JP4216856B2 - Multilayer electronic components - Google Patents

Description

  The present invention relates to a multilayer electronic component.

Some multilayer common mode filters as a type of multilayer electronic component use Cu—Zn-based ferrite as a nonmagnetic material that forms the periphery of a coil conductor that constitutes the inductor. As described above, when Cu—Zn based ferrite is used as the non-magnetic material, the dielectric constant becomes a relatively high value of 14 to 16, and there is a problem that the attenuation characteristic of the noise component in the high frequency band is insufficient. In order to solve this problem, it has been proposed to use ceramic or glass as the nonmagnetic material (see Patent Document 1 below).
JP 2002-270451 A

  By the way, the ceramic used as the non-magnetic material is not necessarily suitable for any kind of ceramic. For example, when a certain type of ceramic is used, the differential mode characteristics may not extend to the high frequency band to the extent required. In addition, when a certain type of ceramic is used, so-called delamination may occur between the magnetic layer and the nonmagnetic layer.

  Accordingly, an object of the present invention is to provide a multilayer electronic component that can improve the attenuation characteristics of noise components in a high-frequency band and can reduce the possibility of occurrence of problems such as delamination. .

  A multilayer electronic component according to the present invention is a multilayer electronic component comprising at least one magnetic layer and at least one nonmagnetic layer, and the nonmagnetic layer contains Zn. It contains forsterite ceramic.

  According to the present invention, since the nonmagnetic layer contains forsterite-based ceramic containing Zn, it is possible to improve the attenuation characteristics of noise components in the high frequency band and to cause problems such as delamination. Can be reduced.

  In the multilayer electronic component according to the present invention, it is also preferable that the nonmagnetic layer includes a coil conductor constituting an inductor. Since the nonmagnetic layer includes the coil conductor, it is possible to provide a multilayer electronic component as a coil component having the above-described characteristics.

  The multilayer electronic component according to the present invention preferably has a pair of coil conductors and functions as a common mode filter. It is possible to provide a multilayer electronic component as a common mode filter capable of improving the attenuation characteristics of noise components in a high frequency band.

  The multilayer electronic component according to the present invention preferably includes a capacitor together with an inductor and functions as an LC filter. With such a configuration, a multilayer electronic component as an LC filter having the above-described characteristics can be provided.

  The multilayer electronic component according to the present invention preferably includes a capacitor together with a common mode filter and functions as an LC filter. With such a configuration, a multilayer electronic component as an LC filter having the above-described characteristics can be provided.

  In the multilayer electronic component according to the present invention, it is also preferable that the nonmagnetic layer is sandwiched between a pair of magnetic layers.

  The multilayer electronic component according to the present invention preferably further includes a varistor layer that exhibits a varistor function. With such a configuration, it is possible to provide a multilayer electronic component with a varistor function having the above-described characteristics.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to improve the attenuation | damping property of the noise component in a high frequency band, the multilayer electronic component which can reduce the possibility of malfunctions, such as delamination, can be provided. .

  The knowledge of the present invention can be easily understood by considering the following detailed description with reference to the accompanying drawings shown for illustration only. Subsequently, embodiments of the present invention will be described with reference to the accompanying drawings. Where possible, the same parts are denoted by the same reference numerals, and redundant description is omitted. In the description, the terms “upper”, “right”, and “left” may be used, which correspond to the upward, rightward, and leftward directions of each figure.

  (First embodiment)

  The configuration of the multilayer inductor L1 (multilayer electronic component) according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of the multilayer inductor according to the first embodiment of the present invention. FIG. 2 is a diagram for explaining a cross-sectional configuration of the multilayer inductor according to the first embodiment. FIG. 3 is an exploded perspective view of the multilayer body included in the multilayer inductor according to the first embodiment.

  As shown in FIG. 1, the multilayer inductor L <b> 1 includes a substantially rectangular parallelepiped multilayer body 1, and a pair of terminal electrodes 2 and 3 formed on both side surfaces of the multilayer body 1 in the longitudinal direction. The bottom surface of the multilayer body 1 is a surface that faces the external substrate when the multilayer inductor L1 is mounted on the external substrate (not shown).

  As shown in FIG. 2 and FIG. 3, the laminate 1 is a plurality (14 in the first embodiment) of magnetic material green sheets A1 to A14 that are laminated by a sheet lamination method (this 1st embodiment). A plurality (in this embodiment, four) magnetic layers 4 and a plurality (in the first embodiment, six) non-magnetic green sheets B1 to B6 are laminated by a sheet lamination method (this first embodiment). 3) of nonmagnetic layers 5. Moreover, the laminated body 1 is provided with the several coils 10-16 which consist of conductor patterns C1-C12 inside. The actual multilayer inductor L1 is integrated to such an extent that the boundaries between the magnetic green sheets A1 to A14 and the nonmagnetic green sheets B1 to B6 cannot be visually recognized.

  Each magnetic layer 4 has coils 10, 12, 14, and 16 therein, and the coils 10, 12, 14, and 16 are not in contact with the nonmagnetic layer 5. Each magnetic layer 4 is formed by firing and sintering the magnetic green sheets A1 to A14 as described later, and functions as an insulator having electrical insulation.

  The magnetic green sheets A1 to A14 forming each magnetic layer 4 are formed by applying a slurry made of ferrite (for example, Ni—Cu—Zn based ferrite) as a raw material on a film by a doctor blade method. The thickness of the magnetic green sheets A1 to A14 is, for example, 70 μm.

  Each nonmagnetic material layer 5 has coils 11, 13, and 15 therein, and is positioned between the magnetic material layers 4. Each nonmagnetic layer 5 is formed by firing and sintering nonmagnetic green sheets B1 to B6 as described later, and functions as an insulator having electrical insulation.

  Nonmagnetic green sheets B1 to B6 forming each nonmagnetic layer 5 are formed by applying a slurry of forsterite ceramic containing Zn as a raw material on a film by a doctor blade method. The nonmagnetic green sheets B1 to B6 have a thickness of, for example, 70 μm.

  The coil 10 is formed by electrically connecting the conductor patterns C1 and C2. The coils 11, 13, 15, and 16 are configured by conductor patterns C3, C7, C11, and C12, respectively. The coil 12 is formed by electrically connecting the conductor patterns C4 to C6. The coil 14 is formed by electrically connecting the conductor patterns C8 to C10. Note that the conductor patterns C3, C7, and C11 constituting the coils 11, 13, and 15 function as connection conductors that electrically connect the coils 10, 12, 14, and 16, respectively.

  The conductor pattern C1 corresponds to approximately ½ turn of the coil 10, and is formed in an approximately L shape on the magnetic green sheet A2. A lead-out portion C1a is integrally formed at one end of the conductor pattern C1. The lead-out portion C1a of the conductor pattern C1 is drawn out to the edge of the magnetic green sheet A2, and its end is exposed at the end face of the magnetic green sheet A2. For this reason, the derivation | leading-out part C1a will be electrically connected to the terminal electrode 2. FIG. The other end of the conductor pattern C1 is electrically connected to a through-hole electrode D1 formed through the magnetic green sheet A2 in the thickness direction. For this reason, the conductor pattern C1 is electrically connected to one end of the corresponding conductor pattern C2 through the through-hole electrode D1 in a stacked state.

  The conductor patterns C2 and C12 correspond to approximately one turn of the coils 10 and 16, respectively, and are wound spirally on the magnetic green sheets A3 and A13. One end of each of the conductor patterns C2 and C12 includes a region electrically connected to the through-hole electrodes D1 and D18 in a stacked state. The other ends of the conductor patterns C2 and C12 are electrically connected to through-hole electrodes D2 and D12 formed through the magnetic green sheets A3 and A13 in the thickness direction, respectively. Therefore, the conductor patterns C2 and C12 are electrically connected to the corresponding conductor patterns C13 and C19 via the through-hole electrodes D2 and D12 in a stacked state.

  The conductor patterns C3, C7, and C11 correspond to substantially one turn of the coils 11, 13, and 15, respectively, and are wound spirally on the nonmagnetic green sheets B2, B4, and B6. One end of each conductor pattern C3, C7, C11 includes a region electrically connected to each through-hole electrode D13, D15, D17 in a stacked state. The other ends of the conductor patterns C3, C7, and C11 are electrically connected to through-hole electrodes D3, D7, and D11 formed through the nonmagnetic green sheets B2, B4, and B6 in the thickness direction, respectively. ing. Therefore, the conductor patterns C3, C7, and C11 are electrically connected to the corresponding conductor patterns C14, C16, and C18 through the through-hole electrodes D3, D7, and D11 in a stacked state, respectively. .

  The conductor patterns C4 to C6 correspond to approximately one turn of the coil 12, and are wound spirally on the magnetic green sheets A5 to A7. One end of each of the conductor patterns C4 to C6 includes a region electrically connected to each of the through-hole electrodes D14, D4, and D5 in a stacked state. The other ends of the conductor patterns C4 to C6 are electrically connected to through-hole electrodes D4 to D6 formed through the magnetic green sheets A5 to A7 in the thickness direction, respectively. Therefore, the conductor patterns C4 to C6 are electrically connected to the corresponding conductor patterns C5, C6, and C15 through the through-hole electrodes D4 to D6 in a stacked state.

  The conductor patterns C8 to C10 correspond to approximately one turn of the coil 14, respectively, and are wound spirally on the magnetic green sheets A9 to A11. One end of each of the conductor patterns C8 to C10 includes a region electrically connected to each through-hole electrode D16, D8, D9 in a stacked state. The other ends of the conductor patterns C8 to C10 are electrically connected to through-hole electrodes D8 to D10 formed through the magnetic green sheets A9 to A11 in the thickness direction, respectively. Therefore, the conductor patterns C8 to C10 are electrically connected to the corresponding conductor patterns C9, C10, and C17 through the through-hole electrodes D8 to D10 in a stacked state.

  The conductor patterns C13, C15, and C17 are formed in an island shape on the nonmagnetic green sheets B1, B3, and B5. Each of the conductor patterns C13, C15, and C17 includes regions that are electrically connected to the through-hole electrodes D2, D6, and D10 in a stacked state. Further, in the center of each conductor pattern C13, C15, C17, each through-hole electrode D13, D15, D17 formed through the nonmagnetic green sheets B1, B3, B5 in the thickness direction is electrically connected. It is connected. Therefore, the conductor patterns C13, C15, and C17 are electrically connected to the corresponding conductor patterns C3, C7, and C11 through the through-hole electrodes D13, D15, and D17 in a stacked state. .

  The conductor patterns C14, C16, C18 are formed in an island shape on the magnetic green sheets A4, A8, A12. Each of the conductor patterns C14, C16, and C18 includes regions that are electrically connected to the through-hole electrodes D3, D7, and D11 in a stacked state. Further, at the center of each conductor pattern C14, C16, C18, it is electrically connected to each through-hole electrode D14, D16, D18 formed through each magnetic green sheet A4, A8, A12 in the thickness direction. ing. Therefore, the conductor patterns C14, C16, and C18 are electrically connected to the corresponding conductor patterns C4, C8, and C12 through the through-hole electrodes D14, D16, and D18 in a stacked state, respectively. .

  The conductor pattern C19 is formed in a substantially I shape on the magnetic green sheet A14. One end of the conductor pattern C19 includes a region electrically connected to the through-hole electrode D12 in a stacked state. A lead-out portion C19a is integrally formed with the other end of the conductor pattern C19. The lead-out part C19a of the conductor pattern C19 is drawn out to the edge of the magnetic green sheet A14 and exposed at the end face of the magnetic green sheet A14. For this reason, the derivation | leading-out part C19a will be electrically connected with the terminal electrode 3. FIG.

  Next, a manufacturing method of the multilayer inductor L1 having the above-described configuration will be described with reference to FIG.

First, magnetic green sheets A1 to A14 and nonmagnetic green sheets B1 to B6 are prepared. The density of the magnetic green sheets A1 to A14 and the nonmagnetic green sheets B1 to B6 is adjusted to, for example, about 2.62 g / cm ³ by addition of an acidic compound or the like or deionization treatment. .

  Subsequently, through holes are formed by laser processing or the like at predetermined positions of the magnetic green sheets A2 to A13 and the nonmagnetic green sheets B1 to B6, that is, positions where the through hole electrodes D1 to D18 are to be formed. Form. Next, the conductor patterns C1 to C19 are formed on the magnetic green sheets A2 to A14 and the nonmagnetic green sheets B1 to B6, respectively. Here, each conductor pattern C1-C19 and each through-hole electrode D1-D18 are formed by printing the paste which has silver or nickel as a main component with a metal mask etc.

Subsequently, the magnetic green sheets A1 to A14 and the nonmagnetic green sheets B1 to B6 are stacked in the order shown in FIG. 3, and each magnetic green sheet A1 to A14 and each of the magnetic green sheets A1 to A14 is applied by applying pressure in the stacking direction. The non-magnetic green sheets B1 to B6 are pressure-bonded so that no gap is generated. In this case, the density (2.62 g / cm ³ or so) of the magnetic green sheet A1~A14 and nonmagnetic green sheet B1~B6 compares the density of conventional green sheet (3.0 g / cm ³ or so) Because of the low density, the green sheets A1 to A14 and B1 to B6 at the positions sandwiching the conductor patterns C1 to C19 are greatly recessed and deformed, and the thickness of the conductor patterns C1 to C19 can be absorbed.

  Subsequently, the bonded magnetic green sheets A1 to A14 and nonmagnetic green sheets B1 to B6 are cut into chips, and then fired at a predetermined temperature (for example, about 840 to 900 ° C.). Form. For example, the length of the laminate 1 in the longitudinal direction after firing is 3.2 mm, the width is 2.5 mm, and the height is 1.3 mm. In addition, each of the conductor patterns C1 to C12 has, for example, a width after firing of 250 μm and a thickness of 35 μm.

  Subsequently, terminal electrodes 2 and 3 are formed on the laminate 1. Thereby, the multilayer inductor L1 is formed. The terminal electrodes 2 and 3 are each baked at a predetermined temperature (for example, about 680 to 740 ° C.) by applying an electrode paste mainly composed of silver, nickel or copper to both end faces in the longitudinal direction of the laminate 1. Further, it is formed by performing electroplating. For this electroplating, Cu, Ni, Sn, or the like can be used.

  As described above, in the first embodiment, each of the coils 10, 12, 14, and 16 is provided inside each magnetic layer 4, and each magnetic layer 4 is separated by each nonmagnetic material 5. Yes. For this reason, the number of turns of each of the coils 10, 12, 14, and 16 existing in each magnetic layer 4 is reduced to about 1 to 3 turns, respectively. As compared with the case where the coils are provided in the coil 10, the magnitude of the magnetic field generated by the current flowing through the coils 10, 12, 14, 16 is reduced. As a result, magnetic saturation is suppressed in each magnetic layer 4, and even when a large current is passed through the multilayer inductor L 1 according to the first embodiment, a decrease in inductance value can be suppressed, and the DC superposition characteristics can be suppressed. Can be improved.

  In the first embodiment, the coils 10, 12, 14, and 16 are not in contact with the nonmagnetic layer 5. For this reason, the magnetic flux F generated around each of the coils 10, 12, 14, 16 when a direct current flows through the multilayer inductor L 1 is hardly disturbed by the nonmagnetic layer 5 (FIG. 2). reference). As a result, the initial inductance value of the multilayer inductor L1 can be increased.

  In the first embodiment, since the coils 11, 13, and 15 are connection conductors that electrically connect the coils 10, 12, 14, and 16, they are provided inside the nonmagnetic material layer 5. The initial inductance value of the multilayer inductor L1 can be further increased by the coils 11, 13, and 15 thus obtained.

  In the first embodiment, since each nonmagnetic layer 5 contains forsterite ceramic containing Zn, it is possible to improve the attenuation characteristics of noise components in the high frequency band. In addition, it is possible to reduce the possibility of occurrence of a problem such as delamination between each nonmagnetic layer 5 and each magnetic layer 4.

  (Second Embodiment)

  With reference to FIG. 4, the configuration of the common mode filter CF1 (multilayer electronic component) according to the second embodiment will be described. FIG. 4 is a diagram for explaining a cross-sectional configuration of the common mode filter CF1 according to the second embodiment of the present invention.

  The common mode filter CF1 includes a substantially rectangular parallelepiped laminated body 41 and a pair of terminal electrodes 42 and 43 formed on both side surfaces of the laminated body 41 in the longitudinal direction. The bottom surface of the stacked body 41 is a surface facing the external substrate when the common mode filter CF1 is mounted on the external substrate (not shown).

  The laminated body 41 includes a pair of magnetic layers ML1 and ML2 formed by laminating a plurality of magnetic green sheets (not shown in detail), respectively, and a plurality of non-magnetic green sheets (not shown in detail). Are formed by a non-magnetic layer LS that is laminated by a sheet laminating method and a varistor layer VL that is formed by laminating a plurality of varistor green sheets (not shown in detail) by a sheet laminating method. The actual common mode filter CF1 is integrated so that the boundary between the magnetic green sheet, the non-magnetic green sheet, and the varistor green sheet cannot be visually recognized.

  The magnetic green sheets (not shown in detail) forming the magnetic layers ML1 and ML2 are obtained by applying a slurry of ferrite (for example, Ni—Cu—Zn based ferrite) as a raw material on the film by a doctor blade method. Formed with. The thickness of the magnetic green sheet (not shown in detail) is, for example, 20 μm.

  The non-magnetic layer LS has a coil C41 disposed therein so as to form a common mode filter. Each nonmagnetic layer 5 is formed by firing and sintering a nonmagnetic green sheet (not shown in detail) as will be described later, and functions as an insulator having electrical insulation.

  A non-magnetic green sheet (not shown in detail) forming the non-magnetic layer LS is formed by applying a slurry of forsterite-based ceramic containing Zn as a raw material on a film by a doctor blade method. The thickness of the nonmagnetic green sheet (not shown in detail) is, for example, 20 μm.

The varistor layer VL is formed by firing and sintering a varistor green sheet (not shown in detail) on which a hot electrode or a ground electrode is formed. A varistor green sheet (not shown in detail) is formed by applying a slurry using a mixed powder of ZnO, Co ₃ O ₄ , Pr ₆ O ₁₁ , CaCO ₃ , and SiO ₂ as a raw material on a film by a doctor blade method. The The thickness of the varistor green sheet (not shown in detail) is, for example, 30 μm.

  Next, a method for manufacturing the common mode filter CF1 having the above-described configuration will be described. First, a magnetic green sheet (not shown in detail), a varistor green sheet (not shown in detail) and a non-magnetic green sheet (not shown in detail) are prepared.

  Subsequently, through holes are formed by laser processing or the like at predetermined positions on each non-magnetic green sheet (not shown in detail), that is, positions where through-hole electrodes (not shown in detail) are to be formed. Next, on each magnetic green sheet (not shown in detail), varistor green sheet (not shown in detail) and each non-magnetic green sheet (not shown in detail), each conductor pattern (not shown in detail) Respectively. Here, each conductor pattern (not shown in detail) and each through-hole electrode (not shown in detail) are formed by printing a paste mainly composed of silver or nickel with a metal mask or the like.

  Subsequently, each magnetic green sheet (not shown in detail), a varistor green sheet (not shown in detail) and each non-magnetic green sheet (not shown in detail) are stacked in a predetermined order, and pressure is applied in the stacking direction. Add and crimp.

  Subsequently, the pressure-bonded magnetic green sheet (not shown in detail), the varistor green sheet (not shown in detail) and the non-magnetic green sheet (not shown in detail) are cut into chips, and then a predetermined temperature (for example, , About 840 to 900 ° C.) to form the laminated body 41.

  Subsequently, terminal electrodes 42 and 43 are formed on the laminate 41. As a result, the common mode filter CF1 is formed. The terminal electrodes 42 and 43 are each baked at a predetermined temperature (for example, about 680 to 740 ° C.) by applying an electrode paste mainly composed of silver, nickel or copper to both end surfaces of the laminate 41 in the longitudinal direction. Further, it is formed by performing electroplating. For this electroplating, Cu, Ni, Sn, or the like can be used.

  As described above, in the second embodiment, since the nonmagnetic material layer LS contains forsterite ceramic containing Zn, it is possible to improve the attenuation characteristics of noise components in the high frequency band. In addition, it is possible to reduce the possibility of occurrence of problems such as delamination between the nonmagnetic layer LS and the magnetic layers ML1 and ML2.

  In the first embodiment described above, the multilayer electronic component as the coil component is exemplified, and in the second embodiment described above, the multilayer electronic component as the common mode filter is exemplified. However, the embodiment of the present invention is not limited thereto. Absent.

  As an embodiment of the present invention, a multilayer electronic component comprising at least one magnetic layer and at least one nonmagnetic layer, the nonmagnetic layer containing forsterite ceramic containing Zn Any other form may be adopted. For example, an LC filter including a capacitor that forms a resonance circuit together with an inductor can be employed.

1 is a perspective view of a multilayer inductor according to a first embodiment of the present invention. FIG. 2 is a diagram for explaining a cross-sectional configuration of the multilayer inductor of FIG. 1. FIG. 2 is an exploded perspective view of a multilayer body included in the multilayer inductor of FIG. 1. It is a figure for demonstrating the cross-sectional structure of the common mode filter which is 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Laminated body, 2, 3 ... Terminal electrode, 4 ... Magnetic material layer, 5 ... Nonmagnetic material layer, L1 ... Multilayer inductor.

Claims (7)

At least two or more magnetic layers;
A multilayer electronic component comprising at least one non-magnetic layer,
The non-magnetic layer is a multilayer electronic component that includes a forsterite-based ceramic containing Zn, and is sandwiched between the at least two magnetic layers to separate the magnetic layer .   The multilayer electronic component according to claim 1, wherein the nonmagnetic layer includes a coil conductor constituting an inductor.   The multilayer electronic component according to claim 2, wherein a pair of the coil conductors are formed and function as a common mode filter.   The multilayer electronic component according to claim 2, comprising a capacitor together with the inductor and functioning as an LC filter.   The multilayer electronic component according to claim 3, which includes a capacitor together with the common mode filter and functions as an LC filter.   The multilayer electronic component according to claim 1, wherein the nonmagnetic layer is sandwiched between a pair of the magnetic layers.   The multilayer electronic component according to claim 1, further comprising a varistor layer that exhibits a varistor function.

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