29results about How to "Improve thermal reliability" patented technology

The invention provides a planar gate silicon carbide VDMOS capable of improving short circuit reliability and a preparation method, and the preparation method comprises the steps: depositing metal on the lower side surface of a silicon carbide substrate, and forming drain electrode metal; performing epitaxial growth on the upper side surface of the silicon carbide substrate to form a drift layer; performing ion implantation on the drift layer to form a current sharing layer; forming a barrier layer on the drift layer, and performing etching and ion implantation to form a P-type well region and a low-resistance region; a barrier layer is formed again, etching and ion implantation are carried out, and an N-type source region and a P-type source region are formed; re-forming a barrier layer, etching the barrier layer to form a through hole, and depositing to form a first gate dielectric layer; depositing to form a second gate dielectric layer; a barrier layer is formed again, the barrier layer is etched to form a through hole, metal is deposited, and a gate metal layer is formed; and re-forming a barrier layer, etching the barrier layer to form a through hole, depositing metal, forming a source metal layer, and removing the barrier layer to complete preparation. And the heat conduction capability and the thermal reliability of the insulating medium are effectively improved.

The invention provides a power tube heat dissipation structure, a power supply device and a processing and assembling method.The heat dissipation structure comprises a PCB, a power tube attached to the PCB and a radiator corresponding to the heat dissipation face of the power tube, and one face, attached to the heat dissipation face of the power tube, of the radiator is provided with one or more cofferdam structures; a heat conduction interface material is arranged in an area defined by the cofferdam structure, and the heat dissipation face of the power tube is attached to the heat conduction interface material. The heat conduction insulating layer and the radiator are integrated, no extra insulating part needs to be installed, the manufacturing process is simplified, and the production efficiency is improved. And through the cofferdam structure arranged on the radiator, the heat conduction material is limited in the cofferdam, so that the problems of horizontal slippage, vertical flow and the like of the heat conduction material under the influence of temperature change and vibration factors are prevented, and the thermal reliability of the power supply device is improved.

The application relates to the technical field of semiconductors, and particularly discloses a POI substrate, a preparation method thereof and an acoustic device. The preparation method of the POI substrate comprises the following steps: providing a substrate; growing an amorphous gallium oxide layer on the substrate; and growing a nanocrystalline gallium oxide layer on the amorphous gallium oxide layer; wherein the nanocrystalline gallium oxide layer is c-axis oriented perpendicular to a section; the nanocrystalline gallium oxide layer is subjected to activation treatment to obtain a first intermediate product; a piezoelectric substrate is subjected to ion implantation to form a peeling defect layer at a preset position of the piezoelectric substrate, thereby obtaining a second intermediate product A; the first intermediate product is bonded with the second intermediate product A to obtain a third intermediate product A; the third intermediate product A is treated by using a pulse laser to convert the nanocrystalline gallium oxide layer into an epsilon-phase gallium oxide layer; and the piezoelectric substrate is split and partially peeled along the peeling defect layer to form a piezoelectric layer. By implementing the application, the heat conduction performance and reliability of the POI substrate can be improved.

The present invention discloses a novel heat dissipation system and heat dissipation method thereof, including a temperature equalizing plate, the temperature equalizing plate including an upper cover plate, a lower cover plate and a support column, the upper cover plate and the lower cover plate are sealed and joined to form a chamber, the support column is located in the chamber to support the upper cover plate; a liquid storage tube, the liquid storage tube is filled with a cooling medium, the liquid storage tube is located on one side of the temperature equalizing plate; a liquid spraying tube, the liquid spraying tube is located in the chamber, the liquid spraying tube is connected to the liquid storage tube through a micro pump, and the liquid spraying tube sprays the cooling medium into the chamber; an energy supply group, the energy supply group includes a P-type semiconductor and an N-type semiconductor, the P-type semiconductor, the N-type semiconductor and the temperature equalizing plate are connected by a temperature sensing line to form a series circuit, and the micro pump is located on the series circuit. The present invention uses a micro pump to drive the cooling medium to perform high-speed jet cooling near the lower cover plate, which greatly increases the heat dissipation cooling capacity.

The utility model discloses a control box device for fresh air handling unit belongs to fresh air system control equipment technical field. The device includes the box body of installing in the one -way air duct of fresh air handling unit, and the opening direction of box body is perpendicular with the wind direction and has the outer open box door of hinged, and the door opening direction of box is the adverse wind direction, and the door closing assembly contains the vertical pressure -bearing plate, and one end is fixed to the outside of box door, and the other end is inclined to the direction of away from the box body and forms the pressure -bearing surface. The component of force that the airflow acts on the inclined pressure -bearing surface generates is converted into the door closing moment, realizes the automatic locking of box door. The problem that the control box in the air duct leads to the sealing failure of air flow impact, the operation difficult problem is solved, and the box door is locked by wind energy, and the sealing reliability is improved significantly, and the stability of equipment under the vibration, high pressure difference working condition is enhanced.

The invention provides a magnetic suspension rotating machine which comprises a rotating shaft and an axial magnetic suspension bearing, the bearing comprises an outer cylinder, two axial stator assemblies and a thrust disc are assembled in the outer cylinder, the first axial stator assembly comprises a first stator iron core, the second axial stator assembly comprises a second stator iron core, the thrust disc is located between magnetic poles of the two stator iron cores, and the thrust disc is located between magnetic poles of the two stator iron cores. The magnetic poles of the first stator core comprise a first outer magnetic pole and a first inner magnetic pole, the magnetic poles of the second stator core comprise a second outer magnetic pole and a second inner magnetic pole, outer overcurrent grooves are formed in the magnetic pole end faces of the first outer magnetic pole and the second outer magnetic pole, and inner overcurrent grooves are formed in the magnetic pole end faces of the first inner magnetic pole and the second inner magnetic pole. Cooling airflow can enter the bearing through the inner overflowing groove and the outer overflowing groove in one side in sequence and flow out through the outer overflowing groove and the inner overflowing groove in the other side in sequence. A corresponding cooling structure does not need to be independently configured for cooling the bearing, and the internal structure of the bearing can be effectively cooled.

This invention relates to the field of electronic packaging composite materials technology, and particularly to a thermally conductive epoxy encapsulation material, its preparation method, and its application. The invention uses Fe3O4 nanospheres and sodium polyacrylate solution as raw materials to prepare polyacrylic acid-modified Fe3O4 nanospheres; these are then blended with adipic acid and epoxy resin, and a thermally conductive epoxy encapsulation material is prepared through a curing reaction. The thermally conductive epoxy encapsulation material prepared by the method of this invention exhibits uniform dispersion of Fe3O4 nanospheres, good interfacial compatibility, and high thermal conductivity, demonstrating excellent thermal conductivity, interfacial reliability, and mechanical properties, making it well-suited for electronic chip packaging applications.

A data center cooling system control method and device based on a constraint neural network, the method comprising: acquiring thermodynamic parameters of a data center cooling system in real time, and constructing an original database; preprocessing data in the original database to obtain a power consumption dataset and a chip temperature dataset; training a power consumption prediction neural network using the power consumption dataset and a penalty function; training a chip temperature prediction neural network using the chip temperature dataset and the penalty function; the penalty function for temperature prediction adopts an adaptive penalty function, and a penalty factor is introduced when the model predicted temperature is lower than the actual temperature, so that the model predicted temperature is always higher than the actual temperature; and taking the minimum power consumption of the system as an optimization objective, and taking the actual temperature of the chip being less than the upper limit of the chip temperature as a constraint condition, the optimal control parameters under different environmental temperature and humidity and heat load are optimized. The optimization control result can be maintained within the critical temperature of the chip, and the energy saving of the data center is maximized.

The invention relates to the technical field of servers, and discloses a fan testing method, device and equipment and a storage medium. The method comprises the steps that the lowest testing rotating speed and the highest testing rotating speed of a fan are obtained; according to a preset rotating speed change logic, controlling the rotating speed of the fan to cyclically change for a target duration between the lowest test rotating speed and the highest test rotating speed, and collecting actual operation data of the fan; theoretical operation data, matched with the rotating speed change logic, of the fan are obtained; and according to the difference between the actual operation data and the theoretical operation data, a test result of the fan is determined, and the test result is used for representing whether the fan has potential faults or not. The heat dissipation performance of the server can be improved.

The invention relates to a heat dissipation system based on a hydraulic mechanical transmission of a heavy-duty vehicle, belongs to the technical field of heat dissipation systems of heavy-duty vehicles, solves the technical problem of low heat dissipation efficiency of the heavy-duty vehicles, and comprises a whole vehicle radiator, a torque converter radiator, an electronic fan, a water tank, a water pump, a thermostat, an oil cooler, a one-way valve, a bypass valve and a controller. The controller is used for controlling the thermostat, the bypass valve and the electronic fan to work. The electronic fan is installed on the whole vehicle radiator and the torque converter radiator and used for accelerated heat dissipation of the whole vehicle radiator and the torque converter radiator. The working process of the heat dissipation system comprises water way heat dissipation, torque converter oil way heat dissipation and rear retarder oil way heat dissipation. The heat dissipation system is used for heat dissipation of a hydraulic mechanical transmission, an engine and a rear retarder of a heavy-duty vehicle.

The invention relates to a semiconductor structure, a preparation method thereof and electronic equipment. The semiconductor structure includes: an oxide semiconductor layer; the source / drain electrode is arranged around the oxide semiconductor layer; and the induction layer is positioned between the source / drain electrode and the oxide semiconductor layer and is used for inducing the oxide semiconductor layer to be converted into a crystalline structure from an amorphous structure. The thermal stability and reliability of the oxide transistor can be effectively improved.

The invention relates to the technical field of integrated motors, in particular to an integrated motor based on a new energy automobile and an assembling method thereof.The integrated motor comprises a controller, a steel structure supporting frame and a motor, the lower end of the controller is fixedly connected with the steel structure supporting frame, and one side of the steel structure supporting frame is fixedly connected with the motor; a noise reduction optimization assembly is fixedly connected to the outer side of the motor and comprises a motor frame assembly, the motor frame assembly comprises a housing, a threaded arm is fixedly connected to one side of the housing, an arm lower support is fixedly connected to the lower end of the threaded arm, a supporting square plate is fixedly connected to the lower end of the arm lower support, and a groove between square plates is formed in the inner side of the supporting square plate. According to the noise reduction device, high-frequency noise generated during operation of the motor can be effectively absorbed and isolated, noise attenuation is achieved by improving a transmission path, and the acoustic comfort level in a cockpit is remarkably improved.

The invention discloses a rapid heat dissipation double-layer battery pack and a control method thereof.The rapid heat dissipation double-layer battery pack comprises a double-layer protective shell, a plurality of battery cells are evenly distributed on orientation rotating assemblies, and synchronous driving gear assemblies used for driving the orientation rotating assemblies to rotate synchronously are arranged among the orientation rotating assemblies; the plurality of battery cells on the orientation rotating assembly and the plurality of battery cells on the adjacent orientation rotating assembly are arranged in a staggered and meshed manner in the rotating process, so that compact layout is realized; the inner wall of the protective shell is provided with an air-cooling heat dissipation assembly for blowing and heating the plurality of battery cells positioned on the outer side; the problems that heat dissipation of inner and outer side battery cores of an existing double-layer battery pack is unbalanced, compact layout contradicts with heat dissipation efficiency, heat dissipation response lags behind in a high-temperature scene, and transmission and heat dissipation channels are prone to being interrupted after layering separation are solved, self-adaptive balanced heat dissipation is achieved, the working stability and safety of the battery pack are improved, and the service life of the battery pack is prolonged.

The utility model provides a structure for optimizing ohmic contact on the back surface of a GaN device through a sin insertion layer, which belongs to the technical field of GaN devices, and comprises a GaN substrate and a sin layer arranged on the back surface of the GaN substrate, the sin layer is provided with a concave-convex structure, and the concave-convex structure is provided with a concave-convex groove. The GaN substrate is provided with a concave-convex structure, the concave-convex structure is specifically protrusions formed on the surface of the sin layer, the GaN substrate is further provided with a metal contact layer, the metal contact layer makes contact with the concave-convex structure, the metal contact layer is provided with structures matched with the protrusions on the surface of the sin layer, and the sin layer and the metal contact layer are physically interlocked through the concave-convex structure. According to the utility model, the peeling phenomenon of the contact layer under the condition of high temperature or high pressure is solved, and the long-term reliability of the device is improved.

The application provides a vehicle-mounted air conditioner temperature control system and a vehicle. The vehicle-mounted air conditioner temperature control system comprises a vehicle-mounted air conditioner system, wherein the vehicle-mounted air conditioner system comprises an air outlet pipeline; and a gravity heat pipe assembly, wherein one end of the gravity heat pipe assembly is arranged in the air outlet pipeline, and the other end of the gravity heat pipe assembly is arranged on a vehicle-mounted controller for an entertainment host; and wherein when the vehicle-mounted air conditioner system is working, the gas generated by the vehicle-mounted air conditioner system exchanges heat with the gravity heat pipe assembly at the air outlet pipeline. The vehicle-mounted air conditioner temperature control system adopts gravity capillary action for passive heat dissipation, and the heat in the vehicle-mounted controller for the entertainment host is exchanged by the gravity heat pipe assembly, so that the heat is transferred to the heat dissipation part in the air conditioner channel, and the cold air in the air conditioner channel carries away the heat of the heat dissipation part, thereby achieving heat dissipation of the controller.

The utility model provides a water-cooling and air-cooling composite mechanism which comprises an installation plate, a water-cooling heat exchanger, an LED lamp panel and an LED lamp power source, the water-cooling heat exchanger is fixedly connected to one side of the installation plate, and clamping seats are connected between the tops and the bottoms of the two sides of the front face of the installation plate in a clamped mode. Compared with the prior art, the LED lamp has the following beneficial effects that the water-cooling heat exchanger is started to circularly pump the condensing medium in the heat exchange calandria for circulating cooling, heat energy on the LED lamp panel can be continuously absorbed through the heat exchange calandria, and the water-cooling heat exchanger is used for continuously cooling after the heat energy is absorbed and taken away through the condensing medium; and meanwhile, a plurality of rows of heat dissipation fans are started, cold air blown out by the heat dissipation fans is evenly blown to the LED lamp panel and the pipe face of the heat exchange calandria, the condensation phenomenon caused by excessive water cooling is prevented, electrical faults caused by condensation are avoided, and the heat dissipation reliability is effectively improved.

This invention discloses a silicon-based RC chip co-packaging structure for power devices and its fabrication method. The co-packaging structure includes, from bottom to top, a heat dissipation substrate, a common substrate, a power chip, a silicon-based RC buffer chip, an interconnect structure, power terminals, and auxiliary terminals. The fabrication method includes the following process flows: S100 substrate fabrication, S200 chip mounting, S300 interconnect assembly, and S400 substrate and terminal assembly. This invention achieves high compatibility with existing power module packaging processes, eliminating the need for additional dedicated equipment or significant production line modifications. While reducing manufacturing costs, improving production yield, and shortening production cycles, it ensures consistent performance in mass production through standardized processes. Overall, this invention optimizes parasitic parameters, achieves compact structure, integrates thermal management, and stabilizes performance in power modules, making it suitable for various high-voltage, high-frequency, and high-power-density power electronics applications.

The utility model discloses an electric control heat dissipation system, an air conditioning unit and a vehicle, the electric control heat dissipation system comprises a condensation electric control cavity used for placing a condenser and an electric control box, the opening side of the condensation electric control cavity faces the windward end of the air conditioning unit and is used for introducing external fresh air, and a heat dissipation inlet of the electric control box faces the opening side and is used for feeding air; a heat dissipation outlet of the electric control box is used for discharging air into the condensation electric control cavity, the condenser is provided with a condensation fan, and the condensation fan is used for discharging air from the condensation electric control cavity, so that the condensation electric control cavity, the electric control box and the condenser form an air flow channel for discharging air from the condensation fan. According to the electric control heat dissipation system arranged in the mode, outside fresh air can be fully utilized, the heat dissipation effect of the electric control box is improved on the basis that indoor side return air is not affected, the situation that operation is stopped due to the fact that the temperature of an electric control element is too high is avoided, and heat dissipation reliability is improved.

The invention relates to a single-sided copper-clad ceramic plate, a packaging method thereof and a power module packaging structure, the single-sided copper-clad ceramic plate comprises an insulating heat-conducting ceramic substrate, a copper layer circuit board and a first plastic package body, and the insulating heat-conducting ceramic substrate and the copper layer circuit board are sintered into a whole through a low-temperature sintering material; and the first plastic package body wraps the side surfaces of the insulating heat-conducting ceramic substrate and the copper layer circuit board. According to the single-sided copper-clad ceramic plate, high-temperature welding is replaced by low-temperature sintering, so that overall deformation and warping caused by inconsistent thermal expansion are reduced, the process difficulty is greatly reduced, material bonding interfaces are few, defects such as welding cavities and welding layering generated by two times of high temperature are greatly reduced, meanwhile, the process number and used processing materials are also greatly reduced, and the production cost is reduced. And the processing technology is simpler, the manufacturing cost is lower, the method is more suitable for large-scale production, and the overall advantages are obvious. The low-temperature sintered material can rapidly conduct heat and dissipate heat, has better toughness, plays a buffering role, and reduces the risk of breakage and layering of the middle bonding layer.

The utility model discloses a kind of Mini LED display module and display, it is related to Mini LED display module technical field.The Mini LED display module includes glass backplane, Mini LED lamp bead and panel assembly, the panel assembly is laminated in the surface of the glass backplane, the surface of the glass backplane close to the panel assembly is equipped with mounting groove and circuit slot, the Mini LED lamp bead is installed in the mounting groove, the circuit slot is equipped with conductive circuit, and the conductive circuit is used to power supply to the Mini LED lamp bead.Through glass backplane replaces traditional metal or PCB material, reduce module thickness and weight, simultaneously utilize the thermal expansion coefficient similar to glass and Mini LED chip to reduce thermal stress, with the advantages of light and thin structure, high thermal reliability and simple assembly process.

A method of manufacturing a glass lens disclosed in an embodiment of the present invention includes: providing a mixture by mixing glass particles, a polymer filled between the glass particles, and an additive; injection molding the mixture through a mold assembly having a lens shape; debinding the polymer from a lens-molded piece injection-molded into the lens shape; sintering the glass particles of the debound polymer-molded piece; and machining the sintered molded piece to be provided as a glass lens, wherein at least one of an object-side surface and an image-side surface of the glass lens can have an inflection point.

This invention discloses a multi-powered combined unmanned aerial vehicle (UAV) intelligent cooling system, specifically comprising a core control unit, a power unit, an execution layer unit, a perception layer unit, and a decision-making layer unit. The physical components of each unit are integrated into a frame to form a flight module. The core control unit coordinates the operating conditions of the power unit and the cooling actions of the execution layer unit via a data bus. Temperature sensors in the perception layer unit collect real-time temperature data from the engine block, radiator, and main cooling channel. The decision-making layer unit dynamically generates drive signals based on the temperature data and the engine ECU's requirements. The system innovatively uses hollow tubing within the frame to form the main coolant channel, combining a liquid-cooled engine with an air-cooled radiator to form a composite cooling circuit. Intelligent flow regulation is achieved through solenoid valves and a circulating water pump, providing three modes: basic coordination, differential temperature control, and fuel preheating. This invention upgrades the UAV cooling system from passive heat dissipation to active thermal management, improving the operational efficiency and reliability of multi-powered UAVs.

The embodiment of the utility model provides a light source module and a lighting device, a plurality of ceramic substrates of the light source module are tiled and connected to a copper substrate at intervals, the plurality of ceramic substrates are electrically connected through gold wires, the surface, deviating from the copper substrate, of each ceramic substrate is connected with one or more LED light-emitting chips, and the LED light-emitting chips are electrically connected with the copper substrate. The transparent cover is connected to the copper substrate and covers the LED light-emitting chips, heat of the LED light-emitting chips can be transmitted to the copper substrate through the ceramic substrate, the heat conductivity of the copper substrate is high, the heat generated by the LED light-emitting chips can be rapidly dissipated to surrounding air or other structures, the working temperature is effectively reduced, and the service life of the LED light-emitting chips is prolonged. According to the light source module, the multiple ceramic substrates can jointly disperse the thermal expansion influence of the copper substrate, the situation that due to the fact that a single and large-size ceramic substrate is adopted, serious buckling deformation and even tension cracking happen is avoided, the warping degree of the light source module is effectively reduced, and the potential damage risk caused by thermal stress concentration is further reduced.

The application discloses a kind of jet flow cold plate, machine case and electronic equipment, applied to heat dissipation field, jet flow cold plate includes: cold plate body is equipped with the cavity for placing fin component, inlet and outlet for cooling medium flow are equipped on cavity;Jet flow plate is installed in cavity, and cavity is divided into first cavity and second cavity, fin component is located inside second cavity, jet flow plate is equipped with several jet flow holes, to supply cooling medium jet flow from first cavity to second cavity;And, the included angle between the axial extension direction of jet flow hole and the surface of the bottom plate of fin component is acute angle.The jet flow cold plate provided in the application can effectively flush away the deposits between adjacent fins by forming a certain included angle between the jet flow hole and the bottom plate of the fin component, ensuring the smooth flow of the cooling medium and improving the heat dissipation reliability of the jet flow cold plate.

The invention provides a low-power-consumption infrared detector system and a working method, and solves the technical problems that an existing infrared detector is large in size and high in power consumption, and long-time stable communication of a laser communication system is restricted. The PCB circuit board comprises a first PCB circuit board and a second PCB circuit board. The top of the first PCB is provided with an infrared detector chip, the bottom of the first PCB is connected with the top of the second PCB through an internal connector, the bottom of the second PCB is provided with an external high-speed connector, and the external high-speed connector is used for transmitting infrared image data to the main control processor. The method can be widely applied to the technical field of laser communication.

The utility model belongs to the technical field of electronic device heat management, disclose a kind of power management integrated circuit device with radiating fin structure, including base, chip main body and lower heat-conducting sheet, chip main body and lower heat-conducting sheet are connected in the top of base, the scheme is through optimizing heat dissipation structure, using the combination of integrally formed lower heat-conducting sheet, radiating fin and upper heat-conducting sheet, the thermal resistance between each component is effectively reduced, the efficiency that heat spreads and releases from chip main body outward is improved, make structure simplify and facilitate installation;Through using heat-conducting film, docking block and serpentine cooling channel etc. Design, further improve heat transfer efficiency and heat dissipation capacity;Through the connection with external cooling liquid circulating system, can actively assist heat dissipation, enhance the thermal stability and reliability under high-power operation, ensure that chip can work stably under high heat flux density condition, with significant heat dissipation performance and structural advantages.

The invention discloses a thin film capacitor based on polypropylene modification, a preparation method thereof and a new energy vehicle, and electrical performance and mechanical performance of the capacitor are improved by doping high dielectric constant and wide bandgap nanoparticles in a polypropylene matrix. And a sandwich structure design is adopted, and the high dielectric constant layer and the polypropylene film are compounded through a hot pressing process, so that the overall performance of the capacitor is enhanced. The plasma surface modification technology improves the surface energy of the polypropylene film, enhances the binding force with the aluminum metal layer, and improves the insulation characteristic and moisture resistance of the film. The mechanical property and the electrical property of the polypropylene film are optimized by the two-way stretching process, and the thickness uniformity and the dielectric property of the film are ensured. Through the improvements, the optimized thin film capacitor has higher stability and longer service life when being applied to the new energy vehicle, the thermal runaway risk is reduced, the energy storage efficiency is improved, meanwhile, the size and weight of the capacitor are reduced, and improvement of the overall performance of the new energy vehicle is facilitated.

The utility model relates to the field of big horsepower tractor, more particularly to a kind of tractor expansion space arrangement structure and tractor, it includes: main use expansion water tank and standby expansion water tank, respectively set in the different height of tractor and main use expansion water tank higher than standby expansion water tank;Overflow pipe, overflow port is set in the top of main use expansion water tank, one end of overflow pipe is connected with main use expansion water tank, and the other end is communicated with standby expansion water tank;Wherein, water inlet is set on main use expansion water tank, water inlet is connected with engine water tank by water pipe, for receiving the cooling liquid overflow when engine water tank expansion.It can effectively solve the contradiction between the expansion space demand of big horsepower tractor and the limited space of whole machine, improve the heat dissipation reliability of engine, optimize space layout, reserve more space for other components arrangement of tractor, improve the overall performance and reliability of tractor.

The invention discloses a groove type SiC MOSFET device based on a symmetrical split gate structure and a preparation method, in the groove type SiC MOSFET device designed by the invention, an inverted T type P + shielding layer is designed to realize direct contact between the P + shielding layer and a source electrode, and meanwhile, split gate structures which are symmetrical up and down and left and right are designed, so that the overlapping area of a grid electrode and a drain electrode is reduced, the coupling effect between the grid electrode and the drain electrode is reduced, and the reliability of the device is improved. And device switching loss is reduced. In addition, a multi-stage step type current expansion layer is introduced into the groove type SiC MOSFET device, so that the conduction path of electrons is expanded, the electron concentration is increased, and the thermal performance and reliability of the device are improved.