JPH11126731A - R-c composite electronic component and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a R-C composite electronic component which can be baked under the same conditions as usual laminated ceramic capacitors, without special baking conditions, has a simple manufacturing process and a low production cost, and easily enables R-C or (L/C) R series circuits and controlled resistance values, and manufacture thereof. SOLUTION: In this electronic component, a dielectric layer 2 and an internal electrode 3 are alternately laminated. The electrode 3 and a terminal electrode 4-6 formed at an edge of the R-C composite electronic component are electrically connected to form a capacitor. At least one terminal electrode has three electrode layers 4-6. The first electrode layer 4 is the nearest to the internal electrode and the third one 6 is the farthest. In this R-C composite electronic component, the first electrode layer 4 and the third electrode layer 6 contain Cu and/or Ni and the second electrode layer 5 contains an oxide of the first electrode layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CR composite electronic component in which a resistance or impedance element is added to a multilayer capacitor having a nonmagnetic ceramic dielectric layer.

[0002]

2. Description of the Related Art At present, switching power supplies and DC-DC converters are used for many power supplies of electronic devices. There is a power supply bypass capacitor as a capacitor used for these power supplies. As the power supply bypass capacitor, a low-capacity multilayer ceramic capacitor and a high-capacity electrolytic capacitor such as aluminum or tantalum have been used in accordance with the power supply capacity, switching frequency, and circuit parameters such as a smoothing coil used in combination. By the way, an electrolytic capacitor can easily obtain a large capacity and has an excellent surface as a power supply bypass (smoothing) capacitor. However, it is large, has poor low-temperature characteristics, may cause a short circuit, and has an internal impedance. Is relatively high,
Loss due to equivalent series resistance (ESR) occurs constantly,
There is a problem that heat is generated as a result, frequency characteristics are poor, and smoothness is deteriorated. In recent years,
With the technological innovation, the capacitance of the multilayer ceramic capacitor is approaching the capacitance of the electrolytic capacitor with the progress of thinning of the dielectric and internal electrodes of the multilayer ceramic capacitor and the development of the lamination technology. For this reason, various attempts have been made to replace electrolytic capacitors with multilayer ceramic capacitors.

In a bypass capacitor of a power supply, ripple noise is important as a factor showing a smoothing action. How much the ripple noise is suppressed depends on the equivalent series resistance (ESR) of the capacitor. Here, assuming that the ripple voltage is ΔVr, the current flowing through the choke coil is Δi, and the equivalent series resistance is ESR, then ΔVr = Δi × ESR. Therefore, it is preferable to use a capacitor having a low ESR in a bypass circuit of a power supply, and an attempt has been made to use a multilayer ceramic capacitor having a low ESR in a power supply circuit.

However, in a secondary circuit such as a DC-DC converter or a switching power supply having a feedback circuit, the ESR of the smoothing circuit has a great effect on the phase characteristics of the feedback loop, and a problem occurs particularly when the ESR becomes extremely low. Sometimes. That is, when a multilayer ceramic capacitor having a low ESR is used as the smoothing capacitor, the secondary-side smoothing circuit is equivalently composed of only the L and C components, and the phase components existing in the circuit are ± 90 ° and 0 °. ° only, there is no phase margin, and oscillation occurs easily. A similar phenomenon appears as an oscillation phenomenon at the time of a load change even in a power supply circuit using a three-terminal regulator.

For this reason, various so-called CR composite electronic components in which a resistance component is added to a multilayer ceramic capacitor have been proposed. For example, Japanese Patent Application Laid-Open No. H8-45784 describes a composite electronic component in which an end of a multilayer ceramic capacitor is formed into a semiconductor using a carbide and a reducing agent. However, the manufacturing method is to apply a paste for external electrodes to the multilayer ceramic capacitor body, temporarily calcine the paste in a reducing atmosphere, carbonize the binder and leave it, and then bake it at 700 to 750 ° C. The carbide is made to act as a reducing agent to form a semiconductor. The resistance value is controlled by the amount of the reducing agent. However, in this method, the process of forming a semiconductor is complicated, and if the process of forming a terminal electrode is included, heat treatment is required three times, resulting in reduced productivity and increased energy cost.
Moreover, since the resistance value is controlled by the amount of the reducing agent, it is difficult to obtain a desired value accurately, circuit design becomes difficult, and there are many variations between products. Yield is poor.

[0006] For example, see Japanese Patent Application Laid-Open No. Sho 59-225509.
As described in Japanese Patent Application Laid-Open Publication No. H11-107, there is known a multilayer ceramic capacitor in which a resistor paste such as ruthenium oxide is further laminated and fired simultaneously to form a resistor. However, when the terminal electrode is provided as it is, an equivalent circuit becomes a parallel circuit of C / R or (LC) / R, and a series circuit cannot be obtained. Further, in order to obtain a series circuit, the shape of the terminal electrode is complicated, and the manufacturing process is also complicated.

[0007] Japanese Patent No. 2578264 discloses a CR composite component in which a metal oxide film is provided on the surface of an external electrode to obtain a desired equivalent series resistance. However, in the CR composite component described in the example of the publication, a nickel terminal electrode is heated to form a metal oxide film, and the resistance value is adjusted by barrel polishing. It is done by adjusting. For this reason, it is difficult to obtain a desired resistance value, and adjustment of the resistance value is complicated, resulting in poor mass productivity. Also, on the formed metal oxide film,
Furthermore, the nickel layer is provided by electroless plating,
In this method, it is necessary to provide a mask so that plating does not adhere to portions other than the terminal portions, and the number of manufacturing steps increases. Further, the adhesion between the nickel plating and the metal oxide film is poor, and when a lead wire is provided on the nickel plating, the lead wire is easily peeled off.

Although there is a method of connecting a resistor in series with the smoothing capacitor, it is expensive and not practical.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the need for special firing conditions, to enable firing under the same conditions as ordinary multilayer ceramic capacitors, to simplify the manufacturing process, and to reduce the production cost. , CR or (L / C) R series circuit can be obtained easily, the resistance value can be easily controlled, and the bonding strength of the lead wire is strong.

[0010]

The above object is achieved by the following constitutions (1) to (9). (1) Dielectric layers and internal electrodes are alternately stacked, and the internal electrodes and terminal electrodes formed at the ends of the CR composite electronic component are electrically connected so as to function as capacitors, At least one of the terminal electrodes has first to third electrode layers sequentially from the internal electrode side, the first electrode layer and the third electrode layer contain Cu and / or Ni, and the second electrode layer A CR composite electronic component containing the oxide of the first electrode layer. (2) The second electrode layer is made of Cu ₂ O,
The CR composite electronic component according to the above (1), comprising one or more of Cu ₃ O ₄ , CuO and NiO. (3) The first electrode layer and the third electrode layer are
g, Au, Pt and Pd by one or more of 10
The CR composite electronic component according to any one of the above (1) and (2), which contains not more than% by weight. (4) The CR composite electronic component according to any one of (1) to (3), wherein the first to third electrode layers contain glass. (5) The CR composite electronic component according to any one of (1) to (4) above, wherein the equivalent circuit has a CR or (LC) R series circuit. (6) The above (1) to (1), wherein the internal electrode layer contains Ni.
The CR composite electronic component according to any one of (5). (7) The CR composite electronic component according to any one of (1) to (6), further including a plating layer outside the terminal electrode. (8) Dielectric layers and internal electrode layers are alternately stacked to form a green chip, which is fired to form a chip body,
A paste for a terminal electrode is applied to the chip body and fired in a neutral or reducing atmosphere to form precursor layers for the first to third electrode layers, and then heat-treated in an oxidizing atmosphere to form the precursor layer. Is oxidized to form a precursor layer of the second electrode layer, and further heat-treated in a neutral or reducing atmosphere to reduce the precursor layer of the second electrode layer to form the first to third layers. A method for manufacturing a CR composite electronic component, wherein an electrode layer is formed to obtain the CR composite component according to any one of (1) to (7). (9) The terminal electrode paste has an average particle diameter of 0.01.
(8) The method for producing a CR composite electronic component according to the above (8), which has metal particles of 10 to 10 μm.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The CR composite electronic component of the present invention has a structure in which dielectric layers and internal electrodes are alternately laminated, and the internal electrodes and terminal electrodes formed at the ends of the CR composite electronic component. Are electrically connected so as to form a capacitor, at least one of the terminal electrodes has first to third electrode layers sequentially from the internal electrode side, and the first electrode layer and the third electrode layer are made of Cu and And / or Ni, and the second electrode layer contains the oxide of the first electrode layer. In this manner, by forming the terminal electrode into a three-layer structure and forming the second electrode layer from the oxide of the first electrode layer, the second electrode layer having high resistance is equivalently connected in series to the capacitor. Resistance component
CR with controlled equivalent series resistance (ESR) of capacitor
It becomes a composite electronic component.

The first electrode layer and the third electrode layer of the terminal electrode contain Cu and / or Ni.
-Contains a Ni alloy. In addition to these metals, A
Precious metals such as g, Au, Pt, and Pd, particularly Ag, may be contained in an amount of preferably about 10% by weight or less, more preferably about 5% by weight or less. When adding a noble metal to the Cu, Ni, Cu-Ni alloy, it is not necessary to add the noble metal in a powder state.
A material obtained by coating Cu, Ni, Cu-Ni alloy particles with a noble metal, or a functionally gradient powder of Cu, Ni, Cu-Ni alloy and a noble metal may be used.

The average particle size of the Cu, Ni, Cu—Ni alloy is preferably 0.01 to 10 μm, particularly 0.1 to 5 μm.
The range of μm is preferred. If the particle size of Cu, Ni, or Cu-Ni alloy is smaller than the above range, when a plurality of types of metals are used, the aggregation of the metals becomes severe, and it is difficult for the metal components to completely dissolve during firing. Cu, Ni, Cu-N
If the particle size of the i-alloy is larger than the above range, it becomes difficult to form a paste.

The method for forming the first electrode layer, which is a terminal electrode, is not particularly limited, but a usual dipping method, screen printing method, transfer method, or dry plating method is preferable as a precursor thereof. The dipping method is preferred. Although the thickness of the first electrode to be formed is not particularly limited, it is usually 5 to 100 μm, particularly 10 to 70 μm.
It is preferably about μm.

In order to provide a precursor of the first electrode layer by dipping or the like, a paste obtained by kneading Cu, Ni, Cu-Ni alloy and an organic vehicle may be used. The terminal electrode paste usually contains the above-mentioned Cu, Ni, Cu
Glass frit as an inorganic binder in addition to the Ni alloy,
Contains an organic binder and a solvent. The content of Cu, Ni, and Cu-Ni alloy in the terminal electrode paste is preferably in the range of about 40 to 90 wt%, more preferably about 60 to 80 wt%.

The first electrode layer contains glass for assisting adhesion to the element body and sintering of the conductive material. Such a glass is not particularly limited, but when used for the first electrode layer, it may be fired in a reducing or neutral atmosphere, so long as it functions as a glass even in such an atmosphere. . For example, silicate glass (Si
_{O 2: 20~80wt%, Na 2} O: 80~20wt%),
Borosilicate glass _{(B 2 O 3: 5~50wt%} , SiO
_{2: 5~70wt%, PbO: 1~10wt} %, K 2 O: 1
-15 wt%), alumina silicate glass (Al ₂ O ₃ : 1)
_{~30wt%, SiO 2: 10~60wt%} , Na 2 O: 5~
15wt%, CaO: 1~20wt%, B 2 O 3: 5~30wt
%), Or one or more of the glass frit selected from the above. If necessary, CaO:
0.01-50 wt%, SrO: 0.01-70 wt%, B
aO: 0.01 to 50 wt%, MgO: 0.01 to 5 wt%
%, ZnO: 0.01 to 70 wt%, PbO: 0.01 to
_{5wt%, Na 2 O: 0.01~10wt} %, K 2 O: 0.
Additives such as 01 to 10 wt% and MnO ₂ : 0.01 to ₂₀ wt% may be mixed and used so as to have a predetermined composition ratio. These may be added in a total of 50 wt% or less.
Although the content of the glass is not particularly limited, it is usually about 0.5 to 15% by weight based on the metal component. The average particle size of the glass frit is preferably 0.01
About 30 μm is preferred. If the average particle size of the glass frit is smaller than the above range, aggregation of the glass becomes severe,
A local sintering effect of the conductive material is brought about, which may cause cracks in the terminal electrodes. If the average particle size is larger than the above range, the dispersion of the glass becomes worse, the solid solution of the metal is suppressed, and the adhesion between the terminal electrode and the chip body is reduced.

The organic binder is not particularly limited, and may be appropriately selected from those commonly used as binders for ceramic materials. Examples of such an organic binder include ethyl cellulose, acrylic resin, and butyral resin, and examples of the solvent include terpineol, terpineol, butyl carbitol, kerosene, and the like. The content of the organic binder and the solvent in the paste is not particularly limited, and may be a commonly used amount, for example, about 1 to 5% by weight of the organic binder and about 10 to 50% by weight of the solvent.

Further, in the first electrode layer paste,
If necessary, additives such as various dispersants, plasticizers, dielectrics, and insulators may be contained. Their total content is
It is preferably at most 10% by weight.

The second electrode layer is formed by oxidizing Cu, Ni, or a Cu—Ni alloy contained in the first electrode layer (precursor of the second electrode layer). N
i, Cu-Ni alloy containing layer. That is, by firing the precursor of the first to third electrode layers having the same composition as the first electrode layer and being thicker than the first electrode layer in an oxidizing atmosphere, the precursor is oxidized from the vicinity of the surface of the precursor and has a high resistance. Of the second electrode layer is formed. This precursor of the second electrode layer is reduced near the surface to form the second and third electrode layers.

The oxide present in the second electrode layer is
As described above, Cu, Ni,
Although it is an oxide of a Cu-Ni alloy, all Cu, Ni,
The Cu-Ni alloy does not need to be oxidized, and may be in a partially oxidized state. In this case, it is preferable that the oxide is contained in an amount of preferably at least 10 at%, more preferably at least 25 at%, in terms of oxygen, based on the total metal content in the second electrode layer.

The thickness of the second electrode layer is regulated by the thickness of the oxide layer which is controlled by the oxidation treatment time and the like, and the thickness of the third electrode layer described later. The thickness of the second electrode layer is not particularly limited, and may be appropriately adjusted by adjusting the above conditions according to a desired ESR.
μm, especially about 0.05 to 20 μm. In addition,
Since the first electrode layer (precursor of the second electrode layer) is formed by oxidation, the noble metal and glass are also present in the second electrode layer. The ESR obtained by the second electrode layer is preferably 1 to 2000 mΩ, particularly 10 to 2000 mΩ.
It is preferably about 1000 mΩ. The presence of the oxide can usually be determined by X-ray diffraction, and its composition can be determined by EPMA or the like. In addition, a first electrode layer (a precursor of a second electrode layer)
May be entirely oxidized, but it is preferable to maintain the conductive material of the first electrode layer in a metallic state in order to maintain ohmic properties of the electrical connection with the internal electrodes.

By such oxidation, Cu is replaced by Cu
One or two or more of ₂ O, Cu ₃ O ₄ , CuO, etc. are generated, and NiO is usually generated with Ni. These oxides may deviate somewhat from the stoichiometric composition. The noble metals (except Cu) are not usually oxidized.

The terminal electrode may have one of the above-mentioned electrodes having the above structure to increase the resistance, or both may have the resistance increased. Further, the resistance value of the terminal electrode can be adjusted by adjusting the oxide or the minimum thickness of the second electrode layer.
In the case where both terminal electrodes have a high resistance, the resistance value is the sum of the resistance values of the respective electrodes.

The third electrode layer is formed by reducing the precursor of the second electrode layer outside the second electrode layer, ie, on the terminal side. Therefore, the composition is usually almost the same as that of the first electrode layer, but a part thereof may be oxidized. In this case, it is preferable that the oxide is contained in an amount of preferably less than 10 at%, more preferably 5 at% or less in terms of oxygen with respect to the total amount of Cu, Ni, and Cu-Ni alloy in the third electrode layer. The thickness of the third electrode layer is not particularly limited and may be appropriately adjusted depending on a desired ESR or the like, but is usually 1 to 20 μm, particularly 5 to 10 μm.
The degree is preferred. In addition, since the precursor of the second electrode layer is formed by reduction, the noble metal and the glass are also present in the third electrode layer.

By forming the third electrode layer,
Adhesion strength with the plating layer and the lead terminals is improved.

<Plating Layer> It is preferable to provide a plating layer outside the terminal electrode, that is, on the terminal side. The plating layer includes nickel, tin, solder and the like, and is preferably composed of a nickel plating layer and a tin or tin-lead alloy solder layer. As for the plating layer, a nickel plating layer is formed on the terminal electrode side, and as a material outside the nickel plating layer, a material having low resistivity and good solder wettability is preferable,
Tin or tin-lead alloy solder is preferred, and particularly preferred is one provided with tin-lead alloy solder.
The plating layer improves the solder wettability when attaching the lead wire, ensures the connection between the terminal electrode and the lead wire, and is formed so as to cover the entire terminal electrode. Becomes stable.

The method for forming the plating layer is not particularly limited, and dry plating using a sputtering method or a vapor deposition method is also possible, but a conventionally known electrolytic plating method or electroless plating method is used. It is preferable because it can be easily provided by wet plating. When a wet method is used, it is preferable to use an electrolytic plating method since a nickel plating layer is formed on a terminal electrode. Also, tin or tin - lead alloy solder layer may be Electrolytic plating using either method for the nickel layer is a metal film is formed is preferable. The thickness of the plating layer is preferably 0.1 to 30.
It is preferably about μm.

<Dielectric Layer> The dielectric material constituting the dielectric layer is not particularly limited, and various dielectric materials may be used. For example, titanium oxide-based and titanate-based composite oxides may be used. Or a mixture thereof is preferable. As the titanium oxide-based material, NiO, Cu
TiO ₂ or the like containing a total of about 0.001 to 30 wt% of O, Mn ₃ O ₄ , Al ₂ O ₃ , MgO, SiO _2, etc. is used as the titanate-based composite oxide, and barium titanate BaTiO _{3 is used.}
And the like. The atomic ratio of Ba / Ti is 0.95-
It is preferably about 1.20, and BaTiO ₃ contains MgO, Ca
O, Mn ₃ O ₄ , Y ₂ O ₃ , V ₂ O ₅ , ZnO, ZrO ₂ , N
_{b 2 O 5, Cr 2 O} 3, Fe 2 O 3, P 2 O 5, SrO, Na 2
O, K ₂ O and the like may be contained in a total amount of about 0.001 to 30% by weight. Further, glass such as (BaCa) SiO ₃ glass or the like may be contained for adjusting the firing temperature, the coefficient of linear expansion, and the like.

The thickness of one dielectric layer is not particularly limited, but is usually about 5 to 20 μm. The number of stacked dielectric layers is usually about 2 to 300.

<Internal Electrode Layer> The conductive material contained in the internal electrode layer is not particularly limited, but it is preferable to use an inexpensive base metal by using a reduction layer-resistant material for the dielectric layer constituting material. . As the base metal used as the conductive material, Ni or a Ni alloy is preferable. As the Ni alloy, an alloy of one or more elements selected from Mn, Cr, Co, Al, and the like and Ni is preferable, and the Ni content in the alloy is preferably 95 wt% or more.

Incidentally, various trace components such as P may be contained in Ni or Ni alloy at about 0.1 wt% or less.

The thickness of the internal electrode layer may be appropriately determined according to the application and the like, but is usually 0.5 to 5 μm, particularly 0.5 to 5 μm.
It is preferably about 2.5 μm.

Next, a method of manufacturing a CR composite electronic component according to the present invention will be described.

The CR composite electronic component of the present invention is obtained by producing a green chip by a normal printing method or sheet method using a paste, printing or transferring a resistor paste on at least one end of the chip, and simultaneously firing the chip. Can be manufactured.

<Dielectric Layer Paste> The dielectric layer paste is manufactured by kneading a dielectric material and an organic vehicle.

As the dielectric material, a powder according to the composition of the dielectric layer is used. The method for producing the dielectric material is not particularly limited. For example, when barium titanate is used as the titanate-based composite oxide, BaTi synthesized by a hydrothermal synthesis method or the like is used.
A method of mixing an auxiliary component material with O ₃ can be used. Further, a dry synthesis method in which a mixture of BaCO ₃ , TiO _2, and auxiliary component raw materials is calcined to cause a solid phase reaction may be used, or a hydrothermal synthesis method may be used. In addition, coprecipitation method, sol
It may be synthesized by calcining a mixture of the precipitate obtained by the gel method, alkali hydrolysis method, precipitation mixing method or the like and the raw material of the auxiliary component. In addition, as the auxiliary component raw materials, oxides, various compounds that become oxides by firing, for example, carbonates, oxalates,
At least one of nitrates, hydroxides, organometallic compounds and the like can be used.

The average particle size of the dielectric material may be determined according to the desired average crystal grain size of the dielectric layer, and usually, a powder having an average particle size of about 0.3 to 1.0 μm is used.

The organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used for the organic vehicle is not particularly limited, and may be appropriately selected from various ordinary binders such as ethyl cellulose. In addition, the organic solvent to be used is not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, acetone, and toluene according to a method to be used such as a printing method and a sheet method.

<Paste for Internal Electrode Layer> The paste for the internal electrode layer is composed of the above-mentioned various conductive metals and alloys, or various oxides, organometallic compounds, resinates and the like which become the above-mentioned conductive materials after firing, and the above-mentioned organic material. It is prepared by kneading with a vehicle.

<Paste for Terminal Electrode> The paste for terminal electrode may be prepared in the same manner as the paste for internal electrode layer described above.

<Organic Vehicle Content> The content of the organic vehicle in each of the above-mentioned pastes is not particularly limited, and is usually a content, for example, about 1 to 5% by weight of a binder and 1 to 5% by weight of a solvent.
It may be about 0 to 50 wt%. Further, each paste may contain additives selected from various dispersants, plasticizers, dielectrics, insulators, and the like, as necessary. It is preferable that the total content thereof be 10 wt% or less.

<Preparation of Green Chip> When a printing method is used, a paste for a dielectric layer and a paste for an internal electrode layer are laminated and printed on a substrate such as PET. At this time, the layers are laminated such that one end of the internal electrode paste is alternately exposed to the outside from the end of the dielectric layer paste. Thereafter, the chip is cut into a predetermined shape to form a chip, and is separated from the substrate to form a green chip.

In the case of using the sheet method, a green sheet is formed using a dielectric layer paste, and the internal electrode layer paste is alternately formed on the green sheet. Those printed so as to be exposed from one end of the paste for use are laminated and cut into a predetermined shape to obtain a green chip.

<Binder Removal Step> The conditions of the binder removal processing performed before firing may be ordinary conditions, but when a base metal such as Ni or a Ni alloy is used as the conductive material of the internal electrode layer, the following conditions are particularly preferable. It is preferable to carry out in. Heating rate: 5 to 300 ° C / hour, especially 10 to 100 ° C / hour
Time Holding temperature: 200 to 400 ° C, especially 250 to 300 ° C Temperature holding time: 0.5 to 24 hours, especially 5 to 20 hours Atmosphere: in air

<Firing Step> The atmosphere at the time of firing the green chip may be appropriately determined according to the type of the conductive material in the paste for the internal electrode layer. When a base metal such as Ni or a Ni alloy is used as the conductive material, The firing atmosphere is preferably a mixture of N ₂ as a main component, and H ₂ 1 to 10% mixed with H ₂ O gas obtained by steam pressure at 10 to 35 ° C.
The oxygen partial pressure is preferably set to 10 ^-8 to 10 ^-12 atm. If the oxygen partial pressure is less than the above range, the conductive material of the internal electrode layer may abnormally sinter and be interrupted. If the oxygen partial pressure exceeds the above range, the internal electrode layer tends to be oxidized.

The holding temperature during firing is 1100 to 1400
° C, particularly preferably 1200 to 1300 ° C.
When the holding temperature is lower than the above range, the densification is insufficient, and when the holding temperature is higher than the above range, the internal electrode is easily broken. Further, the temperature holding time during firing is 0.5 to 8 hours,
Particularly, 1 to 3 hours is preferable.

<Annealing Step> When firing in a reducing atmosphere, it is preferable to anneal the CR composite electronic component chip body. Annealing is a process for reoxidizing the dielectric layer, which can significantly increase the IR accelerated life.

The oxygen partial pressure in the annealing atmosphere is preferably 10 ⁻⁶ atm or more, particularly preferably 10 ⁻⁵ to 10 ⁻⁸ atm. When the oxygen partial pressure is less than the above range, it is difficult to reoxidize the dielectric layer, and when the oxygen partial pressure exceeds the above range, the internal electrode layer tends to be oxidized.

The holding temperature at the time of annealing is preferably 1100 ° C. or less, particularly preferably 500 to 1000 ° C. If the holding temperature is less than the above range, the oxidation of the dielectric layer tends to be insufficient and the life tends to be short, and if the holding temperature exceeds the above range, the internal electrode layer is oxidized and the capacity is reduced, It tends to react with the substrate and shorten its life. Note that the annealing step may be configured only by raising and lowering the temperature. In this case, the temperature holding time is zero, and the holding temperature is synonymous with the maximum temperature. The temperature holding time is
0-20 hours, especially 2-10 hours are preferred. It is preferable to use a humidified N ₂ gas or the like as the atmosphere gas.

In the above-described steps of the binder removal processing, firing, and annealing, for example, a wetter may be used to humidify N ₂ , H ₂ , a mixed gas, or the like. In this case, the water temperature is preferably about 5 to 75 ° C.

The binder removing step, the firing step, and the annealing step may be performed continuously or independently.

In the case where these steps are continuously performed, after removing the binder, the atmosphere is changed without cooling, the temperature is raised to the holding temperature for firing, firing is performed, and then cooling is performed. It is preferable to perform the annealing while changing the atmosphere when the temperature reaches.

When these steps are performed independently, in the binder removal treatment step, the temperature is raised to a predetermined holding temperature, held for a predetermined time, and then lowered to room temperature. At that time, the atmosphere for removing the binder is the same as in the case where the process is performed continuously.
Further, in the annealing step, the temperature is raised to a predetermined holding temperature,
After holding for a predetermined time, the temperature is lowered to room temperature. The annealing atmosphere at that time is the same as in the case of performing the annealing continuously. Further, the binder removal step and the firing step may be performed continuously, and only the annealing step may be performed independently. Only the binder removal step may be performed independently, and the firing step and the annealing step may be performed continuously. You may do so.

<Formation of Terminal Electrodes> A paste for terminal electrodes is printed or transferred to the chip body obtained as described above, dried, and fired to first form a precursor of the first electrode layer. The amount of the terminal electrode paste applied is not particularly limited, but it is usually sufficient to set the dry film thickness to 5 to 100 μm. Drying conditions are 60 to 150
It is preferable to carry out at about 10 ° C. for about 10 minutes to 1 hour. The firing conditions for the precursor of the first electrode layer are, for example, N ₂ and H ₂
600 to 1000 ° C in a reducing atmosphere such as a mixed gas with
For about 1 minute to 1 hour.

After forming the precursor of the first electrode layer, heat treatment is performed in an oxidizing atmosphere to oxidize the vicinity of the surface of the first electrode layer to form a precursor of the second electrode layer. The heat treatment conditions for forming the second electrode layer are preferably set, for example, at 300 to 900 ° C. in an oxidizing atmosphere such as air for about 0 minute to 1 hour.

After the precursor of the second electrode layer is formed, heat treatment is performed in a reducing atmosphere to reduce the vicinity of the surface of the precursor of the second electrode layer to form a third electrode layer. At this time
Not to reduce all of the precursors of the electrode layer of
The thin film layer of the electrode layer is formed in the middle. Third
The heat treatment conditions for forming the electrode layer are, for example, H ₂ : 1
10%, N _2: 90~99% of a mixed gaseous atmosphere, 3
It is preferable to set the temperature at 00 to 700 ° C. for about 1 minute to 1 hour.

<Plating Step> Further, the chip body on which the terminal electrodes are formed is immersed in a nickel plating bath or a tin or tin-lead alloy solder plating bath, respectively, to form a plating layer. The thickness of the plating layer is not particularly limited, but is usually about 0.1 to 10 μm.

<Specific Configuration Example> FIG. 1 shows a configuration example of the CR composite electronic component of the present invention manufactured as described above.
In FIG. 1, the CR composite electronic component of the present invention has a dielectric layer 2, an internal electrode layer 3, a first electrode layer 4, a second electrode layer 5, and a third electrode layer 6. . Further, it is preferable that the terminal electrode constituted by the first to third electrode layers has a plating layer on the outside thereof. Further, the second electrode layer 5 has a resistance value corresponding to the minimum film thickness and the conductivity regulated by the oxides of Cu, Ni, Cu-Ni alloy and the like. Here, FIG. 1 shows a case where the second electrode layer 5 is formed on both terminals of the CR composite electronic component. However, the second electrode layer 5 may be formed on only one of the terminals, in which case the terminal contributing to the equivalent series resistance. Only one of the electrodes is used.

[0059]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. Example 1 BaCO ₃ (average particle size: 2.0 μm) and TiO ₂ (average particle size: 2.0) were used as main raw materials of the dielectric layer.
μm). The atomic ratio of Ba / Ti is 1.00. In addition to this, 0.2 wt% of MnCO ₃ as an additive to BaTiO _3, the MgCO ₃ 0.2 wt
%, Y ₂ O ₃ as 2.1 wt%, and (BaCa) SiO ₃ as 2.2 wt%. Each raw material powder was mixed with an underwater ball mill and dried. The obtained mixed powder was calcined at 1250 ° C. for 2 hours. This calcined product was pulverized with an underwater ball mill and dried. An acrylic resin as an organic binder and methylene chloride and acetone as organic solvents were added to the obtained calcined powder and further mixed to obtain a dielectric slurry. The obtained dielectric slurry was used as a dielectric green sheet using a doctor blade method.

Ni powder (average particle size: 0.8 μm) was prepared as an internal electrode material, and ethyl cellulose as an organic binder and terpineol as an organic solvent were added thereto, and kneaded using a three-roll mill. The paste was used.

As a paste material for a terminal electrode, a Cu powder (average particle size: 0.5 μm) and a material obtained by adding 7 wt% of borosilicate glass to the Cu powder were prepared. To this, an acrylic resin as an organic binder and terpineol as an organic solvent were added and kneaded using a three-roll mill,
This was used as a terminal electrode paste.

In order to obtain a predetermined thickness, several green sheets are laminated, and the edges of the internal electrode paste are alternately exposed from the edges of the dielectric layer paste by screen printing on the green sheets. A predetermined number of printed green sheets are laminated, and finally, a predetermined number of green sheets on which no internal electrodes are printed are laminated and thermocompression-bonded, and the shape of the chip is 3.2 × 1. 6 × 1.0mm
To obtain a green chip.

The obtained green chips are put in the air for 80 minutes.
Dry at 30 ° C. for 30 minutes. Then humidified N ₂
+ H ₂ (N ₂ 3%) in a reducing atmosphere, kept at 1300 ° C. for 3 hours, fired, and further humidified N ₂ oxygen partial pressure 10
^It was kept at 1000 ° C. for 2 hours in an atmosphere of ⁻⁷ atm to obtain a chip body.

At the both ends of the obtained chip body, the above Cu
And a glass frit were added to the metal component in an amount of 7 wt%, and a paste for terminal electrodes in which these were dispersed in an organic vehicle was applied, dried, and dried at 770 ° C. in an N ₂ -H ₂ atmosphere at 770 ° C.
The precursor was held for 0 minute and fired to form precursors of the first to third electrode layers.

Next, the chip body on which the electrode layer is formed is subjected to a heat treatment in air at 500 ° C. for 10 minutes to oxidize the vicinity of the surface thereof to form a second oxide layer of the precursor. Of the electrode layer was formed.

Further, the chip on which the precursor of the second electrode layer was formed was placed in a mixed gas atmosphere of H ₂ : 2% and N ₂ : 98% at 500 ° C. at 0,1,2,4. , For 8 minutes, and heat-treated to metallize the oxide near the surface of the second electrode layer to form a third electrode layer.

When the second electrode layer was analyzed by X-ray diffraction, CuO ₂ and Cu ₃ O ₄ were confirmed.

Next, a nickel plating layer and a tin-lead alloy plating layer were sequentially formed on the obtained sample of each additive composition by an electrolytic method to obtain a CR composite electronic component. The capacitance of the obtained sample was 1 μF. In addition, ESR was measured for each of the obtained samples. Table 1 shows the results.

When the obtained CR composite electronic component was used as a power supply bypass capacitor of a DC-DC converter and operated while changing the switching frequency from 100 k to 40 MHz, it operated normally without generating voltage fluctuation phenomenon such as oscillation. did.

[0070]

[Table 1]

As is clear from Table 1, it is understood that the ESR can be changed and controlled by the holding time of the heat treatment for forming the third electrode layer.

<Example 2> In Example 1, instead of Cu powder, Ni powder (average particle size: 0.4 µm), Ni-Cu powder (Ni: 90 wt%,
A sample was obtained in the same manner as in Example 1 except that the average particle size was 0.4 μm.

The ESR of the obtained sample was measured in the same manner as in Example 1.
Almost the same results were obtained although there was a difference in the magnitude of R. The thickness of the first electrode layer was 30 μm, the thickness of the second electrode layer was 10 μm, and the thickness of the third electrode layer was 10 μm.

[0074]

As described above, according to the present invention, no special firing conditions are required, firing can be performed under the same conditions as ordinary multilayer ceramic capacitors, and the manufacturing process is simple.
It is possible to provide a CR composite electronic component in which a production cost is low, a CR or (L / C) R series circuit can be easily obtained, and a resistance value can be easily controlled, and a method of manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a basic configuration of a CR composite electronic component of the present invention.

[Explanation of symbols]

 2 Dielectric layer 3 Internal electrode 4 First electrode layer (terminal electrode) 5 Second electrode layer (terminal electrode) 6 Third electrode layer (terminal electrode)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasunori Tokuoka 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation

Claims (9)

[Claims] 1. A dielectric layer and an internal electrode are alternately laminated, and the internal electrode and a terminal electrode formed at an end of the CR composite electronic component are electrically connected to form a capacitor. , At least one of the terminal electrodes is first to first from the internal electrode side.
A first electrode layer and a third electrode layer each containing Cu and / or Ni; and a second electrode layer containing an oxide of the first electrode layer.
R composite electronic components. 2. The method according to claim 1, wherein the second electrode layer comprises Cu as an oxide.
_2. The CR composite electronic component according to claim 1, comprising one or more of ₂ O, Cu ₃ O ₄ , CuO and NiO. 3. The CR according to claim 1, wherein the first electrode layer and the third electrode layer contain 10% by weight or less of one or more of Ag, Au, Pt, and Pd. Composite electronic components. 4. The CR composite electronic component according to claim 1, wherein said first to third electrode layers contain glass. 5. The CR composite electronic component according to claim 1, wherein the equivalent circuit has a CR or (LC) R series circuit. 6. The CR composite electronic component according to claim 1, wherein said internal electrode layer contains Ni. 7. The CR composite electronic component according to claim 1, further comprising a plating layer outside said terminal electrode. 8. A green chip is formed by alternately laminating a dielectric layer and an internal electrode layer, and sintering the green chip into a chip body. Baking in a reducing atmosphere to form a precursor layer of the first to third electrode layers, and then heat treating in an oxidizing atmosphere to oxidize the vicinity of the surface of the precursor layer to form a precursor layer of the second electrode layer And further heat-treated in a neutral or reducing atmosphere to form the second
A CR for obtaining a CR composite component according to any one of claims 1 to 7 by reducing a precursor layer of the electrode layer of (1) to form first to third electrode layers.
Manufacturing method of composite electronic components. 9. The CR according to claim 8, wherein the terminal electrode paste has metal particles having an average particle size of 0.01 to 10 μm.
Manufacturing method of composite electronic components.