JPH10316468A - Dielectric ceramic composition, dielectric ceramic material and their production, and dielectric device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dielectric ceramic composition, capable of being sintered together with silver, high in dielectric constant and capable of being produced at a low cost and high productivity without forming gaps between the main ingredient and internal silver electrode by including a specified quantity of silver as the auxilary ingredient in a compound oxide of Pb, Ca, W or Ti, Fe and Nb as the main ingredient. SOLUTION: This dielectric ceramic composition comprises a compound oxide of Pb, Ca, R (R is W or Ti), Fe and Nb as the main ingredient, sown by the formula (Pbx Cay )Ox+y (Fet Nbu Rs )Oz [0.99<=(x+y)<=1.08; 0.34h(y)<=0.918; 0.375<=(t)<=0.6; 0<=(s)<=0.25; 0.2<= (u)<=0.5, (s+t+u)=1, and (z)=(3t+5u+4s)/2], incorporated with 0.005 to 1 wt.% (as Ag) of silver as the auxiliary ingredient, and sintered at 950 deg.C or lower. The composition is preferably incorporated with a sintering aid, in order to flower sintering temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric porcelain composition, and more particularly to a dielectric porcelain composition constituting a resonator used in a so-called microwave or millimeter-wave region having a frequency of several hundred M to several tens of GHz. TECHNICAL FIELD The present invention relates to a dielectric ceramic material and a method for manufacturing the same, and a dielectric element and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a microwave device used for a mobile communication device and the like has been developed due to an increase in demand for a mobile communication device such as a car phone, a mobile phone, and a satellite communication, and accompanying high functionality and high performance. There is an increasing demand for miniaturization and the like. Here, the microwave device refers to a dielectric element that is used in the microwave and millimeter wave regions and uses a dielectric ceramic material forming a resonator or the like.

In order to reduce the size of such a microwave device, it is effective to increase the dielectric constant. As a dielectric substrate for a microwave device, a dielectric ceramic having a perovskite structure containing lead, which has a high dielectric constant and can be fired at a relatively low temperature, is widely used. Further, as a conductor, silver having a small specific resistance is preferable among metals that can be fired in air. However, in order to co-fire with a conductor containing silver as a main component, it is necessary to sinter the dielectric at a temperature lower than 960 ° C., which is the melting point of silver. In addition, a conductor having a high melting point can be used as an alloy containing palladium in silver, but the specific resistance increases and the cost increases.

When a dielectric and a silver conductor which can be fired at a temperature lower than 960 ° C. are integrally fired, depending on the conditions of the firing temperature and the firing time for obtaining the dielectric constant required for the dielectric, the end of the silver conductor may be required. There may be a gap between the portion and the dielectric. When such a gap occurs in the dielectric element, for example, in a chip capacitor, the capacitance of the capacitor changes, which may result in a failure. Further, when a gap is formed in a resonator, a filter, or the like used in a high-frequency band, the effective permittivity of a dielectric material, that is, a high-frequency medium is reduced, which may result in a failure. Furthermore, these dielectric elements are mounted on a substrate by surface mounting technology, but when mounting the substrate, it is necessary to have a good solder wettability and a lead electrode with little solder erosion. To prevent solder erosion, Ni plating is applied, and to improve solder wettability, plating of Sn, Pb or the like is applied. Therefore, when the gap exists,
In a plating process such as Ni plating, Sn, Pb, etc., a plating solution may enter the device, resulting in a product failure due to popping or corrosion or a deterioration in device performance.

Further, when the silver conductor and the dielectric are integrated by firing, delamination (peeling) or cracks may occur in the dielectric element. Delamination and cracks are considered to be essentially problems of the difference in the contraction rate and the thermal expansion coefficient between the dielectric and the conductor in the firing step and the strength of the material. As a method to solve this, it is known as a general method to add a sintering inhibitor to the conductor in advance, control the sintering behavior of the conductor, and take sintering matching between the conductor and the dielectric. It is effective depending on the composition of the dielectric. However, it is difficult to prevent the above gap even by the composition of the dielectric and the conductor.

On the other hand, JP-A-6-283024 discloses that (Pb ₁ -x Ca _x ) _{1 + y} ｛(Fe _1/2 Nb _1/2 ).
_1-2 (Fe _2/3 W _1/3 ) _Z ｝ O _{3 + y} , x,
A dielectric porcelain composition in which z and y are in the range of 0.43 <x ≦ 0.63, 0.0 <z ≦ 0.5, 0.0 ≦ y ≦ 0.20 is disclosed. However, although this has a high dielectric constant of 90 or more,
The sintering temperature is as high as about 1000 to 1200 ° C., and simultaneous sintering with silver is impossible. Therefore, it can be fired in air,
A device having a structure in which a low-loss silver conductor is embedded in a dielectric cannot be produced.

[0007] JP-A-7-147111 discloses that P
b, Ca, W, Fe and Nb contained in the form of oxides, when expressed as _{(Pb 1-Z Ca Z)} (W s Fe t Nb u) O 3, s + t + u = 1, 0.3 ≦ z ≦ 0.9, 0.01 ≦ s ≦ 0.2, 0.5 ≦ t ≦ 0.6, and 0.2 ≦ u ≦ 0.49. Have been described. This dielectric ceramic material has a high dielectric constant of 90 or more, and has a sintering temperature equal to or lower than the melting point of silver. But,
Under the conditions of firing temperature and time to obtain sufficient dielectric constant,
There is a problem that a gap is generated between the conductor and the dielectric. In recent years, the demand for miniaturization of microwave band communication equipment has tended to increase further, and it is necessary to improve the dielectric constant of microwave devices in order to meet the demand for further miniaturization.

Japanese Patent Application Laid-Open No. Hei 4-313208 discloses that a dielectric mainly composed of a lead-containing perovskite compound and an internal electrode mainly composed of silver are simultaneously fired in an atmosphere containing silver to obtain an edge. A method for improving the gap between the parts is described. However, this publication does not describe the reason why the gap at the end is improved. Further, in the examples, it is described that a silver co-material was used together with the green chips at the time of firing, and the weight of this co-material was reduced by 5% after firing. Silver is inexpensive among noble metals that do not oxidize even when exposed to high temperatures in the atmosphere, but the unit price is basically high, and such a method of use is problematic in terms of cost and is not practical. In the case of firing the lead-containing perovskite compound, a closed atmosphere is required. However, due to the presence of the silver co-material, the space is reduced and the production efficiency is reduced.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to enable simultaneous sintering with silver, a high dielectric constant, no gap between the internal silver electrode after firing, and low cost. Accordingly, it is an object of the present invention to provide a dielectric ceramic composition, a dielectric ceramic material and a method for producing the same, and a dielectric element and a method for producing the same, which have high production efficiency.

[0010]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that firing can be performed at 950 ° C. or less, and that when silver conductors are simultaneously fired, Even in the case of a dielectric porcelain composition having a gap, a means for substantially eliminating the gap has been found, and the present invention has been accomplished. That is, the present inventor has found that the cause of the gap at the end of the silver conductor is that silver forming the conductor diffuses into the dielectric ceramic material in the state of atoms, colloids, or ions.

In some dielectric ceramic materials, silver easily diffuses, for example, glass (glass ceramic) having a low softening point, oxides such as lead and tungsten, and the like correspond to this. The diffusion of silver into low softening glass is well known as the problem of colloid formation in glass. When the oxide of tungsten is heated in the presence of oxygen,
It has long been known to produce silver tungstate (AgWO ₄ ) having a melting point of about 605 ° C. with metallic silver. Also, JM ater.Res., Vol. 10, No. 11 (1995) p29
33 shows that lead oxide has a eutectic point with metallic silver,
It has been reported that a liquid phase composed of lead oxide and metallic silver exists at a temperature of 5 ° C. or higher. If the oxide that shows such a reaction and the mass of metallic silver are in contact (adhesion) and placed at high temperature, silver will form as particles or ions from the interface between metallic silver and the oxide. The silver diffuses in and the parent silver decreases, causing the so-called silver thinning phenomenon. And
It has been found that such a phenomenon also causes a gap at the end of the silver conductor.

Therefore, by adding silver in the dielectric porcelain composition in advance and making it difficult for silver to diffuse from the silver conductor, it is possible to prevent a phenomenon that a gap is formed at an end.

Further, as described above, since lead oxide and tungsten oxide form a liquid phase with silver, when silver is added to a dielectric ceramic composition comprising a lead-based oxide, it is fired at a lower temperature. It becomes possible. By sintering at a low temperature, a denser sintered body can be easily formed, and the dielectric constant can be improved.

That is, the above object is achieved by the following constitutions. (1) The main components are Pb, Ca, R, (R = W or T
i), a composite oxide of Fe and Nb, when the composite oxide is a composition, expressed _{(Pb X Ca y) O x} + y (Fe t Nb u R s) O z in,, x , Y, s, t and u are 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 ≦ s ≦ 0.25, 0. 2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, where silver is 0.005 to 1 wt.
% And a sintering temperature of 950 ° C. or lower. (2) The composite oxide has R = Ti and has a composition of 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.5, 0 <S ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, wherein (1). (3) The composite oxide has R = W and has a composition of 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 <S ≦ 0.2, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2,2. The dielectric ceramic composition of the above (1). (4) The dielectric ceramic composition according to any one of (1) to (3), further comprising a sintering aid and / or a manganese oxide. (5) As the sintering aid, lead germanate is 0.1 to 0.1%.
The dielectric ceramic composition of (4), wherein 10 wt% is added. (6) The dielectric ceramic composition according to (5), wherein the lead germanate contains Pb ₅ Ge ₃ O ₁₁ . (7) The dielectric ceramic composition according to any one of the above (4) to (6), containing manganese oxide in an amount of 0.5 wt% or less in terms of Mn. (8) 95 parts of the dielectric ceramic composition of (1) to (7)
Dielectric porcelain material fired at 0 ° C or less. (9) The dielectric porcelain material according to (8), wherein a gap with the silver-containing internal conductor is less than 3 μm. (10) Production of a dielectric ceramic material in which a solution containing silver as an auxiliary component is added to a dielectric magnetic composition having a lead and / or tungsten-containing oxide as a main component and sintered at a temperature of 950 ° C. or lower. Method. (11) A predetermined amount of an oxide of Pb and Ti or Fe or W or a compound which becomes an oxide by sintering is mixed and calcined to obtain a first calcined product, and Pb, Ca, Fe and Nb are mixed. A predetermined amount of an oxide or a compound that becomes an oxide by sintering is mixed and calcined to obtain a second calcined product, and the first calcined material and the second calcined material have the final composition of (Pb _x Cay _{) ) O x + y (Fe t} Nb u R s) O z,
(R = W or Ti), where x, y, s, t and u are 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 ≦ s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, mixed and pulverized, calcined, and A method for producing a dielectric ceramic material according to the above (10), in which a calcined product is obtained, and a solution containing silver as an auxiliary component is added thereto and further mixed to obtain a dielectric ceramic composition, which is molded and sintered. . (12) An oxide of Pb, Ca, Fe, and Nb or a compound that becomes an oxide by sintering is mixed in a predetermined amount, and calcined to obtain a second calcined product. The second calcined material, Pb, Ti,
Or a compound with an oxide or sintering of Fe and W become oxides by mixing a predetermined amount, its final _{composition, (Pb X Ca y) O} x + y (Fe t Nb u R s) O z,
(R = W or Ti), where x, y, s, t and u are 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 ≦ s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, mixed and pulverized, calcined, and calcined. (3) A calcined product is obtained, and a solution containing silver as a sub-component is added thereto and further mixed to obtain a dielectric ceramic composition, which is molded and sintered to obtain the dielectric ceramic material of the above (10). Production method. (13) The above-mentioned (11) or (12), wherein a sintering aid and / or manganese oxide or a compound that becomes manganese oxide by firing is added to the third calcined product as other subcomponents to obtain a dielectric ceramic material. A method for producing a dielectric ceramic material. (14) The dielectric ceramic material according to any one of (10) to (13), wherein the silver-containing solution is added so that a silver salt or a silver compound is contained in an amount of 0.005 to 1 wt% in terms of Ag. Production method. (15) The method for producing a dielectric ceramic material according to (14), wherein the solution of the silver compound is a silver nitrate solution. (16) A dielectric element in which a silver conductor pattern is incorporated in the dielectric dielectric ceramic material of (8) or (9). (17) A method for producing a dielectric element according to the above (16), wherein the dielectric ceramic composition according to any one of the above (1) to (7) and silver are simultaneously fired to obtain the dielectric element according to the above (16).

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a specific configuration of the present invention will be described in detail. In the method for producing a dielectric ceramic material of the present invention, a solution containing silver as an auxiliary component is added to a dielectric magnetic composition having a lead and / or tungsten-containing oxide as a main component, and the temperature is 950 ° C. or lower. It is to be sintered.

Silver as a secondary component to be added is silver nitrate,
Inorganic silver salts such as silver acetate and silver carbonate, and organic silver compounds in which a ligand composed of an organic substance such as alkoxide, acetate, acetylacetonate and citric acid is coordinated with silver, etc. According to the method, these salts and compounds are added in the form of a solution. By adding it as a solution, it can be dispersed efficiently and evenly, and even a small amount can effectively suppress the gap generated with the internal conductor.
The solvent depends on the type of acid or base, but in addition to water, 2
Water-soluble solvents such as methoxyethanol, acetone and the like are possible. Among these, it is particularly preferable to use an aqueous silver nitrate solution. The amount of the aqueous solution may be such that the calcined powder is in a slurry state or more, and the solution concentration may be such that the dielectric ceramic composition after the addition falls within the above composition range. In addition, in the addition of the silver component in a particle state,
The above effects are not realized.

Silver as a sub-component is preferably 0.1 to 0.3 in terms of Ag.
005-1 wt% is added. 0.005wt% silver content
If less than the above, the effect of the present invention cannot be obtained, and if it exceeds 1 wt%, the insulation property deteriorates and the Q value decreases. The existence of silver is
It can be analyzed by X-ray fluorescence analysis (XRF), energy dispersive X-ray analysis (EDX), transmission electron microscope (TEM), or the like.

The dielectric porcelain material obtained by the method of the present invention preferably has a gap formed with the silver-containing internal conductor after firing of less than 3 μm, preferably 2 μm or less, particularly 1 μm or less, further preferably 0.5 μm or less. μm or less. By including silver in the dielectric magnetic composition, the silver thinning phenomenon during firing is prevented, and a gap is prevented from being formed between the dielectric magnetic composition and the silver-containing internal conductor. If the gap between the dielectric and the internal conductor is less than 3 μm, it is possible to prevent the occurrence of popping, corrosion, delamination, cracks, and the like due to the entry of the electrolytic solution.

The dielectric ceramic composition to which silver is added is not particularly limited as long as it is a dielectric ceramic composition having a lead and / or tungsten-containing oxide (lead-based oxide) as a main component as described above. It is possible to obtain the effects of the present invention, but the main composition is preferably Pb, Ca, W
Or Ti, a compound oxide of Fe and Nb, a composite oxide is a _{composition, (Pb X Ca y) O} x + y (Fe t Nb u R s) O z,
(R = W or Ti), where x, y, s, t and u are 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 ≦ s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, More preferably, the composite oxide is
R = Ti, and the composition is 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.5, 0 <s ≦ 0.25, 0 2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, or the composite oxide is R = W and the composition is 0.99 ≦ x + y ≦ 1.08 , 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 <s ≦ 0.2, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2 , And is a composite perovskite compound containing lead. In addition to the above-mentioned lead-containing oxide (lead-based oxide), in a dielectric porcelain composition or the like that can be co-fired with silver, depending on the conditions, by adding silver, the same as in the present invention can be obtained. It is conceivable that such effects can be achieved. Therefore, in that case, silver may be added according to the present invention.

Here, the substitution amount of Ca to Pb is preferably set to be in the range of 0.3 ≦ y <0.918, where y is the mole fraction. If the amount of Ca exceeds the above range, the low-temperature sinterability tends to be impaired, while if it is less than that, the electrical properties deteriorate.

When the above y is in the range of 0.3 ≦ y ≦ 0.8, especially 0.4 ≦ y ≦ 0.75, better low-temperature sinterability and higher dielectric constant can be obtained. .

When the molar fraction of O with respect to (Pb _x Ca _y ) is x + y, 0.99 ≦ x + y <1.08
It is.

If x + y is lower than 0.99, sintering becomes difficult, which is not preferable. On the other hand, if x + y is 1.08 or more, sintering becomes difficult. Further, the mole fractions of Fe, Nb, and R (R = Ti or W) are t, u, and s, respectively, and s + t + u = 1. At this time, it is preferable that 0.375 ≦ t ≦ 0.50 0.20 ≦ u ≦ 0.50 0 ≦ s ≦ 0.25, and more preferably, when R = Ti, 0.375 ≦ t ≦ It is preferable that 0.60 0.20 ≦ u ≦ 0.50 0 <s ≦ 0.25, and in particular, when R = W, 0.375 ≦ t ≦ 0.60 0.20 ≦ u ≦ 0 When the sintering aid is added, the perovskite-type crystal phase is formed as a main crystal phase even when sintering is performed at 950 ° C. or less, and when the sintering aid is added, the sintering aid has a high dielectric constant of 85 or more. It is preferable because an excellent dielectric element having no gap at the end can be obtained.

The reason for such a molar fraction is as follows. First, as for s, if it exceeds 0.25, the electrical characteristics deteriorate. If u is less than 0.2, the electrical properties tend to deteriorate, and if it exceeds 0.49, the low-temperature sinterability is impaired. The dielectric constant ε becomes 80 or more by being within the above composition range. And in a preferable aspect, 90-115, especially 1
Values of 00 to 110 are obtained.

_{Further, (Fe t Nb u R s} ) the mole fraction z of O to the amount representing the charge balance (3t + 5U + 4
s) / 2.

The larger the value of ε, the better. This is because, for example, in a resonator, the size is inversely proportional to the square root of ε of the dielectric material, and therefore, when miniaturization is attempted, ε must necessarily be increased. It is important to be big. The dielectric constant ε is preferably 70 or more, particularly preferably 80 or more, and more preferably 90 or more.

[0027] Such _{(Pb X Ca y) O x} + y (Fe
_{t Nb u R s) O z} : (R = W or Ti) is the presence of X
It can be confirmed from a line diffraction spectrum (XRD). Usually, the average grain size is 0.5-15 μm, especially 1-10 μm
m.

It is preferable to add a sintering aid as another auxiliary component to the dielectric ceramic material so as to lower the sintering temperature. As sintering aids, lead germanate, lead oxide,
Preferable examples include a solid solution of lead oxide and silver, silver tungstate or lead tungstate.
There is no particular limitation on the crystal structure at the time of addition as long as the liquid phase becomes liquid at a temperature of 0 ° C. or lower. The addition amount is preferably from 0.1 to 10% by weight, more preferably from 0.5 to 10% by weight based on the above main composition.
４4 wt%. If the added amount of the sintering aid is too large, the electrical properties are adversely affected.

Further, Mn may be contained in the dielectric ceramic material as another auxiliary component in the form of an oxide, usually MnO. The addition amount of Mn is preferably 0.5 wt% or less, more preferably 0.04
It is in the range of 5 to 0.3% by weight. The addition of the Mn oxide improves the insulation resistance. After sintering, the Mn oxide is usually present in the composite perovskite compound.

Next, a method for manufacturing a dielectric ceramic material will be described in detail.

As a starting material, an oxide of a metal element constituting the dielectric ceramic composition, for example, lead oxide, calcium oxide, tungsten oxide, iron oxide, niobium oxide, titanium oxide or the like may be used. Further, various compounds that can be converted into oxides by sintering, for example, carbonates such as calcium carbonate, oxalates, and the like may be used. The mixing ratio of the starting materials is selected so that the ratio of each metal element is the same as the final composition.
The average particle size of the starting materials is about 0.5 to 10 μm. Alternatively, some components may be added as solutions such as sulfates and nitrates.

The mixing of the powders of the starting materials is preferably performed in a wet manner using a ball mill or the like. After mixing, calcination is performed. In this mixing and calcination, when R = W, iron / lead tungstate Pb (Fe
_2/3 W _1/3) O ₃ (hereinafter, referred to as PFW), ferric niobate is a calcined product part of Pb is substituted by _{Ca (Pb x Ca y) O} x + y (Fe _1/2 Nb _1/2 ) O
₃ (hereinafter referred to as PCFN) separately. This mixing of the raw material, when subjected to calcination at a time, CaWO ₄ ends up easily generated, an object (Pb _X Ca _y) O
_{x + y (Fe t Nb u} R s) O z is can not be synthesized. When R = Ti, the first calcined product and the second
It is not necessary to go through a calcined product, but in the case of manufacturing according to the above-mentioned production method, lead titanate PbTiO ₃ (hereinafter, referred to as PT) may be used as the first calcined product.

Therefore, in the case of PFW or PT which is the first calcined product, PbO, Fe
₂ O ₃ , WO ₃ , and TiO ₂ were used. On the other hand, in the case of PCFN as the second calcined product, PbO, Fe ₂ O ₃ , Nb
₂ O ₅ and CaCO ₃ are used separately. Here, the partial substitution amount of P (Pb) by C (Ca) in PCFN is such that y is in the range of 0.3 ≦ x ≦ 0.918, where y is the mole fraction. Set.

[0034] If the amount of partial substitution of Ca exceeds the above range, the low-temperature sinterability is impaired, while if it is less than that, the electrical characteristics deteriorate.

When y is particularly in the range of 0.4 ≦ y ≦ 0.7, better low-temperature sinterability is exhibited and the dielectric constant can be increased.

The calcination is preferably carried out at a temperature of about 800 to 1000 ° C. for PFW or PT, and at a temperature of about 1000 to 1200 ° C. for PCFN for about 1 to 4 hours. After calcination, each is preferably wet-pulverized by a ball mill or the like. The average particle size after pulverization is about 0.7 to 3.0 μm.

Further, PFW, PT, and PCFN are:
As disclosed in US Patent No. 3 330,697 july (1967) and the Japan Glass Material Engineering Subcommittee Achievement Report vol.14 p35 ('96), the metal complex of citric acid and the hydroxyl group in organic compounds A method of calcining the precursor by esterification,
Similarly, it can be obtained by calcining a precursor by an amide bond between a carboxyl group and an amino group.
The starting materials of the metal _{source, Pb (CH 3 COO) 2} -3H 2 O Ca (CH 3 COO) 2 -H 2 O W (OEt) 6 Fe (acac) 3 Nb (OEt) 5 and the like.

Next, the first calcined product PFW or PT
And a main component comprising PCFN, which is a second calcined product, and a subcomponent. The mixing ratio in this case, the main _{composition, (Pb X Ca y) O} x + y (Fe t Nb u R s) O z,
(R = W or Ti), where x, y, s, t and u are 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 ≦ s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, and weigh and calcine. The calcination is usually performed in the atmosphere at 600 to 1100 ° C, particularly 700 to 1000 ° C,
Further, it is preferable to perform the treatment at a temperature of about 900 to 1000 ° C. for about 1 to 4 hours. After calcination, it is pulverized by a ball mill or the like. The average particle size after pulverization is about 0.7 to 1.5 μm. In this manner, the powder composition (Pb _X Ca _y)
The third calcined product represented by _{O x + y (Fe t Nb} u R s) O z obtained (abbreviated as hereinafter PCFNR). And, the sub-component is as follows: 0.005 to 1 wt.
% To obtain the dielectric ceramic composition of the present invention. Note that silver as a subcomponent is the third component as described above.
It is preferable to mix after sintering the calcined product, but it is also possible to mix before that.

Next, it is preferable to mix a sintering aid as necessary as another auxiliary component. As the sintering aid, for example, PbO and GeO ₂ are preferably mixed so that the final composition is preferably Pb ₅ Ge ₃ O ₁₁ ,
After wet mixing for about 4 hours, the dried product is calcined at about 500 ° C., and the obtained calcined product of Pb ₅ Ge ₃ O ₁₁ is wet-pulverized preferably using a ball mill or the like to obtain a sintering aid having a predetermined particle size. Get the agent. In addition, PbO or a solid solution of Ag in PbO is a preferred sintering aid. The sintering aid such as Pb ₅ Ge ₃ O ₁₁ , PbO, and PbO + Ag is usually mixed with the calcined powder before molding.

When Mn is contained in the form of an oxide as another subcomponent, a Mn compound is added. Examples of the Mn compound include oxides such as MnO and MnO ₂ ,
Compounds that become oxides by sintering, such as carbonates and oxalates, can be used. The composite oxides with other components, for example (Pb Ca) (Mn Nb) O 3,
(Pb Ca) (Mn _1/3 Nb _2/3 ) O ₃ or the like can be used. These are obtained by adding Mn to the first calcined product and the second calcined product, and either of them may be used. In these cases, the average particle size is about 0.1 to 1.0 μm. In addition, a solution of a sulfate or a nitrate can be added, and the amount of the Mn compound to be added is the PCFN in terms of Mn.
Is _{R (Pb X Ca y) O} x + y (Fe t Nb u R s)
The total content of O _z and PGO, i.e., Pb, Ca, W, or Ti, 0.5 wt% of total of the total amount and the sintering aid of the oxides of Fe and Nb less, particularly 0.05~0.3wt %. The addition time of the Mn compound may be the same as that of the sintering aid, or may be added several times.

When the high-frequency dielectric ceramic material of the present invention is applied to a resonator as a dielectric element,
A vehicle containing an organic binder and an organic solvent is added to form a paste, laminated by a printing method, a sheet method, or the like, and a strip line is formed between the dielectric layers and is sintered simultaneously.
Sintering is usually performed at a temperature of 950 ° C. or less, particularly 945 ° C. or less, further 940 ° C. or less, generally 910 ° C. or more, particularly 920 ° C. or more, and further 930 ° C. or more in the atmosphere, and the holding time is 1 to 6, especially It is preferably performed for about 1 to 3 hours.
The heating time and the cooling time are arbitrary. As the conductive material used for the internal electrode layer, silver, which is a low-resistance conductive material, is preferably Ag 95% or more, and more preferably 98% or more.

Next, another method for obtaining the third calcined product PCFNR will be described.

As a starting material, an oxide of a metal element constituting the dielectric ceramic composition may be used as described above.

First, a second calcined product (PCFN) is synthesized. The mixing of the starting material powder is preferably performed in a wet manner using a ball mill or the like. After mixing, calcination is performed. The (powder) of the obtained second calcined product PCFN is pulverized if necessary, and this PCFN calcined product or calcined powder is combined with Pb, Fe and W when R = W, or with R = Ti. Is mixed with an oxide of Pb, Fe and Ti, or a compound which becomes an oxide by firing, calcined and pulverized to obtain a third calcined product PCFNR. Thereby, the third calcined product can be obtained by a simpler method than the above method.

More specifically, PbO, Fe ₂ O ₃ , WO ₃ and TiO ₂ are used as starting materials,
On the other hand, in the case of PCFN, which is the second calcined product, PbO,
Fe ₂ O ₃ , Nb ₂ O ₅ , and CaCO ₃ are used separately. Here, the partial substitution amount of P (Pb) by C (Ca) in PCFN is such that y is in the range of 0.3 ≦ x ≦ 0.918, where y is the mole fraction. Set.

The above y is particularly preferably in the range of 0.4 ≦ y ≦ 0.7.

The calcination is preferably performed at a temperature of about 1000 to 1200 ° C. for about 1 to 4 hours. After calcination,
Although it is possible to use it as it is, preferably, it is wet pulverized by a ball mill or the like. The average particle size after grinding is 0.7
About 3.0 μm.

Next, lead oxide, iron oxide, tungsten oxide, titanium oxide, or a compound capable of forming these oxides, and PCFN as the second calcined product are prepared. The mixing ratio in this case, the final _{composition, (Pb X Ca y) O} x + y (Fe t Nb u R s) O z,
(R = W or Ti), where x, y, s, t and u are 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 ≦ s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, weighed, mixed and calcined. The calcination is usually performed at 600 to 1100 ° C. in the atmosphere, particularly 700 to 1
At a temperature of 100 ° C., and even 900-1100 ° C.,
It is preferable to carry out for about 1 to 4 hours. After calcination, it can be used as it is, but preferably it is pulverized by a ball mill or the like. Average particle size after pulverization is 0.7 ~ 1.5μm
Degree. The powder composition thus obtained is (P
obtaining a third calcined product represented by _{b X Ca y) O x +} y (Fe t Nb u R s) O z.

The dielectric element of the present invention can be used not only for a resonator, but also for a band-pass filter, a diplexer, etc. Further, a dielectric layer and an internal electrode layer are alternately laminated, and after sintering, an external electrode is provided. It is also applicable to chip capacitors and the like.

[0050]

EXAMPLES Hereinafter, the present invention will be described in more detail by showing specific examples of the present invention.

<Synthesis Example 1> (No R) PbO, CaCO ₃ , Fe ₂ O ₃ , Nb as starting materials
₂ O ₅ , these were added to a final composition of (Pb _x Ca
_y) when expressed in _{O x + y (Fe t Nb} u R s) O z,
x, y, s, t, and u were weighed and mixed so as to have the composition shown in Table 1, and were wet-mixed by a ball mill for 16 hours. After drying, it was calcined at 850 to 1050 ° C. for 3 hours. This _{calcination, (Pb X Ca y) O} x + y (Fe t Nb u R s)
A third calcined product having O _z (where s = 0: hereinafter may be referred to as PCFN) as a main phase was obtained.

<Synthesis Example 2> (R = Ti) PbO, CaCO ₃ , Fe ₂ O ₃ , N
b ₂ O ₅ , and the final composition thereof is (Pb _X C
When expressed in _{a y) O x + y (} Fe t Nb u R s) O z,
x, y, s, t, and u are weighed and blended so as to have the composition shown in Table 2, mixed, and mixed at about 1000 to 1200 ° C. to 1 to 4
Calcination was performed for a period of time to obtain a second calcined product that was PCFN. This second calcined product was pulverized, PbO, Fe ₂ O ₃ , and TiO ₂ were weighed in predetermined amounts and mixed therewith, and wet-mixed using a ball mill for 16 hours. After drying. Calcination was performed at 850 to 1100 ° C. for 3 hours. This calcination, (Pb _X Ca _y) O
_{x + y (Fe t Nb u} R s) O z, ( although, s = Ti:
Hereinafter, PCFNT) may be obtained.

<Synthesis Example 3> (R = W) PbO, Fe ₂ O ₃ , and WO ₃ were weighed in predetermined amounts as starting materials, mixed and calcined at about 850 ° C. for 2 hours to obtain a first calcined product. Was obtained. On the other hand, PbO, CaCO
₃ , predetermined amounts of Fe ₂ O ₃ and Nb ₂ O ₅ were weighed, mixed, and calcined at about 1150 ° C. for 2 hours to obtain a second calcined product of PCFN, each of which was wet-pulverized by a ball mill.

[0054] These final composition, (Pb _X Ca _{y)
O x + y (Fe t Nb} u R s) when expressed in O _z, x,
y, s, t, u are weighed and blended so as to have the composition shown in Table 3,
The mixture was mixed and calcined at 600 to 1000 ° C. for 2 hours. This _{calcination, (Pb X Ca y) O} x + y (Fe t Nb u R
_s) O _z (hereinafter, may be referred to as PCFNW) to obtain a third calcined product as a main phase.

<Example 1> Each of the third calcined materials (PCFN, PCFNTi, PCFN) obtained in each of Synthesis Examples 1 to 3 described above.
W) to which the amounts of silver shown in Tables 1 to 3 were added, were wet-pulverized with a ball mill, and the average particle size was 0.9 μm.
(Measured by a laser diffraction type particle size distribution meter).

Further, Pb ₅ Ge ₃ O _{11 is} used as a sintering aid.
Is dried by mixing a predetermined amount of lead oxide (PbO) and germanium dioxide (GeO ₂ ) for 14 hours in a wet manner,
This dried product was obtained by reacting at 500 ° C. (hereinafter, may be referred to as PGO). This was wet-pulverized by a ball mill. At this time, the average particle size was 0.9 μm.

Next, the chemical composition of this PGO was changed to Pb ₅ G
When expressed as e ₃ O _11, it was added to the above third calcined product (PCFN, PCFNTi, PCFNW) powder so as to have the composition shown in Tables 1 to 3, wet-mixed with a ball mill, and dried to obtain a final mixture. Was. If necessary, lead tungstate (PWO), lead oxide (PbO), and an average particle diameter of 0.9
μm MnO was added as shown in Tables 1 to 3 in terms of Mn.

Next, polyvinyl alcohol as an organic binder was added to the above mixture, and the mixture was granulated and molded at a pressure of 100 MPa to obtain a cylindrical molded body having a diameter of 12.5 mm and a thickness of 10 mm.

The obtained compact was placed on a zirconia setter on which powder of the same component was spread, and after removing the binder agent in the air, it was sintered at the temperature shown in Table 1 in the air. At the time of sintering, the calcined powder as a compact and a co-material was sealed in a sagger to prevent evaporation of Pb from the compact. The obtained sintered body was processed into a diameter of 10 mm and a thickness of 5 mm.
Dielectric sample Nos. 1-4, 11-1 of the embodiment shown in FIG.
5, 21-29 were obtained.

Of the above samples, sample No. 21
When the phase configuration was examined by X-ray diffraction, it was found that Sample No. 21 was substantially composed of a single PCWFN phase.

As comparative examples, Tables 1 to 3 were made equivalent.
As shown in Table 2, dielectric samples Nos. 5, 6, 16, 17, 30 to 33 were prepared with compositions outside the composition range of the present invention.

For these dielectric samples, the dielectric constant ε was measured. The results are shown in Tables 1 to 3.

Further, each of the samples as the final composition was used, and an organic solvent, a polyvinyl butyral resin, and a dispersant were mixed with each sample to obtain a dielectric slurry.

The obtained dielectric slurry was poured onto a PET film using a doctor blade, dried, and then peeled off from the PET film to obtain a 200 μm-thick dielectric sheet. A silver paste obtained by mixing silver powder, ethyl cellulose, and butyl carbitol was printed on the dielectric sheet thus obtained by a screen printing method. Overlay the dielectric sheet further on this printing surface,
The precursor block was obtained by thermocompression bonding.

The precursor block thus obtained was cut into a predetermined size to obtain a sintering sample. The organic solvent contained in the sample for sintering was removed by leaving it in the air to remove the solvent, sealed in a sagger, and sintered in the same manner as described above.

Each of the sintered samples was cut so as to expose the cross section including the silver conductor, etched, gold sputtered, and the cross section was observed with a scanning electron microscope (SEM) to determine the internal conductor. The length of the gap formed at the end was measured. The results are shown in Tables 1 to 3.

[0067]

[Table 1]

[0068]

[Table 2]

[0069]

[Table 3]

In Comparative Examples shown in Tables 1 to 3, except for No. 30, the gaps at the end portions were extremely large, that is, 5 μm or more. On the other hand, in the case of using the dielectric porcelain material of the present invention, the gap at the end is almost less than 0.3 μm, and it can be seen that the addition of a very small amount of Ag has the effect of suppressing the gap. The reason why the gap between Sample Nos. 27 and 29 is relatively large is that the amount of silver added is relatively small, but there is no practical problem with such a gap. In addition, the dielectric ceramic material of the present invention showed good characteristics with a dielectric constant of 80 or more in all samples. further,
When the specific resistance of Sample No. 30 was measured, it was found that the specific resistance was much lower than the practical level. If the amount of silver added was too large, the specific resistance was lowered, and a practically usable dielectric material was not obtained.

From the above results, the effect of the present invention is clear. That is, by the composition and the production method satisfying the present invention, a dielectric porcelain composition having no gap at the end, a large dielectric constant ε, and excellent in low-temperature sinterability capable of being simultaneously fired with silver was obtained.

Example 2 A sample was prepared in the same manner as in Example 1 except that PbO + Ag prepared by the following method was used instead of PGO, PbO, and PWO as the sintering aid. However, almost the same results were obtained.

PbO and AgNO ₃ were mixed and pulverized in a ball mill for 14 hours in a wet system, dried, and
At 5 ° C. for 5 hours.
The mixture was pulverized for 4 hours and dried to obtain a sintering aid.

Example 3 Sample No. 21 of the present invention prepared in Example 1 and Sample No. 31 as a comparative example were used, and an organic solvent, a polyvinyl butyral resin, and a dispersant were mixed with each other. Thus, dielectric slurries A and B were obtained.

The obtained dielectric slurry was poured onto a PET film using a doctor blade, dried, and then peeled off from the PET film to obtain a 200 μm-thick dielectric sheet. A silver paste obtained by mixing silver powder, ethyl cellulose, and butyl carbitol was printed on the dielectric sheet thus obtained by a screen printing method. Overlay the dielectric sheet further on this printing surface,
The precursor block was obtained by thermocompression bonding.

The precursor block thus obtained was cut into a predetermined size to obtain a sintering sample. The organic solvent contained in the sintering sample was removed by leaving it in the air to remove the solvent, sealed in a sagger, and then sintered in air at the sintering temperature shown below. That is, the precursor block A of sample No. 21 was heated at 920 ° C.
Was sintered at 930 ° C.

Each sintered sample was cut so as to expose a cross section including a silver conductor, etched, gold was sputtered, and the cross section was observed with a scanning electron microscope (SEM). FIGS. 1 and 2 show SEM photographs of the sintered bodies of the precursor blocks A and B, respectively. As is evident from FIG. 1, the sintered body of the precursor block A has a defect-free structure despite being sintered at 920 ° C. On the other hand, as is clear from FIG. 2, the sintered body of the precursor block B sinters at a high temperature of 930 ° C., and has a gap between the silver conductor and the dielectric. Such a gap is a hopping phenomenon, that is, when a plating process performed for surface mounting, the electrolyte enters, and when this becomes a high temperature in the solder reflow process,
It rapidly expands and ruptures, causing product defects and characteristic deterioration.

<Example 4> As a dielectric ceramic composition having a lead-containing oxide other than the composition used in Example 1, Pb was used.
(Mg _1/3 Nb _2/3 ) O ₃ —Pb ₂ O and Pb (Mg _1/3 N
b _2/3 ) O ₃ -PbTiO ₃ -Pb (Mg _1/2 W _1/2 ) O _3, and silver nitrate was added thereto in terms of Ag in the amount of 0.002.
Each of the samples was added in the range of 5 to 1% by weight and fired simultaneously with the silver conductor paste in the same manner as in Example 1 to examine the gaps at the end portions. Was confirmed.

[0079]

As described above, according to the present invention, simultaneous sintering with silver is possible, the dielectric constant is high, there is no gap between the internal silver electrode after firing, and the additive is added. The amount of silver is very small, the cost is low, and a dielectric ceramic composition, a dielectric ceramic material and a method for producing the same, and a dielectric element and a method for producing the same can be realized with high production efficiency.

[Brief description of the drawings]

FIG. 1 is an SEM photograph of a cross section obtained by sintering a dielectric ceramic composition of the present invention together with a silver conductor.

FIG. 2 is an SEM photograph of a cross section obtained by sintering a dielectric ceramic composition of a comparative example together with a silver conductor.

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[Procedure amendment]

[Submission date] December 24, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

In some dielectric ceramic materials, silver easily diffuses, for example, glass (glass ceramic) having a low softening point, oxides such as lead and tungsten, and the like correspond to this. The diffusion of silver into low softening glass is well known as the problem of colloid formation in glass. When the oxide of tungsten is heated in the presence of oxygen,
It has long been known to produce silver tungstate (Ag ₂ WO ₄ ) having a melting point of about 605 ° C. with metallic silver. Also, J.I. Mater. Res. , Vol.
10, No. 11 (1995) p2933, it is reported that lead oxide has a eutectic point with metallic silver and that a liquid phase composed of lead oxide and metallic silver exists at a temperature of 825 ° C. or higher. When the oxide that shows such a reaction and the mass of metallic silver are in contact (adhesion) and placed under high temperature,
From the interface between the metallic silver and the oxide, silver diffuses into the oxide in the form of particles or ions, and the amount of silver in the matrix decreases, resulting in a so-called silver thinning phenomenon. It was also found that such a phenomenon caused the gap at the end of the silver conductor.

Claims (17)

[Claims] 1. A main component, Pb, Ca, R, ( R = W or Ti), a composite oxide of Fe and Nb, a composite oxide is a composition, (Pb _X Ca _y) O _{x + y (Fe t Nb u} R s) O z, in when expressed, x, y, s, t and u is, 0.99 ≦ x + y ≦ 1.08 , 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 ≦ s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, and silver is converted to Ag as a sub-component And a sintering temperature of 950 ° C. or less. 2. The composite oxide has R = Ti and has a composition of 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.5. , 0 <s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, 2. The dielectric ceramic composition according to claim 1, wherein 3. The composite oxide has R = W and has a composition of 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6. , 0 <s ≦ 0.2, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, 2. The dielectric ceramic composition according to claim 1, wherein 4. The dielectric ceramic composition according to claim 1, further comprising a sintering aid and / or a manganese oxide. 5. The dielectric ceramic composition according to claim 4, wherein 0.1 to 10% by weight of lead germanate is added as said sintering aid. 6. The lead germanate is Pb ₅ Ge ₃ O _11.
The dielectric porcelain composition according to claim 5, comprising: 7. A manganese oxide having a Mn equivalent of 0.5 w
The dielectric ceramic composition according to any one of claims 4 to 6, which contains t% or less. 8. The dielectric ceramic composition according to claim 1, wherein
Dielectric porcelain material fired at 0 ° C or less. 9. The gap with the silver-containing internal conductor is 3 μm.
9. The dielectric porcelain material of claim 8, which is less than. 10. A dielectric ceramic material comprising a solution containing silver as a subcomponent added to a dielectric magnetic composition having a lead and / or tungsten-containing oxide as a main component, and sintering at a temperature of 950 ° C. or lower. Manufacturing method. 11. An oxide of Pb and Ti or Fe or W or a compound that becomes an oxide by sintering is mixed in a predetermined amount, and calcined to obtain a first calcined product, wherein Pb, Ca, Fe and A predetermined amount of an oxide of Nb or a compound that becomes an oxide by sintering is mixed and calcined to obtain a second calcined product. The final composition of the first calcined material and the second calcined product is (P
_{b X Ca y) O x +} y (Fe t Nb u R s) O z, (R =
W or Ti), x, y, s, t and u are 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6 , 0 ≦ s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, mixed and pulverized, and calcined to obtain a third calcined product. The method for producing a dielectric porcelain material according to claim 10, wherein a solution containing silver as a subcomponent is added thereto and further mixed to obtain a dielectric porcelain composition, which is molded and sintered. 12. A predetermined amount of an oxide of Pb, Ca, Fe, and Nb or a compound which becomes an oxide by sintering is mixed and calcined to obtain a second calcined product. And Ti, or Fe and W
Oxide or a compound forming an oxide by mixing a predetermined amount by sintering, its final _{composition, (Pb X Ca y) O} x + y (Fe t Nb u R s) O z,
(R = W or Ti), where x, y, s, t and u are 0.99 ≦ x + y ≦ 1.08, 0.3 ≦ y <0.918, 0.375 ≦ t ≦ 0.6, 0 ≦ s ≦ 0.25, 0.2 ≦ u ≦ 0.5, s + t + u = 1, z = (3t + 5u + 4s) / 2, mixed and pulverized, calcined, and calcined. 11. A method for producing a dielectric ceramic material according to claim 10, wherein a calcined product is obtained, and a solution containing silver as an auxiliary component is added thereto and further mixed to obtain a dielectric ceramic composition, which is molded and sintered. Method. 13. The dielectric porcelain according to claim 11, wherein a sintering aid and / or manganese oxide or a compound that becomes manganese oxide by firing is added to the third calcined product as other auxiliary components. A method for producing a dielectric porcelain material. 14. The method for producing a dielectric ceramic material according to claim 10, wherein the silver-containing solution contains a silver salt or a silver compound in an amount of 0.005 to 1 wt% in terms of Ag. Method. 15. The method according to claim 14, wherein the solution of the silver compound is a silver nitrate solution. 16. A dielectric element in which a silver conductor pattern is built in the dielectric dielectric ceramic material according to claim 8. 17. A method of manufacturing a dielectric element according to claim 16, wherein the dielectric ceramic composition according to claim 1 and silver are co-fired to obtain the dielectric element according to claim 16.