An adaptive heat insulation support structure for an ultra-long linear array infrared detector

Abstract

The application discloses an adaptive heat-insulating support structure of an ultra-long linear infrared detector, which comprises a support column, a detector mounting base plate, a cold contraction support, a cold finger and a bottom plate; the upper end of the cold finger is fixed to the lower surface of the detector mounting base plate, and the lower end of the cold finger is fixedly connected with the bottom plate; the lower end of the support column is fixedly connected with the bottom plate; the upper end of the support column is provided with the cold contraction support, and the detector mounting base plate is fixedly connected with the cold contraction support. By virtue of the characteristics that the ultra-long linear infrared detector for space use has no mechanical environment under low-temperature working conditions, the cold contraction size change of the detector mounting base plate and the cold contraction support structure under low temperature is utilized, so that the effects of low stress and low heat leakage are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of low-temperature packaging of infrared detectors, in particular to a self-adaptive heat-insulating support structure for super-long linear array infrared detectors, which is suitable for Dewar packaging of super-long linear array infrared focal plane detector chips. BACKGROUND

[0002] High spatial resolution infrared cameras are core components of infrared remote sensing instruments. There are generally two methods to improve spatial resolution: one is to splice and fuse images after multiple imaging; the other is to increase the number of infrared sensitive elements, that is, in the same height and swath remote sensing instrument, the more sensitive elements, the higher the spatial resolution. Super-long linear array (≥6000 elements) infrared focal plane assembly preparation technology is of great significance in the field of space and aviation infrared. With the expansion of wavelength to long wave and the improvement of detection sensitivity, super-long linear array infrared focal plane detectors must work at deep low temperature, which also makes them mostly adopt Dewar packaging to form super-long linear array infrared focal plane Dewar assemblies.

[0003] Traditional super-long linear array infrared detectors generally adopt a bridge packaging structure, that is, two support columns are installed at both ends of the super-long linear array infrared detector, which provides mechanical support for the infrared detector while requiring good thermal insulation performance. Due to the rigid fixation constraint of the support columns, the bridge structure super-long linear array mounting structure has the problem of heat leakage at low temperature. At the same time, the cold end structure of the detector will be over-constrained when it works at low temperature, which will cause additional stress deformation of the cold end structure of the detector and bring additional structural stress to the detector. Considering that the super-long linear array infrared detector assembly for space application only has high requirements for structural strength during ground mechanical experiments and rocket launch stages, and the infrared detector is in room temperature state under the condition of mechanical requirements. The super-long linear array infrared detector packaging structure requires a packaging structure with high structural support strength at room temperature, and the detector can have self-adaptive heat-insulating support at low temperature (-210℃--196℃) without over-constraint. SUMMARY

[0004] The purpose of the present application is to provide a self-adaptive heat-insulating support structure for super-long linear array infrared detectors, which solves the problem of heat leakage of the support columns at low temperature in the bridge structure super-long linear array mounting structure in the prior art, and the problem of additional stress deformation of the cold end structure of the detector due to over-constraint under the rigid fixation of the bridge support, which brings additional structural stress to the detector.

[0005] To achieve the above purpose, the technical solution of the present application is:

[0006] An adaptive heat-insulating support structure for an ultra-long linear infrared detector, comprising a support column, a detector mounting substrate, a cold contraction support, a cold finger and a bottom plate;

[0007] The upper end of the cold finger is fixed to the lower surface of the detector mounting substrate, and the lower end of the cold finger is fixedly connected to the bottom plate.

[0008] The cold contraction support comprises a cold contraction frame and a cold contraction rod, the cold contraction rod is fixedly arranged in the cold contraction frame, and the material expansion coefficient of the cold contraction frame is greater than that of the cold contraction rod.

[0009] The cold contraction support comprises two or more than two paralleled connected rhombic cold contraction frames, one cold contraction rod is fixedly arranged in each rhombic cold contraction frame, and the cold contraction rod is arranged between two top corners corresponding to the long diagonal of the rhombus.

[0010] The support column comprises a base, an insulating column and a mounting part; the base is fixedly connected to the bottom plate, and the cold contraction support gap is arranged in the mounting part.

[0011] The mounting part has a mounting seat wall; at room temperature, the bottom of the cold contraction support is higher than the bottom of the mounting seat, and the cold contraction frame is fixedly connected to the mounting seat wall through a screw.

[0012] The gap between the mounting seat wall and the cold contraction frame is 1mm-5mm.

[0013] The cold contraction frame of the cold contraction support is made of aluminum or copper with high expansion coefficient; the cold contraction rod is made of Kovar, Invar, titanium alloy or molybdenum with low expansion coefficient.

[0014] The support column is made of titanium alloy, stainless steel or glass steel with low thermal conductivity.

[0015] Two support columns are fixedly arranged on the bottom plate, one cold contraction support is arranged at the upper end of each support column, the support columns are correspondingly arranged on both sides of the detector mounting substrate, and the two sides of the detector mounting substrate are fixedly connected to the cold contraction supports to be fixed on the two support columns.

[0016] The detector mounting substrate is made of Kovar, titanium alloy or molybdenum.

[0017] The present application has the following advantages:

[0018] 1. The support column ensures that the ultra-long linear infrared detector Dewar has good structural rigidity at room temperature; 2. The detector mounting base plate is fixedly connected with the cold shrink support, instead of being directly connected with the support column, thereby effectively reducing the low-temperature thermal stress problem of the bridge-type support structure of the infrared detector; 3. The height of the cold finger is designed to ensure that the bottom of the cold shrink support is not in mechanical contact with the support column, and the cold shrink frame is separated from the screw after cold shrink at the liquid nitrogen temperature zone (-210℃-196℃), so that the cold shrink support and the mounting portion are separated and not in mechanical contact, and the combination of the detector base plate and the cold shrink support is not in mechanical contact with the support column at the liquid nitrogen temperature zone (-210℃-196℃) of the detector, thereby directly avoiding the heat leakage problem of the support column in the low-temperature working state of the detector. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the present application;

[0020] Figure 2 is a support column structural schematic diagram of the present application;

[0021] Figure 3 is a cold shrink support structural schematic diagram of the present application;

[0022] Figure 4 is a support column and cold shrink support connection schematic diagram of the present application;

[0023] In the figure: 1 - support column; 11 - base; 12 - heat insulation column; 13 - mounting seat; 131 - mounting seat wall; 2 - detector mounting base plate; 3 - cold shrink support; 31 - cold shrink frame; 32 - cold shrink rod; 4 - cold finger; 5 - bottom plate. DETAILED DESCRIPTION

[0024] In order to more simply illustrate the present embodiment, some parts which are well known to those skilled in the art but are not related to the main content of the present creation will be omitted in the drawings or description. In addition, some parts will be omitted, enlarged or reduced in the drawings for the convenience of description, but do not represent the size or the whole structure of the actual product.

[0025] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0026] The present application will be further described below in combination with the drawings. The drawings are only used for illustrative description and should not be understood as limiting the present patent.

[0027] The present invention will now be further described in conjunction with the embodiments and accompanying drawings:

[0028] This invention relates to an adaptive thermal insulation support structure for an ultra-long linear infrared detector, such as... Figure 1 As shown, it includes a support column 1, a detector mounting base plate 2, a cold shrink support 3, a cold finger 4, and a base plate 5.

[0029] The upper end of the cold finger 4 is fixed to the lower surface of the detector mounting substrate 2, and the lower end of the cold finger 4 is fixedly connected to the base plate 5. The cold finger 4 is a cold source structure of the refrigerator, and the cold finger 4 and the detector mounting substrate 2 are rigidly fixed. The cold finger 4 is both a heat transfer channel of the detector mounting substrate 2 and a mechanical support structure of the detector mounting substrate 2. Preferably, two support columns 1 are fixedly arranged on the base plate 5, and a cold shrink support 3 is arranged at the upper end of each support column 1. The support columns 1 are correspondingly arranged on both sides of the detector mounting substrate 2, and the two sides of the detector mounting substrate 2 are fixedly connected to the two cold shrink supports 3 respectively, forming a combination of the detector mounting substrate 2 and the cold shrink supports 3. The two cold shrink supports 3 are respectively arranged on the support columns 1 on both sides with gaps.

[0030] The support column 1 provides mechanical support for the infrared detector while also requiring good thermal insulation performance. The support column 1 is typically made of titanium alloy, stainless steel, or fiberglass with low thermal conductivity. The detector mounting substrate 1 is typically made of Kovar, titanium alloy, or molybdenum.

[0031] In the prior art, the support column 1 and the detector mounting substrate 2 are usually directly fixedly connected. However, in low-temperature conditions, due to the small shrinkage of the material of the support column 1 and the large shrinkage of the material of the detector mounting substrate 2, the rigid fixation of the bridge support will cause over-constraint, resulting in the shrinkage and deformation of the detector mounting substrate 2 in low-temperature conditions.

[0032] In this invention, when the detector is operating at a low temperature in the liquid nitrogen temperature range (-210℃ to -196℃), only the cold finger 4 supports the combination of the detector mounting base 2 and the cold shrink support 3. The function of the support column 1 is to provide installation support when the detector is manufactured at room temperature. Under the low temperature operating condition, there is no mechanical contact between the combination of the detector mounting base 2 and the cold shrink support 3 and the support column 1.

[0033] like Figures 1-4 As shown, the lower end of the support column 1 is fixedly connected to the base plate 5; the detector mounting base plate 2 is fixedly connected to the cold shrink support 3. The height of the cold finger 4 is designed so that the bottom of the cold shrink support 3 does not contact the support column 1. That is, the cold shrink support 3 is set at the upper end of the support column 1 with a gap. There is no mechanical connection between the combination of the detector mounting base plate 2 and the cold shrink support 3 and the support column 1.

[0034] Preferably, such as Figure 3As shown, the cold shrink support 3 comprises a cold shrink frame 31 and a cold shrink rod 32, the cold shrink rod 32 is fixedly arranged in the cold shrink frame 31, the cold shrink frame 31 has a material expansion coefficient greater than that of the cold shrink rod 32. Generally, the cold shrink frame 31 of the cold shrink support 3 is made of aluminum or copper with high expansion coefficient; the cold shrink rod 32 is made of Kovar, Invar, titanium alloy or molybdenum with low expansion coefficient. In this way, in a low temperature state, the cold shrink support 3 can better follow the contraction of the detector mounting substrate 2, and the detector mounting substrate 2 will not be deformed due to the contraction, and the cold shrink rod 32 makes the cold shrink support 3 have a certain rigidity.

[0035] Further, the cold shrink support 3 comprises two or more than two paralleled connected rhombic cold shrink frames 31, and one cold shrink rod 32 is fixedly arranged in each rhombic cold shrink frame 31, and the cold shrink rod 32 is arranged between two top corners corresponding to the long diagonal of the rhombus.

[0036] The support column 1 comprises a base 11, an insulation column 12 and a mounting portion 13; the base 11 is fixedly connected with the bottom plate 5, and the cold shrink support 3 is arranged in the mounting portion 13. Preferably, as shown, Figure 2 , Figure 4 The mounting portion 13 has a mounting seat wall 131; further, the mounting portion 13 is a long cuboid with one end opening and surrounded by three mounting portion walls 131, and each mounting seat wall 131 is provided with a screw hole.

[0037] The installation of the detector is carried out at room temperature, and the cold shrink support 3 shown in Figure 3 is placed in the mounting portion 13. Since the combination of the detector mounting substrate 2 and the cold shrink support 3 is supported by the cold fingers 4, in order to avoid mechanical contact between the cold shrink support 3 and the bottom of the mounting portion 13 of the support column 1, the height of the cold fingers 4 will ensure that the bottom of the cold shrink support 3 is higher than the bottom of the mounting portion 13 of the support column 1, and there is no contact between them, that is, the cold shrink support 3 will be suspended in the mounting portion 13. In order to ensure the normal installation of each component of the detector, at room temperature, as shown in Figure 4 , the cold shrink frame 31 is pressed against the mounting seat wall 131 through the screw hole of the mounting seat wall 131 by means of a jacking screw, so that the cold shrink support 3 is suspended and fixed in the mounting portion 13, and the gap between the mounting seat wall 131 and the cold shrink frame 31 is between 1mm and 5mm.

[0038] After being completed at room temperature, the detector with the above structure is in a low temperature working state, due to the contraction of the cold shrink support 3, the cold shrink frame 31 is separated from the jacking screw, and the combination of the detector substrate 2 and the cold shrink support 3 is effectively separated from the support column 1 without mechanical contact, thereby effectively solving the low temperature thermal stress problem caused by the support column 1 and the low temperature heat leakage problem of the support column 1.

[0039] The above merely describes preferred embodiments of the present application, and is not intended to limit the scope of the application. Any equivalent changes and modifications made within the spirit and principle of the present application should be included in the scope of the application.

Claims

1. An adaptive thermal insulation support structure for an ultra-long linear infrared detector, comprising a support column (1), a detector mounting base plate (2), a cold shrink support (3), a cold finger (4), and a base plate (5); characterized in that: The upper end of the cold finger (4) is fixed to the lower surface of the detector mounting base plate (2), and the lower end of the cold finger (4) is fixedly connected to the base plate (5); the lower end of the support column (1) is fixedly connected to the base plate (5); the detector mounting base plate (2) is fixedly connected to the cold shrink support (3); the gap of the cold shrink support (3) is set on the support column (1); The cold shrink support (3) includes a cold shrink frame (31) and a cold shrink rod (32). The cold shrink rod (32) is fixedly installed inside the cold shrink frame (31). The material expansion coefficient of the cold shrink frame (31) is greater than that of the cold shrink rod (32). The cold shrink support (3) includes two or more parallel rhomboid cold shrink frames (31), and a cold shrink rod (32) is fixedly installed in each rhomboid cold shrink frame (31). The cold shrink rod (32) is located between the two vertices corresponding to the long diagonal of the rhomboid.

2. The adaptive thermal insulation support structure for the ultra-long linear infrared detector according to claim 1, characterized in that: The support column (1) includes a base (11), a heat insulation column (12), and a mounting part (13); the base (11) is fixedly connected to the base plate (5), and the gap of the cold shrink support (3) is set in the mounting part (13).

3. The adaptive thermal insulation support structure for the ultra-long linear infrared detector according to claim 2, characterized in that: The mounting part (13) has a mounting wall (131); at room temperature, the bottom of the cold shrink support (3) is higher than the bottom of the mounting base (13), and the cold shrink frame (31) is fixed to the mounting wall (131) by screws.

4. The adaptive thermal insulation support structure for the ultra-long linear infrared detector according to claim 3, characterized in that: The gap between the mounting base wall (131) and the cold shrink frame (31) is 1mm-5mm.

5. The adaptive thermal insulation support structure for the ultra-long linear infrared detector according to claim 1, characterized in that: The cold shrink frame (31) of the cold shrink support (3) is made of aluminum or copper with a high coefficient of expansion; the cold shrink rod (32) is made of Kovar, Invar, titanium alloy or molybdenum with a low coefficient of expansion.

6. The adaptive thermal insulation support structure for the ultra-long linear infrared detector according to claim 1, characterized in that: The support column (1) is made of titanium alloy, stainless steel or fiberglass with low thermal conductivity.

7. The adaptive thermal insulation support structure for the ultra-long linear infrared detector according to any one of claims 1-6, characterized in that: Two support columns (1) are fixedly installed on the base plate (5). A cold shrink support (3) is installed at the upper end of each support column (1). The support column (1) is correspondingly installed on both sides of the detector mounting base plate (2). The two sides of the detector mounting base plate (2) are fixedly connected to the cold shrink support (3) respectively, thus fixing it on the two support columns (1).

8. The adaptive thermal insulation support structure for the ultra-long linear infrared detector according to claim 1, characterized in that: The detector mounting base plate (2) is made of Kovar, titanium alloy, or molybdenum.

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