Digital thermopile temperature sensor

Abstract

The utility model discloses a digital thermopile temperature sensor. The substrate at least comprises a substrate; the heating resistor and the signal conditioning circuit chip are embedded in the substrate; the thermopile infrared sensing chip is arranged on the upper surface of the substrate; the thermopile infrared sensing chip has a thermal shock resistance function; a cap; an infrared filter is externally packaged at the upper part of the cover cap; the cover cap and the substrate form an accommodating space; and the thermopile infrared sensing chip is positioned in the accommodating space. According to the utility model, the sensor works at a stable temperature through the heating of the embedded heating resistor, and the embedded signal conditioning circuit chip can monitor the temperature of the ceramic substrate in real time and condition an analog voltage signal output by the thermopile infrared sensing chip into a digital temperature signal. And an external circuit is not required to process the signal, so that the anti-electromagnetic interference capability is improved. And the embedded structural design can effectively reduce the overall size of the sensor, and can effectively expand the application range.

Description

Technical Field

[0001] The utility model relates to the technical field of temperature measurement, and more specifically to a digital thermopile temperature sensor. Background Art

[0002] As a key electronic device, temperature sensors are widely used in many fields such as industry, medical treatment, automobiles, home appliances, and environmental protection. In the industrial field, temperature sensors can be used to monitor temperature changes in the production process to ensure the stability of the process and the controllability of product quality. In the medical field, temperature sensors play a role in medical equipment such as thermometers and ventilators, providing doctors with patient temperature data support. In the field of automotive electronics, temperature sensors play a key role in engine control, battery management systems, etc., improving vehicle performance and fuel efficiency. In addition, temperature sensors occupy an important position in home appliances, Internet of Things devices, environmental monitoring, and scientific research.

[0003] Thermal shock refers to a situation where the temperature changes rapidly, usually due to instantaneous heating or cooling. This sudden temperature change will affect the output temperature stability of the sensor, causing its measured temperature to change and unable to achieve accurate temperature measurement. Therefore, high-precision temperature sensors need to have the ability to resist thermal shock to ensure accurate temperature measurement. At present, after being subjected to thermal shock, traditional infrared temperature sensors need a certain amount of time to return to normal working state, which will cause uneven temperature distribution inside the sensor and reduce the temperature measurement accuracy of the sensor. In addition, traditional infrared temperature sensors are usually analog output sensors, which use external circuit boards to achieve signal conditioning and temperature calibration, making the overall volume larger and not resistant to electromagnetic interference; or they are TO-packaged (thermopile infrared sensor chip and signal conditioning chip are packaged in a TO tube shell) digital infrared temperature sensors without preheating function, which cannot achieve stable control of ambient temperature.

[0004] Therefore, how to provide a digital thermopile temperature sensor that can resist thermal shock has become an urgent problem to be solved. Utility Model Content

[0005] The utility model provides a digital thermopile temperature sensor. It is used to solve the problem that the conventional infrared temperature sensor in the prior art cannot achieve stable control of the ambient temperature and is not resistant to electromagnetic interference after being subjected to thermal shock. The preferred technical solution among the many technical solutions provided by the utility model can produce many technical effects as described below.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] The utility model provides a digital thermopile temperature sensor, which at least comprises:

[0008] substrate;

[0009] A heating resistor and a signal conditioning circuit chip embedded in the substrate;

[0010] A thermopile infrared sensor chip is arranged on the upper surface of the substrate; the thermopile infrared sensor chip has a thermal shock resistance function;

[0011] A cap; an infrared filter is externally packaged on the upper part of the cap; the cap and the substrate form a receiving space; the thermopile infrared sensor chip is located in the receiving space.

[0012] Optionally, the heating resistor is embedded in the middle of the substrate or on the back of the substrate; the heating resistor is used to heat the digital thermopile temperature sensor so that the digital thermopile temperature sensor works at a stable temperature;

[0013] The signal conditioning circuit chip is embedded in the front side of the substrate or the back side of the substrate.

[0014] Optionally, the signal conditioning circuit chip is embedded in the front cavity of the substrate, and the upper surface of the signal conditioning circuit chip is flush with the surface of the substrate;

[0015] Optionally, the signal conditioning circuit chip is embedded in the back cavity of the substrate; the back cavity has a solder joint, the solder joint is connected to the signal conditioning circuit chip by flip-chip connection, and the solder joint is led to the front and back sides of the substrate through embedded wiring and through holes inside the substrate to realize signal transmission.

[0016] Optionally, the thermopile infrared sensor chip includes a supporting frame, a thermal insulation film, a thermopile structure and a metal reflective layer;

[0017] The thermopile structures on the left and right of the thermopile infrared sensor chip are centrally symmetrical. The cold end and the hot end of the thermopile infrared sensor chip are both located inside the thermal insulation film. The cold end is covered with a metal reflective layer. The cold end and the hot end of the thermopile infrared sensor chip change temperature synchronously.

[0018] Optionally, the signal conditioning circuit chip is connected to the thermopile infrared sensor chip, and the signal conditioning circuit chip is used to monitor the temperature of the substrate in real time and condition the analog voltage signal output by the thermopile infrared sensor chip into a digital temperature signal.

[0019] Optionally, the digital thermopile temperature sensor further includes:

[0020] A signal lead-out pad disposed on the back side of the substrate;

[0021] The flexible circuit board is led out from the signal lead-out pad, the outer layer of the flexible circuit board is wrapped with a metal mesh and grounded to shield electromagnetic interference, the cap and the substrate are hermetically sealed by conductive adhesive, and the metal mesh and the cap wrapped on the outer layer of the flexible circuit board are grounded through the substrate.

[0022] Optionally, the infrared filter is adhered to the upper part of the cap by packaging glue, and the infrared filter is used to make the internal cap reflect the measurement error introduced by the self-heating of the top of the digital thermopile temperature sensor.

[0023] Optionally, the substrate is a ceramic substrate, and the cap is a metal cap.

[0024] Compared with the prior art, in the technical solution provided by the utility model, the digital thermopile temperature sensor at least includes: a substrate; a heating resistor and a signal conditioning circuit chip embedded in the substrate; a thermopile infrared sensor chip arranged on the upper surface of the substrate; the thermopile infrared sensor chip has a heat shock resistance function; a cap; an infrared filter is externally packaged on the upper part of the cap; the cap and the substrate form a storage space; the thermopile infrared sensor chip is located in the storage space. The utility model allows the sensor to work at a stable temperature through the heating of the embedded heating resistor. At the same time, the embedded signal conditioning circuit chip can monitor the temperature of the ceramic substrate in real time, and condition the analog voltage signal output by the thermopile infrared sensor chip into a digital temperature signal without the need for an external circuit to process the signal, thereby avoiding electromagnetic interference when the external conditioning circuit board processes the analog signal and improving the anti-electromagnetic interference capability. In addition, the embedded structural design can effectively reduce the overall size of the sensor and effectively expand the scope of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A cross-sectional schematic diagram of a digital thermopile temperature sensor provided by the utility model;

[0027] FIG2( a ) is a front view of the structure of the thermopile infrared sensor chip provided by the present invention;

[0028] FIG2( b ) is a cross-sectional view of the structure of the thermopile infrared sensor chip provided by the present invention;

[0029] FIG3( a ) is a front view of a ceramic substrate corresponding to a first embedding method of a signal conditioning circuit chip provided by the present invention;

[0030] FIG3( b ) is a cross-sectional view of a ceramic substrate corresponding to the first embedding method of the signal conditioning circuit chip provided by the present invention;

[0031] FIG4( a ) is a front view of a ceramic substrate corresponding to the second embedding method of the signal conditioning circuit chip provided by the present invention;

[0032] FIG4( b ) is a cross-sectional view of a ceramic substrate corresponding to the second signal conditioning circuit chip embedding method provided by the present invention.

[0033] Reference numerals:

[0034] 1-substrate, 2-heating resistor, 3-signal conditioning circuit chip, 4-thermopile infrared sensor chip, 5-cap, 6-infrared filter, 7-signal lead pad, 8-support frame, 9-insulating film, 10-thermopile structure, 11-metal reflective layer, 12-through hole, 13-soldering point. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the utility model.

[0036] In the prior art, traditional infrared temperature sensors have the following defects:

[0037] 1) After being subjected to thermal shock, traditional infrared temperature sensors need a certain amount of time to recover to normal working state, which will cause uneven temperature distribution inside the sensor and reduce the temperature measurement accuracy of the sensor.

[0038] 2) Traditional infrared temperature sensors are usually analog output sensors that use external circuit boards to implement signal conditioning and temperature calibration, making the overall size larger and not resistant to electromagnetic interference.

[0039] In order to overcome the above-mentioned defects, the utility model provides a digital thermopile temperature sensor. The following is an explanation of the embodiments with reference to the accompanying drawings. In addition, the embodiments shown below do not limit the contents of the utility model described in the claims. In addition, the entire contents of the structures represented by the following embodiments are not limited to the solutions required for the utility model described in the claims.

[0040] Figure 1This is a cross-sectional schematic diagram of the digital thermopile temperature sensor provided by the utility model. Figure 1 As shown, the utility model provides a digital thermopile temperature sensor, the structure of which may include:

[0041] substrate1;

[0042] A heating resistor 2 and a signal conditioning circuit chip 3 embedded in the substrate 1;

[0043] A thermopile infrared sensor chip 4 is arranged on the upper surface of the substrate 1; the thermopile infrared sensor chip 4 has a thermal shock resistance function;

[0044] The cap 5 has an infrared filter 6 externally packaged on the upper part of the cap 5; the cap 5 and the substrate 1 form a receiving space; the thermopile infrared sensor chip 4 is located in the receiving space.

[0045] In the utility model, the substrate 1 can be a ceramic substrate, which can be a special process board in which copper foil is directly bonded to the surface (single or double sides) of an aluminum oxide (Al2O3) or aluminum nitride (AlN) ceramic substrate at high temperature. It has excellent electrical insulation performance, high thermal conductivity, and can be etched with various patterns like a PCB board, and has a large current carrying capacity.

[0046] The signal conditioning circuit chip 3 may be a microelectronic device integrating multiple functional modules, and is used to condition, process and enhance electronic signals.

[0047] The digital thermopile temperature sensor uses an infrared filter 6 (light window) to be externally pasted, such as Figure 1 As shown, it is glued to the top of the metal cap by encapsulating glue. The design of the external infrared filter 6 enables the internal metal cap structure to reflect the measurement error introduced by the self-heating of the sensor top. This makes the sensor stable and accurate, meeting the needs of different application scenarios.

[0048] The cap 5 can be a metal cap. The digital thermopile temperature sensor provided by the utility model can include a thermal shock resistant digital infrared temperature sensor chip 4, a ceramic substrate with an embedded heating resistor 2 and a signal conditioning circuit chip 3, a metal cap and an infrared filter 6, which are hermetically sealed.

[0049] The thermopile infrared sensor chip 4 may be a temperature sensor chip with a thermal shock resistance function.

[0050] After the traditional infrared temperature sensor is subjected to thermal shock, it takes a certain amount of time to recover to the normal working state, which will cause the uneven temperature distribution inside the sensor, resulting in a decrease in the temperature measurement accuracy of the sensor. Or the TO package (thermopile chip and signal conditioning chip are packaged in the TO tube shell) digital infrared temperature sensor without preheating function cannot achieve stable control of the ambient temperature. Therefore, this solution embeds the heating resistor 2 and the signal conditioning circuit chip 3 in the substrate 1. When working, power is applied to the heating resistor 2 embedded in the ceramic substrate of the sensor, and the temperature sensor in the conditioning chip embedded in the ceramic substrate is used to monitor the ambient temperature in real time, so that the ambient temperature of the sensor remains stable at a constant temperature, thereby eliminating part of the influence of thermal shock.

[0051] In addition to the above structure, Figure 1 In the present invention, the digital thermopile temperature sensor may further include:

[0052] A signal lead pad 7 is arranged on the back side of the ceramic substrate;

[0053] The flexible circuit board is led out from the signal lead-out pad 7 , and the outer layer of the flexible circuit board is wrapped with a metal wire mesh and grounded to shield electromagnetic interference.

[0054] The metal cap and the ceramic are hermetically packaged by conductive adhesive, and the metal wire mesh wrapped on the outer layer of the flexible circuit board and the metal cap are grounded together by the ceramic substrate.

[0055] Flexible circuit board is a kind of printed circuit board with high reliability and excellent flexibility made of polyimide or polyester film as the base material. It is also called soft board or FPC for short, and has the characteristics of high wiring density, light weight and thin thickness.

[0056] FPC can be bent back and forth due to its flexibility, and the interface has a large degree of freedom. The inner layer of FPC is designed with metal leads, and the outer layer is wrapped with metal wire mesh and grounded to shield electromagnetic interference.

[0057] Figure 1The digital thermopile temperature sensor in the invention may at least include: a substrate 1; a heating resistor 2 and a signal conditioning circuit chip 3 embedded in the substrate 1; a thermopile infrared sensor chip 4 disposed on the upper surface of the substrate 1; the thermopile infrared sensor chip 4 has a heat shock resistance function; a cap 5; an infrared filter 6 is externally packaged on the upper part of the cap 5; the cap 5 and the substrate 1 form a storage space; the thermopile infrared sensor chip 4 is located in the storage space. The utility model allows the sensor to work at a stable temperature through the heating of the embedded heating resistor. At the same time, the embedded signal conditioning circuit chip 3 can monitor the temperature of the ceramic substrate in real time, and condition the analog voltage signal output by the thermopile infrared sensor chip 4 into a digital temperature signal without the need for an external circuit to process the signal, thereby avoiding electromagnetic interference when the external conditioning circuit board processes the analog signal and improving the anti-electromagnetic interference capability. In addition, the embedded structural design can effectively reduce the overall size of the sensor and effectively expand the scope of application. Moreover, the above structural designs can reduce the problem of temperature measurement signal changes caused by sudden changes in ambient temperature, improve the ability to resist thermal shock, and condition the analog signal into a digital temperature signal output that is resistant to electromagnetic interference, thereby eliminating the need for additional signal processing circuits and greatly reducing the volume.

[0058] Next, we can further Figure 1 The various structures in are described in detail:

[0059] Optionally, the signal conditioning circuit chip 3 is connected to the thermopile infrared sensor chip, and the signal conditioning circuit chip 3 is used to monitor the temperature of the substrate 1 in real time and condition the analog voltage signal output by the thermopile infrared sensor chip 4 into a digital temperature signal.

[0060] The analog signal output by the thermopile infrared sensor chip 4 is connected to the signal conditioning circuit chip 3 embedded in the ceramic substrate, and the conditioning algorithm is used to realize the conditioning and calibration of the thermopile chip analog signal to the digital temperature signal.

[0061] As an optional implementation, the structure of the thermopile infrared sensor chip 4 can be described in conjunction with FIG. 2(a) and FIG. 2(b):

[0062] Figure 2(a) is a front view of the thermopile infrared sensor chip structure provided by the present invention; Figure 2(b) is a cross-sectional view of the thermopile infrared sensor chip structure provided by the present invention; as shown in Figures 2(a) and 2(b), the thermopile infrared sensor chip 4 may include a supporting frame 8, an insulating film 9, a thermopile structure 10 and a metal reflective layer 11.

[0063] The thermopile structures 10 on the left and right of the thermopile infrared sensor chip 4 are centrally symmetrical. The cold end and the hot end of the thermopile infrared sensor chip 4 are both located inside the thermal insulation film 9. The cold end covers the metal reflective layer 11. The cold end and hot end temperatures of the thermopile infrared sensor chip 4 change synchronously.

[0064] In the structures shown in FIG2(a) and FIG2(b), the thermopile structure inside the thermal insulation film 9 in the thermopile infrared sensor chip 4 adopts a centrally symmetrical design, the cold end is covered with a metal reflective layer 11, and both the hot and cold ends are located on the thermal insulation film. This design enables the chip to have the characteristics of both thermal shock resistance and stable output. The digital thermopile temperature sensor can work stably in an environment with sudden temperature changes and has better thermal shock resistance.

[0065] At the same time, when working, by applying power to the heating resistor 2 embedded in the ceramic substrate of the digital thermopile temperature sensor, the temperature sensor in the conditioning chip embedded in the ceramic substrate monitors the ambient temperature in real time, so that the ambient temperature of the sensor is kept stable at a constant temperature, thereby eliminating the influence of some thermal shocks. Its working principle is: the infrared radiation of the object to be measured is irradiated to the thermopile infrared sensor chip 4 through the light window, and is absorbed by the chip to generate temperature rise, which causes the output voltage of the thermopile infrared sensor chip 4 to change, and the conditioning chip collects the voltage, and realizes the conditioning conversion of the analog voltage signal to the digital temperature signal through the conditioning algorithm, thereby testing the precise temperature of the object to be measured.

[0066] In the above structure, combined with the advantages of the chip, the cold end and the hot end of the thermopile infrared sensor chip can be set to be located inside the thermal insulation film 9, a certain distance from the frame. This design allows the cold end and the hot end temperatures to change synchronously at the same time when there is a sudden change in ambient temperature (such as the moment of inserting the ear), so the temperature difference between the cold and hot ends remains unchanged, and the output voltage of the thermopile remains unchanged, which can achieve resistance to thermal shock. The thermopile infrared sensor chip uses a central symmetrical design of the left and right thermal pile structures, which can make the output voltage of the left and right thermal piles differential. When there is a thermal shock, the left and right thermal piles are differential, so that the output is 0, achieving resistance to thermal shock. By combining the thermal shock-resistant thermopile infrared sensor chip 4, the new temperature sensor can achieve better results in thermal shock resistance, which significantly improves the measurement stability of the sensor.

[0067] Furthermore, the heating resistor 2 can be embedded in the middle of the substrate 1 or on the back of the substrate 1; the heating resistor 2 is used to heat the digital thermopile temperature sensor so that the digital thermopile temperature sensor works at a stable temperature. Preferably, the heating resistor 2 can be embedded in the middle of the ceramic using the LTCC process. The material of the heating resistor 2 can preferably be metals such as TiCu, Au, WNi or their alloys.

[0068] As for the embedding method of the signal conditioning circuit chip 3, the signal conditioning circuit chip 3 can be embedded in the front side of the substrate 1 or the back side of the substrate 1. Figure 3(a)-Figure 4(b) To explain:

[0069] FIG3(a) is a front view of a ceramic substrate corresponding to the first embedded mode of a signal conditioning circuit chip provided by the present invention; FIG3(b) is a cross-sectional view of a ceramic substrate corresponding to the first embedded mode of a signal conditioning circuit chip provided by the present invention; FIG4(a) is a front view of a ceramic substrate corresponding to the second embedded mode of a signal conditioning circuit chip provided by the present invention; FIG4(b) is a cross-sectional view of a ceramic substrate corresponding to the second embedded mode of a signal conditioning circuit chip provided by the present invention, Figure 3(a)-Figure 4(b) Next, two embedded methods of the signal conditioning circuit chip 3 are described:

[0070] Embedding method 1: the signal conditioning circuit chip 3 is embedded in the front cavity of the substrate 1 .

[0071] As shown in Figure 3(a) and Figure 3(b), the signal conditioning circuit chip 3 can be embedded in the front or back of the ceramic substrate. When embedded in the front of the ceramic substrate, specifically, a cavity is dug in the front of the ceramic substrate, and the signal conditioning circuit chip 3 is buried in the ceramic cavity, so that the upper surface of the chip is flush with the ceramic surface, and the pad of the circuit chip faces the surface side, so as to achieve wire connection with the thermopile infrared sensor chip.

[0072] Embedding method 2: the signal conditioning circuit chip 3 is embedded in the back cavity of the substrate 1 .

[0073] As shown in Figures 4(a) and 4(b), when embedded in the back of the ceramic substrate, a cavity is dug on the back of the ceramic substrate, and a corresponding solder joint 13 is made in the cavity. The solder joint 13 is connected to the signal conditioning circuit chip 3 through a flip-chip connection. The solder joint 13 is led to the front and back sides of the ceramic through the embedded wiring and through-hole 12 inside the ceramic to realize signal transmission.

[0074] Through the above two embedding methods, the analog signal output by the thermopile is conditioned into a precise digital temperature signal and then output through the signal conditioning circuit chip 3 embedded in the ceramic substrate, so that no external conditioning and calibration is required, and the digital output effectively improves the anti-electromagnetic interference capability.

[0075] The digital infrared thermopile temperature sensor provided by this scheme contains a heat shock resistant thermopile temperature sensor chip, which is hermetically sealed by a ceramic substrate with an embedded heating resistor 2 and a signal conditioning circuit chip 3, a metal cap and an infrared filter 6, and finally led out through a flexible circuit board. The embedded structural design allows the sensor volume to be further reduced, expanding its application range. Its working principle is: by applying power to the heating resistor 2 embedded in the ceramic substrate of the sensor, the temperature sensor in the embedded signal conditioning circuit chip 3 is used to monitor the internal temperature of the infrared sensor cavity in real time, so that the sensor ambient temperature is kept stable at a constant temperature, thereby reducing the measurement error introduced by the change of ambient temperature. The infrared radiation of the object to be measured is irradiated onto the thermopile infrared sensor chip 4 through the light window, and is absorbed by the chip to generate a temperature rise. The temperature rise causes the output voltage of the thermopile infrared sensor chip 4 to change. The voltage is conditioned and calibrated by the embedded conditioning circuit, and the digital temperature signal output is converted based on the calibration algorithm. The thermal pile structure inside the thermal insulation film 9 in the thermal shock resistant thermopile temperature sensor chip adopts a central symmetrical design, the cold end is covered with a metal reflective layer 11, and both the hot and cold ends are located on the insulation film, so that the chip has the characteristics of both thermal shock resistance and stable output. The sensor can work stably in an environment with sudden temperature changes and has better thermal shock resistance. The temperature signal conditioning and calibration of the target object has been realized in the sensor, and the output is a digital signal, which has the advantages of strong anti-electromagnetic interference ability, high measurement accuracy, and strong stability.

[0076] Furthermore, for the digital thermopile temperature sensor proposed in the present invention, the corresponding beneficial effects may include:

[0077] 1) Good thermal shock resistance. Through the innovative design of the ceramic substrate temperature control packaging structure and the special symmetrical thermal shock resistant thermopile infrared sensor chip 4, the thermal shock resistant temperature sensor can be protected from the influence of sudden temperature changes (such as the process of inserting into the ear canal from room temperature), thus improving the accuracy of temperature measurement. It eliminates the influence of thermal shock on the sensor and provides more accurate and reliable temperature measurement results.

[0078] 2) Digital output, strong anti-electromagnetic interference capability. The analog signal output by the thermopile is conditioned into a precise digital temperature signal and then output through the signal conditioning circuit chip 3 embedded in the ceramic substrate, so that no external conditioning and calibration is required, and the digital output effectively improves the anti-electromagnetic interference capability.

[0079] 3) Embedded design, small sensor size. By embedding the heating resistor 2 and the signal conditioning circuit chip 3 in the package ceramic substrate, there is no need to add an external board-level signal processing circuit, which greatly reduces the overall size of the sensor. The interface uses a flexible circuit board, which is convenient for free connection with the outside.

[0080] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0081] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Although the utility model is described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations can be made to it without departing from the spirit and scope of the utility model. Accordingly, this specification and the drawings are only exemplary illustrations of the utility model defined by the attached claims, and are deemed to have covered any and all modifications, changes, combinations or equivalents within the scope of the utility model. Obviously, those skilled in the art can make various changes and modifications to the utility model without departing from the spirit and scope of the utility model. In this way, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and their equivalent technologies, the utility model is also intended to include these changes and variations. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be covered within the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. A digital thermopile temperature sensor, characterized in that: At least: substrate; A heating resistor and a signal conditioning circuit chip embedded in the substrate; A thermopile infrared sensor chip is arranged on the upper surface of the substrate; the thermopile infrared sensor chip has a thermal shock resistance function; A cap; an infrared filter is externally packaged on the upper part of the cap; the cap and the substrate form a receiving space; the thermopile infrared sensor chip is located in the receiving space; the heating resistor is embedded in the middle of the substrate or on the back of the substrate; the heating resistor is used to heat the digital thermopile temperature sensor so that the digital thermopile temperature sensor works at a stable temperature; The signal conditioning circuit chip is embedded in the front side of the substrate or the back side of the substrate.

2. The digital thermopile temperature sensor according to claim 1, characterized in that: The signal conditioning circuit chip is embedded in the front cavity of the substrate, and the upper surface of the signal conditioning circuit chip is flush with the surface of the substrate.

3. The digital thermopile temperature sensor according to claim 1, characterized in that: The signal conditioning circuit chip is embedded in the back cavity of the substrate; the back cavity has solder joints, the solder joints are connected to the signal conditioning circuit chip by flip-chip connection, and the solder joints are led to the front and back sides of the substrate through embedded wiring and through holes inside the substrate to realize signal transmission.

4. The digital thermopile temperature sensor according to claim 1, characterized in that: The digital thermopile temperature sensor also includes: A signal lead-out pad disposed on the back side of the substrate; The flexible circuit board is led out from the signal lead-out pad, and the outer layer of the flexible circuit board is wrapped with a metal mesh and grounded to shield electromagnetic interference; the cap and the substrate are hermetically sealed by conductive adhesive, and the metal mesh and the cap wrapped on the outer layer of the flexible circuit board are grounded through the substrate.

5. The digital thermopile temperature sensor according to claim 1, characterized in that: The thermopile infrared sensor chip includes a support frame, a thermal insulation film, a thermopile structure and a metal reflective layer; The thermopile structures on the left and right of the thermopile infrared sensor chip are centrally symmetrical. The cold end and the hot end of the thermopile infrared sensor chip are both located inside the thermal insulation film. The cold end covers the metal reflective layer. The cold end and the hot end of the thermopile infrared sensor chip change temperature synchronously.

6. The digital thermopile temperature sensor according to claim 1, characterized in that: The signal conditioning circuit chip is connected to the thermopile infrared sensor chip. The signal conditioning circuit chip is used to monitor the temperature of the substrate in real time and condition the analog voltage signal output by the thermopile infrared sensor chip into a digital temperature signal.

7. The digital thermopile temperature sensor according to claim 1, characterized in that: The infrared filter is adhered to the upper part of the cap by packaging glue, and the infrared filter is used to make the internal cap reflect the measurement error introduced by the self-heating of the top of the digital thermopile temperature sensor.

8. The digital thermopile temperature sensor according to claim 1, characterized in that: The substrate is a ceramic substrate, and the cap is a metal cap.

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