Optical gas sensor device and method for manufacturing optical gas sensor device

Abstract

The invention relates to an optical gas sensor device and a method for manufacturing the optical gas sensor device. The present invention reduces the influence of an external environment on at least one of a light source and a light receiving unit. An optical gas sensor device (100a) is provided with: a light source that emits infrared rays to a gas to be detected; an optical filter that transmits the infrared rays; a light receiving unit that detects the infrared rays incident through the optical filter and generates a detection signal; and a substrate (6). An optical gas sensor device (100a) is provided with a sealing material (20a) for mounting an optical filter and sealing a light source, and a sealing material (40a) for sealing a light receiving unit. The seals (20a, 40a) are attached to the substrate (6).

Description

Technical Field

[0001] The present invention relates to an optical gas sensor device and a method for manufacturing the optical gas sensor device. Background Art

[0002] In the past, gas concentration observations have always been performed from the perspective of chemical substance management and operator safety in homes, factories, and offices. In the observation of gas concentrations, non-dispersive infrared absorption (NDIR: Non Dispersive InfraRed) gas sensors are known for detecting the concentration of gases such as CO2. NDIR gas sensors use the property that multiple gases absorb inherent infrared wavelengths, and when radiating infrared rays to the gas of the detection object, they detect which wavelength is absorbed and how much, thereby measuring the concentration in the gas of the detection object. For example, it is a gas sensor that has an infrared light source and a light receiving unit, and detects the concentration of the gas to be detected located on the optical path of the light source and the light receiving unit.

[0003] In addition, a light absorption gas sensor is known that includes a light emitting diode, a ring-shaped radiation guide for guiding near infrared rays emitted from the light emitting diode, and a photodiode for detecting the guided near infrared rays (see Patent Document 1). The light emitting diode as a light source and the photodiode as a light receiving portion are mounted on a printed circuit board.

[0004] Prior art literature

[0005] Patent Document 1: Japanese Patent Application No. 2013-517467 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, the above-mentioned light absorption gas sensor exposes the light source and the light receiving part and is mounted on a printed circuit board. It is known that the exposed light source and the light receiving part are greatly affected by the external environment (humidity, temperature, air pressure). The light intensity of the light source mainly changes according to the external environment.

[0008] As an example, the case where the air pressure drops when the light source and the light receiving part are composed of MEMS (Micro Electro Mechanical Systems) is described. The air pressure drop means that the number of molecules in the air that collide with the heater surface of the light source decreases, so it is difficult to take heat from the heater. If it is a vacuum, it becomes a so-called heat-insulating state like a thermos bottle. In this way, when the air pressure drops, when the same energy is applied to the light source, the heat taken by the molecules in the air decreases, so the temperature of the heater surface rises.

[0009] As described above, when the light source is exposed, the amount of light in the infrared region varies depending on the type of gas molecules in contact with the heater surface, the temperature, and the pressure environment. In this structure, unless the parameters of the environment are obtained and feedback is applied, the luminous intensity is different from when it was calibrated at the factory, so the error becomes larger and the gas concentration becomes a value that deviates from the actual value. In addition, in the case of a gas sensor module that has a function such as setting a threshold and issuing a warning, it may become a false alarm. Here, the phenomenon of the light source is shown, but the same phenomenon also exists in the light receiving part.

[0010] An object of the present invention is to reduce the influence of the external environment on at least one of a light source and a light receiving unit.

[0011] Means for solving problems

[0012] In order to solve the above problems, the present invention provides an optical gas sensor device having:

[0013] A light source that emits infrared rays toward the gas to be detected;

[0014] an optical filter that transmits the infrared light;

[0015] a light receiving unit that detects infrared light incident through the optical filter to generate a detection signal; and

[0016] a first substrate,

[0017] The optical gas sensor device includes: a sealing member that carries the optical filter and seals the light source or the light receiving unit.

[0018] The sealing member is mounted on the first substrate.

[0019] In addition, the present invention provides a method for manufacturing an optical gas sensor device, wherein the optical gas sensor device comprises:

[0020] A light source that emits infrared rays toward the gas to be detected;

[0021] an optical filter that transmits the infrared light;

[0022] a light receiving unit that detects infrared light incident through the optical filter to generate a detection signal; and

[0023] a first substrate,

[0024] The manufacturing method of the optical gas sensor device comprises:

[0025] A first mounting step is to mount the light source and the light receiving unit on the first substrate; and

[0026] In a second mounting step, a sealing member that carries the optical filter and seals the light source or the light receiving unit is mounted on the first substrate.

[0027] In the second installation process, a first protective cover surrounding the side of the light source or the light receiving part and having a ventilation hole connected to the space of the light source or the light receiving part is installed on the first substrate, and the optical filter is mounted on the opening of the upper surface of the first protective cover as the sealant. After the light source, the light receiving part and the circuit components are installed on the first substrate and heat treated, the ventilation hole is blocked with an adhesive.

[0028] In addition, the present invention provides a method for manufacturing an optical gas sensor device, wherein the optical gas sensor device comprises:

[0029] A light source that emits infrared rays toward the gas to be detected;

[0030] an optical filter that transmits the infrared light;

[0031] a light receiving unit that detects infrared light incident through the optical filter to generate a detection signal; and

[0032] a first substrate,

[0033] The manufacturing method of the optical gas sensor device comprises:

[0034] A first mounting step is to mount the light source or the light receiving unit on a second substrate; and

[0035] In a second mounting step, a sealing member that carries the optical filter and seals the light source or the light receiving unit is mounted on the first substrate.

[0036] In the second installation process, a first protective cover surrounding the side of the light source or the light receiving part and having a ventilation hole connected to the space of the light source or the light receiving part is installed on the second substrate, and the optical filter is mounted on the opening of the upper surface of the first protective cover as the sealant. After the sealant and circuit components are installed on the first substrate and heat treated, the ventilation hole is blocked with an adhesive.

[0037] In addition, the present invention provides a method for manufacturing an optical gas sensor device, wherein the optical gas sensor device comprises:

[0038] A light source that emits infrared rays toward the gas to be detected;

[0039] an optical filter that transmits the infrared light;

[0040] a light receiving unit that detects infrared light incident through the optical filter to generate a detection signal; and

[0041] a first substrate,

[0042] The manufacturing method of the optical gas sensor device comprises:

[0043] A first installation step is to install the light source or the light receiving part on a second protective cover surrounding the side and bottom surfaces of the light source or the light receiving part;

[0044] a manufacturing step of manufacturing a sealing member that mounts the optical filter on the second protective cover and seals the light source or the light receiving portion; and

[0045] The second mounting step is to mount the sealing member on the first substrate.

[0046] In the manufacturing step, the air is decompressed, and the optical filter is mounted on the second protective cover in the decompressed air.

[0047] In addition, the present invention provides a method for manufacturing an optical gas sensor device, wherein the optical gas sensor device comprises:

[0048] A light source that emits infrared rays toward the gas to be detected;

[0049] an optical filter that transmits the infrared light;

[0050] a light receiving unit that detects infrared light incident through the optical filter to generate a detection signal; and

[0051] a first substrate,

[0052] The manufacturing method of the optical gas sensor device comprises:

[0053] A first installation step is to install the light source or the light receiving part on a second protective cover surrounding the side and bottom surfaces of the light source or the light receiving part;

[0054] a manufacturing step of manufacturing a sealing member that mounts the optical filter on the second protective cover and seals the light source or the light receiving unit; and

[0055] The second mounting step is to mount the sealing member on the first substrate.

[0056] In the manufacturing step, the optical filter is mounted on the second protective cover at a temperature of 100° C. or higher.

[0057] Effects of the Invention

[0058] According to the present invention, the influence of the external environment on at least one of the light source and the light receiving unit is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of an optical gas sensor device according to a first embodiment of the present invention.

[0060] Figure 2 It is a perspective view of an optical gas sensor device.

[0061] Figure 3 It is a partial perspective view of an optical gas sensor device.

[0062] Figure 4 (a) is a perspective view of the sealing member of the first embodiment. (b) is a cross-sectional view of the sealing member of the first embodiment.

[0063] Figure 5 It is an exploded view of the seal member of the first embodiment.

[0064] Figure 6 This is a flowchart showing the method for manufacturing the optical gas sensor device according to the first embodiment.

[0065] Figure 7 It is a graph showing the amount of change in the amount of received light during gas detection in the optical gas sensor device of the comparative example, the optical gas sensor device of the first embodiment, and the optical gas sensor device of the third embodiment.

[0066] Figure 8 It is a perspective view showing a sealing member according to a second embodiment.

[0067] Fig. 9 This is a flowchart showing a method for manufacturing the optical gas sensor device according to the second embodiment.

[0068] Fig.10 Yes means Fig. 9 Flow chart of the seal manufacturing process.

[0069] Fig.11 (a) is a perspective view showing a seal member according to a third embodiment. (b) is a cross-sectional view showing a seal member according to a third embodiment.

[0070] Fig.12 It is a cross-sectional view showing a seal according to a modified example.

[0071] Fig.13 It is a cross-sectional view showing a seal according to a modified example.

[0072] Fig.14 This is a graph showing the absorption wavelengths of various gases and the transmittance range of sapphire glass / Si. DETAILED DESCRIPTION

[0073] Hereinafter, the first to third embodiments and modified examples of the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the examples shown in the drawings.

[0074] (First Embodiment)

[0075] Reference Figure 1 to Figure 7 , the first embodiment of the present invention is described. First, referring to Figure 1 The schematic structure of the optical gas sensor device 100a according to the present embodiment will be described. Figure 1 1 is a schematic diagram of an optical gas sensor device 100 a according to the present embodiment.

[0076] like Figure 1 As shown, the optical gas sensor device 100a of this embodiment is a NDIR gas sensor. The optical gas sensor device 100a includes: an optical cover 1, a light source 2, an AR (Anti Reflection) filter 31, a λ (wavelength) selection filter 32, a light receiving unit 4, a signal processing unit 5, and a switch 81. The AR filter 31 and the λ selection filter 32 are optical filters. In the optical gas sensor device 100a, the light source 2 radiates (emit, emit) infrared rays. The radiated infrared rays are emitted to the gas G of the detection object (measurement object) in the optical cover 1 via the AR filter 31 and the optical path (path) in the optical cover 1. The AR filter 31 is a filter that prevents the reflection of infrared rays and transmits them.

[0077] The molecules of the gas G to be detected existing in the optical path absorb infrared rays, thereby reducing the amount of light reaching the light receiving unit 4. The optical gas sensor device 100a detects infrared rays partially absorbed by the gas G to be detected through the light receiving unit 4 via the λ selection filter 32. The λ selection filter 32 is a filter that transmits infrared rays of the absorption wavelength of the gas G from the incident infrared rays. According to this structure, the light receiving unit 4 does not receive infrared rays before filtering emitted from sources other than the light source 2, and the SN ratio (Signal to Noise ratio) of the sensor is improved.

[0078] The optical gas sensor device 100a processes the detection signal detected by the light receiving unit 4 through the signal processing unit 5, detects (measures) the concentration of the gas G to be detected and outputs it. The switch 81 is a switch for turning on / off the light emission of the light source 2, and is included in the circuit element unit 8 described later. When performing gas detection, the signal processing unit 5 turns on / off the light source 2 via the switch 81.

[0079] The optical cover 1 has a gas inlet port 11 as a gas inlet portion for introducing the gas G to be detected. A contamination filter 12 is attached to the gas inlet port 11. The contamination filter 12 is, for example, a metal mesh filter or a resin porous film, and prevents foreign matter from entering from the outside.

[0080] In this way, the optical gas sensor device 100a filters the infrared light emitted from the light source 2 to the gas G to be detected by the AR filter 31 and the λ selection filter 32, and receives it by the light receiving unit 4. The AR filter 31 is arranged at a position near the light source 2 on the optical path downstream of the light source 2. The λ selection filter 32 is arranged at a position near the light receiving unit 4 on the optical path upstream of the light receiving unit 4.

[0081] However, the AR filter 31 may be arranged near the light receiving unit 4 on the optical path upstream of the light receiving unit 4. In this configuration, the λ selection filter 32 may be arranged near the light source 2 on the optical path downstream of the light source 2.

[0082] In this embodiment, the optical path is designed in such a way that the infrared light received by the light receiving portion 4 is reflected from the light source 2 on the inner surface of the optical cover 1 and arrives. Preferably, the higher the reflectivity of the inner surface of the optical cover 1, the higher the efficiency of light (infrared light) utilization. In addition, the optical path of the infrared light received by the light receiving portion 4 may include a light path that arrives directly from the light source 2 in addition to the light path that arrives by reflection on the inner surface of the optical cover 1.

[0083] In the present embodiment, the light source 2 and the AR filter 31 are packaged in a single component, namely, a sealing member 20 a described later. The λ selection filter 32 and the light receiving unit 4 are packaged in a single component, namely, a sealing member 40 a described later.

[0084] The optical gas sensor device 100a detects the refrigerant of the air conditioner, that is, the alternative Freon refrigerant as the detection object gas G. Alternative Freon is a refrigerant of a synthetic compound (gas) used industrially as a substitute for a specific Freon (chlorofluorocarbon, abbreviated as: CFC). CFC refrigerants have a high ozone depletion coefficient and become the cause of the depletion of the earth's ozone layer. Therefore, they are beginning to be replaced by hydrochlorofluorocarbon (HCFC) refrigerants with low ozone depletion coefficients. In addition, in developed countries, the conversion from HCFC refrigerants to HFC refrigerants (R410A) with an ozone depletion coefficient of 0 is underway.

[0085] It is known that CFC refrigerants, HCFC refrigerants, and HFC refrigerants have high global warming potentials and are greenhouse gases that cause global warming. Therefore, research is underway to replace HFC refrigerants (R410A) with HFC refrigerants (R32) that have lower global warming potentials. In this embodiment, for example, as the gas G to be detected, detection of R32, a freon-based refrigerant, is performed.

[0086] The optical gas sensor device 100a outputs various status signals based on the gas concentration value of the detected gas G to the information processing unit of the device that performs processing based on the status of the optical gas sensor device 100a. The information processing unit is, for example, an MCU (Micro Controller Unit). The status signal is, for example, a fault signal, an alarm signal, and a monitoring signal (normal signal). The fault signal indicates the state of the fault of the optical gas sensor device 100a. The alarm signal indicates that the concentration of the detected gas G is in an abnormal state (alarm state) that requires an alarm. The monitoring signal indicates that the concentration of the detected gas G is in a normal state. In the case where the device is an alarm, various alarms (for example, an alarm of the fault of the optical gas sensor device 100a based on the fault signal, an alarm of the abnormal concentration of the detected gas G based on the alarm signal) are notified according to the various signals received from the optical gas sensor device 100a. The device may be a device including the optical gas sensor device 100a and the MCU, or a device different from the optical gas sensor device 100a. As the above-mentioned device, there are indoor air conditioners, air conditioners for shops / offices, multi-split air conditioners for buildings, etc.

[0087] However, the gas G to be detected is not limited to R32, but may be other Freon-based refrigerants. Furthermore, the gas G to be detected is not limited to Freon-based refrigerants, but may be carbon dioxide, carbon monoxide, propane, methane, butane, ammonia, oxygen disulfide, nitrogen dioxide, nitrogen monoxide, ozone, sulfur hexafluoride, ethylene, etc.

[0088] Next, refer to Figure 2 to Figure 5 , the specific device structure of the optical gas sensor device 100a is described. Figure 2 It is a perspective view of the optical gas sensor device 100a. Figure 3 It is a partial perspective view of the optical gas sensor device 100 a . Figure 4 (a) is a perspective view of the sealing member 20a. Figure 4 (b) is a cross-sectional view of the sealing member 20a. Figure 5 is an exploded view of the seal 20a.

[0089] like Figure 2 and Figure 3As shown, the optical gas sensor device 100a includes: an optical cover 1, seals 20a, 40a, a signal processing unit 5, a substrate 6, a connector 7, and a circuit element unit 8. The seal 20a includes a light source 2 and an AR filter 31. The seal 40a includes a λ selection filter 32 and a light receiving unit 4. Figure 2 In the figure, the x-axis, y-axis, and z-axis are shown. These three axes are the same in other figures. Figure 2 and Figure 3 In the figure, the contamination filter 12 is omitted.

[0090] The optical cover 1 is a cover that is mounted on the +z side of the substrate 6, covers (includes) the seals 20a and 40a, and has a cavity (space) inside that can accommodate the gas G to be detected. The gas G to be detected is introduced into and out of the cavity through the gas introduction port 11. The base of the optical cover 1 is made of resin, for example.

[0091] like Figure 2 As shown, the optical cover 1 has cover parts 110A and 110B. The cover part 110A is a component on the upper side (+z direction side), and is connected to the cover part 110B and integrated by bonding, heat riveting, etc. The cover part 110B is a component on the lower side (-z direction side), and is connected to the cover part 110A and integrated by bonding, heat riveting, etc.

[0092] In addition, if Figure 3 As shown, the optical cover 1 has a light guide portion 13 as a hollow portion for introducing the gas G to be detected into the interior. The light guide portion 13 is a tubular light path, and the cross section perpendicular to the axial direction is circular. The cover portion 110A has a half-tube portion. The cover portion 110B has a half-tube portion. The half-tube portions of the cover portions 110A and 110B are matched to form the light guide portion 13. In this way, the optical cover 1 has the cover portions 110A and 110B divided by the axial cross section of the light guide portion 13. As shown in FIG. Figure 3 As shown, the light guide portion 13 has a three-dimensional substantially U-shape when viewed from the upper surface (the surface in the +z direction).

[0093] The inner surface of the light guide portion 13 is covered with an infrared reflective film. In the present embodiment, gold is used as the infrared reflective film, but it is not limited to this. As the infrared reflective film, silver or aluminum can be used. And, as needed, in order to prevent corrosion of the metal film of the infrared reflective film, a protective film such as silicon oxide or silicon nitride can be formed on the infrared reflective film. The film forming method of the infrared reflective film and the protective film can use a plating method, a sputtering method, a vacuum evaporation method, etc. In addition, for example, it can also be configured to use a metal 3D printer, and the optical cover 1 is integrally formed of a metal such as aluminum. In either case, in order to effectively reflect infrared rays, it is preferred to perform mirror finishing on the inner surface of the light guide portion 13.

[0094] The light guide 13 uses the infrared reflection film on the inner surface to reflect the infrared light emitted from the light source 2 of the seal 20a and incident through the AR filter 31. The light guide 13 emits the reflected infrared light to the light receiving portion 4 through the λ selection filter 32 of the seal 40a. In this way, the optical cover 1 reflects the infrared light emitted from the light source 2 through the infrared reflection film, so that at least a part of the reflected light reaches the light receiving portion 4 through the λ selection filter 32, thereby playing a role of efficiently guiding the infrared light from the light source 2 to the light receiving portion 4 as an optical path.

[0095] In this embodiment, the optical path inside the optical cover 1 is set as a tubular light guide portion 13 with a circular cross section, so that the reflection angle of infrared rays can be kept constant in any direction of three dimensions (x-axis, y-axis, z-axis) regardless of the cross-sectional diameter and path of the light guide portion 13, and the infrared rays emitted from the light source 2 are reflected inside the light guide portion 13 and efficiently incident on the light receiving portion 4. In addition, the axial cross section of the optical path of the light guide portion 13 of the optical cover 1 can also be configured to be elliptical.

[0096] Furthermore, by changing the diameter of the cross section of the light guide portion 13 , the optical path length of infrared light from the light source 2 to the light receiving portion 4 can be changed relatively easily.

[0097] In addition, if Figure 2 , Figure 3 As shown, the optical cover 1 is three-dimensionally designed and formed in such a way that a space portion SP can be formed on the substrate 6 below a portion of the x-axis direction (-z direction) of the axial direction of the light guide portion 13. The signal processing portion 5 and at least a portion of the circuit element portion 8 are arranged in the space portion SP and mounted on the substrate 6.

[0098] In addition, the main part (a part other than the inlet 131 and the outlet 132 described later) of the cross-sectional area of ​​the light guide 13 perpendicular to the axial direction is constant in the axial direction. Since the cross-sectional area is constant, the gas concentration per unit volume of the gas G to be detected entering the light guide 13 is easily uniform, and the infrared rays pass randomly without passing through a specific path, so it is easy to react to changes in the gas concentration of the gas G. Figure 3 The solid arrows indicate the optical path propagation state of a plurality of infrared light paths in the light guide 13. In this way, the infrared light paths in the light guide 13 are random.

[0099] In addition, the infrared light emitted from the light source 2 is incident on the light guide portion 13 on the -x direction side via the AR filter 31. The light guide portion 13 on the -x direction side is extended axially from the -z direction side to the +z direction side, then bent in an R shape, and extended linearly from the -y direction side to the +y direction side. The end of the light guide portion 13 on the incident side of the infrared light is used as the entrance portion 131. The light guide portion 13 extending to the +y direction side is bent in an R shape, and axially extends from the -x direction side to the +x direction side, and then bent in an R shape again.

[0100] Furthermore, the light guide portion 13 on the +x direction side extends linearly from the +y direction side to the -y direction side in the axial direction, and then bends in an R shape to extend to the -z direction side. The infrared rays passing through the light guide portion 13 are emitted toward the λ selection filter 32 and the light receiving portion 4. The end of the infrared ray emission side of the light guide portion 13 is set as the exit portion 132.

[0101] The exit portion 132 is in a tapered shape whose cross-sectional area becomes smaller as the axial direction of the light guide portion 13 moves from the +z direction side to the -z direction side. Similarly, the entrance portion 131 is in a tapered shape whose cross-sectional area becomes smaller as the axial direction of the light guide portion 13 moves from the +z direction side to the -z direction side. Therefore, the concentration of infrared rays emitted from the light guide portion 13 to the light receiving portion 4 can be improved.

[0102] In addition, the cover parts 110A and 110B have hollow parts (not shown) as hollowed-out (thinned) spaces. These hollow parts can reduce the weight of the optical cover 1 (optical gas sensor device 100a).

[0103] In addition, the cover part 110B has a fixing pin (not shown). The fixing pin is a convex portion extending in the +z direction, and is butted with the concave portion (concave hole) (not shown) of the cover part 110A and integrated by bonding, heat riveting, etc. By integrating by bonding or heat riveting, etc., by butting the fixing pin with the concave portion of the cover part 110A, the cover parts 110A and 110B are positioned and fixed, and become an integrated component.

[0104] In addition, if Figure 2As shown, the cover 110A has gas inlets 111 and 112 as the gas introduction port 11. The cover 110B has gas inlets (gas introduction holes) 113 and 114 as the gas introduction port 11. The gas inlets 111 and 112 are holes that are opened from the upper surface of the cover 110A in the -z direction and penetrate to the light guide 13. The gas inlet 113 is a hole that is opened from the side surface of the cover 110B in the -y direction to the +y direction side and penetrates to the space around (next to) the seal 20a. The space around the light source 2 is connected to the light guide 13. The gas inlet 114 is a hole that is opened from the side surface of the cover 110B in the -y direction to the +y direction side and penetrates to the space around (next to) the seal 40a. The space around the seal 40a is connected to the light guide 13.

[0105] The gas inlets 111 and 112 are directly connected to the light guide 13, and a part of the inner surface of the light guide 13 is deleted, so the infrared utilization efficiency is reduced. In contrast, the gas inlet 113 is indirectly connected to the light guide 13 via the space around the seal 20a, so a part of the inner surface of the light guide 13 is not damaged (deleted), and the infrared utilization efficiency is improved. Similarly, the gas inlet 114 is indirectly connected to the light guide 13 via the space around the seal 40a, so a part of the inner surface of the light guide 13 is not damaged, and the infrared utilization efficiency is improved.

[0106] also, Figure 2 The shape, size, and position of the gas introduction port 11 (gas intake ports 111 , 112 , 113 , 114 ) of the optical cover 1 are merely examples and are not limited thereto.

[0107] like Figure 4 (a) Figure 4 As shown in (b), the seal 20a is mounted on the substrate 6, and the light source 2 and the mounting area of ​​the light source 2 to the substrate 6 are sealed. The seal 20a protects the light source 2 and the mounting area from the external environment. The external environment is humidity, environmental influence gas, etc. outside the seal 20a. The seal 20a includes: the light source 2, the protective cover 21, the adhesive 22 and the AR filter 31.

[0108] The light source 2 is a surface mounted component, and is a MEMS type light source mounted on the upper surface (the surface on the +z side) of the substrate 6. Figure 5 As shown, the light source 2 comprises a membrane M of a membrane structure, and electrodes E1 and E2.

[0109] The light source 2 is a diaphragm disposed on a Si substrate, and has a structure in which, for example, a light source layer support layer, a light source layer, an electrode support layer, and a protective layer (all omitted in the figure) are stacked from the -z direction side to the +z direction side. The light source layer support layer has, for example, a silicon oxide film, a silicon nitride film, and an HLD (High temperature low pressure dielectric layer) layer from the -z direction side to the +z direction side. The light source layer is a thin film heater that serves as a light source (metal) layer (light-emitting layer) that radiates infrared rays, and is composed of, for example, MoSi2. The light source layer heats the diaphragm by energizing it, and radiates infrared rays having an intensity and wavelength dependence that depends on the surface temperature and the surface emissivity. The electrode support layer has, for example, two insulating layers from the -z direction side to the +z direction side, and supports the electrode. The protective layer is a protective layer on the upper surface composed of an insulator.

[0110] The light source layer is electrically connected to the electrodes E1 and E2 of the light source 2. The exposed portions of the electrodes E1 and E2 are connected to the electrode pads 61 and 62 ( Figure 5 ) wire bonding, and the light source layer is energized by applying voltage. The light source layer emits infrared rays when energized.

[0111] The light source 2 as a MEMS type light source is small and thin, which can realize miniaturization as a sensor module. In addition, the light source 2 as a MEMS type light source has the characteristics of long life, low power consumption, and short response time, which can realize low power consumption as the entire sensor module. Regarding the short response time characteristic of the MEMS type light source, in the case of intermittent driving, the standby time after power-on can be shortened, and the average power consumption can be reduced.

[0112] In addition, the light source 2 as a MEMS type light source can directly utilize the radiated light from the surface of the high temperature part, so it can also be applied to the detection of gas G with an absorption band at a high wavelength. In addition, the area of ​​the infrared radiation of the light source 2 is patterned with high precision on the plane of the Si substrate of the diaphragm, and the individual deviation of the radiation direction is very small. Therefore, the deviation of the amount of light received when the sensor module is composed of the light source 2 is reduced, which helps to improve the product yield. In addition, the light source 2 is produced together with the MEMS technology based on the silicon wafer, so it is excellent in mass production.

[0113] The protective cover 21 is mounted on the upper surface (the surface on the +z side) of the substrate 6, and is a cover covering the light source 2 and the side of the mounting area, and is, for example, a resin molded product. The protective cover 21 for the light source 2 is intended to ensure optical intensity, to bring the distance between the MEMS light source 2 and the AR filter 31 closer, and to increase the opening width of the AR filter 31 mounting portion. The protective cover 21 of the light receiving portion 4 corresponds to the size of the light receiving portion 4.

[0114] In addition, the protective cover 21 is designed to reduce the size of the AR filter 31 / λ selection filter 32 for the purpose of cost reduction. In addition, the protective cover 21 is designed to minimize the mounting area on the substrate 6 (minimize the outer shape of the substrate 6) for the purpose of cost reduction. In addition, the protective cover 21 is designed to provide a groove 213 described later in order to ensure a process margin.

[0115] like Figure 5 As shown, the protective cover 21 has a recess 211, a hole 212 for a light source, a groove 213, a protrusion 214, a vent 215, and a cut surface 216. The recess 211 is a substantially rectangular recess in which the AR filter 31 is mounted. The height (length in the z-axis direction) of the recess 211 corresponds to the thickness of the AR filter 31. The recess 211 is formed with a protrusion 214 and a vent 215 on the +y direction side.

[0116] The light source hole 212 is a hole in which the light source 2 is disposed. The light source hole 212 is disposed inside the plane of the recessed portion 211. The height (length in the z-axis direction) of the light source hole 212 is higher than the height of the light source 2.

[0117] The groove 213 is provided around the light source hole 212 in the bottom surface of the recess 211 and is a resin reservoir for avoiding the adhesive for the AR filter 31 and is a groove for adjusting the variation of the adhesive coating amount during the process.

[0118] The protrusions 214 are two protrusions protruding from the ends of the recess 211 toward the inside. The protrusions 214 abut against the ends of the AR filter 31 to prevent the position of the AR filter 31 from being offset, so that the AR filter 31 is arranged at a predetermined position in the recess 211. In addition, the protrusions 214 are configured to be provided on one side of the recess 211, but are not limited thereto. For example, from the viewpoint of preventing the AR filter 31 from rotating and tilting, it is more preferable that the protrusions 214 are provided on the four sides of the recess 211.

[0119] The vent hole 215 is a through hole in the z-axis direction disposed on the +y-direction side of the recess 211 and between the two protrusions of the protrusion 214, and is ventilated with the internal space of the light source hole 212. The vent hole 215 prevents the cover from floating due to the expansion of the gas in the protective cover 21 caused by the adhesive (epoxy resin as a thermosetting resin) when the protective cover 21 is mounted on the substrate 6. The vent hole 215 is disposed on the inner side of the adhesive coating area for mounting the protective cover 21 on the substrate 6. The vent hole 215 is disposed between the two protrusions 214 in a manner not to be blocked by the AR filter 31. The vent hole 215 has a diameter of, for example, 0.1 [mm].

[0120] The cut surface 216 is a C-surface cut formed on the +x direction side and one end of the +y direction side of the protective cover 21. In various processes during the manufacture of the seal 20a, the cut surface 216 becomes a reference (index) for the front and back and direction of the protective cover 21. For example, when the protective cover 21 is stored in a fixture (tray), a plurality of storage parts are arranged in the fixture. A convex part corresponding to the cut surface 216 is formed in each storage part. Each protective cover 21 is stored in each storage part with the same front and back and direction through the cut surface 216 and the convex part.

[0121] The adhesive 22 is a UV (Ultra Violet) curing adhesive, and after the AR filter 31 is mounted in the light source hole 212 , the vent hole 215 is closed and sealed to close the internal space of the sealing member 20 a including the light source 2 .

[0122] The AR filter 31 is a filter that prevents reflection of infrared rays and transmits them. The AR filter 31 has, for example, a silicon substrate as a base material and a multilayer film. The multilayer film is formed on the silicon substrate by coating or the like, and is made of ZnS, Ge, etc., which are dielectrics with a refractive index smaller than that of silicon. The spectral characteristics of the AR filter 31 are θ=0[°], T(AVE)8.5~10.0[μm]≥80[%], T(ABS)8.0~12[μm]≥50[%], T(ABS)1.0~6.8[μm]≤1.0[%], T7.5±0.4[μm]=5[%].

[0123] The seal 40a has the same structure as the seal 20a. That is, the seal 40a has a structure in which the AR filter 31 and the light source 2 of the seal 20a are replaced with the λ selection filter 32 and the light receiving unit 4. Therefore, the description of the protective cover of the seal 40a and the like is omitted, and the λ selection filter 32 and the light receiving unit 4 are described.

[0124] The light receiving unit 4 is a surface mounted component, mounted on the surface of the +z side of the substrate 6, and detects the amount of incident infrared light and outputs a detection signal as an analog electrical signal. The light receiving unit 4 is, for example, a thermopile optical sensor (infrared sensor) having a plurality of thermocouples. However, the light receiving unit 4 may also be an infrared sensor of various types shown in Table 1 below.

[0125] Table I

[0126]

[0127]

[0128] The λ selection filter 32 is a filter that is provided so as to cover the light emitting surface of the light source 2 and transmits light (infrared light) having a wavelength λ corresponding to the absorption wavelength inherent in the gas G to be detected. Thus, the transmission wavelength of the λ selection filter 32 is set so as to match the absorption wavelength inherent in the gas G to be detected. As a result, changes in the amount of light caused by gases other than the gas G to be detected are suppressed, and the SN ratio of the detection signal of the light receiving unit 4 is improved.

[0129] The λ selection filter 32 has, for example, a silicon substrate as a base material, a dielectric multilayer film, or a multilayer film formed of an infrared-transmitting material such as Si, Ge, sulfide, and fluoride. The silicon substrate is a planar silicon substrate. However, the material of the substrate is not limited to silicon, and Ge (germanium), quartz, aluminum oxide, BaF2 (barium fluoride), CaF2 (calcium fluoride), etc. can be used. The multilayer film is a multilayer film provided on both sides of the silicon substrate. In addition, the planar shape of the λ selection filter 32 is rectangular, but is not limited to this, and may also be other shapes such as a circle.

[0130] The λ selection filter 32 is a long pass filter that cuts off light on a wavelength side shorter than an arbitrary cutoff wavelength and transmits light including the absorption wavelength of the gas G on the long wavelength side. Alternatively, the λ selection filter 32 may be a band pass filter that transmits light in a wavelength band including the absorption wavelength of the gas G.

[0131] The signal processing unit 5 is mounted on a plane area other than the optical cover 1 on the surface of the +z side of the substrate 6, and is an AFE (Analog Front End)-IC (Integrated Circuit) that is an electronic component (processor) that performs signal processing related to the detection signal of the light receiving unit 4. The signal processing unit 5 amplifies the analog detection signal of the light receiving unit 4 and performs AD conversion, and generates a differential value of the detection value when the light source 2 is turned off based on the detection value when the light source 2 is turned on. The signal processing unit 5 performs corrections on the differential value of the detection value for temperature, individual deviations of the optical gas sensor device 100a, etc., and generates various status signals based on the differential value of the digital detection value. The signal processing unit 5 outputs the differential value of the digital detection value and the status signal.

[0132] The substrate 6 is a PCB (Printed Circuit Board) of FR-4 (Flame Retardant Type-4) with conductor wiring printed on a board of glass epoxy resin or the like. The optical cover 1, the seals 20a, 40a, the signal processing unit 5, the connector 7, and the circuit element unit 8 are mounted on the surface on the +z side of the substrate 6. The +z side surface of the substrate 6 is approximately parallel to the light emitting surface of the light source 2, the AR filter 31, the λ selection filter 32, and the light receiving surface of the light receiving unit 4.

[0133] The connector 7 is mounted on the plane area other than the optical cover 1 and the signal processing unit 5 on the surface on the +z side of the substrate 6, and is a connector for outputting various digital signals output from the signal processing unit 5 to the information processing unit of the subsequent device (such as an alarm). The connector 7 is connected to the information processing unit of the device via a cable with a plug.

[0134] The circuit element section 8 includes circuit elements such as switches, amplifiers, chip resistors, and chip capacitors, etc. The switch 81 is composed of NMOSFET (N-channel Metal-Oxide-Semiconductor Field Effect Transistor), CMOS (Complementary Metal-Oxide-Semiconductor), and the like.

[0135] Next, refer to Figure 6 , a method for manufacturing the optical gas sensor device 100a is briefly described. Figure 6 1 is a flowchart showing a method for manufacturing the optical gas sensor device 100 a according to the present embodiment.

[0136] In the method of manufacturing the optical gas sensor device 100 a , for simplicity of description, each manufacturing process of manufacturing the optical gas sensor device 100 a using various manufacturing devices will be described.

[0137] like Figure 6 As shown, first, as a substrate for the optical gas sensor device 100a, a mother substrate designed in a manner of arranging a plurality of substrates 6 is manufactured (step S31). In parallel with step S31, a wafer including a plurality of light sources 2 is manufactured (step S11). Then, the wafer manufactured in step S11 is singulated by a dicing device to manufacture individual light sources 2 (step S12).

[0138] The light source 2 is a diaphragm structure, so in step S12, it is preferred to apply the stealth cutting technology. This is because if a general cutting device using a blade is used, water during cutting will hit the diaphragm and the diaphragm will be damaged. Stealth cutting is a cutting method that forms a modified layer inside the workpiece by focusing the laser light inside, and then performs chip division by using a band expander or the like.

[0139] In parallel with step S31, a wafer including a plurality of light receiving parts 4 is produced (step S13). Then, the wafer produced in step S13 is singulated by a cutting device to produce each light receiving part 4 (step S14). The light receiving part 4 is also a diaphragm structure like the light source 2, so the invisible cutting technology is applied in step S14.

[0140] Next, the light source 2 produced in step S12 and the light receiving unit 4 produced in step S14 are mounted (chips on board) on the mother substrate produced in step S31 (step S32). In step S32, bare chip bonding is performed at the mounting positions of the light receiving unit 4 and the light source 2 in the substrate 6 using an adhesive. Thereafter, the substrate 6 to which the light receiving unit 4 and the light source 2 are bare chip bonded is heated to thermally cure the adhesive. Next, by wire bonding, the electrodes E1 and E2 of the light source 2 and the light receiving unit 4 are electrically connected to the electrode pads 61 and 62 on the substrate 6 via wires such as gold wires, copper wires, and aluminum wires. This wire bonding is a low-loop wire bonding, thereby achieving a thinner light source 2 and the light receiving unit 4 (seals 20a, 40a). In general wire bonding, the first bonding is performed on the electrode pads on the chip, so the height from the chip surface to the highest point of the wire is as high as about 150 to 180 [μm]. The low-loop wire bonding sets the first bonding to the substrate side and performs the second bonding to the electrode pad on the chip. Therefore, the height of the wire in the first bonding is offset by the thickness of the chip, and the height of the wire on the chip can be pressed down. In the low-loop wire bonding, the height from the chip surface such as the light source 2 and the light receiving unit 4 to the highest point of the wire is 100 [μm] or less.

[0141] To produce the λ selection filter 32, first, a multilayer film for the λ selection filter 32 is formed on a silicon substrate (step S15). Next, the silicon substrate formed in step S15 is cut into pieces by a dicing device to produce individual λ selection filters 32 (step S16).

[0142] The AR filter 31 is manufactured by forming a multilayer film for the AR filter 31 on a silicon substrate (step S17). Next, the silicon substrate after the film formation manufactured in step S17 is cut into pieces by a dicing device or the like to manufacture individual AR filters 31 (step S18).

[0143] The protection cover 21 is manufactured by resin molding (step S19).

[0144] Next, the protective cover 21 produced in S19 and the AR filter 31 and the λ selection filter 32 produced in steps S18 and S16 are mounted on the mother substrate (step S33). In step S33, epoxy resin as an adhesive is applied to a specified position around the light source 2 mounted on the mother substrate in step S32, and epoxy resin is similarly applied to a specified position around the light receiving portion 4. Next, the protective cover 21 is mounted at a specified position on the adhesive around the light source 2 and the light receiving portion 4. In addition, epoxy resin is applied to each groove 213, and the AR filter 31 / λ selection filter 32 is adhered to each recess 211. Thereafter, the epoxy resin is thermally cured by, for example, heating to 120°C, and each protective cover 21 with the AR filter 31 / λ selection filter 32 mounted thereon is mounted on the mother substrate.

[0145] The signal processing unit 5 is formed and wired by a common semiconductor integrated circuit manufacturing technology to produce a wafer including a plurality of signal processing units 5 (AFE-IC) (step S21). The wafer produced in step S21 is singulated by a dicing device, and each signal processing unit 5 is produced by packaging (step S22). In this case, for example, a WLCSP (Wafer Level Chip Size / Scale Package) can be used, which is diced by sealing the portions of each chip other than the electrodes in the wafer state, and is singulated in the packaged state.

[0146] Furthermore, various elements such as amplifiers and transistors constituting the circuit element section 8 are prepared (step S23).

[0147] Next, the signal processing unit 5 of step S22 and the components constituting the circuit element unit 8 of step S23 are surface mounted (SMT; Surface Mount Technology) on the substrate 6 (step S34). In step S34, solder paste is printed at a specified position of the mother substrate on which the signal processing unit 5 and the components constituting the circuit element unit 8 are mounted by a dedicated printing device. After that, the signal processing unit 5 and the components constituting the circuit element unit 8 are mounted at a specified position of the mother substrate using a box, and the mother substrate printed with solder paste is heated at MAX260°C using a reflow furnace, and the terminals of the components constituting the signal processing unit 5 and the circuit element unit 8 are soldered to the terminals of the wiring of the mother substrate.

[0148] Next, an underfill (liquid curable resin) is applied to the mounting portion of the signal processing unit 5 and the circuit element unit 8 and thermally cured (step S35). In step S35, the underfill is thermally cured by heating the mother substrate at 120°C, and the signal processing unit 5 and the circuit element unit 8 are protected.

[0149] Next, the adhesive 22 is applied to the vent holes 215 and irradiated with ultraviolet rays, thereby curing the adhesive 22 to fill and block the vent holes 215 (step S36 ).

[0150] On the other hand, the optical cover 1 is manufactured by resin-molding the cover parts 110A and 110B and integrating them by bonding, heat caulking, or the like (step S24 ).

[0151] Next, after the contamination filter 12 is manufactured (step S25 ), the contamination filter 12 is attached to the gas inlets 111 , 112 , 113 , and 114 of the optical cover 1 by using an adhesive or the like (step S26 ).

[0152] The optical cover 1 produced in step S26 is mounted on a predetermined position of the mother substrate by bonding (thermosetting resin) or thermal caulking (step S37 ).

[0153] Next, the connector 7 is manufactured (step S27), and the connector 7 is soldered and mounted at a predetermined position of the mother substrate (step S38). After that, in order to achieve moisture-proofing / insulation of the substrate 6, the mother substrate on which the components are mounted in step S38 is subjected to moisture-proof coating (step S39). Moisture-proof coating is a coating method in which a moisture-proof coating material (for example, HumiSeal 1B51NSLU) is applied to the substrate 6.

[0154] Next, the mother substrate on which the components are mounted in step S38 is divided into individual substrates 6 by a cutting device, thereby manufacturing individual optical gas sensor devices 100a (step S40). In this case, a dry cutter that does not use water is preferably used as the cutting device.

[0155] Various adjustments are made to the optical gas sensor device 100a manufactured in step S40 (step S41). After that, a final inspection is performed on the optical gas sensor device 100a adjusted in step S41 (step S42). Finally, the optical gas sensor device 100a determined as a qualified product in the final inspection in step S41 is packaged and shipped to the shipping destination (step S43). Through the above manufacturing process, the optical gas sensor device 100a is manufactured.

[0156] Next, refer to Figure 7 , the effects of the seals 20a and 40a will be described. Figure 7 Graphs showing changes in the amount of received light during gas detection in the optical gas sensor device of the comparative example, the optical gas sensor device 100a of the present embodiment, and the optical gas sensor device 100c of the third embodiment.

[0157] like Figure 7As shown, an optical gas sensor device in which the light source 2 and the light receiving part 4 are not sealed but exposed, and an optical gas sensor device 100a of this embodiment are used. The optical gas sensor device 100c will be described later. The optical gas sensor device in which the light source 2 and the light receiving part 4 are exposed is referred to as a "comparative example optical gas sensor device". Figure 7 , two bar graphs are depicted in each optical gas sensor device. The bar graph on the left corresponds to the size of the light receiving area of ​​the light receiving unit 4 being □ (square) 0.710 [mm]. The bar graph on the right corresponds to the size of the light receiving area of ​​the light receiving unit 4 being □ 1.090 [mm].

[0158] In addition, the light source 2 has a seal (protective cover 21), so a light source that is smaller than the exposed light source of the comparative example is used. For example, the light emitting area [mm], the area ratio of the light emitting area (the area ratio of the light source of the comparative example is set to 1), and the total light emission [W] of the exposed light source of the comparative example and the light source 2 that is miniaturized for sealing are shown in Table II below. Due to its miniaturization, the light emitting area, area ratio, and total light emission of the light source 2 are also smaller than those of the exposed light source of the comparative example.

[0159] [Table 2]

[0160] Table II

[0161]

[0162]

[0163] Figure 7 The vertical axis represents the amount of change in the amount of light received during gas detection corresponding to each optical gas sensor device [%]. The amount of change in the amount of light received during gas detection [%] is the amount of change in the amount of light received based on the amount of light received during gas detection by the light receiving portion 4 having a light receiving area of ​​□0.710 [mm] of the optical gas sensor device of the comparative example. The amount of light received (amount of change) of this reference (target value) is set to 100 [%]. In addition, the amount of change in the amount of light received during gas detection by the optical gas sensor device 100a [%] also includes the influence of the miniaturization of the light source 2 mentioned above.

[0164] The light path length is extended and the optical characteristics are degraded by sealing the light source 2 and the light receiving unit 4. Therefore, the light receiving area of ​​the light receiving unit 4 is changed to ensure the amount of light received, and the design of the protective cover 21 is optimized to reduce the influence of the degradation of the optical characteristics.

[0165] In the optical gas sensor device of the comparative example, the amount of light received when the light receiving area is □1.090 [mm] is greater than the amount of light received when the light receiving area is □0.710 [mm]. In addition, the optical gas sensor device 100a has a light receiving portion 4 with a light receiving area of ​​□0.710 [mm]. Therefore, the amount of light received is reduced (55 [%]) compared with the reference (target value) amount of light received of the optical gas sensor device of the comparative example. However, in the optical gas sensor device 100a, the light receiving area is replaced with the light receiving portion 4 with □1.090 [mm]. Therefore, the optical gas sensor device 100a has an increased amount of light received (123 [%]) compared with the reference amount of light received of the optical gas sensor device of the comparative example, which is preferable. In this way, the light receiving area of ​​the light receiving portion 4 can be adjusted to reduce the adverse effects caused by sealing.

[0166] In addition, the specific example of the dimension of the sealing material 20a is shown in the following Table III. The sealing materials 20b and 20c will be described later.

[0167] [Table 3]

[0168] Table III

[0169]

[0170]

[0171] As described above, according to the present embodiment, the optical gas sensor device 100a includes: the light source 2 that emits infrared light to the gas G to be detected, the AR filter 31 and the λ selection filter 32 that are optical filters that transmit infrared light, the light receiving unit 4 that detects the infrared light incident through these optical filters and generates a detection signal, and the substrate 6. The optical gas sensor device 100a includes the seal 20a that carries the AR filter 31 and seals the light source 2, and the seal 40a that carries the λ selection filter 32 and seals the light receiving unit 4. The seals 20a and 40a are mounted on the substrate 6.

[0172] Therefore, the light source 2 and the light receiving unit 4 are sealed and shielded from the external environment by the seals 20a and 40a, thereby reducing the influence of the external environment on the light source 2 and the light receiving unit 4. In addition, the gas concentration of the gas G to be detected can be accurately detected based on the detection signal.

[0173] In addition, the AR filter 31 prevents reflection of infrared rays and transmits them. The λ selection filter 32 transmits infrared rays of a wavelength corresponding to the absorption wavelength of the gas G to be detected. Therefore, the AR filter 31 can reduce stray light of infrared rays. The λ selection filter 32 can accurately detect the gas concentration of the gas G to be detected based on the detection signal.

[0174] In addition, the sealant 20a seals the light source 2 and the electrical connection part (conducting wire, electrodes E1, E2, etc.) of the light source 2. The sealant 40a seals the light receiving part 4 and the electrical connection part (conducting wire, electrodes E1, E2, electrode pads 61, 62, etc.) of the light receiving part 4. Therefore, the electrical connection part between the light source 2 and the light receiving part 4 can be isolated from the external environment such as the humidity of the external air, and the degradation of the connection part can be prevented.

[0175] In addition, the seal 20a has a protective cover 21 surrounding the side of the light source 2. The seal 40a has a protective cover 21 surrounding the side of the light receiving unit 4. The AR filter 31 is mounted on the opening of the upper surface of the protective cover 21 of the seal 20a. The λ selection filter 32 is mounted on the opening of the upper surface of the protective cover 21 of the seal 40a. Therefore, the light source 2 and the light receiving unit 4 can be easily sealed and sealed by the AR filter 31, the λ selection filter 32 and the protective cover 21.

[0176] In addition, the protective cover 21 of the seal 20a has a vent 215 connected to the space of the light source 2. The protective cover 21 of the seal 40a has a vent 215 connected to the space of the light receiving unit 4. The vent 215 is blocked by the adhesive 22. Therefore, the AR filter 31 can be easily mounted on the seal 20a through the vent 215, and the λ selection filter 32 can be easily mounted on the seal 40a. And, by blocking the vent 215 with the adhesive 22, the light source 2 and the light receiving unit 4 can be sealed and sealed.

[0177] In addition, the light source 2 and the light receiving unit 4 of the sealing members 20a and 40a are directly mounted on the substrate 6. Therefore, the material cost and size of the sealing members 20a and 40a can be reduced.

[0178] The optical gas sensor device 100a includes an optical cover 1 that guides infrared light emitted from the light source 2 to the light receiving unit 4 via the gas G to be detected. The optical cover 1 is attached to the substrate 6. Therefore, the optical cover 1 can more accurately detect the gas concentration of the gas G to be detected.

[0179] In addition, an optical gas sensor device 100a is manufactured, which includes a light source 2 that emits infrared light toward a gas G to be detected, an AR filter 31 and a λ selection filter 32 that are optical filters that transmit infrared light, a light receiving unit 4 that detects infrared light incident through these optical filters and generates a detection signal, and a substrate 6. The manufacturing method of the optical gas sensor device 100a includes: a first mounting step (step S32) of mounting the light source 2 and the light receiving unit 4 on the substrate 6; and a second mounting step (steps S33 to S36) of mounting a seal 20a that carries the AR filter 31 and seals the light source 2 and a seal 40a that carries the λ selection filter 32 and seals the light receiving unit 4 on the substrate 6. In the second mounting step, a protective cover 21 that surrounds the side of the light source 2 and has a vent hole 215 connected to the space of the light source 2 is mounted on the substrate 6, and the AR filter 31 is mounted on the opening of the upper surface of the protective cover 21 as the seal 20a. Similarly, a protective cover 21 that surrounds the side of the light receiving unit 4 and has a vent hole 215 connected to the space of the light receiving unit 4 is mounted on the substrate 6, and a λ selection filter 32 is mounted on the opening of the upper surface of the protective cover 21 as a seal 40a. After the heat treatment of the mounting of the light source 2, the light receiving unit 4, and the circuit components (signal processing unit 5, circuit element unit 8), the vent hole 215 is blocked with an adhesive.

[0180] Therefore, the light source 2 and the light receiving unit 4 are hermetically sealed by the seals 20a and 40a, so that the influence of the external environment on the light source 2 and the light receiving unit 4 can be reduced. In addition, the gas concentration of the gas G to be detected can be accurately detected. Such an optical gas sensor device 100a can be manufactured. In addition, it is possible to prevent the cover from floating due to the thermal expansion of the gas in the protective cover 21 caused by the adhesive when the protective cover 21 is mounted on the substrate 6. In addition, the light source 2 and the light receiving unit 4 are directly mounted on the substrate 6, so the material cost and size of the seals 20a and 40a can be reduced.

[0181] In addition, the adhesive 22 is a UV curing resin. Therefore, it is possible to prevent the protective cover 21 from floating due to the thermal expansion of the gas in the protective cover 21 when the adhesive 22 is cured.

[0182] In addition, the manufacturing method of the optical gas sensor device 100a includes a fourth mounting step (step S37) of mounting the optical cover 1 on the substrate 6, wherein the optical cover 1 guides infrared light emitted from the light source 2 to the light receiving unit 4 via the gas G to be detected. Therefore, the gas concentration of the gas G to be detected can be detected more accurately by the optical cover 1.

[0183] (Second Embodiment)

[0184] Reference Figure 8 to Figure 10, a second embodiment of the present invention is described. Figure 8 It is a perspective view showing the sealing member 20b. Fig. 9 1 is a flowchart showing a method for manufacturing the optical gas sensor device 100 b according to the present embodiment. Fig.10 Yes means Fig. 9 Flow chart of the seal manufacturing process.

[0185] In the optical gas sensor device 100a of the first embodiment, the seals 20a and 40a are configured such that the light source 2 and the light receiving unit 4 are directly mounted on the substrate 6 as the mother substrate. In this embodiment, the seals are configured such that the light source 2 and the light receiving unit 4 are mounted on a sub-substrate different from the substrate 6.

[0186] The device structure of this embodiment uses an optical gas sensor device 100b instead of the optical gas sensor device 100a of the first embodiment. However, in the optical gas sensor device 100b, the same parts as those of the optical gas sensor device 100a are denoted by the same reference numerals, and their description is omitted.

[0187] The optical gas sensor device 100b includes an optical cover 1, sealing members 20b and 40b, a signal processing unit 5, a substrate 6, a connector 7, and a circuit element unit 8. Figure 8 The seal 20b will be described.

[0188] The sealing member 20b includes: a light source 2, a protective cover 21, an adhesive 22, an AR filter 31, and a sub-substrate 63. The sub-substrate 63 is made of the same material as the substrate 6, is a substrate different from the substrate 6, and is mounted on the upper surface of the substrate 6. The protective cover 21 is mounted on the sub-substrate 63. The sub-substrate 63 electrically connects the terminal connected to the light source 2 by a wire to the terminal of the substrate 6 through a through hole, for example.

[0189] The sealing member 40 b has the light receiving unit 4 , the protective cover 21 , the adhesive 22 , the λ selection filter 32 , and the sub-substrate 63 , similarly to the sealing member 20 b .

[0190] Next, refer to Fig. 9 and Fig.10 , a method for manufacturing the optical gas sensor device 100b is described.

[0191] like Fig. 9 As shown, first, as a substrate for the optical gas sensor device 100b, a mother substrate designed in such a manner as to arrange a plurality of substrates 6 is manufactured (step S71). However, each substrate 6 of the mother substrate manufactured in step S71 is designed in such a manner that the sealing members 20b and 40b are installed instead of the protective cover 21 in the subsequent process.

[0192] On the other hand, a seal manufacturing process (step S50) is performed to manufacture the seals 20b and 40b. Fig.10 The sealing material manufacturing process of step S50 will be described.

[0193] First, as a substrate for the sealing members 20b and 40b, a sub-substrate designed so as to arrange a plurality of sub-substrates 63 is prepared (step S101). Steps S91 to S94 are Figure 6 Steps S95 and S96 are the same as steps S11 to S14. Figure 6 Step S97 is the same as steps S15 to S18. Figure 6 The same as step S19.

[0194] Next, the plurality of protective covers 21 produced in step S97 are manually placed in the storage portion of the jig and arranged, and plasma treatment is performed on each protective cover 21 (step S98). Plasma treatment is a treatment that uses Ar+ to clean and modify the surface of each protective cover 21. The surface of each protective cover 21 is activated by plasma treatment, and the bonding strength in subsequent bonding is increased and stabilized.

[0195] Next, the light source 2 manufactured in step S92 and the light receiving unit 4 manufactured in step S94 are mounted on the sub-substrate manufactured in step S31 (step S102). In step S102, an adhesive is applied to the mounting positions of the light receiving unit 4 and the light source 2 in the sub-substrate to perform bare-die bonding of the light receiving unit 4 and the light source 2. Then, the operator heats the sub-substrate to which the light receiving unit 4 and the light source 2 are bare-die bonded to heat-cure the adhesive.

[0196] Next, the electrodes E1 and E2 of the light source 2 and the light receiving part 4 after bare chip bonding are electrically connected to the electrode pads on the sub-substrate by wire bonding (step S103). After that, plasma treatment is performed in step S98 to bond the protective cover 21 arranged on the fixture to the sub-substrate (step S104). In step S104, epoxy resin as an adhesive is applied to the specified position around the light source 2 mounted on the sub-substrate, and epoxy resin is also applied to the specified position around the light receiving part 4. Then, the protective cover 21 on the fixture is bonded to the specified position on the epoxy resin around the light source 2 and the light receiving part 4.

[0197] Next, the AR filter 31 / λ selection filter 32 is mounted on each recess 211 by a general-purpose bare die bonding device, and the adhesive is thermally cured (step S105). In step S105, epoxy resin is applied to each groove 213, and the AR filter 31 / λ selection filter 32 is bonded to each recess 211. Thereafter, the epoxy resin is thermally cured by heating to, for example, 120° C. in a heating furnace, and each protective cover 21 with the AR filter 31 / λ selection filter 32 mounted thereon is fixed to the sub-substrate.

[0198] Next, a laser marker is used to print a mark (manufacturing date, etc.) on the back of the sub-substrate 63 for the seal 20b / 40b for traceability (step S106). Then, the sub-substrate on which the components are mounted in step S38 is divided into individual sub-substrates 63 by a cutting device to produce the seals 20b and 40b (step S107).

[0199] Next, the seals 20b and 40b are inspected (performance evaluation, quality determination), and qualified products are loaded into a tray (step S108). During the inspection, the resistance value is measured to determine whether the lead wire is not short-circuited when the seals 20b and 40b are packaged. Then, the seals 20b and 40b loaded into the tray are stored (step S109).

[0200] return Fig. 9 , steps S61 to S67 and Figure 6 The sealing members 20b, 40b on the tray produced in step S50, the signal processing unit 5 produced in step S62, and the circuit element unit 8 produced in step S63 are surface mounted on the mother substrate produced in step S71 (step S72). Steps S73 to S80 are the same as Figure 6 The same as steps S36 to S43.

[0201] In addition, specific examples of the dimensions of the seal 20b are listed in Table III.

[0202] As described above, according to the present embodiment, the sealing member 20b has the sub-substrate 63 on which the light source 2 is mounted. The sealing member 40b has the sub-substrate 63 on which the light receiving unit 4 is mounted. Therefore, the sealing members 20b and 40b can be manufactured and stored without directly mounting the light source 2 and the light receiving unit 4 on the substrate 6. In addition, since the sealing members 20b and 40b are mounted on the substrate 6, the light source 2 and the light receiving unit 4 can be indirectly and easily mounted on the substrate 6.

[0203] In addition, the manufacturing method of the optical gas sensor device 100b includes: a first mounting step (steps S102 and S103) of mounting the light source 2 and the light receiving unit 4 on the sub-substrate 63; and a second mounting step (steps S72 and S73) of mounting the seal 20b and the seal 40b on the sub-substrate 63, wherein the seal 20b carries the AR filter 31 and seals the light source 2, and the seal 40b carries the λ selection filter 32 and seals the light receiving unit 4. In the second mounting step, the protective cover 21 surrounding the side of the light source 2 and having the vent hole 215 connected to the space of the light source 2 is mounted on the sub-substrate 63, and the AR filter 31 is mounted on the opening of the upper surface of the protective cover 21 as the seal 20b. Similarly, the protective cover 21 surrounding the side of the light receiving unit 4 and having the vent hole 215 connected to the space of the light receiving unit 4 is mounted on the sub-substrate 63, and the λ selection filter 32 is mounted on the opening of the upper surface of the protective cover 21 as the seal 40b. After the sealing members 20 b and 40 b and the circuit components (the signal processing unit 5 and the circuit element unit 8 ) are mounted on the substrate 6 and subjected to heat treatment, the vent holes 215 are closed with an adhesive.

[0204] Therefore, the sealing members 20b and 40b can be manufactured and stored without directly attaching the light source 2 and the light receiving unit 4 to the substrate 6. In addition, since the sealing members 20b and 40b are attached to the substrate 6, the light source 2 and the light receiving unit 4 can be indirectly and easily attached to the substrate 6. Furthermore, it is possible to prevent the cover from floating due to the thermal expansion of the gas in the protective cover 21 caused by the adhesive when attaching the sealing members 20b and 40b to the substrate 6.

[0205] (Third Embodiment)

[0206] Reference Fig.11 (a) Fig.11 (b) of the present invention will be described below. Fig.11 (a) is a perspective view showing the sealing member 20c. Fig.11 (b) is a cross-sectional view showing the seal 20c.

[0207] In the optical gas sensor device 100b of the second embodiment, the seals 20b and 40b have a structure in which the protective cover 21 is made of resin and the sub-substrate 63 corresponds to the bottom surface. In this embodiment, the seal has a structure in which the protective cover is made of ceramic and has a bottom surface.

[0208] The device structure of this embodiment uses an optical gas sensor device 100c instead of the optical gas sensor device 100b of Embodiment 2. However, in the optical gas sensor device 100c, the same parts as those of the optical gas sensor device 100b are denoted by the same reference numerals, and their description is omitted.

[0209] The optical gas sensor device 100c includes an optical cover 1, sealing members 20c and 40c, a signal processing unit 5, a substrate 6, a connector 7, and a circuit element unit 8. Fig.11 (a) Fig.11 (b) of the present invention will now be described the seal 20c.

[0210] The sealing member 20c includes a light source 2, a protective cover 21c, and an AR filter 31. The protective cover 21c is made of ceramic and is a cover that protects the light source 2 from the side and bottom. The protective cover 21c is mounted on the substrate 6. In addition, the protective cover 21c has no vent hole compared to the protective cover 21 of the sealing member 20a of the first embodiment, and the AR filter 31 is mounted.

[0211] The protective cover 21c has recesses 211c and 212c. The recess 211c is a recess arranged on the upper surface (+z direction) side, and the planar shape of the opening is rectangular. The recess 212c is a recess arranged on the lower side (-z direction) of the recess 211c, and the planar shape of the opening is rectangular and smaller than the recess 211c. The recess 212c has a bottom surface. The light source 2 is mounted on the bottom surface of the recess 212c. The protective cover 21c electrically connects the terminal connected to the wire of the light source 2 with the terminal of the substrate 6 through, for example, a through hole.

[0212] The AR filter 31 is arranged on the entire surface of the upper surface of the protective cover 21c in a manner covering the opening of the upper surface of the protective cover 21c. The AR filter 31 is attached to the protective cover 21c by an adhesive 33. The adhesive 33 is an epoxy resin or a silicone resin used for airtight sealing of the light source 2. In addition, the adhesive 33 can be a glass material used for sealing the light source 2, or a preform or paste of a metal material such as AuSn or solder. In the case of a metal material, in order to ensure adhesion, it is preferred to implement metallization such as Cr / Ni / Au or Ti / Ni / Au on the protective cover 21c and the AR filter 31 that are adherends at the bonding portion.

[0213] The sealing member 40c includes the light receiving unit 4, the protective cover 21c, and the λ selection filter 32. Thus, the sealing member 40c has a structure in which the light source 2 and the AR filter 31 of the sealing member 20c are replaced with the light receiving unit 4 and the λ selection filter 32.

[0214] Next, a method for manufacturing the optical gas sensor device 100c is described. The method for manufacturing the optical gas sensor device 100c is a method for manufacturing the optical gas sensor device 100c of the second embodiment. Fig. 9 The sealing material manufacturing process of step S50 is replaced by the manufacturing process of the sealing materials 20c and 40c. However, step S73 is omitted.

[0215] The manufacturing process of the seal 20c is the following process. First, a protective cover 21c is manufactured and prepared as a cavity-type ceramic substrate. Next, the light source 2 is mounted on the protective cover 21c (bare chip bonding + wire bonding). After that, as an interpolation in the absence of a vent hole, the air is decompressed (e.g., evacuated) using, for example, an air suction pump, and the adhesive 33 is applied to the protective cover 21c in the decompressed air (e.g., vacuum), and the AR filter 31 is pasted and mounted to manufacture the seal 20c. Alternatively, depending on the physical properties of the adhesive material, the pasting is performed at a temperature higher than normal temperature (above 100°C). At this time, in order to suppress the increase in internal pressure caused by the temperature increase, the filter 31 is fixed to be inactive using a weight stone, a clamp, etc. At this time, in order to reduce the fixed load, it is preferred to mount the filter 31 at a higher temperature.

[0216] The manufacturing process of the seal 40c is the same as the manufacturing process of the seal 20c. First, the protective cover 21c is manufactured and prepared as a cavity-type ceramic substrate. Next, the light receiving unit 4 is mounted on the protective cover 21c. Then, the adhesive 33 is applied to the protective cover 21c, and the λ selection filter 32 is attached and mounted to manufacture the seal 40c.

[0217] Thus, the external environment is isolated from the surface of the light source 2 or the light receiving unit 4, and the influence of the external environment can be minimized. In addition, by adjusting the height (length in the z-axis direction) of the recess 212c, the distance between the AR filter 31 or the λ selection filter 32 and the surface of the light source 2 or the light receiving unit 4 is shortened.

[0218] In addition, the seals 20c and 40c are delivered (stored) as a single piece, unlike the sub-substrate method (storage of the seals 20b and 40b on a tray) of the second embodiment. Therefore, in order to simulate the assembly of the substrate, the seals 20c and 40c are mounted on a fixture with a hole. Fig. 9 In step S50), the sealing members 20c and 40c on the fixture are surface mounted on the substrate 6.

[0219] Next, refer to Figure 7 Next, the effects of the sealing members 20c and 40c of the optical gas sensor device 100c according to the present embodiment will be described.

[0220] The optical gas sensor device 100c has a light receiving portion 4 having a light receiving area of ​​□0.710 [mm]. Therefore, the amount of light received is reduced (76 [%]) compared to the light receiving amount of the reference (target value) of the optical gas sensor device of the comparative example. However, in the optical gas sensor device 100c, the light receiving portion 4 having a light receiving area of ​​□1.090 [mm] is replaced. Therefore, the optical gas sensor device 100c has an increased light receiving amount (167 [%]) compared to the reference light receiving amount of the optical gas sensor device of the comparative example, which is preferable. In this way, the light receiving area of ​​the light receiving portion 4 can be adjusted to reduce the adverse effects caused by sealing.

[0221] In addition, specific examples of the dimensions of the seal 20c are listed in Table III.

[0222] As described above, according to the present embodiment, the seal 20c has a protective cover 21c surrounding the side and bottom surfaces of the light source 2. The seal 40c has a protective cover 21c surrounding the side and bottom surfaces of the light receiving portion 4. The AR filter 31 is mounted on the opening of the upper surface of the protective cover 21c of the seal 20c. The λ selection filter 32 is mounted on the opening of the upper surface of the protective cover 21c of the seal 40c. Therefore, the seals 20c and 40c can be manufactured and stored without directly mounting the light source 2 and the light receiving portion 4 on the substrate 6. In addition, the seals 20c and 40c are not mounted with a sub-substrate, so the structure can be simplified. In addition, since the seals 20c and 40c are mounted on the substrate 6, the light source 2 and the light receiving portion 4 can be indirectly and easily mounted on the substrate 6.

[0223] In addition, the manufacturing method of the optical gas sensor device 100c includes: a first mounting step of mounting the light source 2 and the light receiving unit 4 on the protective cover 21c; a manufacturing step of manufacturing a seal 20c for mounting the AR filter 31 on the protective cover 21c and sealing the light source 2, and a seal 40c for mounting the λ selection filter 32 on the protective cover 21c and sealing the light receiving unit 4; and a second mounting step of mounting the seals 20c and 40c on the substrate 6. In the manufacturing step, the air is decompressed, and in the decompressed air, the AR filter 31 is mounted on the protective cover 21c, and the λ selection filter 32 is mounted on the protective cover 21c.

[0224] Therefore, the sealing members 20c and 40c can be manufactured and stored without directly attaching the light source 2 and the light receiving unit 4 to the substrate 6. In addition, since the sealing members 20c and 40c are attached to the substrate 6, the light source 2 and the light receiving unit 4 can be indirectly and easily attached to the substrate 6. Furthermore, since the air in the internal space of the sealing members 20c and 40c is decompressed, it is possible to prevent the cover from floating due to the thermal expansion of the gas in the protective cover 21c caused by the heat treatment in the previous stage of attaching the sealing members 20c and 40c to the substrate 6.

[0225] In the above-mentioned manufacturing process, the AR filter 31 and the λ selection filter 32 may be mounted on the protective cover 21c at a temperature of 100° C. or higher. According to this method, it is also possible to prevent the cover from floating due to the thermal expansion of the gas in the protective cover 21c caused by the heat treatment before the sealing members 20c and 40c are mounted on the substrate 6.

[0226] (Variation Example)

[0227] Reference Fig.12 , Fig.13 , a modified example of the above-mentioned third embodiment is described. Fig.12 It is a cross-sectional view showing the seal 20d. Fig.13 It is a cross-sectional view showing the seal 20e.

[0228] The optical gas sensor device 100c of the third embodiment may also be configured to include the seals 20d and 40d of this modification instead of the seals 20c and 40c. Fig.12 As shown, the sealing member 20d includes the light source 2, a protective cover 21d, and an AR filter 31. The protective cover 21d is made of ceramics and is mounted on the substrate 6, similarly to the sealing member 20c.

[0229] The protective cover 21d has recesses 211d, 212d, and 213d. The recess 211d is a recess arranged on the upper surface (+z direction) side, and the planar shape of the opening is rectangular, corresponding to the planar shape of the AR filter 31. The recess 212d is a recess arranged on the lower surface (-z direction) side of the recess 211d, and the planar shape of the opening is rectangular and smaller than the recess 211d. The recess 213d is a recess arranged on the lower surface side of the recess 212d, and the planar shape of the opening is rectangular and smaller than the recess 212d. The recess 213d has a bottom surface. The light source 2 is mounted on the bottom surface of the recess 212d. The protective cover 21d electrically connects the terminal connected to the wire of the light source 2 with the terminal of the substrate 6 through a through hole, for example.

[0230] The sealing member 40d includes the light receiving unit 4, the protective cover 21d, and the λ selection filter 32. Thus, the sealing member 40d has a structure in which the light source 2 and the AR filter 31 of the sealing member 20d are replaced with the light receiving unit 4 and the λ selection filter 32.

[0231] The manufacturing process of the seal 20d is the same as that of the seal 20c, but when the AR filter 31 is mounted on the protective cover 21d, the operator places the AR filter 31 into the recess 211d coated with the adhesive 33. With this structure, the bonding strength is increased by increasing the bonding area of ​​the AR filter 31, the sealing degree is improved, and the manufacturing process is simplified (the AR filter 31 can be pressed from above to be cured).

[0232] The manufacturing process of the sealing member 40d is the same as the manufacturing process of the sealing member 20d, and the light receiving unit 4 is attached to the protective cover 21d.

[0233] In addition, the optical gas sensor device 100c of the third embodiment may also be configured to include the sealing members 20e and 40e of this modification instead of the sealing members 20c and 40c. Fig.13 As shown, the sealing member 20e includes the light source 2, a protective cover 21e, and an AR filter 31. The protective cover 21e is made of ceramics and is mounted on the substrate 6, similarly to the sealing member 20c.

[0234] The protective cover 21e has recesses 211e and 212e. The recess 211e is a recess arranged on the upper surface (+z direction) side, and the planar shape of the opening is rectangular, corresponding to the planar shape of the AR filter 31. The recess 212e is a recess arranged on the lower surface (-z direction) side of the recess 211e, and the planar shape of the opening is rectangular and smaller than the recess 211e. The recess 212e has a bottom surface. The light source 2 is mounted on the bottom surface of the recess 212e. The protective cover 21e electrically connects the terminal connected to the wire of the light source 2 to the terminal of the substrate 6 through a through hole, for example.

[0235] The sealing member 40e includes the light receiving unit 4, the protective cover 21e, and the λ selection filter 32. Thus, the sealing member 40e has a structure in which the light source 2 and the AR filter 31 of the sealing member 20e are replaced with the light receiving unit 4 and the λ selection filter 32.

[0236] The manufacturing process of the sealing member 20e is the same as the manufacturing process of the sealing member 20d. The manufacturing process of the sealing member 40e is the same as the manufacturing process of the sealing member 20e, and the light receiving unit 4 is attached to the protective cover 21e.

[0237] As described above, according to the seals 20d, 40d, 20e, and 40e of the present modification, the same effects as those of the seals 20c and 40c of the third embodiment can be obtained.

[0238] In addition, the description in the above-mentioned embodiment is an example of the optical gas sensor device and the method for manufacturing the optical gas sensor device of the present invention, and the present invention is not limited thereto.

[0239] For example, in the cavity (recess) of the protective cover 21c, 21d, 21e of the third embodiment and the modified example, the area of ​​gold (Au) can also be increased. This structure can increase the amount of effective infrared light. This is because the reflectivity R[%] of gold has a high value of 98[%] or more at a wavelength of 1[μm] or more, which is the infrared region. In addition to gold, aluminum (Al), copper (Cu), silver (Ag), etc. have a high reflectivity R[%] value in the infrared region, and therefore, can also be used to increase the area of ​​the above-mentioned cavity.

[0240] In the optical gas sensor device in the above-described embodiment and modified example, the gas G is R32 and the base material of the AR filter 31 and the λ selection filter 32 of the seal is silicon (Si). However, the present invention is not limited to this configuration. Fig.14 This is a graph showing the absorption wavelength [μm] of various gases and the transmittance range of sapphire glass / Si.

[0241] like Fig.14 As shown, when the gas G to be detected is R32, the absorption wavelength of R32 is in the 9-10 [μm] band. Therefore, Si, which uses the absorption wavelength band of R32 as the transmittance range, is used as the base material of the AR filter 31 and the λ selection filter 32. For example, in the case of a gas G that absorbs a gas type with a short wavelength, by using sapphire glass in the base material of the AR filter 31 and the λ selection filter 32, stray light is prevented, and selectivity is improved. The gas G that absorbs a gas type with a short wavelength is CO2, CH4, etc.

[0242] In addition, in the above-mentioned embodiment and modification, the optical gas sensor device is configured to include a set of light source 2, AR filter 31, λ selection filter 32 and light receiving unit 4, but is not limited thereto. The optical gas sensor device may also be configured to include a plurality of sets of light source 2, AR filter 31, λ selection filter 32 and light receiving unit 4.

[0243] In the above-described embodiment and modification, the optical gas sensor device has the light source 2 and the light receiving unit 4 sealed by a sealant, but the present invention is not limited thereto. For example, either the light source 2 or the light receiving unit 4 may be sealed by a sealant.

[0244] In the sealing members 20a, 40a of the first embodiment and the sealing members 20b, 40b of the second embodiment, the protective cover 21 may be configured without the vent hole 215, and the AR filter 31 or the λ selection filter 32 may be attached to and mounted on the protective cover 21 in the air after the decompression treatment, as in the protective cover 21c of the third embodiment. In the sealing members 20c, 40c of the third embodiment and the sealing members 20d, 40d, 20e, 40e of the modified examples, the protective cover 21c, 21d, 21e may be configured with a vent hole, and the AR filter 31 or the λ selection filter 32 may be attached to the protective cover 21c, 21d, 21e, and the vent hole may be filled and blocked with an adhesive after the heat treatment of mounting the components constituting the circuit element section 8 on the substrate 6.

[0245] Furthermore, the detailed structures and detailed operations of the optical gas sensor devices 100a, 100b, and 100c in the above-described embodiment and modified examples can be appropriately modified without departing from the gist of the present invention.

[0246] Explanation of symbols

[0247] 100a, 100b, 100c Optical gas sensor device

[0248] G Gas

[0249] 1 Optical cover

[0250] 110A, 110B cover

[0251] 11 Gas inlet port

[0252] 111, 112, 113, 114 Gas intake

[0253] 12 Contamination filter

[0254] 13 Light guide

[0255] 131 Entrance Department

[0256] 132 Export Department

[0257] SP Space Department

[0258] 20a, 40a, 20b, 40b, 20c, 40c, 20d, 40d, 20e, 40e seals

[0259] 2 Light Source

[0260] M Diaphragm

[0261] E1, E2 electrodes

[0262] 21, 21c, 21d, 21e protective cover

[0263] 211, 211c, 212c, 211d, 212d, 213d, 211e, 212e concave parts

[0264] 212 Light source hole

[0265] 213 slots

[0266] 214 protrusion

[0267] 215 Ventilation hole

[0268] 216 Cutting surface

[0269] 22, 33 Adhesive

[0270] 31 AR filter

[0271] 32 λ selection filter

[0272] 4 Light receiving part

[0273] 5 Signal processing unit

[0274] 6 substrate

[0275] 61, 62 electrode pad

[0276] 63 sub-base

[0277] 7 Connectors

[0278] 8 Circuit Components

[0279] 81 switch.

Claims

1. An optical gas sensor device comprising: a light source that emits infrared rays toward a gas to be detected; an optical filter that transmits the infrared rays; a light receiving unit that detects the infrared rays incident through the optical filter to generate a detection signal; and a first substrate, characterized in that The optical gas sensor device includes: a sealing member that carries the optical filter and seals the light source or the light receiving unit. The sealing member is mounted on the first substrate.

2. The optical gas sensor device according to claim 1, characterized in that: The optical filter is at least one of an AR filter that prevents reflection of the infrared light and transmits the infrared light, and a λ selective filter that transmits the infrared light having a wavelength corresponding to an absorption wavelength of the gas to be detected.

3. The optical gas sensor device according to claim 1, wherein: The sealing member seals an electrical connection portion of the light source or the light receiving portion.

4. The optical gas sensor device according to claim 1, wherein: The sealing member comprises: a first protective cover which surrounds the side surface of the light source or the light receiving portion; The optical filter is mounted on the opening of the upper surface of the first protective cover.

5. The optical gas sensor device according to claim 4, characterized in that: The first protective cover has: a vent hole connected to the space of the light source or the light receiving part, The vent hole is blocked by adhesive.

6. The optical gas sensor device according to claim 4, characterized in that: The light source or the light receiving portion of the sealing member is directly mounted on the first substrate.

7. The optical gas sensor device according to claim 4, characterized in that: The sealing member comprises: a second substrate for mounting the light source or the light receiving unit, The second substrate is mounted on the first substrate.

8. The optical gas sensor device according to claim 1, characterized in that: The sealing member comprises: a second protective cover which surrounds the side surface and the bottom surface of the light source or the light receiving portion, The optical filter is mounted on the opening of the upper surface of the second protective cover.

9. The optical gas sensor device according to any one of claims 1 to 8, characterized in that: The optical gas sensor device includes an optical cover that guides infrared light emitted from the light source to the light receiving unit via the gas to be detected. The optical cover is mounted on the first substrate.

10. A method for manufacturing an optical gas sensor device, the optical gas sensor device comprising: a light source that emits infrared rays toward a gas to be detected; an optical filter that transmits the infrared rays; a light receiving unit that detects the infrared rays incident through the optical filter to generate a detection signal; and a first substrate, characterized in that: The manufacturing method of the optical gas sensor device comprises: A first mounting step is to mount the light source and the light receiving unit on the first substrate; and In a second mounting step, a sealing member that carries the optical filter and seals the light source or the light receiving unit is mounted on the first substrate. In the second installation process, a first protective cover surrounding the side of the light source or the light receiving part and having a ventilation hole connected to the space of the light source or the light receiving part is installed on the first substrate, and the optical filter is mounted on the opening of the upper surface of the first protective cover as the sealant. After the light source, the light receiving part and the circuit components are installed on the first substrate and heat treated, the ventilation hole is blocked with an adhesive.

11. A method for manufacturing an optical gas sensor device, the optical gas sensor device comprising: a light source that emits infrared rays toward a gas to be detected; an optical filter that transmits the infrared rays; a light receiving unit that detects the infrared rays incident through the optical filter to generate a detection signal; and a first substrate, characterized in that: The manufacturing method of the optical gas sensor device comprises: A first mounting step is to mount the light source or the light receiving unit on a second substrate; and In a second mounting step, a sealing member that carries the optical filter and seals the light source or the light receiving unit is mounted on the first substrate. In the second installation process, a first protective cover surrounding the side of the light source or the light receiving part and having a ventilation hole connected to the space of the light source or the light receiving part is installed on the second substrate, and the optical filter is mounted on the opening of the upper surface of the first protective cover as the sealant. After the sealant and circuit components are installed on the first substrate and heat treated, the ventilation hole is blocked with an adhesive.

12. The method for manufacturing an optical gas sensor device according to claim 10 or 11, characterized in that: The adhesive is a UV curable resin.

13. A method for manufacturing an optical gas sensor device, the optical gas sensor device comprising: a light source that emits infrared rays toward a gas to be detected; an optical filter that transmits the infrared rays; a light receiving unit that detects the infrared rays incident through the optical filter to generate a detection signal; and a first substrate, characterized in that: The manufacturing method of the optical gas sensor device comprises: A first installation step is to install the light source or the light receiving part on a second protective cover surrounding the side and bottom surfaces of the light source or the light receiving part; A manufacturing step of manufacturing a seal that mounts the optical filter on the second protective cover and seals the light source or the light receiving part; as well as The second mounting step is to mount the sealing member on the first substrate. In the manufacturing step, air is decompressed, and the optical filter is mounted on the second protective cover in the decompressed air.

14. A method for manufacturing an optical gas sensor device, the optical gas sensor device comprising: a light source that emits infrared rays toward a gas to be detected; an optical filter that transmits the infrared rays; a light receiving unit that detects the infrared rays incident through the optical filter to generate a detection signal; and a first substrate, characterized in that: The manufacturing method of the optical gas sensor device comprises: A first installation step is to install the light source or the light receiving part on a second protective cover surrounding the side and bottom surfaces of the light source or the light receiving part; A manufacturing step of manufacturing a seal that mounts the optical filter on the second protective cover and seals the light source or the light receiving part; as well as The second mounting step is to mount the sealing member on the first substrate. In the manufacturing step, the optical filter is mounted on the second protective cover at a temperature of 100° C. or higher.

15. The method for manufacturing an optical gas sensor device according to claim 10, 11, 13 or 14, characterized in that: The optical filter is at least one of a λ selective filter that transmits infrared light having a wavelength corresponding to an absorption wavelength of the gas to be detected and an AR filter that prevents reflection of the infrared light and transmits the infrared light.

16. The method for manufacturing an optical gas sensor device according to claim 10, 11, 13 or 14, characterized in that: The sealing member seals an electrical connection portion of the light source or the light receiving portion.

17. The method for manufacturing an optical gas sensor device according to claim 10, 11, 13 or 14, characterized in that: The method for manufacturing the optical gas sensor device includes a third mounting step of mounting an optical cover on the first substrate, wherein the optical cover guides infrared light emitted from the light source to the light receiving unit via the gas to be detected.

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