Multilayer Filter

Abstract

To provide a laminated filter capable of improving performance.SOLUTION: A laminated filter 1 comprises a wall 13 which is disposed and grounded between a first inductor 11 and a second inductor 12. Therefore, electromagnetic coupling between the first inductor 11 and the second inductor 12 can be suppressed. A penetration part 30 penetrating in an opposing direction, in which the first inductor 11 and the second inductor 12 are opposed, is formed in the wall 13. In a lamination direction, a size of the penetration part 30 is larger than a size of one insulator layer 7. The wall 13 includes the large penetration part 30 to make a magnetic flux of the second inductor 12 which is a longitudinally wound inductor pass from the penetration part 30. Therefore, it is possible to suppress disturbance of the magnetic flux of the second inductor 12 to enhance a Q-value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a multilayer filter. [Background technology]

[0002] Known technology relating to conventional multilayer filters is that described in Patent Document 1. This multilayer filter includes one inductor and another inductor, and the characteristics are adjusted by removing the ground pattern between them to provide an opening. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-41141 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in multilayer filters, vertically wound inductors are sometimes used to obtain high in-band insertion characteristics. Vertically wound inductors are arranged so that their winding axis extends in a direction perpendicular to the lamination direction. Vertically wound inductors are prone to electromagnetic coupling with adjacent inductors, which can reduce various characteristics. On the other hand, if a grounded wall or other part is placed between inductors, the magnetic flux of the vertically wound inductor can be obstructed. For these reasons, there has been a demand for a solution to these various problems and an improvement in the performance of multilayer filters.

[0005] The present invention has been made to solve the above problems, and an object of the present invention is to provide a laminated filter that can improve performance. [Means for solving the problem]

[0006] A multilayer filter according to one embodiment of the present invention comprises an element body formed by stacking a plurality of insulator layers, a first inductor, a second inductor, and a wall portion disposed between the first inductor and the second inductor and grounded, wherein at least the second inductor is a vertically wound inductor whose winding axis extends in a direction perpendicular to the stacking direction in which the plurality of insulator layers are stacked, and a through portion is formed in the wall portion that penetrates in the opposing direction in which the first inductor and the second inductor face each other, and the size of the through portion in the stacking direction is larger than the size of one insulator layer.

[0007] In this multilayer filter, at least the second inductor is a vertically wound inductor whose winding axis extends in a direction perpendicular to the lamination direction in which the multiple insulator layers are stacked. Using such a vertically wound coil enables the multilayer filter to achieve high in-band insertion loss characteristics. The multilayer filter also includes a wall portion disposed between the first inductor and the second inductor and grounded. This suppresses electromagnetic coupling between the first inductor and the second inductor. The wall portion has a through-hole formed therein, penetrating the first inductor and the second inductor in the opposing direction. In addition, the size of the through-hole in the lamination direction is larger than the size of one insulator layer. The large through-hole in the wall portion allows the magnetic flux of the second inductor, which is a vertically wound inductor, to pass through the through-hole. This suppresses interference with the magnetic flux of the second inductor, improving the Q value. As a result, the performance of the multilayer filter can be improved.

[0008] A terminal electrode may be formed on one side of the element body in the stacking direction, and the wall portion may have a first portion on one side of the through portion in the stacking direction and a second portion on the other side of the through portion in the stacking direction, the first portion being larger than the second portion in the stacking direction. Since the terminal electrode is formed on one side of the element body in the stacking direction, many electrodes are present. Therefore, by enlarging the first portion on one side of the wall portion in the stacking direction, it is possible to suppress the generation of stray capacitance between the electrodes on one side and the other side of the wall portion.

[0009] The first inductor and the second inductor may be in different bands, in which case the wall portion can suppress coupling between the inductors in the different bands.

[0010] One of the first inductor and the second inductor may be a high-band inductor, and the other may be a mid-band inductor. In this case, degradation of isolation characteristics, which is a problem in so-called multiplexers, can be suppressed.

[0011] A terminal electrode may be formed on one side of the element body in the stacking direction, the wall portion may have a second portion on the other side of the through portion in the stacking direction, and the second inductor may have a wiring portion arranged on the other side in the stacking direction, the wiring portion overlapping the second portion when viewed from the opposing direction. In this case, electromagnetic coupling between the wiring portion of the second inductor and the first inductor can be suppressed. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a laminated filter that can improve performance. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view showing a multilayer filter according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the internal structure of the element body shown in FIG. [Figure 3] FIG. 3 is a perspective view showing the internal structure of the element body shown in FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a schematic diagram of the wall portion as viewed from the X-axis direction. [Figure 6] 10 is a plan view of the first inductor, the second inductor, and the wall portion as viewed from the positive side in the Z-axis direction. FIG. [Figure 7] FIG. 7 is a perspective view showing the internal structure of a multilayer filter according to a comparative example. [Figure 8]FIG. 7 is a perspective view showing the internal structure of a multilayer filter according to a comparative example. [Figure 9] FIG. 9(a) shows the measurement results of Comparative Example 1, FIG. 9(b) shows the measurement results of Comparative Example 2, and FIG. 9(c) shows the measurement results of the Example. [Figure 10] FIG. 10(a) shows the measurement results of Comparative Example 1, FIG. 10(b) shows the measurement results of Comparative Example 2, and FIG. 10(c) shows the measurement results of the Example. [Figure 11] FIG. 11(a) shows the measurement results of Comparative Example 1, FIG. 11(b) shows the measurement results of Comparative Example 2, and FIG. 11(c) shows the measurement results of the Example. [Figure 12] FIG. 12 shows the simulation results for Comparative Example 1, Comparative Example 2, and Example. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a multilayer filter according to one aspect of the present invention will now be described in detail with reference to the drawings.

[0015] First, the configuration of a multilayer filter 1 (electronic component) according to this embodiment will be described with reference to FIGS.

[0016] Fig. 1 is a perspective view showing a multilayer filter 1 according to one embodiment. An example of the multilayer filter 1 is a multiplexer. As shown in Fig. 1, the multilayer filter 1 has an element body 2 and terminal electrodes 3, 4, and 6 (terminals).

[0017] The element body 2 has a rectangular parallelepiped shape. The element body 2 has, as its outer surfaces, a pair of side surfaces 2a, 2b facing each other, a pair of principal surfaces 2c, 2d extending to connect the pair of side surfaces 2a, 2b and facing each other, and a pair of side surfaces 2e, 2f extending to connect the pair of principal surfaces 2c, 2d and facing each other. The principal surface 2d is defined as the surface that faces another electronic device (not shown, for example) when the multilayer filter 1 is mounted on the other electronic device (e.g., a circuit board or an electronic component).

[0018] The opposing directions of the side surfaces 2a and 2b, the opposing directions of the main surfaces 2c and 2d, and the opposing directions of the side surfaces 2e and 2f are substantially perpendicular to one another. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. The multilayer filter 1 may be described using an XYZ coordinate system. The X-axis direction is the opposing direction of the side surfaces 2e and 2f. The Y-axis direction is the opposing direction of the side surfaces 2a and 2b. The Z-axis direction is the opposing direction of the main surfaces 2c and 2d. The side surface 2e is located on the positive side of the X-axis direction, and the side surface 2f is located on the negative side of the X-axis direction. The side surface 2a is located on the positive side of the Y-axis direction, and the side surface 2b is located on the negative side of the Y-axis direction. The main surface 2c is located on the positive side of the Z-axis direction, and the main surface 2d is located on the negative side of the Z-axis direction.

[0019] As shown in FIG. 4, the element body 2 is formed, for example, by stacking multiple insulator layers 7. Each insulator layer 7 is stacked in the Z-axis direction. That is, the stacking direction of each insulator layer 7 coincides with the opposing direction of the main surfaces 2c, 2d of the element body 2. Hereinafter, the opposing direction of the main surfaces 2c, 2d may also be referred to as the "stacking direction." Each insulator layer 7 has a substantially rectangular shape. In an actual element body 2, the insulator layers 7 are integrated to the extent that the boundaries between them (shown by two-dot chain lines in the figure) are not visible. Each insulator layer 7 corresponds to one ceramic green sheet before firing.

[0020] Each insulating layer 7 is made of, for example, a sintered ceramic green sheet containing a dielectric material (BaTiO3-based material, Ba(Ti,Zr)O3-based material, (Ba,Ca)TiO3-based material, glass material, alumina material, or the like).

[0021] As shown in FIG. 1, each of the terminal electrodes 3, 4, and 6 is disposed on the principal surface 2d on the negative side in the Z-axis direction (one side in the stacking direction). The terminal electrode 3 is disposed on the principal surface 2d near corners on the negative side in the Y-axis direction and the negative side in the X-axis direction. The terminal electrode 4 is disposed on the principal surface 2d at a position adjacent to the terminal electrode 3 on the positive side in the X-axis direction. The terminal electrode 6 is disposed on the principal surface 2d at a position adjacent to the terminal electrode 3 on the positive side in the Y-axis direction. Of the terminal electrodes 3, 4, and 6, the terminal electrode 3 is an output terminal, and the terminal electrodes 4 and 6 are ground terminals.

[0022] Each of the terminal electrodes 3, 4, and 6 (hereinafter sometimes simply referred to as an electrode) contains a conductive material (such as Ag or Pd). The electrode is formed as a sintered body of a conductive paste containing a conductive material (such as Ag powder or Pd powder). A plating layer is formed on the surface of the electrode. The plating layer is formed, for example, by electroplating. The plating layer has a layer structure consisting of a Cu plating layer, a Ni plating layer, and a Sn plating layer, or a layer structure consisting of a Ni plating layer and a Sn plating layer.

[0023] 2 and 3 are perspective views showing the internal structure of the element body 2 shown in FIG. 1. The element body 2 is omitted from FIGS. 2 and 3. FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. 2. Note that the element body 2 is not omitted from FIG. 4. As shown in FIGS. 2 and 3, the multilayer filter 1 includes a first inductor 11, a second inductor 12, a wall portion 13, and a connection structure 14. Note that other conductors are omitted from FIGS. 2 and 3.

[0024] First inductor 11 is a flat-wound inductor. A flat-wound inductor is an inductor whose winding axis CL1 extends parallel to the Z-axis direction (stacking direction). First inductor 11 is configured by winding a conductor portion in a substantially rectangular ring shape around winding axis CL1. Specifically, first inductor 11 has sides 11A, 11B, 11C, 11D, and 11E. Side 11A extends in the Y-axis direction from a position on the negative side of the X-axis direction with respect to winding axis C1. Side 11B extends from an end of side 11A to the positive side of the X-axis direction with respect to winding axis C1. Side 11C extends from an end of side 11B to the negative side of the Y-axis direction with respect to winding axis C1. Side 11D extends from the end of side 11C toward the negative side in the X direction, at a position on the negative side of the Y direction relative to winding axis C1. Side 11F extends from the end of side 11D toward the positive side in the Y direction, at a position on the negative side of the X direction relative to winding axis C1.

[0025] Sides 11A, 11B, and 11C are formed by conductor patterns 18 formed on the same insulator layer 7 (see FIG. 4). Sides 11D and 11E are formed by conductor patterns 19 formed on the insulator layer 7 on the positive side in the Z-axis direction of conductor pattern 18. The conductor pattern 18 is connected at an end of side 11C on the negative side in the Y-axis direction to an end of conductor pattern 19 on the positive side in the X-axis direction of side 11D via a through-hole conductor. The first inductor 11 has a pair of conductor patterns 18 and 19 of the same shape that face each other in the Z-axis direction. The pair of conductor patterns 18 are electrically connected to each other at both ends via through-hole conductors. The pair of conductor patterns 19 are electrically connected to each other at both ends via through-hole conductors.

[0026] The first inductor 11 is electrically connected to the connection structure 14 via a pillar 16 at the end of the side 11A on the negative side in the Y-axis direction. The first inductor 11 is electrically connected to the connection structure 14 via a pillar 17 at the end of the side 11E on the positive side in the Y-axis direction. The pillars 16 and 17 extend from the end of the first inductor 11 to the negative side in the Z-axis direction. The pillars 16 and 17 are formed by continuously connecting through-hole conductors that penetrate each insulator layer 7 (see FIG. 4) in the Z-axis direction.

[0027] The second inductor 12 is a vertically wound inductor. A vertically wound inductor is an inductor whose winding axis CL2 extends in a direction perpendicular to the Z-axis direction (stacking direction). In this embodiment, the winding axis CL2 extends parallel to the X-axis direction. The second inductor 12 is formed by winding a conductor portion in a gate shape around the winding axis CL2. Specifically, the second inductor 12 includes a wiring portion 20 and pillar portions 21 and 22. The number of turns of the vertically wound inductor is not particularly limited, and may be two or more turns.

[0028] Wiring portion 20 extends in the Y-axis direction at a position on the positive side of winding axis CL2 in the Z-axis direction. Wiring portion 20 is composed of conductor patterns 23 formed on insulator layer 7 (see FIG. 4). Wiring portion 20 has a pair of conductor patterns 23 of the same shape facing each other in the Z-axis direction. The pair of conductor patterns 23 are electrically connected to each other at both ends via through-hole conductors.

[0029] Pillar portion 21 extends in the Z-axis direction at a position on the negative side in the Y-axis direction relative to winding axis CL2. Pillar portion 21 electrically connects the end of wiring portion 20 on the negative side in the Y-axis direction to connection structure 14. Pillar portion 21 is a member extending from the end of wiring portion 20 on the negative side in the Y-axis direction toward the negative side in the Z-axis direction. Pillar portion 22 extends in the Z-axis direction at a position on the positive side in the Y-axis direction relative to winding axis CL2. Pillar portion 22 electrically connects the end of wiring portion 20 on the positive side in the Y-axis direction to connection structure 14. Pillar portion 22 is a member extending from the end of wiring portion 20 on the positive side in the Y-axis direction toward the negative side in the Z-axis direction.

[0030] Here, the first inductor 11 and the second inductor 12 are in different bands. In this embodiment, one of the first inductor 11 and the second inductor is a high-band inductor, and the other is a mid-band inductor. A high-band inductor is an inductor that corresponds to a frequency band of 5150 to 7125 MHz. A mid-band inductor is an inductor that corresponds to a frequency band of 2400 to 2500 MHz. Note that in this embodiment, the first inductor 11 is a mid-band inductor, and the second inductor 12 is a high-band inductor, but this is not particularly limited. Also, the first inductor 11 and the second inductor 12 may be inductors in the same band.

[0031] The wall 13 is a grounded member disposed between the first inductor 11 and the second inductor 12. The thickness direction of the wall 13 is the X-axis direction in which the first inductor 11 and the second inductor 12 face each other, and the wall 13 extends parallel to the YZ plane. The wall 13 includes pillars 26 and 27 and a wall panel member 28.

[0032] The pillar portion 26 extends in the Z-axis direction from the end portion on the negative side in the Y-axis direction of the wall portion 13. The pillar portion 26 is electrically connected to the connection structure 14 at the end portion on the negative side in the Z-axis direction. The pillar portion 27 extends in the Z-axis direction from the end portion on the positive side in the Y-axis direction of the wall portion 13. The pillar portion 27 is electrically connected to the connection structure 14 at the end portion on the negative side in the Z-axis direction.

[0033] Wall plate member 28 extends in the Y-axis direction between pillar portion 26 and pillar portion 27. Wall plate member 28 is configured by a conductive pattern 29 formed on insulator layer 7 (see FIG. 4). Wall plate member 28 has a plurality of conductive patterns 29 of the same shape that face each other in the Z-axis direction. The plurality of conductive patterns 29 are electrically connected to each other at both ends via pillar portions 26, 27.

[0034] The wall portion 13 has a through portion 30 formed therein that penetrates in the X-axis direction, which is the opposing direction in which the first inductor 11 and the second inductor 12 face each other. The through portion 30 is formed by omitting the conductor pattern 29 from a portion of the wall plate member 28 in the Z-axis direction. The wall portion 13 has a first portion 31 on the negative side (one side) of the through portion 30 in the Z-axis direction (stacking direction), and a second portion 32 on the positive side (the other side) of the through portion 30 in the Z-axis direction (stacking direction). In the Z-axis direction, the first portion 31 is larger than the second portion.

[0035] The edge of the through portion 30 in the Z-axis direction corresponds to the conductor pattern 29 on the most positive side in the Z-axis direction in the first portion 31, and the conductor pattern 29 on the most negative side in the Z-axis direction in the second portion 32. The edge of the through portion 30 in the Y-axis direction corresponds to the pillar portion 26 and the pillar portion 27.

[0036] The connection structure 14 is a structure for electrically connecting the first inductor 11, the second inductor 12, and the wall portion 13 to the terminal electrodes 3, 4, and 6. The connection structure 14 is also a structure for forming multiple capacitors. The connection structure 14 has multiple plate-shaped internal electrodes. The lower ends of the pillar portions 16 connected to the first inductor 11 are directly connected to the internal electrode 41. An internal electrode 42A is provided on the negative side of the internal electrode 41 in the Z-axis direction. An internal electrode 42B is provided on the positive side of the internal electrode 41 in the Z-axis direction. The internal electrode 42A is directly connected to the terminal electrode 3 by a through-hole conductor. The internal electrode 42B is directly connected to the internal electrode 42A by a through-hole conductor.

[0037] The lower end of the pillar portion 17 connected to the first inductor 11 is directly connected to the internal electrode 43A. An internal electrode 43B is provided on the negative side of the internal electrode 43A in the Z-axis direction. The internal electrode 43B is directly connected to the internal electrode 43A and the terminal electrode 6 by a through-hole conductor. An internal electrode 43A is provided between the internal electrodes 41 and 42B. An internal electrode 43B is provided between the internal electrodes 43A and 43B. The internal electrode 43B is directly connected to the internal electrode 43A by a through-hole conductor. The internal electrode 43B is integrated with the second conductor pattern 29 from the negative side of the wall portion 13 in the Z-axis direction. An internal electrode 43C extends from the first conductor pattern 29 from the negative side of the wall portion 13 in the Z-axis direction. The internal electrode 43C is directly connected to the terminal electrode 4 by a through-hole conductor.

[0038] The lower ends of the pillar portions 21 of the second inductor 12 are directly connected to the internal electrode 44A. The internal electrode 44A faces the internal electrode 43C on the positive side in the Z-axis direction. The lower ends of the pillar portions 22 of the second inductor 12 are directly connected to the internal electrode 44B. The internal electrode 44B faces the internal electrode 44A on the positive side in the Z-axis direction.

[0039] Next, the positional relationship between the first inductor 11, the second inductor 12, and the wall portion 13 will be described in more detail with reference to Figures 4 to 6. Figure 5 is a schematic diagram of the wall portion 13 as viewed from the X-axis direction. Figure 6 is a plan view of the first inductor 11, the second inductor 12, and the wall portion 13 as viewed from the positive side in the Z-axis direction.

[0040] 4, the wall plate member 28 of the wall portion 13 is composed of conductor patterns 29 provided on each insulator layer 7. Therefore, the conductor patterns 29 are spaced apart in the Z-axis direction, forming gaps. However, because the multilayer filter 1 is a component that handles high frequencies, the wall plate member 28 electrically and magnetically separates the first inductor 11 and the second inductor 12.

[0041] In contrast, the size of through portion 30 in the Z-axis direction is larger than the size of one insulator layer 7. As shown in FIG. 5, size L1 of through portion 30 in the Z-axis direction is larger than the size of first inductor 11 and the size of wiring portion 20 of second inductor 12. When viewed from the X-axis direction, through portion 30 is positioned and sized to overlap winding axis CL2 of second inductor 12. Although not particularly limited, size L1 of through portion 30 in the Z-axis direction may be set to approximately 0.1 to 0.5 mm.

[0042] When viewed from the X-axis direction, the wiring portion 20 of the second inductor 12 overlaps the second portion 32 of the wall portion 13. When viewed from the X-axis direction, the entire area of ​​the wiring portion 20 of the second inductor 12 overlaps the second portion 32 of the wall portion 13. When viewed from the X-axis direction, the first inductor 11 overlaps the second portion 32 of the wall portion 13. When viewed from the X-axis direction, the entire area of ​​the first inductor 11 overlaps the second portion 32 of the wall portion 13. The pillar portion 21 of the second inductor 12 is located at a position on the positive side of the end of the wall portion 13 on the negative side in the Y-axis direction. When viewed from the X-axis direction, the pillar portion 21 of the second inductor 12 is located at a position overlapping the pillar portion 26 of the wall portion 13. When viewed from the X-axis direction, the pillar portion 22 of the second inductor 12 is located near the center position of the wall portion 13.

[0043] 6, the side 11C of the first inductor 11 is disposed at a position spaced apart from the wall 13 on the negative side in the X-axis direction. The wiring portion 20 of the second inductor 12 is disposed at a position spaced apart from the wall 13 on the positive side in the X-axis direction. The side 11C of the first inductor 11 is disposed at a position closer to the wall 13 than the wiring portion 20 of the second inductor 12.

[0044] Next, the functions and effects of the multilayer filter 1 according to this embodiment will be described.

[0045] In this multilayer filter 1, at least the second inductor 12 is a vertically wound inductor whose winding axis CL2 extends in a direction perpendicular to the lamination direction in which the multiple insulator layers 7 are laminated. The use of such a vertically wound coil enables the multilayer filter 1 to achieve high in-band insertion loss characteristics. The multilayer filter 1 also includes a grounded wall portion 13 disposed between the first inductor 11 and the second inductor 12. This suppresses electromagnetic coupling between the first inductor 11 and the second inductor 12. The wall portion 13 is formed with a through-hole 30 that penetrates the wall portion 13 in the opposing direction in which the first inductor 11 and the second inductor 12 face each other. The size of the through-hole 30 in the lamination direction is larger than the size of one insulator layer 7. The wall portion 13 having a large through-hole 30 allows the magnetic flux of the second inductor 12, which is a vertically wound inductor, to pass through the through-hole 30. This suppresses interference with the magnetic flux of the second inductor 12, improving the Q value. As a result, the performance of the multilayer filter 1 can be improved.

[0046] Terminal electrodes 3, 4, and 6 are formed on one side of the element body 2 in the stacking direction, and the wall 13 has a first portion 31 on one side of the through portion 30 in the stacking direction and a second portion 32 on the other side of the through portion 30 in the stacking direction, and the first portion 31 may be larger than the second portion 32 in the stacking direction. Since the terminal electrodes 3, 4, and 6 are formed on one side of the element body 2 in the stacking direction, many electrodes are present. Therefore, by making the first portion 31 on one side of the wall 13 in the stacking direction larger, it is possible to suppress the generation of stray capacitance between the electrodes on one side and the other side of the wall 13.

[0047] The first inductor 11 and the second inductor 12 may be in different bands, in which case the wall portion 13 can suppress coupling between the inductors in different bands.

[0048] One of the first inductor 11 and the second inductor 12 may be a high-band inductor, and the other may be a mid-band inductor. In this case, it is possible to suppress degradation of isolation characteristics, which is a problem in so-called multiplexers.

[0049] Terminal electrodes 3, 4, and 6 are formed on one side of the element body 2 in the stacking direction, the wall portion 13 has a second portion 32 on the other side of the through portion 30 in the stacking direction, and the second inductor 12 has a wiring portion 20 arranged on the other side in the stacking direction, and the wiring portion 20 may overlap the second portion 32 when viewed from the opposing direction. In this case, electromagnetic coupling between the wiring portion 20 of the second inductor 12 and the first inductor 11 can be suppressed.

[0050] Next, examples and comparative examples will be described with reference to FIGS. 7 to 12. As comparative example 1, a multilayer filter without walls was prepared as shown in FIG. 7. As comparative example 2, a multilayer filter with walls 113 without openings was prepared as shown in FIG. 8. Note that comparative examples 1 and 2 have the same structure as the examples except for the walls. As an example, a multilayer filter as shown in FIG. 2 was prepared. The results of measuring the characteristics of these multilayer filters are shown in FIGS. 9 to 12. FIG. 9(a) shows the measurement results of comparative example 1, FIG. 9(b) shows the measurement results of comparative example 2, and FIG. 9(c) shows the measurement results of the example. Note that the vertical axis of FIGS. 9 to 11 is decibels (dB), and the horizontal axis is frequency (GHz). FIG. 9 shows the attenuation characteristics of "S31", and FIG. 10 shows the attenuation characteristics of "S41". In Comparative Example 1 in FIGS. 9(a) and 10(a), a peak is formed in the area surrounded by the dashed line. However, as shown in FIGS. 9(b), 9(c), and 10(b), 9(c), no peak is formed in Comparative Example 2 and the Example, which have wall portions. FIG. 11 also shows the isolation characteristics of "S43." As shown in FIGS. 11(a), 11(b), and 11(c), the isolation characteristics at 2400 to 2500 MHz and 5150 to 7125 MHz are improved in Comparative Example 2 and the Example, which have wall portions, compared to Comparative Example 1. FIG. 12 shows the simulation results of the insertion loss characteristics. As shown in FIG. 12, Comparative Example 1 has the best insertion loss characteristics, but as mentioned above, Comparative Example 1 has poor isolation characteristics. In Comparative Example 2, the isolation characteristics are improved by providing the wall portions, but the insertion loss characteristics deteriorate. In contrast, the Example not only improves the isolation characteristics, but also suppresses the deterioration of the insertion loss characteristics.

[0051] The present invention is not limited to the above-described embodiments.

[0052] For example, in the above-described embodiment, one inductor is a flat-wound inductor and the other is a vertical-wound inductor, but the arrangement of the two may be reversed. Also, both may be vertical-wound inductors. Furthermore, the number of inductors is not limited, and three or more inductors may be provided. In this case, a wall may be provided between each inductor. may be provided. [Explanation of symbols]

[0053] 1... multilayer filter, 2... element body, 3, 4, 6... terminal electrodes, 7... insulator layer, 11... first inductor, 12... second inductor, 13... wall portion, 20... wiring portion, 30... through portion, 31... first portion, 32... second portion.

Claims

1. an element body formed by laminating a plurality of insulator layers; a first inductor and a second inductor; a wall portion that is disposed between the first inductor and the second inductor and is grounded; At least the second inductor is a vertically wound inductor having a winding axis extending in a direction perpendicular to a lamination direction in which the plurality of insulator layers are laminated, the wall portion includes a pair of pillars and a wall plate member, and the wall plate member is configured with a plurality of conductor patterns supported at both ends by the pair of pillars; a through-hole is formed in a wall plate member of the wall portion, the through-hole penetrating in a direction in which the first inductor and the second inductor face each other; The multilayer filter, wherein the size of the through portion in the stacking direction is larger than the size of one of the insulating layers.

2. a terminal electrode is formed on one side of the element body in the stacking direction; the wall portion has a first portion on one side of the through portion in the stacking direction and a second portion on the other side of the through portion in the stacking direction, 2. The multilayer filter according to claim 1, wherein the first portion is larger than the second portion in the stacking direction.

3. 3. The multilayer filter according to claim 1, wherein the first inductor and the second inductor are in different bands.

4. 4. The multilayer filter according to claim 1, wherein one of the first inductor and the second inductor is a high-band inductor, and the other is a mid-band inductor.

5. a terminal electrode is formed on one side of the element body in the stacking direction; the wall portion has a second portion on the other side of the through portion in the stacking direction, the second inductor has a wiring portion disposed on the other side in the stacking direction, 5. The multilayer filter according to claim 1, wherein said wiring portion overlaps said second portion when viewed from said opposing direction.

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