JP2007081051A - Common mode filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a common mode filter whose high-frequency characteristics can be improved. <P>SOLUTION: This common mode filter CF comprises a plate-shaped core member 1, first and second terminal electrodes 3, 4 formed on the first side face 1a of the core member 1, third and fourth terminal electrodes 5, 6 formed on the second side face 1b thereof, a first coil conductor 11, and a second coil conductor 13. The first coil conductor 11 has one end thereof electrically connected to the first terminal electrode 3 and the other end thereof electrically connected to the third terminal electrode 5. The second coil conductor 13 has one end thereof electrically connected to the second terminal electrode 4, and the other end thereof electrically connected to the fourth terminal electrode 6. The first and second coil conductors 11, 13 are grown and formed on the third-the sixth side faces of the core member 1, so that they are helically wound about the core member 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a common mode filter.

  Conventional common mode filters include a stacked common mode filter and a wound common mode filter. As a laminated common mode filter, a laminated body in which a plurality of insulators are laminated, first to fourth terminal electrodes formed in the laminated body, and first and second conductors electrically connected to each other There are known ones including a first coil including a second coil including a third conductor and a fourth conductor which are arranged in the laminated body and are electrically connected to each other (for example, Patent Literature 1). 1).

  In the laminated common mode filter as described in Patent Document 1, since the distance between the input terminal electrode and the output terminal electrode is short, the capacitance formed between the input / output terminal electrodes becomes large. Further, since the first to fourth conductors are laminated via the thin insulator layer, the conductors forming the same coil, that is, the first and second conductors, and the third and fourth conductors are formed. A large capacitance is also formed between the conductors. As described above, in the stacked common mode filter disclosed in Patent Document 1, the value of the capacitance that affects the noise removal in the common mode is increased. Therefore, resonance occurs at a low frequency, high frequency common mode noise cannot be sufficiently removed, and high frequency characteristics deteriorate.

On the other hand, a wound common mode filter is known in which a plurality of coils are formed by spirally winding a plurality of conducting wires around a drum core (see, for example, Patent Document 2). In this case, each wound conducting wire forms one coil. In this type of wire wound common mode filter, an input terminal electrode and an output terminal electrode are formed on the flanges at both ends of the drum core. Therefore, a sufficient distance can be secured between the input terminal electrode and the output terminal electrode, and the capacitance formed between the input / output terminal electrodes can be made smaller than that of the multilayer common mode filter. Furthermore, since the space between the winding portions of one conductive wire wound spirally, that is, the space between the conductors forming the same coil can be made larger than that of the laminated type, the same coil is formed. The capacitance formed between the conductors can also be reduced.
JP-A-8-203737 (Patent No. 3601619) JP 2003-168611 A

  When a high frequency signal is passed through a wire wound common mode filter as disclosed in Patent Document 2, a portion of the conducting wire that does not form a coil, that is, a portion that is not spirally wound, begins to function as an inductor. The inductance value becomes large. As a result, the impedance to the signal shows a high value. Furthermore, in the winding type common mode filter as disclosed in Patent Document 2, a large capacitance is formed by a high frequency signal between different conductors forming different coils. The signal is attenuated by this capacitance. In order to suppress the influence on the signal, it is desired to suppress the inductance value of the conducting wire and reduce the value of the capacitance formed between the different conducting wires.

  The inductance value of the conducting wire can be suppressed by magnetically coupling different conducting wires that form different coils to cancel the magnetic flux generated by these conducting wires. In order to magnetically couple different conducting wires to each other, it is necessary to wind these conducting wires close to each other. On the other hand, the capacitance value formed between the different conductors can be suppressed by winding a plurality of conductors around the core so that the interval between the different conductors is increased. Thus, the means for reducing the inductance value and the means for reducing the capacitance value are contradictory.

  Furthermore, if only one of the inductance value and the capacitance value is made extremely small, impedance matching cannot be performed, resulting in a problem of signal reflection. . Therefore, the wound common mode filter is required to reduce the inductance value and the capacitance value in a well-balanced manner. For this purpose, the distance between the different conductors must be set to a suitable value without being too small and not too large.

  Also, if the spacing between different conductors varies, the means for reducing the inductance value and the means for reducing the capacitance value conflict, so that the balance between the inductance value and the capacitance value can be easily achieved. Will collapse. Therefore, it is required to set the interval between different conductors to an appropriate value and to suppress variation in the interval.

  In response to such a demand, the wound common mode filter described in Patent Document 2 is formed by winding a conductive wire around a core. It is very difficult to wind a conducting wire around a core at regular intervals. Therefore, it is difficult for the wire wound common mode filter described in Patent Document 2 to pass a high-frequency signal stably.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a common mode filter capable of improving high frequency characteristics.

  In order to achieve such an object, a common mode filter according to the present invention includes a substantially rectangular parallelepiped core member mainly composed of a magnetic material and having first to sixth side surfaces, and a first side surface of the core member. And the third and fourth terminal electrodes formed at least partially on the second side surface of the core member opposite to the first side surface, respectively. And one end electrically connected to the first terminal electrode and the other end electrically connected to the third terminal electrode. The first coil conductor to be connected and the third to sixth side surfaces of the core member are formed, one end is electrically connected to the second terminal electrode, and the other end is the fourth terminal. A second coil conductor electrically connected to the electrode, and the first and second Yl conductor is characterized in that it is formed on the third to the sixth aspect of the core member so as to wind the core member in a spiral.

  The first and second coil conductors in the common mode filter are formed in a spiral shape on the third to sixth side surfaces of the core member. Thereby, it is suppressed that the space | interval between the 1st and 2nd coil conductors varies. Therefore, in the above-mentioned common mode filter, the impedance value and the capacitance value can be reduced while impedance matching is performed, and a high-frequency signal can be passed stably.

  The first coil conductor and the second coil conductor are preferably formed by plating a conductive material. In this case, since the first and second coil conductors are firmly formed on the third to sixth side surfaces, variation in the distance between the first and second coil conductors is well suppressed. The

  In the third to sixth side surfaces of the core member, the third side surface and the fourth side surface are opposed to each other, and at least a portion formed on the third side surface of the first coil conductor and the first side surface The pattern of the part formed on the side surface of 4, the pattern of the part formed on the third side surface of the second coil conductor and the pattern of the part formed on the fourth side surface are photolithography methods. It is preferable that it is patterned by. According to the photolithography method, patterning can be performed precisely, so that the interval between conductors can be set to a desired value and variation can be suppressed satisfactorily. Further, by applying the photolithography method only to the two opposite side surfaces, the conductor portions of the plurality of common mode filters can be collectively patterned on one substrate. Therefore, manufacture becomes easy.

  And further including an insulator member disposed to face any one of the third to sixth side surfaces of the core member, wherein the first and second terminal electrodes are respectively formed on the first side surface. The third and fourth terminal electrodes are provided on the second side surface. The third and fourth terminal electrodes are respectively connected to the second side surface. It is preferable to have a wraparound portion that wraps around a side surface that is continuous with the portion formed on the side of the insulator member and is located on the side opposite to the side surface facing the core member of the insulator member. By providing the insulator member having the side surface on which the terminal electrode is formed, it is possible to suppress the occurrence of a short circuit during mounting.

  It is preferable to further include a magnetic member arranged to face any one of the third to sixth side surfaces of the core member. By further providing a magnetic member, a closed magnetic circuit structure is obtained, and the impedance against noise can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, the common mode filter which can improve a high frequency characteristic can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  First, the configuration of the common mode filter CF according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing a common mode filter according to the present embodiment. FIG. 2 is an exploded configuration diagram of the common mode filter according to the present embodiment. In addition, illustration of the terminal electrodes 3-6 is abbreviate | omitted in FIG.

  As shown in FIG. 1, the common mode filter CF includes a core member 1, which is a ferrite substrate, an insulator member 21, a magnetic member 23, first to fourth terminal electrodes 3 to 6, and a first member. And second coil conductors 11 and 13. In FIG. 1, a part of the first and second terminal electrodes 3 and 4 and the third and fourth terminal electrodes 5 and 6 are shown by dotted lines.

  The core member 1 has a rectangular parallelepiped shape and has first to sixth side surfaces 1a to 1f. The first and second side surfaces 1a and 1b face each other. The third and fourth side surfaces 1c and 1d face each other. The fifth and sixth side surfaces 1e and 1f face each other. Of the four side surfaces adjacent to the first and second side surfaces 1a and 1b, two side surfaces extending in the longitudinal direction are the third and fourth side surfaces 1c and 1d. Of the four side surfaces adjacent to the first and second side surfaces 1a and 1b, two side surfaces extending in the short direction are the fifth and sixth side surfaces 1e and 1f. The core member 1 is made of a magnetic material such as ferrite.

  The insulator member 21 is disposed so as to face the fourth side surface 1 d of the core member 1. The insulator member 21 is formed in a plate shape so as to cover the fourth side surface 1 d of the core member 1. As the insulator member 21, for example, a ferrite substrate can be used. The insulator member 21 and the core member 1 are bonded together by an adhesive layer 31 inserted therebetween. In the common mode filter CF according to the present embodiment, it is preferable to mount the insulator member 21 so as to face the mounting surface of the substrate or the like.

  The magnetic member 23 is disposed so as to face the third side surface 1 c of the core member 1. The magnetic member 23 is formed in a plate shape so as to cover the fourth side surface 1 d of the core member 1. The magnetic member 23 is made of a magnetic material such as ferrite. The magnetic member 23 and the core member 1 are bonded by an adhesive layer 33 inserted therebetween. The adhesive layers 31 and 33 are formed of resin, for example.

  A part of each of the first and second terminal electrodes 3 and 4 is formed on the first side surface 1a of the core member 1 so as to cover the third side surface 1c and the fourth side surface 1d in a facing direction. Has been. As shown in FIG. 1, the first and second terminal electrodes 3 and 4 are further positioned on the bottom surface of the common mode filter CF, that is, on the side opposite to the side surface of the insulator member 21 facing the core member 1. It has wraparound portions 3A and 4A that wrap around the side surface.

  A part of each of the third and fourth terminal electrodes 5 and 6 is formed on the second side face 1b of the core member 1 so as to cover the third side face 1c and the fourth side face 1d in a facing direction. Has been. As shown in FIG. 1, the third and fourth terminal electrodes 5 and 6 are further positioned on the bottom surface of the common mode filter CF, that is, on the side opposite to the side surface of the insulator member 21 facing the core member 1. It has wraparound portions 5A and 6A that wrap around the side surface.

  The first and second coil conductors 11 and 13 are formed so as to be wound around the core member 1 as shown in FIG. That is, the first and second coil conductors 11 and 13 are each formed in a plurality of times spirally around the core member 1 around the direction in which the first and second side surfaces 1a and 1b of the core member 1 face each other (this embodiment). In the form, it is formed by winding three times each. The first and second coil conductors 11 and 13 are formed such that the distance d between the first coil conductor 11 and the second coil conductor 13 adjacent to each other is substantially constant.

  One end portion 11 a of the first coil conductor 11 extends so as to be drawn to the first side surface 1 a of the core member 1, is exposed to the side surface 1 a, and is electrically connected to the first terminal electrode 3. . The other end portion 11 b of the first coil conductor 11 extends so as to be drawn to the second side surface 1 b of the core member 1 and is exposed to the side surface 1 b, and is electrically connected to the third terminal electrode 5. The One end portion and the other end portions 11a and 11b of the first coil conductor 11 each function as a lead conductor.

  One end portion 13 a of the second coil conductor 13 extends so as to be drawn to the first side surface 1 a of the core member 1 and is exposed to the side surface 1 a and is electrically connected to the second terminal electrode 4. . The other end portion 13 b of the second coil conductor 13 extends so as to be drawn to the second side surface 1 b of the core member 1 and is exposed to the side surface 1 b, and is electrically connected to the fourth terminal electrode 6. The One end portion and the other end portions 13a and 13b of the second coil conductor 13 each function as a lead conductor.

  The first and second coil conductors 11 and 13 are formed on the third to sixth side faces 1c to 1f of the core member 1 so as to grow. More specifically, the first and second coil conductors 11 and 13 are formed on the third to sixth side surfaces 1c to 1f of the core member 1 by plating with a conductive material.

  In the common mode filter CF according to the present embodiment, both ends of the first coil conductor 11 and the first conductor portion 11c formed on the third side surface 1c of the core member 1 are the first coil conductor 11 portions. The patterns of the portions 11a and 11b are patterned by a photolithography method. A pattern of the second conductor portion 11d which is a part of the first coil conductor 11 and is formed on the fourth side surface 1d of the core member 1 is patterned by a photolithography method.

  The pattern of the first conductor portion 13c and the two end portions 13a and 13b of the second coil conductor 13 which are portions of the second coil conductor 13 and formed on the third side surface 1c of the core member 1 is a photolithography method. Is patterned. The pattern of the second conductor portion 13d, which is the portion of the second coil conductor 13 and formed on the fourth side surface 1d of the core member 1, is patterned by photolithography.

  A third conductor portion 11e formed on the fifth side surface 1e of the core member 1 and a portion of the first coil conductor 11, and a portion of the first coil conductor 11 and the sixth coil member 11 of the core member 1. Each of the fourth conductor portions 11f formed on the side surface 1f is formed as a plating by a sputtering method or the like. A portion of the second coil conductor 13 and the third conductor portion 13e formed on the fifth side surface 1e of the core member 1, and a portion of the second coil conductor 13 and the sixth portion of the core member 1. Each of the fourth conductor portions 13f formed on the side surface 1f is formed as a plating by a sputtering method or the like.

  Next, a method for manufacturing the common mode filter CF according to the present embodiment will be described with reference to FIGS.

  FIG. 3A is a process cross-sectional view illustrating a process of forming a thin film of a conductive material on both main surfaces of the circular plate-shaped ferrite substrate 40. As shown in FIG. 3A, thin films (plating) 41 and 42 made of a conductive material are grown and formed on both main surfaces of a plate-like ferrite substrate 40. The thin films 41 and 42 are formed by, for example, a plating method (including electroplating, sputtering, vapor deposition, etc.).

  Next, a process of forming the first and second coil conductors 11 and 13 on both main surfaces of the ferrite substrate 40 will be described with reference to FIG. FIG. 3B is a process cross-sectional view illustrating a process of forming the first and second coil conductors 11 and 13 on both main surfaces of the ferrite substrate 40.

  The thin films 41 and 42 formed on both main surfaces of the ferrite substrate 40 are patterned by a photoresist method. For patterning by photolithography, a photosensitive resist is coated on a thin film, exposed and developed with a mask, and after the resist is shaped according to the mask pattern, unnecessary thin film portions are etched and the resist is removed. Made by doing.

  By patterning in this way, the first conductor portion 11 c of the first coil conductor 11, the first conductor portion 13 c of the second coil conductor 13, and the first coil conductor 11 are formed on one main surface of the ferrite substrate 40. A plurality of patterns corresponding to a plurality (16 in the present embodiment) of common mode filters CF are formed on both ends 11a and 11b of the first and second ends 13a and 13b of the second coil conductor 13. In the patterning, the first conductor portion 11c of the first coil conductor 11 and the first conductor portion 13c of the second coil conductor 13 included in the same common mode filter CF and adjacent to each other are formed with an interval d. Is done. The first conductor portion 11c of the first coil conductor 11 and the first conductor portion 13c of the second coil conductor 13 are both formed in a straight line having a width.

  On the other hand, by patterning, a plurality of patterns of the second conductor portion 11d of the first coil conductor 11 and the second conductor portion 13d of the second coil conductor 13 are formed on the other main surface of the ferrite substrate 40. A plurality of patterns corresponding to 16 (in this embodiment) common mode filters CF are formed. In patterning, the second conductor portion 11d of the first coil conductor 11 and the second conductor portion 13d of the second coil conductor 13 included in the same common mode filter CF and adjacent to each other are formed with a gap d. Is done. The second conductor portion 11d of the first coil conductor 11 and the second conductor portion 13d of the second coil conductor 13 are both formed in a straight line having a width.

  Thus, as shown in FIG. 3B, the first and second conductors of the first and second coil conductors 11 and 13 of the plurality of common mode filters CF on both main surfaces of one ferrite substrate 40, respectively. Portions 11c, 13c, 11d, 13d and end portions 11a, 11b, 13a, 13b (not shown) are formed. 4 shows the first conductor portion 11c and both end portions 11a and 11b of the first coil conductor 11 of the plurality of common mode filters CF and the first conductor portion 13c of the second coil conductor 13 on one main surface. It is a top view of the ferrite substrate 40 in which both ends 13a and 13b are formed. In addition, the dashed-dotted line D of FIG. 4 is the cutting plan position mentioned later.

  Next, with reference to FIG. 5A, a process of bonding the insulator substrate 43 to the ferrite substrate 40 will be described. FIG. 5A is a process cross-sectional view illustrating a process of bonding the insulator substrate 43 to the ferrite substrate 40.

  As shown in FIG. 5A, a plate-like insulator substrate 43 is bonded to the main surface side of the ferrite substrate 40 on which the second conductor portions 11d and 13d are formed via an adhesive 45. Thereby, the main surface of the ferrite substrate 40 on which the second conductor portions 11d and 13d are formed and the insulator substrate 43 are disposed so as to face each other.

  Next, with reference to FIG. 5B, a process of bonding the magnetic substrate 47 to the ferrite substrate 40 will be described. FIG. 5B is a process cross-sectional view illustrating the process of bonding the magnetic substrate 47 to the ferrite substrate 40.

  As shown in FIG. 5B, a plate-like magnetic substrate 47 is bonded to the surface side of the ferrite substrate 40 on which the first conductor portions 11c and 13c are formed via an adhesive 49. Accordingly, the main surface of the ferrite substrate 40 on which the first conductor portions 11c and 13c are formed and the magnetic substrate 47 are arranged so as to face each other. As the magnetic substrate 47, for example, a ferrite substrate can be used.

  Thereafter, as shown in FIG. 5B, the ferrite substrate 40 to which the insulator substrate 43 and the magnetic substrate 47 are bonded is cut at a planned cutting position D (see FIG. 4) to form one common mode filter CF. A corresponding filter element 50 is obtained.

  Of the four side surfaces other than the side surface of the filter element 50 obtained by cutting, that is, the side surface to which the insulator member 21 or the magnetic member 23 is bonded, the first and second coil conductors 11 and 13 respectively. And the third and fourth conductor portions 11e, 11f, 13e, and 13f of the first and second coil conductors 11 and 13 on two side surfaces from which the second conductor portions 11c, 11d, 13c, and 13d are drawn out and face each other. Is formed.

  The conductor portions 11e, 11f, 13e, and 13f are formed by attaching a mask having a pattern of these conductor portions on the side surface of the filter element 50 and growing a conductive material by a sputtering method.

  As a result, the third and fourth conductor portions 11e and 11f of the first coil conductor 11 are electrically connected to the first conductor portion 11c and the second conductor portion 11d of the first coil conductor 11 at their both ends. Connected. The third and fourth conductor portions 13e and 13f of the second coil conductor 13 are electrically connected to the first conductor portion 13c and the second conductor portion 13d of the second coil conductor 13 at both ends. . As a result, the first and second coil conductors 11 and 13 are spirally formed on the third to sixth side surfaces 1c to 1f of the core member 1 so as to wind the core member 1. Become.

  On the other hand, among the four side surfaces other than the side surface of the filter element 50 obtained by cutting, that is, the side surface to which the insulator member 21 or the magnetic member 23 is bonded, each of the first and second coil conductors 11 and 13 is provided. The first and second terminal electrodes 3 and 4 are formed on the side surfaces from which the end portions 11a and 13a are drawn. Further, among the four side surfaces other than the side surface of the filter element 50 obtained by cutting, that is, the side surface to which the insulator member 21 or the magnetic member 23 is bonded, each of the first and second coil conductors 11 and 13 is provided. Third and fourth terminal electrodes 5 and 6 are formed on the side surfaces from which the end portions 11b and 13b are drawn.

  The first to fourth terminal electrodes 3 to 6 are formed by, for example, sequentially forming plating layers (for example, Cr layer and Cu layer) of a conductive material by mask sputtering, and then performing electroplating layers (for example, Cu, Ni, Sn) by barrel plating. Are formed in this order. In addition, as a metal material which forms the terminal electrodes 3-6, Ag, Cu, etc. may be sufficient.

  In the common mode filter CF, terminal electrodes 3 to 6 are formed at both ends of the plate-like core member 1. Therefore, a sufficient distance can be secured between the input terminal electrode and the output terminal electrode, and the capacitance formed between the input / output terminal electrodes can be sufficiently reduced. Further, the interval between the first coil conductors 11 formed in a spiral shape and the interval between the second coil conductors 13 are set so that the value of the capacitance formed between the same coil conductors is sufficiently small. It can be enlarged. Therefore, the common mode filter CF can sufficiently remove high-frequency common mode noise.

  In the common mode filter CF, the first and second coil conductors 11 and 13 formed in a spiral shape are grown on the third to sixth side surfaces 1c to 1f of the core member 1. Therefore, the first and second coil conductors 11 and 13 are formed in close contact with the third to sixth side faces 1c to 1f of the core member 1, and the first and second coil conductors 11, It is suppressed that the interval between 13 varies. Therefore, in the common mode filter CF, it is possible to balance and maintain the inductance value and the capacitance value in consideration of impedance matching while reducing the inductance value and the capacitance value. It becomes. As a result, in the common mode filter CF, the influence on the high frequency signal can be reduced, the high frequency signal can be stably passed, and the high frequency characteristics are improved.

  The core member 1 of the common mode filter CF has first to sixth side faces 1a to 1f and has a rectangular parallelepiped shape. Therefore, for example, as in the manufacturing method described above, the patterns of the first and second conductor portions 11c, 13c, 11d, and 13d of the first and second coil conductors 11 and 13 of the plurality of common mode filters are formed by photolithography. Patterning can be performed at once. On the other hand, for example, when a drum core member having a flange is used as the core member, even if patterning is performed using a photolithography method, a plurality of common mode filters may be used at the same time as in the method for manufacturing the common mode filter CF described above. It is difficult to perform the patterning. Therefore, the common mode filter CF can be easily manufactured.

  The first and second coil conductors 11 and 13 of the common mode filter CF are formed by plating a conductive material. Accordingly, since the first and second coil conductors 11 and 13 are formed in close contact with the third to sixth side surfaces 1c to 1f, the distance between the first and second coil conductors 11 and 13 is determined. It is possible to favorably suppress the variation.

  The patterns of the first and second conductor portions 11c, 11d, 13c, and 13d of the first and second coil conductors 11 and 13 of the common mode filter CF are patterned by photolithography. According to the photolithography method, patterning can be performed accurately, so that the interval between conductors can be set to a desired value and variation can be suppressed well.

  The third and fourth conductor portions 11e, 11f, 13e, and 13f of the first and second coil conductors 11 and 13 of the common mode filter CF are formed by a sputtering method using a mask that is a plating method. By not patterning all the patterns of the first and second coil conductors 11 and 13 by photolithography, but forming a part of the first and second coil conductors 11 and 13 by sputtering using a mask. Further, it becomes possible to facilitate the manufacture.

  The common mode filter CF includes an insulator member 21 and covers the fourth side surface 1 d of the core member 1. Of the fourth side surface 1d of the core member 1, the wraparound portion 3A of the first terminal electrode 3, the wraparound portion 4A of the second terminal electrode 4, the wraparound portion 5A of the third terminal electrode 5, and the fourth terminal A region corresponding to the wraparound portion 6 </ b> A of the electrode 6 is covered with the insulator member 21. Therefore, when the insulator member 21 is mounted on the side surface of the common mode filter CF so as to face the mounting surface such as a substrate, the occurrence of a short circuit can be suppressed.

  The common mode filter CF includes a magnetic member 23 disposed so as to face the third side surface 1 c of the core member 1. By further including the magnetic member 23, a closed magnetic circuit structure is obtained, and the impedance against noise can be increased.

  The preferred embodiments and modifications of the present invention have been described above, but the present invention is not necessarily limited to these embodiments and modifications. For example, the surface of the core member 1 may be covered with resin or the like. Further, both or one of the insulator member 21 and the magnetic member 23 may not be provided. Moreover, the core member 1 may have a substantially rectangular parallelepiped shape with a rounded apex angle, for example.

  Further, the insulator member 21 does not cover the entire surface of the fourth side surface 1d of the core member 1, and the wraparound portion 3A of the first terminal electrode 3 and the second terminal electrode of the fourth side surface 1d of the core member 1 are provided. It is only necessary to cover the region corresponding to the four wraparound portions 4 </ b> A and the region corresponding to the wraparound portion 5 </ b> A of the third terminal electrode 5 and the wraparound portion 6 </ b> A of the fourth terminal electrode 6.

  Further, the insulating member 21 may be formed by a printing technique without providing the adhesive layer 31. For example, the magnetic layer member 23 formed by mixing ferrite powder into resin may be provided without the adhesive layer 33.

  The manufacturing method of the common mode filter CF is not limited to the manufacturing method as described above. For example, the patterns of the conductor portions 11c, 11d, 13c, and 13d of the first and second coil conductors 11 and 13 may not be patterned by photolithography. For example, the first and second coil conductors 11 and 11 Both of 13 may be formed by a sputtering method using a mask. Alternatively, all the patterns of both the first and second coil conductors 11 and 13 may be patterned by a photolithography method. Alternatively, the first and second coil conductors 11 and 13 are not limited to plating, and may be formed by applying and baking a conductive paste, for example. The plating method for forming the first and second coil conductors 11 and 13 is not limited to the sputtering method, and may be, for example, a vapor deposition method.

It is a perspective view which shows the common mode filter which concerns on embodiment. It is the block diagram which decomposed | disassembled and showed the common mode filter which concerns on embodiment. It is a figure for demonstrating the manufacturing method of the common mode filter which concerns on embodiment. It is a top view of a ferrite substrate on which first and second coil conductors are formed. It is a figure for demonstrating the manufacturing method of the common mode filter which concerns on embodiment.

Explanation of symbols

CF: Common mode filter, 1 ... Core member, 1a to 1f ... First to sixth side surfaces, 3 ... First terminal electrode, 4 ... Second terminal electrode, 5 ... Third terminal electrode, 6 ... First 4 terminal electrodes, 11 ... first coil conductor, 13 ... second coil conductor, 21 ... insulator member, 23 ... magnetic member, 31, 33 ... adhesive layer, 40 ... ferrite substrate, 41, 42 ... thin film , 43 ... Insulator substrate, 47 ... Magnetic substrate, 45, 49 ... Adhesive, 50 ... Filter element

Claims (5)

A substantially rectangular parallelepiped core member having a magnetic body as a main component and having first to sixth side surfaces;
First and second terminal electrodes each of which is formed at least partially on the first side surface of the core member;
Third and fourth terminal electrodes each of which is formed at least partially on the second side surface of the core member facing the first side surface;
It is formed on the third to sixth side surfaces of the core member, and one end is electrically connected to the first terminal electrode and the other end is electrically connected to the third terminal electrode. A first coil conductor,
It is formed on the third to sixth side surfaces of the core member, and one end is electrically connected to the second terminal electrode and the other end is electrically connected to the fourth terminal electrode. A second coil conductor,
The common mode filter, wherein the first and second coil conductors are formed on third to sixth side surfaces of the core member so as to spirally wind the core member.   The common mode filter according to claim 1, wherein the first coil conductor and the second coil conductor are formed by plating a conductive material. In the third to sixth side surfaces of the core member, the third side surface and the fourth side surface are opposed to each other,
A pattern of at least a portion formed on the third side surface of the first coil conductor and a portion formed on the fourth side surface; and on the third side surface of the second coil conductor. The common mode filter according to claim 1, wherein the pattern of the formed part and the pattern of the part formed on the fourth side surface are patterned by a photolithography method. An insulator member arranged to face any one of the third to sixth side surfaces of the core member;
Each of the first and second terminal electrodes is continuous with a portion formed on the first side surface, and wraps around a side surface of the insulator member that is opposite to the side surface facing the core member. Having a wraparound part,
Each of the third and fourth terminal electrodes is continuous with the portion formed on the second side surface, and on the side surface located on the opposite side of the insulator member from the side surface facing the core member. The common mode filter according to claim 1, further comprising a wraparound portion.   5. The magnetic member according to claim 1, further comprising a magnetic member disposed to face any one of the third to sixth side surfaces of the core member. Common mode filter as described.

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