An infrared detector and mechanical refrigerator coupling assembly

Abstract

This invention discloses a coupling assembly between an infrared detector and a mechanical refrigerator, belonging to the field of infrared detection technology. The assembly includes a refrigerator assembly, a detector chip assembly, a cold shield, a Dewar assembly, and a thermal insulation support structure. The refrigerator assembly has a hot-end flange, a cold plate, and cold fingers, with the cold fingers and cold plate thermally connected. The detector chip assembly's chip, splicing substrate, and lead substrate are bonded and fixed by a low-temperature adhesive layer. The lead substrate is connected to the cold plate by threaded fasteners, and the interface between the two is filled with a thermally conductive medium layer. The cold shield is fixed to the lead substrate or cold plate and surrounds the chip, thermally connected to both. The Dewar assembly's outer shell is threaded onto the hot-end flange, sealing to form a vacuum insulation space, encapsulating the chip assembly and the cold shield. The thermal insulation support structure consists of thin-walled cylindrical supports spaced apart, connecting the cold plate and the hot-end flange. Flexible hinges or bearing structures can be used to achieve six-degree-of-freedom statically determinate support. This assembly has a stable structure, high heat transfer efficiency, low heat leakage, and can reduce low-temperature thermal stress.

Description

Technical Field

[0001] This application relates to the field of infrared detection technology, and in particular to a coupling component between an infrared detector and a mechanical refrigeration unit. Background Technology

[0002] In the field of infrared detector coupling design with mechanical cryogenic systems, achieving a low-temperature operating environment for the detector chip typically requires efficient transfer of cooling energy from the cryogenic system to the chip assembly. Existing technologies primarily employ two coupling methods, depending on the scale of the detector assembly: one is an insertion coupling method where the Dewar, chip assembly, and cold shield are integrated into a single unit and mounted on the hot-end flange of the cryogenic system's cold finger assembly; the other is a large-scale detector coupling method where the Dewar, chip assembly, and cold shield are mounted separately on the cryogenic system's cold plate and hot-end flange. The insertion coupling method, due to its high structural integration and simplified assembly process, is widely used in applications with smaller detector sizes.

[0003] However, when the detector is large in scale (e.g., linear array greater than 2000 yuan, area array greater than 2000×2000 yuan, or image plane size greater than 60mm in one direction), the following technical problems arise if the insertion coupling method is still used: Since the chip assembly and the cooling finger of the refrigerator are fixed by integrated installation, the cooling energy needs to be transferred through multiple levels of structure, the path is long and the thermal resistance is large, making it difficult to guarantee the chip temperature uniformity; at the same time, during the process of cooling from room temperature to low operating temperature, the thermal stress generated by the difference in thermal expansion coefficients of each component is difficult to release effectively, which can easily lead to the deterioration of chip flatness and thus affect the optical imaging quality; in addition, the chip assembly, cooling screen, etc. are all installed on the same structure, and if a component fails, the whole structure needs to be disassembled and replaced, resulting in high maintenance costs. Summary of the Invention

[0004] This specification provides an embodiment of a coupling assembly between an infrared detector and a mechanical refrigeration unit to solve at least one of the technical problems mentioned above.

[0005] To solve the above-mentioned technical problems, the embodiments in this specification are implemented as follows: According to an embodiment of the present invention, a coupling assembly between an infrared detector and a mechanical refrigerator is provided, comprising: A refrigeration unit having a hot-end flange, a cold plate, and a cold finger, wherein the cold plate is located on one side of the hot-end flange and the cold finger is thermally connected to the cold plate; A detector chip assembly includes a chip, a splicing substrate that supports and fixes the chip, and a lead substrate located on the side of the splicing substrate opposite to the chip. The chip and the splicing substrate, as well as the splicing substrate and the lead substrate, are bonded and fixed by a low-temperature adhesive layer. The side of the lead substrate away from the splicing substrate is connected to the cold plate by a threaded fastener, and a thermally conductive medium layer is filled between the connection interface of the lead substrate and the cold plate. A cold screen is fixed to the lead substrate or the cold plate and is arranged around the chip, and the cold screen is thermally connected to the lead substrate or the cold plate. A Dewar assembly has a Dewar shell and an optical window. The Dewar shell of the Dewar assembly is installed on the hot end flange by a threaded connection. The detector chip assembly and the cold screen located around the detector chip assembly are encapsulated in the Dewar assembly. A sealing ring or indium wire seal is clamped at the connection interface between the Dewar shell and the hot end flange to form a vacuum insulation space inside the Dewar assembly. The thermal insulation support structure consists of at least two spaced thin-walled cylindrical supports, one end of which is connected to the cold plate and the other end of which is connected to the hot-end flange. The connection between the thin-walled cylindrical support and the cold plate and / or the connection between the thin-walled cylindrical support and the hot-end flange may be selectively provided with a flexible hinge structure or a bearing structure so that the cold plate and the hot-end flange form a six-degree-of-freedom statically determinate support.

[0006] In some optional embodiments, the chip, the splicing substrate, the lead substrate, and the cold plate are sequentially bonded together along the thickness direction of the chip.

[0007] In some optional embodiments, there are two splicing substrates, the chip is sandwiched between the two splicing substrates and fixed by bonding with a low-temperature adhesive layer, and the side of each splicing substrate opposite to the chip is bonded to the lead substrate by a low-temperature adhesive layer.

[0008] In some alternative embodiments, the lead substrate and the cold plate are integrated into a composite base, and the splicing substrate is fixed to the side of the composite base facing the chip.

[0009] In some alternative embodiments, the composite substrate is made of sapphire, silicon carbide, silicon, or aluminum oxide.

[0010] In some alternative embodiments, the thin-walled cylindrical support is made of TC4 titanium alloy or titanium alloy-based composite material.

[0011] In some alternative embodiments, the cold screen is a thin-walled structure made of nickel-cobalt alloy, and its inner surface is blackened.

[0012] In some optional embodiments, the projection outline of the lead substrate on a plane parallel to the photosensitive surface of the chip completely surrounds the projection outline of the splicing substrate and the chip; the lead substrate is provided with a mounting area for mounting an electrical transition plate and a connection interface for threaded connection with the cold plate.

[0013] One embodiment of this specification can achieve at least the following beneficial effects: 1. In this application's technical solution, the infrared detector chip, splicing substrate, and lead substrate are bonded together as a single detector chip assembly using a low-temperature adhesive layer. This assembly is then rigidly mechanically connected to the refrigerator's cold plate using threaded fasteners. A thermally conductive medium layer is filled at the connection interface. Simultaneously, the cold shield is fixed to the lead substrate or cold plate and maintained thermally connected to both, complementing the vacuum-sealed structure of the Dewar assembly. This design, on the one hand, provides uniform and stable mechanical support for large-scale chip assemblies through the layered bonding of low-temperature adhesive layers, ensuring the structural integrity and rigidity of the assembly. On the other hand, the threaded fastening combined with the thermally conductive medium interface connection allows for the construction of an efficient, low-thermal-resistance heat transfer path from the cold plate through the lead substrate and splicing substrate to the chip, while ensuring assembly controllability and disassembly. This enables the cooling energy to be uniformly and efficiently transferred to the entire chip surface, thereby improving the chip's temperature uniformity and reducing the refrigerator's power consumption required to maintain the target low-temperature operating temperature. The surrounding cold shield and thermally conductive connection effectively shield background stray radiation, reducing the additional thermal load on the chip. The vacuum insulation space of the Dewar component can block convection and gas conduction heat leakage in the atmospheric environment, creating a stable and clean low-temperature working environment for the chip component.

[0014] 2. To address the thermal stress and structural deformation issues caused by temperature differences in cryogenic environments, this application employs at least two spaced thin-walled cylindrical supports. One end connects to the cryogenic cold plate supporting the chip assembly, and the other end connects to the hot-end flange at room temperature. Flexible hinge structures or bearing structures can be selectively installed at the connection points between the supports and the cold plate and / or the hot-end flange, forming a six-degree-of-freedom statically determinate support. Mechanically, this design ensures reliable support between the cold plate assembly and the hot end, meeting overall structural stiffness requirements. Thermally, the high aspect ratio of the thin-walled cylinder creates efficient thermal insulation, significantly reducing heat transfer from the hot-end flange to the cryogenic cold zone. Furthermore, the combination of discrete thin-walled supports and statically determinate supports provides sufficient structural flexibility, effectively absorbing and buffering thermal expansion and contraction caused by temperature differences. This reduces thermal stress transmitted to the cryogenic zone, protects the brittle chip assembly and adhesive interface, and improves the structural stability and long-term reliability of the entire coupled assembly in cryogenic operating environments. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a typical large-scale detector coupled with a refrigerator in a coupling assembly of an infrared detector and a mechanical refrigerator provided by the present invention; Figure 2 This is a schematic diagram of the conventional structure coupling of a chip in a coupling assembly between an infrared detector and a mechanical refrigeration unit provided by the present invention; Figure 3 This is a schematic diagram of the symmetrical chip coupling structure in a coupling assembly between an infrared detector and a mechanical refrigeration unit provided by the present invention; Figure 4 This is a schematic diagram illustrating the determination of the chip component design dimensions in a coupling assembly between an infrared detector and a mechanical refrigeration unit provided by the present invention. Figure 5 This is a schematic diagram of the thermal insulation support structure design in a coupling assembly between an infrared detector and a mechanical refrigeration unit provided by the present invention.

[0017] 1 represents the hot end flange, 2 represents the cold plate, 3 represents the chip, 4 represents the splicing substrate, 5 represents the lead substrate, 6 represents the cold shield, 7 represents the Dewar assembly, 8 represents the thermal insulation support structure, 9 represents the cold finger, and 10 represents the thermal insulation support connection. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of one or more embodiments of this specification clearer, the technical solutions of one or more embodiments of this specification will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of them. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of one or more embodiments of this specification.

[0019] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another.

[0020] This invention provides a coupling assembly between an infrared detector and a mechanical refrigerator, the assembly comprising: A refrigeration unit having a hot end flange 1, a cold plate 2 and a cold finger 9, wherein the cold plate 2 is located on one side of the hot end flange 1 and the cold finger 9 is thermally connected to the cold plate 2. The detector chip assembly has a chip 3, a splicing substrate 4 that supports and fixes the chip 3, and a lead substrate 5 located on the side of the splicing substrate 4 away from the chip 3. The chip 3 and the splicing substrate 4, as well as the splicing substrate 4 and the lead substrate 5, are bonded and fixed by a low-temperature adhesive layer. The lead substrate 5 is connected to the cold plate 2 on the side opposite to the splicing substrate 4 by a threaded fastener, and a thermally conductive medium layer is filled between the connection interface of the lead substrate 5 and the cold plate 2. A cold screen 6 is fixed on the lead substrate 5 or the cold plate 2 and is arranged around the chip 3, and the cold screen 6 is thermally connected to the lead substrate 5 or the cold plate 2. The Dewar assembly 7 has a Dewar shell and an optical window. The Dewar shell of the Dewar assembly 7 is installed on the hot end flange 1 by a threaded connection. The detector chip assembly and the cold screen 6 located around the detector chip assembly are encapsulated in the Dewar assembly 7. A sealing ring or indium wire seal is sandwiched at the connection interface between the Dewar shell of the Dewar assembly 7 and the hot end flange 1 to form a vacuum insulation space inside the Dewar assembly 7. The thermal insulation support structure 8 consists of at least two spaced thin-walled cylindrical supports. One end of each thin-walled cylindrical support is connected to the cold plate 2, and the other end is connected to the hot end flange 1. The connection between the thin-walled cylindrical support and the cold plate 2 and / or the connection between the thin-walled cylindrical support and the hot end flange 1 may be selectively provided with a flexible hinge structure or a bearing structure so that the cold plate 2 and the hot end flange 1 form a six-degree-of-freedom statically determinate support.

[0021] The following is combined with Figure 1The coupling assembly of the infrared detector and mechanical refrigerator involved in this application has a mechanical structure mainly composed of five component modules assembled in a specific spatial relationship. The first module is the refrigerator assembly, which constitutes the cold source and mechanical mounting reference of the entire assembly. Its structural components include a hot-end flange 1 serving as the mounting surface and hot-end interface, and a cold plate 2 located on one side of the flange for transferring low-temperature cooling. The refrigerator assembly also includes a cold finger 9 thermally connected to the cold plate 2 to provide low-temperature cooling to the cold plate. The second module is the detector chip assembly, which is the core detection unit of the entire assembly. From bottom to top, away from the cold plate, it consists of an infrared detector chip 3, a splicing substrate 4 for supporting and fixing the chip, and a lead substrate 5 located on the side of the splicing substrate 4 opposite to the chip 3, stacked together. The third component is the cold shield 6, which is a cylindrical or dome-shaped structure surrounding the detector chip assembly. The fourth module is the Dewar assembly 7, which serves as a vacuum seal and optical window, comprising a cylindrical Dewar shell and an optical window mounted at the end of the Dewar shell. The fifth module is the thermal insulation support structure 8, which consists of at least two thin-walled cylindrical supports arranged spatially spaced apart from each other, specifically designed to connect the low-temperature zone and the room-temperature zone.

[0022] In the assembled state of this coupling assembly, the components are connected and their relative positions are determined by the following mechanical means. Specifically, firstly, inside the detector chip assembly, the infrared detector chip 3 and the splicing substrate 4, and the splicing substrate 4 and the lead plate 5 are all bonded and fixed with a low-temperature adhesive layer, and the three are solidified into a whole. Secondly, as a whole, the lead plate 5 of the detector chip assembly is mechanically fixed to the cold plate 2 of the refrigerator assembly by threaded fasteners on the side facing away from the splicing substrate 4. Furthermore, a thermally conductive medium layer is filled between the connection interface of the lead plate 5 and the cold plate 2 to ensure good thermal contact between the two. The cold shield 6 is fixed to the lead plate 5 or the cold plate 2, surrounds the chip 3, and maintains a thermally conductive connection with both. Thirdly, the Dewar shell of the Dewar assembly 7 is installed on the hot end flange 1 by a threaded connection, completely encapsulating the detector chip assembly and the surrounding cold shield 6 in its internal cavity. A sealing ring or indium wire seal is clamped at the connection interface between the Dewar shell and the hot end flange 1, so that a vacuum insulation space is formed inside the Dewar assembly 7. Finally, each thin-walled cylindrical support of the thermal insulation support structure 8 is connected to the cold plate 2 at one end and to the hot end flange 1 at the other end. The connection between the support and the cold plate 2 and / or the hot end flange 1 can be optionally provided with a flexible hinge structure or a bearing structure, so that the cold plate 2 and the hot end flange 1 form a six-degree-of-freedom statically determinate support.

[0023] In this application's technical solution, the infrared detector chip, splicing substrate, and lead substrate are bonded together as a single detector chip assembly using a low-temperature adhesive layer. This assembly is then rigidly mechanically connected to the refrigerator's cold plate using threaded fasteners, with a thermally conductive medium layer filling the connection interface. Simultaneously, the cold shield is fixed to the lead substrate or cold plate, maintaining a thermally conductive connection with both, in conjunction with the vacuum-sealed structure of the Dewar assembly. This design, on the one hand, provides uniform and stable mechanical support for large-scale chip assemblies through the layered bonding of low-temperature adhesive layers, ensuring the structural integrity and rigidity of the assembly. On the other hand, the threaded fastening combined with the thermally conductive medium interface connection allows for the construction of an efficient, low-thermal-resistance heat transfer path from the cold plate through the lead substrate and splicing substrate to the chip, while ensuring assembly controllability and disassembly. This enables the cooling energy to be uniformly and efficiently transferred to the entire chip surface, thereby improving the chip's temperature uniformity and reducing the refrigerator's power consumption required to maintain the target low-temperature operating temperature. The surrounding cold shield and thermally conductive connection effectively shield stray radiation from the background, reducing the additional thermal load on the chip. The vacuum insulation space of the Dewar component blocks convection and gas-conducted heat leakage from the atmospheric environment, creating a stable and clean low-temperature operating environment for the chip assembly. Addressing the thermal stress and structural deformation issues caused by temperature differences in deep cryogenic environments, this application employs at least two spaced thin-walled cylindrical supports. One end connects to the cryogenic cold plate supporting the chip assembly, and the other end connects to the hot-end flange at room temperature. Flexible hinge structures or bearing structures can be selectively installed at the connection points between the supports and the cold plate and / or the hot-end flange, forming a six-degree-of-freedom statically determinate support between the cold plate and the hot-end flange. Mechanically, this design provides reliable support between the cold plate assembly and the hot end, meeting the overall structural stiffness requirements. Thermally, the high aspect ratio of the thin-walled cylinder creates an efficient thermal barrier, significantly reducing heat conduction from the hot-end flange to the cryogenic cold zone. Meanwhile, the design of discrete thin-walled support combined with statically determinate support can give the structure sufficient flexibility, effectively absorb and buffer thermal expansion and contraction deformation caused by temperature difference, thereby reducing the thermal stress transmitted to the low temperature region, protecting the brittle chip components and adhesive interfaces, and improving the structural stability and long-term reliability of the entire coupling component in the deep low temperature working environment.

[0024] Based on the technical solutions described above, this specification also provides some specific implementation schemes, which are described below.

[0025] In an optional embodiment, the chip 3, the splicing substrate 4, the lead substrate 5, and the cold plate 2 are sequentially bonded together along the thickness direction of the chip 3.

[0026] In this embodiment, the chip 3, splicing substrate 4, lead substrate 5, and cold plate 2 are sequentially bonded along the thickness direction of the chip 3, forming a regular and stable stacked assembly structure, as shown in the attached figure. Figure 2The conventional chip structure coupling assembly shown depicts a process where, during the assembly of the coupling components, chip 3, splicing substrate 4, lead substrate 5, and cold plate 2 are tightly bonded layer by layer in the order of chip 3 thickness direction, using chip 3, splicing substrate 4, lead substrate 5, and cold plate 2 as the assembly reference. Chip 3 and splicing substrate 4, and splicing substrate 4 and lead substrate 5 are bonded together using low-temperature adhesive layers. Lead substrate 5 and cold plate 2 are bonded and fixed together using threaded fasteners and a thermally conductive medium layer. Each component is sequentially bonded and assembled without offset or gaps along the chip thickness direction. This layered bonding layout provides a regular structural assembly basis for the coupling components of large-scale infrared detectors and mechanical refrigerators. On the one hand, it allows full contact between the bonding interfaces of each component, constructing a continuous linear heat transfer path from cold plate 2 to lead substrate 5, splicing substrate 4, and then to chip 3. This minimizes thermal resistance and ensures efficient and uniform transfer of cooling energy from the refrigerator to chip 3, meeting the temperature uniformity requirements for low-temperature chip operation. On the other hand, the assembly method of sequentially bonding along the chip thickness direction can ensure that the relative positions of each component are accurately fixed, avoiding problems such as excessive flatness of the image plane and excessive chip stress caused by component misalignment or loosening under low temperature conditions, and ensuring the structural stability and assembly accuracy of the coupling component under low temperature working conditions.

[0027] In an optional embodiment, there are two splicing substrates 4. The chip 3 is sandwiched between the two splicing substrates 4 and fixed by bonding with a low-temperature adhesive layer. The side of each splicing substrate 4 facing away from the chip 3 is bonded to the lead substrate 5 by a low-temperature adhesive layer.

[0028] In this embodiment, the number of splicing substrates 4 is set to two, and the chip 3 is sandwiched between the two splicing substrates 4 and fixed by bonding with a low-temperature adhesive layer. Furthermore, the side of each splicing substrate 4 facing away from the chip 3 is bonded to the lead substrate 5 by a low-temperature adhesive layer. This structure achieves symmetrical and balanced assembly, as shown in the attached figure. Figure 3The symmetrical chip coupling assembly shown involves first sandwiching the chip 3 between two splicing substrates 4 during the assembly process. The chip 3 is then tightly bonded to the two splicing substrates 4 using low-temperature adhesive layers. Next, the surfaces of the two splicing substrates 4 facing away from the chip 3 are bonded to the lead substrate 5 using low-temperature adhesive layers, forming a symmetrically stacked and bonded assembly of the chip 3, the two splicing substrates 4, and the lead substrate 5. This symmetrical bonding assembly method provides uniform structural support and stress balance for large-scale infrared detector chip assemblies. On one hand, the symmetrical arrangement of the two splicing substrates 4 clamping the chip 3 ensures uniform stress distribution on the chip 3 under low-temperature operating conditions, effectively mitigating thermal stress caused by differences in material thermal expansion coefficients and preventing stress concentration, cracking, or deformation of the chip 3, thus ensuring the structural integrity and normal operation of the chip 3. On the other hand, the symmetrical bonding and fixation of the two splicing substrates 4 and the lead substrate 5 creates a symmetrical structure for the chip assembly, significantly reducing the difficulty of optimizing the image plane flatness at low temperatures, ensuring that the detector image plane flatness meets design specifications, and maintaining stable optical imaging quality.

[0029] In an optional embodiment, the lead substrate 5 and the cold plate 2 are integrated into a composite base, and the splicing substrate 4 is fixed to the side of the composite base facing the chip 3.

[0030] In this embodiment, the composite base where the lead substrate 5 and the cold plate 2 are integrated, and the splicing substrate 4 is fixed to the side of the composite base facing the chip 3, allows for simple and efficient assembly, as shown in the attached figure. Figure 2 The conventional chip structure coupling assembly shown in the diagram involves integrating the lead substrate 5 and the cold plate 2 into a composite base during the assembly of the coupling components. The splicing substrate 4 is then securely fixed to the side of the composite base facing the chip 3, forming an integrated load-bearing structure. This integrated fixing method provides reliable assembly support for the coupling components of large-scale infrared detectors and mechanical refrigerators. The integrated composite base eliminates the independent connection between the lead substrate 5 and the cold plate 2, significantly reducing interface thermal resistance. This allows the cooling capacity of the refrigerator to be directly and efficiently transferred from the composite base to the splicing substrate 4 and the chip 3, ensuring chip temperature uniformity and cooling capacity transfer efficiency. Furthermore, fixing the splicing substrate 4 to the designated side of the composite base facing the chip 3 precisely locks the assembly position of the splicing substrate 4, preventing issues such as substandard image plane flatness and excessive chip stress caused by component displacement or loosening under low-temperature operating conditions. This ensures the structural stability and operational reliability of the coupling components under low-temperature conditions.

[0031] In an optional embodiment, the composite substrate is made of sapphire, silicon carbide, silicon, or aluminum oxide.

[0032] In this embodiment, the composite base, which is integrally formed by the lead plate and the cold plate, is made of sapphire, silicon carbide, silicon, or alumina, chosen for its mechanical structure and thermal performance compatibility. These materials collectively possess a coefficient of thermal expansion that is relatively close to that of common infrared detector chip materials (such as silicon) at low temperatures. This helps reduce thermal stress caused by the difference in thermal expansion and contraction between the composite base and the chip and bonding substrate bonded above when transitioning from room temperature assembly to low-temperature operating conditions, thereby protecting the structural integrity of the chip and its bonding interface. Simultaneously, these materials possess high rigidity and strength, ensuring the mechanical stability required for the composite base to function as the core support and heat transfer hub of the entire detector chip assembly, reliably supporting the upper structure and maintaining precise installation position. Furthermore, these materials typically have good thermal conductivity, allowing the integrated composite base to efficiently transfer cold energy from the refrigerator's cooling coils or cold chain from its cold plate function area to its lead plate function area, and then to the bonding substrate and chip above, meeting the temperature uniformity requirements of large-scale detectors.

[0033] In an optional embodiment, the material of the thin-walled cylindrical support is TC4 titanium alloy or titanium alloy-based composite material.

[0034] In this embodiment, the thin-walled cylindrical support is designed using TC4 titanium alloy or titanium alloy-based composite material, which enables stable assembly of the thermal insulation support structure, as shown in the attached figure. Figure 5 The thermal insulation support structure design and assembly method shown involves fabricating thin-walled cylindrical support components from TC4 titanium alloy or titanium alloy-based composite materials during the assembly of the coupling components. The two ends of these thin-walled cylindrical support components are then connected and fixed to the cold plate 2 and the hot-end flange 1, respectively. This material selection design provides reliable mechanical and thermal support for the thermal insulation support structure of the coupling components of large-scale infrared detectors and mechanical refrigerators. TC4 titanium alloy and titanium alloy-based composite materials possess excellent low-temperature mechanical properties, sufficient strength, suitable stiffness, and strong structural stability. They provide stable support between the cold plate 2 and the hot-end flange 1, preventing deformation and cracking of the support components under low-temperature operating conditions and ensuring the connection strength of the thermal insulation support structure. Furthermore, these materials have low thermal conductivity and excellent thermal insulation effect. Combined with the thin-walled cylindrical structure, they effectively reduce heat conduction and leakage from the hot-end flange 1 to the low-temperature cold plate 2, meeting the design requirements for heat leakage in the low-temperature zone of the coupling components. Simultaneously, they adapt to the flexible design of the thermal insulation support and the requirements of a six-degree-of-freedom statically determinate support, ensuring the thermal performance and overall structural stability of the coupling components under low-temperature conditions.

[0035] In an optional embodiment, the cold screen 6 is a thin-walled structure made of nickel-cobalt alloy, and its inner surface is blackened.

[0036] In this embodiment, the cold screen 6 adopts a thin-walled structure made of nickel-cobalt alloy, and its inner surface is blackened, which enables efficient and stable stray radiation shielding assembly, as shown in the attached figure. Figure 1 The typical large-scale detector and cooler coupling assembly shown employs a nickel-cobalt alloy material to fabricate a thin-walled cold shield 6 during the assembly of the coupling components. The inner surface of the cold shield 6 is blackened, and the finished cold shield 6 is then fixedly mounted on the lead substrate 5 or cold plate 2 and surrounds the chip 3. This material selection and surface treatment design provide reliable radiation shielding support for the infrared detector chip assembly. Firstly, the thin-walled cold shield 6 made of nickel-cobalt alloy possesses excellent thermal conductivity, enabling rapid temperature equilibrium with the chip assembly. Simultaneously, the thin-walled structure balances lightweight design and installation adaptability, stably surrounding the chip 3 to form all-around protection, effectively blocking external stray radiation interference to the chip 3. Secondly, the blackening treatment of the inner surface of the cold shield 6 significantly improves radiation absorption and suppression, further reducing the additional heat load from stray radiation, avoiding impact on the detection accuracy and operational stability of the chip 3, and ensuring that the infrared detector maintains good detection performance under low-temperature operating conditions.

[0037] In an optional embodiment, the projection outline of the lead substrate 5 on a plane parallel to the photosensitive surface of the chip 3 completely surrounds the projection outline of the splicing substrate 4 and the chip 3; the lead substrate 5 is provided with a mounting area for mounting an electrical transition plate and a connection interface for threaded connection with the cold plate 2.

[0038] In this embodiment, the projection outline of the lead substrate 5 on a plane parallel to the photosensitive surface of the chip 3 completely surrounds the projection outline of the splicing substrate 4 and the chip 3. Furthermore, the lead substrate 5 has a mounting area for mounting an electrical transition plate and a connection interface for threaded connection with the cold plate 2, enabling precise and orderly assembly, as shown in the attached figure. Figure 4The chip assembly design dimensions shown determine the assembly method. During the assembly of the coupling components, the outline size of the lead substrate 5 is determined according to the external specifications of chip 3 and splicing substrate 4, so that the projected outline of the lead substrate 5 completely covers the splicing substrate 4 and chip 3. At the same time, a dedicated electrical transition plate mounting area and a threaded connection interface for the cold plate 2 are reserved on the lead substrate 5. The electrical transition plate is accurately installed into the mounting area of ​​the lead substrate 5, and then the lead substrate 5 and the cold plate 2 are threadedly connected and fixed through the connection interface. This outline coverage and interface integration design can provide stable assembly support for large-scale infrared detector chip assemblies. On the one hand, the projected outline of the lead substrate 5 completely surrounds the splicing substrate 4 and chip 3, which can form comprehensive protection and positioning for chip 3 and splicing substrate 4, avoiding displacement, shaking or damage of chip 3 and splicing substrate 4 during assembly and low-temperature operation, and ensuring the structural stability of the chip assembly. On the other hand, the lead substrate 5 integrates the electrical transition plate mounting area and the cold plate 2 threaded connection interface, which can not only accurately fix the mounting position of the electrical transition plate and ensure the reliable and stable electrical connection of the chip, but also achieve precise docking and assembly of the lead substrate 5 and the cold plate 2 through the dedicated connection interface, ensuring that the connection between the two is firm and the position is accurate, and avoiding the impact of loose connection and positioning deviation on the low-temperature working performance and optical imaging quality of the coupling components.

[0039] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of one embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing the present invention.

[0040] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coupling assembly between an infrared detector and a mechanical refrigerator, characterized in that, include: A refrigeration unit having a hot end flange (1), a cold plate (2) and a cold finger (9), wherein the cold plate (2) is located on one side of the hot end flange (1) and the cold finger (9) is thermally connected to the cold plate (2); The detector chip assembly has a chip (3), a splicing substrate (4) that supports and fixes the chip (3), and a lead substrate (5) located on the side of the splicing substrate (4) away from the chip (3). The chip (3) and the splicing substrate (4), as well as the splicing substrate (4) and the lead substrate (5), are bonded and fixed by a low-temperature adhesive layer. The lead substrate (5) is connected to the cold plate (2) on the side away from the splicing substrate (4) by a threaded fastener, and a thermally conductive medium layer is filled between the connection interface of the lead substrate (5) and the cold plate (2). A cold screen (6) is fixed on the lead substrate (5) or the cold plate (2) and is arranged around the chip (3), and the cold screen (6) is thermally connected to the lead substrate (5) or the cold plate (2). The Dewar assembly (7) has a Dewar shell and an optical window. The Dewar shell of the Dewar assembly (7) is installed on the hot end flange (1) by a threaded connection. The detector chip assembly and the cold screen (6) located around the detector chip assembly are encapsulated in the Dewar assembly (7). A sealing ring or indium wire seal is clamped at the connection interface between the Dewar shell of the Dewar assembly (7) and the hot end flange (1) so that a vacuum insulation space is formed inside the Dewar assembly (7). The thermal insulation support structure (8) consists of at least two thin-walled cylindrical support members spaced apart. One end of each thin-walled cylindrical support member is connected to the cold plate (2), and the other end is connected to the hot end flange (1). The connection between the thin-walled cylindrical support member and the cold plate (2) and / or the connection between the thin-walled cylindrical support member and the hot end flange (1) may be selectively provided with a flexible hinge structure or a bearing structure so that the cold plate (2) and the hot end flange (1) form a six-degree-of-freedom statically determinate support.

2. The coupling assembly between the infrared detector and the mechanical refrigerator according to claim 1, characterized in that, The chip (3), the splicing substrate (4), the lead substrate (5) and the cold plate (2) are sequentially attached along the thickness direction of the chip (3).

3. The coupling assembly between the infrared detector and the mechanical refrigerator according to claim 1, characterized in that, The number of splicing substrates (4) is two. The chip (3) is sandwiched between the two splicing substrates (4) and fixed by bonding with a low-temperature adhesive layer. The side of each splicing substrate (4) away from the chip (3) is bonded to the lead substrate (5) by a low-temperature adhesive layer.

4. The coupling assembly between the infrared detector and the mechanical refrigerator according to claim 1, characterized in that, The lead substrate (5) and the cold plate (2) are integrated into a composite base, and the splicing substrate (4) is fixed to the side of the composite base facing the chip (3).

5. The coupling assembly between the infrared detector and the mechanical refrigerator according to claim 4, characterized in that, The composite substrate is made of sapphire, silicon carbide, silicon, or aluminum oxide.

6. The coupling assembly between the infrared detector and the mechanical refrigerator according to claim 1, characterized in that, The material of the thin-walled cylindrical support is TC4 titanium alloy or titanium alloy-based composite material.

7. The coupling assembly between the infrared detector and the mechanical refrigerator according to claim 1, characterized in that, The cold screen (6) is a thin-walled structure made of nickel-cobalt alloy, and its inner surface is blackened.

8. The coupling assembly between the infrared detector and the mechanical refrigerator according to claim 1, characterized in that, The projection outline of the lead substrate (5) on a plane parallel to the photosensitive surface of the chip (3) completely surrounds the projection outline of the splicing substrate (4) and the chip (3); the lead substrate (5) is provided with a mounting area for mounting an electrical transition plate and a connection interface for threaded connection with the cold plate (2).

Images