Temperature control tester capable of withstanding extreme thermal environment in aerospace and preparation method thereof

Abstract

The present invention provides a temperature control tester capable of withstanding the extreme mechanical and thermal environment of aerospace and a preparation method thereof, wherein the top PCB board and the bottom PCB board are fixedly connected by anti-loosening bolts and anti-loosening nuts; a flexible temperature control unit is fixedly installed between the top PCB board and the bottom PCB board, and the flexible temperature control unit is also electrically connected to the top PCB board and the bottom PCB board respectively; the flexible temperature control unit includes a flexible temperature sensor, a flexible substrate, and a flexible heating sheet from top to bottom; and a nylon isolation column is provided on the anti-loosening bolt. The present invention realizes the high reliability of the flexible temperature control unit in the extreme mechanical and thermal environment of aerospace by combining technologies such as oxygen plasma bonding, conductive silver glue electrical connection, and a pre-tightened sandwich structure of PCB-flexible temperature control unit-PCB, thereby avoiding many problems of the above-mentioned previous technologies.

Description

Technical Field

[0001] The invention provides a method for preparing a temperature control tester capable of withstanding an extreme mechanical and thermal environment in aerospace, and belongs to the technical field of temperature control. Background Art

[0002] With the development of manned space flight, especially long-term manned space station technology, facing the influence of extreme temperature environment in space, astronauts and spacecraft need to use temperature control equipment to maintain a suitable temperature for a long time to prevent damage to personnel and space equipment. At the same time, flexible temperature control systems can withstand certain deformations and can be attached to the complex surface of astronauts or spacecraft, with applicability far exceeding traditional rigid temperature control systems. However, current flexible temperature control technology is often unable to withstand the extreme mechanical and thermal environment of aerospace due to problems such as materials and wiring methods, including strong vibrations, large temperature difference rapid cycles, high-energy particle rays, etc. Therefore, flexible electronic temperature control devices that can withstand the extreme mechanical and thermal environment of aerospace are needed. At present, there are still few people studying this field, so it is still in the early experimental stage.

[0003] Patent CN202111590162.1 provides a relatively simple phase change heat dissipation matrix structure, material composition and preparation method. It describes a space on-orbit test scheme for the heat dissipation effect of flexible electronic devices. However, this method does not take protective measures to adapt to the strong vibration in the aerospace environment, and does not describe the connection method between the heating plate, wire, temperature sensor, and elastic matrix, which significantly affects the operational reliability in the aerospace environment. Specifically, it includes:

[0004] ① The connection method between the lead and the heater, and the lead and the temperature sensor is not described. Since the heater and the temperature sensor are both flexible materials, and the metal layer is extremely thin, it is difficult to apply traditional soldering, ultrasonic and other connection processes. Even if the process power is controlled to successfully connect, the metal layer will fall off due to the strong vibration in the aerospace environment, causing the device to lose electrical connection and lose its effect.

[0005] ② The connection between the substrate and the heating plate, and the substrate and the temperature sensor is not described. Since the flexible heating plate and the flexible temperature sensor are usually made of materials such as polyimide (PI), and the substrate material is often made of materials such as polydimethylsiloxane (PDMS). The two materials have certain differences, and it is difficult to form a highly reliable mechanical connection using traditional methods (such as gluing, co-curing, etc.). In the extreme environment of aerospace, it is easy to fall off due to large vibration, thus causing the device to fail.

[0006] ③ There is another problem with the connection method between the substrate and the heating plate, and between the substrate and the temperature sensor. The traditional method may introduce a gap between the two connections. The existence of the gap makes the thermal interface discontinuous, which will greatly affect the heating effect and increase the complexity of temperature control. Summary of the invention

[0007] The present invention provides a temperature control tester capable of withstanding the extreme thermal environment of aerospace and a preparation method thereof, and aims to solve the following technical problems:

[0008] ① Solve the problem that the lead wire is easy to fall off in the extremely strong vibration environment of aerospace.

[0009] ② Solve the problem of high-reliability connection between the substrate and flexible sensitive units such as heating plates and temperature sensors that can withstand strong vibrations.

[0010] ③ Solve the gap problem between the substrate and the heating plate, temperature sensor and other flexible sensitive units to improve the heating efficiency and the accuracy of temperature control.

[0011] ④ In general, the purpose of the invention is to solve the reliability adaptation problem of flexible temperature control devices in tests under extreme aerospace environments.

[0012] The specific technical solutions are:

[0013] A temperature control tester capable of withstanding the extreme mechanical and thermal environment of aerospace comprises a top PCB board and a bottom PCB board arranged opposite to each other, the top PCB board and the bottom PCB board being fixedly connected by anti-loosening bolts and anti-loosening nuts; a flexible temperature control unit is fixedly installed between the top PCB board and the bottom PCB board, and the flexible temperature control unit is also electrically connected to the top PCB board and the bottom PCB board respectively;

[0014] The flexible temperature control unit comprises, from top to bottom, a flexible temperature sensor, a flexible substrate, and a flexible heating sheet;

[0015] The anti-loosening bolt is provided with a nylon isolation column, and the nylon isolation column is located between the top PCB board and the bottom PCB board.

[0016] The preparation method of a temperature control tester capable of withstanding an extreme thermal environment of aerospace comprises the following steps:

[0017] S1. Preparation of a flexible temperature control unit: placing the flexible heating sheet, the flexible substrate and the flexible temperature sensor in oxygen plasma for 10 minutes for surface modification, and then assembling and pressurizing the flexible temperature sensor, the flexible substrate and the flexible heating sheet in order from top to bottom to form a bond at the interface to form a flexible temperature control unit;

[0018] S2. Connection between PCB board and flexible temperature control unit: This connection includes mechanical connection and electrical connection. The mechanical connection is achieved by highly reliable bonding of the two sides of the flexible temperature control unit to the top PCB board and the bottom PCB board by means of a two-component high-temperature resistant epoxy resin glue that is thermally cured for 10 hours at ℃. The electrical connection is achieved by repeatedly applying conductive silver glue to the pads of the top PCB board and the bottom PCB board and the corresponding pads of the flexible temperature control unit, and repeatedly applying it after curing multiple times; both the top PCB board and the bottom PCB board have double-sided circuit structures, one side of which forms an electrical connection with the flexible temperature control unit, and the pads on the other side are connected to the leads to form hard solder joints.

[0019] S3. Structural reinforcement and improvement of heat conduction: Several corresponding through holes are set on the top PCB board and the bottom PCB board. Anti-loosening bolts are used to pass through the top PCB board, nylon isolation columns and bottom PCB board in sequence, and then connected and locked with anti-loosening nuts and the main structure of the spacecraft.

[0020] The present invention combines technologies such as oxygen plasma bonding, conductive silver glue electrical connection, and a pre-tightened sandwich structure of PCB-flexible temperature control unit-PCB to achieve high reliability of the flexible temperature control unit in the extreme thermal environment of aerospace, thereby avoiding many of the problems mentioned above in the previous technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 It is a schematic diagram of an exploded top view of the structure of the present invention;

[0023] Figure 3 It is a schematic diagram of an exploded structure viewed from above of the present invention. DETAILED DESCRIPTION

[0024] The specific technical solution of the present invention is described in conjunction with the accompanying drawings.

[0025] like Figure 1 , Figure 2 and Figure 3 As shown, the temperature control tester capable of withstanding the extreme mechanical and thermal environment of aerospace comprises a top PCB board 1 and a bottom PCB board 6 arranged opposite to each other in the upper and lower parts, wherein the top PCB board 1 and the bottom PCB board 6 are fixedly connected by anti-loosening bolts 2 and anti-loosening nuts 7; a flexible temperature control unit is fixedly installed between the top PCB board 1 and the bottom PCB board 6, and the flexible temperature control unit is also electrically connected to the top PCB board 1 and the bottom PCB board 6 respectively;

[0026] The flexible temperature control unit comprises, from top to bottom, a flexible temperature sensor 4, a flexible substrate 5, and a flexible heating sheet 8;

[0027] The anti-loosening bolt 2 is provided with a nylon isolation column 3, and the nylon isolation column 3 is located between the top PCB board 1 and the bottom PCB board 6.

[0028] The preparation method of a temperature control tester capable of withstanding an extreme thermal environment of aerospace comprises the following steps:

[0029] S1. Preparation of flexible temperature control unit: The flexible heating sheet 8, the flexible substrate 5 and the flexible temperature sensor 4 are simultaneously placed in oxygen plasma for 5 minutes for surface modification, and then assembled and pressurized in the order of the flexible temperature sensor 4, the flexible substrate 5 and the flexible heating sheet 8 from top to bottom to form a bond at the interface to form a flexible temperature control unit. The purpose of this step is to use oxygen plasma bonding technology to form a highly reliable mechanical connection between the flexible temperature sensor 4, the flexible substrate 5 and the flexible heating sheet 8.

[0030] S2. Connection between PCB board and flexible temperature control unit: This connection includes mechanical connection and electrical connection. The mechanical connection is to achieve high reliability bonding between the two sides of the flexible temperature control unit and the top PCB board 1 and the bottom PCB board 6 by means of two-component high temperature resistant epoxy resin glue through thermal curing at 200°C for 5 hours. The electrical connection is to achieve high reliability electrical connection by repeatedly applying conductive silver glue to the pads of the top PCB board 1 and the bottom PCB board 6 and the pads of the corresponding flexible temperature control unit, repeatedly applying after multiple curing, and observing and verifying the effect under a microscope. The top PCB board 1 and the bottom PCB board 6 are both double-sided circuit structures, one side of which forms a high reliability electrical connection with the flexible temperature control unit, and the pads on the other side can be connected to the leads to form a high reliability hard solder joint. The advantage of this method is that it avoids directly connecting the movable leads to the flexible material, avoiding the disadvantage that the flexible material is susceptible to vibration fracture when in contact with the leads, and using the PCB board as the terminal medium to achieve relative stillness between the flexible material and the PCB board, ensuring the electrical connection stability between the flexible material and the corresponding pads of the PCB board.

[0031] S3, high reliability reinforcement and improvement of heat conduction of the structure: the top PCB board 1 and the bottom PCB board 6 are provided with corresponding through holes, and the anti-loosening bolts 7 are used to pass through the top PCB board 1, the nylon isolation column 3 and the bottom PCB board 6 in sequence, and then connected and locked with the anti-loosening nut 2 and the main structure of the spacecraft. Among them, the height of the nylon isolation column 3 is the same as the height of the flexible substrate 5. Therefore, after the flexible heating plate 8 and the flexible temperature sensor 4 are superimposed, the height of the flexible temperature control unit is slightly larger than the nylon isolation column, about 600 microns larger. Therefore, in this case, locking the anti-loosening bolts will cause the PCBs on both sides to form pre-stress on the flexible temperature control unit in the middle. On the one hand, the flexible temperature control unit can be further reinforced to avoid the electrical connection failure caused by the relative slippage caused by the strong vibration of the aerospace environment. On the other hand, the connection between the flexible temperature sensor 4-flexible substrate 5-flexible heating plate 8 can be strengthened to eliminate the gap, enhance the heating efficiency and improve the temperature control effect. At the same time, the pre-tightening reinforcement can also ensure the consistency and stability of the electrical connection during the rapid thermal barrier and shrinkage of the flexible temperature control unit under extreme temperature cycles in aerospace, avoiding the problem of substrate shrinkage causing electrical circuit disconnection that may exist in non-pre-tightening methods.

Claims

1. A temperature control tester that can withstand the extreme thermal environment of aerospace, characterized by: The flexible temperature control unit comprises a top PCB board (1) and a bottom PCB board (6) which are arranged opposite to each other in an upper and lower manner, wherein the top PCB board (1) and the bottom PCB board (6) are fixedly connected by means of anti-loosening bolts (2) and anti-loosening nuts (7); two sides of the flexible temperature control unit are respectively fixedly connected to the top PCB board (1) and the bottom PCB board (6) by means of thermal curing of a two-component high-temperature resistant epoxy resin glue; at the same time, the top PCB board (1) and the bottom PCB board (6) are electrically connected to the flexible temperature control unit by means of conductive silver glue curing; The flexible temperature control unit comprises a flexible temperature sensor (4), a flexible substrate (5), and a flexible heating sheet (8); the flexible temperature sensor (4), the flexible substrate (5), and the flexible heating sheet (8) are all placed in oxygen plasma for surface modification, and then assembled and pressurized from top to bottom to form a bond at the interface; The anti-loosening bolt (2) is provided with a nylon isolation column (3), and the nylon isolation column (3) is located between the top PCB board (1) and the bottom PCB board (6).

2. The method for preparing a temperature control tester capable of withstanding an extreme thermal environment in aerospace according to claim 1, characterized in that: The following steps are involved: S1. Preparation of a flexible temperature control unit: the flexible heating sheet (8), the flexible substrate (5) and the flexible temperature sensor (4) are simultaneously placed in oxygen plasma for 5 minutes for surface modification, and then assembled and pressurized in the order of the flexible temperature sensor (4), the flexible substrate (5) and the flexible heating sheet (8) from top to bottom to form a bond at the interface, thereby forming a flexible temperature control unit; S2, connection between the PCB board and the flexible temperature control unit: the connection includes mechanical connection and electrical connection; wherein the mechanical connection is achieved by highly reliable bonding of the two sides of the flexible temperature control unit to the top PCB board (1) and the bottom PCB board (6) by means of a two-component high temperature resistant epoxy resin adhesive which is thermally cured at 200° C. for 5 hours; The electrical connection is achieved by repeatedly applying conductive silver glue to the pads of the top PCB board (1) and the bottom PCB board (6) and the pads of the corresponding flexible temperature control unit, and repeatedly applying the conductive silver glue after curing for multiple times; The top PCB board (1) and the bottom PCB board (6) are both double-sided circuit structures, one side of which is electrically connected to the flexible temperature control unit, and the pads on the other side are connected to the leads to form hard solder joints; S3. Structural reinforcement and improvement of heat conduction: A plurality of corresponding through holes are provided on the top PCB board (1) and the bottom PCB board (6). Anti-loosening bolts (2) are used to pass through the top PCB board (1), the nylon isolation column (3) and the bottom PCB board (6) in sequence, and then connected with anti-loosening nuts (7) and the main structure of the spacecraft and locked.

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