JP2000009671A - Gas sensor - Google Patents
Gas sensorInfo
- Publication number
- JP2000009671A JP2000009671A JP18087898A JP18087898A JP2000009671A JP 2000009671 A JP2000009671 A JP 2000009671A JP 18087898 A JP18087898 A JP 18087898A JP 18087898 A JP18087898 A JP 18087898A JP 2000009671 A JP2000009671 A JP 2000009671A
- Authority
- JP
- Japan
- Prior art keywords
- gas sensor
- substrate
- alumina
- oxidation catalyst
- combustion type
- 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.)
- Withdrawn
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、接触燃焼式ガスセ
ンサ技術に関する。[0001] 1. Field of the Invention [0002] The present invention relates to a catalytic combustion type gas sensor technology.
【0002】[0002]
【従来の技術】接触燃焼式ガスセンサは酸化触媒を担持
した担体上での可燃性ガスの酸化反応による発熱を検出
するガスセンサであり、通常、温度等の環境変化の影響
を排除するために、このような担体を酸化触媒層として
有する検出素子と、検出素子における酸化触媒層と同様
の熱挙動を有しながらも酸化触媒性を有しない補償層を
有する補償素子、及び抵抗値既知の電気抵抗を用いてホ
ィートストンブリッジ回路を形成させて用いる。2. Description of the Related Art A catalytic combustion type gas sensor is a gas sensor which detects heat generated by an oxidation reaction of a combustible gas on a carrier carrying an oxidation catalyst. Usually, the gas sensor is used to eliminate the influence of environmental changes such as temperature. A detection element having such a carrier as an oxidation catalyst layer, a compensation element having a compensation layer having the same thermal behavior as the oxidation catalyst layer in the detection element but having no oxidation catalyst, and an electric resistance having a known resistance value. To form and use a Wheatstone bridge circuit.
【0003】なお、このような接触燃焼式ガスセンサは
酸化反応の反応熱を鋭敏に検出するため、及び、検出素
子を接触反応に適した温度に保つヒータの消費電力を減
少させて電池駆動を可能とするため、検出・補償素子付
近からの熱伝導による損失が小さいことが望まれる。こ
こでこのような検出素子付近の熱容量を小さくするため
特開平8−94561号公報記載の技術では、センサ素
子を空洞部上にマイクロマシーニング技術を用いて懸垂
部として形成した酸化シリコン絶縁層に検出素子を構成
することが提案されている(図2参照)。すなわちセン
サ素子はシリコン基板上に酸化絶縁膜を形成し、その上
に白金などの金属抵抗体を用いて形成したヒータ、さら
にその上にパラジウム等の酸化触媒を担持させたアルミ
ナなどの触媒担体による触媒層を形成する。[0003] Such a catalytic combustion type gas sensor can detect the reaction heat of the oxidation reaction sharply and reduce the power consumption of a heater for keeping the detection element at a temperature suitable for the contact reaction. Therefore, it is desired that loss due to heat conduction from the vicinity of the detection / compensation element is small. Here, in order to reduce the heat capacity in the vicinity of such a detection element, in the technique described in Japanese Patent Application Laid-Open No. Hei 8-94561, a sensor element is formed on a silicon oxide insulating layer formed as a suspension using a micromachining technique on a cavity. It has been proposed to configure a detection element (see FIG. 2). That is, the sensor element consists of a heater formed by forming an oxide insulating film on a silicon substrate and using a metal resistor such as platinum, and a catalyst carrier such as alumina on which an oxidation catalyst such as palladium is carried. Form a catalyst layer.
【0004】しかしながらこのような構成を有するセン
サの製造歩留まりは低く、同時に信頼性、耐久性が低い
ものであり、問題となっていた。またこのようなセンサ
としては特開平5−249061号公報記載のもの、及
び特開平7−113776号公報記載のものが知られて
いて、各層の密着性を向上させて上記特開平8−945
61号公報記載技術における欠点を補う試みが提案され
ているが、大幅に向上されたとは云えないのが現状であ
った。However, the production yield of the sensor having such a configuration is low, and at the same time, the reliability and durability are low, which has been a problem. Further, as such a sensor, those described in JP-A-5-249061 and those described in JP-A-7-113776 are known.
Attempts have been made to compensate for the shortcomings of the technology described in Japanese Patent Publication No. 61, but it has not been said that it has been greatly improved.
【0005】[0005]
【発明が解決しようとする課題】本発明は、上記した従
来の問題点を改善する、すなわち、耐久性・信頼性が高
く、製造歩留まりの良好な接触燃焼式ガスセンサを提供
することを目的とする。SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned conventional problems, that is, to provide a contact combustion type gas sensor having high durability and reliability and a good production yield. .
【0006】[0006]
【課題を解決するための手段】上記従来の欠点を詳細に
検討すると、平滑なシリコン基板(あるいはシリコン基
板表面に形成された酸化シリコン絶縁層)上に触媒層を
密着形成することが困難で、そのため製造歩留まりが低
くなっていることが判った。一方、耐久性・信頼性が低
いことに関し、白金ヒータの断線が最大の原因であり、
この原因としてはシリコンと白金との熱膨張率の違いが
挙げられることが判った。これら従来技術に係る接触燃
焼式ガスセンサに関する検討の結果、本発明に至った。
すなわち、本発明の接触燃焼式ガスセンサは上記課題を
解決するため、請求項1に記載の通り、アルミナを主成
分とする基板上に形成された接触燃焼式ガスセンサであ
る。When the above-mentioned conventional disadvantages are examined in detail, it is difficult to form a catalyst layer in close contact with a smooth silicon substrate (or a silicon oxide insulating layer formed on the surface of the silicon substrate). Therefore, it was found that the production yield was low. On the other hand, regarding durability and reliability, disconnection of platinum heater is the biggest cause,
It has been found that the cause is a difference in thermal expansion coefficient between silicon and platinum. As a result of studies on the contact combustion type gas sensor according to the related art, the present invention has been reached.
That is, in order to solve the above-mentioned problem, the contact combustion type gas sensor of the present invention is a contact combustion type gas sensor formed on a substrate containing alumina as a main component.
【0007】[0007]
【発明の実施の形態】本発明の接触燃焼式ガスセンサに
おいて、基板はアルミナを主成分とするものであること
が必要である。すなわち主としてアルミナから基板を構
成することにより、ヒータの断線が著しく減少してセン
サ自体の耐久性、経時安定性及び信頼性が向上すると共
に、基板と検知素子の酸化触媒層との密着性が向上し、
製造工程における歩留まりが大きく向上する。なお、こ
のような効果が得られる限りにおいて、基板材料として
アルミナ以外の成分(例えばジルコニア、酸化イットリ
ウム等白金と熱膨張率が近い複合酸化物等)を基板改良
のため添加することが可能であり、この場合も本発明の
範囲に属する。なお、本発明の接触燃焼式ガスセンサに
おいて、検出素子が形成されている部分の基板が、基板
の他の部分に比べて薄くなっていると、強度や取扱性を
低下させることなく感度を向上させ、かつ、消費電力を
少なくさせることが可能となるため好ましい。なお検出
素子形成部の基板の厚さとしては10〜20μm程度で
あると上記効果が充分に得られる。このような加工はサ
ンドブラスタ等により行うことができる。BEST MODE FOR CARRYING OUT THE INVENTION In the catalytic combustion type gas sensor of the present invention, it is necessary that the substrate is mainly composed of alumina. In other words, by mainly forming the substrate from alumina, the breakage of the heater is significantly reduced, and the durability, stability over time and reliability of the sensor itself are improved, and the adhesion between the substrate and the oxidation catalyst layer of the sensing element is improved. And
The yield in the manufacturing process is greatly improved. In addition, as long as such an effect is obtained, it is possible to add a component other than alumina (for example, a composite oxide having a thermal expansion coefficient close to that of platinum such as zirconia and yttrium oxide) as a substrate material for improving the substrate. This case also belongs to the scope of the present invention. In the contact combustion type gas sensor of the present invention, if the portion of the substrate on which the detection element is formed is thinner than other portions of the substrate, the sensitivity can be improved without lowering the strength or the handleability. This is preferable because power consumption can be reduced. The above effect can be sufficiently obtained when the thickness of the substrate in the detecting element formation portion is about 10 to 20 μm. Such processing can be performed by a sandblaster or the like.
【0008】また、検出素子と補償素子とを同一基板上
に有することにより、センサを小型化し、かつ、消費電
力を少なくさせることが可能となる。なお、このとき検
出素子と補償素子は、それぞれの付近の基板をも含め
て、熱的挙動(熱伝導性、熱容量等)が事実上等しいも
のであることが、良好な感度を得るために必要である。
なお、上記のように検出素子と補償素子とが、同一基板
に設けられた場合には、これら素子の間の基板に熱絶縁
用空孔を設けることが望ましい。すなわち、基板に熱絶
縁用空孔を設けることにより、検出素子の酸化触媒層で
生じた熱が補償素子へ影響することを防止し、その結果
感度の良い検出が可能となる。なお、本発明は上記接触
燃焼式ガスセンサに限定されず、従来、シリコン基板が
用いられていた酸化錫等の半導体のガスセンサに応用可
能であり、そのとき製造歩留まり、耐久性、信頼性向上
効果が得られる。Further, by providing the detection element and the compensation element on the same substrate, it becomes possible to reduce the size of the sensor and reduce the power consumption. At this time, it is necessary for the detection element and the compensation element to have substantially the same thermal behavior (thermal conductivity, heat capacity, etc.) including the substrates near each other in order to obtain good sensitivity. It is.
When the detecting element and the compensating element are provided on the same substrate as described above, it is desirable to provide a heat insulating hole in the substrate between these elements. That is, by providing the insulating holes in the substrate, it is possible to prevent the heat generated in the oxidation catalyst layer of the detecting element from affecting the compensating element, thereby enabling highly sensitive detection. Note that the present invention is not limited to the above-described catalytic combustion type gas sensor, and can be applied to a gas sensor of a semiconductor such as tin oxide in which a silicon substrate has been conventionally used. At that time, the manufacturing yield, durability, and reliability are improved. can get.
【0009】[0009]
【実施例】以下に本発明の接触燃焼式ガスセンサについ
て例を示して具体的に説明する。図1(a)に本発明に
係るガスセンサαを示す。なお、図1(b)は図1
(a)のAAにおける断面図、図1(c)は図1(a)
のBBにおける断面図、また図1(d)は図1(a)の
破線からなる円で囲まれた部分の拡大図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The catalytic combustion type gas sensor of the present invention will be specifically described below with reference to examples. FIG. 1A shows a gas sensor α according to the present invention. FIG. 1 (b) is the same as FIG.
1A is a cross-sectional view taken along the line AA, and FIG.
1 (d) is an enlarged view of a portion surrounded by a circle indicated by a broken line in FIG. 1 (a).
【0010】この本発明に係るガスセンサαはアルミナ
基板(厚さ:300μm、大きさ:3mm×3mm)1
上に検出素子部2、及び補償素子部3が形成されてい
る。これらはそれぞれスパッタリングによって形成され
た白金からなるリード線部2a及び3aを介して検出素
子用接点2b及び補償素子用接点3b(接点の大きさは
すべて0.5mm×0.5mm)に接続されていて、検
知回路(図示せず)との接続が容易となっている。な
お、検出素子部2は「己」字を連ねた形状の白金線上
に、パラジウムを酸化触媒として担持したアルミナから
なる酸化触媒層2cを形成して得たものであり、補償素
子部3は酸化触媒を用いない以外は全く同様にして形成
したものである。なお、このセンサの使用時には、上記
白金線は電圧が印加されて素子部を加熱するヒータとし
ても働く。The gas sensor α according to the present invention has an alumina substrate (thickness: 300 μm, size: 3 mm × 3 mm).
The detection element section 2 and the compensation element section 3 are formed thereon. These are connected to the detecting element contact 2b and the compensating element contact 3b (each contact has a size of 0.5 mm × 0.5 mm) via platinum lead wires 2a and 3a formed by sputtering, respectively. This facilitates connection with a detection circuit (not shown). The detection element section 2 is obtained by forming an oxidation catalyst layer 2c made of alumina carrying palladium as an oxidation catalyst on a platinum wire having a shape of a series of “S” characters. It was formed in exactly the same manner except that no catalyst was used. When the sensor is used, the platinum wire also functions as a heater to which a voltage is applied to heat the element portion.
【0011】これら素子部が形成されている部分のアル
ミナ基板1は裏面からサンドブラスタにより空洞部1a
が形成されて、10μmと薄くなっており、これら素子
の感度を相対的に高めていると共に熱容量を少なくして
加熱のための消費電力を低減している。その結果、この
ガスセンサαは電池による駆動が可能となっている。ま
た、このガスセンサαを用いたところ、白金線の溶断等
の障害が生ぜず、極めて長期間用いることができた。A portion of the alumina substrate 1 where these element portions are formed has a hollow portion 1a from the back side by a sandblaster.
Are formed, and the thickness is reduced to 10 μm. The sensitivity of these elements is relatively increased, and the heat capacity is reduced to reduce the power consumption for heating. As a result, the gas sensor α can be driven by a battery. In addition, when the gas sensor α was used, no trouble such as fusing of the platinum wire occurred, and the gas sensor α could be used for an extremely long time.
【0012】また、これら素子部の間のアルミナ基板1
の部分には、熱絶縁用空孔4が設けられていて、検出素
子部2の酸化触媒層2cで生じた熱が補償素子部3へ伝
わることが防止されている。なお、この本発明に係るガ
スセンサαを用いた実際の検出テストによっても、感度
の良いガス検出が可能であることが確認された。また上
記センサα同様に作製した本発明に係るガスセンサを用
いて行った落下等の衝撃試験の結果、従来技術に係るガ
スセンサに比べ、酸化触媒の脱落が極めて生じにくく、
基板と触媒層の密着性が大きく改善されていることが確
認された。Also, an alumina substrate 1 between these element parts is provided.
Are provided with holes 4 for thermal insulation, so that heat generated in the oxidation catalyst layer 2c of the detection element section 2 is prevented from being transmitted to the compensation element section 3. It should be noted that an actual detection test using the gas sensor α according to the present invention also confirmed that highly sensitive gas detection was possible. In addition, as a result of an impact test such as dropping performed using the gas sensor according to the present invention manufactured in the same manner as the above sensor α, dropping of the oxidation catalyst is extremely unlikely to occur as compared with the gas sensor according to the related art,
It was confirmed that the adhesion between the substrate and the catalyst layer was greatly improved.
【0013】[0013]
【発明の効果】本発明の接触燃焼式ガスセンサは、歩留
まり良く製造が可能で、耐久性・経時安定性及び信頼性
が高い、感度の良好な優れた接触燃焼式ガスセンサであ
る。The catalytic combustion type gas sensor of the present invention is an excellent catalytic combustion type gas sensor which can be manufactured with high yield, has high durability, stability over time, and high reliability, and has good sensitivity.
【図1】本発明に係る接触燃焼式ガスセンサの一例を示
す図である。 (a)本発明に係る接触燃焼式ガスセンサαを示す図で
ある。 (b)図1(a)におけるAAにおける断面を示す図で
ある。 (c)図1(a)におけるBBにおける断面を示す図で
ある。 (d)図1(a)の接触燃焼式ガスセンサαの部分拡大
図である。FIG. 1 is a diagram showing an example of a contact combustion type gas sensor according to the present invention. (A) is a diagram showing a contact combustion type gas sensor α according to the present invention. FIG. 2B is a diagram showing a cross section taken along the line AA in FIG. FIG. 2C is a view showing a cross section taken along a line BB in FIG. (D) A partially enlarged view of the contact combustion type gas sensor α of FIG.
【図2】従来技術に係る接触燃焼式ガスセンサを示す図
である。FIG. 2 is a diagram showing a catalytic combustion type gas sensor according to the related art.
α 本発明に係るガスセンサ 1 アルミナ基板 1a 空洞部 2 検出素子部 2a リード線部 2b 検出素子用接点 2c 酸化触媒層 3 補償素子部 3a リード線部 3b 補償素子用接点 3c 補償層 4 熱絶縁用空孔 α Gas sensor according to the present invention 1 Alumina substrate 1a Cavity 2 Detection element 2a Lead wire 2b Contact for detection element 2c Oxidation catalyst layer 3 Compensation element 3a Lead wire 3b Contact for compensation element 3c Compensation layer 4 Thermal insulation space Hole
Claims (5)
れたことを特徴とする接触燃焼式ガスセンサ。1. A catalytic combustion type gas sensor formed on a substrate mainly composed of alumina.
が、基板の他の部分に比べて薄くなっていることを特徴
とする請求項1に記載の接触燃焼式ガスセンサ。2. The catalytic combustion type gas sensor according to claim 1, wherein a portion of the substrate where the detecting element is formed is thinner than other portions of the substrate.
することを特徴とする請求項1または請求項2に記載の
接触燃焼式ガスセンサ。3. The catalytic combustion type gas sensor according to claim 1, wherein the detecting element and the compensating element are provided on the same substrate.
縁用空孔を有することを特徴とする請求項3に記載の接
触燃焼式ガスセンサ。4. The catalytic combustion type gas sensor according to claim 3, wherein the substrate between the detection element and the compensation element has holes for thermal insulation.
れたことを特徴とするガスセンサ。5. A gas sensor formed on a substrate containing alumina as a main component.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18087898A JP2000009671A (en) | 1998-06-26 | 1998-06-26 | Gas sensor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18087898A JP2000009671A (en) | 1998-06-26 | 1998-06-26 | Gas sensor |
Publications (1)
Publication Number | Publication Date |
---|---|
JP2000009671A true JP2000009671A (en) | 2000-01-14 |
Family
ID=16090925
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP18087898A Withdrawn JP2000009671A (en) | 1998-06-26 | 1998-06-26 | Gas sensor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2000009671A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100814459B1 (en) * | 2006-09-29 | 2008-03-17 | 박진성 | Sensor device and method of manufacturing the same |
JP2009109504A (en) * | 2001-07-16 | 2009-05-21 | Sensor Tech Inc | Sensor device and method for qualitative and quantitative analysis of gas phase substances |
JP2016061592A (en) * | 2014-09-16 | 2016-04-25 | ヤマハファインテック株式会社 | Catalytic combustion type gas sensor |
CN108732212A (en) * | 2018-05-23 | 2018-11-02 | 重庆海士测控技术有限公司 | A kind of manufacturing method, sensor and its application of manifold effect detection integrated gas sensors manufacturing method |
CN111443115A (en) * | 2020-05-07 | 2020-07-24 | 江苏集萃智能集成电路设计技术研究所有限公司 | Catalytic gas sensor element, processing method and catalytic gas sensor |
-
1998
- 1998-06-26 JP JP18087898A patent/JP2000009671A/en not_active Withdrawn
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009109504A (en) * | 2001-07-16 | 2009-05-21 | Sensor Tech Inc | Sensor device and method for qualitative and quantitative analysis of gas phase substances |
KR100814459B1 (en) * | 2006-09-29 | 2008-03-17 | 박진성 | Sensor device and method of manufacturing the same |
JP2016061592A (en) * | 2014-09-16 | 2016-04-25 | ヤマハファインテック株式会社 | Catalytic combustion type gas sensor |
CN108732212A (en) * | 2018-05-23 | 2018-11-02 | 重庆海士测控技术有限公司 | A kind of manufacturing method, sensor and its application of manifold effect detection integrated gas sensors manufacturing method |
CN108732212B (en) * | 2018-05-23 | 2020-12-15 | 哈尔滨工程大学 | Manufacturing method of multi-effect detection integrated gas sensor, sensor and application of sensor |
CN111443115A (en) * | 2020-05-07 | 2020-07-24 | 江苏集萃智能集成电路设计技术研究所有限公司 | Catalytic gas sensor element, processing method and catalytic gas sensor |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20050906 |