WO2010061679A1

WO2010061679A1 - Electronic part

Info

Publication number: WO2010061679A1
Application number: PCT/JP2009/065748
Authority: WO
Inventors: 秀二木原; 治松本
Original assignee: 株式会社村田製作所
Priority date: 2008-11-28
Filing date: 2009-09-09
Publication date: 2010-06-03

Abstract

In an electronic part equipped with a coil having a coil axis orthogonally intersecting the layering direction, the DC superposition characteristics can be improved. A layered body (12) is formed by layering insulation layers (16a to 16k) and an insulation layer (17) having a lower permeability than the insulation layers (16a to 16k). The coil (L) is built in the layered body (12) and has a coil axis which orthogonally intersects the layering direction.

Description

Electronic components

The present invention relates to an electronic component, and more particularly to an electronic component including a coil having a coil axis orthogonal to the stacking direction.

For example, a multilayer chip inductor described in Patent Document 1 is known as a conventional electronic component. In the multilayer chip inductor, a coil having a coil axis orthogonal to the stacking direction is provided inside a multilayer body in which a plurality of ferrite sheets are stacked. And the external electrode connected to the both ends of a coil is provided in the two side surfaces of the laminated body which cross | intersects a coil axis | shaft, respectively. According to the multilayer chip inductor, the number of turns of the coil can be increased or decreased without changing the number of laminated ferrite sheets.

However, the multilayer chip inductor is composed of a ferrite sheet made of a magnetic material. Therefore, when the direct current flowing through the coil is increased, magnetic saturation occurs only when a relatively small direct current flows. As a result, the inductance value of the multilayer chip inductor is rapidly reduced. That is, the multilayer chip inductor does not have a preferable direct current superposition characteristic.

Japanese Unexamined Patent Publication No. 7-320936

Therefore, an object of the present invention is to improve DC superposition characteristics in an electronic component having a coil having a coil axis orthogonal to the stacking direction.

An electronic component according to an embodiment of the present invention includes a stacked body in which a plurality of first insulating layers and a second insulating layer having a lower magnetic permeability than the first insulating layers are stacked. And a coil having a coil axis that is built in the laminated body and orthogonal to the laminating direction.

According to the present invention, the DC superposition characteristics can be improved in an electronic component having a coil having a coil axis orthogonal to the stacking direction.

It is a perspective view of the electronic component which concerns on one Embodiment of this invention. It is a disassembled perspective view of the laminated body of the electronic component of FIG. FIG. 2 is a cross-sectional structural view taken along line AA of the electronic component in FIG. It is the graph which showed the direct current | flow superimposition characteristic of the electronic component of FIG. 1, and the conventional electronic component.

Hereinafter, an electronic component according to an embodiment of the present invention will be described.

(Configuration of electronic parts)
FIG. 1 is a perspective view of an electronic component 10 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the multilayer body 12 of the electronic component 10. FIG. 3 is a sectional structural view taken along the line AA of the electronic component 10 of FIG. Hereinafter, the stacking direction of the electronic component 10 is defined as the z-axis direction, the direction along the long side of the electronic component 10 is defined as the x-axis direction, and the direction along the short side of the electronic component 10 is defined as the y-axis direction. To do. The x axis, the y axis, and the z axis are orthogonal to each other. In FIG. 1, a part of the external electrode 14 b is cut and described so that the internal state can be easily understood.

The electronic component 10 includes a laminate 12 and external electrodes 14a and 14b as shown in FIG. The laminated body 12 has a rectangular parallelepiped shape and incorporates a coil L. The external electrodes 14a and 14b are electrically connected to both ends of the coil L, respectively, and are provided so as to cover the side surfaces of the multilayer body 12 located at both ends in the x-axis direction.

As shown in FIG. 2, the laminate 12 is configured by laminating a plurality of rectangular insulating layers 16a, 16b, 17, 16c to 16k in order from the positive direction side in the z-axis direction. The insulating layers (first insulating layers) 16a to 16k are magnetic layers made of soft magnetic ferrite (for example, Ni—Zn—Cu ferrite). In FIG. 2, the insulating layers 16a to 16k are composed of 11 insulating layers, but the total number of the insulating layers 16a to 16k is not limited to this. In the electronic component 10, in practice, between the insulating layer 16a and the insulating layer 16b, between the insulating layer 16e and the insulating layer 16f, between the insulating layer 16g and the insulating layer 16h, and between the insulating layer 16j and the insulating layer. A further insulating layer is inserted between 16k. Therefore, the dotted lines between the insulating layer 16a and the insulating layer 16b, between the insulating layer 16e and the insulating layer 16f, between the insulating layer 16g and the insulating layer 16h, and between the insulating layer 16j and the insulating layer 16k It is connected with.

The insulating layer (second insulating layer) 17 is provided so as to be sandwiched between the insulating layers 16b and 16c, and has a lower magnetic permeability than the magnetic material constituting the insulating layers 16a to 16k. It is made of a magnetic material having non-magnetic material or a non-magnetic material. In the present embodiment, the insulating layer 17 is made of a non-magnetic material ferrite (eg, Zn—Cu ferrite).

In the following, when referring to the individual insulating layers 16a to 16k, an alphabet is appended to the reference symbol, and when referring to them collectively, the alphabet after the reference symbol is omitted.

The coil L is a spiral coil that advances in the x-axis direction while rotating as shown in FIG. Therefore, the coil axis X of the coil L is parallel to the x-axis direction. As shown in FIG. 2, the coil L includes lead conductors 18a and 18b, a plurality of strip conductors 20a to 20f, 22a to 22g, and a plurality of via hole conductors b1 to b14, b21 to b34.

The lead conductors 18a and 18b and the strip-like conductors 20a to 20f are provided in the multilayer body 12 as shown in FIGS. More specifically, the lead conductors 18a and 18b and the strip-shaped conductors 20a to 20f are provided on the insulating layer 16d. The strip conductors 20a to 20f are inclined so as to have a positive inclination in the xy plane when viewed from the positive side in the z-axis direction, and are arranged in the x-axis direction at equal intervals so as to be parallel to each other. Is provided. Each of the strip conductors 20a to 20f has end portions t1 and t2 (in FIG. 1, only the end portions t1 and t2 of the

strip conductors

20a and 20b are marked). The end portions t1 and t2 are positioned so as to sandwich the coil axis X when viewed from the positive side in the z-axis direction. Specifically, the end t1 is located on the positive direction side in the y-axis direction with respect to the coil axis X, and the end t2 is located on the negative direction side in the y-axis direction with respect to the coil axis X. The strip conductors 20a to 20f are not necessarily parallel.

The lead conductor 18a has a substantially L-shape. More specifically, the lead conductor 18a extends in parallel with the strip conductors 20a to 20f from the positive side in the y-axis direction, and is bent in the middle to extend in the x-axis direction. It has a shape drawn to the side on the negative direction side. Similarly, the lead conductor 18b has a substantially L shape. More specifically, the lead conductor 18b extends in parallel with the strip conductors 20a to 20f from the negative direction side in the y-axis direction, and is bent in the middle to be x It has a shape drawn to the side on the positive direction side in the axial direction. The lead conductors 18a and 18b are connected to the external electrodes 14a and 14b, respectively.

The strip conductors 22a to 22g are provided in the multilayer body 12 as shown in FIGS. More specifically, the strip conductors 22a to 22g are provided on the insulating layer 16i. The band-shaped conductors 22a to 22g are inclined so as to have a negative inclination in the xy plane when viewed from the positive side in the z-axis direction, and are arranged in the x-axis direction at equal intervals so as to be parallel to each other. Is provided. Each of the strip conductors 22a to 22g has ends t3 and t4 (in FIG. 1, only the ends t3 and t4 of the strip conductors 22a and 22b are marked). The ends t3 and t4 are located so as to sandwich the coil axis X when viewed in plan from the positive side in the z-axis direction. Specifically, the end t3 is located on the positive side in the y-axis direction from the coil axis X, and the end t4 is located on the negative direction side in the y-axis direction from the coil axis X. The strip conductors 22a to 22g do not necessarily have to be parallel.

Here, as shown in FIGS. 1 and 2, when viewed in plan from the z-axis direction, the end t1 and the end t3 overlap each other. Further, when viewed in plan from the z-axis direction, the end t2 and the end t4 overlap. More specifically, the strip conductor 22b overlaps at an end t1 and an end t3 of one strip conductor 20a of two

adjacent strip conductors

20a and 20b, and the end of the other strip conductor 20b. It overlaps in the part t2 and the edge part t4. The end portions t3 and t4 of the other strip conductors 22c to 22f overlap the end portions t1 and t2 of the strip conductors 20b to 20f in the same manner as the strip conductor 22b. Thus, when viewed in plan from the z-axis direction, the strip conductors 20a to 20f and 22a to 22g form one zigzag line.

As shown in FIG. 2, the via-hole conductors b21 to b27 are connected to the end on the positive side in the y-axis direction of the lead conductor 18a and the end t1 of the strip conductors 20a to 20f, respectively, and the insulating layer 16d is connected to z It is formed so as to penetrate in the axial direction. The via-hole conductors b28 to b34 are connected to the end t2 of the strip-like conductors 20a to 20f and the end on the negative side in the y-axis direction of the lead conductor 18b, and are formed so as to penetrate the insulating layer 16d in the z-axis direction. Has been.

The via-hole conductors b1 to b7 are provided at positions corresponding to the via-hole conductors b21 to b27 when viewed in plan from the z-axis direction in each of the insulating layers 16e to 16h, and the insulating layers 16e to 16h are arranged in the z-axis direction. It is provided so that it may penetrate. The via-hole conductors b8 to b14 are provided at positions corresponding to the via-hole conductors b28 to b34 when viewed in plan from the z-axis direction in each of the insulating layers 16e to 16h. It is provided so as to penetrate in the axial direction.

As the insulating layers 16a, 16b, 17, 16c to 16k configured as described above are stacked in this order, as shown in FIG. 1, the spiral shape that advances in the x-axis direction while rotating in the stacked body 12 is formed. Coil L is formed. More specifically, the via-hole conductor b1 and the via-hole conductor b21 are connected to each other so as to extend in the z-axis direction and the end of the lead conductor 18a on the positive side in the y-axis direction and the strip-shaped conductor It functions as a connecting portion that connects the end t3 of 22a. The via-hole conductor b2 and the via-hole conductor b22 are connected to each other so as to extend in the z-axis direction, and as a connection portion that connects the end t1 of the strip-shaped conductor 20a and the end t3 of the strip-shaped conductor 22b. It is functioning. The via-hole conductor b3 and the via-hole conductor b23 are connected to each other so as to extend in the z-axis direction and serve as a connection portion that connects the end t1 of the strip-shaped conductor 20b and the end t3 of the strip-shaped conductor 22c. It is functioning. The via-hole conductor b4 and the via-hole conductor b24 extend in the z-axis direction by being connected to each other, and serve as a connection portion that connects the end t1 of the strip-shaped conductor 20c and the end t3 of the strip-shaped conductor 22d. It is functioning. The via-hole conductor b5 and the via-hole conductor b25 extend in the z-axis direction by being connected to each other, and serve as a connection portion that connects the end t1 of the strip-shaped conductor 20d and the end t3 of the strip-shaped conductor 22e. It is functioning. The via-hole conductor b6 and the via-hole conductor b26 are connected to each other so as to extend in the z-axis direction and serve as a connection portion that connects the end t1 of the strip-shaped conductor 20e and the end t3 of the strip-shaped conductor 22f. It is functioning. The via-hole conductor b7 and the via-hole conductor b27 extend in the z-axis direction by being connected to each other, and serve as a connection portion that connects the end t1 of the strip-shaped conductor 20f and the end t3 of the strip-shaped conductor 22g. It is functioning.

The via-hole conductor b8 and the via-hole conductor b28 are connected to each other so as to extend in the z-axis direction and connect the end t2 of the strip-shaped conductor 20a and the end t4 of the strip-shaped conductor 22a. It functions as a department. The via-hole conductor b9 and the via-hole conductor b29 are connected to each other so as to extend in the z-axis direction, and as a connection portion that connects the end t2 of the strip-shaped conductor 20b and the end t4 of the strip-shaped conductor 22b. It is functioning. The via-hole conductor b10 and the via-hole conductor b30 extend in the z-axis direction by being connected to each other, and serve as a connection portion that connects the end t2 of the strip-shaped conductor 20c and the end t4 of the strip-shaped conductor 22c. It is functioning. The via-hole conductor b11 and the via-hole conductor b31 are connected to each other so as to extend in the z-axis direction, and as a connection portion that connects the end t2 of the strip-shaped conductor 20d and the end t4 of the strip-shaped conductor 22d. It is functioning. The via-hole conductor b12 and the via-hole conductor b32 are connected to each other so as to extend in the z-axis direction, and as a connection portion that connects the end t2 of the strip-shaped conductor 20e and the end t4 of the strip-shaped conductor 22e. It is functioning. The via-hole conductor b13 and the via-hole conductor b33 are connected to each other so as to extend in the z-axis direction, and as a connection portion that connects the end t2 of the strip-shaped conductor 20f and the end t4 of the strip-shaped conductor 22f. It is functioning. The via-hole conductor b14 and the via-hole conductor b34 are connected to each other so as to extend in the z-axis direction, and the end of the lead conductor 18b on the negative side in the y-axis direction and the end t4 of the strip-shaped conductor 22g. Functions as a connection part.

(effect)
According to the electronic component 10 configured as described above, since the multilayer body 12 includes the insulating layer 17 having a lower magnetic permeability than the insulating layer 16, as described below, the DC superposition of the electronic component 10 is performed. The characteristics are improved. FIG. 4 is a graph showing the DC superposition characteristics of the electronic component 10 and the type of electronic component 10 in which the insulating layer 17 is not provided (that is, a conventional electronic component). The vertical axis represents the impedance, and the horizontal axis represents the direct current value.

As shown in FIG. 3, the magnetic flux generated in the coil L consists of a magnetic flux φ that circulates around the strip conductors 20a to 20f and the strip conductors 22a to 22g. The insulating layer 17 is provided in the vicinity of the strip conductors 20a to 20f. Therefore, as shown in FIG. 3, the magnetic flux φ circulating around the strip conductors 20a to 20f crosses the insulating layer 17. Therefore, even if the direct current flowing through the coil L increases, the occurrence of magnetic saturation in the coil L is suppressed. As a result, a sudden decrease in inductance value due to an increase in direct current is suppressed, and the direct current superimposition characteristics of the electronic component 10 are improved. For example, as shown in FIG. 4, when the insulating layer 17 is not provided on the electronic component 10, the inductance value decreases rapidly when the direct current value increases, whereas the insulating layer 17 is formed on the electronic component 10. When the direct current value is increased, the inductance value is not greatly reduced even if the direct current value is increased. The electronic component 10 as described above can improve the conversion efficiency of the DCDC converter, for example.

(Method for manufacturing electronic parts)
Below, the manufacturing method of the electronic component 10 is demonstrated, referring drawings.

Ceramic green sheets to be the insulating layers 16a to 16k are produced by the following steps. Ferric oxide (Fe ₂ O ₃ ), zinc oxide (ZnO), nickel oxide (NiO), and copper oxide (CuO) are weighed at a predetermined ratio, and each material is put into a ball mill as a raw material. Mix. The obtained mixture is dried and pulverized, and the obtained powder is calcined at 750 ° C. for 1 hour. The obtained calcined powder is wet pulverized by a ball mill, dried and then crushed to obtain a ferrite ceramic powder.

To this ferrite ceramic powder, a binder (vinyl acetate, water-soluble acrylic, etc.), a plasticizer, a wetting material, and a dispersing agent are added and mixed with a ball mill, and then defoamed under reduced pressure. The obtained ceramic slurry is formed into a sheet shape by the doctor blade method and dried to produce ceramic green sheets to be the insulating layers 16a to 16k.

Next, a ceramic green sheet to be the insulating layer 17 is produced by the following process. Ferric oxide (Fe ₂ O ₃ ), zinc oxide (ZnO), and copper oxide (CuO) are weighed at a predetermined ratio, and the respective materials are put into a ball mill as raw materials, and wet blending is performed. The obtained mixture is dried and pulverized, and the obtained powder is calcined at 750 ° C. for 1 hour. The obtained calcined powder is wet pulverized by a ball mill, dried and then crushed to obtain a ferrite ceramic powder.

To this ferrite ceramic powder, a binder (vinyl acetate, water-soluble acrylic, etc.), a plasticizer, a wetting material, and a dispersing agent are added and mixed with a ball mill, and then defoamed under reduced pressure. The obtained ceramic slurry is formed into a sheet by the doctor blade method and dried to produce a ceramic green sheet to be the insulating layer 17.

Next, via-hole conductors b21 to b34 are formed on the ceramic green sheet to be the insulating layer 16d. Specifically, as shown in FIG. 2, a via hole is formed by irradiating a ceramic green sheet to be the insulating layer 16d with a laser beam. Next, the via hole is filled with a conductive paste such as Ag, Pd, Cu, Au or an alloy thereof by a method such as printing.

Further, via-hole conductors b1 to b14 are formed on the ceramic green sheets to be the insulating layers 16e to 16h. Specifically, as shown in FIG. 2, via holes are formed by irradiating a ceramic green sheet to be the insulating layers 16e to 16h with a laser beam. Next, the via hole is filled with a conductive paste such as Ag, Pd, Cu, Au or an alloy thereof by a method such as printing.

Next, a conductive paste mainly composed of Ag, Pd, Cu, Au, or an alloy thereof is applied onto the ceramic green sheet to be the insulating layer 16d by a method such as a screen printing method or a photolithography method. The lead conductors 18a and 18b and the strip conductors 20a to 20f are formed. Note that the step of forming the strip conductors 20a to 20f and the step of filling the via hole with the conductive paste may be performed in the same step.

Next, a conductive paste mainly composed of Ag, Pd, Cu, Au, or an alloy thereof is applied onto the ceramic green sheet to be the insulating layer 16i by a method such as a screen printing method or a photolithography method. The strip conductors 22a to 22g are formed.

Next, as shown in FIG. 2, ceramic green sheets to be the insulating layers 16a, 16b, 17, 16c to 16k are stacked in this order from the positive direction side in the z-axis direction. More specifically, a ceramic green sheet to be the insulating layer 16k is disposed. Next, the ceramic green sheet to be the insulating layer 16j is disposed and temporarily pressed onto the ceramic green sheet to be the insulating layer 16k. Thereafter, the ceramic green sheets to be the insulating

layers

16i, 16h, 16g, 16f, 16e, 16d, 16c, 17, 16b, and 16a are similarly laminated and temporarily pressed in this order to obtain a mother laminated body. Further, the mother laminate is subjected to main pressure bonding by a hydrostatic pressure press or the like.

Next, the mother laminated body is cut into a laminated body 12 having a predetermined size by pressing and the unfired laminated body 12 is obtained. The unfired laminate 12 is subjected to binder removal processing and firing. The binder removal treatment is performed, for example, in a low oxygen atmosphere at 500 ° C. for 2 hours. Firing is performed, for example, at 1000 ° C. for 2 hours.

The fired laminated body 12 is obtained through the above steps. The laminated body 12 is chamfered by barrel processing. Thereafter, a silver electrode to be the external electrodes 14a and 14b is formed on the surface of the laminate 12 by applying and baking a conductive paste whose main component is silver by a method such as dipping. The silver electrode is dried at 120 ° C. for 10 minutes, and the silver electrode is baked at 890 ° C. for 1 hour. Finally, the external electrodes 14a and 14b are formed by performing Ni plating / Sn plating on the surface of the silver electrode. Through the above steps, the electronic component 10 as shown in FIG. 1 is completed.

(Other embodiments)
The electronic component 10 according to the present invention is not limited to that shown in the embodiment. Therefore, it can be changed within the scope of the gist.

In order to improve the direct current superimposition characteristic of the electronic component 10, the magnetic flux φ that circulates the strip conductors 20a to 20f and 22a to 22g needs to cross the insulating layer 17. Therefore, the insulating layer 17 is desirably provided in a region through which the magnetic flux φ generated by the coil L passes. Therefore, the insulating layer 17 is desirably provided in the vicinity of the strip-shaped conductors 20a to 20f and 22a to 22g.

Further, the place where the insulating layer 17 is provided is not limited to the positive side in the z-axis direction from the strip conductors 20a to 20f. Therefore, the insulating layer 17 may be provided between the strip conductors 20a to 20f and the strip conductors 22a to 22g, or may be provided on the negative side in the z-axis direction from the strip conductors 22a to 22g. Good.

Further, a plurality of insulating layers 17 may be provided. The insulating layer 17 has the same shape as the insulating layer 16, but the insulating layer 17 may be smaller than the insulating layer 16. That is, the insulating layer 17 may be provided on a part of the stacked body 12 in a plane perpendicular to the z-axis direction.

The present invention is useful for electronic parts, and is particularly excellent in that the direct current superposition characteristics can be improved in an electronic part having a coil having a coil axis orthogonal to the stacking direction.

L coil X coil axis b1 to b14, b21 to b34 Via hole conductor t1 to t4 End 10 Electronic component 12 Laminated body 14a, 14b External electrode 16a to 16k, 17 Insulating layer 18a, 18b Lead conductor 20a to 20f, 22a to 22g conductor

Claims

A stacked body in which a plurality of first insulating layers and a second insulating layer having a lower magnetic permeability than the first insulating layers are stacked;
A coil built in the laminate and having a coil axis perpendicular to the lamination direction;
Having
Electronic parts characterized by
The second insulating layer is provided so as to be sandwiched between the first insulating layers;
The electronic component according to claim 1.
The coil is
A plurality of first band-like electrodes that are arranged along the coil axis and have a first end and a second end located so as to sandwich the coil axis when viewed in plan from the stacking direction; ,
A plurality of second strip electrodes arranged in a line along the coil axis and having a third end and a fourth end located so as to sandwich the coil axis when viewed in plan from the stacking direction; ,
A first connection portion and a second connection portion extending in the stacking direction;
With
The plurality of second strip electrodes overlap each other at the first end portion and the third end portion of one of the two adjacent first strip electrodes. And overlaps at the second end and the fourth end of the other first strip electrode,
The first connection portion connects the first end portion and the third end portion,
The second connecting portion connecting the second end portion and the fourth end portion;
The electronic component according to claim 1, wherein: