JP2020155480A - Coil component and manufacturing method therefor - Google Patents

Abstract

To ensure balance between inductance and magnetic saturation characteristics in a coil component having a structure in which a spiral coil pattern is covered with a magnetic element body.SOLUTION: A coil component 1 includes magnetic element bodies M1 and M2, an insulating film 51 located between the magnetic element body M1 and the magnetic element body M2, and a coil pattern CP1 which is embedded in the magnetic element body M2 and wound spirally. The insulating film 51 has a locally small thickness at a portion overlapping an inner diameter region of the coil pattern CP1 when viewed in a coil axis direction. As described above, since the thickness of the insulating film 51 is locally small at the portion overlapping the inner diameter region of the coil pattern CP1, it is possible to ensure the balance between the inductance and the magnetic saturation characteristics even when a relatively thick insulating film 51 is used.SELECTED DRAWING: Figure 4

Description

The present invention relates to a coil component and a method for manufacturing the same, and more particularly to a coil component having a structure in which a plane spiral coil pattern is covered with a magnetic element and a method for manufacturing the same.

A chip-type coil component having a spiral coil pattern may be covered with a magnetic element in order to increase the inductance. For example, Patent Documents 1 and 2 disclose coil components having a structure in which a spiral coil pattern is covered with a magnetic element.

The coil component described in Patent Document 1 has a structure in which a magnetic gap layer is provided between a plurality of laminated coil patterns. On the other hand, the coil component described in Patent Document 2 has a structure in which the insulating film is removed at a position overlapping the inner diameter region of the coil pattern, whereby the upper and lower magnetic elements come into contact with each other at a position overlapping the inner diameter region of the coil pattern. Have.

International Publication No. 2008/007705 Pamphlet Japanese Unexamined Patent Publication No. 2017-11185

However, the coil component described in Patent Document 1 has a problem that the inductance decreases when the thickness of the magnetic gap layer is increased. On the other hand, the coil component described in Patent Document 2 has a problem that it is easily magnetically saturated because there is no magnetic gap.

Therefore, an object of the present invention is to secure a balance between inductance and magnetic saturation characteristics in a coil component having a structure in which a spiral coil pattern is covered with a magnetic element. Another object of the present invention is to provide a method for manufacturing such a coil component.

The coil component according to the present invention is embedded in the first and second magnetic elements, the insulating film located between the first magnetic element and the second magnetic element, and the second magnetic element. It includes a coil pattern wound in a spiral shape, and the insulating film is characterized in that the thickness of a portion overlapping the inner diameter region of the coil pattern when viewed from the coil axis direction is locally thin.

According to the present invention, since the thickness of the insulating film is locally thin in the portion overlapping the inner diameter region of the coil pattern, the inductance and magnetic saturation characteristics are exhibited even when a relatively thick insulating film is used. It is possible to secure the balance.

In the present invention, the insulating film has a first surface in contact with the first magnetic element and a second surface in contact with the second magnetic element, and the first surface is viewed from the coil axis direction. A recess may be provided in a portion overlapping the inner diameter region of the coil pattern. According to this, since the contact area between the insulating film and the first magnetic element increases, peeling at the interface between the insulating film and the first magnetic element is less likely to occur.

In the present invention, the first magnetic element and the second magnetic element may be in contact with each other in the outer region of the coil pattern. According to this, the magnetic resistance in the outer region of the coil pattern can be reduced.

The method for manufacturing a coil component according to the present invention includes a first step of forming an insulating film having a thickness of a second region surrounded by a first region rather than a first region, and a second region of the insulating film. The second step of forming a coil pattern spirally wound on the first region of the insulating film so that is overlapped with the inner diameter region, and the first magnetic element for embedding the insulating film and the coil pattern for embedding the coil pattern. It is characterized by including a third step of forming the magnetic element of 2.

According to the present invention, it is possible to obtain a structure in which the thickness of the insulating film is locally thin at a portion overlapping the inner diameter region of the coil pattern.

In the present invention, the first step may include a step of laminating an insulating film on a support having protrusions. According to this, the shape of the protrusion of the support can be transferred to the insulating film.

As described above, according to the present invention, it is possible to secure a balance between inductance and magnetic saturation characteristics in a coil component having a structure in which a spiral coil pattern is covered with a magnetic element. Further, according to the present invention, it is possible to provide a method for manufacturing such a coil component.

FIG. 1 is a schematic perspective view showing the appearance of the coil component 1 according to the first embodiment of the present invention. FIG. 2 is a side view showing a state in which the coil component 1 is mounted on the circuit board 80, and is a view seen from the stacking direction. FIG. 3 is a cross-sectional view of the coil component 1, showing a cross-sectional view in which the external terminals E1 and E2 appear. FIG. 4 is a cross-sectional view of the coil component 1, showing a cross-sectional view in which the external terminals E1 and E2 do not appear. 5 (a) to 5 (c) are schematic cross-sectional views showing some variations in the shape of the insulating film 51. FIG. 6 is a process diagram for explaining a manufacturing method of the coil component 1. FIG. 7 is a process diagram for explaining a manufacturing method of the coil component 1. FIG. 8 is a process diagram for explaining a manufacturing method of the coil component 1. FIG. 9 is a process diagram for explaining a manufacturing method of the coil component 1. FIG. 10 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 11 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 12 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 13 is a process diagram for explaining a manufacturing method of the coil component 1. FIG. 14 is a process diagram for explaining a manufacturing method of the coil component 1. FIG. 15 is a process diagram for explaining a manufacturing method of the coil component 1. FIG. 16 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 17 is a process diagram for explaining a manufacturing method of the coil component 1. FIG. 18 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 19 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 20 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 21 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 22 is a process diagram for explaining a method of manufacturing the coil component 1. FIG. 23 is a process diagram for explaining the manufacturing method of the coil component 1. FIG. 24 is a plan view showing the pattern shape of the conductor layer 10. FIG. 25 is a plan view showing the pattern shape of the insulating film 52. FIG. 26 is a plan view showing the pattern shape of the conductor layer 20. FIG. 27 is a plan view showing the pattern shape of the insulating film 53. FIG. 28 is a plan view showing the pattern shape of the conductor layer 30. FIG. 29 is a plan view showing the pattern shape of the insulating film 54. FIG. 30 is a plan view showing the pattern shape of the conductor layer 40. FIG. 31 is a plan view showing the pattern shape of the insulating film 55. FIG. 32 is a plan view showing the pattern shape of the insulating film 51. FIG. 33 is a cross-sectional view of the coil component 1A according to the second embodiment of the present invention. FIG. 34 is a cross-sectional view of the coil component 1B according to the third embodiment of the present invention. FIG. 35 is a cross-sectional view of the coil component 1C according to the fourth embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing the appearance of the coil component 1 according to the first embodiment of the present invention.

The coil component 1 according to the first embodiment of the present invention is a surface mount type chip component suitable to be used as an inductor for a power supply circuit, and as shown in FIG. 1, the first and second magnetic elements M1 , M2 and coil portions C embedded in the first and second magnetic elements M1 and M2. The configuration of the coil portion C will be described later, but in the present embodiment, four conductor layers having a spiral coil pattern are laminated, whereby one coil conductor is formed. Then, one end of the coil conductor is connected to the first external terminal E1, and the other end of the coil conductor is connected to the second external terminal E2.

The magnetic elements M1 and M2 are composite members made of a resin containing a metallic magnetic powder made of iron (Fe), a permalloy-based material, or the like, and form a magnetic path of magnetic flux generated by passing an electric current through a coil. As the resin, it is preferable to use a liquid or powder epoxy resin. The material constituting the magnetic element M1 and the material constituting the magnetic element M2 may be the same as each other or may be different from each other.

Unlike a general laminated coil component, the coil component 1 according to the present embodiment is mounted upright so that the z direction, which is the stacking direction, is parallel to the circuit board. Specifically, the surface 2 of the magnetic elements M1 and M2 constituting the xz surface is used as the mounting surface. Then, a first external terminal E1 and a second external terminal E2 are provided on the surface 2. The first external terminal E1 is a terminal to which one end of the coil conductor formed in the coil portion C is connected, and the second external terminal E2 is connected to the other end of the coil conductor formed in the coil portion C. It is a terminal.

As shown in FIG. 1, the first external terminal E1 is continuously formed from the surface 2 to the surface 3 forming the yz surface, and the second external terminal E2 constitutes the yz surface from the surface 2. It is continuously formed over the surface 4. The external terminals E1 and E2 are formed of a laminated film of nickel (Ni) and tin (Sn) formed on the exposed surface of the electrode pattern included in the coil portion C.

FIG. 2 is a side view showing a state in which the coil component 1 according to the present embodiment is mounted on the circuit board 80, and is a view seen from the stacking direction.

As shown in FIG. 2, the coil component 1 according to the present embodiment is mounted upright on the circuit board 80. Specifically, the surface 2 of the magnetic elements M1 and M2 faces the mounting surface of the circuit board 80, that is, the z direction, which is the stacking direction of the coil components 1, is parallel to the mounting surface of the circuit board 80. , Will be implemented.

Land patterns 81 and 82 are provided on the circuit board 80, and the external terminals E1 and E2 of the coil component 1 are connected to these land patterns 81 and 82, respectively. The electrical and mechanical connections between the land patterns 81 and 82 and the external terminals E1 and E2 are made by solder 83. A fillet of solder 83 is formed on the portions of the external terminals E1 and E2 formed on the surfaces 3 and 4 of the coil component 1. The external terminals E1 and E2 are made of a laminated film of nickel (Ni) and tin (Sn), which enhances the wettability of the solder.

3 and 4 are cross-sectional views of the coil component 1 according to the present embodiment, FIG. 3 shows a cross section in which the external terminals E1 and E2 appear, and FIG. 4 shows a cross section in which the external terminals E1 and E2 do not appear.

As shown in FIGS. 3 and 4, the coil portion C included in the coil component 1 is embedded in two magnetic elements M1 and M2, and has an insulating film 51 to 55 and a conductor layer 10, 20, 30, 40. Have a structure in which is alternately laminated. The conductor layers 10, 20, 30, and 40 each have a spiral coil pattern CP1 to CP4, and the upper surface or the lower surface of the coil patterns CP1 to CP4 is covered with an insulating film 51 to 55. The side surfaces of the coil patterns CP1 to CP4 are covered with the in-layer insulation patterns 61 to 64, respectively. Here, the upper surface and the lower surface of the coil patterns CP1 to CP4 refer to a surface perpendicular to the coil shaft, and the side surfaces of the coil patterns CP1 to CP4 refer to a surface horizontal to the coil shaft.

The coil patterns CP1 to CP4 form a coil conductor by being connected to each other via through holes formed in the insulating films 52 to 54. Copper (Cu) is preferably used as the material for the conductor layers 10, 20, 30, and 40. The magnetic element M2 is also embedded in the inner diameter region and the outer region of the coil patterns CP1 to CP4. Of the insulating films 51 to 55, at least the insulating films 52 to 54 are made of non-magnetic materials. A magnetic material may be used for the insulating film 51 located at the bottom layer and the insulating film 55 located at the top layer.

The conductor layer 10 is a first-layer conductor layer formed on the upper surface of the magnetic element M1 via an insulating film 51. The conductor layer 10 is provided with a coil pattern CP1 wound spirally for one turn and two electrode patterns 11 and 12. The side surface of the coil pattern CP1 is covered with the in-layer insulation pattern 61. As shown in FIG. 3, the coil pattern CP1 and the electrode pattern 11 are connected in a predetermined cross section. On the other hand, the electrode pattern 12 is provided independently of the coil pattern CP1. The electrode pattern 11 is exposed from the coil portion C, and an external terminal E1 is formed on the surface thereof. Further, the electrode pattern 12 is exposed from the coil portion C, and an external terminal E2 is formed on the surface thereof.

The conductor layer 20 is a second conductor layer formed on the upper surface of the conductor layer 10 via an insulating film 52. The conductor layer 20 is provided with a coil pattern CP2 wound spirally for one turn and two electrode patterns 21 and 22. The side surface of the coil pattern CP2 is covered with the intra-layer insulation pattern 62. The electrode patterns 21 and 22 are provided independently of the coil pattern CP2. The electrode pattern 21 is exposed from the coil portion C, and an external terminal E1 is formed on the surface thereof. Further, the electrode pattern 22 is exposed from the coil portion C, and an external terminal E2 is formed on the surface thereof.

The conductor layer 30 is a third conductor layer formed on the upper surface of the conductor layer 20 via an insulating film 53. The conductor layer 30 is provided with a coil pattern CP3 wound in a spiral shape for one turn and two electrode patterns 31 and 32. The side surface of the coil pattern CP3 is covered with the intra-layer insulation pattern 63. The electrode patterns 31 and 32 are both provided independently of the coil pattern CP3. The electrode pattern 31 is exposed from the coil portion C, and an external terminal E1 is formed on the surface thereof. Further, the electrode pattern 32 is exposed from the coil portion C, and an external terminal E2 is formed on the surface thereof.

The conductor layer 40 is a fourth conductor layer formed on the upper surface of the conductor layer 30 via an insulating film 54. The conductor layer 40 is provided with a coil pattern CP4 wound in a spiral shape for one turn and two electrode patterns 41 and 42. The side surface of the coil pattern CP4 is covered with the intra-layer insulation pattern 64. As shown in FIG. 3, the coil pattern CP4 and the electrode pattern 42 are connected in a predetermined cross section. On the other hand, the electrode pattern 41 is provided independently of the coil pattern CP4. The electrode pattern 41 is exposed from the coil portion C, and an external terminal E1 is formed on the surface thereof. Further, the electrode pattern 42 is exposed from the coil portion C, and an external terminal E2 is formed on the surface thereof.

Then, the coil patterns CP1 to CP4 are connected via via conductors (not shown) provided so as to penetrate the insulating films 52 to 54. As a result, the coil conductors of 4 turns are formed by the coil patterns CP1 to CP4, one end of which is connected to the external terminal E1 and the other end of which is connected to the external terminal E2.

The coil component 1 according to the present embodiment has a structure in which the insulating film 51 is embedded in the magnetic element M1. The other internal elements, that is, the conductor layers 10, 20, 30, 40, the insulating films 52 to 55, and the in-layer insulation patterns 61 to 64 are embedded in the magnetic element M2. Furthermore, the insulating film 51 has a first region 51 ₁ overlapping the coil pattern CP1~CP4 in plan view, surrounded by the first region 51 _1, second overlapping the inner diameter area of the coil pattern CP1~CP4 in plan view It has a region 51 _2, than the first region 51 ₁ it is the thickness of the second region 51 ₂ is thinner. Further, the portion of the upper surface of the magnetic element M1 that is not in contact with the insulating film 51 is in contact with the magnetic element M2. That is, in a plan view, the magnetic element M1 and the magnetic element M2 are in contact with each other in the outer region of the coil patterns CP1 to CP4, whereby the magnetic resistance in the outer region of the coil patterns CP1 to CP4 is reduced. ..

As described above, in the present embodiment, since the thickness of the insulating film 51 is locally thin in the portion overlapping the inner diameter region of the coil patterns CP1 to CP4 in a plan view, the thickness of the magnetic gap is set to the original thickness of the insulating film 51. Can be made thinner than. Thus, if the original thickness thick and the insulating film 51, even if it is difficult to entirely form a thin insulating film 51, the inductance by adjusting the thickness of the second region 51 ₂ It is possible to secure a balance between the magnetic saturation characteristics and the magnetic saturation characteristics.

There is no particular limitation on the second region 51 ₂ of the cross-sectional shape of the insulating film 51, a first region 51 ₁ and the _second boundary second region 51 is substantially vertical as shown in FIG. 5 (a) it may be, the first region 51 ₁ and the second region 51 ₂ of the boundary as shown in FIG. 5 (b) may be a tapered shape. Further, as shown in FIG. 5 (c), a plurality of _second regions 521 may be provided.

In the present embodiment, of the surface of the insulating film 51, the upper surface 51U in contact with the magnetic element M2 is substantially flat, but the lower surface 51B in contact with the magnetic element M1 has a recess, whereby the second surface is formed. region 51 ₂ the thickness of which is thinned. As a result, the magnetic element M1 is embedded in this recess. As a result, the contact area between the magnetic element M1 and the insulating film 51 increases, so that even if there is a difference in the coefficient of thermal expansion between the magnetic element M1 and the insulating film 51, peeling occurs at the interface between the two. It becomes difficult. In particular, if a plurality of _second regions 521 are provided as shown in FIG. 5C, the contact area between the magnetic element M1 and the insulating film 51 can be further increased. On the other hand, since the magnetic element M2, the insulating films 52 to 55, and the in-layer insulating patterns 61 to 64 have a wide contact area and are intricately intertwined, peeling at the interface between the two is unlikely to occur in the first place. This makes it possible to ensure high reliability of the coil component 1 according to the present embodiment.

Next, a method of manufacturing the coil component 1 according to the present embodiment will be described.

6 to 23 are process diagrams for explaining the manufacturing method of the coil component 1 according to the present embodiment. The process diagrams shown in FIGS. 6 to 23 show a cross section corresponding to one coil component 1, but in reality, a large number of coil components 1 are taken by simultaneously manufacturing a large number of coil components 1 using an assembly substrate. can do.

First, a support 70 provided with a metal foil 72 such as copper (Cu) on the surface of the base material 71 is prepared (FIG. 6), and a protrusion 72a is formed on the metal foil 72 (FIG. 7). As a method for forming the protrusions 72a, a method of selectively plating and growing the metal foil 72 in the region where the protrusions 72a should be formed may be used, or the metal in a state where the region where the protrusions 72a should be formed is masked. A method of etching the exposed surface of the foil 72 may be used.

Next, the insulating film 51 and the seed layer 13 are formed on the surface of the metal foil 72 provided with the protrusions 72a (FIG. 8). The insulating film 51 and the seed layer 13 can be formed by a laminating method. Thus, the shape of the protrusion 72a is transferred to the insulating film 51, ₂ is thicker first region 51 ₁ and the thin second region 51 is formed in the insulating film 51.

Next, a part of the insulating film 51 is exposed by patterning the seed layer 13 (FIG. 9), and then an in-layer insulating pattern 61 is formed in the exposed portion of the insulating film 51 (FIG. 10). The intra-layer insulation pattern 61 is a negative pattern of the coil pattern CP1 made of a photosensitive permanent resist, and therefore the region partitioned by the intra-layer insulation pattern 61 is spiral.

Next, the conductor layer 10 is formed by growing the seed layer 13 by electrolytic plating (FIG. 11). As a result, the spiral coil pattern CP1 is formed in the region partitioned by the intra-layer insulation pattern 61. At this time, the sacrificial pattern VP1 is formed in the inner diameter region and the outer region of the coil pattern CP1. The planar shape of the conductor layer 10 is as shown in FIG. 24, the coil pattern CP1 wound in a spiral shape, the two electrode patterns 11 and 12 located in the outer region of the coil pattern CP1, and the inner diameter of the coil pattern CP1. It consists of a sacrifice pattern VP1 located in the region and the outer region. As shown in FIG. 24, one end of the coil pattern CP1 is connected to the electrode pattern 11.

Next, the insulating film 52 and the seed layer 23 are formed on the surface of the conductor layer 10 (FIG. 12). The insulating film 52 and the seed layer 23 can be formed by a laminating method. Next, after the seed layer 23 and the insulating film 52 are patterned in a spiral shape, a part of the insulating film 52 is exposed by further patterning the seed layer 23 (FIG. 13). The pattern shape of the insulating film 52 is as shown in FIG. 25, and the opening 52a is provided at a position corresponding to the inner diameter region of the coil pattern CP1 and the opening 52b is provided at a position corresponding to the outer region of the coil pattern CP1. Be done. Further, in the insulating film 52, an opening 52c is formed at a position overlapping the other end of the coil pattern CP1, and an opening 52d is formed at a position overlapping the electrode patterns 11 and 12.

Next, the in-layer insulation pattern 62 is formed in the exposed portion of the insulating film 52 (FIG. 14). The intra-layer insulation pattern 62 is a negative pattern of the coil pattern CP2 made of a photosensitive permanent resist, and therefore the region partitioned by the intra-layer insulation pattern 62 is spiral.

Next, the conductor layer 20 is formed by growing the seed layer 23 and the sacrificial pattern VP1 by electrolytic plating (FIG. 15). As a result, the spiral coil pattern CP2 is formed in the region partitioned by the intra-layer insulation pattern 62, and the sacrificial pattern VP2 is formed in the inner diameter region and the outer region of the coil pattern CP2. The planar shape of the conductor layer 20 is as shown in FIG. 26, the coil pattern CP2 wound in a spiral shape, the two electrode patterns 21 and 22 located in the outer region of the coil pattern CP2, and the inner diameter of the coil pattern CP2. It consists of a sacrifice pattern VP2 located in the region and the outer region.

By repeating the above-mentioned method, the seed layer 33 and the insulating film 53 are patterned, the in-layer insulating pattern 63 is formed, and the conductor layer 30 is formed (FIG. 16). As a result, the spiral coil pattern CP3 is formed in the region partitioned by the intra-layer insulation pattern 63, and the sacrificial pattern VP3 is formed in the inner diameter region and the outer region of the coil pattern CP3. The pattern shape of the insulating film 53 is as shown in FIG. 27, and the opening 53a is provided at a position corresponding to the inner diameter region of the coil pattern CP3, and the opening 53b is provided at a position corresponding to the outer region of the coil pattern CP3. Be done. Further, in the insulating film 53, an opening 53c is formed at a position overlapping one end of the coil pattern CP2, and an opening 53d is formed at a position overlapping the electrode patterns 21 and 22. The planar shape of the conductor layer 30 is as shown in FIG. 28, the coil pattern CP3 wound in a spiral shape, the two electrode patterns 31 and 32 located in the outer region of the coil pattern CP3, and the inner diameter of the coil pattern CP3. It consists of a sacrificial pattern VP3 located in the region and the outer region.

By repeating the same steps, the seed layer 43 and the insulating film 53 are patterned, the in-layer insulating pattern 64 is formed, and the conductor layer 40 is formed (FIG. 17). As a result, the spiral coil pattern CP4 is formed in the region partitioned by the intra-layer insulation pattern 64, and the sacrificial pattern VP4 is formed in the inner diameter region and the outer region of the coil pattern CP4. The pattern shape of the insulating film 54 is as shown in FIG. 29, and the opening 54a is provided at a position corresponding to the inner diameter region of the coil pattern CP4, and the opening 54b is provided at a position corresponding to the outer region of the coil pattern CP4. Be done. Further, in the insulating film 54, an opening 54c is formed at a position overlapping one end of the coil pattern CP3, and an opening 54d is formed at a position overlapping the electrode patterns 31 and 32. The planar shape of the conductor layer 40 is as shown in FIG. 30, the coil pattern CP4 wound in a spiral shape, the two electrode patterns 41 and 42 located in the outer region of the coil pattern CP4, and the inner diameter of the coil pattern CP4. It consists of a sacrifice pattern VP4 located in the region and the outer region. As shown in FIG. 30, one end of the coil pattern CP4 is connected to the electrode pattern 42.

Next, after forming the insulating film 55 on the surface of the conductor layer 40 (FIG. 18), the sacrificial pattern VP4 is exposed by patterning the insulating film 55 (FIG. 19). The pattern shape of the insulating film 55 is as shown in FIG. 31, and the opening 55a is provided at a position corresponding to the inner diameter region of the coil pattern CP4, and the opening 55b is provided at a position corresponding to the outer region of the coil pattern CP4. Be done. Next, the sacrificial patterns VP1 to VP4 are removed by performing wet etching (FIG. 20). Since the coil patterns CP1 to CP4 are covered with the insulating films 51 to 55 and the in-layer insulating patterns 61 to 64, they are not etched. As a result, a space S is formed in the inner diameter region and the outer region of the coil patterns CP1 to CP4.

Next, after forming the magnetic element M2 that fills this space S (FIG. 21), the support 70 is peeled off (FIG. 22). As a result, the lower surface 51B of the insulating film 51 having irregularities is exposed. Next, the insulating film 51 is patterned to expose the magnetic element M2 located in the outer region of the coil pattern CP1. The pattern shape of the insulating film 51 is as shown in FIG. 32, and the opening 51b is provided at a position corresponding to the outer region of the coil pattern CP1. To overlap with the inner diameter area of the coil pattern CP1 is provided with a recess, this portion constitutes a ₂ thin second region 51 thickness.

Then, if the magnetic element M1 is formed so as to cover the insulating film 51, the coil component 1 according to the present embodiment is completed.

As described above, in the present embodiment, since the insulating film 51 is laminated on the surface of the metal foil 72 provided with the protrusions 72a, the shape of the protrusions 72a is transferred to the insulating film 51. Thus, it is possible to form a thin second region 51 ₂ thick first region 51 ₁ and the thickness of the thickness. Therefore, even when the thickness of the insulating film 51 to be laminated is thick, the thickness of the insulating film 51 can be locally reduced at a position where it overlaps with the inner diameter region of the coil patterns CP1 to CP4 in a plan view. This makes it possible to secure a balance between the inductance and the magnetic saturation characteristic.

Here, when it is necessary to increase the inductance by a higher height of the projections 72a, it may be thinner second region 51 ₂ of the thickness of the insulating film 51. On the other hand, when it is necessary to more difficult to magnetic saturation, by further reducing the height of the protrusion 72a, it may be thicker second region 51 ₂ of the thickness of the insulating film 51. Thus, regardless of the first region 51 the thickness of ₁ which is the original thickness of the insulating film 51, by adjusting the second region 51 ₂ of the thickness of the insulating film 51, the inductance and magnetic saturation The characteristics can be adjusted. Adjustment of inductance and magnetic saturation characteristic, not only the second region 51 ₂ of the thickness of the insulating film 51, as shown in FIG. 5 (c), also be adjusted by the second region 51 _second number It is possible.

FIG. 33 is a cross-sectional view of the coil component 1A according to the second embodiment of the present invention.

As shown in FIG. 33, the coil component 1A according to the second embodiment of the present invention is first in that a recess is provided on the upper surface 51U side of the surface of the insulating film 51 in contact with the magnetic element M2. It is different from the coil component 1 according to the embodiment of. Since the other basic configurations are the same as those of the coil component 1 according to the first embodiment, the same elements are designated by the same reference numerals, and duplicate description will be omitted. As illustrated in this embodiment, the recess of the insulating film 51 may be provided on any surface.

FIG. 34 is a cross-sectional view of the coil component 1B according to the third embodiment of the present invention.

As shown in FIG. 34, the coil component 1B according to the third embodiment of the present invention has a configuration in which the coil patterns CP1 to CP4 are all wound in a spiral shape for three turns. It is different from the coil component 1 according to the embodiment. Since the other basic configurations are the same as those of the coil component 1 according to the first embodiment, the same elements are designated by the same reference numerals, and duplicate description will be omitted. As illustrated by this embodiment, the number of turns of each coil pattern is not particularly limited.

FIG. 35 is a cross-sectional view of the coil component 1C according to the fourth embodiment of the present invention.

As shown in FIG. 35, the coil component 1C according to the fourth embodiment of the present invention has the coil component 1 according to the first embodiment in that the external terminals E1 and E2 are arranged on the upper surface of the magnetic element M2. Is different from. Since the other basic configurations are the same as those of the coil component 1 according to the first embodiment, the same elements are designated by the same reference numerals, and duplicate description will be omitted. In the present embodiment, bump conductors 91 and 92 penetrating the magnetic element M2 are provided, and the external terminal E1 and the coil pattern CP1 are connected via the bump conductor 91 and the electrode patterns 41, 31, 21 and 11, and the bumps are formed. The external terminal E2 and the coil pattern CP4 are connected via the conductor 92. As illustrated by the present embodiment, the positions where the external terminals E1 and E2 are formed in the present invention are not particularly limited.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention, and these are also the present invention. Needless to say, it is included in the range.

1,1A ~ 1C Coil parts 2-4 Surfaces of coil parts 10, 20, 30, 40 Conductor layers 11, 12, 21, 22, 31, 32, 41, 42 Electrode patterns 13, 23, 33, 43 Seed layers 51 ~ 55 Insulation film 51 ₁ First region 51 ₂ Second region 51B Lower surface 51U Upper surface 52a to 55a, 51b to 55b, 52c to 54c, 52d to 54d Opening 61 to 64 In-layer insulation pattern 70 Support 71 Base material 72 Metal foil 72a Protrusion 80 Circuit board 81, 82 Land pattern 91,92 Bump conductor C Coil part CP1 to CP4 Coil pattern E1, E2 External terminals M1, M2 Magnetic element S Space VP1 to VP4 Sacrifice pattern

Claims (5)

With the first and second magnetic elements,
An insulating film located between the first magnetic element and the second magnetic element,
A coil pattern embedded in the second magnetic element and wound in a spiral shape is provided.
The insulating film is a coil component characterized in that the thickness of a portion overlapping the inner diameter region of the coil pattern when viewed from the coil axis direction is locally thin. The insulating film has a first surface in contact with the first magnetic element and a second surface in contact with the second magnetic element.
The coil component according to claim 1, wherein the first surface is provided with a recess in a portion overlapping the inner diameter region of the coil pattern when viewed from the coil axis direction. The coil component according to claim 1 or 2, wherein the first magnetic element and the second magnetic element are in contact with each other in an outer region of the coil pattern. The first step of forming an insulating film in which the thickness of the second region surrounded by the first region is thinner than that of the first region, and
A second step of forming a coil pattern spirally wound on the first region of the insulating film so that the second region of the insulating film overlaps the inner diameter region.
A method for manufacturing a coil component, which comprises a first magnetic element for embedding the insulating film and a third step for forming a second magnetic element for embedding the coil pattern. The method for manufacturing a coil component according to claim 4, wherein the first step includes a step of laminating the insulating film on a support having a protrusion.

Images