Non-dispersive infrared detection gas sensor

Abstract

We provide a gas sensor based on non-dispersive infrared detection. [Solution] The gas sensor includes a base, a cap, a detection assembly, and an infrared light source assembly. The cap is fitted over the base, and the outer edge of the cap is fixedly connected to the base. The base has a through-hole that penetrates the base, and the side walls of the through-holes in each base extend away from the cap to form a hollow die. Each infrared light source assembly is fitted over one end of the through-hole of one base facing the cap, and the cavity within the infrared light source assembly communicates with the through-hole of one base. Each die wall has a ventilation hole. A pin penetrates the base and its end extends to one side of the infrared light source assembly. Each detection assembly is assembled at one end of the die away from the infrared light source assembly and seals the end of the die. The gas sensor is designed based on an integrated structure of an absorbing gas chamber and a back-transmissive infrared light source assembly.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and particularly to a gas sensor based on non-dispersive infrared detection.

Background Art

[0002] In recent years, NDIR (non-dispersive infrared detection) gas sensing technology has been widely applied in multiple fields such as air quality detection, medical breath examination, intelligent agriculture, and gas monitoring in industrial processes. Most of the conventional NDIR gas sensors adopt a separated assembly and are assembled into product modules through an integration and packaging process, which has major problems in terms of product consistency and miniaturization, and there is a need to further improve the stability and robustness of the products. Also, for some special application scenarios, such as wide-range gas monitoring or mixed multi-gas detection, there is still a lack of design solutions with high stability and robustness at present.

[0003] Generally, an NDIR gas sensor is composed of assemblies such as an infrared light source, an absorption gas chamber, an infrared detector, and a circuit board. The reflection cover, infrared light source, and infrared detector are welded to the circuit board and fixed at both ends of the absorption gas chamber, and are adhered and packaged using a sealant. The overall structure and production process are complex, which is disadvantageous for realizing mass production while ensuring high reliability. The design of a non-integrated structure has relatively poor stability and robustness of the sensor, and the consistency and miniaturization are often not ideal, and further improvement and enhancement are urgently needed. Also, currently, most of the NDIR gas sensors adopt a dual-channel, fixed optical path design, with a narrow detection concentration range, and a single sensor cannot achieve high and low range gas detection. In terms of mixed multi-gas detection, generally, it is composed of a combination of single or multiple infrared light sources and single or multiple infrared detectors, which has disadvantages such as a complex structure, poor robustness, and large volume.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The embodiments of the present invention provide a gas sensor based on non-dispersive infrared detection, aiming to solve the problems of conventional gas sensors, which are characterized by complex structure, poor robustness, and large volume. [Means for solving the problem]

[0005] Embodiments of this application provide a gas sensor based on non-dispersive infrared detection, wherein the gas sensor includes a base, a cap, at least one detection assembly and at least one infrared light source assembly. The cap is placed over the base, and the outer edge of the cap is fixedly connected to the base, and the base is provided with at least one through hole that penetrates the base, and the side walls of each through hole in the base extend away from the cap to form a hollow die. Each of the infrared light source assemblies is installed by covering one end of the through-hole of one of the bases toward the cap, and the cavity within the infrared light source assembly communicates with the through-hole of one of the bases, and each die wall is provided with ventilation holes. The pin penetrates the base and its end extends to one side of the infrared light source assembly, and the heating layer in the infrared light source assembly and the end of the pin are electrically connected via a metal wire. A gas sensor based on non-dispersive infrared detection, characterized in that each detection assembly is assembled at one end of a corresponding die away from the infrared light source assembly, and the end of the die is sealed, at least one infrared detector is provided within each detection assembly, a narrowband filter is provided at one end of each infrared detector facing the infrared light source assembly, and detection pins electrically connected to each infrared detector extend from the inside to the outside of the detection assembly.

[0006] The aforementioned gas sensor based on non-dispersive infrared detection, wherein the infrared light source assembly is a silicon-based MEMS light source assembly, a heating metal foil, or a metal wire. A gas sensor based on non-dispersive infrared detection, characterized in that the side of the silicon-based MEMS light source assembly facing the through hole of the base is recessed inward to form the cavity, and the cap is an arc-shaped cap with one side open, the opening of the arc-shaped cap facing the base.

[0007] The aforementioned gas sensor based on non-dispersive infrared detection, wherein the silicon-based MEMS light source assembly mainly includes a silicon substrate, a heating layer, and a reflective layer. A gas sensor based on non-dispersive infrared detection, characterized in that the silicon substrate has through-holes, the heating layer is bonded to the side of the silicon substrate away from the base and covers the through-holes to form an inwardly recessed cavity, and the reflective layer is bonded to the upper layer of the heating layer.

[0008] The aforementioned gas sensor is based on non-dispersive infrared detection, wherein the reflective layer is a metallic reflective film obtained by manufacturing one or more of the following materials: Au, Pt, Ag, Al, and Cu.

[0009] The aforementioned gas sensor based on non-dispersive infrared detection, wherein the infrared light source assembly is a double-sided silicon MEMS light source assembly, a double-sided silicon heating metal wire, or a double-sided ceramic heating metal wire. The double-sided silicon-based MEMS light source assembly is provided with a cavity that penetrates vertically, and the cap is a tubular cap with both ends open. One or more openings are provided at one end of the cap away from the base, and one of the detection assemblies is provided at each of the openings at the end of the tubular cap away from the base. A gas sensor based on non-dispersive infrared detection, characterized in that a metal-plated pad is provided between the double-sided silicon-based MEMS light source assembly and the base, the metal-plated pad electrically connects the heating layer of the double-sided silicon-based MEMS light source assembly on the side closer to the base, and the metal-plated pad and the end of the pin are electrically connected via a metal wire.

[0010] The aforementioned gas sensor based on non-dispersive infrared detection, wherein the double-sided silicon MEMS light source assembly mainly comprises a silicon substrate, two heating layers, and two infrared radiating material layers. A gas sensor based on non-dispersive infrared detection, characterized in that a through-hole is provided in the silicon substrate, the two heating layers are bonded to both sides of the silicon substrate, the two infrared radiation material layers are bonded to the outer surfaces of the two heating layers, the heating layers located at both ends of the through-hole are combined with the infrared radiation material layers bonded to them to form a single infrared radiation unit, the infrared radiation unit is suspended and installed at an opening outside the through-hole, and the heating layer in the infrared radiation unit extends outward and forms a support arm connected to the heating layer at the outer edge of the through-hole.

[0011] The aforementioned gas sensor is based on non-dispersive infrared detection, wherein the infrared radiation material layer is an amorphous carbon film of nanoplatinum black, nanoblack silicon, carbon nanotubes, graphene, or a doped metal element, or a metasurface material based on Au, Al2O3, or Au material, or a ZnNiP chemical plating layer.

[0012] The gas sensor described above is based on non-dispersive infrared detection, wherein the silicon substrate is a single-crystal silicon substrate or an SOI silicon wafer substrate.

[0013] The aforementioned gas sensor based on non-dispersive infrared detection, wherein the heating layer includes a support layer, a heating electrode, and an isolation layer, which are laminated together, and the heating electrode is a metal composite film layer obtained by manufacturing one or more of the following materials: Pt, Au, W, Al, tin nitride, nickel-chromium alloy, and MoSi2, or a polysilicon film ion-implanted with doping B. The support layer and isolation layer are made of single-layer SiO2, single-layer Si3N4, or single-layer SiN x It is either an SiO2 layer, a Si3N4 layer and SiN x A gas sensor based on non-dispersive infrared detection, characterized by forming a composite film layer with multiple types of film layers among the layers.

[0014] The above-mentioned gas sensor is based on non-dispersive infrared detection, wherein a metal film layer is plated on the inner and outer surfaces of the base, and the metal film layer is formed by plating with one or more materials selected from Ni, Au, Al, and Pt.

[0015] Embodiments of the present invention provide a gas sensor based on non-dispersive infrared detection, the gas sensor comprising a base, a cap, at least one detection assembly and at least one infrared light source assembly, the cap being fitted over the base and the outer edge of the cap being fixedly connected to the base, the base having at least one through-hole penetrating the base, the side walls of each through-hole extending away from the cap to form a hollow die, each infrared light source assembly being fitted over one end of a through-hole in one base toward the cap, the cavity within the infrared light source assembly communicating with the through-hole in one base, each die having a vent hole in its wall, a pin penetrating the base and its end extending toward one side of the infrared light source assembly, the heating layer in the infrared light source assembly and the end of the pin being electrically connected via a metal wire, each detection assembly being assembled at one end of a corresponding die away from the infrared light source assembly and sealing the end of the die. The above gas sensor is designed based on an integrated structure of an absorbent gas chamber and a back-transmitting infrared light source assembly. This eliminates the need to fix the infrared light source with extra structures, effectively reducing the difficulty and volume of sensor integration, and significantly improving its stability and system robustness. [Brief explanation of the drawing]

[0016] To more clearly illustrate the technical concept of the embodiments of the present invention, the following briefly describes the drawings that may be used in the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on the structures shown in these drawings without expending any creative effort.

[0017] [Figure 1] This is a cross-sectional diagram of a gas sensor based on non-dispersive infrared detection according to an embodiment of the present invention. [Figure 2] This is another cross-sectional view of a gas sensor based on non-dispersive infrared detection according to an embodiment of the present invention. [Figure 3] This is yet another cross-sectional view of a gas sensor based on non-dispersive infrared detection according to an embodiment of the present invention. [Figure 4] Another cross-sectional structure diagram of the gas sensor based on non-dispersive infrared detection according to an embodiment of the present invention. [Figure 5] A cross-sectional structure diagram of an infrared light source assembly according to an embodiment of the present invention. [Figure 6] Another cross-sectional structure diagram of a reflector of an infrared light source assembly according to an embodiment of the present invention. [Figure 7] A perspective structure diagram of a pedestal according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0018] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. It is clear that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0019] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements, and / or assemblies, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, assemblies, and / or their combinations.

[0020] It should be further understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "one", and "the" are intended to include the plural forms. It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any one or more combinations and all possible combinations of the related listed items and includes these combinations.

[0021] Referring to Figures 1 and 2, as shown in the figures, an embodiment of the present application discloses a gas sensor based on non-dispersive infrared detection, wherein the gas sensor comprises a base 3, a cap 6, at least one detection assembly 4, and at least one infrared light source assembly, wherein the cap 6 is fitted over the base 3, and the outer edge of the cap 6 is fixedly connected to the base 3, and the base 3 is provided with at least one through-hole that penetrates the base 3, and the side walls of each through-hole of the base extend away from the cap 6 to form a hollow die 31, and each infrared light source assembly is fitted over one end of one of the through-holes of the base facing the cap 6, and the cavity 101 within the infrared light source assembly is through one of the bases A through hole is communicated with each die 31, and a ventilation hole 33 is provided in the wall of each die 31. A pin 32 penetrates the base 3 and its end extends to one side of the infrared light source assembly, and the heating layer 12 in the infrared light source assembly and the end of the pin 32 are electrically connected via a metal wire 8. Each detection assembly 4 is assembled at one end of a corresponding die 31 away from the infrared light source assembly and seals the end of the die 31. At least one infrared detector 41 is provided within each detection assembly 4, and a narrowband filter 42 is provided at one end of each infrared detector 41 facing the infrared light source assembly. A detection pin 43 electrically connected to each infrared detector 41 extends from the inside to the outside of the detection assembly 4.

[0022] The cap 6 is placed over the base 3, and one or more through holes can be provided in the base 3. The side walls of each through hole in the base extend away from the cap 6 to form a hollow die 31. Specifically, as shown in Figure 1, the base 3 is provided with one through hole in Figure 1, and this through hole in the base extends in a corresponding manner to form a die 31. One infrared light source assembly is placed over one end of each through hole in the base facing the cap 6. Figures 1, 2, and 3 all show one infrared light source assembly placed over one end of one through hole in the base, and Figure 4 shows one infrared light source assembly placed over one end of each of the through holes in the base. One detection assembly 4 is assembled at one end of the die 31 away from the infrared light source assembly, and the detection assembly 4 includes at least one infrared detector 41 and at least one narrowband filter 42. As shown in Figure 1, two infrared detectors 41 and two narrowband filters 42 are attached to the detection assembly 4.

[0023] Specifically, a step is provided on the edge of the base 3, and the outer edge of the cap 6 can be fitted into the step, thereby achieving a fixed connection between the cap 6 and the base 3. The pins 32 installed on the base 3 are used to realize the electrical connection of the infrared light source assembly. The size of the base 3 may be designed and manufactured according to the actual demand, and the inner and outer diameters of the die 31 must be determined according to the size of the infrared light source assembly. The diameter of the metal wire 8 is 15 μm to 50 μm.

[0024] In one specific embodiment, the infrared light source assembly comprises a silicon-based MEMS light source assembly 1, a heating metal foil, or a metal wire, wherein the side of the silicon-based MEMS light source assembly 1 facing the through-hole of the base is recessed inward to form the cavity 101, and the cap 6 is an arc-shaped cap 6 with one side open, the opening of the arc-shaped cap 6 facing the base 3. Specifically, as shown in Figure 5, the silicon-based MEMS light source assembly 1 mainly comprises a silicon substrate 11, a heating layer 12, and a reflective layer 13, wherein the silicon substrate 11 is provided with a through-hole, the heating layer 12 is bonded to the side of the silicon substrate 11 away from the base 3 and covers the through-hole to form an inwardly recessed cavity 101, and the reflective layer 13 is bonded to the upper layer of the heating layer 12. Here, the reflective layer 13 is a metal reflective film obtained by manufacturing one or more materials from Au, Pt, Ag, Al, and Cu.

[0025] As shown in Figure 1, the cap 6 is an arc-shaped cap 6 with one side open, and one detection assembly 4 is assembled on only one end of a die 31 away from the infrared light source assembly. The side of the silicon-based MEMS light source assembly 1 facing the through hole of the base is recessed inward to form a cavity 101, which communicates with the through hole of the base. Specifically, the silicon-based MEMS light source assembly 1 includes a silicon substrate 11, a heating layer 12, and a reflective layer 13. The heating layer 12 is electrically heated to emit infrared light outward, and the infrared light is reflected based on the reinforcing reflective action of the reflective layer 13 and emitted outward from the cavity 101 of the silicon substrate 11, thereby forming a back-transmissive silicon-based MEMS infrared light source. Specifically, the cross-section of the cavity 101 of the silicon substrate 11 may be set to be trapezoidal or rectangular, and the opening size of the cavity 101 may be set to be larger than the inner diameter of the die 31. This back-transmissive silicon-based MEMS infrared light source installation structure can effectively reduce the difficulty of integrating and assembling the equipment.

[0026] The silicon-based MEMS light source assembly 1 and the processing method for its reflective layer 13 are not specifically limited in this invention, and the size may be designed and processed according to actual demand. Furthermore, the silicon-based MEMS light source assembly 1 may be replaced with a heat-generating metal foil or metal wire, thereby realizing an application function that emits infrared light to the outside based on the electrothermal principle.

[0027] In another specific embodiment, the infrared light source assembly comprises a double-sided silicon MEMS light source assembly 2, a double-sided silicon heating metal wire, or a double-sided ceramic heating metal wire, wherein a cavity 101 is provided that penetrates the double-sided silicon MEMS light source assembly 2 vertically, the cap 6 is a tubular cap 6 with both ends open, one or more openings are provided at one end of the cap 6 away from the base 3, one detection assembly 4 is provided at each opening on the end of the tubular cap 6 away from the base 3, a metal-plated pad 7 is provided between the double-sided silicon MEMS light source assembly 2 and the base 3, the metal-plated pad 7 electrically connects the heating layer 12 on the side of the double-sided silicon MEMS light source assembly 2 closer to the base 3, and the metal-plated pad 7 and the end of the pin 32 are electrically connected via a metal wire 8.

[0028] As shown in Figures 2 to 4, in order to further improve the ability to detect different gas components (e.g., simultaneously detecting nitric oxide gas and carbon dioxide gas), the infrared light source assembly may be configured as a double-sided silicon MEMS light source assembly 2. The double-sided silicon MEMS light source assembly 2 is provided with a cavity 101 that penetrates vertically, and the cap 6 is a tubular cap 6 with openings at both ends. One opening may be provided at one end of the cap 6 away from the base 3, and the structure may be as shown in Figures 2 and 3, with multiple openings provided at one end of the cap 6 away from the base 3, as shown in Figure 4. One detection assembly 4 is provided at each opening at the end of the tubular cap 6 away from the base 3. The metal-plated pad 7 is used for the electrical connection of the heating layer 12 on the side of the double-sided silicon-based MEMS light source assembly 2 that is closer to the base 3. The metal-plated pad 7 and the end of the pin 32 are electrically connected via a metal wire 8, and the heating layer 12 on the side of the double-sided silicon-based MEMS light source assembly 2 that is further away from the base 3 is directly electrically connected to the end of the pin 32 via the metal wire 8.

[0029] Furthermore, the double-sided silicon MEMS light source assembly 2 may be replaced with a double-sided silicon heating metal wire or a double-sided ceramic heating metal wire, thereby realizing an application function that radiates infrared light bidirectionally from both ends based on the electrothermal principle.

[0030] Specifically, as shown in Figure 6, the double-sided silicon MEMS light source assembly 2 includes a silicon substrate 11, two heating layers 12, and two infrared radiation material layers 21. The silicon substrate 11 has through-holes, the two heating layers 12 are bonded to both sides of the silicon substrate 11, and the two infrared radiation material layers 21 are bonded to the outer surfaces of the two heating layers 12. The infrared radiation material layers 21 bonded to the heating layers 12 located at both ends of the through-holes are combined into a single infrared radiation unit, which is suspended and installed at the opening outside the through-holes. The heating layers 12 in the infrared radiation unit extend outward and form support arms connected to the heating layers 12 at the outer edge of the through-holes. Here, the infrared radiation material layer 21 is an amorphous carbon film of nanoplatinum black, nanoblack silicon, carbon nanotubes, graphene, or doped metal elements, or a metasurface material based on Au, Al2O3, or Au material, or a ZnNiP chemical plating layer.

[0031] The installable double-sided silicon MEMS light source assembly 2 includes a silicon substrate 11, two heating layers 12, and two infrared radiation material layers 21. The heating layers 12 located at the openings at both ends of the substrate through-hole are bonded to the infrared radiation material layers 21 and combined into a single infrared radiation unit. That is, one infrared radiation unit is suspended and installed at each of the openings at both ends of the substrate through-hole. The heating layer 12 in the infrared radiation unit is connected to the heating layer 12 at the outer edge of the substrate through-hole via a support arm, which extends outward from the heating layer 12 in the infrared radiation unit. The heating layers 12 on both sides of the silicon substrate 11 each emit infrared light, and after reinforcement radiation based on the reinforcement radiation effect of the infrared radiation material layers 21, they radiate outward from both sides of the silicon substrate 11, forming an infrared light source with double-sided radiation function. This double-sided silicon MEMS light source assembly 2 can effectively reduce the module volume of the NDIR gas sensor, simplify the infrared light source assembly control circuit, and enable the detection of multi-component gases. The cavity 101, which penetrates vertically within the silicon substrate 11, is hourglass-shaped and is symmetrically arranged along a midline parallel to the heating layer 12. The cross-section of the cavity 101 is formed by combining two symmetrical trapezoids, and the specific structure is shown in Figure 6.

[0032] Furthermore, the size of the openings at both ends of the cavity 101 may be set to be larger than the inner diameter of the die 31, and the size of the infrared radiation unit may be set to be smaller than the inner diameter of the die 31. The processing method for the double-sided silicon-based MEMS light source assembly 2 and the infrared radiation material layer 21 therein is not specifically limited in this invention, and the size may be designed and processed according to actual demand.

[0033] In a more specific embodiment, the silicon substrate 11 is a single-crystal silicon substrate 11 or an SOI silicon wafer substrate. Specifically, the heating layer 12 includes a support layer, a heating electrode and an isolation layer, which are laminated together. The heating electrode is a metal composite film layer obtained by manufacturing one or more materials from Pt, Au, W, Al, tin nitride, nickel-chromium alloy, and MoSi2, or a polysilicon film doped with B by ion implantation. The support layer and isolation layer are made of single-layer SiO2, single-layer Si3N4, or single-layer SiN x The composite film layer is composed of multiple types of film layers, including an SiO2 layer, a Si3N4 layer, and a SiNx layer. Here, a metal film layer is plated onto the inner and outer surfaces of the base, and the metal film layer is formed by plating with one or more materials, including Ni, Au, Al, and Pt.

[0034] The silicon substrate 11 is a single-crystal silicon substrate 11 or an SOI silicon wafer substrate. The base 3 may be made of cold-rolled steel, stainless steel, or Kovar alloy, and the metal film layer electroplated on the inner and outer surfaces of the base 3 is formed by electroplating with one or more materials from Ni, Au, Al, and Pt. The infrared detector 41 is one of a thermopile, pyroelectric, or bolometer. The cap 6 is made of cold-rolled steel, stainless steel, or Kovar alloy, and the inner and outer surfaces of the cap 6 can be plated to form a metal film layer, which is similarly formed by plating with one or more materials from Ni, Au, Al, and Pt. The metal plating pad 7 may be a silicon-based or ceramic-based pad with one or more metal film layers from Au, Pt, Ag, Al, and Cu deposited on its surface.

[0035] As shown in Figure 7, the positions on the base 3 corresponding to the through holes of each base extend outward to form a hollow die 31, the axes of the hollow die 31 are all parallel, a metal film layer that reflects infrared rays is plated on the inner and outer surfaces of the die 31, ventilation holes 33 are further provided on the side walls of the die 31, the outer surface of the ventilation holes 33 is covered with a waterproof ventilation film or coated with a water vapor absorbing material, the water vapor absorbing material may be quicklime or a superabsorbent resin. Specifically, the metal film layer plated on the surface of the die 31 is formed by plating with one or more materials from Ni, Au, Al, and Pt, and the metal film layer may be provided by extending and plating on the inner and outer surfaces of the base 3. By using a hollow die 31 instead of an absorbent gas chamber assembly in the NDIR gas sensor module, the number of discrete sensor assemblies is effectively reduced, improving processing efficiency and system stability and robustness.

[0036] In the specific processing and manufacturing process, as shown in Figure 1, the silicon-based MEMS light source assembly 1 with the back-transparent structure can be die-bonded to the base 3 using silver slurry. The installation position of the silicon-based MEMS light source assembly 1 corresponds to the opening of the through-hole in the base 3, and wire bonding is performed using metal wire 8 to achieve electrical connection between the silicon-based MEMS light source assembly 1 and the pin 32. An infrared reflective metal film layer may be provided on the inner surface of the arc-shaped cap 6. The arc-shaped cap 6 is fixed to the base 3 by laser seal welding or resistance welding, and the silicon-based MEMS light source assembly 1 is packaged in this process. Alternatively, a general cap 6 without an infrared reflective metal film layer may be used for packaging. A detection assembly 4 is installed at one end of the die 31 away from the silicon-based MEMS light source assembly 1, thereby forming a micro NDIR gas sensor. The silicon-based MEMS light source assembly 1 emits infrared light outward from the cavity 101, and the arc-shaped cap 6 ensures maximum entry of infrared light into the die 31. The absorption of infrared light by the target gas that enters the die 31 through the vent holes 33 is governed by Lambert-Beer's law (I=I0e). -εCLThe following equation is used. In the equation, I is the emitted light intensity, I0 is the incident light intensity, ε is the molar extinction coefficient, C is the gas concentration, L is the length of the effective gas chamber, and e is the base of the natural logarithm. Based on the above principle, the target gas concentration can be detected. By using the base 3 of the integrated structure of the absorbent gas chamber and combining it with the back-transmissive silicon-based MEMS light source assembly 1, a simple structure, highly stable and robust NDIR gas sensor is obtained, effectively reducing the difficulty of integration and the volume of the sensor, and improving processing efficiency and sensor consistency.

[0037] In the manufacturing process of a sensor with a different structure, as shown in Figures 2 to 4, the double-sided silicon MEMS light source assembly 2 may be die-bonded to the base 3 with silver slurry. The installation position of the double-sided silicon MEMS light source assembly 2 corresponds to the opening of the through-hole in the base 3, and wire bonding is performed using a metal wire 8 and a metal-plated pad 7 to realize an electrical connection between the double-sided silicon MEMS light source assembly 2 and the pin 32. A tubular cap 6, plated with an infrared-reflective metal film layer on its inner surface, is fixed to the base 3 by laser seal welding or resistance welding, and packaging is realized for the double-sided silicon MEMS light source assembly 2. One detection assembly 4 is installed at one end of the die 31 away from the double-sided silicon MEMS light source assembly 2, and at the same time, one detection assembly 4 is installed at each opening of the tubular cap 6 away from the double-sided silicon MEMS light source assembly 2, thereby forming a micro-NDIR mixed multi-component gas detection sensor. The detection principle of the obtained mixed multi-component gas detection sensor is the same as the detection principle described above, and it realizes that it can simultaneously detect multiple different gas components, rather than just functionally detecting a single gas component.

[0038] As shown in Figures 2 and 3, the base 3 can be designed to have dies 31 of different lengths and tubular caps 6 of different lengths, thereby creating absorbing gas chambers with optical paths of different lengths. The length of the tubular cap 6 in Figure 3 is shorter than the length of the tubular cap 6 in Figure 2. The relatively short tubular cap 6 in Figure 3 can detect high-concentration gases, while the relatively long die 31 can be used to detect low-concentration gases, realizing a wide-range gas sensor based on NDIR. The principle of the detection technique is the same as described above and will not be explained further here.

[0039] To accommodate more complex infrared gas detection application scenarios, an array multi-channel installation structure may be adopted. As shown in Figure 4, a base 3 having multiple dies 31 may be installed, and multiple tubular passages may be installed at one end of the tubular cap 6 away from the double-sided silicon MEMS light source assembly 2. The number of tubular passages on the tubular cap 6 may be equal to the number of dies 31 on the base 3. One detection assembly 4 is installed correspondingly at the end opening of the tubular passages, and multi-channel infrared gas detection is realized using multiple double-sided silicon MEMS light source assemblies 2. The principle of the detection technology is the same as described above and will not be explained further here. Compared to conventional NDIR gas detection modules, the present invention provides a design method that is more stable and robust, has a smaller volume, a simpler structure, and higher processing efficiency.

[0040] Embodiments of the present invention provide a gas sensor based on non-dispersive infrared detection, the gas sensor comprising a base 3, a cap 6, at least one detection assembly 4 and at least one infrared light source assembly, the cap 6 being fitted over the base 3 and the outer edge of the cap 6 being fixedly connected to the base 3, the base 3 having at least one through-hole penetrating the base 3, the side walls of each through-hole extending away from the cap 6 to form a hollow die 31, and each infrared light source assembly having one through-hole of the base The infrared light source assembly is installed by covering one end facing the cap 6, and the cavity 101 within the infrared light source assembly communicates with a through hole in a base, and each die 31 has a ventilation hole 33 in its wall, and the pin 32 penetrates the base 3 and its end extends to one side of the infrared light source assembly, and the heating layer 12 in the infrared light source assembly and the end of the pin 32 are electrically connected via a metal wire 8, and each detection assembly 4 is assembled at one end of the corresponding die 31 away from the infrared light source assembly and seals the end of the die 31. The gas sensor is designed based on a stacked structure of absorbent gas chambers and a back-transmitting infrared light source assembly, eliminating the need to fix the infrared light source with extra structures, simplifying the sensor structure, reducing its volume, effectively reducing the difficulty of manufacturing and integrating the sensor, and greatly improving its stability and system robustness.

[0041] The above description is merely a specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Those skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope presented herein, and all such equivalent modifications or substitutions should be included within the scope of protection of the present invention. Accordingly, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

[0042] (Note) (Note 1) A gas sensor based on non-dispersive infrared detection, wherein the gas sensor includes a base, a cap, at least one detection assembly, and at least one infrared light source assembly. The cap is placed over the base, and the outer edge of the cap is fixedly connected to the base, and the base is provided with at least one through hole that penetrates the base, and the side walls of each through hole in the base extend away from the cap to form a hollow die. Each of the infrared light source assemblies is installed by covering one end of the through-hole of one of the bases toward the cap, and the cavity within the infrared light source assembly communicates with the through-hole of one of the bases, and each die wall is provided with ventilation holes. The pin penetrates the base and its end extends to one side of the infrared light source assembly, and the heating layer in the infrared light source assembly and the end of the pin are electrically connected via a metal wire. A gas sensor based on non-dispersive infrared detection, characterized in that each detection assembly is assembled at one end of a corresponding die away from the infrared light source assembly, and the end of the die is sealed, at least one infrared detector is provided within each detection assembly, a narrowband filter is provided at one end of each infrared detector facing the infrared light source assembly, and detection pins electrically connected to each infrared detector extend from the inside to the outside of the detection assembly.

[0043] (Note 2) The infrared light source assembly is a silicon-based MEMS light source assembly, a heat-generating metal foil, or a metal wire. The non-dispersive infrared detection gas sensor according to Appendix 1, characterized in that the side of the silicon-based MEMS light source assembly facing the through hole of the base is recessed inward to form the cavity, and the cap is an arc-shaped cap with one side open, the opening of the arc-shaped cap facing the base.

[0044] (Note 3) The silicon-based MEMS light source assembly includes a silicon substrate, a heating layer, and a reflective layer. A gas sensor based on non-dispersive infrared detection as described in Appendix 2, characterized in that the silicon substrate has through-holes, the heating layer is bonded to the side of the silicon substrate away from the base and covers the through-holes to form an inwardly recessed cavity, and the reflective layer is bonded to the upper layer of the heating layer.

[0045] (Note 4) The non-dispersive infrared detection gas sensor according to Appendix 3, characterized in that the reflective layer is a metallic reflective film obtained by manufacturing one or more materials from Au, Pt, Ag, Al, and Cu.

[0046] (Note 5) The infrared light source assembly is a double-sided silicon MEMS light source assembly, a double-sided silicon heating metal wire, or a double-sided ceramic heating metal wire. The double-sided silicon-based MEMS light source assembly is provided with a cavity that penetrates vertically, and the cap is a tubular cap with both ends open. One or more openings are provided at one end of the cap away from the base, and one of the detection assemblies is provided at each of the openings at the end of the tubular cap away from the base. A gas sensor based on non-dispersive infrared detection according to Appendix 1, characterized in that a metal-plated pad is provided between the double-sided silicon-based MEMS light source assembly and the base, the metal-plated pad electrically connects the heating layer of the double-sided silicon-based MEMS light source assembly on the side closer to the base, and the metal-plated pad and the end of the pin are electrically connected via a metal wire.

[0047] (Note 6) The double-sided silicon-based MEMS light source assembly includes a silicon substrate, two heating layers, and two infrared radiation material layers. A gas sensor based on non-dispersive infrared detection as described in Appendix 5, characterized in that a through-hole is provided in the silicon substrate, the two heating layers are bonded to both sides of the silicon substrate, the two infrared radiation material layers are bonded to the outer surfaces of the two heating layers, the heating layers located at both ends of the through-hole are combined with the infrared radiation material layers bonded to them to form a single infrared radiation unit, the infrared radiation unit is installed floating at an opening outside the through-hole, and the heating layer in the infrared radiation unit extends outward and forms a support arm connected to the heating layer at the outer edge of the through-hole.

[0048] (Note 7) The non-dispersive infrared detection gas sensor according to Appendix 6, characterized in that the infrared radiation material layer is an amorphous carbon film of nanoplatinum black, nanoblack silicon, carbon nanotubes, graphene, or a doped metal element, or a metasurface material based on Au, Al2O3, or an Au material, or a ZnNiP chemical plating layer.

[0049] (Note 8) The non-dispersive infrared detection gas sensor according to any one of appendices 1 to 7, characterized in that the silicon substrate is a single-crystal silicon substrate or an SOI silicon wafer substrate.

[0050] (Note 9) The heating layer includes a support layer, a heating electrode, and an isolation layer, which are arranged in a laminated manner. The heating electrode is a metal composite film layer obtained by manufacturing one or more materials from Pt, Au, W, Al, tin nitride, nickel-chromium alloy, and MoSi2, or a polysilicon film doped with B by ion implantation. The support layer and isolation layer are made of single-layer SiO2, single-layer Si3N4, or single-layer SiN x It is either an SiO2 layer, a Si3N4 layer and SiN x A gas sensor based on non-dispersive infrared detection according to any one of appendices 1 to 7, characterized in that a composite film layer is formed from multiple types of film layers among the layers.

[0051] (Note 10) A non-dispersive infrared detection gas sensor according to any one of the appendices 1 to 7, characterized in that a metal film layer is plated on the inner and outer surfaces of the base, and the metal film layer is formed by plating with one or more materials selected from Ni, Au, Al, and Pt. [Explanation of Symbols]

[0052] 3 bases 6 caps 4. Detection Assembly 1. Silicon-based MEMS light source assembly 2. Double-sided silicon-based MEMS light source assembly 11 Silicon substrate 101 Cavity 12 Heating layer 13 Reflective layer 21 Infrared radiation material layer 31 Die 32 pins 33 Ventilation holes 41 Infrared detector 42 Narrowband filters 43 detection pins 7 Metal plated pads 8 Metal wire

Claims

1. A gas sensor based on non-dispersive infrared detection, wherein the gas sensor includes a base, a cap, at least one detection assembly, and at least one infrared light source assembly. The cap is placed over the base, and the outer edge of the cap is fixedly connected to the base, and the base is provided with at least one through hole that penetrates the base, and the side walls of each through hole in the base extend away from the cap to form a hollow die. Each of the infrared light source assemblies is installed by covering one end of the through-hole of one of the bases toward the cap, and the cavity within the infrared light source assembly communicates with the through-hole of one of the bases, and each die wall is provided with ventilation holes. The pin penetrates the base and its end extends to one side of the infrared light source assembly, and the heating layer in the infrared light source assembly and the end of the pin are electrically connected via a metal wire. A gas sensor based on non-dispersive infrared detection, characterized in that each detection assembly is assembled at one end of a corresponding die away from the infrared light source assembly, and the end of the die is sealed, at least one infrared detector is provided within each detection assembly, a narrowband filter is provided at one end of each infrared detector facing the infrared light source assembly, and detection pins electrically connected to each infrared detector extend from the inside to the outside of the detection assembly.

2. The infrared light source assembly is a silicon-based MEMS light source assembly, a heating metal foil, or a metal wire. The non-dispersive infrared detection gas sensor according to claim 1, characterized in that the side of the silicon-based MEMS light source assembly facing the through hole of the base is recessed inward to form the cavity, the cap is an arc-shaped cap with one side open, and the opening of the arc-shaped cap faces the base.

3. The silicon-based MEMS light source assembly includes a silicon substrate, a heating layer, and a reflective layer. The gas sensor based on non-dispersive infrared detection according to claim 2, characterized in that the silicon substrate has through-holes, the heating layer is bonded to the side of the silicon substrate away from the base and covers the through-holes to form an inwardly recessed cavity, and the reflective layer is bonded to the upper layer of the heating layer.

4. The non-dispersive infrared detection gas sensor according to claim 3, characterized in that the reflective layer is a metallic reflective film obtained by manufacturing one or more materials from Au, Pt, Ag, Al, and Cu.

5. The infrared light source assembly is a double-sided silicon MEMS light source assembly, a double-sided silicon heating metal wire, or a double-sided ceramic heating metal wire. The double-sided silicon-based MEMS light source assembly is provided with a cavity that penetrates vertically, and the cap is a tubular cap with both ends open. One or more openings are provided at one end of the cap away from the base, and one of the detection assemblies is provided at each of the openings at the end of the tubular cap away from the base. A non-dispersive infrared detection gas sensor according to claim 1, characterized in that a metal-plated pad is provided between the double-sided silicon-based MEMS light source assembly and the base, the metal-plated pad electrically connects the heating layer of the double-sided silicon-based MEMS light source assembly on the side closer to the base, and the metal-plated pad and the end of the pin are electrically connected via a metal wire.

6. The double-sided silicon-based MEMS light source assembly includes a silicon substrate, two heating layers, and two infrared radiation material layers. The gas sensor based on non-dispersive infrared detection according to claim 5, characterized in that the silicon substrate is provided with through-holes, the two heating layers are bonded to both sides of the silicon substrate, the two infrared radiation material layers are bonded to the outer surfaces of the two heating layers, the heating layers located at both ends of the through-holes and the infrared radiation material layers bonded to them are combined into a single infrared radiation unit, the infrared radiation unit is installed floating at the opening outside the through-holes, and the heating layer in the infrared radiation unit extends outward and forms a support arm connected to the heating layer at the outer edge of the through-holes.

7. The infrared radiation material layer is an amorphous carbon film of nanoplatinum black, nanoblack silicon, carbon nanotubes, graphene, or doped metal elements, or Au, Al ２ O ３ The gas sensor based on non-dispersive infrared detection according to claim 6, characterized in that it is a metasurface material based on an Au material, or a ZnNiP chemical plating layer.

8. The non-dispersive infrared detection gas sensor according to any one of claims 1 to 7, characterized in that the silicon substrate is a single-crystal silicon substrate or an SOI silicon wafer substrate.

9. The heating layer includes a support layer, a heating electrode, and an isolation layer, which are arranged in a stack. The heating electrode is made of Pt, Au, W, Al, tin nitride, nickel-chromium alloy, MoSi ２ A metal composite film layer obtained by manufacturing one or more of the following materials, or a polysilicon film doped with B by ion implantation. The support layer and the isolation layer are single-layer SiO ２ or single-layer Si ３ N ４ or single-layer SiN ｘ or SiO ２ layer, Si ３ N ４ layer and SiN ｘ layer, and a composite film layer is formed by a plurality of types of film layers among them. The gas sensor based on non-dispersive infrared detection according to any one of claims 1 to 7, characterized in that.

10. A non-dispersive infrared detection gas sensor according to any one of claims 1 to 7, characterized in that a metal film layer is plated on the inner and outer surfaces of the base, and the metal film layer is formed by plating with one or more materials selected from Ni, Au, Al, and Pt.

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