58 results about "Polyimide dielectric" patented technology

The terahertz metasurface device comprises a top metal structure layer, a middle flexible polyimide dielectric layer and a bottom metal plate layer which are sequentially arranged from top to bottom, and the top metal structure layer, the middle flexible polyimide dielectric layer and the bottom metal plate layer form a Fabry-Perot resonant cavity. The amplitude and the phase can be regulated and controlled at the same time only by rotating the top layer metal structure of the sub-wavelength unit structure, the problems of large size, low precision and the like of an Airy beam generation device are effectively solved, and therefore flexible regulation and control of broadband (0.95-1.8 THz) one-dimensional and two-dimensional Airy beams in the terahertz wave band are achieved. And the possibility is developed for the application in high-capacity and obstacle-avoiding wireless communication.

The invention discloses a preparation method and application of a high-thermal-conductivity polyimide-based paint film for a transformer winding, and relates to a preparation method and application of a polyimide-based paint film. The invention aims to solve the problem of poor heat-conducting property of the existing polyimide dielectric material. The method comprises the following steps: 1, preparing boron nitride nanosheet powder; 2, modifying the surface of the boron nitride nanosheet powder; 3, adding diamine and the boron nitride nanosheet subjected to surface modification into an aprotic polar solvent; 4, adding dianhydride; and 5, carrying out gradient heating to carry out imidization. The heat conductivity coefficient of the high-heat-conductivity polyimide-based paint film for the transformer winding reaches 0.35 W / (m.K) and is improved by 183% compared with that of a pure polyimide material, and meanwhile the high-heat-conductivity polyimide-based paint film has high insulation performance and is used for preparing high-heat-conductivity and high-insulation electrical insulation devices; the electrical insulation device comprises but is not limited to a high-power density motor, a transformer enameled wire and a high-frequency power transformer.

The invention discloses a multi-element random copolymerization polyimide dielectric film as well as a preparation method and application thereof, and belongs to the technical field of dielectric materials. The thin film material is prepared from at least one diamine monomer and at least two dianhydride monomers through a random copolymerization reaction. The specific method comprises the following steps: randomly copolymerizing one or more diamine monomers and two or more anhydride monomers through a conventional two-step method to synthesize a pure polymer, casting and coating the copolymerized polyamide acid synthesized by the reaction into a film shape, carrying out thermal imidization, demolding with deionized water, and drying to obtain the material. The film is suitable for high-temperature dielectric energy storage in high-temperature film capacitors, vehicle-mounted power electronics, aerospace power supplies and oil well / geothermal power systems. Compared with the existing filler modified or monomer homopolymerized PI, the preparation process is simple, the dielectric property is stable, the energy storage density and the breakdown strength at the high temperature of 200 DEG C and the high field are remarkably improved, and excellent stability and manufacturability are achieved.

The invention provides a preparation method and application of a polyimide dielectric film, and the method comprises the following steps: polymerizing a diamine monomer and an excessive dianhydride monomer in a polar solvent in a nitrogen atmosphere to obtain a polyamide acid solution; adding an end-capping reagent containing a phthalonitrile group and an amino group into the polyamide acid solution, and reacting to obtain a phthalonitrile group-terminated polyamide acid solution; adding a ring-closing agent into the phthalonitrile group-terminated polyamide acid solution to generate a phthalonitrile group-terminated polyimide solution, and settling, washing and drying the phthalonitrile group-terminated polyimide solution to obtain phthalonitrile group-terminated polyimide powder; polyimide powder is dissolved in a polar solvent, a wet film is prepared on a substrate in a coating mode, the wet film is heated, and the polyimide dielectric film is obtained.

The invention relates to the field of dielectric energy storage materials, and discloses a polyimide-based composite dielectric film material and a preparation method thereof.The dielectric film is prepared from, by mass, 4-20 parts of modified barium strontium titanate and 100 parts of fluorinated polyamide acid solution, the modified barium strontium titanate is prepared from the following raw materials: hydroxylated barium strontium titanate, 3-glycidyl ether oxypropyl trimethoxy silane, perfluoropolyether alcohol and a catalyst, and the fluorinated polyamide acid solution is prepared from the following raw materials: a fluorine-containing diamine monomer and a fluorine-containing dianhydride monomer; according to the technical scheme, the polyimide film dielectric film is prepared from fluorinated polyamide and modified silane barium strontium titanate, the dispersity of barium strontium titanate in a polyimide matrix is remarkably improved, the compatibility of barium strontium titanate and fluorinated polyimide is remarkably improved, and the dielectric energy storage performance of the dielectric film is remarkably improved; the hydroxylated barium strontium titanate is modified through the 3-glycidyl ether oxypropyl trimethoxy silane and the perfluoropolyether alcohol, so that the dielectric loss of the dielectric film is remarkably reduced.

The invention relates to the technical field of dielectric materials, in particular to a heterocycle-containing semi-aromatic polyimide dielectric film as well as a preparation method and application thereof. The heterocycle-containing semi-aromatic polyimide dielectric film provided by the invention is obtained by carrying out polymerization and imidization reaction on diamine containing a benzimidazole structure or a benzoxazole structure and alicyclic dianhydride. The polyimide dielectric film not only has a high dielectric constant, but also can significantly inhibit high-temperature conductivity loss, and is efficiently and stably used in an extreme environment (T = 150-300 DEG C).

The invention relates to a chip three-dimensional security packaging structure and packaging method, the chip three-dimensional security packaging structure comprises a cipher chip, a back layer, a middle layer and a rewiring layer, the middle layer is provided with an inverted trapezoidal groove, the cipher chip is arranged in the groove, and a TSV is arranged on the middle layer close to the groove; copper lines are embedded in the back layer, are uniformly arranged in an S shape and are electrically connected with the TSVs; the rewiring layer comprises a polyimide dielectric layer and a copper wire, the lower end face of the polyimide dielectric layer is filled in the groove and covers the groove and the password chip, the copper wire is arranged in the polyimide dielectric layer, one end of the copper wire is electrically connected with the TSV and the password chip, the other side end of the copper wire penetrates out of the polyimide dielectric layer to be connected with a solder ball, and a packaging method is set. The whole chip is wrapped by the metal wiring net formed by the copper lines in the back layer, the copper conductors in the middle layer and the copper wires in the re-wiring layer, three-dimensional safety protection of the chip is achieved, and the problem that the packaging difficulty is large is solved in combination with a packaging method.

The present invention relates to the technical field of dielectric material preparation, and discloses a crosslinked polyimide-based dielectric film material. A diamine monomer with a carboxyl group is introduced into the polyimide-based material for co-condensation, and then through imidization and decarboxylation crosslinking, the crosslinked polyimide-based electrolyte film material is obtained. The preparation method of the crosslinked polyimide-based dielectric film provided by the present invention does not add additional process technologies on the basis of synthesizing commercial polyimide-based dielectrics, and the surface and cross-section of the prepared dielectric film are flat, smooth and have no obvious defects.

The invention discloses an artificial metasurface for terahertz light wave regulation and control and a design method of the artificial metasurface. The metasurface is an array formed by a plurality of monomer structures, and each monomer structure comprises a reflection substrate layer; a polyimide dielectric layer; and patterning the top layer. The device is characterized in that the patterned top layer is composed of an outer-layer circular ring composed of metal and a conductivity-adjustable active material and an inner-layer circular ring composed of a conductivity-adjustable active material; and the reflection regulation and control of the terahertz wave can be completed by controlling the stepping rotation angle of the two circular rings and the conductivity change of the active material. According to the invention, the design is simple, and the modulation capability of terahertz wave reflection vortex beams is greatly improved.

The invention relates to the field of terahertz metamaterial devices, and provides a reconfigurable broadband / multi-frequency terahertz wave absorber based on vanadium dioxide. The wave absorber is composed of metamaterial square units which are arranged periodically, and adjacent units are gapless. Each unit is composed of six layers of structures including a vanadium dioxide resonance layer, an upper polyimide dielectric layer, a vanadium dioxide thin film layer, a copper resonance layer, a lower polyimide dielectric layer and a copper substrate layer. Vanadium dioxide can realize reversible phase change between a metal state and an insulation state through external excitation. In a metal state, the wave absorber has an ultra-wideband terahertz wave absorption function; and in an insulated state, a double-narrow-band absorption function is shown. According to the invention, the reconstruction of the absorption frequency and the bandwidth of the terahertz wave absorber is effectively realized, the problems of complex structure and fixed function of a traditional terahertz sensor are solved, and the potential of the terahertz wave absorber in sensing application of a single narrow-band wave absorber is further discussed.

The application relates to the technical field of energy storage materials, and particularly discloses a dielectric composition, a polyimide dielectric film, a preparation method and application. The dielectric composition provided by the application is a naphthylamine block polyamide acid, a naphthalene anhydride block polyamide acid, a polyamide acid and a transition metal phthalocyanine-based covalent organic framework material. The polyimide dielectric film prepared from the dielectric composition can still maintain a high energy density under a high-temperature environment, and the energy storage density under a 150 DEG C condition can reach 2.70 J / mm 2 The breakdown field strength can reach 350 kV / mm or more, and the Young's modulus can reach 2.2 GPa or more, so that the balance between the high-temperature energy storage performance and the mechanical performance is achieved, and the polyimide dielectric film can be widely applied to the fields of high-temperature energy storage devices, aerospace power systems, high-temperature industrial sensors and the like, and has a wide application prospect.

The invention discloses a polyimide dielectric film containing carboxyl betaine and a preparation method thereof. The carboxyl betaine-containing polyimide dielectric film is prepared from carboxyl betaine-containing polyimide, and the carboxyl betaine-containing polyimide is prepared by the following steps: firstly, taking a precursor of carboxyl betaine, m-phenylenediamine and bisphenol a type diether dianhydride as monomers, and carrying out condensation polymerization to obtain polyamide acid; carrying out complete imidization on the polyamide acid under the action of a catalyst isoquinoline to obtain polyimide containing a precursor; and reacting the polyimide containing the precursor with sodium bromoacetate to obtain polyimide containing carboxyl betaine. The zwitterions are introduced into the polyimide structure to improve the dielectric and energy storage performance of the polyimide dielectric film, and meanwhile, the preparation method has the advantages of being low in cost, simple in process, controllable and adjustable in performance, suitable for large-scale application and the like.

In an embodiment of the present disclosure, a Quad-CAP high-voltage isolation capacitor and a digital isolator are provided, which include two interconnected isolation capacitor units. Each isolation capacitor unit includes a lower electrode plate, an upper electrode plate, and an SiO2 dielectric layer and a Polyimide dielectric layer sequentially arranged between the lower electrode plate and the upper electrode plate. The thickness of the SiO2 dielectric layer is 9-11 um, and the thickness of the Polyimide dielectric layer is 18-22 um. The isolation capacitor of the present disclosure can effectively increase the isolation breakdown voltage value of the digital isolator chip, thereby improving the reliability of the isolator chip and meeting the requirements of some high-voltage applications at the same time.

The invention discloses an adjustable ultra-wideband terahertz metamaterial wave absorber, and belongs to the technical field of terahertz wave absorbers. The wave absorber is composed of a plurality of same metamaterial structure units which are periodically arranged, and each metamaterial structure unit is made of three layers of composite materials, wherein the first layer is a graphene pattern layer, the second layer is a polyimide dielectric layer, and the third layer is a copper reflecting layer. Wherein the graphene pattern layer adopts a combined design of four groups of square and L-shaped structures, and the four groups of structures form a biaxial symmetry layout through geometric coupling. The structure has the characteristics of wide absorption bandwidth, high absorption rate and dynamic adjustability, can realize more than 90% of efficient absorption in the frequency band of 2.28-4.68 THz, and can adjust the Fermi level of the graphene by externally applying bias voltage to realize rapid switching between the absorption state and the reflection state. The device is suitable for various application scenes such as terahertz communication, sensing and stealth.

The invention discloses a multi-mode circular dichroism chiral metasurface design based on an adjustable material. The metasurface structure is composed of a thermal phase change material VO2 and an electric phase change material Dirac on the upper layer, a polyimide dielectric layer in the middle and a gold substrate. The provided circular dichroism chiral metasurface can achieve regulation and control of the transmissivity and the reflectivity within the frequency band of 0.6-0.8 THz, and then the reflection circular dichroism is effectively controlled. The maximum value of the reflection circular dichroism of the metasurface can reach 0.69, the minimum value of the reflection circular dichroism of the metasurface can be close to 0, and regulation and control functions under four working modes are achieved. By changing the conductivity of the thermal phase change material VO2 and the electrical phase change material Dirac, dynamic regulation and control of four circular dichroism states are realized.

The invention discloses a block copolymerized polyimide film and application thereof in a capacitor, and belongs to the technical field of dielectric polymer materials and film capacitors. A molecular chain in the copolymer is formed by alternately connecting flexible soft chain segments and rigid hard chain segments, and the soft chain segments and the hard chain segments are incompatible in thermodynamics and can be driven in the polymer to form a nano-scale microphase separation structure. A fluorine-containing electron withdrawing group and a sulfone-containing large dipole moment group are introduced into a hard chain segment, so that a nano microphase separation interface is formed in the polymer and can be used as a deep energy level trap, and the electron forbidden band width of the material is synergistically widened. The design inhibits carrier generation and migration under high temperature and high electric field, and improves the breakdown field strength and dielectric constant of the material. The block copolymer film has high static energy storage density, excellent charge and discharge efficiency and cycling stability exceeding 100,000 times, and is suitable for high-temperature-resistant and high-energy-density film capacitors and electrical insulating materials.

The invention discloses a terahertz detector antenna integration method, which adopts photosensitive polyimide as a dielectric layer, integrates an antenna and a field effect transistor to different planes to form an antenna-photosensitive polyimide-field effect transistor terahertz detector structure, and connects the antenna and the field effect transistor through a feeder line. The antenna transmits the received terahertz signal to the field effect transistor through the feeder line, and then the terahertz signal is read out through the drain end of the field effect transistor. Photosensitive polyimide is used as the dielectric layer between the terahertz detector antenna and the field effect transistor, so that the antenna and the transistor are located in different planes, electromagnetic interference and noise coupling are reduced, the spatial layout and the integration degree are optimized, and the reliability of the terahertz detector is improved. And meanwhile, the dielectric loss is reduced by adjusting the thickness of the photosensitive polyimide dielectric, and the radiation efficiency and gain of the antenna are improved, so that the overall performance of the terahertz detector is improved.

The application discloses a kind of polyimide dielectric film and its preparation method and application, belong to material field.The material will PDA be dissolved in solvent after adding cesium fluoride, then stirring 20~35min in oxygen-free environment, finally under the condition of stirring, reaction is carried out for 18~20h at 75~85 ℃, reaction mixture is filtered, finally obtained FPDA;After FPDA is dissolved in solvent, then under the condition of-5~5 ℃, diphenyl ether dianhydride is added in batches and stirred for 8~10h, to obtain polyamide acid PAA solution, solution is dropped on glass substrate and is treated by thermal imidization reaction, after reaction, glass substrate is placed in deionized water and film is stripped, and film with thickness of 1~20 μm is obtained.The product prepared by the application has lower leakage current loss, higher glass transition temperature and charge-discharge efficiency, and has overall excellent energy storage characteristics.

The present invention proposes a polyimide dielectric film and its preparation method and application, the preparation method of the polyimide dielectric film comprising: subjecting carboxylated multi-walled carbon nanotubes and 2,4-diaminophenol to a condensation reaction to obtain multi-walled carbon nanotubes bonded with aminobenzoxazole; then subjecting the multi-walled carbon nanotubes bonded with aminobenzoxazole to a polycondensation reaction with an aromatic diamine monomer and an aromatic dianhydride monomer, and then subjecting the film to a thermal imidization reaction to obtain the polyimide dielectric film. The present invention proposes a polyimide dielectric film and its preparation method and application, by introducing multi-walled carbon nanotubes bonded with aminobenzoxazole into polyimide synthesis, so that the resulting polyimide dielectric film has excellent mechanical properties while obtaining a high dielectric constant and low dielectric loss.

The invention relates to the technical field of dielectric materials, in particular to a blended polyimide dielectric film and a preparation method and application thereof. The blended polyimide dielectric film provided by the invention comprises benzimidazole semi-aromatic polyimide and polyetherimide, wherein the mass ratio of the benzimidazole semi-aromatic polyimide to the polyetherimide is 1: (0.25-4). The blended polyimide dielectric film has excellent high-temperature energy storage performance and can be applied at 200 DEG C.

The invention relates to a terahertz transmission array metasurface antenna based on continuous phase modulation, which is formed by arranging N * N metasurface units, and each unit structure comprises a top arc metal corner structure, a middle polyimide dielectric layer and a bottom arc metal strip, the transmission amplitude gt of the 2THz-frequency linearly polarized electromagnetic waves is realized by adjusting the distance between the top-layer metal strips, the length of the bottom-layer metal strips and the corresponding central angle of the arc-shaped structure; and the continuous phase modulation of 0.8 is realized. The unit structure parameters are determined through collaborative design of a neural network and a genetic algorithm, when N is equal to 25 and the focal diameter ratio is 1, the antenna can efficiently convert spherical waves emitted by a feed source at the focal point into plane waves, the far-field gain of the antenna reaches 29.6 dBi, and the aperture efficiency is 52%. The invention has the characteristics of simple structure, easiness in manufacturing and high transmission efficiency, and can be widely applied to the fields of terahertz communication, imaging and the like.

The invention relates to the field of dielectric films, in particular to a polyimide dielectric film and a preparation method and application thereof. The preparation method of the polyimide dielectric film comprises the following steps: mixing 1, 3-m-phenylenediamine, a tC diamine monomer, an anhydride monomer and an organic solvent in an inert atmosphere to obtain a mixed solution; carrying out condensation polymerization on the mixed solution in an inert atmosphere to obtain a precursor solution; and coating a substrate with the precursor solution for imidization to obtain the polyimide dielectric film. Semi-aromatic PI constructed by common MPD is used as a matrix, tC type diamine monomers with high rigidity and configuration disturbance characteristics are copolymerized and introduced into a main chain in a controllable proportion, cooperative regulation and control of chain segment thermal motion and an aggregation state structure are achieved, and therefore better high-temperature energy storage stability and breakdown reliability are obtained.

The present application relates to the technical field of polymer materials, and particularly relates to a polyimide precursor resin, a polyimide material and a preparation method and application of a photosensitive resin. The polyimide precursor resin is obtained by polycondensation of a diamine monomer and an aromatic tetracarboxylic dianhydride. By designing basic diamine monomers with different side group positions and flexible bridging groups, the free volume and degree of freedom of the polymer chain are increased, and the polymerization reaction with anhydride is more likely to occur. Compared with the polyimide material containing a nitrogen-containing heterocyclic ring in the main chain, the nitrogen-containing heterocyclic ring in the side chain is more conducive to increasing the interaction between molecules to improve the thermal stability of the material. Meanwhile, the larger side group can increase the free volume of the molecular chain and reduce the dielectric constant, which is conducive to reducing the transmission loss of the polyimide dielectric material. The prepared polyimide precursor resin can accelerate the reaction process of imidization in the process of heat curing, so that the imidization rate of the polyimide precursor resin is significantly improved at 200 DEG C.

This application relates to the field of dielectric material preparation technology, and more particularly to a semi-aromatic polyimide dielectric film and its preparation method. The preparation method of the semi-aromatic polyimide dielectric film includes the following steps: mixing an aliphatic dianhydride monomer, a rigid diamine monomer containing side ethyl groups, and a solvent to perform a copolymerization reaction to obtain a precursor solution; after forming the precursor solution into a film, performing an imidization reaction to obtain the semi-aromatic polyimide dielectric film; wherein the imidization reaction includes a first heat preservation stage, a second heat preservation stage, and a third heat preservation stage. This application improves the crosslinking density by introducing ethyl side chains into the semi-aromatic polyimide structure, and simultaneously controls the short-range ordered structure using a specific imidization process, thereby controlling the structure of the resulting dielectric film at the molecular level and significantly improving the high-temperature energy storage performance of the dielectric film.

This invention relates to a broadband amplitude-coherent terahertz metasurface device, comprising a top metal structure layer, an intermediate flexible polyimide dielectric layer, and a bottom metal plate layer arranged sequentially from top to bottom. The top metal structure layer, the intermediate flexible polyimide dielectric layer, and the bottom metal plate layer form a Fabry-Perot resonator. This invention achieves simultaneous amplitude and phase modulation solely through rotating the top metal structure of the subwavelength unit structure, effectively solving the problems of large size and low precision of Airy beamforming devices. This enables flexible modulation of broadband (0.95-1.8 THz) one-dimensional and two-dimensional Airy beams in the terahertz band, opening up possibilities for its application in high-capacity, obstacle-avoiding wireless communication.

The present invention relates to the field of electromagnetic metasurfaces, and specifically to a switchable terahertz dual-function device based on a vanadium dioxide metasurface, wherein the switchable metasurface is composed of a diagonally placed vanadium dioxide pattern layer, a polysilicon dielectric layer, a gold pattern layer composed of a gold split ring resonator and an L-shaped gold bar, a vanadium dioxide film layer, a polyimide dielectric layer, and a gold reflective layer arranged in sequence from the top layer to the bottom layer, and when the vanadium dioxide is in a metallic state, the switchable metasurface realizes a broadband absorption function; when the vanadium dioxide is in an insulating state, the switchable metasurface realizes a reflective linear polarization conversion function. The present invention utilizes the phase change characteristics of vanadium dioxide materials to integrate the characteristics of these two dual-function devices, a broadband absorber and a reflective linear polarization converter, into a metasurface structure, thereby solving the problem of single function in traditional metasurface structures and making their application more flexible and extensive.

The invention relates to the technical field of polymer dielectric preparation, in particular to a high-temperature-resistant polyimide dielectric film and a preparation method and application thereof. The conjugated structure of the high-temperature-resistant polyimide dielectric film provided by the invention mainly adopts out-of-plane orientation or in-plane orientation. The polyimide dielectric film still has excellent electrical insulation performance and energy storage performance under the condition of high temperature.

The invention belongs to the technical field of photoelectric detectors, and discloses a spectrum-width-adjustable near-infrared avalanche photoelectric detector and a preparation method thereof, and the spectrum-width-adjustable near-infrared avalanche photoelectric detector sequentially comprises a silicon-on-insulator substrate, an intrinsic silicon layer, a p-type silicon charge region and a germanium-silicon alloy layer from bottom to top; the upper surface of the silicon-on-insulator substrate, the intrinsic silicon layer table-board structure and the germanium-silicon alloy layer table-board structure are coated by an oxidation dielectric layer; a polyimide dielectric layer is spin-coated on the outer surface of the oxidation dielectric layer; a first metal electrode is arranged in the center of the top of the germanium-silicon alloy layer, penetrates through the polyimide dielectric layer and is in contact with the upper surface of the germanium-silicon alloy layer; a second metal electrode is arranged on the back face of the silicon-on-insulator substrate and located on the periphery of the oxidation dielectric layer. According to the invention, visible light-near-infrared wide spectrum detection and near-infrared band special detection can be respectively realized under the conditions of forward light incidence and backward light incidence, and a band multiplexing detection function is realized.

The invention relates to the technical field of energy storage materials, and particularly discloses a dielectric composition, a polyimide dielectric film, a preparation method and application. The dielectric composition provided by the invention comprises naphthylamine block polyamic acid, anhydride naphthalene block polyamic acid, polyamic acid and a transition metal phthalocyanine covalent organic framework material. The polyimide dielectric film prepared from the dielectric composition can still keep high energy density in a high-temperature environment, the energy storage density can reach 2.70 J / mm < 2 > or above under the condition of 150 DEG C, the breakdown field strength can reach 350 kV / mm or above, meanwhile, the polyimide dielectric film has good mechanical performance, the Young modulus can reach 2.2 GPa or above, balance of the high-temperature energy storage performance and the mechanical performance is achieved, and the polyimide dielectric film can be widely applied to the field of electronic devices. The material can be widely applied to the fields of high-temperature energy storage devices, aerospace power systems, high-temperature industrial sensors and the like, and has wide application prospects.

The invention relates to the technical field of multi-band terahertz metamaterial wave absorbing devices, and provides a terahertz multi-band wave absorbing device insensitive to polarization. The wave absorber is composed of a plurality of periodically arranged square units, and each unit is composed of a three-layer structure including a gold pattern layer, a polyimide dielectric layer and a gold substrate layer from top to bottom. The gold pattern layer and the gold substrate layer are attached to the upper surface and the lower surface of the polyimide dielectric layer respectively, and the geometric centers are on the same straight line. The designed wave absorber is insensitive to the polarization direction of incident electromagnetic waves due to the symmetrical structure, and has good polarization stability. The multiband wave absorber provided by the invention has the advantages of simple structure and capability of realizing high absorption at four frequency bands, and shows wide application prospects in the fields of terahertz sensing, filtering, communication and the like.