JP2790852B2 - Oxygen sensor element for controlling air-fuel ratio and method of manufacturing the same - Google Patents
Oxygen sensor element for controlling air-fuel ratio and method of manufacturing the sameInfo
- Publication number
- JP2790852B2 JP2790852B2 JP1130230A JP13023089A JP2790852B2 JP 2790852 B2 JP2790852 B2 JP 2790852B2 JP 1130230 A JP1130230 A JP 1130230A JP 13023089 A JP13023089 A JP 13023089A JP 2790852 B2 JP2790852 B2 JP 2790852B2
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- Prior art keywords
- measurement electrode
- electrode
- solid electrolyte
- sensor element
- ceramic
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- Measuring Oxygen Concentration In Cells (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は各種燃焼機器の酸素濃度を検知するための酸
素センサ素子及びその製造方法，特に内燃機関からの排
ガスを浄化するために利用される空燃比制御用の酸素セ
ンサ素子及びその製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is used for an oxygen sensor element for detecting the oxygen concentration of various combustion equipment and a method for manufacturing the same, particularly for purifying exhaust gas from an internal combustion engine. The present invention relates to an oxygen sensor element for controlling an air-fuel ratio and a method for manufacturing the same.
［従来技術及び課題］ 空燃比制御用酸素センサの素子は，一般に，酸素イオ
ン伝導性の固体電解質体とその内外面に備えられる一対
の電極（基準電極，測定電極）とからなっている。従
来，この種の酸素センサ素子における電極の形成法とし
ては，固体電解質材料を焼成した後，電極材料をメッ
キ，スパッタリング処理する方法が汎用されていた。し
かし，近年，小型センサ素子（板状型，円柱状型）とし
て，固体電解質材料を焼成することなく生の状態をもっ
て電極材料をペースト塗布し，その後同時焼成する方法
がある。その代表例が特公昭52-30699,更には同59-2438
2に開示されている。[Prior Art and Problems] An element of an oxygen sensor for controlling an air-fuel ratio generally includes an oxygen ion conductive solid electrolyte body and a pair of electrodes (a reference electrode and a measurement electrode) provided on the inner and outer surfaces thereof. Heretofore, as a method of forming an electrode in this type of oxygen sensor element, a method in which a solid electrolyte material is fired, and then the electrode material is plated and sputtered has been widely used. However, in recent years, as a small sensor element (plate type or column type), there is a method in which an electrode material is paste-applied in a raw state without firing a solid electrolyte material, and then fired simultaneously. A typical example is JP-B 52-30699, and 59-2438.
2 disclosed.
しかし，特公昭52-30699に開示された製法によって得
られたセンサ素子（固体電解質電池）を耐久使用した場
合，電極材料と排ガス中のカーボンとが反応して電極が
剥離する問題があった。更に，公知のプラズマ溶射によ
って電極を被覆して保護層を備えた場合であっても，内
燃機関の苛酷な条件下では同様な反応により保護層の剥
離，更には電極の剥離は不可避であった。However, when the sensor element (solid electrolyte battery) obtained by the manufacturing method disclosed in Japanese Patent Publication No. 52-30699 is used in a durable manner, there has been a problem that the electrode material reacts with carbon in the exhaust gas and the electrode is peeled off. Furthermore, even when the protective layer is provided by coating the electrode by known plasma spraying, under the severe conditions of the internal combustion engine, the protective layer is peeled off by the same reaction, and further, the electrode is inevitable. .
又，特公昭59-24382に開示される製法によって得られ
た保護層を備えたセンサ素子についても，やはり，同様
な問題を生じていた。Further, a sensor element provided with a protective layer obtained by the manufacturing method disclosed in Japanese Patent Publication No. 59-24382 also has a similar problem.
本発明の課題は，センサ素子の耐久性を向上せしめ，
しかも高価な貴金属の使用を極力抑えると共に，低温か
ら高温に至るまでセンサとしての機能を充分に果たすセ
ンサ素子を得るための製法を開発することにある。An object of the present invention is to improve the durability of a sensor element,
Moreover, it is an object of the present invention to minimize the use of expensive noble metals and to develop a manufacturing method for obtaining a sensor element that sufficiently functions as a sensor from a low temperature to a high temperature.
［解決手段及び作用］ そこで，本発明はかかる課題を下記手段によって解決
した。[Solution Means and Action] Therefore, the present invention has solved the above problem by the following means.
固体電解質体の一面側に基準電極、その他面側に測定
電極を備え、少なくとも測定電極を被覆するセラミック
スからなる保護層を備えた空燃比制御用酸素センサ素子
を製造する方法であって、測定電極材料が、主として貴
金属及びセラミックス（前駆体を含む。以下同じ）を含
有してなるペーストであって、セラミックスを0.05〜10
wt％（貴金属及びセラミックスの合計量に対して）含有
しており、 該測定電極材料を、成形後かつ未焼成の固体電解質材
料の表面において、測定電極材料の存在部と不存在部と
が交互に分布して位置すると共に隣接する各存在部が相
互に連通してなるパターンで施し、少なくとも測定電極
材料及び固体電解質材料を同時焼成すること。A method for manufacturing an air-fuel ratio control oxygen sensor element comprising a reference electrode on one surface side of a solid electrolyte body, a measurement electrode on the other surface side, and a protective layer made of ceramics covering at least the measurement electrode, comprising: A paste in which the material mainly contains a noble metal and a ceramic (including a precursor; the same applies hereinafter).
wt% (based on the total amount of precious metals and ceramics), and the presence and absence of the measurement electrode material are alternated on the surface of the unfired solid electrolyte material after molding. In a pattern in which the existing portions that are distributed and located adjacent to each other communicate with each other, and simultaneously firing at least the measurement electrode material and the solid electrolyte material.
または、固体電解質体の一面側に基準電極、その他面
側に測定電極を備え、少なくとも測定電極を被覆するセ
ラミックスからなる保護層を備えた空燃比制御用酸素セ
ンサ素子であって、前記測定電極は、主として貴金属及
びセラミックス（前駆体を含む。以下同じ）からなり、
該セラミックスを0.05〜10wt％（貴金属及びセラミック
ス合計量に対して）含有してなり、さらに、前記測定電
極は、前記固体電解質材料の表面において、該測定電極
の存在部と不存在部とが交互に分布して位置すると共に
隣接する各存在部が相互に連通してなるパターンを有し
てなること。Alternatively, a reference electrode on one surface side of the solid electrolyte body, a measurement electrode on the other surface side, an air-fuel ratio control oxygen sensor element having a protective layer made of ceramics covering at least the measurement electrode, wherein the measurement electrode is Mainly composed of precious metals and ceramics (including precursors; the same applies hereinafter),
The ceramic contains 0.05 to 10% by weight (based on the total amount of the noble metal and the ceramic), and the measuring electrode has a portion where the measuring electrode is present and a portion where the measuring electrode is absent alternately on the surface of the solid electrolyte material. And the adjacent existing portions have a pattern of communicating with each other.
通常，電極材料として主に貴金属が用いられ，この貴
金属電極はセラミックスからなる固体電解質との結合力
が弱い。そのため，電極材料中にセラミックスを含有さ
せることも行なわれる。センサ耐久性を考慮した場合，
そのセラミックス量は少なくとも15wt％以上（貴金属及
びセラミックスの合計量に対して）必要である。一方，
電極材料と固体電解質材料とを同時焼成する方法におい
ては，一般に，工程短縮・コスト低減の見地から，電極
部，リード部及び出力取出部を同時に形成・焼成する場
合が多い。この場合，リード部としての抵抗を低く抑え
（数Ω程度，検知部ないしは電極部より小）導通性を確
保するため，逆に，セラミックスの含有量を20wt％以下
にする必要がある。従って，単に電極材料中のセラミッ
クス量を規定しただけでは，センサ素子の耐久性，又は
その電極に係る導通性のいずれかを犠牲にせざるを得な
い。又、リード導通性を確保するためその厚みを厚くす
ることも考えられる。しかし，この場合電極の焼成・収
縮との関係で，電極・リード等の形成部と非形成部との
境界において固体電解質体にキレが入り易い等，他の問
題を生ずる。Usually, a noble metal is mainly used as an electrode material, and this noble metal electrode has a weak bonding force with a solid electrolyte made of ceramics. For this reason, ceramics are sometimes included in the electrode material. Considering sensor durability,
The amount of ceramics must be at least 15 wt% or more (based on the total amount of precious metals and ceramics). on the other hand,
In the method of simultaneously firing the electrode material and the solid electrolyte material, generally, the electrode portion, the lead portion, and the output extraction portion are often formed and fired simultaneously from the viewpoint of shortening the process and reducing the cost. In this case, conversely, the content of ceramics must be reduced to 20 wt% or less in order to suppress the resistance as the lead portion (several ohms, smaller than the detection portion or the electrode portion) and to secure conductivity. Therefore, merely specifying the amount of ceramics in the electrode material has to sacrifice either the durability of the sensor element or the conductivity of the electrode. It is also conceivable to increase the thickness to ensure lead conductivity. However, in this case, other problems occur, such as the solid electrolyte body being easily broken at the boundary between the formation portion and the non-formation portion of the electrode / lead, etc. due to the firing and shrinkage of the electrode.
本発明の上記手段によれば，固体電解質表面における
測定電極材料の存在部によって導通性を確保しつつ，そ
の不存在部によってセラミックスからなる保護層との固
着強度を高めることができ，上述の課題を解決する。そ
のため，保護層材料についても，測定電極材料及び固体
電解質材料と共に同時焼成することが好ましい。更に，
センサ（素子）耐久性が向上する。According to the above-mentioned means of the present invention, while the conductivity is ensured by the existence portion of the measurement electrode material on the solid electrolyte surface, the adhesion strength to the protective layer made of ceramics can be increased by the absence portion, and the above-mentioned problems can be solved. Solve. For this reason, it is preferable that the protective layer material is simultaneously fired together with the measurement electrode material and the solid electrolyte material. Furthermore,
Sensor (element) durability is improved.
測定電極（排ガスに接触する電極）材料についてセラ
ミックスは貴金属粉末及びセラミックスの合計量に対し
て0.05〜10wt％含有される。尚，セラミックスは粉末と
して，又その前駆体である溶液として混合される。0.05
wt％以上としたのは，上述の如く電極材料と固体電解質
材料との反応性を向上させ，固着強度を高めるためであ
り，好ましくは0.2wt％以上が良い。これによって，貴
重な貴金属の使用量を抑えることもできる。又,10wt％
以下としたのはリード部，電極部の所定の導通性（抵抗
性）を得るためであり，好ましくは8wt％以下が良い。With respect to the material of the measurement electrode (electrode in contact with exhaust gas), the ceramic is contained in an amount of 0.05 to 10% by weight based on the total amount of the noble metal powder and the ceramic. The ceramics are mixed as a powder or as a precursor solution. 0.05
The reason why the content is set to not less than wt% is to improve the reactivity between the electrode material and the solid electrolyte material and to increase the fixing strength, as described above, and preferably not less than 0.2 wt%. As a result, the amount of precious metals used can be reduced. Also, 10wt%
The reason for the following is to obtain a predetermined conductivity (resistance) of the lead portion and the electrode portion, and preferably 8 wt% or less.
貴金属粉末の平均粒径は２μｍ以下，より好ましくは
1.5μｍ以下の細いものに，その形状は球状にするとよ
い。電極及びリードの導通性をより確実にできる。又，
セラミックス粉末として混合する場合，セラミックス粉
末の平均粒径（ｙ）については，貴金属粉末の平均粒径
（ｘ）に対してｘ×0.7≧ｙになるようにより細かなも
のにするとよい。リード導通性をより確実にし，しかも
電極材料と固体電解質材料との固着強度をより高めるこ
とができる。The average particle size of the noble metal powder is 2 μm or less, more preferably
It is good to make the shape of a thin thing of 1.5 μm or less spherical. The conductivity of the electrodes and the leads can be more reliably ensured. or,
When mixed as a ceramic powder, the average particle size (y) of the ceramic powder may be made finer so that x × 0.7 ≧ y with respect to the average particle size (x) of the noble metal powder. The lead conductivity can be further ensured, and the bonding strength between the electrode material and the solid electrolyte material can be further increased.
尚，貴金属粉末としては例えばPt,Pd,又セラミックス
としては例えばZrO2,Al2O3など又その前駆体としては例
えばZr(OH)4など種々のものが使用でき特に限定されな
い。又，測定電極材料用ペーストは，これらの粉末に通
常のバインダ（有機樹脂），溶剤等を配合して調整され
る。The noble metal powder may be, for example, Pt, Pd, the ceramics may be, for example, ZrO 2 , Al 2 O 3, etc., and the precursor thereof may be, for example, Zr (OH) 4 . The measurement electrode material paste is prepared by mixing a normal binder (organic resin), a solvent and the like with these powders.
測定電極材料は，固体電解質材料の表面において前記
所定のパターンで施される。好ましくは網目状ないしは
格子状パターンで存在させる。導通性を確保しつつ，固
体電解質と保護層（測定電極）との固着密度を高め，し
かも貴重な貴金属の使用量を抑えることができる。この
見地から，パターン要素の幅は例えば0.05〜0.5mm,隣接
するパターン要素間の離間長さは例えば0.05〜0.5mmに
するとよい。又，その厚み（焼成後）は30μｍ程度以下
にするとよい。固体電解質シートと測定電極ペーストと
の焼成収縮率が異なるので，より厚くすると，シートに
クラック等の欠陥が生じ易くなる。The measurement electrode material is applied in the predetermined pattern on the surface of the solid electrolyte material. Preferably, they are present in a mesh or lattice pattern. It is possible to increase the fixation density between the solid electrolyte and the protective layer (measuring electrode) while keeping the conductivity, and to suppress the amount of precious metal used. From this viewpoint, it is preferable that the width of the pattern element is, for example, 0.05 to 0.5 mm, and the separation length between adjacent pattern elements is, for example, 0.05 to 0.5 mm. The thickness (after firing) is preferably set to about 30 μm or less. Since the baking shrinkage ratios of the solid electrolyte sheet and the measuring electrode paste are different, if the thickness is larger, defects such as cracks are likely to occur in the sheet.
測定電極（の電極部）は，複数に分散配置して（各パ
ターンユニット相互間は導通のみ）形成してもよい。特
に，素子の周回り方向に分散配置すれば，センサの排ガ
スに対する方向性を少なくでき，安定したセンサ特性が
得られる。また電極に別々の被覆を施して耐久性を向上
させることもできる。例えば，二つに分割し，一の測定
電極を被覆する保護層中に貴金属を含有させ，他の測定
電極を被覆する保護層中に貴金属を含有させなくした
り，或いは，一の保護層中にIIa族成分を含有させてシ
リコン（Si）に対する耐被毒性を高める態様にしてもよ
い。又，パターン外周面積（この種の測定電極における
従来パターンの外周面積に相当）に対して電極材料の存
在部に係る面積を50〜95％にすることもできる。The measurement electrodes (electrode portions thereof) may be formed by dispersing them in a plurality (only conducting between the pattern units). In particular, if the elements are dispersedly arranged in the circumferential direction of the element, the directionality of the sensor with respect to exhaust gas can be reduced, and stable sensor characteristics can be obtained. In addition, the electrodes can be separately coated to improve durability. For example, it is divided into two parts, and the noble metal is contained in the protective layer covering one measuring electrode, and the noble metal is not contained in the protective layer covering the other measuring electrode. A mode may be adopted in which a group IIa component is contained to increase the poisoning resistance to silicon (Si). Further, the area related to the portion where the electrode material is present can be set to 50 to 95% of the pattern outer peripheral area (corresponding to the outer peripheral area of the conventional pattern in this type of measurement electrode).
ペースト施用された測定電極材料は，固体電解質材料
と同時焼成することにより，両者の固着強度を高め得
る。測定電極を保護するために電極を被覆して備えられ
る保護層の材料（例えばアルミナ，スピネル，チタニ
ア）についても，測定電極材料及び固体電解質材料と共
に同時焼成することが好ましい。更に，固体電解質材料
と保護層材料とは共にセラミックスとなるので，同時焼
成によって固着強度が高められ，センサ（素子）の耐久
性が向上する。測定電極（の電極部）を分割し，各分割
された測定電極に保護層を備える場合には，少なくとも
一の保護層材料を同時焼成に供してもよい。特に，固体
電解質材料のグリーンシートに電極材料，保護層材料等
のペーストをスクリーン印刷（ないしは転写）し，この
印刷グリーンシートを筒状基材（例えばジルコニア，ア
ルミナ）に巻回被着して焼成一体化するとよい。尚，測
定電極を構成する電極部，リード部及び出力取出部をい
ずれも同時焼成に供することが好ましい。The measurement electrode material to which the paste is applied can be co-fired with the solid electrolyte material to increase the bonding strength between them. It is also preferable that the material of the protective layer (for example, alumina, spinel, titania) provided to cover the electrode for protecting the measurement electrode is co-fired with the measurement electrode material and the solid electrolyte material. Furthermore, since the solid electrolyte material and the protective layer material are both ceramics, the co-firing increases the fixing strength and improves the durability of the sensor (element). When the measurement electrode (the electrode part thereof) is divided and each divided measurement electrode is provided with a protective layer, at least one protective layer material may be subjected to simultaneous firing. In particular, paste such as electrode material and protective layer material is screen-printed (or transferred) onto a green sheet of a solid electrolyte material, and the printed green sheet is wound around a cylindrical substrate (eg, zirconia, alumina) and fired. It is good to integrate. In addition, it is preferable that all of the electrode part, the lead part, and the output extraction part constituting the measurement electrode be subjected to simultaneous firing.
又、こうして得られるセンサ素子にヒータを内存，併
設等することにより，センサを低温から高温域までより
有効に機能させることもできる。Further, by providing a heater in the sensor element obtained in this way or by providing the heater together, the sensor can be made to function more effectively from a low temperature to a high temperature range.
本発明の製法は種々のタイプの酸素センサ素子の製造
に適用でき，特に，板状，筒状型など小型用センサ素子
の製造として好適である。尚，下記にその例を示すが，
これらに限定されないことは勿論である。The manufacturing method of the present invention can be applied to the manufacture of various types of oxygen sensor elements, and is particularly suitable for the manufacture of small-sized sensor elements such as plate-shaped and cylindrical-shaped sensor elements. An example is shown below.
Of course, it is not limited to these.
［実施例］ （１）固体電解質シートの作成 純度99.9％のY2O3粉末を5.5モル％になる様に，純度9
9.9％のZrO2粉末に加え，回転機にて60時間混合した。
乾燥後20メッシュの篩を通し,1380℃２時間の仮焼を行
なった。これにポリビニールブチラール樹脂を加え，ト
ルエン，メチルエチルケトン等により30時間混合した。
この混合材料を用いてドクターブレード法により厚さ0.
4mmのシートを作成し，次いで所定の寸法（70×100mm）
に切断した。[Example] (1) a Y 2 O 3 powder of creating a purity of 99.9% of the solid electrolyte sheet so as to become 5.5 mol%, purity 9
It was added to 9.9% ZrO 2 powder and mixed for 60 hours with a rotating machine.
After drying, it was passed through a 20-mesh sieve and calcined at 1380 ° C for 2 hours. Polyvinyl butyral resin was added thereto, and mixed with toluene, methyl ethyl ketone and the like for 30 hours.
Using this mixed material by the doctor blade method to a thickness of 0.
Create a 4mm sheet, then set dimensions (70 x 100mm)
Cut into pieces.
（２）筒状基体の作成 上記の同様のセラミックス材料を1300℃で仮焼し，こ
れを回転機にて220時間粉砕後，スプレードライ法にて
約70〜80μｍに造粒した。これにマイクロワックス系の
樹脂と水を加え，押出し成形をして第１図に示す両端側
開口の中空筒状体を製作した。これを1200℃にて素焼し
後工程で内側電極（基準電極）が形成される位置にφ1m
mの貫通穴を２ケ所に設けた。更に上記造粒粉末を用い
て，厚さ0.3mmの円板をプレス成形により得，上記筒状
体の一開口端に付着させた。この場合の接着剤として，
上記筒状体製作時の泥漿を用いた。(2) Preparation of cylindrical substrate The same ceramic material as described above was calcined at 1300 ° C, crushed with a rotating machine for 220 hours, and then granulated to about 70 to 80 µm by spray drying. A micro-wax resin and water were added to the mixture, and the mixture was extruded to produce a hollow cylindrical body having openings at both ends shown in FIG. This is fired at 1200 ° C, and φ1m at the position where the inner electrode (reference electrode) is formed in the post-process.
m through holes were provided at two places. Further, a disk having a thickness of 0.3 mm was obtained by press molding using the above-mentioned granulated powder, and attached to one opening end of the above-mentioned cylindrical body. As an adhesive in this case,
The slurry from the production of the cylindrical body was used.
（３）電極材料の作成 下記表に示されるように貴金属（Ptブラック1:Ptスポ
ンジ３の割合）及びセラミックス材料を調合し,4時間混
合後，アクリル系バインダ，ブチルカルビトールを加え
てペーストとした（ペースト１）。なおセラミックス材
料としては，水酸化Zr塩溶液，ZrO2（第一稀元素工業
（株）のSPZ粉末,CBZ粉末）を粉砕して１μｍとしたも
のを使用した。又，測定電極及び基準電極のいずれもこ
の材料を用いた。(3) Preparation of electrode material Noble metal (Pt black 1: Pt sponge 3 ratio) and ceramic material were mixed as shown in the table below, and after mixing for 4 hours, an acrylic binder and butyl carbitol were added to form a paste. (Paste 1). As the ceramic material, a Zr hydroxide solution or ZrO 2 (SPZ powder, CBZ powder of Daiichi Rare Element Industrial Co., Ltd.) was pulverized to 1 μm. This material was used for both the measurement electrode and the reference electrode.
（４）保護層材料の作成 Al2O3粉末にMgO,CaO,SiO2からなるフラックスを加
え，更に有機バインダとブチルカルビトールを加え，ペ
ーストを得た（ペースト２）。更にペースト２におがく
ず等を加えた（ペースト３）。(4) Preparation of protective layer material A flux composed of MgO, CaO, and SiO 2 was added to Al 2 O 3 powder, and an organic binder and butyl carbitol were further added to obtain a paste (paste 2). Further, sawdust and the like were added to paste 2 (paste 3).
（５）センサ素子の作成 シート上に第１図の如く，ペースト１にてスクリーン
印刷した（厚さ20μｍ）。更に電極部4aを除くリード部
4c等を被膜する様にペースト２にてスクリーン印刷し
（厚さ30μｍ），絶縁層を設けた。更に電極部にはペー
スト３にて厚さ20μｍの保護層を設けた。次にペースト
１にてヒータ部を印刷し（厚さ20μｍ），更にその上に
ペースト２を印刷した（厚さ20μｍ）。(5) Preparation of sensor element As shown in FIG. 1, paste printing was performed on the sheet with paste 1 (thickness: 20 μm). Furthermore, the lead part except the electrode part 4a
Screen printing (thickness: 30 μm) was performed with paste 2 so as to coat 4c and the like, and an insulating layer was provided. Further, a protective layer having a thickness of 20 μm was provided with paste 3 on the electrode portion. Next, the heater portion was printed with paste 1 (thickness 20 μm), and further paste 2 was printed thereon (thickness 20 μm).
こうしてスクリーン印刷された固体電解質シートを筒
状基体に巻き付けて400℃×24時間の樹脂抜きした後,14
60℃×２時間焼成して，各センサ素子（No.1〜14）を得
た。The screen-printed solid electrolyte sheet was wound around a cylindrical substrate and the resin was removed at 400 ° C for 24 hours.
Each sensor element (No. 1 to 14) was obtained by firing at 60 ° C. for 2 hours.
得られた酸素センサ素子の一例を第３図，第４図に示
す。各図において,1は基体,2は基準電極,3は固体電解質
体,4は測定電極,5は保護層,6,8は絶縁層,7はヒータを夫
々示す。更に,2a,4aは電極部,2b,4b,9は端子部,2c,4cは
リード部,3aは導通口,6a,8aは保護層５に対応した位置
に形成された開口,7aは発熱部,7bは端子部を夫々示す。An example of the obtained oxygen sensor element is shown in FIG. 3 and FIG. In each figure, 1 is a base, 2 is a reference electrode, 3 is a solid electrolyte body, 4 is a measurement electrode, 5 is a protective layer, 6, 8 are insulating layers, and 7 is a heater. Furthermore, 2a and 4a are electrode portions, 2b, 4b and 9 are terminal portions, 2c and 4c are lead portions, 3a is a conduction hole, 6a and 8a are openings formed at positions corresponding to the protective layer 5, and 7a is a heat generating member. Reference numeral 7b denotes a terminal.
尚，測定電極４の電極部4aは二つの格子状パターンユ
ニットが素子の周回り方向に分散配置で形成されてい
る。又，パターン要素の幅は0.3mm,隣接するパターン要
素間の離間長さは0.25mm,又リード部の幅は0.5〜1mmで
ある。In the electrode section 4a of the measurement electrode 4, two lattice-shaped pattern units are formed in a dispersive arrangement in the circumferential direction of the element. The width of the pattern element is 0.3 mm, the distance between adjacent pattern elements is 0.25 mm, and the width of the lead is 0.5 to 1 mm.
［比較例］ 保護層をスピネル溶射によって形成し（比較例１），
又電極材料を格子状ではなく全面に亘り施し（比較例2,
3），前記同様に酸素センサ素子を製造した。Comparative Example A protective layer was formed by spinel spraying (Comparative Example 1).
Also, the electrode material was applied over the entire surface instead of the grid (Comparative Example 2,
3) An oxygen sensor element was manufactured as described above.
［試験］ こうした実施例１〜14及び比較例１〜３によって得ら
れた酸素センサ素子について，特性を比較した。[Test] The characteristics of the oxygen sensor elements obtained in Examples 1 to 14 and Comparative Examples 1 to 3 were compared.
試験1: 各センサ素子について，測定電極のリード部の抵抗
（Ω）をマルチメータによって測定した。Test 1: For each sensor element, the resistance (Ω) of the lead of the measurement electrode was measured with a multimeter.
試験2: 各センサ素子をブンゼンバーナーで加熱し,900℃30
0℃の加熱サイクルをもって200時間耐久を行い，測定電
極・保護層の剥離の有無を調べた。Test 2: Each sensor element was heated with a Bunsen burner at 900 ° C 30
The endurance was performed for 200 hours with a heating cycle of 0 ° C, and the presence of peeling of the measurement electrode and the protective layer was examined.
これらの結果も第１表に示す。 These results are also shown in Table 1.
上記表から明らかなように，実施例１〜14（No.1,6,9
を除く）に係るセンサ素子はリード部の抵抗が10Ω以下
と低く，かつハクリも全く認められなかった。これに対
して，比較例に係るものは保護層のハクリ，又はリード
部に一部断線を生じた。 As is clear from the above table, Examples 1 to 14 (Nos. 1, 6, 9
The sensor element according to (1) had a low lead resistance of 10Ω or less, and no peeling was observed. On the other hand, in the case of the comparative example, the protective layer was partially peeled or the lead portion was partially broken.
又，実施例6,9の結果から，セラミックス粉末の平均
粒径が好ましい範囲（ｘ×0.7≧ｙ）を外れたり，又セ
ラミック粉末の量が0.05〜10wt％から外れた場合にも，
リード部抵抗の増大や導通抵抗のバラツキが生ずること
も確認できた。Also, from the results of Examples 6 and 9, even when the average particle size of the ceramic powder is out of the preferable range (x × 0.7 ≧ y) or when the amount of the ceramic powder is out of the range of 0.05 to 10 wt%,
It was also confirmed that an increase in lead resistance and a variation in conduction resistance occurred.
［発明の効果］ 本発明によれば，リード部の導通性を高水準に維持
（抵抗10Ω以下）しつつ，内燃機関の苛酷な耐久条件下
においても2000hr以上電極・保護層に剥離を生じない。[Effects of the Invention] According to the present invention, the electrode / protective layer does not peel off for more than 2000 hours even under severe endurance conditions of an internal combustion engine while maintaining the conductivity of the lead portion at a high level (resistance of 10Ω or less). .
又，貴重な天然資源である貴金属の使用量を従来例
（全面に施すもの）に比して約30％削減できる。In addition, the amount of precious metals, which are valuable natural resources, can be reduced by about 30% compared to the conventional example (applied entirely).
第１図は本発明の一実施例について，電極材料の施用状
態を示す模式図， 第２図は上記例で使用される筒状基体を示す斜視図， 第３図は上記例によって得られるセンサ素子を各要素ご
とに示した斜視図，そして 第４図は上記例によって得られるセンサ素子の断面図
（電極部）， を夫々表わす。FIG. 1 is a schematic view showing an application state of an electrode material according to an embodiment of the present invention, FIG. 2 is a perspective view showing a cylindrical base used in the above example, and FIG. 3 is a sensor obtained by the above example. FIG. 4 is a perspective view showing the element for each element, and FIG. 4 is a sectional view (electrode portion) of the sensor element obtained by the above example.
フロントページの続き (56)参考文献 特開 昭59−3252（ＪＰ，Ａ) 特開 昭63−98558（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) G01N 27/409Continuation of front page (56) References JP-A-59-3252 (JP, A) JP-A-63-98558 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) G01N 27 / 409
Claims (6)
面側に測定電極を備え、少なくとも測定電極を被覆する
セラミックスからなる保護層を備えた空燃比制御用酸素
センサ素子を製造する方法であって、 測定電極材料が、主として貴金属及びセラミックス（前
駆体を含む。以下同じ）を含有してなるペーストであっ
て、セラミックスを0.05〜10wt％（貴金属及びセラミッ
クスの合計量に対して）含有しており、 該測定電極材料を、成形後かつ未焼成の固体電解質材料
の表面において、測定電極材料の存在部と不存在部とが
交互に分布して位置すると共に隣接する各存在部が相互
に連通してなるパターンで施し、 少なくとも測定電極材料及び固体電解質材料を同時焼成
する、 ことを特徴とする酸素センサ素子の製造方法。1. A method for manufacturing an oxygen sensor element for controlling an air-fuel ratio, comprising a reference electrode on one surface of a solid electrolyte body, a measurement electrode on the other surface, and a protective layer made of ceramic covering at least the measurement electrode. The measurement electrode material is a paste mainly containing a noble metal and a ceramic (including a precursor; the same applies hereinafter), and contains 0.05 to 10 wt% of the ceramic (based on the total amount of the noble metal and the ceramic). On the surface of the unmolded solid electrolyte material after molding, the measurement electrode material is formed such that the existence part and the non-existence part of the measurement electrode material are alternately distributed and the adjacent existence parts are mutually separated. A method for producing an oxygen sensor element, wherein the method is performed in a communication pattern, and at least a measurement electrode material and a solid electrolyte material are simultaneously fired.
と共に、前記保護層材料をも同時焼成する請求項１記載
の製造方法。2. The method according to claim 1, wherein said protective layer material is co-fired together with said measurement electrode material and said solid electrolyte material.
極部を有し、該複数の電極部を夫々被覆する複数の前記
保護層を備えた酸素センサ素子を製造する方法であっ
て、 前記複数の保護層のうち少なくとも一を、前記固体電解
質材料、前記測定電極材料及び前記保護層材料の同時焼
成によって形成する請求項２記載の製造方法。3. A method for manufacturing an oxygen sensor element comprising: a plurality of electrode portions in which the measurement electrodes are dispersedly arranged; and a plurality of the protective layers covering the plurality of electrode portions, respectively. 3. The method according to claim 2, wherein at least one of the plurality of protective layers is formed by simultaneously firing the solid electrolyte material, the measurement electrode material, and the protective layer material.
ある請求項１記載の製造方法。4. The method according to claim 1, wherein the average particle size (x) of the metal powder is 2 μm or less.
粉末の平均粒径（ｘ）に対してｘ×0.7≧ｙである請求
項１記載の製造方法。5. The method according to claim 1, wherein the average particle size (y) of the ceramic powder is x × 0.7 ≧ y with respect to the average particle size (x) of the noble metal powder.
面側に測定電極を備え、少なくとも測定電極を被覆する
セラミックスからなる保護層を備えた空燃比制御用酸素
センサ素子であって、 前記測定電極は、主として貴金属及びセラミックス（前
駆体を含む。以下同じ）からなり、該セラミックスを0.
05〜10wt％（貴金属及びセラミックスの合計量に対し
て）含有してなり、さらに、 前記測定電極は、前記固体電解質材料の表面において、
該測定電極の存在部と不存在部とが交互に分布して位置
すると共に隣接する各存在部が相互に連通してなるパタ
ーンを有していることを特徴とする酸素センサ素子。6. An air-fuel ratio controlling oxygen sensor element comprising: a reference electrode on one side of a solid electrolyte body; a measurement electrode on the other side; and a protective layer made of ceramics covering at least the measurement electrode. The measurement electrode is mainly composed of a noble metal and a ceramic (including a precursor; the same applies hereinafter).
05 to 10 wt% (based on the total amount of the noble metal and the ceramic), and the measurement electrode is provided on the surface of the solid electrolyte material,
An oxygen sensor element, characterized in that existing portions and non-existing portions of the measurement electrode are alternately distributed and located, and each of the adjacent existing portions has a pattern communicating with each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1130230A JP2790852B2 (en) | 1989-05-25 | 1989-05-25 | Oxygen sensor element for controlling air-fuel ratio and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1130230A JP2790852B2 (en) | 1989-05-25 | 1989-05-25 | Oxygen sensor element for controlling air-fuel ratio and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02310459A JPH02310459A (en) | 1990-12-26 |
| JP2790852B2 true JP2790852B2 (en) | 1998-08-27 |
Family
ID=15029216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1130230A Expired - Fee Related JP2790852B2 (en) | 1989-05-25 | 1989-05-25 | Oxygen sensor element for controlling air-fuel ratio and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2790852B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150097068A (en) * | 2014-02-18 | 2015-08-26 | (주)유민에쓰티 | Tape type gas detecting sensor |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0720018A1 (en) * | 1994-12-27 | 1996-07-03 | General Motors Corporation | Thick film heater with multiple inks for the serpentine and the lead |
| EP0853239A3 (en) * | 1997-01-13 | 2001-01-17 | Kabushiki Kaisha Riken | Gas sensor and heater unit |
| CN1336016A (en) * | 1999-10-08 | 2002-02-13 | 全球热电公司 | Composite electrodes for solid state electrochemical devices |
| DE10040505A1 (en) * | 2000-08-18 | 2002-04-04 | Bosch Gmbh Robert | Gas sensor, especially Lambada probe |
| JP2002168828A (en) * | 2000-11-28 | 2002-06-14 | Kyocera Corp | Oxygen sensor |
| JP4530529B2 (en) * | 2000-12-27 | 2010-08-25 | 京セラ株式会社 | Heater integrated oxygen sensor element |
| JP4490122B2 (en) * | 2004-01-19 | 2010-06-23 | 日立オートモティブシステムズ株式会社 | Oxygen concentration detection element |
| US7611612B2 (en) * | 2005-07-14 | 2009-11-03 | Ceramatec, Inc. | Multilayer ceramic NOx gas sensor device |
| JP2018009817A (en) * | 2016-07-11 | 2018-01-18 | 株式会社デンソー | Gas sensor |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS593252A (en) * | 1982-06-29 | 1984-01-09 | Ngk Spark Plug Co Ltd | Oxygen sensor |
| JPS6398558A (en) * | 1986-10-15 | 1988-04-30 | Mitsubishi Heavy Ind Ltd | Preparation of element for detecting concentration of oxygen |
-
1989
- 1989-05-25 JP JP1130230A patent/JP2790852B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150097068A (en) * | 2014-02-18 | 2015-08-26 | (주)유민에쓰티 | Tape type gas detecting sensor |
| KR102205501B1 (en) * | 2014-02-18 | 2021-01-20 | (주)유민에쓰티 | Tape type gas detecting sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02310459A (en) | 1990-12-26 |
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