Processing method of three-dimensional hot cloak

Abstract

The processing method of the three-dimensional thermal cloak comprises the following steps: performing focusing line scanning on the front surface of a polyimide film by using a laser; dropwise adding a potassium hydroxide solution to the front surface of the polyimide film; performing high-temperature crystallization on the polyimide film dropwise added with the potassium hydroxide solution; washing crystals of the polyimide film by using diluted hydrochloric acid; cleaning and drying are carried out; a laser is used for scanning the back face of the polyimide film, graphene is generated through induction, and a bent heat shielding film is obtained; and the two heat shielding films are respectively clamped on the fixing clamps, so that the two heat shielding films are enclosed to form a hollow cylinder. A potassium hydroxide solution is dropwise added on a polyimide film to react to generate polyimide acid sensitive to water vapor, and the polyimide film can be stretched from a bent state to a straight state after absorbing water; and the graphene on the back surface of the polyimide film can guide the heat flow to be dispersed to the outside through the heat shielding film, so that electronic components in the center of the heat cloak are not influenced.

Description

Technical Field

[0001] The invention relates to the technical field of heat shielding, and in particular to a processing method of a three-dimensional heat cloak. Background Art

[0002] With the development of society, the functional loss and integration of electronic devices are constantly improving. As the functional loss and integration of electronic devices increase, the distribution of heat flow becomes uneven, which may shorten the service life of electronic devices and greatly reduce their reliability during use. Therefore, it is necessary to effectively manage the thermal performance of electronic devices and improve the thermal management strategy of electronic devices.

[0003] Due to the thermal effect of current in electronic integrated circuits, some electronic components will accumulate too much heat within the range of themselves, resulting in excessively high local temperatures. The operation of electronic components that are susceptible to temperature will be affected. For example, the capacitance of electrolytic capacitors will be affected to varying degrees at too high or too low temperatures. The thermal management of electronic equipment must have appropriate safety precautions to shield the impact of unstable external temperatures and keep electronic components in a stable temperature range, which is conducive to enhancing the reliability of electronic components and greatly improving their service life. This is very critical in the microelectronics industry. Summary of the invention

[0004] In response to the problems raised by the background technology, the purpose of the present invention is to propose a processing method for a three-dimensional thermal cloak, by which a three-dimensional thermal cloak is obtained to solve the problem that electronic integrated circuits are affected by temperature due to the thermal effect of electric current, thus affecting the reliability and service life of electronic components.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A method for processing a three-dimensional thermal cloak comprises the following steps:

[0007] Step S1, using a laser to perform focused line scanning on the front side of the polyimide film;

[0008] Step S2, adding a potassium hydroxide solution dropwise to the front surface of the polyimide film;

[0009] Step S3, performing high temperature crystallization on the polyimide film to which the potassium hydroxide solution is added;

[0010] Step S4, using dilute hydrochloric acid to clean the crystals of the polyimide film; and cleaning and drying the polyimide film;

[0011] Step S5, using a laser to scan the back side of the polyimide film according to the introduced graphene pattern, inducing the generation of graphene, and obtaining a curved heat shielding film;

[0012] Step S6: clamp the two heat shielding films on the fixing fixtures respectively, so that the two heat shielding films are enclosed to form a hollow cylinder, thereby obtaining a three-dimensional heat cloak.

[0013] Preferably, in step S1, the size of the polyimide film is 30 mm×45 mm×30 μm;

[0014] The laser is arranged on a Z-direction moving device, an XY moving platform is arranged below the laser, the polyimide film is placed on the XY moving platform, and the laser is provided with a CCD camera, which is used to accurately locate the scanning area of ​​the laser.

[0015] Preferably, in step S1, the laser power of the laser is 6.2 W, the number of laser scanning times of the laser is set to once, the laser scanning interval of the laser is 0.08 mm, and the laser scanning speed of the laser is 150 mm / s.

[0016] Preferably, in step S2, a coating machine is used to spin-coat the potassium hydroxide solution with a concentration of 100 g / L on the front side of the polyimide film, the spin-coating speed is 2500 r / min-3200 r / min, and the spin-coating time is 30 s-70 s.

[0017] Preferably, in step S3, the crystallization temperature is 70°C-90°C, and the crystallization time is 10 min-15 min.

[0018] Preferably, in step S4, the crystallized polyimide film is soaked in hydrochloric acid with a concentration of 0.1 mol / L for a soaking time of 5 min to 7 min;

[0019] After the crystals on the front side of the polyimide film are washed away, the hydrochloric acid residues on the polyimide film are washed away with clean water, and the polyimide film is dried.

[0020] Preferably, in step S5, the desired graphene pattern is introduced into the control system of the laser;

[0021] The back side of the polyimide film is placed upward on the XY moving platform. After the laser positions and focuses the polyimide film, the laser performs laser scanning on the back side of the polyimide film according to the introduced pattern.

[0022] Preferably, in step 5, the laser performs two laser scans, and two graphenes with different densities are generated on the back side of the polyimide film;

[0023] The first laser scan acts on the first area on the back side of the polyimide film, wherein the laser power of the laser is 2.5 W, the number of laser scans of the laser is set to once, the laser scanning pitch of the laser is 0.03 mm, the laser scanning speed of the laser is 300 mm / s, and the laser is defocused downward by 5 mm;

[0024] The second laser scan acts on the second area on the back side of the polyimide film, wherein the laser power of the laser is 7W, the number of laser scans of the laser is set to once, the laser scanning spacing of the laser is 0.03mm, the laser scanning speed of the laser is 300mm / s, and the laser is defocused 5mm downward.

[0025] Preferably, the second region is located at the center of the polyimide film, and the first region is located at the periphery of the second region.

[0026] Preferably, in step S6, the fixing fixture comprises a bottom plate and two clamping arms, the two clamping arms are arranged on the top surface of the bottom plate, the two clamping arms are arranged opposite to each other, and the clamping arms are used to clamp the heat shielding film.

[0027] Compared with the prior art, one of the above technical solutions has the following beneficial effects:

[0028] By dripping potassium hydroxide solution on the polyimide film, it reacts to generate polyimide acid that is sensitive to water vapor. After absorbing moisture, the polyimide film will stretch from a bent state to a straight state; and the graphene on the back of the polyimide film can guide the heat flow through the heat shielding film to evacuate to the outside, thereby not affecting the electronic components in the center of the thermal cloak. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a processing flow chart of a three-dimensional thermal cloak of the present invention;

[0030] Figure 2 is a schematic diagram of a laser processing apparatus of the present invention;

[0031] Figure 3 is a graphene pattern of the heat shielding film of the present invention;

[0032] Figure 4 is a schematic diagram of a fixing fixture of the present invention;

[0033] Figure 5 It is a schematic structural diagram of the three-dimensional thermal cloak of the present invention (the thermal shielding film is in a bent state);

[0034] Figure 6 It is a schematic structural diagram of the three-dimensional thermal cloak of the present invention (the thermal shielding film is in an unfolded state).

[0035] Among them: a control system 1, a laser 2, a polyimide film 3, a first region graphene 31, a second region graphene 32, an XY moving platform 4, a heat shielding film 5, a fixing fixture 6, a base plate 61 and a clamping arm 62. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0037] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0038] In addition, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, features defined as "first", "second" and "third" may explicitly or implicitly include one or more of the features.

[0039] It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] The following is combined with Figures 1 to 6 The technical solution of the present invention is further illustrated by specific implementation methods.

[0041] A method for processing a three-dimensional thermal cloak comprises the following steps:

[0042] Step S1, using the laser 2 to perform focused line scanning on the front side of the polyimide film 3; by using the laser 2 to perform focused line scanning on the front side of the polyimide film 3, the front side of the polyimide film 3 is modified, so that the front and back sides of the polyimide film 3 are subjected to uneven force and present a curved state, and laser induced graphene will not be generated after the focused line scanning.

[0043] Step S2, adding a potassium hydroxide solution dropwise to the front surface of the polyimide film 3;

[0044] Step S3, performing high temperature crystallization on the polyimide film 3 to which the potassium hydroxide solution is added;

[0045] Step S4, using dilute hydrochloric acid to clean the crystals of the polyimide film 3; and cleaning and drying the polyimide film 3; after adding potassium hydroxide solution to the surface of the polyimide film 3, potassium polyamic acid crystals will be generated on the surface of the polyimide film 3; the polyimide film 3 with potassium polyamic acid generated is soaked in hydrochloric acid to achieve the effect of cleaning the potassium polyamic acid crystals; after the soaking reaction, polyimide acid sensitive to water vapor is generated on the surface of the polyimide film 3.

[0046] Step S5, using laser 2 to scan the back side of the polyimide film 3 according to the introduced graphene pattern, inducing the generation of graphene, and obtaining a heat shielding film 5; by using laser 2 to laser scan the back side of the polyimide film 3, local heating and oxidation reaction are generated on the back side, resulting in vibration of the polyimide lattice, causing extremely high local temperature (greater than 2500°C), this high temperature easily breaks the CO, C=O and NC bonds, realizes the rearrangement of carbon atoms, thereby generating laser-induced graphene, and obtaining a heat shielding film 5.

[0047] Step S6, clamping the two heat shielding films 5 on the fixing fixture 6 respectively, so that the two heat shielding films 5 are enclosed to form a hollow cylinder; since the polyimide film 3 after the focus line scan is in a curved state, the two curved heat shielding films 5 are clamped on the fixing fixture 6, and the two curved heat shielding films 5 can be enclosed to form a hollow cylinder, forming a three-dimensional thermal cloak (such as Figure 5 shown).

[0048] The three-dimensional thermal cloak prepared by the present invention is used to protect electronic components that are susceptible to temperature. Specifically, the hollow position of the three-dimensional thermal cloak is used to accommodate electronic components. When current passes through the conductor in the integrated circuit, due to the existence of resistance, the electrical energy will be converted into thermal energy, resulting in an increase in the temperature of the integrated circuit and its surrounding environment. This temperature increase may cause the packaging material of the integrated circuit to release water vapor due to the thermal expansion and contraction effect or the change of material properties. The water vapor acts on the polyimide acid of the three-dimensional thermal cloak (heat shielding film 5), causing the curved heat shielding film 5 to stretch into a horizontal state (such as Figure 6At this time, the stretched heat shielding film 5 can guide the heat energy to be dissipated outward along the graphene structure, so that the heat energy will not affect the electronic components at the center of the three-dimensional heat cloak for a long time, thereby protecting the electronic components.

[0049] To further illustrate, for electrolytic capacitors, the life of electrolytic capacitors is usually 2000 hours under a 105°C environment. Thermal metamaterials can effectively reduce the temperature of electrolytic capacitors and slow down the rate of capacity decay. After using the three-dimensional thermal cloak, the specific life can be increased by 30%-50%. For power semiconductor components (such as MOSFET, IGBT), the service life of power semiconductor components can reach decades under normal conditions of use, but in high-power applications, power semiconductor components often face high thermal loads, resulting in excessive junction temperature, which affects the performance and life of the components. After using the three-dimensional thermal cloak made of thermal metamaterials, the junction temperature of semiconductor components can be reduced by optimizing the heat conduction path, significantly improving the thermal management effect, and increasing its service life by 20%-40%. For pressure sensors, under long-term pressure and temperature changes, the life of pressure sensors may be 5 to 10 years. After using the three-dimensional thermal cloak made of thermal metamaterials, its service life can be increased by about 20%.

[0050] Further, in step S1, the size of the polyimide film is 30 mm×45 mm×30 μm;

[0051] The laser 2 is arranged on a Z-direction moving device, an XY moving platform 4 is arranged below the laser, the polyimide film 3 is placed on the XY moving platform 4, and the laser 2 is provided with a CCD camera, which is used to accurately locate the scanning area of ​​the laser 2.

[0052] The size of the polyimide film 3 is specified to be 30 mm × 45 mm × 30 μm, which helps to ensure that the polyimide film 3 can maintain consistency and predictability in subsequent processing steps, thereby optimizing the performance and quality of the final product. By introducing the Z-moving device and the XY moving platform 4, precise control of the laser 2 in three-dimensional space can be achieved. This high-precision positioning capability is crucial for the laser focus line scanning step of the laser 2, because it ensures that the laser can accurately act on the predetermined area of ​​the polyimide film 3, thereby achieving a uniform modification effect and the expected bending state. The laser 2 equipped with a CCD camera can monitor the scanning area in real time to ensure the accuracy and consistency of the laser scanning, which plays an important role in the positioning and focusing of the laser 2.

[0053] Specifically, the polyimide film 3 is laid on a glass sheet (processing carrier), and the glass sheet is placed on an XY moving platform 4. The XY moving platform 4 moves the polyimide film 3 to be focused and line-scanned to the bottom of the laser 2 (CCD camera). The CCD camera feeds back the acquired information of the polyimide film 3 to the control system 1 of the laser, and controls the Z-axis moving device to drive the laser 2 to move up and down for focusing, so that the laser of the laser 2 can accurately scan the polyimide film.

[0054] Furthermore, in step S1, the laser power of the laser is 6.2 W, the number of laser scanning times of the laser is set to once, the laser scanning interval of the laser is 0.08 mm, and the laser scanning speed of the laser is 150 mm / s.

[0055] By clearly setting the working parameters of the laser, precise control of the modification process of the polyimide film 3 can be achieved. This precision helps to ensure that the uneven force on the front and back sides of the polyimide film 3 is consistent, thereby obtaining the expected bending state, while avoiding performance problems caused by over-modification or under-modification.

[0056] Further, in step S2, a coating machine is used to spin-coat the potassium hydroxide solution with a concentration of 100 g / L on the front side of the polyimide film, the spin-coating speed is 2500 r / min-3200 r / min, and the spin-coating time is 30 s-70 s.

[0057] The potassium hydroxide solution is spin-coated on the surface of the polyimide film 3 by a coating machine in an atmospheric environment, the spin-coating speed is 2500-3200 r / min, and the spin-coating time is 30-50 s. The potassium hydroxide solution is applied by spin coating rather than by direct dropwise addition in order to make the potassium hydroxide solution evenly distributed on the surface of the polyimide film. The rotation speed and time of the coating machine are controlled mainly to control the film thickness on the polyimide film.

[0058] Preferably, a potassium hydroxide solution with a concentration of 100 g / L is dripped onto the glass sheet with the polyimide film 3 attached, and the glass sheet is placed in a glue machine for spin coating. Specifically, a corresponding spin coating program is selected in the glue machine, and the rotation speed and time are adjusted to 2000 r / min and 50 s after entering the program; the glass sheet with the polyimide film 3 attached is placed on the tray of the glue machine, and the potassium hydroxide solution is dripped onto the center of the glass sheet using a pipette gun, the top cover of the glue machine is closed, and the vacuum button is pressed to adsorb the glass sheet onto the tray of the glue machine; the glue machine is started to start spin coating; after the spin coating is completed, the vacuum inside the glue machine is removed, and the top cover of the glue machine is opened to remove the glass sheet that has been spin coated.

[0059] Further, in step S3, the crystallization temperature is 70°C-90°C, and the crystallization time is 10min-15min.

[0060] Setting the crystallization temperature within the range of 70℃-90℃ can ensure that the material crystallizes at the appropriate temperature, thereby optimizing the crystallization process. This temperature range usually enables the material to achieve the best crystallization rate and crystallinity, which helps to improve the quality and performance of the product. Too high or too low a temperature may have an adverse effect on the crystallization process of the material. Too high a temperature may cause the material to decompose or produce unnecessary side reactions, while too low a temperature may make the crystallization process too slow or even lead to incomplete crystallization.

[0061] Setting the crystallization time within the range of 10min-15min can ensure that the material has enough time to fully crystallize. This helps to form a more complete and dense crystal structure, thereby improving the strength and durability of the product. Reasonable crystallization time can not only ensure product quality, but also improve production efficiency. Too long crystallization time may lead to extended production cycle and increased production costs; while too short crystallization time may lead to unstable product quality.

[0062] Further, in step S4, the crystallized polyimide film is soaked in hydrochloric acid with a concentration of 0.1 mol / L for a soaking time of 5 min to 7 min;

[0063] After the crystals on the front side of the polyimide film are washed away, the hydrochloric acid residues on the polyimide film are washed away with clean water, and the polyimide film is dried.

[0064] Soaking the crystallized polyimide film 3 in hydrochloric acid with a concentration of 0.1 mol / L can effectively remove the potassium polyamic acid crystals on the surface of the polyimide film 3. These crystals may affect the performance and appearance of the polyimide film 3. Through the soaking treatment with hydrochloric acid, the surface of the polyimide film 3 can be ensured to be clean and flat. The soaking time is set to 5min-7min, which can ensure sufficient contact and reaction between the hydrochloric acid and the film surface, and avoid unnecessary damage to the film caused by too long soaking time.

[0065] Using clean water to wash the hydrochloric acid residue on the polyimide film 3 can avoid the influence of hydrochloric acid on the subsequent processing or use of the polyimide film 3, which helps to ensure the quality and stability of the film. Drying the polyimide film 3 can remove surface moisture and prevent moisture from affecting the performance of the polyimide film 3. At the same time, the drying process can also make the polyimide film 3 more stable and improve its durability and service life.

[0066] Furthermore, in step S5, the desired graphene pattern is introduced into the control system of the laser;

[0067] The back side of the polyimide film is placed upward on the XY moving platform. After the laser positions and focuses the polyimide film, the laser performs laser scanning on the back side of the polyimide film according to the introduced pattern.

[0068] The polyimide film 3 is attached to a glass sheet (processing carrier) with the back side facing upward, and then the glass sheet is placed on an XY moving platform 4. The CCD camera of the laser 2 performs positioning and focusing, and performs laser scanning on the polyimide film 3 according to the pattern signal of the control system 1.

[0069] Further explanation is that by introducing the desired graphene pattern into the control system of the laser, high-precision patterning can be achieved. The laser scanning technology can accurately process the polyimide film 3 according to the preset pattern, avoiding the errors and irregularities that may be caused by traditional processing methods.

[0070] Further, in step 5, the laser performs two laser scans, and two graphenes with different densities are generated on the back side of the polyimide film;

[0071] The first laser scan acts on the first area on the back side of the polyimide film, wherein the laser power of the laser is 2.5 W, the number of laser scans of the laser is set to once, the laser scanning pitch of the laser is 0.03 mm, the laser scanning speed of the laser is 300 mm / s, and the laser is defocused downward by 5 mm;

[0072] The second laser scan acts on the second area on the back side of the polyimide film, wherein the laser power of the laser is 7W, the number of laser scans of the laser is set to once, the laser scanning spacing of the laser is 0.03mm, the laser scanning speed of the laser is 300mm / s, and the laser is defocused 5mm downward.

[0073] Through two laser scans, two graphenes with different densities can be generated on the back of the polyimide film 3. Graphenes with different densities have different electrical, thermal and mechanical properties. By adjusting the density of graphene, its performance and distribution in the polyimide film 3 can be optimized, thereby improving the overall performance of the three-dimensional thermal cloak.

[0074] Specifically, after the positioning and focusing of the laser 2 are completed, the processing parameters for the first laser scanning of the laser 2 are set, and the specific settings are as follows: the laser power is set to 2.5W, the number of laser scanning is set to 1 time, the scanning spacing is set to 0.03mm, and the laser scanning speed is set to 300mm / s, and the laser 2 is defocused downward by 5mm to avoid excessive power of the laser 2, which affects the processing quality of the sample; after the processing parameters are set, the laser 2 is laser scanned on the first area on the back of the polyimide film 3 to obtain the first area graphene 31 with low processing thermal conductivity. Then, the processing parameters for the second laser scanning of the laser 2 are set, and the specific settings are as follows: the laser power is set to 7W, the number of laser scanning is set to 1 time, the scanning spacing is set to 0.03mm, and the laser scanning speed is set to 300mm / s, and the laser 2 is defocused downward by 5mm; after the processing parameters are set, the laser 2 is laser scanned on the second area on the back of the polyimide film 3 to obtain the second area graphene 32 with high processing thermal conductivity. At this point, the heat shielding film 5 is manufactured.

[0075] Furthermore, the second area is located at the center of the polyimide film 3, and the first area is located at the periphery of the second area.

[0076] Since the second region is located at the center of the polyimide film 3 and high-density graphene (second region graphene 32) is generated by high-power laser scanning, this region will have higher thermal conductivity. High thermal conductivity helps to quickly transfer and diffuse heat in the central region, thereby improving the thermal response speed and thermal management efficiency of the three-dimensional thermal cloak.

[0077] It is worth noting that among the two graphenes with different densities generated on the back of the polyimide film 3, the thermal conductivity of the first region is lower, while the thermal conductivity of the laser-induced graphene in the second region located in the central ring is higher. Such a model is determined by theoretically designing heat shielding based on the coordinate transformation thermodynamics theory and the effective medium theory. The concentric ring pattern in the second region makes the obtained heat shielding film 5 isotropic, which is conducive to more uniform temperature conduction outward.

[0078] Further, in step S6 , the fixing fixture 6 includes a bottom plate 61 and two clamping arms 62 . The two clamping arms 62 are disposed on the top surface of the bottom plate 61 . The two clamping arms 62 are disposed opposite to each other, and the clamping arms 62 are used to clamp the heat shielding film 5 .

[0079] The heat shielding film 5 can be precisely clamped and positioned by two clamping arms 62 that are arranged opposite to each other. The two curved heat shielding films 5 can be enclosed into a hollow cylinder for accommodating the electrical components that need to be protected.

[0080] Preferably, the bottom plate 61 is a cubic plate of 50 mm×50 mm×10 mm; the clamping arm 62 is composed of two rectangular clamping pieces of 10 mm×50 mm, and the heat shielding film 5 is arranged between the two clamping pieces.

[0081] The present invention is described in more detail below through an embodiment.

[0082] The processing method of the three-dimensional thermal cloak of this embodiment is as follows:

[0083] Step S1:

[0084] Cut out a polyimide film 3 of size 30mm×45mm×30μm, and use a small roller brush to stick the polyimide film 3 on the glass sheet with blue film, and use a small roller brush to squeeze out the air between the polyimide film 3 and the glass sheet, so that the polyimide film 3 is completely attached to the glass sheet, and no bubbles are allowed to exist to avoid affecting the surface quality of laser processing. Place the glass sheet with the polyimide film 3 to be processed on the XY moving platform 4, so that the polyimide film 3 can be processed more steadily and smoothly. The laser 2 obtains the position information of the polyimide film 3 located on the XY moving platform 4 through the CCD camera and transmits it to the control system 1, and moves along the X-axis and Y-axis directions through the XY moving platform 4, so that the polyimide film 3 to be processed is located directly below the laser 2, and the laser 2 is focused by adjusting the Z-direction moving device.

[0085] After adjusting the focal length and accurate positioning, set the processing parameters of laser 2. The specific settings are as follows: the laser power is set to 6.2W, the number of laser scans is set to 1, the scanning interval is set to 0.08mm, and the laser scanning speed is set to 150mm / s. After the processing parameters are set, let the laser 2 focus on the polyimide film 3 (the front side) to complete the modification of the front side of the polyimide film 3, so that the force on the front and back sides of the polyimide film 3 is uneven and presents a curved state.

[0086] Step S2:

[0087] A potassium hydroxide solution with a concentration of 100 g / L is dripped onto the glass sheet with the polyimide film 3 attached, and the glass sheet is placed in a coating machine for spin coating. Specifically, a corresponding spin coating program is selected in the coating machine, and the rotation speed and time are adjusted to 2000 r / min and 50 s after entering the program; the glass sheet with the polyimide film 3 attached is placed on the tray of the coating machine, and the potassium hydroxide solution is dripped onto the center of the glass sheet using a pipette gun, and the top cover of the coating machine is closed and the vacuum button is pressed to make the glass sheet adsorbed on the tray of the coating machine; the coating machine is started to start spin coating; after the spin coating is completed, the vacuum inside the coating machine is removed, and the top cover of the coating machine is opened to remove the glass sheet that has been spin coated.

[0088] Step S3:

[0089] Place the spin-coated glass sheet with the polyimide film 3 on a heating table, set the temperature of the heating table, and heat it at 70-90° C. for 10-15 minutes until white crystals appear on the surface of the polyimide film 3, and then remove the heated glass sheet.

[0090] Step S4:

[0091] Take 150mL of 0.1mol / L hydrochloric acid and pour it into a beaker. Then place the heated glass piece with the polyimide film 3 in the 0.1mol / L hydrochloric acid and soak it at room temperature for 5-7 minutes. Wash off the white crystals on the sample. After washing, take out the sample and wash off the hydrochloric acid remaining on the sample with clean water, and then put it on a heating table to dry.

[0092] Step S5:

[0093] See also Figure 3 , the graphene pattern of the heat shielding film 5 is introduced into the control system 1 of the laser.

[0094] Carefully tear off the dried polyimide film 3 from the glass sheet, turn the front and back of the polyimide film 3 over, and then stick it back on the glass sheet, and then repeat the positioning and focusing steps in the above step S1. After positioning and focusing are completed, set the processing parameters for the first laser scan of the laser 2, and the specific settings are as follows: the laser power is set to 2.5W, the number of laser scans is set to 1, the scanning interval is set to 0.03mm, and the laser scanning speed is set to 300mm / s, and the laser 2 is defocused downward by 5mm to avoid excessive power of the laser 2, which affects the processing quality of the sample; after the processing parameters are set, let the laser 2 perform laser scanning on the first area on the back of the polyimide film 3 to obtain the first area graphene 31 with lower processing thermal conductivity. Then, the processing parameters for the second laser scanning of the laser 2 are set, and the specific settings are as follows: the laser power is set to 7W, the number of laser scanning is set to 1 time, the scanning interval is set to 0.03mm, and the laser scanning speed is set to 300mm / s, and the laser 2 is defocused downward by 5mm; after the processing parameters are set, the laser 2 performs laser scanning on the second area on the back of the polyimide film 3 to obtain the second area graphene 32 with higher processing thermal conductivity. At this point, the heat shielding film 5 is obtained.

[0095] Step S6:

[0096] See also Figure 5 Two pieces of heat shielding films 5 processed with the same parameters and steps are clamped in a fixing fixture 6 to form a hollow cylinder to obtain a three-dimensional heat cloak.

[0097] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A method for processing a three-dimensional thermal cloak, characterized in that: The following steps are involved: Step S1, using a laser to perform focused line scanning on the front side of the polyimide film; Step S2, adding a potassium hydroxide solution dropwise to the front surface of the polyimide film; Step S3, performing high temperature crystallization on the polyimide film to which the potassium hydroxide solution is added; Step S4, using dilute hydrochloric acid to clean the crystals of the polyimide film; and cleaning and drying the polyimide film; Step S5, using a laser to scan the back side of the polyimide film according to the introduced graphene pattern, inducing the generation of graphene, and obtaining a curved heat shielding film; Step S6: clamp the two heat shielding films on the fixing fixtures respectively, so that the two heat shielding films are enclosed to form a hollow cylinder, thereby obtaining a three-dimensional heat cloak.

2. A method for processing a three-dimensional thermal cloak according to claim 1, characterized in that: In step S1, the size of the polyimide film is 30 mm×45 mm×30 μm; The laser is arranged on a Z-direction moving device, an XY moving platform is arranged below the laser, the polyimide film is placed on the XY moving platform, and the laser is provided with a CCD camera, which is used to accurately locate the scanning area of ​​the laser.

3. A method for processing a three-dimensional thermal cloak according to claim 2, characterized in that: In step S1, the laser power of the laser is 6.2 W, the laser scanning times of the laser is set to once, the laser scanning pitch of the laser is 0.08 mm, and the laser scanning speed of the laser is 150 mm / s.

4. The method for processing a three-dimensional thermal cloak according to claim 1, characterized in that: In step S2, a coating machine is used to spin-coat the potassium hydroxide solution with a concentration of 100 g / L on the front side of the polyimide film. The rotation speed of the spin coating is 2500 r / min-3200 r / min, and the spin coating time is 30 s-70 s.

5. The method for processing a three-dimensional thermal cloak according to claim 1, characterized in that: In step S3, the crystallization temperature is 70°C-90°C, and the crystallization time is 10min-15min.

6. The method for processing a three-dimensional thermal cloak according to claim 1, characterized in that: In step S4, the crystallized polyimide film is soaked in hydrochloric acid with a concentration of 0.1 mol / L for a soaking time of 5 min to 7 min; After the crystals on the front side of the polyimide film are washed away, the hydrochloric acid residues on the polyimide film are washed away with clean water, and the polyimide film is dried.

7. The method for processing a three-dimensional thermal cloak according to claim 3, characterized in that: In step S5, the desired graphene pattern is introduced into the control system of the laser; The back side of the polyimide film is placed upward on the XY moving platform. After the laser positions and focuses the polyimide film, the laser performs laser scanning on the back side of the polyimide film according to the introduced pattern.

8. The method for processing a three-dimensional thermal cloak according to claim 7, characterized in that: In step 5, the laser performs two laser scans, and two graphenes with different densities are generated on the back side of the polyimide film; The first laser scan acts on the first area on the back side of the polyimide film, wherein the laser power of the laser is 2.5 W, the number of laser scans of the laser is set to once, the laser scanning pitch of the laser is 0.03 mm, the laser scanning speed of the laser is 300 mm / s, and the laser is defocused downward by 5 mm; The second laser scan acts on the second area on the back side of the polyimide film, wherein the laser power of the laser is 7W, the number of laser scans of the laser is set to once, the laser scanning spacing of the laser is 0.03mm, the laser scanning speed of the laser is 300mm / s, and the laser is defocused 5mm downward.

9. A method for processing a three-dimensional thermal cloak according to claim 8, characterized in that: The second region is located at the center of the polyimide film, and the first region is located at the periphery of the second region.

10. The method for processing a three-dimensional thermal cloak according to claim 1, characterized in that: In step S6, the fixing fixture includes a bottom plate and two clamping arms, the two clamping arms are arranged on the top surface of the bottom plate, the two clamping arms are arranged opposite to each other, and the clamping arms are used to clamp the heat shielding film.

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