JPS62123061A - Dielectric ceramic composition - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は１１００℃以下で焼成される高誘電率系誘電体
磁器組成物に関し、特に低酸素分圧雰囲気で焼成でき高
い抵抗率の得られる組成物に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high dielectric constant dielectric ceramic composition that is fired at a temperature of 1100°C or lower, and in particular a composition that can be fired in a low oxygen partial pressure atmosphere and has a high resistivity. Regarding.

従来の技術 近年セラミックコンデンサにおいては素子の小型化、大
容量化への要求からＩ、Ｗ型セラミックコンデンサが急
速に普及しつつある。積層型セラミックコンデンサは内
部電極とセラミックを一体焼成する工程によって通常製
造される。従来より高誘電率系のセラミックコンデンサ
材料にはチタン酸バリウム系の材料が用いられてきたが
、焼成温度が１３００℃程度と高いため、内部電極材料
としてはＰｔ、Ｐｄなどの高価な金属を用いる必要があ
った。BACKGROUND OF THE INVENTION In recent years, I- and W-type ceramic capacitors are rapidly becoming popular due to the demand for smaller elements and larger capacitance in ceramic capacitors. Multilayer ceramic capacitors are typically manufactured by a process of integrally firing internal electrodes and ceramics. Barium titanate-based materials have traditionally been used for high-permittivity ceramic capacitor materials, but because the firing temperature is as high as 1,300°C, expensive metals such as Pt and Pd are used as internal electrode materials. There was a need.

これに対し空気中１０００℃以下で焼成でき内部電極と
して安価なＡｇ系材料を用いることができる鉛複合ペロ
ブスカイト系材料や、低酸素分圧雰囲気中で焼成できＮ
ｉなとの卑金属材料を内部電極として使用できるチタン
酸バリウム系材料が開発されている。前者については発
明者らはすでにＰｂＴｉ０３−Ｐｂ（Ｍｇｓ、３Ｎｂｑ
ｔ３）Ｏｓ　　Ｐｂ（Ｎ　ｉ　１／２　Ｗｌ／２　）　
Ｏｓを含む誘電体磁器組成物を提案している。後者につ
いては特公昭５６−４６６４１号公報に記載の材料など
が知られている。On the other hand, there are lead composite perovskite materials that can be fired in air at temperatures below 1000°C and inexpensive Ag-based materials can be used as internal electrodes, and N-based composite materials that can be fired in a low oxygen partial pressure atmosphere.
Barium titanate-based materials have been developed that allow use of base metal materials as internal electrodes. Regarding the former, the inventors have already developed PbTi03-Pb(Mgs, 3Nbq
t3) Os Pb (N i 1/2 Wl/2 )
A dielectric ceramic composition containing Os is proposed. Regarding the latter, materials such as those described in Japanese Patent Publication No. 56-46641 are known.

ＰｂＴｉＯ３−Ｐｂ（Ｍｇｔ／ｓ　Ｎｂ２ｔｓ　）０＋
　−Ｐｂ（Ｎｉｓｚ２Ｗｌ／２　）０＋系固溶体は低温
で焼成でき、誘電率の温度変化率が同程度のチタン酸バ
リウム系材料に比べ高い誘電率が得られる。従ってこの
誘電体磁器組成物とＡｇ系内部電極からなる積層コンデ
ンサは、素子の大容量、小型化、低コスト化が図れる利
点を有している。しかし近年さらに内部電極材料の低コ
スト化が図れるＣｕなどの卑金属を内部電極として用い
ることが求められている。このため、同時焼成したとき
Ｃｕなどの金属が酸化しないような低酸素分圧雰囲気で
焼成したとき誘電体磁器の抵抗率が低下しない材料が必
要とされている。PbTiO3-Pb(Mgt/s Nb2ts)0+
The -Pb(Nisz2Wl/2)0+-based solid solution can be fired at a low temperature and has a higher dielectric constant than a barium titanate-based material with a similar rate of change in dielectric constant with temperature. Therefore, a multilayer capacitor made of this dielectric ceramic composition and an Ag-based internal electrode has the advantage that the device can have a large capacity, be small in size, and low in cost. However, in recent years, there has been a demand for using base metals such as Cu as internal electrodes, which can further reduce the cost of internal electrode materials. Therefore, there is a need for a material that does not reduce the resistivity of dielectric ceramics when fired in a low oxygen partial pressure atmosphere that does not oxidize metals such as Cu when fired simultaneously.

発明が解決しようとする問題点 ＰｂＴｉＣ）＋　　−Ｐｂ（Ｍｇ＋／３　Ｎｂ２ｔｓ　
　）Ｏｓ　　−Ｐｂ（Ｎ　ｉ　ｔ　ｔ　ｓｉ　Ｗ　１　
／　２　）　Ｏｓ系固溶体は低酸素分圧雰囲気で焼成す
るとチ密に焼結せず、また抵抗率が小さくなる傾向があ
る。Problems to be solved by the invention PbTiC)+ -Pb(Mg+/3 Nb2ts
) Os −Pb(N it t si W 1
/2) When an Os-based solid solution is fired in a low oxygen partial pressure atmosphere, it does not sinter densely and tends to have a low resistivity.

本発明はＰｂＴｉ０３−Ｐｂ（Ｍｇｔｚ３ＮＥ１２ｚｓ
　）０３−Ｐｂ（ＮｉｔｚＱＷｌ／２　）０３系のもつ
高い誘電率と低温焼結性をそこなわず、低酸素分圧雰囲
気で焼成したとき抵抗値が高い誘電体磁器組成物を提供
することを目的としている。The present invention uses PbTi03-Pb (Mgtz3NE12zs
)03-Pb(NitzQWl/2) The purpose is to provide a dielectric ceramic composition that does not impair the high dielectric constant and low-temperature sinterability of the 03 series and has a high resistance value when fired in a low oxygen partial pressure atmosphere. It is said that

問題点を解決するための手段 本発明の誘電体磁器組成物は、（Ｐ　ｂａ　Ｂａｂ　）
（Ｍｇｓｚ＊　Ｎｂ２ｚ３）ｘＴｉｚ（Ｎｉｔｚ２Ｗｌ
／２　）０２＋、＋１゜で表され（ただしｘ＋ｙ＋ｚ＝
１）、０．００１≦　ｂ　≦０．２５０，１．０００≦
ａ＋ｂ≦１．２００の範囲の組成である。Means for Solving the Problems The dielectric ceramic composition of the present invention has (P ba Bab )
(Mgsz* Nb2z3)xTiz(Nitz2Wl
/2 )02+, +1° (however, x+y+z=
1), 0.001≦ b ≦0.250, 1.000≦
The composition is in the range of a+b≦1.200.

作用 本発明の組成物においては、低酸素分圧雰囲気、１１０
０℃以下の焼成温度でチ密な焼成物が得られ、高い抵抗
率を有する信頼性の高い素子がえられる。Operation In the composition of the present invention, a low oxygen partial pressure atmosphere, 110
A dense fired product can be obtained at a firing temperature of 0° C. or lower, and a highly reliable device with high resistivity can be obtained.

実施例 出発原料には化学的に高純度なＰｂＯ，ＭｇＯ。Example The starting materials are chemically highly pure PbO and MgO.

ＢａＣＯ３、Ｎｂ２Ｏ５，ＴｉＯ２，Ｎｉ○、ＷＯ２を
用いた。これらを純度補正をおこなったうえで所定量を
秤量し、メノウ製玉石を用い純水を溶媒としボールミル
で１７時時間式混合した。これを吸引ろ過して水分の大
半を分離した後乾燥し、その後ライカイ機で充分解砕し
た後粉体量の５　ｗ　ｔ％の水分を加え、直径６０ｎｍ
＋高さ約５０ｍｍの円柱状に成形圧力５００ｋｇ／ＣＩ
ｌ＋２　　で成形した。これをアルミナルツボ中に入れ
同質のフタをし、７５０℃〜８８０℃で多時間仮焼した
。次に仮焼物をアルミナ乳鉢で粗砕し、さらにメノウ製
玉石を用い純水を溶媒としてボールミルで１７時間粉砕
し、これを吸引ろ過し水分の大半を分離した後乾燥した
。　以上の仮焼、粉砕、乾燥を数回くりかえした後この
粉末にポリビニルアルコール６ｗｔ％水溶液を粉体量の
６ｗｔ％加え、３２メツシユふるいを通して造粒し、成
形圧力１０００ｋｇ／ｃｍ２で直径１３ｍｍ高さ約５酬
の円柱状に成形した。成形物は空気中で７００℃まで昇
温し１時間保持しポリビルアルコール分をバーンアウト
した。これを上述の仮焼粉を体積の１／３程度敷きつめ
た上に２００メツシユＺｒＯ２粉を約１　ｍｍ敷いたマ
・グネシャ磁器容器に移し、同質のフタをし、管状電気
炉の炉心管内に挿入し、炉心管内をロータリーポンプで
脱気したのちＮ２−Ｈ２混合ガスで置換し、酸素分圧（
ＰＯ２）が１．　Ｏｘ　１００−８ａｔになるようＮ２
とＨ２ガスの混合比を調節しながら混合ガスを流し所定
温度まで４００°Ｃ／ｈｒで昇温し２時間保持後４００
℃／ｈｒで降温した。炉心管内のＰｏ２は挿入した安定
化ジルコニア酸素センサーにより測定した。第２図に焼
成時のマグネシャ磁器容器の構造を、第３図に炉心管内
部をそれぞれ断面図で示す。BaCO3, Nb2O5, TiO2, Ni○, and WO2 were used. After correcting the purity of these, a predetermined amount was weighed, and mixed using an agate cobblestone and pure water as a solvent in a ball mill for 17 hours. This was filtered by suction to remove most of the water, then dried, and then thoroughly crushed using a Raikai machine. After adding 5 wt% of water to the powder amount, it was made into a powder with a diameter of 60 nm.
+ Molding pressure 500kg/CI into a cylindrical shape with a height of about 50mm
It was molded at l+2. This was placed in an alumina crucible, covered with a homogeneous lid, and calcined at 750°C to 880°C for many hours. Next, the calcined product was roughly crushed in an alumina mortar, and further crushed in a ball mill using agate cobblestones and pure water as a solvent for 17 hours, filtered under suction to remove most of the moisture, and then dried. After repeating the above calcining, crushing, and drying several times, 6 wt % of a 6 wt % aqueous solution of polyvinyl alcohol was added to the powder, and the powder was granulated through a 32-mesh sieve to a diameter of 13 mm in height at a compacting pressure of 1000 kg/cm2. It was molded into a cylindrical shape with 5 positions. The molded product was heated to 700° C. in air and held for 1 hour to burn out the polyvinyl alcohol content. This was transferred to a Ma-Gnesha porcelain container in which about 1/3 of the volume of the calcined powder was spread, and 200 mesh ZrO2 powder was spread to a thickness of about 1 mm, covered with a homogeneous lid, and inserted into the core tube of a tubular electric furnace. After degassing the inside of the reactor core tube with a rotary pump, the atmosphere was replaced with N2-H2 mixed gas, and the oxygen partial pressure (
PO2) is 1. N2 to make Ox 100-8at
The mixed gas was flowed while adjusting the mixing ratio of H2 gas and the temperature was raised to the specified temperature at 400°C/hr, and after holding for 2 hours,
The temperature was lowered at a rate of °C/hr. Po2 in the reactor core tube was measured by an inserted stabilized zirconia oxygen sensor. FIG. 2 shows the structure of the Magnesia porcelain container during firing, and FIG. 3 shows a cross-sectional view of the inside of the furnace tube.

第２図において１はマグネシア容器であり、その上部は
マグネシア容器蓋２で封じた。マグネシア容器１の下部
には仮焼粉３を配置し、その上にジルコニア紛４を配置
した。さらにその上に試料５を配置した。In FIG. 2, 1 is a magnesia container, the upper part of which is sealed with a magnesia container lid 2. Calcined powder 3 was placed at the bottom of magnesia container 1, and zirconia powder 4 was placed on top of it. Further, sample 5 was placed on top of it.

第２図のように準備されたマグネシア容器１を第３図の
ように炉心管６内に配置した。７は安定化ジルコニア酸
素センサーである。The magnesia container 1 prepared as shown in FIG. 2 was placed in the furnace core tube 6 as shown in FIG. 7 is a stabilized zirconia oxygen sensor.

焼成物は厚さ１　ｍｍの円板状に切断し、両面にＣｒ−
Ａｕを蒸着し、誘電率、ｔａｎδを１ｋＨｚＩＶ／ｍｍ
の電界下で測定した。また抵抗率は１　ｋ　Ｖ　／　ｍ
ｍの電圧を印加後１分値から求めた。The fired product was cut into a disk shape with a thickness of 1 mm, and both sides were coated with Cr-
Au was deposited, and the dielectric constant and tan δ were set to 1kHzIV/mm.
Measured under an electric field of Also, the resistivity is 1 kV/m
The voltage of m was determined from the value 1 minute after application.

なお焼成温度は焼成物の密度がもっとも大きくなる温度
とした。The firing temperature was set to the temperature at which the density of the fired product was the highest.

表１に本発明の組成範囲および周辺組成の成分［ａ、ｂ
、ｘ、ｙ、ｚは（Ｐｂ＋　Ｂａｂ）（Ｍｇ１ｚ３Ｎｂ２
ｔｓ　）ｘＴｉｙ（Ｎｉ１ｚ２ｗ、、２）ｚ　Ｏ２＋ａ
＋ｂ　　と表したときの値１．低酸素分圧雰囲気で焼成
したときの焼成温度、誘電率、誘電率の温度変化率（２
０°Ｃに対する）、ｔａｎδ、抵抗率、密度を示した。Table 1 shows the composition range of the present invention and the peripheral composition components [a, b
, x, y, z are (Pb+Bab)(Mg1z3Nb2
ts ) x Tiy (Ni1z2w,,2)z O2+a
The value 1 when expressed as +b. Firing temperature, dielectric constant, temperature change rate of dielectric constant (2
), tan δ, resistivity, and density are shown.

第１図は表１に示した各試料を（Ｐ　ｂ　ｎ　Ｂａ　ｂ
）Ｔｉ○２＋３＋ｌ）　、　　（Ｐｂ　ａＢａ　ｂ）（
Ｍｇ１ｚ３Ｎｂ２ｔｚ　）Ｑ２＋、＋ｂ、（Ｐｂ　ａ　
Ｂａ　ｂ）（Ｎｉｘ／２Ｗ１２　）０２＋２＋ｂを端成
分とする三角組成図中に示したもので、斜線の範囲が発
明の範囲である。Figure 1 shows each sample shown in Table 1 (P b n B a b
)Ti○2+3+l), (Pb aBa b)(
Mg1z3Nb2tz ) Q2+, +b, (Pb a
B a b ) (Nix/2W12 )02+2+b is shown in a triangular composition diagram having end members, and the shaded range is the scope of the invention.

発明範囲外の組成物では、ａ＋ｂが１．０００より小さ
いと低酸素分圧雰囲気で焼成したときチ密な焼結物が得
られない、もしくは抵抗率が低（なる難点を有しており
、１．２００より大きくなると誘電率および抵抗率が低
下する難点を有する。またｂが０．２５０より大きいと
誘電率が低下する。ｘ、ｙ、ｚが限定の範囲外の組成物
はキュリ一点が室温から大きくはずれ誘電率が低くなる
、もしくは誘電率の温度変化率が太きなる難点を有して
いる。発明の範囲内の組成物では前記の問題がいずれも
克服されている。Compositions outside the scope of the invention have the disadvantage that if a + b is less than 1.000, a dense sintered product cannot be obtained when fired in a low oxygen partial pressure atmosphere, or the resistivity is low. If b is larger than 1.200, the dielectric constant and resistivity will decrease.If b is larger than 0.250, the dielectric constant will decrease.For compositions in which x, y, and z are outside the specified ranges, a single point of Curie However, the compositions within the scope of the present invention overcome all of the above-mentioned problems.

なお焼成雰囲気として選択した低酸素分圧雰囲気ＰＯ２
；　１．０ｘｌＯ−８ａｔｎ＋　　は焼成温度におケル
銅の平衡酸素分圧より低く金属はほとんど酸化しないと
考えられる。Note that the low oxygen partial pressure atmosphere PO2 selected as the firing atmosphere
It is considered that 1.0xlO-8atn+ is lower than the equilibrium oxygen partial pressure of Kel copper at the firing temperature, and the metal is hardly oxidized.

発明の効果 本発明によれば、低酸素分圧雰囲気１１００℃以下の焼
成で積層コンデンサ素子として高信頼性を得るためのチ
密で抵抗率の高い焼結体が得られ、内部電極としてＣｕ
などの卑金属材料を用いることか可能になる優れた誘電
体磁器組成物でを実現できる。Effects of the Invention According to the present invention, a dense and highly resistive sintered body for obtaining high reliability as a multilayer capacitor element can be obtained by firing at 1100°C or lower in a low oxygen partial pressure atmosphere, and Cu is used as the internal electrode.
Excellent dielectric ceramic compositions can be realized by using base metal materials such as.

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

第１図は本発明に係る磁器組成物の成分組成を示す三角
組成図、第２図は焼成時に磁器を入れるマグネシャ容器
の断面図、第３図は焼成時の炉心管を示す断面図である
。 １；マグネシャ容器、２；マグネシャ容器蓋、３：仮焼
粉、４；ジルコニア粉、５；試料、６；炉心管。 ７；安定化ジルコニア酸素センサー。 代理人の氏名　弁理士　中尾敏男　はが１名第１図 （Ｐｂａ［１ａｂＸＮｉ＋／２Ｗ＋／２）０２＋ａ＋ｂ
　　　　ｚ　　　　　　　　　　　　　（ＰｂａＢａｂ
）Ｔｉ０２＋ａ＋ｂ第３図Fig. 1 is a triangular composition diagram showing the composition of the porcelain composition according to the present invention, Fig. 2 is a cross-sectional view of a magnesia container in which the porcelain is placed during firing, and Fig. 3 is a cross-sectional view showing the furnace tube during firing. . 1: Magnesia container, 2: Magnesia container lid, 3: Calcined powder, 4: Zirconia powder, 5: Sample, 6: Furnace tube. 7; Stabilized zirconia oxygen sensor. Name of agent Patent attorney Toshio Nakao 1 person Figure 1 (Pba[1abXNi+/2W+/2)02+a+b
z (PbaBab
)Ti02+a+bFigure 3

Claims (1)

【特許請求の範囲】 （Ｐｂ＿３Ｂａ＿ｂ）｛（Ｍｇ＿１＿／＿３Ｎｂ＿２＿
／＿３）＿ｘＴｉ＿ｙ（Ｎｉ＿１＿／＿２Ｗ＿１＿／＿
２）＿ｚ｝Ｏ＿２＿＋＿ａ＿＋＿ｂで表される組成式（
ただし、ｘ＋ｙ＋ｚ＝１）において ０．００１≦ｂ≦０．２５０ １．０００≦ａ＋ｂ≦１．２００ の範囲にあり、この範囲内の各ａ、ｂの値に対し（Ｐｂ
＿ａＢａ＿ｂ）（Ｍｇ＿１＿／＿３Ｎｂ＿２＿／＿３）
Ｏ＿２＿＋＿ａ＿＋＿ｂ、 Ｐｂ＿ａＢａ＿ｂ）ＴｉＯ＿２＿＋＿ａ＿＋＿ｂ、 （Ｐｂ＿ａＢａ＿ｂ）（Ｎｉ＿１＿／＿２Ｗ＿１＿／＿
２）Ｏ＿２＿＋＿ａ＿＋＿ｂを頂点とする三角座標にお
いて下記組成点、Ａ、Ｂ、Ｃ、Ｄ、Ｅ、を頂点とする五
角形の領域内の組成物からなることを特徴とする誘電体
磁器組成物。 Ａ；ｘ＝０．９５０　ｙ＝０．０４９　ｚ＝０．００１ Ｂ；ｘ＝０．７５０　ｙ＝０．２４９　ｚ＝０．００１ Ｃ；ｘ＝０．０１０　ｙ＝０．８００　ｚ＝０．１９０ Ｄ；ｘ＝０．０１０　ｙ＝０．４５０　ｚ＝０．５４０ Ｅ；ｘ＝０．９００　ｙ＝０．０５０　ｚ＝０．０５０[Claims] (Pb_3Ba_b) {(Mg_1_/_3Nb_2_
/_3)_xTi_y(Ni_1_/_2W_1_/_
2) Compositional formula represented by _z}O_2_+_a_+_b (
However, at
_aBa_b) (Mg_1_/_3Nb_2_/_3)
O_2_+_a_+_b, Pb_aBa_b) TiO_2_+_a_+_b, (Pb_aBa_b) (Ni_1_/_2W_1_/_
2) A dielectric ceramic composition comprising a composition within a pentagonal region whose vertices are the following composition points A, B, C, D, and E in triangular coordinates whose vertices are O_2_+_a_+_b. A; x=0.950 y=0.049 z=0.001 B; x=0.750 y=0.249 z=0.001 C; x=0.010 y=0.800 z=0. 190 D; x=0.010 y=0.450 z=0.540 E; x=0.900 y=0.050 z=0.050