Patent Application
20240331922
The present disclosure relates to electronic components each including first and second coils inside of an insulating body and separated by an interval, and magnetically coupled to each other.
Japanese Unexamined Patent Application Publication No. 2001-307933 discloses a transformer including a primary coil and a secondary coil that are laminated and magnetically coupled to each other in a body having an insulating property. In this transformer, a prepreg (a sheet-shaped fiber impregnated with a resin) is located between the primary coil and the secondary coil. A coupling coefficient between the primary coil and the secondary coil can be adjusted by adjusting the number of sheets constituting the prepreg.
In the configuration of the transformer disclosed in Japanese Unexamined Patent Application Publication No. 2001-307933, a distance between the primary coil and the secondary coil can be changed only by the number of sheets constituting the prepreg, and there is a problem in which the coupling coefficient cannot be finely adjusted.
Example embodiments of the present invention provide electronic components each including first and second coils inside of a body, in which a coupling coefficient between the first coil and the second coil can be finely adjusted while preventing an increase in height of the body.
According to an example embodiment of the present disclosure, an electronic component includes a body with an insulating property and a plurality of insulating layers, and a first coil and a second coil inside of the body and separated by an interval between the first coil and the second coil in a lamination direction in which the insulating layers are laminated, and connected in series to each other. The first coil includes a plurality of first wiring patterns separated by intervals in the lamination direction. The second coil includes a plurality of second wiring patterns separated by intervals in the lamination direction, and a gap in at least one region of a plurality of regions which are sandwiched between the second wiring patterns adjacent to each other in the lamination direction among the plurality of second wiring patterns. A dimension of the gap is larger than a distance between the second wiring patterns adjacent to each other in the lamination direction without the gap and is different from a distance between the first wiring patterns adjacent to each other.
According to an example embodiment of the present disclosure, the first coil and the second coil that are connected in series to each other are positioned side by side inside of the body with the interval in the lamination direction. The gap is in the second coil but not between the first coil and the second coil. Therefore, a coupling coefficient between the first coil and the second coil can be finely adjusted, as compared with a case where the gap is between the first coil and the second coil. Further, since the gap is not in the first coil, an increase in height (dimension in the lamination direction) of the body is prevented. As a result, the coupling coefficient can be finely adjusted while preventing the increase in height of the body.
The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.
Hereinafter, example embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The same or corresponding elements, features, and characteristics in the drawings are denoted by the same reference numerals, and the description is not repeated.
The electronic component 1 includes external terminals T1, T2, and T4, and a primary coil L1 and a secondary coil L2 that are connected in series between the external terminal T1 and the external terminal T2. The primary coil L1 and the secondary coil L2 are magnetically coupled to each other. In the present example embodiment, the primary coil L1 and the secondary coil L2 are connected to each other in a movable manner. The primary coil L1 and the secondary coil L2 may be differentially connected to each other. A state in which inductors are connected to each other in a movable manner is a connection state in which a magnetic field generated by the two inductors is enhanced in the same direction in a case where a current flows from one inductor to the other inductor in a direction of the other inductor with a connection point interposed therebetween, and is a connection state in which a magnetic flux intersecting a wiring pattern of the inductor is shared. For example, in a case where coil openings of the two inductors have a coil shape overlapping with each other in a plan view, a winding direction from an end portion different from a connection point of one inductor to the connection point, and a winding direction from a connection point of the other inductor to an end portion different from the connection point, are the same.
A connection point N1 between the primary coil L1 and the secondary coil L2 is connected to the external terminal T4. In the present example embodiment, the external terminal T4 is grounded. Therefore, the connection point N1 is grounded with the external terminal T4 interposed therebetween.
The body 3 has a rectangular or substantially rectangular parallelepiped shape. Specifically, the body 3 includes a rectangular or substantially rectangular bottom surface 4 and a top surface 5 that face each other, and four side surfaces 6 to 9 that connect the bottom surface 4 and the top surface 5.
Hereinafter, a lamination direction of the insulating layer in the body 3 is also referred to as a “Z-axis direction”, a direction along a short side of the bottom surface 4 is also referred to as an “X-axis direction”, and a direction along a long side of the bottom surface 4 is also referred to as a “Y-axis direction”. In addition, in the following description, a positive direction (a direction from the bottom surface 4 to the top surface 5) of the Z-axis in each drawing may be referred to as an upper side, and a negative direction may be referred to as a lower side.
The four external terminals T1 to T4 are respectively located at four corners of the bottom surface 4 of the body 3 in a case where the body 3 is viewed in a plan view in the Z-axis direction. As illustrated in
Four electrodes connected to the external terminals T1 to T4 are located at each of four corners of the insulating layers 3a to 3j. In the electronic component 1 according to the present example embodiment, the external terminal T1 is an input terminal (IN) to which a signal from the outside is input, the external terminal T2 is an output terminal (OUT) from which a signal from the electronic component 1 is output to the outside, the external terminal T3 is a non-connect terminal (NC) that is not connected to an internal circuit of the electronic component 1, and the external terminal T4 is a ground terminal (GND) that is connected to an outside ground.
The primary coil L1 is formed by laminating the five insulating layers 3a to 3e. Each of four wiring patterns 11 to 14 is provided at an upper surface of each of the insulating layers 3a, 3b, 3c, and 3e. A wiring pattern is not provided at the insulating layer 3d. One end portion of the wiring pattern 11 on the insulating layer 3a is connected to the external terminal T1 which is an input terminal. The other end portion of the wiring pattern 11 is connected to one end portion of the wiring pattern 12, which is a one-upper layer, with a via V1 interposed therebetween, which penetrates the insulating layer 3b. The other end portion of the wiring pattern 12 is connected to one end portion of the wiring pattern 13, which is a one-upper layer, with a via V2 interposed therebetween. The other end portion of the wiring pattern 13 is connected to one end portion of the wiring pattern 14, which is a two-upper layer, with a via V3 interposed therebetween, which penetrates the insulating layer 3d and the insulating layer 3e. The other end portion of the wiring pattern 14 is connected to the external terminal T4 which is a ground terminal.
The secondary coil L2 is formed by laminating the five insulating layers 3f to 3j. Each of five wiring patterns 15 to 19 is provided at an upper surface of each of the insulating layers 3f to 3j. One end portion of the wiring pattern 15 on the insulating layer 3f is connected to the external terminal T4 which is a ground terminal. The other end portion of the wiring pattern 15 is connected to one end portion of the wiring pattern 16, which is a one-upper layer, with a via V4 interposed therebetween, which is formed to penetrate the insulating layer 3g. The other end portion of the wiring pattern 16 is connected to one end portion of the wiring pattern 17, which is a one-upper layer, with a via V5 interposed therebetween. The other end portion of the wiring pattern 17 is connected to one end portion of the wiring pattern 18, which is a one-upper layer, with a via V6 interposed therebetween. The other end portion of the wiring pattern 18 is connected to one end portion of the wiring pattern 19, which is a one-upper layer, with a via V7 interposed therebetween. The other end portion of the wiring pattern 19 is connected to the external terminal T2, which is an output terminal.
As illustrated in
A winding axis of the primary coil L1 is included in an opening of the secondary coil L2 when viewed from the Z-axis direction. In addition, a winding axis of the secondary coil L2 is included in an opening of the primary coil L1 when viewed from the Z-axis direction. The “winding axis” of each coil is an axis passing through a center of a formation region of each coil in a case where each coil is viewed in a plan view from the Z-axis direction, and is an axis passing through a strongest portion of a magnetic field generated in each coil. The “opening” of each coil is an inner portion surrounded by a wiring pattern of each coil in a case where each coil is viewed in a plan view from the lamination direction.
In this manner, by positioning the winding axes of both the primary coil L1 and the secondary coil L2 such that both the winding axes are included in both the openings, the opening of the primary coil L1 and the opening of the secondary coil L2 largely overlap with each other when viewed from the Z-axis direction, so that the magnetic coupling between the primary coil L1 and the secondary coil L2 can be strengthened.
In addition, in the present example embodiment, as described above, the shape of each of the wiring patterns 11 to 19 of the primary coil L1 and the secondary coil L2 is a loop shape of less than one lap. Therefore, the opening of each coil can be formed wider than in a case where the shape of each of the wiring patterns 11 to 19 has a loop shape (spiral shape or helical shape) of one or more laps, and a disturbance of the magnetic field generated in each coil can be reduced. Therefore, the magnetic coupling between the primary coil L1 and the secondary coil L2 can be further strengthened.
Each of the insulating layers 3a to 3j is formed of, for example, a ceramic green sheet. Each of the wiring patterns 11 to 19 can be formed by pattern-printing with a conductive paste on a ceramic green sheet on which each of the wiring patterns 11 to 19 is located.
In the electronic component 1 according to the present example embodiment, the insulating layer 3d in which no wiring pattern is formed is interposed in a region (fourth layer from the bottom surface 4) between the insulating layer 3c and the insulating layer 3e, among the five layers in which the primary coil L1 is located. Therefore, the insulating layer 3d functions as a “gap GA” located in the primary coil L1.
The primary coil L1 is formed by connecting the wiring patterns 11 to 14 of four layers, which are separated by intervals in the Z-axis direction, to each other through the vias V1 to V3. The secondary coil L2 is formed by connecting the wiring patterns 15 to 19 of five layers, which are separated by intervals in the Z-axis direction, to each other through the vias V4 to V7.
The gap GA is formed by interposing the insulating layer 3d in which no wiring pattern is formed in a region (fourth layer from the bottom surface 4) between the insulating layer 3c in which the wiring pattern 13 is formed at the upper surface and the insulating layer 3e in which the wiring pattern 14 is formed at the upper surface, among the five layers in which the primary coil L1 is located. Therefore, a dimension of the gap GA (dimension in the Z-axis direction) is a thickness of the insulating layer 3d and the insulating layer 3e (thickness of two insulating layer sheets) interposed between the wiring pattern 13 and the wiring pattern 14. On the other hand, distances between the adjacent wiring patterns in the Z-axis direction in the body 3 without the gap GA are all the thickness of one insulating layer sheet.
Therefore, the dimension of the gaps GA is larger than the distance between the adjacent wiring patterns in the Z-axis direction in the primary coil L1 without the gaps GA. That is, the dimension of the gap GA is larger than a distance between the wiring patterns 11 and 12 and a distance between the wiring patterns 12 and 13.
Further, the dimension of the gaps GA is different from the distance in the Z-axis direction between the wiring patterns in the secondary coil L2. Specifically, the dimension of the gap GA is larger than a distance between the wiring patterns 15 and 16, a distance between the wiring patterns 16 and 17, a distance between the wiring patterns 17 and 18, and a distance between the wiring patterns 18 and 19.
Further, the dimension of the gap GA is larger than a distance in the Z-axis direction between the primary coil L1 and the secondary coil L2 (a distance between the wiring pattern 14 of the primary coil L1 and the wiring pattern 15 of the secondary coil L2 which are adjacent to each other, hereinafter, also referred to as “inter-coil distance GB”).
In the electronic component 1, as illustrated in
The region in which the gap GA is located is not necessarily limited to the region closest to the secondary coil L2.
In any of the electronic components 1, 1A, and 1B, the gap GA corresponding to an interval of two insulating layer sheets is provided in the primary coil L1, instead of between the primary coil L1 and the secondary coil L2. In the electronic components 1, 1A, and 1B, the positions of the gaps GA (distances from the boundary BL to the gap GA) are different. Therefore, in any of the electronic components 1, 1A, and 1B, a coupling coefficient k between the primary coil L1 and the secondary coil L2 can be finely and gradually adjusted while maintaining the height of the body 3 at the predetermined value H.
The present inventors performed a simulation of calculating an inductance value of the primary coil L1, an inductance value of the secondary coil L2, and the coupling coefficient k between the primary coil L1 and the secondary coil L2 for each of Model 1, Model 2, and Model 3, in which the electronic component 1 illustrated in
In the simulation, the same simulation was performed for configurations of Comparative Examples 1 and 2, to compare with Models 1 to 3.
The coupling coefficient k of Comparative Example 1 in which no gap GA is provided is “0.585”. The coupling coefficient k of Comparative Example 2 in which the gap GA is provided between the coils is “0.460”, and a significant decrease of approximately 21% is caused, with a reference of the coupling coefficient k of “0.585” of Comparative Example 1 in which no gap GA is provided.
On the other hand, the coupling coefficients k of Models 1 to 3 in which the gap GA is provided in the primary coil L1 are “0.500”, “0.550”, and “0.580”, respectively, and the significant decrease as in Comparative Example 2 does not occur, with respect to Comparative Example 1. In addition, there is no significant difference in the inductance values of the coils L1 and L2 of each of Models 1 to 3 from Comparative Examples 1 and 2.
As can be seen from the simulation result, in Models 1 to 3 of the present application, as compared with Comparative Example 2 in which the gap GA is provided between the coils, the coupling coefficient k can be finely changed without largely changing the inductance values of the primary coil L1 and the secondary coil L2.
Further, if Model 2 and Model 3 are compared with Model 1 as a reference, each inductance value of the coils L1 and L2 of Model 2 and Model 3 is reduced to a decrease width of less than 3.6% from the reference. On the other hand, the coupling coefficient k of Model 2 has a increase width of approximately 9.1% from the reference. Meanwhile, the coupling coefficient k of Model 3 has a increase width of approximately 14.1% from the reference, which is significantly changed than Model 2.
As can be seen from this simulation result, it can be seen that the change in coupling coefficient k is larger than the change in inductance value of each coil L1 and L2 by changing the insertion position of the gap GA (distance in the Z-axis direction from the boundary BL to the gap GA) in the primary coil L1. In other words, the coupling coefficient k can be gradually changed without significantly changing the inductance value of each of the coils L1 and L2 by changing the insertion position of the gap GA in the primary coil L1.
In particular, in Model 3, since the gap GA is located at a position farthest from the boundary BL, the gap GA is not involved in the coupling between the primary coil L1 and the secondary coil L2. In other words, in Model 3, the coupling coefficient k can be more finely adjusted, as compared with Model 1 and Model 2.
As described above, in each of the electronic components 1, 1A, and 1B according to the present example embodiment, the gap GA is located in the primary coil L1, instead of between the primary coil L1 and the secondary coil L2. Therefore, the coupling coefficient k can be more finely adjusted than in a case where the gap GA is located between the primary coil L1 and the secondary coil L2. Further, since the gap GA is not located in the secondary coil L2, the height of the body 3 can be reduced, as compared with a case where the gap GA is located in both the primary coil L1 and the secondary coil L2. As a result, the coupling coefficient k can be finely adjusted while preventing an increase in height of the body 3.
Further, in the electronic components 1, 1A, and 1B, the insertion positions of the gaps GA are made different from each other in the primary coils L1. Therefore, the coupling coefficient k between the primary coil L1 and the secondary coil L2 can be gradually adjusted while maintaining the height of the body 3 at the predetermined value H.
In the present example embodiment, the example is described in which the shapes of the respective wiring patterns 11 to 19 are all loop shapes of less than one lap when viewed in the Z-axis direction, and the shapes of the respective wiring patterns 11 to 19 are not limited to this.
For example, the shapes of the wiring patterns 14 and 15 closest to the boundary BL may be in a loop shape (spiral shape) of one or more laps while the shapes of the wiring patterns 11 and 19 farthest from the boundary BL is maintained in a loop shape of less than one lap. By doing so, an inductance value of each of the primary coil L1 and the secondary coil L2 can be increased. The other wiring patterns 12, 13, and 16 to 18 may be changed to a spiral shape as necessary.
In addition, in the present example embodiment, the example is described in which the gap GA is formed by adding the insulating layer 3d in which no wiring pattern is formed to the primary coil L1, and the method of forming the gap GA is not limited to this.
For example, in
In addition, in the present example embodiment, the example is described in which the gap GA is located in the primary coil L1, and a coil in which the gap GA is to be located need only be either the primary coil L1 or the secondary coil L2. That is, the gap GA may be located in the secondary coil L2 instead of the primary coil L1.
The capacitor Cp2 is connected between the external terminal T4 and the external terminal T3. The external terminal T4 is connected to the connection point N1 between the primary coil L1 and the secondary coil L2, and the external terminal T3 is grounded. Therefore, the capacitor Cp2 is connected between the connection point N1 of the primary coil L1 and the secondary coil L2 and the ground.
The capacitor Cp2 has a parasitic inductance, and the parasitic inductance can be canceled by a mutual inductance M generated by the magnetic coupling between the primary coil L1 and the secondary coil L2. The mutual inductance M can be represented by the following Expression (1) by using the coupling coefficient k.
In Expression (1), “L1” is an inductance value of the primary coil L1, and “L2” is an inductance value of the secondary coil L2.
The capacitor Cb1 is connected in parallel to the primary coil L1 and the secondary coil L2. Specifically, the capacitor Cb1 is connected between the connection point N2 between the external terminal T1 and the primary coil L1, and the connection point N3 between the external terminal T2 and the secondary coil L2.
In general, in a case where a shape of each coil is changed to adjust inductance values (L values) of a primary coil and a secondary coil, resonance characteristics (Q values) or the coupling coefficient k is also changed at the same time. Therefore, in a case of designing a filter or the like using the mutual inductance M, such as the electronic component 1C, a method may be adopted in which a shape of each coil is first designed such that the desired L value and Q value are obtained, and then the coupling coefficient k is adjusted such that a desired mutual inductance value is obtained. In a case where such a design method is adopted, as described in Example Embodiment 1 described above, the gap GA is located in one coil instead of between the coils, so that the coupling coefficient k can be finely adjusted without changing the inductance value of each coil very much.
The primary coil L1 in the electronic component 1C is formed by laminating the four insulating layers 6e to 6h. Each of three wiring patterns 21 to 23 is provided at each of upper surfaces of the insulating layers 6e, 6g, and 6h. No wiring pattern is provided at an upper surface of the insulating layer 6f. That is, the gap GA is located in the primary coil L1 by the insulating layer 6f.
The secondary coil L2 in the electronic component 1C is formed by laminating the three insulating layers 6i to 6k. Each of three wiring patterns 24 to 26 is provided at each of upper surfaces of the insulating layers 6i to 6k. The gap GA is not formed in the secondary coil L2.
All the wiring patterns 21 to 26 have a loop shape (spiral shape) of one or more laps.
Further, in a region between the primary coil L1 and the bottom surface 4, the insulating layers 6a to 6c to define the capacitors Cp2 and Cb1 are provided.
Each of the flat plate-shaped capacitance electrodes 31 and 34 is provided at an upper surface of each of the insulating layers 6a and 6c, and each of ground electrodes 32 and 36 in a flat plate shape is provided at an upper surface of each of the insulating layers 6b and 6d. The capacitance electrode 31, ground electrode 32, capacitance electrode 34, and ground electrode 36 are alternately laminated in order of the capacitance electrode and the ground electrode, whereby the capacitor Cp2 is provided.
A capacitance electrode 33 is provided at the upper surface of the insulating layer 6c separately from the capacitance electrode 34, and a capacitance electrode 35 is provided at the upper surface of the insulating layer 6d separately from the ground electrode 36. The capacitor Cb1 is formed by laminating the capacitance electrode 33 and the capacitance electrode 35.
As described above, in the electronic component 1C (filter) according to present Example Embodiment 2, the coupling coefficient k can be finely adjusted by providing the gap GA in the primary coil L1, so that a circuit constant as a filter can be finely adjusted. As a result, the degree of freedom in designing the filter characteristics can be improved.
In Example Embodiments 1 and 2 described above, the example is illustrated in which one end of the primary coil L1 and one end of the secondary coil L2 are connected to each other by the external terminal (outer electrode). Meanwhile, the primary coil L1 and the secondary coil L2 may be a four-terminal transformer-coil using, for example, a non-connect terminal (NC), without being electrically connected to each other. A connection portion between the wiring pattern and the external terminal may be defined as a coil end portion, and a coil group in which the coil end portion and the coil end portion are connected to each other may be defined as a primary coil L1 and a secondary coil L2, respectively.
While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-022961 | Feb 2022 | JP | national |
This application claims the benefit of priority to Japanese Patent Application No. 2022-022961 filed Feb. 17, 2022 and is a Continuation application of PCT Application No. PCT/JP2023/002068 filed on Jan. 24, 2023. The entire contents of each application are hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2023/002068 | Jan 2023 | WO |
| Child | 18743164 | US |
