JP3552878B2 - Method for manufacturing low-temperature sintered dielectric porcelain - Google Patents
Method for manufacturing low-temperature sintered dielectric porcelain Download PDFInfo
- Publication number
- JP3552878B2 JP3552878B2 JP15781397A JP15781397A JP3552878B2 JP 3552878 B2 JP3552878 B2 JP 3552878B2 JP 15781397 A JP15781397 A JP 15781397A JP 15781397 A JP15781397 A JP 15781397A JP 3552878 B2 JP3552878 B2 JP 3552878B2
- Authority
- JP
- Japan
- Prior art keywords
- weight
- volume
- mol
- dielectric
- dielectric constant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Insulating Materials (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、マイクロ波帯において使用する積層構造の共振器等に好適な高誘電率誘電体磁器の製造方法に関するものである。更に詳しく述べると、Ｂｉ2 Ｏ3 とＡｌ2 Ｏ3 を含有するＢａＯ−ＴｉＯ2 −Ｎｄ2 Ｏ3 系の高誘電率材料に対して、ＺｎＯ−Ｂ2 Ｏ3 −ＳｉＯ2 −Ａｌ2 Ｏ3 系のガラス材料と金属酸化物（ＺｎＯ又はＳｎＯ）を適量添加することにより、誘電体磁器組成物の低温焼結化と誘電特性の向上を図る技術に関するものである。
【０００２】
【従来の技術】
自動車電話や携帯電話など、マイクロ波を利用した移動体通信用機器では、フィルタ等の材料として誘電体磁器が使用されている。近年の通信機器の小形化に伴い、誘電体フィルタも一層の小形化が要求され、それに対応すべく一部で積層型ストリップ線路フィルタが採用されている。これは、内部の直線状のストリップ線路型共振器内導体を電極材（導体ペースト）のスクリーン印刷法で未焼成の誘電体シート（グリーンシート）上にパターニングし、それを含めて誘電体シートを多数積層して圧着一体化し、外部アース導体と入出力電極を形成して焼結することによって製造する。通常、多数個取りができるように、大きな誘電体シートを使用し、圧着一体化した後に縦横に切断してチップ状にする製法を採用している。λ／４共振器では、共振器内導体は共振波長の１／４の奇数倍の長さに設定し、その一端が開放となり、他端が誘電体チップの外表面の外部アース導体に短絡されるように構成する。誘電体チップの内部で、このような共振器内導体を複数個、フィルタ特性に応じた結合度が得られるように所定の間隔で配列することによって、帯域通過フィルタが得られる。
【０００３】
このような構造を実現するためには、内部電極材による各種導体パターンが崩れない温度で焼結できる高誘電率の誘電体磁器が必要となる。誘電体磁器の低温焼結化を図る方法として、ガラス材料を添加する技術が開発されている（例えば特開平７−６９７１９号公報参照）。そこではＳｉＯ２ −Ｂ２ Ｏ３ −ＢａＯ系のガラス材料を用いている。ガラス材料を添加することによる利点は低温焼結が可能になることであるが、反面、ガラス材料の添加によって比誘電率が低下する問題が生じる。また低温焼結による他の問題点は、焼結体の相対密度が低くなり、そのため焼結した誘電体磁器の比誘電率が変動することである。
【０００４】
そのような問題を解決できる方法として、本発明者等は先に、Ｂｉ２ Ｏ３ とＡｌ２ Ｏ３ を含有するＢａＯ−ＴｉＯ２ −Ｎｄ２ Ｏ３ 系の高誘電率材料に対して、ＺｎＯ−Ｂ２ Ｏ３ −ＳｉＯ２ −Ａｌ２ Ｏ３ 系のガラス材料を添加し、粉体を微粉砕処理することにより、誘電体磁器の低温焼結化と誘電特性の安定化を図る製造方法を提案した（特開平８−２３９２６３号公報参照）。具体的には、主成分としてＢａＯが１０〜１６モル％、ＴｉＯ２ が６７〜７２モル％、Ｎｄ２ Ｏ３ が１６〜１８モル％の組成を有し、それに対し副成分としてＢｉ２ Ｏ３ を７〜１０重量％、Ａｌ２ Ｏ３ を０．３〜１．０重量％含有している仮焼済みのＢａＯ−ＴｉＯ２ −Ｎｄ２ Ｏ３ 系の高誘電率材料に、ＺｎＯが４５〜７０重量％、Ｂ２ Ｏ３ が５〜１３重量％、ＳｉＯ２ が７〜４０重量％、Ａｌ２ Ｏ３ が８〜２０重量％である組成の既にガラス化されている材料を、前記高誘電率材料に対して３〜２０容積％添加し、粉体の平均粒径を０．１μｍ以下に調整して、８８０〜１０００℃で焼成し相対密度を９５％以上にする低温焼結誘電体磁器の製造方法である（以下、これを「先行技術」という）。その有効性を裏付ける実験結果の一例を表１に再掲する。
【０００５】
【表１】
表１において良否判定の基準で○（良品）と判定したのは、相対密度が９５％以上、フィルタなどの材料として特に問題の生じないＱｆ が１５００（ＧＨｚ）以上、τｆ が±１５（ｐｐｍ／℃）以内となる材料である。良品は、１０００℃以下の焼成温度で、良好な誘電特性が得られる。特に試料▲１▼の条件では、１０００℃の焼成温度で相対密度９８％、比誘電率８５を達成した。Ａｇ（銀）の融点は９６０℃であるが、内部電極材にＡｇを用いて誘電体材料を積層して焼成した場合、１０００℃で焼成しても内部電極パターンの崩れが生じないことが分かっており、その点から見てもこの試料▲１▼の条件で得られる誘電体磁器は有用である。更に試料▲２▼の条件では、銀の融点以下である９３０℃の焼成で相対密度９９％が達成された。従って、この試料▲２▼の条件で得られる誘電体磁器は、特に低い温度で焼結可能な材料として極めて有用である。
【０００７】
【発明が解決しようとする課題】
上記の先行技術は、８８０〜１０００℃で焼結して相対密度を９５％以上にできる優れた方法である。しかし、所望の特性を発現させるためには、粉体を平均粒径が０．１μｍ以下となるまで超微粉化処理する必要がある。しかし、このような誘電体材料の超微粉化は、その工程に多くの時間を要し、経済的に不利である。また誘電体磁器の相対密度が向上することで比誘電率の変動を抑えることができるが、反面、材料の超微粉化の工程を経るために、それに起因する特性不安定性が生じる恐れがある。
【０００８】
本発明の目的は、内部電極材を含んだ構造の各種の誘電体部品を低温で（内部電極材に損傷を与えない温度で）焼結でき、粉体の微粉砕工程が長くなりすぎることもなく、誘電特性及び特性安定性が向上するような低温焼結誘電体磁器の製造方法を提供することである。
【０００９】
【課題を解決するための手段】
本発明は、上記の先行技術を利用し、更に改良を加えたものである。そのために高誘電率材料とガラス材料の基本組成はそのまま利用している。即ち、主成分としてＢａＯが１０〜１６モル％、ＴｉＯ2 が６７〜７２モル％、Ｎｄ2 Ｏ3 が１６〜１８モル％の組成を有し、それに対し副成分としてＢｉ2 Ｏ3 を７〜１０重量％、Ａｌ2 Ｏ3 を０．３〜１．０重量％含有している仮焼済みのＢａＯ−ＴｉＯ2 −Ｎｄ2 Ｏ3 系の高誘電率材料に、ＺｎＯが４５〜７０重量％、Ｂ2 Ｏ3 が５〜１３重量％、ＳｉＯ2 が７〜４０重量％、Ａｌ2 Ｏ3 が８〜２０重量％である組成の既にガラス化されている材料を適量添加し、低温焼成する誘電体磁器の製造方法である。ここで本発明では、高誘電率材料に対して、既にガラス化されている材料を３−ｘ〜２０−ｘ容積％添加すると共に、それとは別にＺｎＯをｘ容積％（但し、ｘ＝０．１〜１．５容積％）添加し、粉体の平均粒径を０．３μｍ以下に調整して、成形後、１０００℃以下の温度で焼成する。ＺｎＯに代えて、ＳｎＯを０．３〜１．２容積％添加してもよい。なお、組成を示す数値範囲（モル％、重量％及び容積％）の両端は、全ての場合に本発明の範囲内に含まれる。
【００１０】
更に好ましい金属酸化物の添加範囲は、ＺｎＯでは０．２〜１．２容積％、ＳｎＯでは０．５〜１．０容積％であり、それらの中でも特にＺｎＯを０．５〜１．０容積％添加することが最も効果的であり比誘電率を高めることができる。
【００１１】
母材となるＢｉ２ Ｏ３ とＡｌ２ Ｏ３ を含有するＢａＯ−ＴｉＯ２ −Ｎｄ２ Ｏ３ 系の誘電体材料は、それ自身、高誘電率を呈する誘電特性をもつ。しかし、それ単独で良好な特性を発現させるためには１３００℃程度以上の高温での通常焼成を行わねばならない。内部電極材として、例えばＣｕ（銅）あるいはＡｇ（銀）を用いると１０００℃程度の焼成温度に耐えられる。因に、Ｃｕ（銅）の融点は１０８３℃、Ａｕ（金）の融点は１０６３℃である。なおＡｇ（銀）の融点は９６０℃であるが、誘電体材料の内部にＡｇを埋設して焼成した場合、１０００℃で焼成しても内部の銀電極パターンは崩れないことが分かっている。従って、１０００℃以下（可能であれば更に低い温度で）で焼結できれば、内部電極材を含んだ誘電体成形物を焼成して、誘電体部品を製造できることになる。
【００１２】
このような低温焼結化のために、本発明では、Ｂｉ2 Ｏ3 とＡｌ2 Ｏ3 を含有するＢａＯ−ＴｉＯ2 −Ｎｄ2 Ｏ3 系の誘電体材料（母材）に対して、ＺｎＯ−Ｂ2 Ｏ3 −ＳｉＯ2 −Ａｌ2 Ｏ3 系ガラス材料の添加と、ＳｎＯ又はＺｎＯの微少添加という手法を採用し、材料粉体の過度の微粉化を避けている。
【００１３】
ＢａＯ−ＴｉＯ２ −Ｎｄ２ Ｏ３ 系の誘電体材料において、各成分範囲を限定した理由は、材料自体の最良の特性を発現させるためであり、次の通りである。主成分であるＢａＯは、１０モル％未満では比誘電率が小さくなり、１６モル％を超えると温度係数が大きくなる。ＴｉＯ２ は、６７モル％未満では焼結性が悪くなり、７２モル％を超えると温度係数が大きくなる。Ｎｄ２ Ｏ３ は、１６モル％未満では温度係数が悪く、１８モル％を超えると比誘電率が小さくなる。また副成分であるＢｉ２ Ｏ３ は、７重量％未満では温度係数の改善効果が小さく、１０重量％を超えると焼結性が悪くなる。Ａｌ２ Ｏ３ は、０．３重量％未満ではＱ及び温度係数の改善効果が少なく、１．０重量％を超えると比誘電率が小さくＱが減少する。
【００１４】
次にガラス材料は、高誘電率材料を低温焼結化するためのものであるが、種々の組成系のガラスについて実験を行った結果、ＺｎＯ−Ｂ２ Ｏ３ −ＳｉＯ２ −Ａｌ２ Ｏ３ 系のガラス材料の適量添加が焼結磁器の相対密度（実際の密度／理論密度）の向上に有効であることが分かった。各成分範囲の限定は次の理由による。ＺｎＯは、４５重量％未満では相対密度が低下するし、７０重量％を超えると比誘電率が小さくなる。Ｂ２ Ｏ３ は、５重量％未満ではＱが低くなり、１３重量％を超えると相対密度が低くなる。ＳｉＯ２ は、７重量％未満では温度係数改善の効果が少なく、４０重量％を超えると相対密度が低くなる。Ａｌ２ Ｏ３ は、８重量％未満ではＱが低くなり、２０重量％を超えると比誘電率が小さくなる。このようなガラス材料を、母材であるＢａＯ−ＴｉＯ２ −Ｎｄ２ Ｏ３ 系の誘電体材料に対して３〜２０容積％添加することで、８８０〜１０００℃の適当な温度で焼成した時に、相対密度９５％以上を達成することができる。ガラス質材料の添加量が３容積％未満では低温焼結化せず、２０容積％を超えると比誘電率が低下してしまう。
【００１５】
更に本発明において、ＺｎＯ又はＳｎＯを適量同時添加するのは、誘電特性を向上させるためである。ここで重要なことは、これらの金属酸化物は、母材となる高誘電率材料及び既にガラス化された材料とは別に添加し、それらと一緒に平均粒径０．３μｍ以下まで微粉化することである。実験の結果によれば、高誘電率材料中あるいはガラス材料中に、それらの金属酸化物が余分に含まれていたとしても本発明の所望の効果は生じなかった。平均粒径を０．３μｍ以下まで微粉化するのは、反応性を高めて低温焼結化を促進するためである。上記のような特定の金属酸化物を適量添加することで、先行技術のような過度（０．１μｍ以下）の超微粉化を避けることができる。但し、実験結果によると、平均粒径が０．５μｍあるいは０．４μｍの場合には所望の特性が得られなかったため、０．３μｍ以下にすることは必要である。なお金属酸化物としてＭｇＯ、Ｂ2 Ｏ3 、Ａｌ2 Ｏ3 を同様に添加した実験では、Ｑf のみならず相対密度や比誘電率も低下し、好ましくない結果となった。
【００１６】
ガラス材料の添加による低温焼結のメカニズムは、焼成時にガラス材料が軟化して高誘電率材料粒子を引きつけ合い、固相成長させることによる。そこで特定の金属酸化物（ＺｎＯ又はＳｎＯ）を適量、ガラス材料とは別に添加すると、それがガラス材料に付着してその軟化を促進し、全体として焼結温度を下げ、誘電特性を向上させるものと考えられる。具体的には、先行技術に対して、更に３０〜５０℃程度、焼成温度を下げることが可能であり、９７０℃以下で焼成できるようになる。そのため、平均粒径を０．１μｍ以下まで超微粉化しなくても、所望の特性が発現することになる。
【００１７】
【実施例】
実施した誘電体磁器の製造フローは次の通りである。
▲１▼配合
既に仮焼が終了した高誘電率材料に、予めガラス化した材料と特定の金属酸化物（ＣｕＯ、ＺｎＯ、ＳｎＯのいずれか１種）を適量添加する。ここで使用した高誘電率材料は、主成分として、
ＢａＯ…１５モル％、
ＴｉＯ２ …６９モル％、
Ｎｄ２ Ｏ３ …１６モル％に対して、副成分として
Ｂｉ２ Ｏ３ …８重量％、
Ａｌ２ Ｏ３ …０．３重量％を添加した組成である。またガラス材料は、
ＺｎＯ…７０重量％、
Ｂ２ Ｏ３ …７重量％、
ＳｉＯ２ …１１重量％、
Ａｌ２ Ｏ３ …１２重量％からなる組成である。これらを容積比率で、高誘電率材料：ガラス材料：金属酸化物＝９５：（５−ｘ）：ｘの割合で混合して種々の試料を調整した。添加量ｘは、０．１〜２．０容積％までの範囲で変化させた。高誘電率材料及びガラス材料は、前記従来技術で、特に低い温度で焼結可能な材料として極めて有用とされた試料▲２▼を基本とする組成である。
▲２▼粉砕
媒体攪拌ミルにより平均粒径０．３μｍに微粉砕した。粉砕に使用したボールは、直径１ｍｍφ以下の部分安定化ジルコニア製である。粉砕時は、粉体が微粉化するため凝集しないように必要に応じて分散剤を適量添加した。
▲３▼乾燥
粉砕した粉体を乾燥し、これによって低温焼結用の材料粉体を得た。
▲４▼造粒、成形、焼成
その後の工程は、従来方法と同様であり、バインダーを加えて造粒し、所定形状にプレス成形した後、所定温度で焼成した。焼成は全て９００℃で行った。
【００１８】
実験結果を表２に示す。比誘電率及びＱf の測定は、空洞開放形誘電体共振器法（測定周波数：６ＧHz）で行った。なお、ＣｕＯの添加は参考例である。
【００１９】
【表２】
ＣｕＯ（参考例）、ＺｎＯ、ＳｎＯのいずれか１種を適量添加すると（○を付した添加量ｘ）、添加しない場合（比較例）よりも比誘電率εr が向上する。その様子を図１に示す。なおＱf が若干低下する場合もあるが、フィルタとして使用する場合には１５００ＧHz以上あればよいとされるため、十分な値と考えられる。これらのことから、添加量ｘは、ＺｎＯでは０．１〜１．５容積％、ＳｎＯでは０．３〜１．２容積％とする。なかでも、ＺｎＯを０．２〜１．２容積％、ＳｎＯを０．５〜１．０容積％とすると、比誘電率は７４以上と大きくなり好ましい。とりわけ、ＺｎＯを０．５〜１．０容積％とすると、比誘電率は７５以上と更に大きくなり最適である。また９００℃という低い温度で良質の誘電体磁器を焼成でき、銀ペーストを用いての外部電極の同時焼付けも十分可能となる。
【００２１】
上記の実施例では、基本組成となる高誘電率材料及びガラス材料については、それぞれ１種のみで系統的に行った結果を示しているが、非系統的な各種の実験でも、また前記先行技術を踏まえてみても、前記従来技術で規定する基本組成の範囲内では、ほぼ同様の傾向を示すことが分かっており、本発明で規定する範囲内で有効であることは十分推測できる。
【００２２】
【発明の効果】
本発明は、Ｂｉ2 Ｏ3 とＡｌ2 Ｏ3 を含有するＢａＯ−ＴｉＯ2 −Ｎｄ2 Ｏ3 系の高誘電率材料に対して、ＺｎＯ−Ｂ2 Ｏ3 −ＳｉＯ2 −Ａｌ2 Ｏ3 系のガラス材料と金属酸化物（ＺｎＯ又はＳｎＯ）を適量添加する製造方法であり、それによって粉体の微粉砕工程が長くなりすぎることもなく、内部電極材を含んだ構造の各種の誘電体部品を１０００℃以下の低温で（内部電極材に損傷を与えない温度で）焼結でき、経済性に優れ工程管理も容易で、且つ誘電特性及び特性安定性が向上する。
【図面の簡単な説明】
【図１】金属酸化物添加量ｘに対する比誘電率εｒ の関係を示すグラフ。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a high dielectric constant dielectric porcelain suitable for a resonator having a laminated structure used in a microwave band. More particularly, Bi 2 O 3 and Al 2 O 3 with respect to BaO-TiO 2 -Nd 2 O 3 based high dielectric constant material containing, ZnO-B 2 O 3 -SiO 2 -Al 2 O 3 The present invention relates to a technique for adding a suitable amount of a glass material and a metal oxide ( ZnO or SnO 2 ) to achieve low-temperature sintering of a dielectric ceramic composition and improvement of dielectric characteristics.
[0002]
[Prior art]
2. Description of the Related Art In mobile communication devices using microwaves, such as mobile phones and mobile phones, dielectric porcelain is used as a material for filters and the like. With the recent miniaturization of communication devices, dielectric filters have been required to be further miniaturized, and in order to cope with this, laminated strip line filters have been partially adopted. This is done by patterning the inner straight stripline type resonator inner conductor on an unfired dielectric sheet (green sheet) by screen printing of an electrode material (conductor paste), and forming a dielectric sheet including it. It is manufactured by laminating a large number, crimping and integrating, forming an external ground conductor and input / output electrodes, and sintering. Usually, a large dielectric sheet is used so that a large number of pieces can be formed, and a manufacturing method in which a large dielectric sheet is crimped and integrated and then cut vertically and horizontally into chips is adopted. In the λ / 4 resonator, the length of the conductor in the resonator is set to an odd multiple of 1/4 of the resonance wavelength, one end of the resonator is open, and the other end is short-circuited to the external ground conductor on the outer surface of the dielectric chip. It is configured so that: By arranging a plurality of such conductors in the resonator inside the dielectric chip at predetermined intervals so as to obtain a degree of coupling according to the filter characteristics, a bandpass filter can be obtained.
[0003]
In order to realize such a structure, a dielectric ceramic having a high dielectric constant that can be sintered at a temperature at which various conductor patterns formed by the internal electrode material do not collapse is required. As a method of achieving low-temperature sintering of dielectric ceramics, a technique of adding a glass material has been developed (for example, see Japanese Patent Application Laid-Open No. 7-69719). Here, a SiO 2 —B 2 O 3 —BaO-based glass material is used. The advantage of adding a glass material is that low-temperature sintering becomes possible, but on the other hand, there is a problem that the relative permittivity is lowered by the addition of the glass material. Another problem with low-temperature sintering is that the relative density of the sintered body is reduced, and the relative dielectric constant of the sintered dielectric ceramic fluctuates.
[0004]
As a method capable of solving such a problem, the present inventors have first proposed a method of using a BaO—TiO 2 —Nd 2 O 3 -based high dielectric constant material containing Bi 2 O 3 and Al 2 O 3 with ZnO. -B 2 O 3 was added -SiO 2 -Al 2 O 3 based glass material by the powder milling process, a manufacturing method of stabilizing the low temperature co Yuika and dielectric properties of the dielectric ceramic It has been proposed (see Japanese Patent Application Laid-Open No. 8-239263). Specifically, BaO has a composition of 10 to 16 mol%, TiO 2 has a composition of 67 to 72 mol%, and Nd 2 O 3 has a composition of 16 to 18 mol%, whereas Bi 2 O 3 is a sub component. 7-10 wt%, the Al 2 O 3 with high dielectric constant material calcined already BaO-TiO 2 -Nd 2 O 3 system containing 0.3 to 1.0 wt%, ZnO is 45 An already vitrified material having a composition of 70% by weight, 5 to 13% by weight of B 2 O 3, 7 to 40% by weight of SiO 2 , and 8 to 20% by weight of Al 2 O 3 Low-temperature sintered dielectric porcelain which is added at 3 to 20% by volume with respect to the rate material, adjusts the average particle diameter of the powder to 0.1 μm or less, and is fired at 880 to 1000 ° C. to make the relative density 95% or more. (Hereinafter referred to as “prior art”). An example of the experimental results supporting the effectiveness is shown in Table 1.
[0005]
[Table 1]
In Table 1, the criteria of good or bad in the criteria of good or bad are that the relative density is 95% or more, Qf is 1500 (GHz) or more which does not cause any problem as a material for a filter or the like, and τf is ± 15 (ppm / ppm). C). Good products have good dielectric properties at a firing temperature of 1000 ° C. or lower. In particular, under the conditions of sample (1), a relative density of 98% and a relative dielectric constant of 85 were achieved at a firing temperature of 1000 ° C. Although the melting point of Ag (silver) is 960 ° C., it has been found that when a dielectric material is laminated and fired using Ag as the internal electrode material, the internal electrode pattern does not collapse even when fired at 1000 ° C. From this point of view, the dielectric ceramic obtained under the conditions of the sample (1) is useful. Further, under the conditions of sample (2), a relative density of 99% was achieved by firing at 930 ° C., which is lower than the melting point of silver. Therefore, the dielectric porcelain obtained under the conditions of the sample (2) is extremely useful as a material which can be sintered particularly at a low temperature.
[0007]
[Problems to be solved by the invention]
The above prior art is an excellent method that can be sintered at 880 to 1000 ° C. to make the relative density 95% or more. However, in order to exhibit desired properties, it is necessary to subject the powder to ultrafine powder treatment until the average particle size becomes 0.1 μm or less. However, such ultra-fine pulverization of a dielectric material requires a lot of time in the process, and is economically disadvantageous. Further, the relative density of the dielectric porcelain can be improved to suppress a change in the relative dielectric constant. However, since the material is subjected to a process of ultra-fine pulverization, characteristic instability due to the process may be caused.
[0008]
An object of the present invention is to sinter various dielectric components having a structure including an internal electrode material at a low temperature (at a temperature at which the internal electrode material is not damaged), and it is also possible to make the powder pulverization process too long. It is another object of the present invention to provide a method for producing a low-temperature sintered dielectric porcelain having improved dielectric characteristics and characteristic stability.
[0009]
[Means for Solving the Problems]
The present invention utilizes the above-mentioned prior art and further improves it. For this purpose, the basic compositions of the high dielectric constant material and the glass material are used as they are. That, BaO 10 to 16 mol% as a main component, TiO 2 is 67 to 72 mol%, Nd 2 O 3 has a composition of 16 to 18 mol%, the Bi 2 O 3 with respect to it as a sub-component 7 10 wt%, the high dielectric constant material calcined already BaO-TiO 2 -Nd 2 O 3 system which contains Al 2 O 3 0.3 to 1.0 wt%, ZnO 45-70 wt% , B 2 O 3 is 5 to 13 wt%, SiO 2 is 7-40 wt%, Al 2 O 3 is added an appropriate amount of previously material being vitrified composition is 8-20 wt%, a low temperature fired This is a method for manufacturing a dielectric porcelain. Here in the present invention, the high dielectric constant material, along with already added material being vitrified 3-x~20-x volume%, x% by volume separately Zn O from that (where, x = 0 ( 1 to 1.5% by volume), adjust the average particle size of the powder to 0.3 μm or less, and after the compacting, bake at a temperature of 1000 ° C. or less. Instead of Zn O, it may be added to S nO 0.3 to 1.2 volume%. In addition, both ends of the numerical range (mol%, weight%, and volume%) indicating the composition are included in the scope of the present invention in all cases.
[0010]
Further addition range of preferred metal oxides, Z nO in 0.2 to 1.2 volume%, a SnO at 0.5 to 1.0% by volume, in particular ZnO Among these 0.5-1.0 It is most effective to add% by volume, and the relative dielectric constant can be increased.
[0011]
BaO-TiO 2 -Nd 2 O 3 based dielectric material containing Bi 2 O 3 and Al 2 O 3 as a base material itself has dielectric properties that exhibits a high dielectric constant. However, in order to exhibit good characteristics by itself, ordinary firing at a high temperature of about 1300 ° C. or more must be performed. If Cu (copper) or Ag (silver) is used as the internal electrode material, it can withstand a firing temperature of about 1000 ° C. Incidentally, the melting point of Cu (copper) is 1083 ° C., and the melting point of Au (gold) is 1063 ° C. Although the melting point of Ag (silver) is 960 ° C., it has been found that when Ag is embedded in a dielectric material and fired, the silver electrode pattern inside does not collapse even when fired at 1000 ° C. Therefore, if sintering can be performed at a temperature of 1000 ° C. or less (at a lower temperature if possible), a dielectric component including the internal electrode material can be fired to produce a dielectric component.
[0012]
For such low-temperature sintering Yuika, in the present invention, with respect to Bi 2 O 3 and Al 2 O 3 containing BaO-TiO 2 -Nd 2 O 3 based dielectric material (base material), ZnO and adding -B 2 O 3 -SiO 2 -Al 2 O 3 based glass material, SnO or employ a technique called micro addition of Zn O, and avoiding excessive pulverization of the material powder.
[0013]
In BaO-TiO 2 -Nd 2 O 3 based dielectric material, reasons for limiting the components range is in order to express the best characteristics of the material itself, is as follows. When BaO, which is a main component, is less than 10 mol%, the relative dielectric constant becomes small, and when it exceeds 16 mol%, the temperature coefficient becomes large. If TiO 2 is less than 67 mol%, the sinterability deteriorates, and if it exceeds 72 mol%, the temperature coefficient increases. If Nd 2 O 3 is less than 16 mol%, the temperature coefficient is poor, and if it exceeds 18 mol%, the relative permittivity becomes small. When the content of Bi 2 O 3 as a subcomponent is less than 7% by weight, the effect of improving the temperature coefficient is small, and when it exceeds 10% by weight, the sinterability deteriorates. If the content of Al 2 O 3 is less than 0.3% by weight, the effect of improving the Q and temperature coefficient is small, and if it exceeds 1.0% by weight, the relative dielectric constant is small and Q is reduced.
[0014]
Next, the glass material is for sintering a high dielectric constant material at a low temperature. As a result of conducting experiments on glasses of various composition systems, ZnO—B 2 O 3 —SiO 2 —Al 2 O 3 It has been found that the addition of an appropriate amount of the glass material of the system is effective for improving the relative density (actual density / theoretical density) of the sintered porcelain. The limitation of each component range is based on the following reason. If the ZnO content is less than 45% by weight, the relative density decreases, and if it exceeds 70% by weight, the relative dielectric constant decreases. When B 2 O 3 is less than 5% by weight, Q is low, and when it exceeds 13% by weight, the relative density is low. If the content of SiO 2 is less than 7% by weight, the effect of improving the temperature coefficient is small, and if it exceeds 40% by weight, the relative density becomes low. When Al 2 O 3 is less than 8% by weight, Q becomes low, and when it exceeds 20% by weight, the relative dielectric constant becomes small. Such glass materials, by adding 3 to 20 volume% relative to the BaO-TiO 2 -Nd 2 O 3 based dielectric material as the base material, when fired at a suitable temperature of from 880 to 1,000 ° C. , A relative density of 95% or more can be achieved. If the amount of the vitreous material is less than 3% by volume, low-temperature sintering will not be performed, and if it exceeds 20% by volume, the relative dielectric constant will be reduced.
[0015]
Further, in the present invention, the reason why ZnO or SnO is simultaneously added in an appropriate amount is to improve the dielectric properties. What is important here is that these metal oxides are added separately from the base material of the high dielectric constant material and the already vitrified material, and pulverized together with them to an average particle size of 0.3 μm or less. That is. According to the results of the experiment, the desired effects of the present invention did not occur even if the metal oxide was excessively contained in the high dielectric constant material or the glass material. The reason why the average particle size is reduced to 0.3 μm or less is to increase reactivity and promote low-temperature sintering. By adding an appropriate amount of the specific metal oxide as described above, excessive (0.1 μm or less) ultrafine powdering as in the prior art can be avoided. However, according to the experimental results, when the average particle size was 0.5 μm or 0.4 μm, the desired characteristics could not be obtained, so it is necessary to reduce the average particle size to 0.3 μm or less. In an experiment in which MgO, B 2 O 3 , and Al 2 O 3 were similarly added as metal oxides, not only Qf but also the relative density and the relative permittivity decreased, resulting in undesirable results.
[0016]
The mechanism of the low-temperature sintering by the addition of the glass material is based on the fact that the glass material softens at the time of firing, attracts the high dielectric constant material particles, and causes solid phase growth. Therefore, when an appropriate amount of a specific metal oxide ( ZnO or SnO 2 ) is added separately from the glass material, it adheres to the glass material to promote its softening, lower the sintering temperature as a whole, and improve the dielectric properties. it is conceivable that. Specifically, the firing temperature can be further reduced by about 30 to 50 ° C. with respect to the prior art, and firing can be performed at 970 ° C. or lower. Therefore, the desired characteristics can be exhibited even if the average particle size is not ultrafinely reduced to 0.1 μm or less.
[0017]
【Example】
The manufacturing flow of the implemented dielectric porcelain is as follows.
{Circle around (1)} Compounding A suitable amount of a vitrified material and a specific metal oxide (one of CuO, ZnO and SnO) are added to the high dielectric constant material which has already been calcined. The high dielectric constant material used here is, as a main component,
BaO: 15 mol%,
TiO 2 ... 69 mol%,
Nd 2 O 3 … 16 mol%, Bi 2 O 3 … 8% by weight as an auxiliary component,
Al 2 O 3 ... A composition to which 0.3% by weight is added. The glass material is
ZnO: 70% by weight,
B 2 O 3 ... 7% by weight,
SiO 2 ... 11% by weight,
Al 2 O 3 ... A composition comprising 12% by weight. These were mixed at a volume ratio of high dielectric constant material: glass material: metal oxide = 95: (5-x): x to prepare various samples. The addition amount x was changed in a range from 0.1 to 2.0% by volume. The high dielectric constant material and the glass material are compositions based on the sample (2) which is extremely useful as a material which can be sintered at a low temperature in the above-mentioned conventional technology.
{Circle around (2)} Finely pulverized to an average particle size of 0.3 μm by a pulverizing medium stirring mill. The ball used for the pulverization is made of partially stabilized zirconia having a diameter of 1 mmφ or less. At the time of pulverization, an appropriate amount of a dispersant was added as necessary so that the powder was pulverized and did not agglomerate.
{Circle around (3)} The dried and pulverized powder was dried to obtain a material powder for low-temperature sintering.
{Circle around (4)} Granulation, molding, and firing The subsequent steps are the same as those in the conventional method. The binder was added, granulated, press-molded into a predetermined shape, and fired at a predetermined temperature. All firings were performed at 900 ° C.
[0018]
Table 2 shows the experimental results. The relative permittivity and Qf were measured by the open cavity dielectric resonator method (measuring frequency: 6 GHz). The addition of CuO is a reference example.
[0019]
[Table 2]
When an appropriate amount of any one of CuO (Reference Example) , ZnO, and SnO is added (addition amount x with a circle), the relative dielectric constant εr is improved as compared with the case where no addition is performed (Comparative Example). This is shown in FIG. Although Qf may be slightly reduced, it is considered to be a sufficient value since it is sufficient that the frequency is 1500 GHz or more when used as a filter. For these reasons, the addition amount x is the Z in nO 0.1 to 1.5 volume%, SnO in 0.3 to 1.2% by volume. Above all , when ZnO is 0.2 to 1.2% by volume and SnO is 0.5 to 1.0% by volume, the relative dielectric constant is preferably as large as 74 or more. In particular, when ZnO is 0.5 to 1.0% by volume, the relative dielectric constant is further increased to 75 or more, which is optimal. In addition, high-quality dielectric porcelain can be fired at a temperature as low as 900 ° C., and simultaneous firing of external electrodes using silver paste is sufficiently possible.
[0021]
In the above examples, the results of systematically performing only one kind each for the high dielectric constant material and the glass material, which are the basic compositions, are shown. In view of the above, it is known that the same tendency is exhibited within the range of the basic composition defined by the above-mentioned conventional technology, and it can be sufficiently inferred that the composition is effective within the range defined by the present invention.
[0022]
【The invention's effect】
The present invention relates to a ZnO—B 2 O 3 —SiO 2 —Al 2 O 3 -based material for a BaO—TiO 2 —Nd 2 O 3 -based high dielectric constant material containing Bi 2 O 3 and Al 2 O 3. A suitable amount of a glass material and a metal oxide ( ZnO or SnO 2 ), whereby the powder fine grinding step does not become too long, and various dielectric components having a structure including an internal electrode material are provided. Can be sintered at a low temperature of 1000 ° C. or less (at a temperature that does not damage the internal electrode material), and it is economical, easy in process control, and has improved dielectric characteristics and characteristic stability.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the relative dielectric constant εr and the amount x of a metal oxide added.
Claims (2)
高誘電率材料に対して、既にガラス化されている材料を３−ｘ〜２０−ｘ容積％添加すると共に、それとは別にＺｎＯをｘ容積％（但し、ｘ＝０．１〜１．５容積％）添加し、粉体の平均粒径を０．３μｍ以下に調整して、成形後、１０００℃以下で焼成することを特徴とする低温焼結誘電体磁器の製造方法。BaO 10 to 16 mol% as a main component, TiO 2 is 67 to 72 mol%, Nd 2 O 3 has a composition of 16-18 mol%, 7-10 weight Bi 2 O 3 with respect to it as a sub-component % Of Al 2 O 3 , a calcined BaO—TiO 2 —Nd 2 O 3 -based high dielectric material containing 0.3 to 1.0% by weight, ZnO being 45 to 70% by weight, B Dielectric porcelain which is added with an already vitrified material having a composition of 5 to 13% by weight of 2 O 3, 7 to 40% by weight of SiO 2 and 8 to 20% by weight of Al 2 O 3 and fired at a low temperature. In the manufacturing method of
To the high dielectric constant material, 3-x to 20-x volume% of the already vitrified material is added, and ZnO is separately added to x volume% (where x = 0.1 to 1.5 volume%). %), The powder is adjusted to have an average particle diameter of 0.3 μm or less, molded, and fired at 1000 ° C. or less.
高誘電率材料に対して、既にガラス化されている材料を３−ｘ〜２０−ｘ容積％添加すると共に、それとは別にＳｎＯをｘ容積％（但し、ｘ＝０．３〜１．２容積％）添加し、粉体の平均粒径を０．３μｍ以下に調整して、成形後、１０００℃以下で焼成することを特徴とする低温焼結誘電体磁器の製造方法。BaO 10 to 16 mol% as a main component, TiO 2 is 67 to 72 mol%, Nd 2 O 3 has a composition of 16-18 mol%, 7-10 weight Bi 2 O 3 with respect to it as a sub-component % Of Al 2 O 3 , a calcined BaO—TiO 2 —Nd 2 O 3 -based high dielectric material containing 0.3 to 1.0% by weight, ZnO being 45 to 70% by weight, B Dielectric porcelain which is added with an already vitrified material having a composition of 5 to 13% by weight of 2 O 3, 7 to 40% by weight of SiO 2 and 8 to 20% by weight of Al 2 O 3 and fired at a low temperature. In the manufacturing method of
To the high dielectric constant material, 3-x to 20-x volume% of the already vitrified material is added and SnO is separately added to x volume% (where x = 0.3 to 1.2 volume%). %), The powder is adjusted to have an average particle diameter of 0.3 μm or less, molded, and fired at 1000 ° C. or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15781397A JP3552878B2 (en) | 1997-05-30 | 1997-05-30 | Method for manufacturing low-temperature sintered dielectric porcelain |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15781397A JP3552878B2 (en) | 1997-05-30 | 1997-05-30 | Method for manufacturing low-temperature sintered dielectric porcelain |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10330161A JPH10330161A (en) | 1998-12-15 |
| JP3552878B2 true JP3552878B2 (en) | 2004-08-11 |
Family
ID=15657862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15781397A Expired - Fee Related JP3552878B2 (en) | 1997-05-30 | 1997-05-30 | Method for manufacturing low-temperature sintered dielectric porcelain |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3552878B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4837204B2 (en) * | 2001-05-01 | 2011-12-14 | サムソン エレクトロ−メカニックス カンパニーリミテッド． | Dielectric porcelain composition, porcelain capacitor using the same, and manufacturing method thereof |
| JP2002326867A (en) * | 2001-05-01 | 2002-11-12 | Samsung Electro Mech Co Ltd | Dielectric ceramic composition and ceramic capacitor using it and method of manufacturing them |
| US7276461B2 (en) | 2003-05-20 | 2007-10-02 | Ube Industries, Ltd. | Dielectric ceramic composition, method of manufacturing the same, and dielectric ceramics and laminated ceramic part using the same |
| US7396785B2 (en) | 2004-01-30 | 2008-07-08 | Murata Manufacturing Co. Ltd | Composition for ceramic substrate, ceramic substrate, process for producing ceramic substrate and glass composition |
| CN100532323C (en) | 2004-03-05 | 2009-08-26 | 宇部兴产株式会社 | Dielectric particle aggregate, low temperature sinterable dielectric ceramic composition using same, low temperature sintered dielectric ceramic produced by using same |
| JP2007043162A (en) * | 2006-07-31 | 2007-02-15 | Ngk Insulators Ltd | Electronic component |
| KR101581925B1 (en) | 2011-02-14 | 2015-12-31 | 가부시키가이샤 무라타 세이사쿠쇼 | Multilayer ceramic capacitor and multilayer ceramic capacitor manufacturing method |
| JP6063729B2 (en) * | 2012-12-21 | 2017-01-18 | Fdk株式会社 | Method for manufacturing dielectric ceramic composition, method for manufacturing multilayer chip component |
-
1997
- 1997-05-30 JP JP15781397A patent/JP3552878B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10330161A (en) | 1998-12-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0779257B1 (en) | Dielectric porcelain, process for production thereof, and electronic parts produced therefrom | |
| JP3552878B2 (en) | Method for manufacturing low-temperature sintered dielectric porcelain | |
| JP3737774B2 (en) | Dielectric ceramic composition | |
| JP4613952B2 (en) | Dielectric ceramic composition and high frequency device using the same | |
| JP2781500B2 (en) | Dielectric ceramic composition for low temperature firing | |
| JP2786977B2 (en) | Dielectric porcelain composition for low-temperature firing and method for producing the same | |
| JP2781503B2 (en) | Dielectric porcelain composition for low-temperature firing, dielectric resonator or dielectric filter obtained using the same, and methods for producing them | |
| JP2515611B2 (en) | Dielectric porcelain composition | |
| JP2526701B2 (en) | Dielectric porcelain composition | |
| JP3595596B2 (en) | Method for manufacturing low-temperature sintered dielectric porcelain | |
| JP3002613B2 (en) | Dielectric porcelain composition for producing dielectric resonator or filter for microwave, method for producing the same, dielectric resonator or filter for microwave obtained using the dielectric porcelain composition, and method for producing the same | |
| JPH0597508A (en) | Dielectric porcelain composition for high-frequency | |
| JP2526702B2 (en) | Dielectric porcelain composition | |
| JP2781501B2 (en) | Dielectric ceramic composition for low temperature firing | |
| JP2000086337A (en) | Dielectric porcelain composition for low-temperature firing | |
| KR100343523B1 (en) | Method for Manufacturing Ceramic Electronic Device | |
| JP3375450B2 (en) | Dielectric porcelain composition | |
| JP2781502B2 (en) | Dielectric porcelain composition for low-temperature firing, dielectric resonator or dielectric filter obtained using the same, and methods for producing them | |
| JP3909366B2 (en) | Low dielectric constant porcelain composition and method for producing substrate for electronic circuit using the porcelain composition | |
| JPH0769719A (en) | Production of low-temperature sintering dielectric porcelain | |
| JP3193157B2 (en) | Dielectric porcelain composition for low-temperature firing, dielectric resonator or dielectric filter obtained using the same, and methods for producing them | |
| JP4235896B2 (en) | DIELECTRIC CERAMIC COMPOSITION, PROCESS FOR PRODUCING THE SAME, DIELECTRIC CERAMIC USING THE SAME, AND MULTILAYER CERAMIC COMPONENT | |
| JPH03290359A (en) | Dielectric ceramic composition | |
| JP3597244B2 (en) | Dielectric porcelain composition | |
| JP4006655B2 (en) | Dielectric porcelain composition for microwave |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20040106 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20040305 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20040406 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040427 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080514 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090514 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090514 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100514 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110514 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110514 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120514 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130514 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140514 Year of fee payment: 10 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |