7results about How to "Relief Concentration" patented technology

The present application relates to a kind of lightweight biomimetic discontinuous fiber spiral composite protective structure, belong to lightweight protective structure design technical field.The lightweight high-strength high-toughness biomimetic discontinuous fiber spiral composite protective structure of the present application is stacked by unit intermittent fiber fabric according to different arrangement angles and arrangement ways, under the condition of local stress concentration in relaxation layer, shear stress is distributed to the intermittent connecting part in each layer, the concentration of interlaminar shear stress is relieved, using the interlaminar shear stress distribution mechanism of the composite material makes crack frequently deflect when it bears load, can delay material failure and destruction, greatly improve the bearing and energy absorption capacity of the composite protective structure.

The invention discloses a terminal structure of a semiconductor power device. The terminal structure comprises a plurality of field limiting rings. Each field limiting ring is of an annular structure formed by connecting a plurality of field limiting ring linear sections and a plurality of field limiting ring corner sections end to end, and each field limiting ring corner section comprises a field limiting ring outer side corner edge and a field limiting ring inner side corner edge. The curvature radius of the field limiting ring outer side corner edge and the curvature radius of the field limiting ring inner side corner edge are independently arranged. The curvature radius of the outer corner edge of the field limiting ring is larger than or equal to a first set value, and the larger the curvature radius of the outer corner edge of the field limiting ring is, the more relieved the electric field concentration at the edge of the field limiting ring is and the smaller the electric field intensity is. The curvature radius of the inner side corner edge of the field limiting ring is smaller than or equal to a second set value, the smaller the curvature radius of the inner side corner edge of the field limiting ring is, the larger the area surrounded by the inner side edge of the field limiting ring is, and the larger the area of the active area is. The invention further discloses a manufacturing method of the terminal structure of the semiconductor power device. The reverse voltage endurance capability of the device can be improved, and the area and the current density of the active region can be improved.

The invention belongs to the technical field of polymer plastic materials. The invention relates to an insulating plastic material, in particular to an insulating plastic material. The product prepared by the invention comprises the following raw materials in parts by weight: 100-110 parts of polypropylene, 20-25 parts of polystyrene and 6-8 parts of micro-carbonized wood fiber. The preparation method of the micro-carbonized wood fiber comprises the following steps: cleaning bagasse, drying, crushing, and sieving with a 80-120-mesh sieve to obtain crushed bagasse; the preparation method comprises the following steps: ultrasonically dispersing crushed bagasse in water, adding ethyl orthosilicate which is 8-10% of the mass of the crushed bagasse, carrying out hydrolysis reaction, filtering, washing and drying to obtain a precursor; and slowly heating the precursor to 300-320 DEG C at the rate of 0.1-0.2 DEG C / min in an inert atmosphere, carrying out heat preservation micro-carbonization treatment for 6-24 hours, and discharging to obtain the micro-carbonized wood fiber.

The invention relates to a light bionic discontinuous fiber spiral composite protection structure, and belongs to the technical field of light protection structure design. The light, high-strength and high-toughness bionic discontinuous fiber spiral composite protection structure is formed by stacking unit discontinuous fiber fabrics according to different arrangement angles and arrangement modes, under the condition that local stress concentration in layers is relieved, shear stress is distributed to discontinuous connecting parts in all the layers, the concentration of interlayer shear stress is relieved, and the stability of the protection structure is improved. By means of an in-layer tensile stress and interlayer shear stress distribution mechanism of the composite material, cracks frequently deflect when the composite material bears loads, failure and damage of the material can be delayed, and the bearing capacity and the energy absorption capacity of the composite protection structure are greatly improved.

The application provides an enhanced HEMT power tube device and a preparation method thereof, wherein a four-layer composite structure of a GaN protection-charge regulation layer, an AlN first etching stop layer, a P-type GaN main body layer and a P-type AlGaN top layer barrier layer is sequentially arranged from bottom to top, the P-type AlGaN top layer barrier layer is used to increase the Schottky barrier height, inhibit the positive forward current of the gate and improve the gate voltage resistance; the P-type GaN main body layer is used to realize the enhanced characteristics of the device by depleting the two-dimensional electron gas below, and the threshold voltage is controlled; the Al-F strong bond energy characteristics are used in the AlN first etching stop layer to realize etching self-stop, and the etching damage to the AlGaN barrier layer is reduced by the joint action of the GaN protection-charge regulation layer; the GaN protection-charge regulation layer is used to reduce the interface state density, reduce the dynamic on-resistance and reduce the occurrence of current collapse, and meanwhile, the gate edge electric field distribution is smoothed, and the breakdown voltage is improved. In addition, a first passivation layer, a source field plate, a second passivation layer and a floating field plate can be further formed, and the GaN protection-charge regulation layer is used to jointly act to relieve the electric field concentration, improve the voltage resistance and reliability of the gate.

The invention discloses a semiconductor device terminal structure and a preparation method thereof, the semiconductor device terminal structure comprises a wide bandgap N-type doped substrate, an N-type doped drift region, a P-type doped buried layer and an N-type doped current diffusion layer, a main junction region is formed at one end, close to an anode, of the terminal structure, a cutting channel is formed at one end, far away from the anode, of the terminal structure, and a terminal region is formed in the middle of the terminal structure; the upper portion of the terminal area is etched into a groove terminal comprising a main groove and an auxiliary groove, the main groove spans the P-type doped main junction area and goes deep into the N-type doped current diffusion layer, the auxiliary groove is etched in the bottom face of the main groove, and the auxiliary groove comprises a middle groove and a side groove. The middle groove penetrates through the P-type doped buried layer, the bottom of the middle groove is located in the N-type doped drift region, the side grooves are located in the direction from the main junction region to the terminal region, the distance between the side grooves in the direction from the cutting channel region to the terminal region is gradually reduced, and / or the size is gradually increased; the P-type doped buried layer with gradually reduced equivalent doping concentration can be reduced, and the problem of electric field concentration near a main junction region and a cutting channel can be relieved.

The invention relates to a preparation method of a carbon fiber reinforced aluminum / glass bead composite metal material. According to the method, nickel-plated carbon fibers are added into aluminum / glass bead powder turbid liquid in a stirring state, and then hot pressed sintering is performed in a graphite mold, so that nickel and aluminum on the surfaces of the nickel-plated carbon fibers tend to form a continuous and uniform Al3Ni thin-film-shaped interface layer at an interface, generation of an Al4C3 brittle phase is hindered, and the performance of the nickel-plated carbon fibers is improved. And the transition of the load from the matrix to the carbon fiber is realized. The proportion of the nickel-plated carbon fibers, the aluminum powder and the glass beads can be properly adjusted according to different purposes, and the material obtained after hot pressing sintering is uniform in component distribution and excellent in performance.