JPH08337471A - Nonreducible dielectric porcelain composition - Google Patents

Abstract

PURPOSE: To fire a compsn. without converting the structure into a semiconductor even under low partial pressure of oxygen and to improve weather resistance by incorporating BaTiO3 , a specified rare earth metal oxide, assistant components and oxide glass. CONSTITUTION: A principal compsn. is composed of 92.0-99.4mol% BaTiO3 , 0.3-4.0mol% at least one kind of rare earth metal oxide selected from among Tb2 O3 , Dy2 O3 , Ho2 O3 and Er2 O3 and 0.3-4.0mol% CeO3 , and 100 pts.wt., in total, of 100mol% of the principal compsn., 0.05-4.0mol% BaO, 0.05-2.0mol% MnO, 0.5-5.0mol% MgO and 0.3-3.0mol% NiO and Al2 O3 as assistant components are blended with 0.5-2.5 pts.wt. oxide glass represented by the formula Li2 O-(Six Ti1-x )O2 -M (where M is Al2 O3 and/or ZrO2 and 0<x<=1.00) to obtain the objective nonreducible dielectric porcelain compsn. having a dielectric constant of >=3,000, an insulation resistance value (C×R) of >=6,000 and the rate of volume change by emperature within the range of ±15% on the basis of volume at 25 deg.C over the range of -15 deg.C to +125 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-reducing dielectric porcelain composition, and in particular, a non-reducing dielectric porcelain used as a dielectric material such as a laminated ceramic capacitor having a base metal such as nickel as an internal electrode material. It relates to a composition.

[0002]

2. Description of the Related Art Conventionally, conventional dielectric porcelain materials containing BaTiO ₃ as a main component have the property that they are reduced by firing under a neutral or reducing low oxygen partial pressure, and become semiconductor. . Therefore, as the internal electrode material,
Does not melt even at high temperatures due to sintering of dielectric ceramic materials, and
It has been necessary to use a noble metal such as Pd or Pt that is not oxidized even if it is fired under a high oxygen partial pressure that does not turn the dielectric ceramic material into a semiconductor. This has been a major hindrance to cost reduction of manufactured monolithic ceramic capacitors.

Therefore, in order to solve the above problems,
For example, it has been desired to use a base metal such as Ni as an internal electrode material. However, when using such a base metal as an internal electrode material and firing under conventional conditions,
The electrode material is oxidized and does not function as an electrode. Therefore, in order to use such a base metal as a material for the internal electrode, even if it is fired in a neutral or reducing atmosphere with a low oxygen partial pressure, it does not become a semiconductor, and is sufficiently used as a dielectric material for a capacitor. A dielectric ceramic material having a specific resistance and excellent dielectric properties has been desired.

As a dielectric ceramic material satisfying these conditions, for example, BaTiO 3 disclosed in JP-A-62-256422.
₃ -CaZrO ₃ -MnO-MgO system composition, or JP 63-103861 BaTiO ₃ -MnO-Mg
O-rare earth oxide type composition or Japanese Patent Publication No. 61-14
No. 610 of BaTiO ₃ — (Mg, Zn, Sr, Ca)
_{O + Li 2 O-SiO 2} -MO ( however, MO: BaO, S
Compositions based on rO, CaO) have been proposed.

[0005]

However, JP-A-62-62
In the non-reducing dielectric ceramic composition disclosed in Japanese Patent No. 256422, CaZrO ₃ and CaT generated in the firing process are used.
Since iO ₃ easily forms a heterogeneous phase together with Mn and the like, there is a risk that reliability may be deteriorated at high temperatures.

Further, in the non-reducing dielectric ceramic composition disclosed in Japanese Patent Laid-Open No. 63-103861, the temperature change rate of insulation resistance and capacitance has a great influence on the crystal grain size of BaTiO ₃ which is the main component. It is difficult to control to obtain stable characteristics. Furthermore, when the insulation resistance value is also shown by the product of the capacitance value (CR product), 1000 to 2000 (Ω ·
F), which was not practical.

The composition disclosed in Japanese Examined Patent Publication No. 61-14610 has a dielectric constant of the dielectric ceramic obtained of 20.
00-2800, which is the dielectric constant of a conventional porcelain composition using a noble metal such as Pd, 3000-35.
It was inferior to 00. Therefore, replacing the composition with the conventional material as it is for cost reduction is disadvantageous in terms of miniaturization and large capacity of the capacitor, and a problem remains.

Further, the non-reducing dielectric ceramic compositions proposed so far, including the above-mentioned compositions, have a higher insulation resistance value at room temperature than conventional materials, but have a significantly high resistance at high temperatures. The value tended to decrease. Therefore, it is inferior in reliability at high temperature, that is, so-called high temperature load characteristics, which is a big obstacle especially when thinning the dielectric thickness.Therefore, laminating thin layers using a non-reducing dielectric ceramic composition. Capacitors have not been put to practical use.
Furthermore, in the conventional non-reducing dielectric ceramic composition,
The reliability at high temperature and high humidity, that is, the so-called moisture resistance load characteristic was also inferior as compared with the conventional material using Pd or the like as the internal electrode.

The present applicants have proposed a new composition as a non-reducing dielectric ceramic composition in order to solve the above-mentioned problems in Japanese Patent Laid-Open Nos. 05-009066 to 05-009068. However, since the required properties in the market thereafter, especially the properties required under high temperature and high humidity, have become more severe, it has become necessary to propose a composition having further excellent properties.

Therefore, the main object of the present invention is to enable the structure to be fired without becoming a semiconductor even under a low oxygen partial pressure, and to have a dielectric constant of 3000 or more and an insulation resistance value expressed by a CR product. 6000 or more, and the rate of change in capacity-temperature is -55 to 12 with reference to the capacity value of 25 degrees.
A non-reducing dielectric porcelain composition that satisfies the requirement of ± 15% over a wide range of 5 degrees and has excellent weather resistance such as high temperature load and moisture resistance load and that can be applied to thin layers is provided. To do.

[0011]

The present invention has completed a non-reducing dielectric ceramic composition in order to solve the above problems. The non-reducing dielectric ceramic composition of the present invention comprises BaTiO ₃ , Tb ₂ O ₃ , Dy ₂ O ₃ and H.
o ₂ O ₃ , at least one rare earth oxide (Re ₂ O ₃ ) selected from Er ₂ O ₃ and Co ₂ O ₃ in a predetermined mixing ratio with respect to the main component, a sub-component As Ba
And O, and MnO, and MgO, NiO, and at least one of Al ₂ O _3, and Li ₂ O- (Si _X T
i _1-X ) O ₂ -M (In the formula, M represents at least one of Al ₂ O ₃ and ZrO _2. X is 0.30 ≦ X ≦
It is 1.00. ) Is contained in a predetermined compounding ratio.

That is, if these are mixed at a predetermined mixing ratio and the mixing ratio is appropriately selected, the non-reducing dielectric ceramic composition of the present invention has a semiconducting structure even under a low oxygen partial pressure. It can be fired without. Also, the dielectric constant is 3
000 or more, 6000 when insulation resistance value is expressed by CR product
The above can be done. In addition, the capacity temperature change rate is
It is possible to satisfy that the capacitance value is within ± 15% over a wide range of −55 ° to 125 ° with reference to the capacitance value of 25 °. Furthermore, it has excellent weather resistance such as high temperature load and humidity resistance load, and can be applied to thin layers.

Therefore, the predetermined compounding ratio referred to in the present invention is
It means the compounding ratio within the range where the above characteristics can be obtained.

Further, in the non-reducing dielectric ceramic composition of the present invention, the compounding ratio of the main components, BaTiO ₃ , the rare earth oxide (Re ₂ O ₃ ) and the Co ₂ O ₃ is set. Of the main component 100 mol%, BaTiO ₃ 9
2.0 to 99.4 mol%, Re ₂ O ₃ 0.3 to 4.0 mol%, and Co ₂ O ₃ 0.3 to 4.0 mol%, is preferably in the range of, whereby , Insulation resistance,
It has been confirmed by experiments that the dielectric constant and the rate of change in capacitance with temperature are improved.

That is, if the compounding ratio is less than 92.0 mol%, the compounding ratios of the rare earth oxide and Co ₂ O ₃ increase, so that the insulation resistance value and the dielectric constant decrease, which is not preferable. On the other hand, the composition ratio of BaTiO ₃ is 9
If it exceeds 9.4 mol%, the effect of adding the rare earth oxide and Co ₂ O ₃ is poor, and the rate of change in capacity temperature in the high temperature region near the Curie point is large (+), which is not preferable.

However, in the present invention, if there is a compounding ratio that improves the insulation resistance value, the dielectric constant, and the temperature change rate of the capacitance, in a portion other than the range of the compounding ratio of these main components, the predetermined ratio is obtained. The compounding ratio also includes the compounding ratio of such a portion.

Further, in the non-reducing dielectric ceramic composition of the present invention, the BaO as the sub ingredient is within the range of 0.05 to 4.0 mol% with respect to 100 mol% of the main component. At the dielectric loss t
It has been confirmed by experiments that an δ, insulation resistance, and sinterability are improved.

That is, if the addition amount is less than 0.05 mol%, the stability of characteristics in the firing atmosphere is deteriorated, tan δ is increased, and the insulation resistance value is decreased, which is not preferable. On the other hand, if the amount added exceeds 4.0 mol%, the sinterability will decrease, which is not preferable.

However, in the present invention, the dielectric loss t is also present in a portion other than the range of the compounding ratio of the subordinate component BaO.
If there is a compounding ratio that improves an δ, insulation resistance, and sinterability, the prescribed compounding ratio also includes the compounding ratio of such a portion.

In the non-reducing dielectric ceramic composition of the present invention, the MnO, which is the sub ingredient, is in the range of 0.05 to 2.0 mol% with respect to 100 mol% of the main component. It has been confirmed by experiments that the insulation resistance value, the high temperature load characteristic, and the moisture resistance load characteristic are improved.

That is, if the addition amount is less than 0.05 mol%, the insulation resistance value is lowered, which is not preferable. On the other hand, when the added amount exceeds 2.0 mol%,
Insulation resistance is slightly reduced, and MTTF (meant)
It is not preferable because the image to failure) becomes short.

However, in the present invention, if there is a compounding ratio that improves the insulation resistance value, the high temperature load characteristic, and the moisture resistance load characteristic in a portion other than the above range of the compounding ratio of the accessory component MnO, a predetermined value is obtained. The compounding ratio of includes the compounding ratio of such a portion.

Further, in the non-reducing dielectric ceramic composition of the present invention, the MgO as the sub ingredient is in the range of 0.5 to 5.0 mol% with respect to 100 mol% of the main component. It has been confirmed by experiments that the temperature change rate of capacitance, the dielectric constant, and the insulation resistance value are improved.

That is, when the amount added is less than 0.5 mol%, the effect of flattening the curve of the temperature change rate of the capacity is poor, and there is a tendency that the curve deviates to the (-) side especially at the low temperature side, and the insulation The effect of improving the resistance value becomes poor, which is not preferable. On the other hand, if the addition amount exceeds 5.0 mol%, the dielectric constant and the insulation resistance value decrease, which is not preferable.

However, in the present invention, if there is a compounding ratio that improves the temperature change rate of the capacity, the dielectric constant, and the insulation resistance value in a portion other than the range of the compounding ratio of the sub-component MgO as well, The predetermined mixing ratio also includes the mixing ratio of such a portion.

In addition, in the non-reducing dielectric ceramic composition of the present invention, the above-mentioned NiO and Al ₂ O ₃ which are the subcomponents are used.
At least one of them is preferably in the range of 0.3 to 3.0 mol% with respect to 100 mol% of the main component, which improves the insulation resistance value, dielectric constant, and dielectric loss. It has been confirmed by experiments that this is the case.

That is, if the addition amount is less than 0.3, the effect of improving the reduction resistance of the structure is poor, the insulation resistance value is lowered, and the MTTF is shortened, which is not preferable. On the other hand, when the addition amount exceeds 3.0 mol%, the insulation resistance value of NiO is reduced and the sinterability of Al ₂ O ₃ is reduced as in the case of MnO, so that the dielectric constant is reduced. At the same time, the dielectric loss increases, which is not preferable.

However, in the present invention, if there is a compounding ratio that improves the insulation resistance value, the dielectric constant, and the dielectric loss in a portion other than the above range of the compounding ratio of the subcomponents,
The predetermined mixing ratio also includes the mixing ratio of such a portion.

In the non-reducing dielectric ceramic composition of the present invention, the content of the alkali metal oxide contained as an impurity in BaTiO ₃ is preferably 0.04% by weight or less. It has been confirmed by experiments that the dielectric constant is improved.

That is, when the content of the alkali metal oxide in BaTiO ₃ exceeds 0.04% by weight, the dielectric constant lowers and it becomes unpractical, which is not preferable.

However, in the present invention, if there is a content ratio that improves the dielectric constant even in a portion other than the range of the alkali metal oxide content of such impurities, the content ratio includes such a portion. The ratio is also included.

Further, the non-reducing dielectric ceramic composition of the present invention is characterized by containing BaZrO ₃ as a sub ingredient in a predetermined compounding ratio.

That is, this is mixed in a predetermined mixing ratio,
By properly selecting the compounding ratio, the non-reducing dielectric ceramic composition of the present invention can be fired even if the oxygen partial pressure is low, without the structure becoming a semiconductor. Also, the dielectric constant is 300
It can be 0 or more, and 7,000 or more when the insulation resistance value is expressed by a CR product. Furthermore, the capacity temperature change rate is 25
It can be satisfied that it is within ± 15% over a wide range of −55 degrees to 125 degrees based on the capacitance value of degrees. Furthermore, it has excellent weather resistance such as high temperature load and humidity resistance load, and can be applied to thin layers.

Therefore, the predetermined compounding ratio in the present invention means
It means the compounding ratio within the range where the above characteristics can be obtained.

In the non-reducing dielectric ceramic composition of the present invention, the BaZrO ₃ is BaTiO ₃ and T
b ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , and at least one rare earth oxide (Re ₂ O ₃ ) selected from Er ₂ O ₃ ;
It is preferable that the content of Co ₂ O ₃ is within the range of 0.3 to 4.0 mol% with respect to 100 mol% of the main component containing a predetermined compounding ratio. It has been confirmed by experiments that the temperature change rate is improved.

That is, if the addition amount is less than 0.3 mol%, the effect of improving the insulation resistance value becomes poor, which is not preferable. On the other hand, when the addition amount exceeds 4.0 mol%, although it is further effective in improving the insulation resistance value,
The curve showing the rate of change in capacity with temperature rotates to the right, and the rate of change in the high temperature portion increases toward the (−) side, which is not preferable.

However, in the present invention, if there is a compounding ratio that improves the insulation resistance value and the temperature change rate of the capacity in a portion other than the range of the compounding ratio of the sub-component BaZrO ₃ , the composition is predetermined. The compounding ratio also includes the compounding ratio of such a portion.

In the non-reducing dielectric ceramic composition of the present invention, the amount of the oxide glass is 0.5 with respect to a total of 100 parts by weight of the main component and the subcomponents excluding the oxide glass. It is preferable to be in the range of from 2.5 to 2.5 parts by weight, and it has been confirmed by experiments that the sinterability, the reduction resistance and the dielectric constant are improved by this.

That is, if the addition amount is less than 0.5 parts by weight, the effects of lowering the sinterability and improving the reduction resistance become poor, which is not preferable. On the other hand, if the addition amount exceeds 2.5 parts by weight, the dielectric constant is lowered, which is not practical and is not preferable.

However, in the present invention, if there is a compounding ratio that improves the sinterability, the reduction resistance and the dielectric constant, there is a compounding ratio outside the range of the compounding ratio of the oxide glass.
The predetermined mixing ratio also includes the mixing ratio of such a portion.

Further, in the non-reducing dielectric ceramic composition of the present invention, the oxide glass has a mol% of (Li _{2
O, (Si X Ti 1-} X) in the ternary composition diagram of _{O 2, M), A (} 20,80,0), B (10,80,10),
C (10, 70, 20), D (35, 45, 20), E
(45,45,10), and F (45,55,0),
On the inside and inside of the hexagon with the vertex as
In the case of the composition on A, it is preferable that X is represented by 0.30 ≦ X <1.00), and it is experimentally found that this improves sinterability, high temperature load characteristics, and moisture resistance load characteristics. It has been confirmed.

That is, if the composition is out of this range, even if it is rapidly cooled in ice water, it does not become glass and there are many parts that devitrify, so that the sinterability decreases, which is not preferable. Further, even in the vitrification range, the composition on the point F-A, and X = 1.
The value of 00 is not preferable because the characteristics are greatly deteriorated under high temperature and high humidity and the reliability is lowered. Further, when the value of X is less than 0.3, it is not preferable because the glass does not become glass like the above and there are many devitrification sites, and the sinterability decreases.

However, in the present invention, if there is a compounding ratio that improves the sinterability, the reduction resistance and the dielectric constant in a portion other than the range of the compounding ratio of the oxide glass,
The predetermined mixing ratio also includes the mixing ratio of such a portion.

[0044]

EXAMPLES Examples of the non-reducing dielectric ceramic composition of the present invention will be described below. (Example 1) As a starting material, BaTiO ₃ having different contents of alkali metal oxides contained as impurities, and Tb ₂ O ₃ , Dy ₂ O ₃ , and H which are rare earth oxides (Re ₂ O ₃ ).
o ₂ O ₃ , and Er ₂ O ₃ , Co ₂ O ₃ , BaCO ₃ , and M
nCO ₃ , MgO, NiO, Al ₂ O ₃ , and oxide glass were prepared. These raw materials were weighed so that the composition ratios shown in Table 1 and Table 2 were obtained to obtain weighed products.

The content of the alkali metal oxide is 0.
Basically, 03% by weight of BaTiO ₃ is used.
For sample No. 34, BaTiO ₃ having an alkali metal oxide content of 0.05% by weight was used.
For 5, the content of alkali metal oxide was 0.07.
Weight percent BaTiO ₃ was used.

[0046]

[Table 1]

[0047]

[Table 2]

Here, the oxide glass was adjusted as follows. First, the raw materials Li ₂ O, SiO ₂ , T
iO ₂ , Al ₂ O ₃ , and ZrO ₂ were prepared. These raw materials were weighed so that the composition ratios shown in Table 3 and Table 4 were obtained,
A weighed product was obtained. Pure water is added to the obtained weighed product, and PSZ is added.
It was mixed and dispersed by a ball mill using balls. Next, after pure water was evaporated and dried, the mixed powder was put into a platinum crucible and heated in a glass melting furnace at 1400 ° C. for 15 minutes. The molten melt was taken out of the furnace and rapidly cooled in ice water to obtain a lump glass. The lump glass was roughly crushed in a mortar and then sufficiently crushed by a ball mill using PSZ together with a dispersion medium. Finally, the dispersion medium was evaporated and dried to obtain glass powder.

[0049]

[Table 3]

[0050]

[Table 4]

[0051] In this way the oxide glass which is manufactured in, Li ₂ O and _{(Si X Ti 1-X)} O 2 and Al ₂ O _3, ZrO
Contains at least one of the _two . As shown in FIG. 1, these mol% are (Li ₂ O, (Si _X T
i _1-X ) O ₂ , M) (provided that at least one of M: Al ₂ O ₃ and ZrO ₂ is present. X: 0.30 ≦ X
≦ 1.00. ) Is shown in the three-component composition diagram.

In FIG. 1, point A, point B, point C, point D,
The points E and F are A (20,80,0) and B (1
0,80,10), C (10,70,20), D (3
5,45,20), E (45,45,10), F (4
5, 55, 0), and the area surrounded by the diagonal lines in FIG. 1 is within the scope of the present invention.

A raw material slurry was prepared by mixing and dispersing the weighed material thus obtained together with a dispersion medium in a ball mill using PSZ balls. An organic binder and a plasticizer were added to the slurry and sufficiently stirred, and then the sheet was formed by a doctor blade method to obtain a ceramic green sheet. At this time, the thickness of the ceramic green sheet was 12 μm.

Next, a Ni conductive paste for forming internal electrodes is screen-printed on one surface of the ceramic green sheet obtained as described above, and after drying, a plurality of ceramic green sheets are alternately laminated, and then in the thickness direction. A laminate was obtained by pressure bonding. A ceramic green unit was obtained by cutting out from this laminated body. This ceramic green unit was debindered in air at 320 ° C. for 5 hours, and then, in a reducing atmosphere gas stream having a volume ratio of H ₂ / N ₂ mixed gas of 3/100, as shown in Table 5. And a sintered body was obtained by firing at the temperature shown in Table 6 for 2 hours. The thickness of the dielectric element of the unit after firing was 8 μm.

[0055]

[Table 5]

[0056]

[Table 6]

Silver paste for external electrode formation was applied to both end faces of the obtained sintered body and baked in air to obtain
A silver electrode was formed to obtain a monolithic ceramic capacitor. Then, the dielectric constant ε ₂₅ , the dielectric loss tan δ, the insulation resistance value (logI
R) and the temperature change rate (TCC) of the capacity, and as a weather resistance performance evaluation, a high temperature load test and a moisture resistance load test were performed. The results are summarized in Table 5 and Table 6. The number of samples used for the measurement is n = 36 for each item.

Here, regarding the dielectric constant ε ₂₅ and the dielectric loss tan δ, the temperature is 25 ° C., the frequency is 1 KHz, and the AC voltage is 1 V.
It was measured under the conditions. The insulation resistance value was measured by applying a DC voltage of 16 V for 2 minutes at a temperature of 25 ° C., and the result is shown as the product of the capacitance value (CR product).
Furthermore, regarding the temperature change rate (TCC) of the capacity, 25
The rate of change in capacitance at -55 ° C and 125 ° C (ΔC _-55 / C ₂₅ , ΔC ₁₂₅ , respectively) based on the capacitance value at ℃
/ C ₂₅ ), and between −55 ° C. and 125 ° C., the absolute value of the maximum temperature change rate of the capacity, that is, the maximum change rate (| ΔC / C ₂₅ | _max ) is shown.

Regarding the weather resistance performance evaluation, in the high temperature load test, the number of defects generated after 500 hours after application of a DC voltage of 64 V at a temperature of 175 ° C. is shown. (It should be noted that MTTF is indicated when all defectives have been reached before 500 hours have passed.) Further, regarding the humidity resistance load test, after a DC voltage of 16 V was applied at a temperature of 121 ° C. and a humidity of 100%, a failure occurred after 250 hours had passed. The number of occurrences is similarly shown. (In this case as well, the MTTF is similarly shown when all defectives occur before the elapse of 250 hours.) As is clear from Tables 5 and 6, the effect of the present invention is remarkable and the present invention It can be seen that the thin-layer laminated ceramic capacitor using such a non-reducing dielectric ceramic composition exhibits characteristics comparable to conventional products using Pd or the like for the internal electrodes.

Here, in the present embodiment, the sample number is *
Those marked with are different from the predetermined compounding ratio in the present invention and are out of the scope of the present invention.

The samples marked with * will be described below. First, for sample No. 4, BaTiO ₃
Since the composition ratio is 90.0 mol%, the composition ratios of the rare earth oxide and Co ₂ O ₃ increase, and the insulation resistance value and the dielectric constant decrease.

For sample No. 3, BaTiO 3
_Since the composition ratio of ₃ is 99.6 mol%, there is no effect of the addition of the rare earth oxide and Co ₂ O ₃ , and the capacity temperature change rate in the high temperature region near the Curie point is large and deviates to the (+) side. I will end up.

Further, in the case of Sample No. 9, since the added amount of BaO is 0.03 mol%, the characteristic stability in the firing atmosphere is deteriorated, and tan δ is increased and the insulation resistance value is decreased.

Further, with respect to sample No. 12, the sinterability is lowered because the added amount of BaO is 5.0 mol%.

With respect to Sample No. 17, the amount of MnO added is 0.03 mol%, which causes a decrease in the insulation resistance value.

Further, in the case of Sample No. 15, since the amount of MnO added is 2.5 mol%, the insulation resistance value is slightly lowered and the MTTF is shortened.

Further, with respect to Sample Nos. 24 and 25, since the amounts of MgO added were 0.2 mol% and 0.4 mol%, respectively, the effect of flattening the curve of the temperature change rate of capacity was poor, and At the low temperature side, it tends to deviate to the (-) side, and the effect of improving the insulation resistance value becomes poor.

With respect to sample No. 29, since the amount of MgO added is 6.0 mol%, the dielectric constant and the insulation resistance value are lowered.

With respect to Sample No. 18, since the amount of NiO added was 0.2 mol%, the effect of improving the reduction resistance of the structure was poor, and the insulation resistance value was lowered.
MTTF is also shortened.

Further, in the case of Sample No. 21, the insulation resistance value is lowered because the added amount of NiO is 3.5 mol%.

For sample No. 22, Al ₂ O ₃
Since the addition amount of is 3.5 mol%, the sinterability is lowered, the dielectric constant is lowered, and the dielectric loss is increased.

For sample Nos. 34 and 35, the contents of alkali metal oxides contained as impurities in BaTiO ₃ were 0.05% by weight and 0.07%, respectively.
Since the content is% by weight, the dielectric constant is lowered.

With respect to Sample No. 33, the effect of reducing the sinterability and improving the reduction resistance is lost because the amount of oxide glass added is 0.3% by weight.

Further, in the case of sample No. 31, since the amount of oxide glass added was 3.0% by weight, the dielectric constant was lowered.

For sample Nos. 37 to 41, A, B, C, D, E, in the three-component composition diagram shown in FIG.
Since it is outside the region inside and inside the hexagon connecting the six points of F, even if it is rapidly cooled in ice water, there are many parts that devitrify instead of becoming glass, and the sinterability deteriorates.

For sample Nos. 43 and 45, the composition on point F-A and X = 1.00, even within the vitrification range on the sides and inside of the hexagon, were high temperature. However, the characteristic deterioration under high humidity becomes large.

Further, with respect to the sample No. 36, since the value of X is 0.20, the sinterability is deteriorated because there are many devitrifying portions instead of being glass like the above.

By the way, the present invention is not limited to the above-mentioned embodiments, and modifications can be made without departing from the gist of the present invention.

For example, various components may be added as auxiliary additives, if necessary, within a range that does not impair the above-mentioned characteristics.

Example 2 As a starting material, BaT having different contents of alkali metal oxides contained as impurities
iO ₃ and Tb ₂ O ₃ , which is a rare earth oxide (Re ₂ O ₃ ),
Dy ₂ O ₃ , Ho ₂ O ₃ , and Er ₂ O ₃ with Co ₂ O ₃ ,
BaCO ₃ , MnCO ₃ , MgO, NiO, Al ₂ O ₃ , B
aZrO ₃ and oxide glass were prepared. These raw materials were weighed so that the composition ratios shown in Tables 7 and 8 were obtained to obtain weighed products.

The content of the alkali metal oxide was 0.
Basically, 03% by weight of BaTiO ₃ is used.
For sample No. 40, BaTiO ₃ having an alkali metal oxide content of 0.05% by weight was used, and sample No. 4 was used.
For 1, the content of alkali metal oxide is 0.07
Weight percent BaTiO ₃ was used.

[0082]

[Table 7]

[0083]

[Table 8]

Here, the oxide glass was adjusted as follows. First, the raw materials Li ₂ O, SiO ₂ , T
iO ₂ , Al ₂ O ₃ , and ZrO ₂ were prepared. These raw materials were weighed so that the composition ratios shown in Tables 9 and 10 were obtained to obtain weighed products. Pure water is added to the obtained weighed product, and P
It was mixed and dispersed by a ball mill using SZ balls.
Next, after pure water was evaporated and dried, the mixed powder was put into a platinum crucible and heated in a glass melting furnace at 1400 ° C. for 15 minutes. The molten melt was taken out of the furnace and rapidly cooled in ice water to obtain a lump glass. The lump glass was roughly crushed in a mortar and then sufficiently crushed by a ball mill using PSZ together with a dispersion medium. Finally, the dispersion medium was evaporated and dried to obtain glass powder.

[0085]

[Table 9]

[0086]

[Table 10]

[0087] In this way the oxide glass which is manufactured in, Li ₂ O and _{(Si X Ti 1-X)} O 2 and Al ₂ O _3, ZrO
Contains at least one of the _two . As shown in FIG. 1, these mol% are (Li ₂ O, (Si _X T
i _1-X ) O ₂ , M) (provided that at least one of M: Al ₂ O ₃ and ZrO ₂ is present. X: 0.30 ≦ X
≦ 1.00. ) Is shown in the three-component composition diagram.

In FIG. 1, point A, point B, point C, point D,
The points E and F are A (20,80,0) and B (1
0,80,10), C (10,70,20), D (3
5,45,20), E (45,45,10), F (4
5,55,0).

Then, a Ni conductive paste for forming internal electrodes is screen-printed on one surface of the ceramic green sheet obtained as described above, and after drying, a plurality of ceramic green sheets are alternately laminated, and then in the thickness direction. A laminate was obtained by pressure bonding. A ceramic green unit was obtained by cutting out from this laminated body. This ceramic green unit was debindered in air at 320 ° C. for 5 hours and then debindered. Then, in a reducing atmosphere gas flow having a volume ratio of H ₂ / N ₂ mixed gas of 3/100, Table 11, And a sintered body was obtained by firing at the temperatures shown in Table 12 for 2 hours. The thickness of the dielectric element of the unit after firing was 8 μm.

[0090]

[Table 11]

[0091]

[Table 12]

Silver paste for external electrode formation was applied to both end faces of the obtained sintered body and baked in air to obtain
A silver electrode was formed to obtain a monolithic ceramic capacitor. Then, the dielectric constant ε ₂₅ , the dielectric loss tan δ, the insulation resistance value (logI
R) and the temperature change rate (TCC) of the capacity, and as a weather resistance performance evaluation, a high temperature load test and a moisture resistance load test were performed. The results are summarized in Table 5 and Table 6. The number of samples used for the measurement is n = 36 for each item.

Here, regarding the dielectric constant ε ₂₅ and the dielectric loss tan δ, the temperature is 25 ° C., the frequency is 1 KHz, and the AC voltage is 1 V.
It was measured under the conditions. The insulation resistance value was measured by applying a DC voltage of 16 V for 2 minutes at a temperature of 25 ° C., and the result is shown as the product of the capacitance value (CR product).
Furthermore, regarding the temperature change rate (TCC) of the capacity, 25
The rate of change in capacitance at -55 ° C and 125 ° C (ΔC _-55 / C ₂₅ , ΔC ₁₂₅ , respectively) based on the capacitance value at ℃
/ C ₂₅ ), and between −55 ° C. and 125 ° C., the absolute value of the maximum temperature change rate of the capacity, that is, the maximum change rate (| ΔC / C ₂₅ | _max ) is shown.

Further, regarding the weather resistance performance evaluation, in the high temperature load test, the number of defects generated after 500 hours after the application of the DC voltage of 64 V at the temperature of 175 ° C. is shown. (It should be noted that MTTF is indicated when all defectives have been reached before 500 hours have passed.) Further, regarding the humidity resistance load test, after a DC voltage of 16 V was applied at a temperature of 121 ° C. and a humidity of 100%, a failure occurred after 250 hours had passed. The number of occurrences is similarly shown. (In this case as well, MTTF is similarly shown when all defectives are reached before 250 hours have passed.) As is clear from Tables 11 and 12, the effect of the present invention is remarkable and the present invention It can be seen that the thin-layer laminated ceramic capacitor using such a non-reducing dielectric ceramic composition exhibits characteristics comparable to conventional products using Pd or the like for the internal electrodes.

Here, in this embodiment, the sample number is *
Those marked with are different from the predetermined compounding ratio in the present invention and are out of the scope of the present invention.

The samples marked with * will be described below. First, for sample No. 4, BaTiO ₃
Since the composition ratio is 90.0 mol%, the composition ratios of the rare earth oxide and Co ₂ O ₃ increase, and the insulation resistance value and the dielectric constant decrease.

For sample No. 3, BaTiO 3
_Since the composition ratio of ₃ is 99.6 mol%, there is no effect of the addition of the rare earth oxide and Co ₂ O ₃ , and the capacity temperature change rate in the high temperature region near the Curie point is large and deviates to the (+) side. I will end up.

Further, in the case of Sample No. 9, since the added amount of BaO is 0.03 mol%, the characteristic stability in the firing atmosphere is deteriorated, and tan δ is increased and the insulation resistance value is decreased.

Further, with respect to Sample No. 12, the sinterability is lowered because the added amount of BaO is 5.0 mol%.

Further, with respect to the sample No. 17, since the amount of MnO added is 0.03 mol%, the insulation resistance value is lowered.

Further, with respect to the sample No. 15, since the amount of MnO added is 2.5 mol%, the insulation resistance value is slightly lowered and the MTTF is shortened.

Further, with respect to Sample Nos. 24 and 25, since the addition amounts of MgO were 0.2 mol% and 0.4 mol%, respectively, the effect of flattening the temperature change rate curve of the capacity was poor, and especially, At the low temperature side, it tends to deviate to the (-) side, and the effect of improving the insulation resistance value becomes poor.

Further, with respect to the sample No. 29, since the amount of MgO added is 6.0 mol%, the dielectric constant and the insulation resistance value decrease.

Further, in the case of Sample No. 18, since the added amount of NiO was 0.2 mol%, the effect of improving the reduction resistance of the structure was poor, and the insulation resistance value was lowered.
MTTF is also shortened.

Further, in the case of Sample No. 21, the insulation resistance value is lowered because the added amount of NiO is 3.5 mol%.

For sample No. 22, Al ₂ O ₃
Since the addition amount of is 3.5 mol%, the sinterability is lowered, the dielectric constant is lowered, and the dielectric loss is increased.

For sample Nos. 40 and 41, the contents of alkali metal oxides contained as impurities in BaTiO ₃ were 0.05% by weight and 0.07%, respectively.
Since the content is% by weight, the dielectric constant is lowered.

For sample No. 39, BaZr
Since the amount of O ₃ added is 0.1 mol%, the effect of improving the insulation resistance is lost.

For sample No. 36, BaZr
Since the addition amount of O ₃ is 5.0 mol%, it is further effective in improving the insulation resistance value, but the curve showing the temperature change rate of the capacity rotates to the right, and the change rate in the high temperature part becomes (− ) Side becomes big.

Further, in the case of sample No. 33, the effect of reducing the sinterability and improving the resistance to reduction is lost because the amount of oxide glass added is 0.3% by weight.

Further, with respect to the sample No. 31, since the amount of oxide glass added was 3.0% by weight, the dielectric constant was lowered.

Further, for sample numbers 43 to 47, A, B, C, D, E, in the three-component composition diagram shown in FIG.
Since it is outside the region inside and inside the hexagon connecting the six points of F, even if it is rapidly cooled in ice water, there are many parts that devitrify instead of becoming glass, and the sinterability deteriorates.

Further, for sample numbers 49 and 51, even if they were within the vitrification range on the sides and inside of the hexagon, the composition on the point F-A and X = 1.00, and therefore high temperature However, the characteristic deterioration under high humidity becomes large.

Further, in the case of sample No. 42, the value of X is 0.20, so that there are many devitrifying sites instead of glass as in the above case, so that the sinterability deteriorates.

By the way, the present invention is not limited to the above-mentioned embodiments, and modifications can be made without departing from the gist of the present invention.

For example, various components can be added as auxiliary additives, if necessary, within a range that does not impair the characteristics shown above.

[0117]

The non-reducing dielectric ceramic composition of the present invention is
1260 to 1300 in neutral or reducing atmosphere
Even if it is fired at a temperature of ° C, the structure is not reduced to become a semiconductor. Furthermore, this non-reducing dielectric porcelain composition,
When the product has a high dielectric constant of 3,000 or more, and the insulation resistance value is expressed by the product of the capacitance (CR product), it shows 6000 or more, and the rate of change of the capacitance temperature is also specified by EIA.
Satisfies the 7R characteristic, and further exhibits excellent characteristics without deterioration of characteristics under high temperature and high humidity.

Therefore, when the non-reducing dielectric ceramic composition according to the present invention is used as a dielectric material of a multilayer capacitor, a base metal represented by Ni or the like can be used as an internal electrode material. Therefore, compared with the conventional one using a noble metal such as Pd, it is possible to significantly reduce the cost without deteriorating all the characteristics including weather resistance such as high temperature load and room temperature load characteristics. .

In addition, in the non-reducing dielectric ceramic composition of the present invention, the main component is such that the compounding ratio of BaTiO ₃ , the rare earth oxide (Re ₂ O ₃ ) and Co ₂ O ₃ is
Of the main component 100 mol%, BaTiO ₃ 92.0
˜99.4 mol%, Re ₂ O ₃ 0.3-4.0 mol%, and Co ₂ O ₃ 0.3-4.0 mol%, which are preferable. It is possible to improve the value and the dielectric constant.

Further, in the non-reducing dielectric ceramic composition of the present invention, the BaO of the subcomponent is the main component 1
It is preferably in the range of 0.05 to 4.0 mol% with respect to 00 mol%, whereby the dielectric loss tan
It is possible to improve δ, insulation resistance, and sinterability.

Further, in the non-reducing dielectric ceramic composition of the present invention, the MnO of the sub-component is the main component 1
It is preferably in the range of 0.05 to 2.0 mol% with respect to 00 mol%, whereby the insulation resistance value, high temperature load characteristic, and moisture resistance load characteristic can be improved.

Further, in the non-reducing dielectric ceramic composition of the present invention, the MgO of the sub ingredient is mixed with the main ingredient 1
It is preferably in the range of 0.5 to 5.0 mol% with respect to 00 mol%, which makes it possible to improve the temperature change rate of the capacitance, the dielectric constant, and the insulation resistance value.

Further, in the non-reducing dielectric ceramic composition of the present invention, at least one of the sub-components NiO and Al ₂ O ₃ is 0.3% with respect to 100 mol% of the main component. It is preferably in the range of 3.0 mol% to improve the insulation resistance value, dielectric constant and dielectric loss.

In the non-reducing dielectric ceramic composition of the present invention, it is preferable that the content of the alkali metal oxide contained as an impurity in BaTiO ₃ is 0.04 wt% or less. It is possible to improve the dielectric constant.

Further, the non-reducing dielectric ceramic composition of the present invention is characterized by containing BaZrO ₃ as a sub ingredient in a predetermined compounding ratio.

As a result, even if firing is performed at a temperature of 1260 to 1300 ° C. in a neutral or reducing atmosphere, the structure will not be reduced and become a semiconductor. Further, this non-reducing dielectric ceramic composition exhibits a high dielectric constant of 3000 or more, and a high insulation resistance value of 7,000 or more when the insulation resistance value is represented by the product (CR product) with the electrostatic capacitance. In addition, the capacity temperature change rate also satisfies the X7R characteristics specified by EIA, and exhibits excellent characteristics without deterioration of characteristics under high temperature and high humidity.

Therefore, when the non-reducing dielectric ceramic composition according to the present invention is used as a dielectric material of a laminated capacitor, a base metal represented by Ni or the like can be used as an internal electrode. Therefore, compared with the conventional one using a noble metal such as Pd, it is possible to significantly reduce the cost without deteriorating all the characteristics including weather resistance such as high temperature load and room temperature load characteristics. .

In the non-reducing dielectric ceramic composition of the present invention, the BaZrO ₃ is BaTiO ₃ and T
b ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , and at least one rare earth oxide (Re ₂ O ₃ ) selected from Er ₂ O ₃ ;
It is preferable that the content is in the range of 0.3 to 4.0 mol% with respect to 100 mol% of the main component containing Co ₂ O ₃ in a predetermined mixing ratio, thereby improving the insulation resistance value. Is possible.

In the non-reducing dielectric ceramic composition of the present invention, the oxide glass is 0.5 parts by weight based on 100 parts by weight of the total of the main component and the subcomponents other than the oxide glass. It is preferably in the range of about 2.5 parts by weight, which makes it possible to improve sinterability, resistance to reduction, and dielectric constant.

In the non-reducing dielectric ceramic composition of the present invention, the oxide glass has X of 0.30 ≦ X ≦.
Within the range of 1.00 and mol% is (Li _{2
O, (Si X Ti 1-} X) in the ternary composition diagram of _{O 2, M), A (} 20,80,0), B (10,80,10),
C (10, 70, 20), D (35, 45, 20), E
(45,45,10), and F (45,55,0),
On the inside and inside of the hexagon with the vertex as
In the case of the composition on A, X is preferably represented by 0.30 ≦ X <1.00), which makes it possible to improve sinterability, high temperature load characteristics, and moisture resistance load characteristics. is there.

[Brief description of drawings]

[1] _{Li 2 O- (Si X Ti 1} -X) O 2 -M (M: A
A three-component composition diagram of at least one of l ₂ O ₃ and ZrO ₂ .

Claims (11)

[Claims] 1. BaTiO ₃ and Tb ₂ O ₃ , Dy ₂ O ₃ ,
At least one rare earth oxide (Re ₂ O ₃ ) selected from Ho ₂ O ₃ and Er ₂ O ₃ and Co ₂ O ₃ are contained in a predetermined mixing ratio with respect to the main component, and a sub-component. As B
and aO-, and MnO, and MgO, NiO, Al ₂ and at least one of O _3, and _{Li 2 O- (Si X Ti 1} -X) O 2 -M ( wherein, M is Al ₂ O _3, At least one of ZrO ₂ is shown, and X is 0 <X ≦ 1.00) as a main component, and a non-reducing feature is contained. Dielectric porcelain composition. Wherein said main component, the compounding ratio of the BaTiO ₃ as the rare earth oxide and (Re ₂ O ₃₎ and the Co ₂ O ₃ is one of the main component as 100 mol%, BaTiO ₃
92.0 to 99.4 mol%, Re ₂ O ₃ 0.3~
4.0 mol%, and Co ₂ O ₃ 0.3 to 4.0
The non-reducing dielectric ceramic composition according to claim 1, wherein the non-reducing dielectric ceramic composition is in the range of mol%. 3. The BaO of the subcomponent is in the range of 0.05 to 4.0 mol% with respect to 100 mol% of the main component, according to claim 1 or 2. The non-reducing dielectric ceramic composition described. 4. The MnO of the sub-component is in the range of 0.05 to 2.0 mol% with respect to 100 mol% of the main component, according to claim 1. The non-reducing dielectric ceramic composition according to any one of claims. 5. The MgO sub-component is in the range of 0.5 to 5.0 mol% with respect to 100 mol% of the main component, according to claim 1. The non-reducing dielectric ceramic composition according to any one of claims. 6. At least one of the sub-components NiO and Al ₂ O ₃ is in the range of 0.3 to 3.0 mol% with respect to 100 mol% of the main component. The non-reducing dielectric ceramic composition according to any one of claims 1 to 5. 7. The non-reduced BaTiO _{3 according} to any one of claims 1 to 6, wherein the content of the alkali metal oxide contained as an impurity is 0.04% by weight or less. Dielectric porcelain composition. 8. The method according to claim 1, wherein BaZrO ₃ is contained as a sub-component in a predetermined compounding ratio.
The non-reducing dielectric ceramic composition according to any one of 1. 9. The BaZrO ₃ is BaTiO ₃ and
At least one rare earth oxide (Re ₂ O ₃ ) selected from Tb ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , and Er ₂ O _3.
And Co ₂ O ₃ in a predetermined compounding ratio 10
It exists in the range of 0.3-4.0 mol% with respect to 0 mol%, The non-reducing dielectric ceramic composition of Claim 8 characterized by the above-mentioned. 10. The oxide glass is in the range of 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the total of the main component and the subcomponents excluding the oxide glass. The non-reducing dielectric ceramic composition according to any one of claims 1 to 9. 11. The oxide glass has X of 0.30 ≦.
Within the range of X ≦ 1.00, and the mol% is (L
i ₂ O, in the ternary composition diagram of _{(Si X Ti 1-X)} O 2, M), A (20,80,0), B (10,80,1
0), C (10, 70, 20), D (35, 45, 2)
0), E (45,45,10), and F (45,5)
5,0) on the sides and inside of a hexagon with vertices (however, in the case of the composition on the straight line F-A, X is 0.30 ≦ X <
The non-reducing dielectric ceramic composition according to any one of claims 1 to 10, which is represented by the formula (1.00).