Laminated coil components

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 multilayer coil component.

Background Art

[0002] Patent Document 1 describes a multilayer coil component including a base body, a coil, and an external electrode disposed on the bottom surface of the base body and spaced apart from the end surface. In this multilayer coil component, the external electrode is embedded in the base body so as to be exposed from the bottom surface of the base body.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

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

[0005] One aspect of the present disclosure provides a multilayer coil component capable of suppressing the occurrence of cracks or chips in the base body.

Means for Solving the Problems

[0006] A multilayer coil component according to one aspect of the present disclosure includes a base body formed by laminating a plurality of insulator layers, a coil disposed in the base body, and an external terminal formed by laminating a plurality of conductor layers and electrically connected to the coil. The base body has a main surface and a first side surface adjacent to the main surface. The external terminal is embedded in the base body so as to be spaced apart from the first side surface and exposed from the main surface, and has a first separation surface that is spaced apart from the first side surface as it is spaced apart from the main surface.

[0007] In this laminated coil component, the external terminals are embedded in the base body so as to be spaced apart from the first side surface and exposed from the main surface. As a result, the base body has a portion sandwiched between the first side surface and the external terminals. Since this portion is thinner than other parts, it is prone to cracking or chipping. Therefore, the external terminals have a first separation surface that is spaced further apart from the first side surface as it is spaced further away from the main surface. This increases the thickness of the thin portion sandwiched between the first side surface and the external terminals, thereby suppressing the occurrence of cracking or chipping. In addition, since the area of ​​the exposed surface of the external terminals used for mounting can be maintained, a decrease in mounting strength can be suppressed.

[0008] The ridge 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 susceptible to cracking or chipping. Therefore, a configuration in which the external terminal has a first separation surface is more effective.

[0009] The ridges have a rounded chamfered shape, and the thickness of the external terminal may be greater than the radius of curvature of the ridges. In this case, the thin portion sandwiched between the first side surface and the external terminal becomes longer, making it more prone to cracking or chipping. Therefore, a configuration in which the external terminal has a first separation surface is more effective.

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

[0011] External terminals may be located on the outside of the ridge. In this case, the ridge can be constructed using only the base material. The ease of polishing varies depending on the material. Therefore, a chamfered shape is more easily formed by polishing a ridge made of only the base material compared to a ridge made of multiple materials.

[0012] The body further has a pair of second sides adjacent to each of its main surfaces, the first side is adjacent to each of the pair of second sides, the pair of second sides face each other, and the external terminals may further have a pair of second separated surfaces that are further apart from the pair of second sides as they are further apart from the main surface. In this case, the body has three thin parts sandwiched between the first side and each of the pair of second sides. It is possible to suppress the occurrence of cracks or chips in all of these thin parts.

[0013] Another form of laminated coil component comprises a base body made of multiple insulator layers, a coil disposed within the base body, and an external terminal made of multiple conductor layers and electrically connected to the coil. The base body has a rectangular main surface and a pair of side surfaces that are adjacent to each other and also adjacent to the main surface. The external terminal is spaced apart from the pair of side surfaces and embedded in the base body so as to be exposed from the main surface. When viewed from a direction perpendicular to the main surface, it has a second corner adjacent to the first corner between the pair of side surfaces, and the radius of curvature of the second corner is greater than the radius of curvature of the first corner.

[0014] In this laminated coil component, the external terminals are embedded in the base body, spaced apart from a pair of side surfaces and exposed from the main surface. Therefore, the base body has a portion sandwiched between the pair of side surfaces and the external terminals. Because this portion has a smaller volume than other parts, it is prone to cracking or chipping. To address this, the radius of curvature of the second corner of the external terminal adjacent to the first corner between the pair of side surfaces of the base body, viewed from a direction perpendicular to the main surface, is made larger than the radius of curvature of the first corner between the pair of side surfaces. This increases the volume of the portion sandwiched between the pair of side surfaces and the external terminals, thereby suppressing the occurrence of cracking or chipping. [Effects of the Invention]

[0015] According to one embodiment of the present invention, a laminated coil component is provided that can suppress the occurrence of cracks or chips in the base body. [Brief explanation of the drawing]

[0016] [Figure 1] FIG. 1 is a perspective view of a stacked coil component according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the stacked coil component of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view of the stacked coil component of FIG. 1. [Figure 4] FIG. 4 is a bottom view of the stacked coil component of FIG. 1. [Figure 5] FIG. 5 is an exploded perspective view of the stacked coil component of FIG. 1. [Figure 6] FIG. 6 is a partially enlarged cross-sectional view of a stacked coil component according to a first modification. [Figure 7] FIG. 7 is a partially enlarged cross-sectional view of a stacked coil component according to a second modification.

BEST MODE FOR CARRYING OUT THE INVENTION

[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 denoted by the same reference numerals, and redundant descriptions are omitted.

[0018] As shown in FIGS. 1 to 5, the stacked coil component 1 includes a rectangular parallelepiped-shaped body 2, a pair of external terminals 3, a coil 10, and connection conductors 26 and 27. The rectangular parallelepiped shape includes a rectangular parallelepiped shape in which the corners and ridge lines are chamfered, and a rectangular parallelepiped shape in which the corners and ridge lines are rounded. The stacked coil component 1 is, for example, a stacked high-frequency inductor. In FIGS. 1 to 4, the illustration of the coil 10 and the connection conductors 26 and 27 is omitted.

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

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

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

[0022] The main surfaces 2a and 2b extend in a second direction D2 to connect a pair of side surfaces 2c. The main surfaces 2a and 2b also extend in a first direction D1 to connect a pair of side surfaces 2e. The pair of side surfaces 2c extend in a third direction D3 to connect the main surfaces 2a and 2b. The pair of side surfaces 2c also extend in a first direction D1 to connect a pair of side surfaces 2e. The pair of side surfaces 2e extend in a third direction D3 to connect the main surfaces 2a and 2b. The pair of side surfaces 2e also extend in a second direction D2 to connect a pair of side surfaces 2c. The laminated coil component 1 is solder-mounted to electronic equipment (e.g., a circuit board or electronic components). In the laminated coil component 1, the main surface 2a constitutes the mounting surface facing the electronic equipment.

[0023] As shown in Figure 5, the base body 2 is constructed by stacking multiple insulating layers 6 in the first direction D1. The base body 2 has multiple insulating layers 6 stacked in the first direction D1. In the base body 2, the stacking direction in which the multiple insulating layers 6 are stacked coincides with the first direction D1. In the actual base body 2, the multiple insulating layers 6 are integrated to such an extent that the boundaries between each insulating layer 6 are not visible.

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

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

[0026] As shown in Figures 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 base 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 or the sides 2c and 2e. The pair of external terminals 3 are spaced apart from each other in the second direction D2. When viewed from a direction perpendicular to the main surface 2a (third direction D3), the pair of external terminals 3 are spaced apart from the pair of sides 2c and the pair of sides 2e, respectively. One external terminal 3 is provided on one side 2c of the base body 2. The other external terminal 3 is provided on the other side 2c of the base body 2. The pair of external terminals 3 have the same shape as each other.

[0027] It can also be said that the pair of external terminals 3 are arranged within a pair of recesses 4 provided on the main surface 2a. Each recess 4 is a space recessed inward from the main surface 2a into 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 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 greater 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 face each other in the thickness direction (third direction D3). The exposed surface 3a faces outward from the base body 2 and is exposed from the main surface 2a. The exposed surface 3a is located in substantially the same plane as the main surface 2a, but may be located outside the base body 2 from the main surface 2a, or inside the base body 2 from the main surface 2a. That is, each external terminal 3 may protrude outward from the main surface 2a from the base body 2, or may be recessed inward from the main surface 2a from the base body 2.

[0029] The bottom surface 3b faces inward from the body 2 and is opposite 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 direction of the long sides of the exposed surface 3a and the bottom surface 3b coincides with the first direction D1. The direction of the short sides of the exposed surface 3a and the bottom surface 3b coincides with the second direction D2.

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

[0031] The connecting surface 3c is further away from the plane containing the corresponding side surface 2c in the second direction D2 as it moves away from the main surface 2a. The plane containing side surface 2c is a hypothetical plane. The distance dc between the connecting surface 3c and the plane containing side surface 2c in the second direction D2 increases as they move away from the main surface 2a. Here, the connecting surface 3c may 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 move further away from the plane containing side surface 2c as it moves away from the main surface 2a. The distance dc should simply increase as it moves away from the main surface 2a. A simple increase means that it does not tend to decrease.

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

[0033] The connecting surface 3d is curved such that, as it moves further away from the main surface 2a, it approaches the plane containing the corresponding side surface 2c, on the bottom surface 3b side. On the exposed surface 3a side, the connecting surface 3d is parallel to the plane containing the side surface 2c.

[0034] Each connecting surface 3e is further away from the main surface 2a as it moves away from the plane containing the corresponding side surface 2e in the first direction D1. The distance de between the planes containing the connecting surfaces 3e in the first direction D1 increases as they move away from the main surface 2a. Here, the connecting surfaces 3e may include portions parallel to the plane containing the connecting surfaces 3e. In this case, the distance de remains constant in the portions parallel to the plane containing the connecting surfaces 3e. It is sufficient that the connecting surfaces 3e tend to move further away from the plane containing them as they move away from the main surface 2a. The distance de simply increases as it moves further away from the main surface 2a.

[0035] Each connecting surface 3e is curved with a radius of curvature larger than that of the edge 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 so as to bulge inward toward the 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 edge portion 2h. The entire connecting surface 3e may be curved with a radius of curvature larger than that of the edge portion 2h.

[0036] Each external terminal 3 is positioned outside each edge section 2g, 2h when viewed from a direction perpendicular to the main surface 2a (third direction D3). In other words, each external terminal 3 is positioned within the range of the main surface 2a when viewed from the third direction D3, and does not span across the edge sections 2g, 2h. That is, the external terminals 3 are positioned at a distance from the plane containing the corresponding side surface 2c that is greater than or equal to the design value of the radius of curvature of edge section 2g, or the measured radius of curvature of edge sections 2i, 2j, 2k. The external terminals 3 are positioned at a distance from the plane containing the corresponding side surface 2e that is greater than or equal to the design value of the radius of curvature of edge section 2h, or the measured radius of curvature of edge sections 2i, 2j, 2k. The design values ​​of the edge sections 2g, 2h, 2i, 2j, 2k are, for example, equivalent to each other. Since the ridge sections 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 sections 2g and 2h may be smaller than the design value due to the influence of the external terminal 3. Since the ridge sections 2i, 2j, and 2k are not adjacent to the main surface 2a, the radii of curvature of the ridge sections 2i, 2j, and 2k are not affected 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 sections 2g and 2h, the measured values ​​of the radii of curvature of the ridge sections 2i, 2j, and 2k may be used. Because the ridge section 2g has a chamfered shape, it is not in contact with either the plane containing the side surface 2c or the plane containing the main surface 2a. Because the ridge section 2h has a chamfered shape, it is not in contact 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 a hypothetical plane.

[0037] Viewed from a direction perpendicular to the main surface 2a (third direction D3), the base body 2 has a corner A1 between adjacent sides 2c and 2e. Corner A1 is composed of a ridge 2i. The base body 2 has four corners A1. Each external terminal 3 has four corners when viewed from a direction perpendicular to the main surface 2a (third direction D3). Of the four corners of the external terminal 3, two corners A2 are positioned adjacent to their corresponding corners A1. In other words, the external terminal 3 has corners A2 positioned adjacent to the corner A1 between sides 2c and 2e. Note that "adjacent" means closest to each other. The radius of curvature of each corner A2 is greater than the radius of curvature of the adjacent corner A1.

[0038] As shown in Figure 5, the external terminal 3 is constructed 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 a 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 defect formed in the corresponding insulator layer 6. The defect 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 constructed as a sintered body of a conductive paste containing 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 composed of a sintered body of a conductive paste containing a metal component made of conductive material powder and a glass component. The glass component is a compound of the elements that make up 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 set as appropriate. Each electrode layer 11 extends along the second direction D2.

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

[0041] Coil 10 includes 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 in the order of first coil conductor 22, second coil conductor 23, third coil conductor 24, and fourth coil conductor 25 along the first direction D1. The first coil conductor 22, the second coil conductor 23, the third coil conductor 24, and the fourth coil conductor 25 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 with a predetermined 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.

[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, which is 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 formed integrally.

[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 and in direct contact in the first direction D1. 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 and in direct contact in the first direction D1. 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, which is 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 one of the electrode layers 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 one of the electrode layers 11 are formed integrally.

[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, 27 contain a conductive material. The conductive material includes, 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, 27 are constructed as sintered bodies of a conductive paste containing conductive material powder. The conductive material powder includes, 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, 27 contain the same conductive material as each external terminal 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, 27 may contain a different conductive material than each external terminal 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 insulating layer 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 within the defects formed in the green sheet.

[0050] The defects formed in the green sheet are formed, for example, by the following process. First, a green sheet is formed by applying a base paste containing the constituent materials of the insulating layer 6 and a photosensitive material onto a substrate. The substrate is, for example, a PET film. The photosensitive material contained in the base paste may be either negative or positive type, and known materials can be used. Next, the green sheet is exposed and developed by photolithography using a mask corresponding to the defects to form defects in the green sheet on the substrate. The green sheet with the defects formed is a base 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, 27 are formed, for example, by the following process.

[0052] First, a conductive material layer is formed by applying a conductive paste containing a photosensitive material onto a substrate. The photosensitive material contained in the conductive paste may be either negative or positive type, and known types can be used. Next, using a mask corresponding to the defect, the conductive material layer is exposed and developed by photolithography to form a conductive pattern on the substrate corresponding to the shape of the defect.

[0053] The laminated coil component 1 is obtained, for example, by the following process following the process described above. A sheet is prepared in which the base pattern and the conductor pattern are in the same layer by combining the conductor pattern with the conductor pattern in the missing parts of the base pattern. After heat treatment of the laminate obtained by laminating a predetermined number of the prepared sheets, a plurality of green chips are obtained from the laminate. In this process, for example, the green laminate is cut into chip shapes with a cutting machine. This gives a plurality of green chips of a predetermined size. Next, the green chips are fired. This firing gives the laminated coil component 1. 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 using such a photolithography method, the external terminals 3 can be formed in any shape. That is, a shape in which each connection surface 3c, 3d, and 3e is curved with a desired radius of curvature can be easily realized. In the above manufacturing method, a sheet in which the base pattern and the conductor pattern are in the same layer is prepared, and then a predetermined number of the prepared sheets are stacked to form a laminate, but the laminate may be formed by other methods. For example, the laminate may be formed by sequentially forming the base pattern and the conductor pattern on a single substrate for stacking using the photolithography method. That is, the base 2 only needs to have a plurality of insulating layers 6 having a laminated structure, regardless of the manufacturing method. The external terminals 3 only need to 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 base body 2 so as to be spaced apart from each side surface 2c and 2e and exposed from the main surface 2a. Therefore, the base 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. Since these portions are thinner than other portions, they are prone to cracking or chipping.

[0056] The connection surface 3c of the external terminal 3 is further away from the side surface 2c as it is further away from the main surface 2a. This increases the thickness (length in the second direction D2) of the portion sandwiched between the side surface 2c and the external terminal 3 in the base body 2, thereby suppressing the occurrence of cracks or chips. Similarly, the connection surface 3e of the external terminal 3 is further away from the side surface 2e as it is further away from the main surface 2a. This increases the thickness (length in the first direction D1) of the portion sandwiched between the side surface 2e and the external terminal 3 in the base body 2, thereby suppressing the occurrence of cracks or chips. Since the area of ​​the exposed surface 3a used for mounting of the external terminal 3 can be kept large, a decrease in mounting strength can be suppressed.

[0057] The ridge portion 2g between the main surface 2a and the side surface 2c has a chamfered shape. As a result, the thin portion sandwiched between the side surface 2c and the external terminal 3 becomes even thinner, making it more susceptible to cracking or chipping. Therefore, a configuration in which the external terminal 3 has the aforementioned connection surface 3c is more effective. The ridge portion 2h between the main surface 2a and the side surface 2e has a chamfered shape. As a result, the thin portion sandwiched between the side surface 2e and the external terminal 3 becomes even thinner, making it more susceptible to cracking or chipping. Therefore, a configuration in which the external terminal 3 has the aforementioned connection surface 3e is more effective.

[0058] The ridges 2g and 2h have a rounded chamfered shape, and the thickness t of the external terminal 3 is greater than the radius of curvature of the ridges 2g and 2h. Therefore, compared to the case where the thickness t of the external terminal 3 is less than or equal to the radius of curvature of the ridge 2g, the thin portion sandwiched between the side surface 2c and the external terminal 3 becomes longer in the thickness direction (third direction D3) of the external terminal 3. As a result, 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 the case where the thickness t of the external terminal 3 is less than or equal to the radius of curvature of the ridge 2h, the thin portion sandwiched between the side surface 2e and the external terminal 3 becomes longer in the thickness direction of the external terminal 3. As a result, 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 connecting surface 3c is curved with a larger radius of curvature than the ridge portion 2g. This allows for a greater increase in the thickness of the thin portion sandwiched between the side surface 2c and the external terminal 3. The ridge portion 2h has a rounded chamfered shape, and the connecting surface 3e is curved with a larger radius of curvature than the ridge portion 2h. This allows for a greater increase in the thickness of the thin portion sandwiched between the side surface 2e and the external terminal 3.

[0060] External terminals 3 are positioned on the outside of the ridge sections 2g and 2h. Therefore, the ridge sections 2g and 2h can be constructed using only the base body 2. The ease of polishing varies depending on the material. Thus, ridge sections 2g and 2h, constructed using only the base body 2, are easier to form chamfered shapes through polishing compared to ridge sections constructed using multiple materials. This improves the product shape and suppresses cracking or chipping of the base body 2.

[0061] The external terminal 3 is, for example, more difficult to polish than the base body 2 before firing. Therefore, if the external terminal 3 is also exposed on the side 2c and forms a ridge 2g, the ridge 2g is difficult to polish and difficult to form a chamfered shape. As a result, compared to the other ridges 2h, 2i, 2j, and 2k formed by the base body 2 when the external terminal 3 is not exposed, the ridge 2g becomes pointed and is more likely to become the starting point for cracks or chips. If the polishing conditions are set to suit the external terminal 3, the other ridges 2h, 2i, 2j, and 2k formed by the base body 2 when the external terminal 3 is not exposed will be polished too much, making the base body 2 more prone to rolling. Therefore, handling the laminated coil component 1 becomes difficult. The example given was when 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.

[0062] Even when the external terminal 3 is spaced away from the plane including the side surface 2c, if the distance between the external terminal 3 and the plane including the side surface 2c is insufficient, specifically if the distance is shorter than the design value of the radius of curvature of the ridge sections 2g, 2h, 2i, 2j, and 2k, the polishing of the ridge section 2g is hindered by the external terminal 3, making it difficult to bring the radius of curvature of the ridge section 2g to the design value. As a result, the ridge section 2g is prone to becoming the starting point for cracks or chips. If the polishing conditions are adjusted to the ridge section 2g, the radius of curvature of the ridge section 2g can be brought to the design value, but the other ridge sections 2h, 2i, 2j, and 2k are polished too much, and their radii of curvature exceed the design value. As a result, the base body 2 becomes more prone to rolling, making it difficult to handle the laminated coil component 1. The example given was when the distance between the external terminal 3 and the plane including the side surface 2c is insufficient, but a similar problem exists when the distance between the external terminal 3 and the plane including the side surface 2e is insufficient.

[0063] In the laminated coil component 1, the external terminals 3 are embedded in the base body 2 so as to be spaced apart from adjacent side surfaces 2c and 2e, and exposed from the main surface 2a. As a result, the base body 2 has a portion sandwiched between side surfaces 2c and 2e and the external terminals 3. Since this portion has a smaller volume than other parts, 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 side surfaces 2c and 2e of the base body 2 and the adjacent corner A2 of the external terminal 3 are made larger. This increases the volume of the portion sandwiched between side surfaces 2c and 2e and the external terminals 3, thereby suppressing the occurrence of cracking or chipping.

[0064] Since the pair of external terminals 3 are exposed only 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 will also be formed on the side surface 2c, increasing the mounting area.

[0065] While embodiments of the present invention have been described above, the present invention is not necessarily limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0066] Figure 6 is an enlarged cross-sectional view of a part of a laminated coil component according to the first modified example. The laminated coil component 1A according to the first modified example shown in Figure 6 differs from the laminated coil component 1 shown in Figures 1 to 5 in that it has 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 insulating layers 6 may be laminated in the third direction D3, or they may be laminated in the first direction D1 or the second direction D2.

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

[0068] The multiple electrode layers 31, 32, and 33 have different lengths in the second direction D2. For example, the multiple electrode layers 31, 32, and 33 are arranged so that their center positions in the second direction D2 coincide. As a result, the positions of the end faces on the side surfaces 2c and 2d of the multiple electrode layers 31, 32, and 33 are offset in a step-like manner. That is, the connecting surfaces 3c and 3d each exhibit a step-like shape. In this way, even in the laminated coil component 1A, the connecting surface 3c is further away from the side surface 2c as it is further away from the main surface 2a. Therefore, even in the laminated coil component 1A, it is possible to increase the thickness of the portion sandwiched between the side surface 2c and the external terminal 3, thereby suppressing the occurrence of cracks or chips.

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

[0070] In the laminated coil component 1, a configuration in which the coil 10 has a coil axis aligned with 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 was described as an example. However, the coil axis of the coil 10 does not have to be aligned with the first direction D1. The coil axis of the coil 10 may be aligned with, for example, the second direction D2 or the third direction D3. Also, the number of coil conductors constituting the coil 10 is not limited to four.

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

[0072] In the laminated coil component 1, the external terminal 3 is composed of six electrode layers 11, but it is sufficient if 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 if they are composed of at least two or more electrode layers.

[0073] In the laminated coil components 1A and 1B, the connection surface 3c is stepped, but the connection surface 3e may 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, thereby suppressing the occurrence of cracks or chips. [Explanation of symbols]

[0074] 1, 1A, 1B...Laminated coil component, 2...Base body, 2a...Main surface, 2c, 2e...Side surface, 2g, 2h...Edge section, 3...External terminal, 3c, 3e...Connection surface, 6...Insulating layer, 10...Coil, 11...Electrode layer, 31, 32, 33...Electrode layer, A1, A2...Corner section, t...Thickness.

Claims

1. A base body consisting of multiple insulator layers stacked on top of each other, A coil arranged within the aforementioned body, It comprises an external terminal which is electrically connected to the coil and is made up of multiple conductor layers stacked on top of each other, The aforementioned body has a main surface and a first side surface adjacent to the main surface, The external terminal is embedded in the 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 where the external terminals are located. The inner surface of the recess faces the opposite side of the first side and has a first spaced surface that is further away from the first side as it is further away from the main surface. The ridge between the main surface and the first side surface has a rounded chamfered shape. The depth of the recess is greater than the radius of curvature of the ridge. The first separation surface is curved with a larger radius of curvature than the radius of curvature of the ridge portion. The external terminal is located on the outside of the ridge portion. Multilayer coil components.

2. Each of the above-mentioned bodies further has a pair of second surfaces adjacent to the main surface, The first side is adjacent to each of the pair of second sides, The pair of second sides are facing each other, The inner surface of the recess has a pair of second spaced surfaces that face away from the pair of second surfaces and are further spaced away from the pair of second surfaces as they are spaced away from the main surface. The laminated coil component according to claim 1.

3. A base body consisting of multiple insulator layers stacked on top of each other, A coil arranged within the aforementioned body, It comprises an external terminal which is electrically connected to the coil and is made up of multiple conductor layers stacked on top of each other, The aforementioned body has a rectangular main surface and a pair of side surfaces that are adjacent to each other and also adjacent to the main surface, The external terminals are embedded in the 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 where the external terminals are located. The recess has a second corner portion that is positioned adjacent to the first corner portion between the pair of side surfaces when viewed from a direction perpendicular to the main surface, The radius of curvature of the second corner is greater than the radius of curvature of the first corner. The external terminal has a first spaced-out surface that faces the first of the pair of sides and is spaced further away from the main surface than it is spaced further away from the first side. The ridge between the main surface and the first side surface has a rounded chamfered shape. The depth of the recess is greater than the radius of curvature of the ridge. The first separation surface is curved with a larger radius of curvature than the radius of curvature of the ridge portion. The external terminal is located on the outside of the ridge portion. Multilayer coil components.

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