Patent Application
20130135075
The present application claims priority to Japanese Patent Application No. 2011-256901 filed on Nov. 25, 2011, the entire contents of this application being incorporated herein by reference in their entirety.
The technical field relates to electronic components and manufacturing methods thereof, and more particularly relates to an electronic component embedded with a coil and to a manufacturing method thereof.
As an invention relating to a conventional electronic component, for example, a laminate electronic component described in Japanese Unexamined Patent Application Publication No. 2005-268455 is known. The electronic component described in Japanese Unexamined Patent Application Publication No. 2005-268455 includes a rectangular-parallelepiped chip body configured by stacking rectangular sheets. The electronic component also includes two coils that configure a choke coil. The two coils are configured with respective spiral conductive patterns formed on the sheets.
Meanwhile, an increase in diameter of a coil without an increase in element size is generally requested for the electronic component embedded with a coil.
The present disclosure provides an electronic component in which the diameter of a coil can be increased without an increase in element size, and a manufacturing method thereof.
An electronic component according to an aspect of the present disclosure includes a rectangular-parallelepiped stack configured by stacking a plurality of insulating layers, and a first coil in the stack having a coil axis substantially parallel to a stacking direction of the stack. The stacking direction and the coil axis are not parallel to sides that configure the stack.
In another aspect of the present disclosure, a manufacturing method of an electronic component includes steps of fabricating a mother stack that is configured by stacking a plurality of mother insulating layers and is embedded with a first coil group including a plurality of first coils arranged in rows and columns in which a row direction is orthogonal to a column direction, cutting the mother stack in an area between the rows of the plurality of first coils along the row direction, in a direction orthogonal to a principal plane of the mother stack, cutting the mother stack in an area between the columns of the plurality of first coils along the column direction, in a first direction inclined with respect to the principal plane of the mother stack, and cutting the mother stack in an area between the columns of the plurality of first coils along the column direction, in a second direction orthogonal to the first direction.
An electronic component and a manufacturing method thereof according to exemplary embodiments will now be described with reference to the drawings.
A configuration of an exemplary electronic component is described first with reference to the drawings.
The electronic component 10 is a chip electronic component embedded with a common mode choke coil. As shown in
As shown in
Also, as shown in
As described above, since the stacking direction of the stack 12 is not parallel to either of the x-axis direction, y-axis direction, and z-axis direction, the magnetic layers 16 and the non-magnetic layers 17 have different-size rectangular shapes. More specifically, the widths in the α-axis direction of the magnetic layers 16a to 16i and the non-magnetic layers 17a and 17b increase from the positive side to the negative side in the β-axis direction. The magnetic layers 16a to 16i and the non-magnetic layers 17a and 17b have equivalent lengths in the x-axis direction. Also, the respective widths in the α-axis direction of the non-magnetic layer 17c and the magnetic layers 16j to 16r are decreased from the positive side to the negative side in the β-axis direction. The non-magnetic layer 17c and the magnetic layers 16j to 16r have equivalent lengths in the x-axis direction. Since the magnetic layers 16 and the non-magnetic layers 17 are formed as described above, the side surfaces S3 and S4 each have a square shape. In
The magnetic layers 16 are formed of, for example, a magnetic material, such as Ni—Cu—Zn ferrite. The non-magnetic layers 17 are formed of a non-magnetic material, such as Cu—Zn ferrite or glass. In the following description, a surface of each of the magnetic layers 16 and the non-magnetic layers 17 at the positive side in the β-axis direction is called front surface, and a surface of each of the magnetic layers 16 and the non-magnetic layers 17 at the negative side in the β-axis direction is called back surface.
The coil L1 is a spiral coil provided in the stack 12. Also, the coil axis of the coil L1 is substantially parallel to the stacking direction of the stack 12, i.e., the β-axis direction. Hence, the coil axis of the coil L1 is not parallel to the edges of the side surfaces that configure the stack 12.
A configuration of the coil L1 will now be described in detail. The coil L1 includes coil portions 18a and 18b, and a via-hole conductor v1. The coil portion 18a is a linear conductor that is provided on the front surface of the non-magnetic layer 17b and has a spiral form that turns clockwise toward the center. Hereinafter, an end at the outer side of the coil portion 18a is defined as end t1, and an end at the center side of the coil portion 18a is defined as end t2. The end t1 is one end of the coil L1. Hence, the coil portion 18a includes the one end of the coil L1. As shown in
Also, the coil portion 18b is a linear conductor that is provided on the front surface of the non-magnetic layer 17a and has an L shape. Hereinafter, an end at the negative side in the x-axis direction of the coil portion 18b is defined as end t3, and an end at the positive side in the x-axis direction of the coil portion 18b is defined as end t4. The end t4 is the other end of the coil L1. Hence, the coil portion 18b includes the other end of the coil L1. As shown in
The via-hole conductor v1 penetrates through the non-magnetic layer 17a in the β-axis direction, and connects the end t2 of the coil portion 18a to the end t3 of the coil portion 18b.
The coil L2 is a spiral coil provided in the stack 12. Also, the coil axis of the coil L2 is substantially parallel to the stacking direction of the stack 12, i.e., the β-axis direction. Hence, the coil axis of the coil L2 is not parallel to the sides that configure the stack 12.
A configuration of the coil L2 is described below in detail. To be more specific, the coil L2 includes coil portions 20a and 20b, and a via-hole conductor v2. The coil portion 20a is a linear conductor that is provided on the front surface of the non-magnetic layer 17c and has a spiral form that turns clockwise toward the center. A spiral part of the coil portion 20a has the same shape as the shape of a spiral part of the coil portion 18a, and is aligned with the spiral part of the coil portion 18a in plan view in the β-axis direction. Hereinafter, an end at the outer side of the coil portion 20a is defined as end t5, and an end at the center side of the coil portion 20a is defined as end t6. The end t5 is one end of the coil L2. Hence, the coil portion 20a includes the one end of the coil L2. The end t5 is located at the negative side in the α-axis direction with respect to the intersection P1 of the diagonals A1 and A2 in the side surface S3. The end t5 is located at the negative side in the β-axis direction slightly with respect to the diagonal A1. Accordingly, the ends t1 and t5 are located to be point symmetric about the intersection P1 of the diagonals A1 and A2 in the side surface S3.
Also, the coil portion 20b is a linear conductor that is provided on the front surface of the magnetic layer 16j and has an L shape. Hereinafter, an end at the negative side in the x-axis direction of the coil portion 20b is defined as end t7, and an end at the positive side in the x-axis direction of the coil portion 20b is defined as end t8. The end t8 is the other end of the coil L2. Hence, the coil portion 20b includes the other end of the coil L2. The end t8 is located at the negative side in the α-axis direction with respect to the intersection P2 of the diagonals A3 and A4 in the side surface S3. The end t8 is located at the negative side in the β-axis direction slightly with respect to the diagonal A3. Accordingly, the ends t4 and t8 are located to be point symmetric about the intersection P2 of the diagonals A3 and A4 in the side surface S4. Also, the end t7 is aligned with the end t6 in plan view in the β-axis direction.
The via-hole conductor v2 penetrates through the magnetic layer 17c in the β-axis direction, and connects the end t6 of the coil portion 20a to the end t7 of the coil portion 20b.
As described above, the coil L1 is provided on the front surfaces of the non-magnetic layers 17a and 17b, and the coil L2 is provided on the front surfaces of the non-magnetic layer 17c and the magnetic layer 16j. Hence, the coils L1 and L2 face each other with the diagonal A1 of the side surface S3 interposed therebetween when viewed in the direction of the normal to the side surface S3, i.e., in the x-axis direction. Accordingly, the coils L1 and L2 are electromagnetically coupled with each other, and form a common mode choke coil.
The outer electrodes 14a and 14b are provided on the side surface S3 of the stack 12, and are connected to the ends t1 and t5, respectively. To be more specific, the outer electrodes 14a and 14b extend in the z-axis direction in the side surface S3 of the stack 12. The outer electrode 14a is provided at the negative side in the y-axis direction as compared with the outer electrode 14b. The ends t1 and t5 are covered with the outer electrodes 14a and 14b, respectively. Also, each of the outer electrodes 14a and 14b is folded back to the upper surface S1 and the lower surface S2.
The outer electrodes 14c and 14d are provided on the side surface S4 of the stack 12, and are connected to the ends t4 and t8, respectively. To be more specific, the outer electrodes 14c and 14d extend in the z-axis direction in the side surface S4 of the stack 12. The outer electrode 14c is provided at the negative side in the y-axis direction as compared with the outer electrode 14d. The ends t4 and t8 are covered with the outer electrodes 14c and 14d, respectively. Also, each of the outer electrodes 14c and 14d is folded back to the upper surface S1 and the lower surface S2.
In the electronic component 10 configured as described above, the coils L1 and L2 are aligned with each other in plan view in the β-axis direction. Hence, a magnetic flux generated by the coil L1 passes through the coil L2, and a magnetic flux generated by the coil L2 passes through the coil L1. Accordingly, the coil L1 and the coil L2 are magnetically coupled with each other, and the coil portion 20a and the coil portion 20b configure a common mode choke coil. The outer electrodes 14a and 14b are used as input terminals, and the outer electrodes 14c and 14d are used as output terminals. In particular, a differential transmission signal is input to the outer electrodes 14a and 14b, and is output from the outer electrodes 14c and 14d. If the differential transmission signal includes a common mode noise, the coils L1 and L2 generate magnetic fluxes in the same direction because of the common mode noise. Owing to this, the magnetic fluxes enhance each other, and impedance for the common mode is generated. As the result, the common mode noise is converted into heat, and the signal is interrupted from passing through the coils L1 and L2.
An exemplary manufacturing method of the electronic component 10 configured as described above will now be described with reference to the drawings.
First, ceramic green sheets (mother insulating layers), which become the magnetic layers 16 and the non-magnetic layers 17, are fabricated. The ceramic green sheets each have a large rectangular shape. A fabricating step of the respective ceramic green sheets, which become the magnetic layers 16 and the non-magnetic layers 17, is a well-known step, and hence further description is not provided.
Then, via holes are formed in the respective ceramic green sheets, which become the non-magnetic layers 17a and 17c, by irradiating formation positions of the via-hole conductors v1 and v2 with a laser beam. Further, the via-hole conductors v1 and v2 are formed by filling the via holes with conductive paste. The conductive paste has a conductor such as Ag as a principal component.
Then, the coil portions 18a, 18b, 20a, and 20b shown in
Then, the respective ceramic green sheets, which become the magnetic layers 16a to 16i, the non-magnetic layers 17a to 17c, and the magnetic layers 16j to 16r, are stacked and press-bonded in that order from the positive side to the negative side in the β-axis direction. Accordingly, as shown in
Then, the mother stack 112 is cut in an area between the rows of the plurality of sets of coils L1 and L2 along the row direction, in a direction orthogonal to the principal plane of the mother stack 112. That is, the mother stack 112 is cut by arranging a dicer to be orthogonal to the principal plane of the mother stack 112 and by moving the dicer along a cut line CL1 shown in
Then, the mother stack 112 is cut in an area between the columns of the plurality of sets of coils L1 and L2 along the column direction, in a first direction inclined to the principal plane of the mother stack 112 by 45° (see
Then, the mother stack 112 is cut in an area between the columns of the plurality of sets of coils L1 and L2 along the row direction, in a second direction orthogonal to the first direction (see
Then, binder removing processing and firing are performed on the unfired stacks 12. Then, barrel polishing processing is performed on the front surfaces of the stacks 12 for chamfering.
Then, electrode paste, which is made of a conductive material having a conductor such as Ag as a principal component, is applied on the side surfaces S3 and S4, the upper surface S1, and the lower surface S2 of each of the stacks 12, and the applied electrode paste is baked. Accordingly, respective silver electrodes, which become the outer electrodes 14, are formed. Further, the front surfaces of the respective silver electrodes, which become the outer electrodes 14, are treated with Ni plating/Sn plating. Thus, the outer electrodes 14 are formed. With the above-described steps, the electronic component 10 is completed.
With the electronic component 10 configured as described above, the diameter of the coils L1 and L2 can be increased without an increase in element size. To be more specific, with the electronic component 10, the stacking direction of the stack 12 and the coil axes of the coils L1 and L2 are not parallel to the sides that configure the stack 12. In this embodiment, in particular, the plurality of magnetic layers 16 and non-magnetic layers 17 are orthogonal to the side surface S3 of the stack 12. Accordingly, the area of the non-magnetic layer 17 near the center in the stacking direction (in the β-axis direction) is larger than the area of the upper surface S1. Hence, with the electronic component 10, the diameter of the coils L1 and L2 can be increased without an increase in element size. Further, with the electronic component 10, the number of turns of each of the coils L1 and L2 can be increased.
Further, the magnetic layers 16 and the non-magnetic layers 17 are parallel to the diagonal A1 of the side surface S3. At this time, the area of the non-magnetic layer 17 near the center in the stacking direction (the β-axis direction) is the maximum. Hence, with the electronic component 10, the diameter of the coils L1 and L2 can be further increased without an increase in element size. Further, with the electronic component 10, the number of turns of each of the coils L1 and L2 can be further increased.
The inventor of the subject application performed computer simulation (described below) in order to clarify effects attained by the electronic component 10. In particular, a first model corresponding to the electronic component 10 according to this embodiment, and a second model corresponding to an electronic component according to a comparative example were fabricated. The second model has the same size as the first model, and is a model in which magnetic layers and non-magnetic layers are stacked in the z-axis direction. Then, for each of the first model and the second model, an attenuation of a signal output from the outer electrode 14c with respect to a signal input to the outer electrode 14a was calculated.
Referring to
Also, with the electronic component 10, formation of the outer electrodes 14a to 14d is facilitated as described below.
As shown in
An electronic component and a manufacturing method thereof according to the present disclosure are not limited to the electronic component 10 and the manufacturing method thereof described in the embodiment, and the electronic component 10 and the manufacturing method thereof may be changed within the scope of the present disclosure.
In the manufacturing method of the electronic component 10, the mother stack 112 is cut while the dicer is inclined. However, with the following exemplary manufacturing method of the electronic component 10, the mother stack 112 can be cut while the dicer is not inclined.
With the manufacturing method according to this embodiment, a stack group 113 for a single row cut along a cut line CL1 is rotated about the α-axis by 90° as shown in
Then, a plurality of the stack groups 113 are arranged in line in the x-axis direction.
Then, the stack groups 113 are cut along a cut line CL2 in a direction orthogonal to the side surface S3. Further, the stack groups 113 are cut along a cut line CL3 in a direction orthogonal to the side surface S3. Accordingly, the mother stack 112 is divided into a plurality of stacks 12.
While the electronic component 10 uses the magnetic layers 16 and the non-magnetic layers 17, the magnetic layers 16 may not be used. In this case, the electronic component 10 can be efficiently manufactured by the following manufacturing method.
Hereinafter, a manufacturing method of an electronic component 10 according to still another exemplary embodiment will now be described with reference to the drawings.
First, respective ceramic green sheets, which become non-magnetic layers 17 and 117 (see
Then, via holes are formed in the respective ceramic green sheets, which become the non-magnetic layers 17a and 17c, by irradiating formation positions of the via-hole conductors v1 and v2 with a laser beam. Further, the via-hole conductors v1 and v2 are formed by filling the via holes with conductive paste. The conductive paste has a conductor such as Ag as a principal component.
Then, the coil portions 18a, 18b, 20a, and 20b shown in
Then, the respective ceramic green sheets, which become the non-magnetic layers 117a to 117i, 17a to 17c, and 117j to 117r, are stacked and press-bonded in that order from the positive side to the negative side in the β-axis direction. At this time, as shown in
Then, the mother stack 112a is cut in an area between the rows of the plurality of sets of coils L1 and L2 along the row direction, in a direction orthogonal to the principal plane of the mother stack 112a. That is, the mother stack 112a is cut by arranging a dicer to be orthogonal to the principal plane of the mother stack 112a and by moving the dicer along a cut line CL1 shown in
Then, the mother stack 112a is cut in an area between the columns of the plurality of sets of coils L1 and L2 along the column direction, in a first direction inclined to the principal plane of the mother stack 112a by 45° (see
Then, the mother stack 112a is cut in an area between the columns of the plurality of sets of coils L1 and L2 along the row direction, in a second direction orthogonal to the first direction (see
Then, barrel polishing processing is performed on the front surfaces of the unfired stacks 12 for chamfering. Then, binder removing processing and firing are performed on the unfired stacks 12.
Then, electrode paste, which is made of a conductive material having a conductor such as Ag, as a principal component, is applied on the side surfaces S3 and S4, the upper surface S1, and the lower surface S2 of each of the stacks 12, and the applied electrode paste is baked. Accordingly, respective silver electrodes, which become the outer electrodes 14, are formed. Further, the front surfaces of the respective silver electrodes, which become the outer electrodes 14, are treated with Ni plating/Sn plating. Thus, the outer electrodes 14 are formed. With the above-described steps, the electronic component 10 is completed.
With the above-described exemplary manufacturing method of manufacturing the electronic component 10, an unused region in the mother stack 112 in
Alternatively, the stack 12 may be entirely fabricated by magnetic layers.
As described above, embodiments according to the present disclosure are useful for an electronic component and a manufacturing method thereof. In particular, embodiments according to the present disclosure are excellent in that the diameter of a coil can be increased without an increase in element size.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-256901 | Nov 2011 | JP | national |
