Lightweight infrared detector and preparation method thereof

Abstract

The invention provides a lightweight infrared detector and a preparation method, the lightweight infrared detector comprises a Dewar shell, the Dewar shell comprises an outer layer hollow interlayer, at least a local area of the Dewar shell comprises an inner layer hollow interlayer, and the Dewar shell forms a double-layer interlayer structure composed of the inner layer hollow interlayer and the outer layer hollow interlayer in the area with the inner layer hollow interlayer. And the outer hollow interlayer is an outer vacuum interlayer. The material consumption can be greatly reduced by adopting the multiple hollow interlayers, the dead weight of the detector is further effectively reduced, external heat can be more effectively prevented from being conducted to the inside by utilizing the heat insulation layer formed by the hollow structure, the dependence on an expensive and complex gold plating process is reduced, the manufacturing process is simplified, the cost is reduced, and the production efficiency is improved. And stray light generated by self heat radiation in the Dewar is weakened.

Description

Technical Field

[0001] The present invention relates to the technical field of infrared detectors, and in particular to a lightweight infrared detector and a preparation method thereof. Background Art

[0002] In modern naval aviation operations, carrier-based fighter aircraft, especially early warning aircraft, play a crucial role. These aircraft must possess a long combat radius and robust detection capabilities to meet the demands of complex and dynamic maritime environments. However, carrier-based aircraft are subject to strict takeoff weight restrictions, necessitating a lightweight design while maintaining detection performance. Traditional photoelectric detector designs are no longer able to meet these lightweight requirements.

[0003] Currently, infrared detectors typically use a solid metal casing with a thickness of 1.5-2mm. To achieve optimal heat shielding, the window frame and outer surface of the cold shield often require gold plating. Even with gold plating, this does not address the industry's problem of significant heat radiation from the window components to the cold shield at room temperature. Furthermore, the support rods transfer window heat to the cold shield via heat conduction, significantly increasing the cooling time of the cold head. Therefore, achieving lightweight photodetectors without sacrificing detection performance has become a pressing issue. Summary of the Invention

[0004] Based on the above content, the present invention provides a lightweight infrared detector and a preparation method, aiming to solve the technical problems of weight and heat insulation of the detector in the prior art.

[0005] A lightweight infrared detector includes a dewar shell, the dewar shell includes an outer hollow interlayer, and at least a local area of ​​the dewar shell includes an inner hollow interlayer. The dewar shell forms a double-layer interlayer structure consisting of an inner hollow interlayer and an outer hollow interlayer in the area having the inner hollow interlayer, and the outer hollow interlayer is an outer vacuum interlayer.

[0006] Furthermore, the Dewar housing includes a window frame portion and a main shell portion, the window frame portion is above the main shell portion, and an optical window is opened at the top of the window frame portion;

[0007] The area of ​​the Dewar shell containing the inner hollow interlayer includes at least the window frame portion.

[0008] Furthermore, the outer hollow interlayer is a grid structure.

[0009] Furthermore, the inner hollow interlayer is a spiral structure.

[0010] Furthermore, a first connecting pipe is connected to the inner hollow interlayer, and the first connecting pipe is connected to an external refrigeration module. The refrigeration module transports refrigeration fluid to the inner hollow interlayer through the first connecting pipe for refrigeration.

[0011] Furthermore, the first connecting pipe is a copper pipe.

[0012] Furthermore, the lower end of the Dewar shell is connected to a cold finger base, which is a multi-layer vacuum sandwich structure.

[0013] Furthermore, at least one intermediate vacuum interlayer is provided between the inner hollow interlayer and the outer vacuum interlayer of the Dewar shell.

[0014] A method for preparing a lightweight infrared detector is used to prepare the aforementioned lightweight infrared detector, including a step of preparing a Dewar shell. In the step of preparing the Dewar shell, a Dewar shell with an outer hollow interlayer and an inner hollow interlayer is formed by vacuum three-dimensional printing, and the outer hollow interlayer of the Dewar shell is an outer vacuum interlayer.

[0015] A method for preparing a lightweight infrared detector, for preparing the aforementioned lightweight infrared detector, comprising the steps of preparing a dewar shell and exhausting the interior space of the dewar shell.

[0016] In the step of preparing the Dewar shell, a preliminary Dewar shell is formed with an outer hollow interlayer and an inner hollow interlayer in at least a partial area. The outer hollow interlayer is connected to a second connecting pipe, which is connected to an external vacuum module. The vacuum module is used to perform a first exhaust of the outer hollow interlayer.

[0017] During the exhaust step inside the Dewar shell, the internal accommodating space of the Dewar shell accommodates the cold finger components as well as the substrate, cold shield and chip. The vacuum module is simultaneously connected to the outer hollow interlayer and the internal accommodating space of the Dewar shell, and simultaneously performs the second exhaust of the outer hollow interlayer after the first exhaust and the exhaust of the internal accommodating space of the Dewar shell, thereby obtaining a Dewar shell containing an outer vacuum interlayer, and the internal accommodating space of the Dewar shell forms a vacuum.

[0018] The beneficial technical effects of the present invention are: by introducing a multi-layer hollow interlayer design to replace the traditional thick solid metal wall Dewar shell, the use of multi-layer hollow layers can greatly reduce the material usage, thereby effectively reducing the weight of the detector, and the thermal insulation layer formed by the hollow structure can more effectively block the external heat from being conducted to the inside, reducing the dependence on expensive and complex gold plating process, simplifying the manufacturing process and reducing costs. The new design helps to reduce the stray light generated by the thermal radiation from the Dewar itself, improves the detection accuracy and signal clarity, and through the carefully designed multi-level structure, enhances the vacuum sealing performance of the equipment, extends the working life of the Dewar, reduces the maintenance frequency, and improves the reliability and availability of the system, that is, achieves multiple effects including efficient thermal shielding, excellent vacuum sealing and optimized refrigeration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of an embodiment of a lightweight infrared detector of the present invention;

[0020] Figure 2 This is a structural schematic diagram of another embodiment of a lightweight infrared detector of the present invention;

[0021] Figure 3 This is a schematic structural diagram of an embodiment of a lightweight infrared detector of the present invention;

[0022] Figure 4-6 A schematic diagram of an outer vacuum interlayer of a lightweight infrared detector of the present invention;

[0023] in,

[0024] 1a-Window frame part of the Dewar housing;

[0025] 1b-main shell part of the Dewar housing;

[0026] 2-Outer vacuum interlayer;

[0027] 3-Inner hollow interlayer;

[0028] 4-Cold finger base;

[0029] 5-first connecting pipe;

[0030] 6-cold finger components;

[0031] 7-Optical window. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0035] See also Figure 1The present invention provides a lightweight infrared detector, comprising a dewar shell, the dewar shell comprising an outer hollow interlayer (2), at least a local area of ​​the dewar shell comprising an inner hollow interlayer (3), the dewar shell forming a double-layer interlayer structure consisting of the inner hollow interlayer (3) and the outer hollow interlayer (2) in the area having the inner hollow interlayer (3), and the outer hollow interlayer being an outer vacuum interlayer.

[0036] The internal accommodation space of the Dewar housing is integrated with a cold finger component (7) and components assembled on the upper end of the cold finger component (7), such as a substrate, a chip, a cold screen, a filter on the cold screen, and the like.

[0037] Specifically, the Dewar shell is made of metal.

[0038] The infrared detector is a cooled infrared detector.

[0039] Specifically, the inner hollow interlayer (3) and the outer hollow interlayer (2) are not connected.

[0040] Specifically, the inner hollow interlayer (3) is an inner vacuum interlayer or may not be a vacuum interlayer.

[0041] By introducing a multi-layer hollow metal layer design to replace the traditional thick solid metal wall Dewar shell, the use of multi-layer hollow metal layers can greatly reduce the amount of material used, thereby effectively reducing the weight of the detector. The thermal insulation layer formed by the hollow structure can more effectively block the external heat from being conducted to the inside, reducing the dependence on expensive and complex gold plating process, simplifying the manufacturing process and reducing costs. The new design helps to reduce the stray light generated by the thermal radiation from the Dewar itself, improving the detection accuracy and signal clarity. Through the carefully designed multi-level structure, the vacuum sealing performance of the equipment is enhanced, the working life of the Dewar is extended, the maintenance frequency is reduced, and the reliability and availability of the system are improved, that is, multiple effects including efficient thermal shielding, excellent vacuum sealing and optimized cooling efficiency are achieved.

[0042] like Figure 1 As shown, further, the Dewar housing includes a window frame portion (1a) and a main shell portion (1b), the window frame portion (1a) is above the main shell portion (1b), and an optical window (7) is opened at the top of the window frame portion (1a);

[0043] The area of ​​the Dewar shell containing the inner hollow interlayer (3) at least includes the window frame portion (1a).

[0044] A wire lead ring is provided between the window frame portion (1a) and the main housing portion (1b).

[0045] Furthermore, a first connecting pipe (5) is connected to the inner hollow interlayer (3), and the first connecting pipe (5) is connected to an external refrigeration module. The refrigeration module transports refrigeration fluid to the inner hollow interlayer (3) through the first connecting pipe (5) for refrigeration.

[0046] Specifically, the refrigeration fluid is liquid nitrogen.

[0047] Specifically, the first connecting pipe (5) is a copper pipe.

[0048] The first connecting pipe (5) is fixed to the Dewar shell by brazing. The first connecting pipe (5) is used to connect to the refrigeration module. The refrigeration module transports liquid nitrogen. When the inner hollow interlayer (3) is in the window frame part, the liquid nitrogen can cool the inner surface of the window frame part, thereby reducing the heat radiation of the inner surface of the window frame part to the cold screen and the amount of stray light.

[0049] Furthermore, the entire area of ​​the Dewar shell forms a double-layer sandwich structure consisting of an inner hollow interlayer (3) and an outer hollow interlayer (2), that is, the Dewar shell is an integral double-layer sandwich structure.

[0050] like Figure 3 As shown, the window frame part (1a) and the main shell part (1b) are both double-layer structures, that is, an overall double-layer sandwich structure.

[0051] In the case of an overall double-layer sandwich structure, in order to achieve the ultimate thermal radiation shielding, the liquid nitrogen in the inner hollow sandwich (3) can cool the entire inner surface of the Dewar shell.

[0052] Furthermore, the outer hollow interlayer (2) is a grid structure.

[0053] like Figure 4-Figure 6 As shown, the shape of the grid structure can be hexagonal, quadrilateral or triangular.

[0054] Specifically, the side length of the grid structure is 0.1-1 mm.

[0055] Specifically, the outer hollow interlayer (2) can be a fully enclosed structure, not connected to the outside world, and the vacuum degree is 10 -4 The outer hollow interlayer (2) can be formed into a fully enclosed structure by vacuum three-dimensional printing.

[0056] Specifically, the outer hollow interlayer (2) can be a semi-enclosed structure, that is, the outer hollow interlayer is connected to a second connecting pipe, the second connecting pipe is connected to an external vacuum module, and the vacuum module performs vacuuming. The outer hollow interlayer (2) can be formed into a semi-enclosed structure by vacuum three-dimensional printing.

[0057] By vacuum 3D printing, a partial double-layer sandwich structure or an overall double-layer sandwich structure can be formed in one go. By vacuum 3D printing, the inner layer and the outer layer are formed by printing simultaneously, so that the inner hollow sandwich and the outer hollow sandwich can both be vacuum-type, and the inner hollow sandwich and the outer hollow sandwich can be printed as a fully enclosed type, that is, no connecting pipes are designed to communicate with the outside world. Of course, vacuum 3D printing can also print semi-enclosed types, for example, the inner hollow sandwich is printed to be connected to a first connecting pipe (5) to inject liquid nitrogen when communicating with the outside world.

[0058] Furthermore, the inner hollow interlayer (3) is a spiral structure.

[0059] See also Figure 3 Furthermore, the lower end of the Dewar shell is connected to a cold finger base (4), and the cold finger base (4) is a multi-layer vacuum sandwich structure.

[0060] The cold finger base (4) is also configured as a vacuum sandwich structure, which helps to achieve lightweighting of the infrared detector.

[0061] Furthermore, at least one intermediate hollow interlayer is provided between the inner hollow interlayer (3) and the outer hollow interlayer (2) of the Dewar shell. The intermediate hollow interlayer may be an intermediate vacuum interlayer.

[0062] If only vacuum and thermal insulation performance are considered, the Dewar shell can be a hollow sandwich with more than two layers. However, if it exceeds four layers, the lightweight effect may be reduced.

[0063] Specifically, the thickness of the thin wall of each hollow interlayer formed in the Dewar shell is 0.1-0.4 mm.

[0064] Specifically, the thickness of the overall double-layer sandwich Dewar shell (from the inner surface of the inner wall to the outer surface of the outer wall) is 1.5-4 mm.

[0065] The present invention provides a method for preparing a lightweight infrared detector, which is used to prepare a lightweight infrared detector as described above, including a step of preparing a Dewar shell. In the step of preparing the Dewar shell, the Dewar shell with an outer hollow interlayer and an inner hollow interlayer is formed by vacuum three-dimensional printing, and the outer hollow interlayer of the Dewar shell is an outer vacuum interlayer.

[0066] The vacuum degree is maintained at 10 during printing. -4 The printed Dewar shell structure is a closed cavity. After printing, the vacuum inside the hollow structure is consistent with the vacuum of the printer environment. -4 Pa order of magnitude.

[0067] The present invention also provides a method for preparing a lightweight infrared detector, which is used to prepare a lightweight infrared detector as described above, including the steps of preparing a Dewar shell and exhausting the internal accommodating space of the Dewar shell;

[0068] In the step of preparing the Dewar shell, a preliminary Dewar shell is formed with an outer hollow interlayer and an inner hollow interlayer in at least a partial area. The outer hollow interlayer is connected to a second connecting pipe, which is connected to an external vacuum module. The vacuum module is used to perform a first exhaust of the outer hollow interlayer.

[0069] During the exhaust step inside the Dewar shell, the internal accommodation space of the Dewar shell accommodates the cold finger components as well as the substrate, cold shield and chip. The vacuum module is simultaneously connected to the outer hollow interlayer and the internal accommodation space of the Dewar shell, and simultaneously performs the second exhaust of the outer hollow interlayer after the first exhaust and the exhaust of the internal accommodation space of the Dewar shell, thereby obtaining a Dewar shell containing an outer vacuum interlayer, and the internal accommodation space of the Dewar shell forms a vacuum.

[0070] Specifically, the second connecting pipe is a copper pipe.

[0071] Brazing copper tube, through secondary exhaust (exhaust at the same time as the dewar internal) to achieve a vacuum degree of 10 -6 -10 -8 Compared to 3D printing's fully enclosed outer vacuum interlayer, the vacuum layer provides a higher vacuum level, ensuring a longer vacuum life within the Dewar. The outer vacuum interlayer is a vacuum space, isolating the atmosphere and acting as a transition layer to the ultra-vacuum within the Dewar. The vacuum interlayer acts as a transition layer, extending the Dewar's ultra-vacuum life.

[0072] The invention achieves multiple functions such as heat shielding, vacuum and refrigeration through multiple hollow metal layers. It not only improves the reliability of heat insulation and vacuum, but also effectively reduces the stray light caused by the heat radiation inside the dewar.

[0073] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A lightweight infrared detector, comprising a dewar housing, characterized in that: The Dewar shell includes an outer hollow interlayer, and at least a local area of ​​the Dewar shell includes an inner hollow interlayer. The Dewar shell forms a double-layer interlayer structure consisting of the inner hollow interlayer and the outer hollow interlayer in the area having the inner hollow interlayer, and the outer hollow interlayer is an outer vacuum interlayer.

2. A lightweight infrared detector according to claim 1, characterized in that: The Dewar housing includes a window frame portion and a main shell portion, wherein the window frame portion is above the main shell portion, and an optical window is opened on the top of the window frame portion; The area of ​​the Dewar shell containing the inner hollow interlayer includes at least the window frame portion.

3. The lightweight infrared detector according to claim 1, characterized in that: The outer hollow interlayer is a grid structure.

4. The lightweight infrared detector according to claim 1, characterized in that: The inner hollow interlayer is a spiral structure.

5. The lightweight infrared detector according to claim 1, characterized in that: The inner hollow interlayer is connected to a first connecting pipe, and the first connecting pipe is connected to an external refrigeration module. The refrigeration module transports refrigeration fluid to the inner hollow interlayer through the first connecting pipe for refrigeration.

6. The lightweight infrared detector according to claim 5, characterized in that: The first connecting pipe is a copper pipe.

7. The lightweight infrared detector according to claim 1, characterized in that: The lower end of the Dewar shell is connected to a cold finger base, and the cold finger base is a multi-layer vacuum sandwich structure.

8. The lightweight infrared detector according to claim 1, characterized in that: At least one intermediate vacuum interlayer is provided between the inner hollow interlayer and the outer vacuum interlayer of the Dewar shell.

9. A method for preparing a lightweight infrared detector, characterized in that: Used to prepare a lightweight infrared detector as described in any one of claims 1 to 8, including a preparation step of a Dewar shell, in which the Dewar shell with the outer hollow interlayer and the inner hollow interlayer is formed by vacuum three-dimensional printing, and the outer hollow interlayer of the Dewar shell is an outer vacuum interlayer.

10. A method for preparing a lightweight infrared detector, characterized in that: A method for preparing a lightweight infrared detector according to any one of claims 1 to 8, comprising the steps of preparing a Dewar shell and exhausting the interior space of the Dewar shell. In the step of preparing the Dewar shell, a preliminary Dewar shell is formed with an outer hollow interlayer and an inner hollow interlayer in at least a partial area, the outer hollow interlayer is connected to a second connecting pipe, the second connecting pipe is connected to an external vacuum module, and the outer hollow interlayer is exhausted for the first time using the vacuum module; In the exhaust step inside the Dewar shell, the internal accommodating space of the Dewar shell accommodates a cold finger component as well as a substrate, a cold shield and a chip. The vacuum module is simultaneously connected to the outer hollow interlayer and the internal accommodating space of the Dewar shell, and simultaneously performs a second exhaust of the outer hollow interlayer after the first exhaust and an exhaust of the internal accommodating space of the Dewar shell, thereby obtaining the Dewar shell containing the outer vacuum interlayer, and forming a vacuum in the internal accommodating space of the Dewar shell.

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