JP3106371B2 - Dielectric porcelain composition - Google Patents
Dielectric porcelain compositionInfo
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- JP3106371B2 JP3106371B2 JP03183581A JP18358191A JP3106371B2 JP 3106371 B2 JP3106371 B2 JP 3106371B2 JP 03183581 A JP03183581 A JP 03183581A JP 18358191 A JP18358191 A JP 18358191A JP 3106371 B2 JP3106371 B2 JP 3106371B2
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Description
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【産業上の利用分野】この発明は誘電体磁器組成物に関
し、特に積層コンデンサなどの材料として用いられる誘
電体磁器組成物に関する。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 used as a material for a multilayer capacitor or the like.
【０００２】[0002]
【従来の技術】従来より、高誘電率で、誘電率温度変化
の小さい誘電体磁器組成物としては、たとえば、ＢａＴ
ｉＯ3 を主成分とし、これにＢｉ2 Ｏ3 −ＴｉＯ2 ，Ｂ
ｉ2 Ｏ3 −ＳｎＯ2 ，Ｂｉ2 Ｏ3 −ＺｒＯ2 などのビス
マス化合物と希土類元素とを副成分として添加したもの
がある。また、ＢａＴｉＯ3 を主成分とし、これにビス
マス化合物とＭｇＯ，ＳｉＯ2 などを副成分として添加
したものも広く採用されている。2. Description of the Related Art Conventionally, as a dielectric ceramic composition having a high dielectric constant and a small change in dielectric constant temperature, for example, BaT
iO 3 as a main component, and Bi 2 O 3 —TiO 2 , B
There are those in which a bismuth compound such as i 2 O 3 —SnO 2 or Bi 2 O 3 —ZrO 2 and a rare earth element are added as subcomponents. Further, a material containing BaTiO 3 as a main component and a bismuth compound, MgO, SiO 2 or the like added thereto as a sub component has been widely adopted.
【０００３】一方、上記の組成の誘電体磁器組成物とは
別に、ＢａＴｉＯ3を主成分とし、これにＮｂ2 Ｏ5 ，
Ｎｄ2 Ｏ3 およびＭｎ，Ｃｒ，Ｆｅ，Ｎｉ，Ｃｏの酸化
物を副成分として添加したものもある（特開昭５１−１
４３８９９号，特開昭５７−９２５７５号）。こうした
組成の誘電体磁器組成物においても、平坦な誘電率温度
特性が得られると報告されている。On the other hand, apart from the dielectric ceramic composition having the above composition, BaTiO 3 is mainly used, and Nb 2 O 5 ,
In some cases, Nd 2 O 3 and oxides of Mn, Cr, Fe, Ni, and Co are added as subcomponents (Japanese Patent Laid-Open No. 51-1
43899, JP-A-57-92575). It has been reported that even a dielectric ceramic composition having such a composition can obtain flat dielectric temperature characteristics.
【０００４】また、最近の磁器コンデンサは小型化の傾
向にあり、特に積層コンデンサにおいては、磁器誘電体
の厚みが５〜１５μｍというものが実用化されつつあ
る。したがって、磁器組成物としては、高誘電率だけで
なく、磁器のグレインサイズが小さいこと、さらには電
圧依存性の小さいことも望まれている。Further, recent ceramic capacitors tend to be miniaturized. In particular, multilayer capacitors having a thickness of a ceramic dielectric of 5 to 15 μm are being put to practical use. Therefore, as the porcelain composition, not only a high dielectric constant but also a small grain size of the porcelain and a low voltage dependency are desired.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、ＢａＴ
ｉＯ3 を主成分とし、ビスマス化合物を添加した誘電体
磁器組成物は、高周波に対する誘電損失ｔａｎδが大き
く、誘電率が１０００〜２０００と低かった。また、誘
電率を高くすると、静電容量の温度変化率が大きくな
り、逆に、静電容量の温度変化率を小さくすると、誘電
率が低下するという相反する傾向を示していた。そのた
め、この誘電体磁器組成物をコンデンサの材料として用
いた場合、コンデンサの小型大容量化には限界があっ
た。However, BaT
The dielectric ceramic composition containing iO 3 as a main component and adding a bismuth compound had a large dielectric loss tan δ at high frequencies and a low dielectric constant of 1000 to 2000. In addition, when the dielectric constant is increased, the temperature change rate of the capacitance is increased, and conversely, when the temperature change rate of the capacitance is reduced, the dielectric constant is decreased. Therefore, when this dielectric porcelain composition is used as a material for a capacitor, there has been a limit in increasing the size and capacity of the capacitor.
【０００６】また、このような誘電体磁器組成物では、
焼成時にＢｉ2 Ｏ3 が蒸発して磁器に歪が生じたり、組
成割合が変化して必要な電気的特性にばらつきを生じた
りするという問題点があった。さらに、こうした組成物
を積層コンデンサの材料に用いた場合には、内部電極と
してＰｄあるいはＡｇ−Ｐｄ合金が用いられると、この
ＰｄとＢｉ2 Ｏ3 が反応して、電極の特性が損なわれて
しまう。そのため、Ｂｉ2 Ｏ3と反応しない高価なＰｔ
を、内部電極として使用せざるを得なかった。Further, in such a dielectric porcelain composition,
There have been problems in that Bi 2 O 3 evaporates during firing and distortion occurs in the porcelain, and the composition ratio changes to cause variations in required electrical characteristics. Further, when such a composition is used as a material for a multilayer capacitor, if Pd or an Ag—Pd alloy is used as an internal electrode, the Pd and Bi 2 O 3 react to deteriorate the characteristics of the electrode. I will. Therefore, expensive Pt that does not react with Bi 2 O 3
Had to be used as an internal electrode.
【０００７】特開昭５１−１４３８９９号に開示されて
いる組成の誘電体磁器組成物は、−２５℃〜＋８５℃の
狭い温度範囲においてさえ、−２７％以上の誘電率温度
変化率を示していた。そのため、−５５℃〜＋１２５℃
の広い温度範囲においては、±１５％以内の平坦な誘電
率温度特性を得ることができなかった。The dielectric ceramic composition having the composition disclosed in JP-A-51-143899 exhibits a dielectric constant temperature change rate of -27% or more even in a narrow temperature range of -25.degree. C. to + 85.degree. Was. Therefore, -55 ° C to + 125 ° C
In a wide temperature range, a flat dielectric temperature characteristic within ± 15% could not be obtained.
【０００８】また、特開昭５７−９２５７５号に開示さ
れている組成の誘電体磁器組成物は、−５５℃〜＋１２
５℃の温度範囲において、誘電率温度変化率は１５％以
下の値を示しているが、誘電率２８００以上、誘電損失
２．５％以下、焼成温度１２５０℃以下という条件を満
足するまでには至っていない。A dielectric porcelain composition having a composition disclosed in Japanese Patent Application Laid-Open No. 57-92575 has a temperature of -55 ° C. to + 12 ° C.
In the temperature range of 5 ° C., the temperature change rate of the dielectric constant shows a value of 15% or less, but it is necessary to satisfy the conditions of a dielectric constant of 2800 or more, a dielectric loss of 2.5% or less, and a firing temperature of 1250 ° C. Not reached.
【０００９】一方、３０００〜５０００の誘電率を有
し、平坦な誘電率温度特性を有する組成物が開示されて
いる（特開昭６４−４５７７２号）。しかし、これら大
きな誘電率を有する組成物は、焼成温度が１２８０℃以
上と高い。また、これらの誘電体磁器組成物は電圧依存
性が大きいため、最近の薄膜化に対応できず、小型大容
量の積層コンデンサを作製することができなかった。On the other hand, a composition having a dielectric constant of 3000 to 5000 and a flat dielectric constant-temperature characteristic has been disclosed (JP-A-64-45772). However, these compositions having a large dielectric constant have a high firing temperature of 1280 ° C. or higher. Further, since these dielectric ceramic compositions have a large voltage dependency, they cannot cope with recent thinning, and a small-sized and large-capacity multilayer capacitor cannot be produced.
【００１０】それゆえに、この発明の主たる目的は、誘
電率が３５００以上で、広い温度範囲にわたって静電容
量の温度変化率が小さく平坦で、誘電損失が小さく、電
圧依存性が小さく、グレインサイズが１μｍ以下と小さ
く、かつ１２５０℃以下という比較的低い温度で焼結す
ることが可能な、誘電体磁器組成物を提供することであ
る。Therefore, the main objects of the present invention are to provide a dielectric material having a dielectric constant of 3500 or more, a small temperature change rate of capacitance over a wide temperature range, a flat surface, a small dielectric loss, a small voltage dependency, and a small grain size. An object of the present invention is to provide a dielectric ceramic composition which is as small as 1 μm or less and can be sintered at a relatively low temperature of 1250 ° C. or less.
【００１１】[0011]
【課題を解決するための手段】この発明は、不純物とし
てのアルカリ金属酸化物の含有量が０．０３重量％以下
のＢａＴｉＯ3 １００重量部に対し、Ｎｂ2 Ｏ5 を０．
６〜２．０重量部と、Ｃｏ2 Ｏ3 を０．１〜０．８重量
部と、ＭｎＯ2 を０．０５〜０．３重量部と、Ｌａ2 Ｏ
3 ，Ｎｄ2 Ｏ3 ，ＣｅＯ2 ，Ｐｒ6 Ｏ11，Ｄｙ2 Ｏ3 ，
Ｓｍ2 Ｏ3 のうち１種類以上からなる希土類酸化物ＲＯ
（ただし、Ｎｄ 2 Ｏ 3 を単独で使用する場合を除く）を
０．０２〜０．５重量部と、ＢａＯ−Ｂ2 Ｏ3 −Ｌｉ2
Ｏ−ＳｉＯ2 を主成分とする酸化物ガラスを０．０５〜
１．０重量部とを含有し、そのグレインサイズが１μｍ
以下である、誘電体磁器組成物であるAccording to the present invention, Nb 2 O 5 is added to 100 parts by weight of BaTiO 3 containing 0.03% by weight or less of alkali metal oxide as an impurity.
6 to 2.0 parts by weight, 0.1 to 0.8 parts by weight of Co 2 O 3 , 0.05 to 0.3 parts by weight of MnO 2 , La 2 O
3, Nd 2 O 3, CeO 2, Pr 6 O 11, Dy 2 O 3,
Rare earth oxides RO comprising at least one of Sm 2 O 3
(Except when Nd 2 O 3 is used alone) in an amount of 0.02 to 0.5 part by weight, and BaO—B 2 O 3 —Li 2
0.05 The oxide glass mainly composed of O-SiO 2
1.0 parts by weight, and the grain size is 1 μm
The following is a dielectric porcelain composition
【００１２】[0012]
【作用】ＢａＴｉＯ3 ，Ｎｂ2 Ｏ3 ，Ｃｏ2 Ｏ3 系の高
誘電率組成物において、主成分であるＢａＴｉＯ3 中に
不純物として存在するＳｒＯ，ＣａＯなどのアルカリ土
類金属酸化物、Ｎａ2 Ｏ，Ｋ2 Ｏなどのアルカリ金属酸
化物、その他Ａｌ2 Ｏ3 ，ＳｉＯ2 などの酸化物のう
ち、特にＮａ2 Ｏ，Ｋ2 Ｏなどのアルカリ土類酸化物の
含有量が電気的特性に大きな影響を与える。また、希土
類酸化物ＲＯおよびＢａＯ−Ｂ2 Ｏ3 −Ｌｉ2 Ｏ−Ｓｉ
Ｏ2 を主成分とする酸化物ガラスを含有することによ
り、焼結性がよく、電圧依存性の小さい誘電体磁器組成
物が得られる。In a high dielectric constant composition based on BaTiO 3 , Nb 2 O 3 and Co 2 O 3 , alkaline earth metal oxides such as SrO and CaO present as impurities in BaTiO 3 as a main component, Na 2 Among alkaline metal oxides such as O and K 2 O, and other oxides such as Al 2 O 3 and SiO 2 , particularly, the content of alkaline earth oxides such as Na 2 O and K 2 O is affected by the electric characteristics. Have a big impact. In addition, rare earth oxide RO and BaO—B 2 O 3 —Li 2 O—Si
By containing an oxide glass containing O 2 as a main component, a dielectric ceramic composition having good sintering properties and low voltage dependency can be obtained.
【００１３】ここで、Ｎａ2 Ｏ，Ｋ2 Ｏなどのアルカリ
金属酸化物については、それがＢａＴｉＯ3 に対して不
純物として０．０３重量を超えると誘電率が低下し、３
５００以下の値となる。Ｎｂ2 Ｏ5 は、ＢａＴｉＯ3 １
００重量部に対して０．６重量部未満では、焼結性が悪
くなり、誘電損失が大きくなる。さらに、静電容量の温
度変化率が大きくなり、−５５〜＋１２５℃の温度範囲
で±１５％より大きな値になる。一方、Ｎｂ2 Ｏ5 が
２．０重量部を超えると、誘電率が低下して３５００以
下の値となる。Ｃｏ2 Ｏ3 は、ＢａＴｉＯ3 １００重量
部に対して０．１重量部未満では、目的とする平坦な誘
電率温度特性が得られない。一方、Ｃｏ2 Ｏ3 が０．８
重量部を超えると、誘電損失が著しく大きくなり、静電
容量の温度変化率が大きくなる。ＭｎＯ2 は、ＢａＴｉ
Ｏ3 １００重量部に対して、０．０５重量部未満では、
焼結性を向上させる効果に乏しく、かつ目的とする平坦
な誘電率温度特性が得られない。一方、ＭｎＯ2 が０．
３重量部を超えると、誘電率が３５００を超えず、誘電
損失も大きくなる。希土類酸化物ＲＯは、ＢａＴｉＯ3
１００重量部に対して０．０５重量部未満では、焼結性
を向上させる効果に乏しく、かつ交流電圧依存性が大き
くなる。一方、ＲＯが０．５重量部を超えると、Ｃｏ2
Ｏ3 の量が少ない場合には容量温度変化率が著しく大き
くなり、Ｃｏ2 Ｏ3 の量が多い場合には誘電率の低下が
著しく３５００以下となる。ＢａＯ−Ｂ2 Ｏ3 −Ｌｉ2
Ｏ−ＳｉＯ2 を主成分とする酸化物ガラスは、ＢａＴｉ
Ｏ3 １００重量部に対して０．０５重量部未満では、焼
結性を向上させる効果に乏しく、かつ交流電圧依存性が
大きくなる。一方、酸化物ガラスが１．０重量部を超え
ると、誘電率が低下する。[0013] Here, Na about 2 O, alkali metal oxides such as K 2 O, it permittivity decreases exceeds 0.03 weight as an impurity with respect to BaTiO 3, 3
The value is 500 or less. Nb 2 O 5 is BaTiO 3 1
If the amount is less than 0.6 parts by weight with respect to 00 parts by weight, the sinterability deteriorates and the dielectric loss increases. Furthermore, the temperature change rate of the capacitance becomes large, and becomes a value larger than ± 15% in a temperature range of −55 to + 125 ° C. On the other hand, when Nb 2 O 5 exceeds 2.0 parts by weight, the dielectric constant decreases to a value of 3500 or less. If Co 2 O 3 is less than 0.1 part by weight with respect to 100 parts by weight of BaTiO 3 , the desired flat dielectric temperature characteristic cannot be obtained. On the other hand, when Co 2 O 3 is 0.8
If the amount exceeds the weight part, the dielectric loss becomes extremely large, and the temperature change rate of the capacitance becomes large. MnO 2 is BaTi
If less than 0.05 part by weight with respect to 100 parts by weight of O 3 ,
The effect of improving the sinterability is poor, and the intended flat dielectric temperature characteristic cannot be obtained. On the other hand, when MnO 2 is 0.1.
If it exceeds 3 parts by weight, the dielectric constant does not exceed 3500 and the dielectric loss increases. The rare earth oxide RO is BaTiO 3
If the amount is less than 0.05 part by weight per 100 parts by weight, the effect of improving the sinterability is poor, and the AC voltage dependency becomes large. On the other hand, when RO exceeds 0.5 parts by weight, Co 2
When the amount of O 3 is small, the rate of change in capacitance with temperature is significantly increased, and when the amount of Co 2 O 3 is large, the dielectric constant is significantly reduced to 3500 or less. BaO-B 2 O 3 -Li 2
The oxide glass mainly composed of O—SiO 2 is made of BaTi
If the amount is less than 0.05 part by weight with respect to 100 parts by weight of O 3, the effect of improving the sinterability is poor and the dependency on the AC voltage becomes large. On the other hand, when the oxide glass exceeds 1.0 part by weight, the dielectric constant decreases.
【００１４】[0014]
【発明の効果】この発明によれば、＋２５℃における静
電容量を基準とした時、−５５℃〜＋１２５℃の広い温
度範囲にわたって静電容量の温度変化率が±１５％以内
と平坦で、かつ誘電損失が１．２％以下と小さく、交流
電界２００Ｖ／ｍｍを印加しても、３．０％以下と電圧
依存性が小さい誘電体磁器組成物が得られる。また、こ
の組成物は、このような平坦な温度特性であるにもかか
わらず、その誘電率が３５００以上と高い値を示してい
る他、グレインサイズが１μｍ以下と小さく、１２５０
℃以下という比較的低い温度で焼結することが可能であ
る。According to the present invention, when the capacitance at + 25 ° C. is used as a reference, the temperature change rate of the capacitance is flat within ± 15% over a wide temperature range from −55 ° C. to + 125 ° C. In addition, a dielectric ceramic composition having a small dielectric loss of 1.2% or less and a small voltage dependence of 3.0% or less even when an AC electric field of 200 V / mm is applied can be obtained. In addition, this composition has a high dielectric constant of 3500 or more despite having such flat temperature characteristics, and a small grain size of 1250 μm or less.
It is possible to perform sintering at a relatively low temperature of not more than ° C.
【００１５】したがって、この発明の誘電体磁器組成物
を用いれば、磁器誘電体層の厚みを薄くすることができ
る。そして、内部電極として３０Ａｇ−７０Ｐｄ（数字
は重量％）の使用が可能であり、安価かつ小型大容量で
温度特性の良好な積層セラミックコンデンサを得ること
ができる。Therefore, when the dielectric ceramic composition of the present invention is used, the thickness of the ceramic dielectric layer can be reduced. And 30Ag-70Pd (the number is% by weight) can be used as the internal electrode, and a low-cost, small-sized, large-capacity multilayer ceramic capacitor having good temperature characteristics can be obtained.
【００１６】この発明の上述の目的，その他の目的，特
徴および利点は、以下の実施例の詳細な説明から一層明
らかとなろう。The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments.
【００１７】[0017]
（実施例１）まず、出発原料として、種々の純度のＴｉ
Ｃｌ4 とＢａ（ＮＯ3 ）2 とを準備し、これらの原料を
ＢａイオンとＴｉイオンとのモル比が１．０００となる
ように秤量して秤量物を得た。この秤量物を蓚酸によっ
て、ＢａＴｉＯ（Ｃ2 Ｏ4 ）・４Ｈ2Ｏとして沈殿させ
沈殿物を得た。この沈殿物を７００℃以上の温度で加熱
分解して、ＢａＴｉＯ3 を合成した。この合成物を、平
均粒子径が１μｍ以下になるまで、乾式粉砕機によって
粉砕した。このようにして、表１に示すＡ〜Ｅの純度の
異なった５種類のＢａＴｉＯ3 を得た。(Example 1) First, as starting materials, various purity Ti
Cl 4 and Ba (NO 3 ) 2 were prepared, and these raw materials were weighed such that the molar ratio of Ba ions to Ti ions became 1.000 to obtain a weighed material. The weighed material was precipitated as BaTiO (C 2 O 4 ) · 4H 2 O with oxalic acid to obtain a precipitate. This precipitate was thermally decomposed at a temperature of 700 ° C. or more to synthesize BaTiO 3 . This synthesized product was pulverized by a dry pulverizer until the average particle diameter became 1 μm or less. Thus, five types of BaTiO 3 having different purities of A to E shown in Table 1 were obtained.
【００１８】[0018]
【表１】 [Table 1]
【００１９】次いで、原料として、Ｎｂ2 Ｏ5 ，Ｃｏ2
Ｏ3 ，ＭｎＯ2 ，希土類酸化物ＲＯおよびＢａＯ−Ｂ2
Ｏ3 −Ｌｉ2 Ｏ−ＳｉＯ2 を主成分とする酸化物ガラス
を用い、表２に示した割合の組成物が得られるように秤
量し、酢酸ビニル系バインダを加えて、１６時間湿式混
合を行って混合物を得た。Next, Nb 2 O 5 , Co 2
O 3 , MnO 2 , rare earth oxide RO and BaO—B 2
Using an oxide glass containing O 3 —Li 2 O—SiO 2 as a main component, the composition was weighed so as to obtain a composition having a ratio shown in Table 2, a vinyl acetate-based binder was added, and wet mixing was performed for 16 hours. The mixture was obtained.
【００２０】[0020]
【表２】 [Table 2]
【００２１】さらに、得られた混合物を乾燥し、造粒し
た後、２０００ｋｇ／ｃｍ2 の圧力で直径１０ｍｍ、厚
さ０．５ｍｍの円板状にプレス成形して成形体を得た。
その後、この成形体を、表３に示す焼成温度で２時間焼
成し、円板状の磁器を得た。Further, the obtained mixture was dried and granulated, and then press-formed into a disk having a diameter of 10 mm and a thickness of 0.5 mm at a pressure of 2000 kg / cm 2 to obtain a formed body.
Thereafter, the molded body was fired at the firing temperature shown in Table 3 for 2 hours to obtain a disc-shaped porcelain.
【００２２】得られた磁器表面を走査型電子顕微鏡に
て、倍率１５００倍で観察し、グレインサイズを測定し
た。The surface of the obtained porcelain was observed with a scanning electron microscope at a magnification of 1500 times, and the grain size was measured.
【００２３】そして、得られた磁器の主表面に銀電極を
焼き付けて測定試料（コンデンサ）とし、その室温での
誘電率（ε），誘電損失（ｔａｎδ）および温度変化に
対する静電容量の変化率を測定した。Then, a silver electrode is baked on the main surface of the obtained porcelain to obtain a measurement sample (capacitor). Was measured.
【００２４】この場合、誘電率（ε）および誘電損失
（ｔａｎδ）は、温度２５℃，１ｋＨｚ，１Ｖｒｍｓの
条件で測定した。また、温度変化に対する静電容量の変
化率については、２５℃での静電容量（Ｃ25）を基準と
して、−５５℃と＋１２５℃での温度変化率（ΔＣ／Ｃ
25）と、−５５℃〜＋１２５℃の間における温度変化率
が最大である値の絶対値、いわゆる最大変化率（｜ΔＣ
／Ｃ25｜max ）とを示した。さらに、周波数１ｋＨｚで
２００Ｖ／ｍｍの電界を印加した時の誘電損失（ｔａｎ
δ）を測定した。In this case, the dielectric constant (ε) and the dielectric loss (tan δ) were measured at a temperature of 25 ° C., 1 kHz, and 1 Vrms. The rate of change of capacitance with respect to temperature change is based on the capacitance (C 25 ) at 25 ° C., and the rate of change of temperature (ΔC / C at −55 ° C. and + 125 ° C.).
25 ) and the absolute value of the value at which the rate of temperature change between -55 ° C and + 125 ° C is the maximum, the so-called maximum rate of change (| ΔC
/ C 25 | max ). Furthermore, dielectric loss (tan) when an electric field of 200 V / mm is applied at a frequency of 1 kHz.
δ) was measured.
【００２５】以上の各試験の結果を、表３に合わせて示
す。The results of the above tests are shown in Table 3.
【００２６】[0026]
【表３】 [Table 3]
【００２７】表３から明らかなように、本発明の範囲内
にある磁器組成物は、誘電率（ε）がいずれも３５００
と高い。しかも、このような高誘電率にもかかわらず、
静電容量の変化率が小さく平坦な温度特性を示し、ＥＩ
Ａ規格に規定するＸ７Ｒ特性を満足している。また、誘
電損失（ｔａｎδ）も１．２％以下と小さく、２００Ｖ
／ｍｍの交流電界下でも、３．０％以下と小さい値を保
つ。グレインサイズも１．０μｍ以下と小さく、さらに
１２５０℃以下の比較的低温でも焼結可能である。As is clear from Table 3, the porcelain compositions falling within the scope of the present invention have a dielectric constant (ε) of 3500
And high. Moreover, despite such a high dielectric constant,
The rate of change of the capacitance is small and shows a flat temperature characteristic.
It satisfies the X7R characteristics specified in the A standard. Further, the dielectric loss (tan δ) is as small as 1.2% or less, and is 200 V
/ Mm even under an AC electric field of 3.0% or less. The grain size is as small as 1.0 μm or less, and sintering is possible even at a relatively low temperature of 1250 ° C. or less.
【００２８】次に、添加物である酸化物の添加量の範囲
を限定した理由を説明する。すなわち、Ｎｂ2 Ｏ5 につ
いて、その範囲を０．６〜２．０重量部としたのは、試
料番号１のように、０．６重量部未満では焼結温度が高
く、誘電損失が大きくなる。また、静電容量の温度変化
率が、−５５℃〜＋１２５℃の温度範囲で±１５％より
も大きな値となる。また、試料番号４のように、２．０
重量部を超えると誘電率が低下する。Next, the reason why the range of the additive amount of the oxide as an additive is limited will be described. That is, the Nb 2 O 5, to that the range as from 0.6 to 2.0 parts by weight, as in Sample No. 1, sintering temperature is high, the dielectric loss increases is less than 0.6 part by weight . Further, the temperature change rate of the capacitance becomes a value larger than ± 15% in a temperature range of −55 ° C. to + 125 ° C. In addition, as shown in sample number 4, 2.0
Exceeding parts by weight lowers the dielectric constant.
【００２９】Ｃｏ2 Ｏ3 について、その範囲を０．１〜
０．８重量部としたのは、試料番号７のように、０．１
重量部未満では、静電容量の温度変化率が、−５５℃〜
＋１２５℃の温度範囲で±１５％よりも大きな値とな
る。また、試料番号８のように、０．８重量部を超える
と、誘電損失が著しく大きくなり、静電容量の温度変化
率も大きくなる。The range of Co 2 O 3 is 0.1 to
0.8 parts by weight was used, as in sample number 7,
When the amount is less than the weight part, the temperature change rate of the capacitance is from −55 ° C.
The value is larger than ± 15% in the temperature range of + 125 ° C. If the amount exceeds 0.8 parts by weight, as in sample No. 8, the dielectric loss becomes extremely large, and the temperature change rate of the capacitance also becomes large.
【００３０】ＭｎＯ2 について、その範囲を０．０５〜
０．３重量部としたのは、試料番号１８のように、０．
０５重量部未満では、焼結性を向上させる効果が乏し
く、静電容量の温度変化率が大きくなる。また、試料番
号１９のように、０．３重量部を超えると、誘電率が３
５００を超えず、誘電損失が大きくなる。For MnO 2 , the range is from 0.05 to
The amount of 0.3 parts by weight was 0.1% as in Sample No. 18.
If the amount is less than 05 parts by weight, the effect of improving the sinterability is poor, and the temperature change rate of the capacitance becomes large. Further, as shown in Sample No. 19, if it exceeds 0.3 parts by weight, the dielectric constant becomes 3
It does not exceed 500, and the dielectric loss increases.
【００３１】Ｌａ2 Ｏ3 ，Ｎｄ2 Ｏ3 ，ＣｅＯ2 ，Ｐｒ
6 Ｏ11，Ｄｙ2 Ｏ3 ，Ｓｍ2 Ｏ3 のうち１種類以上から
なる希土類酸化物ＲＯ（ただし、Ｎｄ 2 Ｏ 3 を単独で使
用する場合を除く）について、その範囲を０．０２〜
０．５重量部とし、ＢａＯ−Ｂ2 Ｏ3 −Ｌｉ2 Ｏ−Ｓｉ
Ｏ2 を主成分とする酸化物ガラスを０．０５〜１．０重
量部としたのは、この組成範囲内では焼結性が改善さ
れ、電圧依存性が小さくなるが、試料番号１２，２２お
よび２３のように、希土類酸化物あるいは酸化物ガラス
の添加量が少ないと、焼結性が悪くなり、交流電圧依存
性が大きくなる。また、試料番号１３のように、酸化物
ガラスが１．０重量部を超えると、誘電率が３５００よ
り低くなる。さらに、試料番号２０のように、希土類酸
化物が０．３重量部を超え、Ｃｏ2 Ｏ3 の添加量が多い
と、誘電率が３５００より低くなる。また、試料番号２
１のように、ＲＯが０．３重量部を超え、Ｃｏ2 Ｏ3 の
添加量が少ない場合は、静電容量の温度変化率が、−５
５℃〜＋１２５℃の温度範囲で±１５％よりも大きな値
となる。La 2 O 3 , Nd 2 O 3 , CeO 2 , Pr
Rare earth oxide RO composed of at least one of 6 O 11 , Dy 2 O 3 and Sm 2 O 3 (however, Nd 2 O 3 is used alone)
Use range ) of 0.02 to
0.5 parts by weight, and BaO—B 2 O 3 —Li 2 O—Si
The reason why the oxide glass containing O 2 as the main component is 0.05 to 1.0 part by weight is that the sinterability is improved and the voltage dependency is reduced within this composition range. When the addition amount of the rare earth oxide or oxide glass is small as in Examples 23 and 23, the sinterability deteriorates and the AC voltage dependency increases. Also, as in Sample No. 13, when the oxide glass exceeds 1.0 part by weight, the dielectric constant becomes lower than 3500. Further, as in Sample No. 20, when the rare earth oxide exceeds 0.3 parts by weight and the amount of Co 2 O 3 added is large, the dielectric constant becomes lower than 3500. Sample No. 2
When the RO exceeds 0.3 parts by weight and the addition amount of Co 2 O 3 is small as in 1, the temperature change rate of the capacitance is −5.
The value is larger than ± 15% in a temperature range of 5 ° C. to + 125 ° C.
【００３２】さらに、アルカリ金属の含有量を０．０３
重量％以下としたのは、試料番号２４のように、０．０
３重量％を超えると誘電率が３５００を超えない。Further, the content of the alkali metal is set to 0.03
% Or less, as in sample No. 24,
If it exceeds 3% by weight, the dielectric constant does not exceed 3500.
【００３３】（実施例２）実施例１の試料番号５および
試料番号２３の誘電体セラミック原料粉末を用意した。
この誘電体セラミック原料粉末に、ポリビニルブチラー
ル系バインダおよびエタノールなどの有機溶剤を加え、
ボールミルによって湿式混合して、セラミック・スラリ
ーを調整した。その後、このセラミック・スラリーを、
ドクターブレード法によってシート成形し、厚み１２μ
ｍの矩形のグリーンシートを得た。(Example 2) Dielectric ceramic raw material powders of Sample Nos. 5 and 23 of Example 1 were prepared.
To this dielectric ceramic raw material powder, add an organic solvent such as polyvinyl butyral-based binder and ethanol,
A ceramic slurry was prepared by wet mixing with a ball mill. Then, this ceramic slurry is
Sheet molded by doctor blade method, thickness 12μ
m rectangular green sheets were obtained.
【００３４】次に、このセラミック・グリーンシート上
に、Ｐｄを主体とする導電ペーストを印刷し、内部電極
を構成するための導電ペースト層を形成した。そして、
導電ペースト層が形成されたセラミック・グリーンシー
トを、導電ペースト層の引き出されている側が互い違い
となるように複数枚積層し、積層体を得た。Next, a conductive paste mainly composed of Pd was printed on the ceramic green sheet to form a conductive paste layer for forming internal electrodes. And
A plurality of ceramic green sheets on which the conductive paste layer was formed were laminated such that the side from which the conductive paste layer was drawn out was alternated, to obtain a laminate.
【００３５】得られた積層体を空気中において、表４に
示す温度で２時間焼成した。焼成後、得られたセラミッ
ク焼結体の両端面に銀ペーストを塗布し、大気中におい
て７５０℃の温度で焼き付け、内部電極と電気的に接続
された外部電極を形成した。The obtained laminate was fired in air at a temperature shown in Table 4 for 2 hours. After firing, a silver paste was applied to both end surfaces of the obtained ceramic sintered body and baked at 750 ° C. in the air to form external electrodes electrically connected to the internal electrodes.
【００３６】上述のようにして得られた積層コンデンサ
の外形寸法は、幅３．２ｍｍ，長さ１．６ｍｍ，厚さ
１．２ｍｍであり、内部電極間に介在する誘電体セラミ
ック層の厚みは８μｍである。また、有効誘電体セラミ
ック層の総数は１９であり、一層当たりの対向電極の面
積は２．１ｍｍ2 である。The external dimensions of the multilayer capacitor obtained as described above are 3.2 mm in width, 1.6 mm in length and 1.2 mm in thickness, and the thickness of the dielectric ceramic layer interposed between the internal electrodes is 8 μm. The total number of effective dielectric ceramic layers is 19, and the area of the counter electrode per layer is 2.1 mm 2 .
【００３７】静電容量（Ｃ）および誘電損失（ｔａｎ
δ）を測定するために、自動ブリッジ式測定器を用い
て、各試料の積層コンデンサに１ｋＨｚ，１Ｖｒｍｓの
電圧を印加した。次に、２５℃，１２５℃の絶縁抵抗
（Ｒ）を測定するために、絶縁抵抗計を用いて、１６Ｖ
の電圧を２分間印加した。そして、静電容量（Ｃ）と絶
縁抵抗（Ｒ）との積、すなわちＣＲ積を求めた。The capacitance (C) and the dielectric loss (tan)
In order to measure δ), a voltage of 1 kHz and 1 Vrms was applied to the multilayer capacitor of each sample using an automatic bridge type measuring device. Next, in order to measure the insulation resistance (R) at 25 ° C. and 125 ° C., an insulation resistance meter was used to measure 16V.
Was applied for 2 minutes. Then, the product of the capacitance (C) and the insulation resistance (R), that is, the CR product was obtained.
【００３８】また、温度変化に対する静電容量の変化率
を測定した。さらに、１ｋＨｚ，１Ｖｒｍｓの電圧を印
加した上に、直流電圧を１６Ｖ重畳した時の静電容量の
変化率を測定した。なお、温度変化に対する静電容量の
変化率については、２５℃での静電容量（Ｃ25）を基準
として、−５５℃および＋１２５℃での温度変化率（Δ
Ｃ／Ｃ25）と、−５５℃〜＋１２５℃の間における温度
変化率が最大である値の絶対値、いわゆる最大変化率
（｜ΔＣ／Ｃ25｜max ）とを示した。Further, the change rate of the capacitance with respect to the temperature change was measured. Further, the rate of change in capacitance when a DC voltage of 16 V was superimposed on a voltage of 1 kHz and 1 Vrms was measured. The rate of change of the capacitance with respect to the temperature change is based on the capacitance (C 25 ) at 25 ° C., and the rate of change of the temperature at −55 ° C. and + 125 ° C. (Δ
C / C 25 ) and the absolute value of the value at which the temperature change rate is maximum between −55 ° C. and + 125 ° C., that is, the so-called maximum change rate (| ΔC / C 25 | max ).
【００３９】以上の各試験の結果を、表４に合わせて示
す。The results of the above tests are shown in Table 4.
【００４０】[0040]
【表４】 [Table 4]
【００４１】表４から明らかなように、本発明の範囲内
にある試料番号５の積層セラミックコンデンサは、大き
な誘電率が得られるにもかかわらず、静電容量の変化率
が小さく平坦な温度特性を示し、誘電損失も小さい。ま
た、この積層セラミックコンデンサは、絶縁抵抗にも優
れ、直流電圧を重畳した時の容量変化率も小さい。As is clear from Table 4, the multilayer ceramic capacitor of Sample No. 5 within the scope of the present invention has a small capacitance change rate and a flat temperature characteristic despite obtaining a large dielectric constant. And the dielectric loss is also small. The multilayer ceramic capacitor also has excellent insulation resistance and a small rate of change in capacitance when a DC voltage is superimposed.
【００４２】このように、本発明の組成による積層セラ
ミックコンデンサは、誘電体セラミック層が８μｍと薄
くなっても良好な特性を示し、小型大容量の積層セラミ
ックコンデンサとして期待できる。さらに、焼成温度が
１２５０℃以下と低いため、内部電極として３０Ａｇ−
７０Ｐｄ（数字は重量％）の使用が可能である。As described above, the multilayer ceramic capacitor according to the composition of the present invention shows good characteristics even when the dielectric ceramic layer is as thin as 8 μm, and can be expected as a small-sized and large-capacity multilayer ceramic capacitor. Furthermore, since the firing temperature is as low as 1250 ° C. or less, 30 Ag-
It is possible to use 70 Pd (the number is% by weight).
【００４３】これに対して、本発明の範囲外の試料番号
２３の積層セラミックコンデンサは、誘電体セラミック
層が８μｍと薄くなると大きな誘電率が得られるもの
の、静電容量の温度変化率が大きく、ＥＩＡ規格に規定
するＸ７Ｒ特性を満足しない。また、この積層セラミッ
クコンデンサは、誘電損失も大きく、直流電圧を重畳し
た時の容量変化率も大きい。さらに、このコンデンサ
は、高温（１２５℃）での絶縁抵抗が低く、焼成温度も
高い。On the other hand, the multilayer ceramic capacitor of Sample No. 23 outside the scope of the present invention has a large dielectric constant when the dielectric ceramic layer is thinned to 8 μm, but has a large capacitance temperature change rate. Does not satisfy the X7R characteristics specified in the EIA standard. Further, this multilayer ceramic capacitor has a large dielectric loss and a large capacitance change rate when a DC voltage is superimposed. Further, this capacitor has a low insulation resistance at a high temperature (125 ° C.) and a high firing temperature.
【００４４】なお、上記実施例では、ＢａＴｉＯ3 とし
て蓚酸法によって作製したものを用いたが、これに限定
されるものではなく、アルコキシド法や共沈法によって
作製されたＢａＴｉＯ3 や、たとえば、ＢａＣＯ3 とＴ
ｉＯ2 の粉末を用いて作製したＢａＴｉＯ3 でも同様の
効果が得られる。また、その他の添加物を酸化物粉末と
して添加したが、Ｎｂ，Ｃｏ，Ｍｎおよび希土類元素Ｒ
を、酸化物換算で本発明の請求範囲になるように配合す
れば、溶液による添加でも同様の効果が得られる。In the above embodiment, BaTiO 3 produced by the oxalic acid method was used. However, the present invention is not limited to this. BaTiO 3 produced by the alkoxide method or the coprecipitation method, for example, BaCO 3 is used. 3 and T
The same effect can be obtained with BaTiO 3 produced using iO 2 powder. Further, other additives were added as oxide powders, but Nb, Co, Mn and rare earth element R were added.
Is added so as to fall within the scope of the present invention in terms of oxides, the same effect can be obtained by addition of a solution.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平５−6711（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01B 3/12 303 C04B 35/46 H01G 4/12 358 ────────────────────────────────────────────────── (5) References JP-A-5-6711 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H01B 3/12 303 C04B 35/46 H01G 4 / 12 358
Claims (1)
有量が０．０３重量％以下のＢａＴｉＯ3 １００重量部
に対し、 Ｎｂ2 Ｏ5 を０．６〜２．０重量部、 Ｃｏ2 Ｏ3 を０．１〜０．８重量部、 ＭｎＯ2 を０．０５〜０．３重量部、 Ｌａ2 Ｏ3 ，Ｎｄ2 Ｏ3 ，ＣｅＯ2 ，Ｐｒ6 Ｏ11，Ｄｙ
2 Ｏ3 ，Ｓｍ2 Ｏ3 のうち１種類以上からなる希土類酸
化物ＲＯ（ただし、Ｎｄ 2 Ｏ 3 を単独で使用する場合を
除く）を０．０２〜０．５重量部、およびＢａＯ−Ｂ2
Ｏ3 −Ｌｉ2 Ｏ−ＳｉＯ2 を主成分とする酸化物ガラス
を０．０５〜１．０重量部含有し、そのグレインサイズ
が１μｍ以下である、誘電体磁器組成物。1. Nb 2 O 5 : 0.6 to 2.0 parts by weight, Co 2 O 3: 100 parts by weight of BaTiO 3 containing 0.03% by weight or less of alkali metal oxide as an impurity the 0.1 to 0.8 parts by weight, the MnO 2 0.05 to 0.3 parts by weight, La 2 O 3, Nd 2 O 3, CeO 2, Pr 6 O 11, Dy
Rare earth oxide RO composed of at least one of 2 O 3 and Sm 2 O 3 (However, when Nd 2 O 3 is used alone,
0.02 to 0.5 parts by weight ) and BaO-B 2
A dielectric ceramic composition containing 0.05 to 1.0 parts by weight of an oxide glass mainly containing O 3 —Li 2 O—SiO 2 and having a grain size of 1 μm or less.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03183581A JP3106371B2 (en) | 1991-06-27 | 1991-06-27 | Dielectric porcelain composition |
| DE19924215638 DE4215638C2 (en) | 1991-05-13 | 1992-05-12 | Dielectric, ceramic composition |
| FR9205816A FR2678605A1 (en) | 1991-05-13 | 1992-05-13 | COMPOSITION OF DIELECTRIC CERAMIC. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03183581A JP3106371B2 (en) | 1991-06-27 | 1991-06-27 | Dielectric porcelain composition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0512918A JPH0512918A (en) | 1993-01-22 |
| JP3106371B2 true JP3106371B2 (en) | 2000-11-06 |
Family
ID=16138323
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03183581A Expired - Lifetime JP3106371B2 (en) | 1991-05-13 | 1991-06-27 | Dielectric porcelain composition |
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| Country | Link |
|---|---|
| JP (1) | JP3106371B2 (en) |
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1991
- 1991-06-27 JP JP03183581A patent/JP3106371B2/en not_active Expired - Lifetime
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| Publication number | Publication date |
|---|---|
| JPH0512918A (en) | 1993-01-22 |
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