JPH08167327A - Dielectric porcelain composition - Google Patents

Abstract

PURPOSE: To provide a composition with high specific dielectric constant, high Q value, small temperature coefficient of resonance frequency and low sintering temperature in a dielectric porcelain used in a microwave region. CONSTITUTION: A dielectric porcelain comprises calcium oxide, lead oxide, magnesium oxide, cobalt oxide, niobium oxide and titanium oxide, and is represented by the following chemical formula 4. The dielectric porcelain has a low sintering temperature, high specific dielectric constant of 40 or more, a temperature coefficient of resonance frequency of almost 0ppm/ deg.C, and allows a dielectric resonator to be made compact and have high performance. Chemical formula 4: (Ca1-x Pb)x [ Mg1-z Co2 )1/3 Nb2/3 }1-y Tiy ]O3 .

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明はマイクロ波領域などで使
用さ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 ceramic composition used in the microwave range and the like.

【０００２】[0002]

【従来の技術】近年、自動車電話や可搬型電話、または
衛星放送など、マイクロ波領域の電磁波を利用する通信
の進展にともない、機器の小型化が要求されている。こ
のためには、機器を構成する個々の部品が小型化される
必要がある。誘電体はこれらの機器において、フィルタ
素子や発振素子に誘電体共振器として組み込まれてい
る。誘電体共振器の大きさは同じ共振モードを利用する
場合、誘電体材料の持つ比誘電率（ε_r ）の平方根に逆
比例するため、小型の誘電体共振器を作製するには、高
い比誘電率を有する材料が必要である。加えて、誘電体
共振器として実用化するためには、マイクロ波領域で低
損失であること、すなわちＱ値が高いこと、さらに共振
周波数の温度係数（τ_f ）が小さいことが必要である。2. Description of the Related Art In recent years, with the progress of communication using electromagnetic waves in the microwave range, such as car telephones, portable telephones, and satellite broadcasting, miniaturization of equipment is required. For this purpose, it is necessary to reduce the size of individual parts that make up the device. In these devices, the dielectric is incorporated as a dielectric resonator in a filter element or an oscillating element. When the same resonance mode is used, the size of the dielectric resonator is inversely proportional to the square root of the relative permittivity (ε _r ) of the dielectric material. Materials with a dielectric constant are needed. In addition, for practical use as a dielectric resonator, it is necessary that the loss be low in the microwave region, that is, the Q value be high, and that the temperature coefficient (τ _f ) of the resonance frequency be small.

【０００３】従来誘電体共振器用のマイクロ波誘電体と
して、Ｂａ（Ｚｎ_1/3Ｔａ_2/3Ｏ₃）系のようにＡサイト
にＢａを含むペロブスカイト系の磁器組成物が、例えば
特公昭５９−４８４８４号公報に提案されている。これ
らの誘電体は、非常に高いＱ値をもっている。As a microwave dielectric material for a conventional dielectric resonator, a perovskite-based porcelain composition containing Ba at the A site, such as Ba (Zn _1/3 Ta _2/3 O ₃ ) system, has been disclosed, for example, in Japanese Examined Patent Publication 59. -48484. These dielectrics have very high Q values.

【０００４】[0004]

【発明が解決しようとする課題】しかし前記誘電体磁器
組成物では比誘電率が３０程度と低く、小型化の上で実
用性に乏しいという問題があった。したがって、誘電体
共振器を小型化するため、より比誘電率が高く、高いＱ
値と小さい共振周波数の温度係数をもつ誘電体磁器の開
発が望まれていた。また、前記誘電体磁器組成物の焼結
温度は1400℃以上と高いため、製造コストの面からより
焼結温度の低い誘電体磁器の開発が望まれていた。However, the above-mentioned dielectric ceramic composition has a problem that it has a low relative permittivity of about 30 and is impractical for miniaturization. Therefore, since the dielectric resonator is downsized, the relative dielectric constant is higher and the Q factor is higher.
It has been desired to develop a dielectric porcelain having a low temperature coefficient and a small resonance frequency temperature coefficient. Further, since the sintering temperature of the dielectric ceramic composition is as high as 1400 ° C. or higher, development of a dielectric ceramic having a lower sintering temperature has been desired from the viewpoint of manufacturing cost.

【０００５】本発明は、上記の課題を解決するため、マ
イクロ波領域で使用する誘電体磁器において、高い比誘
電率とＱ値を有し、かつ小さい共振振周波数の温度係数
を同時に満足させ、かつ焼結温度の低い誘電体磁器組成
物を提供することを目的としている。In order to solve the above problems, the present invention has a dielectric ceramic used in the microwave region, which has a high relative permittivity and a Q value and simultaneously satisfies a small temperature coefficient of resonance vibration frequency. Moreover, it is an object to provide a dielectric ceramic composition having a low sintering temperature.

【０００６】[0006]

【課題を解決するための手段】前記目的を達成するた
め、本発明の第１の誘電体磁器組成物は、酸化カルシウ
ム、酸化マグネシウム、酸化コバルト、及び酸化ニオブ
からなり、前記式（化１）で示される組成物である。In order to achieve the above object, the first dielectric ceramic composition of the present invention comprises calcium oxide, magnesium oxide, cobalt oxide, and niobium oxide, and has the above formula (Formula 1). Is a composition represented by.

【０００７】また、本発明の第２の誘電体磁器組成物
は、酸化カルシウム、酸化マグネシウム、酸化コバル
ト、酸化ニオブ、及び酸化チタンからなり、前記式（化
２）で示される組成物である。The second dielectric ceramic composition of the present invention is a composition represented by the above formula (Formula 2), which is composed of calcium oxide, magnesium oxide, cobalt oxide, niobium oxide, and titanium oxide.

【０００８】また、本発明の第３の誘電体磁器組成物
は、酸化カルシウム、酸化鉛、酸化マグネシウム、酸化
コバルト、及び酸化ニオブからなり、前記式（化３）で
示される組成物である。The third dielectric ceramic composition of the present invention is a composition represented by the above formula (Formula 3), which is composed of calcium oxide, lead oxide, magnesium oxide, cobalt oxide, and niobium oxide.

【０００９】また、本発明の第４の誘電体磁器組成物
は、酸化カルシウム、酸化鉛、酸化マグネシウム、酸化
コバルト、酸化ニオブ、及び酸化チタンからなり、前記
式（化４）で示される組成物である。The fourth dielectric ceramic composition of the present invention is composed of calcium oxide, lead oxide, magnesium oxide, cobalt oxide, niobium oxide, and titanium oxide and is represented by the above formula (Formula 4). Is.

【００１０】[0010]

【作用】前記本発明の第１の誘電体磁器組成物によれ
ば、酸化カルシウム、酸化マグネシウム、及び酸化ニオ
ブからなり、前記式（化１）で示される組成物であるこ
とにより、高い比誘電率とＱ値、かつ小さい共振振周波
数の温度係数を有し、さらに低い焼結温度を持つ誘電体
磁器組成物を達成できる。According to the first dielectric ceramic composition of the present invention, which has a high dielectric constant, it is composed of calcium oxide, magnesium oxide and niobium oxide and is represented by the formula (Formula 1). It is possible to achieve a dielectric porcelain composition having a low coefficient of resonance and a frequency coefficient, a small temperature coefficient of resonance frequency, and a lower sintering temperature.

【００１１】前記本発明の第２の誘電体磁器組成物によ
れば、酸化カルシウム、酸化マグネシウム、酸化ニオ
ブ、及び酸化タンタルからなり、前記式（化２）で示さ
れる組成物であることにより、同様に高い比誘電率とＱ
値、かつ小さい共振振周波数の温度係数を有し、さらに
低い焼結温度を持つ誘電体磁器組成物を達成できる。According to the second dielectric porcelain composition of the present invention, which is composed of calcium oxide, magnesium oxide, niobium oxide and tantalum oxide, and which is represented by the above formula (Formula 2), Similarly high dielectric constant and Q
It is possible to achieve a dielectric ceramic composition that has a low temperature coefficient of resonance vibration frequency and a lower sintering temperature.

【００１２】また、前記本発明の第３の誘電体磁器組成
物によれば、酸化カルシウム、酸化鉛、酸化マグネシウ
ム、酸化コバルト、及び酸化ニオブからなり、前記式
（化３）で示される組成物であることにより、前記同
様、高い比誘電率とＱ値、かつ小さい共振振周波数の温
度係数を有し、さらに低い焼結温度を持つ誘電体磁器組
成物を達成できる。Further, according to the third dielectric ceramic composition of the present invention, a composition comprising calcium oxide, lead oxide, magnesium oxide, cobalt oxide, and niobium oxide and represented by the above formula (Formula 3) Thus, similarly to the above, it is possible to achieve a dielectric ceramic composition having a high relative dielectric constant, a Q value, a small temperature coefficient of resonance vibration frequency, and a lower sintering temperature.

【００１３】また、前記本発明の第４の誘電体磁器組成
物によれば、酸化カルシウム、酸化鉛、酸化マグネシウ
ム、酸化コバルト、酸化ニオブ、及び酸化チタンからな
り、前記式（化４）で示される組成物であることによ
り、前記同様、高い比誘電率とＱ値、かつ小さい共振振
周波数の温度係数を有し、さらに低い焼結温度を持つ誘
電体磁器組成物を達成できる。According to the fourth dielectric ceramic composition of the present invention, it is composed of calcium oxide, lead oxide, magnesium oxide, cobalt oxide, niobium oxide, and titanium oxide, and is represented by the above formula (Formula 4). As described above, a dielectric ceramic composition having a high relative permittivity and a Q value, a small temperature coefficient of resonance vibration frequency, and a low sintering temperature can be achieved by the composition described above.

【００１４】すなわち、前記本発明の第１〜４の誘電体
磁器組成物によれば誘電特性を低下させることなく、焼
結温度を低下させることができる。よって、誘電体磁器
の製造コストを低減させることができる。That is, according to the first to fourth dielectric porcelain compositions of the present invention, the sintering temperature can be lowered without lowering the dielectric characteristics. Therefore, the manufacturing cost of the dielectric porcelain can be reduced.

【００１５】[0015]

【実施例】以下、実施例を用いて本発明を具体的に説明
する。 （実施例１）出発原料には化学的に高純度のＣａＣＯ
₃ 、ＭｇＯ、Ｃｏ₃Ｏ₄、及びＮｂ₂Ｏ₅を用いた。原料の
純度補正を行なったのち、前記式（化１）のｙを０．１
になるように秤量した。これらの粉体を、ポリエチレン
製のボールミルに入れ、直径５ｍｍの安定化ジルコニア
の玉石と純水を加え、１７時間混合した。混合後、スラ
リーを乾燥し、アルミナ製の坩堝にいれ、９００から１
１００℃で４時間仮焼した。仮焼体をライカイ機で解砕
した後、前述したボールミルで１７時間粉砕し、乾燥さ
せ、原料粉体とした。この粉体にバインダとしてポリビ
ニルアルコールの５重量％水溶液を６重量％加えて混合
後、３２メッシュのふるいを通して造粒し、１００ＭＰ
ａで直径１３ｍｍ、厚み約５ｍｍの円柱状にプレス成形
した。成形体を６５０℃で２時間加熱してバインダを焼
却後、マグネシア製の磁器容器に入れ、蓋をし、１１０
０から１５００℃の種々の温度で２時間保持して焼成し
た。密度が最高となる温度で焼成した焼結体についてマ
イクロ波での誘電特性を測定した。共振周波数とＱ値は
誘電体共振器法により求めた。焼結体の寸法と共振周波
数より誘電率を算出した。共振周波数は、２〜５ＧＨｚ
であった。また、−２５℃、２０℃及び８５℃における
共振周波数を測定し、最小二乗法により、その温度係数
（τ_f）を算出した。その結果は表１の番号２に示すよ
うに、比誘電率が２７、Ｑｆ積が６２０００ＧＨｚ、τ
_fが−４６であった。EXAMPLES The present invention will be specifically described below with reference to examples. (Example 1) Starting material is chemically high purity CaCO
₃ , MgO, Co ₃ O ₄ , and Nb ₂ O ₅ were used. After the raw material purity was corrected, y in the above formula (Formula 1) was adjusted to 0.1.
Was weighed so that These powders were placed in a polyethylene ball mill, stabilized zirconia boulders having a diameter of 5 mm and pure water were added and mixed for 17 hours. After mixing, dry the slurry and put it in an alumina crucible.
It was calcined at 100 ° C. for 4 hours. The calcined body was crushed with a raikai machine, crushed with the above-described ball mill for 17 hours, and dried to obtain a raw material powder. To this powder was added 6% by weight of a 5% by weight aqueous solution of polyvinyl alcohol as a binder, mixed, and then granulated through a 32 mesh sieve to obtain 100MP
In a, it was pressed into a cylindrical shape having a diameter of 13 mm and a thickness of about 5 mm. The molded body is heated at 650 ° C. for 2 hours to incinerate the binder, and then placed in a magnesia porcelain container, and the lid is closed.
Baking was performed by holding at various temperatures from 0 to 1500 ° C. for 2 hours. The dielectric properties of the sintered body that was fired at the temperature at which the density was highest were measured by microwaves. The resonance frequency and the Q value were obtained by the dielectric resonator method. The dielectric constant was calculated from the dimensions of the sintered body and the resonance frequency. Resonance frequency is 2-5 GHz
Met. In addition, the resonance frequencies at -25 ° C, 20 ° C, and 85 ° C were measured, and the temperature coefficient (τ _f ) was calculated by the least square method. As a result, as shown in No. 2 of Table 1, the relative permittivity is 27, the Qf product is 62000 GHz, and τ
_f was -46.

【００１６】[0016]

【表１】 [Table 1]

【００１７】（実施例２）出発原料には化学的に高純度
のＣａＣＯ₃ 、ＭｇＯ、Ｃｏ₃Ｏ₄、Ｎｂ₂Ｏ₅、及びＴｉ
Ｏ₂を用いた。原料の純度補正を行なったのち、前記式
（化２）のｘおよびｙが表１に示した種々の値になるよ
うに秤量した。これらの粉体から実施例１と同様に焼結
体を作製し、各種の値を求めた。その結果も表１に示
す。(Example 2) As starting materials, chemically high-purity CaCO ₃ , MgO, Co ₃ O ₄ , Nb ₂ O ₅ , and Ti were used.
O ₂ was used. After correcting the purity of the raw materials, the raw materials were weighed so that x and y in the above formula (Formula 2) have various values shown in Table 1. A sintered body was produced from these powders in the same manner as in Example 1, and various values were obtained. Table 1 also shows the results.

【００１８】表１に示したように、前記式（化２）でｘ
およびｙの値を適当に選択することにより、焼結体が、
比誘電率がほぼ４０以上で、Ｑｆ積が２００００ＧＨｚ
以上と良好な特性を示すことが確認できた。また誘電特
性をほとんど低下させることなく、焼結温度を低下させ
ることができた。一方、前記式（化２）の範囲外の組成
になると、τ_f が５０ppm/℃より大きくなるか、または
Ｑｆ積が１５０００ＧＨｚ以下のいずれかとなり、実用
的でないと判断した。As shown in Table 1, x in the above formula (Formula 2)
By appropriately selecting the values of y and y,
Dielectric constant of about 40 or more, Qf product of 20000 GHz
It was confirmed that the above characteristics were excellent. Moreover, the sintering temperature could be lowered without substantially lowering the dielectric properties. On the other hand, if the composition is out of the range of the above formula (Formula 2), τ _f becomes larger than 50 ppm / ° C., or the Qf product becomes 15000 GHz or less, and it was judged to be not practical.

【００１９】（実施例３）出発原料には化学的に高純度
のＣａＣＯ₃ 、ＰｂＯ、ＭｇＯ、Ｃｏ₃Ｏ₄、及びＮｂ₂
Ｏ₅を用いた。原料の純度補正を行なったのち、前記式
（化３）のｘおよびｚが表２に示した種々の値になるよ
うに秤量した。これらの粉体から実施例１と同様に焼結
体を作製し、各種の値を求めた。その結果を表２に示
す。(Example 3) As starting materials, chemically high purity CaCO ₃ , PbO, MgO, Co ₃ O ₄ , and Nb _{2 were used.}
O ₅ was used. After correcting the purity of the raw materials, the raw materials were weighed so that x and z in the formula (Formula 3) had various values shown in Table 2. A sintered body was produced from these powders in the same manner as in Example 1, and various values were obtained. The results are shown in Table 2.

【００２０】[0020]

【表２】 [Table 2]

【００２１】表２に示したように、前記式（化３）でｘ
およびｚの値を適当に選択することにより、焼結体が、
比誘電率がほぼ４０以上で、Ｑｆ積が２００００ＧＨｚ
以上と良好な特性を示すことが確認できた。また誘電特
性をほとんど低下させることなく、焼結温度を低下させ
ることができた。As shown in Table 2, x in the above formula (Formula 3)
By appropriately selecting the values of z and z,
Dielectric constant of about 40 or more, Qf product of 20000 GHz
It was confirmed that the above characteristics were excellent. Moreover, the sintering temperature could be lowered without substantially lowering the dielectric properties.

【００２２】（実施例４）出発原料には化学的に高純度
のＣａＣＯ₃ 、ＰｂＯ、ＭｇＯ、Ｃｏ₃Ｏ₄、Ｎｂ ₂Ｏ₅、
及びＴｉＯ₂を用いた。原料の純度補正を行なったの
ち、前記式（化４）のｘ、ｙおよびｚが表２に示す種々
の値になるように秤量した。これらの粉体から実施例１
と同様に焼結体を作製し、各種の値を求めた。その結果
も表２に示す。(Embodiment 4) The starting raw material has a chemically high purity.
CaCO₃ , PbO, MgO, Co₃O_Four, Nb ₂O_Five,
And TiO₂Was used. The purity of the raw material was corrected
Where x, y and z in the formula (Formula 4) are various values shown in Table 2.
Was weighed so that Example 1 from these powders
A sintered body was prepared in the same manner as in, and various values were obtained. as a result
Are also shown in Table 2.

【００２３】図１は、実施例３及び４の各実験例のｘの
値を横軸に、ｙの値を縦軸に取ったグラフである。表２
の結果によれば、図１の四角形の頂点ＡＢＣＤに囲まれ
た領域内で、前記式（化４）のｘおよびｙの値を適当に
選択し、ｚが０＜ｚ≦０．５０の範囲であるとき、焼結
体の比誘電率がほぼ４０以上で、Ｑｆ積が２００００Ｇ
Ｈｚ程度以上と良好な特性を示すことが確認できた。ま
た誘電特性をほとんど低下させることなく、焼結温度を
低下させることができた。一方、図１の四角形の頂点Ａ
ＢＣＤに囲まれた領域外の組成になると、τ_f が５０pp
m/℃より大きくなるか、またはＱｆ積が１５０００ＧＨ
ｚ以下のいずれかとなり、実用的でないと判断した。FIG. 1 is a graph in which the abscissa represents the value of x and the ordinate represents the value of y in each experimental example of Examples 3 and 4. Table 2
According to the result, in the region surrounded by the quadrangle apex ABCD of FIG. 1, the values of x and y in the formula (Formula 4) are appropriately selected, and z is in the range of 0 <z ≦ 0.50. When the relative dielectric constant of the sintered body is about 40 or more, the Qf product is 20000 G
It was confirmed that good characteristics were exhibited at about Hz or higher. Moreover, the sintering temperature could be lowered without substantially lowering the dielectric properties. On the other hand, the vertex A of the quadrangle in FIG.
When the composition is outside the area surrounded by BCD, τ _f is 50 pp
Greater than m / ℃ or Qf product is 15000GH
It was judged to be unpractical because it was one of z or less.

【００２４】なお、前記式（化１）〜（化４）に示され
る以外の元素、特にＢａ、Ｃｒ、Ｆｅ、Ｎｉ、Ｃｕ、Ｓ
ｉ、Ａｌ、Ｂｉ、Ｇｅ、Ｓｂ、および希土類元素等から
なる酸化物なども誘電特性に悪い影響を与えない範囲で
あれば含有させることができる。Elements other than those represented by the formulas (Formula 1) to (Formula 4), particularly Ba, Cr, Fe, Ni, Cu, S
Oxides such as i, Al, Bi, Ge, Sb, and rare earth elements can be contained as long as they do not adversely affect the dielectric properties.

【００２５】以上より明らかなように、本実施例の誘電
体磁器組成物によると、比誘電率が４０以上と非常に高
いときに、高いＱ値と小さいτ_f を実現できるため、誘
電体共振器の小型化が可能となる。また、焼結温度も低
いため製造コストを低減させることができる。さらに、
実施例の誘電体磁器は、誘電体共振器のみならず、高周
波用の回路基板、磁器積層コンデンサなどにも利用で
き、工業的価値が大きいものである。As is clear from the above, according to the dielectric ceramic composition of this embodiment, when the relative permittivity is as high as 40 or more, a high Q value and a small τ _f can be realized, so that the dielectric resonance occurs. The size of the container can be reduced. Further, since the sintering temperature is low, the manufacturing cost can be reduced. further,
The dielectric ceramics of the examples can be used not only for dielectric resonators but also for high-frequency circuit boards, porcelain multilayer capacitors, etc., and have great industrial value.

【００２６】[0026]

【発明の効果】以上説明した通り、本発明の第１〜４の
誘電体磁器組成物によれば、高い比誘電率とＱ値、かつ
小さい共振振周波数の温度係数を有し、さらに低い焼結
温度を持つ誘電体磁器組成物を提供できるので、誘電体
共振器の小型化が可能となり、かつ製造コストを低減す
ることができる。As described above, according to the first to fourth dielectric ceramic compositions of the present invention, they have a high relative permittivity and a Q value, a small temperature coefficient of resonance vibration frequency, and a lower firing temperature. Since the dielectric ceramic composition having the binding temperature can be provided, the dielectric resonator can be downsized and the manufacturing cost can be reduced.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の一実施例の誘電体磁器組成物の組成範
囲を表わす図。FIG. 1 is a diagram showing a composition range of a dielectric ceramic composition of an example of the present invention.

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.⁶ 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０１Ｐ 7/10 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01P 7/10

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 酸化カルシウム、酸化マグネシウム、酸
化コバルト、及び酸化ニオブからなり、下記式（化１）
で示される誘電体磁器組成物。 【化１】 1. Calcium oxide, magnesium oxide, cobalt oxide, and niobium oxide, represented by the following formula (Formula 1)
The dielectric ceramic composition shown by. Embedded image 【請求項２】 酸化カルシウム、酸化マグネシウム、酸
化コバルト、酸化ニオブ、及び酸化チタンからなり、下
記式（化２）で示される誘電体磁器組成物。 【化２】 2. A dielectric ceramic composition consisting of calcium oxide, magnesium oxide, cobalt oxide, niobium oxide, and titanium oxide, which is represented by the following formula (Formula 2). Embedded image 【請求項３】 酸化カルシウム、酸化鉛、酸化マグネシ
ウム、酸化コバルト、及び酸化ニオブからなり、下記式
（化３）で示される誘電体磁器組成物。 【化３】 3. A dielectric ceramic composition consisting of calcium oxide, lead oxide, magnesium oxide, cobalt oxide, and niobium oxide, which is represented by the following formula (Formula 3). Embedded image 【請求項４】 酸化カルシウム、酸化鉛、酸化マグネシ
ウム、酸化コバルト、酸化ニオブ、及び酸化チタンから
なり、下記式（化４）で示される誘電体磁器組成物。 【化４】 4. A dielectric ceramic composition composed of calcium oxide, lead oxide, magnesium oxide, cobalt oxide, niobium oxide, and titanium oxide, which is represented by the following formula (Formula 4). [Chemical 4]