JP2006275950A - Semiconductor gas detecting element and manufacturing method of the same - Google Patents
Semiconductor gas detecting element and manufacturing method of the same Download PDFInfo
- Publication number
- JP2006275950A JP2006275950A JP2005099028A JP2005099028A JP2006275950A JP 2006275950 A JP2006275950 A JP 2006275950A JP 2005099028 A JP2005099028 A JP 2005099028A JP 2005099028 A JP2005099028 A JP 2005099028A JP 2006275950 A JP2006275950 A JP 2006275950A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- semiconductor
- detection element
- metal oxide
- particles
- 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.)
- Granted
Links
Abstract
Description
金属酸化物半導体を主成分とするガス感応部を備える半導体式ガス検知素子、及びその製造方法に関する。 The present invention relates to a semiconductor type gas detection element including a gas sensitive part mainly composed of a metal oxide semiconductor and a method for manufacturing the same.
一般に、半導体式ガス検知素子は、金属酸化物半導体を主成分とするガス感応部を備えている。そして、検知対象となるガス（以下、「被検知ガス」と称する）が前記半導体式ガス検知素子に接触すると、前記ガス感応部において、被検知ガスは前記金属酸化物半導体によって酸化され、同時に前記金属酸化物半導体は還元される。この反応に伴って被検知ガスと前記半導体との間に電子の授受がなされ、この電子の授受によって前記半導体の抵抗値は変化する。このため前記半導体式ガス検知素子を備えるガスセンサ等は、前記半導体の抵抗値の変化を測定することによって被検知ガスを検知することができる。また、還元された前記金属酸化物半導体は空気に接触することによって酸化され、再びガス検知機能を回復することができる。 In general, the semiconductor type gas detection element includes a gas sensitive part whose main component is a metal oxide semiconductor. When a gas to be detected (hereinafter referred to as “detected gas”) comes into contact with the semiconductor type gas detection element, the detected gas is oxidized by the metal oxide semiconductor in the gas sensitive portion, and at the same time, The metal oxide semiconductor is reduced. Along with this reaction, electrons are exchanged between the gas to be detected and the semiconductor, and the resistance value of the semiconductor changes due to the exchange of electrons. For this reason, the gas sensor etc. provided with the said semiconductor type gas detection element can detect to-be-detected gas by measuring the change of the resistance value of the said semiconductor. Further, the reduced metal oxide semiconductor is oxidized by contact with air, and the gas detection function can be restored again.
前記半導体式ガス検知素子を備えるガスセンサ等によって検知可能な被検知ガスとしては、例えば、メタンやアルコール等の可燃性ガス、一酸化炭素や窒素酸化物等の有毒ガス、硫黄化合物等の悪臭ガス等、様々なものを挙げることができる。
例えば、硫黄化合物等の悪臭ガスを検知対象にする場合には、硫化水素等の硫黄系臭気は嗅覚閾値が低いため非常に低濃度であっても検知する必要がある。このため、半導体式ガス検知素子のガス感応部における金属酸化物半導体としては、水素、一酸化炭素、炭化水素等に対して低感度にしつつ、硫化水素等の還元性硫黄化合物、アルコール、アルデヒド、カルボン酸等の有機化合物に対しては高感度にして、選択的に検出できるように酸化スズより酸化活性の低い酸化亜鉛を適用している。
Examples of the gas to be detected that can be detected by a gas sensor including the semiconductor gas detection element include flammable gases such as methane and alcohol, toxic gases such as carbon monoxide and nitrogen oxides, and malodorous gases such as sulfur compounds. Various things can be mentioned.
For example, when a bad odor gas such as a sulfur compound is to be detected, it is necessary to detect a sulfur-based odor such as hydrogen sulfide even at a very low concentration because the olfactory threshold is low. For this reason, as a metal oxide semiconductor in the gas sensitive part of the semiconductor type gas detection element, while reducing sensitivity to hydrogen, carbon monoxide, hydrocarbons, etc., reducing sulfur compounds such as hydrogen sulfide, alcohols, aldehydes, For organic compounds such as carboxylic acids, zinc oxide having a lower oxidation activity than tin oxide is applied so as to be highly sensitive and selectively detectable.
さらには、酸化亜鉛半導体からなるガス感応部の表面に、被検知ガス以外のガスを選択的に分解除去できる触媒層を設け、被検知ガスに対する選択性を高めたガスセンサ（例えば、特許文献１参照）が知られている。 Furthermore, a gas sensor (see, for example, Patent Document 1) that has a catalyst layer capable of selectively decomposing and removing a gas other than the gas to be detected on the surface of the gas-sensitive portion made of a zinc oxide semiconductor to enhance the selectivity with respect to the gas to be detected. )It has been known.
また、基板型半導体式ガス検知素子においては、ガス感応部中の検出電極間通電領域に被検知ガスの反応を触媒する触媒部を設けること（例えば、特許文献２参照）が提案されている。これによれば、被検知ガスのみを電極間通電領域の触媒部で化学反応させることにより、ガス感応部の見かけ抵抗の変化を大きくして検出感度を高くすることができ、さらには被検知ガスの検出感度を相対的に高めることでガス選択性を高くすることができる。 In addition, in the substrate type semiconductor gas detection element, it has been proposed to provide a catalyst part that catalyzes the reaction of the gas to be detected in the region between the detection electrodes in the gas sensitive part (see, for example, Patent Document 2). According to this, the detection sensitivity can be increased by causing a chemical reaction of only the gas to be detected in the catalyst portion in the inter-electrode energization region, thereby increasing the change in the apparent resistance of the gas sensitive portion. The gas selectivity can be increased by relatively increasing the detection sensitivity.
上述の通り、従来の半導体式ガス検知素子において被検知ガスに対する検知感度や選択性を高めることについては、これまで様々な改良が試みられている。 As described above, various improvements have been attempted so far for improving the detection sensitivity and selectivity of the gas to be detected in the conventional semiconductor gas detection element.
しかし、被検知ガスを検知する応答時間、及び被検知ガスを検知した後、再び検知機能を回復するまでの時間（以下、「応答復帰時間」と称する）については問題が生じていた。 However, there has been a problem with respect to the response time for detecting the gas to be detected and the time until the detection function is recovered again after detecting the gas to be detected (hereinafter referred to as “response return time”).
被検知ガスを検知する応答時間を短縮するためには、電極付近のガス感応層の抵抗変化はガス感応層全体のバルク抵抗変化に最も敏感であるため、被検知ガスのガス感応部の内部への拡散性を高める必要があるが、検知感度を高めるためにはガス感応部における被検知ガスとの接触面積を大きくする必要があり、応答時間の短縮と高感度化とを両立することは困難であった。 In order to shorten the response time for detecting the gas to be detected, the resistance change in the gas sensitive layer near the electrode is most sensitive to the bulk resistance change in the entire gas sensitive layer. However, in order to increase the detection sensitivity, it is necessary to increase the contact area with the gas to be detected in the gas sensitive part, and it is difficult to achieve both a reduction in response time and an increase in sensitivity. Met.
また、応答復帰時間を短縮するためには、被検知ガスを検知した後、ガス感応部内の被検知ガスを直ちに空気に置換し、還元された金属酸化物に接触させて酸化させる必要があるが、高感度化を図ることによって金属酸化物半導体は低濃度の被検知ガスに対しても反応し易くなるため、ガス感応部の内部の被検知ガスを金属酸化物半導体と反応しない濃度まで空気に置換させるのに時間がかかり、応答復帰時間が長くなっていた。 In order to shorten the response recovery time, it is necessary to immediately detect the gas to be detected and then replace the gas to be detected in the gas sensitive part with air and oxidize it by contacting with the reduced metal oxide. Because the metal oxide semiconductor can react easily even with a low concentration of the gas to be detected by increasing the sensitivity, the gas to be detected inside the gas sensitive part is brought into the air to a concentration that does not react with the metal oxide semiconductor. It took a long time to replace, and the response recovery time was long.
本発明は、上記課題に鑑みてなされたものであり、被検知ガスに対して応答時間及び応答復帰時間が短い半導体式ガス検知素子、及びその製造方法を提供することを目的とする。 This invention is made | formed in view of the said subject, and it aims at providing the semiconductor type gas detection element with a short response time and response return time with respect to to-be-detected gas, and its manufacturing method.
上記目的を達成するための本発明に係る半導体式ガス検知素子の第１特徴構成は、金属酸化物半導体を主成分とするガス感応部を備える半導体式ガス検知素子であって、前記ガス感応部のガスを検知する側の表面と内部とに亘る孔部を有し、当該孔部が前記表面における溝状の開口部に連通している点にある。 In order to achieve the above object, a first characteristic configuration of a semiconductor type gas detection element according to the present invention is a semiconductor type gas detection element including a gas sensitive part mainly composed of a metal oxide semiconductor, the gas sensitive part There is a hole extending between the surface on the gas detection side and the inside, and the hole communicates with a groove-shaped opening on the surface.
つまり、この構成によれば、溝状の開口部を有しているため被検知ガスがガス感応部の内部へ入りやすく、また、溝状の開口部はガス感応部の表面から内部に亘る孔部と連通しているためガス感応部の内部への拡散性を高くすることができる。さらに、拡散性が良好であるため一旦内部へ入ったガスであっても、ガス感応部の内部を他のガスと容易に置換することができる。
したがって、被検知ガスに対する応答速度を速め、応答時間を短縮することができると共に応答復帰時間も短縮することができるため、測定効率を向上させることができる。
In other words, according to this configuration, since the groove-shaped opening is provided, the gas to be detected can easily enter the inside of the gas sensitive part, and the groove-shaped opening is a hole extending from the surface of the gas sensitive part to the inside. Since it communicates with the part, the diffusibility into the inside of the gas sensitive part can be increased. Furthermore, since the diffusibility is good, even if the gas once enters the inside, the inside of the gas sensitive part can be easily replaced with another gas.
Therefore, the response speed to the gas to be detected can be increased, the response time can be shortened, and the response return time can also be shortened, so that the measurement efficiency can be improved.
本発明に係る半導体式ガス検知素子の第２特徴構成は、前記表面の開口率は、１０〜５０％である点にある。 The second characteristic configuration of the semiconductor gas detection element according to the present invention is that the aperture ratio of the surface is 10 to 50%.
つまり、この構成によれば、被検知ガスに対する検出感度を維持しつつ、応答時間及び応答復帰時間を短縮することができる。 That is, according to this configuration, it is possible to shorten the response time and the response return time while maintaining the detection sensitivity for the gas to be detected.
本発明に係る半導体式ガス検知素子の第３特徴構成は、前記ガス感応部は、酸化亜鉛半導体を主成分とする点にある。 A third characteristic configuration of the semiconductor type gas detection element according to the present invention is that the gas sensitive part is mainly composed of a zinc oxide semiconductor.
つまり、この構成によれば、硫化水素等の還元性硫黄化合物や、アルコール、アルデヒド、カルボン酸等の有機化合物に対して選択的に検出できるため、測定効率の高い臭気センサとして適用することができる。 That is, according to this configuration, it can be selectively detected for reducing sulfur compounds such as hydrogen sulfide and organic compounds such as alcohols, aldehydes, and carboxylic acids, so that it can be applied as an odor sensor with high measurement efficiency. .
本発明に係る半導体式ガス検知素子の製造方法の第１特徴手段は、金属酸化物半導体を主成分とするガス感応部を備える半導体式ガス検知素子の製造方法であって、金属酸化物粒体と熱消失性粒体とを混合した後、当該混合物を熱処理することにより前記熱消失性粒体を除去すると共に前記金属酸化物を焼結させて前記ガス感応部を形成する点にある。 A first characteristic means of a manufacturing method of a semiconductor type gas detection element according to the present invention is a manufacturing method of a semiconductor type gas detection element including a gas sensitive part mainly composed of a metal oxide semiconductor, and includes metal oxide particles. And the heat-dissipating particles are mixed, and then the mixture is heat-treated to remove the heat-dissipating particles and sinter the metal oxide to form the gas sensitive part.
つまり、この手段によれば、熱消失性粒体は除去される際、気体として外部に放出されるため、表面と内部とに亘る孔部、及び孔部と連通する溝状の開口部を形成させることができる。尚、粒体とは、粒子、粉末等を含むものであり、その形状、大きさは問わない。 That is, according to this means, when the heat-dissipating particles are removed, they are released to the outside as a gas, so that a hole extending between the surface and the inside and a groove-like opening communicating with the hole are formed. Can be made. In addition, a granule contains particle | grains, powder, etc., The shape and magnitude | size are not ask | required.
本発明に係る半導体式ガス検知素子の製造方法の第２特徴手段は、前記熱消失性粒体として、焼失性粒体を用いる点にある。 The 2nd characteristic means of the manufacturing method of the semiconductor type gas detection element which concerns on this invention exists in the point which uses a burnable particle as the said heat-dissipating particle.
つまり、この手段によれば、焼失する際に発熱し、焼失性粒体周辺の金属酸化物粒体に対して局所的に熱をかけることができる。したがって、焼失性粒体は、その周辺の金属酸化物粒体が焼結し形状が固定された後、除去されるため、表面及び内部に被検知ガスが良好に拡散できる大きさの孔部を設けることができる。 That is, according to this means, heat is generated when burned out, and heat can be locally applied to the metal oxide particles around the burnable particles. Therefore, the burnable particles are removed after the surrounding metal oxide particles are sintered and fixed in shape, so that the pores are sized so that the gas to be detected can diffuse well on the surface and inside. Can be provided.
本発明に係る半導体式ガス検知素子の製造方法の第３特徴手段は、前記混合物として、前記熱消失性粒体の粒径が前記金属酸化物粒体の最大粒径より小さいものを用いる点にある。 The third characteristic means of the method for producing a semiconductor type gas detection element according to the present invention is that the mixture uses a mixture in which the particle size of the heat-dissipating particles is smaller than the maximum particle size of the metal oxide particles. is there.
つまり、この手段によれば、熱消失性粒体は金属酸化物粒体の粒子間に入り込むことができるため、焼結後において被検知ガスが拡散するのに適した大きさの孔部を設けることができる。 That is, according to this means, since the heat-dissipating particles can enter between the particles of the metal oxide particles, a hole having a size suitable for diffusion of the gas to be detected is provided after sintering. be able to.
本発明に係る半導体式ガス検知素子は、金属酸化物半導体を主成分とするガス感応部を備える半導体式ガス検知素子であって、前記ガス感応部のガスを検知する側の表面と内部とに亘る孔部を有し、当該孔部が前記表面における溝状の開口部に連通しているものである。これにより被検知ガスに対する応答速度を速め、応答時間を短縮することができると共に応答復帰時間も短縮することができるため、測定効率の向上、測定試料の少量化、リアルタイム測定方式の精度向上を確保することができる。 The semiconductor type gas detection element according to the present invention is a semiconductor type gas detection element including a gas sensitive part mainly composed of a metal oxide semiconductor, and includes a gas detection side surface and an inside of the gas sensitive part. It has a hole extending over, and the hole communicates with a groove-shaped opening on the surface. This speeds up the response to the gas to be detected, shortens the response time, and shortens the response recovery time, ensuring improved measurement efficiency, a smaller amount of measurement sample, and improved accuracy of the real-time measurement method. can do.
以下、本発明に係る半導体式ガス検知素子の一実施形態について、図面を参照して説明する。ここでは、絶縁基板上に一対の検出電極を設けると共に、これら一対の検出電極に亘ってガス感応部を設けた基板型半導体式ガス検知素子を例示するが、これに限られるものではない。その他の半導体式ガス検知素子としては、熱線型半導体式ガス検知素子、直熱型半導体式ガス検知素子、傍熱型半導体式ガス検知素子等が挙げられる。 Hereinafter, an embodiment of a semiconductor gas detection element according to the present invention will be described with reference to the drawings. Here, a substrate type semiconductor gas detection element in which a pair of detection electrodes is provided on an insulating substrate and a gas sensitive part is provided across the pair of detection electrodes is illustrated, but the present invention is not limited thereto. Examples of other semiconductor gas detection elements include a hot-wire semiconductor gas detection element, a direct heat semiconductor gas detection element, and an indirectly heated semiconductor gas detection element.
本実施形態に係る基板型半導体式ガス検知素子１は、図１に示すように絶縁基板３の上面に金属酸化物半導体を主成分とするガス感応部２と、ガス感応部２の電気抵抗を検知する一対の櫛型の検出電極４ａ、４ｂが設けてあり、絶縁基板３の下面には、基板型半導体式ガス検知素子１の動作温度を維持するため、薄膜ヒータ５が設けてある。 As shown in FIG. 1, the substrate type semiconductor gas detection element 1 according to the present embodiment has a gas sensitive part 2 mainly composed of a metal oxide semiconductor on the upper surface of an insulating substrate 3, and electric resistances of the gas sensitive part 2. A pair of comb-shaped detection electrodes 4 a and 4 b to be detected is provided, and a thin film heater 5 is provided on the lower surface of the insulating substrate 3 in order to maintain the operating temperature of the substrate type semiconductor gas detection element 1.
絶縁基板３は、従来の基板型半導体式ガス検知素子に用いられるものが好ましく適用でき、その大きさ、形状等は特に限定されない。また、絶縁基板３の材質は、絶縁体であればよく、例えば、アルミナ、シリカ、ガラス等が適用できる。中でもアルミナを絶縁基板３として用いることは、その表面は完全な平滑ではなく、ナノオーダーの凹凸を有するため、アンカー効果により検出電極４ａ、４ｂや薄膜ヒータ５との接合を強固にすることができ、好ましい。 As the insulating substrate 3, those used in conventional substrate type semiconductor gas detection elements can be preferably applied, and the size, shape, etc. are not particularly limited. The material of the insulating substrate 3 may be an insulating material, and for example, alumina, silica, glass, etc. can be applied. Among them, the use of alumina as the insulating substrate 3 has a surface that is not completely smooth and has nano-order irregularities, and therefore, the bonding with the detection electrodes 4a and 4b and the thin film heater 5 can be strengthened by the anchor effect. ,preferable.
また、検出電極４ａ、４ｂ及び薄膜ヒータ５についても、特に制限されるものではなく、例えば、白金、金、白金パラジウム合金等を蒸着等によって設けることができる。特に白金は非常に耐久性に優れた材料であり、検出電極４ａ、４ｂや薄膜ヒータ５に好ましく適用することができる。 Further, the detection electrodes 4a and 4b and the thin film heater 5 are not particularly limited, and for example, platinum, gold, platinum palladium alloy or the like can be provided by vapor deposition or the like. In particular, platinum is an extremely durable material and can be preferably applied to the detection electrodes 4a and 4b and the thin film heater 5.
ガス感応部２は、検出電極４ａ、４ｂを覆うように設けてあり、上述の通り被検知ガスを検知する側の表面と内部とに亘る孔部を有し、当該孔部が前記表面における溝状の開口部に連通しているものである。そして、少なくとも被検知ガスを検知する側の表面の開口率は１０〜５０％であることが好ましい。すなわち、表面における開口率が小さくなり過ぎると、被検知ガスがガス感応部２の内部に入り難くなり、応答速度及び応答復帰速度が低下する傾向がある。一方、開口率が大きくなり過ぎると、被検知ガスは内部に拡散し易くなるもののガス感応部２おける被検知ガスとの接触面積が小さくなり、検出感度が低下する傾向がある。さらには、開口率が大きくなることによりガス感応部２にクラックが生じる可能性もある。このような観点から、前記表面の開口率は、２０〜５０％であることがより好ましい。また、溝状開口部における溝幅についても、同様の観点から０．１〜２μｍであることが好ましい。 The gas sensitive part 2 is provided so as to cover the detection electrodes 4a and 4b, and has a hole extending between the surface on the side for detecting the gas to be detected and the inside as described above, and the hole is a groove on the surface. It communicates with the shaped opening. And it is preferable that the aperture ratio of the surface at the side which detects a to-be-detected gas at least is 10 to 50%. That is, if the aperture ratio on the surface becomes too small, the gas to be detected does not easily enter the inside of the gas sensitive part 2, and the response speed and the response return speed tend to decrease. On the other hand, if the aperture ratio becomes too large, the gas to be detected is likely to diffuse inside, but the contact area with the gas to be detected in the gas sensitive portion 2 tends to be small, and the detection sensitivity tends to decrease. Furthermore, a crack may occur in the gas sensitive part 2 due to an increase in the aperture ratio. From such a viewpoint, the aperture ratio of the surface is more preferably 20 to 50%. Moreover, it is preferable that it is 0.1-2 micrometers also about the groove width in a groove-shaped opening part from the same viewpoint.
ガス感応部２の主成分である金属酸化物半導体は、特に限定されず、酸化スズ半導体、酸化亜鉛半導体、酸化タングステン半導体、酸化インジウム半導体等、被検知ガスの種類によって任意に選択することができる。例えば、酸化亜鉛半導体は酸化スズ半導体に比べて還元性ガスに対する酸化活性が低いため、酸化亜鉛半導体を主成分とするガス感応部２であれば、硫化水素等の還元性硫黄化合物や、アルコール、アルデヒド、カルボン酸等の有機化合物に対して選択的に検出でき、臭気センサとして適用することができる。 The metal oxide semiconductor that is the main component of the gas sensitive portion 2 is not particularly limited, and can be arbitrarily selected depending on the type of gas to be detected, such as a tin oxide semiconductor, a zinc oxide semiconductor, a tungsten oxide semiconductor, an indium oxide semiconductor, or the like. . For example, since a zinc oxide semiconductor has a lower oxidation activity with respect to a reducing gas than a tin oxide semiconductor, if the gas sensitive part 2 is composed mainly of a zinc oxide semiconductor, a reducing sulfur compound such as hydrogen sulfide, alcohol, It can detect selectively with respect to organic compounds, such as an aldehyde and carboxylic acid, and can be applied as an odor sensor.
また、ガス感応部２における金属酸化物半導体は必ずしも１種類である必要はなく、例えば、酸化亜鉛に酸化スズを添加する等、２種以上の混合物であってもよい。さらには、図示しないが、ガス感応部２の被検知ガスを検知する側の表面に、検知を妨害するガスを除去するために除去層を設けることも可能である。このような除去層には、酸化タングステンを担持したアルミナ等、除去したいガス種によって任意に選択可能である。 Moreover, the metal oxide semiconductor in the gas sensitive part 2 does not necessarily need to be 1 type, For example, 2 or more types of mixtures, such as adding a tin oxide to a zinc oxide, may be sufficient. Further, although not shown, a removal layer may be provided on the surface of the gas sensitive unit 2 on the side where the gas to be detected is detected in order to remove the gas that hinders detection. Such a removal layer can be arbitrarily selected depending on the type of gas to be removed, such as alumina supporting tungsten oxide.
このような本発明に係る半導体式ガス検知素子のガス感応部は、金属酸化物粒体と熱消失性粒体とを混合した後、当該混合物を熱処理することにより前記熱消失性粒体を除去すると共に前記金属酸化物粒体を焼結させて形成させることができる。熱処理によって熱消失性粒体を除去しつつ金属酸化物粒体を焼結させることにより、多孔質体を形成することができるが、熱消失性粒体は除去される際、気体として外部に放出されるため、表面と内部とに亘る孔部、及び孔部と連通する溝状の開口部を形成させることができる。 The gas sensitive part of the semiconductor type gas detection element according to the present invention removes the heat-dissipating particles by mixing the metal oxide particles and the heat-dissipating particles and then heat-treating the mixture. In addition, the metal oxide particles can be formed by sintering. A porous material can be formed by sintering metal oxide particles while removing heat-dissipating particles by heat treatment, but when heat-dissipating particles are removed, they are released to the outside as a gas. Therefore, a hole extending over the surface and the inside, and a groove-shaped opening communicating with the hole can be formed.
本発明の製造方法に使用する金属酸化物粒体は、酸化スズ、酸化亜鉛、酸化タングステ
ン、酸化インジウム等、任意に選択可能であり、２種類以上の金属酸化物粒体を用いることもできる。また、金属酸化物粒体の粒径は、特に限定されないが、例えば、０．１〜５０μｍのものを用いることができる。
The metal oxide particles used in the production method of the present invention can be arbitrarily selected from tin oxide, zinc oxide, tungsten oxide, indium oxide and the like, and two or more kinds of metal oxide particles can also be used. Moreover, the particle diameter of a metal oxide granular material is although it does not specifically limit, For example, a 0.1-50 micrometers thing can be used.
熱消失性粒体は、熱によって消失するものであれば特に制限はなく、昇華によって消失するもの、燃焼によって消失するもの等、任意に選択することができる。中でも、燃焼によって消失する焼失性粒体は、焼失する際に発熱し、焼失性粒体周辺の金属酸化物粒体に対して局所的に熱をかけることができるため、好ましく用いることができる。すなわち、焼失性粒体は、その周辺の金属酸化物粒体が焼結し、形状が固定された後、除去されるため、表面及び内部に被検知ガスの拡散に適した大きさの孔部を設けることができる。熱消失性粒体としては、例えば、カーボン、ポリメチルメタクリル酸、スチロールビーズ、ナフタレン等、比較的粒径の揃った炭素や炭化水素を用いることができる。 The heat-dissipating granules are not particularly limited as long as they disappear by heat, and can be arbitrarily selected from those that disappear by sublimation and those that disappear by combustion. Among these, the burnable particles that disappear due to combustion generate heat when burned, and can be preferably used because they can locally heat the metal oxide particles around the burnable particles. That is, the burnable particles are removed after the surrounding metal oxide particles are sintered and fixed in shape, so that the pores of a size suitable for the diffusion of the gas to be detected are formed on the surface and inside. Can be provided. As the heat-dissipating granules, for example, carbon or hydrocarbons having a relatively uniform particle diameter such as carbon, polymethylmethacrylic acid, styrene beads, naphthalene, and the like can be used.
また、熱消失性粒体は、任意の粒径のものを用いることができるが、金属酸化物粒体と熱消失性粒体との混合物においては、熱消失性粒体の粒径は金属酸化物粒体の最大粒径より小さいことが好ましい。熱消失性粒体の粒径を金属酸化物粒体の最大粒径より小さくすることにより、熱消失性粒体は、金属酸化物粒体の粒子間に入り込むことができるため、焼結後において適度な大きさの孔部を設けることができる。尚、この熱消失性粒体の粒径は、混合する際の大きさを問わず、混合する際に粉砕され、混合後に金属酸化物粒体の最大粒径よりも小さくなるものでも、同様に好ましく適用することができる。
また、前記混合物における金属酸化物粒体と熱消失性粒体との混合割合は任意に設定可能であり、例えば重量比で金属酸化物粒体１００に対して０．２〜５の熱消失性粒体を混合することができる。
In addition, the heat-dissipating particles can be of any particle size, but in a mixture of metal oxide particles and heat-dissipating particles, the particle size of the heat-dissipating particles is metal oxide. It is preferable that the particle size is smaller than the maximum particle size. By making the particle size of the heat-dissipating particles smaller than the maximum particle size of the metal oxide particles, the heat-dissipating particles can enter between the particles of the metal oxide particles. An appropriately sized hole can be provided. The particle size of the heat-dissipating particles is pulverized when mixing regardless of the size when mixing, and even if the particle size becomes smaller than the maximum particle size of the metal oxide particles after mixing. It can be preferably applied.
In addition, the mixing ratio of the metal oxide particles and the heat-dissipating particles in the mixture can be arbitrarily set, for example, 0.2 to 5 heat-dissipating property with respect to the metal oxide particles 100 by weight ratio. Granules can be mixed.
本発明に係る製造方法の熱処理は、熱消失性粒体を除去でき、かつ金属酸化物粒体を焼結させることができる条件であれば特に制限はなく、例えば、６００〜１３００℃で５〜８時間処理することによって達成することができる。 The heat treatment of the production method according to the present invention is not particularly limited as long as the heat-dissipating particles can be removed and the metal oxide particles can be sintered. This can be achieved by treating for 8 hours.
本実施形態の基板型半導体式ガス検知素子１の場合には、検出電極４ａ、４ｂ及び薄膜ヒータ５を蒸着させた絶縁基板１に前記混合物を塗布し、熱処理することによって製造することができる。具体的には、金属酸化物粒体と熱消失性粒体とを混合する際、または混合した後に、例えば蒸留水等と混合してペースト状にしたものを、絶縁基板３に厚みが８０〜１５０μｍ程度になるように層状に塗り付ける。これにより焼結後の厚みが約１５〜３０μｍの層状のガス感応部２とすることができる。層の厚みは特に限定はされないが、薄過ぎる場合には熱処理の際に割れてしまう場合がある。また、除去層を設ける場合には、従来の方法と同様に熱処理によってガス感応部２を形成させた後、その上に形成させることができる。 In the case of the substrate type semiconductor gas sensing element 1 of the present embodiment, the substrate can be manufactured by applying the mixture to the insulating substrate 1 on which the detection electrodes 4a and 4b and the thin film heater 5 are deposited and heat-treating them. Specifically, when the metal oxide particles and the heat-dissipating particles are mixed or after mixing, for example, a paste formed by mixing with distilled water or the like has a thickness of 80 to 80 on the insulating substrate 3. Apply in layers so as to be about 150 μm. Thereby, it can be set as the layered gas sensitive part 2 whose thickness after sintering is about 15-30 micrometers. The thickness of the layer is not particularly limited, but if it is too thin, it may crack during heat treatment. Moreover, when providing a removal layer, after forming the gas sensitive part 2 by heat processing similarly to the conventional method, it can be formed on it.
尚、その他の半導体式ガス検知素子の構成、機能については、従来公知の半導体式ガス検知素子と同様である。そして、本発明に係る半導体式ガス検知素子は、既知のガス検知回路等に組み込むことにより、ガスセンサ等に適用することができる。 In addition, about the structure and function of another semiconductor type gas detection element, it is the same as that of a conventionally well-known semiconductor type gas detection element. The semiconductor gas detection element according to the present invention can be applied to a gas sensor or the like by being incorporated in a known gas detection circuit or the like.
以下に本実施形態に係る基板型半導体式ガス検知素子１を用いた実施例について説明する。
（実施例１）
絶縁基板３として、１ｍｍ×１ｍｍのアルミナ基板を用い、従来の基板型半導体式ガス検知素子の製造方法と同様にして、白金の検出電極４ａ、４ｂ及び白金の薄膜ヒータ５を蒸着させた。次いで、蒸留水に、金属酸化物粒体として粒径が０．１〜５μｍの酸化亜鉛粉末と、熱消失性粒体として粒径が約３μｍのカーボン粒子とを重量比で１２０：１となるように加えて混合したペースト状物を、検出電極４ａ、４ｂを蒸着させた側の絶縁基板３上に約１００μｍの厚みになるように層状に塗布し、室温で１時間乾燥させた。その後、５℃／分で昇温し、１１００℃で５時間保持した。この時の熱重量変化を測定したところ、図２に示すように５６３．２℃から９１７．６℃の間で減量しており、本実施例のように熱消失性粒体としてカーボン粒子を使用する場合には、９２０℃までに消失が完了していることが分かった。
このようにして得られた基板型半導体式ガス検知素子１におけるガス感応部２の表面及び断面を電子顕微鏡で観察したところ、図３及び４に示すように表面と内部とに亘る孔部を有しており、表面には孔部と連通する溝状の開口部が形成されていた。尚、このときのガス感応部２は、約２０μｍの厚みの層状で、表面における開口率が約３０％であり、溝の幅が０．１〜１．５μｍ、平均約１μｍであった。
An example using the substrate type semiconductor gas detection element 1 according to the present embodiment will be described below.
Example 1
As the insulating substrate 3, a 1 mm × 1 mm alumina substrate was used, and platinum detection electrodes 4 a and 4 b and a platinum thin film heater 5 were vapor-deposited in the same manner as in the conventional substrate type semiconductor gas detection element manufacturing method. Next, in the distilled water, the weight ratio of zinc oxide powder having a particle size of 0.1 to 5 μm as metal oxide particles and carbon particles having a particle size of about 3 μm as heat-dissipating particles is 120: 1. The paste-like material added and mixed in this manner was applied in a layered manner to a thickness of about 100 μm on the insulating substrate 3 on the side where the detection electrodes 4a and 4b were deposited, and dried at room temperature for 1 hour. Thereafter, the temperature was raised at 5 ° C./min and held at 1100 ° C. for 5 hours. When the thermogravimetric change at this time was measured, the amount was reduced between 563.2 ° C. and 917.6 ° C. as shown in FIG. 2, and carbon particles were used as the heat-dissipating granules as in this example. It was found that the disappearance was completed by 920 ° C.
When the surface and cross section of the gas sensitive part 2 in the substrate type semiconductor gas sensing element 1 thus obtained were observed with an electron microscope, there were holes extending between the surface and the inside as shown in FIGS. On the surface, a groove-like opening communicating with the hole was formed. In addition, the gas sensitive part 2 at this time was a layer having a thickness of about 20 μm, an opening ratio on the surface was about 30%, a groove width was 0.1 to 1.5 μm, and an average was about 1 μm.
（実施例２〜４）
カーボン粒子の粒径をそれぞれ約１０μｍ、約２０μｍ、約５０μｍにして、実施例１と同様に方法により、基板型半導体式ガス検知素子１を作製した。
(Examples 2 to 4)
Substrate type semiconductor gas detection element 1 was produced by the same method as in Example 1 with the carbon particle diameters being about 10 μm, about 20 μm, and about 50 μm, respectively.
（比較例）
カーボン粒子を混合しないこと以外は、実施例１と同様の方法によって基板型半導体式ガス検知素子１を作製し、そのガス感応部２の表面及び断面を電子顕微鏡にて観察した。その結果、図５及び６に示すように多孔質体ではあるが、表面及び内部にはあまり大きな孔部は有していなかった。
(Comparative example)
A substrate type semiconductor gas detection element 1 was produced by the same method as in Example 1 except that the carbon particles were not mixed, and the surface and cross section of the gas sensitive part 2 were observed with an electron microscope. As a result, although it was a porous body as shown in FIGS. 5 and 6, the surface and the inside did not have very large pores.
実施例１〜４及び比較例によって得られたそれぞれの基板型半導体式ガス検知素子１を用いて、硫化水素ガスに対する応答特性を調べた。すなわち、クリーンエアの状態から硫化水素ガスを、その濃度が１８０秒毎に０．０１ｐｐｍ、０．１ｐｐｍ、０．５ｐｐｍ、１ｐｐｍ、３ｐｐｍとなるように順に加えた後、ルームエアに置換し、空気中における電気抵抗値に対するガスの濃度における電気抵抗値の比として、それぞれの抵抗変化率を測定した。そして、硫化水素ガスをルームエアに置換する直前の抵抗変化率を１とし、これに対するそれぞれのガス濃度における抵抗変化率の比を相対感度として示した。その結果、図７に示すようにカーボン粒子を混合して作製したもの（実施例１〜４）は、それぞれのガス濃度において１８０秒間でほぼ出力が安定したのに対し、カーボン粒子を混合せずに作製したもの（比較例）は１８０秒間では出力は安定しなかった。 Using each of the substrate-type semiconductor gas sensing elements 1 obtained in Examples 1 to 4 and the comparative example, the response characteristics to hydrogen sulfide gas were examined. That is, hydrogen sulfide gas is added from clean air in order so that its concentration becomes 0.01 ppm, 0.1 ppm, 0.5 ppm, 1 ppm, 3 ppm every 180 seconds, and then replaced with room air. Each resistance change rate was measured as a ratio of the electrical resistance value at the gas concentration to the electrical resistance value inside. The resistance change rate immediately before replacing the hydrogen sulfide gas with room air was set to 1, and the ratio of the resistance change rate at each gas concentration to this was shown as the relative sensitivity. As a result, as shown in FIG. 7, those produced by mixing carbon particles (Examples 1 to 4) were stable in output for 180 seconds at each gas concentration, but not mixed with carbon particles. The output produced in (a comparative example) was not stable in 180 seconds.
また、硫化水素ガスの濃度をそれぞれ変化させた際のカーボンの粒径と９０％応答時間との関係を調べたところ、図８に示すようにカーボン粒子を混合したもの（実施例１〜４）は、いずれもカーボン粒子を混合しないもの（比較例）よりも応答時間は短くなった。また、カーボン粒子を混合したもののうちでは、粒径が小さい方が応答時間は短くなる傾向があり、本実施例の中では粒径が３μｍのもの（実施例１）が最も応答時間が短くなった。この結果から、本実施例においては、応答時間を短くするためには、特にカーボン粒子の粒径は１〜５μｍ程度がより好ましいことが分かった。 Further, when the relationship between the carbon particle size and the 90% response time when the concentration of the hydrogen sulfide gas was changed, carbon particles were mixed as shown in FIG. 8 (Examples 1 to 4). The response time was shorter than those in which no carbon particles were mixed (comparative example). Among the mixed carbon particles, the smaller the particle size, the shorter the response time. In this example, the response time is the shortest when the particle size is 3 μm (Example 1). It was. From this result, it was found that in this example, in order to shorten the response time, the particle diameter of the carbon particles is particularly preferably about 1 to 5 μm.
（実施例５〜８）
また、実施例１と同様の方法により、酸化亜鉛粉末と、粒径が約３μｍのカーボン粒子とをそれぞれ重量比で４８０：１、１２０：１、６０：１、３０：１となるように加えて混合したペースト状物を用い、熱消失性粒体であるカーボン粒子の混合量を変えることでガス感応部２の表面の開口率が１０％、３０％、４０％、５０％の基板型半導体式ガス検知素子１を作製した。そして、それぞれの基板型半導体式ガス検知素子１に対して硫化水素ガス濃度を０．０１ｐｐｍから０．１ｐｐｍへ変化させた際の開口率と９０％応答時間との関係を調べたところ、図９に示すようにいずれの開口率においても応答時間が短く、また開口率が大きい方が応答時間は短くなることが分かった。尚、開口率が６０％のものを得ることを目的として、酸化亜鉛粉末と粒径が約３μｍのカーボン粒子とを重量比で１５：１となるように加えて混合したペースト状物を用いて基板型半導体式ガス検知素子１を作製したが、ガス感応部２にはクラックが生じ、センサとして使用できなかった。
以上により、ガス感応部２の開口率は１０〜５０％のいずれにおいても良好な結果が得られたが、さらに応答時間を短くする観点からは、２０〜５０％が好ましく、３０〜５０％がより好ましいことが分かった。
(Examples 5 to 8)
Further, by the same method as in Example 1, zinc oxide powder and carbon particles having a particle size of about 3 μm were added so that the weight ratios would be 480: 1, 120: 1, 60: 1, and 30: 1, respectively. Substrate-type semiconductors having an aperture ratio of 10%, 30%, 40%, and 50% on the surface of the gas-sensitive portion 2 by changing the amount of carbon particles that are heat-dissipating granules by using paste-like materials mixed together A gas detector 1 was prepared. Then, when the relationship between the opening ratio and the 90% response time when the hydrogen sulfide gas concentration was changed from 0.01 ppm to 0.1 ppm for each substrate type semiconductor gas sensing element 1 was examined, FIG. As shown in the figure, it was found that the response time was shorter at any aperture ratio, and the response time was shorter as the aperture ratio was larger. For the purpose of obtaining a product having an opening ratio of 60%, a paste-like material in which zinc oxide powder and carbon particles having a particle diameter of about 3 μm are added in a weight ratio of 15: 1 and mixed is used. Although the substrate type semiconductor gas detection element 1 was produced, the gas sensitive part 2 was cracked and could not be used as a sensor.
From the above, good results were obtained at any opening ratio of the gas sensitive part 2 of 10 to 50%. However, from the viewpoint of further shortening the response time, 20 to 50% is preferable, and 30 to 50% is preferable. It turned out to be more preferable.
本発明に係る半導体式ガス検知素子は、従来のガスセンサ、ガス警報器、ガス測定器等に適用することができる。 The semiconductor gas detection element according to the present invention can be applied to conventional gas sensors, gas alarms, gas measuring devices, and the like.
１ 基板型半導体式ガス検知素子
２ ガス感応部
３ 絶縁基板
４ａ、４ｂ 検出電極
５ 薄膜ヒータ
DESCRIPTION OF SYMBOLS 1 Substrate type | mold semiconductor type gas detection element 2 Gas sensitive part 3 Insulating substrate 4a, 4b Detection electrode 5 Thin film heater
Claims (6)
前記ガス感応部のガスを検知する側の表面と内部とに亘る孔部を有し、当該孔部が前記表面における溝状の開口部に連通している半導体式ガス検知素子。 A semiconductor type gas detection element including a gas sensitive part mainly composed of a metal oxide semiconductor,
A semiconductor type gas detection element having a hole extending between the surface and the inside of the gas sensitive part that detects gas, and the hole communicating with a groove-shaped opening on the surface.
金属酸化物粒体と熱消失性粒体とを混合した後、当該混合物を熱処理することにより前記熱消失性粒体を除去すると共に前記金属酸化物を焼結させて前記ガス感応部を形成する半導体式ガス検知素子の製造方法。 A method for producing a semiconductor type gas sensing element comprising a gas sensitive part mainly composed of a metal oxide semiconductor,
After mixing the metal oxide particles and the heat-dissipating particles, the heat-dissipating particles are removed by heat treating the mixture and the metal oxide is sintered to form the gas sensitive part. Manufacturing method of semiconductor type gas detection element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005099028A JP4870938B2 (en) | 2005-03-30 | 2005-03-30 | Manufacturing method of semiconductor gas detection element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005099028A JP4870938B2 (en) | 2005-03-30 | 2005-03-30 | Manufacturing method of semiconductor gas detection element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2006275950A true JP2006275950A (en) | 2006-10-12 |
| JP4870938B2 JP4870938B2 (en) | 2012-02-08 |
Family
ID=37210860
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005099028A Expired - Fee Related JP4870938B2 (en) | 2005-03-30 | 2005-03-30 | Manufacturing method of semiconductor gas detection element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4870938B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010002336A (en) * | 2008-06-20 | 2010-01-07 | New Cosmos Electric Corp | Resistance change type gas detection element and its manufacturing method |
| JP2010002335A (en) * | 2008-06-20 | 2010-01-07 | New Cosmos Electric Corp | Gas detection element |
| US8638111B2 (en) | 2010-06-17 | 2014-01-28 | Caterpillar Inc. | Zinc oxide sulfur sensor measurement system |
| US8653839B2 (en) | 2009-07-17 | 2014-02-18 | Caterpillar Inc. | Zinc oxide sulfur sensors and method of using said sensors |
| KR101519033B1 (en) | 2011-02-09 | 2015-05-13 | 한국전자통신연구원 | Micro Electro Mechanical Systems Type Semiconductor Gas Sensor Using Microheater Having Many Holes and Method for Manufacturing the Same |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5722546A (en) * | 1980-07-16 | 1982-02-05 | Ngk Spark Plug Co Ltd | Element for sensing gas component and manufacture thereof |
| JPS57107002A (en) * | 1980-12-24 | 1982-07-03 | Ngk Spark Plug Co | Moisture sensitive resistance element and method of producing same |
| JPS5944801A (en) * | 1982-09-06 | 1984-03-13 | 株式会社豊田中央研究所 | Moisture sensitive resistance element |
| JPS59119253A (en) * | 1982-12-25 | 1984-07-10 | Ngk Spark Plug Co Ltd | Gas sensitive element |
| JPS6340816A (en) * | 1985-04-01 | 1988-02-22 | ツインフア・ユニバ−シテイ | Ceramic element for temperature-humidity-gas concentration detection multifunctional ceramics sensor element and manufacture thereof |
| JPH0466857A (en) * | 1990-07-06 | 1992-03-03 | New Cosmos Electric Corp | Malodorant gas sensor |
| JPH1181193A (en) * | 1997-08-29 | 1999-03-26 | Sekisui Plastics Co Ltd | Interior sheet |
| JP2003270186A (en) * | 2002-03-18 | 2003-09-25 | Osaka Gas Co Ltd | Gas sensor and its manufacturing method |
| JP2004138551A (en) * | 2002-10-18 | 2004-05-13 | Hitachi Unisia Automotive Ltd | Hydrogen sensor |
| JP2004150811A (en) * | 2002-10-28 | 2004-05-27 | Hitachi Unisia Automotive Ltd | Carbon monoxide sensor |
| JP2004203655A (en) * | 2002-12-25 | 2004-07-22 | National Institute Of Advanced Industrial & Technology | Manufacturing method of detection portion of oxygen partial pressure of resistance type oxygen probe |
| JP2004294364A (en) * | 2003-03-28 | 2004-10-21 | New Cosmos Electric Corp | Semiconductor type gas detection device |
-
2005
- 2005-03-30 JP JP2005099028A patent/JP4870938B2/en not_active Expired - Fee Related
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5722546A (en) * | 1980-07-16 | 1982-02-05 | Ngk Spark Plug Co Ltd | Element for sensing gas component and manufacture thereof |
| JPS57107002A (en) * | 1980-12-24 | 1982-07-03 | Ngk Spark Plug Co | Moisture sensitive resistance element and method of producing same |
| JPS5944801A (en) * | 1982-09-06 | 1984-03-13 | 株式会社豊田中央研究所 | Moisture sensitive resistance element |
| JPS59119253A (en) * | 1982-12-25 | 1984-07-10 | Ngk Spark Plug Co Ltd | Gas sensitive element |
| JPS6340816A (en) * | 1985-04-01 | 1988-02-22 | ツインフア・ユニバ−シテイ | Ceramic element for temperature-humidity-gas concentration detection multifunctional ceramics sensor element and manufacture thereof |
| JPH0466857A (en) * | 1990-07-06 | 1992-03-03 | New Cosmos Electric Corp | Malodorant gas sensor |
| JPH1181193A (en) * | 1997-08-29 | 1999-03-26 | Sekisui Plastics Co Ltd | Interior sheet |
| JP2003270186A (en) * | 2002-03-18 | 2003-09-25 | Osaka Gas Co Ltd | Gas sensor and its manufacturing method |
| JP2004138551A (en) * | 2002-10-18 | 2004-05-13 | Hitachi Unisia Automotive Ltd | Hydrogen sensor |
| JP2004150811A (en) * | 2002-10-28 | 2004-05-27 | Hitachi Unisia Automotive Ltd | Carbon monoxide sensor |
| JP2004203655A (en) * | 2002-12-25 | 2004-07-22 | National Institute Of Advanced Industrial & Technology | Manufacturing method of detection portion of oxygen partial pressure of resistance type oxygen probe |
| JP2004294364A (en) * | 2003-03-28 | 2004-10-21 | New Cosmos Electric Corp | Semiconductor type gas detection device |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010002336A (en) * | 2008-06-20 | 2010-01-07 | New Cosmos Electric Corp | Resistance change type gas detection element and its manufacturing method |
| JP2010002335A (en) * | 2008-06-20 | 2010-01-07 | New Cosmos Electric Corp | Gas detection element |
| US8653839B2 (en) | 2009-07-17 | 2014-02-18 | Caterpillar Inc. | Zinc oxide sulfur sensors and method of using said sensors |
| US8638111B2 (en) | 2010-06-17 | 2014-01-28 | Caterpillar Inc. | Zinc oxide sulfur sensor measurement system |
| KR101519033B1 (en) | 2011-02-09 | 2015-05-13 | 한국전자통신연구원 | Micro Electro Mechanical Systems Type Semiconductor Gas Sensor Using Microheater Having Many Holes and Method for Manufacturing the Same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4870938B2 (en) | 2012-02-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Saruhan et al. | Influences of semiconductor metal oxide properties on gas sensing characteristics | |
| Korotcenkov et al. | Instability of metal oxide-based conductometric gas sensors and approaches to stability improvement (short survey) | |
| Katoch et al. | Bifunctional sensing mechanism of SnO2–ZnO composite nanofibers for drastically enhancing the sensing behavior in H2 gas | |
| JP2011506940A (en) | Gas sensor with improved selectivity | |
| JP4870938B2 (en) | Manufacturing method of semiconductor gas detection element | |
| JP4056987B2 (en) | Hydrogen sensor and hydrogen detection method | |
| JP2005315874A (en) | Gas sensor chip and manufacturing method therefor | |
| JP5155748B2 (en) | Gas detection element | |
| Zhang et al. | Adverse effect of substrate surface impurities on O2 sensing properties of TiO2 gas sensor operating at high temperature | |
| Lin et al. | Nanotechnology on toxic gas detection and treatment | |
| Yao et al. | Towards one key to one lock: Catalyst modified indium oxide nanoparticle thin film sensor array for selective gas detection | |
| JP2005017182A (en) | Thin film gas sensor and method for manufacturing the same | |
| JP7158680B2 (en) | gas sensor | |
| JP2010038692A (en) | Gas detecting element | |
| JP2005134251A (en) | Thin-film gas sensor | |
| KR20060076922A (en) | Thin film gas sensor and manufacturing method thereof | |
| JP4010738B2 (en) | Gas sensor, gas detector and gas detection method | |
| KR101094277B1 (en) | Gas sensors using nano-porous cobalt oxide structures and fabrication method thereof | |
| JP4340639B2 (en) | Hydrogen sensor and hydrogen detection method | |
| KR101721119B1 (en) | Gas Sensor for Benzene | |
| JP2011075421A (en) | Gas sensing element and gas sensor | |
| JP4315992B2 (en) | Gas sensor, gas detector and gas detection method | |
| JP4002969B2 (en) | Combustible gas sensor | |
| JP3845937B2 (en) | Gas sensor | |
| JP4382245B2 (en) | Gas sensor and gas detector |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080215 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100521 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100603 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100802 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20110120 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110418 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20110418 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20110517 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110804 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110929 |
|
| 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: 20111027 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20111118 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4870938 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20141125 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |