plane containing the corresponding side surface 2e, at a distance greater than or equal to the design value of the radius of curvature of the ridge portion 2h or the measured radius of curvature 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, 2h are adjacent to the main surface 2a where the external terminals 3 are located, the radii of curvature of the ridge portions 2g, 2h may sometimes be affected by the external terminals 3 and become smaller than the design value. Since the ridge portions 2i, 2j, and 2k are not adjacent to the main surface 2a, their radii of curvature are not affected by the external terminal 3 and are close to the design values. Therefore, the measured values ​​of the radii of curvature of the ridge portions 2i, 2j, and 2k can be used instead of the design values ​​of the radii of curvature of the ridge portions 2g and 2h. Because the ridge portion 2g has a chamfered shape, it does not connect with either the plane containing the side surface 2c or the plane containing the main surface 2a. Because the ridge portion 2h has a chamfered shape, it also does not connect with either the plane containing the connecting surface 3e or the plane containing the main surface 2a. The plane containing the main surface 2a is an imaginary plane.

[0041] Viewed from a direction orthogonal to the main face 2a (third direction D3), the body 2 has corner A1 between adjacent side faces 2c and 2e. Corner A1 is formed by edge portion 2i. The body 2 has four corner A1. Each external terminal 3, viewed from a direction orthogonal to the main face 2a (third direction D3), has four corners. Of the four corners of the external terminal 3, two corners A2 are arranged adjacent to the corresponding corner A1. That is, the external terminal 3 has corners A2 arranged adjacent to the corner A1 between side faces 2c and 2e. Furthermore, adjacent means closest. The radius of curvature of each corner A2 is larger than the radius of curvature of the adjacent corner A1.

[0042] like Figure 5As shown, the external terminal 3 is constructed by stacking multiple electrode layers 11 in the first direction D1. The external terminal 3 has multiple electrode layers 11 stacked in the first direction D1. The multiple electrode layers 11 are integrated to such an extent that the boundaries between the electrode layers 11 are indistinguishable. In this embodiment, the number of electrode layers 11 is "6". Each electrode layer 11 is disposed at a notch formed in the corresponding insulating layer 6. The notch forms a recess 4. The electrode layer 11 contains a conductive material. The conductive material includes, for example, Ag or Pd. The electrode layer 11 is constructed as a sintered body of a conductive paste containing conductive material powder. The conductive material powder includes, for example, Ag powder or Pd powder.

[0043] Electrode layer 11 may further contain a glass component. That is, electrode layer 11 may also be a sintered body containing a conductive paste consisting of a metallic component made of conductive material powder and a glass component. The glass component is a compound of the elements constituting the base body 2, and is the same component as the glass component contained in the base body 2. The content of the glass component can be appropriately set. Each electrode layer 11 extends along the second direction D2.

[0044] The coil 10 and connecting conductors 26 and 27 are disposed within the body 2 and do not protrude from the body 2. The coil 10 has a coil shaft along a first direction D1. A pair of ends of the coil 10 are connected to a pair of external terminals 3 (see reference). Figure 2 Electrical connection. One end is electrically connected to an external terminal 3 via connecting conductor 26. The other end is electrically connected to another external terminal 3 via connecting conductor 27.

[0045] 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 following order: first coil conductor 22, second coil conductor 23, third coil conductor 24, and 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 in a ring-shaped form with a partial interruption, each having one end and the other end.

[0046] The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, and the fourth coil conductor 25 are formed with a specified width (length in the 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 with equal width and height to each other.

[0047] 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 another electrode layer 11 located in the same layer via a connecting conductor 26. The connecting conductor 26 is located in the same layer as the pair of electrode layers 11 and the first coil conductor 22. The connecting 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 connecting conductor 26. 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 connecting conductor 26, and the other electrode layer 11 are integrally formed.

[0048] The second coil conductor 23 is located in the same layer as the pair of electrode layers 11. The second coil conductor 23 is separate 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 directly connected to each other. 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.

[0049] The third coil conductor 24 is located in the same layer as the pair of electrode layers 11. The third coil conductor 24 is separate 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 D13 and are directly connected to 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.

[0050] 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 an electrode layer 11 located in the same layer via a connecting conductor 27. The connecting conductor 27 is located in the same layer as the pair of electrode layers 11 and the fourth coil conductor 25. The connecting conductor 27 connects the fourth coil conductor 25 to an electrode layer 11. The other end of the fourth coil conductor 25 is connected to the connecting 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 connecting conductor 27, and the electrode layer 11 are integrally formed.

[0051] 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 may contain, 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 constructed as a sintered body of a conductive paste containing conductive material powder. The conductive material powder may contain, for example, Ag powder or Pd powder.

[0052] 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 each external terminal 3. Alternatively, 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 different conductive material than each external terminal 3.

[0053] 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 disposed in the notches formed in the corresponding insulating 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 sintering a conductive paste located in the notches formed in the green sheet.

[0054] The notch in the green film is formed, for example, through the following process. First, a green film is formed by applying a substrate paste containing a structural material comprising an insulating layer 6 and a photosensitive material to a substrate. The substrate is, for example, a PET film. The photosensitive material contained in the substrate paste can be either negative or positive, and known materials can be used. Next, the green film is exposed and developed using photolithography using a mask corresponding to the notch, forming the notch in the green film on the substrate. The green film with the notch is a substrate pattern.

[0055] Electrode layer 11, first coil conductor 22, second coil conductor 23, third coil conductor 24, fourth coil conductor 25 and connecting conductors 26 and 27 are formed, for example, by the following process.

[0056] First, a conductive material layer is formed by applying a conductive paste containing a photosensitive material to a substrate. The photosensitive material contained in the conductive paste can be either negative or positive, and known materials can be used. Next, using a mask corresponding to the notch, the conductive material layer is exposed and developed using photolithography to form a conductor pattern on the substrate corresponding to the shape of the notch.

[0057] The multilayer coil component 1 is obtained, for example, through the following process following the above-described process. A conductor pattern is combined with a notch in the substrate pattern to prepare a sheet where the substrate pattern and conductor pattern are on the same layer. After heat treatment of the multilayer obtained from a predetermined number of prepared sheets, multiple green chips are obtained from the multilayer. In this process, for example, the green multilayer is cut into chip shapes using a dicing machine. Multiple green chips of a predetermined size are thus obtained. Next, the green chips are sintered. Through this sintering, the multilayer coil component 1 is obtained. A plating layer may also 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.

[0058] The stacked coil component 1 is formed using this photolithography method, thus enabling the external terminals 3 to be formed in any shape. That is, each connecting surface 3c, 3d, and 3e can be easily shaped with a desired radius of curvature. In the above manufacturing method, after preparing a sheet with the substrate pattern and conductor pattern on the same layer, a predetermined number of prepared sheets are stacked to form a stack. However, the stack can also be formed using other methods. For example, the substrate pattern and conductor pattern can be sequentially formed on a substrate for stacking using photolithography to form the stack. That is, the substrate 2 is independent of the manufacturing method and can be formed by having multiple insulating layers 6 with a stacked structure. The external terminals 3 are independent of the manufacturing method and can be formed by having multiple electrode layers 11 with a stacked structure.

[0059] As explained above, in the laminated coil component 1 of this embodiment, the external terminal 3 is embedded in the body 2 in a manner that separates it from each side surface 2c, 2e and exposes it from the main surface 2a. Therefore, the body 2 has a portion sandwiched between the side surface 2c and the external terminal 3 and a portion sandwiched between the side surface 2e and the external terminal 3. Such a portion is thinner than the other portions, and therefore is prone to cracks or gaps.

[0060] The more the connecting surface 3c of the external terminal 3 separates from the main surface 2a, the more it separates from the side surface 2c. Therefore, in the body 2, the thickness (length in the second direction D2) of the portion sandwiched between the side surface 2c and the external terminal 3 can be increased, suppressing the generation of cracks or gaps. Furthermore, the more the connecting surface 3e of the external terminal 3 separates from the main surface 2a, the more it separates from the side surface 2e. Therefore, in the body 2, the thickness (length in the first direction D1) of the portion sandwiched between the side surface 2e and the external terminal 3 can be increased, suppressing the generation of cracks or gaps. Because the area of ​​the exposed surface 3a for mounting in the external terminal 3 can be maintained relatively large, the decrease in mounting strength can be suppressed.

[0061] 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 thinner, making it more prone to cracking or chipping. Thus, the structure of the external terminal 3 with the connecting surface 3c as described above is more effective. 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 thinner, making it more prone to cracking or chipping. Thus, the structure of the external terminal 3 with the connecting surface 3e as described above is more effective.

[0062] The ridge portions 2g and 2h have rounded chamfered shapes, and the thickness t of the outer terminal 3 is larger than the radius of curvature of the ridge portions 2g and 2h. Therefore, compared to the case where the thickness t of the outer terminal 3 is less than or equal to the radius of curvature of the ridge portion 2g, the thin portion sandwiched between the side surface 2c and the outer terminal 3 becomes longer in the thickness direction (third direction D3) of the outer terminal 3. As a result, the structure of the outer terminal 3 having a connecting surface 3c is more effective because cracks or gaps are more likely to occur. Furthermore, compared to the case where the thickness t of the outer terminal 3 is less than or equal to the radius of curvature of the ridge portion 2h, the thin portion sandwiched between the side surface 2e and the outer terminal 3 becomes longer in the thickness direction of the outer terminal 3. As a result, the structure of the outer terminal 3 having a connecting surface 3e is more effective because cracks or gaps are more likely to occur.

[0063] The ridge portion 2g has a rounded chamfered shape, and the connecting surface 3c is bent with a radius of curvature larger than that of the ridge portion 2g. Therefore, the thickness of the thin portion sandwiched between the side surface 2c and the external terminal 3 can be further increased. The ridge portion 2h has a rounded chamfered shape, and the connecting surface 3e is bent with a radius of curvature larger than that of the ridge portion 2h. Therefore, the thickness of the thin portion sandwiched between the side surface 2e and the external terminal 3 can be further increased.

[0064] External terminals 3 are disposed on the outer side of the ridge portions 2g and 2h. Therefore, the ridge portions 2g and 2h can be constructed using only the base body 2. The ease of grinding varies depending on the material. Thus, the ridge portions 2g and 2h constructed using only the base body 2 are easier to chamfer by grinding compared to ridge portions constructed from multiple materials. This allows for optimization of the product shape and suppression of cracks or gaps in the base body 2.

[0065] The external terminal 3 is more difficult to grind than the raw body 2 before sintering. Therefore, when the external terminal 3 is also exposed on the side 2c, forming the ridge portion 2g, the ridge portion 2g is difficult to grind and difficult to form a chamfered shape. Thus, compared to the other ridge portions 2h, 2i, 2j, and 2k formed by the raw body 2 where the external terminal 3 is not exposed, the ridge portion 2g becomes a sharp shape, easily becoming the starting point of cracks or gaps. When grinding conditions are set to match the external terminal 3, the other ridge portions 2h, 2i, 2j, and 2k formed by the raw body 2 where the external terminal 3 is not exposed are easily over-ground, and the raw body 2 is prone to rolling. Therefore, the processing of the laminated coil component 1 becomes difficult. The example given is the case where the external terminal 3 is exposed on the side 2c, but the same problem exists when the external terminal 3 is exposed on the side 2e.

[0066] Even when the external terminal 3 is separated from the plane including the side 2c, if the distance between the external terminal 3 and the plane including the side 2c is insufficient—specifically, if this distance is shorter than the design value of the curvature radius of the ridge portions 2g, 2h, 2i, 2j, and 2k—the grinding of the ridge portion 2g is hindered by the external terminal 3, making it difficult to achieve the design value for the curvature radius of the ridge portion 2g. Therefore, the ridge portion 2g is prone to becoming the starting point of cracks or gaps. While matching the grinding conditions to the ridge portion 2g can achieve the design value for the curvature radius of the ridge portion 2g, it may lead to over-grinding of the other ridge portions 2h, 2i, 2j, and 2k, causing the curvature radius to exceed the design value. Consequently, the body 2 becomes prone to rolling, making the processing of the stacked coil component 1 difficult. The example given is the case where the distance between the external terminal 3 and the plane including the side 2c is insufficient; the same problem exists when the distance between the external terminal 3 and the plane including the side 2e is insufficient.

[0067] In the laminated coil component 1, the external terminal 3 is embedded in the body 2 in a manner that separates it from the adjacent sides 2c and 2e and exposes it from the main surface 2a. Therefore, the body 2 has a portion sandwiched between the sides 2c and 2e and the external terminal 3. This portion is smaller in volume than the other portions, making it prone to cracking or gaps. Therefore, when viewed from a direction orthogonal to the main surface 2a (third direction D3), the radius of curvature of the corner A2 of the external terminal 3 adjacent to corner A1 is made larger than the radius of curvature of the corner A1 between the sides 2c and 2e of the body 2. This increases the volume of the portion sandwiched between the sides 2c and 2e and the external terminal 3, suppressing the formation of cracks or gaps.

[0068] Because the pair of external terminals 3 are only exposed on the main surface 2a, the mounting area can be reduced. For example, if the external terminals 3 are exposed on both the main surface 2a and the side surface 2c, solder is also formed on the side surface 2c, thus increasing the mounting area.

[0069] The embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit.

[0070] Figure 6 This is an enlarged cross-sectional view of a portion of the stacked coil component in the first modified example. Figure 6 The first modified example shown has a multilayer coil component 1A comprising an external terminal 3A formed by stacking multiple electrode layers 31, 32, and 33 on a third-direction D3, which is consistent with... Figures 1-5 The stacked coil component 1 shown is different. In addition, the multiple insulating layers 6 can be stacked either on the third direction D3, or on the first direction D1 or the second direction D2.

[0071] Multiple electrode layers 31, 32, and 33 are arranged in this order, starting from the main surface 2b. That is, electrode layer 31 is arranged closest to the main surface 2b, and electrode layer 33 is arranged closest to the main surface 2a. Electrode layer 32 is disposed between electrode layers 31 and 33. The exposed surface 3a is formed by one surface of electrode layer 33 in the thickness direction (third direction D3). The bottom surface 3b is formed by one surface of electrode layer 31 in the thickness direction (third direction D3).

[0072] The lengths of the second direction D2 of the multiple electrode layers 31, 32, and 33 are different from each other. The multiple electrode layers 31, 32, and 33 are arranged, for example, with their centers aligned in the second direction D2. Therefore, the end faces of the side surfaces 2c and 2d of the multiple electrode layers 31, 32, and 33 are staggered in a stepped manner. That is, the connecting surface 3c and the connecting surface 3d are stepped. Thus, in the laminated coil component 1A, the connecting surface 3c separates further from the main surface 2a and further from the side surface 2c. Consequently, in the laminated coil component 1A, the thickness of the portion sandwiched between the side surface 2c and the external terminal 3 can be increased, suppressing the generation of cracks or gaps.

[0073] Figure 7 This is an enlarged cross-sectional view of a portion of the stacked coil component in the second variation. Figure 7 The second modified example shown has a stacked coil component 1B with electrode layers 31, 32, and 33 and an external terminal 3A (see reference). Figure 6 The external terminal 3B is different from the laminated coil component 1A (see reference). Figure 6 The difference lies in the connection surface 3d of the external terminal 3B, which is arranged with multiple electrode layers 31, 32, and 33 in a manner that forms a plane along the third direction D3. Similarly, the connection surface 3c of the external terminal 3B is stepped, as is the case with the external terminal 3A. Therefore, in the laminated coil component 1B, the thickness of the portion sandwiched between the side surface 2c and the external terminal 3 can be increased, suppressing the generation of cracks or gaps.

[0074] In the laminated coil component 1, an example is provided where the coil 10 has a coil axis along a 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 may not be along the first direction D1. The coil axis of the coil 10 may, for example, be along a second direction D2 or a third direction D3. Furthermore, the number of coil conductors constituting the coil 10 is not limited to four.

[0075] In the stacked coil component 1, each edge portion 2g, 2h, 2i, 2j, and 2k has a rounded chamfer shape. However, each edge portion 2g, 2h, 2i, 2j, and 2k may also have a chamfer shape composed of a plane, or it may not have a chamfer shape.

[0076] In the stacked coil component 1, the external terminal 3 is composed of six electrode layers 11, but it is acceptable as long as it is composed of at least two electrode layers 11. In the stacked coil components 1A and 1B, the external terminals 3A and 3B are composed of three electrode layers 31, 32, and 33, but it is acceptable as long as they are composed of at least two electrode layers.

[0077] In the laminated coil components 1A and 1B, the connecting surface 3c is stepped, but the connecting surface 3e can also be stepped. In this case, the thickness of the portion sandwiched between the side surface 2e and the external terminal 3 can be increased, suppressing the generation of cracks or gaps.

Claims

1. A laminated coil component, characterized in that: have: The base body is composed of multiple layers of insulating material; A coil, which is disposed within the body; and External terminals, which are composed of multiple stacked conductor layers, are electrically connected to the coil. The substrate has a main surface, a first side surface adjacent to the main surface, and a pair of second side surfaces each adjacent to the main surface. The first side is adjacent to each of the pair of second sides. The pair of second sides face each other. The external terminal is embedded in the body in a manner that separates it from the first side and the pair of second side and exposes it from the main surface, and has a first separation surface that separates it further from the first side as it separates from the main surface. The edge portion between the main surface and the first side surface has a rounded chamfer shape. The thickness of the external terminal in the direction orthogonal to the main surface is greater than the radius of curvature of the ridge portion.

2. The laminated coil component as described in claim 1, characterized in that: The first separation surface bends with a radius of curvature larger than that of the ridge portion.

3. The laminated coil component as described in claim 1, characterized in that: The external terminal is located on the outside of the ridge portion.

4. The laminated coil component as described in claim 2, characterized in that: The external terminal is located on the outside of the ridge portion.

5. The laminated coil component as described in any one of claims 1 to 4, characterized in that: The external terminal also has a pair of second separation surfaces that separate from the pair of second side surfaces as they separate from the main surface.

6. A laminated coil component, characterized in that: have: The base body is composed of multiple layers of insulating material; A coil, which is disposed within the body; and External terminals, which are composed of multiple stacked conductor layers, are electrically connected to the coil. The body has a rectangular main face and a pair of side faces that are adjacent to each other and each adjacent to the main face. The external terminals are embedded in the body in a manner that separates them from the pair of side surfaces and exposes them from the main surface, and have a second corner portion arranged adjacent to the first corner portion between the pair of side surfaces when viewed from a direction orthogonal to the main surface. The radius of curvature of the second corner is larger than that of the first corner. The edge portion between the main surface and the pair of side surfaces has a rounded chamfer shape. The thickness of the external terminal in the direction orthogonal to the main surface is greater than the radius of curvature of the ridge portion.

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