Coil component

Abstract

A coil component includes: a magnetic substrate including a magnetic metal material and having a first surface; a conductor provided inside the magnetic base; external electrodes electrically connected to the conductor and extending along the first surface of the magnetic substrate, each external electrode having a first electrode portion embedded in the magnetic substrate and a second electrode portion exposed from the magnetic substrate; and an insulating layer covering a region of the first surface other than a region in which the external electrode is provided.

Description

Technical Field

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

[0002] As electronic devices become more miniaturized and more functional, it is necessary to mount electronic components on circuit boards at a higher density. However, in high-density mounting, the number of electronic components that can be mounted on the surface of a circuit board is limited. Therefore, in order to increase the number of electronic components that can be mounted on a circuit board and to further miniaturize and further functionalize electronic devices, smaller electronic components with higher performance are required.

[0003] In order to miniaturize electronic components, magnetic elements in coil components have been made of magnetic metal materials (rather than ferrite magnetic materials). Using magnetic metal materials with high magnetic saturation characteristics reduces the volume of magnetic material required for magnetic saturation.

[0004] Since such a magnetic metal material has low electrical resistance, a coil component using such a magnetic metal material needs to have electrical insulation on the surface on which the external electrode is provided. Therefore, a structure in which the outside of the component body is covered with an insulating layer is sometimes adopted.

[0005] For example, Patent Document 1 discloses an electronic component including an insulator containing magnetic metal powder and a resin coating on the insulator.

[0006] Patent Document 1: JP 2016-178282 A Summary of the invention

[0007] However, whether the coil component is mounted on the surface of the circuit board or embedded in the circuit board, the external electrode should have a sufficient thickness. Therefore, in the case where an insulating layer is provided on the component body, the insulating layer also has a certain thickness, which leads to an increase in the external size of the coil component.

[0008] On the contrary, if the outer dimensions are fixed, the size of the component body including the magnetic metal material should be reduced in consideration of the thickness of the insulating layer, which will reduce the performance of the coil component. Therefore, there is a limit to the miniaturization of the coil component.

[0009] Therefore, the present invention provides a miniaturized coil component having an insulating layer.

[0010] According to one aspect of the present invention, there is provided a coil component, comprising: a magnetic substrate comprising a magnetic metal material and having a first surface; a conductor arranged inside the magnetic substrate; external electrodes electrically connected to the conductor and extending along the first surface of the magnetic substrate, each of the external electrodes having a first electrode portion embedded in the magnetic substrate and a second electrode portion exposed from the magnetic substrate; and an insulating layer covering an area of ​​the first surface except an area where the external electrodes are arranged.

[0011] When viewed in a direction perpendicular to the first surface, the second electrode portion may be located within an outline of the corresponding first electrode portion.

[0012] The outer periphery of the first electrode portion may be covered with an insulating layer.

[0013] The thickness of the first electrode portion may be greater than the thickness of the second electrode portion.

[0014] The external electrode may protrude beyond the insulating layer in a direction perpendicular to the first surface.

[0015] At least a portion of a surface of the insulating layer may have an inclined surface which is inclined to be closer to the first surface as a distance from the external electrode increases.

[0016] On the first surface, the insulating layer may be wider than the second electrode part.

[0017] The magnetic base may have a plurality of surfaces including a first surface, and the external electrode may be provided only on the first surface among the plurality of surfaces.

[0018] The surface roughness of the insulating layer may be smaller than the surface roughness of the magnetic substrate.

[0019] The insulating layer may be made of at least one insulating material of a resin, a glass material, and a metal oxide.

[0020] The insulating layer may protrude beyond the external electrode in a direction perpendicular to the first surface.

[0021] The first electrode portion may be mainly composed of the same metal element as the conductor.

[0022] The second electrode portion may include Cu at least on a surface thereof.

[0023] The coil component may include three or more external electrodes.

[0024] The coil component may include a plurality of conductors, each of which may be an inductor element.

[0025] According to the present invention, the size of the coil component having the insulating layer can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In the following, various embodiments of the present invention are described with reference to the accompanying drawings. In the accompanying drawings:

[0027] Figure 1 is a perspective view showing a coil component according to a first embodiment of the present invention;

[0028] Figure 2 It is along Figure 1 A cross-sectional view of the coil component taken along line II in FIG.

[0029] Figure 3 shows a first step in a method of manufacturing a coil component according to a comparative example;

[0030] Figure 4 shows a second step in the method for manufacturing a coil component according to a comparative example;

[0031] Figure 5 shows a third step in the method for manufacturing a coil component according to a comparative example;

[0032] Figure 6 shows a fourth step in the method for manufacturing a coil component according to a comparative example;

[0033] Figure 7 A first step in the method for manufacturing a coil component according to the first embodiment is shown;

[0034] Figure 8 shows a second step in the method for manufacturing the coil component according to the first embodiment;

[0035] Fig. 9 shows a third step in the method for manufacturing the coil component according to the first embodiment;

[0036] Fig.10 shows a fourth step in the method for manufacturing the coil component according to the first embodiment;

[0037] Fig.11 is a cross-sectional view showing a coil component according to a first modification example of the first embodiment;

[0038] Fig.12 is a cross-sectional view showing a coil component according to a second modification example of the first embodiment;

[0039] Fig.13 is a cross-sectional view showing a coil component according to a third modification example of the first embodiment;

[0040] Fig.14 is a cross-sectional view showing a coil component according to a fourth modification example of the first embodiment;

[0041] Fig.15is a perspective view showing a coil component according to a second embodiment of the present invention;

[0042] Fig.16 It is along Fig.15 A cross-sectional view taken along line II-II in FIG.

[0043] Fig.17 It is along Fig.15 A cross-sectional view taken along line III-III in FIG. 1 ; and

[0044] Fig.18 is a cross-sectional view showing a circuit board layout according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following embodiments are not intended to limit the present invention, and not all features in the embodiments are essential to the present invention. The embodiments may be appropriately modified or changed depending on the specifications and conditions (usage conditions, usage environment, etc.) of the device to which the present invention is applied.

[0046] The technical scope of the present invention is defined by the appended claims and is not limited by the following embodiments. In order to facilitate the understanding of the embodiments, the drawings used for the following description may differ from the actual structure in terms of proportion and shape. In the drawings, the same reference numerals will be used to identify the same or similar parts.

[0047] First embodiment

[0048] Figure 1 and Figure 2 A coil component according to a first embodiment of the present invention is shown. Figure 2 Shown along Figure 1 The cross section is taken along line II in FIG.

[0049] The coil component 10 according to the first embodiment has a magnetic base 11 made of a magnetic metal material, two external electrodes 12 arranged on the first surface 11a of the magnetic base 11, a conductor arranged in a part of the magnetic base 11, and an insulating layer 14 arranged between the two external electrodes 12. An example of a conductor is an internal conductor 13 arranged inside the magnetic base 11. The term "arranged on the surface" means that the external electrode 12 is located at a position visible when the surface is observed, and the external electrode 12 may protrude beyond the plane of the surface, or may be located at a position recessed behind the plane of the surface. As described later, the external electrode 12 partially protrudes beyond the plane of the first surface 11a and is partially embedded in the first surface 11a. The range of the first surface 11a of the magnetic base 11 is the entire range defined by its contour, so that the first surface 11a includes the area where the external electrode 12 is located. In other words, the first surface 11a may be an uneven surface having a recessed portion on which the external electrode 12 is arranged.

[0050] The coil component 10 may be mounted on the surface of the circuit board or embedded in the circuit board together with the resin. Alternatively, the coil component 10 may be packaged together with the resin as a packaged component. In the case where the coil component 10 is embedded in the circuit board or packaged, the coil component 10 may be encapsulated by the resin.

[0051] For example, soft magnetic metal particles are used for the magnetic material of the magnetic base 11. The magnetic base 11 may be formed by any known technique.

[0052] In this specification, unless otherwise understood from the context, directions are based on Figure 1 The L-axis, W-axis, and H-axis are collectively referred to as the length direction, width direction, and height direction.

[0053] The coil component 10 has a rectangular parallelepiped profile. That is, the coil component 10 has end surfaces at both ends in the length direction L, has an upper surface and a lower surface at both ends in the height direction H, and has a front surface and a rear surface at both ends in the width direction W. The entire surface or a portion of the surface of the coil component 10 may be flat or curved. In addition, a portion of the eight vertices and twelve edges of the coil component 10 may be rounded or chamfered.

[0054] In this specification, even if a portion of the surface of the coil component 10 is curved or uneven, and / or even if a portion of the vertex portion and the edge portion is rounded or chamfered, the outline of the coil component 10 is also referred to as "cuboid". In other words, the term "cuboid" used herein does not refer to a cuboid in a strict mathematical sense.

[0055] In the first embodiment, the first surface 11a of the magnetic substrate 11 is the main surface of the coil component 10. If the coil component 10 is mounted on the surface of a circuit board, the main surface of the coil component 10 is the mounting surface facing the surface of the circuit board. In the first embodiment, since the external electrode 12 is only provided on the first surface 11a of the surface of the magnetic substrate 11, the influence of the thickness of the external electrode 12 on the size of the coil component 10 is limited to the height direction H substantially perpendicular to the first surface 11a, which will contribute to the miniaturization of the coil component 10.

[0056] According to the coil component 10 of the first embodiment, it has two external electrodes 12 separated from each other in the length direction L, for example, on the first surface 11a of the magnetic base 11. In order to electrically connect with the components on the circuit board, a plating layer is provided on the surface of each external electrode 12. Preferably, the plating layer contains Cu for better connection with the components on the circuit board.

[0057] Each external electrode 12 extends along the length direction L and the width direction W on the first surface 11a. In the height direction H, each external electrode 12 has a first electrode portion 12a embedded in the magnetic base 11 and a second electrode portion 12b exposed from the magnetic base 11. The first electrode portion 12a and the second electrode portion 12b are made of, for example, Ag or Cu. The first electrode portion 12a and the second electrode portion 12b may be made of the same or different materials.

[0058] Each outer electrode 12 is electrically connected to one end of the inner conductor 13 via the first electrode portion 12a. The inner conductor 13 may be any conductor having inductance. For example, although illustration is omitted, the conductor may be a coil wound around the coil axis a predetermined number of times.

[0059] The coil component 10 is a small electronic component, and its area and volume are small. For example, in the first embodiment, the inner conductor 13 and the two outer electrodes 12 constitute an electrical connection element, and the area of ​​the first surface 11a is not less than 0.5mm 2 And no more than 1.5mm 2 .

[0060] For example, in the case where the coil component 10 has two electrical connection elements, the area of ​​the first surface 11a is not less than 2.0 mm due to the restriction of the distance between the external electrodes 12. 2 And no more than 3.5mm 2 The external electrodes 12 are provided at a pitch of, for example, 0.5 mm or less.

[0061] The insulating layer 14 is formed of an electrically insulating material having excellent insulating properties, and covers the region between the two external electrodes 12. The resistivity of the insulating layer 14 is greater than that of the magnetic substrate 11. The material of the insulating layer 14 is, for example, a resin material such as silicone resin, epoxy resin, or phenolic resin; a glass material such as borosilicate glass; or a metal oxide such as a P (phosphorus) oxide. A thermosetting material is preferably used as the material of the insulating layer 14.

[0062] In the coil component 10 of the first embodiment, the entire area between the external electrodes 12 on the first surface 11a of the magnetic base 11 is covered by the insulating layer 14. On the first surface 11a, the insulating layer 14 is wider than the second electrode portion 12b. In other words, the total area of ​​the insulating layer 14 is larger than the total area of ​​the second electrode portion 12b.

[0063] The surface resistance of a portion of the magnetic base 11 using a magnetic metal material can be smaller than the surface resistance of a magnetic base using ferrite. Therefore, the insulating layer 14 is provided on the magnetic base 11. The insulating layer 14 prevents a short circuit from occurring due to a decrease in insulation resistance between the external electrodes 12, even if the coil component is provided with a plating layer on each external electrode 12. On the other hand, since the first electrode portion 12a of the external electrode 12 is embedded in the magnetic base 11, the thickness of the insulating layer 14 can be reduced to correspond to the thickness of the second electrode portion 12b of the external electrode 12. Thus, the coil component 10 including the insulating layer 14 can be more miniaturized.

[0064] The process for forming the insulating layer 14 includes applying an insulating material (which will become the insulating layer 14) to the surface of the magnetic base 11, thermally curing the insulating material, and surface treating the insulating layer 14, and through this forming process, the insulating layer 14 having a necessary thickness is obtained. For the surface treatment, treatment means such as sandblasting, grinding, drum polishing, laser irradiation and / or solvent etching can be used.

[0065] The surface roughness of the insulating layer 14 is smaller than the surface roughness of the first surface 11a of the magnetic base 11. In other words, the surface of the insulating layer 14 is smoother than the surface of the first surface 11a of the magnetic base 11. The smoother surface of the insulating layer 14 can facilitate the flow of the sealing resin during the resin encapsulation process, thereby minimizing the formation of voids.

[0066] The surface roughness of the insulating layer 14 and the surface roughness of the first surface 11a of the magnetic substrate 11 can be expressed as an arithmetic mean height Sa, which is calculated using, for example, a measuring instrument in accordance with ISO 25178. The arithmetic mean height Sa is measured by a commercially available instrument capable of measuring the arithmetic mean height Sa, such as a shape analysis laser microscope ("VK-X250") manufactured by Keyence Corporation (Osaka, Japan).

[0067] Method for manufacturing coil component

[0068] Figures 3 to 6 A method for manufacturing a coil component according to a comparative example is shown. Figures 7 to 10 A method of manufacturing the coil component 10 according to the embodiment is shown.

[0069] For the comparative example, Figure 3 In the first step shown, a magnetic base part 21 made of a magnetic metal material and an internal conductor part 23 made of a conductor are formed. The magnetic base part 21 corresponds to the magnetic base 11, and the internal conductor part 23 corresponds to the internal conductor 13. Figures 3 to 10 , only the end portion of the inner conductor portion is schematically shown.

[0070] The formation process of the magnetic base 21 and the internal conductor 23 is performed by printing or plating a conductor pattern on a magnetic metal material sheet and laminating a plurality of sheets. The internal conductor 23 is formed so that its end is exposed on the surface of the magnetic base 21.

[0071] exist Figure 4 In the second step shown, the insulating layer 24 is formed on the surface of the magnetic base 21 (the end of the inner conductor 23 is exposed on the surface). The insulating layer 24 is formed to have a sufficient thickness D1 because the thickness D1 should be equal to the thickness of the external electrode 12.

[0072] exist Figure 5 In the third step shown, holes H are formed in the insulating layer 24. That is, portions of the insulating layer 24 are removed to expose the inner conductor portion 23.

[0073] exist Figure 6 In the fourth step shown, the external electrode 22 is formed in the hole H in the insulating layer 24, for example, by plating. The insulating layer 24 corresponds to the insulating layer 14, and the external electrode 22 corresponds to the external electrode 12. Since the external electrode 22 should have a certain thickness, the above-mentioned thickness D1 of the insulating layer 24 is also large, which makes it difficult to miniaturize the coil component. In addition, when the Figure 4 When the insulating layer 24 is formed in the second step shown, the greater thickness D1 of the insulating layer 24 may cause the formation of voids.

[0074] In contrast, with the coil component 10 according to the embodiment, Figure 7In the first step shown, a magnetic base portion 31 made of a magnetic metal material, an internal conductor portion 33 made of a conductor, and a first electrode portion 32a are formed. The magnetic base portion 31 corresponds to the magnetic base 11, and the internal conductor portion 33 corresponds to the internal conductor 13. The first electrode portion 32a corresponds to the first electrode portion 12a. The formation process of the magnetic base portion 31, the internal conductor portion 33, and the first electrode portion 32a is also performed by a combination of printing or plating a conductor pattern on a magnetic metal material sheet and laminating a plurality of sheets. Therefore, if the internal conductor portion 33 and the first electrode portion 32a are made of the same type of conductor (that is, if they are mainly composed of the same metal element), it is easy to form the internal conductor portion 33 and the first electrode portion 32a.

[0075] The magnetic base portion 31, the inner conductor portion 33, the first electrode portion 32a, etc. may be formed as a single layer corresponding to a plurality of coil components 10. The single layer may then be cut or divided into a plurality of coil components 10, thereby improving the manufacturing efficiency of the coil components 10.

[0076] exist Figure 8 In the second step shown in FIG. 1 , an insulating layer 34 is formed on the first surface 31a of the magnetic base portion 31. The thickness D2 of the insulating layer 34 is equal to Figure 2 The thickness of the second electrode portion 12b of the external electrode 12 shown in FIG. 1 is smaller than the thickness D1 of the insulating layer 24 in the comparative example, which contributes to miniaturization of the coil component. The insulating layer 34 may be formed when forming the above-mentioned single layer or after division.

[0077] exist Fig. 9 In the third step shown, a plurality of portions of the insulating layer 34 are removed to form holes H for exposing the first electrode portion 32a. Since each hole H is formed within a range defined by the contour of the first electrode portion 32a, it is possible to prevent the surface of the magnetic base portion 31 surrounding the first electrode portion 32a from being damaged. The holes H for exposing the first electrode portion 32a may also be formed when the insulating layer 34 is formed, rather than by removing a plurality of portions of the insulating layer 34.

[0078] exist Fig.10 In the fourth step shown, the second electrode portion 32b is formed on the exposed portion of the first electrode portion 32a, respectively, by plating, for example. The second electrode portion 32b corresponds to the second electrode portion 12b. Thus, an external electrode 32 each having a first electrode portion 32a and a second electrode portion 32b is formed. The external electrode 32 corresponds to the external electrode 12. Although the external electrode 32 has a sufficient thickness, since the first electrode portion 32a of the external electrode 32 is embedded in the magnetic base portion 31, the thickness of the insulating layer 34 can be minimized, thereby contributing to the miniaturization of the coil component 10.

[0079] Variations

[0080] Next, description will be given of a modification of the coil component 10. Hereinafter, for structural elements similar to those in the above-described first embodiment, duplicate explanation will be omitted.

[0081] Figures 11 to 13 First to third modifications are shown in which the shape of the external electrode 12 is different from that in the first embodiment. Fig.14 A fourth modification is shown in which the shape of the insulating layer 14 is different from that in the first embodiment. Figures 11 to 14 Shown with Figure 2 The cross-section shown is the same cross-section.

[0082] exist Fig.11 In the first modification shown, the second electrode portion 12b is thinner and has a smaller area than the first electrode portion 12a. That is, in the thickness direction perpendicular to the first surface, the thickness of the first electrode portion 12a is greater than the thickness of the second electrode portion 12b. In addition, when observed in a direction perpendicular to the first surface 11a, the second electrode portion 12b is respectively located within the outline of the first electrode portion 12a. Since the second electrode portion 12b is thinner than the first electrode portion 12a, the thickness of the insulating layer 14 can be smaller. Since the first electrode portion 12a is wider and thicker than the second electrode portion 12b, the contact area can be increased, and therefore the adhesion of the first electrode portion 12a to the magnetic substrate 11 and the durability of the external electrode 12 can be improved.

[0083] Since the area of ​​the second electrode portion 12b is smaller than the area of ​​the first electrode portion 12a, for example, Fig. 9 In the third step shown, the inner surface of the hole H can be located inside the first electrode portion 12a. Therefore, when the hole H is formed, the periphery of the first electrode portion 12a is not damaged, and the first surface 11a of the magnetic substrate 11 is not damaged. In addition, since the area of ​​the second electrode portion 12b is smaller than that of the first electrode portion 12a, the outer periphery of the first electrode portion 12a is covered by the insulating layer 14.

[0084] exist Fig.12 In the second modification shown, a portion of each first electrode portion 12a is wedge-shaped. In the wedge-shaped portion, the outer edge of the first electrode portion 12a becomes wider as the distance from the first surface 11a increases, thereby further increasing the contact area and thus improving the adhesion of the first electrode portion 12a to the magnetic base 11. Therefore, even if the area of ​​the external electrode 12 is small, electrode peeling can be prevented.

[0085] exist Fig.13In the third modification shown, the outer periphery of each first electrode 12a is located inside the corresponding side surface 11b of the magnetic base 11. This structure also increases the contact area and thus improves the adhesion between the first electrode portion 12a and the magnetic base 11, thereby improving the durability of the external electrode 12.

[0086] In the third modification, the insulating layer 14 has a thickness greater than that of the second electrode portion 12b and protrudes in a thickness direction perpendicular to the first surface 11a beyond the external electrode 12. Therefore, the insulating layer 14 having a smoother surface improves handling and resin encapsulation processes of the coil component 10.

[0087] exist Fig.14 In the fourth modification shown, the thickness of the insulating layer 14 relative to the first surface 11a is larger near the external electrode 12, and smaller in the middle of the insulating layer 14. For example, the insulating layer 14 has a concave or inclined surface 14a. The greater the distance from the external electrode 12, the smaller the distance between the inclined surface 14a and the first surface 11a. This shape of the insulating layer 14 helps the flow of the sealing resin during the resin encapsulation process, thereby minimizing the formation of voids. In addition, in the fourth modification, the thickness of the external electrode 12 is greater than the thickness of the insulating layer 14, and protrudes beyond the insulating layer 14 in the thickness direction perpendicular to the first surface 11a, so that the flow of the sealing resin is further improved during the resin encapsulation process.

[0088] The thickness at the center of the insulating layer 14 is preferably less than 0.2 times the thickness of the second electrode portion 12b (i.e., the distance between the outer surface of the second electrode portion 12b and the first surface 11a). If the thickness at the center of the insulating layer 14 is less than 0.2 times the thickness of the second electrode portion 12b, a larger space is ensured between the insulating layer 14 and the plane in contact with the coil component 10 during the resin encapsulation process, so that the sealing resin can easily flow along the inclined surface 14a of the insulating layer 14. In order to ensure a larger space for the resin to flow during the resin encapsulation process, the thickness at the center of the insulating layer 14 is more preferably less than 0.1 times the thickness of the second electrode portion 12b, and may even be so small as to be difficult to measure.

[0089] The insulating layer 14 having a smaller thickness at the center can be formed, for example, by surface treatment. The surface treatment of the insulating layer 14 can be performed by sandblasting, grinding, barrel polishing, and / or other known surface treatments. In barrel polishing, an abrasive having a diameter larger than the space between the external electrodes 12 is used so that the abrasive contacts the center of the insulating layer 14 and does not contact the end of the insulating layer 14 near the external electrodes 12. This surface treatment forms the top inclined surface 14a of the insulating layer 14 into a curved surface that is concave toward the center.

[0090] Second embodiment

[0091] Next, another coil component according to a second embodiment of the present invention will be described.

[0092] Figures 15 to 17 A coil component according to a second embodiment of the present invention is shown. Fig.16 Shown along Fig.15 The section taken along line II-II in Fig.17 Shown along Fig.15 A cross section taken along line III-III in FIG.

[0093] The coil component 40 according to the second embodiment has a magnetic base 41 made of a magnetic metal material, a plurality of external electrodes 42 provided on a first surface 41a of the magnetic base 41, an internal conductor 43 provided inside the magnetic base 41, and an insulating layer 44 provided between the external electrodes 42. The magnetic base 41, the external electrodes 42, the internal conductor 43, and the insulating layer 44 in the second embodiment correspond to the magnetic base 11, the external electrodes 12, the internal conductor 13, and the insulating layer 14 in the first embodiment, respectively.

[0094] The coil component 40 according to the second embodiment is an array type electronic component including a plurality of elements, each element having two external electrodes 42 and an internal conductor 43 electrically connected to the two external electrodes 42. In such an array type electronic component, a plurality of elements are packaged as a single component to reduce the installation space for the plurality of elements. The coil component 40 has a plurality of internal conductors 43, each of which is, for example, an inductor element.

[0095] The coil component 40 having multiple elements has three or more external electrodes 42 ( Fig.15 In the coil component 40 of the second embodiment, eight external electrodes 42 are arranged on the first surface 41a, and are spaced apart from each other in the length direction L and the width direction W, for example. That is, four external electrodes 42 are aligned in the length direction L, and two external electrodes 42 are aligned in the width direction W.

[0096] The multiple elements in the coil component 40 can have equivalent characteristics to each other and can be independent of each other in the circuit. The coil component 40 can have multiple elements with different characteristics, or a combination of multiple elements that interact magnetically and / or electrically, and this combination can be, for example, a transformer, an LC filter, etc.

[0097] In addition, in the coil component 40 of the second embodiment, each external electrode 42 has a first electrode portion 42a embedded in the magnetic substrate 41 and a second electrode portion 42b exposed from the magnetic substrate 41, so that the thickness of the insulating layer 44 arranged between the external electrodes 42 can be minimized, thereby contributing to the miniaturization of the coil component 40.

[0098] Similar to Fig.14 In the fourth modification of the first embodiment shown in FIG. 1 , the thickness of the insulating layer 44 in the second embodiment is larger near the external electrode 42 and smaller in the middle of the insulating layer 44. This applies to the width direction W (see FIG. 1 ). Fig.16 ) and the length direction L (see Fig.17 The insulating layer 44 in the second embodiment has a curved surface in the width direction W and in the length direction L.

[0099] On the first surface 41a, the total area of ​​the insulating layer 44 is larger than the total area of ​​the eight external electrodes 42. Therefore, the insulating layer 44 maintains insulation between the external electrodes 42.

[0100] exist Fig.17 In the example shown, the dimension (length) L1 of the external electrode 42 in the longitudinal direction L is larger than the dimension L2 of the insulating layer 44 (ie, the interval between the external electrodes 42 ) in the longitudinal direction L. Conversely, the dimension L2 may be larger than the dimension L1 .

[0101] If the dimension L2 of the insulating layer 44 in the length direction L is smaller than the dimension L1 of the external electrode 42 in the length direction L, then Fig.16 As shown in FIG. 1 , the dimension (width) W2 of the wide portion of the insulating layer 44 in the width direction W is preferably larger than the dimension (width) W1 of the external electrode 42 in the width direction W. Thus, as described above, on the first surface 41 a, the total area of ​​the insulating layer 44 is larger than the total area of ​​the external electrode 42. In particular, as shown in FIG. Fig.16 As shown, when two external electrodes 42 are arranged in the width direction W, the dimension W2 of the wide portion of the insulating layer 44 in the width direction W is preferably larger than the sum of the dimensions W1 of the two external electrodes 42 in the width direction W (i.e., twice the dimension W1), so that the total area of ​​the insulating layer 44 is sufficiently larger than the total area of ​​the external electrodes 42.

[0102] On the contrary, if the dimension W2 of the wide portion of the insulating layer 44 in the width direction W is smaller than the dimension W1 of the external electrode 42 in the width direction W, the dimension L2 of the insulating layer 44 in the length direction L is preferably larger than the dimension L1 of the external electrode 42 in the length direction L, so that the total area of ​​the insulating layer 44 is larger than the total area of ​​the external electrode 42. In other words, the intervals between the external electrodes 42 along the width direction W are negatively correlated with the intervals between the external electrodes 42 along the length direction L.

[0103] In the case where the size of the coil component 40 in the length direction L is larger than that in the width direction W, it is preferred in design that the external electrodes 42 are arranged more in the length direction L than in the width direction W. Therefore, the interval between the external electrodes 42 in the shorter direction of the coil component 40 is preferably larger than the interval between the external electrodes 42 in the length direction of the coil component 40. In this case, the interval between the external electrodes 42 in the shorter direction of the coil component 40 should be larger than the size of the external electrodes 42 in the shorter direction to provide sufficient insulation.

[0104] Third embodiment

[0105] Next, a third embodiment according to the present invention will be described.

[0106] Fig.18 is a cross-sectional view of a circuit board layout according to a third embodiment of the present invention.

[0107] In the third embodiment, the coil component 40 according to the above-described second embodiment is built into a circuit board arrangement 50 .

[0108] The circuit board arrangement 50 has the coil component 40 , an insulating layer 52 , a first resin layer 53 , a second resin layer 54 , and a wiring pattern 55 .

[0109] The insulating layer 52 is a part of a multilayer printed circuit board or a substrate of a circuit board. The insulating layer 52 is formed of an electrically insulating material such as a glass-epoxy resin composite. The coil component 40 is placed in a hole formed in the insulating layer 52 or disposed between two adjacent insulating layers 52.

[0110] The first resin layer 53 is formed around the coil component 40 placed in a hole of a single insulating layer 52 or provided between two adjacent insulating layers 52. The first resin layer 53 is formed of, for example, a thermosetting resin.

[0111] The second resin layer 54 is formed as an insulating layer 44 covering the coil component 40. The second resin layer 54 can be formed by the same thermosetting resin as the thermosetting resin used for the first resin layer 53. The second resin layer 54 encapsulates or seals the coil component 40 in the circuit board arrangement 50. When the second resin layer 54 is formed (when performing the resin encapsulation process), the curved surface of the insulating layer 44 is conducive to the flow of resin. Therefore, the formation of voids in the second resin layer 54 for encapsulating the coil component 40 can be suppressed to the greatest extent.

[0112] The wiring pattern 55 is formed by a process of forming a through hole in the second resin layer 54 , a plating process, and an etching process, and is electrically connected to the external electrode 42 .

[0113] The coil component 40 is thus built into the circuit board arrangement 50 , so that the mounting density of components in the circuit board arrangement 50 can be improved, and miniaturization of the electronic device can be contributed to.

Claims

1. A coil component, comprising: a magnetic substrate comprising a magnetic metal material and having a first surface; A conductor, which is arranged inside the magnetic matrix; external electrodes electrically connected to the conductor and extending along the first surface of the magnetic substrate, each of the external electrodes having a first electrode portion embedded in the magnetic substrate and a second electrode portion exposed from the magnetic substrate; as well as An insulating layer covers a region of the first surface except a region where the external electrode is provided.

2. The coil component according to claim 1, wherein When viewed in a direction perpendicular to the first surface, the second electrode portion is located within an outline of the corresponding first electrode portion.

3. The coil component according to claim 1, wherein The outer periphery of the first electrode portion is covered by the insulating layer.

4. The coil component according to claim 1, wherein The thickness of the first electrode portion is greater than the thickness of the second electrode portion.

5. The coil component according to claim 1, wherein The external electrode protrudes beyond the insulating layer in a direction perpendicular to the first surface.

6. The coil component according to claim 1, wherein At least a portion of a surface of the insulating layer has an inclined surface that is inclined to be closer to the first surface as a distance from the external electrode increases.

7. The coil component according to claim 1, wherein On the first surface, the insulating layer is wider than the second electrode portion.

8. The coil component according to claim 1, wherein The magnetic base has a plurality of surfaces including the first surface, and wherein the external electrode is provided only on the first surface among the plurality of surfaces.

9. The coil component according to claim 1, wherein The surface roughness of the insulating layer is smaller than the surface roughness of the magnetic substrate.

10. The coil component according to claim 1, wherein The insulating layer is made of at least one insulating material selected from the group consisting of resin, glass material, and metal oxide.

11. The coil component according to claim 1, wherein The insulating layer protrudes beyond the external electrode in a direction perpendicular to the first surface.

12. The coil component according to claim 1, wherein The first electrode portion is mainly composed of a metal element that is the same as a metal element of the conductor.

13. The coil component according to claim 1, wherein The second electrode portion includes Cu at least on a surface thereof.

14. The coil component according to claim 1, wherein Includes three or more external electrodes.

15. The coil component according to claim 1, wherein A plurality of conductors is included, each of the plurality of conductors being an inductor element.

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