Coil components

Abstract

To reduce the chip size of a coil component having such a structure that a plurality of coil parts are embedded in a magnetic element assembly.SOLUTION: A coil component 100 includes: a magnetic support layer 103; a coil part C1 which is embedded on a main surface 141 side of the magnetic support layer 103; a coil part C2 which is embedded on a main surface 142 side of the magnetic support layer 103; a magnetic resin layer 101 which is provided on the main surface 141 so as to cover the coil part C1; and a magnetic resin layer 102 which is provided on the main surface 142 so as to cover the coil part C1. The magnetic support layer 103 has an inner diameter region 161 surrounded by the coil part C1, an inner diameter region 162 surrounded by the coil part C2, and an inter-coil region 165 which is positioned between the coil parts C1 and C2. Thus, the coil parts C1 and C2 are embedded in the surface and the rear face of the magnetic support layer 103, which can reduce the chip size.SELECTED DRAWING: Figure 7

Description

Technical Field

[0005]

[0001] The present disclosure 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 plurality of coil portions are embedded in a magnetic element and a method for manufacturing the same.

Background Art

[0002] Patent Document 1 discloses a coil component incorporating a plurality of inductors. By using such so-called array products, it becomes possible to reduce the number of components.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the coil component described in Patent Document 1 has a problem that the chip size becomes large because the plurality of coil portions constituting the inductor are only arranged in one direction.

[0005] In the present disclosure, a technique for miniaturizing the chip size in a coil component having a structure in which a plurality of coil portions are embedded in a magnetic element and a method for manufacturing the same is described.

Means for Solving the Problems

[0006] The coil component according to this disclosure comprises a magnetic support layer having a first main surface and a second main surface located opposite the first main surface; a first coil portion embedded on the first main surface side of the magnetic support layer; a second coil portion embedded on the second main surface side of the magnetic support layer; a first magnetic resin layer provided on the first main surface of the magnetic support layer so as to cover the first coil portion; and a second magnetic resin layer provided on the second main surface of the magnetic support layer so as to cover the second coil portion. The magnetic support layer has a first inner diameter region surrounded by the first coil portion, a second inner diameter region surrounded by the second coil portion, and an inter-coil region located between the first coil portion and the second coil portion.

[0007] According to this disclosure, since the first coil portion and the second coil portion are embedded on both sides of the magnetic support layer, it is possible to reduce the chip size. Moreover, the volume of the magnetic support layer is increased compared to the case where the magnetic support layer exists only in the region between the coils.

[0008] In this disclosure, the magnetic support layer may further have a first outer region located radially outside the first coil portion and a second outer region located radially outside the second coil portion. This increases the volume of the magnetic support layer.

[0009] In this disclosure, the magnetic support layer may have a higher magnetic permeability than the first and second magnetic resin layers. This suppresses the magnetic coupling between the first coil and the second coil. As a result, the first coil and the second coil function as independent inductors, making it possible to suppress crosstalk between the signal flowing through the first coil and the signal flowing through the second coil.

[0010] In this disclosure, the first coil portion includes a first conductor layer and a second conductor layer laminated via a first interlayer insulating film, and the second coil portion includes a third conductor layer and a fourth conductor layer laminated via a second interlayer insulating film, and within the magnetic support layer, the first conductor layer, the second conductor layer, the third conductor layer and the fourth conductor layer are laminated in this order, the first conductor layer and the second conductor layer are connected to each other via a first via conductor provided through the first interlayer insulating film, the third conductor layer and the fourth conductor layer are connected to each other via a second via conductor provided through the second interlayer insulating film, the first via conductor may have a shape in which its diameter decreases from the second conductor layer toward the first conductor layer, and the second via conductor may have a shape in which its diameter decreases from the third conductor layer toward the fourth conductor layer. According to this, even when an external force is applied to the coil component, damage due to stress via the first and second via conductors can be reduced.

[0011] The coil component according to this disclosure further comprises first and second terminal electrodes connected to one and the other end of a first coil portion, respectively, and third and fourth terminal electrodes connected to one and the other end of a second coil portion, respectively. The magnetic support layer further has first and second side surfaces that are perpendicular to the first and second main surfaces and located on opposite sides. The first and third terminal electrodes are provided on the first side surface, and the second and fourth terminal electrodes are provided on the second side surface. One and the other end of the first coil portion may be exposed from the first and second side surfaces, respectively, to connect to the first and second terminal electrodes, and one and the other end of the second coil portion may be exposed from the first and second side surfaces, respectively, to connect to the third and fourth terminal electrodes. This makes it possible, for example, to use the first side surface as the input side and the second side surface as the output side, enabling connections suitable for array products.

[0012] The method for manufacturing a coil component according to this disclosure comprises: a first step of forming first and second coil portions; a second step of preparing a magnetic support layer having a first main surface and a second main surface located on the opposite side of the first main surface, embedding the first coil portion on the first main surface side and embedding the second coil portion on the second main surface side; and a third step of providing a first magnetic resin layer on the first main surface so as to cover the first coil portion and providing a second magnetic resin layer on the second main surface so as to cover the second coil portion.

[0013] According to this disclosure, the volume of the magnetic support layer can be increased, and it becomes unnecessary to use materials with excellent embedding properties as the materials for the first and second magnetic resin layers.

[0014] In this disclosure, the first step includes the steps of forming first and second coil portions on one and the other surface of a support substrate, and peeling the first and second coil portions from the support substrate; the second step includes pressing the surface of the first coil portion opposite to the surface that was in contact with one surface of the support substrate against a first main surface, and pressing the surface of the second coil portion opposite to the surface that was in contact with the other surface of the support substrate against a second main surface; and the third step may include the steps of providing a first magnetic resin layer so as to cover the surface of the first coil portion that was in contact with one surface of the support substrate, and providing a second magnetic resin layer so as to cover the surface of the second coil portion that was in contact with the other surface of the support substrate. This increases manufacturing efficiency and makes it possible to have a magnetic support layer that has not only an inter-coil region located between the first and second coil portions, but also a first inner diameter region surrounded by the first coil portion and a second inner diameter region surrounded by the second coil portion. [Effects of the Invention]

[0015] Thus, according to this disclosure, a coil component having a structure in which multiple coil parts are embedded in a magnetic element, and a method for manufacturing the same, are provided, which is a technology for reducing the chip size. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a substantially perspective view showing the appearance of a coil component 100 according to a first embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic perspective view of the coil component 100 as seen from the Z direction. [Figure 3]FIG. 3 is a plan view for explaining the configuration of the coil portion C1, (a) shows the pattern shape of the coil pattern 121 located in the conductor layer L1, and (b) shows the pattern shape of the coil pattern 122 located in the conductor layer L2. [Figure 4] FIG. 4 is a plan view for explaining the configuration of the coil portion C2, (a) shows the pattern shape of the coil pattern 123 located in the conductor layer L3, and (b) shows the pattern shape of the coil pattern 124 located in the conductor layer L4. [Figure 5] FIG. 5 is a schematic cross-sectional view taken along the line A-A shown in FIGS. 3 and 4. [Figure 6] FIG. 6 is a schematic cross-sectional view taken along the line B-B shown in FIGS. 3 and 4. [Figure 7] FIG. 7 is a schematic cross-sectional view taken along the line C-C shown in FIGS. 3 and 4. [Figure 8] FIG. 8 is a process diagram for explaining the manufacturing method of the coil component 100. [Figure 9] FIG. 9 is a process diagram for explaining the manufacturing method of the coil component 100. [Figure 10] FIG. 10 is a process diagram for explaining the manufacturing method of the coil component 100. [Figure 11] FIG. 11 is a process diagram for explaining the manufacturing method of the coil component 100. [Figure 12] FIG. 12 is a process diagram for explaining the manufacturing method of the coil component 100. [Figure 13] FIG. 13 is a process diagram for explaining the manufacturing method of the coil component 100. [Figure 14] FIG. 14 is a schematic perspective view showing the appearance of the coil component 200 according to the second embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0018] Figure 1 is a substantially perspective view showing the appearance of the coil component 100 according to the first embodiment of this disclosure. Figure 2 is a substantially perspective plan view of the coil component 100 as seen from the Z direction.

[0019] As shown in Figure 1, the coil component 100 according to the first embodiment comprises a magnetic element consisting of magnetic resin layers 101, 102 and a magnetic support layer 103, coil portions C1, C2 embedded in the magnetic support layer 103, and terminal electrodes 111 to 114 provided on the surface of the magnetic element. The magnetic resin layers 101, 102 and the magnetic support layer 103 may be made of a composite magnetic material in which magnetic particles made of a high-permeability material such as ferrite or permalloy are solidified with a resin binder. The coil axes of the coil portions C1, C2 embedded in the magnetic support layer 103 are in the Z direction. The XY plane of the magnetic element is the mounting surface, and the terminal electrodes 111 to 114 are formed on the sides that constitute the XZ plane and are located opposite each other. Parts of the terminal electrodes 111 to 114 wrap around to the mounting surface, so that the terminal electrodes 111 to 114 have a C shape.

[0020] As shown in Figure 2, coil section C1 includes coil patterns 121 and 122, and coil section C2 includes coil patterns 123 and 124. Coil patterns 121, 122, 123, and 124 are stacked in this order in the Z direction and are connected to terminal electrodes 111 to 114, respectively.

[0021] Figure 3 is a plan view illustrating the configuration of the coil section C1, where (a) shows the pattern shape of the coil pattern 121 located in the conductor layer L1, and (b) shows the pattern shape of the coil pattern 122 located in the conductor layer L2.

[0022] As shown in Figure 3(a), one end of coil pattern 121 is exposed to the side surface 143 of the magnetic support layer 103 and connected to the terminal electrode 111, while the other end is connected to the via conductor 131. Similarly, as shown in Figure 3(b), one end of coil pattern 122 is exposed to the side surface 144 of the magnetic support layer 103 and connected to the terminal electrode 112, while the other end is connected to the via conductor 131. As a result, a coil of approximately one turn, consisting of the two coil patterns 121 and 122, is connected between the terminal electrodes 111 and 112. The ends of coil patterns 121 and 122 have a planar shape in which the pattern width widens as it approaches the terminal electrodes 111 and 112. This increases the contact area between the coil patterns 121 and 122 and the terminal electrodes 111 and 112, thereby reducing the connection resistance between them. An interlayer insulating film 151 is provided between the coil patterns 121, 122 and the magnetic support layer 103, thereby preventing contact between the coil patterns 121, 122 and the magnetic support layer 103. An interlayer insulating film 151 is also provided between the conductor layer L1 and the conductor layer L2, and the via conductor 131 is provided penetrating the interlayer insulating film 151.

[0023] Figure 4 is a plan view illustrating the configuration of the coil section C2, where (a) shows the pattern shape of the coil pattern 123 located in the conductor layer L3, and (b) shows the pattern shape of the coil pattern 124 located in the conductor layer L4.

[0024] As shown in Figure 4(a), one end of the coil pattern 123 is exposed to the side surface 143 of the magnetic support layer 103 and connected to the terminal electrode 113, while the other end is connected to the via conductor 132. Similarly, as shown in Figure 4(b), one end of the coil pattern 124 is exposed to the side surface 144 of the magnetic support layer 103 and connected to the terminal electrode 114, while the other end is connected to the via conductor 132. As a result, a coil of approximately one turn, consisting of the two coil patterns 123 and 124, is connected between the terminal electrodes 113 and 114. The ends of the coil patterns 123 and 124 have a planar shape in which the pattern width widens as it approaches the terminal electrodes 113 and 114. This increases the contact area between the coil patterns 123 and 124 and the terminal electrodes 113 and 114, thereby reducing the connection resistance between them. An interlayer insulating film 152 is provided between the coil patterns 123, 124 and the magnetic support layer 103, thereby preventing contact between the coil patterns 123, 124 and the magnetic support layer 103. An interlayer insulating film 152 is also provided between the conductor layer L3 and the conductor layer L4, and the via conductor 132 is provided penetrating the interlayer insulating film 152.

[0025] Figure 5 is a schematic cross-sectional view along line AA shown in Figures 3 and 4. Figure 6 is a schematic cross-sectional view along line BB shown in Figures 3 and 4. Figure 7 is a schematic cross-sectional view along line CC shown in Figures 3 and 4.

[0026] As shown in Figures 5 to 7, the magnetic support layer 103 has main surfaces 141 and 142 that constitute the XY plane and are located on opposite sides, and side surfaces 143 and 144 that constitute the XZ plane and are located on opposite sides. The coil portion C1, consisting of coil patterns 121 and 122, is embedded on the main surface 141 side of the magnetic support layer 103, and the coil portion C2, consisting of coil patterns 123 and 124, is embedded on the main surface 142 side of the magnetic support layer 103. The magnetic resin layer 101 is provided on the main surface 141 of the magnetic support layer 103 so as to cover the coil portion C1. The magnetic resin layer 102 is provided on the main surface 142 of the magnetic support layer 103 so as to cover the coil portion C2.

[0027] Therefore, while the magnetic resin layers 101 and 102 are plate-like bodies with a nearly constant thickness in the Z direction, the magnetic support layer 103 has an inner diameter region 161 surrounded by the coil portion C1 when viewed from the coil axis direction, an inner diameter region 162 surrounded by the coil portion C2 when viewed from the coil axis direction, an outer region 163 located radially outside the coil portion C1 when viewed from the coil axis direction, an outer region 164 located radially outside the coil portion C2 when viewed from the coil axis direction, and an inter-coil region 165 located between the coil portion C1 and the coil portion C2.

[0028] Thus, since the magnetic support layer 103 fills not only the inter-coil region 165 located between coil sections C1 and C2, but also the inner diameter regions 161, 162 and outer regions 163, 164 of coil sections C1 and C2, the volume of the magnetic support layer 103 increases compared to the case where the magnetic support layer 103 exists only in the inter-coil region 165. In contrast, since the thickness of the magnetic resin layers 101 and 102 is almost constant, there is no need to use a material with excellent embedding properties.

[0029] The magnetic material constituting the magnetic support layer 103 may be a material with a higher magnetic permeability than the magnetic materials constituting the magnetic resin layers 101 and 102. In this case, the magnetic field generated by the current flowing through the coil sections C1 and C2 circulates efficiently through the magnetic support layer 103, resulting in very small magnetic coupling between them. As a result, since coil section C1 and coil section C2 function as independent inductors, it is possible to suppress crosstalk between the signal flowing through coil section C1 and the signal flowing through coil section C2.

[0030] Furthermore, as shown in Figure 5, the via conductor 131 has a shape in which its diameter decreases from the conductor layer L2 towards the conductor layer L1. Similarly, as shown in Figure 6, the via conductor 132 has a shape in which its diameter decreases from the conductor layer L3 towards the conductor layer L4. As a result, even when an external force in the Z direction is applied to the coil component 100, damage due to stress mediated by the via conductors 131 and 132 can be reduced. This is because the stress is distributed as the diameter of the via conductors 131 and 132 expands along the direction in which the stress is transmitted. If the shape of the via conductor 131 were such that its diameter decreased from the conductor layer L1 towards the conductor layer L2, stress would concentrate at the bottom of the via conductor 131, potentially causing severe damage to the connection between the conductor layer L2 and the via conductor 131. In contrast, if the via conductors 131 and 132 have the shapes shown in Figures 5 and 6, it is possible to reduce damage to the conductor layers L2 and L3 via the via conductors 131 and 132.

[0031] Next, a method for manufacturing the coil component 100 according to this embodiment will be described.

[0032] Figures 8 to 13 are process diagrams illustrating the manufacturing method of the coil component 100 according to this embodiment.

[0033] First, as shown in Figure 8, a support substrate 170 is prepared with metal foils 171 and 172 made of Cu or the like on both sides. A coil portion C1 is formed on one surface via an insulating film 173, and a coil portion C2 is formed on the other surface via an insulating film 174. Coil portions C1 and C2 can be formed simultaneously. In the formation of coil portion C1, the conductor layer L1 is located as the lower layer and the conductor layer L2 is located as the upper layer when viewed from the support substrate 170. Therefore, the via conductor 131 connecting the conductor layers L1 and L2 is formed simultaneously with the conductor layer L2, and has a shape in which the diameter decreases from the conductor layer L2 towards the conductor layer L1. On the other hand, in the formation of coil portion C2, the conductor layer L4 is located as the lower layer and the conductor layer L3 is located as the upper layer when viewed from the support substrate 170. Therefore, although not shown in the cross-section in Figure 8, the via conductor 132 connecting the conductor layers L3 and L4 is formed simultaneously with the conductor layer L3, and has a shape in which the diameter decreases from the conductor layer L3 towards the conductor layer L4.

[0034] Next, as shown in Figure 9, the coil portions C1 and C2 are peeled off from the support substrate 170. At this time, the metal foil 171 and insulating film 173 remain on the coil portion C1 side, and the metal foil 172 and insulating film 174 remain on the coil portion C2 side. Next, as shown in Figure 10, the coil portions C1 and C2 are inverted vertically and embedded in the uncured magnetic support layer 103. Here, coil portion C1 is embedded on the main surface 141 side of the magnetic support layer 103, and coil portion C2 is embedded on the main surface 142 side of the magnetic support layer 103. Since both coil portions C1 and C2 are embedded in the magnetic support layer 103 in an inverted state, coil portion C1 is embedded by pressing the surface opposite to the surface that was in contact with one surface of the support substrate 170 against the main surface 141 of the magnetic support layer 103, and coil portion C2 is embedded by pressing the surface opposite to the surface that was in contact with the other surface of the support substrate 170 against the main surface 142 of the magnetic support layer 103. As a result, coil portions C1 and C2 are embedded in the magnetic support layer 103 as shown in Figure 11. Consequently, as explained with reference to Figure 7, inner diameter regions 161, 162, outer regions 163, 164, and inter-coil region 165 are formed in the magnetic support layer 103.

[0035] Next, as shown in Figure 12, the metal foils 171 and 172 are removed by etching or the like, and the insulating films 173 and 174 are removed by desmearing or the like. At this time, the insulating films 173 and 174 may be left on the exposed portions of the conductive layers L1 and L4. Then, as shown in Figure 13, a magnetic resin layer 101 is provided on the main surface 141 of the magnetic support layer 103 so as to cover the coil portion C1, and a magnetic resin layer 102 is provided on the main surface 142 of the magnetic support layer 103 so as to cover the coil portion C2. As described above, since both coil portions C1 and C2 are embedded in the magnetic support layer 103 in an inverted state, the magnetic resin layer 101 is provided on the coil portion C1 so as to cover the surface that was in contact with one surface of the support substrate 170, and the magnetic resin layer 102 is provided on the coil portion C2 so as to cover the surface that was in contact with the other surface of the support substrate 170.

[0036] Subsequently, by curing the magnetic resin layers 101, 102 and the magnetic support layer 103, the coil component 100 according to this embodiment is completed. In this embodiment, since the coil portions C1 and C2 are formed simultaneously using both sides of the support substrate 170, and then the coil portions C1 and C2 are embedded in the magnetic support layer 103 in an inverted state, the volume of the magnetic support layer 103 is increased, and it becomes possible to use sheet-like magnetic material in a semi-cured state for the magnetic resin layers 101 and 102.

[0037] Figure 14 is a substantially perspective view showing the appearance of a coil component 200 according to a second embodiment of the present disclosure.

[0038] As shown in Figure 14, the coil component 200 according to the second embodiment has a structure in which three coil components 100 according to the first embodiment are arranged in the X direction. According to the coil component 200 of this embodiment, it is possible to provide an array of six coils.

[0039] While embodiments of the technology described herein have been explained above, it goes without saying that the technology described herein is not limited to the embodiments described above, and various modifications are possible without departing from its spirit, and these modifications are also included within the scope of the technology described herein. [Explanation of symbols]

[0040] 100,200 coil components 101,102 Magnetic resin layer 103 Magnetic support layer 111~114 Terminal electrode 121-124 Coil Patterns 131,132 via conductors 141,142 Main surface 143,144 Side view 151,152 Interlayer insulating film 161,162 Inner diameter area 163,164 outer area 165 Inter-coil region 170 Support board 171,172 Metal foil 173,174 insulating film C1, C2 coil section L1~L4 Conductor Layers

Claims

1. A magnetic support layer having a first main surface and a second main surface located on the opposite side of the first main surface, The first coil portion embedded on the first main surface side of the magnetic support layer, The second coil portion embedded on the second main surface side of the magnetic support layer, A first magnetic resin layer is provided on the first main surface of the magnetic support layer so as to cover the first coil portion, A second magnetic resin layer is provided on the second main surface of the magnetic support layer so as to cover the second coil portion, A first interlayer insulating film having a portion located between the first coil portion and the magnetic support layer, The device comprises a second interlayer insulating film having a portion located between the second coil portion and the magnetic support layer, The magnetic support layer has a first inner diameter region surrounded by the first coil portion, a second inner diameter region surrounded by the second coil portion, and an inter-coil region located between the first coil portion and the second coil portion. The first coil portion includes a first conductor layer and a second conductor layer laminated via another portion of the first interlayer insulating film, The second coil portion includes a third conductor layer and a fourth conductor layer laminated via another portion of the second interlayer insulating film, Within the magnetic support layer, the first conductor layer, the second conductor layer, the third conductor layer, and the fourth conductor layer are stacked in this order. The first conductor layer and the second conductor layer are connected to each other via a first via conductor provided through the other portion of the first interlayer insulating film. The third conductor layer and the fourth conductor layer are connected to each other via a second via conductor provided through the other portion of the second interlayer insulating film. The first via conductor has a shape in which its diameter decreases from the second conductor layer toward the first conductor layer. The second via conductor is a coil component having a shape in which the diameter decreases from the third conductor layer toward the fourth conductor layer.

2. The coil component according to claim 1, wherein the magnetic support layer further comprises a first outer region located radially outside the first coil portion and a second outer region located radially outside the second coil portion.

3. The coil component according to claim 1, wherein the magnetic support layer has a higher magnetic permeability than the first and second magnetic resin layers.

4. First and second terminal electrodes connected to one end and the other end of the first coil portion, The device further comprises third and fourth terminal electrodes connected to one end and the other end of the second coil portion, respectively. The magnetic support layer further has first and second side surfaces that are perpendicular to the first and second main surfaces and located on opposite sides of each other. The first and third terminal electrodes are provided on the first side surface, The second and fourth terminal electrodes are provided on the second side surface, One end and the other end of the first coil portion are exposed from the first and second sides, respectively, and are connected to the first and second terminal electrodes. The coil component according to any one of claims 1 to 3, wherein one end and the other end of the second coil portion are exposed from the first and second side surfaces, respectively, and connected to the third and fourth terminal electrodes.

Images