JP2013098378A - Coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component which inhibits peeling of an external electrode.SOLUTION: A coil component 1 includes: a laminated body 13 formed by alternately laminating insulator layers 15 and coil patterns 17; a first magnetic material substrate 11A and a second magnetic material substrate 11B which sandwich the laminated body 13 in the lamination direction; and an external electrode 5 which connects with a drawing part 19 of the coil pattern 17 and is exposed to the exterior of a lamination structure 3 composed of the laminated body 13, the first magnetic material substrate 11A, and the second magnetic material substrate 11B. The first magnetic material substrate 11A and the second magnetic material substrate 11B have recessed parts 3r on side surfaces. The external electrode 5 has bonding parts 7 respectively bonded to inner surfaces of the recessed parts 3r.

Description

  The present invention relates to a coil component.

  Chip-type coil components are known. For example, in Patent Document 1, a laminate in which insulator layers and coil patterns are alternately laminated, a first magnetic substrate and a second magnetic substrate sandwiching the laminate in the lamination direction, and a coil pattern And a coil component having an external electrode that covers the end surface of the multilayer structure including the multilayer body, the first magnetic substrate, and the second magnetic substrate.

JP-A-8-203737

  In Patent Document 1, since the external electrode is only bonded to the end surface of the laminated structure, there is a possibility that peeling occurs.

  The objective of this invention is providing the coil component which can suppress peeling of an external electrode.

  A coil component according to an aspect of the present invention includes a laminate in which insulator layers and coil patterns are alternately laminated, and the first magnetic substrate and the second magnetic body that sandwich the laminate in the lamination direction. An external electrode connected to the lead portion of the coil pattern and exposed to the outside of the multilayer structure including the multilayer body, the first magnetic substrate, and the second magnetic substrate, and At least one of the laminated body, the first magnetic substrate, and the second magnetic substrate has a concave portion on a side surface, and the external electrode has an adhesive portion bonded to the inner surface of the concave portion.

  Preferably, the first magnetic substrate has the recess, and the lead portion of the coil pattern is provided at a position overlapping the recess on the main surface of the laminate on the first magnetic substrate side. The bonding portion is bonded to the drawing portion of the coil pattern in the recess.

  Preferably, the first and second magnetic substrates have the concave portions on the side surfaces, and the lead portions of the coil pattern are provided at positions overlapping the concave portions on the upper and lower main surfaces of the laminate, The bonding portion is bonded to the drawing portion of the coil pattern in the recess.

  Preferably, the adhesive portion is made of a conductive resin.

  Preferably, the external electrode has a film portion made of metal that covers the side surfaces of the first magnetic substrate, the second magnetic substrate, and the laminate and is bonded to the bonding portion.

  Preferably, the magnetic substrate is made of a resin containing magnetic powder.

  According to said structure, peeling of an external electrode can be suppressed.

The perspective view which shows the external appearance of the coil component which concerns on the 1st Embodiment of this invention. The perspective view which abbreviate | omits and shows a part of coil component of FIG. FIG. 2 is an exploded perspective view of the laminated structure of the coil component of FIG. 1. Sectional drawing in the IV-IV line of FIG. FIGS. 5A to 5D are cross-sectional views illustrating a method for manufacturing the coil component of FIG. FIG. 6A to FIG. 6C are cross-sectional views showing a continuation of FIG. The perspective view which shows the external appearance of the coil component which concerns on the 2nd Embodiment of this invention.

(First embodiment)
FIG. 1 is a perspective view showing an appearance of a coil component 1 according to the first embodiment of the present invention.

  Note that the coil component 1 may have any direction as a vertical direction or a horizontal direction. However, for the sake of convenience, an xyz coordinate system is defined below, and the positive side and the negative side in the z direction are set upward. In addition, the terms “upper surface”, “lower surface”, and the like are sometimes used as “lower”.

  Also, for the same or similar components, different numbers and uppercase alphabets are used for the same name and the same reference symbol, such as “first magnetic substrate 11A” and “second magnetic substrate 11B”. In some cases, it may be distinguished, and simply “magnetic substrate 11” may not be distinguished.

  The coil component 1 is configured as a chip-type coil component, and for example, the outer shape thereof is generally a rectangular parallelepiped as a whole, and the size of one side thereof is 0.3 to 1 mm. In addition, the coil component 1 includes a laminated structure 3 including a coil to be described later, and a pair of external electrodes 5 connected to the coil and exposed to the outside of the laminated structure 3. The coil component 1 is surface-mounted, for example, by making the lower surface side (the negative side in the z direction) face a mounting board (not shown) and bonding the external electrode 5 to the land on the mounting board with solder. .

  FIG. 2 is a perspective view of the coil component 1 in which a part of the coil component 1 (external electrode 5) is omitted.

  The laminated structure 3 is formed in a substantially rectangular parallelepiped shape, and has an upper surface 3a, a lower surface 3b, a pair of first side surfaces 3c facing in the x direction, and a pair of second side surfaces 3d facing in the y direction. Yes. A recess 3r is formed in the second side surface 3d. The concave portion 3r is formed on the upper surface 3a side and the lower surface 3b side, for example, on the center side in the x direction of the second side surface 3d.

  The concave portion 3 r is filled with an adhesive portion 7 that is a part of the external electrode 5. As understood from the comparison between FIG. 1 and FIG. 2, the external electrode 5 has a film portion 9 that covers a part of the laminated structure 3 in addition to the adhesive portion 7.

  The bonding part 7 is made of, for example, a resin containing a conductive filler, that is, a conductive resin. The conductive filler is made of, for example, a metal such as copper or silver. The resin is, for example, an epoxy resin or a phenol resin. For example, the bonding portion 7 is exposed to the outside of the multilayer structure 3 on the second side surface 3d and the upper surface 3a or the lower surface 3b. The exposed surface to the outside of the laminated structure 3 is flush with, for example, the second side surface 3d and the upper surface 3a or the lower surface 3b.

  For example, the film unit 9 covers the entire second side surface 3d of the multilayer structure 3 and covers a part of the upper surface 3a, the lower surface 3b, and the first side surface 3c on the second side surface 3d side. Further, the film part 9 also covers the exposed surface of the adhesive part 7 from the laminated structure 3. And the film | membrane part 9 is adhere | attached with respect to these covered parts. The film part 9 is made of metal, for example. Specifically, for example, the external electrode 5 is made of copper constituting most of the outer electrode 5 and nickel and tin plated thereon, or made of silver.

  FIG. 3 is an exploded perspective view of the laminated structure 3.

  The laminated structure 3 includes a first magnetic substrate 11A, a laminated body 13 and a second magnetic substrate 11B which are sequentially laminated from above (see also FIGS. 1 and 2). The laminated body 13 includes a plurality of (three in this embodiment) insulator layers 15 and one or more (two in this embodiment) coil patterns 17 that are alternately laminated. A lead part 19 for connecting the external electrode 5 is provided.

  For example, the first magnetic substrate 11A and the second magnetic substrate 11B have the same configuration. The magnetic substrate 11 is formed in, for example, a generally rectangular flat plate shape. Each of the side surfaces (side surfaces constituting the second side surface 3d) facing in the y direction of the magnetic substrate 11 is formed with the above-described recess 3r (notch). The shape of the recess 3r may be an appropriate shape. In this embodiment, the case where the shape of the recessed part 3r is a rectangular parallelepiped shape which has 6 surfaces parallel to 6 surfaces of the magnetic substrate 11 is illustrated. The dimensions of the magnetic substrate 11 and the recess 3r may be set as appropriate. As an example, the size of one side of the recess 3r in a plan view is 5 to 50 μm.

  The magnetic substrate 11 is made of, for example, a resin containing magnetic powder. The magnetic body is, for example, a ferrite such as nickel zinc ferrite or manganese zinc ferrite. The resin is, for example, an epoxy resin or a phenol resin.

  For example, the plurality of insulator layers 15 have substantially the same configuration. For example, the insulator layer 15 is formed in a flat plate shape that is substantially the same (rectangular) in shape and size in plan view. The insulator layer 15 has no recess formed on the side surface. Accordingly, the main surface of the uppermost layer and the lowermost insulator layer 15 (the main surface 13a of the multilayer body 13) is not covered with the magnetic substrate 11 and is exposed in the recess 3r. The insulator layer 15 is made of, for example, a resin such as polyimide or polyester.

  The coil pattern 17 is composed of a conductive layer formed on the main surface of the insulator layer 15 and, for example, circulates along the outer periphery of the insulator layer 15. The number of coil patterns 17 (and insulator layer 15) stacked and the connection method thereof may be set as appropriate. In FIG. 3, the coil pattern 17 is provided only between the insulator layers 15, but may be provided between the magnetic substrate 11 and the insulator layer 15. The coil pattern 17 is made of a metal such as copper or silver, for example.

  The lead portion 19 is provided on the main surface 13 a of the stacked body 13. More specifically, at least a part of the main surface 13a is located in a region that is not covered by the magnetic substrate 11 and is exposed in the recess 3r. The lead portion 19 is configured by a conductive layer made of a metal such as copper or silver, for example, similarly to the coil pattern 17.

  The connection between the coil patterns 17 and the connection between the coil pattern 17 and the lead portion 19 are made by, for example, a through conductor 21 that penetrates the insulator layer 15. The through conductor 21 is made of, for example, a metal such as copper or silver.

  4 is a cross-sectional view taken along line IV-IV in FIG.

  As described above, the drawer portion 19 is provided on the main surface 13a of the multilayer body 13 and is located in the recess 3r. On the other hand, the bonding portion 7 is filled in the recess 3r. Therefore, the drawer | drawing-out part 19 and the adhesion part 7 are adhere | attached with the area of the recessed part 3r. The film portion 9 is bonded to the end face of the drawer portion 19.

  FIG. 5A to FIG. 6C are cross-sectional views corresponding to FIG. 4 for explaining the method for manufacturing the coil component 1. Note that a large number of laminated structures 3 of the coil component 1 are taken from the mother board. FIG. 5A to FIG. 6C show a range corresponding to one coil component 1 and part of the coil components 1 located on both sides of the mother board.

  First, as shown in FIG. 5A, a magnetic layer 33 to be the second magnetic substrate 11 </ b> B is formed on the support substrate 31. For example, although not particularly illustrated, the support substrate 31 is configured by forming a release layer made of an adhesive on a glass substrate or a silicon substrate. The magnetic layer 33 is formed, for example, by applying an uncured resin containing magnetic powder on the support substrate 31 with a coater.

  Next, as shown in FIG. 5B, a cavity that becomes the recess 3 r is formed in the magnetic layer 33. The cavity is formed by, for example, photolithography. The etching may be dry etching such as reactive ion etching or wet etching using a chemical solution.

  Next, as shown in FIG. 5C, a material 35 that becomes the bonding portion 7 is filled into the cavity that becomes the recess 3r. The material 35 is an uncured resin containing a conductive filler. The filling is performed by, for example, a printing method such as screen printing or a dispenser method.

  Next, as shown in FIG. 5D, a wiring layer 37 to be the stacked body 13 is formed. For example, the wiring layer 37 is formed by a build-up method or the like in the same manner as the multilayer wiring board. The conductive portion (coil pattern 17 or the like) may be formed by an appropriate method such as plating or printing.

  Next, as shown in FIG. 6 (a), as in FIGS. 5 (a) to 5 (c), the formation of the magnetic layer to be the first magnetic substrate 11A, the formation of the cavity to be the recess 3r, And the material 35 used as the adhesion part 7 to the said cavity is filled.

  Next, as shown in FIG. 6B, dicing is performed to form a piece 41 (the state shown in FIG. 2) composed of the laminated structure 3 and the bonding portion 7. Dicing is performed by, for example, a dicing blade 39. It may be done by a laser or the like.

  Next, as shown in FIG. 6C, the pieces 41 are picked up from the support substrate 31. And the coil part 1 shown in FIG. 4 is formed by forming the film | membrane part 9 of the external electrode 5 in the side surface of the piece 41. As shown in FIG.

  The film part 9 is formed by, for example, electroless plating or electrolytic plating. In the case of performing electroplating, an electrode for applying a voltage is formed on the peeling layer of the support substrate 31 before the step of FIG. 5A, or the steps of FIG. An electrode for applying a voltage may be formed on the first magnetic substrate 11A during the step (b).

  As described above, in this embodiment, the coil component 1 includes the laminated body 13 in which the insulator layers 15 and the coil patterns 17 are alternately laminated, and the first magnetic substrate 11A that sandwiches the laminated body 13 in the lamination direction. And an external electrode that is connected to the lead portion 19 of the coil pattern 17 and is exposed to the outside of the laminated structure 3 including the laminated body 13, the first magnetic substrate 11A, and the second magnetic substrate 11B. 5. At least one of the multilayer body 13, the first magnetic substrate 11A, and the second magnetic substrate 11B (in this embodiment, the magnetic substrate 11) has a recess 3r on the side surface. The external electrode 5 has a bonding portion 7 bonded to the inner surface of the recess 3r.

  Therefore, for example, compared with the case where the external electrode 5 is simply bonded to the side surface of the laminated structure 3 (when the concave portion 3r and the bonding portion 7 are not provided), the bonding area is as much as the concave portion 3r is formed. It is expanded and the peeling of the external electrode 5 is suppressed. Further, since the external electrode 5 is fitted into the recess 3r, it is expected that the separation of the external electrode 5 is suppressed by the engagement.

  In the present embodiment, the first magnetic substrate 11A has the recess 3r. The lead-out portion 19 of the coil pattern 17 is provided at a position overlapping the concave portion 3r on the main surface 13a of the laminated body 13 on the first magnetic substrate 11A side. The bonding portion 7 is bonded to the drawing portion 19 of the coil pattern 17 in the recess 3r.

  Accordingly, the external electrode 5 is bonded to the lead portion 19 with a relatively large bonding area as compared with the case where the film portion 9 is merely in contact with the end face of the lead portion 19. That is, the recess 3 r contributes not only to suppression of peeling of the external electrode 5 from the laminated structure 3 but also to an increase in the adhesion area between the external electrode 5 and the lead portion 19. Further, since the recess 3r is formed in the first magnetic substrate 11A, the coil pattern is formed by forming the recess 3r as compared with the case where the recess is formed in the multilayer body 13 (see the second embodiment). There is also a low possibility that the formation area of 17 is narrowed.

  In the present embodiment, similarly to the first magnetic substrate 11A, on the second magnetic substrate 11B side, the recess 3r is formed, and the drawing portion 19 provided at a position overlapping the recess 3r on the main surface 13a. The bonding portion 7 is bonded to the surface. Therefore, the above-described effect is also exhibited on the second magnetic substrate 11B side, and further peeling suppression and conductivity improvement can be achieved. Further, the degree of freedom in design related to the connection between the coil pattern 17 and the external electrode 5 is improved.

  In the present embodiment, the bonding portion 7 is made of a conductive resin. In general, since the conductive resin has higher adhesion to an insulator or a magnetic material than metal, it is expected that the peeling of the bonded portion 7 is further suppressed.

  Further, in the present embodiment, in addition to the adhesive portion 7 made of a conductive resin, the external electrode 5 covers the side surfaces of the first magnetic substrate 11A, the second magnetic substrate 11B, and the laminated body 13, and the adhesive portion 7 And a film portion 9 made of metal, which is bonded to the substrate.

  Therefore, for example, the area of the external electrode 5 can be increased by a metal having a resistance smaller than that of the conductive resin. As a result, it is possible to facilitate mounting while suppressing deterioration in characteristics of the coil component 1. Furthermore, since the conductive resin (adhesive portion 7) is interposed between the metal (film portion 9) and the insulator or magnetic body (laminated structure 3), the metal and the insulator are directly connected. Compared with the case of bonding (when the concave portion 3r and the bonding portion 7 are not provided), it is expected that the peeling of the film portion 9 is suppressed.

  In addition to the adhesive portion 7 being made of a conductive resin, the magnetic substrate 11 is made of a resin containing magnetic powder. Therefore, for example, it is expected that the adhesion between the bonding portion 7 and the magnetic substrate 11 is improved as compared with the case where the magnetic substrate 11 is made of ceramic. In addition, since the conductive resin does not need to be heated at a high temperature as compared with metal baking, it is also suitable for the magnetic substrate 11 made of a resin containing magnetic powder, which has lower heat resistance than ceramic. Available.

(Second Embodiment)
FIG. 7 is a cross-sectional view corresponding to FIG. 4 showing the coil component 201 according to the second embodiment.

  The coil component 201 is different from the first embodiment only in the position of the concave portion and the adhesion portion of the external electrode. Specifically, it is as follows.

  The laminated structure 203 of the coil component 201 includes a laminated body 213 and a pair of magnetic substrates 211 that sandwich the laminated body 213, as in the first embodiment. However, the concave portion for adhering the external electrode 205 is not formed on the side surface of the magnetic substrate 211, and the concave portion 203 r for adhering the external electrode 205 is provided on the side surface of the multilayer body 213.

  The recess 203r is formed over the entire stacked body 213 in the stacking direction of the plurality of insulator layers 215, for example. The planar shape of the recess 203r may be the same as that in the first embodiment.

  The adhesive portion 207 of the external electrode 205 is filled in the concave portion 203r as in the first embodiment. The lead portion 219 of the coil pattern 17 is provided, for example, between the insulating layers 215, and is bonded to the bonding portion 207 at the end face.

  The manufacturing method of the coil component 201 may be substantially the same as that of the first embodiment. However, instead of the magnetic substrate 11, the insulating layer 215 is etched to form the recess 203 r.

  According to the second embodiment described above, the coil component 201 has the bonding portion 207 bonded to the inner surface of the recess 203r, as in the first embodiment, and therefore the first embodiment. The same effect as the above, that is, the effect of suppressing peeling of the external electrode 205 is exhibited.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The magnetic substrate is not limited to one constituted by a resin containing magnetic powder. For example, the magnetic substrate may be made of ceramic. In addition, the insulator layer is not limited to one made of resin. For example, the insulator layer may be made of ceramic.

  A recessed part is not limited to what is formed in the side surface of a magnetic body substrate, or the whole laminated body. For example, the concave portions may be formed in all of the magnetic substrate and the laminated body, or the concave portions may be formed only for some of the insulator layers in the laminated body. In addition, the position in the direction along the side surface of the recess (the x direction in the embodiment) may be set as appropriate. The planar shape of the recess is not limited to a rectangle, and may be a shape that makes the engagement with the adhesive portion of the external electrode strong, such as a trapezoid whose outer side is a short side. Further, the shape of the concave portion in a side view may be a shape in which engagement with the external electrode is strengthened by the tapered surface.

  The external electrodes are not limited to two external electrodes provided on two (one pair) side surfaces of the laminated structure. For example, three or more external electrodes may be provided on two side surfaces, or three or more external electrodes may be provided on three or more side surfaces. In other words, the coil component may input or output two or more types of signals.

  The adhesion part of the external electrode does not need to be filled in the recess. That is, the adhesive portion may be formed in a film shape, or the surface exposed to the outside may be concave due to the concave portion although it is formed thick. Further, the film part may not be provided. That is, the state shown in FIG. 2 may be a completed form.

  The external electrode may be entirely made of metal including the adhesive portion. In this case, for example, when the magnetic substrate is made of a resin containing magnetic powder, the external electrode may be formed by plating. For example, when the magnetic substrate is made of ceramic, the external electrode may be formed by baking or plating. Conversely, the entire outer electrode including the film part may be made of a conductive resin. Further, the bonding portion or the like may be made of a conductive polymer.

  DESCRIPTION OF SYMBOLS 1 ... Coil component, 3 ... Laminated structure, 3r ... Recessed part, 5 ... External electrode, 7 ... Adhesion part, 11A ... 1st magnetic substrate, 11B ... 2nd magnetic substrate, 13 ... Laminated body, 15 ... Insulator Layer, 17 ... coil pattern, 19 ... drawer part.

Claims (6)

A laminate in which insulator layers and coil patterns are alternately laminated;
The first magnetic substrate and the second magnetic substrate sandwiching the stacked body in the stacking direction;
An external electrode connected to the lead portion of the coil pattern and exposed to the outside of the multilayer structure including the multilayer body, the first magnetic substrate, and the second magnetic substrate;
With
At least one of the laminate, the first magnetic substrate, and the second magnetic substrate has a recess on a side surface,
The external electrode has a bonding part bonded to the inner surface of the recess. The first magnetic substrate has the recess,
The lead portion of the coil pattern is provided at a position overlapping the concave portion on the main surface of the laminate on the first magnetic substrate side,
The coil component according to claim 1, wherein the bonding portion is bonded to a drawing portion of the coil pattern in the concave portion. The first and second magnetic substrates have the recesses on the side surfaces,
The coil pattern lead portion is provided at a position overlapping the concave portion on the upper and lower main surfaces of the laminate,
The coil component according to claim 1, wherein the bonding portion is bonded to a drawing portion of the coil pattern in the concave portion. The coil component according to any one of claims 1 to 3, wherein the adhesive portion is made of a conductive resin. 5. The coil according to claim 4, wherein the external electrode has a film part made of metal that covers side surfaces of the first magnetic substrate, the second magnetic substrate, and the laminated body and is bonded to the bonding part. parts. The coil component according to claim 4, wherein the magnetic substrate is made of a resin containing magnetic powder.

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