JP2008078228A - Laminated inductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated inductor capable of improving high-frequency characteristics by reducing a stray capacitance. <P>SOLUTION: The laminated inductor is constituted by laminating non-magnetic substance layers A1 to A15 in this order, and has a laminate 10 with a pair of main surfaces S1 and S2 opposed so as to mutually run parallel, a coil L electrically connecting conductor patterns B1 to B9 mutually and leading-out conductors C1 and C2. The leading-out conductor C1, the conductor patterns B1 to B9 and the leading-out conductor C2 are formed on the surfaces of the non-magnetic substance layers A3 to A13 respectively, and juxtaposed in the opposite direction of a pair of the main surfaces S1 and S2. The conductor patterns B1 to B9 are placed between the leading-out conductor C1 and the leading-out conductor C2. Conductor patterns adjacent the opposite direction among the conductor patterns B1 to B9 intersect at right angles from the opposite direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multilayer inductor.

Conventionally, a laminate in which a plurality of insulator layers are laminated and a coil provided in the laminate by electrically connecting a plurality of conductor patterns to each other, each conductor pattern being substantially C-shaped. A multilayer inductor is known (for example, see Patent Document 1).
JP 2005-166745 A

  However, in the conventional multilayer inductor described in Patent Document 1, since each conductor pattern constituting the coil is substantially C-shaped, stray capacitance is generated in a portion where the conductor pattern is bent. Therefore, there is a problem that desired characteristics cannot be obtained when the multilayer inductor is used in a high frequency region.

  An object of the present invention is to provide a multilayer inductor capable of reducing the stray capacitance and improving the high frequency characteristics.

  A multilayer inductor according to the present invention is configured by laminating a plurality of insulator layers, and includes a multilayer body having a pair of main surfaces facing each other so as to be parallel to each other, and a first multilayer body disposed on the outer surface of the multilayer body. The first and second external electrodes and a plurality of linear conductor patterns are electrically connected to each other. The coil is provided in the laminated body, and is electrically connected to one end of the coil. A first lead conductor electrically connected to one outer conductor, and a second lead conductor electrically connected to the other end of the coil and electrically connected to the second external electrode. The plurality of conductor patterns are juxtaposed in the opposing direction so as to be located in mutually different virtual planes among the plurality of virtual planes perpendicular to the opposing direction of the pair of main surfaces, and in the opposing direction among the plurality of conductor patterns. Adjacent conductor pattern Down each other, characterized in that it is arranged so as to intersect when viewed from the opposing direction.

  In the multilayer inductor according to the present invention, a plurality of linear conductor patterns are electrically connected to each other to form a coil. Therefore, the bent portion does not exist in the conductor pattern. As a result, it is possible to reduce the stray capacitance generated in the portion where the conductor pattern is bent, as compared with the conventional multilayer inductor, and to improve the high frequency characteristics. Further, in the multilayer inductor according to the present invention, the plurality of conductor patterns are juxtaposed in the facing direction so as to be located in mutually different virtual planes among the plurality of virtual planes perpendicular to the facing direction of the pair of main surfaces. . Therefore, the number of conductor patterns adjacent to each other in the opposing direction with respect to one conductor pattern is two or less. As a result, compared to the case where a plurality of conductor patterns are located on a predetermined virtual plane perpendicular to the opposing direction, the number of conductor patterns adjacent in the opposing direction is reduced. It is also possible to reduce the stray capacitance generated between the two.

  The first lead conductor is formed so as to increase in width from one end of the coil toward the first external electrode, and the second lead conductor extends from the other end of the coil to the second external electrode. It is preferable that the width is increased as it goes. This increases the contact area between the first external electrode and the first lead conductor and the contact area between the second external electrode and the second lead conductor. For this reason, it is possible to improve the connection reliability between the first external electrode and the first lead conductor and the connection reliability between the second external electrode and the second lead conductor. In this way, there is no sudden change in the transmission path of the electrical signal at the connection portion between the first lead conductor and one end of the coil and at the connection portion between the second lead conductor and the other end of the coil. That is, since the impedance and the size of the cross-sectional area of the conductor are inversely proportional, the impedance of the first lead conductor gradually increases from the first external electrode toward the one end of the coil, and from the second external electrode. As it goes to the other end of the coil, the impedance of the second lead conductor gradually increases. As a result, impedance matching is performed, and reflection of the electric signal can be reduced.

  In addition, the first lead conductor, the plurality of conductor patterns, and the second lead conductor are juxtaposed in opposite directions so as to be located in different virtual planes among the plurality of virtual planes, and the plurality of conductor patterns are The first lead conductor and the second lead conductor are preferably located between the first lead conductor and the second lead conductor. When the first lead conductor and the conductor pattern are integrally formed, and the second lead conductor and the conductor pattern are integrally formed, the connection portion between the first lead conductor and the conductor pattern is A stray capacitance is generated by bending, and a stray capacitance may be generated by bending at the connection portion between the second lead conductor and the conductor pattern. In this case, the first and second lead Both conductors are not integrally formed with any of the plurality of conductor patterns. As a result, there is no bending and the stray capacitance can be further reduced.

  Moreover, it is preferable that the conductor patterns adjacent to each other in the facing direction among the plurality of conductor patterns are orthogonal to each other when viewed from the facing direction. If it does in this way, compared with the case where the conductor patterns adjacent to an opposing direction are not orthogonally seeing from an opposing direction, it becomes possible to ensure a big coil diameter.

  According to the present invention, it is possible to provide a multilayer inductor capable of reducing stray capacitance and improving high frequency characteristics.

  Preferred embodiments of the present invention will be described with reference to the drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and a duplicate description is omitted.

  The configuration of the multilayer inductor 1 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing a multilayer inductor according to the present embodiment. FIG. 2 is an exploded perspective view for explaining the configuration of the multilayer body included in the multilayer inductor according to the present embodiment. 3A is a side perspective view of the multilayer body included in the multilayer inductor according to the present embodiment, and FIG. 3B is a top perspective view of the multilayer body included in the multilayer inductor according to the present embodiment.

  As shown in FIG. 1, the multilayer inductor 1 includes a substantially rectangular parallelepiped multilayer body 10, a pair of external electrodes 12 and 14 formed on both side surfaces in the longitudinal direction of the multilayer body 10, and the multilayer body 10. Inside, a linear (substantially I-shaped) conductor pattern B1 to B9 is provided with a coil L that is electrically connected to each other. The laminated body 10 has a pair of main surfaces S1 and S2 that face each other so as to be parallel to each other.

  As illustrated in FIG. 2, the stacked body 10 is configured by stacking nonmagnetic layers A1 to A15 in this order. That is, the upper surface of the nonmagnetic material layer A1 constitutes the main surface S1 of the multilayer body 10, and the lower surface of the nonmagnetic material layer A15 constitutes the main surface S2 of the multilayer body 10 (see FIG. 2). , S2 facing direction (hereinafter referred to as facing direction) coincides with the stacking direction (hereinafter referred to as stacking direction) of the stacked body 10 (nonmagnetic layers A1 to A15) in the present embodiment. The nonmagnetic layers A1 to A15 function as an insulator having electrical insulation. The nonmagnetic layers A1 to A9 can be formed using, for example, a glass-based ceramic containing strontium, calcium, alumina, silicon oxide, and the like. The actual multilayer inductor 1 is integrated to such an extent that the boundaries of the nonmagnetic layers A1 to A15 cannot be visually recognized. Therefore, “the surface of the non-magnetic layer” used to describe the configuration of the multilayer inductor 1 in the following means a virtual plane.

  A lead conductor C1 is formed on the surface of the nonmagnetic layer A3. One end of the lead conductor C1 is electrically connected to a through-hole electrode D1 formed through the nonmagnetic layer A3 in the thickness direction. For this reason, the lead conductor C1 is electrically connected to the corresponding conductor pattern B1 through the through-hole electrode D1 in a stacked state. The lead conductor C1 is drawn out to the edge of the nonmagnetic layer A3 on the side where the external electrode 12 is formed, and its end is exposed at the end face of the nonmagnetic layer A3. The lead conductor C1 is directed from the terminal axis P along which the conductor pattern B1 (one end of the coil L) extends toward the axial center of the coil L (toward the far edge of the nonmagnetic layer A3 when viewed from the terminal axis P). It is formed to extend. The lead conductor C1 increases in width from the conductor pattern B1 (one end of the coil L) toward the end surface (external electrode 12) of the nonmagnetic layer A3.

  A conductor pattern B1 is formed on the surface of the nonmagnetic layer A4. The conductor pattern B1 is disposed so as to be positioned at one end of the coil L. The conductor pattern B1 is disposed so as to be orthogonal to the conductor pattern B2 adjacent in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B1 includes a region electrically connected to the through-hole electrode D1 in a stacked state. For this reason, the conductor pattern B1 is electrically connected to the external electrode 12 through the lead conductor C1. The other end of the conductor pattern B1 is electrically connected to a through-hole electrode D2 formed through the nonmagnetic layer A4 in the thickness direction. For this reason, the conductor pattern B1 is electrically connected to the corresponding conductor pattern B2 through the through-hole electrode D2 in a stacked state.

  A conductor pattern B2 is formed on the surface of the nonmagnetic layer A5. The conductor pattern B2 is disposed so as to be orthogonal to the conductor patterns B1 and B3 adjacent to each other in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B2 includes a region electrically connected to the through-hole electrode D2 in a stacked state. The other end of the conductor pattern B2 is electrically connected to a through-hole electrode D3 formed through the nonmagnetic layer A5 in the thickness direction. For this reason, the conductor pattern B2 is electrically connected to the corresponding conductor pattern B3 through the through-hole electrode D3 in a stacked state.

  A conductor pattern B3 is formed on the surface of the nonmagnetic layer A6. The conductor pattern B3 is disposed so as to be orthogonal to the conductor patterns B2 and B4 adjacent to each other in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B3 includes a region electrically connected to the through-hole electrode D3 in a stacked state. The other end of the conductor pattern B3 is electrically connected to a through-hole electrode D4 formed through the nonmagnetic layer A6 in the thickness direction. For this reason, the conductor pattern B3 is electrically connected to the corresponding conductor pattern B4 through the through-hole electrode D4 in a stacked state.

  A conductor pattern B4 is formed on the surface of the nonmagnetic layer A7. The conductor pattern B4 is disposed so as to be orthogonal to the conductor patterns B3 and B5 adjacent to each other in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B4 includes a region electrically connected to the through-hole electrode D4 in a stacked state. The other end of the conductor pattern B4 is electrically connected to a through-hole electrode D5 formed so as to penetrate the nonmagnetic layer A7 in the thickness direction. For this reason, the conductor pattern B4 is electrically connected to the corresponding conductor pattern B5 through the through-hole electrode D5 in a stacked state.

  A conductor pattern B5 is formed on the surface of the nonmagnetic layer A8. The conductor pattern B5 is arranged so as to be orthogonal to the conductor patterns B4 and B6 adjacent to each other in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B5 includes a region electrically connected to the through-hole electrode D5 in a stacked state. The other end of the conductor pattern B5 is electrically connected to a through-hole electrode D6 formed through the nonmagnetic layer A8 in the thickness direction. For this reason, the conductor pattern B5 is electrically connected to the corresponding conductor pattern B6 via the through-hole electrode D6 in a stacked state.

  A conductor pattern B6 is formed on the surface of the nonmagnetic layer A9. The conductor pattern B6 is disposed so as to be orthogonal to the conductor patterns B5 and B7 adjacent to each other in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B6 includes a region electrically connected to the through-hole electrode D6 in a stacked state. The other end of the conductor pattern B6 is electrically connected to a through-hole electrode D7 formed so as to penetrate the nonmagnetic layer A9 in the thickness direction. For this reason, the conductor pattern B6 is electrically connected to the corresponding conductor pattern B7 through the through-hole electrode D7 in a stacked state.

  A conductor pattern B7 is formed on the surface of the nonmagnetic layer A10. The conductor pattern B7 is disposed so as to be orthogonal to the conductor patterns B6 and B8 adjacent to each other in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B7 includes a region electrically connected to the through-hole electrode D7 in a stacked state. The other end of the conductor pattern B7 is electrically connected to a through-hole electrode D8 formed through the nonmagnetic layer A10 in the thickness direction. For this reason, the conductor pattern B7 is electrically connected to the corresponding conductor pattern B8 via the through-hole electrode D8 in a stacked state.

  A conductor pattern B8 is formed on the surface of the nonmagnetic layer A11. The conductor pattern B8 is arranged so as to be orthogonal to the conductor patterns B7 and B9 adjacent to each other in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B8 includes a region electrically connected to the through-hole electrode D8 in a stacked state. The other end of the conductor pattern B8 is electrically connected to a through-hole electrode D9 formed through the nonmagnetic layer A11 in the thickness direction. For this reason, the conductor pattern B8 is electrically connected to the corresponding conductor pattern B9 through the through-hole electrode D9 in a stacked state.

  A conductor pattern B9 is formed on the surface of the nonmagnetic layer A12. The conductor pattern B9 is located at the other end of the coil L, and is disposed so as to be orthogonal to the conductor pattern B8 adjacent in the facing direction (stacking direction) when viewed from the facing direction (stacking direction). One end of the conductor pattern B9 includes a region electrically connected to the through-hole electrode D9 in a stacked state. The other end of the conductor pattern B9 is electrically connected to a through-hole electrode D10 formed through the nonmagnetic layer A12 in the thickness direction. For this reason, the conductor pattern B9 is electrically connected to the corresponding lead conductor C2 through the through-hole electrode D10 in a stacked state.

  A lead conductor C2 is formed on the surface of the nonmagnetic layer A13. One end of the lead conductor C2 includes a region electrically connected to the through-hole electrode D10 in a stacked state. The lead conductor C2 is drawn to the edge of the nonmagnetic layer A13 on the side where the external electrode 14 is formed, and its end is exposed at the end face of the nonmagnetic layer A13. The lead conductor C2 is directed from the terminal axis Q along the conductor pattern B9 (the other end of the coil L) toward the axial center of the coil L (toward the far edge of the nonmagnetic layer A13 when viewed from the terminal axis Q). ) It is formed to extend. The lead conductor C2 increases in width from the conductor pattern B9 (the other end of the coil L) toward the end surface (external electrode 14) of the nonmagnetic layer A13.

  In the laminate 10 in which the above-described nonmagnetic layers A1 to A15 are laminated, as shown in FIG. 3A, the lead conductor C1, the conductor patterns B1 to B9, and the lead conductor C2 are opposed to each other (stacking direction). ). Moreover, in the laminated body 10 in which the above-described nonmagnetic layers A1 to A15 are laminated, as shown in FIG. 3B, the conductor patterns B1 to B9 are opposed to each other when viewed from the opposite direction (lamination direction). The conductor patterns adjacent in the direction (stacking direction) are orthogonal to each other.

  As described above, in the present embodiment, the linear conductor patterns B1 to B9 are electrically connected to each other to constitute the coil L. Therefore, the bent part does not exist in the conductor patterns B1 to B9. As a result, it is possible to reduce the stray capacitance generated in the portion where the conductor pattern is bent, as compared with the conventional multilayer inductor, and to improve the high frequency characteristics.

  In the present embodiment, the conductor patterns B1 to B9 are formed on the surfaces of the nonmagnetic layers A4 to A12, respectively, and are juxtaposed in the facing direction (stacking direction). Therefore, the number of conductor patterns adjacent to each other in the facing direction (lamination direction) with respect to one conductor pattern is two or less. As a result, compared to the case where a plurality of conductor patterns are formed on the surface of the nonmagnetic material layer, the number of conductor patterns adjacent to each other in the facing direction (stacking direction) is reduced. It is possible to reduce stray capacitance generated between adjacent conductor patterns.

  In the present embodiment, the lead conductor C1 extends from the terminal axis P along the conductor pattern B1 (one end of the coil L) toward the axial center of the coil L (as viewed from the terminal axis P). It is formed so as to extend toward the far edge, and the width becomes wider from the conductor pattern B1 (one end of the coil L) toward the end surface (external electrode 12) of the nonmagnetic layer A3. The lead conductor C2 extends from the terminal axis Q along the conductor pattern B9 (the other end of the coil L) toward the axial center of the coil L (on the far edge of the nonmagnetic layer A12 as viewed from the terminal axis Q). The width of the conductor pattern B9 increases from the conductor pattern B9 (the other end of the coil L) toward the end surface (the external electrode 14) of the nonmagnetic layer A12. For this reason, it is possible to improve the connection reliability between the external electrode 12 and the lead conductor C1 and the connection reliability between the external electrode 14 and the lead conductor C2. In addition, in the connection portion between the lead conductor C1 and one end of the coil L (conductor pattern B1) and the connection portion between the lead conductor C2 and the other end of the coil L (conductor pattern B9), a sudden change in the transmission path of the electrical signal occurs. Disappear. That is, since the impedance and the size of the cross-sectional area of the conductor are inversely proportional, the impedance of the lead conductor C1 gradually increases from the external electrode 12 toward one end of the coil L (conductor pattern B1), and from the external electrode 14 As it goes to the other end of the coil L (conductor pattern B9), the impedance of the lead conductor C2 gradually increases. As a result, impedance matching is performed, and reflection of the electric signal can be reduced.

  In the present embodiment, the lead conductors C1 and C2 are respectively formed on the nonmagnetic layers A3 and A13 different from the nonmagnetic layers A4 to A12 on which the conductor patterns B1 to B9 are formed, and the conductor patterns B1 to B9 are formed. Is located between the lead conductor C1 and the lead conductor C2. When the lead conductors C1 and C2 are formed integrally with any one of the conductor patterns B1 to B9, stray capacitance may occur due to bending at the connection portion between the lead conductors C1 and C2 and the conductor pattern. In this way, the lead conductors C1 and C2 are not formed integrally with any of the conductor patterns B1 to B9. As a result, there is no bending and the stray capacitance can be further reduced.

  In the present embodiment, the conductor patterns B1 to B9 are arranged so that the conductor patterns adjacent to each other in the facing direction (stacking direction) are orthogonal to each other when viewed from the facing direction (stacking direction). Therefore, when viewed from the facing direction (stacking direction), it is possible to ensure a large coil diameter as compared with the case where the conductor patterns B1 to B9 are not orthogonal to the conductor pattern adjacent in the facing direction (stacking direction). Become.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments. For example, in this embodiment, the lead conductor C1 is far from the nonmagnetic layer A3 when viewed from the terminal axis P toward the axial center side of the coil L from the terminal axis P along which the conductor pattern B1 (one end of the coil L) extends. The lead conductor C2 extends from the terminal axis Q along the conductor pattern B9 (the other end of the coil L) toward the axial center side of the coil L (from the terminal axis Q). Although it is formed so as to extend toward the far edge of the nonmagnetic layer A13 as viewed, it is not limited to this. That is, the lead conductor C1 is directed from the terminal axis P along which the conductor pattern B1 (one end of the coil L) extends to the opposite side of the axis of the coil L (as viewed from the terminal axis P, the edge closer to the nonmagnetic layer A3). The lead conductor C2 may extend from the terminal axis Q along the conductor pattern B9 (the other end of the coil L) toward the opposite side of the axis of the coil L (terminal axis Q). It may be formed so as to extend toward the near edge of the nonmagnetic layer A13 when viewed from the side. The lead conductor C1 may be formed so as to extend toward both sides across the terminal axis P along which the conductor pattern B1 (one end of the coil L) extends, and the lead conductor C2 may be formed in the conductor pattern B9 (the coil L). It may be formed so as to extend toward both sides with the terminal axis Q along the other end. Further, the lead conductors C1 and C2 may be formed so as to be linear (substantially I-shaped).

  In the present embodiment, the conductor patterns B1 to B9 are arranged so that the conductor patterns adjacent to each other in the facing direction (stacking direction) are orthogonal to each other when viewed from the facing direction (stacking direction). Conductor patterns B1 to B9 may be arranged so that conductor patterns adjacent to each other in the direction) intersect.

  In the present embodiment, the lead conductor C1 and the conductor pattern are not integrally formed, and the lead conductor C2 and the conductor pattern are not integrally formed. The lead conductor C2 and the conductor pattern may be integrally formed.

  Moreover, in this embodiment, although the laminated body 10 was comprised by laminating | stacking nonmagnetic material layer A1-A15, you may comprise a laminated body by laminating | stacking a magnetic body layer. The magnetic layer can be formed using, for example, a ferrite such as Ni—Cu—Zn ferrite, Ni—Cu—Zn—Mg ferrite, Cu—Zn ferrite, or Ni—Cu ferrite.

1 is a perspective view showing a multilayer inductor according to an embodiment. It is a disassembled perspective view for demonstrating the structure of the laminated body with which the multilayer inductor which concerns on this embodiment is provided. (A) is a side perspective view of the multilayer body provided in the multilayer inductor according to the present embodiment, and (b) is a top perspective view of the multilayer body provided in the multilayer inductor according to the present embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Multilayer inductor, 10 ... Laminated body, 12, 14 ... External electrode, A1-A15 ... Nonmagnetic material layer, B1-B9 ... Conductor pattern, C1, C2 ... Lead-out conductor, D1-D10 ... Through-hole electrode, L ... coil, P, Q ... terminal axis.

Claims (4)

A laminate having a pair of main surfaces that are configured by laminating a plurality of insulator layers and facing each other so as to be parallel to each other;
First and second external electrodes respectively disposed on the outer surface of the laminate;
A plurality of linear conductor patterns are configured to be electrically connected to each other, and a coil provided inside the laminate,
A first lead conductor electrically connected to one end of the coil and electrically connected to the first outer conductor;
A second lead conductor electrically connected to the other end of the coil and electrically connected to the second external electrode;
The plurality of conductor patterns are juxtaposed in the facing direction so as to be located in different virtual planes among a plurality of virtual planes perpendicular to the facing direction of the pair of main surfaces,
Among the plurality of conductor patterns, conductor patterns adjacent to each other in the facing direction are arranged so as to intersect each other when viewed from the facing direction. The first lead conductor is formed to increase in width from one end of the coil toward the first external electrode,
2. The multilayer inductor according to claim 1, wherein the second lead conductor is formed to have a width that increases from the other end of the coil toward the second external electrode. 3. The first lead conductor, the plurality of conductor patterns, and the second lead conductor are juxtaposed in the facing direction so as to be located in different virtual planes among the plurality of virtual planes,
The multilayer inductor according to claim 2, wherein the plurality of conductor patterns are located between the first lead conductor and the second lead conductor.   4. The multilayer inductor according to claim 1, wherein among the plurality of conductor patterns, conductor patterns adjacent to each other in the facing direction are orthogonal to each other when viewed from the facing direction. .

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