WO2010150787A1 - 赤外線式ガス検知器および赤外線式ガス計測装置 - Google Patents
赤外線式ガス検知器および赤外線式ガス計測装置 Download PDFInfo
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- WO2010150787A1 WO2010150787A1 PCT/JP2010/060570 JP2010060570W WO2010150787A1 WO 2010150787 A1 WO2010150787 A1 WO 2010150787A1 JP 2010060570 W JP2010060570 W JP 2010060570W WO 2010150787 A1 WO2010150787 A1 WO 2010150787A1
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Definitions
- the present invention relates to an infrared gas detector and an infrared gas measuring device.
- an infrared type gas measuring device that measures gas by utilizing infrared light having a specific wavelength absorbed by gas.
- An infrared type gas measuring device measures the concentration of a measurement gas by measuring the absorbance of infrared light (infrared light) having an absorption wavelength determined according to the molecular structure of the measurement gas (Japanese Patent Laid-Open No. 7-72078). JP-A-3-205521, JP-A-10-281866).
- An infrared gas sensor described in Japanese Patent Laid-Open No. 7-72078 includes a filter that transmits infrared light having a predetermined wavelength and a pyroelectric light sensor that detects infrared light transmitted through the filter.
- the filter is formed directly on the pyroelectric light sensor.
- An infrared detector described in Japanese Patent Laid-Open No. 3-205521 has a package composed of a case and a stem.
- a holder for accommodating the infrared detection element is accommodated in the package.
- the case has an opening for allowing infrared rays to enter the infrared detection element.
- the opening is closed by a window material that transmits infrared rays such as sapphire.
- An optical filter is attached to the holder so as to be positioned in front of the infrared detection element.
- the optical filter has a substrate.
- a band pass surface (transmission filter) that transmits infrared rays of a predetermined wavelength band is formed on one surface of the substrate, and a short long cut surface (removing infrared rays other than the predetermined wavelength band) is formed on the other surface of the substrate.
- a cutoff filter) is formed.
- the transmission filter and the cutoff filter are multilayer films in which a Ge film and a SiO film are stacked.
- the SiO film also has a characteristic of absorbing infrared rays having a longer wavelength band than the infrared wavelength band (that is, the transmission band) transmitted by the transmission filter. Therefore, the temperature of the transmission filter or the cutoff filter itself may rise, and infrared rays in the absorption wavelength band may be emitted.
- An object of the present invention is to provide an infrared gas detector and an infrared gas measuring device capable of reducing cost and increasing sensitivity.
- An infrared gas detector includes an infrared light receiving unit, a package for housing the infrared light receiving unit, and an optical filter.
- the infrared light receiving unit includes a plurality of thermal infrared detection elements that detect infrared rays using heat.
- the plurality of thermal infrared detection elements are arranged side by side.
- the package has a window hole for allowing infrared light to enter the infrared light receiving unit.
- the optical filter is bonded to the package so as to close the window hole, and has a plurality of filter element portions respectively corresponding to the plurality of thermal infrared detection elements.
- Each of the filter element portions includes a filter substrate formed of a material that transmits infrared rays, a transmission filter configured to selectively transmit infrared rays having a predetermined selection wavelength, and the selection wavelength of the transmission filter. And a cutoff filter configured to absorb infrared rays having a long wavelength.
- the transmission filter and the cutoff filter are each formed on the filter substrate.
- the filter substrate is thermally coupled to the package.
- the filter elements have different selection wavelengths for the transmission filter.
- the infrared light receiving unit has a pair of the thermal infrared detection elements.
- the thermal infrared detecting element is a pyroelectric element or a thermopile.
- the pair of thermal infrared detection elements are connected in reverse series or reverse parallel.
- an amplification circuit for amplifying the output of the infrared light receiving unit is provided.
- the amplifier circuit is housed in the package.
- the infrared gas detector includes an amplifier circuit.
- the infrared light receiving unit has a pair of the thermal infrared detection elements.
- the thermal infrared detecting element is a pyroelectric element or a thermopile.
- the amplifier circuit is a differential amplifier circuit that amplifies a difference between outputs of the pair of thermal infrared detection elements.
- the filter substrate is formed of a Si substrate or a Ge substrate.
- the package includes a metal shield part that prevents electromagnetic waves from entering the package.
- the filter substrate is electrically connected to the shield part.
- the filter substrate has a first surface facing the inside of the package and a second surface facing the outside of the package.
- the transmission filter is formed on the first surface of the filter substrate.
- the cutoff filter is formed on the second surface of the filter substrate.
- the filter substrates of the filter element portions are integrally formed with each other.
- the transmission filter includes a first ⁇ / 4 multilayer film, a second ⁇ / 4 multilayer film, the first ⁇ / 4 multilayer film, and the second ⁇ / 4 multilayer film. And a wavelength selection layer interposed between the two.
- the first ⁇ / 4 multilayer film and the second ⁇ / 4 multilayer film are formed by laminating a plurality of types of thin films having different refractive indexes and the same optical film thickness.
- the optical film thickness of the wavelength selection layer is set to a size different from the optical film thickness of the thin film according to the selected wavelength of the transmission filter.
- the cutoff filter is a multilayer film formed by laminating a plurality of types of thin films having different refractive indexes. At least one of the plurality of types of thin films is formed of a far-infrared absorbing material that absorbs far-infrared rays.
- An infrared gas measuring device includes an infrared light source that emits infrared light into a predetermined space, and an infrared gas detector that receives the infrared light that has passed through the predetermined space.
- the infrared gas detector includes an infrared light receiving unit, a package that houses the infrared light receiving unit, and an optical filter.
- the infrared light receiving unit includes a plurality of thermal infrared detection elements that detect infrared rays using heat. The plurality of thermal infrared detection elements are arranged side by side.
- the package has a window hole for allowing infrared light to enter the infrared light receiving unit.
- the optical filter is bonded to the package so as to close the window hole, and has a plurality of filter element portions respectively corresponding to the plurality of thermal infrared detection elements.
- Each of the filter element portions includes a filter substrate formed of a material that transmits infrared rays, a transmission filter configured to selectively transmit infrared rays having a predetermined selection wavelength, and the selection wavelength of the transmission filter. And a cutoff filter configured to absorb infrared rays having a long wavelength.
- the transmission filter and the cutoff filter are each formed on the filter substrate.
- the filter substrate is thermally coupled to the package.
- the filter elements have different selection wavelengths for the transmission filter.
- a drive circuit for driving the infrared light source is provided so that the infrared light source emits infrared light intermittently.
- the infrared light source comprises a substrate, a holding layer formed on the substrate, an infrared radiation layer laminated on the holding layer, and a gas interposed between the substrate and the holding layer.
- the infrared radiation layer is configured to emit infrared light by heat generated with energization.
- the gas layer suppresses a decrease in temperature of the holding layer when the infrared radiation layer is energized, and promotes heat transfer from the holding layer to the substrate when the infrared radiation layer is not energized. Configured to do.
- the voltage applied to the infrared radiation layer is a sinusoidal voltage with a frequency f [Hz]
- the thermal conductivity of the gas layer is ⁇ g [W / mK]
- the volumetric heat capacity of the gas layer Is Cg [J / m 3 K]
- the retention layer has a lower thermal conductivity than the substrate.
- the holding layer absorbs heat generated in the energized infrared emitting layer, or reflects the infrared ray emitted from the infrared emitting layer, so that the infrared ray traveling from the holding layer to the infrared emitting layer is transmitted.
- the infrared radiation layer is configured to transmit infrared rays generated by the holding layer.
- the infrared type gas detector of Embodiment 1 is shown, (a) is a schematic plan view, (b) is a schematic sectional drawing. It is a schematic exploded perspective view of an infrared type gas detector same as the above.
- the infrared light receiving element in an infrared type gas detector same as the above is shown, (a) is a schematic plan view, (b) is a circuit diagram, and (c) is a circuit diagram of another configuration example.
- FIG. 1 It is a schematic block diagram of the infrared type gas measuring device provided with the infrared type gas detector same as the above. It is a relationship explanatory drawing of the temperature of an object, and radiant energy.
- the other structural example of an infrared light source is shown, (a) is a schematic sectional drawing, (b) is a principal part schematic sectional drawing. It is explanatory drawing of the output of an infrared light source. It is explanatory drawing of the optical filter in the same as the above. It is explanatory drawing of the output of the infrared light receiving element same as the above.
- the other example of a structure of the infrared light receiving element in an infrared type gas detector same as the above is shown, (a) is a schematic plan view, (b) is a circuit diagram, (c) is a circuit diagram of another structure example. It is explanatory drawing of the permeation
- the other example of a structure of the thermal type infrared detection element in an infrared type gas detector same as the above is shown, (a) is a principal part schematic plan view, (b) is a schematic sectional drawing.
- FIG. 3 is a schematic configuration diagram illustrating an overall configuration of a second embodiment. It is sectional drawing of the transmission filter used for the same as the above. It is a characteristic view of the transmission filter and cutoff filter used for the same as the above. It is sectional drawing which shows an example of the radiation element used for the same as the above. It is operation
- FIG. 1 shows the temperature characteristic of the holding layer of a radiation element same as the above.
- A shows the waveform of the drive voltage applied between the electrodes of a radiation element
- (b) shows the temperature change of an infrared radiation layer
- (c) is the infrared radiation of the 1st comparative example of a radiation element. The temperature change of a layer is shown
- (d) shows the temperature change of the infrared radiation layer of the 2nd comparative example of a radiation element.
- It is a cross-sectional schematic diagram of the 1st modification of a radiation element same as the above. It is a top view of the 1st modification of a radiation element same as the above.
- the infrared gas detector (infrared light receiving unit) of the present embodiment has an infrared light receiving element (infrared ray) having a plurality (here, two) of pyroelectric elements 4 1 and 4 2.
- a circuit block 6 provided with a signal processing circuit for performing signal processing on outputs of the light receiving unit 40 and the infrared light receiving element 40, and a package 7 formed of a can package for storing the circuit block 6.
- the pyroelectric elements 4 1 and 4 2 are thermal infrared detection elements that detect infrared rays using heat.
- the package 7 includes a metal stem 71 and a metal cap 72.
- the circuit block 6 is mounted on the stem 71 via a spacer 9 made of an insulating material.
- the cap 72 is fixed to the stem 71 so as to cover the circuit block 6.
- the stem 71 is provided with a plurality (three in this case) of terminal pins 75 that are electrically connected to appropriate portions of the circuit block 6 so as to penetrate the stem 71.
- the stem 71 is formed in a disc shape, and the cap 72 is formed in a bottomed cylindrical shape with an open rear surface. The rear surface of the cap 72 is closed by the stem 71.
- the spacer 9 is fixed to the circuit block 6 and the stem 71 using an adhesive.
- the cap 72 constitutes a part of the package 7.
- the cap 72 has a front wall located in front of the infrared light receiving element 40.
- a rectangular (in this embodiment, square) window hole 7 a is formed in the front wall of the cap 72.
- the window hole 7 a is used for causing infrared light to enter the infrared light receiving element 40.
- An infrared optical filter (optical filter) 20 is attached to the inside of the cap 72 so as to cover the window hole 7a. In short, the optical filter 20 is positioned in front of the infrared light receiving element 40 and joined to the package 7 so as to close the window hole 7a of the package 7.
- the stem 71 is provided with a plurality of terminal holes 71b through which the terminal pins 75 are inserted in the thickness direction. Each terminal pin 75 is sealed to the stem 71 using a sealing portion 74 in a form inserted through the terminal hole 71b.
- the cap 72 and the stem 71 are made of a steel plate.
- the cap 72 is sealed to the stem 71 by welding an outer flange portion 72c extending outward from the rear end edge of the cap 72 to a flange portion 71c formed on the peripheral portion of the stem 71.
- the circuit block 6 includes a first circuit board 62, a resin layer 65, a shield plate 66, and a second circuit board 67.
- the first circuit board 62 is a printed wiring board (for example, a composite copper-clad laminate) in which the integrated circuit 63 and the chip-like electronic component 64 that are components of the signal processing circuit are mounted on different surfaces. is there.
- the resin layer 65 is laminated on the mounting surface of the electronic component 64 in the first circuit board 62.
- the shield plate 66 includes an insulating base material made of glass epoxy or the like, and a metal layer (hereinafter referred to as a shield layer) made of a metal material (for example, copper) formed on the surface of the insulating base material.
- the shield plate 66 is laminated on the resin layer 65.
- the second circuit board 67 is a printed wiring board (for example, a composite copper-clad laminate).
- the infrared light receiving element 40 is mounted on the second circuit board 67.
- the second circuit board 67 is laminated on the shield plate 66.
- the shield layer may be formed only with a copper foil or a metal plate.
- the integrated circuit 63 is flip-chip mounted on the first surface (the lower surface in FIG. 2) of the first circuit board 62.
- the plurality of electronic components 64 are mounted on the second surface (the upper surface in FIG. 2) of the first circuit board 62 by solder reflow.
- the infrared light receiving element 40 includes a pair of pyroelectric elements 4 1 and 4 2 having different polarities and a pyroelectric element forming substrate 41 made of a pyroelectric material (for example, lithium tantalate).
- the pair of pyroelectric elements 4 1 and 4 2 is arranged side by side on the pyroelectric element forming substrate 41.
- Infrared receiving component 40 is a two pyroelectric elements 4 1, 4 2 differential outputs Two so as to obtain a pyroelectric element 4 1, 4 dual element 2 is connected in reverse series (FIG. 3 ( b)).
- the integrated circuit 63 includes an amplification circuit (bandpass amplifier) 63a (see FIG. 18) that amplifies the output of the infrared light receiving element 40 in a predetermined frequency band (for example, about 0.1 to 10 Hz), and a window in the subsequent stage of the amplification circuit 63a. It has a comparator.
- amplification circuit bandpass amplifier
- the circuit block 6 in the present embodiment includes the shield plate 66, it is possible to prevent the occurrence of an oscillation phenomenon due to capacitive coupling between the infrared light receiving element 40 and the amplifier circuit. Further, the infrared light receiving element 40 only needs to be configured to obtain a differential output of the pair of pyroelectric elements 4 1 and 4 2 . Therefore, the pair of pyroelectric elements 4 1 and 4 2 may be connected in antiparallel as shown in FIG. 3C, for example.
- the second circuit board 67 is provided with thermal insulation holes 67a for thermally insulating the pyroelectric elements 4 1 and 4 2 and the second circuit board 67 in the thickness direction. Therefore, a gap is formed between the pyroelectric elements 4 1 and 4 2 and the shield plate 66, and sensitivity is increased. Instead of penetrating the heat insulating hole 67 in the second circuit board 67, a gap is formed in the second circuit board 67 between the pyroelectric elements 4 1 , 4 2 and the second circuit board 67. You may project and provide the support part which supports the infrared light receiving element 40 in the form formed.
- the first circuit board 62, the resin layer 65, the shield plate 66, and the second circuit board 67 are respectively provided with through holes 62b, 65b, 66b, and 67b through which the terminal pins 75 are inserted in the thickness direction. .
- the infrared light receiving element 40 and the signal processing circuit are electrically connected via a terminal pin 75.
- the through-hole which penetrates in the thickness direction of the circuit block 6 is formed after laminating
- the sealing portions 74 and 74 (74a and 74b) for sealing the terminal pins 75a and 75b to the stem 71 are formed of sealing glass having insulating properties.
- the sealing portion 74 (74c) for sealing the terminal pin 75c to the stem 71 is formed of a metal material.
- the terminal pins 75 a and 75 b are electrically insulated from the stem 71, while the terminal pin 75 c has the same potential as the stem 71.
- the potential of the shield plate 66 is set to the ground potential.
- the potential of the shield plate 66 may be a potential other than the ground potential as long as it is a specific potential capable of performing a shielding function.
- the cap 72 and the stem 71 constitute a shield part that shields electromagnetic waves from the outside.
- the package 7 includes a metal shield part that prevents electromagnetic waves from entering the package 7.
- the circuit block 6 on which the infrared light receiving element 40 is mounted is mounted on the stem 71 via the spacer 9.
- the outer flange portion 72c of the cap 72 to which the infrared optical filter 20 is fixed so as to close the window hole 7a is welded to the flange portion 71c of the stem 71 to seal the inside of the package 7.
- dry nitrogen is sealed in the package 7 in order to prevent the characteristic change of the infrared light receiving element 40 due to the influence of humidity or the like.
- the package 7 in this embodiment is a can package, the shielding effect with respect to an external noise can be improved, and since airtightness can be improved, a weather resistance can be improved.
- the package 7 may be a ceramic package having a shield effect provided with a shield layer made of a metal layer as a shield part.
- the optical filter 20 has a filter main body 20a and a flange 20b.
- the filter body 20 a includes a filter forming substrate (filter substrate) 1, a narrow band transmission filter unit (transmission filter) 2 (2 1 , 2 2 ), and a broadband cutoff filter unit (cut filter) 3.
- the flange portion 20b extends outward from the peripheral portion of the filter main body portion 20a (the peripheral portion of the filter substrate 1).
- the flange portion 20 b is fixed to the peripheral portion of the window hole 7 a in the cap 72 using the joint portion 58. As a result, the filter substrate 1 is thermally coupled to the package 7.
- an adhesive having a high thermal conductivity such as a silver paste (an epoxy resin containing a metallic filler), a solder paste, or the like is used for the joint 58.
- a silver paste an epoxy resin containing a metallic filler
- a solder paste or the like is used for the joint 58.
- the shape of the filter portion 20a in plan view is a rectangular shape (in the present embodiment, a square shape), and the outer peripheral shape of the flange portion 20b is a rectangular shape (in the present embodiment, a square shape).
- the planar shape of the filter body 20a is a square of several mm ⁇ , but the planar shape and dimensions of the filter body 20a are not particularly limited.
- the optical filter 20 selectively transmits infrared light having a predetermined selection wavelength with the filter substrate 1 formed of an infrared transmitting material (for example, Si).
- a pair of transmission filters 2 1 and 2 2 configured, and a cutoff filter 3 configured to absorb infrared rays having a wavelength longer than a selected wavelength of any of the transmission filters 2 1 and 2 2 .
- the transmission filters 2 1 and 2 2 and the cutoff filter 3 are respectively formed on the filter substrate 1.
- the pair of transmission filters 2 1 and 2 2 are formed on the first surface (upper surface in FIG. 4) of the filter substrate 1 so as to correspond to the pyroelectric elements 4 1 and 4 2, respectively.
- the pair of transmission filters 2 1 and 2 2 have different selection wavelengths.
- the cutoff filter 3 is formed on the second surface (lower surface in FIG. 4) of the filter substrate 1.
- the cutoff filter 3 absorbs infrared rays having a longer wavelength than the infrared reflection band set by the transmission filters 2 1 and 2 2 . That is, the cutoff filter 3 absorbs infrared rays that exceed a predetermined wavelength that is longer than the selected wavelength of each of the transmission filters 2 1 and 2 2 .
- a filter element portion is configured.
- the plurality of filter element portions share the filter forming substrate 1.
- the filter substrates 1 of the respective filter element portions are formed integrally with each other.
- Transmission filter 2 1 the first lambda / 4 multilayer film (first multilayer film) 21, a second lambda / 4 multilayer film (second multilayer film) 22, a first multilayer film 21 second multilayer film And a wavelength selection layer 23 (23 1 ) interposed between them. It comprises transmission filter 2 2, a first multilayer film 21, a second multilayer film 22, and a wavelength selection layer 23 (23 2) interposed between the first multilayer film 21 and the second multilayer film 22 ing.
- the first multilayer film 21 and the second multilayer film 22 are formed by alternately laminating a plurality of types (here, two types) of thin films 21b and 21a having different refractive indexes and the same optical film thickness. .
- the first multilayer film 21 is formed on the first surface of the filter substrate 1.
- the second multilayer film 22 is formed on the first multilayer film 21. That is, the second multilayer film 22 is formed on the opposite side of the first multilayer film 21 from the filter substrate 1 side.
- the optical film thicknesses of the wavelength selection layers 23 1 and 23 2 are set to be different from the optical film thicknesses of the thin films 21a and 21b according to the selection wavelengths of the transmission filters 2 1 and 2 2 .
- the allowable range of variation in optical film thickness of each thin film 21a, 21b is about ⁇ 1%, and the allowable range of variation in physical film thickness is determined according to the variation in optical film thickness.
- the thin film 21b is a low refractive index layer having a lower refractive index than the thin film 21a.
- the material (low refractive index material) of the thin film 21b is Al 2 O 3 which is a kind of far infrared ray absorbing material that absorbs far infrared rays.
- the thin film 21a is a high refractive index layer having a higher refractive index than the thin film 21b.
- the material (high refractive index material) of the thin film 21a is Ge.
- the material of the wavelength selection layer 23 1 is the same as the material of the second thin film 21b from the top of the first multilayer film 21 immediately below the wavelength selection layer 23 1.
- the material of the wavelength selection layer 23 2 is the same as the material of the second thin film 21a over the first multilayer film 21 immediately below the wavelength selection layer 23 2.
- the thin films 21b and 21b farthest from the filter substrate 1 in the second multilayer film 22 are formed of the above-described low refractive index material.
- the far-infrared-absorbing material is not limited to Al 2 O 3, SiO 2 and an oxide other than Al 2 O 3, may be employed Ta 2 O 5. Since the refractive index of SiO 2 is lower than that of Al 2 O 3 , the refractive index difference between the high refractive index material and the low refractive index material can be increased.
- various gases that may be generated in a house include CH 4 (methane), SO 3 (sulfur trioxide), CO 2 (carbon dioxide), CO (carbon monoxide), NO (one Nitric oxide).
- the specific wavelength (absorption wavelength) for detecting (sensing) gas is determined by the type of gas.
- the specific wavelength of CH 4 (methane) is 3.3 ⁇ m
- the specific wavelength of SO 3 (sulfur trioxide) is 4.0 ⁇ m
- the specific wavelength of CO 2 (carbon dioxide) is 4.3 ⁇ m
- CO carbon monoxide
- the specific wavelength is 4.7 ⁇ m
- the specific wavelength of NO (nitrogen monoxide) is 5.3 ⁇ m.
- the reflection band In order to selectively detect all the specific wavelengths listed here, it is necessary to have a reflection band in the infrared region of about 3.1 ⁇ m to 5.5 ⁇ m. In addition, a reflection bandwidth ⁇ of 2.4 ⁇ m or more is indispensable. As shown in FIG. 5, the reflection band has a wave number that is the reciprocal of the wavelength of the incident light as shown in FIG. 5 when the set wavelength corresponding to four times the optical film thickness common to the thin films 21a and 21b is ⁇ 0 . In the transmission spectrum diagram with the axis and transmittance as the vertical axis, 1 / ⁇ 0 is the center of symmetry.
- the first multilayer film 21 and the second multilayer film 22 are set so that the various gases described above can be detected by appropriately setting the optical film thicknesses of the wavelength selection layers 23 1 and 23 2.
- the wavelength ⁇ 0 is set to 4.0 ⁇ m.
- the physical film thickness of the thin film 21a is ⁇ 0 / 4n H where n H is the refractive index of the high refractive index material.
- the physical film thickness of the thin film 21b is ⁇ 0 / 4n L when the refractive index n L of the low refractive index material is used.
- the high refractive index material is Ge
- n H 4.0
- the physical film thickness of the thin film 21a is 250 nm.
- the low refractive index material is Al 2 O 3
- n L 1.7, so that the physical film thickness of the thin film 21b is 588 nm.
- FIG. 6 shows the simulation result of the transmission spectrum.
- the number of laminated ⁇ / 4 multilayer films (refractive index periodic structure) formed by alternately laminating the filter substrate 1 with the Si substrate and the thin films 21b and the thin films 21a is 21, and absorption by the thin films 21a and 21b. (That is, the extinction coefficient of each thin film 21a, 21b is assumed to be 0).
- the set wavelength ⁇ 0 is 4 ⁇ m.
- the horizontal axis indicates the wavelength of incident light (infrared rays), and the vertical axis indicates the transmittance.
- FIG. 7 shows a simulation result of the reflection bandwidth ⁇ of the ⁇ / 4 multilayer film (refractive index periodic structure) when the refractive index of the low refractive index material is changed using Ge as the high refractive index material. Note that S10, S11, and S12 in FIG. 7 correspond to points S10, S11, and S12 in FIG. 6, respectively.
- the reflection bandwidth ⁇ increases as the refractive index difference between the high refractive index material and the low refractive index material increases.
- the high refractive index material is Ge
- the low refractive index material by adopting Al 2 O 3 or SiO 2 as the low refractive index material, at least a reflection band in the infrared region of 3.1 ⁇ m to 5.5 ⁇ m can be secured. It can be seen that the reflection bandwidth ⁇ can be 2.4 ⁇ m or more.
- the number of stacked first multilayer films 21 is four, and the number of stacked second multilayer films 22 is six.
- the high refractive index material of the thin film 21a is Ge
- the low refractive index material of the thin film 21b is Al 2 O 3
- the material of the wavelength selection layer 23 is Al 2 O 3 which is a low refractive index material.
- the optical film thickness of the wavelength selection layer 23 was changed in the range of 0 nm to 1600 nm.
- An arrow A1 in FIG. 8 indicates incident light
- an arrow A2 indicates transmitted light
- an arrow A3 indicates reflected light.
- the optical film thickness of the wavelength selection layer 23 is the product of the refractive index n and the physical film thickness d, where n is the refractive index of the material of the wavelength selection layer 23 and d is the physical film thickness of the wavelength selection layer 23. That is, it is obtained by nd. In this simulation, it is assumed that there is no absorption in each thin film 21a, 21b (that is, the extinction coefficient of each thin film 21a, 21b is 0).
- the set wavelength ⁇ 0 was 4 ⁇ m
- the physical film thickness of the thin film 21a was 250 nm
- the physical film thickness of the thin film 21b was 588 nm.
- the first multilayer film 21 and the second multilayer film 22 form a reflection band in the infrared region of 3 ⁇ m to 6 ⁇ m. It can also be seen that a narrow transmission band is localized in the reflection band of 3 ⁇ m to 6 ⁇ m by appropriately setting the optical film thickness nd of the wavelength selection layer 23. Specifically, by changing the optical film thickness nd of the wavelength selection layer 23 in the range of 0 nm to 1600 nm, the transmission peak wavelength can be continuously changed in the range of 3.1 ⁇ m to 5.5 ⁇ m. I understand that.
- the transmission peak wavelengths are 3.3 ⁇ m, 4.0 ⁇ m, 4.3 ⁇ m, 4.7 ⁇ m and 5.3 ⁇ m.
- CH 4 having a specific wavelength of 3.3 ⁇ m and a specific wavelength of Various gases such as 4.0 ⁇ m SO 3 , CO 2 with a specific wavelength of 4.3 ⁇ m, CO with a specific wavelength of 4.7 ⁇ m, NO with a specific wavelength of 5.3 ⁇ m, and flames with a specific wavelength of 4.3 ⁇ m Sensing is possible.
- gases such as 4.0 ⁇ m SO 3 , CO 2 with a specific wavelength of 4.3 ⁇ m, CO with a specific wavelength of 4.7 ⁇ m, NO with a specific wavelength of 5.3 ⁇ m, and flames with a specific wavelength of 4.3 ⁇ m Sensing is possible.
- the range of 0 nm to 1600 nm of the optical film thickness nd corresponds to the range of 0 nm to 941 nm of the physical film thickness d.
- the transmission peak wavelength is 4000 nm, which is the first multilayer film 21 and the second multilayer film 22.
- the set wavelength ⁇ 0 is set to 4 ⁇ m (4000 nm).
- the infrared reflection band set by the first multilayer film 21 and the second multilayer film 22 that is, the infrared reflection band set by the transmission filters 2 1 and 2 2
- Al 2 O 3 which is a far-infrared absorbing material that absorbs infrared rays in a long wavelength region is employed.
- far-infrared absorbing materials five kinds of materials such as MgF 2 , Al 2 O 3 , SiO x , Ta 2 O 5 , and SiN x were examined.
- the film thickness of each of the MgF 2 film, Al 2 O 3 film, SiO x film, Ta 2 O 5 film, and SiN x film is 1 ⁇ m.
- Table 1 below shows film formation conditions when forming each of the MgF 2 film, Al 2 O 3 film, SiO x film, Ta 2 O 5 film, and SiN x film on the Si substrate.
- an ion beam assisted vapor deposition apparatus was used as a film forming apparatus for the MgF 2 film, Al 2 O 3 film, SiO x film, Ta 2 O 5 film, and SiN x film.
- IB conditions indicate ion beam assist conditions when forming a film with an ion beam assist vapor deposition apparatus. “No IB” means no ion beam irradiation, “oxygen IB” means oxygen ion beam irradiation, and “ArIB” means argon ion beam irradiation.
- the horizontal axis indicates the wavelength and the vertical axis indicates the transmittance.
- S20 is an Al 2 O 3 film
- S21 is a Ta 2 O 5 film
- S22 is a SiO x film
- S23 is a SiN x film
- S24 is a MgF 2 film.
- the evaluation was performed based on the absorption rate of far infrared rays of 6 ⁇ m or more calculated from the transmission spectrum of FIG.
- Table 2 for each evaluation item, “ ⁇ (Very good)”, “ ⁇ (Good)”, “ ⁇ (Average)”, “ ⁇ (Poor)” are listed in order from the highest to lowest. It is.
- the evaluation item “optical characteristics: absorption” the higher the far infrared absorptivity, the higher the evaluation rank, and the lower the far infrared absorptivity, the lower the evaluation rank.
- the evaluation item of “refractive index” from the viewpoint of increasing the difference in refractive index from the high refractive index material, the lower the refractive index, the higher the evaluation rank, and the higher the refractive index, the lower the evaluation rank.
- the evaluation rank is higher as the dense film is easily obtained by the vapor deposition method or the sputtering method, and the evaluation rank is lower as the dense film is difficult to obtain.
- SiNx is the result of the evaluation as Si 3 N 4.
- the far-infrared absorptivity is improved as compared with the case where the far-infrared absorbing material is SiO x or SiN x. Can do.
- Al 2 O 3 is more preferable than T 2 O 5 from the viewpoint of increasing the refractive index difference from the high refractive index material.
- SiN x is employed as the far infrared ray absorbing material, the moisture resistance of the thin film 21b formed of the far infrared ray absorbing material can be improved.
- the difference in refractive index from the high refractive index material can be increased, and the first ⁇ / 4 multilayer film 21 and the second ⁇ / 4 multilayer film 22 The number of stacked layers can be reduced.
- a first multilayer film forming step is performed.
- a thin film 21b having a predetermined physical film thickness (here, 588 nm) made of Al 2 O 3 which is a low refractive index material is formed on the entire first surface of the filter substrate 1 made of an Si substrate.
- the first multilayer film 21 is formed by alternately laminating thin films 21a having a predetermined physical film thickness (here, 250 nm) made of Ge, which is a high refractive index material.
- a wavelength selection layer forming step is performed.
- the same material as the thin film 21b located second from the top of the first multilayer film 21 (here, Al 2 O 3 which is a low refractive index material) is formed on the entire surface of the first multilayer film 21.
- the wavelength selection layer 23 1 having an optical film thickness set in accordance with the selection wavelength of one transmission filter 21 is formed.
- each of the thin film 21b, as 21a and method of forming the wavelength-selective layer 23 1, for example, it can be employed as vapor deposition or sputtering. In this case, two types of thin films 21b and 21a can be continuously formed.
- the low refractive index material is Al 2 O 3 as described above, it is preferable to adopt an ion beam assisted vapor deposition method and irradiate an oxygen ion beam at the time of forming the thin film 21b to improve the denseness of the thin film 21b.
- the low refractive index material SiO x , T 2 O 5 , SiN x which is a far infrared ray absorbing material other than Al 2 O 3 may be adopted.
- the chemical composition of the thin film 21b made of a low refractive index material can be precisely controlled, and the denseness of the thin film 21b can be enhanced.
- a resist layer forming step is performed.
- the resist layer forming step a resist layer 31 which covers a portion only corresponding to the transmissive filter 2 1 formed utilizing photolithographic technique. As a result, the structure shown in FIG.
- a wavelength selection layer patterning step is performed.
- the resist layer 31 as a mask, selectively etching the unnecessary portion of the wavelength selection layer 23 1 at the top of the thin film 21a as an etching stopper layer of the first multilayer film 21.
- the structure shown in FIG. in the wavelength selection layer patterning step, if the low refractive index material is an oxide (Al 2 O 3 ) and the high refractive index material is a semiconductor material (Ge) as described above, a hydrofluoric acid solution is used as an etching solution.
- the wet etching used it is possible to perform etching with a higher etching selectivity than when dry etching is employed.
- dilute hydrofluoric acid for example, dilute hydrofluoric acid having a hydrofluoric acid concentration of 2%) made of a mixture of hydrofluoric acid (HF) and pure water (H 2 O) is used as the hydrofluoric acid-based solution.
- the etching rate is about 300 nm / min of Al 2 O 3, the etching rate ratio of Al 2 O 3 and Ge 500: about 1. Therefore, etching with a high etching selectivity can be performed.
- a resist layer removing step is performed.
- the structure shown in FIG. 12D is obtained by removing the resist layer 31.
- a second multilayer film forming step is performed.
- a thin film 21 a having a predetermined physical film thickness (250 nm) made of Ge as a high refractive index material and Al 2 O 3 as a low refractive index material are formed on the entire surface of the wavelength selection layer 23.
- the second multilayer film 22 is formed by alternately laminating thin films 21b having a predetermined physical film thickness (588 nm). As a result, the structure shown in FIG.
- the second multilayer film forming process in the region corresponding to the transmissive filter 2 2, directly on the top layer of the thin film 21a of the first multilayer film 21, the bottom layer of the thin film 21a of the second multilayer film 22 Are stacked.
- the uppermost thin film 21 a of the first multilayer film 21 and the lowermost thin film 21 a of the second multilayer film 22 constitute the wavelength selection layer 23 2 of the transmission filter 2 2 .
- the transmission spectrum of the transmission filter 2 2, the optical thickness nd of the simulation results of FIG. 10 corresponds to the case of 0 nm.
- a film-forming method of each thin film 21a, 21b if the vapor deposition method, a sputtering method, etc.
- the low refractive index material is Al 2 O 3
- the wavelength selection layer forming process is performed once. Thereby, a plurality of transmission filter portions 2 1 and 2 2 are formed.
- the wavelength selective layer forming step includes a wavelength selective layer forming step and a wavelength selective layer patterning step.
- unnecessary portions other than the portion corresponding to the arbitrary one transmission filter 2 i in the wavelength selection layer 23 formed in the wavelength selection layer formation step are placed on the top of the laminated film. Etch the layer as an etching stopper layer.
- the wavelength selection layer forming step is performed a plurality of times in the middle of the above basic steps, the optical filter 20 having more selection wavelengths can be manufactured. Therefore, the optical filter 20 for sensing all the above gases (CH 4 , SO 3 , CO 2 , CO, NO) can be realized with one chip.
- a thin film made of the same material as the second layer from the top of the laminated film (here, the first multilayer film 21) already formed at that time during the basic process.
- a thin film having a set thickness is formed on the laminated film.
- a plurality of patterns of the wavelength selection layer 23 may be formed.
- the wavelength selection layer 23 2 when the optical film thickness than the wavelength selection layer 23 1 is the same material as and wavelength selection layer 23 1 is set small, halfway the thin film on the laminated film etching By doing so, the pattern of the two wavelength selection layers 23 1 and 23 2 may be formed.
- the far-infrared absorbing material of one of the two types of thin films 21a and 21b is SiO x or SiN x and the other thin film 21a is Si
- Si Alternatively, an ion beam assisted vapor deposition apparatus that uses as an evaporation source may be used.
- Thin film when forming a thin film 21a made of Si is set to a vacuum atmosphere, when forming the thin film 21b made of SiO x is an oxide illuminates the oxygen ion beam, consisting of SiN x is a nitride What is necessary is just to irradiate a nitrogen ion beam when forming 21b into a film.
- a vacuum atmosphere is used when the Si thin film 21a is formed
- an oxygen atmosphere is used when the SiO x thin film 21b is formed
- a nitrogen atmosphere is used when the SiN x thin film 21b is formed. That's fine. In this way, the same target can be used for the two types of thin films 21a and 21b. Therefore, it is not necessary to prepare a sputtering apparatus having a plurality of targets, and the manufacturing cost can be reduced.
- the infrared optical filter 20 having transmission peak wavelengths of 3.8 ⁇ m and 4.3 ⁇ m as shown in FIG. It can be realized with a chip.
- the first multilayer film 21 and the second multilayer film 22 need only have a refractive index periodic structure, and may be a laminate of three or more types of thin films.
- the cutoff filter 3 is a multilayer film formed by laminating a plurality of types (here, two types) of thin films 3a and 3b having different refractive indexes.
- Al 2 O 3 which is a kind of far-infrared absorbing material that absorbs far-infrared is adopted as the material of the thin film 3a which is a low-refractive index layer having a relatively low refractive index.
- Ge is adopted as the material of the thin film 3b which is a high refractive index layer having a high refractive index.
- the thin films 3 a and the thin films 3 b are alternately stacked, and the number of stacked layers is eleven. However, the number of stacked layers is not particularly limited.
- the uppermost layer farthest from the filter forming substrate 1 is constituted by the thin film 3a which is a low refractive index layer from the viewpoint of stability of optical characteristics.
- the far-infrared-absorbing material is not limited to Al 2 O 3, may be employed SiO 2, Ta 2 O 5 is an oxide other than Al 2 O 3. Since the refractive index of SiO 2 is lower than that of Al 2 O 3 , the refractive index difference between the high refractive index material and the low refractive index material can be increased. Further, as the far-infrared absorbing material, SiN x that is a nitride may be employed.
- the cutoff filter 3 is formed of Al 2 O 3 which is a far-infrared absorbing material in which one of the two types of thin films 3a and 3b absorbs far infrared rays. At least one of them may be formed of a far-infrared absorbing material.
- a far-infrared absorbing material For example, three types as the thin Ge film and the Al 2 O 3 film and the SiO x film, Ge film -Al 2 O 3 from the side close to the filter substrate 1 made of Si substrate film -Ge film -SiO x film -Ge
- a multilayer film may be laminated in the order of film-Al 2 O 3 film-Ge film. In this case, two kinds of thin films among the three kinds of thin films are formed of the far-infrared absorbing material.
- the above-described cutoff filter 3 absorbs far infrared rays having a longer wavelength range than the infrared reflection band set by the transmission filters 2 1 and 2 2 .
- the cutoff filter 3 employs Al 2 O 3 as a far-infrared absorbing material that absorbs infrared rays.
- MgF 2 as the far-infrared absorbing material, MgF 2 , Five types of Al 2 O 3 , SiO x , Ta 2 O 5 and SiN x were examined.
- FIG. 14 shows the results of analysis by FT-IR, where the horizontal axis indicates the wave number and the vertical axis indicates the absorption rate.
- S40 in FIG. 14 is the sample without ion beam assist, and S41, S42, S43, S44, and S45 show the analysis results of each sample when the ion beam irradiation amount is changed from the smaller one to the larger one. ing.
- the far-infrared absorptivity is higher than when the far-infrared absorbing material is SiO x or SiN x . Can be improved.
- the inventors of the present application measured a transmission spectrum of a reference example in which a 1 ⁇ m Al 2 O 3 film was formed on a Si substrate, and obtained an actual measurement value as shown in S50 of FIG. Moreover, the knowledge that measured value S50 has shifted
- both the refractive index and the absorption coefficient are not constant in the wavelength range of 800 nm to 20000 nm, and the refractive index gradually decreases as the wavelength increases. In the wavelength range of 7500 nm to 15000 nm, the absorption coefficient gradually increases as the wavelength increases.
- S60 of FIG. 16 shows the simulation result of the transmission spectrum about the optical filter 20 of the Example using the new optical parameter of the above-mentioned Al 2 O 3 film.
- transmission filter 2 1 the transmission peak wavelength has a laminated structure in the following Table 3 is 4.4 [mu] m
- cut-off filter 3 has a laminated structure of Table 4 .
- S61 in FIG. 16 without using a new optical parameter of the Al 2 O 3 film described above, Al 2 O 3 constant refractive index of the film, the optical filter 20 of the comparative example in which a constant absorption coefficient at 0 The simulation result about is shown. In each of the examples and comparative examples, simulation was performed with the refractive index of Ge being constant at 4.0 and the absorption coefficient being constant at 0.0.
- the horizontal axis indicates the wavelength of incident light (infrared rays), and the vertical axis indicates the transmittance.
- the wavelength at the cut-off filter 3 of the laminated number 29 and transmission filter 2 1 number of layers 11 can block the broadband infrared 800 nm ⁇ 20000 nm. As a result, a narrow transmission band can be localized only in the vicinity of 4.4 ⁇ m.
- the transmission spectrum of the cutoff filter 3 is, for example, as shown in FIG. In the example shown in FIG. 17, near infrared rays of 4 ⁇ m or less and far infrared rays of 5.6 ⁇ m or more are blocked.
- the transmission filters 2 1 and 2 2 may be formed as described above.
- the cutoff filter forming step the cutoff filter 3 is formed by alternately laminating thin films 3a made of, for example, Al 2 O 3 films and thin films 3b made of, for example, Ge films, on the second surface of the filter substrate 1 made of an Si substrate. .
- the infrared gas measurement device shown in FIG. 18 includes an infrared light source 10, a drive circuit 11, a lens 12, a chamber 13, an infrared light receiving element 40, an optical filter 20, an amplifier circuit 63a, an arithmetic circuit ( (Not shown).
- the infrared light source 10 is, for example, a halogen lamp.
- the drive circuit 11 is configured to drive the infrared light source 10.
- the lens 12 is configured to collimate infrared rays emitted from the infrared light source 10.
- the chamber 13 is formed with a gas inflow passage 13b through which a measurement gas (detection target gas) is introduced and a gas exhaust passage 13c through which the measurement gas is discharged.
- the amplifier circuit 63a is configured to amplify the output of the infrared light receiving element 40 (the differential output of the pair of pyroelectric elements 4 1 and 4 2 ).
- the arithmetic circuit is configured to perform an operation for obtaining the gas concentration based on the output of the amplifier circuit 63a.
- the infrared gas measuring apparatus having the configuration shown in FIG. 18 radiates infrared rays from the infrared light source 10 to a predetermined space that is an internal space of the chamber 13 and uses absorption of infrared rays in the detection target gas in the predetermined space. To detect the target gas.
- This infrared gas measuring device includes the above-described infrared gas detector as an infrared light receiving unit that receives infrared light emitted from the infrared light source 10 and passed through a predetermined space. Note that although the amplifier circuit 63a and the arithmetic circuit are provided in the integrated circuit 63 described above, these circuits may be provided outside the package 7.
- the infrared light source 10 that generates infrared rays by heat radiation such as a halogen lamp
- the emission spectrum is very broad compared to the light emitting diode.
- the object is a black body
- the intensity (light emission power) of the light emitted from the infrared light source 10 is modulated by the drive circuit 11.
- the drive circuit 11 is configured to periodically change the intensity of light emitted from the infrared light source 10 at a constant period.
- the drive circuit 11 may change the intensity
- the infrared light source 10 is not limited to a halogen lamp.
- the infrared light source 10 may include an infrared radiation element 110 and a package 100 including a can package that houses the infrared radiation element 110.
- the infrared radiation element 110 includes a support substrate 111 made of a single crystal silicon substrate (semiconductor substrate), a heater layer (heating element layer) 114 formed on one surface of the support substrate 111, a heater layer 114, and the support substrate 111. And a heat insulating layer 113 made of a porous silicon layer.
- the infrared radiation element 110 includes a pair of pads 115 and 115 electrically connected to the heater layer 114.
- the pads 115 and 115 are electrically connected to terminal pins 125 and 125 through bonding wires 124 and 124, respectively.
- infrared voltage is radiated from the heater layer 114 by applying a voltage between the pair of terminal pins 125 and 125 and applying input power to the heater layer 114.
- a window hole 100 a located in front of the infrared radiation element 110 is formed in the package 100.
- the window hole 100a is closed by an optical member 130 that transmits infrared rays.
- an insulating film 112 made of a silicon oxide film is formed on the surface of the support substrate 111 where the thermal insulating layer 113 is not formed.
- the material of the heater layer 114 is not particularly limited.
- W, Ta, Ti, Pt, Ir, Nb, Mo, Ni, TaN, TiN, NiCr, conductive amorphous silicon, or the like can be used.
- the support substrate 111 is formed of a single crystal silicon substrate, and the thermal insulation layer 113 is formed of a porous silicon layer. Therefore, each of the heat capacity and the thermal conductivity of the support substrate 111 is larger than that of the heat insulating layer 113. Therefore, the support substrate 111 has a function as a heat sink. Therefore, it is small in size, has a high response speed to the input voltage or input current, and can improve the stability of infrared radiation characteristics.
- the gas to be measured is CO 2
- the intensities (powers) P 1 and P 2 of the infrared rays transmitted through the transmission filters 2 1 and 2 2 are expressed by the following formulas (1) and (2), respectively.
- I 1 ⁇ 1 P a cos ( ⁇ t) ⁇ (3)
- I 2 ⁇ T (C) ⁇ 2 P a cos ( ⁇ t) (4)
- the two pyroelectric elements 4 1 and 4 2 are connected so as to obtain a differential output of the two pyroelectric elements 4 1 and 4 2 . Therefore, when the output of the infrared light receiving element 40 is I, the output I is expressed by the following equation (5).
- the DC bias component bias component due to extraneous light such as miscellaneous gas or sunlight
- the DC bias component bias component due to extraneous light such as miscellaneous gas or sunlight
- the dynamic range of the output of the infrared light receiving element 40 can be increased.
- the size can be reduced. Can be planned.
- the gain of the amplifier circuit 63a can be increased and the S / N ratio can be improved.
- the infrared gas detector of the present embodiment includes an infrared light receiving element (infrared light receiving unit) 40, a package 7 that houses the infrared light receiving element 40, and the optical filter 20.
- the infrared light receiving element 40 includes a plurality of thermal infrared detecting elements (pyroelectric elements) 4 1 and 4 2 that detect infrared rays using heat.
- the plurality of pyroelectric elements 4 1 and 4 2 are arranged side by side.
- the package 7 has a window hole 7 a for allowing infrared rays to enter the infrared light receiving element 40.
- the optical filter 20 is joined to the package 7 so as to close the window hole 7a, and has a plurality of filter element portions respectively corresponding to the plurality of pyroelectric elements 4 1 and 4 2 .
- Each filter element unit includes a filter substrate 1 formed of a material that transmits infrared rays, a transmission filter 2 configured to selectively transmit infrared rays having a predetermined selection wavelength, and a selection wavelength of the transmission filter 2. And a cutoff filter 3 configured to absorb infrared rays having a long wavelength.
- the transmission filter 2 and the cutoff filter 3 are each formed on the filter substrate 1.
- Filter substrate 1 is thermally coupled to package 7.
- the transmission wavelengths 2 1 and 2 2 of the filter element units have different selection wavelengths.
- the infrared gas detector of the present embodiment heat generated by absorbing infrared rays in the cutoff filter 3 is efficiently radiated through the package 7. Therefore, the temperature rise and temperature distribution of the transmission filters 2 1 and 2 2 can be suppressed, and high sensitivity can be achieved at low cost.
- the circuit block 9 is housed in the package 7, but is radiated from the circuit component due to the temperature rise of the circuit component of the circuit block 9 and reflected by the inner wall surface of the package 7. Infrared light can be absorbed by the cutoff filter 3, and high sensitivity can be achieved by improving the S / N ratio.
- two pairs of pyroelectric elements 4 1 and 4 2 are connected in anti-series or anti-parallel on the pyroelectric element-forming substrate 41, but two pairs of pyroelectric elements. 4 1, 4 2 without connecting the two pair of pyroelectric element 4 1, 4 2 of the amplifier circuit for amplifying the difference between the respective outputs may be provided with (differential amplifier circuit).
- the size and cost can be reduced as compared with the case where a plurality of amplifier circuits for individually amplifying the outputs of the pyroelectric elements 4 1 and 4 2 are provided.
- the filter substrate 1 has a first surface facing the inside of the package 7 and a second surface facing the outside of the package 7.
- the transmission filter 2 is formed on the first surface of the filter substrate 1
- the cutoff filter 3 is formed on the second surface of the filter substrate 1. Therefore, the heat generated by absorbing the infrared rays in the cutoff filter 3 is not easily transferred to the pyroelectric elements 4 1 and 4 2 . Therefore, compared with the case where the cutoff filter 3 is formed on the first surface of the filter substrate 1, the responsiveness can be improved while reducing the height of the package 7.
- the transmission filters 2 1 and 2 2 are formed on the first surface of the filter substrate 1, it is possible to suppress the occurrence of crosstalk due to infrared rays incident on the optical filter 20 from an oblique direction. Therefore, high sensitivity can be achieved by increasing the light receiving area of the pyroelectric elements 4 1 and 4 2 .
- the infrared light receiving element 40 includes a pair of pyroelectric elements 4 3 and 4 4 in addition to the pair of pyroelectric elements 4 1 and 4 2. May be provided. These pyroelectric elements 4 1 , 4 2 , 4 3 and 4 4 are connected as shown in FIGS. 24B and 24C so that a differential output can be obtained.
- the optical filter 20 may have the transmission filter 2 corresponding to each pyroelectric element 4 1 , 4 2 , 4 3 , 4 4 .
- two types of gas can be detected.
- each of the transmission filters 2 1 and 2 2 includes the first multilayer film 21, the second multilayer film 22, the first multilayer film 21, and the second multilayer film 22. And a wavelength selection layer 23 interposed therebetween.
- the first multilayer film 21 and the second multilayer film 22 are formed by laminating a plurality of types of thin films 21 a and 21 b having different refractive indexes and the same optical film thickness.
- the optical film thickness of the wavelength selection layer 23 is set to a size different from the optical film thickness of the thin films 21a and 21b according to the selection wavelength of the transmission filters 2 1 and 2 2 . Therefore, the optical filter 20 can be reduced in size and the cost can be reduced.
- the distance between the centers of the plurality of transmission filters 2 1 and 2 2 can be shortened, and the difference in optical path length between the detection light and the reference light can be reduced. Therefore, the light receiving efficiency of the pyroelectric elements 4 1 and 4 2 of the infrared light receiving element 40 can be improved.
- the filter substrate 1 is shared by a plurality of filter element portions, compared with the case where the transmission filters 2 1 and 2 2 are formed on different filter substrates 1.
- the plurality of filter element units may be individual parts.
- the package 7 is provided with as many window holes 7a as the number of filter element portions. That is, the optical filter 20 includes a plurality of filter element portions that are joined to the package 7 so as to close the window holes 7a.
- the cutoff filter 3 is a multilayer film formed by laminating a plurality of types of thin films 3a and 3b having different refractive indexes. At least one type of thin film 3a among the plurality of types of thin films 3a, 3b is formed of a far infrared ray absorbing material that absorbs far infrared rays. Therefore, an infrared blocking function in a wide band from near infrared rays to far infrared rays can be realized by the light interference effect by the multilayer film constituting the cutoff filter 3 and the far infrared ray absorption effect of the thin film 3a constituting the multilayer film. Therefore, since it is not necessary to use a sapphire substrate, the cost can be reduced.
- the infrared type gas detector of the present embodiment also in the transmission filters 2 1 and 2 2 , the light interference effect by the first multilayer film 21 and the second multilayer film 22, the first multilayer film 21 and the wavelength selection layer.
- the far-infrared absorption effect of the far-infrared absorbing material of the thin film 21b in the multilayer film composed of 23 1 , 23 2 and the second multilayer film 22 it has an infrared blocking function in a wide band from near infrared to far infrared.
- the optical filter 20 that has an infrared ray blocking function in a wide band from the near infrared ray to the far infrared ray and can selectively transmit infrared rays having a desired selection wavelength.
- the optical filter 20 since the optical filter 20 employs an oxide or nitride as the far infrared ray absorbing material, it prevents the thin film 3a, 21b made of the far infrared ray absorbing material from being oxidized and changing its optical characteristics. be able to.
- the uppermost layer farthest from the filter substrate 1 is formed of the above-described oxide or nitride in both the cutoff filter 3 and the transmission filters 2 1 and 2 2 . For this reason, it is possible to prevent the physical properties of the uppermost thin films 3a and 21b from being changed due to reaction with moisture or oxygen in the air, adsorption or adhesion of impurities, and the like. Therefore, the stability of the filter performance is increased. Further, since the reflection on the surfaces of the cutoff filter 3 and the transmission filters 2 1 and 2 2 can be reduced, the filter performance can be improved.
- the blocking filter 3 alternately includes the thin film 3a formed of the far infrared absorbing material and the thin film 3b formed of Ge which is a higher refractive index material than the far infrared absorbing material. It is a multilayer film formed by laminating. Therefore, the refractive index difference between the high refractive index material and the low refractive index material can be increased as compared with the case where the high refractive index material is Si, PbTe, or ZnS. Therefore, the number of multilayer films constituting the cutoff filter 3 can be reduced.
- the difference in refractive index between the high refractive index material and the low refractive index material in the multilayer film may be larger than when the high refractive index material is ZnS. it can. Therefore, the number of multilayer films constituting the cutoff filter 3 can be reduced. Further, regarding the transmission filters 2 1 and 2 2 , the number of stacked layers can be reduced for the same reason.
- a Si substrate is used as the filter substrate 1, but the filter substrate 1 is not limited to the Si substrate, and a Ge substrate may be used.
- the data disclosed on the Internet regarding the transmission characteristics of Si and Ge are shown in FIGS. 25 and 26, respectively ([Search February 25, 2009], Internet ⁇ URL: http://www.spectra.co .jp / kougaku.files / k # kessho.files / ktp.htm>).
- the manufacturing cost can be reduced as compared with the case where a sapphire substrate, a MgO substrate, or a ZnS substrate is used.
- Ge has a relatively high thermal conductivity, and especially Si has a high thermal conductivity. Therefore, the temperature rise of the filter substrate 1 can be suppressed, and infrared radiation due to the temperature rise of the optical filter 20 can be suppressed.
- the package 7 is made of metal, and the conductive filter substrate 1 such as Si or Ge is attached to the cap 72 of the package 7 with a conductive bonding material (for example, silver paste). , Solder, etc.). That is, the filter substrate 1 is electrically connected to the package 7. Therefore, electromagnetic shielding can be performed between the filter substrate 1 and the package 7. Therefore, it is possible to prevent the infrared light receiving element 40 from being affected by external radiation noise (electromagnetic noise), and high sensitivity can be achieved by improving the S / N ratio.
- a conductive bonding material for example, silver paste). , Solder, etc.
- the window hole 7a is rectangular shape.
- the optical filter 20 is formed with a stepped portion 20c positioned on the inner peripheral surface and the peripheral portion of the window hole 7a in the cap 72.
- the step portion 20 c is fixed to the cap 72 via the joint portion 58. Therefore, the parallelism between the optical filter 20 and the infrared light receiving element 40 can be increased.
- the distance accuracy between the transmission filters 2 1 and 2 2 and the pyroelectric elements 4 1 and 4 2 of the infrared light receiving element 40 in the optical axis direction of the transmission filters 2 1 and 2 2 of the optical filter 20 is improved.
- the alignment accuracy between the optical axes of the transmission filters 2 1 and 2 2 and the optical axes of the light receiving surfaces of the pyroelectric elements 4 1 and 4 2 can be increased.
- an amplification circuit 63a (a component thereof) for amplifying the output of the infrared light receiving element 40 is housed in the package 7. Therefore, the electrical path between the infrared light receiving element 40 and the amplifier circuit 63a can be shortened.
- the amplifier circuit 63a is also electromagnetically shielded. Therefore, high sensitivity can be achieved by further improving the S / N ratio.
- the pyroelectric elements 4 1 and 4 2 are exemplified as the thermal infrared detection element.
- the thermal infrared detection element is not limited to this, for example, a thermopile as shown in FIG. It may be a resistance bolometer type infrared detecting element.
- the outputs of a pair of thermopile may be differentially amplified by a differential amplifier circuit.
- a pair of thermopiles TP1 and TP2 may be connected in anti-series and the output voltage Vout may be amplified by an amplifier circuit.
- thermopiles TP1 and TP2 may be connected in antiparallel to amplify the output voltage with an amplifier circuit.
- a bridge circuit may be configured by a pair of resistance bolometer type infrared detection elements and two fixed resistors having the same resistance value. In this case, the presence or concentration of the detection target gas may be obtained based on the output of the bridge circuit.
- the thermal infrared detection element having the configuration shown in FIG. 27 described above is formed on a support substrate 42 made of a single crystal silicon substrate having a main surface of ⁇ 100 ⁇ plane, and formed on the main surface of the support substrate 42.
- a membrane part 43 made of a supported silicon nitride film and a thermopile TP formed on the opposite side of the membrane part 43 from the support substrate 42 side are provided.
- An opening 42a that is opened in a rectangular shape is formed in the support substrate 42 so as to expose the surface of the membrane portion 3 on the support substrate 42 side.
- the opening 42a is formed using wet anisotropic etching utilizing the crystal orientation dependence of the etching rate.
- the thermopile TP is composed of a plurality of thermocouples connected in series with each other.
- thermocouples is an elongated first thermoelectric element 44 formed across the region of the membrane portion 43 that overlaps the opening portion 42a of the support substrate 42 and the region that overlaps the peripheral portion of the opening portion 42a of the support substrate 42. And an elongated second thermoelectric element 45.
- a hot junction is formed by a joint portion between one end portions of the first thermoelectric element 44 and the second thermoelectric element 45, and the other end portion of the first thermoelectric element 44 of the thermocouple different from each other and the second thermoelectric element 45.
- a cold junction is formed at the junction with the other end of the thermoelectric element 45.
- the first thermoelectric element 44 is formed of a material having a positive Seebeck coefficient
- the second thermoelectric element is formed of a material having a negative Seebeck coefficient.
- the main surface of the support substrate 42 is insulated to cover the portions where the thermoelectric elements 44 and 45 are not formed in the thermoelectric elements 44 and 45 and the membrane portion 43.
- a film 46 is formed.
- an infrared absorbing portion 47 is formed to cover a predetermined region including each hot junction of the thermopile TP.
- the infrared absorbing portion 47 is formed using an infrared absorbing material (for example, gold black).
- the pair of pads 49, 49 of the infrared light receiving element 40 are exposed through an opening (not shown) formed in the insulating film 46.
- the insulating film 46 is, for example, a laminated film of a BPSG film, a PSG film, and an NSG film. However, the insulating film 46 may be a laminated film of a BPSG film and a silicon nitride film, for example.
- FIG. 27B is a schematic cross-sectional view corresponding to the X-X ′ cross section of FIG. 27A, and the insulating film 46 is not shown in FIG. 27A.
- the basic configuration of the infrared light receiving element 40 having the configuration shown in FIG. 28 is substantially the same as that of the thermal infrared detecting element having the configuration shown in FIG. 27, and two thermopiles TP1, TP1, 1 having the same configuration as the thermopile TP in FIG.
- the only difference is that the two thermopiles TP1 and TP2 are connected in reverse series via the metal layer 48 (in series connection with reverse polarity).
- the two thermopiles TP1 and TP2 described above may be connected in antiparallel (parallel connection with reverse polarity).
- thermopile TP1 and TP2 in anti-series or anti-parallel, it is possible to cancel the DC bias components of the two thermopiles that form a pair, and to increase the dynamic range of the output of the infrared light receiving element 40. it can.
- the size can be reduced.
- the gain of the amplifier circuit 63a can be increased and the S / N ratio can be improved.
- an infrared gas measuring device used for applications such as a gas leak alarm will be described.
- this type of infrared gas measuring device has an infrared light source 1001 that emits infrared light by inputting an electric signal, and an infrared sensor (infrared detector) 1002 that detects infrared light. Yes.
- a gas detection tube 1003 is disposed between the infrared light source 1001 and the infrared sensor 1002.
- a detection target gas (measurement gas) is introduced into the gas detection tube 1003.
- the infrared sensor 102 the infrared detector described in the first embodiment can be employed.
- the gas detection tube 1003 has a conduit 1031 for guiding infrared rays from the infrared light source 1001 to the infrared sensor 1002.
- the inner peripheral surface of the pipe line 1031 is configured to reflect infrared rays.
- a reflection film that reflects infrared rays is formed on the inner peripheral surface of the pipe line 1031.
- the reflective film is, for example, a metal thin film such as Au, and is formed on the entire inner peripheral surface of the pipe line 1031 by a thin film forming method such as sputtering (in this case, the surface of the reflective film is substantially the tube surface). This is the inner peripheral surface of the path 1031).
- the gas detection tube 1003 may be formed of a material that reflects infrared rays.
- the infrared rays emitted from the infrared light source 1001 are repeatedly reflected on the inner peripheral surface of the pipe line 1031 and reach the infrared sensor 1002 as indicated by a broken line in FIG.
- the gas detection tube 1003 has a large number of communication holes 1032 that allow the internal space of the conduit 1031 to communicate with the external space.
- the communication hole 1032 is provided through the pipe wall of the pipe line 1031. Therefore, the detection target gas existing in the external space of the pipe line 1031 is introduced into the internal space of the pipe line 1031 through the communication hole 1032. If the detection target gas exists in the pipe line 1031 of the gas detection tube 1003, a part of the infrared ray emitted from the infrared light source 1001 is absorbed or reflected by the detection target gas. Changes. By detecting this change in received light intensity, it is possible to detect the presence and concentration of the detection target gas. That is, the detection target gas is detected using the internal space of the pipe line 1031 as a monitoring space.
- the pipe line 1031 may be a straight pipe, it is preferably in a meandering shape as shown in FIG. Since the inner peripheral surface of the pipe line 1031 reflects infrared rays, infrared rays can be transmitted from the infrared light source 1001 to the infrared sensor 1002 even if the pipe line 1031 is formed in a meandering shape.
- the infrared path from the infrared light source 1001 to the infrared sensor 1002 can be lengthened. Therefore, the distance that infrared rays pass through the detection target gas introduced into the pipe line 1031 becomes long. Therefore, it becomes easy to detect the influence on the infrared rays by the detection target gas existing in the pipe line 1031.
- the sensitivity to the detection target gas can be increased by using the meandering gas detection pipe 1003 (the pipe line 1031).
- the infrared light source 1001 emits infrared rays intermittently when a voltage is intermittently applied from the drive circuit 1004. That is, the drive circuit 1004 is configured to drive the infrared light source 1001 so that the infrared light source 1001 emits infrared light intermittently.
- the infrared light source 1001 is configured so that the rise time from the start of energization is short and the fall time from the end of energization is short. A specific configuration of the infrared light source 1001 will be described later.
- the voltage waveform applied from the drive circuit 1004 to the infrared light source 1001 is a single pulse wave or a burst wave composed of a plurality of (about 5 to 10) pulses.
- the time interval for applying the voltage to the infrared light source 1001 is set to 10 to 60 s, for example.
- the time for applying voltage to the infrared light source 1001 depends on the response speed of the infrared sensor 1002, but is set to 100 ⁇ s to 10 ms, for example. When burst waves are used, the duration is about 100 ms, for example. And
- the infrared light source 1001 includes a metal package (can package) 1010 and a radiating element (infrared radiating element) 1011 housed in the can package 1010.
- a window hole 1012 positioned in front of the radiating element 1011 is formed in the package 1010.
- a projection lens 1013 is attached to the window hole 1012.
- the light projection lens 1013 is formed using Si as a material, and is formed by a semiconductor process.
- two lead pins 1014 for connecting the radiating element 1011 to the drive circuit 1004 are projected from the package 1010.
- the light projection lens 1013 is formed with an infrared antireflection film on both sides so as to suppress reflection in a specific wavelength band necessary for gas detection.
- a condensing mirror may be provided instead of the light projecting lens 1013.
- the infrared sensor 1002 includes a metal package (can package) 1020 and two light receiving elements 1021a and 1021b including pyroelectric elements housed in the package 1020.
- the package 1020 is formed with one window hole 1022 positioned in front of the two light receiving elements 1021a and 1021b.
- a filter (optical filter) 1029 for selecting the wavelength of infrared light that enters the light receiving elements 1021 a and 1021 b from the internal space of the pipe line 1031 is attached to the window hole 1022.
- a lead pin 1024 for connecting the light receiving elements 1021 a and 1021 b to the detection circuit 1005 is projected from the package 1020.
- the light receiving elements 1021a and 1021b can be either a thermal infrared detecting element or a quantum infrared detecting element, but it is preferable to use a thermal infrared detecting element such as a pyroelectric element.
- the thermal infrared detection element is easier to handle than the quantum infrared detection element, is highly sensitive, and is inexpensive.
- the filter 1029 includes two transmission filters (narrow band transmission filter units) 1025a and 1025b and one wide band cutoff filter unit (removal filter, cutoff filter) 1026.
- the two transmission filters 1025a and 1025b are respectively arranged on the incident paths of infrared rays from the monitoring space, which is the internal space of the pipe line 1031, to the light receiving elements 1021a and 1021b, and selectively transmit infrared rays in a specific wavelength band. It is configured.
- the cutoff filter 1026 is configured to absorb infrared rays in a wavelength range other than infrared rays in a specific wavelength band that passes through the transmission filters 1025a and 1025b.
- the two transmission filters 1025a and 1025b and the cutoff filter 1026 are overlapped.
- the filter 1029 has a filter substrate (filter forming substrate) 1023 made of Si.
- Two transmission filters 1025a and 1025b are formed side by side on the first surface of the filter substrate 1023 (one surface on the light receiving elements 1021a and 1021b side).
- a blocking filter 1026 is formed on the second surface (other surface) of the filter substrate 1023. That is, each of the transmission filters 1025a and 1025b is disposed on an infrared incident path from the monitoring space to each of the light receiving elements 1021a and 1021b.
- the cutoff filter 1026 is disposed between the monitoring space and the transmission filters 1025a and 1025b. Therefore, after the wavelength band transmitted by the removal filter 1026 is narrowed by infrared light from the monitoring space, only the specific wavelength band is selectively transmitted by the transmission filters 1025a and 1025b and reaches the light receiving elements 1021a and 1021b.
- the transmission filters 1025a and 1025b each have a narrow band transmission characteristic in the mid-infrared or far-infrared wavelength range radiated by the radiating element 1011.
- the transmission characteristics are designed so that one transmission filter 1025a transmits a specific wavelength band where absorption by the detection target gas occurs, and the other transmission filter 1025b transmits a specific wavelength band where absorption by the detection target gas does not occur.
- the transmission filter 1025a is configured to transmit a specific wavelength band corresponding to the detection target gas.
- the detection target gas is carbon dioxide, it is configured to transmit a specific wavelength band centered at 4.3 ⁇ m, and when the detection target gas is carbon monoxide, the specific wavelength centered at 4.7 ⁇ m.
- the detection target gas is methane, the detection target gas is configured to transmit a specific wavelength band centered on 3.3 ⁇ m.
- the transmission filter 25b is configured to transmit, for example, a specific wavelength band centered on 3.9 ⁇ m so that absorption by these detection target gases does not occur.
- the transmission filters 1025a and 1025b include a first ⁇ / 4 multilayer film (first multilayer film) 1127a, a second ⁇ / 4 multilayer film (second multilayer film) 1127b, A wavelength selection layer 1028 interposed between the first multilayer film 1127a and the second multilayer film 1127b.
- the first multilayer film 1127a and the second multilayer film 1127b are formed by laminating a plurality of types of thin films 1027x and 1027y having different refractive indexes and the same optical film thickness. In the example shown in FIG. 31, thin films 1027x and thin films 1027y are alternately stacked.
- the first multilayer film 1127a and the second multilayer film 1127b are multilayer films having a periodic structure.
- the optical film thickness of the wavelength selection layer 1028 is set to a size different from the optical film thickness of the thin films 1027x and 1027y according to the selection wavelength (specific wavelength band) of the transmission filters 1025a and 1025b. Note that the wavelength selection layer 1028 may be omitted depending on the selection wavelength of the transmission filters 1025a and 1025b.
- the thin films 1027x and 1027y are each configured to have an optical film thickness of a quarter wavelength.
- the cutoff filter 1026 is an infrared absorption layer formed of a material that absorbs infrared rays (infrared absorption material). Al 2 O 3 or Ta 2 O 3 is used as the infrared absorbing layer material.
- the cutoff filter 1026 may be a multilayer filter, similar to the transmission filters 1025a and 1025b. That is, the cutoff filter 1026 may be a multilayer film formed by laminating a plurality of types of thin films having different refractive indexes.
- Al 2 O 3 which is a kind of far-infrared absorbing material that absorbs far-infrared can be adopted as a thin film material that is a low-refractive index layer having a relatively low refractive index.
- Ge can be adopted as a material for a thin film which is a high refractive index layer having a high refractive index. That is, at least one layer of the multilayer filter is an infrared absorbing layer that absorbs far infrared rays having a longer wavelength than the specific wavelength band that transmits the transmission filters 1025a and 1025b.
- the cutoff filter 1026 is the above-described infrared absorption layer, it is possible to absorb infrared on a longer wavelength side than the specific wavelength band over a wide band without absorbing the infrared of the specific wavelength band transmitted through the transmission filters 1025a and 1025b. Further, in the case where the cutoff filter 1026 is the multilayer filter described above, it is possible to prevent an infrared ray in an unnecessary wavelength region from being incident on the light receiving elements 1021a and 1021b by using not only the absorption of infrared rays but also reflection.
- FIG. 32 shows the relationship between the characteristics of the transmission filters 1025a and 1025b (the characteristic S70 is the transmission filter 1025a and the characteristic S71 is the transmission filter 1025b) and the cutoff filter 1026 (characteristic S72).
- the cutoff filter 1026 removes the infrared light in the unnecessary wavelength region on the long wavelength side (the far infrared wavelength region) without absorbing it. Therefore, in the short wavelength side wavelength range (mid-infrared to far-infrared wavelength range) that has passed through the cutoff filter 1026, infrared rays of a specific wavelength band pass through the narrow-band transmission filters 1025a and 1025b.
- the filter substrate 1023 has a function of supporting the transmission filters 1025a and 1025b and the cutoff filter 1026. Further, the filter substrate 1023 is thermally coupled to the package 20 and thereby has a function of radiating heat from the cutoff filter 1026.
- the filter substrate 1023 is formed of a material that transmits infrared light in a specific wavelength band that transmits through the transmission filters 1025a and 1025b.
- a material of the filter substrate 1023 for example, Ge or ZnS can be used in addition to the above-described Si.
- the difference or ratio between the output values (outputs) of the two light receiving elements 1021a and 1021b may be obtained.
- the outputs of both the light receiving elements 1021a and 1021b when the detection target gas does not exist in the gas detection tube 1003 are Va and Vb, respectively.
- the light receiving intensity decreases when carbon dioxide is present in the light receiving element 1021a in which the transmission filter 1024a is disposed in the front, and the light receiving element 1021b in which the transmission filter 1024b is disposed in the front receives light even if carbon dioxide is present. Strength does not decrease. Therefore, it is reasonable to assume that only the output of the light receiving element 1021a decreases when the detection target gas exists.
- the difference between the outputs of the two light receiving elements 1021a and 1021b changes from (Va ⁇ Vb) to (Va ⁇ V ⁇ Vb), and the ratio of the outputs of the two light receiving elements 1021a and 1021b is ⁇ Va / Vb) It changes to (Va ⁇ V) / Vb ⁇ .
- the difference between the outputs of the light receiving elements 1021a and 1021b can be obtained using the polarity of the pyroelectric elements.
- both light receiving elements 1021a and 1021b may be connected in reverse series.
- a differential amplifier differential amplifier circuit
- the difference between the outputs of both the light receiving elements 1021a and 1021b can be obtained regardless of the type of the light receiving elements 1021a and 1021b.
- the difference between the light receiving elements 1021a and 1021b is output to the detection circuit 1005 by connecting the light receiving elements 1021a and 1021b in reverse series.
- the detection circuit 1005 detects, for example, the presence of carbon dioxide having a predetermined concentration or more as a target gas in the gas detection tube 1003 from the difference between the outputs of the light receiving elements 1021a and 1021b.
- the detection circuit 1005 may be provided either inside the package 1020 or outside.
- the detection circuit 1005 is configured to determine whether or not the concentration of the detection target gas in the gas detection tube 1003 is equal to or higher than a specified value, and to output an alarm signal when the concentration of the detection target gas exceeds a predetermined value. Yes.
- the alarm signal is output to an alarm device that gives an alarm audibly or visually.
- the detection circuit 1005 includes, for example, a current-voltage conversion circuit, a comparator, and an output circuit.
- the current-voltage conversion circuit has an integration function that averages the outputs of the light receiving elements 1021a and 1021b corresponding to burst waves.
- the comparator is configured to compare the output value of the current-voltage conversion circuit with a threshold value.
- the output circuit is configured to output an alarm signal based on the comparison result of the comparator.
- the detection circuit 1005 is not limited to the above configuration.
- the detection circuit 1005 may be configured to generate an output corresponding to the concentration of the detection target gas.
- the detection circuit 1005 includes the current-voltage conversion circuit, a conversion circuit that converts the output value of the current-voltage conversion circuit into the concentration of the detection target gas, and the concentration of the detection target gas based on the conversion result of the conversion circuit. And an output circuit for generating an output corresponding to.
- the radiating element 1011 is required to have a response speed of about 10 ⁇ s to 10 ms.
- An example of the radiating element 1011 that satisfies this requirement is shown in FIG.
- the configuration of the radiating element 1011 illustrated in FIG. 33 is an example, and the present invention is not limited to this configuration.
- the 33 includes a substrate 1041, a holding layer 1042, and an infrared radiation layer 1043.
- the holding layer 1042 is a thin film formed on one surface of the substrate 1041.
- the infrared radiation layer 1043 is a thin film stacked on the surface of the holding layer 1042 opposite to the substrate 1041 side.
- the infrared radiation layer 1043 is configured to emit infrared light by heat generated by energization.
- a gas layer 1044 having a small thickness and surrounded by part of the substrate 1041 and the holding layer 1042 is formed on one surface of the substrate 1041 where the holding layer 1042 is provided.
- the radiating element 1011 includes a gas layer 1044 interposed between the substrate 1041 and the holding layer 1042.
- a recess 1046 is formed on one surface of the substrate 1041.
- the upper surface of the recess 1046 is closed by the holding layer 1042.
- a space between the inner surface of the recess 1046 and the holding layer 1042 is used as the gas layer 1044.
- the substrate 1041 is a semiconductor substrate (for example, a single crystal silicon substrate) and is formed in a rectangular parallelepiped shape.
- the holding layer 1042 is formed by making the substrate 1041 porous by performing anodization on a region where the peripheral portion of one surface of the substrate 1041 is left.
- the anodizing conditions are appropriately set according to the conductivity type and conductivity of the substrate 1041.
- a holding layer 1042 made of a porous semiconductor layer (for example, a porous silicon layer) having a porosity of approximately 70% is formed.
- the conductivity type of the substrate 1041 may be either p-type or n-type.
- the p-type silicon substrate has a porosity higher than that of the n-type silicon substrate when anodized. Easy to grow. Therefore, it is desirable to use a p-type silicon substrate for the substrate 41.
- the holding layer 1042 formed by making a part of the substrate 1041 porous by anodic oxidation has features of low heat capacity and thermal conductivity, high heat resistance, and smooth surface. Further, in order to reduce the thermal conductivity of the holding layer 1042, part or all of the holding layer 1042 may be oxidized or nitrided. If the oxidation or nitridation is performed, the electrical insulation is increased.
- the holding layer 1042 may be a semiconductor oxide film formed by thermal oxidation. Further, instead of forming the semiconductor oxide film to be the holding layer 1042 by thermal oxidation, the holding layer 1042 made of a material containing an oxide can be formed by a CVD method. If the holding layer 1042 is formed by thermal oxidation or CVD, the manufacturing process is simplified as compared with the case where the holding layer 1042 is formed by making it porous, so that mass productivity can be improved. Note that in the case where the holding layer 1042 is formed by a CVD method, an oxide with high thermal insulation such as alumina or a material containing this kind of oxide can be used. The holding layer 1042 can also be formed of a porous body of this kind of material.
- the infrared radiation layer 1043 is formed of a material selected from TaN and TiN. Since these materials are excellent in heat resistance and oxidation resistance, the infrared radiation layer 1043 can be used in an air atmosphere. Therefore, the radiating element 1011 can be mounted on the substrate as a bare chip without being housed in the package. Further, even when the radiating element 1011 is housed in the package, it is not necessary to close the window hole formed in the package with the window member in order to emit infrared rays from the radiating element 1011. Therefore, since infrared rays are not attenuated by the window member, infrared radiation efficiency can be increased. These materials have a physical property that the sheet resistance becomes a desired value in a thickness dimension (several tens of nm) suitable for ensuring responsiveness while satisfying the durability as the infrared radiation layer 1043.
- the infrared radiation layer 1043 can be formed at a predetermined position by reactive sputtering with TaN. Then, by controlling the partial pressure of nitrogen gas, the sheet resistance can be formed to a desired value at a predetermined heat generation temperature.
- materials other than TaN and TiN can be used as the material for forming the infrared radiation layer 1043, and other metal nitrides or metal carbides may be used.
- the driving voltage can be reduced for the infrared radiation layer 1043 having a lower sheet resistance if the power applied to the infrared radiation layer 1043 is the same. . If the drive voltage is low, loss due to boosting can be reduced. In addition, since the electric field strength in the radiating element 1011 is reduced, the radiating element 1011 can be prevented from being damaged. Therefore, it is desirable that the sheet resistance is small.
- the infrared radiation layer 1043 has a negative resistance temperature coefficient in which the sheet resistance decreases as the temperature increases. Therefore, even if the driving voltage is the same, the sheet resistance decreases as the temperature increases, and the current flowing through the infrared radiation layer 1043 increases. That is, as the temperature rises, the input power increases, and the ultimate temperature can be increased.
- the temperature coefficient of resistance is set to ⁇ 0.001 [° C. ⁇ 1 ] when the material of the infrared radiation layer 1043 is TaN. In this case, if the highest temperature reached is 500 [° C.] and the sheet resistance at the highest temperature is 300 [ ⁇ sq], the sheet resistance of the infrared radiation layer 1043 at room temperature is 571 [ ⁇ sq].
- the booster circuit when the drive voltage is generated using the booster circuit, the booster circuit is provided while increasing the maximum temperature at the highest point by giving the infrared radiation layer 1043 a negative resistance temperature coefficient as described above. An increase in the step-up ratio can be suppressed. Therefore, power loss in the booster circuit can be suppressed.
- a pair of electrodes 1045 made of a highly conductive metal material is provided on the surface of the infrared radiation layer 1043.
- the pair of electrodes 1045 are stacked on the left and right ends of the infrared radiation layer 1043, respectively.
- a metal material used for the electrode 1045 iridium which does not easily react with the material of the infrared radiation layer 1043 and has excellent stability at high temperatures is suitable.
- a material such as aluminum can be used for the electrode 1045.
- the material of the electrode 1045 is not limited to these metal materials, and other conductive materials can be used.
- the radiating element 1011 is housed in the package 1010.
- Each electrode 1045 of the radiating element 1011 is connected to each lead pin 1014 via a bonding wire 1015.
- the infrared radiation layer 1043 when energized between both electrodes 1045 (a voltage is applied between both electrodes 1045), the infrared radiation layer 1043 is heated by Joule heat, and infrared radiation is emitted from the infrared radiation layer 1043. Further, when the energization is stopped, the infrared radiation from the infrared radiation layer 1043 is stopped.
- the energization time is relatively short when the infrared radiation layer 1043 is energized, heat transfer by heat conduction and convection is not performed in the gas layer 1044, and the temperature drop of the holding layer 1042 is suppressed. As a result, the infrared radiation layer 1043 can be maintained at a high temperature, and infrared radiation is promoted.
- a voltage changing in a sine wave shape may be applied between the pair of electrodes 1045. Even in this case, the temperature of the infrared radiation layer 1043 can be increased during the voltage increase period, and the temperature of the infrared radiation layer 1043 can be decreased during the voltage decrease period. Therefore, the intensity of the infrared light emitted from the infrared light source 1001 can be modulated by applying a voltage that changes sinusoidally between the electrodes 1045.
- the layer 1043 emits infrared light with good responsiveness from the rise of voltage, and stops emitting infrared light in a relatively short time from the fall of voltage.
- the thermal conductivity of the holding layer 1042 is ⁇ p [W / mK], and the volumetric heat capacity of the holding layer 1042 (product of specific heat capacity and density).
- Is Cp [J / m 3 K] and the frequency at which the infrared radiation layer 1043 can respond (twice the frequency of the applied voltage) is f [Hz]
- the thermal diffusion length ⁇ of the holding layer 1042 is It is represented by (10).
- the holding layer 1042 has a boundary between the holding layer 1042 and the gas layer 1044, when infrared heat radiated from the infrared emitting layer 1043 toward the holding layer 1042 is applied from the infrared emitting layer 1043. It is necessary to set the thickness dimension Lp so as to be passed to the gas layer 1044 on the surface. In other words, the thickness dimension Lp of the holding layer 1042 needs to be a size that allows infrared rays emitted from the infrared radiation layer 1043 toward the holding layer 1042 to reach the gas layer 1044 through the holding layer 1042. That is, it is desirable that the thickness dimension Lp of the holding layer 1042 is set to a value that is at least smaller than the thermal diffusion length ⁇ (Lp ⁇ ).
- the holding layer 1042 In order to further increase the infrared radiation efficiency, it is desirable to form the holding layer 1042 so that the resonance condition is established for the infrared light. If the resonance condition is satisfied, infrared rays from the infrared radiation layer 1043 toward the holding layer 1042 can be reflected at the boundary surface between the holding layer 1042 and the gas layer 1044. As a result, the amount of wasted infrared rays emitted behind the infrared emitting layer 1043 can be reduced. Therefore, the intensity of infrared light emitted from the infrared radiation layer 1043 can be increased as compared with the case where the resonance condition is not satisfied. In order to enable this operation, the thickness dimension of the holding layer 1042 may be set so as to satisfy the resonance condition of the infrared light having the target wavelength.
- the optical path length of the holding layer 1042 for the infrared ray of the target wavelength must be an odd multiple of a quarter wavelength of the infrared ray of the target wavelength.
- the holding layer 1042 described above does not hinder the temperature rise of the infrared radiation layer 1043.
- the volumetric heat capacity of the holding layer 1042 can be reduced as compared with the case where the holding layer 1042 is formed using a dense material. Therefore, the volumetric heat capacity of the infrared radiation layer 1043 and the holding layer 1042 as a whole can be reduced. Further, as the porosity increases, the thermal conductivity of the holding layer 1042 decreases and the volumetric heat capacity decreases.
- the volumetric heat capacity of the holding layer 1042 can be reduced, and the holding layer 1042 does not hinder the temperature rise of the infrared radiation layer 1043, so that the temperature raising efficiency of the infrared radiation layer 1043 can be increased. Therefore, it becomes possible to respond to the change of the applied voltage at high speed. Therefore, the modulation frequency of the applied voltage can be increased.
- the surface of the holding layer 1042 opposite to the surface in contact with the infrared radiation layer 1043 is in contact with the gas layer 1044. Since the gas layer 1044 has a lower thermal conductivity than the holding layer 1042, the thermal resistance of the heat conduction path from the infrared radiation layer 1043 through the holding layer 1042 increases. As a result, heat dissipation to the periphery of the infrared radiation layer 1043 is suppressed. Therefore, as indicated by a curve S81 in FIG. 35, the temperature of the holding layer 1042 rises when the infrared radiation layer 1043 generates heat, but a large temperature difference does not occur in the depth direction of the holding layer 1042. A curve S80 in FIG. 35 indicates a change in temperature in the depth direction of the holding layer 1042 when the gas layer 1044 is not provided.
- the thickness dimension Lg of the gas layer 1044 is set under the following conditions.
- the applied voltage to the infrared radiation layer 1043 is sinusoidal, the frequency of the applied voltage is f [Hz], the thermal conductivity of the gas layer 1044 is ⁇ g [W / mK], and the volumetric heat capacity of the gas layer 1044 is Cg [J / m 3 K].
- the thickness dimension Lg of the gas layer 1044 is set to a thickness that maximizes the temperature amplitude ratio within the range determined by the above equation (12).
- the gas layer 1044 has a function of either heat insulation or heat dissipation depending on the temperature of the holding layer 1042 and the thickness dimension Lg.
- the voltage applied to the infrared radiation layer 1043 increases as shown in FIGS. 36 (a) and (b).
- the gas layer 1044 is provided with heat insulation during the period (temperature increase period) T1, and the gas layer 1044 is provided with heat dissipation during the period (temperature decrease period) T2 during which the applied voltage to the infrared radiation layer 1043 decreases. It becomes possible.
- the period in which the gas layer 1044 has heat insulation or heat dissipation substantially coincide with the period in which the voltage applied to the infrared radiation layer 1043 increases or decreases. Even when the voltage applied to the infrared radiation layer 1043 is modulated at a high frequency, the temperature of the infrared radiation layer 1043 can be changed so as to be substantially synchronized with the frequency of the voltage. That is, it is possible to improve responsiveness by providing the gas layer 1044.
- FIG. 36C shows the temperature change of the infrared radiation layer of the first comparative example of the radiation element 1011.
- This first comparative example does not include the gas layer 1044.
- the heat insulating performance is insufficient and the heat radiating performance exceeds the heat insulating performance.
- a driving voltage modulated at 10 kHz see FIG. 36A
- the temperature of the infrared radiation layer 1043 is changed during the temperature rising period T1.
- the temperature is not increased to a temperature (predetermined temperature) at which a predetermined infrared intensity can be obtained, and the heat is dissipated during the temperature decrease period T2, so that the temperature is kept low.
- FIG. 36 (d) shows the temperature change of the infrared radiation layer of the second comparative example of the radiation element 1011.
- the thickness dimension Lg of the gas layer 1044 exceeds 3Lg ′ which is the upper limit of the above formula (12) (for example, Lg is 525 ⁇ m). Therefore, the heat dissipation performance is insufficient.
- a driving voltage modulated at 10 kHz see FIG. 36A
- the temperature of the infrared radiation layer 1043 is set during the temperature rising period T1.
- the temperature of the infrared radiation layer 1043 cannot be sufficiently lowered during the temperature lowering period T2, and the temperature of the infrared radiation layer 1043 increases every time the temperature rises and falls repeatedly and is maintained at a high temperature. .
- FIG. 33 illustrates a direct heat type configuration (radiating element 1011) that emits infrared rays from the infrared radiation layer 1043 by causing the infrared radiation layer 1043 to generate heat by energizing the infrared radiation layer 1043.
- an indirectly heated configuration (radiating element 1011) that emits infrared rays from the infrared radiation layer 1043 by energizing a heating layer provided separately from the infrared radiation layer 1043 and heating the infrared radiation layer 1043 may be used.
- the heating layer is provided, for example, between the holding layer 1042 and the infrared radiation layer 1043 or on the opposite side of the holding layer 1042 with the infrared radiation layer 1043 interposed therebetween.
- the infrared radiation layer 1043 can also be used as the holding layer 1042. Further, in the indirectly heated radiating element 110, a heating layer is formed so that resonance conditions are established with respect to infrared light of a target wavelength so that infrared light radiated from the infrared radiation layer 1043 is transmitted through the heating layer, It is necessary to increase the radiation efficiency of the infrared of the target wavelength. Instead of providing the gas layer 1044, a reflective layer (not shown) that reflects infrared light may be provided. In short, the radiating element 1011 only needs to be configured so that the intensity of infrared rays changes following a pulse having an ON period of about 10 ⁇ s to 10 ms.
- the infrared gas measurement device detects infrared light that has been emitted from the infrared light source 1001 that emits infrared light and the monitoring space that is radiated from the infrared light source 1001 and into which the detection target gas is introduced.
- the infrared gas measurement device of the present embodiment detects the detection target gas in the monitoring space using the output of the infrared sensor 1001.
- the infrared sensor 1001 includes light receiving elements 1021a and 1021b, transmission filters 1025a and 1025b, and a cutoff filter 1026.
- the light receiving elements 1021a and 1021b are configured to convert infrared rays into electrical signals.
- the transmission filters 1025a and 1025b are arranged on the infrared incident path from the monitoring space to the light receiving elements 1021a and 1021b.
- the transmission filters 1025a and 1025b are configured to selectively transmit infrared rays in a specific wavelength band.
- the cutoff filter 1026 is disposed between the monitoring space and the transmission filters 1025a and 1025b.
- the cutoff filter 1026 is configured to remove infrared rays in a wide band by absorbing infrared rays in a wavelength range excluding a specific wavelength band that passes through the transmission filters 1025a and 1025b.
- the light receiving elements 1021a and 1021b are sensitive to infrared rays in a specific wavelength band that passes through the transmission filters 1025a and 1025b.
- the drive circuit 1004 drives the infrared light source 1001 to emit infrared light intermittently.
- the sensitivity to the detection target gas can be increased.
- infrared rays may be emitted from the cutoff filter 1026 due to a temperature rise due to unnecessary absorption of infrared rays.
- infrared light is intermittently emitted from the infrared light source 1001, an increase in the temperature of the cutoff filter 1026 due to unnecessary absorption of infrared light can be suppressed.
- the wavelength shift accompanying the temperature change of the cutoff filter 1026 caused by the infrared radiation from the infrared light source 1001 can also be suppressed.
- the function of removing unnecessary infrared rays by the cutoff filter 1026 can be effectively used, and the detection target gas can be detected with high accuracy.
- the input power can be reduced as compared with the case where the infrared light source 1001 is radiated continuously.
- the infrared light source 1001 includes a substrate 1041, a holding layer 1042 formed on the substrate 1041, an infrared radiation layer 1043 stacked on the holding layer 1042, and a gas interposed between the substrate 1041 and the holding layer 1042.
- the infrared radiation layer 1043 is configured to emit infrared light by heat generated by energization.
- the gas layer 1044 suppresses the temperature of the holding layer 1042 from decreasing when the infrared radiation layer 1043 is energized, and promotes heat transfer from the holding layer 1042 to the substrate 1041 when the infrared radiation layer 1044 is not energized. Configured to do.
- the gas layer 1044 suppresses the temperature drop of the holding layer 1042 while power is applied to the infrared radiation layer 1043. . Therefore, the amount of infrared radiation with respect to the input power (the power supplied to the infrared radiation layer 1043) can be increased.
- the gas layer 1044 promotes heat transfer from the holding layer 1042 to the substrate 1041 to reduce the temperature of the holding layer 1042 while power is not supplied to the infrared radiation layer 1043. Therefore, infrared radiation can be stopped in a short time.
- infrared radiation and stop can be performed with high responsiveness to the application and stop of power to the infrared radiation layer 1043. Moreover, infrared rays can be efficiently radiated with respect to the input power. Therefore, power consumption can be reduced as compared with a case where an incandescent bulb is used as the infrared light source 1001 or a structure in which a filament is provided in a dielectric film.
- the cutoff filter 1026 When a multilayer filter including an infrared absorption layer is used as the cutoff filter 1026, it is possible to adjust the wavelength to be removed using not only absorption but also reflection.
- the wavelength range of infrared rays absorbed by the blocking filter 1026 is determined by the material used for the infrared absorption layer.
- the infrared wavelength range reflected by the blocking filter 1026 is determined by the refractive index and film thickness of each thin film constituting the multilayer film. Therefore, it is possible to expand the range of the wavelength range to be removed by using absorption and reflection in a complementary manner.
- the infrared light source 1001 that emits broadband infrared light, it is possible to remove infrared light having a wavelength unnecessary for detection of the detection target gas as much as possible. Therefore, it is possible to suppress infrared rays having a wavelength unnecessary for detection of the detection target gas from being incident on the light receiving elements 1021a and 1021b, and as a result, it is possible to increase sensitivity to the detection target gas.
- the far infrared absorptance can be increased as compared with the case of using SiOx or SiNx as the material of the infrared absorption layer.
- the material of the infrared absorption layer is selected from Al 2 O 3 and Ta 2 O 3 .
- the far infrared absorptance can be increased as compared with the case of using SiOx or SiNx as the material of the infrared absorption layer.
- Al 2 O 3 is used as the material of the infrared absorption layer
- Si the material of the filter substrate 1023.
- the multilayer filter blocking filter 1026
- a thermal infrared detection element having sensitivity to all wavelengths of infrared rays emitted from the infrared light source 1001 is used as the light receiving elements 1021a and 1021b, various types can be obtained only by changing the design of the transmission filters 1025a and 1025b and the cutoff filter 1026. It becomes possible to cope with the detection target gas. Therefore, it is possible to share components between infrared gas measuring devices having different detection target gases. As a result, the manufacturing cost of the infrared gas measuring device can be reduced.
- FIG. 37 and 38 show a first modification of the radiating element 1011 (radiating element 1011A).
- the vertical direction and the horizontal direction in FIG. 37 are defined as the vertical direction and the horizontal direction of the radiating element 1011A, respectively.
- the radiating element 1011 ⁇ / b> A includes a columnar support portion (support) 1047 between the bottom surface of the recess 1046 and the holding layer 1042 in order to support the holding layer 1042. Different from the radiating element 1011.
- the support portion 1047 is formed in a substantially truncated cone shape whose diameter increases from bottom to top with single crystal silicon having higher mechanical strength than the porous layer.
- four support portions 1047 are provided in the gas layer 1044 at a predetermined interval.
- Each support portion 1047 connects the upper surface of the substrate 1041 (the bottom surface of the recess 1046 of the substrate 1041) and the lower surface of the holding layer 1042, and supports the holding layer 1042 with respect to the substrate 1041. Therefore, the holding layer 1042 can be prevented from adhering to the substrate 1041 when the temperature of the infrared emitting layer 1045 changes due to the difference in thermal expansion coefficient between the infrared emitting layer 1045 and the holding layer 1042.
- the holding layer 1042 can be prevented from adhering to the substrate 1041 during drying after the wet process.
- the thickness dimension Lp of the holding layer 1042 satisfies the resonance condition
- the holding layer 1042 may be deformed by heat generation.
- the support portion 1047 the holding layer 1042 can be prevented from being deformed by heat generation. In the example shown in FIG. 37, the support portion 1047 is in contact with the lower surface of the holding layer 1042, but the support portion 1047 may be supported in a state of penetrating the holding layer 1042.
- the substrate 1041 is formed of single crystal silicon
- a part of the substrate 1041 may be left as the support portion 1047 when the recess 1046 is formed.
- the stress generated at the connection portion between the support portion 1047 and the substrate 1041 becomes zero. That is, since the support portion 1047 is formed integrally with the substrate 1041, the strength of the support portion 1047 can be further increased.
- the infrared radiation layer 1043 when the infrared radiation layer 1043 is energized by applying a voltage between the electrodes 1045, the infrared radiation E1 is radiated upward from the infrared radiation layer 1043 as shown in FIG. Further, since the holding layer 1042 directly supports the infrared radiation layer 1043, heat is directly transferred from the infrared radiation layer 1043 to the holding layer 1042. The holding layer 1042 is heated by heat transfer from the infrared radiation layer 1043 to the holding layer 1042, and infrared rays E ⁇ b> 2 are radiated from the holding layer 1042 due to a partial temperature increase of the holding layer 1042.
- the infrared radiation layer 1043 is formed to have infrared transparency. Therefore, infrared rays emitted from the holding layer 1042 toward the infrared emission layer 1043 are transmitted through the infrared emission layer 1043 and emitted above the infrared emission layer 1043. That is, from the radiating element 1011A, the infrared ray E1 radiated upward from the infrared radiating layer 1043 and the infrared ray E2 transmitted from the holding layer 1042 through the infrared radiating layer 1043 and emitted above the infrared radiating layer 1043 are combined. Radiated.
- the infrared radiation layer 1043 functions as a directly heated infrared radiation source
- the holding layer 1042 functions as an indirectly heated infrared radiation source.
- the holding layer 1042 emits infrared rays by using part of the energy radiated from the infrared radiation layer 1043 toward the holding layer 1042. Therefore, the infrared radiation efficiency with respect to the input power can be increased. In other words, the input power required to emit a desired amount of infrared light can be reduced.
- the temperature increase period T1 can be shortened.
- the temperature drop period T2 can be shortened.
- the temperature change of the infrared radiation layer 1043 can be synchronized with the waveform of the input voltage. Therefore, it is possible to increase the output of infrared rays emitted from the radiating element 1011A and to drive the radiating element 1011A at a high frequency. Furthermore, since the time required for gas measurement can be shortened, power consumption can be reduced.
- the holding layer 1042 is a porous layer.
- the porous layer has a smaller heat capacity and lower thermal conductivity than a dense insulating material. Therefore, since the holding layer 1042 does not hinder the temperature increase of the infrared radiation layer 1043, the temperature increase period T1 can be shortened. Therefore, compared with the case where the holding layer 1042 is not a porous layer, power consumption can be reduced by increasing the temperature greatly with small energy.
- the holding layer 1042 is preferably porous silicon or porous polysilicon.
- the heat resistance of the holding layer 1042 can be improved, and the holding layer 1042 can be prevented from being deformed or damaged by the temperature increase of the infrared radiation layer 1043.
- the holding layer 1042 is fixed to the substrate 1041 at the outer peripheral surface thereof.
- the outer peripheral surface of the holding layer 1042 is bonded to the inner peripheral surface of the recess 1046 of the substrate 1041. Therefore, it is possible to prevent the holding layer 1042 from being deformed or damaged by the stress generated due to the difference in thermal expansion coefficient between the infrared emitting layer 1043 and the holding layer 1042 when the temperature of the infrared emitting layer 1043 is increased.
- the number of support portions 1047 is one.
- the substrate 1041 a p-type semiconductor substrate having a substantially rectangular plate shape with a specific resistance of about 80 to 120 ⁇ cm is used.
- a doping process is first performed.
- a rectangular first impurity diffusion region 1048 and a second impurity diffusion region 1049 are formed on the first surface of the substrate 1041 (the upper surface in FIG. 39A).
- the first impurity diffusion region 1048 is formed in the center of a rectangular region (holding layer forming region) for forming the holding layer 1042 on the first surface of the substrate 1041.
- the second impurity diffusion region 1049 is formed in a rectangular frame shape surrounding the holding layer forming region.
- the first impurity diffusion region 1048 and the second impurity diffusion region 1049 are formed by injecting n-type impurities (for example, P ions) at a high concentration into the first surface of the substrate 1041 and then performing drive-in. Note that the first impurity diffusion region 1048 is formed to have a larger outer size than the support portion 1047. The first impurity diffusion region 1048 is formed to have the same thickness as the gas layer 1044.
- n-type impurities for example, P ions
- an annealing process (annealing process) is performed.
- the impurities in the first impurity diffusion region 1048 and the second impurity diffusion region 1049 are diffused and activated.
- the first impurity diffusion region 1048 and the second impurity diffusion region 1049 function as an n-type anodic oxidation mask.
- the mask forming process is performed.
- a silicon oxide film is formed on the entire surface of the first surface (upper surface in FIG. 39A) and the second surface (lower surface in FIG. 39B) of the substrate 1041 by performing an oxidation process.
- the silicon oxide film formed on the first surface of the substrate 1041 is patterned using a photolithography technique and an etching technique to form an anodic oxidation mask 1050 (see FIG. 39B).
- the anodic oxidation mask 1050 is formed so as to expose a part of the holding layer forming region and the second impurity diffusion region 1049.
- the silicon oxide film formed on the second surface of the substrate 1041 is removed using an etching technique. Thereafter, an aluminum electrode 1051 for back contact is formed on the second surface of the substrate 1041 by using a sputtering method.
- the aluminum electrode 1051 is used for applying a potential to the substrate 1041 when performing anodization. Therefore, the aluminum electrode 1051 is formed so as to be in ohmic contact with the substrate 1041.
- the porous process is performed.
- the region excluding the first impurity diffusion region 1048 and the second impurity diffusion region 1049 in the holding layer forming region is made porous by performing anodization.
- a holding layer 1042 made of porous silicon is formed as shown in FIG.
- a 30% hydrogen fluoride solution obtained by mixing an aqueous hydrogen fluoride solution and ethanol is used as the anodizing electrolyte.
- the first surface of the substrate 1041 is immersed in the electrolytic solution.
- a voltage is applied between a platinum electrode (not shown) arranged to face the first surface of the substrate 1041 and an aluminum electrode 1051 formed on the second surface of the substrate 1041 to obtain a predetermined current.
- a current having a density (for example, 100 mA / cm 2 ) is supplied for a predetermined time.
- the holding layer 1042 having a thickness dimension Lp of 1 ⁇ m is formed.
- first impurity diffusion region 1048 and the second impurity diffusion region 1049 In order to cause the first impurity diffusion region 1048 and the second impurity diffusion region 1049 to function as an n-type anodic oxidation mask, light is present in the first impurity diffusion region 1048 and the second impurity diffusion region 1049 during anodic oxidation. It is necessary not to.
- the thickness dimension Lp of the holding layer 1042 only needs to be set to a value that is at least smaller than the thermal diffusion length ⁇ .
- Electrolytic polishing process is performed after the porous process.
- the recess 1046 gas layer 1044 is formed in the substrate 1041 by performing anodization under different conditions from the above-described porous process (see FIG. 39D).
- the first impurity diffusion region 1048 acts as a mask
- the portion of the substrate 1041 below the first impurity diffusion region 1048 remains without being polished, thereby forming the support portion 1047.
- the support portion 1047 has a substantially truncated cone shape whose diameter increases from the bottom to the top.
- the gas layer 1044 and the support portion 1047 are formed simultaneously.
- a 15% hydrogen fluoride solution obtained by mixing an aqueous hydrogen fluoride solution and ethanol is used as the anodizing electrolyte.
- the holding layer 1042 and the anodic oxidation mask 1050 are immersed in the electrolytic solution. Then, a voltage is applied between a platinum electrode (not shown) arranged to face the first surface of the substrate 1041 and the aluminum electrode 1051, and a predetermined current density (for example, 1000 mA / cm 2 ) is applied. A current is supplied for a predetermined time. Since the holding layer 1042 is made porous, the substrate 1041 is polished through the holding layer 1042.
- a gas layer 1044 having a thickness dimension Lg of 25 ⁇ m is formed.
- the first impurity diffusion region 1048 acts as a mask as described above, a portion of the substrate 1041 that becomes the support portion 1047 remains without being polished.
- the thickness Lg of the gas layer 1044 is set so as to satisfy the above equation (12).
- the substrate 1041 is polished isotropically. Therefore, when the second impurity diffusion region 1049 does not exist, the substrate 1041 is also polished at the periphery of the holding layer 1042, as shown in FIG. As a result, the holding layer 1042 is supported only by the anodic oxidation mask 1050. Therefore, the mechanical strength of the radiating element 1011A is reduced.
- the periphery of the holding layer 1042 is bonded to the substrate 1041 through the second impurity diffusion region 1049 (n-type region). The Therefore, the mechanical strength of the radiating element 1011A is increased.
- the doping step of forming the second impurity diffusion region 1049 extending over the region where the anodic oxidation mask 1050 is formed and the holding layer formation region on the first surface of the substrate 1041 is performed before the masking step. (Second dope process) is performed.
- Second impurity diffusion region 1049 acts as an anodic oxidation mask. Therefore, a portion of the substrate 1041 below the second impurity diffusion region 1049 is not electrolytically polished in the thickness direction of the substrate 1041. Therefore, the substrate 1041 supports the second impurity diffusion region 1049 from below.
- the second impurity diffusion region 1049 and the portion of the substrate 1041 that supports the second impurity diffusion region 1049 from below function as a reinforcing portion that reinforces the bonding between the holding layer 1042 and the substrate 1041. . Therefore, the strength of the joint between the holding layer 1042 and the substrate 1041 can be increased, and the holding layer 1042 can be prevented from being deformed or damaged.
- an infrared radiation layer forming process is performed.
- the infrared radiation layer 1043 is formed on the holding layer 1042 (a region surrounded by the anodizing mask 1050).
- the infrared radiation layer 1043 is formed across the inner periphery of the holding layer 1042 and the anodic oxidation mask 1050.
- the infrared radiation layer 1043 is formed of a noble metal (for example, Ir) that generates heat when energized.
- the thickness dimension of the infrared radiation layer 1043 is set to about 100 nm.
- the material of the infrared radiation layer 1043 is not limited to Ir, and may be any heat-resistant material that generates heat when energized, such as a heat-resistant metal, metal nitride, or metal carbide, and a material with high infrared emissivity is preferable.
- the electrode forming step is performed.
- electrodes 1045 are formed on both ends of the infrared radiation layer 1043 (left and right ends in FIG. 39E), respectively.
- the electrode 1045 is formed using an evaporation method using a metal mask or the like.
- the manufacturing method of the radiating element 1011A includes the mask process for forming the anodic oxidation mask 1050, the porous process for forming the holding layer 1042 made of a porous layer using anodization, and the anodization process.
- the holding layer 1042 is formed by performing porosity using anodization in the porosification step
- electrolysis is performed using anodization in the electropolishing step.
- the gas layer 1044 is formed by polishing. That is, by performing the anodic oxidation twice under different conditions, the holding layer 1042 having a small volumetric heat capacity and high heat insulation can be easily formed on the hollow.
- the manufacturing method of the radiating element 1011A includes a doping step (first doping step) for forming the first impurity diffusion layer 1048 in the holding layer forming region before the masking step.
- the first impurity diffusion region 1048 is not made porous in the porous process, and is not electropolished in the electropolishing process.
- the first impurity diffusion region 1048 functions as an anodic oxidation mask. Therefore, the portion of the substrate 1041 below the first impurity diffusion region 1048 is not electropolished in the thickness direction of the substrate 1041. Therefore, a support portion 1047 is formed below the first impurity diffusion region 1048.
- the first impurity diffusion region 1048 is used as an anodic oxidation mask. Therefore, it is not necessary to form the anodic oxidation mask 1050 in the holding layer forming region in the mask process.
- the anodic oxidation mask 1050 is formed in the holding layer formation region, a step is generated between the anodic oxidation mask 1050 and the surface of the holding layer formation region (the first surface of the substrate 1041). That is, by forming the first impurity diffusion region 1048, it is not necessary to form the anodic oxidation mask 1050 with a separate step in the mask process.
- the radiating element 1011A capable of stable operation can be manufactured.
- a drying process is performed in which the substrate 1041 and the holding layer 1042 are washed and dried. Since the support portion 1047 is formed in the electrolytic polishing process, the holding layer 1042 is formed in the drying process. It can prevent adhering to.
- FIG. 41 shows another example of the holding layer 1042.
- the holding layer 1042 shown in FIG. 41 is formed using bulk silicon.
- the holding layer 1042 includes a plate-like macroporous silicon portion 1042a.
- a plurality of macropores 1042b are formed along the thickness direction of the macroporous silicon portion 1042a.
- the size of the macropore 1042b is, for example, about several ⁇ m.
- a nanoporous silicon portion 1042c is formed without a gap.
- nanopores of about several nm are formed.
- the surface of the protective layer 1042 (upper surface in FIG. 41) corresponding to the nanoporous silicon portion 1042c is microscopically undulated.
- Such a holding layer 1042 can be formed by appropriately selecting the conductivity type and specific resistance of the substrate 1041 and the conditions (the composition of the electrolytic solution, the current density, and the processing time) for making the substrate 1041 porous.
- the substrate 1041 a high-resistance p-type silicon substrate having a resistance of about 100 ⁇ cm can be used as the substrate 1041.
- a high concentration hydrofluoric acid solution having a hydrofluoric acid concentration of about 25% may be used as the electrolytic solution, and the current density may be set to a relatively large value of about 100 mA / cm 2 .
- the holding layer 1042 shown in FIG. 41 has a structure in which the macropores 1042b that radiate infrared rays by cavity emission during heating are formed in the bulk semiconductor, and the nanopores are formed in the macropores 1042b.
- the holding layer 1042 when the holding layer 1042 is heated by the heat from the infrared radiation layer 1043, cavity emission by the macropores 1042b occurs. Therefore, the infrared radiation efficiency can be further increased.
- a nanoporous silicon portion 1042c in which nanopores are formed is formed. Therefore, it is possible to compensate for the decrease in the strength of the holding layer 1042 due to the formation of the macropore 1042b without hindering the cavity emission by the macropore 1042b. Further, the heat insulating performance of the holding layer 1042 can be improved.
- the thickness dimension of the infrared radiation layer 1043 cannot be set to about several tens of nm.
- the nanoporous silicon portion 1042b is formed in the macropore 1042b, only nano-sized fine irregularities are generated on the surface of the holding layer 1042. Therefore, the surface state of the holding layer 1042 hardly affects the infrared radiation layer 1043. Therefore, the thickness of the infrared radiation layer 1043 can be about several tens of nm.
- the thickness dimension Lp of the holding layer 1042 is set to 0.5 ⁇ m or more. Note that, as described above, the thickness dimension Lp of the holding layer 1042 is set to a value smaller than ⁇ determined by the above equation (10).
- FIG. 42 shows a second modification of the radiating element 1011 (radiating element 1011B).
- the radiating element 1011B unlike the radiating element 1011A in which the infrared radiation layer 1043 is laminated on the entire upper surface of the holding layer 1042, three infrared radiation layers 1043 are formed on the upper surface of the holding layer 1042. Three infrared radiation layers 1043 are arranged at predetermined intervals along a predetermined direction (vertical direction in FIG. 42). Therefore, the holding layer 1042 has an exposed portion 1042d whose upper surface is exposed from between the infrared radiation layers 1043.
- the support portion 1047 is configured to support the holding layer 1042 with the exposed portion 1042 d of the holding layer 1042. In the example shown in FIG.
- the support portion 1047 penetrates the exposed portion 1042d of the holding layer 1042 in the thickness direction.
- the holding layer 1042 has two exposed portions 1042d, and each exposed portion 1042d is formed by two support portions 1047 arranged at a predetermined interval along a predetermined direction (left-right direction in FIG. 42). It is supported by the substrate 1041. 42, three infrared radiation layers 1043 are provided, but two infrared radiation layers 1043 may be provided, or four or more infrared radiation layers 1043 may be provided.
- the infrared radiation layer 1043 is not in direct contact with the support portion 1047.
- heat generated in the infrared radiation layer 1043 is transmitted to the support portion 1047 through the holding layer 1042.
- the infrared radiation layer 1043 has higher thermal conductivity than the holding layer 1042 (in other words, the holding layer 1042 has lower thermal conductivity than the infrared radiation layer 1043). Therefore, compared with the case where the infrared radiation layer 1043 is in direct contact with the support portion 1047, heat generated in the infrared radiation layer 1043 can be suppressed from being transmitted to the substrate 1041 via the support portion 1047. Therefore, the infrared light emission efficiency (radiation efficiency) of the infrared radiation layer 1043 can be increased.
- the infrared radiation layer 1043 and the support portion 1047 are not in direct contact with each other, it is possible to suppress the occurrence of a large temperature gradient between the infrared radiation layer 1043 and the support portion 1047. Therefore, it is possible to prevent the infrared radiation layer 1043 and the support portion 1047 from being damaged by a large thermal stress due to the temperature gradient.
- the support portion 1047 may be configured to connect the lower surface of the exposed portion 1042d of the holding layer 1042 and the bottom surface of the recess 1046, thereby supporting the holding layer 1042. Even in this case, the infrared radiation layer 1043 can be moved away from the support portion 1047 as compared to the example shown in FIG. Therefore, heat generated in the infrared radiation layer 1043 can be suppressed from being transmitted to the substrate 1041 through the support portion 1047, and the light emission efficiency (radiation efficiency) of the infrared radiation layer 1043 can be increased. Even in this case, generation of a large temperature gradient between the infrared radiation layer 1043 and the support portion 1047 can be suppressed. Therefore, the infrared radiation layer 1043 and the support portion 1047 can be prevented from being damaged by a large thermal stress caused by the temperature gradient.
- FIG. 42F shows a third modification of the radiating element 1011 (radiating element 1011C).
- the radiating element 1011C includes a substrate 1041, a holding layer 1042, an infrared radiating layer 1043, a gas layer 1044, an electrode 1045, and a support portion 1047.
- a recess 1046 for the gas layer 1044 is formed not in the substrate 1041 but in the holding layer 1042.
- a sacrificial layer forming step is first performed.
- a sacrificial layer 1052 is formed on the first surface of the substrate 41 (the upper surface in FIG. 43A).
- the sacrificial layer 1052 is removed in a later etching step.
- the sacrificial layer 1052 is, for example, a silicon oxide film having a thickness of about 5 ⁇ m.
- the sacrificial layer 1052 is formed, for example, by patterning a silicon oxide film having a thickness of about 5 ⁇ m formed using a plasma CVD method using a photolithography technique and an etching technique.
- the polysilicon layer forming step is performed.
- the polysilicon layer forming step first, as shown in FIG. 43B, an aluminum electrode 1051 is formed on the second surface of the substrate 1041 (the lower surface in FIG. 43B). Thereafter, a polysilicon layer 1053 covering the sacrificial layer 1052 is formed on the first surface of the substrate 1041.
- the polysilicon layer 1053 is the basis of the holding layer 1042.
- the polysilicon layer 1053 is formed with a thickness such that the surface thereof is flat.
- the conductivity type of the polysilicon layer 1053 is P-type.
- the polysilicon layer 1053 is formed, for example, by forming a non-doped polysilicon layer using a CVD method and then performing drive-in after ion implantation of P-type impurities into the non-doped polysilicon layer.
- the polysilicon layer 1053 is formed, for example, so that the thickness of the portion located on the sacrificial layer 1052 is 1 ⁇ m.
- the thickness Lp of the holding layer 1042 only needs to be set to a value smaller than ⁇ determined by the above equation (10).
- the thickness Lp of the holding layer 1042 refers to the thickness of the portion of the holding layer 1042 located on the gas layer 1044.
- the doping step is performed.
- a diffusion region 1054 is formed.
- the impurity diffusion region 1054 is formed by injecting n-type impurities (eg, P ions) into the holding layer 1042 at a high concentration and then driving.
- the impurity diffusion region 1054 is formed so as to penetrate the holding layer 1042 in the thickness direction.
- the impurity diffusion region 1054 is annealed to diffuse and activate the impurities in the impurity diffusion region 1054.
- the impurity diffusion region 1054 functions as an n-type anodic oxidation mask.
- the porous process is performed.
- the portion other than the impurity diffusion region 1054 in the polysilicon layer 1053 is made porous by anodizing.
- a holding layer 1042 made of porous silicon is formed as shown in FIG.
- a 30% hydrogen fluoride solution obtained by mixing an aqueous hydrogen fluoride solution and ethanol is used as an electrolytic solution for anodization.
- the polysilicon layer 1053 is immersed in the electrolytic solution. Then, a voltage is applied between the platinum electrode (not shown) disposed on the surface of the polysilicon layer 1053 (the upper surface in FIG. 43 (d)) and the aluminum electrode 1051, and a predetermined current density (for example, 100 mA / cm 2 ) is applied for a predetermined time.
- a predetermined current density for example, 100 mA / cm 2
- the etching process is performed.
- the sacrificial layer 1052 is removed by etching to form a gas layer 1044.
- the sacrificial layer 1052 is covered with the holding layer 1042, but since the holding layer 1042 is made porous, the sacrificial layer 1052 can be etched away using an etching solution (eg, HF solution).
- the impurity diffusion region 1054 functions as an etching mask.
- the portion of the sacrificial layer 1052 below the impurity diffusion region 1054 remains without being removed by etching, whereby a support portion 1047 is formed.
- the gas layer 1044 and the support portion 1047 are formed at the same time.
- an infrared radiation layer forming process is performed.
- the infrared radiation layer 1043 is formed on the holding layer 1042.
- the infrared radiation layer 1043 is formed to have a slightly larger outer size than the gas layer 1044.
- the infrared radiation layer 1043 is formed of a noble metal (for example, Ir) that generates heat when energized.
- the thickness dimension of the infrared radiation layer 1043 is set to about 100 nm.
- the material of the infrared radiation layer 1043 is not limited to Ir, and may be any heat-resistant material that generates heat when energized, such as a heat-resistant metal, metal nitride, or metal carbide, and a material with high infrared emissivity is preferable.
- the electrode forming step is performed.
- electrodes 1045 are formed on both ends of the infrared radiation layer 1043 (left and right ends in FIG. 43E), respectively.
- the electrode 1045 is formed using an evaporation method using a metal mask or the like.
- the manufacturing method of the radiating element 1011C includes the sacrificial layer forming step, the polysilicon layer forming step, the porous step, the etching step, and the infrared radiating layer forming step.
- a sacrificial layer forming step a sacrificial layer 1052 is formed in a predetermined region of the first surface of the substrate 1041.
- an impurity-doped polysilicon layer 1053 is formed on the surface of the sacrificial layer 1052.
- the porous step the holding layer 1042 made of a porous layer is formed by anodizing the polysilicon layer 1053.
- the sacrificial layer 1052 is removed by etching through the holding layer 1042 to form the gas layer 1044.
- the polysilicon layer 1053 covering the sacrificial layer 1052 is made porous to form the holding layer 1042, and then the sacrificial layer 1052 is removed by etching through the holding layer 1042.
- the gas layer 1044 is formed. Therefore, the gas layer 1044 and the holding layer 1042 can be easily formed.
- the manufacturing method of the radiating element 1011C includes a doping process between the polysilicon layer forming process and the porous process.
- a doping process between the polysilicon layer forming process and the porous process.
- an impurity diffusion region 1054 that is not made porous by anodic oxidation in the porous process is formed in the polysilicon layer 1053.
- the impurity diffusion region 1054 acts as an etching mask for the sacrificial layer 1052 in the etching process after the porous process. Therefore, the sacrificial layer 1052 is etched away leaving a portion overlapping with the impurity diffusion region 1054 in the thickness direction. A portion of the sacrificial layer 1052 that has not been etched away becomes the support portion 1047.
- the gas layer 1044 and the support portion 1047 can be formed easily and simultaneously.
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Abstract
Description
本実施形態の赤外線式ガス検知器(赤外線受光ユニット)は、図1および図2に示すように、複数(ここでは、2つ)の焦電素子41,42を有する赤外線受光素子(赤外線受光部)40および赤外線受光素子40の出力を信号処理する信号処理回路が設けられた回路ブロック6と、回路ブロック6を収納するキャンパッケージからなるパッケージ7とを備えている。なお、本実施形態では、焦電素子41,42は、熱を利用して赤外線を検出する熱型赤外線検出素子である。
P1=τ1(Pasin(ωt)+Pb) ・・・(1)
P2=T(C)τ2(Pasin(ωt)+Pb) ・・・(2)
また、透過フィルタ21を透過した赤外線を受光する焦電素子41の受光面側の極性を正(+)、透過フィルタ22を透過した赤外線を受光する焦電素子42の受光面側の極性を負(-)とすると、各焦電素子41,42の出力I1,I2は、それぞれ下記(3)式、下記(4)式で表される(ただし、焦電素子41,42での電流変換による定数は省いてある)。
I1=ωτ1Pacos(ωt) ・・・(3)
I2=-T(C)ωτ2Pacos(ωt) ・・・(4)
図3(b)に示すように、2つの焦電素子41,42は、2つの焦電素子41,42の差動出力が得られるように接続されている。そのため、赤外線受光素子40の出力をIとすると、出力Iは下記(5)式で表される。
I=I1+I2=ωτ1Pacos(ωt)-T(C)ωτ2Pacos(ωt) ・・・(5)
τ1=τ2とすれば、赤外線受光素子40の出力Iは、下記(6)式で表される。
I=ωτ1Pacos(ωt)(1-T(C)) ・・・(6)
また、物質に固有の吸収係数(その物質の吸収波長および温度により決まる定数)をα、物質の濃度をC、光路長をLとすると、赤外線の吸収率T(C)は、ランベルト・ベールの法則に基づいて、下記(7)で表される。
T(C)=10-αCL ・・・(7)
したがって、赤外線受光素子40の出力Iは、(6)式に(7)式を代入することにより、下記(8)式で表される。
I=ωτ1Pacos(ωt)(1-10-αCL) ・・・(8)
この(13)式に基づいて、ガスの濃度Cと赤外線受光素子40の出力信号(出力I)との関係をグラフにすると、図23に示すようになる。よって、赤外線受光素子40の出力信号の振幅を計測することでガスの濃度を求めることができる。
本実施形態では、ガス漏れ警報器のような用途に用いる赤外線式ガス計測装置について説明する。この種の赤外線式ガス計測装置は、図30に示すように、電気信号の入力により赤外線を放射する赤外光源1001と、赤外線を検知する赤外線センサ(赤外線式検知器)1002とを有している。赤外光源1001と赤外線センサ1002との間には、ガス検知管1003が配置されている。ガス検知管1003内には、検知対象ガス(測定ガス)が導入される。なお、赤外線センサ102としては、実施形態1に記載の赤外線式検知器を採用できる。
λ=2898/T ・・・(9)
したがって、赤外線放射層1043の温度を変化させることにより、赤外線放射層1043から放射される赤外線のピーク波長を変化させることができる。赤外線放射層1043の温度を調節するには、電極1045に印加する電圧の振幅や波形などを調節し、単位時間当たりに発生するジュール熱を変化させればよい。
μ=(2αp/ωCp)1/2 ・・・(10)
ただし、ω=2πfである。
n・Lp=(2m-1)λ/4 ・・・(11)
ここに、mは正整数である。
0.05Lg′<Lg<3Lg′ ・・・(12)
ただし、Lg′=(2αg/ωCg)1/2、ω=2πfである。
Claims (14)
- 赤外線受光部と、
上記赤外線受光部を収納するパッケージと、
光学フィルタと、を備え、
上記赤外線受光部は、熱を利用して赤外線を検出する複数の熱型赤外線検出素子を有し、
上記複数の熱型赤外線検出素子は、並べて配置され、
上記パッケージは、赤外線を上記赤外線受光部に入射させるための窓孔を有し、
上記光学フィルタは、上記窓孔を閉塞するように上記パッケージに接合され、上記複数の熱型赤外線検出素子にそれぞれ対応する複数のフィルタ要素部を有し、
上記各フィルタ要素部は、赤外線を透過させる材料により形成されたフィルタ基板と、所定の選択波長の赤外線を選択的に透過させるように構成された透過フィルタと、上記透過フィルタの上記選択波長よりも波長が長い赤外線を吸収するように構成された遮断フィルタとを、備え、
上記透過フィルタおよび上記遮断フィルタは、それぞれ上記フィルタ基板上に形成され、
上記フィルタ基板は、上記パッケージに熱的に結合され、
上記各フィルタ要素部は、上記透過フィルタの上記選択波長が互いに異なっている
ことを特徴とする赤外線ガス検出器。 - 上記赤外線受光部は、一対の上記熱型赤外線検出素子を有し、
上記熱型赤外線検出素子は、焦電素子またはサーモパイルであり、
上記一対の熱型赤外線検出素子は、逆直列または逆並列に接続されている
ことを特徴とする請求項1記載の赤外線式ガス検知器。 - 上記赤外線受光部の出力を増幅する増幅回路を備え、
上記増幅回路は、上記パッケージに収納されている
ことを特徴とする請求項2記載の赤外線式ガス検知器。 - 増幅回路を備え、
上記赤外線受光部は、一対の上記熱型赤外線検出素子を有し、
上記熱型赤外線検出素子は、焦電素子またはサーモパイルであり、
上記増幅回路は、上記一対の熱型赤外線検出素子のそれぞれの出力の差を増幅する差動増幅回路である
ことを特徴とする請求項1記載の赤外線式ガス検知器。 - 上記フィルタ基板は、Si基板もしくはGe基板により形成されている
ことを特徴とする請求項1記載の赤外線式ガス検知器。 - 上記パッケージは、上記パッケージの内部に電磁波が入ることを防止する金属製のシールド部を備え、
上記フィルタ基板は、上記シールド部に電気的に接続されている
ことを特徴とする請求項5記載の赤外線式ガス検知器。 - 上記フィルタ基板は、上記パッケージの内側を向いた第1表面と、上記パッケージの外側を向いた第2表面と、を有し、
上記透過フィルタは、上記フィルタ基板の上記第1表面に形成され、
上記遮断フィルタは、上記フィルタ基板の上記第2表面に形成されている
ことを特徴とする請求項1記載の赤外線式ガス検知器。 - 上記各フィルタ要素部の上記フィルタ基板は、互いに一体に形成されている
ことを特徴とする請求項1記載の赤外線式ガス検知器。 - 上記透過フィルタは、第1のλ/4多層膜と、第2のλ/4多層膜と、上記第1のλ/4多層膜と上記第2のλ/4多層膜との間に介在された波長選択層と、を備え、
上記第1のλ/4多層膜および上記第2のλ/4多層膜は、それぞれ屈折率が互いに異なり且つ光学膜厚が互いに等しい複数種類の薄膜を積層して形成され、
上記波長選択層の光学膜厚は、上記透過フィルタの上記選択波長に応じて上記薄膜の光学膜厚と異なる大きさに設定され、
上記遮断フィルタは、屈折率が互いに異なる複数種類の薄膜を積層して形成された多層膜であり、
上記複数種類の薄膜のうちの少なくとも1種類は、遠赤外線を吸収する遠赤外線吸収材料により形成されている
ことを特徴とする請求項1記載の赤外線式ガス検知器。 - 所定の空間に赤外線を放射する赤外光源と、
上記所定の空間を通過した赤外線を受け取る請求項1記載の赤外線式ガス検知器と、を備える
ことを特徴とする赤外線式ガス計測装置。 - 上記赤外光源が間欠的に赤外線を放射するように上記赤外線光源を駆動する駆動回路を備える
ことを特徴とする請求項10記載の赤外線式ガス計測装置。 - 上記赤外光源は、基板と、上記基板に形成された保持層と、上記保持層に積層された赤外線放射層と、上記基板と上記保持層との間に介在された気体層と、を備え、
上記赤外線放射層は、通電に伴って発生した熱によって赤外線を放射するように構成され、
上記気体層は、上記赤外線放射層が通電されているときには上記保持層の温度が低下することを抑制し、上記赤外線放射層が通電されていないときには上記保持層から上記基板への熱伝達を促進するように構成される
ことを特徴とする請求項11記載の赤外線式ガス計測装置。 - 上記赤外線放射層に与えられる電圧が周波数f〔Hz〕の正弦波電圧であり、上記気体層の熱伝導率がαg〔W/mK〕であり、上記気体層の体積熱容量がCg〔J/m3K〕であるとき、上記気体層の厚みLgは、0.05×Lg´<Lg<3×Lg´の(ただし、Lg´=(2αg/ωCg)1/2、ω=2πf)の関係を満たすように設定される
ことを特徴とする請求項12記載の赤外線式ガス計測装置。 - 上記保持層は、熱伝導率が上記基板よりも低く、
上記保持層は、通電された上記赤外線放射層で発生した熱を吸収すること、または、上記赤外線放射層から放射された赤外線を反射することによって、上記保持層から上記赤外線放射層に向かう赤外線を発生させるように構成され、
上記赤外線放射層は、上記保持層が発生させた赤外線を透過させるように構成される
ことを特徴とする請求項13記載の赤外線式ガス計測装置。
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US13/380,810 US20120235038A1 (en) | 2009-06-25 | 2010-06-22 | Infrared gas detector and infrared gas measuring device |
EP10792105A EP2447705A1 (en) | 2009-06-25 | 2010-06-22 | Infrared gas detector and infrared gas measuring device |
KR1020127001935A KR101311322B1 (ko) | 2009-06-25 | 2010-06-22 | 적외선식 가스 검지기 및 적외선식 가스 계측 장치 |
CN2010800366287A CN102575983A (zh) | 2009-06-25 | 2010-06-22 | 红外线式气体检测器以及红外线式气体测量装置 |
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JP2009217332A JP5374292B2 (ja) | 2008-12-19 | 2009-09-18 | 赤外線放射素子及び当該赤外線放射素子を備えた赤外線式ガス検知器及び当該赤外線放射素子の製造方法 |
JP2009217333A JP5374293B2 (ja) | 2009-09-18 | 2009-09-18 | 赤外線式ガス検知器 |
JP2009219202A JP5374297B2 (ja) | 2009-06-25 | 2009-09-24 | 赤外線式ガス検知器および赤外線式ガス計測装置 |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2011071011A1 (ja) * | 2009-12-09 | 2011-06-16 | パナソニック電工株式会社 | 赤外線式炎検知器 |
CN102435578A (zh) * | 2011-09-21 | 2012-05-02 | 河南汉威电子股份有限公司 | 全量程红外气体探测器及其测量方法 |
JP2017138305A (ja) * | 2016-01-22 | 2017-08-10 | エクセリタス テクノロジーズ シンガポール プライヴェート リミテッド | 動作および存在検出器 |
US11320572B2 (en) | 2019-12-05 | 2022-05-03 | Asahi Kasei Microdevices Corporation | NDIR gas sensor, optical device, and optical filter for NDIR gas sensor |
US11346775B2 (en) | 2018-08-29 | 2022-05-31 | Asahi Kasei Microdevices Corporation | NDIR gas sensor and optical device |
Families Citing this family (39)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5966405B2 (ja) | 2012-02-14 | 2016-08-10 | セイコーエプソン株式会社 | 光学フィルターデバイス、及び光学フィルターデバイスの製造方法 |
EP2848914A4 (en) | 2012-05-09 | 2015-10-21 | Panasonic Ip Man Co Ltd | INFRARED RADIATION ELEMENT |
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US9178126B2 (en) * | 2012-07-05 | 2015-11-03 | Electronics And Telecommunications Research Institute | Thermoelectric elements using metal-insulator transition material |
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CN103969209A (zh) * | 2013-01-24 | 2014-08-06 | 上海朝辉压力仪器有限公司 | 浓度传感器 |
EP2775464B1 (de) * | 2013-03-06 | 2018-01-17 | Siemens Schweiz AG | Gefahrenmelder mit einem kontaktlos arbeitenden Wärmestrahlungssensor zur Ermittlung einer Umgebungstemperatur |
KR101469238B1 (ko) * | 2013-04-25 | 2014-12-10 | 전자부품연구원 | 적외선 광원 장치 및 이를 포함하는 가스 측정 광학계 |
WO2015058166A2 (en) * | 2013-10-18 | 2015-04-23 | Flir Systems, Inc. | Measurement device for lighting installations and related methods |
JP6323652B2 (ja) * | 2013-12-24 | 2018-05-16 | セイコーエプソン株式会社 | 発熱体、振動デバイス、電子機器及び移動体 |
JP6390117B2 (ja) * | 2014-02-26 | 2018-09-19 | セイコーエプソン株式会社 | 光学モジュール、及び電子機器 |
KR20160059815A (ko) * | 2014-11-19 | 2016-05-27 | 주식회사 아이디스 | 감시 카메라 및 초점 제어 방법 |
CN107209057B (zh) | 2015-02-09 | 2019-08-13 | 三菱电机株式会社 | 电磁波检测器以及气体分析装置 |
TWI652457B (zh) | 2016-03-16 | 2019-03-01 | 原相科技股份有限公司 | 穿戴式裝置 |
US10168220B2 (en) | 2015-03-20 | 2019-01-01 | Pixart Imaging Inc. | Wearable infrared temperature sensing device |
US10113912B2 (en) | 2015-05-30 | 2018-10-30 | Pixart Imaging Inc. | Thermopile module |
JP6575989B2 (ja) * | 2015-03-31 | 2019-09-18 | 日本電信電話株式会社 | So3分析方法および分析装置 |
US10527497B2 (en) * | 2015-05-22 | 2020-01-07 | Irnova Ab | Infrared imaging detector |
EP3139141A3 (fr) * | 2015-09-03 | 2017-03-29 | Commissariat à l'énergie atomique et aux énergies alternatives | Composant pour la détection d'un rayonnement électromagnétique dans une gamme de longueurs d'onde et procédé de fabrication d'un tel composant |
FR3042272B1 (fr) * | 2015-10-09 | 2017-12-15 | Commissariat Energie Atomique | Bolometre a forte sensibilite spectrale. |
CN105352865B (zh) * | 2015-11-27 | 2017-12-12 | 东北大学 | 一种基于红外线光电转换的pm2.5传感器及pm2.5探测方法 |
FR3046879B1 (fr) * | 2016-01-20 | 2022-07-15 | Ulis | Procede de fabrication d'un detecteur de rayonnement electromagnetique a micro-encapsulation |
DE102016108544A1 (de) | 2016-05-09 | 2017-11-09 | Technische Universität Dresden | Messeinrichtung und Verfahren zur Erfassung unterschiedlicher Gase und Gaskonzentrationen |
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JPWO2017204030A1 (ja) * | 2016-05-25 | 2019-04-04 | パナソニックIpマネジメント株式会社 | デバイス |
JP6547967B2 (ja) * | 2016-10-06 | 2019-07-24 | パナソニックIpマネジメント株式会社 | 赤外線検出装置 |
KR102221892B1 (ko) * | 2016-10-24 | 2021-03-02 | 미쓰비시덴키 가부시키가이샤 | 반도체 장치 |
US10466174B2 (en) * | 2016-12-13 | 2019-11-05 | Infineon Technologies Ag | Gas analyzer including a radiation source comprising a black-body radiator with at least one through-hole and a collimator |
KR101896480B1 (ko) | 2017-02-24 | 2018-09-07 | 주식회사 쏠락 | 수소가스 누출 감지장치 |
US10101212B1 (en) * | 2017-03-13 | 2018-10-16 | The United States Of America As Represented By The Secretary Of The Air Force | Wavelength-selective thermal detection apparatus and methods |
CN106895293B (zh) * | 2017-04-25 | 2019-03-15 | 苏州诺联芯电子科技有限公司 | 光源组件及具有该光源组件的气体传感器 |
IT201700097976A1 (it) * | 2017-08-31 | 2019-03-03 | Co Mac Srl | Dispositivo e metodo per il rilevamento di microfughe da fusti e simili contenitori |
US10883804B2 (en) * | 2017-12-22 | 2021-01-05 | Ams Sensors Uk Limited | Infra-red device |
US10436646B2 (en) * | 2018-02-28 | 2019-10-08 | Ams Sensors Uk Limited | IR detector arrays |
FR3087007B1 (fr) * | 2018-10-05 | 2021-03-12 | Commissariat Energie Atomique | Dispositif de detection pyroelectrique a membrane rigide |
CN109738075A (zh) * | 2019-02-15 | 2019-05-10 | 东莞传晟光电有限公司 | 一种to基座热释电传感器 |
KR102267334B1 (ko) | 2020-03-30 | 2021-06-22 | 한국전력공사 | 전력설비 절연물 분해가스의 검출 방법과 이를 이용한 휴대용 검출 장치 |
EP4333560A1 (en) * | 2022-09-05 | 2024-03-06 | 4K-Mems Sa | Thermal light emitting device |
KR20240079583A (ko) | 2022-11-29 | 2024-06-05 | (주)에스엠소프트 | 초음파카메라를 활용한 배관 점검용 무인비행장치 |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6214028A (ja) * | 1985-07-11 | 1987-01-22 | Nippon Ceramic Kk | 焦電型センサ |
JPH0395502A (ja) * | 1989-09-08 | 1991-04-19 | Sumitomo Bakelite Co Ltd | 炎センサ用フィルタ |
JPH03205521A (ja) | 1989-09-30 | 1991-09-09 | Horiba Ltd | 赤外線検出器 |
JPH0674818A (ja) * | 1992-08-26 | 1994-03-18 | Matsushita Electric Works Ltd | 赤外線検出装置 |
JPH0772078A (ja) | 1993-09-02 | 1995-03-17 | Matsushita Electric Ind Co Ltd | 赤外線式ガスセンサー |
JPH07174624A (ja) * | 1993-12-16 | 1995-07-14 | Kureha Chem Ind Co Ltd | デュアル焦電センサ |
JPH07190852A (ja) * | 1993-12-24 | 1995-07-28 | Matsushita Electric Ind Co Ltd | 赤外線センサ |
JPH10281866A (ja) | 1997-04-09 | 1998-10-23 | Matsushita Electric Works Ltd | 焦電型赤外線検出装置 |
JP2001221737A (ja) * | 2000-02-08 | 2001-08-17 | Yokogawa Electric Corp | 赤外線光源及びその製造方法及び赤外線ガス分析計 |
JP2004257885A (ja) * | 2003-02-26 | 2004-09-16 | Horiba Ltd | 多素子型赤外線検出器 |
JP2009109348A (ja) * | 2007-10-30 | 2009-05-21 | Yokogawa Electric Corp | 赤外線光源 |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NO149679C (no) * | 1982-02-22 | 1984-05-30 | Nordal Per Erik | Anordning ved infraroed straalingskilde |
CN1003103B (zh) * | 1986-05-07 | 1989-01-18 | 日本陶瓷株式会社 | 热电型红外探测器 |
JP2642963B2 (ja) * | 1988-09-12 | 1997-08-20 | オプテックス 株式会社 | 赤外線検出装置 |
US5041723A (en) * | 1989-09-30 | 1991-08-20 | Horiba, Ltd. | Infrared ray detector with multiple optical filters |
US5574375A (en) * | 1995-03-15 | 1996-11-12 | Kureha Kagaku Kogyo Kabushiki Kaisha | Dual pyroelectric sensor |
US5962854A (en) * | 1996-06-12 | 1999-10-05 | Ishizuka Electronics Corporation | Infrared sensor and infrared detector |
KR100301747B1 (ko) * | 1997-03-26 | 2001-09-03 | 이마이 기요스케 | 초전형적외선검출장치 |
JP2002071457A (ja) * | 2000-08-31 | 2002-03-08 | Fuji Denshi Kogyo Kk | 光センサのフィルタ取付構造 |
TW490554B (en) * | 2001-06-06 | 2002-06-11 | Bruce C S Chou | Miniaturized infrared gas analyzing apparatus |
US20040187904A1 (en) * | 2003-02-05 | 2004-09-30 | General Electric Company | Apparatus for infrared radiation detection |
JP4449906B2 (ja) * | 2003-10-27 | 2010-04-14 | パナソニック電工株式会社 | 赤外線放射素子およびそれを用いたガスセンサ |
DE10356508B4 (de) * | 2003-12-03 | 2019-05-02 | Robert Bosch Gmbh | Mikromechanische Infrarotquelle |
WO2006120862A1 (ja) * | 2005-05-11 | 2006-11-16 | Murata Manufacturing Co., Ltd. | 赤外線センサおよびその製造方法 |
US8591716B2 (en) * | 2005-08-26 | 2013-11-26 | Panasonic Corporation | Process of making a semiconductor optical lens and a semiconductor optical lens fabricated thereby |
-
2010
- 2010-06-22 US US13/380,810 patent/US20120235038A1/en not_active Abandoned
- 2010-06-22 WO PCT/JP2010/060570 patent/WO2010150787A1/ja active Application Filing
- 2010-06-22 EP EP10792105A patent/EP2447705A1/en not_active Withdrawn
- 2010-06-22 KR KR1020127001935A patent/KR101311322B1/ko not_active IP Right Cessation
- 2010-06-22 CN CN2010800366287A patent/CN102575983A/zh active Pending
- 2010-06-23 TW TW099120477A patent/TWI426259B/zh not_active IP Right Cessation
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6214028A (ja) * | 1985-07-11 | 1987-01-22 | Nippon Ceramic Kk | 焦電型センサ |
JPH0395502A (ja) * | 1989-09-08 | 1991-04-19 | Sumitomo Bakelite Co Ltd | 炎センサ用フィルタ |
JPH03205521A (ja) | 1989-09-30 | 1991-09-09 | Horiba Ltd | 赤外線検出器 |
JPH0674818A (ja) * | 1992-08-26 | 1994-03-18 | Matsushita Electric Works Ltd | 赤外線検出装置 |
JPH0772078A (ja) | 1993-09-02 | 1995-03-17 | Matsushita Electric Ind Co Ltd | 赤外線式ガスセンサー |
JPH07174624A (ja) * | 1993-12-16 | 1995-07-14 | Kureha Chem Ind Co Ltd | デュアル焦電センサ |
JPH07190852A (ja) * | 1993-12-24 | 1995-07-28 | Matsushita Electric Ind Co Ltd | 赤外線センサ |
JPH10281866A (ja) | 1997-04-09 | 1998-10-23 | Matsushita Electric Works Ltd | 焦電型赤外線検出装置 |
JP2001221737A (ja) * | 2000-02-08 | 2001-08-17 | Yokogawa Electric Corp | 赤外線光源及びその製造方法及び赤外線ガス分析計 |
JP2004257885A (ja) * | 2003-02-26 | 2004-09-16 | Horiba Ltd | 多素子型赤外線検出器 |
JP2009109348A (ja) * | 2007-10-30 | 2009-05-21 | Yokogawa Electric Corp | 赤外線光源 |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2011071011A1 (ja) * | 2009-12-09 | 2011-06-16 | パナソニック電工株式会社 | 赤外線式炎検知器 |
CN102435578A (zh) * | 2011-09-21 | 2012-05-02 | 河南汉威电子股份有限公司 | 全量程红外气体探测器及其测量方法 |
CN102435578B (zh) * | 2011-09-21 | 2013-09-11 | 河南汉威电子股份有限公司 | 全量程红外气体探测器及其测量方法 |
JP2017138305A (ja) * | 2016-01-22 | 2017-08-10 | エクセリタス テクノロジーズ シンガポール プライヴェート リミテッド | 動作および存在検出器 |
CN107036719A (zh) * | 2016-01-22 | 2017-08-11 | 埃塞力达技术新加坡有限私人贸易公司 | 双元件热释电运动和存在检测器 |
US11346775B2 (en) | 2018-08-29 | 2022-05-31 | Asahi Kasei Microdevices Corporation | NDIR gas sensor and optical device |
US11921038B2 (en) | 2018-08-29 | 2024-03-05 | Asahi Kasei Microdevices Corporation | Optical device |
US11320572B2 (en) | 2019-12-05 | 2022-05-03 | Asahi Kasei Microdevices Corporation | NDIR gas sensor, optical device, and optical filter for NDIR gas sensor |
US11740396B2 (en) | 2019-12-05 | 2023-08-29 | Asahi Kasei Microdevices Corporation | Optical device |
Also Published As
Publication number | Publication date |
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KR20120071381A (ko) | 2012-07-02 |
KR101311322B1 (ko) | 2013-09-25 |
EP2447705A1 (en) | 2012-05-02 |
TWI426259B (zh) | 2014-02-11 |
CN102575983A (zh) | 2012-07-11 |
TW201129790A (en) | 2011-09-01 |
US20120235038A1 (en) | 2012-09-20 |
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