152results about How to "Reduce the risk of electric leakage" patented technology

The invention relates to a detection circuit, a liquid crystal display panel and a manufacturing method of the liquid crystal display panel. The detection circuit comprises a control switch unit which is arranged between a test signal input end and liquid crystal display panel signal lines and comprises a first switch transistor and a second switch transistor. In the period of detection, the first switch transistor and the second switch transistor are kept on, and a test signal is enabled to enter the liquid crystal display panel signal lines; after detection, the second switch transistor is kept off, the control end of the first switch transistor is in short-circuit connection with the first end, and accordingly leakage current flowing into the liquid crystal display panel signal lines from the second switch transistor is reduced. By the liquid crystal display panel with the detection circuit, risk of electric leakage between the signal lines in the panel is lowered effectively under the condition that operation is unaffected, and image display quality is ensured.

The invention belongs to the field of welding materials, and particularly relates to a halogen-free, low-residue, high-impedance and cleaning-free flux, which comprises the following components: 2-15wt% of activator, 0.05-2wt% of dispersing agent, 0.5-4wt% of film-forming agent, 0.1-4wt% of additive and 75-97.35wt% of solvent. Compared with the prior art, the flux has the advantages that the expansion ratio of the flux is higher than 80% of the standard, the flux is moderate in weldability and halogen-free, ionic contamination is at the highest I grade, the flux is applicable to high-reliability electronic products, the surface insulation resistance of the flux is at a 1010 grade after a copper mirror corrosion test, and the flux has the advantages that the flux is high in insulation impedance, high in insulation resistance, low in electric leakage risk, low in solid content, environment-friendly, clean and cleaning-free, residue is less, a post-weld board is tack-free and the like.

The invention relates to a solar module and a preparation method thereof. The solar module comprises at least two battery packs in series connection; each battery pack comprises at least two cell trains in parallel connection; each cell train comprises at least two cell cutting blades in series connection, and connecting pieces used for installing adjacent cell cutting blades in series; the cell cutting blades are formed by cutting solar cells along an extending direction perpendicular to main grids. Each cell cutting blade possesses a cut end and an uncut end which are opposite, wherein the uncut end of the cell cutting blade is opposite to the cut end of an adjacent cell cutting blade, and a gap is left therebetween for the penetration of a connecting piece; one end of the connecting piece is in connection with the front surface electrode at the uncut end of the cell cutting blade, and the other end penetrates the gap to be in connection with the back electrode at the cut end of the adjacent cell cutting blade. The solar module reduces short circuit, thereby cuts electric leakage risks, and is in favor of application.

The invention relates to an ultraviolet LED packaging structure. The ultraviolet LED packaging structure comprises an ultraviolet LED chip of an inverted structure, a packaging substrate with at leasttwo substrate electrodes and a packaging adhesive material covering the ultraviolet LED chip. Positive and negative chip electrodes of the ultraviolet LED chip are respectively conducted with the twosubstrate electrodes. An insulation gap is formed between the positive chip electrode, the negative chip electrode and the two substrate electrodes. The insulation gap is filled with a shielding object, and the shielding object is a fluororesin material containing part of crystal substances. The problem that an existing ultraviolet LED packaging structure is poor in reliability is solved.

The invention discloses a method for manufacturing a high-performance double-layer polysilicon bipolar transistor. The method comprises the following steps that 1), LOCOS and CVD are adopted to deposit SiO2 to form a composite isolation structure, and high-temperature process time is reduced; 2), the SiO2 is used as an etching stopping layer of base polysilicon, and etching damage is avoided; 3), a composite side wall structure is formed through SiO2 and N+polysilicon, and emitter resistance is reduced. The method has the advantages that on the premise of not lowering the isolation effect, the high-temperature process time is reduced, therefore, a relatively thin epitaxial layer can be adopted, the better microwave performance is obtained, SiO2 is adopted as the etching stopping layer, the etching damage to the silicon epitaxial layer is eliminated, breakdown characteristics are improved, current amplifying coefficients are increased, and noise coefficients are reduced. The composite side wall structure with SiO2 and N+polysilicon is adopted, it can be guaranteed that emitter-base electric isolation is carried out, and meanwhile the emitter resistance is lowered, the current amplifying coefficients are increased, and the noise coefficients are reduced.

The invention provides an LED vertical chip structure and a manufacturing method thereof. The method comprises the following steps of S1, providing a sapphire substrate and growing an unintentionally-doped GaN layer, an N-type GaN layer, a multi-quantum well layer and a P-type GaN layer successively on the substrate; S2, forming several discrete P electrodes; S3, forming several discrete first bonding metal layers which cover the P electrodes; and providing a bonding substrate and forming several discrete second bonding metal layers on a surface of the bonding substrate; S4, carrying out alignment bonding on the first bonding metal layers and the second bonding metal layers; S5, removing the sapphire substrate; S6, removing the unintentionally-doped GaN layer, and using a dry method etching technology to form a cutting channel, wherein the cutting channel avoids an area where the bonding metal layers are located; and S7, forming an N electrode. In the invention, a graphical bonding structure (formed by several discrete bonding metal layers) is adopted so that a metal splashing problem generated when ICP etches the cutting channel is effectively avoided; and a chip electric leakage risk is reduced so that chip reliability is effectively increased.

The invention provides a power distribution cabinet which is easy to maintain, which includes a cabinet body, and evenly distributed accommodation boxes are fixedly installed on both sides of the inner wall of the cabinet, and a cover plate is hinged on one side of the accommodation box through a rotating shaft to accommodate The bottom of the inner cavity of the box is fixed with a slide rail, one side of the outer surface of the slide rail is slidably connected with a slider through a chute opened, one side of the slider is fixedly connected with a torsion spring, and the other side of the slider is welded with a first As for the connecting rod, one end of the first connecting rod is hinged to the second connecting rod through a rotating shaft, and one end of the first arc-shaped rod extends to the inside of the through groove. The easy-to-maintain power distribution cabinet, through the arrangement of the accommodation box, enables the wires and electrical appliances inside the cabinet to be placed in categories and fixedly installed. The opening of the plate makes it easier to open the cover plate, thereby facilitating the maintenance of the electrical appliances and electric wires inside the storage box.

The invention discloses a method of eliminating etching residues of emitting electrode polycrystalline silicon in duotriode type transistor technology. A base region germanium-silicon outer extension layer is developed. A layer of an oxidation film is developed on the base region germanium-silicon outer extension layer. The oxidation film and the germanium-silicon outer extension layer are etched through a drying method, thus a base electrode of the duotriode type transistor is formed. The oxidation film on the base electrode can be clearly eliminated by using the drying method. A medium film is deposited by the composition of the oxidation film and a nitride film. The medium film is etched, thus an emitting electrode window is formed. The emitting electrode polycrystalline silicon is deposited and an ion is injected. The emitting electrode is formed by etching. End surfaces on two sides of an outer base region polycrystalline silicon are filled by the medium layer forming the emitting electrode window, thus the residue on two sides of the base electrode polycrystalline silicon when the emitting electrode polycrystalline silicon is etched is prevented. The problem that the emitting electrode polycrystalline silicon is residued when the emitting electrode polycrystalline silicon is etched is solved, thus risks of leakage of the base electrode and a collecting electrode are solved. Distance between the base electrode polycrystalline silicon and a deep contacting hole is reduced and an integration level of a device is improved.

The action switch structure of refrigerator distributor includes water supply button set below water taking port and capable of sliding up and down, link rod linked with the water supply button to rotate with the vertical motion of the water supply button, and action switch capable of being turned on or off with the action of the link rod. The present invention avoids electric leakage of the action switch caused by the water from the distributor effectively owing to the link rod to separate the water taking button from the action switch by certain distance, and the preventing wall between the action switch and the water taking port.

The invention discloses an intelligent foot massage physical therapy device. The device comprises a wooden barrel, a pedal placed at the bottom of the wooden barrel, and a host hung on the opening of the wooden barrel; a circuit board and two water pumps are installed in an electrical installation cavity, the upper part of the host is molded with a hung flanging matched with the opening of the wooden barrel; a water outlet valve column capable of generating massage water flow is installed on the pedal. The wooden barrel is made of wood and has a good heat insulation effect. The host is hung on the opening of the wooden barrel through the hung flanging, so the host can be taken out when water is added into the wooden barrel or poured out from the wooden barrel, and electronic parts in the host can't be dampen by accident to generate electronic leakage; the pedal and parts installed on the pedal are also detachable, convenient to clean and has no sanitary blind angles.

The invention provides a back-contact solar cell and a preparation method. The back-contact solar cell comprises a silicon wafer substrate. The back side of the silicon wafer substrate is provided with an N+ first conductive area and a P+ second conductive area with an interval. The N+ first conductive area is provided with a first electrode, and the P+ second conductive area is provided with a second electrode. An isolation area is arranged between the N+ first conductive area and the P+ second conductive area. The top surfaces of the first electrode and the second electrode are on the same horizontal plane, and the top surface of the isolation area is higher than that of the first electrode and the second electrode. According to the back-contact solar cell, through arranging the isolation area between the N+ first conductive area and the P+ second conductive area, the electrodes are lower than the isolation area, the problem of electrode offset printing is solved well, the problem of positive electrode and negative electrode short circuit caused by metal slurry offset is solved, and the stability of the cell is improved greatly.

The invention discloses an integrated circuit device and a manufacturing method thereof. The integrated circuit device comprises a plurality of stacked semiconductor devices; each semiconductor devicecomprises a substrate and a dielectric layer formed on the substrate, and the dielectric layers of two adjacent semiconductor devices are combined together in the stacking direction; a plurality of functional devices and a plurality of isolation structures are formed in the dielectric layer of at least one of the semiconductor devices, and the isolation structures are used for isolating the adjacent functional devices; each isolation structure comprises an isolation trench and a filler applied in the isolation trench, and an opening of the isolation trench is located in the surface, back on to the substrate, of the dielectric layer. According to the invention, the electric leakage risk and the capacitance coupling risk between the functional devices can be effectively reduced, and the reliability of metal interconnection on the hybrid bonding interface is effectively improved, so that the wafer bonding stability is improved.

The invention provides a 3D NAND memory and a manufacturing method thereof. The method comprises the following steps of: by etching a substrate, strip-shaped raised first raised parts are formed on the substrate; the back selection gate oxides formed on the upper portions and the side walls of the first raised parts form back selection gate tangent lines, the subsequently-formed back selection gates are cut off, separation control over the back selection gates is achieved, the control time of the device is prolonged, and the RC delay effect of a word line layer of the device is reduced. Or while the first raised part is formed, columnar raised second raised parts which are distributed in an array manner are formed on the substrate. The storage structures distributed in an array mode and formed in the stacking structure correspond to the second protruding parts in a one-to-one mode, and part of the storage structures are formed on the first raised parts. The first raised parts and the second raised parts replace a selective epitaxial structure formed in a channel hole, the substrate patterning process is easy to control, and etching post-processing is not needed.

The invention discloses a display device, display system and manufacturing method. The display device comprises a display panel and a chip on film, wherein the chip on film comprises a driving chip, afirst electrode array, a second electrode array and a plurality of leads, the driving chip is provided with a plurality of chip pins; a plurality of chip pins are respectively led out by electrodes in the first electrode array; a second electrode array is used for providing a plurality of signal channels between the driving chip and the display panel; and the plurality of leads are respectively used for connecting the effective pins in the plurality of chip pins to the corresponding signal channels, so that the effective pins are electrically connected with the corresponding driving terminalson the display panel, when the plurality of chip pins comprise at least one idle pin and at least one effective pin, the leads, the effective pins and the driving terminals are the same in number. The chip of the display device comprises at least one idle pin, and the wiring density of the lead is reduced, so that the short circuit and electric leakage risks of the display device caused by overlarge wiring density are reduced, and the problem of increased coupling capacitance is avoided.

The invention discloses a pixel defining layer and a manufacturing method thereof, a display panel and a manufacturing method thereof and a display device. The pixel defining layer comprises a first pixel defining layer arranged on a substrate; a second pixel defining layer located at the side of the first pixel defining layer away from the substrate, wherein the orthographic projection of the surface of the second pixel defining layer close to the substrate on the substrate covers the orthographic projection of the surface of the first pixel defining layer away from the substrate on the substrate, and the second pixel defining layer is made of hydrophobic material. Ink climbing on the pixel defining layer can be effectively suppressed, the electric leakage risk of the device layer of theorganic light emitting diode can be reduced and the film formation uniformity can be improved.

The invention discloses an intelligent foot bath machine which comprises a barrel, a pedal placed at the bottom of the barrel and a host hung on the opening of the barrel. The intelligent foot batch machine is characterized in that a control circuit and a water pump are installed in an electrical installation cavity of the host, and a hanging flange fittingly connected with the opening of the barrel is formed on the upper portion of the host; a sealing plate is hermetically connected to the lower end of the electrical installation cavity, a heating pipe is installed on the sealing plate, the upper end of the heating plate is fixedly connected on the sealing plate, the lower end of the heating pipe extends downwardly to be hermetically connected with a pipe sheet, a water inlet pipe is fixedly connected in the middle of the lower end of the pipe sheet, the lower end of the heating pipe penetrates the pipe sheet to extends into the water inlet pipe, and two water outlet pipes are fixedly connected to the lower end of the pipe sheet. The barrel made of wood is good in heat preservation, and the host is hung on the opening of the barrel through the hanging flanging, so that the host can be taken out when water is filled into the barrel or poured out of the barrel, and electrical parts in the host cannot be wetted accidentally to cause dangerous leakage of electricity.

The invention provides a GOA circuit and a liquid crystal display device. A thin film transistor connected in a diode mode is added to a pull-up control circuit on the basis of a conventional GOA circuit, and a reverse signal with the phase, opposite to the signal connected to the pull-up control circuit, is connected, thereby enabling a drain electrode of a first thin film transistor of the pull-up control circuit to be connected with a high-potential DC signal. Therefore, there is no need of a new DC signal line. Accordingly, the GOA circuit achieves a purpose that the drain electrode of thefirst thin film transistor is connected with the high-potential DC signal through a conventional signal under the condition that a fan-out space of the GOA circuit is not increased, and can greatly reduce the electric leakage risk of an n-th-stage GOA unit node Q(n) at a potential maintaining stage, thereby improving the reliability of the GOA circuit, enabling the size of a frame not to be increased, and facilitating the implementation of the narrow-frame design of a display panel.

The invention relates to a method for forming a gate isolation groove of a three-dimensional storage device and a photomask used by the method. The method for forming the gate isolation groove of thethree-dimensional storage device comprises the following steps of providing a semiconductor structure, wherein the semiconductor structure comprises a lamination structure, and a channel hole array isarranged on the lamination structure; photoetching the semiconductor structure by using the photomask, wherein the photomask is provided with one or more lines for forming one or more gate isolationgrooves, and at least one of the lines is bent towards a center of the photomask; and etching the semiconductor structure to form one or more gate isolation grooves. By the method, the distance between the gate isolation groove and each channel hole in each line of channel holes adjacent to the gate isolation groove can be trend to be consistent, and an electric leakage risk of the three-dimensional storage device is reduced.

The invention provides a flip-chip light emitting diode chip and a method of manufacturing the flip-chip light emitting diode chip. An N-type metal electrode layer extends to the edge of an N-type semiconductor step. A light emitting layer, a P-type semiconductor layer and a transparent conductive layer are disposed in a middle portion of the flip-chip light emitting diode chip, and thus, a Mesa step (a quantum well) is away from the edge of the chip. When crack breakage happens to the edge of the flip-chip light emitting diode chip and solder paste is connected with a P or N pole, short circuit of a P-type metal electrode layer and an N-type metal electrode layer is not caused, and leakage failure does not occur. Through three times of photoetching of the flip-chip light emitting diode chip manufacturing method, the number of photoetching processes is reduced, the use cost of raw materials such as a photoresist and a developer involved in the photoetching process can be saved, and theyield loss brought by photoresist residue can be effectively improved.

The invention is applicable for the technical field of a cable, and discloses a high-insulation cable with high flexibility and easy to bend. The high-insulation cable with high flexibility and easy to bend comprises a conductor, a high-insulation layer and a sheath, wherein the sheath comprises a low smoke zero halogen flame-retardant inner layer and a low smoke zero halogen flame-retardant outer layer, second protruding thorns are densely arranged on an external circumferential surface of the low smoke zero halogen flame-retardant inner layer and are internally embedded onto an internal circumferential surface of the low smoke zero halogen flame-retardant outer layer, the conductor is formed by twisting a single conductor line or a plurality of conductor lines and is coated in the high-insulation layer, and first protruding thorns are densely arranged on an external circumferential surface of the high-insulation layer and are internally embedded onto an internal circumferential surface of the low smoke zero halogen flame-retardant inner layer coated at the periphery of the high-insulation layer. The high-insulation cable with high flexibility and easy to bend is reasonable in structure, adjacent layers are highly engaged, the high-insulation cable with high flexibility and easy to bend still has relatively high bending and flexible performance in a low-temperature environment, is long in service life, and has a high insulation effect, and the risk of electric leakage is reduced.

The invention discloses a 3D memory device and a manufacturing method thereof. The 3D memory device comprises a substrate; an isolation layer covering the substrate; a laminated structure covering theisolation layer and comprising a plurality of gate conductor layers and interlayer insulating layers which are alternately stacked; and a plurality of channel columns penetrating through the laminated structure and the isolation layer, wherein the substrate is provided with a plurality of epitaxial parts, the channel columns are respectively in contact with the corresponding epitaxial parts and the gate conductor layers are separated from the epitaxial structures by the isolation layer at the epitaxial parts. The channel columns are in contact with the epitaxial parts acting as the epitaxialstructures to provide the selection transistor and the storage transistor of the 3D memory device with the laminated structure. Compared with the conventional process, the substrate is directly connected into the form of having the epitaxial parts to replace the scheme of forming the epitaxial structures in contact with the substrate at the bottom of the channel hole in the conventional process soas to avoid the problems of inconsistent height of the epitaxial structures in the deep hole, uneven surface and difficult control of ion doping concentration.

The invention provides an upside-down mounted LED chip and a manufacturing method thereof. N type metal electrode layers are arranged in the peripheral edges of the upside-down mounted LED chip, and aP type metal electrode layer is arranged in the middle part of the upside-down mounted LED chip. Even if solder paste is connected with P or N poles due to damage of an insulating layer in the edge of the upside-down mounted LED chip, the P type and N type metal electrode layers are avoided from short circuit and electric leakage failure. A light emitting layer, a P type semiconductor layer and the P type metal layer are arranged in the middle part of the upside-down mounted LED chip, so that a mesa step (quantum well) is far from the edge of the chip, and the problem that a traditional upside-down mounted LED chip has the risk of electric leakage due to tendency to short circuit of the P and N electrodes and lack of an isolated slot is solved. The leakage risk can be reduced effectively,the working reliability of products is improved, and the yield rate of the products is improved.

The invention provides a charging method, a charger and a mobile terminal. The charger comprises a first central processing unit and a controller; the first central processing unit is used for detecting whether an outage instruction sent by the mobile terminal is received or not and outputting a first control signal to the controller if the outrage instruction is detected; the controller is used for controlling the charger to stop outputting charging voltage according to the first control signal. After charging of the mobile terminal is completed, the outrage instruction is sent to the charger, the charger stops outputting the charging voltage after receiving the outrage instruction, a USB (universal serial bus) connector of the mobile terminal cannot be in a state of continuously being plugged into a power supply, risk of electric leakage among pins in the USB connector is lowered, accelerated corrosion oxidation of the USB connector of the mobile terminal under the charged state is prevented, and service life of the USB connector is prolonged.

The invention discloses an intelligent foot physical therapy machine which comprises a wooden barrel, pedals placed at the bottom of the barrel and a host suspended on an opening of the wooden barrel. A control circuit board and a water pump are installed inside an electric installation cavity of the host. A suspension flange connected with the opening of the wooden barrel in a matched mode is formed at the upper portion of the host. The pedals are provided with massage rotating discs driven by water flow jet by a water pump. The wooden barrel is made of wood and is good in heat preservation effect. The host is hung to the opening of the wooden barrel through the suspension flange, in this way, the host can be taken out when water is added into the wooden barrel or water in the wooden barrel is poured out, and an electric component inside the host will not be subjected to electric leakage risk by accidental wetting; the pedals and the components installed on the pedals are detachable and convenient to clean, and no sanitary dead angles exist.

The invention discloses an intelligent foot massage physiotherapy apparatus, comprising a wooden cask, a pedal placed at the bottom of the wooden cask, and a main unit suspended at the mouth of the wooden cask. A control circuit board and a water pump are mounted in an electrical mounting cavity of the main unit. A suspension flanging matching with the mouth of the wooden cask for suspension connection is formed on the upper portion of the main unit. Massage columns driven by water flows jetted by the water pump are mounted on the pedal. The wooden cask is made of wood with good thermal insulation effect. The main unit is suspended at the mouth of the wooden cask by the suspension flanging; in such a way, the main unit can be taken out when water is added to the wooden cask or water in the wooden cask is poured out, and electrical parts in the main unit cannot be accidentally wetted to cause electric leakage. The pedal and the parts mounted on the pedal can also be dismounted, thereby being conducive to cleaning without hygienic dead angle.

The invention discloses a red phosphorus flame-retardant reinforced nylon composite material and application thereof. The red phosphorus flame-retardant reinforced nylon composite material comprises the following components by weight: 35-55 parts of nylon resin, 3-20 parts of thermoplastic polyester, 5-20 parts of a red phosphorus flame retardant, and 10-45 parts of a reinforcing filler, wherein the thermoplastic polyester is selected from one or a combination of two of polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). A certain amount of thermoplastic polyester is added into a red phosphorus flame-retardant reinforced nylon composite material system, so that the release amount of PH3 gas in the thermal forming processing process of the composite material, especially under the condition of relatively high thermal forming processing temperature, can be effectively reduced, the harm to the body health of personnel is reduced, and the use safety of the material is improved; and the composite material is suitable for the fields of connectors, socket connectors, circuit breakers, low-voltage switches and the like in electronic and electrical appliances.

The invention provides a manufacturing method of a three-dimensional memory. The method is used in a process of forming sacrificial layers. The top sacrificial layer has a first etching selection ratio A for the bottom sacrificial layer; the top sacrificial layer has a second etching selection ratio B for the middle sacrificial layer; A and B satisfy a relational expression that: A<= B<=1, and A is not equal to 1; and therefore, material components are changed in the deposition stage of the sacrificial layers; the etching rate of the sacrificial layers is changed in the process of removing thesacrificial layers by wet etching; the etching rate of the sacrificial layer on the lower layer is higher than that of the sacrificial layer on the upper layer; the difference of the etching rates can balance the difference of the etching rates of the lower sacrificial layer and the upper sacrificial layer caused by an etching load effect in the process; damage to part of a charge barrier layer in contact with the upper sacrificial layer is reduced; the problem of uneven damage of the charge barrier layer at the upper position and the lower position is effectively solved; and the step coverage capacity of the charge barrier layer at the upper position and the lower position is improved.

The invention provides a real-time measuring device and a measuring system for ice layer thickness of an ice pool. A fixing box of a lifting device fixes the lifting device and a measuring and separating device on a wall above an ice pool. The fixing box of the lifting device is also internally provided with a stepping motor, a shaft coupling, a steel pipe U-type pulley, and a vertical bearing pedestal, and other components. The bottom of the fixing box is connected with five extension tubes. A steel wire rope is wound on the steel pipe U-type pulley of the lifting device. The steel wire ropeis connected with the fixing box of the measuring and separating device through the extension tube. The fixing box of the measuring and separating device is also internally provided with a stepping motor, a resistance-type ice thickness measuring instrument, a direction connection base, a shaft coupling, a resistance outer sleeve, a bearing, a bearing supporting plate, and a shockproof pipe clamp,and other components. The device and the system are suitable for real-time measurement of ice layer thickness of a water surface of an ice pool in an ice making process, and are advantaged by convenient measurement, high precision, and real-time measurement of ice layer thicknesses on different positions, and effectively improve efficiency of ice layer thickness measurement of the ice pool in anice making process.

The invention discloses an intelligent physiotherapy device for foot massage. The device comprises a wooden barrel, a step plate placed at the bottom of the wooden barrel and a host hung on a barrel opening of the wooden barrel; a control circuit board and two water pumps are installed in an electric installation cavity of the host, and a hanging flange connected with the barrel opening of the wooden barrel in a matched and hung mode is formed in the upper portion of the host; a water outlet valve column capable of generating massage water flow is installed on the step plate. The wooden barrel is made of wood and is good in heat insulation effect, the host is hung on the barrel opening of the wooden barrel through the hanging flange, thereby when water is added into the wooden barrel or water in the wooden barrel is poured out, the host can be taken out, and the risk of electric leakage due to the fact that electric components in the host are moistened by accident is avoided; the step plate and components installed on the step plate can be detached, cleaning is convenient to conduct, and no sanitary dead corner exists.