JPH09330819A - Ceramic inductor, and method for manufacturing composite ceramic and ceramic inductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a ceramic inductor and a composite ceramic which can improve saturation characteristics of the inductor to increase a transformer coupling coefficient, and also to provide a method for manufacturing a multilayered ceramic inductor. SOLUTION: A ceramic inductor 1 comprises a ceramic inductor body, a coil-shaped inductor electrode formed within the inductor body, and external electrodes 3a and 3b provided on the inductor body to be electrically connected with the coil-shaped inductor electrode. A region of the inductor body where the coiled electrode is formed, is made of nonmagnetic ceramic material, a region of the body inside of the coiled-electrode region is made of magnetic ceramic material, and all peripheral parts of the body outside of the coiled- electrode region are made of magnetic material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a ceramic inductor and a composite ceramic, or a method for manufacturing a ceramic inductor.

[0002]

2. Description of the Related Art Recently, various electronic devices such as communication devices are
With the increase in applications such as portable use, miniaturization and weight reduction have been demanded. Ceramic electronic components used in these electronic devices are also required to be smaller and lighter and to be surface-mounted, and electronic components such as coils are rapidly being miniaturized and surface-mounted.

Conventionally, for miniaturization and surface mounting of a coil, a conductor pattern is formed on one main surface of a sheet made of a magnetic material such as ferrite, and the sheets having the conductor pattern are laminated and integrated to form a coil. Formed monolithic ceramic inductors and monolithic ceramic transformers are known.

The above-mentioned monolithic ceramic inductor has a problem that the linearity and the direct current superposition characteristic are not good because the coil portion is entirely covered with the magnetic material. Similarly, in the monolithic ceramic transformer, since the magnetic flux around the primary side is entirely magnetic, it returns to the primary side coil without interlinking with the secondary side coil, resulting in poor transformer efficiency. Included. The efficiency of this transformer is related to the power consumption, and if the efficiency of the transformer used in the power supply circuit is poor, the battery used as the energy source of the portable electronic device will be consumed faster, and the operating time of the portable electronic device will be reduced. There was a problem that was shortened.

A composite laminated transformer that solves these problems is proposed in Japanese Patent Laid-Open No. 5-217772. FIG. 7 shows a composite laminated transformer disclosed in Japanese Patent Laid-Open No. 5-217772.
7A is an external perspective view of the composite laminated transformer, and FIG.
7B is a cross-sectional view of the xy plane passing through the center of FIG. 7A.

As shown in FIG. 7, a composite laminated transformer 51.
Is a coil forming portion 52 formed by stacking non-magnetic material sheets and magnetic material layers 56a, 56b, 57, 58a, 58b formed so as to sandwich or surround the coil forming portion 52.
And external electrodes 53a, 53b, 59a, 5 electrically connected to the coil layer 55 formed in the coil forming portion 52.
9b. The coil layer 55 is a magnetic layer 56a,
A hole is provided in the center of the coil layer 55 along the winding axis direction of the coil so as to form a closed magnetic circuit by being surrounded by 56b, 57, 58a, and 58b. The body paste is filled and fired.

[0007]

However, the composite laminated transformer 51 requires a processing step of forming holes in each laminated body, and if the positions where the holes are formed are misaligned, the coil layer is broken. There was a problem.

An object of the present invention is to provide a ceramic inductor which has a structure in which a coil layer is surrounded by a non-magnetic material layer and a surrounding material is surrounded by a magnetic material without providing a hole in the laminated body, thereby improving the saturation characteristic of the inductor. provide. Also, by eliminating the processing step of providing holes in the laminated body, coil breakage is prevented, and by surrounding the coil layer with a non-magnetic layer and surrounding it with a magnetic layer, the saturation characteristics of the inductor can be improved. Provided is a method for manufacturing a composite ceramic or a method for manufacturing a ceramic inductor, which is improved and increases the coupling coefficient of a transformer.

[0009]

The invention according to claim 1 is
The ceramic inductor body, a coil-shaped inductor electrode formed in the ceramic inductor body, and an external electrode formed on the surface of the ceramic inductor body and electrically connected to the coil-shaped inductor electrode, the coil The region in which the electrode for the coiled inductor is formed is made of a non-magnetic ceramic material, the inside of the region in which the electrode for the coiled inductor is formed is made of a magnetic ceramic material, and the electrode for the coiled inductor is formed. This is a ceramic inductor in which the entire circumference of the outer side surface of the region is made of a magnetic material.

According to a second aspect of the present invention, there is provided a ceramic inductor body, a coil-shaped inductor electrode formed in the ceramic inductor body, and a coil-shaped inductor electrode electrically formed on the surface of the ceramic inductor body. A region where the coil-shaped inductor electrode is formed is made of a non-magnetic ceramic material, and an inside of the region where the coil-shaped inductor electrode is formed is made of a magnetic ceramic material. The entire circumference of the outer surface of the region where the coil-shaped inductor electrode is formed is made of a magnetic ceramic material,
A ceramic inductor in which upper and lower surfaces of a region where the coil-shaped inductor electrode is formed are made of a magnetic ceramic material.

The invention according to claim 3 is a ceramic inductor, wherein the coil-shaped inductor electrode includes a primary coil and a secondary coil.

According to a fourth aspect of the invention, a part of the surface of the ceramic green sheet which becomes an insulating nonmagnetic ceramic by firing is provided with a modifier for changing the ceramic green sheet from nonmagnetic to magnetic ceramic by firing. It is a method for producing a composite ceramic by applying and firing the ceramic green sheet.

According to a fifth aspect of the present invention, a part of the surface of the ceramic green sheet that becomes an insulating nonmagnetic ceramic by firing is provided with a modifier that changes the ceramic green sheet from nonmagnetic to magnetic ceramic by firing. Give a plurality of laminated ceramic green sheets,
It is a method for producing a composite ceramic by firing the obtained laminated body.

According to a sixth aspect of the present invention, a modifier for changing the ceramic green sheet from non-magnetic to magnetic ceramic by firing is provided on a part of the surface of the ceramic green sheet which becomes an insulating non-magnetic ceramic by firing. It is a method of manufacturing a ceramic inductor, which comprises applying, forming an inductor electrode in the other region of the ceramic green sheet, and firing the ceramic green sheet.

According to a seventh aspect of the present invention, a modifier for changing the ceramic green sheet from non-magnetic to magnetic ceramic by firing is provided on a part of the surface of the ceramic green sheet which becomes an insulating non-magnetic ceramic by firing. This is a method for manufacturing a ceramic inductor, in which a coil-shaped inductor electrode is formed in the other area of the ceramic green sheet, a plurality of the ceramic green sheets are laminated, and the obtained laminated body is fired.

In the invention according to claim 8, the electrode paste for the coiled inductor is applied to a part of the surface of the ceramic green sheet which becomes an insulating nonmagnetic ceramic by firing, and the electrode paste for the coiled inductor is applied. A modifier paste that changes the ceramic green sheet from non-magnetic to magnetic ceramic by firing is applied to the inside of the region where the coil-shaped inductor electrode paste is applied to the entire outer periphery of the region. This is a method for manufacturing a ceramic inductor, in which a modifier paste for changing a ceramic green sheet from non-magnetic to magnetic ceramic is applied, a plurality of the ceramic green sheets are laminated, and the obtained laminated body is fired.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A ceramic inductor according to the present invention, a method for manufacturing the same, and a method for manufacturing a composite ceramic will be described below with reference to the drawings. The parts corresponding to those of the above-mentioned conventional technique will be described with the same reference numerals.

First, the structure of the ceramic inductor according to the present invention will be described. 1A and 1B are views showing a ceramic inductor, in which FIG. 1A is an external perspective view, and FIG. 1B is A in FIG.
It is a longitudinal cross-sectional view taken along the line A. As shown in FIG. 1, the ceramic inductor 1 includes a coil forming portion 2 and a coil forming portion 2.
External electrode 3 electrically connected to the coil formed inside
It consists of a and 3b. The coil forming portion 2 is formed by alternately laminating a ceramic layer (hereinafter, referred to as a non-magnetic material layer) 4 made of an insulator and a non-magnetic material and an electrode layer 5 serving as a coil so as to surround the electrode layer 5. Magnetic parts 6 and 7 formed
Consists of

The electrode layer 5 forms a coil with each other through a through hole (not shown), one end of which is led out to one end of the main body of the ceramic inductor 1 and the external electrode 3a formed at this end. It is electrically connected. The other end of the electrode layer 5 is led out to the other end of the main body of the ceramic inductor 1 and electrically connected to the external electrode 3b formed at the other end. Thus, the electrode layer 5
Is surrounded by the non-magnetic layer 4, and the surroundings are covered with magnetic portions 6 and 7 to form a closed magnetic circuit.

Next, a method of manufacturing the ceramic inductor 1 will be described with reference to FIG. FIG. 2 is an exploded perspective view of the ceramic inductor 1. As shown in FIG. 2, a ceramic green sheet made of an insulating material and a non-magnetic material (hereinafter,
Non-magnetic sheet) 4a, 4b, 4c, 4d, 4e
Is prepared, and conductor patterns 5a, 5b, 5c to be internal electrodes are screen-printed on one main surface of the non-magnetic sheets 4b, 4c, 4d with a conductive paste. This conductor pattern 5
The a, 5b and 5c are electrically connected to each other through a through hole (not shown) provided in the non-magnetic sheet to form a coil. These nonmagnetic sheets 4b, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4d, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4c, 4d, 4c, 4c, 4c, 4d, 4c, 4d, 4c, 4c, 4d, 4c, 4c, 4c, 4d, 4c, 4c, 4c, 4c, 4d, 4c, 4c, 4d, 4c, 4d, 4c, 4d, 4c,
Modification material pattern 6 for changing 4d to magnetic ceramic
b, 6c, 6d, 7b, 7c, 7d are formed. Also,
A non-magnetic sheet 4a on which no conductor pattern is formed,
At predetermined positions on the upper layer of 4e, modifier patterns 6a, 6e, 7a, 7e for changing these non-magnetic sheets 4a, 4e into magnetic ceramics are formed in a firing step. The non-magnetic sheets 4a, 4b, 4c, 4d and 4e are laminated in the order shown in the figure and pressure-bonded to form a laminated body.

The thus obtained laminated body is subjected to binder combustion in the atmosphere and then fired at 1350 ° C. for 2 hours to obtain a sintered body. The silver paste is applied to the surface of the obtained sintered body and heat-treated in the atmosphere at 800 ° C. for 1 hour to form the external electrode 3
Then, a and 3b are formed, and Ni and Sn or solder is plated on the external electrodes to obtain the ceramic inductor 1.

The non-magnetic sheets 4a, 4b, 4c,
4d and 4e are made of a material containing zinc oxide and iron oxide as main components. Further, the conductive paste forming the conductor patterns 5a, 5b, 5c is a paste in which silver powder and varnish are mixed. Further, the modified material patterns 6a, 6b, 6
The paste forming c, 6d, 6e, 7a, 7b, 7c, 7d, 7e is Fe ₂ O ₃ : 40 to 50 mol%, ZnO:
1 to 35 mol%, NiO: 0 to 50 mol%, CuO: 0 to 2
Co ₃ O ₄ as an additive to 0 _{mol%, SiO 2, SnO 2,} B
A blended raw material containing 0 to 5 wt% of at least one of i ₂ O ₃ is put in a polyethylene pot together with pure water and zirconia balls, water, a binder and a dispersant are added, and wet mixing is performed with the zirconia balls for 12 hours It is obtained by crushing.

The stacking order is such that the nonmagnetic sheet 4a is the uppermost layer and the nonmagnetic sheet 4e is the lowermost layer. Alternatively, the non-magnetic sheet 4e may be the uppermost layer and the non-magnetic sheet 4a may be the lowermost layer. In FIG. 2, the nonmagnetic material sheets 4a to 4e are described as five sheets, but the number of laminated layers is arbitrary depending on the intended use and shape of the ceramic inductor.

FIG. 3 shows a modified example of the ceramic inductor of the present invention, in which (a) is an external perspective view and (b) is (a).
3 is a vertical cross-sectional view taken along line BB of FIG. As shown in FIG. 3, the ceramic inductor 11 includes a coil forming portion 12 and external electrodes 13a and 13b electrically connected to the coil formed in the coil forming portion 12. Coil forming part 12
Is composed of a non-magnetic material layer 14 and an electrode layer 15 serving as a coil, which are alternately laminated, and magnetic material parts 16, 17, 18a, 18b formed so as to surround the electrode layer 15.

The electrode layer 15 forms a coil with each other through a through hole (not shown), one end of which is led out to one end of the body of the ceramic inductor 11 and the external electrode 13a formed at this end. It is electrically connected.
Further, the other end of the electrode layer 15 has the ceramic inductor 1
One of the main bodies is led out to the other end and electrically connected to the external electrode 13b formed at the other end. In this way, the circumference of the electrode layer 15 is surrounded by the non-magnetic material layer 14, and the circumference thereof is further surrounded by the magnetic material parts 16, 17, 18a, 1a.
It is covered with 8b to form a closed magnetic circuit. In addition, the magnetic body part 1
8a and 18b may be formed by applying or printing the magnetic paste on the entire surface of the non-magnetic sheet and baking it. Alternatively, the entire surface is made of a magnetic sheet and integrated together with the firing of the ceramic inductor 11 main body. Good.

Next, the ceramic transformer included in the ceramic inductor according to the present invention will be described. 4A and 4B are views showing a ceramic transformer which is an example of a composite ceramic, wherein FIG. 4A is an external perspective view, and FIG. 4B is a vertical cross-sectional view taken along line CC of FIG. As shown in FIG. 4, the ceramic transformer 21 includes a coil forming portion 22 and external electrodes 23a, 23b, 29a, 29b electrically connected to the coils formed in the coil forming portion 22. The coil forming portion 22 includes a non-magnetic layer 24 and an electrode layer 25.
Alternatively, the non-magnetic material layer 24 and the electrode layer 30 are alternately laminated, and the magnetic material portions 26 and 27 are formed so as to surround the electrode layers 25 and 30.

The electrode layer 25 forms a primary coil through through holes (not shown), and one end of the electrode layer 25 is led out to one side surface of the ceramic transformer 21 main body, and the external electrode formed on this one side surface. 23a is electrically connected. The other end of the electrode layer 25 is led out to the other side surface of the ceramic transformer 21 body facing the external electrode 23a, and is electrically connected to the external electrode 23b formed on the other surface of the ceramic transformer 21 body facing the external electrode 23a.

Furthermore, the electrode layer 30 forms a secondary coil through a through hole (not shown), and one end thereof is led out to the same side surface as the external electrode 23a of the ceramic transformer 21 body. It is electrically connected to an external electrode 29a formed on the same side surface as 23a. The other end of the electrode layer 30 is led out to the same side surface as the external electrode 23b of the ceramic transformer 21 body, and is electrically connected to the external electrode 29b formed on the same side surface as the external electrode 23b. As described above, the electrode layers 25 and 30 are surrounded by the non-magnetic layer 24, and the magnetic layers 26 and 27 are further covered to form a closed magnetic circuit.

Next, a method of manufacturing the ceramic transformer 21 will be described with reference to FIG. FIG. 5 is an exploded perspective view of the ceramic transformer 21. As shown in FIG. 5, the non-magnetic sheet 24a, 24b, 24c, 24d, 24e, 24
f, 24g, 24h are prepared, and the non-magnetic sheet 24b,
Conductor patterns 25a, 25b, 25c, which will be primary coils, are formed on one main surface of 24c, 24d by the non-magnetic sheet 24.
The conductor patterns 30a, 30b, 30c to be the secondary coils are screen-printed with a conductive paste on one main surface of e, 24f, 24g. The conductor patterns 25a, 25b, 2
5c is electrically connected through a through hole (not shown) provided in the non-magnetic sheet to form a primary coil,
The conductor patterns 30a, 30b, 30c are electrically connected to each other through a through hole (not shown) provided in the non-magnetic sheet to form a secondary coil.

The conductor patterns 25a, 25b, 25c
Non-magnetic sheet 24b, 24c, 24 having
d and the non-magnetic material sheets 24e, 24f and 24g on which the conductor patterns 30a, 30b and 30c are formed, the non-magnetic material sheets 24b and 2g are placed at predetermined positions in the upper layer.
Modification material patterns 26b, 26c, 26 for changing 4c, 24d, 24e, 24f, 24g into magnetic ceramics
d, 26e, 26f, 26g, 27b, 27c, 27
d, 27e, 27f and 27g are formed. Further, the non-magnetic sheets 24a, 24 having no conductor pattern formed thereon
At predetermined positions on the upper layer of h, modifier material patterns 26a, 26h, 27a, 27h that change these non-magnetic sheets 24a, 24h into magnetic ceramics at the firing stage are formed.
The non-magnetic sheets 24a, 24b, 24c, 24d,
24e, 24f, 24g, and 24h are stacked in the order shown in the figure,
Crimping is performed to form a laminated body.

The laminate thus obtained is burned with a binder in the atmosphere and then fired at 1350 ° C. for 2 hours to obtain a sintered body. The silver paste is applied to the surface of the obtained sintered body and heat-treated in the atmosphere at 800 ° C. for 1 hour to form the external electrode 2
3a, 23b, 29a, 29b are formed, and a ceramic transformer 21 having two coils inside is obtained. Also,
Ni and Sn are formed on the external electrodes 23a, 23b, 29a, 29b to improve the strength and solderability of the external electrodes.
Alternatively, solder plating may be applied.

FIG. 6 is a modification of the ceramic transformer, where (a) is an external perspective view and (b) is a vertical sectional view taken along the line D-D of (a). As shown in FIG. 6, the ceramic transformer 31 includes a coil forming portion 32 and an external electrode 33 electrically connected to the coil formed in the coil forming portion 32.
a, 33b, 39a, 39b. The coil forming portion 32 is formed by alternately stacking the non-magnetic material layer 34 and the electrode layer 35 or the non-magnetic material layer 34 and the electrode layer 40, and the magnetic material portion 36 formed so as to surround the electrode layers 35, 40. , 3
7, 38a, 38b.

The electrode layer 35 forms a primary coil through a through hole (not shown), one end of which is led out to one side surface of the ceramic transformer 31 main body, and an external electrode formed on this one side surface. It is electrically connected to 33a. The other end of the electrode layer 35 is led out to the other side surface of the body of the ceramic transformer 31 facing the external electrode 33a, and is electrically connected to the external electrode 33b formed on the other side surface of the ceramic transformer 31 facing the external electrode 33a.

Further, the electrode layer 40 forms a secondary coil through a through hole (not shown), and one end thereof is led out to the same side surface as the external electrode 33a of the ceramic transformer 31 main body. It is electrically connected to an external electrode 39a formed on the same side surface as 33a. The other end of the electrode layer 40 is led out to the same side surface as the external electrode 33b of the ceramic transformer 31 body, and is electrically connected to the external electrode 39b formed on the same side surface as the external electrode 33b. As described above, the electrode layers 35 and 40 are surrounded by the non-magnetic layer 34, and the magnetic layers 36, 37, 38a, and 38b are further surrounded to form a closed magnetic path.

The magnetic material parts 38a and 38b may be formed by applying or printing the magnetic material paste on the entire surface of the non-magnetic material sheet and baking it. Alternatively, the entire surface of the non-magnetic material sheet may be formed by using the magnetic material sheet and the ceramic transformer 31. It may be integrated at the same time as the firing of the main body.

As a conventional example, it is obtained by using the same manufacturing method as the ceramic transformer shown in FIGS. 4 and 5 and forming an electrode layer on a magnetic layer which is entirely made of a magnetic material without using a non-magnetic material layer. A ceramic transformer was produced and the characteristic values were measured in the same manner as in the example. Comparing the coupling coefficients of the ceramic transformer of the present invention and the conventional ceramic transformer,
The ceramic transformer of the present invention has a coupling coefficient of 98%, the conventional ceramic transformer has a coupling coefficient of 80%, and the ceramic transformer of the present invention has a coupling coefficient of 18%.
Has improved. The reason why the coupling coefficient of the ceramic transformer of the present invention is improved is that since the primary coil and the secondary coil and the conductor are non-magnetic, most of the magnetic flux generated from the primary coil passes through the magnetic layer. This is for interlinking the secondary coils. Therefore, the degree of coupling between the primary coil and the secondary coil increases. On the other hand, the value of the coupling coefficient of the conventional example is small, because the coil is a magnetic material around the coil, a magnetic flux is generated only around the primary coil, and the degree of coupling between the primary coil and the secondary coil is poor. It is due to becoming.

As described above, according to the present invention, since the coil forming portion of the ceramic inductor or the ceramic transformer is formed by integrally sintering the alternate laminated body of the non-magnetic material layer and the electrode layer, the circumference of the coil is made of the non-magnetic material. By being surrounded and surrounding it with a magnetic material, a closed magnetic circuit can be formed, the coupling coefficient can be increased, and high inductance can be obtained. Moreover, since the coil forming portion of the ceramic transformer is formed by integrally sintering the alternate laminated body of the non-magnetic material layers and the electrode layers, the dielectric strength between the primary coil and the secondary coil can be increased.

Moreover, since the stray capacitance can be reduced, it is possible to obtain a ceramic inductor and a ceramic transformer which are small in size, can cope with high energy, and have excellent high frequency characteristics. Further, the ceramic inductor and the composite ceramic described in the embodiments have a closed magnetic circuit structure, and the linearity of characteristics and the direct current superposition characteristics are improved.

The ceramic inductor and composite ceramic of the present invention are not limited to those described above, and the following materials and construction methods may be used. The magnetic material sheet made of the above-mentioned insulator may be a spinel type ferrite magnetic material such as Ni ferrite, Ni-Zn ferrite, Ni-Cu ferrite, Mn-Zn ferrite, in addition to Ni-Zn-Cu ferrite. The magnetic layer may be formed by a printing method or a green sheet method.

The material of the conductor pattern formed on the surface of the non-magnetic sheet may be a silver alloy such as Ag or Ag-Pd. The forming method may be printing, coating, vapor deposition, sputtering or the like. The external electrode material may be Ag-Pd, Ni, Cu, etc., or alloys thereof, in addition to the above Ag, and may be formed by printing, vapor deposition, sputtering or the like. Further, an external electrode may be formed on the end surface of the raw chip before firing and the firing may be performed simultaneously.

Furthermore, in order to improve the strength and solderability of the external electrodes, Sn, solder or the like may be plated.
The shape of the chip is not particularly limited, and the number of turns of the coil is not limited, and can be arbitrarily selected depending on the number of conductor patterns.

The method of forming the magnetic material portion surrounding the ceramic inductor or the composite ceramic coil according to the present invention is not limited to the above embodiment, and a non-magnetic material sheet may be formed with a modifying material pattern in advance. Good.

[0043]

According to the ceramic inductor of the present invention, the coil has a closed magnetic circuit structure, and the linearity of characteristics and the direct current superposition characteristic are good. Further, the coil forming portion of the ceramic inductor of the present invention, by integrally sintering the alternate laminated body of the non-magnetic material layer and the electrode layer, by surrounding the electrode layer with a non-magnetic material and surrounding it with a magnetic material, Since a closed magnetic circuit is formed and the magnetic flux hardly circulates between the electrode layers, the coupling coefficient can be increased and high inductance can be obtained.

Further, according to the ceramic transformer which is a specific example of the ceramic inductor of the present invention, the primary and secondary coils are made of non-magnetic material by the integral sintering of the non-magnetic material layer and the electrode layer. It is possible to increase the dielectric strength between the primary and secondary coils. In addition, by surrounding the coil with a non-magnetic material and surrounding it with a magnetic material, the magnetic flux hardly circulates between the coil electrode layers, the coupling coefficient can be increased, and high inductance can be obtained. It is possible to obtain a transformer that can handle high energy. Moreover, since a non-magnetic material having a small dielectric constant can be selected as the non-magnetic material between the primary and secondary coils, stray capacitance can be reduced and a transformer having excellent high frequency characteristics can be obtained.

Further, according to the manufacturing method of the present invention, a non-magnetic ceramic green sheet made of an insulating material is provided with a modifier containing a material which becomes magnetic after firing, and a plurality of the ceramic green sheets are laminated. By firing this laminate, the magnetic portion and the non-magnetic portion can be surely produced. Further, in the conventional example, a hole was formed in the laminated body in order to provide the magnetic body portion in the non-magnetic body, and the hole was filled with the magnetic paste and fired. However, according to the manufacturing method of the present invention, Since no holes are provided in the body, disconnection of the electrode layer can be prevented, the number of steps for providing holes can be reduced, and the manufacturing method can be simplified and omitted.

[Brief description of drawings]

FIG. 1 is an embodiment of a ceramic inductor of the present invention, (a) is an external perspective view, and FIG. 1 (b) is AA of (a).
It is sectional drawing in a line.

FIG. 2 is an exploded perspective view of an embodiment of the ceramic inductor of the present invention.

FIG. 3 is a modified example of the ceramic inductor of the present invention, in which (a) is an external perspective view and (b) is a vertical cross-sectional view taken along line BB.

FIG. 4 is a ceramic transformer of one embodiment of the composite ceramic of the present invention, (a) is an external perspective view, and (b) is a vertical cross-sectional view taken along line CC of (a).

FIG. 5 is an exploded perspective view of an embodiment of the ceramic transformer of the present invention.

FIG. 6 is a modification of the ceramic transformer of the present invention, in which (a) is an external perspective view and (b) is a vertical cross-sectional view taken along the line D-D.

7A and 7B show a conventional composite laminated transformer, FIG. 7A is an external perspective view, and FIG. 7B is a cross-sectional view taken along the xy plane of FIG. 7A.

[Explanation of symbols]

 1,11 Ceramic inductor 2,12 Coil forming part 3a, 3b, 13a, 13b External electrode 4,14 Non-magnetic material layer 5,15 Electrode layer 6,7,16,17,18a, 18b Magnetic material part 4a-4e Non Magnetic sheet 5a to 5c Conductor pattern 6a to 6e Modified material pattern 7a to 7e Modified material pattern 21,31 Ceramic transformer 22,32 Coil forming part 23a, 23b, 29a, 29b External electrode 24,34 Nonmagnetic layer 25,30 , 35, 40 Electrode layer 26, 27, 36, 37, 38a, 38b Magnetic material part 33a, 33b, 39a, 39b External electrode 24a-24h Non-magnetic material sheet 25a-25c Conductor pattern 30a-30c Conductor pattern 26a-26h Modified Material pattern 27a-27h Modified material pattern

Claims (8)

[Claims] 1. A ceramic inductor body, a coil-shaped inductor electrode formed in the ceramic inductor body, and an external electrode formed on a surface of the ceramic inductor body and electrically connected to the coil-shaped inductor electrode. The region in which the coil-shaped inductor electrode is formed is made of a non-magnetic ceramic material, and the inside of the region in which the coil-shaped inductor electrode is formed is made of a magnetic ceramic material, A ceramic inductor characterized in that the entire outer peripheral surface of the region where the electrodes for electrodes are formed is made of a magnetic material. 2. A ceramic inductor body, a coil-shaped inductor electrode formed in the ceramic inductor body, and an external electrode formed on a surface of the ceramic inductor body and electrically connected to the coil-shaped inductor electrode. The region in which the coil-shaped inductor electrode is formed is made of a non-magnetic ceramic material, and the inside of the region in which the coil-shaped inductor electrode is formed is made of a magnetic ceramic material, The entire periphery of the outer side surface of the region where the electrode for electrodes is formed is made of a magnetic ceramic material, and the upper and lower surfaces of the region where the electrode for the coiled inductor is formed is made of a magnetic ceramic material. And ceramic inductor. 3. The ceramic inductor according to claim 1, wherein the coil-shaped inductor electrode includes a primary coil and a secondary coil. 4. A ceramic green sheet, which becomes an insulating non-magnetic ceramic by firing, is provided with a modifier for changing the ceramic green sheet from non-magnetic to magnetic ceramic by firing. A method for producing a composite ceramic, which comprises firing a sheet. 5. A ceramic green sheet, which becomes an insulator and non-magnetic ceramic by firing, is provided with a modifier for changing the ceramic green sheet from non-magnetic to magnetic ceramic by firing, and the ceramic green sheet is provided. A method for producing a composite ceramic, comprising laminating a plurality of sheets and firing the obtained laminated body. 6. A ceramic green sheet, which becomes an insulating non-magnetic ceramic by firing, is provided with a modifier for changing the ceramic green sheet from non-magnetic to magnetic ceramic by firing to obtain a ceramic green sheet. A method for manufacturing a ceramic inductor, comprising forming an inductor electrode in the other region of the sheet and firing the ceramic green sheet. 7. A ceramic green sheet, which is an insulator and becomes a non-magnetic ceramic by firing, is provided with a modifier for changing the ceramic green sheet from non-magnetic to magnetic ceramic by firing, and the ceramic green sheet is provided. A method of manufacturing a ceramic inductor, comprising forming a coil-shaped inductor electrode in the other region of the sheet, laminating a plurality of the ceramic green sheets, and firing the obtained laminated body. 8. A coil-shaped inductor electrode paste is applied to a part of the surface of a ceramic green sheet that becomes an insulating non-magnetic ceramic by firing, and the coil-shaped inductor electrode paste is applied inside the region where the coil-shaped inductor electrode paste is applied. A modifier paste that changes the ceramic green sheet from non-magnetic to magnetic ceramic by firing is applied, and the ceramic green sheet is non-magnetic around the entire outer surface of the area where the coil-shaped inductor electrode paste is applied. A method of manufacturing a ceramic inductor, characterized in that a modifier paste for changing from the above to a magnetic ceramic is applied, a plurality of the ceramic green sheets are laminated, and the obtained laminated body is fired.