CN111664950B

CN111664950B - Infrared detector and preparation method and application thereof

Info

Publication number: CN111664950B
Application number: CN202010338053.XA
Authority: CN
Inventors: 姜利军; 张云胜; 钱良山
Original assignee: Hangzhou Dali Microelectronic Co ltd
Current assignee: Hangzhou Dali Microelectronic Co ltd
Priority date: 2020-04-26
Filing date: 2020-04-26
Publication date: 2021-11-05
Anticipated expiration: 2040-04-26
Also published as: CN111664950A

Abstract

The invention provides an infrared detector and a preparation method and application thereof, which can improve the temperature measurement precision and the measurement accuracy of the infrared detector. Infrared detector for carry out infrared detection to the measured object, including demarcation module for carry out infrared detection's demarcation, include: the sealing cover is covered on the upper surface of the substrate, and a first closed space is formed on the upper surface of the substrate; the reference pixel is arranged in the first closed space and used for detecting infrared light; and the radiation source is arranged in the first closed space and used for emitting infrared light for the reference pixel to acquire and detect, and the temperature of the radiation source is controllable.

Description

Infrared detector and preparation method and application thereof

Technical Field

The invention relates to the technical field of infrared detectors, in particular to an infrared detector and a preparation method and application thereof.

Background

The infrared detector is an important sensor in the applications of industry, Internet of things, security, home life and the like. The infrared detector can realize the functions of existence detection, night vision, non-contact temperature measurement and the like by detecting infrared heat radiation emitted by a target object and outputting an electric signal. The infrared non-contact temperature measurement technology has the advantages of high response speed, no disturbance to a measured target, capability of measuring temperature remotely and the like, and is more and more widely applied to industrial production and daily life. Typical products include industrial thermometers, medical ear thermometers, forehead thermometers, industrial thermal imagers, medical thermal imagers, and the like. The core unit of the infrared non-contact temperature measuring instrument is an infrared detector, and the infrared detector is divided into a unit type, an array type and a focal plane type according to the number of sensitive elements in the detector. The array type and the focal plane type can output infrared images and a plurality of temperature points, so the application field is very wide.

In the prior art, as the service life of the infrared detector is prolonged, the temperature measurement precision of the infrared detector is gradually reduced, and the measurement accuracy is also gradually reduced.

An important link from the infrared detector receiving infrared light to outputting a reliable temperature value is temperature measurement calibration. The process of temperature measurement calibration is generally completed by a manufacturer by using a standard blackbody radiation source. The infrared temperature measuring device mainly adopts a plurality of black bodies with different temperatures as temperature references, so that the infrared light of the reference black body is full of the view field of the infrared detector, and a temperature measuring curve is fitted by collecting the output voltage of the sensor when the black bodies with different temperatures radiate, thereby achieving the function of non-contact temperature measurement.

However, in the use process after the factory shipment, the output temperature measurement curve gradually shifts, the temperature measurement precision of the instrument is reduced, and the measurement accuracy of the infrared detector is affected.

Disclosure of Invention

The infrared detector and the preparation method and application thereof are provided below, and the temperature measurement precision and the measurement accuracy of the infrared detector can be improved.

In order to solve the above problem, the following provides an infrared detector for performing infrared detection on a detected object, including a calibration module, including: the sealing cover is covered on the upper surface of the substrate, and a first closed space is formed on the upper surface of the substrate; the reference pixel is arranged in the first closed space and used for detecting infrared light; and the radiation source is arranged in the first closed space and used for emitting infrared light for the reference pixel to acquire and detect, and the temperature of the radiation source is controllable.

Optionally, still include the detection module for carry out infrared detection to the measured object, include: the upper cover is covered on the upper surface of the substrate, and a second closed space is formed on the upper surface of the substrate; the detection pixel is arranged in the second closed space and used for detecting infrared light of the detected object; the upper cover comprises a transparent area, and infrared light of the object to be detected penetrates through the transparent area and enters the detection pixel.

Optionally, the radiation source comprises: and the control circuit is connected to the radiation source and is used for controlling the radiation source to work at a preset temperature and emit known infrared light.

Optionally, the radiation source is attached to an inner wall of the top surface of the sealing cover, or is suspended on the inner wall of the top surface of the sealing cover, and a coating for increasing the emissivity is coated on the surface of the radiation source, and the coating includes at least one of a gold black coating, a platinum black coating, or a carbon black coating.

Optionally, the first enclosed space is evacuated, and a reflective area is formed on an outer surface of the sealing cover, and is coated with a reflective layer for reflecting infrared light outside the sealing cover.

Optionally, the inner surface and the outer surface of the bottom surface of the upper cover are covered with antireflection films, and getters are arranged in the first closed space and the second closed space.

In order to solve the above problems, the following further provides a method for manufacturing an infrared detector, comprising the following steps: providing a first substrate and a second substrate; digging a first groove on the upper surface of the first substrate; forming a radiation source in the first groove or forming a radiation source above the second substrate, wherein the temperature of the radiation source is controllable; and the first substrate is reversely buckled to the surface of the second substrate, the reference picture element is arranged in the first groove, and the radiation source is also arranged in the first groove.

Optionally, before the first substrate is flipped over to the surface of the second substrate, the method further includes the following steps: digging a second groove on the upper surface of the first substrate, wherein the size of the second groove is equal to that of the first groove; and forming a detection pixel on the surface of the second substrate, wherein the position of the detection pixel corresponds to the position of the second groove, so that the detection pixel is arranged in the second groove when the first substrate is reversely buckled on the surface of the second substrate.

Optionally, the first groove and the second groove are respectively formed on the left side and the right side of the first substrate, the thickness of the left sidewall of the first groove is equal to the thickness of the right side of the second groove, and after the first substrate is flipped onto the surface of the second substrate, the method further includes the following steps: and etching the first substrate vertically and downwards in a directional manner along a direction vertical to the upper surface of the second substrate until the upper surface of the second substrate is exposed, wherein an etched area of the first substrate is positioned between the first groove and the second groove, and after etching, the thickness of the right side wall of the first groove, the thickness of the left side wall of the second groove, the thickness of the left side wall of the first groove and the thickness of the right side surface of the second groove are equal.

Optionally, when the radiation source is formed in the first groove, the method includes the following steps: forming a coating for increasing emissivity on the surface of the radiation source, wherein the coating comprises at least one of a gold black coating, a platinum black coating or a carbon black coating; digging a through hole on the bottom surface of the first groove; and forming a control circuit in the through hole, connecting the control circuit with the radiation source, and enabling the radiation source to be controlled by the control circuit, work at a specified temperature and emit known infrared light.

Optionally, when the radiation source is formed over the second substrate, the method includes the following steps: forming a coating for increasing emissivity on the surface of the radiation source, wherein the coating comprises at least one of a gold black coating, a platinum black coating or a carbon black coating; and forming a control circuit in the second substrate, and connecting the control circuit and the radiation source to control the radiation source to work at a specified temperature and emit known infrared light.

Optionally, before the first substrate is flipped over to the surface of the second substrate, the method further includes the following steps: getter is arranged in the first groove and the second groove; and forming antireflection films on the inner surface and the outer surface of the bottom surface of the second groove.

Optionally, before the first substrate is flipped over to the surface of the second substrate, the method further includes the following steps: forming solder on the top surfaces of the side walls of the first groove and the second groove; forming solder on the upper surface of the second substrate, wherein the position of the solder is matched with the position of the solder formed on the top surfaces of the side walls of the first groove and the second groove; before the first substrate is flipped over to the second substrate surface, further comprising the steps of: and aligning the solder on the upper surface of the second substrate with the solder on the top surfaces of the side walls of the first groove and the second groove, and performing vacuum welding packaging.

In order to solve the above problem, the following further provides an application of the infrared detector, including the following steps: controlling a radiation source of a calibration module to work at a plurality of preset temperatures, enabling the radiation source to emit known infrared light, and controlling the reference pixel to detect the known infrared light; acquiring calibration data according to the data detected by the reference pixel and the known infrared light to form a calibration curve; and detecting the infrared light of the detected object by using the detection module, and comparing the detected data with the calibration curve so as to obtain the actual infrared light of the detected object.

The infrared detector, the preparation method and the application thereof adopt the additionally arranged radiation source with controllable temperature as a signal source of a calibration curve, and the radiation source is arranged at different temperatures to replace the blackbody radiation reference in the prior art, so that the temperature measurement calibration efficiency of the infrared detector can be effectively improved, and the production cost is reduced. In addition, in the using process of the instrument, the radiation source can be used for carrying out regular correction and real-time correction on the infrared detector, so that the precision of the infrared temperature measuring instrument is improved and ensured.

Drawings

FIG. 1 is a schematic diagram of an infrared detector in accordance with an embodiment of the present invention;

fig. 2(a) to 2(f) are schematic structural diagrams corresponding to steps in a method for manufacturing an infrared detector according to an embodiment of the present invention;

fig. 3(a) to 3(e) are schematic structural diagrams corresponding to steps in a method for manufacturing an infrared detector according to an embodiment of the present invention;

FIG. 4 is a schematic flow chart illustrating steps of a method for manufacturing an infrared detector according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an infrared detector in accordance with an embodiment of the present invention;

fig. 6(a) to 6(d) are schematic structural diagrams corresponding to steps in a method for manufacturing an infrared detector according to an embodiment of the present invention;

fig. 7(a) to 7(e) are schematic structural diagrams corresponding to steps in a method for manufacturing an infrared detector according to an embodiment of the present invention;

fig. 8 is a flowchart illustrating steps of an application of an infrared detector according to an embodiment of the present invention.

Detailed Description

Research finds that the temperature measurement precision of the infrared detector gradually decreases, and the measurement accuracy also gradually decreases because the infrared detector has an important link from receiving infrared light to outputting a reliable temperature value: and (6) temperature measurement calibration. The process of temperature measurement calibration is generally completed by a manufacturer by using a standard blackbody radiation source. The infrared temperature measuring device mainly adopts a plurality of black bodies with different temperatures as temperature references, so that the infrared light of the reference black body is full of the view field of the infrared detector, and a temperature measuring curve is fitted by collecting the output voltage of the sensor when the black bodies with different temperatures radiate, thereby achieving the function of non-contact temperature measurement. However, in the use process after shipment, the output temperature measurement curve gradually shifts with the change of environmental conditions or the aging of the infrared detector, the instrument, and the like, the temperature measurement accuracy of the infrared detector gradually decreases, and the measurement accuracy also gradually decreases.

In addition, in this case, if the calibration needs to be performed again after the factory return, time and labor are wasted.

The following detailed description of the infrared detector and the manufacturing method and application thereof according to the present invention will be made with reference to the accompanying drawings.

Referring to fig. 1, a schematic structural diagram of an infrared detector in an embodiment of the present invention is shown, in which an infrared detector is provided for performing infrared detection on a measured object, and a calibration module 20 is further included for performing calibration of infrared detection, including: a sealing cover 21 covering the upper surface of the substrate 11, and forming a first sealed space 14 on the upper surface of the substrate 11; a reference pixel 29, disposed in the first enclosed space 14, for detecting infrared light; and the radiation source 22 is arranged in the first closed space 14 and used for emitting infrared light to be acquired and detected by the reference pixel 29, and the temperature of the radiation source 22 is controllable.

In the infrared detector in this embodiment, the additionally arranged radiation source 22 with controllable temperature is used as a signal source for calibrating the curve, and the radiation source 22 is set at different temperatures to realize regular correction and real-time correction of the infrared detector, so that the precision of the infrared temperature measuring instrument is improved and ensured, the temperature measurement calibration efficiency of the infrared detector is effectively improved, and the production cost is reduced. The infrared detector has a self-calibration function, and can improve the temperature measurement precision and the long-term reliability of temperature measurement data without returning to a factory for calibration.

In a specific embodiment, the infrared detector further includes a detection module 10, configured to perform infrared detection on a detected object, including: an upper cover 17 covering the upper surface of the substrate 11, and forming a second enclosed space 15 on the upper surface of the substrate 11; the detection pixel 12 is arranged in the second closed space 15 and is used for detecting infrared light of a detected object; the upper cover 17 includes a transparent region through which infrared light of the object to be detected is incident to the detection pixel 12.

In the embodiment shown in fig. 1, in order to realize infrared detection, a reference pixel 29 and a detection pixel 12 are further disposed in the substrate 11, and the reference pixel and the detection pixel are electrically connected to the surface of the substrate 11. In the embodiment shown in fig. 1, the sealing cap 21 is bonded to the substrate 11 by hermetic sealing, and infrared light is irradiated to the reference pixel 29 on the surface of the substrate 11 for calibration test. In the embodiment shown in fig. 1, the number of the reference pixels 29 is at least 1, and at least one of the reference pixels 29 can receive the infrared light emitted by the radiation source, so as to complete calibration of the test data.

In the embodiment shown in fig. 1, calibration is achieved by controlling the radiation source 22 to be at different temperatures so that the radiation source 22 emits different infrared light outwards. When radiation source 22 is operating at a known temperature, the infrared light emitted by radiation source 22 is known. Therefore, the calibration of the current infrared detector can be realized only by changing the working temperature of the radiation source 22 to make it work at different temperatures, acquiring the data detected by the reference pixel 29 at different temperatures, and corresponding the temperature value and the detected data.

Specifically, the user controls the radiation source 22 to work at different temperatures, the temperature range covers the measurement range of the detection module 10, and the temperature is corresponding to the detection data detected by the reference pixel 29 to form a temperature-detection data calibration comparison table. When the detection module 10 measures the infrared light of the measured object, the detection value of the measured object obtained by the detection module 10 is searched in the temperature-detection data calibration comparison table, so that the temperature corresponding to the detection value is obtained.

In the specific implementation mode, if the user feels that the current measurement value is inaccurate, the calibration module can be controlled to perform a new round of calibration at any time to obtain new calibration data, and temperature measurement curve deviation caused by the increase of the use duration and the aging of equipment does not exist. This can effectively ensure the temperature measurement accuracy of the infrared detector and the measurement accuracy of the infrared detector.

In this specific embodiment, in a calibration process, the more data sets are acquired, the more accurate the temperature of the measured object detected by the infrared detector is.

In one embodiment, the radiation source 22 comprises: and a control circuit 25 connected to the radiation source 22 for controlling the radiation source 22 to operate at a preset temperature and emit known infrared light.

In the embodiment shown in fig. 1, the control circuit 25 is formed inside the bottom surface of the sealing cap 21, specifically, in a through hole penetrating the bottom surface of the sealing cap 21, and is connected to a bias power source through a metal pad 26 disposed outside the sealing cap 21. By controlling the bias power supply to provide different bias voltages to the radiation source 22, the radiation source 22 operates at different temperatures.

In fact, the control circuit 25 may be formed above the bottom surface of the sealing cover 21, which facilitates maintenance by a user.

In a specific embodiment, the radiation source 22 is attached to the inner wall of the top surface of the sealed enclosure 21, or suspended from the inner wall of the top surface of the sealed enclosure 21, and the surface of the radiation source 22 is coated with a coating for increasing emissivity, including at least one of a gold black coating, a platinum black coating, or a carbon black coating.

In this embodiment, the through hole and the control circuit 25 are formed by micro-processing such as Through Silicon Via (TSV) process, the conductive structure in the control circuit 25 is made of copper, aluminum, or the like, the metal pad 26 is made of aluminum, gold, or the like, and the radiation source 22 is made of platinum, tungsten, or another metal material and is shaped like a circle or a circle, or the like, so as to uniformly emit infrared light outwards in the first enclosed space 14.

In the embodiment shown in fig. 1, the radiation source 22 is formed as an air-suspended micro-bridge structure formed on the inner wall of the top surface, and the radiation source 22 is supported on the inner wall of the top surface by the anchor points.

In one embodiment, the first enclosed space 14 is evacuated to reduce energy dissipation and improve temperature stability. And in this specific embodiment, the outer surface of the sealed cover 21 is formed with a reflection area coated with a reflection layer 24 for reflecting infrared light outside the sealed cover 21 and avoiding the influence of external radiation on the detection data of the reference pixel 29.

In a specific embodiment, the inner and outer surfaces of the bottom surface of the upper cover 17 are covered with antireflection films 27, and the first enclosed space 14 and the second enclosed space 15 are provided with getters 28.

Referring to fig. 2(a) to fig. 2(f), fig. 3(a) to fig. 3(e), and fig. 4, in this embodiment, a method for manufacturing an infrared detector is further provided, which includes the following steps: providing a first substrate 18 and a second substrate 11, wherein said first substrate 18 is detailed in fig. 2(a), preferably a double-side polished silicon wafer, and said second substrate 11 is detailed in fig. 3(a), preferably a single-side polished silicon wafer; digging a first groove on the upper surface of the first substrate 18, as shown in detail in fig. 2 (c); forming a radiation source 22 in the first groove 14 (labeled with the first closed space 14), as shown in fig. 2(e) in detail, or forming the radiation source 22 above the second substrate 11, wherein the temperature of the radiation source 22 is controllable; forming reference pixels 29 on the surface of the second substrate 11, as shown in detail in fig. 3 (b); the first substrate 18 is flipped over to the surface of the second substrate 11, the reference pixels 29 are disposed in the first groove 14, and the radiation source 22 is also covered in the first groove 14, as shown in fig. 3(d) and 3 (e).

In the method for manufacturing the infrared detector in this embodiment, the radiation source for calibration is formed on the surface of the first substrate, the radiation source 22 is directly disposed at a position corresponding to the reference pixel 29, and the reference pixel 29 directly detects the infrared light emitted by the radiation source 22, and since the temperature of the radiation source 22 is controllable, the radiation source 22 can be used as a signal source for drawing a calibration curve, and the radiation source 22 is disposed at different temperatures to replace a black body radiation reference in the prior art method, thereby effectively improving the temperature measurement calibration efficiency of the infrared detector and reducing the production cost.

In the embodiment shown in fig. 2(a) to 2(f) and 3(a) to 3(e), before digging the first groove 14 on the upper surface of the first substrate 18, the following steps are further included: solder 23 required for vacuum packaging is deposited on the upper surface of the first substrate 18.

In one embodiment, the step of flipping the first substrate 18 to the surface of the second substrate 11 further comprises: a second groove 15 (the same as the second closed space 15 in reference number) is dug on the upper surface of the first substrate 18, see fig. 2(c) in detail, a second groove 15 is dug on the right side of the first groove 14, the size of the second groove 15 is equal to that of the first groove 14, and the thicknesses of the first groove 14 and the second groove 15 are equal; and forming detection pixels 12 on the surface of the second substrate 11, as shown in detail in fig. 3(b), wherein the positions of the detection pixels 12 correspond to the positions of the second grooves 15, so that the detection pixels 12 are arranged in the second grooves 15 when the first substrate 18 is reversely buckled on the surface of the second substrate 11, as shown in fig. 3(d) and 3 (e).

In this particular embodiment, the first substrate 18 is a transparent substrate.

In a specific embodiment, a method for forming the first groove 14 and the second groove 15 includes dry etching or wet etching, which is not limited herein.

In the specific embodiment shown in fig. 2(a) to 2(f) and 3(a) to 3(e), the number of the reference pixels 29 is 2, and the number of the detection pixels 12 is 4. In one embodiment, the reference pixel 29, the detection pixel 12, and the circuitry disposed within the second substrate 11 form an infrared detection chip.

In the embodiment shown in fig. 2(a) to 2(f) and 3(a) to 3(e), the first groove 14 and the second groove 15 are respectively formed on the left side and the right side of the first substrate 18, the thickness of the left sidewall of the first groove 14 is equal to the thickness of the right sidewall of the second groove 15, and the following steps are further included after the first substrate 18 is flipped to the surface of the second substrate 11; and (e) etching the first substrate 18 vertically downward in a direction perpendicular to the upper surface of the second substrate 11 until the upper surface of the second substrate 11 is exposed, where fig. 3(e) can be seen, and the etched region of the first substrate 18 is located between the first groove 14 and the second groove 15, and after etching, the right sidewall of the first groove 14, the left sidewall of the second groove 15, the thickness of the left sidewall of the first groove 14, and the thickness of the right side surface of the second groove 15 are equal.

In the specific embodiment shown in fig. 2(a) to 2(f) and 3(a) to 3(e), before etching the first substrate 18 to make the thicknesses of the left and right side walls of the first groove 14 and the second groove 15 equal, before the first substrate 18 is turned over to the surface of the second substrate 11, a third groove 16 is formed between the first groove 14 and the second groove 15, the depth of the third groove 16 is equal to the depths of the first groove 14 and the second groove 15, and the three grooves are adjacently arranged, and the thicknesses of the side walls are equal, which can be referred to fig. 3 (d). In this way, in the process of etching the first substrate 18 until the upper surface of the second substrate 11 is exposed, the first groove 14 and the second groove 15 can be separated by only etching a small depth or performing a simple scribing operation.

In one embodiment, forming radiation source 22 within first recess 14 comprises the steps of: a radiation source 22 is disposed within the first recess 14; forming an emissivity-increasing coating on a surface of the radiation source 22, the emissivity-increasing coating including at least one of a gold black, platinum black, or carbon black coating; a through hole is dug in the bottom surface of the first groove 14; and forming a control circuit 25 in the through hole, and connecting the control circuit 25 and the radiation source 22, so that the radiation source 22 is controlled by the control circuit 25 to work at a specified temperature and emit known infrared light.

In one embodiment, the material of the radiation source 22 may be platinum, tungsten, or other materials, and the shape of the radiation source 22 may be a meander shape, a circle, or the like. In the embodiment shown in fig. 2(a) to 2(f) and 3(a) to 3(e), the radiation source 22 is formed as a flying microbridge structure supported above the bottom surface of the first groove 14 by the anchor points, and in fact, the radiation source 22 may be attached to the bottom surface of the first groove 14.

In the embodiment shown in fig. 2(a) to 2(f) and 3(a) to 3(e), the first substrate 18 is turned upside down, the lower surface is facing up, and the upper surface is facing down, and a Through Silicon Via (TSV) process is used to form the through holes and the control circuit 25 in the through holes. The length direction of the through hole is perpendicular to the lower surface of the first substrate 18, and the through hole is connected to an external bias power supply through a metal pad arranged on the outer side of the lower surface of the first substrate 18.

In this specific embodiment, when in use, the metal pad is required to supply power to the radiation source 22, and by setting different bias voltages, the radiation source 22 operates at different temperatures, and the infrared light emitted by the radiation source 22 is received by the reference pixel 29, so that the temperature measurement calibration efficiency of the infrared detector is effectively improved, and the production cost is reduced.

In one embodiment, before the first substrate 18 is flipped over to the surface of the second substrate 11, the method further comprises the steps of: getter 28 is arranged in the first groove 14 and the second groove 15; antireflection films 27 are formed on the inner and outer surfaces of the bottom surface of the second groove 15, and the antireflection film 27 is an infrared antireflection film for increasing the infrared transmittance of the second groove 15. In one embodiment, antireflection film 27 formed on the inner and outer surfaces of the bottom surface of second groove 15 has the same thickness. In one embodiment, the material of the infrared antireflection film comprises zinc sulfide, silicon, germanium, amorphous silicon germanium or the like.

In fact, in the embodiments shown in fig. 2(a) to 2(f) and 3(a) to 3(e), the getter 28 is also formed in the second groove 15. The getter 28 is formed beside the antireflection film 27. The material of the getter 28 can be a metal with an active surface, such as a getter 28 alloy composed of one or more of zirconium (Zr), vanadium (V), titanium (Ti), etc., and can also be other types of non-evaporable getter 28 materials.

In the embodiment shown in fig. 2(a) to 2(f) and 3(a) to 3(e), before the first substrate 18 is flipped over to the surface of the second substrate 11, the following steps are further included: a material film for isolating external infrared light is deposited on the lower surface of the first substrate 18, so that more accurate temperature control can be realized, and interference of external environment radiation can be avoided. In this embodiment, the through-hole also passes through the material film, and the metal pad is formed on a lower surface of the material film. In one embodiment, the conductive portion of the control circuit 25 is made of copper, aluminum, or the like, and the metal pad is made of aluminum, gold, or the like.

In one embodiment, before the first substrate 18 is flipped over to the surface of the second substrate 11, solder 23(13) required for vacuum packaging is further deposited on the upper surface of the second substrate 11, as shown in fig. 3 (c). The solder 23(13) on the surface of the first substrate 18 is bonded with the solder 23(13) on the surface of the second substrate 11 to form a vacuum package, as shown in fig. 3 (d). Preferably, the packaging form adopts a wafer level vacuum packaging method.

Please refer to fig. 5, fig. 6(a) to fig. 6(d), and fig. 7(a) to fig. 7(e), which illustrate a method for manufacturing an infrared detector according to another embodiment. In this embodiment, first, a first groove 14, a second groove 15, and a third groove 16 are formed on a first substrate 18 illustrated in fig. 6(a), and a solder 23(13) is formed on an upper surface of a sidewall of the first groove 14.

In the embodiment shown in fig. 5, fig. 6(a) to fig. 6(d), and fig. 7(a) to fig. 7(e), the getter 28 is formed on the bottom surface of the first groove 14, and the getter 28 and the infrared reflection reducing film are formed on the bottom surface of the second groove 15. The getter 2828 may be a metal with an active surface, such as a getter 28 alloy composed of one or more of zirconium (Zr), vanadium (V), and titanium (Ti), and may also be other types of non-evaporable getter 28 materials, and the material of the infrared anti-reflection film 27 includes zinc sulfide, silicon, germanium, or amorphous silicon germanium, and the like.

In the embodiments shown in fig. 5, fig. 6(a) to fig. 6(d), and fig. 7(a) to fig. 7(e), a second substrate 11 as shown in fig. 7(a) is provided, the second substrate 11 preferably being a single-side polished silicon wafer.

In this particular embodiment, when forming radiation source 22 over second substrate 11, the following steps are included: forming an emissivity-increasing coating on a surface of the radiation source 22, the emissivity-increasing coating including at least one of a gold black coating, a platinum black coating, or a carbon black coating; a control circuit 25 is formed in the second substrate 11 and is connected to the control circuit 25 and the radiation source 22, so that the radiation source 22 is controlled by the control circuit 25 to operate at a specified temperature and emit known infrared light.

In the preparation of the infrared detector, the preparation of the circuits and pixels of the infrared detector and the radiation source 22 are completed on the second substrate 11, as shown in fig. 7 (b). The circuit of the infrared detector and the control circuit 25 of the radiation source 22 are manufactured by adopting a semiconductor CMOS (complementary metal oxide semiconductor) process, and the pixel of the infrared detector and the radiation source 22 are manufactured by adopting an MEMS (micro-electro-mechanical systems) micro-processing process; radiation source 22 may be coated with gold black, platinum black, carbon black, or the like on the interior surfaces of its structure to increase emissivity.

In this embodiment, solder 23(13) required for packaging is also deposited on the upper surface of the second substrate 11, as shown in fig. 7 (c). When the first substrate 18 is flipped over to the second substrate 11 for packaging, a vacuum package is formed by solder 23(13) bonding, as shown in fig. 7 (d). Preferably, the packaging form adopts a wafer level vacuum packaging method.

In this embodiment, the wafer with the vacuum package completed is diced, and the dicing area is the third groove 16, as shown in fig. 7 (e).

Fig. 8 is a schematic flowchart illustrating steps of an application of an infrared detector according to an embodiment of the present invention. In this embodiment, there is also provided a use of an infrared detector, comprising the steps of: s81, controlling the radiation source 22 to work at a plurality of preset temperatures, enabling the radiation source 22 to emit known infrared light, and controlling the reference pixel 29 to detect the known infrared light; s82, obtaining calibration data according to the data detected by the reference pixel 29 and the known infrared light to form a calibration curve; s83, the infrared light of the object to be detected is detected by the detection module, and the detected data is compared with the calibration curve, so that the actual infrared light of the object to be detected is obtained.

The infrared detector adopts the additionally arranged radiation source 22 with controllable temperature as a signal source of a calibration curve, and the radiation source 22 is arranged at different temperatures to replace the blackbody radiation reference in the prior art, so that the temperature measurement calibration efficiency of the infrared detector can be effectively improved, and the production cost is reduced. In addition, the radiation source 22 can also be used for carrying out regular correction and real-time correction on the infrared detector during the use process of the instrument, so that the precision of the infrared thermometry instrument is improved and ensured.

The micro-processing method is integrated with the detector chip, and the temperature of the infrared detector is controlled by an electric signal, so that the regular correction and the real-time correction of the infrared detector can be realized, and the method is an effective method for improving and ensuring the precision of an infrared temperature measuring instrument.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides an infrared detector for carry out infrared detection to the measured object, its characterized in that, including demarcation module, the demarcation module includes:

the sealing cover is covered on the upper surface of the substrate, and a first closed space is formed on the upper surface of the substrate;

the reference pixel is arranged in the first closed space and used for detecting infrared light;

the radiation source is arranged in the first closed space and used for emitting infrared light to be acquired and detected by the reference pixel, and the temperature of the radiation source is controllable;

still including detecting the module for carry out infrared detection to the measured object, include:

the upper cover is covered on the upper surface of the substrate, and a second closed space is formed on the upper surface of the substrate;

the detection pixel is arranged in the second closed space and used for detecting infrared light of the detected object;

the upper cover comprises a transparent area, and infrared light of the object to be detected penetrates through the transparent area and enters the detection pixel.

2. The infrared detector of claim 1, characterized in that the radiation source comprises:

and the control circuit is connected to the radiation source and is used for controlling the radiation source to work at a preset temperature and emit known infrared light.

3. The infrared detector as set forth in claim 1, wherein the radiation source is attached to or suspended from an inner wall of a top surface of the sealed enclosure, and a surface of the radiation source is coated with a coating for increasing emissivity, including at least one of a gold black coating, a platinum black coating, or a carbon black coating.

4. The infrared detector as set forth in claim 1, wherein the first closed space is evacuated and an outer surface of the sealed cover is formed with a reflection area coated with a reflection layer for reflecting infrared light outside the sealed cover.

5. The infrared detector as claimed in claim 1, wherein an antireflection film covers both the inner and outer surfaces of the bottom surface of the upper cover, and getters are disposed in both the first and second enclosed spaces.

6. The preparation method of the infrared detector is characterized by comprising the following steps of:

providing a first substrate and a second substrate;

digging a first groove on the upper surface of the first substrate;

forming a radiation source in the first groove or forming a radiation source above the second substrate, wherein the temperature of the radiation source is controllable;

forming a reference pixel on the surface of the second substrate;

the first substrate is reversely buckled to the surface of the second substrate, the reference pixel is arranged in the first groove, and the radiation source is also arranged in the first groove;

reversing the first substrate to a front of the second substrate surface, further comprising:

digging a second groove on the upper surface of the first substrate, wherein the size of the second groove is equal to that of the first groove;

and forming a detection pixel on the surface of the second substrate, wherein the position of the detection pixel corresponds to the position of the second groove, so that the detection pixel is arranged in the second groove when the first substrate is reversely buckled on the surface of the second substrate.

7. The method for manufacturing an infrared detector according to claim 6, wherein the first and second grooves are formed on left and right sides of the first substrate, respectively, a thickness of a left side wall of the first groove is equal to a thickness of a right side wall of the second groove, and after the first substrate is flipped over to the surface of the second substrate, the method further comprises the steps of:

and etching the first substrate vertically and downwards in a directional manner along a direction vertical to the upper surface of the second substrate until the upper surface of the second substrate is exposed, wherein an etched area of the first substrate is positioned between the first groove and the second groove, and after etching, the thickness of the right side wall of the first groove, the thickness of the left side wall of the second groove, the thickness of the left side wall of the first groove and the thickness of the right side surface of the second groove are equal.

8. The method for manufacturing an infrared detector as set forth in claim 6, wherein the step of forming the radiation source in the first recess includes:

forming a coating for increasing emissivity on the surface of the radiation source, wherein the coating comprises at least one of a gold black coating, a platinum black coating or a carbon black coating;

digging a through hole on the bottom surface of the first groove;

and forming a control circuit in the through hole, connecting the control circuit with the radiation source, and enabling the radiation source to be controlled by the control circuit, work at a specified temperature and emit known infrared light.

9. The method for manufacturing an infrared detector according to claim 6, comprising the steps of, when forming the radiation source over the second substrate:

and forming a control circuit in the second substrate, and connecting the control circuit and the radiation source to control the radiation source to work at a specified temperature and emit known infrared light.

10. The method for manufacturing an infrared detector according to claim 6, further comprising, before the step of reversing the first substrate to the surface of the second substrate, the steps of:

getter is arranged in the first groove and the second groove;

and forming antireflection films on the inner surface and the outer surface of the bottom surface of the second groove.

11. The method for manufacturing an infrared detector according to claim 6, further comprising, before the step of reversing the first substrate to the surface of the second substrate, the steps of:

forming solder on the top surfaces of the side walls of the first groove and the second groove;

forming solder on the upper surface of the second substrate, wherein the position of the solder is matched with the position of the solder formed on the top surfaces of the side walls of the first groove and the second groove;

before the first substrate is flipped over to the second substrate surface, further comprising the steps of:

and aligning the solder on the upper surface of the second substrate with the solder on the top surfaces of the side walls of the first groove and the second groove, and performing vacuum welding packaging.

12. Use of an infrared detector according to any of claims 1 to 5, characterized in that it comprises the following steps:

controlling a radiation source of a calibration module to work at a plurality of preset temperatures, enabling the radiation source to emit known infrared light, and controlling the reference pixel to detect the known infrared light;

acquiring calibration data according to the data detected by the reference pixel and the known infrared light to form a calibration curve;

and detecting the infrared light of the detected object by using the detection module, and comparing the detected data with the calibration curve so as to obtain the actual infrared light of the detected object.