High-integration-level dustproof and waterproof design method suitable for aeromagnetic equipment

Abstract

The invention discloses a high-integration-level dustproof and waterproof design method suitable for aeromagnetic equipment, and relates to the technical field of aeromagnetic equipment design, and the method comprises the following steps: setting constant-pressure breathing buffer layers inside and outside a cavity based on the gas residual characteristics of the cavity in the aeromagnetic equipment; a slow-speed air pressure exchange channel is formed inside and outside the cavity through the balance membrane with the controllable micropore structure, and dynamic balance of air pressure inside and outside the cavity is achieved. Through the constant-pressure breathing buffer layer and the graded moisture absorption composite film, external moisture is effectively prevented from entering and water vapor is captured, the condensation phenomenon is reduced, the corrosion risk is reduced, and long-term stable operation of equipment is ensured. Meanwhile, the low-thermal-conductivity heat insulation sleeve layer disperses the temperature difference and prevents water vapor condensation, electric field distribution is optimized by combining the anti-seepage plating layer and potential balance coating, the anti-condensation, anti-corrosion and anti-short-circuit capacity of equipment is improved, and long-term reliability and precision under the high-integration sealing condition are guaranteed.

Description

A highly integrated dustproof and waterproof design method for aeromagnetic equipment Technical Field

[0001] This invention relates to the field of aeromagnetic equipment design technology, and specifically to a highly integrated dustproof and waterproof design method suitable for aeromagnetic equipment. Background Technology

[0002] The highly integrated dustproof and waterproof design addresses the special needs of airborne magnetic measurement equipment operating in complex environments such as high altitudes, humidity, dust, and drastic pressure changes. Through a comprehensive design concept integrating structural integration, layered sealing, and functional materials, it achieves high-density integration of core units such as sensing, power supply, communication, attitude measurement, and control circuits within a single package. A composite protection system is constructed using multiple sealing rings, resin curing, anodized coating, and anti-permeability interface treatment. This design not only eliminates the risks of dust intrusion, moisture condensation, and liquid immersion inherent in traditional airborne magnetic equipment due to complex external connections and numerous interfaces, but also ensures rapid assembly and stable operation on various aviation platforms such as UAVs, helicopters, and fixed-wing aircraft through lightweight structure and modular interfaces. This significantly enhances the system's anti-interference capability and measurement accuracy while improving environmental adaptability, providing solid engineering support and safety assurance for highly reliable airborne magnetic measurement missions.

[0003] Existing technologies have the following shortcomings: In the highly integrated sealing design of aeromagnetic equipment, when the aircraft frequently switches between high-altitude low-pressure and ground-level atmospheric pressure, a small pressure difference is generated inside and outside the sealed cavity, triggering a latent gas exchange phenomenon. Due to the significant temperature gradient in the flight environment, residual gas inside the cavity will generate trace amounts of water vapor droplets under the condensation effect. These droplets slowly migrate along the microchannels of solder joint gaps and PCB plating during long-term circulation, gradually forming electrochemical corrosion paths. This corrosion process has strong latency and cumulative properties. In the early stages, it usually only manifests as resistance drift or slight signal shift, but with the superposition of multiple ascent and descent cycles, it may eventually lead to solder joint delamination, metal ion migration, and local short circuits, causing distortion of the magnetic sensor output signal, and even causing the entire equipment to fail.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a highly integrated dustproof and waterproof design method suitable for aeromagnetic equipment, so as to solve the problems in the background art mentioned above.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a highly integrated dustproof and waterproof design method suitable for aeromagnetic equipment, comprising the following steps: Step 1: Based on the residual gas characteristics of the internal cavity of the aeromagnetic equipment, a constant pressure breathing buffer layer is set inside and outside the cavity. A slow-speed air pressure exchange channel is formed inside and outside the cavity through a balance membrane with a controllable microporous structure, thereby achieving dynamic balance of air pressure inside and outside the cavity; Step 2: Along the gas flow path of the constant pressure breathing buffer layer, a graded moisture-absorbing composite membrane is laid on the inner wall of the cavity. The graded moisture-absorbing composite membrane is composed of multiple layers of adsorption materials with different moisture absorption rates. A humidity gradient is established through the difference in adsorption rates between the materials, so that trace amounts of water vapor that have seeped into the cavity are captured and fixed in the area adjacent to the sealing layer; Step 3: Step 1: Combining the humidity distribution formed by the graded moisture-absorbing composite membrane, a low thermal conductivity insulation layer is set in the key heat source area inside the cavity. The local temperature difference inside the cavity is stabilized by heat distribution equalization technology, weakening the condensation driving force in the humidity gradient area. Step 2: Based on the thermal steady-state characteristics of the low thermal conductivity insulation layer, a nano-level anti-seepage coating is deposited in the solder joints and electrical connection areas inside the cavity. The anti-seepage coating forms a dense and continuous interface closed structure, blocking the capillary penetration of residual water vapor in the moisture-absorbing composite membrane along the solder joint gaps and circuit microchannels. Step 3: Relying on the closed continuity of the nano-level anti-seepage coating, a potential equalization coating treatment is implemented on the surface of the cavity. A uniform potential surface is formed by conductive polymers to balance the local electric field distribution inside the cavity and eliminate the risks of ion migration and current deviation.

[0007] Preferably, based on the residual gas characteristics of the internal cavity of the aeromagnetic equipment, a constant-pressure breathing buffer layer is set inside and outside the cavity, specifically including the following steps: A constant-pressure breathing buffer layer with a continuous annular channel structure made of fluorinated polyimide composite material is constructed in the outer region of the sealed cavity of the aeromagnetic equipment according to the actual volume and wall thickness parameters of the cavity, and a high-elasticity silicone support layer is added to its outer wall through co-extrusion molding; a three-layer structure consisting of a polytetrafluoroethylene porous membrane, an alumina ceramic porous support layer, and a polyimide microfiber support membrane is set between the outer side of the constant-pressure breathing buffer layer and the outer shell of the aeromagnetic equipment. A balancing membrane, formed by hot pressing and lamination, is continuously sealed with epoxy resin sealant to create a slow-speed gas pressure exchange channel inside and outside the cavity. At the interface between the balancing membrane and the constant-pressure breathing buffer layer, a seepage-proof contact layer consisting of a sealing coating layer and a flexible bonding layer is set, and micro-flow grooves are set inside the seepage-proof contact layer to ensure uniform gas diffusion path at the interface. A siloxane-alkyl polymer protective layer is formed on the outer surface of the constant-pressure breathing buffer layer by vapor deposition, and a chemical bonding interface is formed by plasma pretreatment, giving it weather resistance, UV resistance, and a hydrophobic surface with micro-nano structure.

[0008] Preferably, the surface of the siloxane polymer protective layer is formed into a micro-nano structure by plasma etching, which is used to form an air film layer in the high humidity or salt spray environment of the aircraft to reduce the residence time of liquid on its surface.

[0009] Preferably, a graded moisture-absorbing composite membrane is laid on the inner wall of the cavity to establish a humidity gradient through the difference in adsorption rates between materials. Specifically, this includes the following steps: A region adjacent to the airflow channel of the constant-pressure breathing buffer layer is selected on the inner wall of the sealed cavity of the aeromagnetic equipment. A base layer formed by a polyimide fiber reinforcement layer is constructed and bonded to the inner wall of the cavity using a thermosetting adhesive film to form a continuous coating. A first moisture-absorbing layer composed of molecular sieve-type aluminosilicate material is deposited on the surface of the base layer, forming an interconnected microporous network through a sol-gel process to quickly capture initially infiltrated water vapor. A second moisture-absorbing layer is laid on the outer surface of the first moisture-absorbing layer. The second moisture-absorbing layer is composed of polyvinyl alcohol copolymer and calcium oxide particles, forming a slow humidity gradient to delay the adsorption and graded fixation of incompletely adsorbed water vapor. A third moisture-absorbing protective layer is laid on the outer side of the second moisture-absorbing layer. The protective layer is composed of a cross-linked polymer containing phosphorus groups, and an elastic transition layer composed of polyimide elastomer is provided between it and the second moisture-absorbing layer to achieve final chemical fixation of water vapor and structural interlayer integrity.

[0010] Preferably, the phosphorus-containing cross-linked polymer of the third moisture-absorbing protective layer is fluorinated to form a weakly hydrophobic surface, and the polyimide elastomer of the elastic transition layer is used to absorb deformation between the second moisture-absorbing layer and the third moisture-absorbing protective layer, so that the graded moisture-absorbing composite membrane maintains the stability of interlayer bonding and maintains the final chemical fixation effect of water vapor in the alternating high and low temperature environment.

[0011] Preferably, a low thermal conductivity insulation layer is installed in the key heat source area within the cavity. This is achieved through heat distribution equalization technology to stabilize the local temperature difference within the cavity. Specifically, this includes the following steps: Within the sealed cavity of the aeromagnetic equipment, the arrangement range of the low thermal conductivity insulation layer is determined based on the heat distribution characteristics. A ring-shaped area is selected as the main insulation layout zone, and installation grooves for the insulation layer are set around the key heat source to achieve a tight fit. Within the insulation area, a composite layer of ceramic microspheres reinforced with siloxane, a polyimide thermally conductive and slow-release layer, and a fluorinated polymer heat-resistant insulation layer are constructed. The insulation jacket, composed of three layers, is integrally formed by hot-pressing and bonding with thermosetting silicone adhesive. A metal oxide composite elastic thermally conductive buffer layer is placed between the insulation jacket and the heat source, forming a discrete contact structure by point bonding to balance local heat flow distribution and suppress condensation driving force. A fluorosiloxane composite coating is applied to the outer surface of the insulation jacket, forming a low surface energy film through vapor deposition and isothermal curing to reflect external radiant heat and prevent the intrusion of ambient moisture, thereby maintaining the temperature and humidity balance inside the cavity.

[0012] Preferably, the surface of the fluorosiloxane composite coating is formed by plasma etching to create a uniformly distributed micro-nano structure. The micro-nano structure is used to form a stable gas film layer in a high-humidity environment to reduce the probability of water vapor condensation, and maintains the low-energy characteristics of the surface through the fluorine-containing side chain structure, thereby further improving the moisture-proof and corrosion-resistant performance of the thermal insulation layer.

[0013] Preferably, based on the thermal stability characteristics of the low thermal conductivity insulation layer, a nanoscale anti-seepage coating is deposited in the solder joints and electrical connection areas within the cavity. Specifically, this includes the following steps: Under the stable thermal environment formed by the low thermal conductivity insulation layer, the surfaces of the solder joints and electrical connection areas within the cavity are pretreated using a combination of plasma surface activation and chemical reduction to remove the oxide layer and form a highly active metal surface; after surface activation, an atomic layer deposition technique is used to form a composite nano-anti-seepage coating in the solder joints and electrical connection areas, consisting of alternating layers of alumina and titanium oxide, and deposition is carried out at a constant temperature of 80°C to ensure coating density; after the anti-seepage coating is formed, it undergoes ion-assisted densification treatment by applying a pulsed ion current in a high-purity argon atmosphere to rearrange the coating atoms and generate an alumina-metal transition interface layer, thereby eliminating microporous diffusion paths; a conductive polymer potential-equalizing coating layer is sprayed onto the surface of the anti-seepage coating, in which nano-silver particles are uniformly dispersed and activated by plasma to form covalent bonds, thereby constructing an overall closed anti-seepage structure to prevent electrochemical reactions.

[0014] Preferably, the conductive polymer potential equalization coating uses a polythiophene derivative as the matrix, and disperses silver nanoparticles therein to form a current equalization network; the coating and the composite nano anti-seepage coating are bonded by chemical covalent bonds through plasma activation to enhance the interfacial adhesion and improve the sealing stability and anti-corrosion performance under high and low temperature cycling and humid heat environments.

[0015] Preferably, a potential equalization coating treatment is performed on the surface of the cavity to form a uniform potential surface through a conductive polymer. Specifically, this includes the following steps: after the formation of the nanoscale anti-seepage coating, the cavity surface undergoes surface activation and pre-coating treatment. Energy activation is performed using low-energy argon plasma in a constant temperature environment of 40°C to 50°C, followed by spraying a conductive guiding underlayer composed of a fluorinated polyethylene matrix and a carbon nanotube dispersion. After the conductive guiding underlayer cures, a conductive polymer potential layer composed of a polythiophene derivative and a polypyrrole copolymer system is uniformly coated onto the cavity surface. Silver-coated copper composite particles are dispersed in the potential layer and cured at 80°C to 90°C in a nitrogen atmosphere to form a continuous conductive network. After the potential layer is formed, an inert gas containing chloride and lithium ions is introduced for ion doping, and the surface is directionally cured by infrared irradiation heating to form a multi-layer electron conduction band structure in the thickness direction. A silanized polyurethane sealing layer is spin-coated on the outer surface of the potential layer and cured at 60°C for two hours to form a chemical bond interface, so that the potential-equalizing coating has moisture resistance and electrochemical stability, thereby achieving overall potential balance and protection functions.

[0016] The technical effects and advantages provided by this invention, as described above, are as follows: By setting a constant-pressure breathing buffer layer and a graded moisture-absorbing composite membrane inside and outside the cavity, this invention effectively inhibits external moisture from entering the equipment. The constant-pressure breathing buffer layer utilizes a microporous structure to achieve a dynamic balance of air pressure inside and outside the cavity, preventing moisture penetration caused by air pressure changes. The graded moisture-absorbing composite membrane establishes a humidity gradient, capturing and fixing trace amounts of water vapor to prevent condensation. This measure effectively reduces water vapor accumulation, significantly lowers the risk of internal corrosion, and ensures the long-term stable operation of the equipment.

[0017] This invention incorporates a low thermal conductivity insulation layer in key heat source areas within the cavity, effectively dispersing the temperature gradient, weakening the condensation driving force, and further reducing the likelihood of water vapor condensation. Combined with the protective effect of the anti-seepage coating, the potential equalization coating treatment balances the electric field distribution within the cavity, eliminating localized potential differences. Through these innovative measures, not only are the equipment's anti-condensation, anti-corrosion, and short-circuit protection capabilities improved, but the long-term reliability and high-precision measurement performance of each electrical component under highly integrated and sealed conditions are also ensured. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 is a flowchart of a highly integrated dustproof and waterproof design method for aeromagnetic equipment according to the present invention. Detailed Implementation

[0020] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art.

[0021] This invention provides a highly integrated dustproof and waterproof design method for aeromagnetic equipment, as shown in Figure 1, comprising the following steps: Step 1: Based on the residual gas characteristics of the internal cavity of the aeromagnetic equipment, a constant-pressure breathing buffer layer is set inside and outside the cavity. A slow-speed air pressure exchange channel is formed inside and outside the cavity through a balance membrane with a controllable microporous structure to achieve dynamic balance of air pressure inside and outside the cavity, thereby suppressing external moisture from entering the cavity during the take-off and landing of the aircraft due to air pressure fluctuations. The specific implementation process of this step is as follows: The main structure of the constant-pressure breathing buffer layer is constructed in the outer region of the sealed cavity of the aeromagnetic equipment according to the actual volume and wall thickness parameters of the cavity. Specifically, an annular space matching the outer shell of the cavity is selected, and a continuous annular channel is made of a polymer inert material. The selected material is fluorinated polyimide composite, which has excellent gas inertness, pressure resistance, and long-term fatigue resistance. The interior of the buffer layer is processed into a closed cavity structure with equal wall thickness, and the ratio of the inner diameter to the outer diameter is controlled between 1:1.15 and 1:1.25, so that the cavity can deform uniformly in the radial direction when the air pressure changes. The outer wall of the buffer layer is coated with a highly elastic silicone support layer through co-extrusion molding. This support layer maintains high flexibility at low temperatures, ensuring that the structure will not break under sudden changes in air pressure. Both ends of the buffer layer are connected to the cavity shell via micro-welding, forming a closed buffer zone with micro-elastic response characteristics between the inner and outer parts of the cavity. When the aircraft ascends, the gas inside the cavity tends to expand as the external air pressure decreases. During this process, the annular cavity of the buffer layer undergoes radial micro-expansion, increasing its internal volume by approximately 3% to 5%, absorbing part of the pressure difference. When the aircraft descends, the external air pressure rises again, and the annular cavity of the buffer layer slightly contracts and returns to its original position, thus achieving smooth pressure compensation. This design ensures that air pressure changes do not directly affect the sealed circuit cavity of the avionics equipment, thereby preventing stress concentration or micro-cracks in the cavity structure due to pressure difference impacts.

[0022] A controllable microporous balancing membrane is installed between the outer side of the constant-pressure breathing buffer layer and the outer shell of the aeromagnetic equipment to establish a slow pressure exchange channel. The balancing membrane employs a three-layer composite material structure. The outer layer is a porous polytetrafluoroethylene membrane with a surface treated by fluorinated silane chemical vapor deposition to create hydrophobic microtextures, achieving a contact angle of over 118 degrees, preventing liquid droplets from forming a continuous liquid film on its surface. The middle layer is a porous alumina ceramic support layer, which forms a slow-release channel for gas transport and withstands the pressure difference between the inside and outside of the chamber. The inner layer is a polyimide microfiber support membrane, providing overall tensile strength and stabilizing the pore size morphology. The three layers are bonded together using a hot-pressing lamination method to form an integral structure, with continuous edge sealing using epoxy resin sealant to ensure that gas can flow only through the microporous channels. During ascent, as the external air pressure gradually decreases, the gas inside the cavity is slowly released through the constant-pressure breathing buffer layer and then discharged slowly through the micropores of the balancing membrane. The flow rate is controlled within the range of 0.5 to 0.8 ml per minute, maintaining an internal and external air pressure balance ratio of 0.8 to 1.0. When the spacecraft descends, the external air pressure increases, and air molecules outside the balancing membrane are drawn into the buffer layer at a very low rate through the micropores. The annular cavity of the buffer layer absorbs the instantaneous pressure increase under deformation, forming a pressure buffer absorption zone that ensures that the pressure change inside the cavity is balanced within 5 to 8 seconds. Through this slow-moving gas channel, the gas flow inside the cavity exhibits a gradual dynamic exchange state, avoiding the structural instability problems caused by sudden pressure changes in traditional sealed cavities.

[0023] To improve the stability and impermeability of the constant-pressure breathing buffer layer during long-term gas pressure cycling, multiple impermeable contact layers are designed at the interface between the balancing membrane and the buffer layer. This impermeable contact layer consists of two parts: the first part is a sealing coating layer approximately 8 micrometers thick. Active carboxyl groups are introduced onto the surface of the balancing membrane through plasma activation treatment, followed by a siloxane polymerization reaction to form a dense cross-linked structure. A low-permeability curing band is formed at the edge region, with the permeability of the curing band controlled below 10⁻¹³, ​​ensuring that gas can only pass through the microporous channels. The second part is a flexible bonding layer composed of a high-molecular-weight block copolymer. Its elastic modulus is similar to that of the buffer layer matrix, allowing it to deform synchronously with changes in gas pressure, preventing peeling or cracking due to differences in material hardness. The two layers are bonded together by thermosetting, maintaining chemical bonding stability even in high-humidity environments. To further improve the gas diffusion path, micro-flow channels are designed inside the contact layer, allowing gas passing through the balancing membrane to diffuse uniformly along the contact layer interface, reducing local airflow velocity, and thus preventing moisture-carrying effects that could cause liquid water vapor to penetrate the interface. Through this structure, a flexible, sealed connection area is formed between the constant-pressure breathing buffer layer and the balancing membrane, which is both airtight and deformable, allowing the two materials to remain tightly bonded under long-term alternating air pressure.

[0024] Finally, a weather-resistant protective layer is applied to the outer surface of the constant-pressure breathing buffer layer to ensure its long-term reliability in complex external environments. This protective layer is made of siloxane-alkyl polymer material and is formed into a continuous thin film on the outer wall of the buffer layer via vapor deposition. The surface of the protective layer is then plasma-etched to form a uniformly distributed micro / nano structure. This micro / nano structure forms a stable gas film layer in the air; when external water droplets come into contact with it, they are dispersed into tiny droplets and roll off under surface tension, thus reducing the liquid's residence time on the surface. The protective layer contains a high proportion of Si-O bonds, exhibiting excellent resistance to ultraviolet aging and maintaining flexibility and hydrophobicity within a temperature range of −50℃ to 120℃. A chemical bonding interface is formed between the protective layer and the underlying buffer layer through plasma pretreatment to prevent delamination due to temperature cycling. This protective layer effectively isolates corrosive media in high-humidity environments or salt spray atmospheres in aircraft, ensuring that the elastic material of the buffer layer is not chemically eroded; simultaneously, it maintains surface energy stability under long-term ultraviolet irradiation, preventing material aging and cracking.

[0025] Through the above steps, the constant-pressure breathing buffer layer forms an adaptive pressure buffering system during the aircraft's ascent and descent cycles. The elastic deformation of the buffer layer absorbs the energy of sudden pressure changes, the microporous structure of the balancing membrane enables slow gas exchange, the dense bonding of the impermeable contact layer blocks the channels for moisture infiltration, and the surface structure of the weather-resistant protective layer extends the service life of the overall sealing structure. Together, these four elements constitute a sealed protective structure that can maintain dynamic pressure balance for a long time and prevent external moisture intrusion, ensuring that the internal cavity of the aeromagnetic equipment remains dry and stable under micro-pressure conditions in complex flight environments.

[0026] Step Two: A graded moisture-absorbing composite membrane is laid on the inner wall of the cavity along the gas flow path of the constant-pressure breathing buffer layer. This membrane consists of multiple layers of adsorbent materials with different moisture absorption rates. A humidity gradient is established through the difference in adsorption rates between the materials, allowing trace amounts of water vapor penetrating the cavity to be captured and fixed in the area adjacent to the sealing layer, preventing the formation of condensation nuclei. The specific implementation process of this step is as follows: A region adjacent to the airflow channel of the constant-pressure breathing buffer layer is selected on the inner wall of the sealed cavity of the aeromagnetic equipment to construct the base layer of the graded moisture-absorbing composite membrane. This base layer is directly attached to the inner wall of the cavity, and its main function is to serve as the supporting foundation for the moisture-absorbing structure and maintain overall adhesion stability. Specifically, the base layer uses a polyimide fiber reinforcement layer, which is uniformly bonded to the inner wall of the cavity to form a continuous coating through a thermosetting adhesive film. Polyimide fibers have excellent heat resistance and dimensional stability, and will not deform within a temperature range of −55℃ to 150℃. Simultaneously, its surface microporosity is controlled between 18% and 22%, providing a uniform diffusion path for water vapor conduction in the upper adsorbent layer. To ensure a reliable bond between the substrate layer and the inner wall of the cavity, a surface activation process is employed before bonding. This involves activating the surface of the inner wall of the cavity using low-pressure plasma, introducing polar functional groups onto the cavity material surface and enhancing the adhesion of the substrate layer. This structure enables the subsequent multilayer adsorbent material to be deposited stably and maintain its integrity during long-term gas pressure cycling, laying the foundation for a stable humidity distribution.

[0027] A first layer of hygroscopic material is sequentially deposited on the substrate surface. This layer is primarily used to rapidly capture water vapor that initially infiltrates into the gas release channels. This layer is made of an inorganic porous material with a high moisture absorption rate, such as a molecular sieve-type aluminosilicate, with an average pore size controlled between 2 and 4 nanometers and a pore volume of 0.45 cubic centimeters per gram. An adsorption layer is formed on the substrate surface using a sol-gel process, followed by isothermal drying at 80°C to stabilize the microporous structure. To improve gas permeability between the adsorption layer and the substrate layer, a pulse spraying method is used during deposition, resulting in an interconnected microporous network within the adsorption layer, ensuring uniform distribution of water vapor before it reaches the adsorption surface. This first hygroscopic layer is characterized by a fast reaction rate and high moisture saturation value, rapidly capturing and fixing approximately 70% of the water vapor within the micropores during the initial gas flow. The captured water molecules bind to the hydroxyl groups on the material surface through van der Waals forces and are not released again at room temperature, providing a relatively dry environment for subsequent deeper adsorption layers.

[0028] A second layer of absorbent material is laid on the outer surface of the first absorbent layer. This layer is designed to delay and progressively fix any moisture not fully adsorbed by the first absorbent layer, thereby further establishing a humidity gradient. The second absorbent material is an organic-inorganic composite porous polymer with a polyvinyl alcohol copolymer matrix and uniformly dispersed nano-sized calcium oxide particles. This structure combines high absorbency with a moderate adsorption rate, ensuring that moisture entering this layer is not instantly absorbed but gradually diffuses along the thickness direction, thus forming a slow humidity gradient within the layer. A continuous layer is formed using a spray-coating-film-forming process, with the surface roughness controlled below 0.2 micrometers to ensure stable airflow adhesion. The second absorbent material contains a small number of carboxyl functional groups, which form intermolecular hydrogen bonds with the hydroxyl groups on the surface of the first layer, creating a stable interlayer interaction and preventing delamination under temperature or pressure changes. As the aircraft ascends, the air pressure inside the cavity decreases, and the buffer layer releases gas outward. Water vapor permeates layer by layer along the flow direction and is further captured in this layer. During descent, the external air pressure increases, and the humidity distribution inside the moisture-absorbing layer is readjusted. Water vapor forms a dynamic adsorption balance between the two layers, thereby maintaining overall humidity stability.

[0029] A third moisture-absorbing protective layer is laid outside the second moisture-absorbing layer, closest to the gas inflow side of the constant-pressure breathing buffer layer. This layer is used to finally fix trace amounts of residual moisture and prevent it from diffusing to the central area of ​​the cavity. This layer uses a reactive moisture-absorbing material with chemical adsorption capabilities, specifically a cross-linked polymer containing phosphorus groups. Its molecular structure contains active phosphate ester bonds, which can form a stable chemical bond with water molecules to form non-volatile hydroxyphosphates. After uniform film formation through spin coating, it is cured at low temperature to form a dense and continuous protective layer. The chemical adsorption properties of the third layer make it difficult to release moisture after capturing it, forming a permanent fixation effect. At the same time, its surface is fluorinated to exhibit weak hydrophobicity, preventing external moisture from condensing on the layer surface to form droplets. To prevent stress concentration between layers, an elastic transition layer is set between the third and second layers. This layer is made of polyimide elastomer and plays a role in buffering thermal expansion differences and absorbing deformation, allowing the multilayer structure to maintain interlayer integrity in alternating high and low temperature environments.

[0030] Through the above implementation steps, the graded moisture-absorbing composite membrane forms a multi-layered moisture-absorbing structure on the inner wall of the cavity, consisting of a fast-absorbing layer, a slow-absorbing layer, and a chemically immobilized layer. A stable humidity gradient is established between the layers through differences in adsorption rates, ensuring that any trace amount of water vapor penetrating the cavity is preferentially adsorbed in the outermost layer, gradually immobilized in the middle layer, and finally chemically captured in the inner layer. Because the first and second layers form a physical adsorption equilibrium zone, and the third layer forms a permanent bond through chemical reaction, the entire moisture-absorbing structure maintains a stable moisture-absorbing capacity under alternating high and low pressure cycles, and will not release adsorbed water vapor due to temperature changes or pressure increases. This structure effectively prevents the formation of condensation nuclei under the long-term high-altitude operation conditions of aeromagnetic equipment, avoiding corrosion of electronic components by internal condensation, while maintaining the internal humidity within a safe range.

[0031] Step 3: Based on the humidity distribution formed by the graded moisture-absorbing composite membrane, a low thermal conductivity insulation layer is installed in the key heat source areas within the cavity. This stabilizes the local temperature difference within the cavity through heat distribution equalization technology, weakening the condensation driving force in the humidity gradient zone, thereby further suppressing water vapor condensation. The specific implementation process of this step is as follows: The arrangement range of the low thermal conductivity insulation layer is determined within the sealed cavity of the aeromagnetic equipment based on the heat distribution characteristics. The cavity typically contains multiple heat-generating components such as a magnetic sensing unit, a power supply stabilization unit, an attitude control circuit, and a data acquisition unit. The magnetic sensing unit and the stabilization power supply area are the main heat source concentration areas. To determine the coverage range of the insulation layer, a structural analysis of the internal temperature field is performed using steady-state heat conduction theory. Using the central axis of the cavity as a reference, a ring-shaped area is selected as the main insulation layout zone. This layout zone partially overlaps with the humidity distribution area of ​​the graded moisture-absorbing composite membrane in the previous step, allowing the insulation layer to directly act on the humidity gradient zone, forming a heat and humidity synergistic regulation zone. After the placement location is determined, the heat source distribution path is marked on the cavity surface. A precision positioning process is used to create mounting grooves around key heat sources to ensure a tight fit of the insulation layer without affecting the overall dimensional stability of the cavity. This method allows the insulation layer to form a continuous coverage over the heat source area, achieving a more even distribution of heat conduction paths in space.

[0032] The main structure of the insulation jacket, characterized by low thermal conductivity, is constructed within the defined insulation area. This jacket employs a multi-layer composite design to achieve a synergistic effect of thermal insulation, thermal conductivity balance, and structural stability. The innermost layer is a 0.15 mm thick ceramic microsphere-reinforced siloxane composite layer. This layer achieves low thermal conductivity by dispersing hollow alumina microspheres, with a thermal conductivity controlled between 0.045 and 0.055 W / m Kelvin. The ceramic microspheres are uniformly distributed within the siloxane elastic matrix, forming numerous closed microcavities that effectively block direct heat conduction. The middle layer is a polyimide thermally conductive slow-release layer with a thermal conductivity of approximately 0.15 W / m Kelvin, slightly higher than the inner layer, used to balance temperature gradients between different areas and prevent localized over-insulation. The outer layer is a fluorinated polymer heat-resistant protective layer, possessing both temperature resistance and moisture-proof properties, preventing trace amounts of water vapor released from the hygroscopic composite film from accumulating on the insulation layer surface and forming a liquid film. The three layers are integrally formed through a hot-pressing lamination process, with thermosetting silicone adhesive bonding between the layers to ensure continuous thermal conductivity at the interface. The thermal insulation layer formed by this composite structure remains elastically stable under pressure changes and high and low temperature cycles, and will not delaminate or warp due to differences in the thermal expansion coefficients of the materials, laying a stable foundation for subsequent heat flow equilibrium.

[0033] After the low thermal conductivity insulation layer is formed, the heat transfer path between the insulation layer and the heat source area is balanced and controlled. Since the heat source is relatively concentrated inside the cavity, if heat is concentrated in a small area, it will lead to increased local temperature differences, thereby enhancing the condensation driving force in the humidity gradient area. To avoid this, a thermally conductive buffer layer is set between the insulation layer and the heat source. This buffer layer uses a metal oxide composite elastic layer, internally mixed with trace amounts of magnesium oxide and silicon oxide particles, with the particle size controlled below 200 nanometers, to form a microscale heat conduction path. This buffer layer is distributed between the heat source area and the insulation layer using a point-bonding method, with the spacing between each bonding point controlled at 2 to 3 millimeters, forming a discrete contact structure that allows local heat to diffuse outward at a controlled rate. The surface of the buffer layer is plasma-treated to form a high-energy bonding surface, tightly adhering to the insulation layer to ensure a stable heat transfer path. Through this heat dissipation and conduction design, heat is gradually diffused through multiple interfaces as it is conducted outward from the heat source, smoothing out local high-temperature points and making the temperature distribution inside the cavity more uniform. At the same time, the humidity gradient within the graded moisture-absorbing composite membrane is suppressed, and the condensation driving force caused by the reduced temperature difference is significantly weakened. This step achieves heat flow balance while maintaining the integrity and moisture-proof capability of the overall structure, ensuring that the insulation layer can both block heat flow concentration and not affect the overall heat dissipation balance of the cavity.

[0034] Finally, to ensure the low thermal conductivity insulation layer maintains stable performance under long-term high and low temperature cycling and high humidity environments, a surface-stabilizing coating is applied to the outer surface of the insulation layer to further enhance its environmental resistance and thermal stability. This coating is a fluorosiloxane composite coating, formed into a continuous thin film through vapor deposition. The coating surface contains trace amounts of fluorinated alkyl side chains, which can form a low surface energy film in high humidity environments, reducing the probability of water vapor condensation. To prevent material expansion differences caused by repeated temperature changes, a constant-temperature curing process is used after coating deposition to form chemical bonds between the coating and the insulation layer surface. In addition to its hydrophobic properties, this coating also has high infrared reflectivity, which can effectively reduce the external radiative heat input of the cavity. When the aircraft operates in a high-altitude, low-temperature environment, the coating can reflect external radiative heat, maintaining a stable internal temperature; when the aircraft returns to a low-altitude, high-temperature region, the insulation layer slows down the rate of internal temperature rise through slow-release heat conduction, thereby achieving dynamic equilibrium of the internal heat distribution throughout the flight. The stabilizing coating works synergistically with the aforementioned graded moisture-absorbing composite film to maintain a balanced temperature and humidity environment inside the cavity during pressure changes and humidity cycles, preventing condensation nuclei from forming near the heat source.

[0035] Through the specific implementation of the above steps, the low thermal conductivity insulation jacket and the graded moisture-absorbing composite membrane form an integrated thermal and humidity control structure. The insulation jacket weakens the local thermal gradient through its multi-layer composite structure, the thermally conductive buffer layer balances the heat flow diffusion path, and the surface stabilizing coating prevents the intrusion of environmental heat and humidity. The three elements work together to create a smooth temperature field and a controlled humidity field inside the cavity, thereby effectively reducing the condensation driving force and ensuring the long-term stable operation of the aeromagnetic equipment in complex flight environments. This protects the internal circuits and sensors from the risks of corrosion and performance drift caused by humidity and temperature difference coupling.

[0036] Step Four: Based on the thermal stability characteristics of the low thermal conductivity insulation layer, a nanoscale anti-seepage coating is deposited on the solder joints and electrical connection areas within the cavity. This anti-seepage coating forms a dense and continuous interface sealing structure to block the capillary penetration of residual moisture from the hygroscopic composite film along the solder joint gaps and circuit microchannels, preventing electrochemical reactions. The specific implementation process of this step is as follows: Under the stable thermal environment formed by the low thermal conductivity insulation layer, the solder joint surfaces and electrical connection areas inside the cavity are pretreated to ensure that the anti-seepage coating can form a uniform and dense bonding interface on the metal substrate. The solder joints inside the cavity are typically composed of tin-silver-copper alloys or silver-tin-bismuth alloys, and their surfaces are prone to forming non-conductive films due to oxidation or residual flux, affecting coating adhesion. Therefore, this step employs a dual pretreatment process of plasma surface activation and chemical reduction. Specifically, the cavity is first heated to 45°C to maintain the temperature uniformity of the low thermal conductivity insulation layer and prevent thermal stress from affecting solder joint stability. Subsequently, the solder joint surface is bombarded using low-pressure argon plasma to remove the surface oxide layer and generate a highly reactive surface atomic layer. The treatment duration is controlled between 15 and 25 seconds, with a plasma power of 100 watts. Afterwards, a low concentration of formic acid vapor is introduced into a hydrogenated environment for chemical reduction, completely reducing the residual oxides on the solder joint surface to a metallic state. Through this process, the solder joints and electrical connection ports form a clean and highly reactive metallic surface while maintaining the structural integrity of the low thermal conductivity insulation layer, providing an ideal substrate for subsequent nanodeposition.

[0037] After surface activation, an initial deposition of a nanoscale anti-seepage coating is performed on the solder joints and electrical connection areas. This deposition process employs atomic layer deposition (ALD) technology, alternately introducing precursor and reactive gases to allow the material to accumulate layer by layer at atomic thicknesses, forming a highly dense coating. The coating material is a composite structure of alumina and titanium oxide to balance high density and excellent insulation. The alumina layer thickness is controlled at 20-30 nm to provide strong interfacial adhesion and excellent moisture barrier properties; the titanium oxide layer thickness is controlled at 10-15 nm, primarily to enhance mechanical toughness and crack resistance. The entire deposition process is conducted at a constant temperature of 80°C to match the thermal stability characteristics of the low thermal conductivity insulation layer and prevent thermal gradient-induced coating stress. After each layer deposition, residual reactive gases are removed by nitrogen purging to ensure the purity of the coating interface. After multiple deposition cycles, a composite nanoscale anti-seepage coating is formed. This coating has a smooth surface without microcracks, with a surface roughness of less than 5 nm, ensuring that water vapor molecules cannot penetrate to the metal interface through capillary channels.

[0038] After the initial deposition of the nanoscale anti-seepage coating, the interface between the coating and the solder joints is densified to eliminate potential diffusion paths between micropores and the interface. To achieve this effect, an ion-assisted densification process is performed immediately after coating deposition. Specifically, high-purity argon gas is introduced into the chamber at a constant temperature, and a pulsed ion current is applied to the coating surface, with the ion energy controlled between 60 and 80 electron volts for 30 to 40 seconds. The ion bombardment process causes the atoms on the coating surface to rearrange, filling the nanoscale gaps created during atomic layer deposition, thereby forming a highly dense and continuous crystalline network structure. Simultaneously, to enhance the interfacial bonding strength, trace amounts of oxygen are introduced during the ion-assisted stage, causing transitional bonds to form between the oxide coating and the metal atoms on the solder joint surface, generating an alumina-metal transition interface layer. This transition layer combines high bonding strength with low permeability, effectively blocking residual moisture from the hygroscopic composite membrane from forming capillary channels along the solder joint gaps. In addition, the continuity of the anti-seepage coating is maintained in the electrical connection area through the same process, so that the wire port and the pad interface form an integral closed structure, preventing trace amounts of moisture from seeping into the circuit through the electrical connection interface.

[0039] To enhance the overall sealing stability and corrosion resistance of the anti-seepage coating, a potential-equalizing conductive coating layer is applied to the surface of the nanocomposite coating to achieve surface potential homogenization and long-term environmental protection. This coating layer utilizes an organic-inorganic hybrid material containing a conductive polymer, with a polythiophene derivative as the matrix and uniformly dispersed nano-silver particles within it, with particle diameters controlled within the range of 30 to 50 nanometers. The coating layer is uniformly applied to the entire solder joint and electrical connection area surface via spray deposition. The conductive polymer matrix provides a flexible protective layer while simultaneously forming a uniform potential surface, preventing weak potential differences between different electrical connection areas. The dispersed nano-silver particles form a current-equalizing network on the surface, preventing ion migration or electrochemical corrosion caused by localized electric field concentration. To enhance the bonding between the coating and the underlying anti-seepage coating, a plasma activation process is used before deposition to form surface active sites, enabling covalent bonding between the two layers. After isothermal curing, the coating layer and the nano-anti-seepage coating form a multi-layered integrated sealed structure, maintaining stable adhesion and excellent anti-seepage performance even under repeated takeoffs and landings, high and low temperature cycles, and alternating humid and hot environments.

[0040] Through the implementation of the above steps, a multi-layered composite anti-seepage sealing system is formed in the solder joints and electrical connection areas: the surface activation layer provides a high bonding interface, the nano-anti-seepage coating constructs a continuous seepage barrier, the ion densification layer eliminates diffusion channels, and the conductive coating layer achieves potential equalization and corrosion protection. The four layers work synergistically to maintain stable performance in the thermally stable environment of the low thermal conductivity insulation layer. This structure effectively blocks the capillary permeation path of residual moisture in the graded hygroscopic composite membrane, preventing electrochemical reactions and metal ion migration in the solder joint area, thereby maintaining the long-term reliability of the internal circuitry and the accurate and stable signal output of the aeromagnetic equipment.

[0041] Step 5: Relying on the closed continuity of the nano-level anti-seepage coating, a potential equalization coating treatment is performed on the surface of the cavity. A uniform potential surface is formed through the conductive polymer, balancing the local electric field distribution within the cavity and eliminating the risks of ion migration and current drift. This constructs an integrated protection system against condensation, corrosion, and short circuits under highly integrated sealing conditions. The specific implementation process of this step is as follows: After the nano-level anti-seepage coating is deposited inside the cavity, based on the dense interface closed structure formed by the coating, the cavity surface is activated and pre-coated to establish a high bonding interface between the conductive polymer and the anti-seepage coating. Specifically, maintaining a thermally stable environment with a low thermal conductivity insulation layer inside the cavity, the cavity temperature is controlled at 40℃ to 50℃ to ensure the fluidity and adhesion stability of the coating material. Under this temperature condition, low-energy argon plasma is used to perform energy activation treatment on the surface of the anti-seepage coating for 20 to 30 seconds to remove the surface-adsorbed molecular layer and introduce hydroxyl and carboxyl active groups onto the coating surface, thereby improving the coating's adhesion. Subsequently, a conductive underlayer is sprayed, consisting of a fluorinated polyethylene matrix and a carbon nanotube dispersion. The diameter of the carbon nanotubes is controlled at approximately 20 nanometers, and the surface is carboxylated to enhance polar compatibility. After curing, the underlayer forms a uniform conductive base film, providing a continuous conductive path and chemical bonding basis for the subsequent deposition of the potential equalization coating. This allows the coating to form a stable electronic coupling interface with the anti-seepage coating during the subsequent deposition process.

[0042] A conductive polymer coating is uniformly applied to the pretreated cavity surface to form an overall potential equalization layer. The coating material is a polymer containing a highly conductive π-conjugated structure, such as a polythiophene derivative and a polypyrrole copolymer system. To ensure consistent conductivity across different regions, nanoscale silver-coated copper composite particles are introduced into the conductive polymer. The silver coating inhibits copper oxidation and improves overall conductivity stability. The polymer to composite particle mass ratio is controlled at 7:3 to balance flexibility and conductivity. The coating material is uniformly deposited onto the cavity surface using an electrostatic spraying process. To prevent material buildup leading to uneven thickness, a rotating clamping method is used during spraying to ensure uniform distribution of the coating across solder joints, electrical connection ports, sealing edges, and the cavity inner wall. Subsequently, low-temperature curing is performed under a nitrogen protective atmosphere, with the temperature controlled between 80°C and 90°C and the curing time between 45 and 60 minutes, allowing the conjugated system in the polymer chain structure to fully extend, thus forming a continuous conductive network. The surface conductivity of this layer is maintained within the range of 10⁻² to 10⁻³ Siemens per centimeter, ensuring rapid potential equalization in different areas inside the cavity and preventing the generation of local potential differences.

[0043] After the potential equalization layer is formed, to stabilize the electric field distribution on the coating surface and prevent potential drift caused by moisture or temperature changes, the potential equalization coating undergoes interface stabilization treatment. This process includes two steps: ion doping and surface directional curing. First, an inert gas containing low concentrations of chloride and lithium ions is introduced to uniformly distribute the charge carriers on the conductive polymer surface. Chloride ions, as dopant ions, form stable ionized coordination structures between polymer chains, reducing the aggregation of free electrons and thus suppressing local potential concentration. Subsequently, infrared irradiation heating is used to reorient the polymer surface micro-segments, forming a conjugated layer structure parallel to the surface. The irradiation intensity is controlled at 1.5 W / cm² for 25 minutes. This treatment creates a multi-layer electron conduction band structure in the thickness direction of the potential equalization coating, resulting in a more uniform electron flow distribution within the layer, thereby balancing the local electric field within the cavity. Due to the sealing properties of the aforementioned nano-impermeable coating, dopant ions in the potential equalization layer will not diffuse downwards into the circuit metal region, ensuring the electrochemical stability of the overall structure. After processing, a uniform potential surface is formed on the surface of the cavity at the microscale, and the rate of change of the electric field gradient in the spatial distribution is less than 0.5 volts per millimeter, effectively preventing ion migration and current shift.

[0044] To ensure the electrochemical inertia and protective capabilities of the potential equalization coating during long-term operation, a protective sealing layer is applied to the outer surface of the coating, followed by overall protective reinforcement treatment. This sealing layer utilizes a silanized polyurethane composite material, whose molecules contain cross-linked siloxane chains and hydrophobic methyl end groups, forming a low-surface-energy moisture barrier on the coating surface. The sealing layer is uniformly applied to the surface of the potential equalization layer using a spin-coating process. After spin-coating, it is cured at 60°C for two hours, allowing partial cross-linking between the sealing layer and the underlying conductive polymer, forming a chemically bonded interface. In addition to its moisture-proof properties, this sealing layer also exhibits high permeability, allowing trace amounts of heat generated inside the cavity to slowly escape under pressure differential, thus maintaining stable internal and external pressure. The surface of the sealing layer undergoes plasma micro-etching to form a micro-nano-scale textured structure, which rapidly repels moisture upon contact due to its high contact angle, further preventing condensation and droplet formation. Through this process, the potential equalization coating is strengthened both mechanically and chemically, exhibiting long-term resistance to moisture corrosion and stable conductivity.

[0045] Through the implementation of the above steps, a multi-layered potential equilibrium system is formed on the surface of the cavity, consisting of a conductive guiding bottom layer, a conductive polymer potential layer, a stable interface layer, and a sealed protective layer. This system, together with the aforementioned nanoscale anti-seepage coating, forms an electrochemically integrated structure, achieving overall equilibrium of electron migration at the microscale and preventing ion migration and electrochemical corrosion caused by local electric field concentration inside the cavity. Simultaneously, the moisture protection provided by the sealing layer effectively blocks the intrusion of external moisture, and the potential balance formed by the conductive layer stabilizes the current distribution, preventing short circuits and noise interference. Thus, under the highly integrated sealing conditions of the aeromagnetic equipment, the overall protection goals of anti-condensation, anti-corrosion, and anti-short circuit are achieved, ensuring the long-term stable operation and high-precision magnetic measurement performance of the equipment in complex flight environments.

[0046] This invention effectively inhibits external moisture from entering the equipment by incorporating a constant-pressure breathing buffer layer and a graded moisture-absorbing composite membrane inside and outside the cavity. The constant-pressure breathing buffer layer utilizes a microporous structure to achieve a dynamic balance of air pressure inside and outside the cavity, preventing moisture penetration due to pressure changes. The graded moisture-absorbing composite membrane establishes a humidity gradient to capture and fix trace amounts of water vapor, preventing condensation. This measure effectively reduces water vapor accumulation, significantly lowers the risk of internal corrosion, and ensures the long-term stable operation of the equipment.

[0047] This invention incorporates a low thermal conductivity insulation layer in key heat source areas within the cavity, effectively dispersing the temperature gradient, weakening the condensation driving force, and further reducing the likelihood of water vapor condensation. Combined with the protective effect of the anti-seepage coating, the potential equalization coating treatment balances the electric field distribution within the cavity, eliminating localized potential differences. Through these innovative measures, not only are the equipment's anti-condensation, anti-corrosion, and short-circuit protection capabilities improved, but the long-term reliability and high-precision measurement performance of each electrical component under highly integrated and sealed conditions are also ensured.

[0048] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A highly integrated dustproof and waterproof design method suitable for aeromagnetic equipment, characterized in that, Includes the following steps: Step 1: Based on the residual gas characteristics of the internal cavity of the aeromagnetic equipment, a constant-pressure breathing buffer layer is set inside and outside the cavity. A slow-speed air pressure exchange channel is formed inside and outside the cavity through a balance membrane with a controllable microporous structure, achieving dynamic balance of air pressure inside and outside the cavity. Step 2: Along the gas flow path of the constant-pressure breathing buffer layer, a graded moisture-absorbing composite membrane is laid on the inner wall of the cavity. The graded moisture-absorbing composite membrane is composed of multiple layers of adsorbent materials with different moisture absorption rates. A humidity gradient is established through the difference in adsorption rates between the materials, allowing trace amounts of water vapor that seeps into the cavity to be captured and fixed in the area adjacent to the sealing layer. Step 3: Combining the humidity distribution formed by the graded moisture-absorbing composite membrane, key heat sources within the cavity... The first step involves setting up a low thermal conductivity insulation layer in the area to stabilize the local temperature difference inside the cavity through heat distribution equalization technology, thereby weakening the condensation driving force in the humidity gradient zone. The second step involves depositing a nanoscale anti-seepage coating on the solder joints and electrical connection areas inside the cavity based on the thermal steady-state characteristics of the low thermal conductivity insulation layer. This anti-seepage coating forms a dense and continuous interface closed structure, blocking the capillary penetration of residual water vapor in the moisture-absorbing composite membrane along the gaps between solder joints and the microchannels of the circuit. The third step involves applying a potential equalization coating to the surface of the cavity based on the closed continuity of the nanoscale anti-seepage coating. This coating forms a uniform potential surface through conductive polymers, balancing the local electric field distribution inside the cavity and eliminating the risks of ion migration and current drift.

2. The highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 1, characterized in that, Based on the residual gas characteristics of the internal cavity of the aeromagnetic equipment, a constant-pressure breathing buffer layer is set inside and outside the cavity. The specific steps include: Constructing a constant-pressure breathing buffer layer with a continuous annular channel structure made of fluorinated polyimide composite material in the outer region of the sealed cavity of the aeromagnetic equipment, according to the actual volume and wall thickness parameters of the cavity; adding a high-elasticity silicone support layer to its outer wall through co-extrusion molding; setting a balance membrane between the outer side of the constant-pressure breathing buffer layer and the outer shell of the aeromagnetic equipment, consisting of a polytetrafluoroethylene porous membrane, an alumina ceramic porous support layer, and a polyimide microfiber support membrane, through hot pressing; continuously sealing the edges with epoxy resin sealant to form a slow-speed gas pressure exchange channel inside and outside the cavity; setting an impermeable contact layer consisting of a sealing coating layer and a flexible bonding layer at the interface between the balance membrane and the constant-pressure breathing buffer layer, with micro-flow grooves inside the impermeable contact layer; forming a siloxane-alkyl polymer protective layer on the outer surface of the constant-pressure breathing buffer layer using vapor deposition, and forming a chemical bonding interface through plasma pretreatment.

3. The highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 2, characterized in that, The surface of the siloxane polymer protective layer is formed into a micro-nano structure through plasma etching, which is used to form an air film layer in the high humidity or salt spray environment of the aircraft.

4. The highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 2, characterized in that, A graded moisture-absorbing composite membrane is laid on the inner wall of the cavity to establish a humidity gradient through the difference in adsorption rates between materials. The specific steps include: selecting an area adjacent to the airflow channel of the constant pressure breathing buffer layer on the inner wall of the sealed cavity of the aeromagnetic equipment, constructing a base layer formed by a polyimide fiber reinforcement layer, and bonding it to the inner wall of the cavity with a thermosetting adhesive film to form a continuous coating; depositing a first moisture-absorbing layer composed of molecular sieve-type aluminosilicate material on the surface of the base layer, and forming an interconnected microporous network through a sol-gel process; laying a second moisture-absorbing layer on the outer surface of the first moisture-absorbing layer, the second moisture-absorbing layer being composed of polyvinyl alcohol copolymer and calcium oxide particles, forming a slow humidity gradient to delay the adsorption and graded fixation of incompletely adsorbed water vapor; laying a third moisture-absorbing protective layer on the outside of the second moisture-absorbing layer, the protective layer being composed of a cross-linked polymer containing phosphorus groups, and setting an elastic transition layer composed of polyimide elastomer between it and the second moisture-absorbing layer.

5. A highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 4, characterized in that, The phosphorus-containing cross-linked polymer of the third moisture-absorbing protective layer is fluorinated to form a weakly hydrophobic surface, and the polyimide elastomer of the elastic transition layer is used to absorb deformation between the second moisture-absorbing layer and the third moisture-absorbing protective layer, so that the graded moisture-absorbing composite membrane maintains the stability of interlayer bonding and maintains the final chemical fixation of water vapor in the alternating high and low temperature environment.

6. The highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 4, characterized in that, A low thermal conductivity insulation jacket is installed in the key heat source area within the cavity. The local temperature difference within the cavity is stabilized using heat distribution equalization technology. Specifically, the steps include: determining the layout range of the low thermal conductivity insulation jacket within the sealed cavity of the aeromagnetic equipment based on heat distribution characteristics; selecting a ring-shaped area as the main insulation layout zone; and setting jacket mounting grooves around the key heat source. Within the insulation area, a low thermal conductivity insulation jacket is constructed, consisting of a ceramic microsphere-reinforced siloxane composite layer, a polyimide thermally conductive slow-release layer, and a fluorinated polymer heat-resistant protective layer. The three layers are integrally formed through a hot-pressing lamination process and bonded with thermosetting silicone adhesive. A metal oxide composite elastic thermally conductive buffer layer is installed between the insulation jacket and the heat source, forming a discrete contact structure through point bonding to balance local heat flow distribution and suppress condensation driving force. A fluorosiloxane composite coating is applied to the outer surface of the insulation jacket, forming a low surface energy film through vapor deposition and isothermal curing to reflect external radiant heat.

7. A highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 6, characterized in that, The surface of the fluorosiloxane composite coating is formed by plasma etching to create uniformly distributed micro-nano structures. These micro-nano structures are used to form a stable gas film layer in high humidity environments, reducing the probability of water vapor condensation, and maintaining the low-energy characteristics of the surface through fluorine-containing side chain structures.

8. A highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 6, characterized in that, Based on the thermal stability characteristics of the low thermal conductivity insulation layer, a nanoscale anti-seepage coating is deposited in the weld joints and electrical connection areas within the cavity. The specific steps include: Pre-treating the weld joint surfaces and electrical connection areas within the cavity using a combination of plasma surface activation and chemical reduction under the stable thermal environment formed by the low thermal conductivity insulation layer, removing the oxide layer and forming a highly active metal surface; after surface activation, forming a composite nano-anti-seepage coating composed of alternating layers of alumina and titanium oxide using atomic layer deposition technology in the weld joints and electrical connection areas, and depositing it at a constant temperature of 80℃ to ensure coating density; after the anti-seepage coating is formed, it undergoes ion-assisted densification treatment, applying a pulsed ion current in a high-purity argon atmosphere to rearrange the coating atoms and generate an alumina-metal transition interface layer, eliminating microporous diffusion paths; a conductive polymer potential-equalizing coating layer is sprayed onto the anti-seepage coating surface, with uniformly dispersed nano-silver particles in the coating layer, which are then activated by plasma to form covalent bonds, constructing an overall closed anti-seepage structure to prevent electrochemical reactions.

9. A highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 8, characterized in that, The conductive polymer potential equalization coating uses polythiophene derivatives as the matrix and disperses silver nanoparticles in it to form a current equalization network; the coating and the composite nano anti-seepage coating are bonded by chemical covalent bonds through plasma activation, which enhances the interfacial adhesion.

10. A highly integrated dustproof and waterproof design method for aeromagnetic equipment according to claim 9, characterized in that, A potential equalization coating treatment is performed on the surface of the cavity to form a uniform potential surface through a conductive polymer. Specifically, this includes the following steps: After the formation of a nanoscale anti-seepage coating, the cavity surface undergoes surface activation and pre-coating treatment. Energy activation is performed using low-energy argon plasma in a constant temperature environment of 40℃ to 50℃, followed by spraying a conductive guiding underlayer composed of a fluorinated polyethylene matrix and carbon nanotube dispersion. After the conductive guiding underlayer cures, a conductive polymer potential layer composed of a polythiophene derivative and a polypyrrole copolymer system is uniformly coated onto the cavity surface. Silver-coated copper composite particles are dispersed in the potential layer, and the layer is cured in a nitrogen atmosphere at 80℃ to 90℃ to form a continuous conductive network. After the potential layer is formed, an inert gas containing chloride and lithium ions is introduced for ion doping, and surface-oriented curing is performed using infrared irradiation heating to form a multi-layer electron conduction band structure in the thickness direction. A silanized polyurethane sealing layer is spin-coated onto the outer surface of the potential layer and cured at 60℃ for two hours to form a chemically bonded interface.

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