WO2024174315A1

WO2024174315A1 - Thermopile infrared detector and preparation method therefor, and ndir detection system

Info

Publication number: WO2024174315A1
Application number: PCT/CN2023/082760
Authority: WO
Inventors: 徐德辉
Original assignee: 上海烨映微电子科技股份有限公司
Priority date: 2023-02-24
Filing date: 2023-03-21
Publication date: 2024-08-29
Also published as: CN116124728A

Abstract

A thermopile infrared detector (130) and a preparation method therefor, and an NDIR detection system. The thermopile infrared detector (130) comprises a housing (10), a substrate (20), a TEC temperature control chip (30), an ambient temperature sensor chip (40), a thermopile sensor chip (50) and an infrared filter (60). In the thermopile infrared detector (130), the TEC temperature control chip (30) is placed below the thermopile infrared sensor chip (50) and the ambient temperature sensor chip (40), and when an ambient temperature rises, cooling control can be performed by means of the TEC temperature control chip (30), such that the ambient temperature of the thermopile sensor chip (50) is controlled in a constant temperature state all the time, the thermopile infrared sensor chip (50) is not affected by a thermal shock when an external light source is turned on, and a reference output of the thermopile infrared detector (130) is maintained at a constant value, thereby increasing the resolution of the thermopile infrared detector (130), and thus increasing the detection resolution for a gas to be tested.

Description

Thermopile infrared detector and preparation method thereof and NDIR detection system

Technical Field

The invention relates to the field of detectors, and in particular to a thermopile infrared detector and a preparation method thereof, and an NDIR detection system.

Background Art

Non-Dispersive InfraRed (NDIR) detection system is a commonly used gas detection method. It is mainly used to measure compounds, such as CH ₄ , CO ₂ , N ₂ O, CO, SO ₂ , NH ₃ , ethanol, benzene, etc., as well as most organic substances (Hydrocarbon, HC), including volatile organic compounds (Volatile Organic Compounds, VOC).

The NDIR detection system is an optical gas sensor composed of an infrared light source (IR source), an optical path (Optics Cell), a thermopile infrared detector (Thermopile IR Detector) (as shown in Figure 1), an electronic circuit (Electronics) and a software algorithm (Algorithm). In the application of the NDIR detection system, since the infrared light source directly determines the intensity of the radiated infrared light, the greater the power of the infrared light source, the greater the intensity of the radiated infrared light. However, since the entire NDIR detection system is a sealed optical path structure, the heat generated by the infrared light source will accumulate in the sealed structure, thereby causing the ambient temperature of the entire NDIR detection system to rise. The greater the power of the infrared light source, the greater the temperature rise of the NDIR detection system. In order to reduce the power consumption of the NDIR detection system, the existing technology generally adjusts the infrared light source to shorten the working time of the infrared light source, thereby reducing the power consumption of the NDIR detection system.

According to the above working characteristics of the NDIR detection system, the infrared light source of the NDIR detection system is constantly turned on and off during operation. Turning on the infrared light source will cause the ambient temperature of the NDIR detection system to rise, while turning off the infrared light source will cause the ambient temperature of the NDIR detection system to drop. Therefore, during the operation of the NDIR detection system, the ambient temperature of the thermopile infrared detector is also constantly changing, which in turn affects the output voltage of the thermopile infrared detector. The reference output of the thermopile infrared sensor will increase rapidly, reducing the resolution of the thermopile infrared detector's response to infrared light, thereby reducing the gas detection accuracy of the NDIR detection system. In addition, changes in the external ambient temperature of the NDIR detection system will also cause changes in the response of the thermopile infrared detector, resulting in the characteristics of the NDIR detection system being related to the external ambient temperature, and unable to guarantee stable gas detection accuracy.

In view of the above, it is necessary to provide a thermopile infrared detector and a preparation method thereof and an NDIR detection system to solve the problems of the constant change of ambient temperature and detection accuracy of the thermopile infrared detector in the prior art.

Summary of the invention

In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a thermopile infrared detector and a preparation method thereof and an NDIR detection system to solve the problems of the thermopile infrared detector in the prior art such as the constantly changing ambient temperature and the detection accuracy.

In order to achieve the above-mentioned object and other related objects, the present invention provides a thermopile infrared detector, the thermopile infrared detector comprising:

case;

A base, located below the shell and forming a sealed cavity with the shell;

A TEC temperature control chip, located above the substrate in the cavity, for controlling the temperature of the thermopile infrared detector to keep it in a constant temperature state;

An ambient temperature sensor chip, located above the TEC temperature control chip in the cavity, for monitoring the temperature of the thermopile infrared detector;

A thermopile sensor chip is located above the TEC temperature control chip in the cavity and is spaced apart from the ambient temperature sensor chip, and is used to detect the gas to be tested;

The infrared filter is located on the top surface of the housing and corresponds to the thermopile sensor chip in a vertical position with a spacing therebetween.

Optionally, the number of the thermopile sensor chips ranges from 1 to 4.

Optionally, the number of the infrared filters is the same as the number of the thermopile sensor chips.

Optionally, the substrate includes a TO metal tube seat and a packaging substrate.

Optionally, when the substrate is a TO metal tube socket, the shell is a TO metal tube cap.

Optionally, when the base is a packaging substrate, the shell includes a packaging side wall and a packaging top plate.

Optionally, the thermopile infrared detector further includes pins electrically connected to each chip.

The present invention also provides a method for preparing a thermopile infrared detector, the method for preparing the thermopile infrared detector comprising:

S1: Provide substrate, TEC temperature control chip, thermopile sensor chip, ambient temperature sensor chip, infrared filter and housing;

S2: mounting the TEC temperature control chip on the substrate;

S3: Using the TEC temperature control chip as a substrate, mounting the thermopile sensor chip and the ambient temperature sensor chip on the TEC temperature control chip, and the thermopile sensor chip and the ambient temperature sensor chip are spaced apart from each other;

S4: bonding wires to the TEC temperature control chip, the thermopile sensor chip, and the ambient temperature sensor chip respectively;

S5: mounting the infrared filter on the top surface of the shell, and packaging the shell and the substrate to obtain a complete thermopile infrared detector.

Optionally, the method for preparing the thermopile infrared detector further includes: providing pins, and electrically connecting the pins respectively after wire bonding in step S4.

The present invention also provides a NDIR detection system, the NDIR detection system comprising:

Infrared light source, gas chamber, optical path, circuit and any one of the thermopile infrared detectors described above;

The infrared light source and the thermopile infrared detector are respectively located on opposite sides of the gas chamber and have a distance therebetween, and the distance is the optical path through which the infrared light emitted by the infrared light source passes; the gas chamber is used to place the gas to be measured;

The infrared light source and the thermopile infrared detector are connected to the circuit respectively.

As described above, the thermopile infrared detector and its preparation method and NDIR detection system of the present invention have the following beneficial effects:

The thermopile infrared detector of the present invention places the TEC temperature control chip below the thermopile infrared sensor chip and the ambient temperature sensor chip. When the ambient temperature rises, the TEC temperature control chip can be used to control the temperature, so that the ambient temperature of the thermopile sensor chip is always controlled at a constant temperature, so that the thermopile infrared sensor chip is not affected by the thermal shock when the external light source is turned on, so that the reference output of the thermopile infrared sensor is maintained at a constant value, the resolution of the thermopile infrared sensor is improved, and then the resolution of the gas to be tested is improved; the thermopile infrared detector of the present invention does not need to use the same packaging form as the traditional thermopile infrared detector to resist thermal shock because it integrates the TEC temperature control chip, and the freedom of substrate and shape design is greater, which can not only be more miniaturized, but also reduce the packaging cost; the size of the thermopile infrared detector of the present invention can be consistent with the size of the thermopile infrared detector in the existing NDIR detection system, so as to achieve compatible application and reduce the replacement cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the structure of a conventional thermopile infrared detector.

FIG. 2 is a schematic diagram showing the structure of a thermopile infrared detector according to a first embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a second embodiment of a thermopile infrared detector according to the present invention.

FIG. 4 is a schematic structural diagram of a third embodiment of the thermopile infrared detector of the present invention.

FIG. 5 is a schematic flow chart showing a method for preparing a thermopile infrared detector according to the present invention.

FIG. 6 is a schematic diagram showing the structure of the NDIR detection system of the present invention.

Component number description

10, shell; 11, TO metal cap; 12, package side wall; 13, package top plate; 20, base; 21, TO metal Tube socket; 22, packaging substrate; 30, TEC temperature control chip; 40, ambient temperature sensor chip; 50, thermopile sensor chip; 60, infrared filter; 70, wire bonding; 80, pins; 90, infrared light source; 100, gas chamber; 110, optical path; 120, gas to be tested; 130, thermopile infrared detector.

DETAILED DESCRIPTION

The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional views showing the device structures will not be partially enlarged according to the general scale, and the schematic views are only examples, which should not limit the scope of protection of the present invention.

For ease of description, spatial relational terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one structure or feature shown in the drawings to other structures or features. It will be understood that these spatial relational terms are intended to include other directions of the device in use or operation in addition to the directions depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there may be one or more intervening layers. As used herein, "between..." means including the end point values.

In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

Please refer to Figures 1 to 6. It should be noted that the illustrations provided in this embodiment are only schematic illustrations of the basic concept of the present invention, and the illustrations only show components related to the present invention rather than the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

Embodiment 1

As shown in FIG. 2 , this embodiment provides a thermopile infrared detector 130 , and the thermopile infrared detector 130 includes:

Housing 10;

The base 20 is located below the housing 10 and forms a sealed cavity with the housing 10;

A semiconductor refrigerator (TEC) temperature control chip 30 is located above the substrate 20 in the cavity and is used to control the temperature of the thermopile infrared detector 130 to keep it in a constant temperature state;

An ambient temperature sensor chip 40 , located above the TEC temperature control chip 30 in the cavity, for monitoring the temperature of the thermopile infrared detector 130 ;

The thermopile sensor chip 50 is located above the TEC temperature control chip 30 in the cavity and is spaced apart from the ambient temperature sensor chip 40 , and is used to detect the gas to be tested;

The infrared filter 60 is located on the top surface of the housing 10 , vertically corresponding to the thermopile sensor chip 50 , and has a spacing therebetween.

The thermopile infrared detector 130 of the present embodiment places the TEC temperature control chip 30 below the thermopile infrared sensor chip 50 and the ambient temperature sensor chip 40. When the ambient temperature rises, the ambient temperature sensor chip 40 detects that the temperature exceeds the specified temperature range, and the TEC temperature control chip 30 can be used to control the temperature, so that the ambient temperature of the thermopile sensor chip 50 is always controlled at a constant temperature, so that the thermopile infrared sensor chip 50 is not affected by the thermal shock when the external light source is turned on, so that the reference output of the thermopile infrared sensor 130 is maintained at a constant value, the resolution of the thermopile infrared sensor 130 is improved, and then the resolution of the gas to be tested is improved; the thermopile infrared detector 130 of the present embodiment does not need to use the same packaging form as the traditional thermopile infrared detector to resist thermal shock because the TEC temperature control chip 30 is integrated, and the substrate 20 and the shape design have greater freedom, which can not only be more miniaturized, but also reduce the packaging cost.

As shown in FIG. 2 , as an example, the substrate 20 is a TO metal tube seat 21 , and the shell 10 is a TO metal tube cap 11 .

The combination of the TO metal tube seat 21 and the TO metal tube cap 11 is a common combination in the prior art (as shown in FIG. 1 ), which has the characteristics of thermal stability, airtightness and reliability, and is used to resist the thermal shock brought by the outside of the thermopile infrared detector 130. This packaging structure can also be used in the present embodiment. On the basis of not changing the original thermopile infrared detector, the thermopile infrared detector 130 can be cooled and controlled by simply adding the TEC temperature control chip 30, so that the ambient temperature of the thermopile sensor chip 50 is always controlled in a constant temperature state. The TO metal tube socket 21 and the TO metal tube cap 11 are made of iron-nickel-plated material. Of course, in other examples, the TO metal tube socket 21 and the TO metal tube cap 11 can also be made of other metal materials such as copper, aluminum and copper alloy, but the use of iron-nickel-plated material not only has better anti-corrosion and oxidation effects, but also can effectively reduce the surface reflection of the TO metal tube cap 11 and reduce detection interference. The use of the TO metal tube cap 11 made of iron-nickel-plated material not only helps to improve detection accuracy, but also helps to make the thermopile infrared detector 130 suitable for more application scenarios.

As an example, the thermopile infrared detector 130 further includes pins 80 electrically connected to each chip.

The TEC temperature control chip 30, the ambient temperature sensor chip 40 and the thermopile sensor chip 50 are electrically connected to the pins 80 through the bonding wires 70. In the packaging structure of this embodiment, the pins 80 need to be protruded from the The lower surface of the substrate 20 is controlled by an external control chip, or sends electrical signals to other external device structures. It should be noted that, according to the actual packaging requirements of the thermopile sensor, the pin 80 may include any number of pins 80, and the distribution of the pins 80 may be any one of a single-row distribution, a double-row distribution, and a circular distribution, which may be set according to actual needs and is not limited here. In addition, under normal circumstances, the substrate 20 itself will also be connected to a pin 80 for conducting static electricity to avoid damaging the chip in the cavity of the thermopile infrared detector 130.

Embodiment 2

As shown in FIG. 3 , this embodiment provides a multi-channel thermopile infrared detector. The multi-channel thermopile infrared detector is different from the first embodiment in that a plurality of thermopile sensor chips 50 are provided.

As an example, the number of the thermopile sensor chips 50 ranges from 1 to 4.

The arrangement of multiple thermopile sensor chips 50 can prepare multiple gas detection channels to be tested. Multiple thermopile sensor chips 50 are arranged at intervals above the TEC temperature control chip 30, which is suitable for more application scenarios. The thermopile infrared detector 130 can be used as a comprehensive detector to detect the gas to be tested. In this embodiment, the number of the thermopile sensor chips 50 is 2, which is used to detect two gases. Because the space in the cavity is limited, the number range of the thermopile sensor chips 50 is also limited. The specific number can be set according to actual needs and is not limited here.

As an example, the number of the infrared filters 60 is the same as the number of the thermopile sensor chips 50 .

The infrared filter 60 and the thermopile sensor chip 50 cooperate with each other, correspond to each other in vertical position, and are provided with a spacing. In this embodiment, the number of the thermopile sensor chips 50 is 2, and the number of the infrared filter 60 is also 2. The infrared filter 60 preferably adopts a silicon infrared filter, which filters out stray light in the external environment and only allows thermal radiation waves of the expected wavelength to irradiate the thermopile sensor chip 50, which is conducive to ensuring that the dispersed infrared light within the detection range can be received in a concentrated manner, which helps to improve the gas detection accuracy. Of course, the selection of the specific material of the infrared filter 60 can also be selected according to actual needs, and there is no limitation here.

Embodiment 3

As shown in FIG. 4 , this embodiment provides a thermopile infrared detector 130 . The difference between the thermopile infrared detector 130 and the first embodiment is that the packaging structure is different.

As an example, the base 20 is a packaging substrate 22 , and the housing 10 includes a packaging side wall 12 and a packaging top plate 13 .

In this embodiment, the thermopile infrared detector 110 does not need to use the same packaging form as the traditional thermopile infrared detector to resist thermal shock because it integrates the TEC temperature control chip 30. The packaging substrate 22 and the shape design have greater freedom, which can not only be more miniaturized, but also reduce the packaging cost. The infrared filter 60 is mounted on the packaging top plate 13. In this embodiment, there is only one thermopile sensor chip 50, corresponding to one infrared filter 60. When there is only one infrared filter 60, a piece of infrared filter 60 can also be directly mounted on the packaging side wall 12. It should be noted here that, in the packaging structure of this embodiment, the pins 80 are flush with the lower surface of the packaging substrate 22 and can be directly used as solder joints.

Of course, the present embodiment can also integrate a plurality of the TEC temperature control chips 30 to form a multi-channel thermopile infrared detector to detect a variety of gases to be tested, with a wider range of applications. When a plurality of the TEC temperature control chips 30 are integrated, a corresponding number of the infrared filters 60 must also be set and mounted on the corresponding positions of the package top plate 13.

In this embodiment, the substrate 20 and the housing 10 can be made of any suitable material as long as the material can play a supporting role and have an infrared light filtering effect. As an example, the substrate 20 and the housing 10 can be made of silicon or germanium. In this embodiment, silicon is preferably used.

Embodiment 4

As shown in FIG5 , this embodiment provides a method for preparing a thermopile infrared detector, which is used to prepare the thermopile infrared detector described in any one of Embodiment 1 and Embodiment 3. The method for preparing the thermopile infrared detector includes:

First, step S1 is performed to provide a substrate 20 , a TEC temperature control chip 30 , a thermopile sensor chip 50 , an ambient temperature sensor chip 40 , an infrared filter 60 and a housing 10 .

Corresponding device components can be provided according to the actual packaging structure or practical application of the thermopile infrared detector 130 , and no limitation is made here as long as the functions and materials can meet the requirements.

Then, step S2 is performed to mount the TEC temperature control chip 30 on the substrate 20; and step S3 is performed to mount the thermopile sensor chip 50 and the ambient temperature sensor chip 40 on the TEC temperature control chip 30 using the TEC temperature control chip 30 as a substrate, and the thermopile sensor chip 50 and the ambient temperature sensor chip 40 are spaced apart from each other.

As an example, the mounting in step S2 and step S3 may both adopt surface mounting technology (Surface Mounted Technology, SMT).

The surface mounting process has the advantages of high precision, light weight, and small area, and can meet the requirements of miniaturization of the thermopile infrared detector 130. Of course, the mounting in step S2 and step S3 includes but is not limited to the surface mounting process, and can also be set according to actual needs, which is not limited here.

Then, step S4 is performed to bond wires 70 to the TEC temperature control chip 30 , the thermopile sensor chip 50 , and the ambient temperature sensor chip 40 .

As an example, the method for preparing the thermopile infrared detector 130 further includes: providing pins 80 , and electrically connecting the pins 80 respectively after bonding the wires 70 in step S4 .

The pins 80 may be specifically arranged according to different packaging structures.

Finally, step S5 is performed to mount the infrared filter 60 on the top surface of the housing 10 , and package the housing 10 and the substrate 20 to obtain a complete thermopile infrared detector 130 .

The infrared filter 60 can be attached to the inner surface of the top surface of the housing 10 by means of epoxy resin with high thermal conductivity, thereby preventing water vapor from entering the cavity inside the thermopile infrared detector 130 while fixing the infrared filter 60 .

Embodiment 5

As shown in FIG6 , this embodiment provides an NDIR detection system, which includes: an infrared light source 90, an air chamber 100, an optical path 110, a circuit, and a thermopile infrared detector 130 described in any one of Embodiments 1 to 3; the infrared light source 90 and the thermopile infrared detector 130 are respectively located on opposite sides of the air chamber 100 and have a spacing, and the spacing is the optical path 110 through which the infrared light emitted by the infrared light source 90 passes; the air chamber 100 is used to place a gas to be measured 120; the infrared light source 90 and the thermopile infrared detector 130 are respectively connected to the circuit.

The working principle of the NDIR detection system is as follows: during the use of the NDIR detection system, the infrared light source 90 radiates infrared light, and the infrared light passes through the gas to be measured 120 along the optical path 110, passes through the infrared filter 60 on the thermopile infrared detector 130, and reaches the thermopile infrared detector 130. The concentration of the gas to be measured 120 is determined by measuring the intensity of the infrared light entering the thermopile infrared detector 130. When there is no gas to be measured 120 in the external environment, the intensity of the infrared light is the strongest. When the gas to be measured 120 enters the gas chamber 100, the gas to be measured 120 absorbs a part of the infrared light, so that the light intensity reaching the thermopile infrared detector 130 is weakened. By calibrating the degree and calibration of infrared light absorption at the zero point and the measuring point, the NDIR detection system can calculate the concentration of the gas to be measured 120.

In summary, the present invention provides a thermopile infrared detector, a preparation method thereof and an NDIR detection system, wherein the thermopile infrared detector comprises: a shell; a substrate, which is located below the shell and forms a sealed cavity with the shell; a TEC temperature control chip, which is located above the substrate in the cavity and is used to control the temperature of the thermopile infrared detector so that it is in a constant temperature state; an ambient temperature sensor chip, which is located above the TEC temperature control chip in the cavity and is used to monitor the temperature of the thermopile infrared detector; a thermopile sensor chip, which is located above the TEC temperature control chip in the cavity and is spaced from the ambient temperature sensor chip and is used to detect a gas to be measured; and an infrared filter, which is located on the top surface of the shell and corresponds to the thermopile sensor chip in a vertical position and has a spacing therebetween. The thermopile infrared detector of the present invention places the TEC temperature control chip below the thermopile infrared sensor chip and the ambient temperature sensor chip. When the ambient temperature rises, the TEC temperature control chip can be used to control the temperature, so that the ambient temperature of the thermopile sensor chip is always controlled at a constant temperature, so that the thermopile infrared sensor chip is not affected by the thermal shock when the external light source is turned on, so that the reference output of the thermopile infrared sensor is maintained at a constant value, the resolution of the thermopile infrared sensor is improved, and then the resolution of the gas to be tested is improved; the thermopile infrared detector of the present invention, because the TEC temperature control chip is integrated, does not need to use the same packaging form as the traditional thermopile infrared detector to resist thermal shock, and the freedom of substrate and shape design is greater, which can not only be more miniaturized, but also reduce the packaging cost; The size of the thermopile infrared detector can be consistent with that of the thermopile infrared detector in the existing NDIR detection system, achieving compatible application and reducing replacement cost. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

A thermopile infrared detector, characterized in that the thermopile infrared detector comprises:

case;

A base, located below the shell and forming a sealed cavity with the shell;

A TEC temperature control chip, located above the substrate in the cavity, for controlling the temperature of the thermopile infrared detector to keep it in a constant temperature state;

An ambient temperature sensor chip, located above the TEC temperature control chip in the cavity, for monitoring the temperature of the thermopile infrared detector;

A thermopile sensor chip, located above the TEC temperature control chip in the cavity and spaced apart from the ambient temperature sensor chip, for detecting the gas to be tested;

The infrared filter is located on the top surface of the housing, corresponds to the thermopile sensor chip in a vertical position, and has a spacing therebetween.
The thermopile infrared detector according to claim 1 is characterized in that the number of the thermopile sensor chips ranges from 1 to 4.
The thermopile infrared detector according to claim 2 is characterized in that the number of the infrared filters is the same as the number of the thermopile sensor chips.
The thermopile infrared detector according to claim 1 is characterized in that the substrate comprises a TO metal tube holder and a packaging substrate.
The thermopile infrared detector according to claim 4 is characterized in that when the substrate is a TO metal tube socket, the shell is a TO metal tube cap.
The thermopile infrared detector according to claim 4, characterized in that: when the base is a packaging substrate, the shell includes a packaging side wall and a packaging top plate.
The thermopile infrared detector according to claim 1 is characterized in that: the thermopile infrared detector also includes pins electrically connected to each chip.
A method for preparing a thermopile infrared detector, characterized in that the method for preparing the thermopile infrared detector comprises:

S1: Provide substrate, TEC temperature control chip, thermopile sensor chip, ambient temperature sensor chip, infrared filter and housing;

S2: mounting the TEC temperature control chip on the substrate;

S3: Using the TEC temperature control chip as a substrate, mounting the thermopile sensor chip and the ambient temperature sensor chip on the TEC temperature control chip, and the thermopile sensor chip and the ambient temperature sensor chip are spaced apart from each other;

S4: bonding wires to the TEC temperature control chip, the thermopile sensor chip, and the ambient temperature sensor chip respectively;

S5: mounting the infrared filter on the top surface of the shell, and packaging the shell and the substrate to obtain a complete thermopile infrared detector.
The method for preparing a thermopile infrared detector according to claim 8 is characterized in that the method for preparing the thermopile infrared detector further comprises: providing pins, and electrically connecting the pins respectively after wire bonding in step S4.
An NDIR detection system, characterized in that the NDIR detection system comprises:

An infrared light source, an air chamber, an optical path, a circuit, and a thermopile infrared detector as claimed in any one of claims 1 to 7;

The infrared light source and the thermopile infrared detector are respectively located on opposite sides of the gas chamber and have a distance therebetween, and the distance is the optical path through which the infrared light emitted by the infrared light source passes; the gas chamber is used to place the gas to be tested;

The infrared light source and the thermopile infrared detector are connected to the circuit respectively.