WO2010084916A1 - Base body for gas sensor and method for manufacturing the base body - Google Patents

Base body for gas sensor and method for manufacturing the base body Download PDF

Info

Publication number
WO2010084916A1
WO2010084916A1 PCT/JP2010/050715 JP2010050715W WO2010084916A1 WO 2010084916 A1 WO2010084916 A1 WO 2010084916A1 JP 2010050715 W JP2010050715 W JP 2010050715W WO 2010084916 A1 WO2010084916 A1 WO 2010084916A1
Authority
WO
WIPO (PCT)
Prior art keywords
upper layer
heating resistor
insulating substrate
region
layer
Prior art date
Application number
PCT/JP2010/050715
Other languages
French (fr)
Japanese (ja)
Inventor
徹治 今村
大輔 桑原
Original Assignee
北陸電気工業株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 北陸電気工業株式会社 filed Critical 北陸電気工業株式会社
Publication of WO2010084916A1 publication Critical patent/WO2010084916A1/en

Links

Images

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
    • G01N27/14—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature
    • G01N27/16—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature caused by burning or catalytic oxidation of surrounding material to be tested, e.g. of gas

Definitions

  • the present invention relates to a base for a gas sensor such as a catalytic combustion type gas sensor and a method for manufacturing the same.
  • Patent Document 1 discloses a catalytic combustion type gas sensor (combustible gas detection device) manufactured using a gas sensor substrate.
  • the gas sensor base has a configuration in which a heating resistor (heater) is built in an insulating substrate.
  • the insulating substrate has a lower layer made of a heat resistant insulator and an upper layer made of a heat resistant insulator formed on the lower layer.
  • the heating resistor is made of a metal thin film, is formed on the lower layer, and is covered with the upper layer.
  • a catalyst including a catalyst that promotes combustion of a detection target gas by heat generated from the heating resistor on a region where the heating resistor of the insulating substrate is formed.
  • a sintered layer is formed.
  • the insulating substrate is further formed with a compensation heating resistor and a compensation sintered layer.
  • the compensation heating resistor has the same structure as the heating resistor.
  • the compensation sintered layer is formed on a portion of the diaphragm where the compensation heating resistor is formed, and is composed of components obtained by removing the catalyst from the catalyst sintered layer. In the compensation sintered layer, the detection target gas does not burn.
  • the resistance value change of the heating resistor based on the temperature change due to the combustion of the detection target gas in the catalyst sintered layer and the resistance value change of the compensation heating resistor based on the temperature change of the compensation sintered layer thus, the concentration of the detection target gas is detected.
  • a pair of electrodes arranged at predetermined intervals are formed on a portion of the insulating substrate on which the heating resistor is formed.
  • a sensitive film containing a metal oxide semiconductor is formed so as to cover the pair of electrodes.
  • the concentration of the detection target gas is detected by a change in resistance value between the pair of electrodes generated by the adsorption of the detection target gas by the sensitive film.
  • the thickness of the insulating substrate of the gas sensor substrate is such that the crack resistance of the insulating substrate is maintained, and the heat of the heating resistor is not dispersed and can be sufficiently transferred to the catalyst sintering layer, the compensation sintering layer or the sensitive film.
  • An object of the present invention is to provide a gas sensor substrate capable of sufficiently increasing the thermal conductivity of a heating resistor to a catalyst sintered layer, a compensation sintered layer or a sensitive film while maintaining the crack resistance of an insulating substrate. It is another object of the present invention to provide a catalytic combustion type gas sensor using the gas sensor substrate.
  • a gas sensor substrate to be improved by the present invention includes an insulating substrate having a lower layer made of a heat-resistant insulator, an upper layer made of a heat-resistant insulator formed on the lower layer, and a lower layer. And a heating resistor made of a metal thin film formed and covered with an upper layer.
  • the heat-resistant insulator is an insulator that can withstand heat, such as a heating resistor, and is, for example, a silicon compound or a metal compound.
  • a bottomed concave portion that opens toward the side opposite to the side where the lower layer is located is formed in the portion of the upper layer where the heating resistor is formed.
  • the base for a gas sensor of the present invention can be used for various gas sensors formed by forming a heating resistor in an insulating substrate such as a catalytic combustion type gas sensor or a semiconductor type gas sensor.
  • a heating resistor in an insulating substrate such as a catalytic combustion type gas sensor or a semiconductor type gas sensor.
  • the portion of the insulating substrate where the heating resistor is formed has a small thickness, so that the heat of the heating resistor is dispersed.
  • the heat conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film can be sufficiently increased.
  • the thickness dimension of the upper layer around the above-mentioned area is large, crack resistance can be maintained. Further, the crack resistance of the portion of the insulating substrate where the heating resistor is formed can also be maintained by disposing the catalyst sintered layer, the compensating sintered layer, or the sensitive film in the recess.
  • the recess can be formed by etching the upper layer. In this way, the recess can be easily formed.
  • the thickness dimension of the region where the heating resistor of the upper layer of the insulating substrate is formed can be set to 1 ⁇ 2 or less of the thickness dimension of the upper layer around the region. If it does in this way, while maintaining the crack resistance of an insulated substrate, the thermal conductivity to the catalyst sintering layer or sensitive film
  • one or more through holes penetrating the insulating substrate may be formed around the region where the heating resistor of the upper layer of the insulating substrate is formed.
  • the one or more through holes are formed around the region so as to be adjacent to the region where the heating resistor is formed.
  • the heat of the heating resistor is more difficult to disperse due to the presence of the through holes.
  • the thermal conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film can be further enhanced.
  • Such a through hole can be easily formed because it can be formed by etching the upper layer and the lower layer constituting the insulating substrate.
  • the gas sensor substrate of the present invention can be manufactured as follows. First, a silicon substrate made of a silicon single crystal is prepared. Then, a lower layer is formed on one surface of the silicon substrate, and a heating resistor made of a metal thin film is formed on the lower layer. Next, an upper layer is formed on the lower layer so as to cover the heating resistor. Next, etching is performed on the region of the upper layer where the heating resistor is formed to form a bottomed recess. Before or after forming the recess, etching is performed from the other side of the silicon substrate to reduce the thickness of the aforementioned region of the silicon substrate corresponding to the heating resistor to form an insulating substrate to manufacture a gas sensor substrate.
  • etching is performed from one side of the silicon substrate to form a through hole penetrating the insulating substrate.
  • the recesses and / or the through holes can be easily formed by etching.
  • a catalytic combustion gas sensor manufactured using the gas sensor substrate of the present invention includes an insulating substrate having a lower layer made of a heat-resistant insulator and an upper layer made of the heat-resistant insulator formed on the lower layer.
  • a gas detection heating resistor made of a metal thin film formed on the lower layer and covered by the upper layer, and a gas detection heating resistor formed on the region where the gas detection heating resistor of the upper layer is formed.
  • a catalyst sintered layer including a catalyst that promotes combustion of the detection target gas by heat generated from the heating resistor.
  • a bottomed recess that opens in a direction opposite to the direction toward the lower layer is formed on a region where the heating resistor for gas detection of the upper layer is formed.
  • the thickness dimension of the region in which the heating resistor for gas detection of the layer is formed is smaller than the thickness dimension of the upper layer around the region.
  • An insulating substrate having a lower layer made of a heat-resistant insulator and an upper layer made of a heat-resistant insulator formed on the lower layer, and a metal thin film formed on the lower layer and covered by the upper layer
  • a compensation heating layer comprising a component obtained by removing the aforementioned catalyst from the catalyst sintering layer, formed on a region where the compensation heating resistor of the upper layer is formed, and It has further. Then, a bottomed recess that opens in a direction opposite to the direction toward the lower layer is formed on the upper layer where the compensation heating resistor is formed.
  • the thickness dimension of the region where the compensation heating resistor for the upper layer is formed is smaller than the thickness dimension of the upper layer around the region.
  • One insulating substrate may be shared between the insulating substrate on which the gas detection heating resistor is formed and the insulating substrate on which the compensation heating resistor is formed, or separate insulating substrates may be used. According to the catalytic combustion type gas sensor of the present invention, while maintaining the crack resistance of the insulating substrate, the thermal conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film is sufficiently increased. Can do.
  • a plurality of through holes penetrating the insulating substrate can be formed adjacent to the region around the region where the heating resistor of the upper layer of the insulating substrate is formed.
  • a through hole By providing such a through hole, a space is formed around the region where the heating resistor is formed, so that the heat of the heating resistor becomes more difficult to disperse, and the catalyst sintered layer of the heating resistor, It is possible to provide a contact combustion type gas sensor in which the thermal conductivity to the compensation sintered layer or the sensitive film is further improved.
  • FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is a top view of the contact combustion type gas sensor using the base for gas sensors of other embodiments of the present invention. It is a reverse view of the contact combustion type gas sensor using the base for gas sensors of other embodiments of the present invention.
  • FIG. 6 is a sectional view taken along line VI-VI in FIG. 4.
  • (A) to (G) are diagrams used for explaining a method of manufacturing the catalytic combustion type gas sensor shown in FIGS. 1 and 4.
  • FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is a top view of the contact combustion type gas sensor using the base for gas sensors of other embodiments of the present invention. It is a reverse view of the contact combustion type gas sensor using the base for gas sensors of other embodiments of the present invention.
  • FIG. 6 is a sectional view taken along line VI-VI in FIG. 4.
  • (A) to (G) are diagrams used for explaining a method of manufacturing the catalytic
  • FIG. 1 and 2 are a plan view and a back view of a catalytic combustion type gas sensor using a gas sensor substrate according to an embodiment of the present invention
  • FIG. 3 is a sectional view taken along line III-III in FIG.
  • the catalytic combustion type gas sensor of this example includes a gas sensor substrate 1, a catalyst sintered layer 3, and a compensation sintered layer 5.
  • the gas sensor substrate 1 includes a support portion 7, an insulating substrate 9, a gas detection heating resistor (gas detection heater) 11, and a compensation heating resistor (compensation heater) 13.
  • the support portion 7 is made of a silicon single crystal, and an insulating substrate 9 is disposed above the support portion 7.
  • the support part 7 has a cylindrical part 7a having a rectangular tube shape and a central wall part 7b that divides the inside of the cylindrical part 7a into two parts.
  • two opening holes 7 c and 7 d are formed in the support portion 7.
  • the upper portions of the two portions of the insulating substrate 9 in which the opening holes 7c and 7d are formed constitute the diaphragms 15A and 15B.
  • the insulating substrate 9 including the diaphragms 15A and 15B includes a lower layer 17 made of a heat resistant insulator and an upper layer 19 made of a heat resistant insulator formed on the lower layer 17. is doing.
  • the lower layer 17 is formed by laminating a thin film SiO 2 layer 17a having a thickness of 6000 mm and a thin film Si 3 N 4 layer 17b having a thickness of 400 mm.
  • the upper layer 19 has a thickness of 3 ⁇ m and is made of SiO 0.7 N 0.7 .
  • the upper layer 19 was formed using a plasma chemical vapor deposition (P-CVD) thin film formation technique until the thickness reached 3 ⁇ m.
  • a bottomed recess 19a that opens in a direction opposite to the direction in which the lower layer 17 is located, 19b is formed.
  • the openings of the recesses 19a and 19b both have a circular shape.
  • the thickness dimension of the portion is smaller than the thickness dimension of the upper layer 19 (the peripheral portion 19c of the recesses 19a and 19b) around the region.
  • the diameter L1 of the recesses 19a and 19b is 400 ⁇ m
  • the portion of the upper layer 19 of the insulating substrate 9 where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed (the recess of the upper layer 19
  • the thickness dimension L2 of the portion 19a, 19b) is 1.5 ⁇ m
  • the thickness dimension L3 of the peripheral portion 19c of the recess 19a, 19b (the portion where the recess 19a, 19b of the upper layer 19 is not formed). 3 of 3 ⁇ m).
  • a thin film SiO 2 layer 21a having a thickness of 6000 mm and a thin film Si 3 N 4 layer 21b having a thickness of 400 mm are also laminated below the support portion 7.
  • the gas detection heating resistor 11 is formed at the center of the diaphragm 15A, and is formed on the lower layer 17 while being covered by the upper layer 19.
  • the heating resistor 11 for gas detection is composed of a thin film layer in which Pt having a thickness of 4000 mm, Ta having a thickness of 100 mm and Ti having a thickness of 40 mm are laminated on the lower layer 17 in this order, as shown in FIGS. 1 and 2. It has a meandering pattern shape. Both ends of the gas detection heating resistor 11 are connected to a pair of electrodes 25 via a conductive portion 23.
  • the gas detection heating resistor 11, the conductive portion 23, and the pair of electrodes 25 are integrally formed.
  • An Au film 27 is formed above each of the pair of electrodes 25.
  • a rectangular opening 19d is formed in the portion of the upper layer 19 where the pair of electrodes 25 are formed. Therefore, a connection body or the like can be connected to the pair of electrodes 25 from above the insulating substrate 9 through the opening 19d.
  • the compensation heating resistor 13 is formed at the center of the diaphragm 15B, and is formed on the lower layer 17 in a state of being covered by the upper layer 19 as shown in FIG.
  • the compensation heating resistor 13 has the same structure as the gas detection heating resistor 11. As shown in FIG. 1, both ends of the compensation heating resistor 13 are connected to a pair of electrodes 31 via a conductive portion 29.
  • the compensation heating resistor 13, the conductive portion 29, and the pair of electrodes 31 are integrally formed.
  • Au films 33 are respectively formed above the pair of electrodes 31.
  • a rectangular opening 19e is formed in the portion of the upper layer 19 where the pair of electrodes 31 is formed. Therefore, a connection body or the like can be connected to the pair of electrodes 31 from above the insulating substrate 9 through the opening 19e.
  • the catalyst sintered layer 3 is obtained by curing a paste containing a catalyst such as Pt, Pd, or Au, ceramic powder such as alumina, silica, or tin oxide, and a binder such as ethyl cellulose, terpineol, or polyethylene glycol. ,
  • a catalyst such as Pt, Pd, or Au is used as a catalyst for accelerating combustion of a detection target gas composed of a flammable gas such as methane gas, propane gas, carbon monoxide, or alcohol by heat generated from the gas detection heating resistor 11. Plays the role of
  • the compensation sintered layer 5 is obtained by curing a paste containing ceramic powder such as alumina, silica, and tin oxide, and a binder such as ethyl cellulose, terpineol, and polyethylene glycol. Filled and formed. That is, the compensation sintered layer 5 is composed of components obtained by removing the catalyst (Pt or the like) from the catalyst sintered layer 3.
  • the catalyst sintering layer 3 is heated by the gas detection heating resistor 11 and the compensation sintering layer 5 is heated by the compensation heating resistor 13.
  • the detection target gas such as methane gas, propane gas, carbon monoxide, alcohol, etc.
  • the catalyst is sintered by the catalyst (Pt, etc.) of the catalyst sintering layer 3. Combustion occurs in layer 3. Even if a gas to be detected (combustible gas such as methane gas, propane gas, carbon monoxide, alcohol) exists in the vicinity of the compensation sintered layer 5, a catalyst (Pt or the like) is contained in the compensation sintered layer 5. There is no combustion.
  • the resistance value change of the heating resistor 11 for gas detection based on the temperature change due to the combustion of the detection target gas (combustible gas such as methane gas, propane gas, carbon monoxide, alcohol) in the catalyst sintered layer 3 is compensated.
  • the concentration of the detection target gas (combustible gas such as methane gas, propane gas, carbon monoxide, alcohol) is detected based on the change in resistance value of the compensation heating resistor 13 based on the temperature change of the sintered layer 5 for use.
  • Specific density detection can be performed by a known method disclosed in Japanese Patent Application Laid-Open No. 2005-156364.
  • FIG. 4 and 5 are a plan view and a back view of a catalytic combustion type gas sensor using a gas sensor substrate according to another embodiment of the present invention
  • FIG. 6 is a sectional view taken along line VI-VI in FIG. .
  • portions common to the above-described example of the present invention are described by adding the reference numerals of 100 to the number of reference numerals attached to FIGS. Omitted.
  • four through holes 119f penetrating the insulating substrate 109 are provided around the region (peripheral portion 119c) of the upper layer 119 of the insulating substrate 109 where the gas detection heating resistor 111 is formed.
  • the four through-holes penetrating the insulating substrate 109 are formed around the region where the heat generating resistor 113 for compensation of the upper layer 119 of the insulating substrate 109 is formed (peripheral portion 119c). 119g is formed at intervals in the circumferential direction of the region.
  • the four through holes 119f are formed adjacent to the region where the gas detection heating resistor 111 is formed, and the four through holes 119g are adjacent to the region where the compensation heating resistor 113 is formed. It is formed as follows. In another example, as shown in FIGS. 4 and 5, the region where the gas detection heating resistor 111 is formed has an opening 109a of an insulating substrate 109 formed by forming four through holes 119f.
  • the four coupling portions 119h couple the region where the gas detection heating resistor 111 is formed and the portion where the four through-holes 119f around this region (the peripheral portion 119c) are not formed in a state of being arranged inside
  • the shape of the four through-holes 119f is determined (in this example, the shape of the four through-holes 119f is L-shaped so as to surround the peripheral portion of the gas detection heating resistor 111). Is in the shape).
  • the compensation heating resistor 113 is formed in a state where the region where the compensation heating resistor 113 is formed is arranged inside the opening 109b of the insulating substrate 109 formed by forming the four through holes 119g.
  • the shape of the four through-holes 119g is determined so that the four coupling portions 119i are coupled to the region in which the four through-holes 119g are not formed in the periphery (peripheral portion 119c) of this region.
  • each of the four through holes 119g has an L shape so as to surround the peripheral edge of the gas detection heating resistor 111).
  • the four coupling portions 119h and the four coupling portions 119i constitute diaphragms 115A and 115B of the gas sensor, respectively.
  • the shapes of the four through holes 119f and the four through holes 119g can be determined as appropriate depending on the shapes and wiring patterns of the gas detection heating resistor 111 and the compensation heating resistor 113.
  • a base material 41 shown in FIG. 7A is formed.
  • the base material 41 is formed by thin film SiO 2 layers 17a and 45a having a thickness of 6000 mm on both surfaces of a silicon substrate 43 made of silicon single crystal by thermal oxidation.
  • thin film Si 3 N 4 layers 17b and 45b each having a thickness of 400 mm are formed on the thin film SiO 2 layers 17a and 45a by a low-pressure chemical vapor deposition (LP-CVD) thin film forming technique.
  • LP-CVD low-pressure chemical vapor deposition
  • the thin film Si 3 N 4 layer 17b (one surface of the silicon substrate 43) is sputtered with a thickness of 4000 mm of Pt, a thickness of 100 mm of Ta, and a thickness of 40 mm of Ti in this order. To complete.
  • the heat generating resistor forming layer 47 is etched with Ar plasma to form the gas detecting heat generating resistor 11 and the compensating heat generating resistor 13.
  • the conductive portion 23 and the pair of electrodes 25 shown in FIG. 1 are formed integrally with the gas detection heating resistor 11, and the conductive portion 29 and the pair of electrodes 31 are formed integrally with the compensation heating resistor 13. .
  • an upper layer 19 made of SiO 0.7 N 0.7 having a thickness of 3 ⁇ m is formed over 120 minutes using a P-CVD thin film formation technique.
  • the upper layer 19 is etched by reactive ion etching (RIE) using CF 4 gas to form the openings 19d and 19e shown in FIG. 1, and the pair of electrodes 25 and the pair of electrodes 31 are formed. Expose to the outside.
  • Au films 27 and 33 are formed on the pair of electrodes 25 and the pair of electrodes 31 by sputtering, respectively.
  • FIG. 7D reactive ion etching using CF 4 gas on the region of the upper layer 19 where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed. Etching is performed by (RIE) to form bottomed recesses 19a and 19b, respectively.
  • FIG. 7E the thin film Si 3 N 4 layer 45b is etched by reactive ion etching (RIE) using CF 4 gas to form a thin film Si 3 N 4 layer 21b.
  • the SiO 2 layer 45a is etched with buffered hydrofluoric acid (BHF) to form a thin film SiO 2 layer 21a.
  • BHF buffered hydrofluoric acid
  • the silicon substrate 43 is etched with tetramethylammonium hydroxyoxide (TMAH) from the side where the thin film SiO 2 layer 21a and the thin film Si 3 N 4 layer 21b are formed,
  • TMAH tetramethylammonium hydroxyoxide
  • the support part 7 provided with the opening holes 7c and 7d is formed.
  • the insulating substrate 9 is formed by reducing the thickness of the region of the silicon substrate 9 corresponding to the gas detection heating resistor 11 and the compensation heating resistor 13.
  • the silicon substrate 43 was annealed at 600 ° C. for 3 hours to complete the gas sensor substrate 1.
  • a ceramic powder containing Pt chloride or Pt colloid and a paste containing ethyl cellulose, terpineol and the like are filled in the recess 19a and then cured to form the catalyst sintered layer 3, and the ceramic powder Then, a paste containing ethyl cellulose, terpineol or the like was placed in the recess 19b and then cured to form the compensation sintered layer 5, thereby completing the catalytic combustion type gas sensor shown in FIGS.
  • FIG. 4 (G) When another example of the catalytic combustion type gas sensor of the present invention shown in FIGS. 4 to 6 is manufactured, as shown in FIG. 4 (G), the gas detection heating resistor 111 and the compensation heat generation of the upper layer 119 are used.
  • Four through-holes are formed around the region where the resistor 13 is formed by reactive ion etching (RIE) using CF 4 gas to leave four coupling portions 119h and four coupling portions 119i. 119f and four through holes 119g are formed.
  • RIE reactive ion etching
  • the portions of the insulating substrate 9 where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed are formed (the recesses 19a and 19b of the upper layer 19 are formed). Since the thickness dimension is small, the heat of the gas detection heating resistor 11 and the compensation heating resistor 13 can be prevented from being dispersed, and the catalyst sintered layer 3 of the gas detection heating resistor 11 can be prevented. The thermal conductivity to the compensation sintered layer 5 of the compensation heating resistor 13 can be sufficiently increased. Moreover, since the thickness dimension of the peripheral part 19c of the recessed parts 19a and 19b is large as an insulating substrate, crack resistance can be maintained.
  • the gas detection heating resistor 11 and the compensation heating resistor 13 of the insulating substrate 9 are also formed by disposing the catalyst sintering layer 3 and the compensation sintering layer 5 in the recesses 19a and 19b.
  • the crack resistance of the part can be maintained.
  • a space is formed around the area where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed (the portion where the four through holes 119f and the four through holes 119g are formed).
  • the heat of the gas detection heating resistor 11 and the compensation heating resistor 13 can be made more difficult to disperse, and the thermal conductivity of the gas detection heating resistor 111 to the catalyst sintered layer 103 and the compensation heating resistor can be reduced.
  • the thermal conductivity of the body 113 to the compensation sintered layer 105 can be further increased.
  • both the gas detection heating resistor 11 and the compensation heating resistor 13 are formed on one insulating substrate 9, but two insulating substrates are prepared, and the gas detection heating is provided on each insulating substrate.
  • a resistor and a compensation heating resistor may be formed.
  • the structure of the gas sensor substrate 1 of the above example can be applied to a semiconductor gas sensor. In that case, a pair of electrodes arranged at a predetermined interval is formed on a portion of the insulating substrate where the heating resistor is formed, and a sensitive film including a metal oxide semiconductor so as to cover the pair of electrodes. May be formed.
  • the portion of the insulating substrate where the heat generating resistor is formed (the portion where the concave portion of the upper layer is formed) has a small thickness dimension, so that the heat of the heat generating resistor can be prevented from being dispersed.
  • the heat conductivity of the heating resistor to the catalyst sintering layer, the compensation sintering layer or the sensitive film can be sufficiently increased.
  • the thickness dimension of the peripheral part of a recessed part is large as an insulated substrate, crack resistance can be maintained.
  • the crack resistance of the portion of the insulating substrate where the heating resistor is formed can also be maintained by disposing the catalyst sintered layer, the compensating sintered layer, or the sensitive film in the recess. Therefore, while maintaining the crack resistance of the insulating substrate, the thermal conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film can be sufficiently increased.

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 Electric Means (AREA)

Abstract

Provided is a base body for a gas sensor, by which heat conductivity of a heat resistive element to a catalyst sintered layer, compensating sintered layer or sensitive membrane is sufficiently improved, while maintaining breaking resistance of an insulating substrate. Circular recessed sections (19a, 19b) with opened tops are respectively formed on the portions where a gas detecting heat resistive element (11) and a compensating heat resistive element (13) are formed in an upper layer (19) of an insulating substrate (9). With the presence of the recessed sections (19a, 19b), the thickness of the insulating substrate (9) portions where the gas detecting heat resistive element (11) and the compensating heat resistive element (13) are formed is reduced to be smaller than that of a circumferential section (19c).

Description

ガスセンサ用基体及びその製造方法Gas sensor substrate and method of manufacturing the same
　本発明は、接触燃焼式ガスセンサ等のガスセンサ用基体及びその製造方法に関するものである。 The present invention relates to a base for a gas sensor such as a catalytic combustion type gas sensor and a method for manufacturing the same.
　特開２００５－１５６３６４号公報（特許文献１）には、ガスセンサ用基体を用いて製造した接触燃焼式ガスセンサ（可燃性ガス検出装置）が示されている。ガスセンサ用基体は、絶縁基板内に発熱抵抗体（ヒータ）が内蔵された構成を有している。絶縁基板は、耐熱性絶縁物からなる下部層と該下部層上に形成された耐熱性絶縁物からなる上部層とを有している。発熱抵抗体は、金属薄膜からなり、下部層上に形成されて上部層によって覆われている。ガスセンサ用基体を用いて製造した接触燃焼式ガスセンサでは、絶縁基板の発熱抵抗体が形成された領域の上に、発熱抵抗体から生じる熱によって検知対象ガスが燃焼するのを促進する触媒を含む触媒焼結層が形成されている。また、絶縁基板には、補償用発熱抵抗体と補償用焼結層とが更に形成されている。補償用発熱抵抗体は、発熱抵抗体と同じ構造を有している。補償用焼結層は、ダイヤフラムの補償用発熱抵抗体が形成された部分の上に形成されて、触媒焼結層から前述の触媒が除かれた成分から構成されている。補償用焼結層では、検知対象ガスは燃焼しない。この接触燃焼式ガスセンサでは、触媒焼結層における検知対象ガスの燃焼による温度変化に基づく発熱抵抗体の抵抗値変化と、補償用焼結層の温度変化に基づく補償用発熱抵抗体の抵抗値変化とにより検知対象ガスの濃度を検知する。 Japanese Patent Application Laid-Open No. 2005-156364 (Patent Document 1) discloses a catalytic combustion type gas sensor (combustible gas detection device) manufactured using a gas sensor substrate. The gas sensor base has a configuration in which a heating resistor (heater) is built in an insulating substrate. The insulating substrate has a lower layer made of a heat resistant insulator and an upper layer made of a heat resistant insulator formed on the lower layer. The heating resistor is made of a metal thin film, is formed on the lower layer, and is covered with the upper layer. In a contact combustion type gas sensor manufactured using a gas sensor substrate, a catalyst including a catalyst that promotes combustion of a detection target gas by heat generated from the heating resistor on a region where the heating resistor of the insulating substrate is formed. A sintered layer is formed. The insulating substrate is further formed with a compensation heating resistor and a compensation sintered layer. The compensation heating resistor has the same structure as the heating resistor. The compensation sintered layer is formed on a portion of the diaphragm where the compensation heating resistor is formed, and is composed of components obtained by removing the catalyst from the catalyst sintered layer. In the compensation sintered layer, the detection target gas does not burn. In this contact combustion type gas sensor, the resistance value change of the heating resistor based on the temperature change due to the combustion of the detection target gas in the catalyst sintered layer and the resistance value change of the compensation heating resistor based on the temperature change of the compensation sintered layer Thus, the concentration of the detection target gas is detected.
　また、この種のガスセンサ用基体を用いて半導体式ガスセンサを製造するには、絶縁基板の発熱抵抗体が形成された部分の上に、所定の間隔を隔てて配置された一対の電極を形成し、該一対の電極を覆うように金属酸化物半導体を含む感応膜を形成する。この半導体式ガスセンサでは、感応膜による検知対象ガスの吸着によって生じる一対の電極の間の抵抗値変化で検知対象ガスの濃度を検知する。 In order to manufacture a semiconductor gas sensor using this type of gas sensor substrate, a pair of electrodes arranged at predetermined intervals are formed on a portion of the insulating substrate on which the heating resistor is formed. A sensitive film containing a metal oxide semiconductor is formed so as to cover the pair of electrodes. In this semiconductor type gas sensor, the concentration of the detection target gas is detected by a change in resistance value between the pair of electrodes generated by the adsorption of the detection target gas by the sensitive film.
特開２００５－１５６３６４号公報JP 2005-156364 A
　ガスセンサ用基体の絶縁基板の厚みは、絶縁基板の耐割れ性が維持され、発熱抵抗体の熱が分散することなく、触媒焼結層、補償用焼結層または感応膜に十分伝達できる寸法に設定する必要がある。従来より、絶縁基板の耐割れ性を維持した上で、発熱抵抗体の触媒焼結層、補償用焼結層または感応膜への熱伝導性を十分に高めることが課題となっている。 The thickness of the insulating substrate of the gas sensor substrate is such that the crack resistance of the insulating substrate is maintained, and the heat of the heating resistor is not dispersed and can be sufficiently transferred to the catalyst sintering layer, the compensation sintering layer or the sensitive film. Must be set. Conventionally, while maintaining the crack resistance of the insulating substrate, it has been a problem to sufficiently increase the thermal conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film.
　本発明の目的は、絶縁基板の耐割れ性を維持した上で、発熱抵抗体の触媒焼結層、補償用焼結層または感応膜への熱伝導性を十分に高めることができるガスセンサ用基体及びその製造方法並びに該ガスセンサ用基体を用いた接触燃焼式ガスセンサを提供することにある。 An object of the present invention is to provide a gas sensor substrate capable of sufficiently increasing the thermal conductivity of a heating resistor to a catalyst sintered layer, a compensation sintered layer or a sensitive film while maintaining the crack resistance of an insulating substrate. It is another object of the present invention to provide a catalytic combustion type gas sensor using the gas sensor substrate.
　本発明が改良の対象とするガスセンサ用基体は、耐熱性絶縁物からなる下部層と、該下部層上に形成された耐熱性絶縁物からなる上部層とを有する絶縁基板と、下部層上に形成されて上部層によって覆われた金属薄膜からなる発熱抵抗体とを有している。ここでいう耐熱性絶縁物とは、発熱抵抗体等の熱に耐えられる絶縁物であり、例えば、ケイ素化合物や金属化合物である。本発明では、上部層の発熱抵抗体が形成された部分に下部層が位置する側とは反対の側に向かって開口する有底の凹部が形成されている。そして、この凹部の存在により、絶縁基板の上部層の発熱抵抗体が形成された領域の厚み寸法が該領域の周囲の上部層の厚み寸法より小さくなっている。本発明のガスセンサ用基体は、接触燃焼式ガスセンサ、半導体式ガスセンサ等の絶縁基板内に発熱抵抗体を形成して構成する種々のガスセンサに用いることができる。本発明のように凹部を形成すると、絶縁基板の上部層の発熱抵抗体が形成された部分（凹部が形成された部分）では、厚み寸法が小さいため、発熱抵抗体の熱が分散するのを防ぐことができ、発熱抵抗体の触媒焼結層、補償用焼結層または感応膜への熱伝導性を十分に高めることができる。また、絶縁基板としては、前述の領域の周囲の上部層の厚み寸法が大きいので耐割れ性を維持できる。また、凹部内に触媒焼結層、補償用焼結層または感応膜が配置されることによっても、絶縁基板の発熱抵抗体が形成された部分の耐割れ性を維持することができる。 A gas sensor substrate to be improved by the present invention includes an insulating substrate having a lower layer made of a heat-resistant insulator, an upper layer made of a heat-resistant insulator formed on the lower layer, and a lower layer. And a heating resistor made of a metal thin film formed and covered with an upper layer. Here, the heat-resistant insulator is an insulator that can withstand heat, such as a heating resistor, and is, for example, a silicon compound or a metal compound. In the present invention, a bottomed concave portion that opens toward the side opposite to the side where the lower layer is located is formed in the portion of the upper layer where the heating resistor is formed. Due to the presence of the recess, the thickness dimension of the upper layer of the insulating substrate in which the heating resistor is formed is smaller than the thickness dimension of the upper layer around the area. The base for a gas sensor of the present invention can be used for various gas sensors formed by forming a heating resistor in an insulating substrate such as a catalytic combustion type gas sensor or a semiconductor type gas sensor. When the concave portion is formed as in the present invention, the portion of the insulating substrate where the heating resistor is formed (the portion where the concave portion is formed) has a small thickness, so that the heat of the heating resistor is dispersed. The heat conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film can be sufficiently increased. Moreover, as an insulating substrate, since the thickness dimension of the upper layer around the above-mentioned area is large, crack resistance can be maintained. Further, the crack resistance of the portion of the insulating substrate where the heating resistor is formed can also be maintained by disposing the catalyst sintered layer, the compensating sintered layer, or the sensitive film in the recess.
　凹部は、上部層をエッチングして形成することができる。このようにすれば、凹部を容易に形成することができる。 The recess can be formed by etching the upper layer. In this way, the recess can be easily formed.
　絶縁基板の上部層の発熱抵抗体が形成された領域の厚み寸法は、領域の周囲の上部層の厚み寸法の１／２以下にすることができる。このようにすれば、絶縁基板の耐割れ性を維持した上で、発熱抵抗体の触媒焼結層または感応膜への熱伝導性を十分に高めることができる。 The thickness dimension of the region where the heating resistor of the upper layer of the insulating substrate is formed can be set to ½ or less of the thickness dimension of the upper layer around the region. If it does in this way, while maintaining the crack resistance of an insulated substrate, the thermal conductivity to the catalyst sintering layer or sensitive film | membrane of a heating resistor can fully be improved.
　なお、絶縁基板の上部層の発熱抵抗体が形成された領域の周囲に、絶縁基板を貫通する１以上の貫通孔を形成してもよい。この場合は、１以上の貫通孔は、発熱抵抗体が形成された領域に隣接するように該領域の周囲に間隔をあけて形成するのが好ましい。このような１以上の貫通孔を形成すると、貫通孔の存在により発熱抵抗体の熱がさらに分散し難くなる。その結果、発熱抵抗体の触媒焼結層、補償用焼結層または感応膜への熱伝導性をさらに高めることができる。 It should be noted that one or more through holes penetrating the insulating substrate may be formed around the region where the heating resistor of the upper layer of the insulating substrate is formed. In this case, it is preferable that the one or more through holes are formed around the region so as to be adjacent to the region where the heating resistor is formed. When one or more such through holes are formed, the heat of the heating resistor is more difficult to disperse due to the presence of the through holes. As a result, the thermal conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film can be further enhanced.
　また、このような貫通孔は、絶縁基板を構成する上部層及び下部層をエッチングして形成することができるので、容易に形成することができる。 Further, such a through hole can be easily formed because it can be formed by etching the upper layer and the lower layer constituting the insulating substrate.
　本発明のガスセンサ用基体は、次のようにして製造することができる。まず、シリコン単結晶からなるシリコン基板を用意する。そして、シリコン基板の一方の面上に下部層を形成し、該下部層上に、金属薄膜からなる発熱抵抗体を形成する。次に、発熱抵抗体を覆うように、下部層上に上部層を形成する。次に、上部層の発熱抵抗体が形成された領域の上にエッチングを施して有底の凹部を形成する。凹部を形成する前または後に、シリコン基板の他方側からエッチングを施して発熱抵抗体に対応するシリコン基板の前述の領域の厚みを薄くして絶縁基板を形成してガスセンサ用基体を製造する。貫通孔を形成する場合は、さらに、凹部を形成する前または後に、シリコン基板の一方側からエッチングを施して絶縁基板を貫通する貫通孔を形成する。このようにガスセンサ用基体を製造すれば、エッチングにより凹部および／または貫通孔を容易に形成することができる。 The gas sensor substrate of the present invention can be manufactured as follows. First, a silicon substrate made of a silicon single crystal is prepared. Then, a lower layer is formed on one surface of the silicon substrate, and a heating resistor made of a metal thin film is formed on the lower layer. Next, an upper layer is formed on the lower layer so as to cover the heating resistor. Next, etching is performed on the region of the upper layer where the heating resistor is formed to form a bottomed recess. Before or after forming the recess, etching is performed from the other side of the silicon substrate to reduce the thickness of the aforementioned region of the silicon substrate corresponding to the heating resistor to form an insulating substrate to manufacture a gas sensor substrate. In the case of forming the through hole, before or after forming the recess, etching is performed from one side of the silicon substrate to form a through hole penetrating the insulating substrate. When the gas sensor substrate is manufactured in this manner, the recesses and / or the through holes can be easily formed by etching.
　本発明のガスセンサ用基体を用いて製造される接触燃焼式ガスセンサは、耐熱性絶縁物からなる下部層と、該下部層上に形成された耐熱性絶縁物からなる上部層とを有する絶縁基板と、下部層上に形成されて上部層によって覆われた金属薄膜からなるガス検知用発熱抵抗体と、上部層のガス検知用発熱抵抗体が形成された領域の上に形成されて、ガス検知用発熱抵抗体から生じる熱によって検知対象ガスが燃焼するのを促進する触媒を含む触媒焼結層とを有している。上部層のガス検知用発熱抵抗体が形成された領域の上に下部層に向かう方向とは反対の方向に向かって開口する有底の凹部が形成され、該凹部の存在により、絶縁基板の上部層のガス検知用発熱抵抗体が形成された領域の厚み寸法が該領域の周囲の上部層の厚み寸法より小さくなっている。また、耐熱性絶縁物からなる下部層と、この下部層上に形成された耐熱性絶縁物からなる上部層とを有する絶縁基板と、下部層上に形成されて上部層によって覆われた金属薄膜からなる補償用発熱抵抗体と、上部層の補償用発熱抵抗体が形成された領域の上に形成されて、触媒焼結層から前述の触媒が除かれた成分からなる補償用焼結層とを更に有している。そして、上部層の補償用発熱抵抗体が形成された領域の上に下部層に向かう方向とは反対の方向に向かって開口する有底の凹部が形成され、該凹部の存在により、絶縁基板の上部層の補償用発熱抵抗体が形成された領域の厚み寸法が該領域の周囲の上部層の厚み寸法より小さくなっている。ガス検知用発熱抵抗体が形成される絶縁基板と、補償用発熱抵抗体が形成される絶縁基板とは、１つの絶縁基板が共有されてもよく、別々の絶縁基板を用いるものでもよい。本発明の接触燃焼式ガスセンサによれば、絶縁基板の耐割れ性を維持した上で、発熱抵抗体の触媒焼結層、補償用焼結層または感応膜への熱伝導性を十分に高めることができる。 A catalytic combustion gas sensor manufactured using the gas sensor substrate of the present invention includes an insulating substrate having a lower layer made of a heat-resistant insulator and an upper layer made of the heat-resistant insulator formed on the lower layer. A gas detection heating resistor made of a metal thin film formed on the lower layer and covered by the upper layer, and a gas detection heating resistor formed on the region where the gas detection heating resistor of the upper layer is formed. And a catalyst sintered layer including a catalyst that promotes combustion of the detection target gas by heat generated from the heating resistor. A bottomed recess that opens in a direction opposite to the direction toward the lower layer is formed on a region where the heating resistor for gas detection of the upper layer is formed. The thickness dimension of the region in which the heating resistor for gas detection of the layer is formed is smaller than the thickness dimension of the upper layer around the region. An insulating substrate having a lower layer made of a heat-resistant insulator and an upper layer made of a heat-resistant insulator formed on the lower layer, and a metal thin film formed on the lower layer and covered by the upper layer A compensation heating layer comprising a component obtained by removing the aforementioned catalyst from the catalyst sintering layer, formed on a region where the compensation heating resistor of the upper layer is formed, and It has further. Then, a bottomed recess that opens in a direction opposite to the direction toward the lower layer is formed on the upper layer where the compensation heating resistor is formed. The thickness dimension of the region where the compensation heating resistor for the upper layer is formed is smaller than the thickness dimension of the upper layer around the region. One insulating substrate may be shared between the insulating substrate on which the gas detection heating resistor is formed and the insulating substrate on which the compensation heating resistor is formed, or separate insulating substrates may be used. According to the catalytic combustion type gas sensor of the present invention, while maintaining the crack resistance of the insulating substrate, the thermal conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film is sufficiently increased. Can do.
　このような接触燃焼式ガスセンサでも、絶縁基板の上部層の発熱抵抗体が形成された領域の周囲に、領域に隣接して絶縁基板を貫通する複数の貫通孔を形成することができる。このような貫通孔を設けることにより、発熱抵抗体が形成された領域の周囲に空間が形成されるため、発熱抵抗体の熱がより分散し難くなって、発熱抵抗体の触媒焼結層、補償用焼結層または感応膜への熱伝導性がさらに向上した接触燃焼式ガスセンサを提供することができる。 Even in such a contact combustion type gas sensor, a plurality of through holes penetrating the insulating substrate can be formed adjacent to the region around the region where the heating resistor of the upper layer of the insulating substrate is formed. By providing such a through hole, a space is formed around the region where the heating resistor is formed, so that the heat of the heating resistor becomes more difficult to disperse, and the catalyst sintered layer of the heating resistor, It is possible to provide a contact combustion type gas sensor in which the thermal conductivity to the compensation sintered layer or the sensitive film is further improved.
本発明の一実施の形態のガスセンサ用基体を用いた接触燃焼式ガスセンサの平面図である。It is a top view of the contact combustion type gas sensor using the base for gas sensors of one embodiment of the present invention. 本発明の一実施の形態のガスセンサ用基体を用いた接触燃焼式ガスセンサの裏面図である。It is a reverse view of the contact combustion type gas sensor using the base for gas sensors of one embodiment of the present invention. 図１のIII－III線断面図である。FIG. 3 is a sectional view taken along line III-III in FIG. 1. 本発明の他の実施の形態のガスセンサ用基体を用いた接触燃焼式ガスセンサの平面図である。It is a top view of the contact combustion type gas sensor using the base for gas sensors of other embodiments of the present invention. 本発明の他の実施の形態のガスセンサ用基体を用いた接触燃焼式ガスセンサの裏面図である。It is a reverse view of the contact combustion type gas sensor using the base for gas sensors of other embodiments of the present invention. 図４のVI－VI線断面図である。FIG. 6 is a sectional view taken along line VI-VI in FIG. 4. （Ａ）～（Ｇ）は、図１及び図４に示す接触燃焼式ガスセンサの製造方法を説明するために用いる図である。(A) to (G) are diagrams used for explaining a method of manufacturing the catalytic combustion type gas sensor shown in FIGS. 1 and 4. FIG.
　以下、本発明のガスセンサ用基体の一例について図面を参照しながら説明する。図１及び図２は、本発明の一実施の形態のガスセンサ用基体を用いた接触燃焼式ガスセンサの平面図及び裏面図であり、図３は、図１のIII－III線断面図である。図３に示すように、本例の接触燃焼式ガスセンサは、ガスセンサ用基体１と触媒焼結層３と補償用焼結層５とを有している。ガスセンサ用基体１は、支持部７と、絶縁基板９と、ガス検知用発熱抵抗体（ガス検知用ヒータ）１１と、補償用発熱抵抗体（補償用ヒータ）１３とを有している。支持部７は、シリコン単結晶からなり、上方には絶縁基板９が配置されている。図２に示すように、支持部７は、角筒形状の筒状部７ａと、筒状部７ａ内を２つに区分する中央壁部７ｂとを有している。これにより、支持部７内には２つの開口孔７ｃ，７ｄが形成されている。絶縁基板９の開口孔７ｃ，７ｄが形成された２箇所の部分の上方がダイヤフラム１５Ａ，１５Ｂを構成することになる。図３に示すように、ダイヤフラム１５Ａ，１５Ｂを含む絶縁基板９は、耐熱性絶縁物からなる下部層１７と、該下部層１７上に形成された耐熱性絶縁物からなる上部層１９とを有している。下部層１７は、厚み６０００Åの薄膜ＳｉＯ２層１７ａと厚み４００Åの薄膜Ｓｉ３Ｎ４層１７ｂとが積層されて構成されている。 Hereinafter, an example of the gas sensor substrate of the present invention will be described with reference to the drawings. 1 and 2 are a plan view and a back view of a catalytic combustion type gas sensor using a gas sensor substrate according to an embodiment of the present invention, and FIG. 3 is a sectional view taken along line III-III in FIG. As shown in FIG. 3, the catalytic combustion type gas sensor of this example includes a gas sensor substrate 1, a catalyst sintered layer 3, and a compensation sintered layer 5. The gas sensor substrate 1 includes a support portion 7, an insulating substrate 9, a gas detection heating resistor (gas detection heater) 11, and a compensation heating resistor (compensation heater) 13. The support portion 7 is made of a silicon single crystal, and an insulating substrate 9 is disposed above the support portion 7. As shown in FIG. 2, the support part 7 has a cylindrical part 7a having a rectangular tube shape and a central wall part 7b that divides the inside of the cylindrical part 7a into two parts. Thus, two opening holes 7 c and 7 d are formed in the support portion 7. The upper portions of the two portions of the insulating substrate 9 in which the opening holes 7c and 7d are formed constitute the diaphragms 15A and 15B. As shown in FIG. 3, the insulating substrate 9 including the diaphragms 15A and 15B includes a lower layer 17 made of a heat resistant insulator and an upper layer 19 made of a heat resistant insulator formed on the lower layer 17. is doing. The lower layer 17 is formed by laminating a thin film SiO 2 layer 17a having a thickness of 6000 mm and a thin film Si 3 N 4 layer 17b having a thickness of 400 mm.
　上部層１９は、厚み３μｍを有しておりＳｉＯ０．７Ｎ０．７から形成されている。上部層１９は、プラズマ化学蒸着（Ｐ－ＣＶＤ）の薄膜形成技術を用いて厚みが３μmになるまで形成した。上部層１９のガス検知用発熱抵抗体１１及び補償用発熱抵抗体１３が形成された部分には、下部層１７が位置する方向とは反対側の方向に向かって開口する有底の凹部１９ａ，１９ｂがそれぞれ形成されている。凹部１９ａ，１９ｂの開口部は、いずれも円形の形状を有している。このような凹部１９ａ，１９ｂの存在により、絶縁基板９の上部層１９のガス検知用発熱抵抗体１１及び補償用発熱抵抗体１３が形成された領域（上部層１９の凹部１９ａ，１９ｂが形成された部分）の厚み寸法は、該領域の周囲の上部層１９（凹部１９ａ，１９ｂの周囲部１９ｃ）の厚み寸法よりも小さくなっている。本例では、凹部１９ａ，１９ｂの直径Ｌ１は、４００μmであり、絶縁基板９の上部層１９のガス検知用発熱抵抗体１１及び補償用発熱抵抗体１３が形成された部分（上部層１９の凹部１９ａ，１９ｂが形成された部分）の厚み寸法Ｌ２は、１．５μmであり、凹部１９ａ，１９ｂの周囲部１９ｃ（上部層１９の凹部１９ａ，１９ｂが形成されていない部分）の厚み寸法Ｌ３（３μm）の１／２となっている。 The upper layer 19 has a thickness of 3 μm and is made of SiO 0.7 N 0.7 . The upper layer 19 was formed using a plasma chemical vapor deposition (P-CVD) thin film formation technique until the thickness reached 3 μm. In the upper layer 19 where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed, a bottomed recess 19a that opens in a direction opposite to the direction in which the lower layer 17 is located, 19b is formed. The openings of the recesses 19a and 19b both have a circular shape. Due to the presence of the recesses 19a and 19b, regions where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed in the upper layer 19 of the insulating substrate 9 (the recesses 19a and 19b of the upper layer 19 are formed). The thickness dimension of the portion) is smaller than the thickness dimension of the upper layer 19 (the peripheral portion 19c of the recesses 19a and 19b) around the region. In this example, the diameter L1 of the recesses 19a and 19b is 400 μm, and the portion of the upper layer 19 of the insulating substrate 9 where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed (the recess of the upper layer 19 The thickness dimension L2 of the portion 19a, 19b) is 1.5 μm, and the thickness dimension L3 of the peripheral portion 19c of the recess 19a, 19b (the portion where the recess 19a, 19b of the upper layer 19 is not formed). 3 of 3 μm).
　また、本例では、支持部７の下方にも、厚み６０００Åの薄膜ＳｉＯ２層２１ａと、厚み４００Åの薄膜Ｓｉ３Ｎ４層２１ｂとが積層されて形成されている。 In this example, a thin film SiO 2 layer 21a having a thickness of 6000 mm and a thin film Si 3 N 4 layer 21b having a thickness of 400 mm are also laminated below the support portion 7.
　ガス検知用発熱抵抗体１１は、ダイヤフラム１５Ａの中央部に形成されており、上部層１９によって覆われた状態で下部層１７上に形成されている。ガス検知用発熱抵抗体１１は、厚み４０００ÅのＰｔと厚み１００ÅのＴａと厚み４０ÅのＴｉとがこの順番で下部層１７上に積層された薄膜層からなり、図１及び図２に示すように蛇行するパターン形状を有している。ガス検知用発熱抵抗体１１の両端は、導電部２３を介して一対の電極２５に接続されている。ガス検知用発熱抵抗体１１、導電部２３及び一対の電極２５は、一体成形されている。一対の電極２５の上方には、Ａｕ膜２７がそれぞれ形成されている。上部層１９の一対の電極２５が形成された部分には、矩形の開口部１９ｄがそれぞれ形成されている。このため、絶縁基板９の上方から開口部１９ｄを介して一対の電極２５に接続体等の接続が可能になっている。 The gas detection heating resistor 11 is formed at the center of the diaphragm 15A, and is formed on the lower layer 17 while being covered by the upper layer 19. The heating resistor 11 for gas detection is composed of a thin film layer in which Pt having a thickness of 4000 mm, Ta having a thickness of 100 mm and Ti having a thickness of 40 mm are laminated on the lower layer 17 in this order, as shown in FIGS. 1 and 2. It has a meandering pattern shape. Both ends of the gas detection heating resistor 11 are connected to a pair of electrodes 25 via a conductive portion 23. The gas detection heating resistor 11, the conductive portion 23, and the pair of electrodes 25 are integrally formed. An Au film 27 is formed above each of the pair of electrodes 25. A rectangular opening 19d is formed in the portion of the upper layer 19 where the pair of electrodes 25 are formed. Therefore, a connection body or the like can be connected to the pair of electrodes 25 from above the insulating substrate 9 through the opening 19d.
　補償用発熱抵抗体１３は、ダイヤフラム１５Ｂの中央部に形成されており、図３に示すように、上部層１９によって覆われた状態で下部層１７上に形成されている。補償用発熱抵抗体１３は、ガス検知用発熱抵抗体１１と同じ構造を有している。図１に示すように、補償用発熱抵抗体１３の両端は、導電部２９を介して一対の電極３１に接続されている。補償用発熱抵抗体１３、導電部２９及び一対の電極３１は、一体成形されている。一対の電極３１の上方には、Ａｕ膜３３がそれぞれ形成されている。上部層１９の一対の電極３１が形成された部分には、矩形の開口部１９ｅがそれぞれ形成されている。このため、絶縁基板９の上方から開口部１９ｅを介して一対の電極３１に接続体等の接続が可能になっている。 The compensation heating resistor 13 is formed at the center of the diaphragm 15B, and is formed on the lower layer 17 in a state of being covered by the upper layer 19 as shown in FIG. The compensation heating resistor 13 has the same structure as the gas detection heating resistor 11. As shown in FIG. 1, both ends of the compensation heating resistor 13 are connected to a pair of electrodes 31 via a conductive portion 29. The compensation heating resistor 13, the conductive portion 29, and the pair of electrodes 31 are integrally formed. Au films 33 are respectively formed above the pair of electrodes 31. A rectangular opening 19e is formed in the portion of the upper layer 19 where the pair of electrodes 31 is formed. Therefore, a connection body or the like can be connected to the pair of electrodes 31 from above the insulating substrate 9 through the opening 19e.
　触媒焼結層３は、Ｐｔ，Ｐｄ，Ａｕ等の触媒と、アルミナ、シリカ、酸化スズなどのセラミック粉体と、エチルセルロース、テレピネオール、ポリエチレングリコールなどのバインダーとを含むペーストを硬化させたものであり、絶縁基板９の凹部１９ａ内に充填されて形成されている。Ｐｔ，Ｐｄ，Ａｕ等の触媒は、ガス検知用発熱抵抗体１１から生じる熱によってメタンガス、プロパンガス、一酸化炭素、アルコールなどの可燃性ガスからなる検知対象ガスが燃焼するのを促進する触媒としての役割を果たしている。 The catalyst sintered layer 3 is obtained by curing a paste containing a catalyst such as Pt, Pd, or Au, ceramic powder such as alumina, silica, or tin oxide, and a binder such as ethyl cellulose, terpineol, or polyethylene glycol. , The recess 19a of the insulating substrate 9 is filled and formed. A catalyst such as Pt, Pd, or Au is used as a catalyst for accelerating combustion of a detection target gas composed of a flammable gas such as methane gas, propane gas, carbon monoxide, or alcohol by heat generated from the gas detection heating resistor 11. Plays the role of
　補償用焼結層５は、アルミナ、シリカ、酸化スズなどのセラミック粉体と、エチルセルロース、テレピネオール、ポリエチレングリコール等のバインダーとを含むペーストを硬化させたものであり、絶縁基板９の凹部１９ｂ内に充填されて形成されている。即ち、補償用焼結層５は、触媒焼結層３から触媒（Ｐｔ等）を除いた成分から構成されている。 The compensation sintered layer 5 is obtained by curing a paste containing ceramic powder such as alumina, silica, and tin oxide, and a binder such as ethyl cellulose, terpineol, and polyethylene glycol. Filled and formed. That is, the compensation sintered layer 5 is composed of components obtained by removing the catalyst (Pt or the like) from the catalyst sintered layer 3.
　本例の接触燃焼式ガスセンサでは、ガス検知用発熱抵抗体１１により触媒焼結層３を加熱し、補償用発熱抵抗体１３により補償用焼結層５を加熱する。検知対象ガス（メタンガス、プロパンガス、一酸化炭素、アルコールなどの可燃性ガス）が触媒焼結層３の近傍に存在する場合は、触媒焼結層３の触媒（Ｐｔ等）により、触媒焼結層３に燃焼が生じる。補償用焼結層５の近傍に検知対象ガス（メタンガス、プロパンガス、一酸化炭素、アルコールなどの可燃性ガス）が存在しても、補償用焼結層５に触媒（Ｐｔ等）が含まれていないため燃焼はおきない。これにより、触媒焼結層３における検知対象ガス（メタンガス、プロパンガス、一酸化炭素、アルコールなどの可燃性ガス）の燃焼による温度変化に基づくガス検知用発熱抵抗体１１の抵抗値変化と、補償用焼結層５の温度変化に基づく補償用発熱抵抗体１３の抵抗値変化とにより、検知対象ガス（メタンガス、プロパンガス、一酸化炭素、アルコールなどの可燃性ガス）の濃度を検知する。具体的な濃度の検知は、特開２００５－１５６３６４号公報等に示される公知の方法で行うことができる。 In the contact combustion type gas sensor of this example, the catalyst sintering layer 3 is heated by the gas detection heating resistor 11 and the compensation sintering layer 5 is heated by the compensation heating resistor 13. When the detection target gas (combustible gas such as methane gas, propane gas, carbon monoxide, alcohol, etc.) is present in the vicinity of the catalyst sintering layer 3, the catalyst is sintered by the catalyst (Pt, etc.) of the catalyst sintering layer 3. Combustion occurs in layer 3. Even if a gas to be detected (combustible gas such as methane gas, propane gas, carbon monoxide, alcohol) exists in the vicinity of the compensation sintered layer 5, a catalyst (Pt or the like) is contained in the compensation sintered layer 5. There is no combustion. Thereby, the resistance value change of the heating resistor 11 for gas detection based on the temperature change due to the combustion of the detection target gas (combustible gas such as methane gas, propane gas, carbon monoxide, alcohol) in the catalyst sintered layer 3 is compensated. The concentration of the detection target gas (combustible gas such as methane gas, propane gas, carbon monoxide, alcohol) is detected based on the change in resistance value of the compensation heating resistor 13 based on the temperature change of the sintered layer 5 for use. Specific density detection can be performed by a known method disclosed in Japanese Patent Application Laid-Open No. 2005-156364.
　次に、本発明のガスセンサ用基体の他の例について説明する。図４及び図５は、本発明の他の実施の形態のガスセンサ用基体を用いた接触燃焼式ガスセンサの平面図及び裏面図であり、図６は、図４のVI－VI線断面図である。なお、本発明の他の例において、上述した本発明の一例と共通する部分については、図１～図３に付した符号の数に１００の数を加えた数の符号を付して説明を省略する。この他の例では、絶縁基板１０９の上部層１１９のガス検知用発熱抵抗体１１１が形成された領域の周囲（周囲部１１９ｃ）には、絶縁基板１０９を貫通する４つ貫通孔１１９ｆが該領域の周方向に間隔をあけて形成され、絶縁基板１０９の上部層１１９の補償用発熱抵抗体１１３が形成された領域の周囲（周囲部１１９ｃ）には、絶縁基板１０９を貫通する４つ貫通孔１１９ｇが該領域の周方向に間隔をあけて形成されている。 Next, another example of the gas sensor substrate of the present invention will be described. 4 and 5 are a plan view and a back view of a catalytic combustion type gas sensor using a gas sensor substrate according to another embodiment of the present invention, and FIG. 6 is a sectional view taken along line VI-VI in FIG. . In addition, in other examples of the present invention, portions common to the above-described example of the present invention are described by adding the reference numerals of 100 to the number of reference numerals attached to FIGS. Omitted. In another example, four through holes 119f penetrating the insulating substrate 109 are provided around the region (peripheral portion 119c) of the upper layer 119 of the insulating substrate 109 where the gas detection heating resistor 111 is formed. The four through-holes penetrating the insulating substrate 109 are formed around the region where the heat generating resistor 113 for compensation of the upper layer 119 of the insulating substrate 109 is formed (peripheral portion 119c). 119g is formed at intervals in the circumferential direction of the region.
　４つ貫通孔１１９ｆは、ガス検知用発熱抵抗体１１１が形成された領域に隣接するように形成されており、４つ貫通孔１１９ｇは、補償用発熱抵抗体１１３が形成された領域に隣接するように形成されている。この他の例では、図４及び図５に示すように、ガス検知用発熱抵抗体１１１が形成された領域が、４つ貫通孔１１９ｆを形成したことにより形成された絶縁基板１０９の開口部１０９ａの内側に配置された状態で、ガス検知用発熱抵抗体１１１が形成された領域とこの領域の周囲（周囲部１１９ｃ）の４つ貫通孔１１９ｆが形成されない部分とを４つの結合部１１９ｈが結合するように、４つの貫通孔１１９ｆの形状が定められている（本例では、４つの貫通孔１１９ｆの形状は、いずれもガス検知用発熱抵抗体１１１の周縁部を囲むように、Ｌの字状になっている）。また、補償用発熱抵抗体１１３が形成された領域が、４つ貫通孔１１９ｇを形成したことにより形成された絶縁基板１０９の開口部１０９ｂの内側に配置された状態で、補償用発熱抵抗体１１３が形成された領域とこの領域の周囲（周囲部１１９ｃ）の４つ貫通孔１１９ｇが形成されない部分とを４つの結合部１１９ｉが結合するように、４つの貫通孔１１９ｇの形状が定められている（本例では、４つの貫通孔１１９ｇの形状は、いずれもガス検知用発熱抵抗体１１１の周縁部を囲むように、Ｌの字状になっている）。４つの結合部１１９ｈおよび４つの結合部１１９ｉはそれぞれガスセンサのダイヤフラム１１５Ａ，１１５Ｂを構成する。なお、４つの貫通孔１１９ｆおよび４つの貫通孔１１９ｇの形状は、ガス検知用発熱抵抗体１１１および補償用発熱抵抗体１１３の形状や配線パターンにより適宜に定めることができる。このような貫通孔１１９ｆ，１１９ｇを形成すると、貫通孔１１９ｆ，１１９ｇの存在により発熱抵抗体が形成された領域の周囲（周囲部１１９ｃ）に空間が形成されるため、ガス検知用発熱抵抗体１１１および補償用発熱抵抗体１１３の熱がさらに分散し難くなる。そのため、ガス検知用発熱抵抗体１１１の触媒焼結層１０３への熱伝導性及び補償用発熱抵抗体１１３の補償用焼結層１０５への熱伝導性をさらに高めることができる。 The four through holes 119f are formed adjacent to the region where the gas detection heating resistor 111 is formed, and the four through holes 119g are adjacent to the region where the compensation heating resistor 113 is formed. It is formed as follows. In another example, as shown in FIGS. 4 and 5, the region where the gas detection heating resistor 111 is formed has an opening 109a of an insulating substrate 109 formed by forming four through holes 119f. The four coupling portions 119h couple the region where the gas detection heating resistor 111 is formed and the portion where the four through-holes 119f around this region (the peripheral portion 119c) are not formed in a state of being arranged inside Thus, the shape of the four through-holes 119f is determined (in this example, the shape of the four through-holes 119f is L-shaped so as to surround the peripheral portion of the gas detection heating resistor 111). Is in the shape). In addition, the compensation heating resistor 113 is formed in a state where the region where the compensation heating resistor 113 is formed is arranged inside the opening 109b of the insulating substrate 109 formed by forming the four through holes 119g. The shape of the four through-holes 119g is determined so that the four coupling portions 119i are coupled to the region in which the four through-holes 119g are not formed in the periphery (peripheral portion 119c) of this region. (In this example, each of the four through holes 119g has an L shape so as to surround the peripheral edge of the gas detection heating resistor 111). The four coupling portions 119h and the four coupling portions 119i constitute diaphragms 115A and 115B of the gas sensor, respectively. The shapes of the four through holes 119f and the four through holes 119g can be determined as appropriate depending on the shapes and wiring patterns of the gas detection heating resistor 111 and the compensation heating resistor 113. When such through holes 119f and 119g are formed, a space is formed around the region where the heating resistor is formed (peripheral portion 119c) due to the presence of the through holes 119f and 119g. In addition, the heat of the compensation heating resistor 113 becomes more difficult to disperse. Therefore, the thermal conductivity of the gas detection heating resistor 111 to the catalyst sintering layer 103 and the thermal conductivity of the compensation heating resistor 113 to the compensation sintering layer 105 can be further enhanced.
　以下、本例の接触燃焼式ガスセンサの製造方法について説明する。まず、図７（Ａ）に示す基体用材料４１を形成する。基体用材料４１は、まず、シリコン単結晶からなるシリコン基板４３の両面に熱酸化により、厚み６０００Åの薄膜ＳｉＯ２層１７ａ，４５ａを形成する。次に、薄膜ＳｉＯ２層１７ａ，４５ａ上に低圧化学蒸着（ＬＰ－ＣＶＤ）の薄膜形成技術により厚み４００Åの薄膜Ｓｉ３Ｎ４層１７ｂ，４５ｂをそれぞれ形成する。そして、薄膜Ｓｉ３Ｎ４層１７ｂ（シリコン基板４３の一方の面）上にのみ厚み４０００ÅのＰｔと厚み１００ÅのＴａと厚み４０ÅのＴｉとをこの順番でスパッタを施して発熱抵抗体形成層４７を形成して完成する。 Hereinafter, the manufacturing method of the contact combustion type gas sensor of this example will be described. First, a base material 41 shown in FIG. 7A is formed. First, the base material 41 is formed by thin film SiO 2 layers 17a and 45a having a thickness of 6000 mm on both surfaces of a silicon substrate 43 made of silicon single crystal by thermal oxidation. Next, thin film Si 3 N 4 layers 17b and 45b each having a thickness of 400 mm are formed on the thin film SiO 2 layers 17a and 45a by a low-pressure chemical vapor deposition (LP-CVD) thin film forming technique. Then, only the thin film Si 3 N 4 layer 17b (one surface of the silicon substrate 43) is sputtered with a thickness of 4000 mm of Pt, a thickness of 100 mm of Ta, and a thickness of 40 mm of Ti in this order. To complete.
　次に、図７（Ｂ）に示すように、発熱抵抗体形成層４７にＡｒプラズマによりエッチングを施してガス検知用発熱抵抗体１１と補償用発熱抵抗体１３とを形成する。なお、図１に示す導電部２３及び一対の電極２５は、ガス検知用発熱抵抗体１１と一体に形成し、導電部２９及び一対の電極３１は、補償用発熱抵抗体１３と一体に形成する。 Next, as shown in FIG. 7B, the heat generating resistor forming layer 47 is etched with Ar plasma to form the gas detecting heat generating resistor 11 and the compensating heat generating resistor 13. The conductive portion 23 and the pair of electrodes 25 shown in FIG. 1 are formed integrally with the gas detection heating resistor 11, and the conductive portion 29 and the pair of electrodes 31 are formed integrally with the compensation heating resistor 13. .
　次に、図７（Ｃ）に示すように、Ｐ－ＣＶＤの薄膜形成技術を１２０分かけて厚み３μｍのＳｉＯ０．７Ｎ０．７からなる上部層１９を形成する。次に、上部層１９にＣＦ４ガスを用いた反応性イオンエッチング（ＲＩＥ）によりエッチングを施して、図１に示す開口部１９ｄ，１９ｅを形成して、一対の電極２５及び一対の電極３１を外部に露出させる。そして、一対の電極２５及び一対の電極３１上にスパッタによりＡｕ膜２７，３３をそれぞれ形成する。 Next, as shown in FIG. 7C, an upper layer 19 made of SiO 0.7 N 0.7 having a thickness of 3 μm is formed over 120 minutes using a P-CVD thin film formation technique. Next, the upper layer 19 is etched by reactive ion etching (RIE) using CF 4 gas to form the openings 19d and 19e shown in FIG. 1, and the pair of electrodes 25 and the pair of electrodes 31 are formed. Expose to the outside. Then, Au films 27 and 33 are formed on the pair of electrodes 25 and the pair of electrodes 31 by sputtering, respectively.
　次に、図７（Ｄ）に示すように、上部層１９のガス検知用発熱抵抗体１１及び補償用発熱抵抗体１３が形成された領域の上にＣＦ４ガスを用いた、反応性イオンエッチング（ＲＩＥ）によりエッチングを施して有底の凹部１９ａ，１９ｂをそれぞれ形成する。次に、図７（Ｅ）に示すように、薄膜Ｓｉ３Ｎ４層４５ｂをＣＦ４ガスを用いた反応性イオンエッチング（ＲＩＥ）によりエッチングして薄膜Ｓｉ３Ｎ４層２１ｂを形成し、薄膜ＳｉＯ２層４５ａをバッファードフッ酸（ＢＨＦ）によりエッチングして薄膜ＳｉＯ２層２１ａを形成する。 Next, as shown in FIG. 7D, reactive ion etching using CF 4 gas on the region of the upper layer 19 where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed. Etching is performed by (RIE) to form bottomed recesses 19a and 19b, respectively. Next, as shown in FIG. 7E, the thin film Si 3 N 4 layer 45b is etched by reactive ion etching (RIE) using CF 4 gas to form a thin film Si 3 N 4 layer 21b. The SiO 2 layer 45a is etched with buffered hydrofluoric acid (BHF) to form a thin film SiO 2 layer 21a.
　次に、図７（Ｆ）に示すように、シリコン基板４３の薄膜ＳｉＯ２層２１ａ及び薄膜Ｓｉ３Ｎ４層２１ｂが形成された側からテトラメチルアンモニウムヒドロキシオキサイド（ＴＭＡＨ）によりエッチングを施して、開口孔７ｃ，７ｄを備える支持部７を形成する。このように、ガス検知用発熱抵抗体１１及び補償用発熱抵抗体１３に対応するシリコン基板９の領域の厚みを薄くして絶縁基板９を形成する。そして、シリコン基板４３に６００℃、３時間のアニール処理を施してガスセンサ用基体１を完成した。 Next, as shown in FIG. 7F, the silicon substrate 43 is etched with tetramethylammonium hydroxyoxide (TMAH) from the side where the thin film SiO 2 layer 21a and the thin film Si 3 N 4 layer 21b are formed, The support part 7 provided with the opening holes 7c and 7d is formed. Thus, the insulating substrate 9 is formed by reducing the thickness of the region of the silicon substrate 9 corresponding to the gas detection heating resistor 11 and the compensation heating resistor 13. The silicon substrate 43 was annealed at 600 ° C. for 3 hours to complete the gas sensor substrate 1.
　次に、塩化ＰｔやＰｔコロイドなどを含有させたセラミック粉体と、エチルセルロース、テレピネオールなどを含むペーストとを凹部１９ａ内に充填した後に硬化させて触媒焼結層３を形成し、セラミック粉体と、エチルセルロース、テレピネオールなどを含むペーストとを凹部１９ｂ内にした後に硬化させて補償用焼結層５を形成して、図１～図３に示す接触燃焼式ガスセンサを完成した。 Next, a ceramic powder containing Pt chloride or Pt colloid and a paste containing ethyl cellulose, terpineol and the like are filled in the recess 19a and then cured to form the catalyst sintered layer 3, and the ceramic powder Then, a paste containing ethyl cellulose, terpineol or the like was placed in the recess 19b and then cured to form the compensation sintered layer 5, thereby completing the catalytic combustion type gas sensor shown in FIGS.
　図４～図６に示す本発明の接触燃焼式ガスセンサの他の例を製造する場合は、さらに図４（Ｇ）に示すように、上部層１１９のガス検知用発熱抵抗体１１１及び補償用発熱抵抗体１３が形成された領域の周囲に、ＣＦ４ガスを用いた反応性イオンエッチング（ＲＩＥ）によりエッチングを施して、４つの結合部１１９ｈおよび４つの結合部１１９ｉを残すように４つの貫通孔１１９ｆおよび４つの貫通孔１１９ｇを形成する。 When another example of the catalytic combustion type gas sensor of the present invention shown in FIGS. 4 to 6 is manufactured, as shown in FIG. 4 (G), the gas detection heating resistor 111 and the compensation heat generation of the upper layer 119 are used. Four through-holes are formed around the region where the resistor 13 is formed by reactive ion etching (RIE) using CF 4 gas to leave four coupling portions 119h and four coupling portions 119i. 119f and four through holes 119g are formed.
　本例の接触燃焼式ガスセンサ及びガスセンサ用基体によれば、絶縁基板９のガス検知用発熱抵抗体１１や補償用発熱抵抗体１３が形成された部分（上部層１９の凹部１９ａ，１９ｂが形成された部分）では、厚み寸法が小さいため、ガス検知用発熱抵抗体１１や補償用発熱抵抗体１３の熱が分散するのを防ぐことができ、ガス検知用発熱抵抗体１１の触媒焼結層３への熱伝導性及び補償用発熱抵抗体１３の補償用焼結層５への熱伝導性を十分に高めることができる。また、絶縁基板としては、凹部１９ａ，１９ｂの周囲部１９ｃの厚み寸法が大きいので耐割れ性を維持できる。また、凹部１９ａ，１９ｂ内に触媒焼結層３、補償用焼結層５が配置されることによっても、絶縁基板９のガス検知用発熱抵抗体１１や補償用発熱抵抗体１３が形成された部分の耐割れ性を維持することができる。さらに、ガス検知用発熱抵抗体１１や補償用発熱抵抗体１３が形成された領域の周囲（４つの貫通孔１１９ｆおよび４つの貫通孔１１９ｇが形成された部分）には、空間が形成されるため、ガス検知用発熱抵抗体１１や補償用発熱抵抗体１３の熱をさらに分散し難くすることができ、ガス検知用発熱抵抗体１１１の触媒焼結層１０３への熱伝導性及び補償用発熱抵抗体１１３の補償用焼結層１０５への熱伝導性をさらに高めることができる。 According to the contact combustion type gas sensor and the gas sensor base of this example, the portions of the insulating substrate 9 where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed (the recesses 19a and 19b of the upper layer 19 are formed). Since the thickness dimension is small, the heat of the gas detection heating resistor 11 and the compensation heating resistor 13 can be prevented from being dispersed, and the catalyst sintered layer 3 of the gas detection heating resistor 11 can be prevented. The thermal conductivity to the compensation sintered layer 5 of the compensation heating resistor 13 can be sufficiently increased. Moreover, since the thickness dimension of the peripheral part 19c of the recessed parts 19a and 19b is large as an insulating substrate, crack resistance can be maintained. Further, the gas detection heating resistor 11 and the compensation heating resistor 13 of the insulating substrate 9 are also formed by disposing the catalyst sintering layer 3 and the compensation sintering layer 5 in the recesses 19a and 19b. The crack resistance of the part can be maintained. Furthermore, a space is formed around the area where the gas detection heating resistor 11 and the compensation heating resistor 13 are formed (the portion where the four through holes 119f and the four through holes 119g are formed). Further, the heat of the gas detection heating resistor 11 and the compensation heating resistor 13 can be made more difficult to disperse, and the thermal conductivity of the gas detection heating resistor 111 to the catalyst sintered layer 103 and the compensation heating resistor can be reduced. The thermal conductivity of the body 113 to the compensation sintered layer 105 can be further increased.
　なお、上記例では、１つの絶縁基板９にガス検知用発熱抵抗体１１と補償用発熱抵抗体１３の両方を形成したが、２つの絶縁基板を用意し、それぞれの絶縁基板にガス検知用発熱抵抗体と補償用発熱抵抗体を形成しても構わない。また、上記例のガスセンサ用基体１の構造を半導体式ガスセンサに適用することもできる。その場合、絶縁基板の発熱抵抗体が形成された部分の上に、所定の間隔を隔てて配置された一対の電極を形成し、該一対の電極を覆うように金属酸化物半導体を含む感応膜を形成すればよい。 In the above example, both the gas detection heating resistor 11 and the compensation heating resistor 13 are formed on one insulating substrate 9, but two insulating substrates are prepared, and the gas detection heating is provided on each insulating substrate. A resistor and a compensation heating resistor may be formed. In addition, the structure of the gas sensor substrate 1 of the above example can be applied to a semiconductor gas sensor. In that case, a pair of electrodes arranged at a predetermined interval is formed on a portion of the insulating substrate where the heating resistor is formed, and a sensitive film including a metal oxide semiconductor so as to cover the pair of electrodes. May be formed.
　本発明によれば、絶縁基板の発熱抵抗体が形成された部分（上部層の凹部が形成された部分）では、厚み寸法が小さいため、発熱抵抗体の熱が分散するのを防ぐことができ、発熱抵抗体の触媒焼結層、補償用焼結層または感応膜への熱伝導性を十分に高めることができる。また、絶縁基板としては、凹部の周囲部の厚み寸法が大きいので耐割れ性を維持できる。また、凹部内に触媒焼結層、補償用焼結層または感応膜が配置されることによっても、絶縁基板の発熱抵抗体が形成された部分の耐割れ性を維持することができる。そのため、絶縁基板の耐割れ性を維持した上で、発熱抵抗体の触媒焼結層、補償用焼結層または感応膜への熱伝導性を十分に高めることができる。 According to the present invention, the portion of the insulating substrate where the heat generating resistor is formed (the portion where the concave portion of the upper layer is formed) has a small thickness dimension, so that the heat of the heat generating resistor can be prevented from being dispersed. The heat conductivity of the heating resistor to the catalyst sintering layer, the compensation sintering layer or the sensitive film can be sufficiently increased. Moreover, since the thickness dimension of the peripheral part of a recessed part is large as an insulated substrate, crack resistance can be maintained. Further, the crack resistance of the portion of the insulating substrate where the heating resistor is formed can also be maintained by disposing the catalyst sintered layer, the compensating sintered layer, or the sensitive film in the recess. Therefore, while maintaining the crack resistance of the insulating substrate, the thermal conductivity of the heating resistor to the catalyst sintered layer, the compensation sintered layer or the sensitive film can be sufficiently increased.

Claims (12)

  1. 　耐熱性絶縁物からなる下部層と、前記下部層上に形成された耐熱性絶縁物からなる上部層とを有する絶縁基板と、
    　前記下部層上に形成されて前記上部層によって覆われた金属薄膜からなる発熱抵抗体とを有し、
    　前記上部層には、前記発熱抵抗体が形成された部分に、前記下部層が位置する方向とは反対側の方向に向かって開口する有底の凹部が形成され、
    　前記凹部の存在により、前記絶縁基板の前記上部層の前記発熱抵抗体が形成された領域の厚み寸法が、前記領域の周囲の前記上部層の厚み寸法よりも小さくなっており、
    　前記凹部は、前記上部層がエッチングされて形成され、
    　前記絶縁基板の前記発熱抵抗体が形成された前記領域の厚み寸法が、前記領域の周囲の前記上部層の厚み寸法の１／２以下であり、
    　前記領域の周囲には、前記領域に隣接して前記絶縁基板を貫通する複数の貫通孔が形成され、
    　前記貫通孔は、前記上部層及び前記下部層がエッチングされて形成されていることを特徴とするガスセンサ用基体。     An insulating substrate having a lower layer made of a heat resistant insulator and an upper layer made of a heat resistant insulator formed on the lower layer;
    A heating resistor formed of a metal thin film formed on the lower layer and covered with the upper layer;
    The upper layer is formed with a bottomed recess that opens in a direction opposite to the direction in which the lower layer is located in the portion where the heating resistor is formed,
    Due to the presence of the recess, the thickness dimension of the upper layer of the insulating substrate in which the heating resistor is formed is smaller than the thickness dimension of the upper layer around the area,
    The recess is formed by etching the upper layer,
    The thickness dimension of the region where the heating resistor of the insulating substrate is formed is ½ or less of the thickness dimension of the upper layer around the region,
    Around the region, a plurality of through holes penetrating the insulating substrate are formed adjacent to the region,
    The gas sensor substrate according to claim 1, wherein the through hole is formed by etching the upper layer and the lower layer.
  2. 　耐熱性絶縁物からなる下部層と、前記下部層上に形成された耐熱性絶縁物からなる上部層とを有する絶縁基板と、
    　前記下部層上に形成されて前記上部層によって覆われた金属薄膜からなる発熱抵抗体とを有し、
    　前記上部層には、前記発熱抵抗体が形成された部分に、前記下部層が位置する方向とは反対側の方向に向かって開口する有底の凹部が形成されており、
    　前記凹部の存在により、前記絶縁基板の前記上部層の前記発熱抵抗体が形成された領域の厚み寸法が、前記領域の周囲の前記上部層の厚み寸法よりも小さくなっていることを特徴とするガスセンサ用基体。     An insulating substrate having a lower layer made of a heat resistant insulator and an upper layer made of a heat resistant insulator formed on the lower layer;
    A heating resistor made of a metal thin film formed on the lower layer and covered by the upper layer;
    The upper layer is formed with a bottomed recess that opens in a direction opposite to the direction in which the lower layer is located in the portion where the heating resistor is formed,
    Due to the presence of the recess, the thickness dimension of the upper layer of the insulating substrate in which the heating resistor is formed is smaller than the thickness dimension of the upper layer around the area. Gas sensor substrate.
  3. 　前記凹部は、前記上部層がエッチングされて形成されていることを特徴とする請求項２に記載のガスセンサ用基体。 3. The gas sensor substrate according to claim 2, wherein the recess is formed by etching the upper layer.
  4. 　前記絶縁基板の前記上部層の前記発熱抵抗体が形成された前記領域の厚み寸法が、前記領域の周囲の前記上部層の厚み寸法の１／２以下であることを特徴とする請求項３に記載のガスセンサ用基体。 4. The thickness dimension of the region where the heating resistor of the upper layer of the insulating substrate is formed is ½ or less of the thickness dimension of the upper layer around the region. The base for gas sensors as described.
  5. 　前記領域の周囲には、前記絶縁基板を貫通する１以上の貫通孔が形成されていることを特徴とする請求項２に記載のガスセンサ用基体。 3. The gas sensor substrate according to claim 2, wherein one or more through holes penetrating the insulating substrate are formed around the region.
  6. 　前記１以上の貫通孔は、前記領域の外周に沿って間隔をあけて形成された複数の貫通孔からなることを特徴とする請求項５に記載のガスセンサ用基体。 6. The gas sensor substrate according to claim 5, wherein the one or more through holes include a plurality of through holes formed at intervals along the outer periphery of the region.
  7. 　前記貫通孔は、前記上部層及び前記下部層がエッチングされて形成されていることを特徴とする請求項６に記載のガスセンサ用基体。 The gas sensor substrate according to claim 6, wherein the through hole is formed by etching the upper layer and the lower layer.
  8. 　耐熱性絶縁物からなる下部層と、前記下部層上に形成された耐熱性絶縁物からなる上部層とを有する絶縁基板と、
    　前記下部層上に形成されて前記上部層によって覆われた金属薄膜からなる発熱抵抗体とを有するガスセンサ用基体の製造方法であって、
    　シリコン単結晶からなるシリコン基板を用意し、
    　前記シリコン基板の一方側の面上に下部層を形成し、
    　前記下部層上に金属薄膜からなる発熱抵抗体を形成し、
    　前記発熱抵抗体を覆うように、前記下部層上に前記上部層を形成し、
    　前記上部層の前記発熱抵抗体が形成された領域の上にエッチングを施して有底の凹部を形成し、
    　前記凹部を形成する前または後に、前記シリコン基板の他方側からエッチングを施して前記発熱抵抗体に対応する前記シリコン基板の領域の厚みを薄くして前記絶縁基板を形成するガスセンサ用基体の製造方法。     An insulating substrate having a lower layer made of a heat resistant insulator and an upper layer made of a heat resistant insulator formed on the lower layer;
    A method of manufacturing a gas sensor substrate having a heating resistor formed of a metal thin film formed on the lower layer and covered with the upper layer,
    Prepare a silicon substrate made of silicon single crystal,
    Forming a lower layer on one side of the silicon substrate;
    Forming a heating resistor made of a metal thin film on the lower layer;
    Forming the upper layer on the lower layer so as to cover the heating resistor;
    Etching is performed on the region where the heating resistor of the upper layer is formed to form a bottomed recess,
    Before or after forming the recess, a method for manufacturing a gas sensor substrate, wherein the insulating substrate is formed by performing etching from the other side of the silicon substrate to reduce the thickness of the region of the silicon substrate corresponding to the heating resistor. .
  9. 　前記凹部を形成する前または後に、前記凹部を形成する領域の周囲に前記シリコン基板の前記一方側からエッチングを施して前記絶縁基板を貫通する複数の貫通孔を形成する請求項８に記載のガスセンサ用基体の製造方法。 The gas sensor according to claim 8, wherein a plurality of through holes penetrating the insulating substrate are formed by etching from the one side of the silicon substrate around a region where the concave portion is formed before or after the concave portion is formed. Manufacturing method for a substrate.
  10. 　耐熱性絶縁物からなる下部層と、前記下部層上に形成された耐熱性絶縁物からなる上部層とを有する絶縁基板と、
    　前記下部層上に形成されて前記上部層によって覆われた金属薄膜からなるガス検知用発熱抵抗体と、
    　前記上部層の前記ガス検知用発熱抵抗体が形成された領域の上に形成されて、前記ガス検知用発熱抵抗体から生じる熱によって検知対象ガスが燃焼するのを促進する触媒を含む触媒焼結層とを有し、
    　前記上部層の前記ガス検知用発熱抵抗体が形成された領域の上に前記下部層に向かう方向とは反対の方向に向かって開口する有底の凹部が形成され、
    　前記凹部の存在により、前記絶縁基板の前記上部層の前記ガス検知用発熱抵抗体が形成された領域の厚み寸法が、前記領域の周囲の前記上部層の厚み寸法より小さいことを特徴とする接触燃焼式ガスセンサ。     An insulating substrate having a lower layer made of a heat resistant insulator and an upper layer made of a heat resistant insulator formed on the lower layer;
    A heating resistor for gas detection made of a metal thin film formed on the lower layer and covered with the upper layer;
    Catalyst sintering including a catalyst formed on the upper layer where the gas detection heating resistor is formed, and promoting the combustion of the detection target gas by the heat generated from the gas detection heating resistor. And having a layer
    A bottomed recess that opens in a direction opposite to the direction toward the lower layer is formed on the upper layer in the region where the gas detection heating resistor is formed,
    The contact is characterized in that due to the presence of the recess, the thickness dimension of the upper layer of the insulating substrate in which the gas detection heating resistor is formed is smaller than the thickness dimension of the upper layer around the area. Combustion type gas sensor.
  11. 　耐熱性絶縁物からなる下部層と、前記下部層上に形成された耐熱性絶縁物からなる上部層とを有する絶縁基板と、
    　前記下部層上に形成されて前記上部層によって覆われた金属薄膜からなる補償用発熱抵抗体と、
    　前記上部層の前記補償用発熱抵抗体が形成された領域の上に形成されて、前記触媒焼結層から前記触媒が除かれた成分からなる補償用焼結層とを更に有し、
    　前記上部層の前記補償用発熱抵抗体が形成された領域の上に前記下部層に向かう方向とは反対の方向に向かって開口する有底の凹部が形成され、
    　前記凹部の存在により、前記絶縁基板の上部層の前記補償用発熱抵抗体が形成された領域の厚み寸法が、前記領域の周囲の前記上部層の厚み寸法より小さいことを特徴とする請求項１０に記載の接触燃焼式ガスセンサ。     An insulating substrate having a lower layer made of a heat resistant insulator and an upper layer made of a heat resistant insulator formed on the lower layer;
    A heating resistor for compensation comprising a metal thin film formed on the lower layer and covered by the upper layer;
    A compensation sintered layer formed on a region of the upper layer on which the heat generating resistor for compensation is formed, and comprising a component obtained by removing the catalyst from the catalyst sintered layer;
    A bottomed recess that opens in a direction opposite to the direction toward the lower layer is formed on a region of the upper layer where the heating resistor for compensation is formed,
    11. The thickness dimension of the region where the heating resistor for compensation of the upper layer of the insulating substrate is formed is smaller than the thickness dimension of the upper layer around the region due to the presence of the recess. The contact combustion type gas sensor as described in 2.
  12. 　前記領域の周囲には、前記領域に隣接して前記絶縁基板を貫通する複数の貫通孔が形成されていることを特徴とする請求項９または１０に記載のガスセンサ用基体。 The gas sensor substrate according to claim 9 or 10, wherein a plurality of through holes penetrating the insulating substrate are formed adjacent to the region around the region.
PCT/JP2010/050715 2009-01-21 2010-01-21 Base body for gas sensor and method for manufacturing the base body WO2010084916A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2009-011252 2009-01-21
JP2009011252 2009-01-21

Publications (1)

Publication Number Publication Date
WO2010084916A1 true WO2010084916A1 (en) 2010-07-29

Family

ID=42355968

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2010/050715 WO2010084916A1 (en) 2009-01-21 2010-01-21 Base body for gas sensor and method for manufacturing the base body

Country Status (1)

Country Link
WO (1) WO2010084916A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105609501A (en) * 2016-02-25 2016-05-25 歌尔声学股份有限公司 Environmental sensor, integration device and fabrication method of environmental sensor
US20180106745A1 (en) * 2016-10-13 2018-04-19 Riken Keiki Co., Ltd. Gas sensor
WO2022052392A1 (en) * 2020-09-08 2022-03-17 苏州芯镁信电子科技有限公司 Side-heating type silicon-based thin film catalytic hydrogen sensor and processing method therefor

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05232068A (en) * 1992-02-20 1993-09-07 Mazda Motor Corp Sensor cement
JPH0616857U (en) * 1992-07-31 1994-03-04 能美防災株式会社 Odor sensor
JPH09264862A (en) * 1996-03-29 1997-10-07 Yazaki Corp Microheater and co sensor
JPH1026596A (en) * 1996-07-10 1998-01-27 Hokuriku Electric Ind Co Ltd Sensor chip
JP2004037180A (en) * 2002-07-02 2004-02-05 Denso Corp Integrated sensor device
JP2004093470A (en) * 2002-09-03 2004-03-25 Ngk Spark Plug Co Ltd Microsensor made of silicon
JP2005156364A (en) * 2003-11-26 2005-06-16 Ngk Spark Plug Co Ltd Flammable gas detector
JP2009074977A (en) * 2007-09-21 2009-04-09 Hokuriku Electric Ind Co Ltd Response sensor and its manufacturing method

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05232068A (en) * 1992-02-20 1993-09-07 Mazda Motor Corp Sensor cement
JPH0616857U (en) * 1992-07-31 1994-03-04 能美防災株式会社 Odor sensor
JPH09264862A (en) * 1996-03-29 1997-10-07 Yazaki Corp Microheater and co sensor
JPH1026596A (en) * 1996-07-10 1998-01-27 Hokuriku Electric Ind Co Ltd Sensor chip
JP2004037180A (en) * 2002-07-02 2004-02-05 Denso Corp Integrated sensor device
JP2004093470A (en) * 2002-09-03 2004-03-25 Ngk Spark Plug Co Ltd Microsensor made of silicon
JP2005156364A (en) * 2003-11-26 2005-06-16 Ngk Spark Plug Co Ltd Flammable gas detector
JP2009074977A (en) * 2007-09-21 2009-04-09 Hokuriku Electric Ind Co Ltd Response sensor and its manufacturing method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105609501A (en) * 2016-02-25 2016-05-25 歌尔声学股份有限公司 Environmental sensor, integration device and fabrication method of environmental sensor
US20180106745A1 (en) * 2016-10-13 2018-04-19 Riken Keiki Co., Ltd. Gas sensor
US10697920B2 (en) * 2016-10-13 2020-06-30 Riken Keiki Co., Ltd. Gas sensor
WO2022052392A1 (en) * 2020-09-08 2022-03-17 苏州芯镁信电子科技有限公司 Side-heating type silicon-based thin film catalytic hydrogen sensor and processing method therefor

Similar Documents

Publication Publication Date Title
JP6514336B2 (en) Sensor for detecting conductive and / or polarizable particles, sensor system, method of operating the sensor, method of manufacturing this type of sensor and use of this type of sensor
CN107381495B (en) MEMS micro-hotplate and manufacturing method thereof
US10697920B2 (en) Gas sensor
JP2006024937A (en) Semiconductor heater and its manufacturing method
JP6425960B2 (en) Stacked gas sensor element, gas sensor, and method of manufacturing the same
JP2007278996A (en) Contact combustion type gas sensor and manufacturing method therefor
WO2010084916A1 (en) Base body for gas sensor and method for manufacturing the base body
CN115266848A (en) Multi-channel gas sensor and preparation method thereof
KR100687121B1 (en) Oxygen concentration detecting element and method of producing the same
JP2005292120A (en) Platinum resistor type temperature sensor
CN110658238A (en) Catalytic combustion gas sensor based on ceramic-based micro-hotplate and preparation method thereof
JP4641832B2 (en) Thin film gas sensor
JP3585082B2 (en) Contact combustion type gas sensor and manufacturing method
JP4376093B2 (en) Thin film gas sensor
JP5359985B2 (en) Gas sensor
JP5672339B2 (en) Gas sensor
JPH09264862A (en) Microheater and co sensor
JP2007017217A (en) Thin film gas sensor
JP2015152523A (en) gas detector
KR102219542B1 (en) Contact combustion type gas sensor and method for manufacturing the same
JP4580577B2 (en) Contact combustion type gas sensor and manufacturing method thereof
JP6284300B2 (en) Thin film gas sensor
JP5278086B2 (en) Thin film gas sensor and manufacturing method thereof
WO2020079966A1 (en) Mems gas sensor and mems gas sensor manufacturing method
JP2002296222A (en) Sensor element

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10733523

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10733523

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP