JP2007227473A - Stacked filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stacked filter capable of reducing variation in attenuation characteristics for a frequency between elements, even if a plurality of filter elements are juxtaposed. <P>SOLUTION: The stacked filter according to one embodiment here is provided with a base having a first region and a second region where a plurality of functional layers are stacked; four inductor conductors juxtaposed on the first region; and a plurality of internal electrodes arranged in the second region. The internal electrodes each have four first electrode conductors respectively connected to the four inductor conductors, and juxtaposed in a direction perpendicular to a stacking layer direction of the functional layers; and two second electrode conductors arranged for each two electrode conductor pairs respectively including a first electrode inductor positioned outside the juxtaposition direction of the four first electrode conductors and a first electrode conductor positioned inside thereof out of the four first electrode conductors, and extending so as to oppose the two first electrode conductors included in each electrode conductor pair. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multilayer filter including a plurality of filter elements.

The multilayer filter includes a filter element in which an inductor conductor and a capacitor electrode conductor are formed in an element body in which a plurality of functional layers having electrical insulation properties and electrical semiconductivity are laminated. Patent Document 1 describes a multilayer filter in which four filter elements are provided in parallel in an element body. In this multilayer filter, one capacitor electrode conductor extending in the direction in which the filter elements are provided is formed for the ground of four capacitors.
JP 2005-64267 A

  In the multilayer filter, since the composition component of the functional layer for the inductor conductor and the composition component of the functional layer for the capacitor electrode conductor are different, component diffusion occurs between these functional layers during firing. For example, the composition component of the functional layer for the capacitor electrode conductor having a dielectric constant larger than that of the functional layer for the inductor conductor diffuses into the functional layer for the inductor conductor. As a result, the dielectric constant of the functional layer for the inductor conductor increases, and the parasitic capacitance value between the inductor conductor and the capacitor electrode conductor increases.

  By the way, this component diffusion amount tends to increase from the side to the inside of the multilayer filter. Therefore, in the multilayer filter in which a plurality of filter elements are provided in parallel in the element body, when the number of capacitor electrode conductors is one as in the multilayer filter described in Patent Document 1, compared to the outer filter element. The amount of increase in the parasitic capacitance value between the inductor conductor and the capacitor electrode conductor increases as the inner filter element increases. As a result, in such a multilayer filter, element variation occurs in attenuation characteristics with respect to frequency.

  Therefore, an object of the present invention is to provide a multilayer filter that can reduce variation in attenuation characteristics with respect to frequency even when a plurality of filter elements are provided.

  The multilayer filter of the present invention includes (a) an element body in which a plurality of functional layers are laminated, and (b) four inductor conductors juxtaposed in a direction perpendicular to the lamination direction of the plurality of functional layers in the element body. And (c) a plurality of internal electrodes disposed in the element body so as to face each other in the stacking direction of the plurality of functional layers. (D) The element body has a first region in which the four inductor conductors are disposed and a second region in which the plurality of internal electrodes are disposed along the stacking direction of the plurality of functional layers. . (E) The plurality of internal electrodes are connected to any one of the different inductor conductors among the (e1) four inductor conductors, and are arranged in four directions arranged in a direction orthogonal to the stacking direction of the plurality of functional layers. (E2) Among the four first electrode conductors, the first electrode conductor located on the outer side in the juxtaposition direction of the four first electrode conductors and the first electrode located on the inner side A pair of second electrode conductors arranged for each of two electrode conductor pairs each including a conductor and extending so as to face the two first electrode conductors included in each electrode conductor pair, Have.

  According to this multilayer filter, the four first electrode conductors and the two second electrode conductors in the second region of the element body constitute a capacitor electrode conductor for four capacitors. The four first electrode conductors are connected to different ones of the four inductor conductors in the first region of the element body, so that four filter elements are provided in the element body. Is formed.

  The two second electrode conductors for the four capacitors are the first electrode conductors located on the outside of the four first electrode conductors in the juxtaposition direction of the four first electrode conductors. Since it is arranged for each of two electrode conductor pairs each including the first electrode conductor located on the inside, and extends so as to face the two first electrode conductors included in each electrode conductor pair, There is no electrode conductor between adjacent inner capacitors. Therefore, the inner filter element has a smaller amount of electric field coupling between the inductor conductor and the second electrode conductor for the capacitor than the outer filter element.

  Therefore, according to the multilayer filter, when the element body is fired, the second region functional layer for the capacitor electrode conductor having a higher dielectric constant than the functional layer of the first region for the inductor conductor When component diffusion occurs in the functional layer of the first region and the dielectric constant of the functional layer of the first region increases with an inclination that increases from the side to the inside of the multilayer filter, the inner filter The amount of electric field coupling between the inductor conductor and the second electrode conductor in the element can be made substantially the same as the amount of electric field coupling between the inductor conductor and the second electrode conductor in the outer filter element. As a result, the parasitic capacitance value between the inductor conductor and the second electrode conductor in the inner filter element is set to the same level as the parasitic capacitance value between the inductor conductor and the second electrode conductor in the outer filter element. be able to. Therefore, according to this multilayer filter, the element variation of the parasitic capacitance value is reduced, and the element variation of the attenuation characteristic with respect to the frequency is reduced.

  Another multilayer filter of the present invention includes: (a) an element body in which a plurality of functional layers are laminated; An inductor conductor (N is an even number of 4 or more), and (c) a plurality of internal electrodes disposed in the element body so as to face each other in the stacking direction of the plurality of functional layers. (D) The element body has a first region in which the N-type inductor conductor is disposed and a second region in which the plurality of internal electrodes are disposed along the stacking direction of the plurality of functional layers. . (E) The plurality of internal electrodes are connected to one of the different inductor conductors among (e1) N inductor conductors, and are arranged in an N-th array arranged in a direction orthogonal to the stacking direction of the plurality of functional layers. N / 2 electrodes each including one electrode conductor and (e2) two first electrode conductors adjacent to each other in the juxtaposition direction of the N first electrode conductors among the N first electrode conductors N / 2 second electrode conductors are provided for each electrode conductor pair and extend so as to face the two first electrode conductors included in each electrode conductor pair.

  According to this multilayer filter, the N first electrode conductor and the N / 2 second electrode conductor in the second region of the element body constitute the capacitor electrode conductor for the N capacitor. The N-type first electrode conductor is connected to one of the different inductor conductors among the N-type inductor conductors in the first region of the element body. A filter element is formed.

  The N / 2 second electrode conductors for the N capacitors are two first electrodes adjacent to each other in the juxtaposition direction of the N first electrode conductors among the N first electrode conductors. Since each of the N / 2 electrode conductor pairs each including the electrode conductor is arranged and extends so as to face the two first electrode conductors included in each electrode conductor pair, the adjacent second electrodes There is no electrode conductor between the electrode conductors. That is, there is a region where no electrode conductor exists in either one of the second electrode conductors in the inner filter element. Therefore, the inner filter element has a smaller amount of electric field coupling between the inductor conductor and the second electrode conductor for the capacitor than the filter element adjacent to the outer surface of the element body.

  Therefore, according to the multilayer filter, when the element body is fired, the second region functional layer for the capacitor electrode conductor having a higher dielectric constant than the functional layer of the first region for the inductor conductor When component diffusion occurs in the functional layer of the first region and the dielectric constant of the functional layer of the first region increases with an inclination that increases from the side to the inside of the multilayer filter, the inner filter The amount of electric field coupling between the inductor conductor and the second electrode conductor in the element can be made substantially the same as the amount of electric field coupling between the inductor conductor and the second electrode conductor in the filter element adjacent to the outer surface of the element body. As a result, the parasitic capacitance value between the inductor conductor and the second electrode conductor in the inner filter element is obtained as the parasitic capacitance value between the inductor conductor and the second electrode conductor in the filter element adjacent to the outer surface of the element body. It can be as much as the value. Therefore, according to this multilayer filter, the element variation of the parasitic capacitance value is reduced, and the element variation of the attenuation characteristic with respect to the frequency is reduced.

  As an example of the multilayer filter described above, the functional layer serving as the first region among the plurality of functional layers is made of a material having electrical insulation, and the functional layer serving as the second region among the plurality of functional layers is non-voltage-sensitive. There is a multilayer filter made of a material that exhibits linear characteristics. According to this configuration, a plurality of inductors are formed in the first region of the element body, and a plurality of varistors are formed in the second region of the element body, thereby providing a plurality of surge absorbing elements. A laminated surge absorbing component is constructed. According to this multilayer surge absorbing component, as described above, the element variation of the parasitic capacitance value between the inductor conductor and the second electrode conductor for the varistor is reduced, and the element variation of the attenuation characteristic with respect to the frequency is reduced. Is done.

  ADVANTAGE OF THE INVENTION According to this invention, even if it provides a some filter element in parallel, the multilayer filter which can reduce the element variation of the attenuation characteristic with respect to a frequency is provided.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

[First Embodiment]
FIG. 1 is a perspective view showing a multilayer filter according to a first embodiment of the present invention. A multilayer filter 10 shown in FIG. 1 is a multilayer filter array component in which four L-type filter elements each composed of an inductor and a capacitor are provided in parallel. The multilayer filter 10 includes a substantially rectangular parallelepiped element body 12, four pairs of terminal electrodes 14a and 16a, 14b and 16b, 14c and 16c, 14d and 16d, and a pair of ground terminal electrodes 18a and 18b. It is configured.

  The terminal electrodes 14a, 14b, 14c, and 14d are sequentially provided on the first surface 12a that is the side surface of the element body 12, and each have a shape that extends in the stacking direction of the element body 12. Similarly, the terminal electrodes 16a, 16b, 16c, and 16d are sequentially provided on the second surface 12b that is the side surface opposite to the first surface 12a with respect to the element body 12, and each of the laminated layers of the element bodies 12 is provided. It has a shape extending in the direction. That is, the terminal electrodes 14a, 14b, 14c, 14d and the terminal electrodes 16a, 16b, 16c, 16d each form a pair of terminal electrodes, and are provided on the outer surface of the element body 12 so as to face each other. .

  The ground terminal electrode 18a is provided at the center of the third surface 12c that is a side surface orthogonal to the first surface 12a and the second surface 12b with respect to the element body 12, and extends in the stacking direction of the element body 12. It has an extended shape. Similarly, the ground terminal electrode 18b is provided at the center of the fourth surface 12d, which is the side surface opposite to the third surface 12c with respect to the element body 12, and extends in the stacking direction of the element body 12. It has a shape. That is, the ground terminal electrode 18a and the ground terminal electrode 18b form a pair of ground terminal electrodes, and are provided on the outer surface of the element body 12 so as to face each other.

  A plurality of functional layers are stacked on the element body 12, and the element body 12 has a first region A and a second region B along the stacking direction of the plurality of function layers. In the first region A and the second region B in the element body 12, functional layers having different functions are laminated. Hereinafter, the configuration of the element body 12 will be described in detail.

  FIG. 2 is an exploded perspective view showing the element body shown in FIG. In the first region A of the element body 12, a plurality of functional layers 20, 21, 22, 23, 24, 25, 22, 23, and 26 are sequentially stacked. The functional layers 20 to 26 are made of a material having electrical insulation. For example, a ceramic material mainly composed of ZnO can be used as the material for the functional layers 20 to 26. The ceramic material constituting the functional layer may contain metal elements such as Pr, K, Na, Cs, and Rb as additives in addition to ZnO.

  A plurality of functional layers 27, 28, 29, and 30 are sequentially stacked in the second region B of the element body 12. The functional layers 27 to 30 are made of a dielectric material. In the present embodiment, the functional layers 27 to 30 are made of a dielectric material that exhibits voltage nonlinear characteristics. For example, a ceramic material mainly composed of ZnO can be used as the material for the functional layers 20 to 26. This ceramic material further contains at least one element selected from the group consisting of Pr and Bi, Co and Al as additives.

  Here, since the functional layers 27 to 30 contain Co in addition to Pr, the functional layers 27 to 30 have excellent voltage nonlinear characteristics and a high dielectric constant (ε). Moreover, since Al is further included, it becomes low resistance. The functional layers 27 to 30 may further contain metal elements other than those described above (for example, Cr, Ca, Si, K, etc.) as additives for the purpose of further improving the characteristics.

  In the actual element body 12, the functional layers 20 to 26 and the functional layers 27 to 30 are integrated to such an extent that the boundary between them cannot be visually recognized.

  Next, the configuration of the first region A of the element body 12 will be described in detail. Four conductor patterns 41, 42, 43, 44, 45, 42, 43, 46 are formed on one main surface of the plurality of functional layers 21, 22, 23, 24, 25, 22, 23, 26, respectively. It is provided one by one. The four conductor patterns 41 are juxtaposed in the direction orthogonal to the stacking direction of the functional layers 20 to 26 and in the opposing direction of the pair of ground terminal electrodes 18a to 18b. Similarly, four conductor patterns 42 to 46 are also juxtaposed in the facing direction of the pair of ground terminal electrodes 18a to 18b.

  The conductor patterns 41 and 46 are provided to lead out terminal electrodes, and the conductor patterns 42 to 45 are coiled to increase the inductance. In other words, the conductor patterns 42 to 45 have a U-shape formed along a substantially rectangular side.

  One end 41a of each of the four conductor patterns 41 is provided along one edge of the functional layer 21 forming a part of the first surface 12a shown in FIG. 1, and the terminal electrodes 14a, 14b, 14c, and 14d, respectively. The other ends 41b of the four conductor patterns 41 are respectively connected to one ends 42a of the four conductor patterns 42 via through-hole conductors. The other end 42b of the four conductor patterns 42 is connected to one end 43a of the four conductor patterns 43 via the through-hole conductors, and the other end 43b of the four conductor patterns 43 is connected to the through-hole conductors. To one end 44a of each of the four conductor patterns 44. The other ends 44b of the four conductor patterns 44 are respectively connected to one ends 45a of the four conductor patterns 45 through the through-hole conductors, and the other ends 45b of the four conductor patterns 45 are connected to the through holes. Each of the four conductor patterns 42 is connected to one end 42a via a conductor.

  Similarly, the other ends 42b of the four conductor patterns 42 are respectively connected to one ends 43a of the four conductor patterns 43 via through-hole conductors, and the other ends 43b of the four conductor patterns 43 are connected to the through holes. Each of the four conductor patterns 46 is connected to one end 46a via a hole conductor. The other ends 46b of the four conductor patterns 46 are provided along one edge of the functional layer 26 forming a part of the second surface 12b shown in FIG. 1, and the terminal electrode 16a shown in FIG. , 16b, 16c, and 16d.

  In this way, the conductor patterns 42 to 46 adjacent to each other in the stacking direction of the element body 12 are connected in series to form four inductor conductors 48a, 48b, 48c, and 48d.

  Next, the configuration of the second region B of the element body 12 will be described in detail. A plurality of internal electrodes 51, 52, 53, 54, 55, 56 are arranged between the functional layers 27-30 so as to face each other in the stacking direction of the functional layers 27-30. Specifically, four first electrode conductors 51, 52, 53, 54 are provided on one main surface of the functional layer 29, and two bodies are provided on one main surface of the functional layer 28. The second electrode conductors 55 and 56 are provided.

  The four first electrode conductors 51 to 54 are juxtaposed in the direction orthogonal to the stacking direction of the functional layers 27 to 30 and in the opposing direction of the pair of ground terminal electrodes 18a and 18b. The one ends 51a, 52a, 53a, 54a of the four first electrode conductors 51 to 54 are provided along one edge of the functional layer 29 that forms part of the second surface 12b shown in FIG. And connected to the terminal electrodes 16a, 16b, 16c, and 16d shown in FIG. That is, the one ends 51a to 54a of the four first electrode conductors 51 to 54 are connected to one ends of four different inductor conductors 48a to 48d, respectively.

  The other end 51 b of the first electrode conductor 51 and the other end 52 b of the first electrode conductor 52 are opposed to the second electrode conductor 55 in the stacking direction of the functional layers 27 to 30. That is, the first electrode conductor 51 located outside the juxtaposed direction of the first electrode conductors 51 to 54 and the first electrode conductor 52 located inside form one electrode conductor pair.

  Similarly, the other end 53b of the first electrode conductor 53 and the other end 54b of the first electrode conductor 54 face the second electrode conductor 56 in the stacking direction of the functional layers 27-30. That is, the first electrode conductor 54 located outside the juxtaposed direction of the first electrode conductors 51 to 54 and the first electrode conductor 53 located inside form one electrode conductor pair.

  In other words, the two second electrode conductors 55 and 56 are arranged for each of the two electrode conductor pairs described above, and the two first electrode conductors 51 and 52 included in each electrode conductor pair. The other end portions 51b and 52b and the other end portions 53b and 54b of the two first electrode conductors 53 and 54 extend in the facing direction of the pair of ground terminal electrodes 18a and 18b, respectively. One end 55a of the second electrode conductor 55 and one end 56a of the second electrode conductor 56 are separated from each other in a direction opposite to the pair of ground terminal electrodes 18a and 18b. That is, there is a region C where no electrode conductor exists between the second electrode conductor 55 and the second electrode conductor 56. The other end 55b of the second electrode conductor 55 is provided along one edge of the functional layer 28 that forms a part of the third surface 12c shown in FIG. 1, and is connected to the ground terminal electrode 18a shown in FIG. It is connected. Further, the other end 56b of the second electrode conductor 56 is provided along one edge of the functional layer 28 forming a part of the fourth surface 12d shown in FIG. 1, and the ground terminal electrode shown in FIG. 18b.

  In this way, the surge absorbing element 58a is formed by the one end portion 51b of the first electrode conductor 51, the part 55c of the second electrode conductor 55, and the functional layer 28 between them, and the first electrode A surge absorbing element 58b is formed by one end 52b of the conductor 52, a part 55d of the second electrode conductor 55, and the functional layer 28 therebetween. Similarly, a surge absorbing element 58c is formed by one end portion 53b of the first electrode conductor 53, a part 56c of the second electrode conductor 56, and the functional layer 28 therebetween, and the first electrode conductor 54 is formed. The surge absorbing element 58d is formed by the one end portion 54b, the part 56d of the second electrode conductor 56, and the functional layer 28 therebetween.

  FIG. 3 is a circuit diagram showing the multilayer filter according to the first embodiment. In the multilayer filter 10, four L-type filter elements each formed of inductor conductors 48a, 48b, 48c, 48d and surge absorbing elements 58a, 58b, 58c, 58d are formed.

Next, a method for manufacturing the multilayer filter 10 described above will be described. First, a plurality of inductor green sheets to be the functional layers 20 to 26 in the first region A of the element body 12 are prepared. These inductor green sheets are made of, for example, a slurry using a mixed powder of ZnO, Pr ₆ O ₁₁ , Cr ₂ O ₃ , CaCO ₃ , SiO ₂ and K ₂ CO ₃ as a raw material, for example, with a thickness of about 20 μm. It is formed by coating on a film by the doctor blade method.

In addition, a plurality of varistor green sheets to be the functional layers 27 to 30 in the second region B of the element body 12 are prepared. These varistor green sheets are made of, for example, a slurry using a mixed powder of ZnO, Pr ₆ O ₁₁ , CoO, Cr ₂ O ₃ , CaCO ₃ , SiO ₂ , K ₂ CO ₃ and Al ₂ O ₃ as a raw material. The film is formed on the film by a doctor blade method so that the thickness becomes about 30 μm.

  Subsequently, through holes are formed by laser processing or the like at predetermined positions of the inductor green sheets to be the functional layers 21 to 25 (that is, positions where through holes are to be formed with respect to the conductor patterns 41 to 46).

  Subsequently, conductor patterns 41 to 46 for the inductor conductors 48a to 48d are formed on the inductor green sheets to be the functional layers 21 to 26. The conductor patterns 41 to 46 are formed so as to have a thickness after firing of, for example, about 14 μm by screen-printing a conductor paste mainly composed of Ag and Pd on the inductor green sheet. The through-holes formed in the inductor green sheets serving as the functional layers 21 to 25 are filled with the conductor paste for the through-hole conductors by screen printing of the conductor paste on the inductor green sheets.

  In addition, conductor patterns corresponding to the second electrode conductors 55 and 56 and the first electrode conductors 51 to 54 are formed on the varistor green sheet to be the functional layers 28 and 29. This conductor pattern is formed by screen-printing a conductor paste mainly composed of Ag and Pd on a varistor green sheet, for example, so that the thickness after firing becomes about 3 μm.

  Subsequently, the inductor green sheets to be the functional layers 20 to 26 and the varistor green sheets to be the functional layers 27 to 30 are laminated in a predetermined order and are bonded and cut into chips. Thereafter, the element body 12 is obtained by firing at a predetermined temperature (for example, a temperature of about 1100 to 1200 ° C.).

  Subsequently, four pairs of terminal electrodes 14 a to 14 d and 16 a to 16 d and a pair of ground terminal electrodes 18 a and 18 b are formed on the outer surface of the element body 12 to complete the multilayer filter 10. The terminal electrodes 14a to 14d, the terminal electrodes 16a to 16d, and the ground terminal electrodes 18a and 18b are transferred to a predetermined temperature (for example, 700 ° C to 700 ° C) by transferring a conductive paste mainly composed of Ag onto the outer surface of the element body 12. 800 ° C.) and further electroplating using Ni / Sn, Cu / Ni / Sn, Ni / Au, Ni / Pd / Au, Ni / Pd / Ag, or Ni / Ag. And formed. The completed dimensions of the multilayer filter 10 are a length of 2.0 mm, a width of 1.0 mm, and a thickness of 0.8 mm (2010 type).

  By the way, when the element body 12 is fired, Co and Al in the functional layers 27 to 30 are diffused into the functional layers 20 to 26. As a result, the dielectric constants of the functional layers 20 to 26 are increased. Since this component diffusion amount tends to have a slope that increases from the side portion toward the inside of the element body 12, the magnitude of the dielectric constant of the functional layers 20 to 26 is determined by the side portions of the functional layers 20 to 26. There is a tendency to have a slope that increases from the inside toward the inside.

  FIG. 4 is a cross-sectional view of the element body taken along line III-III in FIG. FIG. 4A shows a cross-sectional view of the element body 12 in this embodiment, and FIG. 4B shows a cross-sectional view of a conventional element body 60.

  The conventional element body 60 shown in FIG. 4B has an element body 12 in that the element body 12 has one second electrode conductor 61 instead of the two second electrode conductors 55 and 56. It is different from the body 12. That is, the second electrode conductor 61 in the element body 60 is not separated and is a single electrode conductor. In such an element body 60, the electric field coupling areas 61a, 61b, 61c and 61d of the second electrode conductor 61 with respect to the four pairs of inductor conductors 48a to 48d have the same size. Therefore, in the element body 60, the electric field coupling amount, that is, the parasitic capacitance value between the inductor conductors 48b and 48c and the second electrode conductor 61 in the inner filter element, due to the above-described gradient characteristic of the dielectric constant, The amount of electric field coupling between the inductor conductors 48a and 48d and the second electrode conductor 61 in the element, that is, the parasitic capacitance value is increased.

  On the other hand, in the element body 12 of the present embodiment shown in FIG. 4A, the two second electrode conductors 55 and 56 are separated from each other, and the electrode conductor is interposed between the second electrode conductors 55 and 56. Therefore, the electric field coupling area 55f of the second electrode conductor 55 with respect to the inductor conductor 48b and the electric field coupling area 56e of the second electrode conductor 56 with respect to the inductor conductor 48c are the same as the second electrode with respect to the inductor conductor 48a. It is smaller than the electric field coupling area 55e of the conductor 55 and the electric field coupling area 56f of the second electrode conductor 56 with respect to the inductor conductor 48d. Therefore, in the element body 12, due to the above-described gradient characteristic of the dielectric constant, the electric field coupling amount, that is, the parasitic capacitance value between the inductor conductor 48 b and the second electrode conductor 55 in the inner filter element is set in the outer filter element. The amount of electric field coupling between the inductor conductor 48a and the second electrode conductor 55, that is, the parasitic capacitance value can be made approximately the same. Similarly, the amount of electric field coupling between the inductor conductor 48c and the second electrode conductor 56 in the inner filter element, that is, the parasitic capacitance value, is the amount of electric field coupling between the inductor conductor 48d and the second electrode conductor 56 in the outer filter element, that is, It can be set to the same level as the parasitic capacitance value.

  According to one measurement result of the capacitance values of the four surge absorbing elements including the parasitic capacitance, the capacitance values of the surge absorbing elements 62a, 62b, 62c, and 62d in the element body 60 are 16.99 pF and 18 respectively. .63 pF, 18.84 pF, and 16.49 pF (1 MHz / 1 V), while the capacitance values of the surge absorbing elements 58a, 58b, 58c, and 58d in the element body 12 are 16.49 pF and 16.49 pF, respectively. They were 62 pF, 16.65 pF, 16.33 pF (1 MHz / 1 V).

  FIG. 5 shows measurement results of attenuation characteristics in the multilayer filter of the present embodiment and the conventional multilayer filter. FIG. 5A shows the attenuation characteristic with respect to frequency in the multilayer filter 10 of the present embodiment, and FIG. 5B shows the attenuation characteristic with respect to frequency in the conventional multilayer filter using the element body 60. It is shown.

  A curve 65 in FIG. 5B is the attenuation characteristic of the outer filter element, and a curve 66 is the attenuation characteristic of the inner filter element. Thus, it can be seen that in the conventional multilayer filter, the attenuation characteristic of the inner filter element is lower than that of the outer filter element due to an increase in the parasitic capacitance value due to component diffusion.

  On the other hand, the curve 63 in FIG. 5A is the attenuation characteristic of the outer filter element, and the curve 64 is the attenuation characteristic of the inner filter element. As described above, in the multilayer filter 10, even if component diffusion occurs, the parasitic capacitance value of the inner filter element can be made comparable to the parasitic capacitance value of the outer filter element. Thus, it can be seen that the attenuation characteristics of the inner filter element are not deteriorated.

  Thus, according to the multilayer filter 10 of the present embodiment, an electrode conductor exists between the two second electrode conductors 55 and 56 for the four surge absorbing elements 58a, 58b, 58c, and 58d. Since there is a region C not to be processed, component diffusion occurs from the functional layers 27 to 30 in the second region B to the functional layers 20 to 26 in the first region A when the element body 12 is fired. When the dielectric constant of the functional layers 20 to 26 in the first region A increases with an inclination that increases from the side to the inside, the inductor conductor 48b and the second electrode conductor 55 in the inner filter element And the electric field coupling amount between the inductor conductor 48c and the second electrode conductor 56, and the electric field coupling amount between the inductor conductor 48a and the second electrode conductor 55 and the inductor conductor 48d in the outer filter element. It can be to the same extent as field coupling amount between the second electrode conductor 56.

  As a result, the parasitic capacitance value between the inductor conductor 48b and the second electrode conductor 55 and the parasitic capacitance value between the inductor conductor 48c and the second electrode conductor 56 in the inner filter element are determined in the outer filter element. The parasitic capacitance value between the inductor conductor 48 a and the second electrode conductor 55 and the parasitic capacitance value between the inductor conductor 48 d and the second electrode conductor 56 can be made comparable. Therefore, according to the multilayer filter 10 of the present embodiment, the element variation of the parasitic capacitance value is reduced, and the element variation of the attenuation characteristic with respect to the frequency is reduced.

[Second Embodiment]
Next, a multilayer filter 10A according to a second embodiment of the present invention will be described. The multilayer filter 10A is a multilayer filter array component in which four π-type filter elements are provided in parallel. The multilayer filter 10A is different from the first embodiment in that the multilayer filter 10A includes an element body 12A instead of the element body 12 in FIG. The other configuration of the multilayer filter 10A is the same as that of the first embodiment.

  FIG. 6 is an exploded perspective view showing the element body according to the second embodiment in an exploded manner for each layer. The element body 12A is different from the first embodiment in that the element body 12 further includes functional layers 70 and 71 between the functional layer 29 and the functional layer 30 in the element body 12. The other configuration of the element body 12A is the same as that of the first embodiment.

  The functional layers 70 and 71 are made of the same material as the functional layers 27 to 30. A plurality of internal electrodes 72, 73, 74, 75, 76, 77 are disposed on the main surfaces of the functional layers 70, 71 so as to face each other in the stacking direction of the functional layers 27-30. Specifically, four first electrode conductors 72, 73, 74, and 75 are provided on one main surface of the functional layer 71, and two bodies are provided on one main surface of the functional layer 70. The second electrode conductors 76 and 77 are provided.

  The four first electrode conductors 72 to 75 are juxtaposed in the facing direction of the pair of ground terminal electrodes 18a and 18b. The one ends 72a, 73a, 74a, and 75a of the four first electrode conductors 72 to 75 are respectively provided along one edge of the functional layer 71 that forms a part of the second surface 12b shown in FIG. Are connected to the terminal electrodes 14a, 14b, 14c, and 14d shown in FIG. That is, the one ends 72a to 75a of the four first electrode conductors 72 to 75 are respectively connected to one ends of four different inductor conductors 48a to 48d.

  The other end portion 72b of the first electrode conductor 72 and the other end portion 73b of the first electrode conductor 73 are opposed to the second electrode conductor 76 in the stacking direction of the functional layers 27-30. That is, the first electrode conductor 72 positioned outside the juxtaposed direction of the first electrode conductors 72 to 75 and the first electrode conductor 73 positioned inside form one electrode conductor pair.

  Similarly, the other end portion 74b of the first electrode conductor 74 and the other end portion 75b of the first electrode conductor 75 are opposed to the second electrode conductor 77 in the stacking direction of the functional layers 27-30. In other words, the first electrode conductor 75 located outside the juxtaposed direction of the first electrode conductors 72 to 75 and the first electrode conductor 74 located inside form one electrode conductor pair.

  In other words, the two second electrode conductors 76 and 77 are arranged for each of the two electrode conductor pairs described above, and the two first electrode conductors 72 and 73 included in each electrode conductor pair. The other end portions 72b and 73b and the other end portions 74b and 75b of the two first electrode conductors 74 and 75 extend in the facing direction of the pair of ground terminal electrodes 18a and 18b, respectively. One end 76a of the second electrode conductor 76 and one end 77a of the second electrode conductor 77 are separated from each other in the opposing direction of the pair of ground terminal electrodes 18a and 18b. That is, there is a region D where no electrode conductor exists between the second electrode conductor 76 and the second electrode conductor 77. The other end 76b of the second electrode conductor 76 is provided along one edge of the functional layer 70 that forms a part of the third surface 12c shown in FIG. 1, and is connected to the ground terminal electrode 18a shown in FIG. It is connected. Further, the other end 77b of the second electrode conductor 77 is provided along one edge of the functional layer 70 that forms a part of the fourth surface 12d shown in FIG. 1, and the ground terminal electrode shown in FIG. 18b.

  In this way, the surge absorbing element 78a is formed by the one end 72b of the first electrode conductor 72, the part 76c of the second electrode conductor 76, and the functional layer 70 therebetween, and the first electrode A surge absorbing element 78a is formed by one end 73b of the conductor 73, a part 76d of the second electrode conductor 76, and the functional layer 70 therebetween. Similarly, a surge absorbing element 78c is formed by the one end 74b of the first electrode conductor 74, a part 74c of the second electrode conductor 74, and the functional layer 70 therebetween, and the first electrode conductor 75 is formed. A surge absorbing element 78d is formed by the one end portion 75b of the second electrode conductor 77, a part 77d of the second electrode conductor 77, and the functional layer 70 therebetween.

  FIG. 7 is a circuit diagram showing the multilayer filter according to the second embodiment. The multilayer filter 10A includes four π-type filters each comprising inductor conductors 48a, 48b, 48c, 48d, surge absorbing elements 58a, 58b, 58c, 58d, and surge absorbing elements 78a, 78b, 78c, 78d. An element is formed.

  According to the multilayer filter 10A of the present embodiment, in addition to the advantages of the multilayer filter 10 of the first embodiment, two second filters for the four surge absorbing elements 78a, 78b, 78c, and 78d are used. Since there is a region D in which no electrode conductor exists between the electrode conductors 76 and 77, the parasitic capacitance value between the inductor conductor 48b and the second electrode conductor 76 in the inner filter element when the element body 12A is fired. In addition, the parasitic capacitance value between the inductor conductor 48c and the second electrode conductor 77 is equal to the parasitic capacitance value between the inductor conductor 48a and the second electrode conductor 76 in the inner filter element, and the second and second inductor conductors 48d and 48. The parasitic capacitance value between the first electrode conductor 77 and the second electrode conductor 77 can be made approximately the same. Therefore, according to the multilayer filter 10A of the present embodiment, as in the multilayer filter 10 of the first embodiment, the element variation of the parasitic capacitance value is reduced, and the element variation of the attenuation characteristic with respect to the frequency is reduced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made.

  In the present embodiment, a multilayer filter including four filter elements has been illustrated, but the idea of the present invention can be applied to a multilayer filter including four or more filter elements.

  In the present embodiment, the L-type multilayer filter and the π-type multilayer filter are exemplified. However, the idea of the present invention can be applied to a T-type multilayer filter.

  In the present embodiment, a multilayer filter having an inductor and a surge absorbing element has been exemplified. However, the concept of the present invention can be applied to a general multilayer filter having an inductor and a capacitor.

1 is a perspective view showing a multilayer filter according to a first embodiment of the present invention. It is a disassembled perspective view which decomposes | disassembles and shows the element body shown in FIG. 1 for every layer. 1 is a circuit diagram showing a multilayer filter according to a first embodiment. FIG. 3 shows a cross-sectional view of the element body along the line III-III in FIG. 1. It is a measurement result of the attenuation characteristic in a multilayer filter. It is a measurement result of the attenuation characteristic in the multilayer filter of this embodiment and the conventional multilayer filter. It is a circuit diagram which shows the multilayer filter which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Multilayer filter, 12 ... Element body, 14a-14d, 16a-16d ... Terminal electrode, 18a, 18b ... Ground terminal electrode, 20-30 ... Functional layer, 41-46 ... Conductor pattern, 48a-48d ... Inductor conductor 51-54 ... 1st electrode conductor (internal electrode), 55, 56 ... 2nd electrode conductor (internal electrode), 58a-58d ... Surge absorption element, A ... 1st area | region, B ... 2nd area | region .

Claims (3)

An element body in which a plurality of functional layers are laminated;
In the element body, four inductor conductors juxtaposed in a direction orthogonal to the stacking direction of the plurality of functional layers;
A plurality of internal electrodes disposed in the element body so as to face each other in the stacking direction of the plurality of functional layers;
The element body includes a first region in which the four inductor conductors are disposed and a second region in which the plurality of internal electrodes are disposed along a stacking direction of the plurality of functional layers. And
The plurality of internal electrodes are:
Four first electrode conductors connected to one of different inductor conductors among the four inductor conductors and juxtaposed in a direction perpendicular to the stacking direction of the plurality of functional layers;
Of the four first electrode conductors, two electrodes each including a first electrode conductor located outside in the juxtaposition direction of the four first electrode conductors and a first electrode conductor located inside Two second electrode conductors arranged for each conductor pair and extending so as to face the two first electrode conductors included in each of the electrode conductor pairs,
Multilayer filter. An element body in which a plurality of functional layers are laminated;
In the element body, N inductor conductors (N is an even number of 4 or more) juxtaposed in a direction orthogonal to the stacking direction of the plurality of functional layers;
A plurality of internal electrodes disposed in the element body so as to face each other in the stacking direction of the plurality of functional layers;
The element body includes a first region in which the N inductor conductors are disposed and a second region in which the plurality of internal electrodes are disposed along a stacking direction of the plurality of functional layers. And
The plurality of internal electrodes are:
N first electrode conductors connected to any one of the N inductor conductors different from each other and juxtaposed in a direction perpendicular to the stacking direction of the plurality of functional layers;
Of the N first electrode conductors, N / 2 electrode conductor pairs each including two first electrode conductors adjacent in the juxtaposition direction of the N first electrode conductors are arranged. And N / 2 second electrode conductors each extending so as to face the two first electrode conductors included in each of the electrode conductor pairs,
Multilayer filter. Of the plurality of functional layers, the functional layer serving as the first region is made of a material having electrical insulation,
Of the plurality of functional layers, the functional layer serving as the second region is made of a material that exhibits voltage nonlinear characteristics.
The multilayer filter according to claim 1 or 2.

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