JP2005222984A - Laminated inductance element and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated inductance element capable of reducing working hours in a printing work, and obtaining thin element thickness, a laminated inductance element that has the same element thickness as before and has a high inductance value; and to provide a method for manufacturing the laminated inductance element. <P>SOLUTION: In the laminated inductance element where a plurality of magnetic body layers and conductor layers are printed and laminated, and spiral conductor layers 8, 9, 10 are formed in the magnetic body layer 5; at least one layer of conductor layer is in a spiral shape having at least two turns. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention mainly relates to a surface mount multilayer inductance element suitable for use in a power supply part of an electronic device or a portable terminal, and a method for manufacturing the same.

  EMI countermeasures are becoming increasingly important as electronic devices become smaller and higher in frequency. For signal systems, it is a common practice to block noise of a target frequency by mounting an inductance element in series. In addition, EMI countermeasures such as suppressing the leakage of signal frequency noise from the active element to the power line are also performed for the power line system of active elements such as power amplifiers. ing.

  In recent years, electrical appliances such as communication devices and home appliances have rapidly evolved. Along with this, electronic components are required to be further reduced in size, increased in density, and improved in performance, and the mainstream of electronic components typified by inductance elements is shifting to multilayer types.

  Patent Document 1 describes a multilayer inductance element in which a magnetic sheet is printed on each layer and laminated to form a coil.

  FIG. 6 is an explanatory diagram of a conventional method for manufacturing a laminated inductance element.

  The laminated inductance element used in the form of being mounted on a printed wiring board or the like is usually on a magnetic body made of soft magnetic ferrite powder and a binder, or on a nonmagnetic body green sheet 1 made of nonmagnetic ceramic powder and a binder. A conductive layer 2 made of conductive powder and a binder is printed using a screen printing method, green sheets are alternately stacked, and a conductive coil is spiraled in a magnetic or non-magnetic material. Provide. Further, the green sheets 4 are laminated by pressing, stacked, cut and simultaneously sintered to form chips. Here, a material having a relative permeability close to 1, particularly 2 or less is referred to as non-magnetic.

JP-A-5-205944

  However, in an inductance element in which a conductive coil is provided in a spiral shape in magnetic or nonmagnetic ceramics, it is necessary to increase the number of printed layers and increase the number of turns in order to obtain a high inductance value. There was a problem of becoming thick. Moreover, there has been a problem that the production capacity is reduced due to an increase in the number of printing steps. Furthermore, the increase in the number of stacked layers increases the probability of a short circuit between layers, resulting in a decrease in manufacturing yield.

  An object of the present invention is to provide a multilayer inductance element that can overcome the conventional problems, reduce the number of man-hours for printing, and has a thin element thickness. It is another object of the present invention to provide a multilayer inductance element having a high inductance value with the same element thickness as that of the prior art and capable of dealing with a direct current superposition characteristic and a method for manufacturing the same.

  According to the present invention, in a multilayer inductance element in which a plurality of magnetic layers or nonmagnetic ceramic layers and a conductor layer are printed and laminated, and the conductor layer forms a conductor coil in a spiral shape, the conductor layer has two turns. Thus, the spiral-shaped multilayer inductance element can be obtained.

  According to the present invention, in the multilayer inductance element in which a plurality of magnetic layers or nonmagnetic ceramic layers and conductor layers are printed, and a spiral conductor coil is formed in the magnetic body or nonmagnetic ceramic, A method for manufacturing a multilayer inductance element is obtained in which the layers are printed in a spiral shape of two or more turns.

The inductance value L of the inductance element can be expressed by the following equation (1).
L = μ ₀ · μ ′ · Ae · N ² / l (1)
μ ₀ : Vacuum permeability, μ ′: Initial permeability of magnetic material, Ae: Magnetic path cross-sectional area, l: Magnetic path length, N: Number of turns.

  That is, the present invention is a multilayer inductance element in which a plurality of magnetic layers and conductor layers are printed and laminated, and a spiral conductor coil is formed in the magnetic material, and at least one conductor layer is formed by two turns. This is a multilayer inductance element having the above spiral shape.

  The present invention also relates to a multilayer inductance element in which a plurality of nonmagnetic ceramic layers and conductor layers are printed and laminated, and a spiral conductor coil is formed in the nonmagnetic ceramics, wherein at least one or more conductor layers are provided. It is a multilayer inductance element having a spiral shape of 2 turns or more.

  The present invention also provides a multilayer inductance element in which a magnetic layer and a conductor layer are printed and laminated a plurality of times, and a nonmagnetic ceramic layer and a conductor layer are printed and laminated a plurality of times. Further, a printed laminated portion of the nonmagnetic ceramic layer and the conductor layer is disposed, and the conductor layer is a laminated inductance element formed by a spiral conductor coil having two or more turns.

  The present invention also relates to a method of manufacturing a laminated inductance element in which a plurality of magnetic layers and conductor layers are printed and laminated, and a spiral conductor coil is formed in the magnetic body, and includes at least one conductor layer Is a manufacturing method of a multilayer inductance element having a spiral shape of 2 turns or more.

  The present invention also relates to a method for manufacturing a laminated inductance element in which a plurality of nonmagnetic ceramic layers and conductor layers are printed and laminated, and a spiral conductor coil is formed in the nonmagnetic ceramics. This is a method for manufacturing a multilayer inductance element in which the body layer is spiral with two or more turns.

  The present invention is also a method for manufacturing a multilayer inductance element, in which a magnetic layer and a conductor layer are printed and laminated a plurality of times, and a nonmagnetic ceramic layer and a conductor layer are printed and laminated a plurality of times. Manufacturing a multilayer inductance element in which a printed laminated portion of the nonmagnetic ceramic layer and a conductor layer is disposed in the central portion of the inductance element, and the conductor layer is a spiral conductor coil having two or more turns. Is the method.

  According to the present invention, an element having a high inductance value with the same thickness as that of the prior art, and in the case of the same inductance value, a reduction in electrical characteristic failure (rare short failure due to multilayer) is realized, and the device Therefore, it is possible to provide a multilayer inductance element that can reduce the man-hours of the printing process, and that can cope with the DC superposition characteristics, and a method for manufacturing the same.

  A multilayer inductance element according to the present invention is a multilayer inductance element in which a plurality of magnetic layers and conductor layers are printed and laminated, and a spiral conductor coil is formed in a magnetic body, as a first configuration, The above conductor layer is formed in a spiral shape having two or more turns.

  A second configuration is a multilayer inductance element in which a plurality of nonmagnetic ceramic layers and conductor layers are printed and laminated, and a spiral conductor coil is formed in the nonmagnetic ceramics, and includes at least one or more conductors The layer is a spiral laminated inductance element having two or more turns. In this case, the multilayer inductance element has a configuration of an air core inductor.

  A third configuration is a multilayer inductance element in which a magnetic layer and a conductor layer are printed and laminated a plurality of times, and a nonmagnetic ceramic layer and a conductor layer are printed and laminated a plurality of times. A printed laminated portion of the nonmagnetic ceramic layer and the conductor layer is disposed in the center portion, and the conductor layer is a laminated inductance element formed of a spiral conductor coil having two or more turns. In this case, the laminated inductance element has a configuration of an inductor having an air core gap in the magnetic material.

  Next, the multilayer inductance element and the manufacturing method thereof according to the present invention will be described in detail with reference to examples.

First, about ferrite paste for magnetic body formation,
Ni-Cu-Zn ferrite powder
(Specific surface area 5.2 m ² / g) 100 parts by weight Binder (polyvinyl butyral) 5 parts by weight Solvent (ethyl cellosolve) 70 parts by weight The above composition is mixed using a spiral mixer, and further kneaded and dispersed in a bead mill. A ferrite paste for body formation was obtained.

For the Ag paste for forming the conductor layer,
Binder (ethyl cellulose) 5 parts by weight Solvent (α-terpineol) 15 parts by weight Solvent (butyl carbitol acetate) 10 parts by weight Silver fine powder (average particle size 0.5 μm) 100 parts by weight The above composition is kneaded in three rolls Dispersed to obtain an Ag paste for forming a conductor layer.

  FIG. 1 is a diagram illustrating a method for manufacturing a multilayer inductance element according to Embodiment 1 of the present invention. 1A shows the green sheet 1, FIG. 1B shows the state of the conductor layer 8 printed on the green sheet 1, and FIG. 1C shows the state of the conductor layer 8. FIG. 1 (d) shows the state of the conductor layer 9 printed on the magnetic layer 5, and FIG. 1 (e) shows the state of the conductor layer 9 printed on the conductor layer 9. 1 (f) shows the state of the conductor layer 10 printed on the magnetic layer 5, and FIG. 1 (g) shows the state of the conductor layer 10 printed on the conductor layer 10. FIG. Shows a green sheet 7 to be printed.

  The manufacturing method will be described in more detail. As shown in FIG. 1A, a green sheet 1 having a thickness of 200 μm is prepared in advance using a ferrite paste by a doctor blade method.

  A spiral conductor layer 8 shown in FIG. 1B is printed thereon. Next, the magnetic layer 3 having the window region shown in FIG. The process shown in FIGS. 1B and 1C is repeatedly printed a plurality of times until the thickness reaches the design value.

  Next, the spiral conductor layer 9 shown in FIG. 1D is printed. Here, the end of the conductor layer 8 and the end of the conductor layer 9 are connected by a through hole through the window region. Next, the magnetic layer 5 having the window region shown in FIG. The steps shown in FIGS. 1D and 1E are repeatedly printed a plurality of times until the thickness reaches the design value. Next, the conductor pattern 10 shown in FIG. 1 (f) is printed. Further, as shown in FIG. 1G, a green sheet 7 is printed on the uppermost part so as to cover the conductor layer. The process shown in FIGS. 1F and 1G is repeatedly printed a plurality of times until the thickness reaches the design value.

  On top of that, a green sheet with a thickness of 200 μm produced by a doctor blade method using ferrite paste is laminated by pressing and cut into a predetermined size (2.0 mm × 1.2 mm), and this is removed as a binder Thereafter, it was integrally fired at 900 ° C.

  A conductive paste mainly composed of Ag is applied to the surface of the fired body where the leads of the laminated coil are exposed, and baking is performed at about 600 ° C. to form external electrodes. Then, Ni and Sn are formed on the external electrodes. Plating was performed to produce a laminated inductance element. The frequency characteristic of the inductance value of the manufactured laminated inductance element was evaluated using an HP inductance analyzer HP4191A.

  FIG. 3 is an explanatory diagram of a multilayer inductance element according to the present invention. FIG. 4 is a perspective view showing the internal structure of the multilayer inductance element according to the present invention. FIG. 4A is a side view of the laminate, and FIG. 4B is a top view of the laminate.

  In this example, the paste was prepared with the above composition, but any other components and blending ratios may be used as long as a printable paste can be obtained. Table 1 shows the results of this sample compared with the conventional pattern.

  In the product of the present invention, when compared with the conventional pattern product, almost the same characteristics were obtained at the same 4.5 turns. Furthermore, the thickness of the element could be reduced by reducing the number of stacked layers. The yield is the same as before, and the reliability is the same as before.

  FIG. 2 is a diagram showing a method for manufacturing a multilayer inductance element according to Example 2 of the present invention. 2A shows the green sheet 1a, FIG. 2B shows the state of the conductor layer 8a printed on the green sheet 1a, and FIG. 2C shows the state of the conductor layer 8a. The state of the magnetic layer 5a to be printed is shown, FIG. 2 (d) shows the state of the conductor layer 9a to be printed on the magnetic layer 5a, and FIG. 2 (e) is the state on the conductor layer 9a. The state of the nonmagnetic layer 50 to be printed is shown, FIG. 2 (f) shows the state of the conductor layer 10a printed on the nonmagnetic layer 50, and FIG. 2 (g) shows the state of the conductor layer 10a. FIG. 2 (h) shows the state of the conductor layer 11a printed on the magnetic layer 5b, and FIG. 2 (i) shows the state of the conductor layer 11a. The state of the green sheet 7a to be printed on is shown.

Here, about the ferrite paste for magnetic body formation,
Ni-Cu-Zn ferrite powder
(Specific surface area 5.2 m ² / g) 100 parts by weight Binder (polyvinyl butyral) 5 parts by weight Solvent (ethyl cellosolve) 70 parts by weight The above composition is mixed using a spiral mixer, and further kneaded and dispersed in a bead mill. A ferrite paste for body formation was obtained.

For ferrite paste for non-magnetic layer formation,
Zn-Cu ferrite powder
(Specific surface area 5.2 m ² / g) 100 parts by weight Binder (polyvinyl butyral) 5 parts by weight Solvent (ethyl cellosolve) 70 parts by weight The above composition is mixed using a spiral mixer, and further kneaded and dispersed in a bead mill. A ferrite paste for forming a magnetic material was obtained. The Curie temperature of this Zn—Cu ferrite powder is in the range of −30 ° C. to −40 ° C., and the relative magnetic permeability is 2 or less in the operating temperature range of the multilayer inductance element.

For the Ag paste for conductor formation,
Binder (ethyl cellulose) 5 parts by weight Solvent (α-terpineol) 15 parts by weight Solvent (butyl carbitol acetate) 10 parts by weight Silver fine powder (average particle size 0.5 μm) 100 parts by weight The above composition is kneaded in three rolls Dispersed to obtain an Ag paste for conductor formation.

  The production method of the present invention will be described in more detail. As shown in FIG. 2A, a green sheet 1 having a thickness of 200 μm is prepared in advance by using a ferrite paste and a doctor blade method.

  A spiral conductor layer 8a shown in FIG. 2B is printed thereon. Next, the magnetic layer 5a having the window region shown in FIG. The process shown in FIGS. 2B and 2C is repeatedly printed a plurality of times until the thickness reaches the design value.

  Next, the spiral conductor layer 9a shown in FIG. Next, the nonmagnetic layer 50 having the window region shown in FIG. The process shown in FIGS. 2D and 2E is repeatedly printed a plurality of times until the thickness reaches the design value. Next, the conductor layer 10a shown in FIG. Further, as shown in FIG. 2G, the magnetic layer 5b is printed. The processes shown in FIGS. 2F and 2G are repeatedly printed a plurality of times until the thickness reaches the design value. Next, the conductor layer 11a shown in FIG. 2 (h) is printed, and the green sheet 7a shown in FIG. 2 (i) is shown.

  On top of that, a green sheet with a thickness of 200 μm produced by a doctor blade method using ferrite paste is laminated by pressing and cut into a predetermined size (2.0 mm × 1.2 mm), and this is removed as a binder Thereafter, it was integrally fired at 900 ° C. A conductive paste mainly composed of Ag is applied to the surface where the lead of the laminated winding of the fired body is exposed and baked at about 600 ° C. to form an external electrode. Sn plating was performed to produce a multilayer inductance element. The frequency characteristic of the inductance value of the manufactured laminated inductance element was evaluated using an HP inductance analyzer HP4191A. In this example, the paste was prepared with the above composition, but any other components and blending ratios may be used as long as a printable paste can be obtained. Table 1 shows the results of this sample compared with the conventional pattern.

  FIG. 8 is a comparison diagram of DC superimposition characteristics of the multilayer inductance element of the first embodiment and the multilayer inductance element of the second embodiment. In the multilayer inductance element of the second embodiment, the inductance value of the DC superimposition characteristic is improved from that of the first embodiment at a DC current of 170 mA or more due to the effect of the gap formed by the nonmagnetic material layer 50.

The figure which shows the manufacturing method of the multilayer inductance element of Example 1 of this invention. The figure which shows the manufacturing method of the multilayer inductance element of Example 2 by this invention. 2A is a diagram showing a green sheet, FIG. 2B is a diagram showing a state of a conductor layer printed on the green sheet, and FIG. 2C is a diagram printed on the conductor layer. FIG. 2 (d) is a diagram showing a state of a conductor layer printed on the magnetic layer, and FIG. 2 (e) is a diagram showing a non-printed state on the conductor layer. FIG. 2 (f) shows the state of the magnetic layer, FIG. 2 (f) shows the state of the conductive layer printed on the non-magnetic layer, and FIG. 2 (g) shows the magnetic printed on the conductive layer. FIG. 2 (h) shows the state of the body layer, FIG. 2 (h) shows the state of the conductor layer printed on the magnetic layer, and FIG. 2 (i) shows the green sheet printed on the conductor layer. The figure which shows a state. 1 is an external perspective view of a multilayer inductance element according to the present invention. The perspective view which shows the internal structure of the multilayer inductance element by this invention. 4A is a side view of the laminate, and FIG. 4B is a top view of the laminate. The perspective view which shows the internal structure of the conventional multilayer inductance element implemented by the comparative example. FIG. 5A is a side view of the laminate, and FIG. 5B is a top view of the laminate. The figure which shows the comparison of the man-hour of the pattern of the laminated inductance element of Example 1 of this invention, and the conventional pattern. Explanatory drawing which shows the manufacturing method of the conventional multilayer inductance element. FIG. 6 is a comparison diagram of DC superposition characteristics of the multilayer inductance element of Example 1 and the multilayer inductance element of Example 2.

Explanation of symbols

1, 1a, 4, 4a, 7, 7a Green sheet 2 Conductor layers 3, 5, 5a, 5b Magnetic layers 8, 8a, 9, 9a, 10, 10a, 11a Conductor layer 11 Magnetic body 50 Non-magnetic body layer

Claims (6)

  In a laminated inductance element in which a ceramic layer and a conductor layer are printed and laminated a plurality of times, and a spiral conductor coil is formed in the ceramic, at least one of the conductor layers has a spiral shape of two or more turns. A multilayer inductance element characterized by that.   2. The multilayer inductance element according to claim 1, wherein the ceramic is a soft magnetic material.   2. The multilayer inductance element according to claim 1, wherein the ceramic has a relative magnetic permeability of 2 or less.   2. The ceramic according to claim 1, wherein the ceramic is a soft magnetic material and a ceramic having a relative permeability of 2 or less, and a ceramic layer having a relative permeability of 2 or less is disposed at a central portion of the multilayer inductance element. Multilayer inductance element.   In the method of manufacturing a laminated inductance element in which a plurality of ceramic layers and conductor layers are printed and laminated, and a spiral conductor coil is formed in the ceramic layer, at least one layer is formed in a spiral shape having two or more turns. A method for manufacturing a laminated inductance element.   6. The multilayer according to claim 5, wherein the ceramic is a soft magnetic material or a ceramic having a relative permeability of 2 or less, and a ceramic layer having a relative permeability of 2 or less is disposed in a central portion of the multilayer inductance element. Inductance element manufacturing method.

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