242results about How to "Improve electromagnetic shielding performance" patented technology

The invention relates to a composite electromagnetic shielding structure for a power terminal and a preparation method thereof, the structure comprises an accommodating shell, the accommodating shell is formed by connecting a plurality of composite electromagnetic shielding plates, and each composite electromagnetic shielding plate comprises an inner surface shielding layer and an outer surface shielding layer which are attached to each other; a heat conduction layer is arranged between the inner surface shielding layer and the outer surface shielding layer, and the inner surface shielding layer is located in the accommodating shell; a protective layer is arranged on the outer layer of the outer surface shielding layer and comprises an insulating layer and a waterproof layer, and the waterproof layer is located on the outer layer of the insulating layer; the outer surface shielding layer is made of a low-frequency electromagnetic field shielding material formed by mixing amorphous magnetic alloy powder, magnetic fibers and nickel powder; and the inner surface shielding layer is made of a high-frequency electromagnetic shielding material formed by mixing silicon carbide and resin foam rubber fibers. The structure can cope with various electromagnetic interference environments, provides electromagnetic shielding protection, and also has better electromagnetic shielding effectiveness for electromagnetic interference of different frequency bands.

The invention discloses a composite cable containing an electromagnetic shielding material and a manufacturing method thereof, the composite cable containing the electromagnetic shielding material comprises an insulating sheath, a conductive wire core and a shielding layer, the insulating sheath wraps the conductive wire core, the shielding layer is embedded in the insulating sheath, the shielding layer comprises a semiconductor and graphene, and the semiconductor and the graphene are arranged in the insulating sheath. A strip-shaped semiconductor is heated to a molten state in a smelting furnace, the surface of the molten semiconductor is coated with graphene, shielding bodies of the semiconductor and the graphene are obtained through cooling, every two shielding bodies form a spatial double-helix structure, and the multiple shielding bodies are woven to form a woven belt-shaped structure. A method for manufacturing the composite cable comprises the following steps: combining the graphene wire core with the metal copper core to obtain the conductive wire core; and then an inner insulating layer, a heat dissipation layer, a shielding layer, a waterproof layer and an outer insulating layer are sequentially coated on the conductive wire core. The semiconductor and the graphene are woven on the periphery of the conductive wire core to form a barrier of a double-helix structure, the effect of isolating a magnetic field is achieved, and the electromagnetic shielding performance is improved.

The invention discloses a large-lamellar MXene material as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out etching treatment on an MAX phase material by using an etching agent to obtain a multi-layer MXene material; and dispersing the multi-layer MXene material in a dispersion medium, and carrying out mechanical stress shear stripping to obtain the large-lamellar MXene material. According to the preparation method provided by the invention, the large-lamellar MXene material with the average transverse size of 4.2 microns or above can be obtained through high-yield stripping, the product quality is high, the yield is high, and industrial batch production is facilitated; the MXene film obtained based on the large-lamellar MXene material has good electromagnetic shielding capability and can be widely applied to the field of electromagnetic absorption shielding.

The invention belongs to the technical field of new materials, and particularly relates to a PEDOT electromagnetic shielding polymer film, a preparation method and application, a substrate coated with an oxidizing agent solution is subjected to a polymerization reaction in steam containing an EDOT monomer, then an oxidizing agent is removed, drying is performed, and the PEDOT electromagnetic shielding polymer film is obtained; the oxidant solution comprises ferric salt, an additive and water, and the additive is one or more of polyvinyl alcohol, polyvinylpyrrolidone, starch, polyethylene glycol and a polyoxypropylene polyoxyethylene copolymer; the PEDOT electromagnetic shielding polymer film provided by the invention has relatively high density and lower resistance, and can improve the electromagnetic shielding effect.

The invention discloses PVA (polyvinyl alcohol) and alkali lignin-based carbon aerogel and a preparation method and application thereof.Soluble nickel salt is added in the aerogel preparation process, Ni < 2 + > and hydroxyl groups of PVA and AL (alkali lignin) form a chelation effect, the pore structure of the carbon aerogel is adjusted by adjusting the adding amount of the soluble nickel salt, and the porosity of the carbon aerogel is adjusted by adjusting the adding amount of the soluble nickel salt; the prepared carbon aerogel has a more developed and richer pore structure, so that the electromagnetic shielding effectiveness of the carbon aerogel reaches an optimal state, in addition, soluble nickel salt is converted into nickel nanoparticles after high-temperature carbonization, and the nickel nanoparticles are uniformly dispersed in the carbon aerogel, so that the conductivity and magnetic conductivity of the carbon aerogel are also favorably improved, and the electromagnetic shielding performance of the carbon aerogel is improved. Therefore, the electromagnetic shielding effectiveness of the carbon aerogel is further improved.

The invention relates to the technical field of electronic materials, and discloses a multi-layer shielding type insulating sheet, which comprises a shielding layer used for shielding electromagnetic interference and in direct contact with an insulating layer; the insulating layer is used for electric insulation and is tightly connected with the shielding layer and the heat dissipation layer; the heat dissipation layer is used for heat conduction and is arranged on the close side of the insulating layer and the buffer layer; the buffer layer is used for providing mechanical buffer and structural support and is attached to the heat dissipation layer and the surface coating; the surface coating is used for protecting the material surface and arranged on the outer surface of the buffer layer, and the shielding layer is made of one or more of copper foil, aluminum foil and a graphene coating. By adopting the copper foil, the aluminum foil or the graphene coating as the shielding layer, electromagnetic interference from the outside can be effectively shielded, in an experiment, the electromagnetic shielding effectiveness of the insulating sheet can reach 95 dB or above, the insulating sheet particularly shows excellent electromagnetic shielding performance in a high-temperature and high-vibration environment, and stable operation of an internal circuit and equipment is ensured.

The utility model provides a three-position switch and a ring main unit, the three-position switch comprises a first fixed seat and a plurality of grounding contacts, each grounding contact corresponds to one phase in a power supply network, and the plurality of grounding contacts are arranged on the first fixed seat; the grounding shielding base is arranged on the first fixing base, the grounding shielding base is configured to be an integrally-formed metal piece, a plurality of open holes are formed in the grounding shielding base, and the grounding contacts are exposed out of the corresponding open holes; each second fixing seat is correspondingly provided with an isolation static contact. And a plurality of moving contacts are arranged on the third fixed seat at intervals, and the moving contacts can rotate relative to the third fixed seat so as to be electrically connected with the grounding contact or the isolation static contact selectively. By optimizing the electric field of the three-position switch, the three-position switch can have a better insulation level, and the overall size of the three-position switch is reduced. Furthermore, the three-position switch can be applied to a small-size ring main unit with space limitation and higher insulation requirements.

The invention provides nickel-carbon conductive shielding foam. The nickel-carbon conductive shielding foam sequentially comprises a conductive layer, foam, a bonding layer and an isolating layer from top to bottom, the foam comprises 25 to 40 parts of nickel-carbon nanotube-cerium oxide composite powder, 1 to 5 parts of an ionic liquid dispersant, 10 to 25 parts of organic silicone oil, 20 to 40 parts of silicone rubber, 5 to 10 parts of polyfuran, 5 to 10 parts of maleimide, 0.5 to 3 parts of a silane coupling agent, 0.01 to 0.1 part of a platinum catalyst and 0.2 to 1.5 parts of a cross-linking agent. The conductive foam can effectively restrain high-frequency electromagnetic interference generated in modern electronic equipment and ensure normal work of the equipment. A self-repairing system is constructed by adding polyfuran and maleimide. When the foam generates cracks under the action of mechanical stress or thermal cycle in the using process, the self-repairing material can automatically repair a conductive network through a reverse Diels-Alder reaction, and the shielding performance and the conductivity of the material are recovered.

The invention provides a preparation method of nickel-carbon conductive shielding foam, which comprises the following steps: S1, mixing carbon nanotubes and cerium oxide in proportion, and adding nano nickel powder to form a suspension; adding a reducing agent to carry out reduction reaction so as to deposit nickel ions on the surfaces of the carbon nanotubes and the cerium oxide particles; s2, mixing the nickel-carbon nanotube-cerium oxide composite powder with an ionic liquid dispersant, mixing organic silicone oil and silicone rubber to serve as a matrix, then adding polyfuran and maleimide, and adding a silane coupling agent to be fully combined; adding the dispersed composite powder into an organic silicon matrix, continuously stirring until the materials are uniformly mixed, then adding a platinum catalyst and a cross-linking agent, pouring the mixture into a mold, and curing to form foam; s3, pasting a conductive layer; S4, setting a bonding layer; and S5, setting an isolation layer. By adopting the nickel-carbon nanotube-cerium oxide composite material, the electromagnetic shielding performance of the foam is greatly improved. The ultra-thin self-repairing function is also realized.

The invention discloses a high-performance water-based polyimide / carbon nanotube composite electromagnetic shielding film and a preparation method thereof. The preparation method comprises the following steps: reacting a first mixed reaction system containing a diamine monomer, a salt-forming reagent and a dianhydride monomer to obtain water-based polyamide acid salt; uniformly mixing the polyvinylpyrrolidone modified carbon nanotube aqueous dispersion liquid with the aqueous polyamide acid salt to form an aqueous polyamide acid salt / carbon nanotube dispersion liquid; and applying the water-based polyamide acid salt / carbon nanotube dispersion liquid to a substrate, and then carrying out thermal imidization treatment to prepare the high-performance water-based polyimide / carbon nanotube composite electromagnetic shielding film. The preparation method provided by the invention is simple, safe and environment-friendly, and is suitable for industrial popularization and application, and the finally prepared composite film can still maintain good mechanical properties and high-temperature electromagnetic shielding performance under the condition of high carbon nanotube content, and is beneficial to application in extreme environments.

The invention relates to a chip packaging structure and a packaging method thereof, and relates to the technical field of chip packaging, the chip packaging structure comprises a packaging substrate, a metal shell and a chip body; the packaging substrate is fixedly connected with the metal shell through a structural adhesive to form a packaging cavity; the chip body is located in the packaging cavity, the chip body is arranged on the upper surface of the packaging substrate, and the upper surface of the chip body is connected with the metal shell through heat-conducting glue; the packaging method comprises the following steps: providing a packaging substrate; arranging a chip body on the upper surface of the packaging substrate, and welding the chip body by using vacuum welding equipment; and coating heat-conducting glue on the upper surface of the chip body, coating structural glue on the packaging substrate, and covering a metal shell to complete chip packaging. According to the invention, the electromagnetic shielding effect is realized on the basis of chip miniaturization.

The utility model relates to an air-cooled plug-in box capable of improving an electromagnetic shielding effect, and solves the problems that an existing plug-in box adopts an air-cooled heat dissipation mode, dust is easy to accumulate in the plug-in box after long-time operation, the overall electromagnetic shielding effect of the plug-in box is reduced, and the space for installing a functional module in the plug-in box is extruded. The heat dissipation device comprises a box body and heat dissipation plates arranged in the box body, the heat dissipation plates comprise an upper heat dissipation plate and a lower heat dissipation plate, gaps exist between the upper heat dissipation plate and an upper cover plate and between the lower heat dissipation plate and a lower cover plate respectively, the gaps form a first heat dissipation channel and a second heat dissipation channel, the right end face of the upper heat dissipation plate and the right end face of the lower heat dissipation plate are connected with a right panel, and gaps exist between the right panel and the upper cover plate and between the right panel and the lower cover plate. The air guide part is arranged relative to the fan on the left panel and guides cold air into the two heat dissipation channels, the inner side face of the air guide part is connected with the left end face of the upper heat dissipation plate and the left end face of the lower heat dissipation plate, the multiple slot plates are arranged between the upper heat dissipation plate and the lower heat dissipation plate, and a groove between a first installation plate and a second installation plate of the air guide part can be used for installing a 3U module.

The invention relates to the technical field of plastic modification processing, in particular to high-conductivity composite system coated black talcum powder and a preparation method thereof as well as a modified master batch containing the black talcum powder and a preparation method of the modified master batch. The high-conductivity composite system coated black talcum powder coating material is prepared from the following components in percentage by mass: 65.0 to 76.0 weight percent of high-conductivity composite system coated black talcum powder, 5.0 to 10.0 weight percent of cobalt ferrite nanoparticles, 15.0 to 20.0 weight percent of carrier resin, 2.0 to 3.0 weight percent of dispersing agent and 0.5 to 1.0 weight percent of lubricating agent, according to the technology provided by the invention, the black talcum powder is changed from a common traditional inorganic filler to a high-end functional filler with a conductive functional modification effect, so that the product added value of the black talcum powder is improved, and an important contribution is made to development and application of black talcum powder ore in China.

The invention relates to a preparation method of a graphene alloy electromagnetic shielding material, and belongs to the technical field of electromagnetic shielding materials. The preparation method of the graphene alloy electromagnetic shielding material comprises the following steps: mixing a reaction monomer, lauryl sodium sulfate, deionized water and an initiator, and carrying out polymerization reaction to obtain modified acrylic resin; the preparation method comprises the following steps: heating and mixing polyol and isocyanate, adding a chain extender and deionized water, and stirring and mixing to obtain waterborne polyurethane; and stirring the modified acrylic resin, the waterborne polyurethane, the modified filler and other auxiliaries at a high speed to obtain the water-based paint. The uniformity and compatibility of alumina / graphene in an electromagnetic shielding material system are remarkably improved through compound modification of multiple components, and then the electromagnetic shielding effect of the composite material is remarkably improved.

The invention discloses an electromagnetic shielding foam material and a preparation forming method thereof, and relates to the technical field of polymer processing. The electromagnetic shielding foam material is prepared by adopting polyphenylene sulfide as a raw material, so that the mechanical strength of the electromagnetic shielding foam material is high, and PPS has excellent mechanical strength, tensile strength, bending strength and other indexes which are at a relatively high level in engineering plastics, and can bear relatively high pressure and wear; the melting point of the PPS exceeds 280 DEG C, the heat distortion temperature exceeds 260 DEG C, the PPS can resist the high temperature of 260 DEG C in a short term, the long-term use temperature can reach 200-220 DEG C, and the PPS still can keep good performance at the high temperature; the PPS has excellent electrical insulation property, low dielectric constant and dielectric loss angle tangent value and good arc resistance, and is suitable for insulating materials in the field of electronic and electric appliances; excellent chemical corrosion resistance and radiation resistance are realized; the PPS electromagnetic shielding foam material prepared by a special process also has a good electromagnetic shielding effect, and can be used in occasions requiring electromagnetic shielding.

The utility model discloses a packaging structure and a radio frequency module, and relates to the technical field of radio frequency module packaging. A metal array composed of metal bodies is arranged around a to-be-shielded device, and a metal shielding layer is connected with one end, exposed out of a first plastic package layer, of each metal body and is connected with a substrate, so that cavity-divided shielding of the to-be-shielded device is realized, a complicated internal shielding structure is not needed, and a special process flow is not needed, and therefore, the shielding of the to-be-shielded device among all chips can be realized. Or the chip is shielded from the outside, a metal body can be freely arranged according to the position needing to be shielded, and the quality of the chip is not influenced; a metal array composed of vertical metal bodies is arranged around a to-be-shielded device, a shielding line arc is arranged on the metal bodies, and the shielding line arc spans the to-be-shielded device and forms a shielding cavity with the metal array, so that space waste caused by an arc line can be reduced; the number of layers of the metal arrays is increased, so that the metal bodies of the adjacent layers of metal arrays are distributed in a staggered mode, and / or the distribution density of shielding wire arcs is increased, and the electromagnetic shielding effect can be further enhanced.

The present application relates to the field of electronic components, and more specifically, it relates to an electromagnetic shielding tape and its preparation method and application. It includes a conductive layer and at least one shielding pressure-sensitive layer, each of which is connected to the conductive layer, and each of which is provided with a protective layer on the side away from the conductive layer, and the gram weight of each shielding pressure-sensitive layer accounts for 100-166% of the gram weight of the conductive layer, and the shielding pressure-sensitive layer is formed by coating and curing a conductive acrylic pressure-sensitive adhesive. The conductive acrylic pressure-sensitive adhesive has good flexibility, conductivity, film-forming stability and adhesion stability. When the gram weight of the shielding pressure-sensitive layer accounts for 100-166% of the gram weight of the conductive layer, the shielding pressure-sensitive layer has good adhesion, so that it has good adhesion stability with the conductive layer, and has good adhesion to the circuit board, reducing the possibility of falling off and cracking, so that the electromagnetic shielding tape obtains a better electromagnetic shielding effect.

The invention provides an MXene-based electromagnetic shielding material for anchoring 0 / 2-dimensional magnetic metal and preparation and application thereof.The electromagnetic shielding material comprises an MXene material, nearly-0-dimensional magnetic alloy microspheres and two-dimensional flaky magnetic metal, the MXene material is of a lamellar structure, the magnetic alloy microspheres and the flaky magnetic metal are embedded between lamellas of the MXene material, and the two-dimensional flaky magnetic metal is embedded between the lamellas of the MXene material. The mass of the magnetic alloy microspheres accounts for 8.3%-33.3% of the total mass of the electromagnetic shielding material, and the mass of the flaky magnetic metal accounts for 8.3%-33.3% of the total mass of the electromagnetic shielding material. The preparation method of the electromagnetic shielding material adopts a direct compounding mode of an anionic surfactant and an ultrasonic process. The preparation method is simple in process, the component proportion is easy to control, and the prepared electromagnetic shielding material is rich in electromagnetic loss mechanism, large in effective shielding bandwidth and remarkable in electromagnetic shielding effectiveness and has wide application prospects in electromagnetic interference prevention of MEMS sensor packaging, automobile electronic products, stealth fighter planes and wearable electronic equipment.

The utility model relates to the field of nuclear radiation detection, and discloses a flow-gas proportional counter module. The flow-gas proportional counter module comprises a sample feeding assembly and a probe assembly, the sample feeding assembly comprises a base and a drawing plate connected with the base in a sliding mode, and the drawing plate is provided with a tray used for containing samples; the probe assembly comprises a proportional counter tube arranged above the tray, a shielding shell is arranged outside the proportional counter tube, and the shell is fixedly connected with the base; by arranging the proportional counter tube in the shielding shell, the contact between the proportional counter tube and the external environment is effectively reduced, the electromagnetic shielding effect is improved, the interference of environment temperature and humidity on detection signals is reduced, the signal detection accuracy of the proportional counter tube is improved, and the detection background is reduced.

The invention provides an ultra-wideband electromagnetic shielding and bulletproof composite structure material and a preparation method thereof, and belongs to the field of preparation of electromagnetic wave-absorbing materials. The invention aims to solve the problems that the current electromagnetic shielding material is narrow in absorption wave band, the composite structure material is high in preparation cost and complex in process, and does not have protection performance. The ultra-wideband electromagnetic shielding and bulletproof composite structural material is mainly composed of four structural modules, namely (1) a wave-transparent skin; (2) preparing an aramid fiber honeycomb sandwich; (3) a reflecting plate; and (4) a bulletproof back plate. Wherein the wave-transparent skin is arranged on the outermost surface and receives incident electromagnetic waves, the aramid honeycomb sandwich, the reflecting plate and the bulletproof back plate are sequentially overlaid downwards, and all structural modules are bonded through modified resin adhesives. The ultra-wideband electromagnetic shielding and bulletproof composite structure material has a very excellent electromagnetic shielding effect, electromagnetic stealth of a target facility is achieved, meanwhile, certain protection performance is achieved, space occupation is reduced due to the multi-functionalization characteristic of the overall composite structure, and therefore the possibility that a target is detected is further reduced from the appearance; and the preparation raw materials of each structure module are rich, the cost is low, the operation process is simple, and industrial popularization and application of the ultra-wideband electromagnetic shielding and bulletproof composite structure material are facilitated.

The invention provides a method and a device for testing electromagnetic compatibility of a power battery applying a metal film, and the method comprises the steps: firstly, building a first shielding effectiveness model which is related with the effect of the material and the layer number of the metal film on a shielding effect; then, a plurality of samples are manufactured, the shielding effectiveness of the samples is actually measured, the model is verified and adjusted, and a more accurate second shielding effectiveness model is formed; finally, the model is applied to a power battery electronic component, and a third shielding effectiveness model is determined through further test verification; according to the invention, a scientific basis can be provided for electromagnetic compatibility evaluation of the power battery.

A highly integrated wide- and narrow-band RF transceiver module includes a housing made of aluminum alloy with a flat structure. An upper cavity is formed with an opening on the housing's surface, and a lower cavity is formed with an opening on the lower surface of the housing. An upper control card and an upper partition are located at the bottom of the upper cavity, with the upper partition fixed to the bottom of the upper cavity by screws. Multiple compartments are formed on the upper partition. An upper cover is fixed to the upper end of the upper cavity. A lower control card and a lower partition are located at the bottom of the lower cavity, with the lower partition located below the lower control card and fixed to the bottom of the lower cavity. Multiple holes are formed on the lower partition, with electronic components on the lower control card located within each hole. A lower cover is fixed to the lower end of the lower cavity. This invention's dual-cavity design evenly distributes the gain in the RF link across both sides, achieving physical isolation and increasing electromagnetic shielding. Simultaneously, power amplifiers and RF front-end circuits arranged on the same side are physically isolated through the upper and lower partitions, ensuring electromagnetic shielding effectiveness.

The utility model discloses a flexible anti-electromagnetic pulse cable assembly which comprises a cable lead, a copper net sleeve, a PTFE film, a flexible anti-wave sleeve, a braided sheath and an electric connector. The cable conductor is fixedly connected with the electric connector, the cable conductor is sleeved with a copper net sleeve in a penetrating mode, the copper net sleeve is wrapped with a PTFE film, the PTFE film is sleeved with a soft wave-proof sleeve in a penetrating mode, and the soft wave-proof sleeve is sleeved with a woven sheath in a penetrating mode; according to the technical scheme, the copper net sleeve and the soft wave-proof sleeve which have the advantages of being light in weight, small in hole, good in shielding performance, good in weldability and the like, and the PTFE film and the woven sheath which have the advantages of being large in expansibility, high in strength, resistant to abrasion, soft, light in weight and the like are adopted for shielding protection, and therefore the assembly is light in weight, good in signal shielding effect and high in strength.

The invention discloses a bamboo charcoal fiber cloth-based composite material as well as a preparation method and application thereof, and belongs to the technical field of electromagnetic shielding materials. The bamboo charcoal fiber cloth-based composite material comprises: a base cloth, which is a bamboo charcoal fiber cloth subjected to oxidation modification and activation treatment by TEMPO (2, 2, 6, 6-tetramethylpiperidine-1-oxygen radical); the gradient copper layer is chemically plated on the surface of the base cloth; the nickel layer is chemically plated on the surface of the gradient copper layer; wherein the density of the base cloth side copper layer is smaller than that of the nickel layer and the copper layer. The bamboo charcoal fiber cloth is subjected to surface treatment modification through a special process, and meanwhile, a gradient copper layer and a gradient nickel layer are formed on the surface of the bamboo charcoal fiber cloth, so that the bamboo charcoal fiber cloth-based composite material with light weight, structural stability and excellent electromagnetic shielding performance is prepared, and the requirements of flexible and broadband electromagnetic shielding application are met.

The invention relates to a conductive and electromagnetically shielding polyaryletherketone-based composite material and a preparation method thereof, comprising the following steps: S1, forming a mixed dispersion of a carbon-based MFI structure molecular sieve and a metal salt, and performing a heating reaction to obtain a loaded carbon-based MFI structure molecular sieve; S2, uniformly mixing the loaded carbon-based MFI structure molecular sieve and polyaryletherketone, and then performing melt blending, extrusion, and granulation to obtain a first material; S3, uniformly mixing a conductive filler and polyaryletherketone, and then performing melt blending, extrusion, and granulation to obtain a second material; S4, mixing the first material and the second material according to a proportion, and then performing melt blending, extrusion molding or granulation to obtain a conductive and electromagnetically shielding polyaryletherketone-based composite material; the composite material of the invention has significant electromagnetic shielding effectiveness and excellent comprehensive mechanical properties.

The present invention relates to the technical field of communication equipment components, specifically to a capacitive coupling structure and a filter, a capacitive coupling structure, comprising an intermediate portion connected to a plurality of adjacent and unconnected resonators, the intermediate portion comprising a connection block for connecting the resonators, and an isolation cavity for isolating the resonators, the electric field directions of the two resonators connected to the same intermediate portion being different. A filter, comprising a plurality of resonators, at least one of the above-mentioned capacitive coupling structures being used between the plurality of resonators, the capacitive coupling structure causing capacitive negative coupling to be generated between the resonators connected thereto. The capacitive coupling structure and filter using the present solution can solve the technical problem in the prior art of using a deep-loaded frequency debugging blind hole to achieve capacitive negative coupling leading to the generation of resonance poles, achieve capacitive negative coupling through a capacitive coupling structure, eliminate low-frequency resonance poles, and avoid excessive out-of-band suppression amplitude.

The invention relates to a high-strength composite polyurethane foam board which is formed by stacking a lower foam layer, a middle foam layer and an upper foam layer, the overall mechanical strength is enhanced through an upper reinforcing net and a lower reinforcing net, and through carbon nanotubes evenly distributed in the foam layers, the mechanical property and toughness of the material are improved; an efficient charge transfer channel is also constructed to support a unique self-repairing function, and a polyurethane chain segment connected by reversible chemical bonds is contained in the foam board, so that the foam board can be broken and reformed to realize self-repairing when being damaged; the catalytic activity functional group modified on the surface of the carbon nano tube further accelerates the dynamic chemical bond recombination process between polyurethane chain segments, so that the self-repairing speed and efficiency are remarkably improved, when the foam board is damaged, an electric signal conducted by the carbon nano tube triggers the self-repairing process, and the self-repairing effect is improved. And a signal is quickly and accurately transmitted to a control system through the quick connector, so that the foam board can automatically restore to the original shape after being slightly damaged.

The invention provides a flexible circuit board and a manufacturing method thereof, the flexible circuit board comprises an insulating substrate, and two opposite end faces of the insulating substrate are respectively provided with a groove. The signal line is arranged in the insulating substrate, and the insulating substrate surrounds the signal line. The two layers of flexible circuit substrates are respectively arranged on two opposite surfaces of the insulating substrate, and each flexible circuit substrate comprises a conductive layer and a power supply layer. The conductive layer extends from one surface of the insulating substrate to the end face and extends into the groove along the end face. The power supply layer is located between the conductive layer and the insulating substrate and is electrically connected with the conductive layer. Wherein one conducting layer is connected with the other conducting layer in the groove, and the two conducting layers are electrically connected with each other. Therefore, the electromagnetic shielding effect of the flexible circuit board can be improved.

The invention discloses a flexible electronic wire harness preparation process, relates to the technical field of flexible electronic wire harness structures, and aims to solve the problem that an existing flexible electronic wire harness cannot be designed and prepared according to own needs due to the fact that the flexible electronic wire harness is prepared by splicing different finished product materials. According to the technical scheme, the method is characterized by comprising the steps of designing, raw material purchasing, wire harness preparation, blanking, crimping and testing, the flexible wire harness can be well prepared, the wire harness can be well prepared and formed through the steps of wire harness preparation and the like, and the quality of the flexible wire harness is better; through the extruding device, the stranding machine and other devices, the preparation effect of the wire harness can be improved, the wire harness has better performance, and meanwhile the performance of the prepared flexible wire harness is detected. And the effect of preparing the electronic wire harnesses with different requirements according to different requirements is achieved.

The utility model belongs to the technical field of shielding cabinets, particularly relates to a portable shielding cabinet made of lightweight composite materials, and aims to solve the problems that a main body structure of an existing device is integrally made of metal materials, and although the metal materials have excellent electromagnetic shielding performance, the self weight of the metal materials is large, so that in a scene needing frequent movement or temporary construction, the electromagnetic shielding performance of the metal materials is poor. In order to solve the problems that a traditional shielding cabinet is extremely inconvenient to carry and consumes a large amount of manpower and material resources, the utility model provides the following scheme that the portable shielding cabinet made of the lightweight composite material comprises a frame main body which adopts a frame type structure; the utility model has the beneficial effects that the frame main body is formed by splicing high-strength aluminum alloy sections, the density is low, the weight is light, the frame type structure is matched, the frame is stable, the portability is obviously improved, the carrying is easy and labor-saving, the corner connecting pieces are made of high-strength engineering plastics, the weight is reduced, electromagnetic conduction is prevented, and the shielding performance is optimized.