JP2008289111A - Multilayer filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer filter, the attenuation characteristic of which is not worsened even when a magnetic layer and a varistor layer are integrally sintered. <P>SOLUTION: A multilayer filter F1 comprises an inductor stacked-layer portion 7 and a varistor stacked-layer portion 9. The varistor stacked-layer portion 9 has a varistor layer 8<SB>1</SB>-8<SB>5</SB>, the main component of which is ZnO and a hot electrode 16 and ground electrode 17<SB>1</SB>, 17<SB>2</SB>positioned in opposite with the varistor layer 8<SB>1</SB>-8<SB>5</SB>intervening, and a region A1, A2 enclosed between the opposing hot electrode 16 and ground electrode 17<SB>1</SB>, 17<SB>2</SB>does not contain a Cu component. Because the region A1, A2 enclosed between the opposing hot electrode 16 and ground electrode 17<SB>1</SB>, 17<SB>2</SB>is a region which manifests varistor characteristics, and thus the region does not contain a Cu component, degradation in the attenuation characteristics can be suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multilayer filter.

In recent years, noise filters having a surge function are used in various electronic devices as EMC countermeasure components. In Patent Document 1, a magnetic layer having a predetermined conductor pattern formed therein and a varistor layer having a predetermined conductor pattern formed therein are stacked, and the magnetic layer and the varistor layer are electrically connected by a through hole. Connected composite laminated electronic components are disclosed.
Japanese Patent No. 2626143

  However, in Patent Document 1, the magnetic layer and the varistor layer are integrally sintered, and the material components constituting each layer may diffuse to each other at the interface between the magnetic layer and the varistor layer. If this material component is diffused, the characteristics of the diffused layer are affected, and the function as a noise filter may be reduced. In Patent Document 1, Ni—Cu—Zn-based ferrite is used for the magnetic layer. However, when the magnetic layer made of such a material is integrally sintered with the varistor layer, the Cu component in the magnetic layer becomes the varistor. The inventors have obtained the knowledge that the varistor function, particularly the attenuation characteristic, is deteriorated by being diffused into the layer and penetrating into a region where the varistor characteristic is expressed.

  Therefore, an object of the present invention is to provide a multilayer filter that does not deteriorate the attenuation characteristics even when the magnetic layer and the varistor layer are integrally sintered.

  The multilayer filter according to the present invention is a multilayer filter including an inductor portion and a varistor portion, and the varistor portion includes a varistor layer mainly composed of ZnO and a plurality of varistors arranged to face each other via the varistor layer. A region having a conductor portion and sandwiched between opposing varistor conductor portions does not contain a Cu component.

  According to the present invention, a Cu component is not contained in a region sandwiched between opposing varistor conductor portions, that is, a region that exhibits varistor characteristics. Therefore, deterioration of the attenuation characteristic can be suppressed.

  In the multilayer filter of the present invention, it is preferable that the inductor part and the varistor part are laminated via an intermediate part, and the intermediate part has a composition different from that of the inductor part and the varistor part and does not contain a Cu component. By providing an intermediate layer having a composition different from that of the inductor portion and the varistor portion, the influence of the inductor portion from the varistor portion and the influence of the varistor portion from the inductor portion can be reduced. Moreover, since this intermediate layer does not contain a Cu component, the possibility that the Cu component is diffused into the varistor layer is extremely low, and deterioration of the attenuation characteristics can be more reliably suppressed.

  In the multilayer filter of the present invention, the inductor portion includes an inductor layer and an inductor conductor portion formed in the inductor layer, and the inductor layer includes Ni—Zn ferrite, Ni—Zn—Mg ferrite, and Zn. It is preferable that it is formed of any of the ferrites and does not contain a Cu component. Since the inductor layer does not contain a Cu component, the possibility that the Cu component is diffused into the varistor layer is further reduced. Therefore, deterioration of the attenuation characteristic can be reliably suppressed. In particular, when an inductor layer is formed using either Ni-Zn based ferrite or Ni-Zn-Mg based ferrite, it has a high inductance value, so the multilayer filter has excellent filter characteristics. Can be.

  In the multilayer filter of the present invention, the inductor part is preferably a common mode choke coil having a sintered body and a plurality of coil conductors arranged inside the sintered body. In this case, since the multilayer electronic component has a common mode choke coil function, a multilayer filter with improved filter characteristics in a high frequency band can be provided.

  In the multilayer filter of the present invention, each coil conductor is composed of a plurality of conductor patterns arranged in the first direction, and the first sintered body is sandwiched between the conductor patterns in the first direction. The first layer and the second layer sandwiching the plurality of coil conductors in the first direction are preferably provided. The first layer is preferably made of a nonmagnetic material, and the second layer is preferably made of a magnetic material. In this case, since the second layer made of the magnetic material is laminated on both sides of the first layer made of the nonmagnetic material and sandwiched between the conductor patterns, the frequency band in which the inductance value of the coil conductor can be secured, It can be increased to a relatively high frequency region. Therefore, it is possible to provide a multilayer filter having better filter characteristics.

  In the multilayer filter of the present invention, each coil conductor is composed of a plurality of conductor patterns arranged in the first direction, and the first sintered body is sandwiched between the conductor patterns in the first direction. The first layer and the second layer sandwiching the plurality of coil conductors in the first direction are preferably provided, and the first and second layers are preferably made of a magnetic material. In this case, since the second layer made of the same magnetic material is laminated on both sides of the first layer made of the magnetic material and sandwiched between the conductor patterns, the first layer is made of the non-magnetic material and the second layer is made of the second material. Compared with a layer made of a magnetic material, the inductance value of the coil conductor in a lower frequency region can be further increased. Therefore, it is possible to provide a multilayer filter having better filter characteristics.

  In the multilayer filter of the present invention, each coil conductor is composed of a plurality of conductor patterns arranged in the first direction, and the first sintered body is sandwiched between the conductor patterns in the first direction. The first layer and the second layer sandwiching the plurality of coil conductors in the first direction are preferably provided, and the first and second layers are preferably made of a nonmagnetic material. In this case, since the second layer made of the same nonmagnetic material is laminated on both sides of the first layer made of the nonmagnetic material and sandwiched between the conductor patterns, the first layer is made of the nonmagnetic material. Compared with the case where the second layer is made of a magnetic material, the frequency band in which the inductance value of the coil conductor can be secured can be further increased to the high frequency region. Therefore, it is possible to provide a multilayer filter having more excellent filter characteristics.

  According to the present invention, it is possible to provide a multilayer filter that does not deteriorate the attenuation characteristics even if the magnetic layer and the varistor layer are integrally sintered.

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 embodiment)

  FIG. 1 is a schematic perspective view showing the multilayer filter according to the first embodiment, and FIG. 2 is an exploded perspective view showing the laminated body of the multilayer filter according to the first embodiment in an exploded manner. FIG. 3 is a sectional view showing a central section of the multilayer filter according to the first embodiment, and FIG. 4 is an equivalent circuit diagram of the multilayer filter according to the first embodiment. In addition, the cross section in FIG. 3 is a surface parallel to the longitudinal direction and lamination direction of a laminated body. FIG. 1 also serves as a perspective view of a multilayer filter according to a second embodiment to be described later.

  The multilayer filter F1 shown in FIG. 1 is a multilayer filter array component, and as shown in FIG. 4, four L-type filter elements each composed of an inductor 13 and a varistor 20 are provided in parallel. It is. The multilayer filter F1 includes a multilayer body CE1 having a substantially rectangular parallelepiped shape, four input terminal electrodes 3, four output terminal electrodes 4, and a pair of ground terminal electrodes 5.

  The stacked body CE1 has first and second end faces CE1a, CE1b, first and second side faces CE1c, CE1d, and first and second main faces CE1e, CE1f. The first and second main surfaces CE1e, CE1f have a rectangular shape and face each other. The first and second end faces CE1a, CE1b extend in the short side direction of the first and second main faces CE3e, CE3f so as to connect the first and second main faces CE1e, CE1f and face each other. ing. The first and second side surfaces CE1c, CE1d extend in the long side direction of the first and second main surfaces CE1e, CE1f so as to connect the first and second main surfaces CE1e, CE1f and face each other. ing.

  The four input terminal electrodes 3 are sequentially provided on the first side face CE1c of the multilayer body CE1, and each has a shape extending in the stacking direction of the multilayer body CE1. Similarly, the four output terminal electrodes 4 are sequentially provided on the second side surface CE1d of the multilayer body CE1, and each has a shape extending in the stacking direction of the multilayer body CE1. The input terminal electrode 3 and the output terminal electrode 4 are provided so as to face each other.

  One of the pair of ground terminal electrodes 5 is arranged at the center of the first end face CE1a of the multilayer body CE1, and has a shape extending in the stacking direction of the multilayer body CE1. The other of the pair of ground terminal electrodes 5 is disposed at the center of the second end face CE1b of the multilayer body CE1, and has a shape extending in the stacking direction of the multilayer body CE1. The pair of ground terminal electrodes 5 are provided so as to face each other.

The stacked body CE1 will be described in detail. As shown in FIGS. 2 and 3, the laminate CE1 is an inductor multilayer section inductor layer ₆₁ through ₉ are laminated with the (inductor portion) 7, the varistor layer ₈ 1-8 ₅ are stacked A varistor laminated portion (varistor portion) 9 and an intermediate laminated portion (intermediate portion) 10 formed by laminating a plurality of intermediate layers 11 are included. The inductor laminated portion 7 and the varistor laminated portion 9 are laminated via the intermediate laminated portion 10.

The inductor layer ₆₁ through ₉ are exhibited rectangular thin plate shape, and a ferrite material. As the ferrite material, any one of Ni—Zn ferrite, Ni—Zn—Mg ferrite, and Zn ferrite is used. In particular, when Ni—Zn-based ferrite and Ni—Zn—Mg-based ferrite are used, a high inductance value is obtained, so that the filter characteristics are further improved. The inductor layers 6 _{1 to} 6 ₉ may contain a Cu component.

Varistor layer 8 _{1-8 5} has the shape of a rectangular thin plate shape, and a ceramic material composed mainly of ZnO. This ceramic material may contain Pr, Bi, Co, Al or the like as an additive component. When Co is contained in addition to Pr, it has excellent varistor characteristics and also has a high dielectric constant (ε). Further, when Al is further contained, the resistance becomes low. Moreover, other additives, for example, elements such as Cr, Ca, Si, and K may be included as necessary. However, the varistor layer ₈ 1-8 ₅ and contains no Cu component.

Each of the top of the inductor layer ₆ 2-6 _9, the inductor conductor portions ₁₂ 1 to 12 ₈ comprising a material containing Ag and Pd is formed. Among the inductor conductor portions ₁₂ 1 to 12 _8, the inductor conductor ₁₂ 7, 12 ₈ is provided for the terminal electrode lead, the inductor conductor portions ₁₂ 1 to 12 ₆ coiled in order to increase the inductance value There is no.

More specifically, on each of the inductor layers 6 ₃ and 6 ₇ , an inductor having a U-shape along the first and second end faces CE1a and CE1b and the second side face CE1d of the multilayer body CE1. Four conductor portions 12 ₁ and 12 ₂ are formed. On the inductor layer _{6 5,} first and second end faces CE1a of laminate CE1, CE1b the inductor conductor 12 ₃ exhibited shaped co along a first side CE1c is 4 body formed . On each of the inductor layers 6 ₄ and 6 ₈ , inductor conductor portions 12 ₄ and 12 having a U-shape along the second end face CE1b and the first and second side faces CE1c and CE1d of the multilayer body CE1. Four bodies ₅ are formed. On the inductor layer _{6 6} first end face CE1a the first and second side CE1c of the multilayer body CE1, the inductor conductor 12 ₆ exhibited shaped co along the CE1d are formed 4-body . On the inductor layer 6 _2, the inductor conductor 12 ₇ are 4 bodies formed, on the inductor layer 6 _9, the inductor conductor 12 ₈ is 4-body formation.

One end of the 4 body of the inductor conductor 12 ₇ is led to the first side CE1c of the multilayer body CE1, are connected to four input terminal electrode 3. The inductor conductor 12 ₇ the other end of the 4 body _is connected to the 4 body inductor conductor portion 12 ₁ of the end through the through-hole, the inductor conductor 12 ₁ of the other end of the 4 body, the through-hole Are connected to one end of each of the _four inductor conductor portions 124. Inductor conductor portion 12 ₄ of the other end of the 4 body is connected to the 4 body inductor conductor portion 12 ₃ at one end through the through-hole, the inductor conductor 12 ₃ at the other end of the 4 body, the through-hole It is connected to the inductor conductor 12 ₆ one end of the 4 body through. The inductor conductor 12 ₆ the other end of the 4 body is connected to the 4 body inductor conductor portion 12 ₂ at one end through the through hole, the other end of the inductor conductor 12 ₂ of 4 body, the through-hole It is connected to one end of the 4 body of the inductor conductor 12 ₅ through. Inductor other end of the conductor portion 12 ₅ of the 4-body is connected to one end of the 4 body of the inductor conductor 12 ₈ via the through hole, the other end of the 4 body of the inductor conductor 12 _8, laminate It is drawn out to the second side face CE1d of CE1, and is connected to the four output terminal electrodes 4, respectively. By the inductor conductor portions 12 ₁ to 12 ₈ are electrically connected in this way, so that the four inductors 13 shown in FIG. 3 is formed.

Between the varistor layer ₈ 1-8 _5, the hot electrode (varistor conductor portion) 16 of 4 body so as to face the lamination direction of the varistor layer ₈ 1-8 _5, the ground electrode (varistor conductor portions) ₁₇ 1, 17 ₂ is arranged. The hot electrode 16 and the ground electrodes 17 ₁ and 17 ₂ are made of a material containing Ag and Pd.

More specifically, on the varistor layer 8 _3, first and second end faces CE1a of laminate CE1, extending along the CE1b, hot electrode 16 has a generally rectangular shape is 4 body formed. One end of each of the four hot electrodes 16 is drawn out to the second side face CE1d of the multilayer body CE1 and connected to the four output terminal electrodes 4, respectively. That is, one end of the 4 body of the hot electrode 16 is connected to the other end of the inductor conductor 12 ₈ of the different 4-body. Each on the varistor layer ₈ 2, _{8 5,} the ground electrodes ₁₇ 1, 17 ₂ having a wide portion is formed in the center. One end of each of the ground electrodes 17 ₁ and 17 ₂ is led out to the first end face CE1a of the multilayer body CE1, and is connected to the ground terminal electrode 5 disposed on the first end face CE1a. The other ends of the ground electrodes 17 ₁ and 17 ₂ are drawn out to the second end face CE1b of the multilayer body CE1 and connected to the ground terminal electrode 5 arranged on the second end face CE1b.

4 body hot electrode 16 and ground electrodes ₁₇ 1, and 17 ₂ of the wide portion, partially through the varistor layer ₈ 2, _{8 3} overlap when viewed from the laminate direction of the varistor layer ₈ 1-8 _5, Opposite. The four varistors 20 shown in FIG. 3 are formed by the four hot electrodes 16 and the ground electrodes 17 ₁ and 17 ₂ arranged in this way.

Intermediate layer 11 of the intermediate stacking unit 10 is the shape of a rectangular thin plate shape, and has a composition different from the inductor layer ₆₁ through ₉ and the varistor layer ₈ 1-8 _5. More specifically, the intermediate layer 11 is made of an insulating material having electrical insulation, and for example, an insulating material containing ZnO and Fe ₂ O ₃ as main components is used. By providing the intermediate layer 11 made of such a material between the inductor multilayer portion 7 and the varistor multilayer portion 9, it is possible to suppress crosstalk between them, and as a result, the inductor multilayer portion 7 becomes a varistor multilayer. The influence received from the part 9 and the influence that the varistor multilayer part 9 receives from the inductor multilayer part 7 can be reduced. The intermediate layer 11 does not contain a Cu component.

  Next, a method for manufacturing the multilayer filter F1 described above will be described.

First, a inductor green sheets for inductor layer ₆₁ through _9. This inductor green sheet is formed by, for example, a slurry made of ferrite such as Ni—Zn ferrite, Ni—Zn—Mg ferrite, Zn ferrite and the like by a doctor blade method so as to have a thickness of about 20 μm, for example. It is formed by applying on top.

Also, providing a varistor green sheet comprising a varistor layer ₈ 1-8 _5. For example, this varistor green sheet is obtained by using a doctor blade method to produce a slurry using a mixed powder of ZnO, Pr ₆ O ₁₁ , CoO, Cr ₂ O ₃ , CaCO ₃ , SiO ₂ , K ₂ CO ₃ and Al ₂ O ₃ as a raw material. It is formed by coating on a film. Note that the slurry does not contain a Cu component.

Further, an intermediate material green sheet to be the intermediate layer 11 is prepared. The intermediate material green sheet is an insulator having electrical insulation, and is formed by applying a slurry using a mixed powder mainly composed of ZnO and Fe ₂ O ₃ on a film by a doctor blade method. The thickness of the intermediate green sheet 2 is, for example, 30 μm. Note that the number of intermediate green sheets is appropriately adjusted so that the thickness D1 of the intermediate laminated portion 10 after firing is sufficient. More specifically, the number of intermediate green sheets is preferably adjusted so that the thickness D1 of the intermediate laminated portion 10 after firing is 60 μm or more. In order to adjust the shrinkage ratio of the intermediate green sheet, it is preferable to add one or more of NiO, CoO, Pr ₆ O ₁₁ , CaCO ₃ , and SiO ₂ to the mixed powder. Note that the slurry does not contain a Cu component.

Subsequently, a predetermined position of the inductor green sheets for inductor layer 6 _{2-6 8} (i.e., position for forming a through-hole with respect to the inductor conductor portions 12 ₁ to 12 ₇₎ in the through hole by laser processing, etc. Form.

Subsequently, the inductor layer ₆ 2-6 ₉ become inductor green sheets to form a conductive pattern corresponding to the inductor conductor portions ₁₂ 1 to 12 _8. This conductor pattern is formed by screen-printing a conductor paste mainly composed of Ag and Pd on the inductor green sheet. Note that the through holes formed in the inductor green sheets for inductor layer 6 _{2-6 8,} by screen printing of a conductive paste to the inductor green sheets, conductive paste is filled.

Further, the varistor green sheets to be the varistor layer ₈ 2-8 _4, to form a conductor pattern corresponding to the hot electrode 16 and ground electrodes ₁₇ 1, 17 _2. This conductor pattern is formed by screen-printing a conductor paste mainly composed of Ag and Pd on a varistor green sheet.

Subsequently, the inductor green sheets for inductor layer ₆₁ through _9, the intermediate material green sheet becomes the intermediate layer 11, by laminating the varistor green sheets for a varistor layer 8 _{1-8 5} in a predetermined order crimping And cut into chips. Thereafter, firing is performed at a predetermined temperature (for example, a temperature of about 1100 to 1200 ° C.) to obtain a multilayer body CE1 in which the inductor multilayer portion 7 and the varistor multilayer portion 9 are laminated via the intermediate multilayer portion 10.

  Subsequently, a conductor paste containing Ag as a main component is transferred to a position corresponding to the four input terminal electrodes 3, the four output terminal electrodes 4, and the ground terminal electrode 5 on the outer surface of the multilayer body CE1. Baking is performed at a temperature (for example, a temperature of 700 ° C. to 800 ° C.), and Ni / Sn, Cu / Ni / Sn, Ni / Au, Ni / Pd / Au, Ni / Pd / Ag, or Ni / Ag is further added. Apply the electroplating used. Thereby, terminal electrodes 3 to 5 are formed.

  Through the above steps, the multilayer filter F1 is completed.

By the way, when each green sheet is laminated and fired, if Cu diffuses into the regions A1 and A2 sandwiched between the hot electrode 16 and the ground electrodes 17 ₁ and 17 ₂ , the produced multilayer filter is desired. May not have the high frequency characteristics (that is, the attenuation characteristics deteriorate).

  Therefore, in the multilayer filter F1 of the present embodiment, a varistor green sheet is formed from a slurry that does not contain a Cu component. In this case, the Cu component is not contained in the regions A1 and A2 before firing. Further, the intermediate green sheet adjacent to the varistor green sheet is also formed from a slurry containing no Cu component. In this case, the Cu component of the intermediate material green sheet does not diffuse into the regions A1 and A2.

Furthermore, in the multilayer filter F1 of this embodiment, the thickness D1 of the intermediate laminated part 10 is made sufficient by overlapping a plurality of intermediate green sheets. The intermediate stacking unit 10 is positioned between the inductor layer ₆₁ through ₉ and the varistor layer 8 _{1-8 5,} even contain Cu component if the inductor green sheets, diffusion of the Cu component Will be blocked by thick green sheets of intermediate material.

In this manner, in this embodiment, not only form the varistor layer 8 _{1-8 5} from the slurry containing no Cu component, also formed from a slurry containing no Cu component of the intermediate material green sheet, and the intermediate member green sheets the with sufficient thickness, Cu component varistor layer 8 _{1-8 5} at the time of firing is suppressed likely to be diffused. Therefore, it is possible to obtain a varistor layer 8 _{1-8 5} is extremely unlikely that contains a Cu component.

Regions A1 and A2 sandwiched between the hot electrode 16 and the ground electrodes 17 ₁ and 17 ₂ are regions that exhibit varistor characteristics. Regions A1, A2 is composed of the varistor layer ₈ 2, _{8 3,} the varistor layer ₈ 2, _{8 3,} since it is highly unlikely that contains a Cu component for the reasons mentioned above, the inductor layer 6 ₁ and 6 ₉ and the varistor layer 8 _2, 8 ₃ are integrally sintered, and deterioration of the attenuation characteristic can be obtained multilayer filter F1 with suppressed. In addition, since the intermediate laminated portion 10 has a sufficient thickness and is made of an insulating material, crosstalk between the inductor laminated portion 7 and the varistor laminated portion 9 can be sufficiently prevented.

As shown in FIG. 3, the region A1 sandwiched between the hot electrode 16 and ground electrodes 17 _1, when viewed from the laminating direction of the multilayer body CE1, overlaps the hot electrode 16 and ground electrodes 17 ₁ It is an area. The region sandwiched between A2 in hot electrode 16 and ground electrodes 17 _2, when viewed from the laminate direction of the laminate CE1, it is a region in which the hot electrode 16 and ground electrode 17 ₂ overlap. Further, the varistor layer _{8 2,} a region A1 in which hot electrode 16 and ground electrodes 17 ₁ overlap when viewed from the laminating direction of the multilayer body CE1, other regions, that is, the hot electrode 16 and ground electrodes 17 _{1-overlapping} There are no areas. Varistor layer 8 _3, the area A2 hot electrode 16 and ground electrode 17 ₂ overlap when viewed from the laminating direction of the multilayer body CE1, the other regions, i.e. do not overlap the hot electrode 16 and ground electrode 17 ₂ region It is made up of.

  The preferred embodiments of the multilayer filter F1 and the manufacturing method thereof have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made.

For example, in the first embodiment, the inductor layers 6 _{1 to} 6 ₉ may contain a Cu component, but the inductor layers 6 _{1 to} 6 ₉ may not contain a Cu component. In this way, since the Cu component does not diffuse from the inductor layer, the possibility of the Cu component being diffused into the varistor layer is further reduced. Therefore, deterioration of the attenuation characteristic can be reliably suppressed. In this case, the multilayer filter may not include the intermediate multilayer portion.
(Second Embodiment)

FIG. 5 is an exploded perspective view showing the laminated body of the multilayer filter according to the second embodiment in an exploded manner, and FIG. 6 is an equivalent circuit diagram of the multilayer filter according to the second embodiment. Multilayer filter F2 according to the second embodiment, as shown in FIG. 6, in which the inductor 13 and the varistor 20 _1, 20 ₂ which four π-type filter elements which are arranged out is provided in parallel is there. The multilayer filter F2 according to the second embodiment is different in the configuration of the multilayer body CE2 from the multilayer body CE1 of the multilayer filter F1 according to the first embodiment. More specifically, the configuration of the varistor stacked portion 9 in the stacked body CE2 is partially different from that of the stacked body CE1.

  That is, the multilayer body CE2 includes first and second end faces CE2a, CE2b, first and second side faces CE2c, CE2d, and first and second main faces CE2e, CE2f. This surface is the same as the first and second end surfaces CE1a, CE1b, the first and second side surfaces CE1c, CE1d, and the first and second main surfaces CE1e, CE1f of the multilayer body CE1.

The multilayer body CE2 includes an inductor multilayer portion 7, a varistor multilayer portion 9, and an intermediate multilayer portion 10. Among these, the inductor multilayer portion 7 and the intermediate multilayer portion 10 have the same configuration as the inductor multilayer portion 7 and the intermediate multilayer portion 10 of the multilayer body CE1. Varistor multilayer section 9, a plurality of varistor layers 8 _2, 8 _3, 8 ₄ are formed by laminating in this order between the varistor layer 8 ₁ and the varistor layer 8 _5. Configuration of the varistor layer _{8 1,} 8 _2, 8 4, _{8 5} is the same as the varistor layer _{8 1,} 8 _2, 8 4, _{8 5} of the laminate CE1, different configurations of the varistor layer _{8 3} and laminate CE1 ing.

On the varistor layer _{8 3,} first and second end faces CE2a of the stack CE2, extending along the CE2b reside, hot electrodes ₁₆ 1, 16 ₂ are formed by four body which has a substantially rectangular shape. One end of _each of the four hot electrodes 161 is drawn out to the first side face CE2c of the multilayer body CE2 and connected to the four input terminal electrodes 3, respectively. That is, one end of the hot electrode 16 ₁ of 4 body is connected to the inductor conductor 12 ₇ the other end of the different 4-body. Hot electrodes 16 ₂ 4 body is opposed to the hot electrodes 16 ₁ in the previous 4 body. One end of the hot electrode 16 ₂ of the 4 body is drawn to the second side face CE2d of the stack CE2, are connected to the four output electrode 4. That is, one end of the hot electrode 16 ₂ of the 4 body is connected to the other end of the inductor conductor 12 ₈ of the different 4-body. The hot electrode 16 ₁ and the hot electrodes 16 ₂ are arranged so other ends are separated.

In this configuration of the varistor multilayer section 9, the ground electrodes ₁₇ 1, 17 ₂ and 4 body and the hot electrodes 16 ₁ of by sandwiching the varistor layer ₈ 2, _{8 3,} four varistors 20 ₁ is formed. Further, the ground electrode ₁₇ 1, 17 ₂ and the 4-body hot electrode 16 ₂ by sandwiching the varistor layer ₈ 2, _{8 3,} four varistors 20 ₂ is formed.

In the multilayer filter F2 configured as described above, the varistor layers 8 ₂ and 8 ₃ are located in a region sandwiched between the hot electrodes 16 ₁ and 16 ₂ and the ground electrodes 17 ₁ and 17 ₂ . Since the possibility that the varistor layers 8 ₂ and 8 ₃ contain a Cu component is extremely low, deterioration of the attenuation characteristics can be suppressed.

  The stacked body CE2 can be configured as follows. FIG. 7 is a modified example of the multilayer body CE2 and is an exploded perspective view thereof. The stacked body CE2 shown in FIG. 7 is different from that of the stacked body CE2 according to the second embodiment in the formation positions of the hot electrode and the ground electrode.

That is, as shown in FIG. 7, the hot electrode 16 ₁ of 4 body is arranged on the varistor layer 8 _2, hot electrodes 16 ₂ 4 body are juxtaposed on the varistor layer 8 _4. The ground electrode 17 is formed on the varistor layer 8 _3.

The varistor stack unit 9 having such a configuration, the hot electrode 16 _first ground electrode 17 and the 4 body is by sandwiching the varistor layer 8 _3, four varistors 20 ₁ is formed. Also, the hot electrode 16 ₂ of the ground electrode 17 and the 4 body is by sandwiching the varistor layer _{8 2,} four varistors 20 ₂ is formed. Also in this case, the varistor layers 8 ₂ and 8 ₃ that are very unlikely to contain a Cu component are located in a region sandwiched between the hot electrodes 16 ₁ and 16 ₂ and the ground electrodes 17 ₁ and 17 _2. Therefore, deterioration of the attenuation characteristic can be suppressed.
(Third embodiment)

  FIG. 8 is a schematic perspective view showing the multilayer filter according to the third embodiment, and FIG. 9 is an exploded perspective view showing the laminated body of the multilayer filter according to the third embodiment in an exploded manner. FIG. 10 is an equivalent circuit diagram of the multilayer filter according to the third embodiment. FIG. 8 also serves as a perspective view of a multilayer filter according to a fourth embodiment to be described later.

  As shown in FIG. 10, the multilayer filter F3 shown in FIG. 8 is provided with one L-type filter element composed of an inductor 13 and a varistor 20. The multilayer filter F3 includes a multilayer body CE3 having a substantially rectangular parallelepiped shape, one input terminal electrode 3, one output terminal electrode 4, and a pair of ground terminal electrodes 5.

  The stacked body CE3 includes first and second end faces CE3a, CE3b, first and second side faces CE3c, CE3d, and first and second main faces CE3e, CE3f. The first and second main surfaces CE3e and CE3f have a rectangular shape and face each other. The first and second end faces CE3a, CE3b extend in the short side direction of the first and second main faces CE3e, CE3f so as to connect the first and second main faces CE3e, CE3f and face each other. ing. The first and second side surfaces CE3c and CE3d extend in the long side direction of the first and second main surfaces CE3e and CE3f so as to connect the first and second main surfaces CE3e and CE3f and face each other. ing.

  The input terminal electrode 3 is provided on the first end face CE3a of the multilayer body CE3, and has a shape extending in the stacking direction of the multilayer body CE3. The output terminal electrode 4 is provided on the second end face CE3b of the multilayer body CE3, and has a shape extending in the stacking direction of the multilayer body CE3. The input terminal electrode 3 and the output terminal electrode 4 are provided so as to face each other.

  One of the pair of ground terminal electrodes 5 is disposed at the center of the first side face CE3c of the multilayer body CE1, and has a shape extending in the stacking direction of the multilayer body CE3. The other of the pair of ground terminal electrodes 5 is disposed at the center of the second end face CE3d of the multilayer body CE1, and has a shape extending in the stacking direction of the multilayer body CE3. The pair of ground terminal electrodes 5 are provided so as to face each other.

The stacked body CE3 will be described in detail. As shown in FIG. 7, the laminate CE1 is varistor stack portion where the inductor multilayer section 7 in which a plurality of inductor layers ₆₁ through ₉ are laminated, a plurality of varistor layers 8 _{1-8 5} formed by stacking 9 and the intermediate laminated part 10 are included. The inductor laminated portion 7 and the varistor laminated portion 9 are laminated via the intermediate laminated portion 10. The inductor layer ₆₁ through ₉ and the varistor layer 8 _{1-8 5} has exhibited the same shape as the first embodiment, also are formed of the same material.

Each of the top of the inductor layer ₆ 2-6 _9, the inductor conductor portions ₁₂ 1 to 12 ₈ comprising a material containing Ag and Pd is formed. Among the inductor conductor portions ₁₂ 1 to 12 _8, the inductor conductor ₁₂ 7, 12 ₈ is provided for the terminal electrode lead, the inductor conductor portions ₁₂ 1 to 12 ₆ No coiled to increase the inductance ing.

Inductor More specifically, on each of the inductor layer ₆ 3, _{6 7,} which exhibited the first and second sides CE3c of laminate CE3, a shaped co along the CE3d and the second end face CE3b Conductor portions 12 ₁ and 12 ₂ are formed. On the inductor layer _{6 5,} first and second side CE3c of laminate CE3, CE3d the inductor conductor 12 ₃ exhibited shaped co along the first end face CE3a is formed. On each of the inductor layers 6 ₄ and 6 ₈ , inductor conductor portions 12 ₄ and 12 having a U-shape along the first and second end faces CE3a and CE3b and the first side face CE3c of the multilayer body CE3. ₅ is formed. On the inductor layer _{6 6} the first and second end surfaces CE3a of the laminate CE3, the inductor conductor 12 ₆ exhibited CE3b and shaped co along the second side CE3d is formed. On the inductor layer 6 _2, the inductor conductor 12 ₇ are formed, on the inductor layer 6 _9, the inductor conductor 12 ₈ are formed.

One end of the inductor conductor 12 ₇ is led to the first end surface CE3a of laminate CE3, and is connected to the input terminal electrode 3. The other end of the inductor conductor 12 _{7 is} connected to one end of the inductor conductor 12 ₁ via the through hole, the other end of the inductor conductor 12 _1, one end of the inductor conductor 12 ₄ through the through hole It is connected to the. The other end of the inductor conductor 12 ₄ is connected to one end of the inductor conductor 12 ₃ via a through-hole, the other end of the inductor conductor 12 _3, one end of the inductor conductor 12 ₆ through the through hole It is connected to the. The other end of the inductor conductor 12 ₆ is connected to one end of the inductor conductor 12 ₂ via the through hole, the other end of the inductor conductor 12 _2, one end of the inductor conductor 12 ₅ through the through hole It is connected to the. The other end of the inductor conductor 12 ₅ is connected to one end of the inductor conductor 12 ₈ via the through hole, the other end of the inductor conductor 12 ₈ is drawn on the second end face CE3b of laminate CE3 The output terminal electrode 4 is connected. In this manner, the inductor conductor portions 12 _{1 to} 12 ₈ are electrically connected to form the inductor 13 shown in FIG.

Between the varistor layers 8 ₁ to 8 ₄ , a hot electrode 16 and a ground electrode 17 are arranged so as to face each other in the stacking direction of the varistor layers 8 ₁ to 8 ₄ . The hot electrode 16 and the ground electrode 17 are made of a material containing Ag and Pd.

More specifically, on the varistor layer 8 _3, first and second side CE3c of laminate CE3, extending along the CE3d, hot electrode 16 has a generally rectangular shape is formed. One end of the hot electrode 16 is drawn out to the second end face CE3b of the multilayer body CE3 and connected to the output terminal electrode 4, respectively. That is, one end of the hot electrode 16 is connected to the other end of the inductor conductor 12 _8. On the varistor layer _{8 2,} first and second end faces CE3a of the laminate CE3, extending along the CE3b, the ground electrode 17 is formed with a substantially rectangular shape. One end of the ground electrode 17 is drawn out to the first side face CE3c of the multilayer body CE3, and is connected to the ground terminal electrode 5 disposed on the first side face CE3c. The other end of the ground electrode 17 is drawn out to the second side face CE3d of the multilayer body CE3 and connected to the ground terminal electrode 5 arranged on the second side face CE3d.

The hot electrode 16 and ground electrode 17, a portion through the varistor layer 8 ₂ overlap faces when viewed from the laminate direction of the varistor layer 8 _{1-8 4.} A varistor 20 shown in FIG. 10 is formed by the hot electrode 16 and the ground electrode 17 arranged in this manner.

The intermediate layer 11 of the intermediate stacked unit 10 is the same as the intermediate layer 11 in the first embodiment. That is, the intermediate layer 11 has a rectangular thin plate shape and has a composition different from that of the inductor layers 6 _{1 to} 6 ₉ and the varistor layers 8 ₁ to 8 ₄ . More specifically, the intermediate layer 11 is made of an insulating material having electrical insulation, and for example, an insulating material containing ZnO and Fe ₂ O ₃ as main components is used. The intermediate layer 11 does not contain a Cu component.

Even in the multilayer filter F3 constituted as described above, the region between the hot electrode 16 and ground electrode 17 is located varistor layer 8 _2, the varistor layer 8 ₂ of the first embodiment For the same reason, the possibility of containing a Cu component is extremely low. Therefore, deterioration of the attenuation characteristic can be suppressed.
(Fourth embodiment)

FIG. 11 is an exploded perspective view showing the laminated body of the multilayer filter according to the fourth embodiment in an exploded manner, and FIG. 12 is an equivalent circuit diagram of the multilayer filter according to the fourth embodiment. The multilayer filter F4 of the fourth embodiment, as shown in FIG. 12, inductor 13 and the varistor 20 _1, 20 ₂ which one π-type filter elements which are arranged out in which is provided. The multilayer filter F4 according to the fourth embodiment is different in the configuration of the multilayer body CE4 from the multilayer body CE3 of the multilayer filter F3 according to the third embodiment. More specifically, the configuration of the varistor stacked portion 9 in the stacked body CE4 is partially different from that of the stacked body CE3.

  That is, the multilayer body CE4 includes first and second end faces CE4a and CE4b, first and second side faces CE4c and CE4d, and first and second main faces CE4e and CE4f. This surface is the same as the first and second end surfaces CE1a, CE1b, the first and second side surfaces CE1c, CE1d, and the first and second main surfaces CE1e, CE1f of the multilayer body CE1. The multilayer body CE4 includes an inductor multilayer part 7, a varistor multilayer part 9, and an intermediate multilayer part 10, and the configurations of the inductor multilayer part 7 and the intermediate multilayer part 10 are the same as those of the multilayer body CE3.

Varistor multilayer section 9, a plurality of varistor layers 8 _2, 8 _3, 8 ₄ are formed by laminating in this order between the varistor layer 8 ₁ and the varistor layer 8 _5. Configuration of the varistor layer ₈ 1, _{8 5} is the same as that of the laminated body CE3, configuration of the varistor layer _{8 2,} 8 3, _{8 4} differs from the laminate CE3.

On the varistor layer _{8 2,} first and second side CE4c of laminate CE4, extending along the CE1d, hot electrodes 16 ₁ is formed with a substantially rectangular shape. One end of the hot electrode 16 ₁ is drawn to the second end face CE1b of the laminate CE4, is connected to the output terminal electrode 4. That is, one end of the hot electrode 16 ₁ is connected to the other end of the inductor conductor 12 _8. On the varistor layer _{8 4,} first and second side CE4c of laminate CE4, extending along the CE1d, hot electrodes 16 ₂ are formed with a substantially rectangular shape. One end of the hot electrode 16 ₂ is drawn to the first end surface CE1a of the laminate CE4, are connected to the input terminal electrode 3. That is, one end of the hot electrode 16 ₂ is connected to the other end of the inductor conductor 12 _7.

On the varistor layer _{8 3,} first and second end faces CE4a of the laminate CE4, extending along the CE4b, the ground electrode 17 is formed with a substantially rectangular shape. One end of the ground electrode 17 is drawn out to the first side face CE4c of the multilayer body CE4, and is connected to the ground terminal electrode 5 disposed on the first side face CE4c. The other end of the ground electrode 17 is drawn out to the second side face CE4d of the multilayer body CE4 and connected to the ground terminal electrode 5 disposed on the second side face CE4d.

The varistor multilayer section 9 of this structure, the ground electrode 17 and the hot electrode 16 ₂ by sandwiching the varistor layer 8 _2, the varistor 20 ₁ is formed. The ground electrode 17 and the hot electrode hot electrodes 16 ₂ by sandwiching the varistor layer _{8 3,} the varistor 20 ₂ is formed.

Also in the multilayer filter F4 configured as described above, the varistor layers 8 ₂ and 8 ₃ are located in the region sandwiched between the hot electrodes 16 ₁ and 16 ₂ and the ground electrode 17, and the varistor layer 8 _2. , 8 ₃ from it highly unlikely that contains a Cu component can be suppressed deterioration of the attenuation characteristic.
(Fifth embodiment)

  FIG. 13 is a perspective view of the multilayer filter according to the fifth embodiment. FIG. 14 is an exploded perspective view of the multilayer filter according to the fifth embodiment. FIG. 15 is an equivalent circuit diagram of the multilayer filter according to the fifth embodiment.

  As shown in FIG. 15, the multilayer filter F5 is provided with one π-type filter element, and a plurality of (π in this embodiment) such π-type filter elements form a common mode choke coil. Coils 70 and 72, and a plurality (four in this embodiment) of varistors 81 to 84.

  As shown in FIG. 13, the multilayer electronic component F5 includes a multilayer body CE5 that has a substantially rectangular parallelepiped shape. Input terminal electrodes 34 and 36 are formed at one end in the longitudinal direction of the multilayer body CE5, and output terminal electrodes 38 and 40 are formed at the other end in the longitudinal direction of the multilayer body CE5. Yes. A pair of ground terminal electrodes 42 are formed on both side surfaces in the longitudinal direction of the multilayer body CE5.

  As shown in FIG. 14, the multilayer body CE5 includes an inductor multilayer portion 53, an intermediate multilayer portion 55, and a varistor multilayer portion 67.

Inductor laminated portion 53 has a first sintered body in which a plurality of inductor layers ₄₄ 1 _{to 44 7,} 46 1 to 46 ₄ are stacked, and a coil conductor 48 made of a conductor pattern ₄₈ 1, 48 _2, the conductive pattern And a coil conductor 50 composed of 50 ₁ and 50 ₂ . The coil conductors 48 and 50 are disposed inside the first sintered body. More specifically, the coil conductors 48 and 50 is disposed between the inductor layers ₄₄ 1 _{to 44 7,} 46 1 to 46 _4. The coil conductor 48 and the coil conductor 50 are magnetically coupled to each other in the first sintered body.

The first sintered body is integrally fired with the second sintered bodies of the intermediate laminated portion 55 and the varistor laminated portion 67. First sintered body has a first layer 53 ₁ and the second layer ₅₃ 2, 53 _3. The first layer 53 _1, the inductor layer _{44 1-44 7,} 46 1-46 ₄ conductor patterns ₄₈ 1 in the laminating direction (first direction) _of 48 _2, 50 1, 50 sandwiched by part ₂ Contains.

More specifically, the first layer 53 _1, the conductor patterns _{48 1,} 48 _2, 50 1, 50 ₂ contains an inductor layer ₄₆ 1-46 ₄ formed. Conductor pattern 48 ₁ is formed on the inductor layer 46 _1, the conductor pattern 48 ₂ is formed on the inductor layer 46 _2. The conductor patterns 48 ₁ and 48 ₂ are formed in a spiral shape from the center toward the edge. In the conductive pattern 48 _1, one end portion located on the veranda is drawn to the end face of the inductor layer 46 ₁ so as to be connected to the output terminal electrode 38. In the conductor pattern 48 _2, one end portion located on the veranda is drawn to an end surface of the inductor layer 46 ₂ so as to be connected to the input terminal electrode 34. The other end portion of the conductor pattern 48 ₁ and the conductor pattern 48 ₂ of the other end, are electrically connected through via conductor 49 formed on the inductor layer 46 _1. The conductor patterns 48 ₁ and 48 ₂ constitute a coil conductor 48, and the coil conductor 48 corresponds to the coil 70 shown in the circuit diagram of FIG.

Conductive pattern 50 ₁ is formed on the inductor layer 46 _3, the conductor pattern 50 ₂ is formed on the inductor layer 46 _4. The conductor patterns 50 ₁ and 50 ₂ are formed in a spiral shape from the center toward the edge. In the conductive pattern 50 _1, one end portion located on the veranda is drawn to an end surface of the inductor layer 46 ₃ so as to be connected to the input terminal electrode 36. In the conductor pattern 50 _2, one end portion located on the veranda is drawn to the end face of the inductor layer 46 ₄ to be connectable to the output terminal electrode 40. The other end portion of the conductor pattern 50 ₁ and the conductor pattern 50 ₂ of the other end, are electrically connected through via conductor 51 formed on the inductor layer 46 _3. The conductor patterns 50 ₁ and 50 ₂ constitute a coil conductor 50, and the coil conductor 50 corresponds to the coil 72 shown in the circuit diagram of FIG.

The second layer ₅₃ 2, 53 ₃ is a partial sandwiching the coil conductors 48 and 50 in the stacking direction of the inductor layers ₄₄ 1 _{to 44 7,} 46 1 to 46 _4. More specifically, the second layer 53 ₂ is located above the first layer 53 ₁ is made up of the inductor layer 44 _{1-44 4} conductor pattern is not formed. The second layer 53 ₃ is located on the lower side of the first layer 53 ₁ is made up of the inductor layer ₄₄ 4-44 ₇ conductor pattern is not formed. Incidentally, the inductor layer 46 ₄ in this embodiment is contained in the first layer 53 ₁ may be included in the first layer 53 ₁ rather than second layer 53 _3.

The inductor layers ₄₄ 1 _{to 44 7,} 46 1 to 46 ₄ is made of a non-magnetic material. Thus, the region sandwiched between the conductor patterns 48 ₂ and the conductor patterns 50 _1, and thus be composed of non-magnetic material. The region located inside the conductor patterns 48 _1, region located inside the conductor patterns 48 _2, a region located inside the conductor patterns 50 _1, region located inside the conductor patterns 50 _2, the conductive pattern 48 ₁ and the region sandwiched between conductive patterns 48 _2, and the area sandwiched between the conductive patterns 50 ₁ and the conductor pattern 50 _2, and thus be composed of non-magnetic material. The inductor layer _{44 1-44 7,} 46 1-46 _4, it is possible to use ferrite (e.g. Zn ferrite). In the case of using Zn-based ferrite, a high inductance value can be obtained, so that a good filter characteristic can be obtained. Incidentally, the inductor layer _{44 1-44 7,} 46 1-46 ₄ may contain a Cu component.

Conductive patterns ₄₈ 1 _and 48 _2, 50 1, 50 ₂ and the conductive material used for the via conductor 49 and 51, the inductor layer _{44 1-44 7,} 46 1 using -46 ₄ simultaneously fired possible metallic material. More specifically, since the firing temperature of ferrite is usually about 800 ° C. to 1400 ° C., a metal material that does not melt at that temperature is used. For example, Ag, Pd, or an alloy thereof can be preferably used.

In addition to the inductor multilayer portion 53, the multilayer body CE5 has a varistor multilayer portion 67 that exhibits voltage nonlinear characteristics. The varistor laminated portion 67 includes a second sintered body in which a plurality of varistor layers 56 _{1 to} 56 ₁₀ are laminated, hot electrodes 60, 62, 64 and 66, and ground electrodes 58 _{1 to} 58 ₅ (a plurality of internal electrodes). ).

The plurality of varistor layers 56 _{1 to} 56 ₁₀ are stacked in this order from the top. The varistor layer _{56 2,} 56 _4, 56 _6, 56 8, _{56 10} on the ground electrode ₅₈ 1-58 ₅ of the ground terminal electrode 42 electrically connected to a substantially rectangular shape are respectively formed. Substantially Further, on the varistor layer 56 _third input terminal electrode 36 is electrically connected to the substantially rectangular hot electrode 60 is formed, on the varistor layer 56 ₅ connected the input terminal electrode 34 and the electrically is formed rectangular hot electrode 62, is formed on the varistor layer 56 ₇ are formed substantially rectangular hot electrodes 64 connected electrically to the output terminal electrode 40, is formed on the varistor layer 56 ₉ output terminal electrodes 38 A substantially rectangular hot electrode 66 that is electrically connected to each other is formed.

By partially through the varistor layer ₅₆ 2, 56 ₃ are opposed them overlap when the hot electrode 60 and ground electrodes ₅₈ 1, 58 ₂ are viewed from the laminating direction, the varistor 83 shown in FIG. 15 is a varistor multilayer section 67. Varistor layer ₅₆ when the hot electrode 62 and ground electrodes ₅₈ 2, 58 ₃ is viewed from the laminating direction 4, 56 ₅ is partially opposed them overlap it through the varistor 81 shown in FIG. 15 is a varistor multilayer section 67. Hot electrodes 64 and ground electrodes ₅₈ 3, 58 ₄ and that faces partially them overlap via the varistor layer ₅₆ 6, 56 ₇ when viewed from the lamination direction, the varistor 84 shown in FIG. 15 is a varistor multilayer section 67. Hot electrodes 66 and ground electrodes ₅₈ 4, 58 ₅ and that faces partially them overlap via the varistor layer ₅₆ 8, 56 ₉ when viewed from the laminating direction, the varistor multilayer section varistor 82 shown in FIG. 15 67. In this manner, the hot electrode 60, 62, 64, 66 and the ground electrode ₅₈ 1-58 _5, a part through the varistor layer ₅₆ 2-56 ₉ faces them overlap when viewed from the laminating direction Thus, four varistors 81 to 84 are formed in the varistor laminated portion 67.

The varistor layers 56 _{1 to} 56 ₁₀ are made of a ceramic material mainly composed of ZnO. This ceramic material may contain Pr, Bi, Co, Al or the like as an additive component. When Co is contained in addition to Pr, it has excellent varistor characteristics and also has a high dielectric constant (ε). Further, when Al is further contained, the resistance becomes low. Moreover, other additives, for example, elements such as Cr, Ca, Si, and K may be included as necessary. However, the varistor layers 56 _{1 to} 56 ₁₀ do not contain a Cu component.

Ground electrodes ₅₈ 1 to 58 ₅ and the hot electrodes 60, 62, 64, 66 are formed of the same conductive material as the ground electrodes ₁₇ 1, 17 ₂ and the hot electrode 16 in the first embodiment. That is, the ground electrode ₅₈ from 1 to 58 ₅ and the hot electrode 60, 62, 64, 66 using a ceramic material fired simultaneously may metallic material constituting the varistor layer _{56 1-56 10.} More specifically, since the firing temperature of the varistor ceramic is usually about 800 ° C. to 1400 ° C., for example, Ag, Pd, or an alloy thereof can be suitably used as a metal material that does not melt at that temperature.

The multilayer body CE5 includes an intermediate multilayer portion 55 in addition to the inductor multilayer portion 53 and the varistor multilayer portion 67. The intermediate laminated portion 55 is a portion provided for the purpose of adjusting the reduction ratio between the inductor laminated portion 53 and the varistor laminated portion 67, and is located between the inductor laminated portion 53 and the varistor laminated portion 67. The intermediate laminated portion 55 includes intermediate layers 54 ₁ and 54 ₂ . The intermediate layers 54 ₁ and 54 ₂ are insulating layers and are made of, for example, a ceramic material mainly composed of ZnO and Fe ₂ O ₃ and do not contain a Cu component. By providing such an intermediate laminated portion 55, it is possible to more reliably suppress the Cu component from diffusing from the inductor laminated portion 53 into the varistor laminated portion 67.

  Next, a method for manufacturing the multilayer electronic component E5 will be described.

First, a inductor green sheets for inductor layers ₄₄ 1 _{to 44 7,} 46 1 to 46 _4. This inductor green sheet is formed by applying a slurry made of ferrite such as Zn-based ferrite on a film by a doctor blade method so that the thickness becomes, for example, about 20 μm.

Subsequently, a through hole is formed at a desired position of the inductor green sheet, that is, a position where the via conductors 49 and 51 are to be formed. The through hole can be formed by a laser processing machine or the like. After the through holes are formed, conductor patterns 48 ₁ , 48 ₂ , 50 ₁ , 50 ₂ are formed on the inductor green sheet by screen printing or the like. Also, via conductors 49 and 51 are formed by filling the through holes formed in the inductor green sheet with a conductive paste. As the conductive paste used for printing the conductor patterns 48 ₁ , 48 ₂ , 50 ₁ , 50 ₂ and the via conductors 49, 51, a paste containing Ag, Pd, an alloy thereof or the like as a main component can be used.

Subsequently, varistor green sheets to be varistor layers 56 _{1 to} 56 ₁₀ are prepared. This inductor green sheet is, for example, a slurry made of a mixed powder containing a predetermined amount of ZnO, Pr ₆ O ₁₁ , CoO, Cr ₂ O ₃ , CaCO ₃ , SiO ₂ , K ₂ CO ₃ and Al ₂ O ₃ , For example, it is formed by coating on a film by a doctor blade method so that the thickness becomes about 30 μm. The form of the raw material powder of the slurry is not particularly limited as long as it becomes a varistor having a predetermined composition after integral firing, and a varistor powder obtained by pre-calcining and pulverizing a varistor ceramic having a predetermined composition may be used. good. However, the slurry does not contain a Cu component.

Subsequently, by using a conductive paste on the varistor green sheet to form a ground electrode ₅₈ 1-58 ₅ and hot electrodes 60, 62, 64, 66 by a screen printing method or the like. As the conductive paste, one containing Ag, Pd, or an alloy thereof as a main component can be used.

Subsequently, to prepare intermediate material green sheet becomes the intermediate layer ₅₄ 1, 54 _2. The intermediate material green sheet is an insulator having electrical insulation properties. For example, a slurry using a mixed powder mainly composed of ZnO and Fe ₂ O ₃ as a raw material, for example, by a doctor blade method so as to have a thickness of about 30 μm. It is formed by coating on a film. Note that the slurry does not contain a Cu component.

Subsequently, an inductor green sheet in which conductor patterns 48 ₁ , 48 ₂ , 50 ₁ , 50 ₂ and via conductors 49, 51 having a predetermined shape are formed, an inductor green sheet in which no conductor pattern and via conductors are formed, and hot a varistor green sheet electrodes 60, 62, 64, 66 are formed, a varistor green sheet ground electrodes ₅₈ 1 to 58 ₅ is formed, and varistor green sheet hot electrode and the ground electrode is not formed, the intermediate member The green sheets are sequentially laminated and pressed as shown in FIG. 14, and then cut into chips to obtain a green laminate. Thereafter, firing is performed under predetermined conditions (for example, 1100 ° C. to 1200 ° C. in the air) to obtain the multilayer body CE5.

  Subsequently, a conductive paste is applied to the end portion in the longitudinal direction of the multilayer body CE5 and the center of both side surfaces in the longitudinal direction, and heat treatment is performed under predetermined conditions (for example, 700 ° C. to 800 ° C. in the atmosphere) to obtain terminal electrodes. Bake. As the conductive paste, a paste containing powder containing Ag as a main component can be used. Thereafter, the surface of the terminal electrode is plated to obtain the multilayer electronic component E5 in which the input terminal electrodes 34 and 36, the output terminal electrodes 38 and 40, and the ground terminal electrode 42 are formed. The plating is preferably electrolytic plating, and as the material, for example, Ni / Sn, Cu / Ni / Sn, Ni / Pd / Au, Ni / Pd / Ag, Ni / Ag, or the like can be used.

As described above, according to the present embodiment, in the multilayer filter including the inductor part constituting the common mode choke coil and the varistor part constituting the varistor, the varistor layers 56 _{1 to} 56 ₁₀ are formed from the slurry not containing the Cu component. Forming. As a result, the multilayer filter F5 does not easily deteriorate the attenuation characteristics in the varistor portion. Further, in the multilayer filter F5, the intermediate material green sheet is also formed from a slurry containing no Cu component, and the intermediate material green sheet has a sufficient thickness so that the varistor layers 56 _{1 to} 56 ₁₀ contain Cu components during firing. Suppresses the possibility of spreading. Therefore, in the multilayer filter F5, the deterioration of the attenuation characteristics in the varistor portion is less likely to occur.

Further, according to this embodiment, the first sintered body of the inductor multilayer section 53, on both sides of the first layer 53 ₁ made of a nonmagnetic material, the second layer 53 ₂ similarly made of a nonmagnetic material, the 53 ₃ formed by laminating. Therefore, the frequency band in which the inductance value can be obtained by the coil conductors 48 and 50 (coils 81 and 82) can be increased to a higher frequency region, and the multilayer electronic component E5 can be more excellent in filter characteristics.

  The preferred embodiments of the multilayer filter F5 and the manufacturing method thereof have been described above, but the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made.

For example, in the above embodiment, the inductor layers ₄₆ 1 to 46 ₄ to form the first layer 53 ₁ is a non-magnetic layer, the whole of the inductor layer ₄₆ 1-46 ₄ even without a non-magnetic material Good. That is, a predetermined region in the inductor layer ₄₆ 1-46 ₄ respectively, it is sufficient that the non-magnetic member. More specifically, among the inductor layer ₄₆ 1-46 _4, at least, a region sandwiched between between the conductive patterns ₄₈ 1, 48 ₂ and the conductor patterns ₅₀ 1, 50 _2, the conductive pattern ₄₈ 1, 48 ₂ The region located inside and the region located inside the conductor patterns 50 ₁ and 50 ₂ may be non-magnetic.

In the above embodiment, the inductor layers ₄₄ 1 to 44 ₇ to form the inductor layer ₄₆ 1-46 ₄ and the second layer ₅₃ 2, 53 ₃ for forming the first layer 53 ₁ are both non-magnetic material was as a layer, the inductor layer ₄₄ 1-44 ₇ is a magnetic layer, the inductor layer ₄₆ 1-46 ₄ may be the non-magnetic layer. In this case, on both sides of the first layer 53 ₁ made of a nonmagnetic material, since the stacking the second layer ₅₃ 2, 53 ₃ made of magnetic material, the coil conductors 48 and 50 (coils 81, 82) The frequency band in which the inductance value can be secured can be increased to a relatively high frequency region. Therefore, it is possible to provide the multilayer filter F5 with more excellent filter characteristics of the common mode choke coil.

The inductor layer _{44 1-44 7,} 46 1-46 ₄ may be either a magnetic layer. When the magnetic layer is used, it is preferable to use Ni—Zn ferrite or Ni—Zn—Mg ferrite as the ferrite material. In this case, on both sides of the first layer 53 ₁ made of a magnetic material, since the same and thus stacking the second layer 53 ₂ made of a magnetic material, a second first layer 53 ₁ is made of non-magnetic material layer 53 ₂ is compared to that made of a magnetic material, it is possible to further increase the inductance value of the coil conductors 48 and 50 (coils 81, 82) in the region of the lower frequency. Therefore, it is possible to provide the multilayer filter F5 with more excellent filter characteristics of the common mode choke coil.

  Moreover, in the said embodiment, although the number of coil conductors (coils) was two, it is not restricted to this.

  As mentioned above, although 1st-5th embodiment was demonstrated, it demonstrates concretely by Example 1 and Comparative Examples 1-3 that deterioration of an attenuation characteristic can be suppressed in this embodiment. The attenuation characteristic uses the resonance phenomenon of inductance (L) and capacitance (C). In Example 1 and Comparative Examples 1 to 3, the amount of change and rate of change in capacitance are used as the constituent characteristics of the attenuation characteristic. Looking for.

In Example 1, a multilayer filter having the same configuration as that of the multilayer filter F1 of the first embodiment was used. Comparative Examples 1 to 3 have substantially the same configuration as the multilayer filter F1, but used a varistor layer corresponding to the varistor layers 8 ₂ and 8 ₃ having a Cu component amount different from that of the multilayer filter F1. . That is, in Comparative Example 1, a multilayer filter in which the Cu component amount in the varistor laminated portion is 0.020 wt% is used, and in Comparative Example 2, the Cu component amount in the varistor laminated portion is 0.012 wt%. In Comparative Example 3, a multilayer filter having a Cu component amount of 0.003 wt% in the varistor multilayer portion was used.

  The attenuation characteristics of the multilayer filter of Example 1 are shown in FIG. 17 shows the attenuation characteristics of the multilayer filter of Comparative Example 1, FIG. 18 shows the attenuation characteristics of the multilayer filter of Comparative Example 2, and FIG. 19 shows the attenuation characteristics of the multilayer filter of Comparative Example 3. FIG. 16A, FIG. 17A, FIG. 18A, and FIG. 19A show the amount of change in capacitance in Example 1 and Comparative Examples 1-3. FIGS. 16B, 17 </ b> B, 18 </ b> B, and 19 </ b> B show the capacitance change rates of Example 1 and Comparative Examples 1 to 3. FIGS. As can be seen from FIG. 16, the multilayer filter of Example 1 maintains a sufficient capacitance in the high frequency region. Therefore, it can be said that the multilayer filter of Example 1 is a multilayer filter having excellent attenuation characteristics in a high frequency region. As shown in FIG. 16, in the multilayer filter of Example 1, the capacitance is substantially constant in the frequency range of 1 to 1000 MHz, and when the frequency exceeds about 1000 MHz, the capacitance decreases rapidly. That is, in the multilayer filter of Example 1, it can be clearly determined that the cutoff frequency is 1000 MHz. Therefore, the attenuation characteristics in the high frequency region can be designed by using such discrimination. On the other hand, as shown in FIGS. 14 to 15, in the multilayer filters of Comparative Examples 1 to 3, the capacitance decreases as the frequency increases even in the frequency range of 1 to 1000 MHz. . That is, since discrimination cannot be used, it is difficult to design attenuation characteristics in a high frequency region. From the above, the effectiveness of the present embodiment was confirmed.

1 is a schematic perspective view showing a multilayer filter according to a first embodiment. It is a disassembled perspective view which decomposes | disassembles and shows the laminated body of the laminated filter which concerns on 1st Embodiment. It is sectional drawing which shows the center cross section of the multilayer filter which concerns on 1st Embodiment. It is an equivalent circuit diagram of the multilayer filter according to the first embodiment. It is a disassembled perspective view which decomposes | disassembles and shows the laminated body of the laminated filter which concerns on 2nd Embodiment. It is an equivalent circuit diagram of the multilayer filter according to the second embodiment. It is a modification of the laminated body of the laminated filter which concerns on 2nd Embodiment, Comprising: It is the disassembled perspective view. It is a schematic perspective view which shows the multilayer filter which concerns on 3rd Embodiment. It is a disassembled perspective view which decomposes | disassembles and shows the laminated body of the laminated filter which concerns on 3rd Embodiment. It is an equivalent circuit diagram of the multilayer filter according to the third embodiment. It is a disassembled perspective view which decomposes | disassembles and shows the laminated body of the laminated filter which concerns on 4th Embodiment. It is an equivalent circuit diagram of the multilayer filter according to the fourth embodiment. It is a schematic perspective view which shows the multilayer filter which concerns on 5th Embodiment. It is a disassembled perspective view which decomposes | disassembles and shows the laminated body of the laminated filter which concerns on 5th Embodiment. FIG. 10 is an equivalent circuit diagram of a multilayer filter according to a fifth embodiment. 3 is a graph showing attenuation characteristics of the multilayer filter of Example 1. 5 is a graph showing attenuation characteristics of the multilayer filter of Comparative Example 1. 10 is a graph showing attenuation characteristics of the multilayer filter of Comparative Example 2. 10 is a graph showing attenuation characteristics of the multilayer filter of Comparative Example 3.

Explanation of symbols

F1 to F5 ... multilayer filter, CE1 to CE5 ... laminate, 6 _{1 to} 6 ₉ , 44 _{1 to} 44 ₇ , 46 _{1 to} 46 ₄ ... inductor layer, 3, 34, 36 ... input terminal electrodes, 4, 38, 40 ... output terminal electrode, 5,42 ... ground terminal electrode, 7,53 ... inductor laminated portion (inductor portion), 8 ₁ to 8 ₅ , 56 _{1 to} 56 ₁₀ ... varistor layer, 9,67 ... varistor laminated portion (varistor) Part), 10, 55 ... intermediate laminated part (intermediate part), 11, 54 ₁ , 54 ₂ ... intermediate layer, 12 _{1 to} 12 ₈ ... inductor conductor part, 16, 16 ₁ , 16 ₂ , 60, 62, 64, 66 ... hot _electrode, 17 _1, 17 2, ₅₈ 1 to 58 5 _... ground electrode, 48, 50 ... coil conductor _section, 48 _1, 48 2, ₅₀ 1, 50 2 _... conductor pattern.

Claims (7)

A multilayer filter comprising an inductor part and a varistor part,
The varistor part has a varistor layer mainly composed of ZnO, and a plurality of varistor conductor parts arranged to face each other with the varistor layer interposed therebetween.
A multilayer filter characterized in that a Cu component is not contained in a region sandwiched between the opposing varistor conductor portions. The inductor part and the varistor part are laminated via an intermediate part,
The multilayer filter according to claim 1, wherein the intermediate portion has a composition different from that of the inductor portion and the varistor portion and does not contain a Cu component. The inductor portion has an inductor layer and an inductor conductor portion formed in the inductor layer,
3. The inductor layer according to claim 1, wherein the inductor layer is formed of any one of Ni—Zn ferrite, Ni—Zn—Mg ferrite, and Zn ferrite and does not contain a Cu component. Multilayer filter.   The multilayer filter according to claim 1 or 2, wherein the inductor section is a common mode choke coil having a sintered body and a plurality of coil conductors arranged inside the sintered body. Each of the coil conductors is composed of a plurality of conductor patterns arranged in the first direction,
The first sintered body has a first layer sandwiched between the conductor patterns in the first direction, and a second layer sandwiching a plurality of the coil conductors in the first direction,
5. The multilayer composite electronic component according to claim 4, wherein the first layer is made of a non-magnetic material, and the second layer is made of a magnetic material. Each of the coil conductors is composed of a plurality of conductor patterns arranged in the first direction,
The first sintered body has a first layer sandwiched between the conductor patterns in the first direction, and a second layer sandwiching a plurality of the coil conductors in the first direction,
The multilayer composite electronic component according to claim 4, wherein the first and second layers are made of a magnetic material. Each of the coil conductors is composed of a plurality of conductor patterns arranged in the first direction,
The first sintered body has a first layer sandwiched between the conductor patterns in the first direction, and a second layer sandwiching a plurality of the coil conductors in the first direction,
The multilayer composite electronic component according to claim 4, wherein the first and second layers are made of a nonmagnetic material.

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