阅读说明：本技术 一种双级制冷红外探测器 (Double-stage refrigeration infrared detector ) 是由 黄立 张杨文 沈星 洪晓麦 程海玲 刘道进 许思佳 江程鹏 张丽芳 王玲 于 2021-11-18 设计创作，主要内容包括：本发明提供了一种双级制冷红外探测器,包括双级制冷组件和封装杜瓦,所述双级制冷组件包括外壳以及真空封装于外壳内的MEMS节流制冷器和半导体制冷器,MEMS节流制冷器贴装于半导体制冷器的冷端,所述封装杜瓦包括窗框以及真空封装于窗框内的冷屏和芯片,窗框固设于外壳上,芯片贴装于T型导热块上,T型导热块和冷屏的底部均固设于MEMS节流制冷器上。该发明采用MEMS节流制冷器对光学结构器件进行制冷,相比传统的机械式节流探测器,大大减小了本身热质量,同时还采用半导体制冷器对MEMS节流制冷器进行一级预冷,有效解决了MEMS节流制冷器制冷量不足以及冷量分布不均匀带来的问题；并且通过半导体制冷器的设置还解决了制冷结构及光学结构器件的支撑和漏热问题。(The invention provides a two-stage refrigeration infrared detector which comprises a two-stage refrigeration assembly and a packaging Dewar, wherein the two-stage refrigeration assembly comprises a shell, an MEMS throttling refrigerator and a semiconductor refrigerator which are vacuum packaged in the shell, the MEMS throttling refrigerator is attached to the cold end of the semiconductor refrigerator, the packaging Dewar comprises a window frame, a cold screen and a chip, the cold screen and the chip are vacuum packaged in the window frame, the window frame is fixedly arranged on the shell, the chip is attached to a T-shaped heat conduction block, and the bottoms of the T-shaped heat conduction block and the cold screen are fixedly arranged on the MEMS throttling refrigerator. The MEMS throttling refrigerator is adopted to refrigerate the optical structure device, compared with the traditional mechanical throttling detector, the thermal mass of the MEMS throttling refrigerator is greatly reduced, and meanwhile, the semiconductor refrigerator is adopted to carry out primary precooling on the MEMS throttling refrigerator, so that the problems caused by insufficient refrigerating capacity and uneven refrigerating capacity distribution of the MEMS throttling refrigerator are effectively solved; and the problems of support and heat leakage of the refrigerating structure and the optical structure device are solved through the arrangement of the semiconductor refrigerator.)

1. A double-stage refrigeration infrared detector is characterized in that: the double-stage refrigeration device comprises a double-stage refrigeration assembly and an encapsulation dewar, wherein the double-stage refrigeration assembly comprises a shell, and an MEMS throttling refrigerator and a semiconductor refrigerator which are vacuum-encapsulated in the shell, the MEMS throttling refrigerator is attached to a cold end of the semiconductor refrigerator, the encapsulation dewar comprises a window frame, and a cold screen and a chip which are vacuum-encapsulated in the window frame, the window frame is fixedly arranged on the shell, the chip is attached to a T-shaped heat conduction block, and the bottoms of the T-shaped heat conduction block and the cold screen are fixedly arranged on the MEMS throttling refrigerator.

2. The infrared detector of claim 1, characterized in that: and the inner walls of the shell and the window frame are plated with gold.

3. The infrared detector of claim 1, characterized in that: and a groove is formed in the surface of the cold end of the semiconductor refrigerator, and two ends of the MEMS throttling refrigerator are arranged on the side wall of the groove.

4. The infrared detector of claim 1, characterized in that: the cold screen is arranged in an intermediate temperature area of the MEMS throttling refrigerator for cooling, and the T-shaped heat conduction block and a chip on the T-shaped heat conduction block are arranged in a lowest refrigerating temperature area of the MEMS throttling refrigerator.

5. The infrared detector of claim 1, characterized in that: the MEMS throttling refrigerator comprises a refrigerator heat exchange channel, the refrigerator heat exchange channel comprises a throttling element, a cold fluid channel and a hot fluid channel, one end of the hot fluid channel is an air inlet connected with a high-pressure gas source, the other end of the hot fluid channel is communicated with one end of the cold fluid channel after passing through the throttling element, and the other end of the cold fluid channel is an air outlet and flows to the atmosphere through an exhaust pipe.

6. The infrared detector of claim 5, characterized in that: the outlet of the throttling element is communicated with the cold fluid channel through an expansion cavity.

7. The infrared detector of claim 5, characterized in that: the MEMS throttling refrigerator comprises a glass carrier, wherein a refrigerator heat exchange channel is etched on the glass carrier through an etching process, and the refrigerator heat exchange channel is a spiral channel.

8. The infrared detector of claim 7, characterized in that: the MEMS throttling refrigerator further comprises a glass cover plate, and the glass cover plate is attached to and sealed with the glass carrier.

9. The infrared detector of claim 7, characterized in that: the cold fluid channel and the hot fluid channel are tightly attached to form fluid sets, a space is arranged between every two adjacent fluid sets, and the flowing directions of the fluid in the cold fluid channel and the fluid in the hot fluid channel are opposite.

Technical Field

The invention belongs to the technical field of infrared detection, and particularly relates to a two-stage refrigeration infrared detector.

Background

The infrared detector is a core component of the infrared technology and is also a precursor for the development of the infrared technology. The infrared detector has wide application in civil and military fields such as missile guidance, aerospace detection, early warning satellite and reconnaissance. The mechanical throttling refrigerator has the characteristics of small volume, light weight, compact structure, no moving part at a low temperature end and the like, and is widely applied to the field of infrared detection.

However, the existing mechanical throttling refrigeration detector generally adopts one-stage refrigeration, and only the mechanical throttling refrigeration device is used for refrigerating the detector, meanwhile, the mechanical throttling refrigeration device has larger thermal mass, most of cold energy needs to be consumed in the process of utilizing the cooling device to cool the detector, so that the problems of larger required refrigerating capacity and air consumption are caused, the refrigerating capacity is not uniformly distributed, the cold energy of an intermediate temperature region is large, the cold energy outside the intermediate temperature region is small, cold screen refrigeration is not in place, in addition, the heat conduction and heat leakage of a support structure at the lower part of the existing mechanical throttling refrigeration device are serious, and the above are key factors for limiting the practical application of the throttling refrigeration infrared detector.

Disclosure of Invention

The invention aims to provide a double-stage refrigeration infrared detector which can at least solve part of defects in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

the double-stage refrigeration infrared detector comprises a double-stage refrigeration assembly and an encapsulation dewar, wherein the double-stage refrigeration assembly comprises a shell, an MEMS (micro electro mechanical System) throttling refrigerator and a semiconductor refrigerator, the MEMS throttling refrigerator is attached to a cold end of the semiconductor refrigerator, the encapsulation dewar comprises a window frame, a cold screen and a chip, the cold screen and the chip are vacuum-encapsulated in the window frame, the window frame is fixedly arranged on the shell, the chip is attached to a T-shaped heat conduction block, and the bottoms of the T-shaped heat conduction block and the cold screen are fixedly arranged on the MEMS throttling refrigerator.

Further, the inner walls of the shell and the window frame are all plated with gold.

Furthermore, a groove is formed in the surface of the cold end of the semiconductor refrigerator, and two ends of the MEMS throttling refrigerator are arranged on the side wall of the groove.

Furthermore, the cold screen is arranged in an intermediate temperature zone of the MEMS throttling refrigerator for cooling, and the T-shaped heat conduction block and the chip on the T-shaped heat conduction block are arranged in a lowest refrigerating temperature zone of the MEMS throttling refrigerator.

Furthermore, the MEMS throttling refrigerator comprises a refrigerator heat exchange channel, the refrigerator heat exchange channel comprises a throttling element, a cold fluid channel and a hot fluid channel, one end of the hot fluid channel is an air inlet connected with a high-pressure gas source, the other end of the hot fluid channel is communicated with one end of the cold fluid channel after passing through the throttling element, and the other end of the cold fluid channel is an air outlet and flows to the atmosphere through an exhaust pipe.

Further, the outlet of the throttling element is communicated with the cold fluid channel through the expansion cavity.

Furthermore, the MEMS throttling refrigerator comprises a glass carrier, wherein a refrigerator heat exchange channel is carved on the glass carrier through an etching process, and the refrigerator heat exchange channel is a spiral channel.

Furthermore, the MEMS throttling refrigerator also comprises a glass cover plate, and the glass cover plate is attached and sealed with the glass carrier.

Furthermore, the cold fluid channel and the hot fluid channel are tightly attached to form fluid sets, a space is arranged between every two adjacent fluid sets, and the flowing directions of the fluid in the cold fluid channel and the fluid in the hot fluid channel are opposite.

Compared with the prior art, the invention has the beneficial effects that:

the double-stage refrigeration infrared detector provided by the invention adopts the MEMS throttling refrigerator to refrigerate the optical structure device, greatly reduces the thermal mass of the double-stage refrigeration infrared detector compared with the traditional mechanical throttling detector, and simultaneously adopts the semiconductor refrigerator to carry out primary precooling on the MEMS throttling refrigerator, thereby effectively solving the problems caused by insufficient refrigerating capacity and uneven distribution of refrigerating capacity of the MEMS throttling refrigerator; and the problems of support and heat leakage of the refrigerating structure and the optical structure device are solved through the arrangement of the semiconductor refrigerator.

The present invention will be described in further detail below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of a two-stage refrigeration infrared detector according to the present invention;

FIG. 2 is a schematic structural diagram of a two-stage refrigeration assembly in the two-stage refrigeration infrared detector of the present invention;

FIG. 3 is a top view of a dual stage refrigeration assembly in the dual stage refrigeration infrared detector of the present invention;

FIG. 4 is a schematic cross-sectional view of the MEMS throttle refrigerator in the dual-stage refrigeration infrared detector of the present invention;

FIG. 5 is a schematic diagram of the refrigerator heat exchange channel of the MEMS throttling refrigerator in the two-stage refrigeration infrared detector of the invention.

Description of reference numerals: 1. a housing; 2. a semiconductor refrigerator; 3. an MEMS throttling refrigerator; 4. a window frame; 5. a window piece; 6. cooling the screen; 7. a chip; 8. a T-shaped heat conducting block; 9. an exhaust pipe; 10. a groove; 11. an air inlet; 12. a thermal fluid channel; 13. a glass carrier; 14. a glass cover plate; 15. an expansion chamber; 16. a cold fluid channel; 17. an air outlet; 18. a throttling element.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of the present invention, "a plurality" means two or more unless otherwise specified.

As shown in fig. 1, 2 and 3, the present embodiment provides a two-stage refrigeration infrared detector, which includes a two-stage refrigeration assembly and a packaging dewar, where the two-stage refrigeration assembly includes a housing 1, and an MEMS throttling refrigerator 3 and a semiconductor refrigerator 2 vacuum-packaged in the housing 1, the semiconductor refrigerator 2 is adhered to the bottom of the housing 1, the MEMS throttling refrigerator 3 is adhered to the cold end of the semiconductor refrigerator 2, the packaging dewar includes a window frame 4, and a cold screen 6 and a chip 7 vacuum-packaged in the window frame 4, the window frame 4 is fixed on the housing 1, the chip 7 is adhered to a T-shaped heat conducting block 8, and the bottoms of the T-shaped heat conducting block 8 and the cold screen 6 are both fixed on the MEMS throttling refrigerator 3.

The window frame 4 of the packaging Dewar and the shell 1 of the double-stage refrigeration assembly are welded in a laser mode, a window sheet 5 is arranged on the top of the window frame 4, the window sheet 5 and the window frame 4 are connected in a soft soldering mode, meanwhile, a getter is activated in the packaging Dewar, vacuumizing and clamping sealing are conducted, the vacuum environment in the packaging Dewar is guaranteed, and heat leakage of a refrigerator, a cold screen 6 and the like is reduced.

In the embodiment, the semiconductor refrigerator 2 is used for primary refrigeration to cool the MEMS throttling refrigerator 3, the MEMS throttling refrigerator 3 is used for secondary refrigeration to cool the components such as the cold screen 6, the chip 7 and the like in the packaging Dewar, and meanwhile, the vacuum environment is kept in the packaging Dewar to reduce the loss of cold energy caused by convection heat exchange; in addition, in the embodiment, the MEMS throttling refrigerator 3 is adopted to refrigerate optical structure devices such as the cold screen 6 and the chip 7, the thermal mass of the MEMS throttling refrigerator is greatly reduced compared with that of a traditional mechanical throttling detector, and meanwhile, the semiconductor refrigerator 2 is adopted to carry out primary precooling on the MEMS throttling refrigerator 3, so that the problems caused by insufficient refrigerating capacity and uneven refrigerating capacity distribution of the MEMS throttling refrigerator 3 are effectively solved. In addition, in this embodiment, the semiconductor refrigerator 2 is disposed below the MEMS throttling refrigerator 3, and can support the MEMS throttling refrigerator 3, the optical structure devices such as the cold shield 6 and the chip 7, so as to replace the supporting structure of the lower portion of the existing mechanical throttling refrigerator, and further solve the problem of serious heat leakage of the supporting structure of the existing mechanical throttling refrigerator due to heat conduction.

Preferably, the inner walls of the housing 1 and the window frame 4 are plated with gold to further reduce the radiation heat leakage of the cold shield 6 and the refrigerator, etc.

Further, in this embodiment, the input power of the semiconductor refrigerator 2 can be controlled to assist the temperature control of the chip 7.

Because the semiconductor refrigerator 2 can refrigerate at 200K or above, but does not refrigerate below 200K, but can heat, and in order to further ensure the precooling effect of the semiconductor refrigerator 2 on the MEMS throttling refrigerator 3, preferably, a groove 10 is provided on the surface of the cold end of the semiconductor refrigerator 2, two ends of the MEMS throttling refrigerator 3 are disposed on the side wall of the groove 10, i.e. a certain gap is left between the lower surface of the MEMS throttling refrigerator 3 and the upper surface of the semiconductor refrigerator 2; when the temperature is above 200K, the semiconductor refrigerator 2 can provide cold energy to the MEMS throttling refrigerator 3 to assist in refrigeration, and when the temperature is at a low temperature (i.e. below 200K), the semiconductor refrigerator 2 is provided with the groove 10, so that the semiconductor refrigerator 2 does not take the cold energy of the central temperature zone of the MEMS throttling refrigerator 3 to affect the refrigeration of the central temperature zone of the MEMS throttling refrigerator 3.

As a specific embodiment, as shown in fig. 4 and 5, the MEMS throttling refrigerator 3 includes a refrigerator heat exchange channel, the refrigerator heat exchange channel includes a throttling element 18, a cold fluid channel 16 and a hot fluid channel 12, one end of the hot fluid channel 12 is an air inlet 11 connected to a high-pressure air source, the other end of the hot fluid channel 12 is communicated with one end of the cold fluid channel 16 after passing through the throttling element 18, and the other end of the cold fluid channel 16 is an air outlet 17 and flows to the atmosphere through an exhaust pipe 9. Preferably, the outlet of the throttling element 18 communicates with the cold fluid channel 16 via an expansion chamber 15.

High-pressure gas working medium enters a hot fluid channel 12 from an air inlet 11 and then flows into a throttling element 18, the throttling element 18 is a micro channel with the size smaller than that of a cold fluid channel and a hot fluid channel, the hot fluid enters the throttling element 18 from the hot fluid channel 12 to generate larger pressure drop, namely, throttling refrigeration effect, so that cold fluid is generated by refrigeration in the throttling element 18, the cold fluid further releases pressure in an expansion cavity 15, enters a cold fluid channel 16 and exchanges heat with the hot fluid, and then the hot fluid entering the MEMS throttling refrigerator 3 is cooled until the hot fluid in the throttling element 18 reaches stable refrigeration temperature, namely, the lowest refrigeration temperature; and the cold fluid after heat exchange with the hot fluid flows out of the air outlet 17 and flows to the atmosphere through an exhaust pipe 9 arranged on the shell 1.

In the process, the expansion cavity 15 accumulates part of cold fluid working medium which is refrigerated by the throttling element 18 to reach the lowest refrigeration temperature, so that the T-shaped heat conducting block 8 and the chip 7 on the T-shaped heat conducting block 8 are arranged in the lowest refrigeration temperature area of the MEMS throttling refrigerator 3, the refrigeration effect of the chip 7 is ensured, meanwhile, the T-shaped heat conducting block 8 is designed to be adopted between the MEMS throttling refrigerator 3 and the chip 7 for heat transfer refrigeration, because the area of the lowest refrigeration temperature area of the MEMS throttling refrigerator 3 is small, the bottom surface area of the T-shaped heat conducting block 8 is small, the top surface area is large, the bottom of the T-shaped heat conducting block 8 is contacted with the lowest refrigeration temperature area, the cold energy is transferred to the top of the T-shaped heat conducting block 8, the chip 7 arranged at the top of the T-shaped heat conducting block 8 is cooled, on one hand, the structural design fully utilizes the cold energy of the lowest refrigeration temperature area of the MEMS refrigerator 3, on the other hand, the surface of the chip 7 is ensured to be uniformly cooled; and the cold screen 6 is arranged in the intermediate temperature zone of the MEMS throttling refrigerator 3 for cooling, and the cold energy of the intermediate temperature zone is used for cooling, so that the utilization rate of the cooling capacity is improved, and the waste of the cold energy is avoided.

Specifically, the MEMS throttling refrigerator 3 includes a glass carrier 13, wherein the throttling element 18, the cold fluid channel 16, the hot fluid channel 12, and the like are all micro-channels formed on the surface of the glass carrier 13 by using a photolithography and etching process, and in order to ensure the miniaturization of the MEMS throttling refrigerator 3, the refrigerator heat exchanging channel on the glass carrier 13 can be designed as a spiral channel. Preferably, a glass cover plate 14 can be arranged on the glass carrier 13, and the glass cover plate 14 is attached and sealed with the glass carrier 13 by adopting a bonding process to form the complete MEMS throttling refrigerator 3, so as to ensure that the cold fluid channel 16 and the hot fluid channel 12 in the MEMS throttling refrigerator 3 are independent from each other.

Furthermore, the adjacent cold fluid channels 16 and the adjacent hot fluid channels 12 are designed to have the same curvature and are tightly attached to form fluid groups, so that the heat conduction between the cold fluid channel and the hot fluid channel is enhanced, the heat exchange effect is ensured, meanwhile, the fluids in the cold fluid channels 16 and the hot fluid channels 12 adopt opposite flowing directions, namely, a mode of countercurrent heat exchange is adopted, a gap is formed between the two adjacent fluid groups, namely, a certain distance is kept between the adjacent cold fluid channels 16 or the adjacent hot fluid channels 12, so that the radial temperature gradient is ensured, and the radial heat conduction loss of the refrigerator is reduced.

In conclusion, the two-stage refrigeration infrared detector provided by the invention adopts the MEMS throttling refrigerator to refrigerate the optical structure device, compared with the traditional mechanical throttling detector, the two-stage refrigeration infrared detector greatly reduces the thermal mass per se, and simultaneously adopts the semiconductor refrigerator to carry out primary precooling on the MEMS throttling refrigerator, thereby effectively solving the problems caused by insufficient refrigerating capacity and uneven distribution of refrigerating capacity of the MEMS throttling refrigerator; and the problems of support and heat leakage of the refrigerating structure and the optical structure device are solved through the arrangement of the semiconductor refrigerator.

The above examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention, which is intended to be covered by the claims and any design similar or equivalent to the scope of the invention.