5results about How to "High breakdown field" patented technology

The invention relates to a silicon carbide gate oxide layer, a preparation method thereof and a semiconductor device. The preparation method of the silicon carbide gate oxide layer comprises the following steps: performing oxidation treatment on a silicon carbide epitaxial wafer in a nitrogen-containing atmosphere, and preparing a gate oxide film on the surface of the silicon carbide epitaxial wafer to form a first structure; performing bias temperature stress treatment on the first structure to prepare a second structure; performing wet etching on the second structure to prepare a third structure; and carrying out annealing treatment on the third structure. According to the preparation method of the silicon carbide gate oxide layer, a gate oxide film with low effective charge density and high breakdown field strength can be obtained. The semiconductor device prepared by using the silicon carbide gate oxide layer can have more stable threshold voltage.

The invention discloses a self-sensing insulating material based on graphene gradient distribution and a preparation method, and belongs to the technical field of functional composite materials. The material is composed of an insulating polymer matrix and graphene dispersed in the insulating polymer matrix, and the core of the material is that the concentration of the graphene is in non-uniform gradient distribution along the thickness direction of the material, so that the material can sense the stress, strain or aging state through the resistance change of the material while maintaining the excellent insulating property. The preparation method comprises the following steps: preparing dispersion liquids with different graphene concentrations; constructing a gradient structure by adopting a layer-by-layer tape casting or gradient centrifugal sedimentation technology; and carrying out curing molding. The material provided by the invention realizes integration of insulation and sensing functions, can realize real-time and in-situ monitoring of the state of electrical equipment without an external sensor, and has the characteristics of high sensitivity, good reliability and long service life.

This invention provides a high dielectric constant pulse energy storage ceramic composition and its preparation method, relating to the field of energy storage ceramic materials technology. The ceramic composition uses Ba(Zr) x Ti 1‑x The main component is a perovskite compound (Bi2O3). In addition, it contains Bi as a first secondary component (a composite of Bi2O3 and Bi2O3·nTiO2), and Ca, Sr, Mg, Mn, and Si as secondary components. The ceramic composition of this invention possesses a high dielectric constant (over 900), low dielectric loss, high breakdown field strength, and fine grain structure, making it suitable for high energy density, miniaturized pulse power capacitors.

The invention belongs to the technical field of capacitor films, and relates to a polypropylene capacitor film and a preparation method and application thereof. The polypropylene capacitor film comprises a layer C, a layer B, a layer A, a layer B and a layer C. The layer A comprises, by mass, 94-98 wt% of polypropylene and 2-6 wt% of an olefin block copolymer; the layer B comprises the following components in percentage by weight: 98.5 to 99.5 percent of polypropylene and 0.5 to 1.5 percent of olefin block copolymer; the layer C is prepared from 87 to 98.7 weight percent of polypropylene, 1 to 10 weight percent of aliphatic-aromatic polycarbonate and 0.3 to 3 weight percent of compatilizer; the content of the olefin block copolymer is gradually reduced from the A layer to the B layer, and the C layer is not added with the olefin block copolymer. The prepared polypropylene capacitor film has excellent high and low temperature breakdown field strength and low thermal shrinkage rate, and meets the use requirements of high-end electric power equipment.

This invention discloses a Ca2Nb2O7 glass-ceramic material with excellent energy storage efficiency and its preparation method. The method includes: Step 1, mixing Na2CO3, K2CO3, BaCO3, SrCO3, CaCO3, Bi2O3, TiO2, Nb2O5 and SiO2 evenly to obtain mixture A; Step 2, adding mixture A into a crucible preheated to 1100-1300℃, then raising the temperature to 1450℃ and holding it at that temperature to completely melt mixture A. The process continues until no more bubbles are generated, resulting in a melt. This melt is then poured into a mold preheated to 200°C, and after molding, product B is obtained. Step 3: Product B is transferred to an annealing furnace preheated to 500–600°C and held at that temperature. After cooling in the furnace, a glass sample is obtained. Step 4: The glass sample is placed in a muffle furnace and heated from room temperature to 800–1000°C at a rate of 5°C / min, and held at that temperature to crystallize the glass sample. After cooling in the furnace, Ca2Nb2O7 glass-ceramic material is obtained. This invention not only has a simple preparation process, but also produces Ca2Nb2O7 glass-ceramic with high breakdown strength and high energy storage efficiency.