Thermal shock resistant thermopile chip

Abstract

The invention belongs to the field of semiconductor chips, and discloses a thermal shock resistant thermopile chip, which comprises a hot end chip and a cold end chip, each of the hot end chip and the cold end chip comprises a chip substrate, the surface of each chip substrate is provided with a cavity structure and an insulating layer, and the area, opposite to the cavity structure, of each insulating layer is provided with a suspended beam film structure. The suspended film is connected with the insulating layer through a suspended beam, the insulating layer is provided with a plurality of thermocouple strips at intervals in the circumferential direction of the suspended film, the insulating layer is provided with a bonding layer on the periphery of an area defined by the thermocouple strips, and the cold end chip and the hot end chip are in sealed connection through the bonding layer; the hot end chip suspended film is provided with an infrared absorption layer; the thermocouple strips on the suspended thin films of the cold end chip and the hot end chip are alternately distributed in the circumferential direction of the suspended thin films in the thickness direction of the suspended thin films, and the thermocouple strips on the hot end chip and the cold end chip are connected in series, so that the hot end chip and the cold end chip form a thermopile chip; and the thermocouple strips on the suspended beam film adopt a form that the first type of thermocouple strips and the second type of thermocouple strips are alternately arranged.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor chips, and particularly relates to a thermopile chip with heat shock resistance. Background Art

[0002] A thermopile is a common non-cooled infrared sensitive structure, which has the advantages of low cost, large range, dynamic and static signal detection, and being inherently passive. It is widely used in non-contact temperature measurement fields such as industry, medical treatment, and smart home, such as medical thermometers and food temperature detection.

[0003] A thermopile is an array of thermocouples formed by connecting two materials with different Seebeck coefficients in series. Its working principle is that the carrier migration characteristics of different materials at the cold and hot ends are inconsistent, thus forming a voltage difference at both ends of the series connection, and then realizing the measurement of the infrared thermal radiation of an object. Therefore, a necessary condition for the normal operation of a thermopile chip is that the temperature difference between the cold and hot ends of the thermopile caused by the infrared radiation of the object to be measured is large enough to generate a strong enough thermoelectric potential difference, and achieve a high signal-to-noise ratio under the condition of a comparable noise level.

[0004] To increase the temperature difference between the cold and hot ends, the current mainstream solution is to use MEMS technology to hollow out the hot end to form a suspended film or bridge structure, inhibit the heat conduction from the hot end to the cold end, and localize the heat of the suspended hot end irradiated by light in the center; while the cold end is placed in a non-suspended area and kept at the same temperature after being bonded to the packaging case. However, in actual use scenarios, sudden changes in the ambient temperature (cold end temperature) often occur. For example, when an ear thermometer is inserted into the ear canal, or when a temperature measuring gun is placed in front of molten iron for temperature measurement. At this time, due to the inconsistent heat transfer efficiency between the cold and hot ends of the thermopile, an abnormal overshoot phenomenon will occur in the output signal of the sensor, which seriously affects the environmental adaptability, performance stability, and accuracy of the sensor.

[0005] In order to solve the problem of abnormal signal overshoot caused by thermal shock, it has been proposed to use active cold-end cooling (such as patent CN116124728A) to force the cold-end temperature to remain stable, thereby improving measurement stability. However, this increases the complexity of the sensor system, which in turn increases the cost and reduces system reliability. There are back-end compensation methods through algorithms, but this method requires a single sensor to be adapted and calibrated for specific scenarios, which is costly and has poor applicability to migration to different application scenarios. There are also methods that arrange two thermopile chips, shield one of them for infrared signals, and then use voltage differential to improve thermal shock stability (such as patent CN 214667293 U), but this sensor is large in size, which is not conducive to application in high-resolution infrared array imaging equipment and small portable smart devices (such as smart phones, smart glasses, etc.). Improving the chip structure is the most direct and effective method. Currently, researchers have proposed placing the cold end and the hot end together on a suspended membrane to reduce the difference in the response of the cold end and the hot end to the ambient temperature (such as patents CN 115849292 A and CN118765152 A, etc.), thereby reducing the output overshoot problem caused by the ambient temperature.

[0006] However, placing both the cold end and the hot end on a suspended membrane brings another problem. That is, if the cold end is far from the non-suspended area, the environmental adaptability of the thermopile chip is better and the output overshoot is smaller, but the temperature difference between the hot and cold ends is small and the output signal-to-noise ratio is poor; if the cold end is close to the non-suspended area, the output sensitivity is higher, but the environmental adaptability is poor. In addition, when the cold end and the hot end receive infrared radiation on the same suspended membrane, it is very difficult to ensure a large temperature difference to achieve high sensitivity. Especially for high-resolution thermopile sensor arrays, the size of the suspended end is originally very small, such as 300-700μm. It is almost impossible to place the hot end and the cold end at the same time and maintain a high temperature difference between the hot and cold ends. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a thermopile chip resistant to thermal shock. The present invention can effectively overcome the problem of abnormal signal overshoot caused by thermal shock of the existing thermopile chip, and improve the sensitivity and signal-to-noise ratio of the thermopile chip.

[0008] To achieve the above object, the present invention adopts the following technical solutions: A thermopile chip resistant to thermal shock, comprising a hot-end chip and a cold-end chip. Both the hot-end chip and the cold-end chip include a chip substrate. The surface of the chip substrate is provided with a concave cavity structure and an insulating layer. The area on the insulating layer opposite to the cavity structure is set as a suspended beam film structure. The suspended beam film structure includes a suspended thin film and a suspended beam. The suspended thin film is connected to the insulating layer through the suspended beam. A plurality of thermocouple strips arranged at intervals are provided on the circumferential direction of the suspended thin film and on the circumferential direction of the insulating layer where the suspended thin film is located. A bonding layer is provided on the insulating layer outside the area surrounded by all the thermocouple strips. The hot-end chip and the cold-end chip are hermetically connected through the bonding layer; an infrared absorption layer is provided in the area surrounded by all the thermocouple strips on the suspended thin film of the hot-end chip; along the thickness direction of the suspended thin film, in the circumferential direction of the suspended thin film, the thermocouple strips on the suspended thin films of the hot-end chip and the cold-end chip are alternately distributed, and the thermocouple strips on the hot-end chip and the cold-end chip are connected in series to form a thermopile chip; wherein, the thermocouple strips on the suspended thin film and the insulating layer are both arranged in an alternating form of the first type of thermocouple strips and the second type of thermocouple strips.

[0009] Preferably, an intermediate bonding chip is bonded between the hot-end chip and the cold-end chip; Wherein, the hot-end chip is hermetically connected to the intermediate bonding chip through a bonding layer, and the cold-end chip is hermetically connected to the intermediate bonding chip through a bonding layer; The intermediate bonding chip is provided with a conductive metal column in its thickness direction. When the thermocouple strips on the hot-end chip and the cold-end chip are connected in series, the thermocouple strips on the hot-end chip and the cold-end chip are electrically connected through the conductive metal column.

[0010] Preferably, the thermopile chip resistant to thermal shock of the present invention further includes an infrared reflection layer. The infrared reflection layer is arranged opposite to the infrared absorption layer. The distance between the infrared reflection layer and the infrared absorption layer satisfies the following conditions: The infrared light reflected by the infrared reflection layer and the infrared light incident from the hot-end chip interfere constructively on the infrared absorption layer; When an intermediate bonding chip is bonded between the hot-end chip and the cold-end chip, the infrared reflection layer is arranged on the surface of the intermediate bonding chip; When the hot-end chip and the cold-end chip are directly hermetically connected through a bonding layer, the infrared reflection layer is arranged on the surface of the suspended beam film structure of the cold-end chip.

[0011] Preferably, the infrared reflection layer is a composite film formed by laminating one or several of Al thin film, Au thin film, Cu thin film and photonic crystal thin film.

[0012] Preferably, the material of the intermediate bonding chip is glass or silicon.

[0013] Preferably, bonding electrodes for electrical connection are provided on the thermocouple strips of the hot-end chip and the cold-end chip, and the height of the bonding electrodes is the same as the height of the bonding layer.

[0014] Preferably, the cross-sectional shape of the cavity structure is circular, rectangular, trapezoidal or parallelogram, the suspended film is circular and coaxial with the central axis of the cavity structure, and a plurality of suspended beams are evenly arranged in the circumferential direction of the suspended film; The shape of the infrared absorption layer is circular and coaxial with the suspended film; Along the thickness direction of the suspended film, in the circumferential direction of the suspended film, the thermocouple strips on the hot-end chip suspended film are distributed on the same circumference, and the circumference where the thermocouple strips are located is coaxial with the central axis of the suspended film; the thermocouple strips on the cold-end chip suspended film are distributed on the same circumference, and the circumference where the thermocouple strips are located is coaxial with the central axis of the suspended film.

[0015] Preferably, the suspended beam film structure and the insulating layer are an integral structure.

[0016] Preferably, the materials of the first type of thermocouple strips and the second type of thermocouple strips are N-type single-crystalline polysilicon, N-type polysilicon, P-type single-crystalline silicon, P-type polysilicon, Al, Au, Ag or Ni, and the materials of the first type of thermocouple strips and the second type of thermocouple strips are different.

[0017] Preferably, the infrared absorption layer adopts a composite structure of one or several of a silicon nitride layer, a black silicon layer, a black gold layer, a CNTs nano-forest layer and a photonic crystal layer; The shape surrounded by the bonding layer is a closed figure, and the material of the bonding layer is an alloy formed by one or several of Au, Sn, Cu, Al, In and Pt; The insulating layer adopts a composite film layer composed of one or several of a silicon nitride thin film, a silicon dioxide thin film and an aluminum oxide thin film; Both ends of the overall circuit after the output electrode is connected in series with the thermocouple strip are connected with output electrodes, and the output electrodes are arranged on the cold-end chip.

[0018] Compared with the prior art, the present invention has the following beneficial effects: In the thermopile chip of the present invention that is resistant to thermal shock, the hot end of the entire thermopile chip is disposed on the hot-end chip, and the cold end is disposed on the cold-end chip. By integrating the cold end and the hot end of the thermopile in a non-coplanar manner rather than the same suspended film integration method, the present invention can effectively reduce the heat transfer between the hot and cold ends of the thermopile chip, thereby suppressing the heating effect of infrared radiation on the cold end, increasing the temperature difference between the hot and cold ends, and further improving the sensitivity and signal-to-noise ratio. The thermocouple strips on the hot-end chip are vertically and electrically connected to the thermocouple strips on the cold-end chip, and the connection area has the same temperature as the substrate. Although it is vulnerable to changes in the ambient temperature, according to the intermediate temperature theorem, that is, the change in the intermediate temperature of the thermocouple strip has no effect on the output, thus effectively overcoming the problem of abnormal signal overshoot caused by thermal shock in the existing thermopile chip. In the present invention, the hot-end chip and the cold-end chip are hermetically connected through a bonding layer. Therefore, both the hot end and the cold end of the entire thermopile chip are in the sealed vacuum chamber surrounded by the bonding layer, which can improve the photothermal conversion performance of the device, protect the fragile and sensitive structures, and enhance the robustness of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0020] Figure 1 It is a three-dimensional structure diagram of the thermopile chip according to an embodiment of the present invention.

[0021] Figure 2 It is a schematic structural diagram of the hot-end chip of the thermopile chip according to an embodiment of the present invention.

[0022] Figure 3 is Figure 2 the schematic sectional view taken along line A-A in

[0023] Figure 4 It is a schematic structural diagram of the cold-end chip of the thermopile chip according to an embodiment of the present invention.

[0024] Figure 5 is Figure 4 the schematic sectional view taken along line B-B in

[0025] Figure 6 It is a schematic diagram of the connection method between the cold-end and hot-end chips of the thermopile chip according to an embodiment of the present invention.

[0026] Figure 7 It is a schematic overall sectional view of the thermopile chip when adopting a two-layer structure according to an embodiment of the present invention.

[0027] Figure 8Schematic diagram of the overall cross-section of the thermopile chip in the embodiment of the present invention when it adopts a three-layer structure.

[0028] Figure 9 Schematic diagram of depositing an insulating layer and fabricating thermocouple bars in the manufacturing process of the thermopile chip in the embodiment of the present invention.

[0029] Figure 10 Schematic diagram of depositing an insulating layer, opening a window in the insulating layer, and depositing bonding metal in the manufacturing process of the thermopile chip in the embodiment of the present invention.

[0030] Figure 11 Schematic diagram of depositing an infrared reflection layer in the manufacturing process of the thermopile chip in the embodiment of the present invention.

[0031] Figure 12 Schematic diagram of depositing an infrared absorption layer in the manufacturing process of the thermopile chip in the embodiment of the present invention.

[0032] Figure 13 Schematic diagram of front-side etching to release the suspended structure in the manufacturing process of the cold-end chip of the thermopile chip in the embodiment of the present invention.

[0033] Figure 14 Schematic diagram of front-side etching to release the suspended structure in the manufacturing process of the hot-end chip of the thermopile chip in the embodiment of the present invention.

[0034] Figure 15 Schematic diagram of cold-end to hot-end wafer bonding in the manufacturing process of the thermopile chip in the embodiment of the present invention.

[0035] Reference numerals in the figures: 1 - hot - end chip, 11 - infrared absorption layer, 12 - hot - end chip suspended beam film, 121 - hot - end chip suspended thin film, 122 - hot - end chip suspended beam, 13 - hot - end chip cavity structure, 14 - hot - end chip wafer bonding layer, 15 - hot - end chip insulation layer, 151 - hot - end chip insulation layer 1, 152 - hot - end chip insulation layer 2, 153 - hot - end chip insulation layer 3, 16 - hot - end chip bonding electrode, 161 - hot - end chip series bonding electrode, 162 - hot - end chip output bonding electrode, 17 - hot - end chip thermocouple strip, 171 - open end of the first - type thermocouple strip in the non - suspended region of the hot - end chip, 172 - series end of the first - type thermocouple strip in the suspended region of the hot - end chip, 173 - series end of the second - type thermocouple strip in the suspended region of the hot - end chip, 174 - open end of the second - type thermocouple strip in the non - suspended region of the hot - end chip, 18 - hot - end chip substrate, 2 - cold - end chip, 21 - infrared reflection layer, 22 - cold - end chip suspended beam film, 221 - cold - end chip suspended thin film, 222 - cold - end chip suspended beam, 23 - cold - end chip cavity structure, 24 - cold - end chip wafer bonding layer, 25 - cold - end chip insulation layer, 251 - cold - end chip insulation layer 1, 252 - cold - end chip insulation layer 2, 253 - cold - end chip insulation layer 3, 26 - cold - end chip bonding electrode, 261 - cold - end chip series bonding electrode, 262 - cold - end chip output bonding electrode, 27 - thermopile output electrode, 271 - first output electrode, 272 - second output electrode, 28 - cold - end chip thermocouple strip, 281 - open end of the first - type thermocouple strip in the non - suspended region of the cold - end chip, 282 - series end of the first - type thermocouple strip in the suspended region of the cold - end chip, 283 - series end of the second - type thermocouple strip in the suspended region of the cold - end chip, 284 - open end of the second - type thermocouple strip in the non - suspended region of the cold - end chip, 29 - cold - end chip substrate, 3 - intermediate - layer bonding chip, 31 - conductive metal column, 32 - intermediate - layer substrate. Detailed implementation mode

[0036] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term “and / or” used herein includes any and all combinations of one or more of the related listed items.

[0038] In view of the disadvantages of the prior art, the present invention provides a thermopile chip with heat shock resistance, which is used to solve the contradiction between output sensitivity and environmental adaptability in the prior art, and provides a manufacturing process method compatible with IC, which can be mass-produced.

[0039] See Figures 1-8 , the thermopile chip with heat shock resistance in this embodiment includes a hot-end chip 1 and a cold-end chip 2. The overall structures of the hot-end chip 1 and the cold-end chip 2 are similar, but there are also differences. Specifically, both the hot-end chip 1 and the cold-end chip 2 include a chip substrate (such as the hot-end chip substrate 18 and the cold-end chip substrate 29). The surface of the chip substrate is provided with a concave cavity structure (such as the hot-end chip cavity structure 13 and the cold-end chip cavity structure 23) and an insulating layer (such as the hot-end chip insulating layer 15 and the cold-end chip insulating layer 25). The area on the insulating layer opposite to the cavity structure (taking the orientation shown in Figure 3 and Figure 5 as an example, this area is the area corresponding to the insulating layer above the cavity structure) is set as a suspended beam film structure. The suspended beam film structure can be obtained by directly processing on the insulating layer, or by removing all the areas on the insulating layer opposite to the cavity structure and then connecting the suspended beam film structure at the removed parts, as long as the suspended beam film structure can be obtained. Specifically, the suspended beam film structure includes a suspended thin film (such as the hot-end chip suspended thin film 121 and the cold-end chip suspended thin film 221) and a suspended beam (the hot-end chip suspended beam 122 and the cold-end chip suspended beam 222). The suspended thin film is connected to the insulating layer through the suspended beam. A plurality of thermocouple strips are arranged at intervals in the circumferential direction of the suspended thin film and in the circumferential direction of the insulating layer around the suspended thin film (substantially in the circumferential direction of the entire suspended beam film structure). A bonding layer (such as the hot-end chip wafer bonding layer 14 and the cold-end chip wafer bonding layer 24) is provided on the insulating layer outside the area surrounded by all the thermocouple strips. The hot-end chip 1 and the cold-end chip 2 are hermetically connected through the bonding layer (for the direct connection method, see Figure 7 , for the indirect connection method (i.e., the case where an intermediate layer bonding chip is provided), see Figure 8 ). When connecting, it is preferably to keep the chamber vacuum after sealing to reduce the heat transfer between the hot end and the cold end of the thermopile chip; see Figure 2 and Figure 3 , an infrared absorption layer 11 is provided in the area surrounded by all the thermocouple strips on the suspended thin film of the hot-end chip 1. The purpose of setting the infrared absorption layer 11 is to effectively increase the temperature difference level between the hot end and the cold end of the thermopile chip within a limited size through the heat absorption effect of the infrared absorption layer 11, thereby improving the sensitivity; see Figure 6 , and in combination with Figure 2 and Figure 4 , along the thickness direction of the suspended thin film (i.e., Figure 2 and Figure 4The perspective direction shown), in the circumferential direction of the suspended thin film, the thermocouple strips on the hot-end chip 1 and the cold-end chip 2 of the suspended thin film are alternately distributed. The thermocouple strips on the hot-end chip 1 and the cold-end chip 2 are sequentially vertically electrically connected through bonding electrodes (that is, the first-type thermocouple strips of the hot-end chip are connected to the first-type thermocouple strips of the cold-end chip, and the second-type thermocouple strips of the hot-end chip are connected to the second-type thermocouple strips of the cold-end chip), so that the thermocouple strips of the hot-end chip and the cold-end chip are in series, jointly forming a thermopile chip. Among them, the heterojunction of the thermocouple strips on the suspended thin film of the hot-end chip 1 is the hot junction of the overall thermopile chip, and the heterojunction of the thermocouple strips on the suspended thin film of the cold-end chip 2 is the cold junction of the overall thermopile chip. The signal of the thermopile chip is finally output through both ends of the overall circuit after the thermocouple strips are in series. The specific circuit connection process belongs to the conventional technology in this field, and the present invention does not make specific limitations; among them, the thermocouple strips on the suspended thin film and the insulating layer are both arranged in the form of alternating first-type thermocouple strips and second-type thermocouple strips, and the materials of the first-type thermocouple strips and the second-type thermocouple strips are different. It can be seen from this embodiment of the present invention that by integrating the cold end and the hot end of the thermopile chip in a non-coplanar manner rather than on the same suspended film, the heat transfer between the hot and cold ends of the thermopile can be effectively reduced, the heating effect of infrared radiation on the cold end can be inhibited, the temperature difference between the hot and cold ends can be increased, and thus the sensitivity and signal-to-noise ratio can be improved. In addition, the bonding electrode is equivalent to the middle part of the thermopile, and its temperature change has no effect on the output of the thermopile. The cold end and the hot end of the thermopile are both at the suspended end and are not sensitive to temperature shock, so the thermal shock resistance performance is improved.

[0040] As a preferred embodiment of the present invention, as described above, when the hot-end chip 1 and the cold-end chip 2 are hermetically connected through a bonding layer, they can be directly bonded and linked in the Figure 7 way described, or they can be bonded and connected in the Figure 8 indirect connection way shown. At this time, an intermediate layer bonding chip 3 is bonded between the hot-end chip 1 and the cold-end chip 2 in this embodiment; among them, the hot-end chip 1 is hermetically connected to the intermediate layer bonding chip 3 through a bonding layer, and the cold-end chip 2 is hermetically connected to the intermediate layer bonding chip 3 through a bonding layer; the intermediate layer bonding chip 3 is provided with a conductive metal column 31 in its thickness direction. When the thermocouple strips on the hot-end chip 1 and the cold-end chip 2 are in series, the thermocouple strips on the hot-end chip 1 and the cold-end chip 2 are electrically connected through the conductive metal column 31. In this embodiment, the conductive metal column 31 is arranged along the thickness direction of the intermediate layer bonding chip 3. When the thermocouple strips are electrically connected through the conductive metal column 31, it belongs to a vertical electrical connection method. By using this vertical electrical connection rather than the planar arrangement differential form, the electrical signal channel can be effectively shortened, and the signal attenuation can be reduced; and the vertical electrical connection can ensure that the area size of the new structure is almost the same as that of the original structure, and the resolution of the infrared array image sensor can be effectively improved on the premise of ensuring the thermal shock stability.

[0041] As a preferred embodiment of the present invention, on the basis of the above embodiments, an infrared reflection layer 21 is further provided in this embodiment. The infrared reflection layer 21 is disposed opposite to the infrared absorption layer 11. By reasonably designing the position of the infrared reflection layer 21, the infrared light at the hot end can be reflected to reheat the hot end, thereby further improving the device performance. Specifically, the distance between the infrared reflection layer 21 and the infrared absorption layer 11 satisfies the following condition: the infrared light reflected by the infrared reflection layer 21 and the infrared light incident from the hot-end chip 1 interfere constructively on the infrared absorption layer 11, and at this time, the hot end can be reheated to further improve the device performance. In this embodiment, the infrared reflection layer 21 can be arranged in the following ways: ①. When an intermediate layer bonding chip 3 is bonded between the hot-end chip 1 and the cold-end chip 2 (i.e., the situation shown in Figure 8 ), the infrared reflection layer 21 is disposed on the surface of the intermediate layer bonding chip 3. On the one hand, such an arrangement can enable the infrared reflection layer 21 to reflect infrared light to the infrared absorption layer 11. On the other hand, by controlling the thickness of the intermediate layer bonding chip 3, the distance between the infrared reflection layer 21 and the infrared absorption layer 11 can be conveniently controlled. In the design and manufacturing process of the infrared reflection layer 21, the process is relatively simple and the operability is strong; ②. When the hot-end chip 1 and the cold-end chip 2 are directly sealed and connected through a bonding layer (i.e., the situation shown in Figure 7 ), the infrared reflection layer 21 is disposed on the surface of the suspended beam film structure of the cold-end chip 2. Among them, the infrared reflection layer 21 can be disposed only on the surface of the suspended thin film of the suspended beam film structure of the cold-end chip 2, or can be disposed on the suspended thin film and the solid part of the suspended beam. At this time, the infrared reflection layer 21 may not be disposed in the area between adjacent suspended beams. In this embodiment, the distance between the infrared reflection layer 21 and the infrared absorption layer 11 can be controlled by the height of the bonding layer (such as the hot-end chip wafer bonding layer 14 and the cold-end chip wafer bonding layer 24).

[0042] As a preferred embodiment of the present invention, in this embodiment, bonding electrodes (such as the hot-end chip bonding electrode 16 and the cold-end chip bonding electrode 26) for electrical connection are provided on the thermocouple bars (such as the open end 171 of the first type of thermocouple bar in the non-suspended region of the hot-end chip, the open end 174 of the second type of thermocouple bar in the non-suspended region of the hot-end chip, the open end 281 of the first type of thermocouple bar in the non-suspended region of the cold-end chip, and the open end 284 of the second type of thermocouple bar in the non-suspended region of the cold-end chip) of the hot-end chip 1 and the cold-end chip 2. The height of the bonding electrode is the same as the height of the bonding layer. The electrical connection of the thermocouple bars of the hot-end chip 1 and the cold-end chip 2 is realized through the bonding electrode, and the means is mature and the connection effect is reliable. The cross-sectional shape of the bonding electrode is rectangular, circular or trapezoidal.

[0043] As a preferred embodiment of the present invention, the cross-sectional shape of the cavity structure in the above solution can be circular, rectangular, trapezoidal or parallelogram. The cross-sectional shape of the cavity structure is related to its manufacturing process, and different manufacturing processes may result in different cross-sectional shapes of the cavity structure. The present invention does not make specific limitations. The suspended film is circular and coaxial with the cavity structure. A plurality of suspended beams are evenly arranged in the circumferential direction of the suspended film. On the one hand, the suspended beams serve as the support for the suspended film, and on the other hand, they also serve as the support carrier for the suspended area of the thermocouple strip. The shape of the suspended beam can be linear, arc-shaped or irregular curve; the shape of the infrared absorption layer 11 is circular and coaxial with the suspended film; along the thickness direction of the suspended film, in the circumferential direction of the suspended film, the thermocouple strips on the hot-end chip 1 on the suspended film are distributed on the same circumference, and the circumference where the thermocouple strips are located is coaxial with the central axis of the suspended film; the thermocouple strips on the cold-end chip 2 on the suspended film are distributed on the same circumference, and the circumference where the thermocouple strips are located is coaxial with the central axis of the suspended film. It should be noted that the diameter of the circumference where the thermocouple strips on the hot-end chip 1 on the suspended film are located can be the same as or different from the diameter of the circumference where the thermocouple strips on the cold-end chip 2 on the suspended film are located; further preferably, along the thickness direction of the suspended film, in the circumferential direction of the suspended film, the angular span of the series-connected parts of the thermocouple strips on the hot-end chip 1 and the cold-end chip 2 is complementary in the entire circumferential direction. For example, on the circumference where the thermocouple strips on the hot-end chip 1 on the suspended film are located, the central angle corresponding to the arc (this arc is the blank area where no thermocouple strip is provided) between the edges of two adjacent thermocouple strips (these two thermocouple strips are respectively denoted as the first thermocouple strip and the second thermocouple strip) on the hot-end chip 1 on the suspended film is 30°. Then, on the cold-end chip 2 on the suspended film, there must be a connecting part (which can be denoted as the third thermocouple strip and the fourth thermocouple strip) between the first thermocouple strip and the second thermocouple strip, and the central angle corresponding to the arc of the connecting part is 30°. At this time, it belongs to the above-mentioned situation of "the angular span of the series-connected parts of the thermocouple strips on the hot-end chip 1 and the cold-end chip 2 is complementary in the entire circumferential direction"; of course, the central angle corresponding to the connecting part of the third thermocouple strip and the fourth thermocouple strip can also be less than or greater than 30°, as long as the thermocouple strips on the hot-end chip 1 and the cold-end chip 2 can be connected in series through the bonding electrodes.

[0044] As a preferred embodiment of the present invention, in the above solution, the infrared reflection layer 21 can be a composite film formed by laminating one or more of an Al film, an Au film, a Cu film, and a photonic crystal film. The material of the intermediate layer bonding chip 3 can be a conventional semiconductor substrate, such as glass or silicon; the materials of the first type of thermocouple strip and the second type of thermocouple strip are N-type single-crystalline or polycrystalline silicon, N-type polycrystalline silicon, P-type single-crystalline silicon, P-type polycrystalline silicon, Al, Au, Ag, or Ni; the infrared absorption layer 11 is a composite structure of one or more of a silicon nitride layer, a black silicon layer, a black gold layer, a CNTs nano-forest layer, and a photonic crystal layer; the shape surrounded by the bonding layer is a closed figure, specifically, it can be a rectangle, a trapezoid, or a circle, and the material of the bonding layer is an alloy material formed by one or more of the metals Au, Sn, Cu, Al, In, and Pt; the insulating layer is a composite film layer composed of one or more of a silicon nitride thin film, a silicon dioxide thin film, and an aluminum oxide thin film; output electrodes are connected to both ends of the overall circuit in series with the thermocouple strips (such as Figure 4 the first output electrode 271 and the second output electrode 272 shown), and the output electrodes are arranged on the cold-end chip 2.

[0045] Example 1 Reference Figures 1-7 , in this example, the thermopile chip with heat shock resistance includes a hot-end chip 1 and a cold-end chip 2 from top to bottom (taking the orientation shown in Figure 7 as an example). The hot-end chip 1 does not have lead electrodes and also serves as a packaging cover in the thermopile chip. The hot-end chip 1 and the cold-end chip 2 are hermetically bonded together through a wafer-level bonding process, forming a sealed chamber. Wafer-level bonding is beneficial for subsequent dicing and miniaturized packaging, reducing the device size and facilitating application in new consumer electronic products. Specifically, the hot-end chip 1 and the cold-end chip 2 are bonded to connect the hot-end chip bonding electrode 16 and the cold-end chip bonding electrode 26, so that the hot-end chip thermocouple strip 17 and the cold-end chip thermocouple strip 28 on the hot-end chip 1 and the cold-end chip 2 are in series, and then the hot-end chip 1 and the cold-end chip 2 form a thermopile chip.

[0046] As Figure 2 shown, in this example, the hot-end chip 1 includes an infrared absorption layer 11, a hot-end chip suspended beam film 12 (a hot-end chip suspended thin film 121 and a hot-end chip suspended beam 122), a hot-end chip cavity structure 13, a hot-end chip wafer bonding layer 14, a hot-end chip insulating layer 15, a hot-end chip bonding electrode 16 (the hot-end chip bonding electrode 16 includes a hot-end chip series bonding electrode 161 and a hot-end chip output bonding electrode 162), a hot-end chip thermocouple strip 17, and a hot-end chip substrate 18.

[0047] Reference Figure 3, the hot-end chip cavity structure 13 is a cavity structure etched from the surface carrying the thermocouple strip into the interior of the hot-end chip substrate 18. The hot-end chip insulating layer 15 corresponding to the hot-end chip cavity structure 13 forms a suspended beam film structure, which includes a hot-end chip suspended thin film 121 and a hot-end chip suspended beam 122. Ten hot-end chip suspended beams 122 are evenly distributed circumferentially on the hot-end chip suspended thin film 121. One end of the hot-end chip suspended beam 122 is connected to the hot-end chip suspended thin film 121, and the other end is connected to the hot-end chip insulating layer 15.

[0048] As Figure 4 shown, the cold-end chip 2 includes an infrared reflection layer 21, a cold-end chip suspended beam 222, a cold-end chip cavity structure 23, a cold-end chip bonding layer 24, a cold-end chip insulating layer 25, a cold-end chip bonding electrode 26, a thermopile output electrode 27, a hot-end chip thermocouple strip 28, and a cold-end chip substrate 29.

[0049] Refer to Figure 5 , the cold-end chip cavity structure 23 is a cavity structure etched from the surface carrying the thermocouple strip into the interior of the cold-end chip substrate 29. The cold-end chip insulating layer 25 corresponding to the cold-end chip cavity structure 23 forms a suspended beam film structure, which includes a cold-end chip suspended thin film 221 and a cold-end chip suspended beam 222. Ten cold-end chip suspended beams 222 are evenly distributed circumferentially on the cold-end chip suspended thin film 221. One end of the cold-end chip suspended beam 222 is connected to the cold-end chip suspended thin film 221, and the other end is connected to the cold-end chip insulating layer 25.

[0050] Refer to Figure 2 and Figure 4 , both the hot-end chip thermocouple strip 17 and the cold-end chip thermocouple strip 28 are structures in which the first type of thermocouple strip and the second type of thermocouple strip are alternately arranged. The hot-end chip thermocouple strip 17 forms an annular array in the circumferential direction around the center of the hot-end chip suspended thin film 121, and a heterojunction is formed in series in the middle of the hot-end chip suspended thin film 121 (including the series connection end 172 of the first type of thermocouple strip in the hot-end chip suspended domain and the series connection end 173 of the second type of thermocouple strip in the hot-end chip suspended domain); the cold-end chip thermocouple strip 28 forms an annular array in the circumferential direction around the center of the cold-end chip suspended thin film 221, and a heterojunction is formed in series in the middle of the cold-end chip suspended thin film 221 (including the series connection end 282 of the second type of thermocouple strip in the cold-end chip suspended domain and the series connection end 283 of the first type of thermocouple strip in the cold-end chip suspended domain). The layout of the heterojunction structures of the hot-end chip thermocouple strip 17 and the cold-end chip thermocouple strip 28 in the suspended domain (i.e., the hot-end chip suspended thin film 121 and the cold-end chip suspended thin film 221) is a complementary relationship in the circumferential direction. That is to say, refer to Figure 6 and Figure 2 and Figure 4 , along the thickness direction of the suspended thin film (i.e.,Figure 2 and Figure 4 In the circumferential direction of the suspended thin film (in the perspective direction shown), on the suspended thin film of the hot-end chip 1 and the cold-end chip 2, thermocouple strips are alternately distributed. At the same time, the thermocouple strips on the suspended thin film are arranged in an alternating form of the first type of thermocouple strip and the second type of thermocouple strip.

[0051] The thermocouple strip 17 of the hot-end chip is a disconnected discrete structure in the non-suspended domain (i.e., the position in the insulating layer 15 of the hot-end chip), including the open end 171 of the first type of thermocouple strip in the non-suspended domain of the hot-end chip and the open end 174 of the second type of thermocouple strip in the non-suspended domain of the hot-end chip. Thermocouple strip series bonding electrodes 161 are provided on both the open end 171 of the first type of thermocouple strip in the non-suspended domain of the hot-end chip and the open end 174 of the second type of thermocouple strip in the non-suspended domain of the hot-end chip; the thermocouple strip 18 of the cold-end chip is a disconnected discrete structure in the non-suspended domain (i.e., the position in the insulating layer 25 of the cold-end chip), including the open end 281 of the first type of thermocouple strip in the non-suspended domain of the cold-end chip and the open end 284 of the second type of thermocouple strip in the non-suspended domain of the cold-end chip. Thermocouple strip series bonding electrodes 261 are provided on both the open end 281 of the first type of thermocouple strip in the non-suspended domain of the cold-end chip and the open end 284 of the second type of thermocouple strip in the non-suspended domain of the cold-end chip.

[0052] Reference Figure 6 , the thermocouple strip series bonding electrodes 161 of the hot-end chip and the thermocouple strip series bonding electrodes 261 of the cold-end chip are conductively connected through bonding. The open end 171 of the first type of thermocouple strip in the non-suspended domain of the hot-end chip and the open end 174 of the second type of thermocouple strip in the non-suspended domain of the hot-end chip on the hot-end chip 1 are respectively connected to the open end 284 of the second type of thermocouple strip in the non-suspended domain of the cold-end chip and the open end 281 of the first type of thermocouple strip in the non-suspended domain of the cold-end chip on the cold-end chip. The heterojunction of the thermocouple strip in the middle of the suspended domain of the hot-end chip 1 (i.e., the series connection end 172 of the first type of thermocouple strip in the suspended domain of the hot-end chip and the series connection end 173 of the second type of thermocouple strip in the suspended domain of the hot-end chip) is the heat junction of the overall thermoelectric pile chip, while the heterojunction in the middle of the suspended domain of the cold-end chip 2 (the series connection end 282 of the second type of thermocouple strip in the suspended domain of the cold-end chip and the series connection end 283 of the first type of thermocouple strip in the suspended domain of the cold-end chip) is the cold junction of the overall thermoelectric pile chip. The signals of the thermoelectric pile chip are finally output through two thermoelectric pile output electrodes (i.e., the first output electrode 271 and the second output electrode 272) on the cold-end chip. The first output electrode 271 and the second output electrode 272 are respectively connected to both ends of the overall circuit after being connected in series with the thermocouple strips.

[0053] Reference Figure 7, the heights of the hot-end chip wafer bonding layer 14, the cold-end chip wafer bonding layer 24, the cold-end chip bonding electrode 26, and the hot-end chip bonding electrode 16 are the same to ensure that the electrical connections of the thermocouple bars (17, 28) on the hot-end chip 1 and the cold-end chip 2 and the airtightness requirements of wafer bonding are simultaneously met. An infrared absorption layer 11 is provided on the hot-end chip. The infrared absorption layer 11 is arranged at the center of the hot-end chip suspended thin film 121 and is circular in shape. The size of the infrared absorption layer 11 is not larger than the area where the thermocouple bars form a heterojunction (172, 173) on the hot-end chip suspended thin film 121. The material of the infrared absorption layer 11 is SiN x layer. An infrared reflection layer 21 is provided on the cold-end chip 2. The infrared reflection layer 21 is disposed on the surface of the suspended beam film structure of the cold-end chip 2. The infrared reflection layer 21 is a single-layer Al thin film. The heights of the hot-end chip wafer bonding layer 14 and the cold-end chip wafer bonding layer 24 relative to the infrared absorption layer 11 and the infrared reflection layer 21 are determined by infrared optical design. The relative height is jointly determined by the thicknesses of the hot-end chip wafer bonding layer 14 and the cold-end chip wafer bonding layer 24 and the heights of the hot-end chip substrate 18 and the cold-end chip substrate 29 at this position. The shapes of the hot-end chip cavity structure 13 and the cold-end chip cavity structure 23 are both frustum-shaped, which is consistent with the radiation characteristics of the central heat source. The cross-sectional shapes of the hot-end chip series bonding electrode 161 and the cold-end chip series bonding electrode 261 are rectangular. The material of the first type of thermocouple bar is N-type polysilicon, and the material of the second type of thermocouple bar is P-type polysilicon.

[0054] The hot-end chip wafer bonding layer 14 and the cold-end chip wafer bonding layer 24 enclose the suspended beam film structures and bonding electrodes of the hot-end chip 1 and the cold-end chip 2. The materials of the hot-end chip wafer bonding layer 14 and the cold-end chip wafer bonding layer 24 are both Au.

[0055] The materials of the hot-end chip insulating layer 15 and the cold-end chip insulating layer 25 are SiN x and SiO 2 alternately formed composite film layers, specifically a three-layer composite film layer formed by alternating SiO x / SiN x / SiO 2 alternately. Specifically, see Figure 7 , the lowermost film layer of the hot-end chip insulating layer 15 completely covers the thermocouple bar structure, and the uppermost film layer of the cold-end chip insulating layer 25 completely covers the thermocouple bar structure. The hot-end chip insulating layer 15 has holes for electrically connecting the hot-end chip series bonding electrode 161 and the hot-end chip thermocouple bar 17 in the non-suspended area, and the cold-end chip insulating layer 25 has holes for electrically connecting the cold-end chip series bonding electrode 261 and the cold-chip thermocouple bar 28 in the non-suspended area.

[0056] In this embodiment, the suspended beam film structure of the hot-end chip 1 (i.e., including the hot-end chip suspended beam 122 and the hot-end chip suspended thin film 121) is a structure formed by processing the hot-end chip insulating layer 15, and the suspended beam film structure of the cold-end chip 2 (i.e., including the cold-end chip suspended beam 222 and the cold-end chip suspended thin film 221) is a structure formed by processing the cold-end chip insulating layer 25. The hot-end chip suspended thin film 121 and the cold-end chip suspended thin film 221 are both circular films and are used to carry the thermocouple bar heterojunction. The shapes of the hot-end chip suspended beam 122 and the cold-end chip suspended beam 222 are linear.

[0057] The working principle of the thermopile chip with heat shock resistance provided in this embodiment is as follows: When the thermopile chip of this embodiment is working, the infrared radiation emitted by the object to be measured first irradiates on the hot-end chip substrate 18. Due to the infrared transmittance of Si in the hot-end chip substrate 18, most of the infrared radiation passes through the hot-end chip substrate 18 and acts on the infrared absorption layer 11 of the hot-end chip 1, causing the temperature of the suspended end of the hot-end chip 1 to rise. A part of the infrared radiation leaked from the hot-end chip 1 irradiates on the cold-end chip 2. Through the design of the infrared reflection layer 21 and a reasonable chamber height (i.e., the chamber between the infrared reflection layer 21 and the infrared absorption layer 11), it is possible to make the infrared light after reflection by the infrared reflection layer 21 interfere with the incident infrared light to enhance the optical absorption at the infrared absorption layer 11 of the hot-end chip, further increasing the temperature of the suspended end of the hot-end chip, while the cold-end chip 2 will not be heated. Therefore, in this embodiment, the temperature difference between the cold end and the hot end of the thermopile chip is large.

[0058] When the external environmental temperature suddenly changes, the substrates of the hot-end chip 1 and the cold-end chip 2 quickly generate a temperature response. However, the hot end of the thermopile chip has a large thermal resistance at the suspended end of the hot-end chip (i.e., the position of the suspended beam film structure and the cavity structure of the hot-end chip 1), and the temperature change is small; the cold end of the thermopile chip has a relatively large thermal resistance at the suspended end of the cold-end chip (i.e., the position of the suspended beam film structure and the cavity structure of the cold-end chip 2), and the temperature change is not obvious either; only the bonding electrodes (i.e., the hot-end chip bonding electrode 16 and the cold-end chip bonding electrode 26) have a large temperature mutation. This is equivalent to the temperature of the cold end and the hot end of a pair of thermocouple bars remaining unchanged, and the same position in the middle part of the hot and cold ends changes a certain temperature at the same time. According to the intermediate temperature law, the theoretical output is unchanged. Therefore, this embodiment realizes the tolerance to environmental temperature shock.

[0059] Reference Figures 9-15 Referring to S1, referring to Figure 9 a single-crystalline silicon wafer is provided, and a layer of SiO 2A thin film (as insulating layer 1). A layer of SiN is fabricated on the surface of the SiO thin film by low-pressure chemical vapor deposition (LPCVD). 2 thin film x thin film (as insulating layer 2). Thus, a two-layer insulating layer is formed. On the SiN thin film, a layer of polycrystalline silicon thin film (poly-Si) is deposited by LPCVD. The thermocouple strip pair composed of N-poly-Si (the first type of thermocouple strip) and P-poly-Si (the second type of thermocouple strip) is fabricated by lithography patterning and ion implantation respectively. x thin film

[0060] S2. Refer to Figure 10 , for the cold-end chip 2, on the local thermocouple strip obtained in S1, the thermopile output electrodes are deposited, and then an SiO insulating layer (as insulating layer 3) is deposited on the thermocouple strip array and the electrodes, and bonding electrode lead holes are etched at the open ends of the thermocouple strips. On this basis, the cold-end chip output bonding electrode 26 and the cold-end chip wafer bonding layer 24 are fabricated. 2 insulating layer

[0061] For the hot-end chip 1, on the thermocouple strip array and the electrodes obtained in S1, an SiO insulating layer (as insulating layer 3) is deposited, and bonding electrode lead holes are etched at the open ends of the thermocouple strips. On this basis, the hot-end chip output bonding electrode 16 and the hot-end chip wafer bonding layer 14 are fabricated. 2 insulating layer

[0062] S3. Refer to Figure 11 , for the cold-end chip 2, an infrared reflection layer 21 is deposited on the structure fabricated in S2 to form the cold-end chip infrared emission layer; Refer to Figure 12 , for the hot-end chip 1, an infrared absorption layer 11 is deposited on the structure fabricated in S2 to form the hot-end chip infrared absorption layer.

[0063] S4. Refer to Figure 13 and Figure 14 , for the cold-end chip 2 and the hot-end chip 1, on the front side of the wafer fabricated in S3, the insulating layer is etched to form openings, and the hot-end chip 1 and the cold-end chip 2 with a suspended beam film structure are formed by dry or wet etching of the substrate silicon.

[0064] S5. Refer to Figure 15 , the hot-end chip 1 and the cold-end chip 2 fabricated in S4 are flip-chip vacuum bonded to form the final thermopile chip.

[0065] Example 2: Refer to Figure 8, this embodiment provides a similar thermopile chip structure with the same working principle based on Embodiment 1. The difference between this embodiment and Embodiment 1 lies in the number of bonded chips. In this embodiment, the hot-end chip 1 is not directly bonded to the cold-end chip 2. Instead, an intermediate bonding chip 3 is used to bond to the hot-end chip 1 and the cold-end chip 2 respectively, and electrical interconnection is achieved through vertical electrical connection (TGV or TSV). In addition, the infrared light reflection layer 21 is placed on the intermediate bonding layer 3. The material of the intermediate bonding chip 3 can be glass or silicon, and the bonding process can be anodic bonding or gold-gold bonding. In this embodiment, by introducing the intermediate bonding layer 3, the optical path design from the infrared partial reflection layer 21 to the infrared absorption layer 11 can be made more flexible, and the temperature of the suspended end of the cold-end chip is less affected by infrared light irradiation, which is beneficial to improving the overall sensitivity of the thermopile and reducing signal noise.

[0066] Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0067] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A thermal shock resistant thermopile chip, characterized in that: The invention comprises a hot end chip (1) and a cold end chip (2), wherein the hot end chip (1) and the cold end chip (2) both comprise a chip substrate, wherein a concave cavity structure and an insulating layer are provided on the surface of the chip substrate, wherein a region on the insulating layer opposite to the cavity structure is provided with a suspended beam membrane structure, wherein the suspended beam membrane structure comprises a suspended membrane and a suspended beam, wherein the suspended membrane and the insulating layer are connected via the suspended beam, wherein the suspended membrane and the insulating layer are provided with a plurality of thermocouple strips arranged at intervals in the circumference thereof and the insulating layer in the circumference thereof, wherein a bonding layer is provided on the insulating layer at the periphery of the region surrounded by all the thermocouple strips, wherein the hot end chip (1) and The cold end chip (2) is sealed and connected via a bonding layer; an infrared absorption layer (11) is provided on the suspended film of the hot end chip (1) in the area surrounded by all the thermocouple bars; along the thickness direction of the suspended film and in the circumferential direction of the suspended film, the thermocouple bars on the suspended films of the hot end chip (1) and the cold end chip (2) are alternately distributed, and the thermocouple bars on the hot end chip (1) and the cold end chip (2) are connected in series, so that the hot end chip (1) and the cold end chip (2) form a thermopile chip; wherein the thermocouple bars on the suspended film and the insulating layer are arranged in a form of alternating first-type thermocouple bars and second-type thermocouple bars.

2. The thermal shock resistant thermopile chip according to claim 1, characterized in that: An intermediate layer bonding chip (3) is bonded between the hot end chip (1) and the cold end chip (2); The hot end chip (1) and the middle layer bonding chip (3) are sealed and connected via a bonding layer, and the cold end chip (2) and the middle layer bonding chip (3) are sealed and connected via a bonding layer; The intermediate layer bonding chip (3) is provided with a conductive metal column (31) in the thickness direction thereof, and when the thermocouple bars on the hot end chip (1) and the cold end chip (2) are connected in series, the thermocouple bars on the hot end chip (1) and the cold end chip (2) are electrically connected via the conductive metal column (31).

3. A thermal shock resistant thermopile chip according to claim 1 or 2, characterized in that: It also includes an infrared reflection layer (21), which is arranged opposite to the infrared absorption layer (11), and the distance between the infrared reflection layer (21) and the infrared absorption layer (11) satisfies the following conditions: The infrared light reflected by the infrared reflection layer (21) and the infrared light incident from the hot end chip (1) are enhanced by interference upward in the infrared absorption layer (11); When an intermediate layer bonding chip (3) is bonded between the end chip (1) and the cold end chip (2), the infrared reflection layer (21) is arranged on the surface of the intermediate layer bonding chip (3); When the hot-end chip (1) and the cold-end chip (2) are directly sealed and connected via a bonding layer, the infrared reflection layer (21) is arranged on the surface of the suspended beam membrane structure of the cold-end chip (2).

4. The thermal shock resistant thermopile chip according to claim 3, characterized in that: The infrared reflection layer (21) is a composite film of one or more of an Al film, an Au film, a Cu film and a photonic crystal film in a stacked arrangement.

5. The thermal shock resistant thermopile chip according to claim 2, characterized in that: The material of the intermediate layer bonding chip (3) is glass or silicon.

6. A thermal shock resistant thermopile chip according to claim 1 or 2, characterized in that: The thermocouple strips of the hot-end chip (1) and the cold-end chip (2) are provided with bonding electrodes for electrical connection, and the height of the bonding electrodes is the same as the height of the bonding layer.

7. The thermal shock resistant thermopile chip according to claim 1, characterized in that: The cross-section of the cavity structure is in the shape of a circle, a rectangle, a trapezoid or a parallelogram, the suspended membrane is circular and coaxial with the central axis of the cavity structure, and a plurality of suspended beams are evenly arranged around the circumference of the suspended membrane; The infrared absorption layer (11) is circular in shape and is coaxially arranged with the suspended membrane; Along the thickness direction of the suspended membrane and in the circumferential direction of the suspended membrane, the thermocouple strips on the suspended membrane of the hot end chip (1) are distributed on the same circumference, and the circumference where the thermocouple strips are located is coaxial with the central axis of the suspended membrane; the thermocouple strips on the suspended membrane of the cold end chip (2) are distributed on the same circumference, and the circumference where the thermocouple strips are located is coaxial with the central axis of the suspended membrane.

8. The thermal shock resistant thermopile chip according to claim 1, characterized in that: The suspended beam membrane structure and the insulating layer are an integrated structure.

9. The thermal shock resistant thermopile chip according to claim 1, characterized in that: The materials of the first type thermocouple bar and the second type thermocouple bar are N-type single polycrystalline silicon, N-type polycrystalline silicon, P-type single crystal silicon, P-type polycrystalline silicon, Al, Au, Ag or Ni, and the materials of the first type thermocouple bar and the second type thermocouple bar are different.

10. The thermal shock resistant thermopile chip according to claim 1, characterized in that: The infrared absorption layer (11) adopts a composite structure of one or more of a silicon nitride layer, a black silicon layer, a black gold layer, a CNTs nano forest layer and a photonic crystal layer; The shape enclosed by the bonding layer is a closed figure, and the material of the bonding layer is an alloy formed by one or more of Au, Sn, Cu, Al, In and Pt; The insulating layer is a composite film layer composed of one or more of a silicon nitride film, a silicon dioxide film and an aluminum oxide film; After the output electrode and the thermocouple bar are connected in series, both ends of the overall circuit are connected to the output electrode, and the output electrode is arranged on the cold end chip (2).

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