WO2008004465A1

WO2008004465A1 - Stacked coil component

Info

Publication number: WO2008004465A1
Application number: PCT/JP2007/062848
Authority: WO
Inventors: Kenichi Kato; Akihiro Nakamura; Keiichi Tsuzuki
Original assignee: Murata Manufacturing Co., Ltd.
Priority date: 2006-07-04
Filing date: 2007-06-27
Publication date: 2008-01-10
Also published as: JPWO2008004465A1; JP4811465B2

Abstract

This invention provides a stacked coil component having good direct current superposition properties. The stacked coil component comprises a spiral coil (L) provided within a laminate comprising a magnetic material layer disposed on both main surfaces of a nonmagnetic material layer. A magnetic material green sheet (3) comprises as main components Fe2O3: 45 to 49 mol%, ZnO: 1 to 32 mol%, and CuO: 5 to 15 mol% with the balance consisting of: NiO and 0.6 to 4 wt% of SnO2 added to the main components. A nonmagnetic material green sheet (4) comprises as main components Fe2O3: 45 to 49 mol% and CuO: 5 to 15 mol% with the balance consisting of ZnO, and 0.6 to 4 wt% of SnO2 added to the main components.

Description

Specification

Multilayer coil parts

Technical field

[0001] The present invention relates to a laminated coil component, and more particularly to an open magnetic circuit type laminated coil component.

Background art

[0002] In Patent Document 1 and Patent Document 2, Ni-Zn-Cu-based materials are provided on both main surfaces of a non-magnetic material layer made of a Cu-Zn-based non-magnetic material for the purpose of improving DC superposition characteristics. An open magnetic circuit type multilayer coil component provided with a magnetic layer made of a magnetic material is described. However, sufficient DC superposition characteristics could not be obtained with this structure alone.

[0003] On the other hand, Patent Document 3 describes that SnO is 0.2 to 3 wt% for Ni-Zn-Cu based magnetic materials.

A technique is described in which the DC superposition characteristics are improved by adding%. Therefore, the inventors of the multilayer coil component described in Patent Document 1 and Patent Document 2 have a force obtained by adding 0.2 to 3 wt% of SnO to a Ni—Zn—Cu based magnetic material. DC superposition characteristics were not obtained.

Patent Document 1: Japanese Patent Laid-Open No. 2005-259774

Patent Document 2: International Publication 2005/122192 Pamphlet

Patent Document 3: Japanese Patent Laid-Open No. 2003-272912

Disclosure of the invention

Problems to be solved by the invention

[0004] Therefore, an object of the present invention is to provide a laminated coil component having good DC superimposition characteristics.

Means for solving the problem

In order to achieve the above object, a laminated coil component according to the present invention includes:

A laminate in which magnetic layers are disposed on both main surfaces of the non-magnetic layer;

A helical coil provided in the laminate;

An external electrode provided on the surface of the laminate and electrically connected to the spiral coil; The magnetic layer is made of a Ni-Zn-Cu-based magnetic material, and the composition ratio is FeO.

: 45 ~ 49mol%, ZnO: l ~ 32mol%, CuO: 5 ~ 15mol%, balance: NiO is the main component, and SnO is added to the main component by 0.6-4wt%. ,

The non-magnetic layer is made of a Cu_Zn-based non-magnetic material, and the composition ratio is FeO: 45-49 mol%, CuO: 5-15 mol%, the balance: ZnO as a main component, and further as a main component. In contrast, 0.6 to 4 wt% of SnO is added,

It is characterized by.

[0006] With the above configuration, the component diffusion at the interface between the magnetic layer and the nonmagnetic layer (co-sintering interface) becomes appropriate by bringing the composition of the nonmagnetic layer closer to the composition of the magnetic layer. .

[0007] In the multilayer coil component according to the present invention, the SnO content of the nonmagnetic layer may be equal to or higher than the SnO content of the magnetic layer. The Sn content in the magnetic layer is equal to or higher than the Sn content in the magnetic layer, so that the Sn component in the magnetic layer is less likely to diffuse into the nonmagnetic layer during co-sintering. Become.

[0008] In the multilayer coil component according to the present invention,

The main component composition of the magnetic layer is

Fe O: amol% (45≤a≤49)

Zn〇: bmol% (However, l≤b≤32)

CuO: cmol% (however, 5≤c≤15)

Ni〇: dmol% (however, a + b + c + d = 100)

The main component composition of the non-magnetic layer is

Fe O: xmol% (0 · 5 + a≤x≤0. 5 + a)

ZnO: ymol% (However, _0. 5 + (b + d) ≤ y ≤ 0.5 + (b + d))

CuO: zmol% (however, -0. 5 + c ≤ z ≤ 0.5 + c, x + y + z = 100) is preferable.

[0009] With the above configuration, the difference in shrinkage behavior between the magnetic layer and the nonmagnetic layer during sintering is further reduced, and the occurrence of cracks and the like is suppressed.

[0010] The thickness of the green sheet constituting the nonmagnetic layer is preferably 25 to 50 μm (the thickness of the NiZn interdiffusion layer after firing / the thickness of the nonmagnetic layer after firing). Is 0.2 It is preferably in the range of ~ 0.6. Inductance value (L value) The temperature change is 12% or less in absolute value, and it becomes a coil component with stable inductance characteristics against temperature change.

[0011] The thickness of the green sheet constituting the nonmagnetic layer is preferably 30 to 50 μΐη (the thickness of the NiZn interdiffusion layer after firing Z the thickness of the nonmagnetic layer after firing) ) Is preferably in the range of 0.2 to 0.5. The L value temperature change is 9% or less in absolute value, and the coil component has stable inductance characteristics against temperature change.

[0012] The thickness of the green sheet constituting the nonmagnetic layer is preferably 6 to 20 am, (the thickness of the NiZn interdiffusion layer after firing Z the thickness of the nonmagnetic layer after firing) May be in the range of 0.7 to 5.0. The L value temperature change is 14 to 35% in absolute value. This coil component can be used, for example, by matching the temperature characteristics of other components (capacitors, etc.) on the wiring board.

[0013] The thickness of the green sheet constituting the nonmagnetic layer is preferably 6 to 10 μm, (the thickness of the NiZn interdiffusion layer after firing / the thickness of the nonmagnetic layer after firing). The (thickness) may be in the range of 1.5 to 5.0. L value temperature change is 25 to 35% in absolute value. This coil component exhibits a negative temperature coefficient having a negative slope almost linearly, and can be used, for example, by matching with the temperature characteristics of other components (capacitors, etc.) on the wiring board.

The invention's effect

[0014] According to the present invention, the component diffusion at the co-sintering interface becomes moderate by bringing the composition of the nonmagnetic layer close to the composition of the magnetic layer, and the magnetic layer and the nonmagnetic layer during sintering The difference in the shrinkage behavior between the two is reduced, and it is possible to suppress cracks. As a result, it is possible to obtain a laminated coil component with good direct current superposition characteristics.

Brief Description of Drawings

FIG. 1 is an exploded perspective view showing a laminated coil component according to the present invention.

2 is an external perspective view of the multilayer coil component shown in FIG.

FIG. 3 is a vertical sectional view of the laminated coil component shown in FIG.

FIG. 4 is an enlarged schematic cross-sectional view of a portion A in FIG.

[Figure 5] L value with respect to temperature when the thickness of the non-magnetic green sheet is 0, 6, 15 zm It is a graph which shows.

FIG. 6 is a graph showing the rate of temperature change when the thickness of the non-magnetic green sheet is 0, 6, 15 / m.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the laminated coil component according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an exploded configuration diagram of the laminated coil component 1. The laminated coil component 1 includes a magnetic green sheet 3 with a coil conductor 5 formed on the surface, a magnetic green sheet 2 with no conductor formed on the surface, and a non-magnetic green with a coil conductor 5 formed on the surface. Sheet 4 and are laminated.

[0018] The magnetic green sheets 2 and 3 are produced as follows. Fe〇, Zn〇, CuO, Ni

twenty three

o is weighed at a specified ratio (see Table 1 below), and each material is put into a ball mill as a raw material and wet mixed. The resulting mixture is dried and then powdered, and the resulting powder is calcined at 750 ° C for 1 hour. The obtained calcined powder is wet pulverized with a ball mill and then dried and force crushed to obtain a magnetic powder.

[0019] A binder, a plasticizer, a wetting agent, and a dispersing agent are added to the magnetic powder and mixed with a ball minolet, and then defoamed under reduced pressure. The obtained magnetic slurry is formed into a sheet using a lip coater, comma coater or die coater and dried to produce magnetic green sheets 2 and 3 made of a Ni_Zn_Cu based magnetic material. The thickness of the magnetic green sheets 2 and 3 is, for example, 25 zm.

[0020] Non-magnetic green sheet 4 made of Cu_Zn-based non-magnetic material is composed of FeO, ZnO, C

twenty three

uO is weighed at a predetermined ratio (see Table 1 below), and each material is processed by the same method as the magnetic green sheets 2 and 3. The thickness of the nonmagnetic green sheet 4 is, for example, 20 μm.

Furthermore, via hole conductor holes are formed at predetermined positions of the sheets 3 and 4 by laser beam or punching. Thereafter, a conductive paste is applied to the surface by screen printing to form the coil conductor 5, and at the same time, the via hole conductor hole is filled with the conductive paste to form the interlayer connection via hole conductor. Coil conductor 5 has high Q as an inductor element. In order to realize the value, it is preferable that the resistance value is low. Therefore, noble metals mainly composed of Ag, Au, Pt and the like, base metals such as Cu and Ni, and alloys thereof are used as the conductive paste. From the viewpoint of simultaneous firing at a low temperature, it is preferable to use Ag or an Ag alloy.

[0022] The coil conductor 5 and the via-hole conductor 10 may be formed separately. The coil conductor 5 may be screen-printed a plurality of times in order to increase the film thickness. Further, instead of the screen printing method, a photolithography method or a transfer method may be used.

[0023] A plurality of sheets 2, 3, and 4 thus obtained are sequentially stacked and pressed to form a laminate. At this time, the non-magnetic green sheet 4 is laminated so as to be positioned approximately at the center in the thickness direction of the laminated body. The respective coil conductors 5 are electrically connected in series via the interlayer connection via-hole conductors 10 to form a spiral ^3- il L in the laminate. The coil axis of the spiral ^3- il is parallel to the stacking direction of the sheets 2, 3, and 4. The lead portions 6a and 6b of the spiral coil L are exposed on the right and left sides of the magnetic green sheet 3, respectively.

[0024] This laminate was cut into a predetermined product size, degreased at 500 ° C for 2 hours, and further fired at 890 ° C for 2 hours to obtain a rectangular parallelepiped shape as shown in Fig. 2. A sintered body 20 is obtained. Next, both ends of the sintered body 20 are immersed in an Ag / Pd (80/20) paste bath, and external electrodes 21 and 22 are formed by baking at 780 ° C. for 2 hours. The external electrodes 21 and 22 are electrically connected to the lead-out portions 6a and 6b of the spiral coil L formed in the sintered body 20. The dimensions of the laminated coil component 1 are, for example, length and width 3.2 mm X l .6 mm and thickness 0.85 mm.

[0025] As shown in Fig. 3, the open magnetic circuit type multilayer coil component 1 obtained in this way has Ni-Zn_Cu formed on both main surfaces of a non-magnetic layer 4 made of a Cu-Zn-based non-magnetic material. Magnetic layers 3 and 2 are formed of a magnetic material. The magnetic flux φ generated by the spiral coil L passes through the open magnetic path formed by the nonmagnetic layer 4.

[0026] Details of the composition of the magnetic green sheets 2 and 3 and the non-magnetic green sheet 4 are as shown in Table 1 below, and the present inventors have the laminated coil components ( Examples:! To 26 and Comparative Examples 1 and 2) were prepared. The thickness of the magnetic green sheets 2 and 3 is 25 zm, and the thickness of the non-magnetic green sheet 4 is 20 zm. Examples made:! -26 and For Comparative Examples 1 and 2, the presence or absence of appearance abnormalities such as cracks was determined, and the inductance value (L value) temperature change rate and 30% current value were measured. The results are also shown in Table 1. L value The rate of change of temperature is the rate of change of the L value of the sample at room temperature (25 ° C) at the high temperature (125 ° C). The -30% current value is the current value when the L value when current is applied is -30%.

[0027] The magnetic material and the non-magnetic material may be added with BiO in the range of 0.10 to 0.30 after the addition.

twenty three

wt% (for example, 0.15 wt%, 0.25 wt%), MnO may be contained in a range of 0.002 to 0.006 wt% (for example, 0.005 wt%).

[0028] [Table 1]

In the case of Example 1, Example 3 12, Example 20 23, that is, SnO amount of magnetic material = non-magnetic

In the case of SnO in the two-component material, the L-value temperature change rate without cracking was small, 10% or less in absolute value, and the 30% current value exceeded 500 mA, indicating good characteristics. [0030] Further, in the case of Example 2 and Examples 13 to 19, that is, SnO amount of magnetic material and Sn of nonmagnetic material

In the case of O amount, cracks do not occur and the L value temperature change rate is also as small as 6.5% or less in absolute value (however, in Example 2 it is 8 · 3%), and the −30% current value is also 500mA. The value was higher than that, and it showed good characteristics.

[0031] On the other hand, in the case of Comparative Example 1, that is, the amount of SnO of the magnetic material is 0.8 wt%,

If the amount of SnO in the non-magnetic material is more than 4. Owt%, such as 6.Owt%, the sinterability will decrease and cracks will occur at the end of the laminate (chip body) during simultaneous firing. Was observed.

[0032] As in Examples 24 to 26, the amount of SnO of the non-magnetic material is set to the amount of SnO of the magnetic material, but Example 24 is a non-magnetic material compared to Example 21. This is the case where the SnO amount is smaller than the SnO amount of the magnetic material, and the Sn component in the magnetic layer diffuses to the non-magnetic material layer. Will deteriorate. Therefore, the -30% current value also decreased from 540mA to 530mA.

[0033] Example 25 is a case where the SnO amount of the nonmagnetic material was made smaller than the SnO amount of the magnetic material as compared with Example 22, and the Sn component in the magnetic layer diffused into the nonmagnetic material layer. As a result, the Sn component in the magnetic layer is reduced, and the direct current superimposition characteristics are deteriorated. Therefore, the 30% current value also decreased from 545 mA to 535 mA.

[0034] Example 26 is a case where the amount of SnO of the nonmagnetic material was smaller than the amount of SnO of the magnetic material compared to Example 23, and the Sn component in the magnetic material layer diffused into the nonmagnetic material layer. As a result, the Sn component in the magnetic layer is reduced, and the direct current superimposition characteristics are deteriorated. Therefore, the 30% current value also decreased from 555 mA to 540 mA.

Here, from the viewpoint of mutual diffusion, the composition other than the magnetic SnO and the non-magnetic SnO

It is preferable that the difference in the content of the composition other than is as small as possible. That is, the main component composition of the magnetic green sheet is

Fe O: amol% (45≤a≤49)

ZnO: bmol% (however, l≤b≤32)

CuO: cmol% (however, 5≤ c≤ 15)

NiO: dmol% (however, a + b + c + d = 100) age,

[0036] The main component composition of the non-magnetic Darine sheet is

Fe O: xmol% (0 · 5 + a≤x≤0. 5 + a)

ZnO: ymol% (However, _0. 5 + (b + d) ≤ y ≤ 0.5 + (b + d))

CuO: zmol% (However, -0. 5 + c ≤ z ≤ 0.5 + c, x + y + z = 100)

It is preferable that

[0037] In Examples 1 to 26 shown in Table 1, all satisfy the above range. For reference, in Comparative Example 2, the composition ratio of the magnetic material is FeO: 48 mol%, ZnO: 20 mol%, CuO:

9mol%, Ni〇: 23mol%, composition ratio of non-magnetic material is Fe〇: 47mol%, CuO: 8mol%

, ZnO: 45 mol%. In this case, the L value temperature change rate was 9.2% in absolute value, but the 30% current value was 465 mA, which is much lower than 500 mA.

[0038] Next, Table 2 shows a case where the laminated coil component 1 is manufactured by using the magnetic material and the nonmagnetic material having the composition of Example 3 shown in Table 1 and changing the thicknesses of the sheets 3 and 4 variously. The evaluation result (L value temperature change rate) is shown. FIG. 4 shows the thickness Tl of the magnetic layer 3 after firing, the thickness Τ2 of the nonmagnetic layer 4 after firing, and the thickness Τ3 of the Ni and Ζη interdiffusion layer after firing. T1 ′ is the thickness of the magnetic green sheet 3 before firing, and T2 ′ is the thickness of the nonmagnetic green sheet 4 before firing.

[0039] [Table 2]

In Sample 14, the thickness of the non-magnetic green sheet was 6 10 μπι, and the L value temperature change rate was in the range of 25 35% in absolute value. Curve A1 in Fig. 5 and curve の 2 in Fig. 6 show the inductance value and temperature change rate (L value / L) when the temperature is changed in the range of -40 to 125 ° C in the laminated coil component fabricated in Sample 1. Value (25 ° C)). Trial Price 1 has a negative slope almost linearly, and has a negative temperature coefficient. In this way, the laminated coil components of Samples 1 to 4 can be used by matching the temperature characteristics of other electronic components (capacitors, etc.) on the wiring board, for example.

[0041] Incidentally, the curve C1 in FIG. 5 and the curve C2 in FIG. 6 each show the characteristics when the nonmagnetic green sheet is not provided. If the thickness of the non-magnetic green sheet is less than 5 μm, it will not remain as a non-magnetic layer due to mutual diffusion.

In Samples 5 to 10, the thickness of the non-magnetic green sheet was 15 to 20 zm, and the L value temperature change rate was in the range of 14 to 20% in absolute value. Sample: The change rate is small compared to! ~ 4. Curve B1 in Fig. 5 and curve B2 in Fig. 6 show the inductance value and rate of change of temperature (L) when the temperature is changed in the range of 40 ° C to 125 ° C for the laminated coil part fabricated in Sample 5. Value ZL value (25 ° C)). As described above, the laminated coil components of Samples 5 to 10 can be used by matching the temperature characteristics of other electronic components (capacitors, etc.) on the wiring board, for example.

In Samples 11 to 13, the thickness of the nonmagnetic green sheet was 25 / im, and the L value temperature change rate was in the range of 10 to 12% in absolute value. As described above, the laminated coil parts of Samples 11 to 13 can be used in various applications as elements having stable inductance characteristics with respect to temperature changes.

In Samples 14 to 22, the thickness of the non-magnetic green sheet was 30 to 50 μm, and the L value temperature change rate was 9% or less in absolute value. As described above, the laminated coil component of Samples 14 to 22 can be used for various applications as an element having a more stable inductance characteristic with respect to a temperature change. If the thickness of the non-magnetic green sheet is 40-50 μm, it is even better. When the thickness of the non-magnetic green sheet exceeds 50 zm, the inductance characteristic as an open magnetic circuit tends to decrease, but it may be adjusted according to the required L value.

Note that the laminated coil component according to the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the gist thereof.

[0046] In particular, in the above-described embodiment, the one in which one nonmagnetic layer is disposed in the central portion of the laminated body is shown. Up and down They may be separated into three layers. Alternatively, the nonmagnetic layer may be arranged in two layers so that the coil is divided into approximately three equal parts. The magnetic layer may be arranged in more than one layer. Industrial applicability

As described above, the present invention is useful for an open magnetic circuit type laminated coil component, and is particularly excellent in that the DC folding characteristic is good.

Claims

The scope of the claims

[1] a laminate in which magnetic layers are arranged on both main surfaces of the nonmagnetic layer;

A spiral ^3- il provided in the laminate,

An external electrode provided on the surface of the laminate and electrically connected to the spiral coil;

The magnetic layer is made of Ni_Zn_Cu-based magnetic material, and the composition ratio is mainly FeO: 45-49 mol%, ZnO ::!-32 mol%, CuO: 5--: 15 mol%, and the remainder: Ni〇. In addition, 0.6% to 4% by weight of SnO is added to the main component.

The non-magnetic layer is made of a Cu—Zn based non-magnetic material, and the composition ratio is Fe 2 O: 45-49 mol%, CuO: 5 to 15 mol%, the remainder: ZnO as a main component, and further, the main component In contrast, SnO should be added at 0, 6-4wt%,

A laminated coil component characterized by

[2] The multilayer coil component according to [1], wherein the SnO content of the nonmagnetic layer is equal to or higher than the SnO content of the magnetic layer.

[3] The main component composition of the magnetic layer is

Fe O: amol% (45≤a≤49)

ZnO: bmol% (however, l≤b≤32)

CuO: cmol% (however, 5≤ c≤ 15)

Ni〇: dmol% (however, a + b + c + d = 100)

The main component composition of the non-magnetic layer is

Fe O: xmol% (However, _0.5 + a≤x≤0.5 + 5)

ZnO: ymol% (However, _0. 5 + (b + d) ≤ y ≤ 0.5 + (b + d))

CuO: zmol% (where -0.5 + c ≤ z ≤ 0.5 + c, x + y + z = 100), described in claim 1 or 2 Laminated coil parts.

[4] The multilayer coil component according to any one of [1] to [3], wherein a thickness of the green sheet constituting the nonmagnetic layer is 25 to 50 μm.

[5] (The thickness of the NiZn interdiffusion layer after firing / the thickness of the non-magnetic layer after firing) is 0.2-0.

The laminated core according to any one of claims 1 to 3, wherein Parts.

[6] The multilayer coil component according to any one of [1] to [3], wherein a thickness of the green sheet constituting the nonmagnetic layer is 30 to 50 μm.

[7] (The thickness of the NiZn interdiffusion layer after firing / the thickness of the non-magnetic layer after firing) is 0.2-0.

The laminated coil component according to any one of claims 1 to 3, wherein the laminated coil component is 5.

[8] The multilayer coil component according to any one of [1] to [3], wherein the thickness of the green sheet constituting the nonmagnetic layer is 6 to 20 μm.

[9] (The thickness of the NiZn interdiffusion layer after firing / the thickness of the non-magnetic layer after firing) is 0.7-5.

The laminated coil component according to any one of claims 1 to 3, wherein the laminated coil component is zero.

[10] The laminated coil component according to any one of [1] to [3], wherein a thickness of the green sheet constituting the nonmagnetic layer is 6 to 10 am.

[11] (The thickness of the NiZn interdiffusion layer after firing / the thickness of the non-magnetic layer after firing) is 1.5-5.