Common mode filter

Abstract

To provide a common mode filter in which a symmetric property is improved in a pair of lines.SOLUTION: A common mode filter 1 includes conductive layers L1 and L2. The conductive layer L1 contains: a coil pattern C1; a connection pattern 11; and a leading pattern 51. The conductive layer L2 contains: a coil pattern C2; a connection pattern 22; and a leading pattern 52. Each winding direction of the coil patterns C1 and C2 is the same as each other. The leading pattern 51 is longer than the leading pattern 52, and a diameter of the coil pattern C2 is larger than that of the coil pattern C1. Thus, since a resistance between lines caused by a difference of a length of the leading pattern 51 and the leading pattern 52 is cancelled by a difference of each diameter of the coil patterns C1 and C2, a symmetric property in a pair of lines can be increased.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a common mode filter, and particularly to a chip-type common mode filter that is surface-mounted.

Background Art

[0002] Patent Document 1 discloses a common mode filter having a structure in which a plurality of conductor layers are laminated. The common mode filter disclosed in Patent Document 1 has four conductor layers, and the outer peripheral ends of the coil patterns formed on each conductor layer are connected to terminal electrodes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the pattern shapes shown in FIGS. 3 and 4 of Patent Document 1, there is a problem that a slight difference occurs in the number of turns between a pair of lines, resulting in a difference in inductance and resistance between the pair of lines. On the other hand, according to the pattern shape shown in FIG. 6 of Patent Document 1, it is possible to make the number of turns of a pair of lines substantially the same. However, in this case, since the lead-out pattern included in one line extends in the opposite direction to the coil pattern over a long distance, there is a problem that the inductance balance between the pair of lines is likely to be disrupted.

[0005] Therefore, an object of the present invention is to provide a common mode filter with enhanced symmetry between a pair of lines.

Means for Solving the Problems

[0006] The common mode filter according to the present invention comprises first and second terminal electrodes, a first conductor layer including a first coil pattern, a first connection pattern connected to the first terminal electrode, and a first lead pattern connecting the outer peripheral end of the first coil pattern to the first connection pattern, and a second conductor layer including a second coil pattern, a second connection pattern connected to the second terminal electrode, and a second lead pattern connecting the outer peripheral end of the second coil pattern to the second connection pattern, wherein the first and second connection patterns are arranged in a first direction when viewed from the stacking direction, and the winding proceeds from the outer peripheral end to the inner peripheral end of the first coil pattern. The winding direction and the winding direction from the outer circumference to the inner circumference of the second coil pattern are the same, the first lead-out pattern includes a first section extending in a first direction from the first connection pattern, and the second lead-out pattern includes a second section extending in a first direction from the second connection pattern. The direction of extension of the first section from the first connection pattern toward the outer circumference of the first coil pattern and the direction of extension of the second section from the second connection pattern toward the outer circumference of the second coil pattern are opposite to each other, the first section is longer than the second section, and the second coil pattern has a larger diameter than the first coil pattern.

[0007] According to the present invention, the resistance difference between lines caused by the difference in length between the first section of the first lead pattern and the second section of the second lead pattern is canceled out by the difference in diameter between the first coil pattern and the second coil pattern, thereby increasing the symmetry between the pair of lines. Moreover, since the first section and the second section extend in opposite directions, it is possible to reduce the difference in planar position between the outer edge of the first coil pattern and the outer edge of the second coil pattern.

[0008] In this invention, the first coil pattern and the second coil pattern do not need to overlap when viewed from the stacking direction. This reduces the stray capacitance between the first coil pattern and the second coil pattern, thereby improving the high-frequency characteristics.

[0009] In the present invention, the first pull-out pattern may further include a third section located between the first section and the outer peripheral end of the first coil pattern, extending in a second direction perpendicular to the first direction, and the second pull-out pattern may further include a fourth section located between the second section and the outer peripheral end of the second coil pattern, extending in a second direction. This makes it possible to adjust the positions of the outer peripheral ends of the first and second coil patterns by the lengths of the third and fourth sections. In this case, the third section and the fourth section may overlap when viewed from the stacking direction. This makes it possible to bring the planar positions of the outer peripheral end of the first coil pattern and the outer peripheral end of the second coil pattern closer together.

[0010] The common mode filter according to the present invention further comprises third and fourth terminal electrodes, a third conductor layer including a third coil pattern whose inner end is connected to the inner end of a first coil pattern, a third connection pattern connected to the third terminal electrode, and a third lead pattern connecting the outer end of the third coil pattern to the third connection pattern, and a fourth conductor layer including a fourth coil pattern whose inner end is connected to the inner end of a second coil pattern, a fourth connection pattern connected to the fourth terminal electrode, and a fourth lead pattern connecting the outer end of the fourth coil pattern to the fourth connection pattern, wherein the third and fourth connection patterns are arranged in a first direction when viewed from the stacking direction, and The winding directions from the outer circumference to the inner circumference of the first and second coil patterns are the same as the winding directions from the inner circumference to the outer circumference of the third and fourth coil patterns. The third lead pattern includes a fifth section extending in the first direction from the third connection pattern, and the fourth lead pattern includes a sixth section extending in the first direction from the fourth connection pattern. The extension directions of the fifth section from the third connection pattern to the outer circumference of the third coil pattern and the extension directions of the sixth section from the fourth connection pattern to the outer circumference of the fourth coil pattern are opposite to each other. The fifth section may be longer than the sixth section, and the fourth coil pattern may have a larger diameter than the third coil pattern. This makes it possible to increase the symmetry between the pair of lines, as the difference in resistance between the lines caused by the difference in length between the fifth section of the third lead pattern and the sixth section of the fourth lead pattern is offset by the difference in diameter between the third and fourth coil patterns. Furthermore, since the fifth and sixth sections extend in opposite directions, it becomes possible to reduce the difference in planar position between the outer edge of the third coil pattern and the outer edge of the fourth coil pattern.

[0011] In this invention, the third coil pattern and the fourth coil pattern do not need to overlap when viewed from the stacking direction. This reduces the stray capacitance between the third coil pattern and the fourth coil pattern, thereby improving the high-frequency characteristics.

[0012] In the present invention, the third lead pattern may further include a seventh section located between the fifth section and the outer peripheral end of the third coil pattern and extending in a second direction, and the fourth lead pattern may further include an eighth section located between the sixth section and the outer peripheral end of the fourth coil pattern and extending in a second direction. This makes it possible to adjust the positions of the outer peripheral ends of the third and fourth coil patterns by the lengths of the seventh and eighth sections. In this case, the seventh and eighth sections may overlap when viewed from the stacking direction. This makes it possible to bring the planar positions of the outer peripheral end of the third coil pattern and the outer peripheral end of the fourth coil pattern closer together.

[0013] In the present invention, the first connection pattern and the third connection pattern are arranged in a second direction perpendicular to the first direction when viewed from the stacking direction, and the second connection pattern and the fourth connection pattern are arranged in a second direction when viewed from the stacking direction. The extension direction from the first connection pattern in the first section toward the outer edge of the first coil pattern is the same as the winding direction from the outer edge to the inner edge of the first coil pattern, the extension direction from the second connection pattern in the second section toward the outer edge of the second coil pattern is opposite to the winding direction from the outer edge to the inner edge of the second coil pattern, the extension direction from the third connection pattern in the third section toward the outer edge of the third coil pattern is the same as the winding direction from the outer edge to the inner edge of the third coil pattern, and the extension direction from the fourth connection pattern in the fourth section toward the outer edge of the fourth coil pattern may be opposite to the winding direction from the outer edge to the inner edge of the fourth coil pattern. This makes it possible to suppress imbalances in inductance caused by the second and fourth lead patterns extending in the opposite direction to the second and fourth coil patterns.

[0014] In the present invention, the radial distance between the inner end of the first coil pattern and a first position located 1 / 2 turn outward from the inner end of the first coil pattern is the first distance; the radial distance between the inner end of the second coil pattern and a second position located 1 / 2 turn outward from the inner end of the second coil pattern is the second distance; the radial distance between the inner end of the third coil pattern and a third position located 1 / 2 turn outward from the inner end of the third coil pattern is the third distance; and the radial distance between the inner end of the fourth coil pattern and a fourth position located 1 / 2 turn outward from the inner end of the fourth coil pattern is the fourth distance. The second distance may be greater than the first distance, and the fourth distance may be greater than the third distance. This makes it possible to reduce the difference in inductance caused by the difference in length between the first and third lead patterns and the second and fourth lead patterns. [Effects of the Invention]

[0015] Thus, according to the present invention, it is possible to provide a common mode filter with enhanced symmetry between a pair of lines. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a schematic perspective view showing the appearance of a common mode filter 1 according to one embodiment of the present invention. [Figure 2] Figure 2 is a schematic plan view illustrating the pattern shape of the conductor layer L1. [Figure 3] Figure 3 is a schematic plan view illustrating the pattern shape of the insulating layer 60. [Figure 4] Figure 4 is a schematic plan view illustrating the pattern shape of the conductor layer L2. [Figure 5] Figure 5 is a schematic plan view illustrating the pattern shape of the insulating layer 70. [Figure 6] Figure 6 is a schematic plan view illustrating the pattern shape of the conductor layer L3. [Figure 7]FIG. 7 is a schematic plan view for explaining the pattern shape of the insulating layer 80. [Figure 8] FIG. 8 is a schematic plan view for explaining the pattern shape of the conductor layer L4. [Figure 9] FIG. 9 is a schematic plan view for explaining the pattern shape of the insulating layer 90. [Figure 10] FIG. 10 is a schematic plan view for explaining the pattern shapes of the terminal electrodes E1 to E4. [Figure 11] FIG. 11 is a schematic plan view showing a state where the conductor layer L1 and the conductor layer L2 are overlapped. [Figure 12] FIG. 12 is a schematic plan view showing a state where the conductor layer L3 and the conductor layer L4 are overlapped. [Figure 13] FIG. 13 is a schematic cross-sectional view taken along the line A-A shown in FIGS. 11 and 12. [Figure 14] FIG. 14 is a schematic cross-sectional view taken along the line B-B shown in FIGS. 11 and 12. [Figure 15] FIG. 15 is a schematic plan view according to a modified example showing a state where the conductor layer L1 and the conductor layer L2 are overlapped. [Figure 16] FIG. 16 is a schematic plan view according to a modified example showing a state where the conductor layer L3 and the conductor layer L4 are overlapped. [Figure 17] FIG. 17 is a schematic cross-sectional view taken along the line A-A shown in FIGS. 15 and 16. [Figure 18] FIG. 18 is a schematic cross-sectional view taken along the line B-B shown in FIGS. 15 and 16.

DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0018] FIG. 1 is a schematic perspective view showing the appearance of the common mode filter 1 according to an embodiment of the present invention.

[0019] As shown in Figure 1, the common mode filter 1 according to this embodiment comprises a base body 2 and four terminal electrodes E1 to E4 embedded in the base body 2. The base body 2 has a support 3 made of a high-permeability material such as ferrite, a coil layer 4 laminated on the support 3, and a magnetic material layer 5 laminated on the coil layer 4. The coil layer 4 has a structure in which insulating layers and conductive layers are alternately laminated in the z direction, and a coil pattern, which will be described later, is formed on the conductive layer. The magnetic material layer 5 may be a composite magnetic material in which magnetic powder made of ferrite or permalloy and resin are mixed. The terminal electrodes E1 to E4 are embedded in the magnetic material layer 5, and a part of their surface is exposed from the base body 2.

[0020] The base body 2 has a roughly rectangular parallelepiped shape and has mounting surfaces S5 and S6 that form the xy plane and are located on opposite sides of each other, side surfaces S1 and S2 that form the xz plane and are located on opposite sides of each other, and side surfaces S3 and S4 that form the yz plane and are located on opposite sides of each other. The mounting surfaces S5 and S6 are perpendicular to the z direction, which is the stacking direction.

[0021] As shown in Figure 1, terminal electrode E1 is exposed at the corner formed by the mounting surface S5 and sides S1 and S3. Terminal electrode E2 is exposed at the corner formed by the mounting surface S5 and sides S1 and S4. Terminal electrode E3 is exposed at the corner formed by the mounting surface S5 and sides S2 and S3. Terminal electrode E4 is exposed at the corner formed by the mounting surface S5 and sides S2 and S4.

[0022] Furthermore, connection patterns included in the coil layer 4 are exposed from sides S1 to S4. Of these, connection patterns 11 to 14 are exposed on sides S1 and S3, overlapping with terminal electrode E1 and connected to terminal electrode E1. Connection patterns 21 to 24 are exposed on sides S1 and S4, overlapping with terminal electrode E2 and connected to terminal electrode E2. Connection patterns 31 to 34 are exposed on sides S2 and S3, overlapping with terminal electrode E3 and connected to terminal electrode E3. Connection patterns 41 to 44 are exposed on sides S2 and S4, overlapping with terminal electrode E4 and connected to terminal electrode E4.

[0023] Next, we will describe the configuration of each layer that makes up coil layer 4.

[0024] The coil layer 4 has a structure in which insulating layers 50, 60, 70, 80, 90 and conductor layers L1 to L4 are alternately stacked on the surface of the support 3, as shown in Figures 2 to 9. As shown in Figure 2, the insulating layer 50 is a layer that covers the xy surface of the support 3, and the conductor layer L1 is formed on its surface. The conductor layer L1 has a spirally wound coil pattern C1, connection patterns 11, 21, 31, 41 and lead-out patterns 51. The coil pattern C1 is wound clockwise from the outer circumference to the inner circumference. The outer circumference of the coil pattern C1 is connected to the connection pattern 11 via the lead-out pattern 51. The other connection patterns 21, 31, 41 are not connected to the coil pattern C1 and are independent conductor patterns in the plane. Connection patterns 11, 21, 31, and 41 are positioned to overlap with terminal electrodes E1 to E4, respectively. Connection patterns 11 and 21 are arranged in the x-direction when viewed from the z-direction, connection patterns 31 and 41 are arranged in the x-direction when viewed from the z-direction, connection patterns 11 and 31 are arranged in the y-direction when viewed from the z-direction, and connection patterns 21 and 41 are arranged in the y-direction when viewed from the z-direction. The lead-out pattern 51 includes a section 51x extending in the x-direction and a section 51y extending in the y-direction. Section 51x is connected to connection pattern 11, and section 51y is connected to the outer edge of coil pattern C1.

[0025] The conductor layer L1 is covered with an insulating layer 60 as shown in Figure 3. The insulating layer 60 has openings 61 to 65. Openings 61 to 64 are located in positions that overlap with connection patterns 11, 21, 31, and 41, respectively. Opening 65 is located in a position that overlaps with the inner circumference end of coil pattern C1.

[0026] A conductor layer L2, as shown in Figure 4, is formed on the surface of the insulating layer 60. The conductor layer L2 has a spirally wound coil pattern C2, connection patterns 12, 22, 32, 42, a lead pattern 52, and a relay pattern 55. The coil pattern C2 is wound clockwise from the outer circumference to the inner circumference. The outer circumference of the coil pattern C2 is connected to the connection pattern 22 via the lead pattern 52. The other connection patterns 12, 32, 42 and the relay pattern 55 are not connected to the coil pattern C2 and are independent conductor patterns in the plane. The lead pattern 52 includes a section 52x extending in the x direction and a section 52y extending in the y direction, with section 52x connected to the connection pattern 22 and section 52y connected to the outer circumference of the coil pattern C2. Connection patterns 12, 22, 32, and 42 are connected to connection patterns 11, 21, 31, and 41 of the conductor layer L1, respectively, through openings 61 to 64 provided in the insulating layer 60. In addition, the relay pattern 55 is connected to the inner circumference end of the coil pattern C1 through an opening 65 provided in the insulating layer 60.

[0027] The conductor layer L2 is covered with an insulating layer 70 as shown in Figure 5. The insulating layer 70 has openings 71 to 76. Openings 71 to 74 are located in positions that overlap with connection patterns 12, 22, 32, and 42, respectively. Opening 75 is located in a position that overlaps with the relay pattern 55. Opening 76 is located in a position that overlaps with the inner circumference end of the coil pattern C2.

[0028] A conductor layer L3, as shown in Figure 6, is formed on the surface of the insulating layer 70. The conductor layer L3 has a spirally wound coil pattern C3, connection patterns 13, 23, 33, and 43, a lead pattern 53, and a relay pattern 56. The coil pattern C3 is wound clockwise from the inner end to the outer end. The outer end of the coil pattern C3 is connected to the connection pattern 33 via the lead pattern 53. The other connection patterns 13, 23, and 43 and the relay pattern 56 are not connected to the coil pattern C3 and are independent conductor patterns in the plane. The lead pattern 53 includes a section 53x extending in the x direction and a section 53y extending in the y direction, with section 53x connected to the connection pattern 33 and section 53y connected to the outer end of the coil pattern C3. Connection patterns 13, 23, 33, and 43 are connected to connection patterns 12, 22, 32, and 42 of the conductor layer L2, respectively, through openings 71 to 74 provided in the insulating layer 70. In addition, the inner circumference end of coil pattern C3 is connected to the relay pattern 55 through opening 75. As a result, the inner circumference end of coil pattern C3 and the inner circumference end of coil pattern C1 are connected to each other via the relay pattern 55. Furthermore, the relay pattern 56 is connected to the inner circumference end of coil pattern C2 through opening 76 provided in the insulating layer 70.

[0029] The conductor layer L3 is covered with an insulating layer 80 as shown in Figure 7. The insulating layer 80 has openings 81 to 85. Openings 81 to 84 are located in positions that overlap with connection patterns 13, 23, 33, and 43, respectively. Opening 85 is located in a position that overlaps with relay pattern 56.

[0030] A conductor layer L4, as shown in Figure 8, is formed on the surface of the insulating layer 80. The conductor layer L4 has a spirally wound coil pattern C4, connection patterns 14, 24, 34, 44, and lead-out patterns 54. The coil pattern C4 is wound clockwise from the inner end to the outer end. The outer end of the coil pattern C4 is connected to the connection pattern 44 via the lead-out pattern 54. The other connection patterns 14, 24, 34 are not connected to the coil pattern C4 and are independent conductor patterns in the plane. The lead-out pattern 54 includes a section 54x extending in the x direction and a section 54y extending in the y direction, with section 54x connected to the connection pattern 44 and section 54y connected to the outer end of the coil pattern C4. The connection patterns 14, 24, 34, 44 are connected to the connection patterns 13, 23, 33, 43 of the conductor layer L3, respectively, via openings 81 to 84 provided in the insulating layer 80. Furthermore, the inner circumference end of coil pattern C4 is connected to the relay pattern 56 via the opening 85. As a result, the inner circumference end of coil pattern C4 and the inner circumference end of coil pattern C2 are connected to each other via the relay pattern 56.

[0031] The conductor layer L4 is covered with an insulating layer 90 as shown in Figure 9. The insulating layer 90 has openings 91 to 94. The openings 91 to 94 are located in positions that overlap with connection patterns 14, 24, 34, and 44, respectively.

[0032] Terminal electrodes E1 to E4, as shown in Figure 10, are formed on the surface of the insulating layer 90. Terminal electrodes E1 to E4 are connected to connection patterns 14, 24, 34, and 44 of the conductor layer L4, respectively, via openings 91 to 94. As a result, coil patterns C1 and C3 are connected in series between terminal electrode E1 and terminal electrode E3, and coil patterns C2 and C4 are connected in series between terminal electrode E2 and terminal electrode E4. Since the coil patterns C1 to C4 are stacked alternately in the z direction, a high magnetic coupling is generated between the inductor made of coil patterns C1 and C3 and the inductor made of coil patterns C2 and C4. In addition, a magnetic material layer 5, as shown in Figure 1, is formed on the portion of the surface of the insulating layer 90 where terminal electrodes E1 to E4 are not formed.

[0033] Figure 11 is a schematic plan view showing the conductor layer L1 and conductor layer L2 superimposed, and Figure 12 is a schematic plan view showing the conductor layer L3 and conductor layer L4 superimposed. Furthermore, Figure 13 is a schematic cross-sectional view along line AA shown in Figures 11 and 12, and Figure 14 is a schematic cross-sectional view along line BB shown in Figures 11 and 12.

[0034] As shown in Figure 11, coil pattern C2 has a larger diameter than coil pattern C1, and the two do not overlap when viewed from the z direction. Also, lead pattern 51 is longer than lead pattern 52. Section 51y of lead pattern 51 and section 52y of lead pattern 52 overlap when viewed from the z direction, and their ends are connected to the outer edges of coil patterns C1 and C2. Sections 51y and 52y are radially connected to coil patterns C1 and C2 and do not constitute part of coil patterns C1 and C2. In other words, coil patterns C1 and C2 are composed of conductor patterns that extend in the circumferential direction. Since lead pattern 51 is longer than lead pattern 52, if coil patterns C1 and C2 had the same diameter, there would be a difference in resistance. However, in this embodiment, since coil pattern C2 has a larger diameter than coil pattern C1, the difference in resistance caused by the difference in length of lead patterns 51 and 52 is canceled out. Furthermore, since coil patterns C1 and C2 do not overlap, the stray capacitance between them is reduced, which in turn improves the high-frequency characteristics. In addition, if there is a misalignment between coil patterns C1 and C2, in some sections coil patterns C1 and C2 will move closer together, increasing the stray capacitance between them, while in other sections coil patterns C1 and C2 will move further apart, decreasing the stray capacitance between them. Thus, changes in high-frequency characteristics caused by misalignment are also suppressed.

[0035] Furthermore, in section 51x of the lead-out pattern 51, the extending direction (+x direction) from the connection pattern 11 toward the outer edge of the coil pattern C1 is the same as the winding direction from the outer edge to the inner edge of the coil pattern C1. Therefore, the magnetic flux generated in this section reinforces the magnetic flux generated by the coil pattern C1. In contrast, in section 52x of the lead-out pattern 52, the extending direction (-x direction) from the connection pattern 22 toward the outer edge of the coil pattern C2 is opposite to the winding direction from the outer edge to the inner edge of the coil pattern C2. Therefore, the magnetic flux generated in this section cancels out the magnetic flux generated by the coil pattern C2. However, in this embodiment, since the diameter of the coil pattern C2 is larger than the diameter of the coil pattern C1, imbalances in inductance are suppressed. Here, the winding direction from the outer edge to the inner edge of the coil pattern C1 refers to the extending direction at each position, which is the +x direction near the outer edge and the -y direction near the inner edge. The winding direction of coil pattern C2, from the outer edge to the inner edge, is -x near the outer edge and -y near the inner edge. The winding direction of coil pattern C3, from the outer edge to the inner edge, is +x near the outer edge and +y near the inner edge. The winding direction of coil pattern C4, from the outer edge to the inner edge, is -x near the outer edge and +y near the inner edge.

[0036] Furthermore, as shown in Figure 2, if we define φ1 as the radial distance between the inner end of coil pattern C1 and position P1 located 1 / 2 turn outward from the inner end of coil pattern C1, and as shown in Figure 4, if we define φ2 as the radial distance between the inner end of coil pattern C2 and position P2 located 1 / 2 turn outward from the inner end of coil pattern C2, then distance φ2 is greater than distance φ1. As a result, the inductance of the innermost turn is greater for coil pattern C2 than for coil pattern C1, thus reducing the inductance difference caused by differences in the length and extension direction of the lead patterns 51 and 52.

[0037] Similarly, as shown in Figure 12, coil pattern C4 has a larger diameter than coil pattern C3, and the two do not overlap when viewed from the z direction. Also, lead pattern 53 is longer than lead pattern 54. Section 53y of lead pattern 53 and section 54y of lead pattern 54 overlap when viewed from the z direction, and their ends are connected to the outer edges of coil patterns C3 and C4. Sections 53y and 54y are radially connected to coil patterns C3 and C4 and do not constitute part of coil patterns C3 and C4. In other words, coil patterns C3 and C4 are composed of conductor patterns that extend in the circumferential direction. Since lead pattern 53 is longer than lead pattern 54, if coil patterns C3 and C4 had the same diameter, there would be a difference in resistance. However, in this embodiment, since coil pattern C4 has a larger diameter than coil pattern C3, the difference in resistance caused by the difference in length of lead patterns 53 and 54 is canceled out. Furthermore, since coil patterns C3 and C4 do not overlap, the stray capacitance between them is reduced, which in turn improves the high-frequency characteristics. In addition, if there is a misalignment between coil patterns C3 and C4, in some sections coil patterns C3 and C4 will move closer together, increasing the stray capacitance between them, while in other sections coil patterns C3 and C4 will move further apart, decreasing the stray capacitance between them. Thus, changes in high-frequency characteristics caused by misalignment are also suppressed.

[0038] Furthermore, in section 53x of the lead-out pattern 53, the extension direction (+x direction) from the connection pattern 33 toward the outer edge of the coil pattern C3 is the same as the winding direction from the outer edge to the inner edge of the coil pattern C3. Therefore, the magnetic flux generated in this section reinforces the magnetic flux generated by the coil pattern C3. In contrast, in section 54x of the lead-out pattern 54, the extension direction (-x direction) from the connection pattern 44 toward the outer edge of the coil pattern C4 is opposite to the winding direction from the outer edge to the inner edge of the coil pattern C4. Therefore, the magnetic flux generated in this section cancels out the magnetic flux generated by the coil pattern C4. However, in this embodiment, since the diameter of the coil pattern C4 is larger than the diameter of the coil pattern C3, imbalances in inductance are suppressed.

[0039] Furthermore, as shown in Figure 6, if the radial distance between the inner end of coil pattern C3 and position P3 located 1 / 2 turn outward from the inner end of coil pattern C3 is defined as φ3, and as shown in Figure 8, if the radial distance between the inner end of coil pattern C4 and position P4 located 1 / 2 turn outward from the inner end of coil pattern C4 is defined as φ4, then distance φ4 is greater than distance φ3. As a result, the inductance of the innermost turn is greater for coil pattern C4 than for coil pattern C3, making it possible to reduce the inductance difference caused by differences in the length and extension direction of the lead patterns 53 and 54.

[0040] Figure 15 is a schematic plan view of a modified example showing conductor layer L1 and conductor layer L2 superimposed, and Figure 16 is a schematic plan view of a modified example showing conductor layer L3 and conductor layer L4 superimposed. Furthermore, Figure 17 is a schematic cross-sectional view along line AA shown in Figures 15 and 16, and Figure 18 is a schematic cross-sectional view along line BB shown in Figures 15 and 16.

[0041] As shown in Figures 15 to 18, in the present invention, the coil patterns C1 to C4 included in the conductor layers L1 to L4 do not need to be one turn, but may be two turns or more. In this case, each turn of coil pattern C2 has a larger diameter than the corresponding turn of coil pattern C1, and each turn of coil pattern C4 has a larger diameter than the corresponding turn of coil pattern C3. Furthermore, it is preferable that, as shown in Figure 15, none of the turns of coil patterns C1 and C2 overlap when viewed from the z direction, and as shown in Figure 16, none of the turns of coil patterns C3 and C4 overlap when viewed from the z direction.

[0042] Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention, and these modifications are also included within the scope of the present invention. [Explanation of symbols]

[0043] 1 Common mode filter 2. Base body 3 Support 4 coil layers 5 Magnetic material layer Connection patterns 11-14, 21-24, 31-34, 41-44 50, 60, 70, 80, 90 Insulating layer 51-54 Drawer Patterns Sections 51x~54x, 51y~54y 55, 56 relay pattern 61-65, 71-76, 81-85, 91-94 Opening C1~C4 Coil Pattern E1~E4 terminal electrode L1~L4 Conductor Layers P1~P4 position S1~S4 side S5 Implementation Side S6 top

Claims

1. The first, second, third, and fourth terminal electrodes, A first conductor layer including a first coil pattern, a first connection pattern connected to the first terminal electrode, and a first lead pattern connecting the outer edge of the first coil pattern to the first connection pattern, A second conductor layer including a second coil pattern, a second connection pattern connected to the second terminal electrode, and a second lead pattern connecting the outer edge of the second coil pattern to the second connection pattern, A third conductor layer comprising: a third coil pattern whose inner end is connected to the inner end of the first coil pattern; a third connection pattern connected to the third terminal electrode; and a third lead pattern connecting the outer end of the third coil pattern to the third connection pattern; A fourth conductor layer comprising: a fourth coil pattern whose inner end is connected to the inner end of the second coil pattern; a fourth connection pattern connected to the fourth terminal electrode; and a fourth lead pattern connecting the outer end of the fourth coil pattern to the fourth connection pattern, The first connection pattern and the second connection pattern are arranged in a first direction when viewed from the stacking direction. The third connection pattern and the fourth connection pattern are arranged in the first direction when viewed from the stacking direction, The winding direction of the first coil pattern from the outer circumference end to the inner circumference end and the winding direction of the second coil pattern from the outer circumference end to the inner circumference end are the same. The winding directions of the first and second coil patterns from the outer circumference end to the inner circumference end and the winding directions of the third and fourth coil patterns from the inner circumference end to the outer circumference end are the same. The first extraction pattern includes a first section extending in the first direction from the first connection pattern, The second extraction pattern includes a second section extending from the second connection pattern in the first direction, The third extraction pattern includes a third section extending from the third connection pattern in the first direction, The fourth extension pattern includes a fourth section extending from the fourth connection pattern in the first direction, The extension direction of the first section from the first connection pattern toward the outer peripheral end of the first coil pattern and the extension direction of the second section from the second connection pattern toward the outer peripheral end of the second coil pattern are opposite to each other. The extension direction of the third section from the third connection pattern toward the outer peripheral end of the third coil pattern and the extension direction of the fourth section from the fourth connection pattern toward the outer peripheral end of the fourth coil pattern are opposite to each other. The first section is longer than the second section. The third section is longer than the fourth section. The second coil pattern has a larger diameter than the first coil pattern. A common mode filter characterized in that the fourth coil pattern has a larger diameter than the third coil pattern.

2. The common mode filter according to claim 1, characterized in that the first coil pattern and the second coil pattern do not overlap when viewed from the stacking direction.

3. The first pull-out pattern further includes a fifth section located between the first section and the outer peripheral end of the first coil pattern, and extending in a second direction perpendicular to the first direction. The common mode filter according to claim 1 or 2, wherein the second lead pattern further includes a sixth section located between the second section and the outer peripheral end of the second coil pattern and extending in the second direction.

4. The common mode filter according to claim 3, characterized in that the fifth section and the sixth section overlap when viewed from the stacking direction.

5. The common mode filter according to any one of claims 1 to 4, characterized in that the third coil pattern and the fourth coil pattern do not overlap when viewed from the stacking direction.

6. The third lead pattern further includes a seventh section located between the third section and the outer peripheral end of the third coil pattern, extending in a second direction perpendicular to the first direction. The common mode filter according to any one of claims 1 to 5, characterized in that the fourth lead pattern further includes an eighth section located between the fourth section and the outer peripheral end of the fourth coil pattern and extending in the second direction.

7. The common mode filter according to claim 6, characterized in that the seventh section and the eighth section overlap when viewed from the stacking direction.

8. The first connection pattern and the third connection pattern are arranged in a second direction perpendicular to the first direction when viewed from the stacking direction. The second connection pattern and the fourth connection pattern are arranged in the second direction when viewed from the stacking direction, The extension direction from the first connection pattern in the first section toward the outer peripheral end of the first coil pattern is the same as the winding direction from the outer peripheral end toward the inner peripheral end of the first coil pattern. The extension direction from the second connection pattern in the second section toward the outer peripheral end of the second coil pattern is opposite to the winding direction from the outer peripheral end toward the inner peripheral end of the second coil pattern. The extension direction from the third connection pattern in the third section toward the outer peripheral end of the third coil pattern is the same as the winding direction from the outer peripheral end toward the inner peripheral end of the third coil pattern. The common mode filter according to any one of claims 1 to 7, characterized in that the extension direction from the fourth connection pattern in the fourth section toward the outer peripheral end of the fourth coil pattern is opposite to the winding direction from the outer peripheral end toward the inner peripheral end of the fourth coil pattern.

9. The radial distance between the inner circumferential end of the first coil pattern and a first position located 1 / 2 turn outward from the inner circumferential end of the first coil pattern is the first distance. The radial distance between the inner circumferential end of the second coil pattern and a second position located 1 / 2 turn outward from the inner circumferential end of the second coil pattern is the second distance. The radial distance between the inner circumferential end of the third coil pattern and a third position located 1 / 2 turn outward from the inner circumferential end of the third coil pattern is the third distance. The radial distance between the inner circumferential end of the fourth coil pattern and the fourth position located 1 / 2 turn outward from the inner circumferential end of the fourth coil pattern is the fourth distance. The second distance is greater than the first distance. The common mode filter according to claim 8, characterized in that the fourth distance is greater than the third distance.

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