A micro self-destruct device based on 3D printing and its integrated assembly molding method

Abstract

The present invention relates to the technical field of self-destruction, and specifically relates to a micro self-destruction device based on 3D printing and its integrated assembly and molding method; the additive manufacturing technology is used to realize the integration of micro energetic devices with self-destruction ability; wherein, the built-in energetic material is an Al-based high-gas-yield nano-thermite, and the nano-thermite uses Al nanoparticles as fuel, nano-alkali metal salts as oxidizer, and fluororubber as binder. The mass ratio of each raw material is: 10-60 parts of fuel, 40-90 parts of oxidizer, and 3-20 parts of binder. The output pressure is generated through redox reaction to achieve the purpose of directional damage; the volume of the self-destruction device manufactured integrally is within 0.7-5 cm<supgt;3< / supgt;, the mass is between 1.5-4.5 g, and the response time is within 1 ms. It has the advantages of being micro, lightweight, and fast in response, and can realize various transient damage responses in complex scenarios.

Description

Technical Field

[0001] The present invention relates to the field of self-destruction technology, and in particular to a 3D printing-based micro self-destruct device and an integrated assembly method thereof. Background Art

[0002] The rapid development of information technology has brought convenience to life and work, but it has also led to more and more attention to the issue of information security protection. How to improve the security of information storage and prevent the leakage of key data has become a key issue that people are paying more and more attention to. Among them, chips, as an important part of modern society, are not only the physical carrier of informatization and intelligence, but also the cornerstone of information security. The improvement of information security is inevitably closely related to the key field of chips. Common methods for protecting internal information of chips include information encryption, demagnetization, and program self-elimination. However, with the continuous development of high technologies such as decryption technology, such software encryption methods have gradually become vulnerable to cracking, and it is difficult to meet the actual high security needs.

[0003] The development of micro-energetic self-destruction devices provides an opportunity to solve this problem. It mainly relies on the transient high efficiency and high energy characteristics of energetic materials, and causes physical damage to the core components inside the chip through stress damage and high-temperature ablation caused by the energy release of energetic materials, thereby achieving the purpose of key information protection (Materials Today, 2016, 28, 3527; Advanced Materials Technology, 2018, 1800044; Chemical Engineering Journal, 2023, 459: 141506). Based on this research idea, Zhang Jian et al. announced in 2020 a self-destruction chip with embedded energetic film developed using MEMS technology (CN212648226U). In 2023, Shen Ruiqi et al. reported an energetic diode used in self-destruction chips and its integrated assembly molding method. (CN116631949A). However, it should be noted that although the above technologies can achieve the expected self-destruction effect, there is still room for improvement. For example, most of the reported research on drug damage remains at the level of principle verification (Advanced Functional Materials, 2021, 31,2103199; Chemical Engineering Journal, 2023, 459: 141506.), and although the reported energetic chips can be integrated into one package, they are highly dependent on expensive equipment. Therefore, how to develop a micro energetic device with self-destruction effect, simple preparation process and low cost has become a problem that needs to be solved urgently.

[0004] Fortunately, the 3D printing (additive manufacturing) technology has pointed out a new direction for this. Such a high-precision, universal and diverse manufacturing method can not only quickly and accurately manufacture structures with sub-micron scale and complex 3D features, but also realize shaped charges, which is an important means for the charging of micro energetic devices. At the same time, the nano-thermite has the characteristics of high volume energy density, has shown excellent application potential in micro propulsion and micro ignition systems, and is also the main material most promising to meet the energy requirements of micro energetic devices. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a micro self-destruction device based on 3D printing. Using a coaxial printer as the manufacturing platform, at one end, a low-cost polymer material is used as the substrate of the device housing, and at the other end, a nano-thermite direct writing ink is assembled. Then, the assembly and integration packaging of the micro energetic device can be completed synchronously. On this basis, by attaching the micro energetic device to the surface of the target chip, it can quickly react under specific stimuli to achieve the destruction of the chip. In this way, not only the constraints of micro self-destruction energetic devices in terms of technology and cost are cleverly relieved, but also it has the advantages of being lightweight and having a high degree of freedom. It can achieve multi-functional responses (single-point and multi-point outputs) by changing the digital model, which helps the micro energetic device to achieve diversification and customization on demand, and endows it with broad application prospects.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: a micro self-destruction device based on 3D printing, including an energetic device substrate and an energetic device cover plate. The energetic device substrate is provided with a ignition groove and an output groove, and a fire transfer channel is communicated between the ignition groove and the output groove; an electrode hole is opened on the energetic device cover plate, and the position of the electrode hole corresponds to that of the ignition groove; bolt holes are opened at the edges of the energetic device substrate and the energetic device cover plate, and the two are connected together by bolts;

[0007] The materials of the energetic device substrate and the energetic device cover plate are renewable polymer materials. The ignition groove, the output groove and the fire transfer channel are internally loaded with nano-thermite. The nano-thermite uses Al nano-particles as fuel, nano-alkali metal salts as oxidants, and fluororubber as a binder. The mass ratio of each raw material is: 10-60 parts of fuel, 40-90 parts of oxidant, and 3-20 parts of binder. Among them, the particle size of the nano-Al particles is 50-200 nm, and the oxidant particles are sub-micron sized, and the decomposition temperature is above 200 °C.

[0008] The volume of the integrally manufactured self-destruction device is within 0.7-5 cm 3 and the mass is between 1.5-4.5 g, and the response time is within 1 ms. It has the advantages of being micro, lightweight, and having a rapid response, and can achieve a variety of transient damage responses in complex scenarios.

[0009] Preferably, the renewable polymer material is a polymer material with a melting point of about 200°C, such as ABS, TPU, PVA or PLA, so as to meet the lightweight characteristics; the oxidant is one or more of potassium periodate, sodium periodate and potassium perchlorate; the binder is replaced by hydroxypropyl methylcellulose or nitrocellulose or one or more of other polymers that can be dissolved in N, N-dimethylformamide and ethyl acetate.

[0010] Preferably, the mass ratio of the raw materials of the nano-thermite is: 10-60 parts of fuel, 40-60 parts of oxidant, and 5-10 parts of binder.

[0011] Furthermore, the micro self-destruct device includes a multi-point micro self-destruct device, a double-point micro self-destruct device and a single-point micro self-destruct device.

[0012] Furthermore, the energetic device substrate of the multi-point micro self-destruct device is a multi-point energetic device substrate, which is a circular plate, an ignition groove is provided at the center of the circular plate, and a plurality of circularly distributed output grooves are uniformly distributed near the edge of the circular plate with the ignition groove as the center of the circle, and a fire transmission channel is connected to the ignition groove and each output groove.

[0013] Furthermore, the dual-point type micro self-destruct device energetic device substrate is a dual-point type energetic device substrate, which is a rectangular plate, one end of which is provided with an ignition slot, and the other end of which is provided with an output slot.

[0014] Furthermore, the single-point type micro self-destruct device energetic device substrate is a single-point type energetic device substrate, the single-point type energetic device substrate is a circular plate, the ignition slot and the output slot of the single-point type energetic device substrate are the same slot, and are opened at the center of the single-point type energetic device substrate.

[0015] By using the high-pressure gas products generated by the reaction to impact the substrate, the target product is physically destroyed, thereby fundamentally preventing information leakage. The device shell uses a polymer material as the substrate, and the gas products are directed through the specific channels reserved inside to achieve different functional responses. The device can effectively solve the application problems of chip self-destruction, and provides an integrated assembly molding method for a micro self-destruct device with simple process and low cost.

[0016] An integrated assembly method for a micro self-destruct device based on 3D printing comprises the following steps:

[0017] (1) dissolving a binder in a corresponding solvent to obtain a binder solution;

[0018] (2) Weighing nano-Al powder and submicron alkali metal salt particles in proportion by mass;

[0019] (3) Pour the weighed nanoparticles and binder solution into a mixing dish, and then mix them evenly using a planetary microgravity mixing system to obtain a nano-thermite direct writing ink;

[0020] (4) Using a 3D printing platform, ink is written into the grooves of the pre-printed micro self-destruct device, dried in a vacuum oven, and finally integrated into a package to obtain a micro self-destruct device.

[0021] Preferably, the solvent in step (1) is ethyl acetate or N, N-dimethylformamide, and the mass concentration of the obtained binder solution is 10-15%.

[0022] Preferably, the vacuum drying conditions in step (4) are drying in a vacuum oven at 50° C. and 0.8 MPa for 24 h.

[0023] The prepared device can release energy quickly at a microscale and achieve multifunctional transient response, and has the characteristics of simple preparation process and low cost.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention uses additive manufacturing technology throughout the process to independently complete the manufacture, filling and integrated molding of micro energetic devices, and destroys the target chip by releasing energy through the reaction of high-energy nano-thermite filled inside. The submicron alkali metal salts and nano-Al particles filled inside not only greatly enhance the efficiency of heat and mass transfer, but also the large amount of gas products produced during the reaction can promote the transformation of the reaction from heat conduction to heat convection, thereby significantly improving the reaction rate and achieving transient high-voltage output. It has important practical value and research significance in micro-propulsion and micro-self-destructive energetic devices.

[0026] The invention has the advantages of simple preparation process, low cost and integrated molding, and can achieve the effect of fixed-point damage to the target within 1ms. The prepared micro self-destruct device has strong compatibility with the semiconductor platform, does not need to change the internal circuit and structure of the chip, has little dependence on specific equipment, and is conducive to mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of energy release during assembly of micro self-destruct device.

[0028] Figure 2 Schematic diagram of the substrate structure of a multi-point energetic device.

[0029] Figure 3 It is a schematic diagram of the structure of a multi-point energetic device cover.

[0030] Figure 4 Schematic diagram of the target silicon wafer and the multi-point micro self-destruct device waiting to be triggered.

[0031] Figure 5 This is a diagram showing the damage process of the multi-point micro self-destruct device on the target silicon wafer.

[0032] Figure 6 This is a picture of the debris after the multi-point micro self-destruct device damaged the target silicon wafer.

[0033] Figure 7 Schematic diagram of the substrate structure of a dual-point energetic device.

[0034] Figure 8 It is a schematic diagram of the double-point energetic device cover structure.

[0035] Fig. 9 Schematic diagram of the target silicon wafer and the dual-point micro self-destruct device waiting to be triggered.

[0036] Fig.10 This is a diagram showing the damage process of the dual-point micro self-destruct device on the target silicon wafer.

[0037] Fig.11 This is a picture of the debris after the double-point micro self-destruct device damaged the target silicon wafer.

[0038] Fig.12 Schematic diagram of the substrate structure of a single-point energetic device.

[0039] Fig.13 This is a schematic diagram of the single-point energetic device cover structure.

[0040] Fig.14 Schematic diagram of the target silicon wafer and the single-point micro self-destruct device waiting to be triggered.

[0041] Fig.15 This is a diagram showing the damage process of a single-point micro self-destruct device on a target silicon wafer.

[0042] Fig.16 This is a picture of the debris after the single-point micro self-destruct device damaged the target silicon wafer.

[0043] The following are marked in the figure:

[0044] 1-bolt hole, 2-output slot, 3-ignition slot, 4-fire transfer channel, 5-electrode hole. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with specific embodiments. Example 1

[0046] Preparation of multi-point micro self-destruction devices:

[0047] Energetic materials choose KIO with high oxygen content 4 60 parts and 35 parts of nano-Al powder, 5 parts of fluororubber F2602 are used as a binder, and polylactic acid (PLA) is selected as the substrate material.

[0048] Preparation of binder solution: A certain mass of F2602 was mixed with ethyl acetate reagent, wherein the mass ratio of solute to solvent was 1:6, and then mixed with a magnetic stirrer at 50°C and 400 rpm for 12 hours to obtain a uniform binder solution.

[0049] Preparation of nano-aluminothermic direct writing ink: Weigh commercial nano-Al powder with an average particle size of 50nm, add binder according to the mass ratio, mix evenly using a planetary microgravity mixing system, and then add nano-KIO 4 and nano graphite powder and mix them evenly, fill them into the printing syringe for later use.

[0050] Micro-device shell preparation: Use CAD software and Solidworks software to design the shell model and use BlueMaker 3D printer to print out the shell model. Figure 2 Multi-point micro energetic device substrate.

[0051] Energetic assembly of microdevices: Writing nanothermite ink using coaxial needles Figure 2 The output slot 2, ignition hole 3 and fire transmission channel 4 in the printer are assembled to complete the energy release body assembly step, and then placed in a vacuum oven at 0.8Mpa and 50℃ for 24 hours for shaping and drying, and then the cover plate is printed as shown in FIG. Figure 3 Finally, tighten the bolts to reinforce the packaging effect, and insert the trigger electrode head to complete the assembly of the multi-point energetic device.

[0052] As above Figure 4 As shown in the figure, a is the target silicon wafer. The target silicon wafer to be damaged has a thickness of 725 μm, a length and width of 3 cm, and a surface area of ​​9 cm 2 The volume of the micro-energy device is 4.24cm 3 , mass is 4.5g. Figure 4 b is a schematic diagram of the target silicon wafer and the multi-point micro self-destruct device waiting to be triggered; high-speed photography is then used to record the damage process and take optical pictures of the wreckage.

[0053] Depend on Figure 5 It can be seen that the energetic micro-device can completely destroy the target Si wafer through violent chemical reactions within 1ms, and can instantly impact a 30×30mm Si wafer into irregular fragments at the sub-millimeter scale with an area of ​​0.1~1.5mm 2 It has the characteristics of lightweight and transient response, achieving the expected goals. Example 2

[0054] Preparation of dual-point micro self-destruct device:

[0055] Energetic materials choose NaIO with high oxygen content 450 parts and 42 parts of nano-Al powder, 8 parts of fluororubber F2311 are used as binder, and ABS plastic is selected as the substrate material.

[0056] Preparation of binder solution: A certain mass of F2311 was mixed with N,N-dimethylformamide reagent, wherein the mass ratio of solute to solvent was 1:6, and then mixed with a magnetic stirrer at 50°C and 400 rpm for 5 hours to obtain a uniform binder solution.

[0057] Preparation of nano-aluminothermic direct writing ink: Weigh commercial nano-Al powder with an average particle size of 50 nm, add binder according to the mass ratio, mix evenly using a planetary microgravity mixing system, and then add nano-NaIO 4 and nano graphite powder and mix them evenly, fill them into the printing syringe for later use.

[0058] Micro-device shell preparation: Use CAD software and Solidworks software to design the shell model and use BlueMaker 3D printer to print out the shell model. Figure 7 Double-dot micro energetic device substrate.

[0059] Energetic assembly of microdevices: Writing nanothermite ink using coaxial needles Figure 7 The output slot 2, ignition hole 3 and fire transmission channel 4 are assembled to complete the energy release body assembly step, and then placed in a vacuum oven at 0.8Mpa and 50℃ for 24 hours for shaping and drying, and then the cover plate is printed. Figure 8 Finally, tighten the fastening bolts to strengthen the packaging effect, and insert the trigger electrode head to complete the assembly of the multi-point energetic device. Figure 8 and 9 shown.

[0060] like Fig. 9 As shown, the target silicon wafer to be damaged has a thickness of 725 μm, a length of 6 cm, a width of 3 cm, and a surface area of ​​4.5 cm 2 , the volume of the micro energetic device is 5cm 3 , with a mass of 2g. High-speed photography was then used to record the damage process and to take optical images of the wreckage.

[0061] From above Fig.10 and 11 The obtained dual-point micro energetic device can destroy the target in 0.8ms, and the debris size is between 1-2mm and the area is between 2~5mm 2 The volume of the debris has increased by more than two times compared with the multi-point type. It is proved that the Si chip can be damaged to different degrees by adjusting the internal structure of the device, which reflects the high degree of freedom and versatility of the micro-energetic self-destruct device. Example 3

[0062] Preparation of single-point micro self-destruction device:

[0063] The energetic material is 40 parts of potassium perchlorate (AP) with high oxygen content and 50 parts of nano-Al powder, 10 parts of fluororubber F2311 is used as a binder, and the substrate material is ABS plastic.

[0064] Preparation of binder solution: A certain mass of F2311 was mixed with N, N-dimethylformamide reagent, wherein the mass ratio of solute to solvent was 1:6, and then mixed with a magnetic stirrer at 50°C and 400 rpm for 5 hours to obtain a uniform binder solution.

[0065] Preparation of nano-thermite direct writing ink: Weigh commercial nano-Al powder with an average particle size of 50nm, add a binder according to the mass ratio, mix evenly using a planetary microgravity mixing system, then add submicron AP and nano-graphite powder in turn and mix evenly, fill them into the printing syringe for later use.

[0066] Micro-device shell preparation: Use CAD software and Solidworks software to design the shell model and use BlueMaker 3D printer to print out the shell model. Fig.12 Single-point micro energetic device substrate.

[0067] Energetic assembly of microdevices: Writing nanothermite ink using coaxial needles Fig.12 The output slot 3 in the output slot 3 is placed in the output slot 3 to complete the energy release body assembly step. Then, it is placed in a vacuum oven at 0.8Mpa and 50℃ for 24 hours for final shaping and drying. Then, the cover is printed and fastened for packaging. Finally, the fastening bolts are screwed in to reinforce the packaging effect, and the trigger electrode head is inserted to complete the assembly of the multi-point energy-containing device. Fig.14 shown.

[0068] The target silicon wafer to be damaged is 725 μm thick, 1.5 cm long and wide, and has a surface area of ​​2.25 cm 2 The volume of the micro energetic device is 1.06 cm 3 , with a mass of 1.5g. High-speed photography was then used to record the damage process and to take optical images of the wreckage.

[0069] Depend on Fig.15 and 16 The single-point micro-energy device can destroy the target in 0.6ms, and the debris size is sub-micron scale, with an area of ​​0.1~0.5mm 2 Compared with the multi-point type, the overall volume of the debris is reduced, and the response speed is increased by 40%. Since the single-point type does not have a complex fire transmission channel and is similar in size to the Si substrate, the debris is smaller and the damage effect is better.

Claims

1. A micro self-destruct device based on 3D printing, characterized in that: The micro self-destruct device is a multi-point micro self-destruct device, comprising an energetic device substrate and an energetic device cover plate, wherein the energetic device substrate is provided with an ignition groove (3) and an output groove (2), and a fire transmission channel (4) is connected between the ignition groove (3) and the output groove (2); the energetic device cover plate is provided with an electrode hole (5), and the electrode hole (5) corresponds to the position of the ignition groove (3); the edges of the energetic device substrate and the energetic device cover plate are provided with bolt holes (1), and the two are connected together by bolts; the energetic device substrate of the multi-point micro self-destruct device is a multi-point energetic device substrate, and the multi-point energetic device substrate is a circular plate, wherein the ignition groove (3) is provided at the center of the circular plate, and a plurality of circularly distributed output grooves (2) are uniformly distributed near the edge of the circular plate with the ignition groove (3) as the center of the circle, and a fire transmission channel (4) is connected between the ignition groove (3) and each output groove (2); The energetic device substrate and the energetic device cover are made of renewable polymer materials. The ignition slot (3), the output slot (2) and the fire transfer channel (4) are loaded with nano-thermite. The nano-thermite uses Al nano-particles as fuel, nano-alkali metal salts as oxidants, and fluororubber as binders. The weight ratio of each raw material is: 10-60 parts of fuel, 40-90 parts of oxidants, and 3-20 parts of binders. The particle size of the nano-Al particles is 50-200 nm, the oxidant particles are submicron-level, and the decomposition temperature is above 200°C.

2. A micro self-destruct device based on 3D printing, characterized in that: The micro self-destruct device is a dual-point type micro self-destruct device, comprising an energetic device substrate and an energetic device cover plate, wherein the energetic device substrate is provided with an ignition groove (3) and an output groove (2), and a fire transmission channel (4) is connected between the ignition groove (3) and the output groove (2); the energetic device cover plate is provided with an electrode hole (5), and the electrode hole (5) corresponds to the position of the ignition groove (3); the edges of the energetic device substrate and the energetic device cover plate are both provided with bolt holes (1), and the two are connected together by bolts; the energetic device substrate of the dual-point type micro self-destruct device is a dual-point type energetic device substrate, and the dual-point type energetic device substrate is a rectangular plate, and the ignition groove (3) is provided at one end of the rectangular plate, and the output groove (2) is provided at the other end; The energetic device substrate and the energetic device cover are made of renewable polymer materials. The ignition slot (3), the output slot (2) and the fire transfer channel (4) are loaded with nano-thermite. The nano-thermite uses Al nano-particles as fuel, nano-alkali metal salts as oxidants, and fluororubber as binders. The weight ratio of each raw material is: 10-60 parts of fuel, 40-90 parts of oxidants, and 3-20 parts of binders. The particle size of the nano-Al particles is 50-200 nm, the oxidant particles are submicron-level, and the decomposition temperature is above 200°C.

3. A micro self-destruct device based on 3D printing, characterized in that: The micro self-destruct device is a single-point micro self-destruct device; it comprises an energetic device substrate and an energetic device cover plate, the energetic device substrate is provided with an ignition groove (3) and an output groove (2), and a fire transmission channel (4) is connected between the ignition groove (3) and the output groove (2); the energetic device cover plate is provided with an electrode hole (5), and the electrode hole (5) corresponds to the position of the ignition groove (3); the edges of the energetic device substrate and the energetic device cover plate are provided with bolt holes (1), and the two are connected together by bolts; the energetic device substrate of the single-point micro self-destruct device is a single-point energetic device substrate, the single-point energetic device substrate is a circular plate, and the ignition groove (3) and the output groove (2) of the single-point energetic device substrate are the same groove, which is provided at the center of the single-point energetic device substrate; The energetic device substrate and the energetic device cover are made of renewable polymer materials. The ignition slot (3), the output slot (2) and the fire transfer channel (4) are loaded with nano-thermite. The nano-thermite uses Al nano-particles as fuel, nano-alkali metal salts as oxidants, and fluororubber as binders. The weight ratio of each raw material is: 10-60 parts of fuel, 40-90 parts of oxidants, and 3-20 parts of binders. The particle size of the nano-Al particles is 50-200 nm, the oxidant particles are submicron-level, and the decomposition temperature is above 200°C.

4. A 3D printing-based micro self-destruct device according to any one of claims 1 to 3, characterized in that: The renewable polymer material is ABS, TPU, PVA or PLA; the oxidant is one or more of potassium periodate, sodium periodate and potassium perchlorate; the binder is replaced by hydroxypropyl methylcellulose or nitrocellulose.

5. A 3D printing-based micro self-destruct device according to any one of claims 1 to 3, characterized in that: The mass proportion of the raw materials of the nano-thermite is: 10-60 parts of fuel, 40-60 parts of oxidant, and 5-10 parts of binder.

6. The integrated assembly method of a micro self-destruct device based on 3D printing according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) dissolving a binder in a corresponding solvent to obtain a binder solution; (2) Weighing nano-Al powder and submicron alkali metal salt particles in proportion by mass; (3) Pour the weighed nanoparticles and binder solution into a mixing dish, and then mix them evenly using a planetary microgravity mixing system to obtain a nano-thermite direct writing ink; (4) Using a 3D printing platform, ink is written into the grooves of the pre-printed micro self-destruct device, dried in a vacuum oven, and finally integrated into a package to obtain a micro self-destruct device.

7. The integrated assembly method of a micro self-destruct device based on 3D printing according to claim 6, characterized in that: The solvent in step (1) is ethyl acetate or N, N-dimethylformamide, and the mass concentration of the obtained binder solution is 10-15%.

8. The integrated assembly method of a micro self-destruct device based on 3D printing according to claim 6, characterized in that: In step (4), the vacuum drying conditions are 50° C. and 0.8 MPa in a vacuum oven for 24 h.

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