COIL COMPONENT

Abstract

Disclosed herein is a coil component that includes a first conductor layer, one or more third conductor layers, and a second conductor layer stacked one another in this order. One end of the coil pattern in the first conductor layer is connected to first terminal patterns in the second and third conductor layers. The first terminal pattern in the second conductor layer is connected to a first terminal electrode. One end of the coil pattern in the second conductor layer is connected to a second terminal electrode. The width in a radial direction of the first terminal pattern positioned in the third conductor layer is larger than the width in the radial direction of the second terminal pattern positioned in the third conductor layer.

Description

FIELD OF THE ART

The present disclosure relates to a coil component and, more particularly, to a coil component having a structure in which a plurality of interlayer insulating films and a plurality of conductor layers are alternately stacked.

DESCRIPTION OF RELATED ART

JP 2020-088330A discloses a coil component having a structure in which a plurality of interlayer insulating films and a plurality of conductor layers are alternately stacked. In the coil component described in JP 2020-088330A, two terminal electrodes are arranged in the stacking direction of the plurality of conductor layers, one of which is connected to one end of a coil pattern positioned in the lowermost layer, and the other one of which is connected to one end of a coil pattern positioned in the uppermost layer.

In the coil component described in JP 2020-088330A, however, one of the two terminal electrodes is connected to a coil pattern positioned in the lowermost layer as described above and has thus a higher connection resistance than the other one thereof.

SUMMARY

It is therefore an object of the present disclosure to reduce a difference between a connection resistance between one terminal electrode and its corresponding coil pattern and a connection resistance between the other terminal electrode and its corresponding coil pattern.

A coil component according to the present disclosure includes: a coil part in which a plurality of interlayer insulating films and a plurality of conductor layers each having a coil pattern are alternately stacked; and first and second terminal electrodes stacked on the coil part. The plurality of conductor layers includes: a first conductor layer positioned in the lowermost layer; a second conductor layer positioned in the uppermost layer; and one or more third conductor layers positioned between the first and second conductor layers. The second and third conductor layers each include a first terminal pattern overlapping one end of the coil pattern positioned in the first conductor layer and the first terminal electrode. The first and third conductor layers each include a second terminal pattern overlapping one end of the coil pattern positioned in the second conductor layer and the second terminal electrode. The one end of the coil pattern positioned in the first conductor layer and the first terminal patterns positioned in the respective second and third conductor layers are connected to one another through via conductors penetrating the interlayer insulating films. The first terminal pattern positioned in the second conductor layer and the first terminal electrode are connected to each other through a via conductor penetrating the interlayer insulating film. The one end of the coil pattern positioned in the second conductor layer and the second terminal electrode are connected to each other through a via conductor penetrating the interlayer insulating film. The width in the radial direction of the first terminal pattern positioned in the third conductor layer is larger than the width in the radial direction of the second terminal pattern positioned in the third conductor layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above features and advantages of the present disclosure will be more apparent from the following description of certain embodiments taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic perspective view illustrating the outer appearance of a coil component 1 according to an embodiment of the present disclosure;

FIG. 2 is a schematic cross-sectional view of the coil component 1;

FIG. 3 is a plan view illustrating the conductor layer L1;

FIG. 4 is a plan view illustrating the conductor layer L2;

FIG. 5 is a plan view illustrating the conductor layer L3;

FIG. 6 is a plan view illustrating the conductor layer L4;

FIG. 7 is a plan view illustrating the conductor layer L2 according to a first embodiment; and

FIG. 8 is a plan view illustrating the conductor layer L2 according to a second embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Some embodiments of the present disclosure will be explained below in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view illustrating the outer appearance of a coil component 1 according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view of the coil component 1.

As illustrated in FIGS. 1 and 2, the coil component 1 according to the present embodiment includes a magnetic element member 2, a coil part 3, and bump terminal electrodes B1 and B2. The coil part 3 and bump terminal electrodes B1 and B2 are embedded in the magnetic element member 2. The magnetic element member 2 is positioned in the inner diameter area of the coil part 3 and is also positioned in the outside area of the coil part 3 so as to sandwich the coil part 3 in the z-direction (coil axis direction). The magnetic element member 2 is a composite magnetic member containing magnetic metal filler made of iron (Fe) or a permalloy-based material and a resin binder and forms a magnetic path for magnetic flux generated by a current flowing in the coil part 3. The magnetic element member 2 has an upper surface 2a constituting the xy plane which is perpendicular to the z-direction (coil axis direction) and a pair of side surfaces 2b and 2c constituting the yz plane which is perpendicular to the upper surface 2a. The surface of the terminal electrode B1 is exposed from the upper surface 2a and side surface 2b of the magnetic element member 2. The surface of the terminal electrode B2 is exposed from the upper surface 2a and side surface 2c of the magnetic element member 2. Upon mounting of the coil component 1, the terminal electrodes B1 and B2 are soldered onto a circuit board such that the upper surface 2a of the magnetic element member 2 faces the circuit board.

The coil part 3 includes interlayer insulating films 50 to 54 and conductor layers L1 to L4 which are alternately stacked in the coil axis direction. The conductor layers L1 to L4 have coil patterns 10, 20, 30, and 40, respectively.

FIGS. 3 to 6 are plan views illustrating the conductor layers L1 to L4, respectively.

As illustrated in FIG. 3, the conductor layer L1 is formed on the surface of the interlayer insulating film 50 and includes the coil pattern 10 and a terminal pattern 12. An outer peripheral end 11 of the coil pattern 10 has an enlarged area and overlaps the terminal electrode B1 as viewed in the z-direction. The terminal pattern 12 is separated from the coil pattern 10 within the surface and overlaps the terminal electrode B2 as viewed in the z-direction. The width in the x-direction of the outer peripheral end 11 of the coil pattern 10 is W0, and the width of the terminal pattern 12 in the x-direction is W2. The width W0 is larger than the width W2. The thus configured conductor layer L1 is covered with the interlayer insulating film 51.

As illustrated in FIG. 4, the conductor layer L2 is formed on the surface of the interlayer insulating film 51 and includes the coil pattern 20 and the terminal patterns 21 and 22. The terminal patterns 21 and 22 are separated from the coil pattern 20 within the surface and overlap the terminal electrodes B1 and B2, respectively, as viewed in the z-direction. The width of the terminal pattern 21 in the x-direction is W1, and the width of the terminal pattern 22 in the x-direction is W2. The width W1 is larger than the width W2. The terminal pattern 21 is connected to the outer peripheral end 11 of the coil pattern 10 through a via conductor 61 penetrating the interlayer insulating film 51. The inner peripheral end of the coil pattern 20 is connected to the inner peripheral end of the coil pattern 10 through a via conductor 62 penetrating the interlayer insulating film 51. The thus configured conductor layer L2 is covered with the interlayer insulating film 52.

As illustrated in FIG. 5, the conductor layer L3 is formed on the surface of the interlayer insulating film 52 and includes the coil pattern 30 and the terminal patterns 31 and 32. The terminal patterns 31 and 32 are separated from the coil pattern 30 within the surface and overlap the terminal electrodes B1 and B2, respectively, as viewed in the z-direction. The width of the terminal pattern 31 in the x-direction is W1, and the width of the terminal pattern 32 in the x-direction is W2. The width W1 is larger than the width W2. The terminal pattern 31 is connected to the terminal pattern 21 through a via conductor 63 penetrating the interlayer insulating film 52. The plane position of the via conductor 63 differs from the plane position of the via conductor 61, thus preventing a recess of the conductor layer which may be caused due to stacking of via conductors. The outer peripheral end of the coil pattern 30 is connected to the outer peripheral end of the coil pattern 20 through a via conductor 64 penetrating the interlayer insulating film 52. The thus configured conductor layer L3 is covered with the interlayer insulating film 53.

As illustrated in FIG. 6, the conductor layer L4 is formed on the surface of the interlayer insulating film 53 and includes the coil pattern 40 and a terminal pattern 41. An outer peripheral end 42 of the coil pattern 40 has an enlarged area and overlaps the terminal electrode B2 as viewed in the z-direction. The terminal pattern 41 is separated from the coil pattern 40 within the surface and overlaps the terminal electrode B1 as viewed in the z-direction. The width in the x-direction of the outer peripheral end 42 of the coil pattern 40 is W3, and the width in the x-direction of the terminal pattern 41 is W1. The width W3 is larger than the width W2. The terminal pattern 41 is connected to the terminal pattern 31 through a via conductor 65 penetrating the interlayer insulating film 53. The plane position of the via conductor 65 differs from the plane position of the via conductor 63, thus preventing a recess of the conductor layer which may be caused due to stacking of via conductors. The inner peripheral end of the coil pattern 40 is connected to the inner peripheral end of the coil pattern 30 through a via conductor 66 penetrating the interlayer insulating film 53. The thus configured conductor layer L4 is covered with the interlayer insulating film 54.

The bump terminal electrodes B1 and B2 are provided on the interlayer insulating film 54. The terminal electrode B1 is connected to the terminal pattern 41 through a via conductor 67 penetrating the interlayer insulating film 54. The terminal electrode B2 is connected to the outer peripheral end 42 of the coil pattern 40 through a via conductor 68 penetrating the interlayer insulating film 54. The plane position of the via conductor 67 differs from the plane position of the via conductor 65, thus preventing a recess of the conductor layer which may be caused due to stacking of via conductors. The plane size of the terminal electrode B1 is larger than those of the terminal patterns 21, 31, and 41, and the plane size of the terminal electrode B2 is larger than those of the terminal patterns 12, 22, and 32.

With the above configuration, the terminal electrode B1 is connected to the outer peripheral end 11 of the coil pattern 10 through the terminal patterns 41, 31, and 21. The outer peripheral end 11 of the coil pattern 10 and the terminal patterns 21, 31, and 41 are exposed from the side surface 2b of the magnetic element member 2. The terminal electrode B2 is connected to the outer peripheral end 42 of the coil pattern 40. The terminal patterns 12, 22, and 32 and the outer peripheral end 42 of the coil pattern 40 are exposed from the side surface 2c of the magnetic element member 2.

In the present embodiment, the width W1 of the terminal patterns 41, 31, and 21 is larger than the width W2 of the terminal patterns 32, 22, and 12, so that a resistance value between the terminal electrode B1 and the outer peripheral end 11 of the coil pattern 10 is reduced. To further reduce this resistance value, the via conductors 61, 63, 65, and 67 connecting the terminal electrode B1 and the outer peripheral end 11 may be made larger in diameter than the other via conductors 62, 64, 66, and 68. For example, when the via conductors 61, 63, 65, and 67 are made larger in diameter than the via conductor 68, a difference between a resistance value between the terminal electrode B1 and the coil pattern 10 and a resistance value between the terminal electrode B2 and the coil pattern 40 is reduced. Further, the width W1 of the terminal patterns 41, 31, and 21 is enlarged, so that even if warpage occurs in a circuit board on which the coil component 1 is mounted, stress to be applied to the via conductors 61, 63, 65, and 67 is relaxed, thereby increasing connection reliability.

In addition, a sufficient distance can be ensured between the via conductors 61, 63, 65, 67 and the side surface 2b in the x-direction, so that when misalignment occurs upon dicing of the coil component 1 for singulation, the via conductors 61, 63, 65, 67 are not exposed to the side surface 2b. The same point is valid in respect of the via conductor 68. That is, the width W3 of the outer peripheral end 42 of the coil pattern 40 is larger than the width W2 of the terminal patterns 12, 22, and 32, so that the via conductor 68 is not exposed to the side surface 2c upon dicing. This increases connection reliability of the via conductors.

Further, the terminal patterns 12, 22, and 32 are not connected to but isolated from one another. That is, via conductors need not be provided, so that a reduction in the width W2 can be easily achieved. This can suppress an increase in chip size due to an increase in the width in the x-direction of the outer peripheral end 11 of the coil pattern 10 and terminal patterns 21, 31, and 41. The width W2 of the terminal patterns 12, 22, and 32 may be smaller than the pattern width of each of the coil patterns 10, 20, 30, and 40. The terminal patterns 12, 22, and 32 may be omitted; however, in a case where the magnetic element member 2 is formed after formation of the bump terminal electrodes B1 and B2 in the manufacturing process of the coil component 1, the terminal patterns 12, 22, and 32 are required to be present to ensure the flatness of the outer peripheral end 42 of the coil pattern 40 serving as the underlayer of the terminal electrode B2.

The terminal patterns 12, 22, and 32 each may not necessarily be a completely independent pattern but may be connected respectively to the coil patterns 10, 20, and 30 within the respective surfaces. For example, as illustrated in FIG. 7, when both ends of the terminal pattern 22 in the y-direction are connected to the coil pattern 20, current flows also in the terminal pattern 22, thereby reducing the DC resistance of the coil part 3. Similarly, the terminal patterns 12 and 32 may be connected at their both ends to the coil patterns 10 and 30, respectively. In this case, as illustrated in FIG. 8, the terminal pattern 22 (12, 32) may not be exposed from the magnetic element member 2. This increases the volume of the magnetic element member 2 and makes a short-circuit failure due to exposure of the terminal patterns 12, 22, and 32 less likely to occur.

When the widths W0 to W3 vary depending on the position in the y-direction, they may each be defined by an average width. Further, the width W1 may not necessarily be the same among the terminal patterns 21, 31, and 41 and may vary thereamong as long as it is larger than the width W2. Similarly, the width W2 may not necessarily be the same among the terminal patterns 12, 22, and 32 and may vary thereamong as long as it is smaller than the width W1. The width W0 of the outer peripheral end 11 of the coil pattern 10 and the width 3 of the outer peripheral end 42 of the coil pattern 40 may be the same as the width W1.

While the one embodiment of the present disclosure has been described, the present disclosure is not limited to the above embodiment, and various modifications may be made within the scope of the present disclosure, and all such modifications are included in the present disclosure.

For example, although the four conductor layers L1 to l4 are stacked through the interlayer insulating films in the above embodiment, the number of conductor layers to be stacked is not limited to this, and a three-layer structure or a five or more-layer structure can be employed.

The technology according to the present disclosure includes the following configuration examples but not limited thereto.

A coil component according to the present disclosure includes: a coil part in which a plurality of interlayer insulating films and a plurality of conductor layers each having a coil pattern are alternately stacked; and first and second terminal electrodes stacked on the coil part. The plurality of conductor layers includes: a first conductor layer positioned in the lowermost layer; a second conductor layer positioned in the uppermost layer; and one or more third conductor layers positioned between the first and second conductor layers. The second and third conductor layers each include a first terminal pattern overlapping one end of the coil pattern positioned in the first conductor layer and the first terminal electrode. The first and third conductor layers each include a second terminal pattern overlapping one end of the coil pattern positioned in the second conductor layer and the second terminal electrode. The one end of the coil pattern positioned in the first conductor layer and the first terminal patterns positioned in the respective second and third conductor layers are connected to one another through via conductors penetrating the interlayer insulating films. The first terminal pattern positioned in the second conductor layer and the first terminal electrode are connected to each other through a via conductor penetrating the interlayer insulating film. The one end of the coil pattern positioned in the second conductor layer and the second terminal electrode are connected to each other through a via conductor penetrating the interlayer insulating film. The width in the radial direction of the first terminal pattern positioned in the third conductor layer is larger than the width in the radial direction of the second terminal pattern positioned in the third conductor layer.

According to the present disclosure, the first terminal pattern poisoned in the third conductor layer is enlarged in area, so that the resistance value between the one end of the coil pattern positioned in the first conductor layer and the first terminal electrode can be reduced. Further, the second terminal pattern positioned in the third conductor layer is reduced in area, so that increase in the plane size of the entire coil component can be suppressed. Furthermore, when the coil component is diced for singulation, it is possible to ensure a sufficient margin between the via conductor connected to the first terminal pattern and a dicing line.

In the present disclosure, the width in the radial direction of the one end of the coil pattern positioned in the second conductor layer may be larger than the widths in the radial direction of the second terminal patterns positioned in the respective first and third conductor layers. Thus, when the coil component is diced for singulation, it is possible to ensure a sufficient margin between the via conductors connected to the second terminal patterns and a dicing line.

In the present disclosure, the one end of the coil pattern positioned in the second conductor layer and the second terminal patterns positioned in the respective first and third conductor layers may be isolated without being connected to one another through via conductors. This eliminates the need to provide via conductors for connecting them, which in turn eliminates the need to ensure a margin between the via conductors and a dicing line.

The coil component according to the present disclosure may further include a magnetic element member embedding therein the coil part and the first and second terminal electrodes, and the first and second terminal patterns may be exposed from the magnetic element member. This improves heat dissipation performance.

As described above, according to the present disclosure, it is possible to reduce a difference between a connection resistance between one terminal electrode and its corresponding coil pattern and a connection resistance between the other terminal electrode and its corresponding coil pattern.

Claims

1. A coil component comprising: a coil part in which a plurality of interlayer insulating films and a plurality of conductor layers each having a coil pattern are alternately stacked; andfirst and second terminal electrodes stacked on the coil part,wherein the plurality of conductor layers includes a first conductor layer positioned in a lowermost layer, a second conductor layer positioned in an uppermost layer, and one or more third conductor layers positioned between the first and second conductor layers,wherein each of the second and third conductor layers includes a first terminal pattern overlapping one end of the coil pattern positioned in the first conductor layer and the first terminal electrode,wherein each of the first and third conductor layers includes a second terminal pattern overlapping one end of the coil pattern positioned in the second conductor layer and the second terminal electrode,wherein the one end of the coil pattern positioned in the first conductor layer and the first terminal patterns positioned in the respective second and third conductor layers are connected to one another through via conductors penetrating the interlayer insulating films,wherein the first terminal pattern positioned in the second conductor layer and the first terminal electrode are connected to each other through a via conductor penetrating the interlayer insulating film,wherein the one end of the coil pattern positioned in the second conductor layer and the second terminal electrode are connected to each other through a via conductor penetrating the interlayer insulating film, andwherein a width in a radial direction of the first terminal pattern positioned in the third conductor layer is larger than a width in the radial direction of the second terminal pattern positioned in the third conductor layer.

2. The coil component as claimed in claim 1, wherein a width in the radial direction of the one end of the coil pattern positioned in the second conductor layer is larger than widths in the radial direction of the second terminal patterns positioned in the respective first and third conductor layers.

3. The coil component as claimed in claim 1, wherein the one end of the coil pattern positioned in the second conductor layer and the second terminal patterns positioned in the respective first and third conductor layers are isolated without being connected to one another through via conductors.

4. The coil component as claimed in claim 1, further comprising a magnetic element member embedding therein the coil part and the first and second terminal electrodes, wherein the first and second terminal patterns are exposed from the magnetic element member.