3347results about How to "Excellent dielectric properties" patented technology

A variety of techniques may be employed, separately or in combination, to improve the gap-filling performance of a dielectric material formed by chemical vapor deposition (CVD). In one approach, a first dielectric layer is deposited using sub-atmospheric chemical vapor deposition (SACVD), followed by a second dielectric layer deposited by high density plasma chemical vapor deposition (HDP-CVD) or plasma-enhanced chemical vapor deposition (PECVD). In another approach, a SACVD dielectric layer is deposited in the presence of reactive ionic species flowed from a remote plasma chamber into the processing chamber, which performs etching during the deposition process. In still another approach, high aspect trenches may be filled utilizing SACVD in combination with oxide layers deposited at high temperatures.

To provide a grain oriented ceramic capable of exerting excellent piezoelectric properties, a production method thereof, and a piezoelectric material, a dielectric material, a thermoelectric conversion element and an ion conducting element each using the grain oriented ceramic, there is provided a grain oriented ceramic comprising, as the main phase, an isotropic perovskite-type compound which is represented by formula (1): {Li_x(K_1−yNa_y)_1−x}(Nb_1−z−wTa_zSb_w)O₃ in which x, y, z and w are in respective composition ranges of 0≦x≦0.2, 0≦y≦1, 0≦z≦0.4, 0≦w≦0.2 and x+z+w>0. The main phase comprises a polycrystalline body containing from 0.0001 to 0.15 mol of any one or more additional element selected from metal elements, semimetal elements, transition metal elements, noble metal elements and alkaline earth metal elements belonging to Groups 2 to 15 of the Periodic Table, per mol of the compound represented by formula (1). A specific crystal plane of each crystal grain constituting said polycrystalline body is oriented.

In electronic devices, heat removal is an important consideration of any device designer. Thermally conductive, high-temperature polyimide composites are disclosed herein which are generally useful as a dielectric layer in an electronic device, or a precursor metal-laminate, where the dielectric is layered on one side (or on both sides) with a metal. The polyimide composites of the present invention contain dispersed therein thermally conductive filler particles at a weight percent between 40 and 85 % weight percent. These film composites have good dielectric strength, good thermal conductivity, and optionally good adhesivity.

The present invention discloses a thermosetting resin composition including: a bi-functional or multi-functional epoxy resin, a SMA uses as a curing agent, an allyl phenol such as diallyl bisphenol A used as a co-curing agent and a toughening agent a low-bromine or high-bromine BPA epoxy resin or tetrabromobispheno A (TBBPA or TBBA) uses as a flame retardant agent, and an appropriate solvent. After the resin composition of the invention is cured, the resin composition has lower dielectric property and better thermal reliability and tenacity. A copper clad laminate made of an enhanced material such as glass fiber has lower dielectric constant (Dk) and loss tangent (Df), high Tg, high thermal decomposition temperature (Td), better tenacity and PCB manufacturability, and thus very suitable to be used as a copper clad laminate and a prepreg for manufacturing PCBs or applied as a molding resin material for contraction, automobile and air navigation.

In accordance with the present invention, deposition of perovskite material, for example barium strontium titanite (BST) film, by a pulsed-dc physical vapor deposition process or by an RF sputtering process is presented. Such a deposition can provide a high deposition rate deposition of a layer of perovskite. Some embodiments of the deposition address the need for high rate deposition of perovskite films, which can be utilized as a dielectric layer in capacitors, other energy storing devices and micro-electronic applications. Embodiments of the process according to the present invention can eliminate the high temperature (>700° C.) anneal step that is conventionally needed to crystallize the BST layer.

The invention relates to an epoxy resin composition as well as a prepreg and a laminated board made of the same. The epoxy resin composition comprises the following components in parts by weight: 1-50 parts of modified polyphenylene oxide resin, 30-80 parts of epoxy resin, 20-60 parts of active ester curing agent, 0-50 parts of filler and 1-20 parts of assistant. The prepreg made of the epoxy resin composition comprises a base material and the epoxy resin composition which is attached to the base material through soaking and drying. The laminated board made of the epoxy resin composition comprises a plurality of laminated prepregs, wherein each prepreg comprises a base material and the epoxy resin composition which is attached to the base material through soaking and drying. The invention has the advantages of high heat resistance, high fire retardancy, low dielectric constant, low dielectric loss, excellent high-frequency dielectric properties and the like, and is suitable to be used as a high frequency circuit substrate material.

The invention discloses a microwave dielectric ceramic and a preparation method thereof. The microwave dielectric ceramic is mainly composed of ZrO2, TiO2 and Nb2O5; the microwave dielectric property of the microwave dielectric ceramic can be improved by selectively adding MgO, CoO, ZnO, NiO and MnO2; the chemical constitution formula of the ceramic is xZrO3-YTiO2-zA(1+W)/3Nb(2-w)/2O3; in formula (I), A is one or more elements of Mg, Co, Zn, Ni and Mn; x, y and z are molar ratios, wherein x is between 0.2 and 0.7, y is between 0.2 and 0.6,, z is between 0.1 and 0.2, and, x plus y plus z is equal to 1; numerical range of w is l between 0 and 0.5. According to the microwave dielectric ceramic and the preparation method thereof, the ceramic has the characteristics that the dielectric constant is high, the loss is low, and the temperature coefficient is close to zero, and is liable to sinter; the preparation method has the characteristics that the price of raw materials is low, and a technology during production is simple.

The invention relates to a computed tomography (CT) scanning heterogeneous model testing system. The system comprises a CT scanning system, a displacement system, an overburden pressure system, a pressure measurement system, a heterogeneous multilayer core clamp holder and a metering system, wherein the heterogeneous multilayer core clamp holder consists of a shell, a rubber cylinder, a core left plug, a core right plug, a left fixing sleeve, a right fixing sleeve, a left fastening sleeve, a right fastening sleeve and a fixed bracket; the core right plug is provided with a plurality of liquid outlets; each liquid outlet is respectively aligned with one layer of core model; and a strip liquid outlet sealing gasket is formed on the core right plug, which correspond to a seam between two adjacent layers of core models, so that liquid flow passing through each layer of core model flows out from the corresponding liquid outlet of each layer of core model, and thus, intraformational heterogeneous water displacing oil layered measurement is realized. By the CT scanning system, the real-time on-line monitoring of the on-way distribution of saturation of fluid on each layer section in a heterosphere is realized so as to observe the interlayer communication phenomenon.

The invention relates to a thermosetting resin composition. The thermosetting resin composition comprises (A) polyphenylene ether resin; (B) epoxy resin; (C) a curing agent and (D) an initiating agent. The thermosetting resin composition can also comprise a compound which simultaneously contains an epoxy group and an olefinic bond type unsaturated group, the curing agent, a flame retardant, an accelerant and the like. The thermosetting resin composition has the characteristics of low dielectric constant and dielectric loss, high heat resistance, flame retardance and the like, and is suitable for laminated boards and the like for prepregs and printed circuits.

A sintering aid for a low-temperature cofired medium ceramic material is composed of, by weight, 31%-45% of silicon dioxide, 1%-10% of boron oxide, 5.1%-10% of zinc oxide, 18%-30% of aluminum oxide, 11%-24% of alkaline earth metallic oxide and 5%-15% of oxide with the general formula of R2O3, wherein R refers to at least one of lanthanum, cerium, praseodymium, neodymium, samarium, europium and dysprosium, and the alkaline earth metallic oxide refers to one of magnesium oxide, calcium oxide, barium oxide and strontium oxide. Adding the sintering aid into the low-temperature cofired medium ceramic material enables the prepared low-temperature cofired medium ceramic to have excellent thermal mechanical performance and dielectric performance. In addition, the invention provides the low-temperature cofired medium ceramic material and application thereof and a method for preparing the low-temperature cofired medium ceramic.

The invention discloses a high-flexible polymer matrix composite membrane with high energy density and a preparation method thereof. The composite membrane is composed of a polymer matrix and core-shell structured nano-fibre dispersed in the polymer matrix; the core layer of the core-shell structured nano-fibre is ceramic fibre; the shell layer is an organic matter coated layer, wherein the mass percentage of the polymer matrix is 50-95%; and the mass percentage of the core-shell structured nano-fibre is 5-50%. The polymer matrix and the core-shell structured nano-fibre are composited into the membrane by adopting a solution blending and tape casting method or a bidirectional membrane pulling method, so that a flexible polymer matrix composite material having the advantages of being good in dielectric property, high in breakdown field strength and high in energy density is obtained. The dielectric constant of the composite material can be modulated to 10-40 by adjusting the content of nano ceramic fibre; simultaneously, the dielectric loss Tan delta is kept to be less than 5%, the breakdown field strength is more than 210 kV/mm, and the energy density is 2-6 kJ/L; and the composite material is a material which can be used for capacitors and high power static energy storage.

The invention relates to an epoxy resin composition and a high-frequency circuit board manufactured thereby. The epoxy resin composition comprises the following solid components: (A) cyanate compound or prepolymer thereof, wherein the molecule of the cyanate compound contains at least two cyanato groups; (B) active ester; and (C) epoxy resin containing a naphthol structure; calculated in solid component in parts by weight, the total amount of the component (A), i.e. the cyanate compound containing at least two cyanato groups in the molecule thereof or the prepolymer thereof, and the component (B), i.e. active ester, is 10-70 parts by weight, and the amount of the component (C), i.e. epoxy resin containing naphthol structure, is 30-90 parts by weight, wherein the weight ratio of the component (A), i.e. the cyanate compound containing at least two cyanato groups in the molecule thereof or the prepolymer thereof, to the component (B), i.e. active ester, is (0.2-5):1. The high-frequency circuit board manufactured by using the epoxy resin composition of the invention comprises a plurality of layers of prepregs which are overlapped mutually, and copper foils which are compressed on the two sides respectively; and each of the plurality of layers of prepregs comprises a base material and the epoxy resin composition which is adhered to the base material through impregnation and drying.

The invention discloses a thermoset resin composition, comprising the following ingredients of: bifunctional groups or polyfunctional group epoxy resin, phenylethylene-maleic anhydride copolymer (SMA) as a curing agent, diallyl bisphenol A-like allylphenol as a co-curing agent and a toughening agent, low-bromine or high-bromine BPA-type epoxy resin or tetrabromobisphenol A (TBBPA or TBBA) as a fire retardant, a proper accelerator and a solvent. The inventive resin composition has, after being cured, relatively low dielectric property and superior thermal reliability and toughness, includes, in contrast to a cooper clad laminate manufactured by reinforcing materials such as glass fiber cloth, relatively low dielectric constant (called Dk for short) and electric loss tangent (called Df for short), high Tg, high thermal cracking temperature (called Td for short), excellent toughness and favorable PCB processibility, is quite suitable for manufacturing the cooper clad laminate for PCB and prepreg, and can also applied to general uses of the epoxy resin, such as molding plastics and the like, and to composite materials for construction, automobile and aviation.

The invention provides a phosphorus-containing flame retardant composition, including: a hypophosphite compound, a DOPO derivative and a polyphosphazene compound. The composition as a flame retardant can play a synergistic effect of several phosphorus-containing compounds, realizes halogen-free flame retardance under small addition amount and reaches level V-0. The invention also provides a contains a polyphenyl ether resin composition containing the above phosphorus-containing flame retardant compositions and a prepreg and a copper clad laminated board prepared from the same. After curing, the polyphenyl ether resin composition achieves flame retardance of V-0 grade under the condition to which the halogen flame retardant does not apply and keeps good dielectric property and heat resistance of polyphenyl ether resin; the prepreg and copper clad laminated board made from the composition have good dielectric property and heat resistance, and realize halogen-free flame retardance to UL 94-V0 grade while ensuring excellent heat resistance and dielectric property; and the composition is applicable to the field of high speed and high frequency printed circuit board, and is in line with the future requirements of green and environmental protection.

The invention relates to a radome with the enhanced ultra-high molecular weight polyethylene (UHMWPE), the preparation method and the application thereof. The radome can be made of a composite material with the enhanced UHMWPE fabric and also be made of the glued joint of a surface material and a sandwich material through a cementing compound with the solidification temperature being below 130 DEG C, wherein the surface material is the composite material with the enhanced UHMWPE, and the sandwich material is the material with low density and low dielectric property. The radome not only good has mechanical property and high wave transmissivity, but also is weather resist, therefore, the radome can provide protection for a radar antenna in terrible conditions and prolong the service life thereof.