JPS6133466B2 - - Google Patents
Info
- Publication number
- JPS6133466B2 JPS6133466B2 JP55177820A JP17782080A JPS6133466B2 JP S6133466 B2 JPS6133466 B2 JP S6133466B2 JP 55177820 A JP55177820 A JP 55177820A JP 17782080 A JP17782080 A JP 17782080A JP S6133466 B2 JPS6133466 B2 JP S6133466B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- sensitivity
- temperature
- indium oxide
- gas sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000007789 gas Substances 0.000 claims description 47
- 238000010304 firing Methods 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 20
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 claims description 17
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 12
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 claims description 11
- 229910003437 indium oxide Inorganic materials 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 239000000758 substrate Substances 0.000 claims description 8
- 229910052763 palladium Inorganic materials 0.000 claims description 4
- 239000000654 additive Substances 0.000 claims description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 2
- 230000000996 additive effect Effects 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 239000001301 oxygen Substances 0.000 claims description 2
- 229910052760 oxygen Inorganic materials 0.000 claims description 2
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 claims description 2
- 229910052710 silicon Inorganic materials 0.000 claims description 2
- 239000010703 silicon Substances 0.000 claims description 2
- 229910052725 zinc Inorganic materials 0.000 claims description 2
- 239000011701 zinc Substances 0.000 claims description 2
- 230000035945 sensitivity Effects 0.000 description 26
- 101150003085 Pdcl gene Proteins 0.000 description 13
- 239000004065 semiconductor Substances 0.000 description 9
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 8
- 229910002091 carbon monoxide Inorganic materials 0.000 description 8
- 239000002994 raw material Substances 0.000 description 8
- 238000001514 detection method Methods 0.000 description 6
- 230000004044 response Effects 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 229910006404 SnO 2 Inorganic materials 0.000 description 4
- 239000000460 chlorine Substances 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 3
- 230000003213 activating effect Effects 0.000 description 3
- 238000007084 catalytic combustion reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000012153 distilled water Substances 0.000 description 3
- HBEQXAKJSGXAIQ-UHFFFAOYSA-N oxopalladium Chemical compound [Pd]=O HBEQXAKJSGXAIQ-UHFFFAOYSA-N 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 229910003445 palladium oxide Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- -1 rare-earth transition metal Chemical class 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- 206010000369 Accident Diseases 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 238000004566 IR spectroscopy Methods 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 235000014633 carbohydrates Nutrition 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910001902 chlorine oxide Inorganic materials 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 230000005274 electronic transitions Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 230000027756 respiratory electron transport chain Effects 0.000 description 1
- 238000011896 sensitive detection Methods 0.000 description 1
- 230000001235 sensitizing effect Effects 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Description
【発明の詳細な説明】
本発明は、産業活動または家庭における可燃性
ガスのガス漏れによる爆発,火災事故,公害等の
未然防止への利用を目的として、酸化インジウム
(In2O3)、塩化パラジウム(PdCl2)および磁器用
粘土の原料から焼成法によつて、絶縁基板上にパ
ラジウム(Pd)添加の焼結型酸化インジウム系
半導体厚膜を生成させる方法に関するものであ
る。[Detailed Description of the Invention] The present invention aims to prevent explosions, fire accidents , pollution , etc. caused by flammable gas leaks in industrial activities or homes. This invention relates to a method for producing a sintered indium oxide semiconductor thick film doped with palladium (Pd) on an insulating substrate by a firing method from raw materials of palladium (PdCl 2 ) and porcelain clay.
従来、ガスの検出方法には、光の屈折率の変化
を利用した光干渉法,赤外スペクトル法,ガスク
ロマトグラフ法,電池の起電力を利用する電気化
学的方法,化学反応を利用した検知管法,接触燃
焼法,半導体センサ法などがある。これらのう
ち、接触燃焼法および半導体センサ法は、ガス濃
度を電気信号としてとり出すことができ、使いや
すいため可撓性ガスの漏洩検知用として用いられ
てきた。 Conventional gas detection methods include optical interference method that uses changes in the refractive index of light, infrared spectroscopy, gas chromatography, electrochemical method that uses the electromotive force of batteries, and detection tubes that use chemical reactions. method, catalytic combustion method, and semiconductor sensor method. Among these, the catalytic combustion method and the semiconductor sensor method can extract the gas concentration as an electrical signal and are easy to use, so they have been used for leak detection of flexible gases.
接触燃焼法は、加熱した白金線にガスを接触燃
焼させ、加熱線の電気抵抗の変化を検出するもの
で、古くから炭鉱などでメタンガスの検出に用い
られているが、素子の劣化や被毒によつて感度が
低下しやすく、得られる電気信号の変化が小さい
ため、これを増幅する必要があつて、高価格にな
る欠点がある。一方、半導体センサは応答速度が
早く、感度が高いので、低濃度のガス検出がで
き、かつ簡単な回路で安価に必要なアラーム処置
を作ることができる。この種のものには、SnO2
系がガスセンサをはじめ、ZnO,V2Os,NiO,
CoO系のものおよび稀土類遷移金属系ペロブスカ
イト型複合酸化物を用いたものなどが提案されて
いるが、SnO2系以外のものは末だ問題点が多
い。SnO2系ガスセンサは家庭用ガス漏れ検出に
広く使われているが、水蒸気の影響を受けやすい
から、劣化が比較的早く、ガスによる電気抵抗の
変化がガス濃度に比例しないなどの難点がある。
また、検出原理には不明な点が多く、実験的事実
が先行して、技術的に未完成のまま用いられたた
め、信頼性の少ない素子という印象が免れない。 The catalytic combustion method involves burning gas in contact with a heated platinum wire and detecting changes in the electrical resistance of the heated wire. It has been used for a long time in coal mines to detect methane gas, but it can cause deterioration of the element and poisoning. Since the sensitivity tends to decrease and the change in the obtained electrical signal is small, it is necessary to amplify this, which has the drawback of increasing the price. On the other hand, semiconductor sensors have a fast response speed and high sensitivity, so they can detect gases at low concentrations, and the necessary alarm measures can be created at low cost with a simple circuit. This kind includes SnO2
The system includes gas sensors, ZnO, V 2 O s , NiO,
CoO-based materials and materials using rare-earth transition metal-based perovskite-type composite oxides have been proposed, but materials other than SnO 2 have many problems. SnO 2 -based gas sensors are widely used to detect household gas leaks, but because they are easily affected by water vapor, they deteriorate relatively quickly and have drawbacks such as the change in electrical resistance due to gas is not proportional to the gas concentration.
In addition, there are many unknowns about the detection principle, and because experimental facts preceded it and it was used without being technologically complete, one cannot help but feel that it is an unreliable device.
このような事情に鑑み、本発明は、In2O3を母
体材料とし、磁器用粘土を添加して、PdCl2で活
性化した焼結型半導体厚膜を絶縁基板上に生成す
ることにより、前記SnO2系半導体ガスセンサの
欠点をほぼ満足しうる状態に除去するとともに、
ガスの選択的能力を付与した酸化インジウム系ガ
スセンサの製造方法を提供することを目的とす
る。 In view of these circumstances, the present invention uses In 2 O 3 as a host material, adds porcelain clay, and generates a sintered semiconductor thick film activated with PdCl 2 on an insulating substrate. In addition to eliminating the drawbacks of the SnO 2 semiconductor gas sensor to a nearly satisfactory state,
An object of the present invention is to provide a method for manufacturing an indium oxide gas sensor that has gas selective ability.
このため本発明の方法は、酸化インジウムを母
体材料とし、塩化パラジウムおよび磁器用粘土を
添加材料として、空気中または制御された酸素雰
囲気中で、約700℃での高温仮焼成と約600℃での
低温本焼成とを行なうことにより、酸化インジウ
ムを主成分としてパラジウム,シリコン,アルミ
ニウム,亜鉛の酸化物を含有する厚膜を絶縁基板
上に焼結させることを特徴としている。 For this reason, the method of the present invention uses indium oxide as a base material, palladium chloride and porcelain clay as additive materials, and involves high-temperature pre-calcination at about 700°C and heating at about 600°C in air or a controlled oxygen atmosphere. The method is characterized in that a thick film containing indium oxide as a main component and oxides of palladium, silicon, aluminum, and zinc is sintered on an insulating substrate by performing low-temperature main firing.
以下図面とともに本発明の製造方法について詳
述する。 The manufacturing method of the present invention will be described in detail below with reference to the drawings.
第1図は、本発明によるIn2O3系ガスセンサの
製造工程図を示したものである。まず市販の高純
度In2O3(99.9%)を1時間にわたり約700℃で仮
焼成して、湿気および不必要な不純物を除去す
る。これをメノウ乳鉢で充分に粉砕し篩にかけ
て、200メツシユ以下の粒度に揃える。粒度の揃
つたIn2O3粉末に活性化原料としてPdC2(5wt%
以下)、抑圧原料磁器用粘土(10wt%以下)を添
加混合し、蒸留水とともに撹拌し、コロイド状の
懸濁液をつくる。この懸濁液の一定量(約10mg)
を計量してこれをステアタイト基板上に塗布し、
乾燥炉内(約100℃)にて約30分保持したのち、
大気雰囲気中で1時間にわたり約600℃で本焼成
する。さらに厚膜の機械的ストレスの解消および
電気的経時変化を安定化するため、空気中におい
て本焼成の終えた厚膜素子を200℃で約1時間焼
鈍処理を行なう。これに銀ペーストを用いて厚膜
素子と被測定ガスの接触面積が1×10(mm)にな
るように電極を構成すると、In2O3(Pd)系半導
体ガスセンサが得られる。なお、素子には感度を
向上させるため、絶縁基板にヒーター処理を施し
てある。第2図は酸化インジウム系ガスセンサの
完成図を示したものであり、第2図中の符号1は
センサ、2はリード線、3は電極、4は絶縁基
板、5は加熱用ヒーターを示している。 FIG. 1 shows a manufacturing process diagram of an In 2 O 3 based gas sensor according to the present invention. First, commercially available high-purity In 2 O 3 (99.9%) is calcined at about 700° C. for 1 hour to remove moisture and unnecessary impurities. Thoroughly crush this in an agate mortar and sieve it to a particle size of 200 mesh or less. PdC 2 (5wt%) was added as an activation raw material to In 2 O 3 powder with uniform particle size.
(below), suppressing raw material porcelain clay (10wt% or less) is added and mixed, and stirred with distilled water to create a colloidal suspension. A certain amount of this suspension (approximately 10 mg)
Measure out and apply it on the steatite substrate,
After keeping it in the drying oven (about 100℃) for about 30 minutes,
Main firing is performed at approximately 600°C for 1 hour in an air atmosphere. Furthermore, in order to relieve the mechanical stress of the thick film and stabilize electrical changes over time, the thick film element after main firing is annealed in air at 200° C. for about 1 hour. When electrodes are constructed using silver paste so that the contact area between the thick film element and the gas to be measured is 1×10 (mm), an In 2 O 3 (Pd)-based semiconductor gas sensor is obtained. Note that in order to improve the sensitivity of the element, the insulating substrate is subjected to a heater treatment. Figure 2 shows a completed diagram of the indium oxide gas sensor. In Figure 2, numeral 1 is the sensor, 2 is the lead wire, 3 is the electrode, 4 is the insulating substrate, and 5 is the heating heater. There is.
上述の方法によつて得られたIn2O3(Pd)系半
導体ガスセンサの電気的特性の測定には、実用的
な電流検出法を用いることができる。すなわち、
ガスセンサ、標準抵抗Rおよび電池の直列回路に
おいて、ガスセンサには予じめ1(mA)の直流
電流を流しておき、これに一定濃度のガスを接触
させると、ガスセンサの素子抵抗rが減少するこ
とから、素子を流れる電流が増加し、標準抵抗の
端子電圧が増加する。これをXYレコーダーで観
測すれば、レスポンス・カーブが得られる。 A practical current detection method can be used to measure the electrical characteristics of the In 2 O 3 (Pd)-based semiconductor gas sensor obtained by the above method. That is,
In a series circuit of a gas sensor, a standard resistor R, and a battery, when a direct current of 1 (mA) is passed through the gas sensor in advance and a constant concentration of gas is brought into contact with it, the element resistance r of the gas sensor decreases. , the current flowing through the element increases and the terminal voltage of the standard resistor increases. If this is observed with an XY recorder, a response curve can be obtained.
第3図は代表的なレスポンス・カーブである。
同図A点はガス注入時を示し、B点はガス注入停
止時を示している。A,B間の時間つまり標準抵
抗の端子電圧が飽和値に達する時間は約9
(sec)で、A点より約1(sec)間に端子電圧は
10(v)に達しており、従来のSnO2系ガスセン
サのそれと同様に、本発明によるIn2O3系ガスセ
ンサの応答速度はきわめて速い。このことは本焼
成時の原料組成を変化して作成した素子について
も、感度の差こそあれ、ほぼ同様な結果が得られ
ている。 Figure 3 shows a typical response curve.
Point A in the figure shows the time when gas is injected, and point B shows when the gas injection is stopped. The time between A and B, that is, the time for the terminal voltage of the standard resistor to reach the saturation value, is approximately 9
(sec), and the terminal voltage is approximately 1 (sec) from point A.
10 (v), and the response speed of the In 2 O 3 based gas sensor according to the present invention is extremely fast, similar to that of the conventional SnO 2 based gas sensor. Almost the same results were obtained with devices made by changing the raw material composition during the main firing, although there were differences in sensitivity.
第6図は、仮焼成温度を0℃,600℃,700℃,
800℃および900℃にした5つの場合のそれぞれに
ついて、本焼成温度と電圧感度との関係を示すグ
ラフを実験的に求めたものである。この実験結果
が明らかなように、本発明の方法のごとく、仮焼
成温度を約700℃とし本焼成温度を約600℃とした
場合に、最も電圧感度が高くなる効果がある。 Figure 6 shows the pre-firing temperatures of 0℃, 600℃, 700℃,
Graphs showing the relationship between main firing temperature and voltage sensitivity were obtained experimentally for each of the five cases of 800°C and 900°C. As is clear from this experimental result, when the preliminary firing temperature is about 700°C and the main firing temperature is about 600°C, as in the method of the present invention, the voltage sensitivity is most effective.
また第7図は、PdCl2の添加量を0Wt%,3Wt
%,5W%および10W%にした4つの場合のそれ
ぞれについて、本焼成温度と電圧感度との関係を
示すグラフを実験的に求めたものであり、PdCl2
の添加量を約5Wt%とし本焼成温度を600℃とし
た場合に、最も電圧感度が高くなつている。 In addition, Figure 7 shows the amount of PdCl 2 added at 0Wt% and 3Wt%.
%, 5W%, and 10W%, graphs showing the relationship between main firing temperature and voltage sensitivity were obtained experimentally .
The voltage sensitivity is highest when the amount of addition is approximately 5 Wt% and the main firing temperature is 600°C.
以下、本発明によるIn2O3系ガスセンサの製造
方法とその電圧感度に関する実験例について説明
する。 Hereinafter, a method for manufacturing an In 2 O 3 gas sensor according to the present invention and an experimental example regarding its voltage sensitivity will be described.
実験例 1
大気雰囲気中、温度700℃で仮焼成したIn2O3粉
末を主成分として、PdCl2および磁器用粘土を無
添加のまま蒸留水で懸濁液とした原料を、温度
500℃,600℃,700℃および800℃で本焼成して得
られた素子では、いずれもガスに対する電圧感度
はほとんど見られない。Experimental example 1 A raw material containing In 2 O 3 powder pre-calcined at a temperature of 700°C in an air atmosphere as a suspension in distilled water with no additives of PdCl 2 and porcelain clay was mixed at a temperature of 700°C.
In the devices obtained by main firing at 500°C, 600°C, 700°C, and 800°C, there is almost no voltage sensitivity to gas.
実験例 2
大気雰囲気中において、温度700℃で1時間仮
焼成した粉末In2O3に、PdCl2 5Wt%および磁器
用粘土1Wt%を添加し、蒸留水でコロイド状に懸
濁した原料を、温度600℃で1時間本焼成する
と、塩素(Cl2)および酸化パラジウム(PdO)の
ほか、微量の金属酸化物を含有するIn2O3系ガス
センサが得られる。Experimental Example 2 PdCl 2 5Wt% and porcelain clay 1Wt% were added to powdered In 2 O 3 that had been calcined for 1 hour at a temperature of 700°C in the air, and the raw material was suspended colloidally in distilled water. After main firing at a temperature of 600°C for 1 hour, an In 2 O 3 -based gas sensor containing chlorine (Cl 2 ), palladium oxide (PdO), and trace amounts of metal oxides is obtained.
この素子のプロパン(C3H8)および一酸化炭素
(CO)に対するガス濃度対電圧感度特性(素子加
熱温度:150℃)を第4図に示す。 FIG. 4 shows the gas concentration vs. voltage sensitivity characteristics of this device for propane (C 3 H 8 ) and carbon monoxide (CO) (device heating temperature: 150° C.).
実験例 3
実験例2の場合と同一条件で仮焼成した粉末
In2O3に、PdCl3 3Wt%および磁器用粘土10Wt%
を添加して、本焼成して得られた素子のC3H8お
よびCOに対するガス濃度対電圧感度特性(素子
加熱温度150℃)を第5図に示す。Experimental example 3 Powder calcined under the same conditions as experimental example 2
In2O3 , PdCl3 3Wt% and porcelain clay 10Wt%
FIG. 5 shows the gas concentration vs. voltage sensitivity characteristics for C 3 H 8 and CO (device heating temperature: 150° C.) of the device obtained by adding and main firing.
第4図によれば、明らかにC3H8およびCOの検
出が可能である。図に示していないが、この素子
はブタン(C4H10),エタン(C2H6),メタン
(CH4)などの炭化水素にもほぼ同様に感度を持つ
ことを確認した。しかし、磁器用粘土の添加量を
1〜3Wt%の範囲の一定量に固定し、PdCl2を1
〜10Ww%の範囲の一定量を添加して得られた素
子では、磁器用粘土の添加量には無関係に、
PdCl2の添加量が2Wt%または7Wt%以上のとき
感度は低く、5Wt%のとき最高感度であることが
判明した。 According to FIG. 4, it is clearly possible to detect C 3 H 8 and CO. Although not shown in the figure, we confirmed that this device has almost the same sensitivity to hydrocarbons such as butane (C 4 H 10 ), ethane (C 2 H 6 ), and methane (CH 4 ). However, the amount of porcelain clay added was fixed at a constant amount in the range of 1 to 3 Wt%, and PdCl 2 was added to 1 to 3 Wt%.
In the element obtained by adding a fixed amount in the range of ~10Ww%, regardless of the amount of porcelain clay added,
It was found that the sensitivity was low when the amount of PdCl 2 added was 2 Wt% or 7 Wt% or more, and the highest sensitivity was achieved when the amount was 5 Wt%.
このように適量のPdCl2の添加によつて、著し
く増感作用があるのは、PdCl2の熱分解によつて
発生する塩素がIn2O3・nH2O中のOH基またはH
基の作用を活発にして、接触ガスとの間に電子的
なエネルギ交換が行なわれるとともに、一方では
In2O3中にPdまたはPdOの新しい不純物準位が形
成されて、この準位からの電子遷移によつて、伝
導帯におけるキヤリア密度が増加し、In2O3系厚
膜の電気抵抗を低下させることに基因するもので
ある。 The reason why the addition of an appropriate amount of PdCl 2 has a remarkable sensitizing effect is that the chlorine generated by the thermal decomposition of PdCl 2 is oxidized to the OH group or H
Activating the action of the group, an electronic energy exchange takes place with the contacting gas, while at the same time
A new impurity level of Pd or PdO is formed in In 2 O 3 and electronic transition from this level increases the carrier density in the conduction band, increasing the electrical resistance of the In 2 O 3 based thick film. This is due to the fact that the
第5図によれば、COに対する感度は多少低下
するに留まるが、C3H8に対する感度の低下が顕
著であつて、結果的にCOに対して高感度を持つ
から、明らかに両者のガス検出にあたつて選択的
能力がある。 According to Figure 5, the sensitivity to CO decreases only slightly, but the decrease in sensitivity to C 3 H 8 is remarkable, and as a result, the sensitivity to CO is high, so it is clear that both gases It has selective ability in detection.
実験例3の素子の添加量は実験例2の素子のそ
れに比して、PdCl2が減少しているとともに磁器
用粘土が増加しているが、磁器用粘土にはSiO,
Al2O3,SrOなどの金属酸化物が含有されている
(例えば益子産粘土)ことから、これらが何らか
の形で、前述の塩素およびPdOの活性化作用を抑
圧する働きをすることに基因して、素子と接触ガ
スとの間の電子移動を不活発にし、C3H8のガス
感度を低下させることができる。このことは
C3H8を初めとする他の炭水化物にも共通であ
る。 Compared to the element of Experimental Example 2, the amount of addition in the element of Experimental Example 3 is that PdCl 2 is decreased and porcelain clay is increased, but the porcelain clay contains SiO,
This is because metal oxides such as Al 2 O 3 and SrO are contained (for example, clay from Mashiko), so these act in some way to suppress the activation effects of chlorine and PdO mentioned above. As a result, electron transfer between the element and the contact gas can be made inactive and the gas sensitivity of C 3 H 8 can be reduced. This thing is
It is also common to other carbohydrates, including C 3 H 8 .
しかし、磁器用粘土の添加量を余りに増加する
と、抑圧作用が増大して、すべてのガスに対して
感度を失うことになる。 However, if the amount of porcelain clay added is increased too much, the suppression effect increases and sensitivity to all gases is lost.
以上詳述したように、本発明の酸化インジウム
系ガスセンサの製造方法によれば、母体材料とし
ての粉末In2O3、活性化原料としてのPdCl2およ
び抑圧材料としての磁器用粘土の3原料から、焼
成法によつて焼結型In2O3系ガスセンサを作成す
ることができる。 As detailed above, according to the method for manufacturing an indium oxide gas sensor of the present invention, three raw materials are used: powdered In 2 O 3 as a base material, PdCl 2 as an activating raw material, and porcelain clay as a suppressing material. A sintered In 2 O 3 -based gas sensor can be produced by the sintering method.
そして、実験例2および実験例3から明らかな
ように、主成分In2O3に活性化材料および抑圧材
料磁器用粘土の適量を添加することにより、
C3H8およびCOに高感度を有する素子と、COに
対して敏感な検出能力を有するが、C3H8に対し
ては感度が低く、ガスの種類に対して選択能力を
有する素子とが得られるのである。 As is clear from Experimental Examples 2 and 3, by adding appropriate amounts of activating material and suppressing material porcelain clay to the main component In 2 O 3 ,
An element with high sensitivity to C 3 H 8 and CO, and an element with a sensitive detection ability for CO but low sensitivity to C 3 H 8 and a selective ability for gas types. is obtained.
また、本発明の方法によれば、高温仮焼成温度
を約700℃とし低温本焼成温度を約600℃とすると
いう簡単な工程で、電圧感度の高い、酸化インジ
ウム系ガスセンサの製造を安価に行なえる利点が
ある。 Furthermore, according to the method of the present invention, an indium oxide gas sensor with high voltage sensitivity can be manufactured at low cost through a simple process of setting the high temperature pre-firing temperature to approximately 700°C and the low-temperature main firing temperature to approximately 600°C. It has the advantage of
図面は本発明の実施概要と本発明の方法により
得られた素子の特性の一例とを示すもので、第1
図はIn2O3(Pd)系半導体ガスセンサの製造工程
図、第2図は完成した素子の平面および断面図、
第3図は可燃性ガスに対する応答曲線の一例を示
すグラフ,第4図はIn2O3を主成分としPdCl2
5Wt%、磁器用粘土1Wt%を添加して温度600℃
で焼結した素子のガス濃度対電圧感度特性図、第
5図はIn2O3を主成分としPdCl2 3Wt%、磁器用
粘土10Wt%を添加して600℃で焼結した素子のガ
ス濃度対電圧感度特性図、第6図は高温仮焼成温
度および低温本焼成温度と感度との関係を示すグ
ラフ、第7図はPdCl2添加濃度と感度との関係を
示すグラフである。
1…センサ、2…リード線、3…電極、4…絶
縁基板、5…加熱用ヒーター。
The drawings show an outline of the implementation of the present invention and an example of the characteristics of the device obtained by the method of the present invention.
The figure is a manufacturing process diagram of an In 2 O 3 (Pd)-based semiconductor gas sensor, and Figure 2 is a plan and cross-sectional view of the completed device.
Figure 3 is a graph showing an example of a response curve to combustible gas, and Figure 4 is a graph showing an example of a response curve for combustible gas .
5Wt%, porcelain clay 1Wt% added and temperature 600℃
Figure 5 shows the gas concentration vs. voltage sensitivity characteristics of an element sintered at 600°C with In 2 O 3 as the main component and 3 Wt% of PdCl 2 and 10 Wt% of porcelain clay added. FIG. 6 is a graph showing the relationship between high temperature preliminary firing temperature and low temperature main firing temperature and sensitivity, and FIG. 7 is a graph showing the relationship between PdCl 2 addition concentration and sensitivity. DESCRIPTION OF SYMBOLS 1...Sensor, 2...Lead wire, 3...Electrode, 4...Insulating substrate, 5...Heating heater.
Claims (1)
ウムおよび磁器用粘土を添加材料として、空気中
または制御された酸素雰囲気中で、約700℃での
高温仮焼成と約600℃での低温本焼成とを行なう
ことにより、酸化インジウムを主成分としてパラ
ジウム、シリコン、アルミニユウム、亜鉛の酸化
物を含有する厚膜を絶縁基板上に焼結させるとを
特徴とする。酸化インジウム系ガスセンサの製造
方法。1. Using indium oxide as a base material and palladium chloride and porcelain clay as additive materials, perform high-temperature pre-firing at about 700°C and low-temperature final firing at about 600°C in air or in a controlled oxygen atmosphere. Accordingly, a thick film containing indium oxide as a main component and oxides of palladium, silicon, aluminum, and zinc is sintered on an insulating substrate. A method for manufacturing an indium oxide gas sensor.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17782080A JPS57101751A (en) | 1980-12-16 | 1980-12-16 | Manufacture of indium oxide series gas sensor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17782080A JPS57101751A (en) | 1980-12-16 | 1980-12-16 | Manufacture of indium oxide series gas sensor |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS57101751A JPS57101751A (en) | 1982-06-24 |
JPS6133466B2 true JPS6133466B2 (en) | 1986-08-02 |
Family
ID=16037665
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP17782080A Granted JPS57101751A (en) | 1980-12-16 | 1980-12-16 | Manufacture of indium oxide series gas sensor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS57101751A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3604594A1 (en) * | 1986-02-14 | 1987-08-20 | Schott Glaswerke | Thin-film gas sensors having high measuring sensitivity as multilayer systems based on dipped indium oxide layers for detection of gas traces in carrier gases |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS51137494A (en) * | 1975-05-23 | 1976-11-27 | Res Inst For Prod Dev | Gas detector element |
-
1980
- 1980-12-16 JP JP17782080A patent/JPS57101751A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS51137494A (en) * | 1975-05-23 | 1976-11-27 | Res Inst For Prod Dev | Gas detector element |
Also Published As
Publication number | Publication date |
---|---|
JPS57101751A (en) | 1982-06-24 |
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