424results about How to "High breakdown strength" patented technology

Devices and systems comprising high current/high voltage GaN semiconductor devices are disclosed. A GaN die, comprising a lateral GaN transistor, is sandwiched between an overlying header and an underlying composite thermal dielectric layer. Fabrication comprises providing a conventional GaN device structure fabricated on a low cost silicon substrate (GaN-on-Si die), mechanically and electrically attaching source, drain and gate contact pads of the GaN-on-Si die to corresponding contact areas of conductive tracks of the header, then entirely removing the silicon substrate. The exposed substrate-surface of the epi-layer stack is coated with the composite dielectric thermal layer. Preferably, the header comprises a ceramic dielectric support layer having a CTE matched to the GaN epi-layer stack. The thermal dielectric layer comprises a high dielectric strength thermoplastic polymer and a dielectric filler having a high thermal conductivity. This structure offers improved electrical breakdown resistance and effective thermal dissipation compared to conventional GaN-on-Si device structures.

The production of low-loss, tunable composite ceramic materials with improved breakdown strengths is disclosed. The composite materials comprise ferroelectric perovskites such as barium strontium titanate or other ferroelectric perovskites combined with other phases such as low-loss silicate materials and/or other low-loss oxides. The composite materials are produced in sheet or tape form by methods such as tape casting. The composite tapes exhibit favorable tunability, low loss and tailorable dielectric properties, and can be used in various microwave devices.

A plurality of transistor cells (T) are arranged in the semiconductor layer (4). Ring-shaped p-type layers (1b) and n-type layers (1a) composed of polysilicon film are formed alternately on an insulating layer (6) in an outer side than the plurality of transistor cells (T) (the peripheral portion of chip), thereby forming a protective diode (1). The most outer layer of the protective diode (1) is contacted to the gate wiring (2) composed of metal film such as Al, which is formed circularly on the most external layer, and the most inner layer is contacted to the source wiring composed of metal layer, thereby the protective diode is connected between the gate and source of a transistor. As a result of this, the semiconductor device with the protective diode which has the small series resistance, can be formed without enlarging chip area and by using unoccupied space of chip, and realize protection function sufficiently, can be obtained.

The invention discloses a polymer dielectric medium with low dielectric constant and low loss and a preparation method of the polymer dielectric medium. The polymer dielectric medium comprises the following raw materials: 50-60% of epoxy resin system, and 40-50% of mixed boron nitride nanoparticles, wherein the mixed boron nitride nanoparticle is a mixture of a boron nitride nanotube and a boron nitride nanotube; the epoxy resin system is formed by 100phr of epoxy resin E-51, 85phr of methyl hexahydrophthalic anhydride and 1phr of benzyl dimethylamine in a mixing manner. The thermal breakdown voltage of the polymer dielectric medium is significantly improved by the polymer dielectric material with high heat conductivity and high electric breakdown, the service life is prolonged, the dielectric constant and loss and the heat expansion coefficient are reduced, the mechanical strength and the tenacity are improved, the highest heat conductivity can be up to 5.26W/mK, the volume resistivity is about 1014ohm.cm, the thermal breakdown voltage is about 2-3kV/mm higher than that of the similar heat-conducting polymer dielectric medium, and the dielectric constant and the loss are a little lower than those of pure resin.

The invention provides a high-voltage direct-current cable material and a preparation method thereof. The high-voltage direct-current cable material comprises the following components in parts by mass: 90-100 parts of low-density polyethylene, 0.5-3.5 parts of modified nanometer magnesia, 0.1-0.5 part of molten paraffin, 0.001-0.08 part of an antioxidant and 0.001-2.5 parts of a benzyl compound. The preparation method comprises the following steps: preparing the modified nanometer magnesia by using a drum ball-milling method, premixing the raw materials, and finally pelleting, thereby obtaining the high-voltage direct-current cable material. The high-voltage direct-current cable material provided by the scheme of the invention is excellent in space charge accumulation inhibition property under the condition of 40kV/mm and high in breakdown field strength, and the requirement of high-voltage direct-current cable power transmission of 100kV can be met.

The invention discloses a high-energy-storage sodium bismuth titanate-strontium titanate matrix material. The chemical formula of the high-energy-storage sodium bismuth titanate-strontium titanate matrix material is 0.5Bi0.5Na0.5TiO3-0.5SrTiO3-x wt%MgO, wherein x=0.5-3.0. A preparation method of the high-energy-storage sodium bismuth titanate-strontium titanate matrix material comprises the following steps of preparing SrCO3, TiO2, Bi2O3, Na2CO3 and MgO by weight ratio according to the chemical formula into a ceramic powder, performing ball milling, drying and pelletizing, and then pressing the ceramic powder in a tablet press into a ceramic blank; rubber-discharging and sintering the ceramic blank inside a muffle furnace to obtain a ceramic sample. The preparation method of the high-energy-storage sodium bismuth titanate-strontium titanate matrix material is simple in preparation process, low in cost and free from pollution; the prepared high-energy-storage sodium bismuth titanate-strontium titanate matrix material achieves a high discharging energy storage density of 1.61-2.17 J/cm3 and a high breakdown strength of 137-226 KV/cm.

Disclosed are photocurable polymers that can be used as active and/or passive organic materials in various electronic, optical, and optoelectronic devices. In some embodiments, the device can include a dielectric layer prepared from such photocurable polymers. In some embodiments, the device can include a passivation layer prepared from the polymers described herein.

The invention is concerned with the manufacture method of the ditch groove power semiconductor device. It is: provides the materials of the basal; forms the first electric transmit epitaxy layer on the basal; forms the second electric transmit zone and the ditch groove inside the epitaxy layer; forms the ebb first electric transmit area and the medium layer with the ditch groove; and then, forms the electric transmit area within the medium layer; forms the first electric transmit source area on the surface of the second electric transmit area; forms the second electric transmit contact area with higher doping PH indicator on the second electric transmit zone surface; forms the passivation layer cap on the top of the ditch groove which must with the medium layer and the electric transmit area; forms the diffusion protecting layer on the surface of the source area and the contact area; finally, forms the structure surface with good electric connection. The invention can control the threshold voltage of the device and improves the breakdown strength of the oxide layer of the device bottom area, and improves its electric connection reliability with no extra cover film printing plate and complex method request.

The invention discloses a preparation method of a polypropylene capacitance film. The preparation method comprises the following steps of: (1) preparing a polypropylene material composite from the following components in parts by weight: 100 parts of polypropylene resin, 0.05-0.15 part of a photoinitiator, 3-5 parts of a cross-linking agent and 0.25-0.35 part of a hindered phenol antioxidant; (2) melting, plasticizing and extruding the polypropylene material composite by an extruder; (3) cooling a extruded melt body and casting into a sheet; (4) stretching the cast sheet in two directions into a film by using a bidirectional stretching equipment; (5) performing ultraviolet (UV) irradiation crosslinking on the stretched thin film; and (6) post-treating the irradiated thin film and reeling the thin film in a reeling machine to obtain a finished product. According to the preparation method of the UV crosslinked BOPP (biaxially-oriented polypropylene) capacitance film, the heat resistance and the breakdown strength of the polypropylene capacitance film are remarkably enhanced, the polypropylene capacitance film can meet the development demands of a strong-current capacitor market on advanced insulating thin film materials, and a new path is opened for high performance of the polypropylene capacitance film. Meanwhile the method is simple and easy to realize and has an extremely high industrial application value.

The invention relates to a cellulose/layered boron nitride high-dielectric nano-composite film and preparation method of the cellulose/layered boron nitride high-dielectric nano-composite film. The cellulose/layered boron nitride high-dielectric nano-composite film has an obvious layered structure and comprises cellulose and boron nitride nanosheet layers uniformly dispersed in the cellulose. Thepreparation comprises the following steps: 1) preparing a boron nitride peeling layer dispersion liquid; 2) preparing a cellulose/boron nitride composite liquid: cooling the boron nitride peeling layer dispersion liquid obtained in the step 1) to below 0 DEG C, adding the cellulose according to the mass ratio of the boron nitride and the cellulose of (5: 95) to (15: 85), rapidly stirring and dissolving, performing centrifugation to remove impurities, thereby obtaining the cellulose/boron nitride composite liquid; 3) carrying out film formation on the prepared cellulose/boron nitride compositeliquid prepared in the step 2) in a coagulation bath to obtain the cellulose/layered boron nitride high-dielectric nano-composite film. The composite material provided by the invention has the layeredstructure and very high dielectric properties and high thermal conductivity (the breakdown voltage reaches 300 to 450 MVm<-1>, and the energy storage density is as high as 4 Jcm<-3> about, the thermal conductivity is about 2Wm<-1>K<-1>), and the cellulose/layered boron nitride high-dielectric nano-composite film has broad application prospects in the field of photovoltaic energy storage materials.

In a protection NMOS transistor serving as an ESD input/output protection element formed on a semiconductor support substrate, a drain region of the N-type protection transistor is formed so as to surround the source region, and a minimum distance between the source and the drain is kept constant, which makes it possible to ensure a sufficient ESD breakdown strength and to realize a structure capable of protecting input/output terminal, particularly an output terminal, of the fully depleted SOI CMOS device vulnerable to ESD noise.

The invention relates to a rare-earth electrode slurry of rare-earth circuit, based on the metal base board and a relative production, wherein it is characterized in that: said slurry is formed by solid material and organic solvent carrier, while their mass ratio is 70-90:30-10; the solid component comprises: silver, palladium, and yttrium composite power and micro-crystal glass powder, while their mass percentage is 99.4-94:0.6-6; said composite power is formed by silver, palladium, and yttrium powders at the ratio as 0.6-10:99-82:0.4-8; said micro-crystal glass is the one in SiO2-Al2O3-CaO-B2O3-Bi2O3-La2O3 group. And the production comprises: (1), preparing rare-earth micro-crystal glass powder; (2), preparing silver, palladium, and yttrium composite powder; (3), preparing organic solvent carrier; (4), mixing material in three-dimension and rolling with three rollers; (5), preparing the rare-earth slurry; (6), bottling. The invention is environment friendly and better humidity compatibility.

Provided is a structure in which a gate electrode of an MMOS transistor of a fully depleted SOT CMOS circuit formed on a semiconductor thin film has an N-type conductivity, while a gate electrode of an protection NMOS transistor as an ESD input/output protection element formed on a semiconductor support substrate has a P-type conductivity, making it possible to protect input/output terminals, especially, an output terminal of a fully depleted SOI CMOS device, which is weak against ESD noise, while ensuring a sufficient ESD breakdown strength.

A high voltage assembly including a valve group and a shield connected to the valve group. A resistor is connected between the shield and the valve group The assembly provides an increased breakdown strength and DC withstand level.

The invention discloses a high-energy density polymer composite dielectric and a preparation method thereof. The composite dielectric comprises, by mass, 55-97.5% of a fluorine-containing ferroelectric polymer matrix and 45-2.5% of a dopamine modified high-dielectric constant nanofiller. The preparation method comprises solution blending, film casting and hot press molding. High-dielectric constant nanoparticles are grafted and modified with dopamine having a long chain structure, and the dopamine having a long chain structure improves the dispersion of the high-dielectric constant nanoparticles, has good compatibility with the fluorine-containing ferroelectric polymer matrix and enhances the interface combination force between the polymer matrix and the high-dielectric constant nanoparticle filler. The high-energy density polymer composite dielectric prepared in the invention has the characteristics of light weight, good flexibility and high energy density, and is suitable for producing high-energy density capacitors, embedded capacitors, field effect transistors and other advanced electronic and electric devices.

The invention relates to an epoxy resin fullerene composite material and a preparation method thereof. The materials of the epoxy resin fullerene composite material include fullerene, epoxy resin and a curing agent. The epoxy resin fullerene composite material has the advantages of remarkably increasing the volume resistivity and breakdown voltage of a polymer matrix, inhibiting the injection of space charges, decreasing dielectric constant and loss, and improving the electrical aging property of the epoxy resin, and moreover, the mechanical strength and toughness of the epoxy resin are also increased to a certain degree.

The invention belongs to the technical field of thermally conductive and insulating materials, and particularly relates to an epoxy resin thermally conductive insulating material and a preparation method thereof. The material includes an epoxy resin basic material, inorganic filler and a curing agent, wherein the inorganic filler is composed of fillers of three different particle sizes. The epoxyresin thermally conductive insulating material has excellent thermal conductivity and insulation performance only through selection of the ratio of three different particle size grading of the inorganic filler, the ratio of the use amount of the filler of different particle sizes and the particle sizes, and no surface-modified inorganic filler is needed, so that the material cost is reduced, and the preparation method of the material is simpler. The thermal conductivity of the material can reach 1.25 W.m<-1>.K<-1> at 30 DEG C, the highest thermal conductivity can reach 1.62 W.m<-1>.K<-1>, theresistivity of the material is 2.9x10<16> omega.cm or above below 30 DEG C, and application requirements of power electronic transformers, saturation resistors and other high insulation scenes can bemet fully.

The invention provides a preparation method for an aluminium oxide ceramic substrate, and a ceramic substrate prepared by the method. The preparation method comprises the following steps that: a first sintering aid and a second sintering aid are added in a ceramic substrate powder; the first sintering aid is the glassy-state powder of XCaO.YMgO.ZSiO2, X is not less than 0.1 and not greater than 0.4, Y is not less than 0.1 and not greater than 0.4, Z is not less than 0.5 and not greater than 0.7, and the sum of X, Y and Z is 1, wherein X: Y: Z is a mass ratio; the second sintering aid is BaO; and the mode of stacking a ceramic substrate blank and a burning-isolating plate interlayer coated with nanometre aluminium oxide powder on the surface together, then placing the ceramic substrate blank and the burning-isolating plate interlayer in a sintering furnace, and sintering is adopted, wherein the prepared aluminium oxide ceramic substrate is high in volume density, good in surface smoothness and high in anti-breakdown strength.

The invention relates to the technical field of energy storage materials, and in particular relates to a method for improving the breakdown strength and energy storage density of a polymer. The methodfor improving the breakdown strength and energy storage density of the polymer comprises the following steps: adding 2-14 parts by weight of hydroxylated hexagonal boron nitride to 100 parts by weight of the polymer. The modified product of BNNSs (hexagonal boron nitride nanosheets) provided by the invention has better dispersion effects in the polymer, so that the agglomeration tendency of the BNNSs in the polymer is greatly weakened, and the method is very beneficial for the improvement of the breakdown strength and energy storage density of a composite capacitor.

A polypropylene for a film capacitor or a polypropylene sheet for a film capacitor which exhibits excellent stretchability when stretched into a film and provides a film having high breakdown voltage and small thermal shrinkage ratio, and which is suitable for a polypropylene film for a film capacitor and a film capacitor comprising the film.

The polypropylene for a film capacitor of the present invention is obtained by irradiating a propylene homopolymer with a radiation with an absorbed dose of 0.1 to 500 kGy, the propylene homopolymer having (1) a melt flow rate (MFR) within a range of 1 to 10 g/10 min as determined at 230° C. under a load of 2.16 kg in accordance with ASTM D1238, (2) an isotactic pentad fraction (mmmm fraction) of not less than 94% as determined using ¹³C-NMR, (3) an ash amount of not more than 30 ppm as obtained by completely burning the propylene homopolymer in air, and (4) a chlorine amount of not more than 10 ppm as determined by ion chromatography.