JP2007088559A - Filter element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter element of a common mode type, capable of realizing proper noise attenuation effect over broadband. <P>SOLUTION: The filter element includes a coil part 2 formed cylindrically, by winding a laminate 8 comprising the lamination of a plurality of belt-like bodies 7 each comprising a belt-like conductor 6 arranged on one side of a belt-like insulator 5 in a prescribed direction; and a coil part 3, formed cylindrically by winding the laminate 8 in a direction reverse to the prescribed direction. Both the coil parts 2, 3 are configured, such that each belt-like conductor 6 is connected to each other at a prescribed position located at the inner circumference part in a cylindrically formed state; the belt-like conductor 6, located at the outermost circumference, functions as a grounding belt-like conductor 6 in a cylindrically formed state among the belt-like conductor 6; and a plurality of belt-like conductors 6, adjacent to each other with the belt-like insulator 5 inbetween among the other belt-like conductors 6, excluding the grounding belt-like conductor 6, act as the belt-like conductors 6 for a signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a filter element including a first coil portion and a second coil portion formed by winding a laminated body in which a plurality of belt-like bodies each having a belt-like conductor disposed on one surface of a belt-like insulator are laminated. Is.

A filter element disclosed in Japanese Patent No. 3125179 is known as this type of filter element. In this filter element, a first layer coil body (first coil portion) and two layers are formed by spirally winding a plurality of insulated rectangular conductive wires whose outer edges are insulated and whose cross section is rectangular. The coil body (second coil portion) of the eye is formed, and the insulation flat conductive wire closest to the center of the first layer coil body is insulated most centrally of the coil body (second coil portion) of the second layer. It is configured as a two-layer coil so as to be connected to a rectangular conductive wire. In this case, at least two of the plurality of insulated rectangular conductive wires are used as current-carrying conductors (usually a signal conductor and a ground conductor). Since this filter element is configured as a two-layer coil, the inductance and capacitance can be sufficiently increased even if the number of turns per layer is reduced, so that a good noise attenuation effect can be obtained in a wide band. Is possible. In addition, in this filter element, the tip of the insulated rectangular conductive wire in the coil body of each layer is drawn out from the outermost periphery, so that work such as mounting of the lead terminal can be easily performed, so that mass productivity can be improved. Yes.
Japanese Patent No. 3125179 (page 3-4, Fig. 1)

  However, the above-described conventional filter element has the following problems. In other words, in this filter element, a two-layer coil having two coil bodies is used, and at least two of the plurality of insulated rectangular conductive wires are used as current-carrying conductors, so that a good noise attenuation effect can be obtained in a wide band. It is possible to get in. Here, for example, one of the plurality of insulated rectangular conductive wires in this filter element is used as a grounding conductor and two are used as signal conductors, and this filter element is used as a five-terminal noise filter. When used as a (common mode filter), the inventors have found from experimental results that the characteristics differ depending on which of the insulated rectangular conductive wires is used as a grounding conductor. However, in the above filter element, it is not clearly shown which one of the insulated rectangular conductive wires should be used as the grounding conductor. Therefore, this filter element is used as a five-terminal noise filter. However, the configuration that can obtain a good noise attenuation effect is unclear, and there is a demand for clarification of this point.

  The present invention has been made to solve the above-described problems, and has as its main object to provide a common mode type filter element that can realize a good noise attenuation effect in a wide band.

  In order to achieve the above object, the filter element according to claim 1 is formed in a cylindrical shape by winding a laminated body in which a plurality of band-shaped bodies each having a band-shaped conductor disposed on one surface of a band-shaped insulator are stacked in a predetermined direction. A filter element comprising: a first coil part; and a second coil part formed in a cylindrical shape by winding the laminated body in a direction opposite to the predetermined direction, wherein the first coil part and The second coil portions are connected to each other in a predetermined portion located on an inner peripheral portion in a state where the second coil portions are formed, and the second coil portions are connected to each other. The strip-shaped conductor located on the outermost periphery in the state of being formed into a cylindrical shape functions as a strip-shaped conductor for grounding, and the strip-shaped insulation of the other strip-shaped conductors other than the strip-shaped conductor for grounding A plurality of adjacent strip conductors across the body It is configured to function as a band-shaped conductor.

  The filter element according to claim 2 is the filter element according to claim 1, wherein the first coil portion includes a boundary portion between a half on one end side of the multilayer body and a half on the other end side of the multilayer body. The second coil portion is formed by winding the other half of the laminated body in a direction opposite to the predetermined direction with the boundary portion as the center. Has been.

  The filter element according to claim 3 is the filter element according to claim 1 or 2, wherein both of the first and second coil parts defined by virtual planes passing through respective central axes of the first coil part and the second coil part are used. A ground line is connected to the grounding strip conductor in one of the two partition portions in the coil portion, and an input line and an output line are connected to the signal strip conductor in the other of the two partition portions. .

  According to the filter element of Claim 1, the strip | belt-shaped conductor located in the outermost periphery in the state formed in the cylinder shape functions as a strip | belt-shaped conductor for grounding, and other strip | belt-shaped except for the strip | belt-shaped conductor for grounding By configuring the first coil portion and the second coil portion so that a plurality of strip-shaped conductors adjacent to each other across the strip-shaped insulator of the conductor function as a strip-shaped conductor for signals, Better noise attenuation in a wider band compared to the configuration in which the strip-shaped conductor located functions as a strip-shaped conductor for signals, that is, the strip-shaped conductor located on the outermost periphery does not function as the strip-shaped conductor for grounding. The effect can be realized.

  According to the filter element of the second aspect, the first coil portion is formed by winding the half on one end side in the laminated body in a predetermined direction around the boundary portion with the half on the other end side, Since the second coil part is formed by winding the other end half of the body in the direction opposite to the predetermined direction with the boundary part as the center, for example, the two coiled bodies are wound respectively to form the first coil part Unlike the configuration in which the strip conductors in both coil portions are connected at the center after forming the second coil portion and the second coil portion separately, the connection efficiency of the strip conductors can be omitted, so that the production efficiency is sufficiently improved. Can be made.

  According to the filter element of the third aspect, the grounding strip conductor is grounded at one of the two partition portions in the first coil portion and the second coil portion partitioned by a virtual plane passing through the central axis. By connecting the line and connecting the input line and the output line to the signal strip conductor in the other of the two partition parts, for example, the ground line, the input line and the output line are all connected to one of the two partition parts or On the other hand, the noise attenuation in the high frequency band can be sufficiently improved as compared with the configuration connected to the strip conductor.

  Hereinafter, a filter element according to the present invention will be described with reference to the accompanying drawings.

  First, the filter element 1 will be described with reference to the drawings.

  As shown in FIG. 1, the filter element 1 includes a first coil portion 2 (hereinafter also referred to as “coil portion 2”), a second coil portion 3 (hereinafter also referred to as “coil portion 3”), and a magnetic element. A body (for example, a columnar (cylindrical in the figure) magnetic core) 4 is provided, and is configured as a distributed constant type 5-terminal noise filter noise filter (low-pass type common mode filter).

  As shown in FIG. 1, the coil portions 2 and 3 are each a laminated body 8 (see also FIG. 2) in which three belt-like bodies 7 having a belt-like insulator 5 and a belt-like conductor 6 are laminated (a plurality of examples in the present invention). Are formed respectively. As an example, the strip insulator 5 is formed in a strip shape using a material having dielectric properties and electrical insulation properties as shown in FIG. For example, the band-shaped conductor 6 is formed using a conductive material in a band shape that is slightly narrower than the band-shaped insulator 5 and slightly shorter than the band-shaped insulator 5 as shown in FIG. At the same time, it is disposed (attached) on one surface of the strip-like insulator 5. In this case, for example, the laminated body 8 can also be configured by laminating three flexible substrates each having a conductor pattern that functions as each band-like conductor 6 patterned on the surface.

  As shown in FIGS. 2 and 3, the coil portion 2 twists (or bends) the laminated body 8 by one turn at the central portion A (the boundary portion between the half on the one end side and the half on the other end side in the present invention). The half of one end of the laminate 8 (in FIG. 2, as an example, the left end half with respect to the central portion A as an example) is wound around the central portion A in the direction of arrow B (counterclockwise in FIG. 3). By doing so, as shown in FIG. 1, it is formed in a cylindrical shape.

  In this case, among the strip-shaped conductors 6 in the laminated body 8, the strip-shaped conductor 6 positioned on the outermost periphery in the state where the coil portion 2 is formed (hereinafter, this strip-shaped conductor 6 is also referred to as “band-shaped conductor 6 a”). ) Functions as a strip-shaped conductor 6 for grounding, and a ground wire 11 is connected to the strip-shaped conductor 6a as shown in FIG. Further, two band-shaped conductors 6 adjacent to each other with the band-shaped insulator 5 among the other band-shaped conductors 6 excluding the band-shaped conductor 6a in the laminated body 8 (hereinafter referred to as "band-shaped conductive"). The body 6b, 6c ") functions as a signal strip conductor 6, and an input line 12 is connected to each strip conductor 6b, 6c as shown in FIG. Here, as shown in FIG. 4, the connection position of the ground wire 11 is defined as two partition parts virtually divided by a virtual plane L passing through the central axis O of the coil portion 2 (hereinafter, these two partition parts are referred to as two partition parts). Each of the half portions P1 and P2 is defined as an outer peripheral side portion in one half (in this case, half P1). Moreover, the connection position of the input line 12 is prescribed | regulated in the outer peripheral side site | part in the other (in this case half P2) of half P1, P2.

  As shown in FIGS. 2 and 3, the coil portion 3 is a coil centered on the center portion A as a half on the other end side of the laminated body 8 (in FIG. 2, a half on the right end side with respect to the center portion A as an example). By winding in the direction of arrow C (clockwise in FIG. 3) opposite to the winding direction of arrow 2 (direction of arrow B), as shown in FIG. Is formed. For example, when the coil unit 3 is attached to a printed circuit board, as shown in FIGS. 1 and 3, the coil unit 2 is located on the side of the coil unit 2 (the right side in FIG. 1 and the lower side in FIG. 3). , 3 are arranged side by side so that the central axes O coincide (or substantially coincide). Accordingly, the air gaps H formed in the central portions of the coil portions 2 and 3 are in communication with each other, and the magnetic core 4 is mounted (inserted) into the air gaps H.

  In this case, in the filter element 1, as described above, the coil portions 2 and 3 are formed by winding the half on one end side and the half on the other end side in one continuous laminated body 8. For this reason, the coil portions 2 and 3 are configured such that the respective strip-like conductors 6 are connected to each other in a one-to-one manner at each central portion (a predetermined portion located in the inner peripheral portion in the present invention). Further, in the filter element 1, the laminated body 8 is twisted by one turn at the central portion A, and is wound in the direction opposite to the winding direction of the coil part 2 to form the coil part 3. For this reason, in the state in which the coil part 3 is formed, the strip-shaped conductor 6a of the laminated body 8 is located on the outermost periphery of the coil section 3 as shown in FIG. 1, and the strip-shaped conductors 6b and 6c are strip-shaped conductors. It is located inside 6a (inner side). Further, an output line 13 is connected to each of the strip conductors 6b and 6c, as shown in FIG. Here, as shown in FIG. 4, the connection position of the output line 13 is defined by two divided parts in the coil section 3 virtually divided by the virtual plane L (hereinafter, these two divided parts are referred to as “half”. (Also referred to as “body P3, P4”) of the coil portion 2 adjacent to the half P2 (in this case, the half P4).

  In the filter element 1, the connection positions of the ground line 11, the input line 12, the output line 13, and the strip-shaped conductor 6 are respectively defined in the outer peripheral side portion of the coil part 2 or the coil part 3. For this reason, as a result of being able to easily connect each of the wires 11, 12, 13 and the strip-shaped conductor 6, production efficiency can be improved. In addition, the filter element 1 includes two coil portions 2 and 3 in which the respective strip-like conductors 6 are connected to each other at the center. For this reason, even if the number of turns per layer is reduced, it is possible to sufficiently increase the inductance and the capacitance. Furthermore, in this filter element 1, the coil portions 2 and 3 are formed using one continuous laminated body 8, so that the respective strip-like conductors 6 are connected to each other at the center portions of the coil portions 2 and 3. The configuration is realized. Therefore, in this filter element 1, for example, after two laminated bodies are wound to form the coil portions 2 and 3 separately, the strip conductors 6 in both the coil portions 2 and 3 are connected at the central portion thereof. Unlike the configuration, the connection efficiency of each strip conductor 6 can be omitted, so that the production efficiency can be further improved.

  The inventor conducted the following experiment in order to verify the characteristics of the filter element 1. In this experiment, first, a filter element 1 as an experiment target was manufactured, and a filter element for comparison (hereinafter, this filter element is also referred to as “filter element 101”) was manufactured. In this case, in this filter element 1, the number of turns of the laminated body 8 in each of the coil portions 2 and 3 is 15 turns, and both the coil portions 2 and 3 are arranged side by side so that the central axes O coincide with each other. A configuration in which the magnetic core 4 is mounted in each gap H (a configuration of 15 turns × 2) was adopted. On the other hand, in the filter element 101, of the three strip conductors 6 in the multilayer body 8, the strip conductor 6 positioned second from the outermost periphery in the state where the coil portions 2 and 3 are formed is the strip conductor for grounding. In order to function as 6, a ground wire 11 was connected to the strip-shaped conductor 6. Further, in this filter element 101, in order to make the other two strip conductors 6 excluding the strip conductor 6 functioned for grounding function as the signal strip conductor 6, the input line 12 and the output line 13 are connected. Each connected. Further, the filter element 101 has a structure of 15 turns × 2 in which the magnetic core 4 is mounted in the gap H between the coil portions 2 and 3 in the same manner as the filter element 1. Next, using a network analyzer, four-port balanced measurement was performed on the filter element 1 to be tested and the filter element 101 to be compared, and the frequency characteristics of the noise attenuation amount for both the filter elements 1 and 101 were measured. As a result, as shown in FIG. 5, it is apparent that the noise attenuation in the frequency band of 400 kHz to 36 MHz is improved by about 30 dB in the filter element 1 as compared with the filter element 101. Next, another comparative filter element (hereinafter, this filter element is also referred to as “filter element 102”) was manufactured. In this case, in the filter element 102, the ground wire 11 and the input line 12 are connected to the strip-shaped conductor 6 at the outer peripheral portion of the half P1 in the coil portion 2, and the output line is connected to the outer peripheral portion of the half P3 in the coil portion 3. 13 was connected to the strip-shaped conductor 6. The filter element 102 has a structure of 15 turns × 2 in which the magnetic core 4 is mounted in the gap H between the coil portions 2 and 3 in the same manner as the filter element 1. Next, using a network analyzer, four-port balanced measurement was performed on the filter element 1 to be tested and the filter element 102 to be compared, and the frequency characteristics of the noise attenuation amount for both the filter elements 1 and 102 were measured. As a result, as shown in FIG. 6, it is apparent that the noise attenuation in the frequency band of 400 kHz to 36 MHz is improved by about 25 dB in the filter element 1 as compared with the filter element 102.

  As described above, according to the filter element 1, the strip-shaped conductor 6 located on the outermost periphery in the state where the coil portions 2 and 3 are formed among the strip-shaped conductors 6 in the multilayer body 8 is used as the strip-shaped conductor for grounding. In addition to functioning as a body 6, two adjacent strip-shaped conductors 6 sandwiching the strip-shaped insulator 5 among the other strip-shaped conductors 6 other than the strip-shaped conductor 6 are each functioned as a signal strip-shaped conductor 6. Thus, the configuration in which the strip-shaped conductor 6 located on the outermost periphery functions as the strip-shaped conductor 6 for signals, that is, the configuration in which the strip-shaped conductor 6 positioned on the outermost periphery is not functioned as the strip-shaped conductor 6 for grounding is compared. Thus, a good noise attenuation effect can be realized in a wider band.

  In addition, according to the filter element 1, the half on one end side of the laminated body 8 is wound in a predetermined direction around the center portion A to form the coil portion 2, and the other half on the other end side in the laminated body 8 is centered. Since the coil part 3 is formed by winding the part A in the direction opposite to the predetermined direction, for example, the two laminated parts are wound to form the coil parts 2 and 3 separately, and then the two coil parts 2 are wound. Unlike the configuration in which the strip conductors 6 are connected at the central portion thereof, the connection efficiency of the strip conductors 6 can be omitted, so that the production efficiency can be sufficiently improved.

  Further, the ground wire 11 is connected to the grounding strip conductor 6 in the half body P1 of the two halves P1 and P2 in the coil part 2 defined by the virtual plane L passing through the central axis O, and the half body P1. , P2, the input line 12 is connected to the signal strip-like conductor 6 in the half P2, and adjacent to the half P2 of the two halves P3, P4 in the coil section 3 partitioned by the virtual plane L Since the output line 13 is connected to the signal strip conductor 6 in the half P4, for example, the ground line 11 and the input line 12 are all connected to the strip conductor 6 in the half P1, and the half P1 is connected to the half P1. Compared with the configuration in which the output line 13 is connected to the strip conductor 6 in the adjacent half P3, the noise attenuation in the high frequency band can be sufficiently improved.

  The present invention is not limited to the configuration described above. For example, in the above configuration, the example in which the coil portions 2 and 3 are formed using one laminated body 8 has been described above. However, as shown in FIG. 7, two coil portions are formed using two laminated bodies 81 and 82. Can be formed separately, and the present invention can also be applied to a filter element in which the respective strip-like conductors 6 are connected one-to-one at the central portion of these two coil portions.

  In addition, the example in which the coil portions 2 and 3 are formed using the laminate 8 in which the three strips 7 are laminated is described above, but the laminate 8 in which four or more strips 7 are laminated (for example, FIG. The coil parts 2 and 3 can also be formed using the laminates 83 to 86) shown in FIG. In this case, as shown in FIG. 8, the two strip-shaped conductors 6 including the strip-shaped conductor 6 located on the outermost periphery in the state where the laminated body 83 is wound to form the coil portions 2 and 3 are connected to the strip-shaped conductor for grounding. As shown in FIGS. 9 and 10, the three strip conductors 6 including the strip conductor 6 located on the outermost periphery can function as the ground strip conductor 6. Further, as shown in FIG. 11, the three strip-shaped conductors 6 including the strip-shaped conductor 6 positioned on the outermost periphery and the two strip-shaped conductors 6 positioned on the inner peripheral side are used as the ground-shaped strip-shaped conductor 6. It can also function. That is, a plurality of strip-shaped conductors 6 including the strip-shaped conductor 6 positioned on the outermost periphery in a state where the coil body 2 and 3 are formed by winding the laminated body 8 function as the strip-shaped conductor 6 for grounding. Can do.

  Further, as shown in FIGS. 9 and 11, three strip conductors 6 adjacent to each other with the strip insulator 5 interposed therebetween function as the strip conductor 6 for signals, or as shown in FIG. The five strip-shaped conductors 6 that are adjacent to each other can function as the strip-shaped conductor 6 for signals. That is, as long as the strip insulators 5 are adjacent to each other, any number of strip conductors 6 can function as the strip conductors 6 for signals. Further, the example in which one band-shaped conductor 6 is disposed on one surface of the band-shaped insulator 5 has been described above. However, as shown in FIG. 12, two regions along the width direction on one surface of the band-shaped insulator 5 have two A laminated body 87 is formed by laminating the belt-like bodies 7A in which the belt-like conductors 41 and 42 are spaced apart from each other (arranged) to form a laminated body 87, and coil portions 2A and 3A formed by winding the laminated body 87 are provided. The present invention can also be applied to the filter element 1A.

  In addition, the example in which each filter element 1 is used alone has been described above, but the present invention is not limited to this. For example, as shown in FIG. 13, a plurality of the filter elements 1 are juxtaposed in a state where each gap H is in communication, and one magnetic core 4 is attached to each gap H, and a connection line (not shown) is used. The filter elements 1 can be connected in series. According to this configuration, the common mode noise can be further attenuated as compared with the configuration in which the filter element 1 is used alone. Although not shown, common mode noise can be further attenuated by connecting a plurality of filter elements 1A in series in the same manner as filter element 1. Further, in each of the filter elements 1 described above, each of the filter elements 1 is configured as a common mode noise filter by using the two band-shaped conductors 6b and 6c as signal band-shaped conductors 6. By using only one of the conductors 6b and 6c, a noise filter for a normal mode can be configured.

3 is a perspective view of the filter element 1 in a state where both ends of the laminated body 8 are unrolled. FIG. 3 is a perspective view showing a configuration of a laminated body 8. FIG. It is explanatory drawing for demonstrating the method of forming each coil part 2 and 3. FIG. 3 is a plan view of the filter element 1 as viewed from the end face side of the coil portion 2. FIG. 6 is a noise attenuation characteristic diagram showing noise attenuation characteristics of the filter elements 1 and 101. FIG. 3 is a noise attenuation characteristic diagram showing noise attenuation characteristics of filter elements 1 and 102. FIG. FIG. 6 is a perspective view showing a configuration of laminated bodies 81 and 82. 4 is a cross-sectional view showing a configuration of a laminated body 83. FIG. 4 is a cross-sectional view showing a configuration of a laminated body 84. FIG. 3 is a cross-sectional view showing a configuration of a laminated body 85. FIG. 3 is a cross-sectional view showing a configuration of a laminated body 86. FIG. It is a perspective view which shows the structure of 1 A of filter elements. It is a perspective view in the state where three filter elements 1 were connected in series.

Explanation of symbols

1, 1A Filter element 2, 2A Coil part 3, 3A Coil part 5 Strip insulator 6, 6a, 6b, 6c, 41, 42 Strip conductor 7, 7A Strip member 8, 81-87 Laminate 11 Ground wire 12 Input Line 13 Output line A Center part B Arrow C Arrow L Virtual plane O Central axis P1-P4 Half

Claims (3)

A first coil portion formed in a cylindrical shape by winding a laminated body in which a plurality of belt-like bodies each having a belt-like conductor disposed on one surface of a belt-like insulator are laminated in a predetermined direction, and the laminated body in the predetermined direction. Is a filter element comprising a second coil portion wound in the opposite direction and formed into a cylindrical shape,
The first coil part and the second coil part are connected to each other in a predetermined part located in an inner peripheral part in the state of being formed in the cylindrical shape, and Of the strip conductors, the strip conductor located on the outermost periphery in the state of being formed in the cylindrical shape functions as a strip conductor for grounding, and the other strip conductors excluding the strip conductor for grounding The filter element comprised so that the some strip | belt-shaped conductor adjacent on both sides of the said strip | belt-shaped insulator of a body may function as a strip | belt-shaped conductor for signals. The first coil portion is formed by winding a half on one end side of the laminated body in a predetermined direction around a boundary portion with a half on the other end side of the laminated body,
2. The filter element according to claim 1, wherein the second coil portion is formed by winding a half of the other end side of the laminated body in a direction opposite to the predetermined direction with the boundary portion as a center.   A ground wire is connected to the grounding strip-shaped conductor at one of the two partition portions of the two coil portions defined by a virtual plane passing through the respective central axes of the first coil portion and the second coil portion. The filter element according to claim 1, wherein an input line and an output line are connected to the signal strip conductor in the other of the two partition parts.

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