JP2006352568A - Multilayer filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To devise a multilayer filter so that attenuation characteristics are further improved. <P>SOLUTION: The filter has a prime field 1 in which a plurality of nonmagnetic materials 11-27 are layered and a coil constituted by mutually and electrically connecting first internal conductors 31-39 arranged in the layered direction of the plurality of nonmagnetic materials 11-27 in the prime field 1. A first terminal electrode electrically connected with one end of the coil and a second terminal electrode electrically connected with the other end of the coil are formed in the prime field 1. Second internal conductors 71-76 which generate stray capacitance among the first internal conductors 31-39 are arranged among the first internal conductors 32-38 adjacent in the layered direction among the plurality of first internal conductors 31-39. The second internal conductors 71-76 are electrically connected with the second terminal electrode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multilayer filter.

As this type of laminated filter, a laminated body in which insulators are laminated, a coil (inductor) and a capacitor (capacitor) arranged in the laminated body, and formed in the laminated body and electrically connected to the coil and the capacitor A terminal electrode is known (see, for example, Patent Document 1). The multilayer filter described in Patent Document 1 is configured by electrically connecting a plurality of coil conductors arranged in the stacking direction of the insulator in the multilayer body. The capacitor is constituted by a capacitor conductor disposed in the laminated body so as to face the laminated direction of the insulator. The coil and the capacitor are connected in parallel.
JP 2005-50973 A

  In a multilayer filter in which a coil and a capacitor are connected in parallel as in the multilayer filter described in Patent Document 1, the attenuation at the resonance frequency is shallow, and the frequency at a predetermined insertion loss (for example, 20 dB) is obtained. Attenuation characteristics with a narrow band (stop band). This is because the impedance of the capacitor in the frequency band higher than the parallel resonance frequency is low, but the input signal passes only through the capacitor in the frequency band higher than the parallel resonance frequency. Is output. When the attenuation characteristics are shallow and the cutoff band is narrow, even if circuit design technology has been established that selectively removes only the frequency band of the noise to be removed, variations in attenuation characteristics among multilayer filters, There may be a problem that noise cannot be sufficiently removed due to variations in the band of generated noise due to component placement.

  An object of the present invention is to provide a multilayer filter capable of further improving the attenuation characteristics.

  In the multilayer filter according to the present invention, a laminated body in which a plurality of nonmagnetic materials are laminated and a plurality of first inner conductors arranged in the lamination direction of the nonmagnetic materials in the laminated body are electrically connected to each other. A first terminal electrode formed in the laminate and electrically connected to one end of the coil, and a second electrode formed in the laminate and electrically connected to the other end of the coil. And a second inner conductor that is arranged between the first inner conductors adjacent to each other in the stacking direction and generates a stray capacitance with the first inner conductor. The second inner conductor is electrically connected to one of the first and second terminal electrodes.

  In the multilayer filter according to the present invention, by having the above configuration, the attenuation is deep and the cutoff band is widened, so that the attenuation characteristic can be further improved.

  The present inventors consider as follows the factors that deepen the attenuation and widen the cutoff band and further improve the attenuation characteristics. Since the second inner conductor that generates stray capacitance with the first inner conductor is electrically connected to one of the first and second terminal electrodes, the plurality of first conductors The coil constituted by the inner conductor includes a portion that can generate stray capacitance with the second inner conductor and a portion that cannot generate stray capacitance with the second inner conductor. Become. For this reason, in the multilayer filter of the present invention, the part of the coil that can generate the stray capacitance with the second inner conductor and the parallel resonant circuit in which the stray capacitance is connected in parallel, and the second of the coils. A portion where no stray capacitance can be generated between the inner conductor and a series resonant circuit in which the stray capacitance is connected in series is configured. And the attenuation characteristic by a parallel resonance circuit and the attenuation characteristic by a series resonance circuit are synthesize | combined, and an attenuation characteristic with a deep attenuation | damping and a wide stop band is implement | achieved.

  Preferably, the second inner conductor is formed along the first inner conductor when viewed from the stacking direction. In this case, it is possible to suppress the second inner conductor from inhibiting the flux generated in the coil and to improve the high frequency characteristics.

  According to the present invention, it is possible to provide a multilayer filter capable of further improving the attenuation characteristics.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted. In the description, the terms “upper” and “lower” may be used, which correspond to the vertical direction of each figure.

(First embodiment)
With reference to FIGS. 1-3, the structure of the multilayer filter F which concerns on 1st Embodiment is demonstrated. FIG. 1 is a perspective view showing the multilayer filter according to the first embodiment. FIG. 2 is an exploded view showing the element body included in the multilayer filter according to the first embodiment. FIG. 3 is a diagram for explaining an equivalent circuit of the multilayer filter according to the first embodiment.

  As shown in FIGS. 1 and 2, the multilayer filter F includes a rectangular parallelepiped element body 1, a coil 30, and first and second terminal electrodes 3 and 5 formed on side surfaces of the element body 1. It has. The coil 30 is disposed in the element body 1. The coil 30 is electrically connected to the first terminal electrode 3 and the second terminal electrode 5.

  As shown in FIG. 2, the element body 1 is a laminated body configured by laminating a plurality (17 layers in this embodiment) of nonmagnetic bodies 11 to 27. The actual multilayer filter F is integrated to such an extent that the boundary between the non-magnetic materials 11 to 27 cannot be visually recognized. The nonmagnetic materials 11 to 27 are configured by firing a nonmagnetic green sheet.

  The coil 30 includes a plurality of first inner conductors 31 to 39. The first inner conductors 31 and 39 are substantially J-shaped. The first inner conductors 32 to 38 are substantially L-shaped. That is, the first inner conductors 32 to 38 are in a facing direction between the side surface from which the first inner conductor 31 is drawn out and the side surface from which the first inner conductor 39 is drawn (hereinafter simply referred to as “side facing direction”). A first portion extending; and a second portion extending in a direction continuous to the first portion and perpendicular to the side surface facing direction and the stacking direction.

  The first inner conductor 31 is located on the nonmagnetic material 11. One end of the first inner conductor 31 is drawn to the side surface of the element body 1 and exposed to the side surface, and is connected to the first terminal electrode 3. The first inner conductor 31 is located at one end of the coil 30. The first inner conductor 31, that is, one end of the coil 30 is electrically connected to the first terminal electrode 3. The first inner conductor 31 functions as a lead conductor.

  A through-hole conductor 41 that penetrates the nonmagnetic body 11 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 31 in the nonmagnetic body 11. The first inner conductor 31 is electrically connected to the through-hole conductor 41 at the other end.

  The first inner conductor 32 is located on the nonmagnetic material 12 and corresponds to approximately ½ turn of the coil 30. The first inner conductor 32 includes a region electrically connected to the through-hole conductor 41 in a state where the nonmagnetic materials 11 and 12 are laminated at one end of the first inner conductor 32. A through-hole conductor 42 penetrating the nonmagnetic body 12 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 32 in the nonmagnetic body 12. The through-hole conductor 42 is electrically connected to the other end portion of the first inner conductor 32.

  On the nonmagnetic material 13, a land-like inner conductor 61 is positioned so as to correspond to the through-hole conductor 42. A through-hole conductor 43 penetrating the nonmagnetic body 13 in the thickness direction is formed at a position corresponding to the inner conductor 61 in the nonmagnetic body 13. The through-hole conductor 43 is electrically connected to the inner conductor 61. The inner conductor 61 is electrically connected to the through-hole conductor 42 in a state where the nonmagnetic materials 12 and 13 are laminated. The internal conductor 61 functions as a through-hole connection conductor.

  The first inner conductor 33 is located on the nonmagnetic material 14 and corresponds to approximately a half turn of the coil 30. The first inner conductor 33 includes a region that is electrically connected to the through-hole conductor 43 in a state where the nonmagnetic materials 13 and 14 are laminated on one end of the first inner conductor 33. A through-hole conductor 44 that penetrates the nonmagnetic body 14 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 33 in the nonmagnetic body 14. The through-hole conductor 44 is electrically connected to the other end portion of the first inner conductor 33.

  A land-like inner conductor 62 is positioned on the nonmagnetic material 15 so as to correspond to the through-hole conductor 44. A through-hole conductor 45 that penetrates the nonmagnetic body 15 in the thickness direction is formed at a position corresponding to the inner conductor 62 in the nonmagnetic body 15. The through-hole conductor 45 is electrically connected to the inner conductor 62. The inner conductor 62 is electrically connected to the through-hole conductor 44 in a state where the nonmagnetic materials 14 and 15 are laminated. The inner conductor 62 functions as a through-hole connection conductor.

  The first inner conductor 34 is located on the nonmagnetic material 16 and corresponds to approximately ½ turn of the coil 30. The first inner conductor 34 includes a region that is electrically connected to the through-hole conductor 45 in a state where the nonmagnetic materials 15 and 16 are laminated on one end of the first inner conductor 34. A through-hole conductor 46 that penetrates the nonmagnetic body 16 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 34 in the nonmagnetic body 16. The through-hole conductor 46 is electrically connected to the other end portion of the first inner conductor 34.

  On the nonmagnetic material 17, a land-like inner conductor 63 is positioned so as to correspond to the through-hole conductor 46. A through-hole conductor 47 that penetrates the nonmagnetic body 17 in the thickness direction is formed at a position corresponding to the inner conductor 63 in the nonmagnetic body 17. The through-hole conductor 47 is electrically connected to the inner conductor 63. The internal conductor 63 is electrically connected to the through-hole conductor 46 in a state where the nonmagnetic materials 16 and 17 are laminated. The inner conductor 63 functions as a through-hole connection conductor.

  The first inner conductor 35 is located on the nonmagnetic material 18 and corresponds to approximately a half turn of the coil 30. The first inner conductor 35 includes a region electrically connected to the through-hole conductor 47 in a state where the nonmagnetic materials 17 and 18 are laminated on one end portion of the first inner conductor 35. A through-hole conductor 48 that penetrates the nonmagnetic body 18 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 35 in the nonmagnetic body 18. The through-hole conductor 48 is electrically connected to the other end portion of the first inner conductor 35.

  On the nonmagnetic material 19, a land-like inner conductor 64 is positioned so as to correspond to the through-hole conductor 48. A through-hole conductor 49 that penetrates the nonmagnetic body 19 in the thickness direction is formed at a position corresponding to the inner conductor 64 in the nonmagnetic body 19. The through-hole conductor 49 is electrically connected to the inner conductor 64. The inner conductor 64 is electrically connected to the through-hole conductor 48 in a state where the nonmagnetic materials 18 and 19 are laminated. The inner conductor 64 functions as a through-hole connection conductor.

  The first inner conductor 36 is located on the nonmagnetic material 20 and corresponds to approximately ½ turn of the coil 30. The first inner conductor 36 includes a region that is electrically connected to the through-hole conductor 49 in a state where the nonmagnetic materials 19 and 20 are laminated on one end of the first inner conductor 36. A through-hole conductor 50 that penetrates the nonmagnetic body 20 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 36 in the nonmagnetic body 20. The through-hole conductor 50 is electrically connected to the other end portion of the first inner conductor 36.

  A land-like inner conductor 65 is positioned on the nonmagnetic material 21 so as to correspond to the through-hole conductor 50. A through-hole conductor 51 that penetrates the nonmagnetic body 21 in the thickness direction is formed at a position corresponding to the inner conductor 65 in the nonmagnetic body 21. The through-hole conductor 51 is electrically connected to the inner conductor 65. The inner conductor 65 is electrically connected to the through-hole conductor 50 in a state where the nonmagnetic materials 20 and 21 are laminated. The inner conductor 65 functions as a through-hole connection conductor.

  The first inner conductor 37 is located on the nonmagnetic material 22 and corresponds to approximately ½ turn of the coil 30. The first inner conductor 37 includes a region that is electrically connected to the through-hole conductor 51 in a state where the nonmagnetic materials 21 and 22 are laminated on one end portion of the first inner conductor 37. A through-hole conductor 52 that penetrates the nonmagnetic body 22 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 37 in the nonmagnetic body 22. The through-hole conductor 52 is electrically connected to the other end portion of the first inner conductor 37.

  A land-like inner conductor 66 is located on the nonmagnetic material 23 so as to correspond to the through-hole conductor 52. A through-hole conductor 53 that penetrates the nonmagnetic body 23 in the thickness direction is formed at a position corresponding to the inner conductor 66 in the nonmagnetic body 23. The through-hole conductor 53 is electrically connected to the internal conductor 66. The internal conductor 66 is electrically connected to the through-hole conductor 52 in a state where the nonmagnetic materials 22 and 23 are laminated. The inner conductor 66 functions as a through-hole connection conductor.

  The first inner conductor 38 is located on the nonmagnetic material 24 and corresponds to approximately ½ turn of the coil 30. The first inner conductor 38 includes a region electrically connected to the through-hole conductor 53 in a state where the nonmagnetic materials 23 and 24 are laminated on one end of the first inner conductor 38. A through-hole conductor 54 that penetrates the nonmagnetic body 24 in the thickness direction is formed at a position corresponding to the other end portion of the first inner conductor 38 in the nonmagnetic body 24. The through-hole conductor 54 is electrically connected to the other end portion of the first inner conductor 38.

  The first inner conductor 39 is located on the nonmagnetic material 25. One end portion of the first inner conductor 39 is drawn to the side surface of the element body 1 (the side surface opposite to the side surface from which the one end portion of the first inner conductor 31 is drawn) and exposed to the side surface, Connected to the terminal electrode 5. The first inner conductor 39 includes a region that is electrically connected to the through-hole conductor 54 in a state where the nonmagnetic materials 24 and 25 are laminated on the other end of the first inner conductor 39. The first inner conductor 39 is located at the other end of the coil 30. The first inner conductor 39, that is, the other end of the coil 30 is electrically connected to the second terminal electrode 5. The first inner conductor 39 functions as a lead conductor.

  As described above, the first inner conductors 31 to 39 are electrically connected through the through-hole conductors 41 to 54 and the inner conductors 61 to 66. Thereby, the 1st inner conductors 31-39 will comprise the coil 30 by being electrically connected mutually.

  As shown in FIG. 2, the multilayer filter F further includes second inner conductors 71 to 76. The second inner conductors 71 to 75 are substantially L-shaped. The second inner conductor 76 has a substantially J shape. The second inner conductors 71 to 76 are formed along the first inner conductors 31 to 39 when viewed from the stacking direction of the nonmagnetic materials 11 to 27 (hereinafter simply referred to as “stacking direction”). .

  The second inner conductor 71 is located on the nonmagnetic material 13. Thereby, the second inner conductor 71 is disposed between the first inner conductor 32 and the first inner conductor 33 adjacent to each other in the stacking direction among the plurality of first inner conductors 31 to 39. Become. A through-hole conductor 81 that penetrates the nonmagnetic body 13 in the thickness direction is formed at a position corresponding to one end portion of the second inner conductor 71 in the nonmagnetic body 13. The through-hole conductor 81 is electrically connected to one end portion of the second inner conductor 71.

  The portion of the second inner conductor 71 extending in the side-facing direction overlaps the first portion of the first inner conductor 32 when viewed from the stacking direction and is adjacent in the stacking direction. The portion extending in the direction perpendicular to the side surface facing direction and the stacking direction of the second inner conductor 71 overlaps with the second portion of the first inner conductor 33 when viewed from the stacking direction and is adjacent in the stacking direction. .

  A land-like inner conductor 91 is located on the nonmagnetic body 14 so as to correspond to the through-hole conductor 81. A through-hole conductor 82 that penetrates the nonmagnetic body 14 in the thickness direction is formed at a position corresponding to the inner conductor 91 in the nonmagnetic body 14. The through-hole conductor 82 is electrically connected to the inner conductor 91. The internal conductor 91 is electrically connected to the through-hole conductor 81 in a state where the nonmagnetic materials 13 and 14 are laminated. The internal conductor 91 functions as a through-hole connection conductor.

  The second inner conductor 72 is located on the nonmagnetic material 15. Thereby, the second inner conductor 72 is disposed between the first inner conductor 33 and the first inner conductor 34 adjacent to each other in the stacking direction among the plurality of first inner conductors 31 to 39. Become. The second inner conductor 72 includes a region electrically connected to the through-hole conductor 82 in a state where the nonmagnetic materials 14 and 15 are laminated on one end portion of the second inner conductor 72. A through-hole conductor 83 that penetrates the nonmagnetic body 15 in the thickness direction is formed at a position corresponding to the other end of the second inner conductor 72 in the nonmagnetic body 15. The through-hole conductor 83 is electrically connected to the other end portion of the second inner conductor 72.

  The portion of the second inner conductor 72 extending in the side-facing direction overlaps with the first portion of the first inner conductor 33 when viewed from the stacking direction and is adjacent to the stacking direction. The portion of the second inner conductor 72 extending in the direction opposite to the side surface and the direction perpendicular to the stacking direction overlaps with the second portion of the first inner conductor 34 as viewed from the stacking direction and is adjacent in the stacking direction. .

  On the nonmagnetic material 16, a land-like inner conductor 92 is positioned so as to correspond to the through-hole conductor 83. A through-hole conductor 84 that penetrates the nonmagnetic body 16 in the thickness direction is formed at a position corresponding to the inner conductor 92 in the nonmagnetic body 16. The through-hole conductor 84 is electrically connected to the inner conductor 92. The inner conductor 92 is electrically connected to the through-hole conductor 83 in a state where the nonmagnetic materials 15 and 16 are laminated. The inner conductor 92 functions as a through-hole connection conductor.

  The second inner conductor 73 is located on the nonmagnetic material 17. Accordingly, the second inner conductor 73 is disposed between the first inner conductor 34 and the first inner conductor 35 adjacent to each other in the stacking direction among the plurality of first inner conductors 31 to 39. Become. The second inner conductor 73 includes a region that is electrically connected to the through-hole conductor 84 in a state where the nonmagnetic materials 16 and 17 are laminated on one end of the second inner conductor 73. A through-hole conductor 85 that penetrates the nonmagnetic material 17 in the thickness direction is formed at a position corresponding to the other end of the second inner conductor 73 in the nonmagnetic material 17. The through-hole conductor 85 is electrically connected to the other end portion of the second inner conductor 73.

  The portion of the second inner conductor 73 that extends in the side-facing direction overlaps the first portion of the first inner conductor 34 when viewed from the stacking direction and is adjacent to the stacking direction. The portion of the second inner conductor 73 extending in the direction opposite to the side surface and the direction perpendicular to the stacking direction overlaps with the second portion of the first inner conductor 35 as viewed from the stacking direction and is adjacent in the stacking direction. .

  A land-like inner conductor 93 is positioned on the nonmagnetic body 18 so as to correspond to the through-hole conductor 85. A through-hole conductor 86 that penetrates the nonmagnetic body 18 in the thickness direction is formed at a position corresponding to the inner conductor 93 in the nonmagnetic body 18. The through-hole conductor 86 is electrically connected to the inner conductor 93. The inner conductor 93 is electrically connected to the through-hole conductor 85 in a state where the nonmagnetic materials 17 and 18 are laminated. The internal conductor 93 functions as a through-hole connection conductor.

  The second inner conductor 74 is located on the nonmagnetic material 19. Thereby, the second inner conductor 74 is disposed between the first inner conductor 35 and the first inner conductor 36 adjacent to each other in the stacking direction among the plurality of first inner conductors 31 to 39. Become. The second inner conductor 74 includes a region electrically connected to the through-hole conductor 86 in a state where the nonmagnetic materials 18 and 19 are laminated at one end of the second inner conductor 74. A through-hole conductor 87 that penetrates the nonmagnetic body 19 in the thickness direction is formed at a position corresponding to the other end portion of the second inner conductor 74 in the nonmagnetic body 19. The through-hole conductor 87 is electrically connected to the other end portion of the second inner conductor 74.

  A portion of the second inner conductor 74 extending in the side surface facing direction overlaps the first portion of the first inner conductor 35 as viewed from the stacking direction and is adjacent to the stacking direction. The portion of the second inner conductor 74 extending in the direction opposite to the side surface and the direction perpendicular to the stacking direction overlaps the second portion of the first inner conductor 36 as viewed from the stacking direction and is adjacent in the stacking direction. .

  A land-like inner conductor 94 is located on the nonmagnetic body 20 so as to correspond to the through-hole conductor 87. A through-hole conductor 88 that penetrates the nonmagnetic body 20 in the thickness direction is formed at a position corresponding to the inner conductor 94 in the nonmagnetic body 20. The through-hole conductor 88 is electrically connected to the inner conductor 94. The inner conductor 94 is electrically connected to the through-hole conductor 87 in a state where the nonmagnetic materials 19 and 20 are laminated. The inner conductor 94 functions as a through-hole connection conductor.

  The second inner conductor 75 is located on the nonmagnetic material 21. Accordingly, the second inner conductor 75 is disposed between the first inner conductor 36 and the first inner conductor 37 adjacent to each other in the stacking direction among the plurality of first inner conductors 31 to 39. Become. The second inner conductor 75 includes a region that is electrically connected to the through-hole conductor 88 in a state where the nonmagnetic materials 20 and 21 are laminated on one end of the second inner conductor 75. A through-hole conductor 89 that penetrates the nonmagnetic material 21 in the thickness direction is formed at a position corresponding to the other end portion of the second inner conductor 75 in the nonmagnetic material 21. The through-hole conductor 89 is electrically connected to the other end portion of the second inner conductor 75.

  The portion of the second inner conductor 75 extending in the side-facing direction overlaps the first portion of the first inner conductor 36 when viewed from the stacking direction and is adjacent in the stacking direction. The portion extending in the direction opposite to the side surface of the second inner conductor 75 and the direction perpendicular to the stacking direction overlaps with the second portion of the first inner conductor 37 when viewed from the stacking direction and is adjacent in the stacking direction. .

  A land-like inner conductor 95 is located on the nonmagnetic material 22 so as to correspond to the through-hole conductor 89. A through-hole conductor 90 that penetrates the nonmagnetic body 22 in the thickness direction is formed at a position corresponding to the inner conductor 95 in the nonmagnetic body 22. The through-hole conductor 90 is electrically connected to the inner conductor 95. The inner conductor 95 is electrically connected to the through-hole conductor 89 in a state where the nonmagnetic materials 21 and 22 are laminated. The inner conductor 95 functions as a through-hole connection conductor.

  The second inner conductor 76 is located on the nonmagnetic material 23. Accordingly, the second inner conductor 76 is disposed between the first inner conductor 37 and the first inner conductor 38 adjacent to each other in the stacking direction among the plurality of first inner conductors 31 to 39. Become. The portion extending in the direction opposite to the side surface of the second inner conductor 76 and the direction perpendicular to the stacking direction overlaps with the second portion of the first inner conductor 38 when viewed from the stacking direction and is adjacent in the stacking direction. .

  One end portion of the second inner conductor 76 is drawn to the side surface of the element body 1 (the side surface from which one end portion of the first inner conductor 39 is drawn) and exposed to the side surface. Connected. The second inner conductor 76 includes a region that is electrically connected to the through-hole conductor 90 in a state where the nonmagnetic materials 22 and 23 are laminated on the other end of the second inner conductor 76. The second inner conductor 76 is electrically connected to the second terminal electrode 5. The second inner conductor 76 functions as a lead conductor.

  As described above, the second inner conductors 71 to 76 are electrically connected through the through-hole conductors 81 to 90 and the inner conductors 91 to 95. Thereby, the second inner conductors 71 to 76 are electrically connected to each other. The second inner conductors 71 to 76 are not electrically connected to the first terminal electrode 3.

  The nonmagnetic material 26 is located on the nonmagnetic material 11 and functions as a base layer for protecting the first inner conductor 31. The nonmagnetic material 27 is located below the nonmagnetic material 25. The nonmagnetic materials 26 and 27 are also used for adjusting the thickness of the element body 1 to a predetermined dimension. The number of nonmagnetic materials 26 may be a plurality of layers. The nonmagnetic material 27 may also have a plurality of layers or may not be laminated.

  Next, a method for manufacturing the multilayer filter F will be described.

First, a non-magnetic green sheet that constitutes the non-magnetic bodies 11 to 27 is prepared. As the non-magnetic green sheet, for example, a slurry obtained by applying a slurry using a mixed powder of Fe ₂ O ₃ , ZnO and CuO as a raw material on a film by a doctor blade method can be used. The thickness of the nonmagnetic green sheet can be set to about 20 μm, for example. Instead of a mixed powder of Fe ₂ O ₃ , ZnO and CuO, a dielectric material (such as a mixed powder of TiO ₂ , CuO, NiO and MnCO) or an oxide ceramic material (Al ₂ O ₃ , SiO ₂ , ZrO) ₂ , forsterite, steatite, cordierite, etc.) or a mixed powder thereof may be used.

  Next, through holes are formed by laser processing or the like at predetermined positions of the nonmagnetic green sheets constituting the nonmagnetic bodies 11 to 24, that is, positions where the throughhole conductors 41 to 54 and 81 to 90 are to be formed. Form.

  Next, it corresponds to the 1st inner conductors 31-39, the 2nd inner conductors 71-76, and the inner conductors 61-66, 91-95 to each green sheet which constitutes nonmagnetic materials 11-24. Each conductor pattern to be formed is formed. Each conductor pattern is formed, for example, by screen-printing a conductor paste (conductor material) mainly composed of silver or nickel and then drying. Each through hole is filled with a conductor paste when each conductor pattern is formed.

  Next, the green sheets are sequentially laminated and pressure-bonded, cut into chips, and then fired at a predetermined temperature (for example, 800 to 900 degrees). As a result, the element body 1 is formed. The element body 1 has, for example, a length in the longitudinal direction after completion of 1.0 mm, a width of 0.5 mm, and a height of 0.5 mm. The thickness of the first inner conductors 31 to 39, the second inner conductors 71 to 76, and the inner conductors 61 to 66, 91 to 95 after firing is set to about 12 μm, for example. The widths after firing of the first inner conductors 31 to 39 and the second inner conductors 71 to 76 are set to about 70 μm, for example.

  Next, the first and second terminal electrodes 3 and 5 are formed on the element body 1. Thereby, the multilayer filter F is obtained. The first and second terminal electrodes 3, 5 are baked at a predetermined temperature (for example, about 700 ° C.) after transferring an electrode paste mainly composed of silver, nickel, or copper onto the outer surface of the element body 1. It is formed by plating. For electroplating, Cu / Ni / Sn, Ni / Sn, Ni / Au, Ni / Pd / Au, Ni / Pd / Ag, Ni / Ag, or the like can be used. Note that the cut-off frequency of the multilayer filter F can be set to 100 MHz, for example.

  In the multilayer filter F configured as described above, as shown in FIG. 3, stray capacitance Cs is generated between the coil 30 (first inner conductors 31 to 39) and the second inner conductors 71 to 76. . In FIG. 3, in order to differentiate the coil 30 (first inner conductors 31 to 39) and the second inner conductors 71 to 76 on the drawing, the second inner conductors 71 to 76 are represented by broken lines. Yes.

  As described above, the multilayer filter F according to the first embodiment has the above-described configuration, so that the attenuation is deep and the cutoff band is widened, so that the attenuation characteristics can be further improved.

  The present inventors consider as follows the factors that deepen the attenuation and widen the cutoff band and further improve the attenuation characteristics. Since the second inner conductors 71 to 76 that generate the stray capacitance Cs between the first inner conductors 31 to 39 are electrically connected to the second terminal electrode 5, the plurality of first inner conductors The coil 30 composed of 31 to 39 generates the stray capacitance Cs between the second inner conductors 71 to 76 and the portion that can generate the stray capacitance Cs between the second inner conductors 71 to 76. Part which cannot be made to be included. Therefore, in the multilayer filter F, a portion of the coil 30 that can generate the stray capacitance Cs between the second inner conductors 71 to 76 and a parallel resonance circuit in which the stray capacitance Cs is connected in parallel, and the coil A portion of 30 where the stray capacitance Cs cannot be generated between the second inner conductors 71 to 76 and a series resonance circuit in which the stray capacitance Cs is connected in series are configured. And the attenuation characteristic by a parallel resonance circuit and the attenuation characteristic by a series resonance circuit are synthesize | combined, and an attenuation characteristic with a deep attenuation | damping and a wide stop band is implement | achieved.

  In the first embodiment, the second inner conductors 71 to 76 are formed along the first inner conductors 31 to 39 as viewed from the stacking direction. Thereby, it can suppress that the 2nd inner conductors 71-76 inhibit the flux which generate | occur | produces in the coil 30, and can improve a high frequency characteristic.

  Further, in the first embodiment, the element body 1 is configured by laminating a plurality of nonmagnetic bodies 11 to 27. Thereby, the multilayer filter F can remove noise in a high frequency band (for example, 300 to 2000 MHz).

(Second Embodiment)
With reference to FIG.4 and FIG.5, the structure of the multilayer filter which concerns on 2nd Embodiment is demonstrated. FIG. 4 is an exploded view showing the element body included in the multilayer filter according to the second embodiment. FIG. 5 is a diagram for explaining an equivalent circuit of the multilayer filter according to the second embodiment.

  Similar to the multilayer filter F shown in FIG. 1, the multilayer filter according to the second embodiment includes a rectangular parallelepiped element body 1, a coil 30, and first and second elements formed on side surfaces of the element body 1. Terminal electrodes 3 and 5. As shown in FIG. 4, the element body 1 is a laminated body formed by laminating a plurality (17 layers in this embodiment) of nonmagnetic bodies 11 to 27.

  The coil 30 includes a plurality of first inner conductors 101 to 111. The first inner conductors 101 and 111 have a substantially I shape. The first inner conductors 102 to 110 are substantially C-shaped.

  The first inner conductor 101 is located on the nonmagnetic material 11. One end of the first inner conductor 101 is drawn to the side surface of the element body 1 and exposed to the side surface, and is connected to the first terminal electrode 3. The first inner conductor 101 is located at one end of the coil 30. The first inner conductor 101, that is, one end of the coil 30 is electrically connected to the first terminal electrode 3. The first inner conductor 101 functions as a lead conductor.

  A through-hole conductor 121 that penetrates the nonmagnetic body 11 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 101 in the nonmagnetic body 11. The first inner conductor 31 is electrically connected to the through-hole conductor 121 at the other end.

  The first inner conductor 102 is located on the nonmagnetic material 12 and corresponds to approximately a half turn of the coil 30. The first inner conductor 102 includes a region that is electrically connected to the through-hole conductor 121 in a state where the nonmagnetic materials 11 and 12 are laminated on one end of the first inner conductor 102. A through-hole conductor 122 that penetrates the nonmagnetic body 12 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 102 in the nonmagnetic body 12. The through-hole conductor 122 is electrically connected to the other end portion of the first inner conductor 102.

  The first inner conductor 103 is located on the nonmagnetic material 13 and corresponds to approximately a half turn of the coil 30. The first inner conductor 103 includes a region that is electrically connected to the through-hole conductor 122 in a state where the nonmagnetic bodies 12 and 13 are laminated on one end of the first inner conductor 103. A through-hole conductor 123 that penetrates the nonmagnetic body 13 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 103 in the nonmagnetic body 13. The through-hole conductor 123 is electrically connected to the other end portion of the first inner conductor 103.

  The first inner conductor 104 is located on the nonmagnetic material 14 and corresponds to approximately a half turn of the coil 30. The first inner conductor 104 includes a region electrically connected to the through-hole conductor 123 in a state where the nonmagnetic materials 13 and 14 are laminated on one end of the first inner conductor 104. A through-hole conductor 124 that penetrates the nonmagnetic body 14 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 104 in the nonmagnetic body 14. The through-hole conductor 124 is electrically connected to the other end portion of the first inner conductor 104.

  A land-like inner conductor 141 is positioned on the nonmagnetic material 15 so as to correspond to the through-hole conductor 124. A through-hole conductor 125 penetrating the nonmagnetic body 15 in the thickness direction is formed at a position corresponding to the inner conductor 141 in the nonmagnetic body 15. The through-hole conductor 125 is electrically connected to the inner conductor 141. The inner conductor 141 is electrically connected to the through-hole conductor 124 in a state where the nonmagnetic materials 14 and 15 are laminated. The internal conductor 141 functions as a through-hole connection conductor.

  The first inner conductor 105 is located on the nonmagnetic material 16 and corresponds to approximately a half turn of the coil 30. The first inner conductor 105 includes a region that is electrically connected to the through-hole conductor 125 in a state where the nonmagnetic materials 15 and 16 are laminated on one end of the first inner conductor 105. A through-hole conductor 126 that penetrates the nonmagnetic body 16 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 105 in the nonmagnetic body 16. The through-hole conductor 126 is electrically connected to the other end portion of the first inner conductor 105.

  A land-like inner conductor 142 is located on the nonmagnetic material 17 so as to correspond to the through-hole conductor 126. A through-hole conductor 127 that penetrates the nonmagnetic body 17 in the thickness direction is formed at a position corresponding to the inner conductor 142 in the nonmagnetic body 17. The through-hole conductor 127 is electrically connected to the inner conductor 142. The internal conductor 142 is electrically connected to the through-hole conductor 126 in a state where the nonmagnetic materials 16 and 17 are laminated. The inner conductor 142 functions as a through-hole connection conductor.

  The first inner conductor 106 is located on the nonmagnetic material 18 and corresponds to approximately a half turn of the coil 30. The first inner conductor 106 includes a region that is electrically connected to the through-hole conductor 127 in a state where the nonmagnetic materials 17 and 18 are laminated on one end of the first inner conductor 106. A through-hole conductor 128 that penetrates the nonmagnetic body 18 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 106 in the nonmagnetic body 18. The through-hole conductor 128 is electrically connected to the other end portion of the first inner conductor 106.

  A land-like inner conductor 143 is located on the nonmagnetic material 19 so as to correspond to the through-hole conductor 128. A through-hole conductor 129 that penetrates the nonmagnetic body 19 in the thickness direction is formed at a position corresponding to the inner conductor 143 in the nonmagnetic body 19. The through-hole conductor 129 is electrically connected to the inner conductor 143. The inner conductor 143 is electrically connected to the through-hole conductor 128 in a state where the nonmagnetic materials 18 and 19 are laminated. The inner conductor 143 functions as a through-hole connection conductor.

  The first inner conductor 107 is located on the nonmagnetic material 20 and corresponds to approximately a half turn of the coil 30. The first inner conductor 107 includes a region that is electrically connected to the through-hole conductor 129 in a state where the nonmagnetic materials 19 and 20 are laminated on one end of the first inner conductor 107. A through-hole conductor 130 that penetrates the nonmagnetic body 20 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 107 in the nonmagnetic body 20. The through-hole conductor 130 is electrically connected to the other end portion of the first inner conductor 107.

  A land-like inner conductor 144 is positioned on the nonmagnetic material 21 so as to correspond to the through-hole conductor 130. A through-hole conductor 131 that penetrates the nonmagnetic body 21 in the thickness direction is formed at a position corresponding to the inner conductor 144 in the nonmagnetic body 21. The through-hole conductor 131 is electrically connected to the inner conductor 144. The inner conductor 144 is electrically connected to the through-hole conductor 130 in a state where the nonmagnetic materials 20 and 21 are laminated. The inner conductor 144 functions as a through-hole connection conductor.

  The first inner conductor 108 is located on the nonmagnetic material 22 and corresponds to approximately ½ turn of the coil 30. The first inner conductor 108 includes a region that is electrically connected to the through-hole conductor 131 in a state where the nonmagnetic materials 21 and 22 are laminated on one end of the first inner conductor 108. A through-hole conductor 132 that penetrates the nonmagnetic body 22 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 108 in the nonmagnetic body 22. The through-hole conductor 132 is electrically connected to the other end portion of the first inner conductor 108.

  The first inner conductor 109 is located on the nonmagnetic material 23 and corresponds to approximately a half turn of the coil 30. The first inner conductor 109 includes a region electrically connected to the through-hole conductor 132 in a state where the nonmagnetic materials 22 and 23 are laminated at one end of the first inner conductor 109. A through-hole conductor 133 that penetrates the nonmagnetic body 23 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 109 in the nonmagnetic body 23. The through-hole conductor 133 is electrically connected to the other end portion of the first inner conductor 109.

  The first inner conductor 110 is located on the nonmagnetic material 24 and corresponds to approximately ½ turn of the coil 30. The first inner conductor 110 includes a region that is electrically connected to the through-hole conductor 133 in a state where the nonmagnetic materials 23 and 24 are laminated on one end of the first inner conductor 110. A through-hole conductor 134 that penetrates the nonmagnetic body 24 in the thickness direction is formed at a position corresponding to the other end of the first inner conductor 110 in the nonmagnetic body 24. The through-hole conductor 134 is electrically connected to the other end portion of the first inner conductor 110.

  The first inner conductor 111 is located on the nonmagnetic material 25. One end portion of the first inner conductor 111 is drawn to the side surface of the element body 1 (the side surface opposite to the side surface from which the one end portion of the first inner conductor 101 is drawn) and exposed to the side surface, Connected to the terminal electrode 5. The first inner conductor 111 includes a region that is electrically connected to the through-hole conductor 134 in a state where the nonmagnetic materials 24 and 25 are laminated on the other end of the first inner conductor 111. The first inner conductor 111 is located at the other end of the coil 30. The first inner conductor 111, that is, the other end of the coil 30 is electrically connected to the second terminal electrode 5. The first inner conductor 111 functions as a lead conductor.

  As described above, the first inner conductors 101 to 111 are electrically connected through the through-hole conductors 121 to 134 and the inner conductors 141 to 144. As a result, the first inner conductors 101 to 111 are electrically connected to each other to constitute the coil 30.

  As shown in FIG. 4, the multilayer filter according to the second embodiment further includes second inner conductors 151 to 154. The second inner conductors 151 to 154 have a substantially Y shape. The second inner conductors 151 to 154 are formed along the first inner conductors 101 to 111 when viewed from the stacking direction of the nonmagnetic materials 11 to 27 (hereinafter simply referred to as “stacking direction”). .

  The second inner conductor 151 is located on the nonmagnetic material 15. Accordingly, the second inner conductor 151 is disposed between the first inner conductor 104 and the first inner conductor 105 adjacent to each other in the stacking direction among the plurality of first inner conductors 101 to 111. Become. One end portion of the second inner conductor 151 is drawn to the side surface of the element body 1 (the side surface from which one end portion of the first inner conductor 101 is drawn) and is exposed to the side surface. Connected. The second inner conductor 151 overlaps the first inner conductor 104 when viewed in the stacking direction and is adjacent in the stacking direction, and the first inner conductor 105 overlaps when viewed from the stacking direction and is adjacent in the stacking direction Including. The second inner conductor 151 is not electrically connected to the second terminal electrode 5.

  The second inner conductor 152 is located on the nonmagnetic material 17. As a result, the second inner conductor 152 is disposed between the first inner conductor 105 and the first inner conductor 106 adjacent to each other in the stacking direction among the plurality of first inner conductors 101 to 111. Become. One end portion of the second inner conductor 152 is drawn to the side surface of the element body 1 (the side surface from which one end portion of the first inner conductor 111 is drawn) and exposed to the side surface. Connected. The second inner conductor 152 overlaps the first inner conductor 105 when viewed from the stacking direction and is adjacent in the stacking direction, and the first inner conductor 106 overlaps when viewed from the stacking direction and is adjacent in the stacking direction Including. The second inner conductor 152 is not electrically connected to the first terminal electrode 3.

  The second inner conductor 153 is located on the nonmagnetic material 19. Accordingly, the second inner conductor 153 is disposed between the first inner conductor 106 and the first inner conductor 107 adjacent to each other in the stacking direction among the plurality of first inner conductors 101 to 111. Become. One end portion of the second inner conductor 153 is drawn to the side surface of the element body 1 (the side surface from which the one end portion of the first inner conductor 101 is drawn) and exposed to the side surface. Connected. The second inner conductor 153 overlaps the first inner conductor 106 when viewed in the stacking direction and is adjacent in the stacking direction, and the first inner conductor 107 overlaps when viewed from the stacking direction and is adjacent in the stacking direction Including. The second inner conductor 153 is not electrically connected to the second terminal electrode 5.

  The second inner conductor 154 is located on the nonmagnetic material 21. Accordingly, the second inner conductor 154 is disposed between the first inner conductor 107 and the first inner conductor 108 adjacent to each other in the stacking direction among the plurality of first inner conductors 101 to 111. Become. One end portion of the second inner conductor 154 is drawn out to the side surface of the element body 1 (the side surface from which one end portion of the first inner conductor 111 is drawn) and is exposed to the side surface. Connected. The second inner conductor 152 overlaps the first inner conductor 107 when viewed from the stacking direction and is adjacent in the stacking direction, and the first inner conductor 108 overlaps when viewed from the stacking direction and is adjacent in the stacking direction Including. The second inner conductor 154 is not electrically connected to the first terminal electrode 3.

  The multilayer filter according to the second embodiment can be produced by a production method similar to the production method of the multilayer filter F, and the description thereof is omitted here.

  In the multilayer filter having the above-described configuration, as shown in FIG. 5, stray capacitance Cs is generated between the coil 30 (first inner conductors 101 to 111) and the second inner conductors 151 to 154. In FIG. 5, in order to differentiate the coil 30 (first inner conductors 101 to 111) and the second inner conductors 151 to 154 on the drawing, the second inner conductors 151 to 154 are represented by broken lines. Yes.

  As described above, in the multilayer filter according to the second embodiment, by having the above configuration, the attenuation is deep and the cutoff band is widened, so that the attenuation characteristic can be further improved.

  The present inventors consider as follows the factors that deepen the attenuation and widen the cutoff band and further improve the attenuation characteristics. The second inner conductors 151 and 153 that generate the stray capacitance Cs between the first inner conductors 101 to 111 are electrically connected to the first terminal electrode 3, and are connected to the first inner conductors 101 to 111. Since the second inner conductors 152 and 154 that generate the stray capacitance Cs between them are electrically connected to the second terminal electrode 5, the coil 30 constituted by the plurality of first inner conductors 101 to 111 is In addition, a portion where the stray capacitance Cs can be generated between the second inner conductors 151 to 154 and a portion where the stray capacitance Cs cannot be generated between the second inner conductors 151 to 154 are included. . For this reason, in the multilayer filter according to the second embodiment, a part of the coil 30 that can generate the stray capacitance Cs between the second inner conductors 151 to 154 and the stray capacitance Cs are connected in parallel. The resonance circuit and a series resonance circuit in which the portion of the coil 30 where the stray capacitance Cs cannot be generated between the second inner conductors 151 to 154 and the stray capacitance Cs are connected in series are configured. And the attenuation characteristic by a parallel resonance circuit and the attenuation characteristic by a series resonance circuit are synthesize | combined, and an attenuation characteristic with a deep attenuation | damping and a wide stop band is implement | achieved.

  In the second embodiment, the second inner conductors 151 to 154 are formed along the first inner conductors 101 to 111 when viewed from the stacking direction. Thereby, it can suppress that the 2nd inner conductor 151-154 inhibits the flux which generate | occur | produces in the coil 30, and can improve a high frequency characteristic.

  Here, it is specifically shown by Examples 1 and 2 and Comparative Example 1 that the attenuation characteristics can be further improved by this embodiment. In Examples 1 and 2 and Comparative Example 1, an insertion loss characteristic is obtained as a frequency characteristic.

  In Example 1, a multilayer filter having the same configuration as the multilayer filter F of the first embodiment was used. In Example 2, a multilayer filter having the same configuration as the multilayer filter of the second embodiment was used. In Comparative Example 1, a multilayer filter having the same configuration as the multilayer filter described in Patent Document 1 was used. All the multilayer filters of Examples 1 and 2 and Comparative Example 1 are designed so that the cutoff frequency is 100 MHz.

  The insertion loss characteristics of the multilayer filters of Examples 1 and 2 and Comparative Example 1 are shown in FIG. A solid line IL1 indicates the insertion loss characteristic of the multilayer filter of the first embodiment, and a broken line IL2 indicates the insertion loss characteristic of the multilayer filter of the second embodiment. A dashed line IL3 indicates the insertion loss characteristic of the multilayer filter of Comparative Example 1. The attenuation band, for example, the frequency band for holding −20 dB attenuation is 450 to 530 MHz in the multilayer filters of Examples 1 and 2, whereas it is 360 to 680 MHz in the multilayer filter of Comparative Example 1. From the above, the effectiveness of the present embodiment was confirmed.

  The preferred embodiments of the present invention have been described above, but the present invention is not necessarily limited to these embodiments.

  The second inner conductors 71 to 76 and 151 to 154 are formed along the first inner conductors 31 to 39 and 101 to 111 as viewed from the stacking direction, but are not limited thereto. For example, the second inner conductors 71 to 76 and 151 to 154 may be formed in a solid shape. When the second inner conductors 71 to 76 and 151 to 154 are formed in a solid shape, the flux generated in the coil 30 may be hindered. For this reason, it is preferable that the second inner conductors 71 to 76 and 151 to 154 are formed along the first inner conductors 31 to 39 and 101 to 111 when viewed from the stacking direction.

  The present invention can be applied to a multilayer filter array FA having a plurality of coils as shown in FIGS. In the multilayer filter array FA shown in FIGS. 7 to 9 as well as the multilayer filter F according to the first and second embodiments, the attenuation is deep and the cutoff band is widened, thereby further improving the attenuation characteristics. be able to. In FIGS. 8 and 9, only some of the components are given reference numerals because the drawings are difficult to see.

1 is a perspective view showing a multilayer filter according to a first embodiment. It is the block diagram which decomposed | disassembled and showed the element body contained in the multilayer filter which concerns on 1st Embodiment. It is a figure for demonstrating the equivalent circuit of the multilayer filter which concerns on 1st Embodiment. It is the block diagram which decomposed | disassembled and showed the element body contained in the multilayer filter which concerns on 2nd Embodiment. It is a figure for demonstrating the equivalent circuit of the multilayer filter which concerns on 2nd Embodiment. It is a diagram which shows the insertion loss characteristic of a multilayer filter. It is a perspective view which shows the multilayer filter array which concerns on this embodiment. It is the block diagram which decomposed | disassembled and showed the element body contained in the multilayer filter array which concerns on this embodiment. It is the block diagram which decomposed | disassembled and showed the element body contained in the multilayer filter array which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Element body, 3 ... 1st terminal electrode, 5 ... 2nd terminal electrode, 11-27 ... Nonmagnetic material, 30 ... Coil, 31-39 ... 1st internal conductor, 41-54 ... Through-hole conductor , 61-66 ... inner conductor, 71-76 ... second inner conductor, 81-90 ... through-hole conductor, 91-95 ... inner conductor, 101-111 ... first inner conductor, 121-134 ... through-hole conductor , 141 to 144, inner conductors, 151 to 154, second inner conductor, Cs, stray capacitance, F, multilayer filter, FA, multilayer filter array.

Claims (2)

A laminate in which a plurality of nonmagnetic materials are laminated;
A coil configured by electrically connecting a plurality of first inner conductors arranged in the stacking direction of the non-magnetic material in the stacked body;
A first terminal electrode formed in the laminate and electrically connected to one end of the coil;
A second terminal electrode formed in the laminate and electrically connected to the other end of the coil;
A second inner conductor disposed between first inner conductors adjacent to each other in the stacking direction among the plurality of first inner conductors and generating a stray capacitance with the first inner conductor. ,
The multilayer filter, wherein the second inner conductor is electrically connected to any one of the first and second terminal electrodes. 2. The multilayer filter according to claim 1, wherein the second inner conductor is formed along the first inner conductor when viewed from the laminating direction.

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