JP2004134808A - Manufacturing method and binder removal method of ceramic electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a highly reliable ceramic electronic component which has no crack at firing, even in an electric component including electrode layers containing base metals and a thinned multilayer dielectric layer. <P>SOLUTION: This method is used for manufacturing a ceramic electronic component having electrode layers 6 and 8 containing base metals and a dielectric layer 4. The manufacturing method comprises: a process in which a green chip which is turned into a ceramic electronic component is subject to a binder removal process in ambient gas containing H<SB>2</SB>O; and a process in which the green chip is subject to a firing process. The ambient gas used for the binder removal process further contains hydrogen. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a method for manufacturing a ceramic electronic component such as a multilayer ceramic capacitor and a method for removing a binder.

積 層 A multilayer ceramic capacitor as a ceramic electronic component is usually manufactured by laminating an internal electrode paste and a dielectric paste by a green sheet method, a printing method, or the like, and firing. In general, Pd and Pd alloy have been used for such internal electrodes. However, since Pd is expensive, relatively inexpensive Ni or Ni alloy is being used.

In the case where the internal electrodes are formed of Ni or a Ni alloy, there is a problem that the electrodes are oxidized when firing is performed in the air. For this reason, in general, after the binder is removed in air, firing is performed at an oxygen partial pressure lower than the equilibrium oxygen partial pressure of Ni and Ni0, and the dielectric layer is reoxidized by a subsequent heat treatment (Japanese Patent Application Laid-Open No. -133116, Japanese Patent No. 2778746).

Multilayer ceramic capacitors having internal electrodes made of Ni or Ni alloy are inexpensive compared to those having internal electrodes made of Pd or Pd alloy, so that the dielectric layers are thinned and the number of dielectric layers is increased. Thus, the storage density per unit volume can be easily increased. However, as the number of layers decreases, the occurrence of structural defects such as delamination or cracks after firing becomes a problem.

Japanese Patent Publication No. 10-284287 discloses a binder removal under a low oxygen partial pressure of 10 ^-13 to 10 ^-15 atm (10 ^-8 to 10 ^-10 Pa). JP-A-5-335177 and JP-A-8-73273 also disclose binder removal at a low oxygen concentration. However, the techniques disclosed in these publications only disclose binder removal at a low oxygen concentration, and in each case, sufficient binder removal cannot be performed.

An object of the present invention is to produce a highly reliable ceramic electronic component free from cracks during firing, even for a ceramic electronic component having an electrode layer containing a base metal and a dielectric layer to be thinned and multilayered. It is to provide a method. Another object of the present invention is to provide a binder removal method suitable for use in manufacturing a ceramic electronic component such as a multilayer ceramic capacitor.

In order to achieve the above object, a method for manufacturing a ceramic electronic component according to the present invention is a method for manufacturing a ceramic electronic component having an electrode layer containing a base metal and a dielectric layer. In an atmosphere gas containing H ₂ O, and a step of firing the green chip subjected to the binder removal.

In the present invention, the material of the dielectric layer is not particularly limited, but is preferably a dielectric composition that can be fired in a non-oxidizing atmosphere.

Further, the binder removal method according to the present invention is characterized in that a green chip having an electrode forming material containing a base metal is subjected to a binder removal treatment under an atmosphere gas containing H ₂ O.

The partial pressure of H ₂ O in the atmosphere gas in the binder removal treatment is preferably 2.8 × 10 ⁻⁴ MPa to 0.012 MPa, more preferably 8.6 × 10 ⁻⁴ MPa to 1.2 × 10 ^{−. 2} MPa, particularly preferably ^{1.2 × 10 -3 MPa~1.2 × 10 -2} MPa, and most preferably ^{2.3 × 10 -3 MPa~7.3 × 10 -3} MPa.

雰 囲 気 It is preferable that the atmosphere gas in the binder removal treatment further contains hydrogen. The atmosphere gas may contain an inert gas such as a nitrogen gas or an argon gas as a carrier gas.

The partial pressure of hydrogen in the atmosphere gas in the binder removal treatment is preferably 2.0 × 10 ⁻⁵ MPa to 2.0 × 10 ⁻² MPa, more preferably 10 ⁻⁴ MPa to 10 ⁻² MPa, and particularly preferably. ^is, 10 -3 ^{MPa~10 -2,} most ^preferably from ¹⁰ -3 MPa~7 × 10 -3 MPa.

The electrode layer is not particularly limited, but preferably contains any of nickel, copper and tungsten, or an alloy thereof.

Preferably, the maximum temperature during the binder removal processing is 200 to 1000 ° C. Further, it is preferable that the temperature increase rate during the binder removal processing is 300 ° C./hour or less.

In the process of manufacturing ceramic electronic components such as multilayer ceramic capacitors, for example, a binder removal step for a green chip is required. In the binder removal step, the residual carbon in the green chip decreases as the binder removal temperature increases. At this time, when the atmosphere of the binder removal is air, the residual carbon is drastically reduced even at a low temperature of about 250 ° C. However, when the binder removal treatment is performed in the air, it is apparent that the base metal constituting the internal electrode in the green chip is also oxidized at the same time. In this case, cracks and delaminations are likely to occur after sintering of the green chip, particularly in an electronic component having multiple dielectric layers and internal electrode layers.

On the other hand, in the method of the present invention, since H ₂ O is contained in the atmosphere gas of the binder removal, the binder removal temperature for decomposing the binder is increased, but the oxidation of the internal electrode is performed in the case of air. More suppressed. Furthermore, by further including hydrogen in the atmosphere gas of the binder removal, it becomes possible to remove the binder while suppressing the oxidation of the internal electrodes. As a result, after sintering of the green chip, generation of cracks and delamination is suppressed.

Therefore, according to the method of the present invention, by performing the binder removal processing in a humidified atmosphere, it is possible to significantly suppress the occurrence of structural defects such as delamination and cracks in electronic components such as a multilayer ceramic capacitor. .

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a sectional view of a multilayer ceramic capacitor manufactured by a method according to an embodiment of the present invention,
FIG. 2 is a diagram showing the relationship between the binder removal temperature and the carbon residual amount in the example of the present invention,
FIG. 3 is a diagram showing the relationship between the residual carbon content and the nickel oxidation rate in the example of the present invention.

As shown in FIG. 1, a multilayer ceramic capacitor 2 manufactured by a manufacturing method according to an embodiment of the present invention includes a first internal electrode layer 6 and a second internal electrode layer 8 via a dielectric layer 4. It has an element body 10 that is alternately multilayered. At both ends of the element body 10, a pair of a first external electrode 12 and a second external electrode, which are electrically connected to the first internal electrode layers 6 or the second internal electrode layers 8 alternately arranged inside the element body 10, respectively. 14 are formed to form a capacitor circuit.

積 層 In the multilayer ceramic capacitor 2 manufactured in the embodiment of the present invention, the internal electrode layers 6 and 8 are made of Ni or a Ni alloy. The Ni alloy is preferably an alloy of Ni containing 95% by mass or more of Ni and one or more metal elements of Cr, Co, Al, and the like.

諸 Various conditions such as the thickness of the internal electrode layers 6 and 8 may be appropriately determined according to the purpose and application, but usually the thickness is about 1 to 5 μm, particularly about 1 to 2 μm.

The dielectric layer 4 is composed of grains and a grain boundary phase. Moreover, what is called a core-shell structure may be used.

The material of the dielectric layer 4 is not particularly limited, but is preferably, for example, a dielectric composition containing a dielectric oxide having a composition represented by the following formula.
[(Ba _1-xy Ca _{x S r y} ) O] _m · (Ti _1-z Zr _z ) O ₂ + αMnO + βY ₂ O ₃ + γV ₂ O ₅ + δWO ₃
In this case, x is 0 to 0.25, preferably 0 to 0.10, y is 0 to 0.05, preferably 0 to 0.01, and z is 0.1 to 0.3, preferably 0.15. ~ 0.20, m is 1.00 to 1.020, preferably 1.002 to 1.015, α is 0.01 to 0.5% by mass, preferably 0.1 to 0.4% by mass, β Is 0.05 to 0.5% by mass, preferably 0.2 to 0.4% by mass, γ is 0.005 to 0.3% by mass, preferably 0.01 to 0.1% by mass, The content is preferably about 0.005 to 0.3% by mass, more preferably about 0.01 to 0.1% by mass.

(4) Although such a dielectric composition can be fired at a relatively low temperature in a non-oxidizing atmosphere, it has a high dielectric constant, and the accelerated life of insulation resistance in the obtained capacitor is improved.

諸 Various conditions such as the number and thickness of the dielectric layer 4 may be appropriately determined according to the purpose and application. Usually, the number of stacked dielectric layers 4 is about 1 to 600, especially about 10 to 500, and the thickness is about 1 to 50 μm, especially about 1 to 10 μm.

導電 In the manufacturing method of the present invention, the conductive material contained in the external electrodes 12 and 14 is not particularly limited, but usually Cu or Cu alloy, Ni or Ni alloy or the like is used. The thickness of the external electrodes 12 and 14 may be appropriately determined according to the use or the like, and may be appropriately determined according to the purpose or use, but is generally about 10 to 100 μm.

形状 The shape and size of the multilayer ceramic capacitor 2 thus obtained may be appropriately determined according to the purpose and application. For example, in the case of a rectangular parallelepiped, it is usually about 0.6 to 3.2 mm × 0.3 to 1.6 mm × 0.3 to 1.6 mm.

方法 The method for manufacturing the multilayer ceramic capacitor 2 according to one embodiment of the present invention will be described more specifically.

First, a slurry (paste) for the dielectric layer 4, a paste for the internal electrode layers 6 and 8, and a paste for the external electrodes 12 and 14 are manufactured, respectively.
The dielectric powder used when producing the slurry for the dielectric layer 4 is not only a powder of a so-called solid phase method obtained by mixing, calcining and pulverizing a dielectric material, but also an oxalate precipitation method or water. Powders obtained by a so-called liquid phase method such as a thermal synthesis method may be used. As the material powder, one having an average particle diameter of about 0.1 to 3 μm is usually used.

添加 Various additives such as a binder, a plasticizer, a dispersant, and a solvent may be used when preparing the slurry for the dielectric layer 4. Further, a glass frit may be added.

ア ク リ ル As the binder, for example, an acrylic resin, a butyral resin, ethyl cellulose, or the like is used. As the plasticizer, for example, polyethylene glycol, phthalic acid ester, dibutyl phthalate and the like are used. As the dispersing agent, for example, oleic acid, rosin, glycerin, octadecylamine, ethyl oleate, mensesden oil and the like are used. As the solvent, toluene, acetone, terbineol, butyl carbitol, methyl ethyl ketone, or the like is used.

When the slurry (paste) is prepared, the ratio of the dielectric material to the entire slurry is about 50 to 80% by mass, the binder is 2 to 5% by mass, the plasticizer is 0.1 to 5% by mass, and the dispersion is The appropriate amount of the agent is about 0.1 to 5% by mass and the amount of the solvent is about 20 to 50% by mass.

Next, the dielectric material is mixed with the above-mentioned materials, and mixed with, for example, a pole mill or a three-roll mill to obtain a dielectric layer slurry (paste).

(4) As an electrode forming material used when producing pastes for the internal electrode layers 6 and 8, it is preferable to use Ni, a Ni alloy, or a mixture thereof.

The shape of such an electrode forming material is not particularly limited, such as a sphere or a scale, and a mixture of these shapes may be used.
The average particle diameter of the electrode forming material is preferably 0.1 to 10 μm, and more preferably about 0.1 to 1 μm. The internal electrode layer paste is obtained by dispersing such an electrode forming material in an organic vehicle.

The organic vehicle contains a binder and a solvent. The binder is not particularly limited, but any known binder such as ethyl cellulose, acrylic resin, and butyral resin can be used. The binder content is suitably about 1 to 5% by mass based on the entire paste.

The solvent is not particularly limited, but any known solvent such as terbineol, glycyl carbitol, kerosene and the like can be used. The content of the solvent is suitably about 20 to 60% by mass based on the whole paste.

他 In addition, a dispersant such as sorbitan fatty acid ester and glycerin fatty acid ester and a plasticizer such as dioctyl phthalate and dibutyl phthalate can be added as needed in a range of about 10% by mass or less in total. For the purpose of preventing delamination or suppressing sintering, various ceramic powders such as dielectrics and insulators can be added to the electrode paste. It is also effective to add an organic metal resinate.

ペ ー ス ト As the paste for the external electrodes 12 and 14, a normal paste containing the above-described conductor material powder may be used.

The paste for the internal electrode layer and the slurry for the dielectric layer thus obtained are alternately laminated by a sheet method, a printing method, a transfer method, or the like, to obtain a laminate.
Next, this laminate is cut into a predetermined size to form a green chip, and then subjected to a binder removal treatment and a baking treatment. Thereafter, a heat treatment is performed to reoxidize the dielectric layer 4.

In the embodiment of the present invention, the atmosphere gas at the time of the binder removal processing contains at least H ₂ O. When H ₂ O is not contained in the atmosphere gas, the binder removal tends to be insufficient, and cracks and delamination tend to occur easily after sintering the green chips.

Further, the atmospheric gas at the time of binder removal, it is preferred containing H 2 _O at the same time as H _2. When H ₂ gas is not contained, the internal electrode layer containing Ni is oxidized and expanded, and cracks and delamination tend to occur easily after sintering.

The following conditions are preferred as the binder removal conditions.
Heating rate: 10 to 300 ° C / hour, especially 50 to 100 ° C / hour,
Holding temperature: 200-900 ° C, especially 250-600 ° C,
Retention time: 0.5-20 hours, especially 1-10 hours.

The atmosphere gas at the time of binder removal is preferably a gas containing H ₂ O and H _{2 using} nitrogen gas as a carrier gas at atmospheric pressure. The H ₂ O partial pressure is preferably from 2.8 × 10 ⁻⁴ MPa to 0.12 MPa, more preferably from 8.6 × 10 ⁻⁴ MPa to 1.2 × 10 ⁻² MPa, particularly preferably 1. ^{2 × 10 -3 MPa~1.2 × 10 -2} MPa, and most preferably ^{2.3 × 10 -3 MPa~7.3 × 10 -3} MPa.
The H ₂ partial pressure is preferably 2.0 × 10 ⁻⁵ MPa to 2.0 × 10 ⁻² MPa, more preferably 10 ⁻⁴ MPa to 10 ⁻² MPa, and particularly preferably 10 ⁻³ MPa to ^10-2, most ^preferably from ¹⁰ -3 MPa~7 × 10 -3 MPa.

By setting the H ₂ O partial pressure in the atmosphere of the binder removal section to the above range and the H ₂ partial pressure to the above range, structural defects such as delamination and cracks after sintering can be effectively suppressed. . When the concentration of water vapor in the atmosphere gas at the time of removing the binder becomes low, the decomposition of the binder becomes insufficient, and structural defects such as delamination and cracks tend to occur. Also, if the concentration of water vapor in the atmosphere gas at the time of binder removal is high and the concentration of hydrogen is too low, the oxidation of the internal electrode layer containing Ni proceeds, and structural defects such as delamination and cracks tend to occur. is there.

Next, the following conditions are preferable as firing conditions. Note that, since Ni or a Ni alloy is used for the internal electrode layer, baking is performed in a reducing atmosphere to prevent oxidation of the internal electrode layer.
Holding temperature: 1150-1400 ° C, especially 1200-1300 ° C, Holding time: 0.5-8 hours, especially 1-3 hours,
Oxygen partial pressure: 10 ^-8 to 10 ^-14 MPa, especially 10 ^-11 to 10 ^-13 MPa,
Cooling rate: 50-500 ° C / hour, especially 200-300 ° C / hour.

It is preferable to use a humidified mixed gas of N ₂ and H ₂ as the atmosphere gas at the time of firing. In the firing, the oxygen partial pressure in an atmosphere of 1100 ° C. or more is preferably 10 ⁻⁹ MPa or less. If the oxygen partial pressure of the atmosphere at 1100 ° C. or higher is higher than 10 ⁻⁹ MPa, the internal electrode layer is easily oxidized.

後 After firing in a reducing atmosphere, the laminate is preferably subjected to heat treatment. The heat treatment is a process for reoxidizing a dielectric partially reduced by the low-oxygen partial pressure firing of the temperature holding unit while suppressing the oxidation of the internal electrode layer, thereby increasing the insulation resistance and increasing the reliability ( (High temperature accelerated life) can be ensured.

The heat treatment is preferably performed under the following conditions.
Holding temperature: 1100C or less, especially 500-1100 ° C,
Retention time: 0 to 20 hours, especially 1 to 10 hours,
Oxygen partial pressure: 10 ⁻⁹ MPa or more, especially 10 ⁻⁸ MPa or more,
Cooling rate: 50-500 ° C / hour, especially 100-300 ° C / hour.

It is preferable to use a humidified mixed gas of N ₂ and H ₂ as the atmosphere gas during the heat treatment.

焼 成 The sintering is performed after the binder removal treatment, but these may be performed independently or continuously.

The firing and heat treatment steps may be performed independently or continuously. In the case where the process is performed continuously, the oxygen partial pressure of the atmosphere in a part of the temperature range of 1100 ° C. or less may be set to 10 ⁻⁹ MPa or more in the temperature lowering section in firing. At this time, a temperature holding unit for holding the temperature constant may be provided in the course of the temperature lowering process. Preferred holding temperature and holding time are as described above.

端 The thus obtained sintered body is subjected to end polishing by, for example, barrel polishing, sand blasting or the like, and the external electrodes 12 and 14 are formed by baking the external electrode paste. If necessary, Sn or a solder layer may be plated on the external electrodes 12 and 14.

Note that the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
For example, in the above embodiment, the multilayer ceramic capacitor is manufactured by the manufacturing method of the present invention. However, the manufacturing method of the present invention can be applied to not only capacitors but also other electronic components. Further, the binder removal method of the present invention is not limited to the case of manufacturing a ceramic electronic component, but can be applied to the binder removal treatment of other components.

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention. However, the present invention is not limited to these examples.
Example 1
The following oxides were prepared as starting materials.
BaCO ₃ : 65.28% by mass,
TiO ₂ : 23.72% by mass,
ZrO ₂ : 7.49% by mass,
CaCO ₃ : 2.88% by mass,
SiO ₂ : 0.05% by mass,
MnCO ₃ : 0.24% by mass,
Y ₂ O ₃ : 0.25% by mass,
V ₂ O ₅ : 0.04% by mass,
WO ₃ : 0.05% by mass.

The above starting materials were wet-mixed with a zirconia pole mill for 16 hours. Next, after drying with a spray drier, it was calcined in air at 1200 ° C. for 3 hours. The obtained calcined material was wet-pulverized with a pole mill for 16 hours to obtain a barium titanate-based dielectric material having an average particle diameter of 0.7 μm.

This dielectric material was blended with the following components and mixed in a ball mill for 16 hours to obtain a dielectric layer slurry.
Dielectric material: 100 parts by mass,
Acetone: 51.6 parts by mass,
Toluene: 14.31 parts by mass,
Ethyl acetate: 17.7 parts by mass,
Dispersant: 0.28 parts by mass,
Plasticizer: 0.13 parts by mass,
Acrylic resin: 5.7 parts by mass.

Next, the following components were mixed with a three-roll mill to obtain an internal electrode paste.
Ni: 44.6% by mass,
Terpineol: 52% by mass,
Ethyl cellulose: 3% by mass,
Benzotriazole: 0.4% by mass.

Using these pastes, the multilayer ceramic capacitor 2 shown in FIG. 1 was manufactured as follows.
First, a green sheet having a thickness of 7 μm was prepared from the dielectric slurry by a so-called doctor blade method. An internal electrode layer was formed on this green sheet by a printing method using an internal electrode paste. Two hundred such sheets were laminated, and thirty dielectric green sheets on which no internal electrodes were printed were laminated one above the other, and heated and pressed at 120 ° C. for 5 minutes at 1 ton / cm ² (about 98 MPa).

Next, after cutting to a predetermined size and performing binder removal treatment, firing and heat treatment were continuously performed under the following conditions.
(Binder removal processing)
Heating rate: 200 ° C / hour,
Holding temperature: 200 ° C,
Retention time: 2 hours,
Atmosphere: A mixed gas of humidified N ₂ gas and H ₂ (5%).

(Fired)
Heating rate: 300 ° C / hour up to 900 ° C, 200 ° C / hour above 900 ° C,
Holding temperature: 1270 ° C,
Retention time: 2 hours,
Cooling rate: 300 ° C / hour,
Atmosphere gas: a mixed gas of humidified N ₂ gas and H ₂ (5%),
Oxygen partial pressure: ^10-13 MPa.

(Heat treatment)
Holding temperature: 1100 ° C,
Retention time: 2 hours,
Cooling rate: 300 ° C / hour,
Atmosphere gas: Humidified N ₂ gas,
Oxygen partial pressure: 10 ^-7 MPa.

A wetter was used to humidify the atmosphere gas for the binder removal treatment, firing, and heat treatment. In the case of firing and heat treatment, the water temperature of the wetter was controlled at 35 ° C. Incidentally, was measured of _{H 2} O partial pressure and _{the H 2} partial pressure in the atmospheric gas at the time of binder removal, _{H 2} O partial pressure, there 5.5 × ¹⁰ -3 MPa, _{H 2} partial pressure is 5. It was 0 × 10 ⁻³ MPa.

端 After end faces of the various sintered bodies obtained as described above were polished by sandblasting, an InGa alloy was applied to form test electrodes.

The size of the multilayer ceramic capacitor manufactured in this way is 3.2 mm × 1.6 mm × 1.4 mm, the thickness of the dielectric layer 4 is 4 μm, and the thickness of the internal electrodes 6 and 8 is 1.3 μm. Was.

Next, the obtained various test capacitors (100 each) are embedded in an epoxy resin, cured, then ground and polished to observe the cross section, and the capacitor having a structural defect such as delamination or crack is generated. The number was checked.
The results obtained are shown in Table 1 below. As shown in Table 1, the structural defect occurrence rate was 8%, which was confirmed to be small. Note that the structural defect occurrence rate indicates the percentage of capacitors in which structural defects such as delamination or cracks have occurred in 100 test capacitors.

Example 2
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of removing the binder was set to 300 ° C., and the incidence of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 3%, which was confirmed to be small.

Example 3
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of removing the binder was set to 400 ° C., and the incidence of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 0%, which was confirmed to be small.

Example 4
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of removing the binder was set to 600 ° C., and the incidence of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 0%, which was confirmed to be small.

Example 5
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of removing the binder was 800 ° C., and the incidence of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 2%, which was confirmed to be small.

Example 6
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of removing the binder was set to 1000 ° C., and the incidence of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 8%, which was confirmed to be small.

Example 7
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of removing the binder was 1200 ° C., and the incidence of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 27%, which was confirmed to be higher than in Examples 1 to 6 but lower than in Comparative Examples.

Example 8
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of removing the binder was set to 100 ° C., and the incidence of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 29%, which was confirmed to be higher than in Examples 1 to 6 but lower than in Comparative Examples.

Example 9
The holding temperature at the time of binder removal was 300 ° C., the atmosphere gas at the time of binder removal was humidified N ₂ gas, the partial pressure of H ₂ O was 5.5 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 0 MPa. A test capacitor was manufactured in the same manner as in Example 1 except that the structural defect occurrence rate was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 12%, which was confirmed to be small.

Example 10
The holding temperature at the time of binder removal was 400 ° C., the atmosphere gas at the time of binder removal was humidified N ₂ gas, the partial pressure of H ₂ O was 5.5 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 0 MPa. A test capacitor was manufactured in the same manner as in Example 1 except that the structural defect occurrence rate was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 13%, which was confirmed to be small.

Example 11
The holding temperature at the time of binder removal was 600 ° C., the atmosphere gas at the time of binder removal was humidified N ₂ gas, the partial pressure of H ₂ O was 5.5 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 0 MPa. A test capacitor was manufactured in the same manner as in Example 1 except that the structural defect occurrence rate was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 15%, which was confirmed to be small.

Example 12
The holding temperature at the time of binder removal is 800 ° C., the atmosphere gas at the time of binder removal is humidified N ₂ gas, the partial pressure of H ₂ O is 5.5 × 10 ⁻³ MPa, and the partial pressure of H ₂ is 0 MPa. A test capacitor was manufactured in the same manner as in Example 1 except that the structural defect occurrence rate was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 16%, which was confirmed to be small.

Comparative Example 1
A test capacitor was manufactured in the same manner as in Example 1 except that the atmosphere gas at the time of binder removal was dry air, and the occurrence rate of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 83%, which was confirmed to increase as compared with the examples.

Comparative Example 2
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of binder removal was 250 ° C. and the atmosphere gas at the time of binder removal was dry air, and the structural defect occurrence rate was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 74%, which was confirmed to increase as compared with the examples.

Comparative Example 3
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of removing the binder was 300 ° C. and the atmosphere gas at the time of removing the binder was dry air, and the occurrence rate of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 100%, which was confirmed to be higher than that of the examples.

Comparative Example 4
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of binder removal was 400 ° C. and the atmosphere gas at the time of binder removal was dry air, and the occurrence rate of structural defects was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 100%, which was confirmed to be higher than that of the examples.

Comparative Example 5
A test capacitor was manufactured in the same manner as in Example 1 except that the holding temperature at the time of binder removal was 500 ° C. and the atmosphere gas at the time of binder removal was dry air, and the structural defect occurrence rate was examined. Table 1 shows the results. As shown in Table 1, the structural defect occurrence rate was 100%, which was confirmed to be higher than that of the examples.

Evaluation 1
Table 1 shows the following. First, when the binder is removed in the air, there is a tendency that structural defects such as delamination or cracks are reduced at a low temperature of 300 ° C. or less, but it cannot be completely suppressed, and the removal of the binder component is insufficient. Become. On the other hand, in humidified nitrogen, although the temperature at which the binder decreases is high, the incidence of structural defects such as delamination and cracks is considerably lower than in air. Furthermore, it clearly shows that the occurrence of structural defects such as delamination and cracks is drastically reduced in a humidified nitrogen / hydrogen mixed gas stream.
Further, by comparing Examples 1 to 6 with Examples 7 and 8, it was confirmed that the holding temperature at the time of binder removal is preferably 200 to 1000 ° C.

(2) Further, as shown in FIG. 2, in the production of the multilayer ceramic capacitor, in the binder removal step, the residual carbon decreases as the binder removal temperature increases. At this time, when the atmosphere of the binder removal is air, the residual carbon is drastically reduced even at a low temperature of about 250 ° C. However, as shown in FIG. 3, when the binder removal treatment is performed in the air, it is apparent that Ni of the internal electrode layer is also oxidized at the same time. In this case, delamination and cracks are likely to occur in the multilayer product.

On the other hand, when the atmosphere of the binder removal is a gas containing H ₂ O, as shown in FIG. 2, although the temperature at which the binder is decomposed increases, as shown in FIG. It is clear that it is more suppressed than in the case. Further, it can be seen that when the atmosphere of the binder removal is H ₂ O + H ₂ , it is possible to remove the binder while preventing the oxidation of Ni.

Example 13
Except that the holding temperature at the time of binder removal was set to 400 ° C., the partial pressure of H ₂ O at the time of binder removal was set to 5.2 × 10 ⁻⁴ MPa, and the partial pressure of H ₂ was set to 4 × 10 ⁻³ MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 11%.

Example 14
Except that the holding temperature at the time of binder removal was set to 400 ° C., the partial pressure of H ₂ O at the time of binder removal was set to 8.6 × 10 ⁻⁴ MPa, and the partial pressure of H ₂ was set to 4 × 10 ⁻³ MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 9%.

Example 15
Except that the holding temperature during binder removal was 400 ° C., the partial pressure of H ₂ O during binder removal was 1.2 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 4 × 10 ⁻³ MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 6%.

Example 16
Except that the holding temperature at the time of binder removal was 400 ° C., the partial pressure of H ₂ O at the time of binder removal was 2.3 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 4 × 10 ⁻³ MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 0%.

Example 17
Except that the holding temperature at the time of binder removal was set to 400 ° C., the partial pressure of H ₂ O at the time of binder removal was set to 7.3 × 10 ⁻³ MPa, and the partial pressure of H ₂ was set to 4 × 10 ⁻³ MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 0%.

Example 18
Except that the holding temperature at the time of binder removal was set to 400 ° C., the partial pressure of H ₂ O at the time of binder removal was set to 1.2 × 10 ⁻² MPa, and the partial pressure of H ₂ was set to 4 × 10 ⁻³ MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 3%.

Example 19
Except that the holding temperature at the time of binder removal was 400 ° C., the partial pressure of H ₂ O at the time of binder removal was 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 5.0 × 10 ⁻⁵ MPa, A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 12%.

Example 20
Example 1 Except that the holding temperature at the time of binder removal was 400 ° C., the partial pressure of H ₂ O at the time of binder removal was 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 1 × 10 ⁻⁴ MPa. In the same manner as in Example 1, a test capacitor was manufactured, and the incidence of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 7%.

Example 21
Example 1 Except that the holding temperature at the time of binder removal was 400 ° C., the partial pressure of H ₂ O at the time of binder removal was 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 1 × 10 ⁻³ MPa. In the same manner as in Example 1, a test capacitor was manufactured, and the incidence of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 0%.

Example 22
Example 1 Except that the holding temperature at the time of binder removal was 400 ° C., the partial pressure of H ₂ O at the time of binder removal was 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 7 × 10 ⁻³ MPa. In the same manner as in Example 1, a test capacitor was manufactured, and the incidence of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 0%.

Example 23
Example 1 Except that the holding temperature at the time of binder removal was 400 ° C., the partial pressure of H ₂ O at the time of binder removal was 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 1 × 10 ⁻² MPa. In the same manner as in Example 1, a test capacitor was manufactured, and the incidence of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 0%.

Example 24
Except that the holding temperature at the time of binder removal was 400 ° C., the partial pressure of H ₂ O at the time of binder removal was 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 2.0 × 10 ⁻² MPa, A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 5%.
Reference Example 1
Except that the holding temperature during binder removal was 400 ° C., the H ₂ O partial pressure during binder removal was 1.2 × 10 ⁻⁴ MPa, and the H ₂ partial pressure was 4.0 × 10 ⁻³ MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 21%.
Reference Example 2
Except that the holding temperature during binder removal was 400 ° C., the H ₂ O partial pressure during binder removal was 5.2 × 10 ⁻² MPa, and the H ₂ partial pressure was 4.0 × 10 ⁻³ MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 20%.
Reference Example 3
Except that the holding temperature at the time of binder removal was 400 ° C., the partial pressure of H ₂ O at the time of binder removal was 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 3.0 × 10 ⁻² MPa. A test capacitor was manufactured in the same manner as in Example 1, and the occurrence rate of structural defects was examined. Table 2 shows the results. As shown in Table 2, the structural defect occurrence rate was 28%.

Evaluation 2
As shown in Table 2, it was confirmed that when the H ₂ O partial pressure and the H ₂ partial pressure were in the following ranges, they were particularly effective in suppressing structural defects. That is, the H ₂ O partial pressure is preferably 2.8 × 10 ⁻⁴ MPa to 0.012 MPa, more preferably 8.6 × 10 ⁻⁴ MPa to 1.2 × 10 ⁻² MPa, and particularly preferably. ^{1.2 × 10 -3 MPa~1.2 × 10 -2} MPa, and most preferably ^{2.3 × 10 -3 MPa~7.3 × 10 -3} MPa. The H ₂ partial pressure is preferably 2.0 × 10 ⁻⁵ MPa to 2.0 × 10 ⁻² MPa, more preferably 10 ⁻⁴ MPa to 10 ⁻² MPa, and particularly preferably 10 ⁻³ MPa to ^10-2, most ^preferably from ¹⁰ -3 MPa~7 × 10 -3 MPa.

Example 25
The rate of temperature rise during binder removal was 250 ° C./hour, the holding temperature was 400 ° C., the partial pressure of H ₂ O during binder removal was 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ was 4 × 10 3 ^A test capacitor was manufactured in the same manner as in Example 1 except that the pressure was changed to ⁻³ MPa, and the occurrence rate of structural defects was examined. Table 3 shows the results. As shown in Table 3, the structural defect occurrence rate was 1%.

Example 26
The rate of temperature rise at the time of binder removal is 300 ° C./hour, the holding temperature at the time of binder removal is 400 ° C., the partial pressure of H ₂ O at the time of binder removal is 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ is A test capacitor was manufactured in the same manner as in Example 1 except that the pressure was changed to 4 × 10 ⁻³ MPa, and the incidence of structural defects was examined. Table 3 shows the results. As shown in Table 3, the structural defect occurrence rate was 4%.

Reference example 4
The rate of temperature rise at the time of binder removal is 350 ° C./hour, the holding temperature at the time of binder removal is 400 ° C., the partial pressure of H ₂ O at the time of binder removal is 1.7 × 10 ⁻³ MPa, and the partial pressure of H ₂ is A test capacitor was manufactured in the same manner as in Example 1 except that the pressure was changed to 4 × 10 ⁻³ MPa, and the incidence of structural defects was examined. Table 3 shows the results. As shown in Table 3, the structural defect occurrence rate was 18%.

Evaluation 3
By comparing Example 25, Example 26, and Reference Example 1, it was confirmed that when the temperature rise rate at the time of binder removal was 300 ° C./hour or less, the rate of occurrence of structural defects particularly decreased.

As described above, according to the method of the present invention, by performing the binder removal process in a humidified atmosphere, the occurrence of structural defects such as delamination and cracks in electronic components such as a multilayer ceramic capacitor is significantly increased. Can be suppressed. In particular, by performing the atmosphere at the time of binder removal in a humidified mixture of nitrogen and hydrogen, the occurrence of structural defects is significantly suppressed.

FIG. 1 is a sectional view of a multilayer ceramic capacitor manufactured by a method according to an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the binder removal temperature and the carbon residual amount in the example of the present invention. FIG. 3 is a diagram showing the relationship between the residual carbon content and the nickel oxidation rate in the example of the present invention.

Explanation of reference numerals

2 multilayer ceramic capacitor 4 dielectric layer 6 first internal electrode layer 8 second internal electrode layer 10 element body 12 first external electrode 14 second external electrode

Claims (12)

A method for manufacturing a ceramic electronic component having an electrode layer and a dielectric layer,
A step of removing the binder from the green chip to be a ceramic electronic component under an atmosphere gas containing H ₂ O;
Baking the binder-removed green chip,
The partial pressure of _{H 2} O atmospheric gas in the binder removal process, a manufacturing method of a ceramic electronic component, which is a ^{8.6 × 10 -4 MPa~1.2 × 10 -2} MPa. The method for manufacturing a ceramic electronic component according to claim 1, wherein the atmosphere gas in the binder removal processing further contains hydrogen. The method for manufacturing a ceramic electronic component according to claim 2, wherein a partial pressure of hydrogen in the atmosphere gas in the binder removal treatment is 2 x ^10-5 MPa to ² x 10-2 MPa. The partial pressure of hydrogen in the atmospheric gas in the binder removal ^process, a manufacturing method of a ceramic electronic component according to claim 2, characterized in that a ¹⁰ -4 MPa~10 -2 MPa. The method for manufacturing a ceramic electronic component according to claim 1, wherein the electrode layer includes one of nickel, copper, and tungsten, or an alloy thereof. The method for manufacturing a ceramic electronic component according to any one of claims 1 to 5, wherein a holding temperature during the binder removal processing is 250 to 600 ° C. The method for manufacturing a ceramic electronic component according to any one of claims 1 to 6, wherein a temperature rising rate during the binder removal processing is 300 ° C / hour or less. Debinding the green chip having the electrode forming material under an atmosphere gas containing H ₂ O;
The binder removal method, wherein the partial pressure of H ₂ O in the atmosphere gas in the binder removal treatment is 8.6 × 10 ⁻⁴ MPa to 1.2 × 10 ⁻² MPa. 9. The binder removal method according to claim 8, wherein the atmosphere gas in the binder removal treatment further contains hydrogen. The binder removal method according to claim 9, wherein a partial pressure of hydrogen in the atmosphere gas in the binder removal treatment is 2 × 10 ⁻⁵ MPa to ² × 10 ⁻² MPa. The binder removal method according to claim 9, wherein a partial pressure of hydrogen in the atmosphere gas in the binder removal treatment is 10 ⁻⁴ MPa to 10 ⁻² MPa. 12. The binder removing method according to claim 8, wherein the electrode forming material includes any one of nickel, copper, and tungsten, or an alloy thereof.

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