CN114965339A - Integrated infrared gas sensor with special-shaped gas chamber and using method thereof - Google Patents
Integrated infrared gas sensor with special-shaped gas chamber and using method thereof Download PDFInfo
- Publication number
- CN114965339A CN114965339A CN202210567389.2A CN202210567389A CN114965339A CN 114965339 A CN114965339 A CN 114965339A CN 202210567389 A CN202210567389 A CN 202210567389A CN 114965339 A CN114965339 A CN 114965339A
- Authority
- CN
- China
- Prior art keywords
- light source
- circuit board
- gas sensor
- reflecting
- sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 14
- 230000003287 optical effect Effects 0.000 claims abstract description 43
- 238000001514 detection method Methods 0.000 claims abstract description 33
- 230000007246 mechanism Effects 0.000 claims description 50
- 239000012528 membrane Substances 0.000 claims description 7
- 230000005611 electricity Effects 0.000 claims 1
- 230000004044 response Effects 0.000 abstract description 20
- 230000004907 flux Effects 0.000 abstract description 18
- 230000035945 sensitivity Effects 0.000 abstract description 18
- 239000007789 gas Substances 0.000 description 72
- 239000000463 material Substances 0.000 description 13
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 238000004088 simulation Methods 0.000 description 7
- 238000010521 absorption reaction Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 229910052581 Si3N4 Inorganic materials 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 239000003245 coal Substances 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 3
- 230000010354 integration Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 238000002310 reflectometry Methods 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 230000005457 Black-body radiation Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000003292 glue Substances 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 238000013041 optical simulation Methods 0.000 description 2
- 238000004806 packaging method and process Methods 0.000 description 2
- 239000002096 quantum dot Substances 0.000 description 2
- WSMQKESQZFQMFW-UHFFFAOYSA-N 5-methyl-pyrazole-3-carboxylic acid Chemical compound CC1=CC(C(O)=O)=NN1 WSMQKESQZFQMFW-UHFFFAOYSA-N 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 229910001369 Brass Inorganic materials 0.000 description 1
- 229910004261 CaF 2 Inorganic materials 0.000 description 1
- AFCARXCZXQIEQB-UHFFFAOYSA-N N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CCNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 AFCARXCZXQIEQB-UHFFFAOYSA-N 0.000 description 1
- 230000004308 accommodation Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910021418 black silicon Inorganic materials 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004070 electrodeposition Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000005459 micromachining Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- -1 polytetrafluoroethylene Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
Abstract
The invention discloses an integrated infrared gas sensor with a special-shaped gas chamber and a using method thereof, wherein the integrated infrared gas sensor with the special-shaped gas chamber comprises: the optical air chamber is arranged on the circuit board and comprises a first reflecting piece and a second reflecting piece, the longitudinal sections of the first reflecting piece and the second reflecting piece are parabolic, and an accommodating space is formed between the first reflecting piece and the circuit board; the light source assembly is arranged on the circuit board and is positioned in the accommodating space; the detection assembly is arranged on the circuit board and is positioned in the accommodating space. According to the invention, through the mutual matching of the first reflecting piece, the second reflecting piece, the light source assembly and the detection assembly, the small-sized sensor has larger optical path and luminous flux, and the sensitivity and response speed of the small-sized sensor can be improved.
Description
Technical Field
The invention relates to the technical field of infrared sensors, in particular to an integrated infrared gas sensor with a special-shaped gas chamber and a using method thereof.
Background
The infrared gas sensor is based on the beer-Lambert law I ═ I 0 EXP (-mu CL), wherein I is the infrared light intensity sensed by the sensitive element after passing through the gas to be measured, and I 0 The gas concentration is determined by measuring the absorption intensity of infrared light by gases with different concentrations. With the demands of environmental protection, security alarm, industrial monitoring and other scenes, higher requirements are put forward on the infrared gas sensor, such as the following main performances: (1) smaller sensor sizes are required; (2) the requirement on detection sensitivity is higher, and the response requirement is quicker; (3) higher degree of integration, etc. The detection principle of the infrared gas sensor obeys the Lambert-beer absorption law, and the optical path of infrared light is reduced along with the reduction of the volume of a gas chamber of the sensor, so that the measurement accuracy of the sensor is influenced.
Chinese patent document CN110132877B discloses an integrated infrared gas sensor based on MEMS, which includes a PCB, an unpackaged MEMS infrared light source, an unpackaged infrared detector, a gas chamber, a filter and a metal casing; the method comprises the steps that infrared light emitted by an unpackaged MEMS infrared light source enters a gas chamber from a light inlet hole, gas sequentially passes through holes in a PCB and vent holes in the gas chamber to reach the interior of the gas chamber, the gas enters and exits the gas chamber, the infrared light can absorb target gas, the infrared light is reflected on the inner wall of the gas chamber and is emitted from a light outlet hole, the infrared light is detected by an unpackaged infrared detector, and the content of the target gas in the gas can be obtained according to a test result of the infrared detector. Although the size of the infrared gas sensor is reduced, the sensitivity of the sensor is low, and the response time is too long.
Chinese patent document CN111693480A discloses a vertical micro infrared gas sensor, which includes: the infrared gas sensor adopts system-level hybrid integrated packaging, although the size of the infrared gas sensor is effectively reduced, the sensitivity of the sensor is low, and the response time is too long.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: in order to solve the technical problems of low sensitivity and long response time of the small-volume infrared sensor in the prior art, the invention provides the integrated infrared gas sensor with the special-shaped gas chamber and the use method thereof, which improve the optical path and luminous flux and the response performance of the infrared gas sensor while ensuring the small volume and size.
The technical scheme adopted by the invention for solving the technical problems is as follows: an integrated infrared gas sensor having a shaped gas cell, comprising: the optical air chamber is arranged on the circuit board and comprises a first reflecting piece and a second reflecting piece, the longitudinal sections of the first reflecting piece and the second reflecting piece are parabolic, and an accommodating space is formed between the first reflecting piece and the circuit board; the light source assembly is arranged on the circuit board and is positioned in the accommodating space; the detection assembly is arranged on the circuit board and is positioned in the accommodating space. Therefore, through the mutual matching among the first reflecting piece, the second reflecting piece, the light source assembly and the detection assembly, the small-sized sensor can have a larger optical path and luminous flux, and the sensitivity and the response speed of the small-sized sensor can be improved.
Further, the first reflecting member has a first reflecting surface, the second reflecting member has a second reflecting surface, and the first reflecting surface and the second reflecting surface are arranged oppositely.
Furthermore, the light source assembly and the detection assembly are respectively located on two sides of the second reflecting piece, and the light source assembly, the second reflecting piece and the detection assembly are located on the same straight line.
Further, in order to increase the optical path, the distance between the first reflecting surface and the second reflecting surface is L, and the distance L gradually increases from the light source assembly side to the detection assembly side.
Further, the light source assembly comprises: the MEMS infrared light source, the collimating mechanism and the Fresnel lens are arranged on the circuit board, the MEMS infrared light source is arranged at the bottom of the collimating mechanism and electrically connected with the circuit board, the Fresnel lens is arranged at the top of the collimating mechanism, and the MEMS infrared light source and the Fresnel lens are arranged oppositely. Therefore, the light beam emitted by the MEMS infrared light source has directionality through the matching of the collimating mechanism and the Fresnel lens.
Further, the detection assembly includes: the focusing mechanism is installed on the circuit board, the photoelectric detector is installed at the bottom of the focusing mechanism, and the photoelectric detector is electrically connected with the circuit board. Thereby, more light is allowed to be received by the photodetector by the focusing mechanism.
Furthermore, an air hole for air to pass through is formed in the first reflecting piece, a waterproof breathable film covers the air hole, and the waterproof breathable film is located on one side, far away from the accommodating space, of the air hole.
Furthermore, the longitudinal section of the inner surface of the collimation mechanism is a first semi-ellipse, the short axis of the first semi-ellipse is parallel to the circuit board, and the MEMS infrared light source is located at the focus of the first semi-ellipse.
Further, the longitudinal section of the inner surface of the focusing mechanism is a second semi-ellipse, the minor axis of the second semi-ellipse is parallel to the circuit board, and the photodetector is located at the focal point of the second semi-ellipse.
The invention also provides a using method of the integrated infrared gas sensor with the special-shaped gas chamber, and the using method comprises the following steps: step S1, reflecting the light emitted by the light source component along the vertical direction to the second reflecting piece by the first reflecting piece; in step S2, the light is reflected between the second reflector and the first reflector for multiple times and then received by the detecting assembly.
The sensor has the advantages that the first reflecting piece, the second reflecting piece, the light source assembly and the detection assembly are matched with each other, so that the small-sized sensor has larger optical path and luminous flux, and the sensitivity and response speed of the small-sized sensor can be improved; the light emitted by the light source has obvious directionality through the collimating mechanism and the Fresnel lens; through the structural design of the first reflecting piece and the second reflecting piece, the optical path of the sensor can be increased, and the detection precision and sensitivity of the infrared gas sensor are improved; the focusing mechanism can improve the absorption flux of the photoelectric detector to light rays and improve the response speed of the infrared gas sensor.
Drawings
The invention is further illustrated with reference to the following figures and examples.
FIG. 1 is a cross-sectional view of an integrated infrared gas sensor of the present invention having a shaped gas cell.
Fig. 2 is a cross-sectional view of a light source assembly of the present invention.
FIG. 3 is a cross-sectional view of a probe assembly of the present invention.
FIG. 4 is a diagram illustrating the effect of light emitted from a light source assembly according to the present invention.
FIG. 5 is a light ray simulation of an integrated infrared gas sensor of the present invention having a shaped gas cell.
Fig. 6 is a graph of the light flux simulation result of the present invention.
Fig. 7 is a graph of the optical path simulation result of the present invention.
FIG. 8 is a flow chart of a method of using the integrated infrared gas sensor with shaped gas cells of the present invention.
In the figure: 1. a circuit board; 2. an optical gas cell; 3. an accommodating space; 4. a light source assembly; 5. a detection component; 21. a first reflective member; 22. a second reflector; 23. air holes; 24. a waterproof breathable film; 211. a first reflective surface; 221. a second reflective surface; 41. an MEMS infrared light source; 42. a collimating mechanism; 43. a Fresnel lens; 51. a photodetector; 52. a focusing mechanism.
Detailed Description
The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, but are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the invention. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
As shown in fig. 1 to 3, the integrated infrared gas sensor with a shaped gas cell of the present invention includes: the light source comprises a circuit board 1, an optical air chamber 2, a light source component 4 and a detection component 5, wherein the optical air chamber 2 is installed on the circuit board 1, the optical air chamber 2 comprises a first reflector 21 and a second reflector 22, the longitudinal sections of the first reflector 21 and the second reflector 22 are parabolic, an accommodating space 3 is formed between the first reflector 21 and the circuit board 1, the light source component 4 is installed on the circuit board 1, the light source component 4 is located in the accommodating space 3, the detection component 5 is installed on the circuit board 1, and the detection component 5 is located in the accommodating space 3. According to the invention, through the mutual matching among the first reflector 21, the second reflector 22, the light source assembly 4 and the detection assembly 5, the small-sized sensor has a larger optical path and luminous flux, and the sensitivity and response speed of the small-sized sensor can be improved.
Specifically, the first reflecting member 21 has a first reflecting surface 211, the second reflecting member 22 has a second reflecting surface 221, and the first reflecting surface 211 and the second reflecting surface 221 are disposed opposite to each other. The light source assembly 4 and the detecting assembly 5 are respectively located at two sides of the second reflector 22, and the light source assembly 4, the second reflector 22 and the detecting assembly 5 are located on the same straight line. The distance between the first reflecting surface 211 and the second reflecting surface 221 is L, and the distance L gradually increases from the light source assembly 4 side to the detection assembly 5 side. For example, the optical air chamber 2 may be made of aluminum, brass or ABS material, and may be formed by micro-machining or injection molding, and a higher machining precision should be selected during machining to ensure the flatness of the surface of the optical air chamber 2 and improve the reflectivity. The first reflecting surface 211 and the second reflecting surface 221 may be coated with a reflecting film, which can improve the reflectivity (the reflectivity can reach 98%), the reflecting film may be a gold film, an aluminum film, a bragg reflecting film, etc., and the reflecting film may be prepared by evaporation of a metal film, electrochemical deposition, etc. The light emitted by the light source assembly 4 can be reflected by the first reflecting surface 211 to the second reflecting surface 221, then reflected to the first reflecting surface 211, and then reflected to the second reflecting surface 221, so that the light can enter the detecting assembly 5 to be received after multiple reflections, and thus, the optical path can be increased, and the energy loss can be reduced by the reflecting film. The distance L between the first reflecting surface 211 and the second reflecting surface 221 gradually increases from the light source unit 4 side to the detection unit 5 side, so that the optical path length can be increased. If the distance L between the first reflection surface 211 and the second reflection surface 221 is set to be equal on the assumption that the gas sensors have the same size, the number of times of reflection of light is reduced, which leads to a reduction in optical length and a reduction in sensor accuracy. For example, the distance between the first reflecting surface 211 and the second reflecting surface 221 is about 1mm on the light source unit 4 side, and the distance between the first reflecting surface 211 and the second reflecting surface 221 is about 1.8mm on the detection unit 5 side. In the present embodiment, the first reflective member 21 and the second reflective member 22 are recessed in the same direction, and both are recessed away from the circuit board 1, and if the recessed directions of the first reflective member 21 and the second reflective member 22 are set to be opposite, the optical path length is reduced, and the accuracy of the sensor is reduced. For example, the distance between the light source assembly 4 and the detecting assembly 5 is about 4.5mm, one end of the second reflector 22 close to the detecting assembly 5 is fixed on the circuit board 1, and one end of the second reflector 22 close to the light source assembly 4 is suspended but is as close as possible to the light source assembly 4 (the light source assembly 4 cannot be blocked), so that the optical path of the sensor can be increased on the premise of enlarging the size of the sensor.
In the present embodiment, the light source assembly 4 includes: the MEMS infrared light source 41, the collimation mechanism 42 and the Fresnel lens 43 are arranged, the collimation mechanism 42 is installed on the circuit board 1, the MEMS infrared light source 41 is installed at the bottom of the collimation mechanism 42, the MEMS infrared light source 41 is electrically connected with the circuit board 1, the Fresnel lens 43 is installed at the top of the collimation mechanism 42, and the MEMS infrared light source 41 and the Fresnel lens 43 are arranged oppositely. The longitudinal cross-section of the inner surface of the collimating mechanism 42 is a first semi-elliptical shape (i.e. the collimating mechanism 42 has a reflective cavity with a diameter gradually decreasing from the top to the bottom), the minor axis of the first semi-elliptical shape is parallel to the circuit board 1, and the MEMS infrared light source 41 is located at the focal point of the first semi-elliptical shape. The MEMS infrared light source 41 includes, from top to bottom, a metal bonding layer, a black body radiation layer, silicon nitride, a support layer, and a silicon substrate, wherein the black body radiation layer can emit a broadband infrared spectrum based on the planck theory, and preferably adopts platinum black, black silicon, and other materials. The MEMS infrared light source 41 can meet the requirements of miniaturization and integration of the infrared gas sensor. The fresnel lens 43 may function to condense light. Referring to fig. 4, the original light emitted by the MEMS infrared light source 41 is divergent, the maximum exit angle may be close to 90 °, and if the light emitted by the MEMS infrared light source 41 is directly reflected by the first reflecting member 21 and the second reflecting member 22, the number of effective light received by the detecting component 5 is small, which results in a small optical path and a small luminous flux of the sensor, and further results in a low detection accuracy and responsivity of the sensor. The collimating mechanism 42 can collimate the light emitted from the MEMS infrared light source 41 for the first time, that is, the light with a larger exit angle can be reflected by the inner surface of the collimating mechanism 42, so as to reduce the exit angle of the light, for example, after being collimated by the collimating mechanism 42, the maximum exit angle of the light can be reduced to 35 °. The light rays collimated by the collimating mechanism 42 for the first time pass through the light condensing action of the fresnel lens 43 (i.e. the second collimation), so that the angle of the light rays finally emitted from the light source assembly 4 is further reduced, and the light rays are emitted nearly horizontally. In other words, by the cooperation of the MEMS infrared light source 41, the collimating mechanism 42 and the fresnel lens 43, more light can be received by the detecting component 5, and the sensitivity and response speed of the sensor can be improved. Because the MEMS infrared light source 41 has a small size, the position of the MEMS infrared light source 41 can be arranged at the focus of the first semiellipse, so that the condensation and collimation effects can be improved, and the short axis of the first semiellipse is parallel to the circuit board 1, so that the emergent orientation effect of light rays can be improved.
In the present embodiment, the detection assembly 5 includes: a photoelectric detector 51 and a focusing mechanism 52, the focusing mechanism 52 is installed on the circuit board 1, the photoelectric detector 51 is installed at the bottom of the focusing mechanism 52, and the photoelectric detector 51 is electrically connected with the circuit board 1.The longitudinal cross-section of the inner surface of the focusing mechanism 52 is a second semi-elliptical shape (i.e., the focusing mechanism 52 has a focusing chamber with a diameter gradually decreasing from the top to the bottom), the minor axis of the second semi-elliptical shape is parallel to the circuit board 1, and the photodetector 51 is located at the focal point of the second semi-elliptical shape. The photodetector 51 may be a photo-thermal photodetector or a photo-electronic photodetector, the photo-thermal photodetector comprises a metal back plate, a narrow-band filter film, a photosensitive material, a silicon nitride thermal insulation plate and a silicon substrate from top to bottom, wherein the photosensitive material may be a pyroelectric film material, such as lithium tantalate, lithium niobate, lead zirconate titanate, etc., the photo-electronic photodetector comprises a narrow-band metal back plate, a filter film, a photosensitive material, a lower gold electrode layer, a silicon nitride thermal insulation plate and a silicon substrate from top to bottom, wherein the photosensitive material may be a colloidal quantum dot film, such as PbS, SnO, etc 2 、WO 3 、ZnO、In 2 O 3 And (3) forming the colloidal quantum dot film. The narrow-band filtering film is an optical resonant cavity formed by a metal or medium nano-structure array based on a nano-size effect, and has a filtering effect on specific wavelengths. The photodetector 51 abandons the conventional CaF 2 The optical filter materials have higher integration level for devices and obviously lower cost. The photodetector 51 can detect the infrared light intensity after the absorption of the gas. The focusing mechanism 52 can receive more reflected light rays by the photoelectric detector 51, the inner surface of the focusing mechanism 52 can play a role in reflection and convergence, the absorption luminous flux of the photoelectric detector 51 to infrared light rays can be improved, and the response speed of the infrared gas sensor to gas concentration detection is further improved. The minor axis of the second semi-ellipse is parallel to the circuit board 1, and the photodetector 51 is located at the focus of the second semi-ellipse, so that more light rays can be absorbed by the photodetector 51, and the sensitivity of the infrared gas sensor is improved.
In this embodiment, the material and manufacturing process of the collimating mechanism 42 and the focusing mechanism 52 are the same as those of the optical gas cell 2, and are not described herein again. The inner surfaces of the collimating and focusing mechanisms 42, 52 may also be coated with a reflective coating.
In this embodiment, the first reflector 21 is provided with an air hole 23 for air to pass through, the air hole 23 is covered with a waterproof permeable membrane 24, and the waterproof permeable membrane 24 is located at a side of the air hole 23 away from the accommodating space 3. The air holes 23 facilitate the entry of air to fill the accommodation space 3. Waterproof ventilated membrane 24 is flexible film material, mainly comprises polytetrafluoroethylene's hydrophobic layer (skin) and non-woven fabrics material's supporting layer (inlayer), has waterproof dustproof ventilative effect, and waterproof ventilated membrane 24 accessible liquid glue, mode such as pressure-sensitive gum are fixed with first reflection part 21, consider special-shaped air chamber structure, preferably fix waterproof ventilated membrane 24 through pressure-sensitive gum, and the laminating nature is better.
In this embodiment, the optical air chamber 2, the MEMS infrared light source 41, the collimating mechanism 42, the photodetector 51, and the focusing mechanism 52 are all mounted on the circuit board 1, and may be bonded by glue such as epoxy resin, acrylic resin, and silicone, and may also be assisted in positioning and limiting by means of a limiting column and a contour line. The MEMS infrared light source 41 and the photodetector 51 may be electrically connected to the circuit board 1 by a lead wire, preferably a gold wire or an aluminum wire having a small contact resistance. The circuit board 1 is provided with metal pads at positions where the light source assembly 4 and the detection assembly 5 are installed, the material of the pads can be set according to lead materials, for example, the pads are made of plating alloy materials, and the metal pads can be used for SMD (surface mounted device) surface mounted packaging.
In order to better illustrate the technical effect of the scheme, the integrated infrared gas sensor with the special-shaped gas chamber is subjected to three-dimensional modeling, optical simulation is carried out by using optical simulation software TracePro (as shown in FIG. 5), the size of the infrared sensor is set to be 25mm multiplied by 10mm, and the size of the infrared sensor can be finely adjusted and optimized according to the selected MEMS infrared light source 41 and the selected photoelectric detector 51 in practical application.
According to the same simulation parameters, optical simulation was performed on example (the present invention), comparative example 1(CN111693480A) and comparative example 2(CN10132870B), respectively, the infrared light sources were all set to be of Lambertian light-emitting field type, the luminous flux was 1W, the total number of rays was 1000, and the luminous flux and the optical path reaching the surface of the photodetector were obtained by tracing the rays.
Fig. 6 is a light flux simulation result of the present invention, in the simulation, 1w of light is split into 1000 pieces, and after various actions of reflection, projection, and refraction, the light flux condition on the action surface (sensitive element) of the photodetector can be obtained, and the result of fig. 6 can represent the efficiency of the sensor, where the total light flux and the light beam received by the photodetector are key parameters for determining the efficiency. As can be seen from fig. 6, the total luminous flux received by the photodetector of the integrated infrared gas sensor with the shaped gas cell of the present invention is 0.34925W, and the bundle of rays is 931 (i.e. 931 out of 1000 rays are received by the photodetector structure). Fig. 7 shows the simulation result of the optical path of the present invention, in which the abscissa of the graph is the optical path and the ordinate is the optical power, and it can be seen from the graph that the optical path of the light reaching the surface of the photodetector ranges from 35mm to 75mm, and when the optical path is 55mm, the optical power is the maximum and is about 0.23W/mm, and when comparing, the average optical path is generally compared with 55 mm. To better compare the results of the examples and comparative examples, please refer to table one.
Watch 1
According to the results in the table I, the average optical path of the integrated infrared gas sensor with the special-shaped gas chamber is 10mm larger than that of the comparison example 1-2, and the luminous flux received by the photoelectric detector is about 13 times that of the comparison example 1 and about 10 times that of the comparison example 2; the number of the light rays received by the photoelectric detector is about 9.6 times that of the comparative example 1 and about 9.3 times that of the comparative example 2. That is, in the sensors of comparative examples 1 and 2, only about 100 light rays (efficiency is only 0.1) out of 1000 light rays emitted by the light source can be received by the photodetector, which results in low sensitivity and response speed of the sensor in practical use; in the 1000 rays emitted by the light source, 931 rays can be received (the efficiency is 0.93), and the sensitivity and the response speed of the sensor are obviously improved. When the infrared gas sensor is applied to underground coal mines (for example, the concentration of gas in the underground coal mines is measured), the sensitivity and the response speed of the sensor are 'life', the condition that the concentration of the gas exceeds the standard or reaches a warning value can be detected in time, and workers in the underground coal mines can take measures in time. According to the invention, through the mutual matching of the light source assembly 4, the optical gas chamber 2 and the detection assembly 5, the small-sized infrared gas sensor still has a larger optical path, and the sensitivity and the response speed of the sensor can be improved.
As shown in fig. 8, the present invention further provides a method for using an integrated infrared gas sensor with a shaped gas chamber, which uses the above-mentioned integrated infrared gas sensor with a shaped gas chamber. The using method comprises the following steps:
step S1, the light emitted by the light source assembly 4 along the vertical direction is reflected by the first reflector 21 onto the second reflector 22; in step S2, the light is reflected between the second reflective member 22 and the first reflective member 21 for multiple times and then received by the detecting assembly 5.
Specifically, the infrared light emitted by the MEMS infrared light source 41 can be collimated and emitted after passing through the collimating mechanism 42 and the fresnel lens 43, and has a significant directionality, and the infrared light can be received by the photodetector 51 after being reflected for multiple times (for example, seven times) between the first reflecting surface 211 and the second reflecting surface 222, wherein a part of the light can be directly received by the photodetector 51, and a part of the light can be received by the photodetector 51 after being reflected by the focusing mechanism 52. According to the invention, through the matching of seven components of the MEMS infrared light source 41, the collimating mechanism 42, the Fresnel lens 43, the first reflecting surface 211, the second reflecting surface 221, the focusing mechanism 52 and the photoelectric detector 51, the sensor is ensured to have small size, and meanwhile, the sensor has larger optical path, higher sensitivity and response speed, and the response performance of the infrared gas sensor is improved.
In summary, according to the integrated infrared gas sensor with the special-shaped gas chamber and the use method thereof, the first reflecting element 21, the second reflecting element 22, the light source assembly 4 and the detection assembly 5 are matched with each other, so that the small-sized sensor has a large optical path and a large luminous flux, and the sensitivity and the response speed of the small-sized sensor can be improved; the collimation mechanism 42 and the Fresnel lens 43 can make the light emitted by the light source have obvious directionality; through the structural design of the first reflecting piece 21 and the second reflecting piece 22, the optical path of the sensor can be increased, and the detection precision and sensitivity of the infrared gas sensor are improved; the absorption flux of the photodetector 51 to light can be increased by the focusing mechanism 52, and the response speed of the infrared gas sensor can be increased.
In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the contents of the specification, and must be determined by the scope of the claims.
Claims (10)
1. An integrated infrared gas sensor having a shaped gas cell, comprising:
circuit board (1), and
the optical air chamber (2) is mounted on the circuit board (1), the optical air chamber (2) comprises a first reflecting piece (21) and a second reflecting piece (22), the longitudinal sections of the first reflecting piece (21) and the second reflecting piece (22) are parabolic, and an accommodating space (3) is formed between the first reflecting piece (21) and the circuit board (1);
the light source assembly (4), the light source assembly (4) is installed on the circuit board (1), and the light source assembly (4) is located in the accommodating space (3);
the detection assembly (5) is installed on the circuit board (1), and the detection assembly (5) is located in the accommodating space (3).
2. The integrated infrared gas sensor with shaped gas cell according to claim 1, characterized in that the first reflector (21) has a first reflecting surface (211) and the second reflector (22) has a second reflecting surface (221), the first reflecting surface (211) being arranged opposite to the second reflecting surface (221).
3. The integrated infrared gas sensor with shaped gas cell as set forth in claim 2, wherein the light source module (4) and the detection module (5) are respectively located at two sides of the second reflector (22), and the light source module (4), the second reflector (22) and the detection module (5) are located on the same straight line.
4. The integrated infrared gas sensor with shaped gas cell as set forth in claim 3, characterized in that the distance between the first reflecting surface (211) and the second reflecting surface (221) is L, which gradually increases from the light source assembly (4) side to the detection assembly (5) side.
5. Integrated infrared gas sensor with shaped gas cell according to claim 3, characterized in that the light source assembly (4) comprises: MEMS infrared light source (41), collimating mechanism (42) and fresnel lens (43), collimating mechanism (42) are installed on circuit board (1), MEMS infrared light source (41) are installed the bottom of collimating mechanism (42), just MEMS infrared light source (41) with circuit board (1) electricity is connected, fresnel lens (43) are installed the top of collimating mechanism (42), MEMS infrared light source (41) with fresnel lens (43) set up relatively.
6. Integrated infrared gas sensor with shaped gas cell according to claim 5, characterized in that the detection assembly (5) comprises: the focusing mechanism (52) is installed on the circuit board (1), the photoelectric detector (51) is installed at the bottom of the focusing mechanism (52), and the photoelectric detector (51) is electrically connected with the circuit board (1).
7. The integrated infrared gas sensor with the shaped gas chamber as set forth in claim 1, wherein the first reflector (21) is provided with a gas hole (23) for gas to pass through, the gas hole (23) is covered with a waterproof gas-permeable membrane (24), and the waterproof gas-permeable membrane (24) is located on one side of the gas hole (23) far away from the accommodating space (3).
8. The integrated infrared gas sensor with shaped gas cell as set forth in claim 5, characterized in that the longitudinal cross-section of the inner surface of the collimating mechanism (42) is a first semi-ellipse, the minor axis of the first semi-ellipse being parallel to the circuit board (1), the MEMS infrared light source (41) being located at the focus of the first semi-ellipse.
9. The integrated infrared gas sensor with shaped gas cell as set forth in claim 6, characterized in that the longitudinal cross-section of the inner surface of the focusing mechanism (52) is a second semi-ellipse, the minor axis of which is parallel to the circuit board (1), the photodetector (51) being located at the focus of the second semi-ellipse.
10. A method of using an integrated infrared gas sensor with a shaped gas cell, wherein the integrated infrared gas sensor with a shaped gas cell as claimed in any one of claims 1 to 9 is used, the method comprising:
step S1, reflecting the light rays emitted by the light source component (4) along the vertical direction to the second reflecting piece (22) by the first reflecting piece (21);
in step S2, the light is reflected between the second reflector (22) and the first reflector (21) for multiple times and then received by the detecting assembly (5).
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210567389.2A CN114965339A (en) | 2022-05-24 | 2022-05-24 | Integrated infrared gas sensor with special-shaped gas chamber and using method thereof |
| PCT/CN2022/115682 WO2023226225A1 (en) | 2022-05-24 | 2022-08-30 | Integrated infrared gas sensor having special-shaped gas chamber and usage method therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210567389.2A CN114965339A (en) | 2022-05-24 | 2022-05-24 | Integrated infrared gas sensor with special-shaped gas chamber and using method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114965339A true CN114965339A (en) | 2022-08-30 |
Family
ID=82984794
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210567389.2A Pending CN114965339A (en) | 2022-05-24 | 2022-05-24 | Integrated infrared gas sensor with special-shaped gas chamber and using method thereof |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN114965339A (en) |
| WO (1) | WO2023226225A1 (en) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8158946B2 (en) * | 2010-08-25 | 2012-04-17 | Airware, Inc. | Intrinsically safe improved sensitivity NDIR gas sensor in a can |
| CN106018330B (en) * | 2016-05-10 | 2019-03-22 | 四川长虹电器股份有限公司 | A kind of pocket-type near infrared spectrometer |
| DE102016010088A1 (en) * | 2016-08-23 | 2018-03-01 | Dräger Safety AG & Co. KGaA | Measuring device for absorption measurement of gases |
| CN206300898U (en) * | 2016-11-30 | 2017-07-04 | 深圳市唯锐科技有限公司 | A kind of compact laser gas sensor |
| CN110132877B (en) * | 2019-06-17 | 2021-03-23 | 山东大学 | Integrated infrared gas sensor based on MEMS |
| CN111879719A (en) * | 2020-09-09 | 2020-11-03 | 成都凯能光电科技有限公司 | Infrared gas sensor based on NDIR technology |
-
2022
- 2022-05-24 CN CN202210567389.2A patent/CN114965339A/en active Pending
- 2022-08-30 WO PCT/CN2022/115682 patent/WO2023226225A1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023226225A1 (en) | 2023-11-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5906407B2 (en) | Gas component detector | |
| TWI759400B (en) | Vcsel narrow divergence proximity sensor | |
| WO2021212931A1 (en) | Two-dimensional, multi-point-reflection, long-optical-distance gas sensor probe, and gas sensor | |
| CA2546845A1 (en) | Gas sensor | |
| US20170030822A1 (en) | Particle sensor | |
| US20110147573A1 (en) | Sensor cap assembly sensor circuit | |
| CN209979482U (en) | Gas sensor for infrared spectroscopic analysis | |
| CN109358019B (en) | Gas sensor based on infrared spectrum analysis | |
| JP2012215396A (en) | Infrared gas sensor | |
| JP6810625B2 (en) | Optical gas sensor and gas detector | |
| JP7123599B2 (en) | Light receiving and emitting device and optical density measuring device | |
| CN114965339A (en) | Integrated infrared gas sensor with special-shaped gas chamber and using method thereof | |
| CN218782178U (en) | Laser methane detection sensor | |
| TW201719154A (en) | Optical sensing module | |
| CN115236021A (en) | Parallel double-channel infrared gas sensor | |
| CN210376127U (en) | Gas concentration detection device with mounting seat and combustible gas alarm device | |
| JP2007218612A (en) | Hydrogen gas sensor | |
| KR20200103482A (en) | Multi gas sensing apparatus | |
| CN219417211U (en) | Quick-response infrared gas sensor | |
| US20240035958A1 (en) | Gas detection apparatus | |
| US11808609B2 (en) | Gas cell housing molding mold, method for manufacturing gas cell housing, gas cell housing for gas sensor, and gas sensor including same | |
| US20230349814A1 (en) | Gas detection device | |
| JP6599675B2 (en) | Optical sensor | |
| US20180088038A1 (en) | Gas detection device | |
| CN114486790B (en) | Gas detection device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |