191 results about "Metal grating" patented technology

The invention discloses a self-isolation type image sensing structure, a sensor and a preparation method, and belongs to the field of semiconductors, the self-isolation type image sensing structure is characterized in that a shallow trench isolation structure is exposed after the back surface of a substrate is thinned, then a first semiconductor layer is extended on the back surface of the substrate, and a first isolation structure is prepared in the first semiconductor layer; sequentially depositing a second semiconductor material layer and a metal grating material layer on the first semiconductor layer; sequentially etching the metal grating material layer and the second semiconductor material layer to form a plurality of metal grating structures distributed at intervals and corresponding self-isolation structures; extending a plurality of photosensitive layers in the photosensitive region groove between the adjacent self-isolation structures to form a photosensitive region; and then activating, preparing a filter layer and the like are carried out to obtain a complete back-illuminated image sensor. The self-isolation photodiode is obtained by changing the structural distribution of the photodiode, unexpectedly, the problem that the substrate is damaged by doping is solved, meanwhile, the crosstalk effect is greatly reduced, and the performance of the image sensor is improved.

The invention relates to the technical field of semiconductor lasers, in particular to a DFB laser based on a top metal grating, and the DFB laser comprises a gain chip, the left end face of the gain chip is plated with a high-reflection HR film, and the right end face of the gain chip is plated with an anti-reflection AR film; the upper end face of the gain chip is provided with a ridge optical waveguide, and the upper end face of the ridge optical waveguide is provided with a metal Bragg reflection grating layer. A self-heterodyne interference method (the line width of a local oscillator is smaller than 500 Hz) is adopted, and the measured value of the 3dB line width is 50 Hz (the measured value of a traditional DFB is 125 kHz). The mode purity degree is verified through a Lorenzian fitting broadening factor 1.15; the wavelength drift is less than 0.05 pm / DEG C within the range of-40 DEG C to 85 DEG C after compensation of the temperature compensation circuit. The temperature tuning coefficient is 0.08 pm / DEG C, the current tuning coefficient is 0.05 pm / mA, and the tuning coverage range is 1530-1545 nm.

The invention relates to the technical field of semiconductor lasers, in particular to an ultra-narrow linewidth wavelength-adjustable external cavity laser based on a planar metal grating, which comprises a gain chip, and the left end face and the right end face of the gain chip are respectively plated with a high reflection film and a first antireflection film; a planar metal grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip is aligned and attached to the left end face of the planar metal grating waveguide, and a second antireflection film and a third antireflection film are plated on the left end face and the right end face of the planar metal grating waveguide respectively; the planar metal grating waveguide comprises a grating waveguide substrate, a ridge optical waveguide is arranged on the upper portion of the grating waveguide substrate, an annular resonance optical waveguide is arranged on the front side of the ridge optical waveguide, a planar metal grating is arranged on the upper portion of the ridge optical waveguide, and a top covering layer is arranged on the upper portion of the planar metal grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 700Hz and M2 less than 0.9 is realized.

The invention relates to the technical field of optoelectronic devices, in particular to a laser based on two different gratings and a metal grating with a phase interval of lambda / 2, which comprises a gain chip, a gain chip optical waveguide, an optical waveguide substrate, an optical waveguide, an annular resonant optical waveguide and a metal BRAGG reflecting grating. A unique outer cavity structure is adopted, a traditional interlayer semiconductor grating is abandoned, a top metal grating is adopted, a traditional DFB sandwich type secondary epitaxy manufacturing process is greatly simplified and avoided, the production cost is reduced, particularly, the metal grating is divided into two parts with similar but different grating constants, and the phase positions of the two gratings are pulled by lambda / 2, so that the performance of the DFB is improved. According to the design, the side mode rejection ratio (SMSR) of laser beams can be effectively improved, the laser line width is compressed, a guarantee is provided for stable work of the laser in a high-performance application scene, and the grating reflection efficiency is effectively improved by combining a'mouth-to-mouth 'coupling butt joint mode of the gain chip and the optical waveguide substrate.

The invention relates to a laminated staggered sub-wavelength polarization grating structure and a preparation method thereof, through staggered arrangement of a first metal grating layer and a second metal grating layer, transmission of polarized light of a transverse electric field can be effectively inhibited, and the extinction ratio is remarkably improved. Through the substrate, the first dielectric layer, the second dielectric layer, the first metal grating layer, the third dielectric layer and the second metal grating layer which are sequentially arranged from bottom to top, the whole device obtains a higher extinction ratio while keeping high transmittance, the overall structure is simple, the processing difficulty and cost are reduced, and the production efficiency is improved. And the number of the used dielectric layers and metal layers is small, the thickness requirement is low, and therefore it is ensured that the cost is controllable.

The invention discloses a polarization sensitive type broadband absorber based on metal-medium stacking, and relates to the technical field of micro-nano photonic devices and infrared detection. The absorber sequentially comprises a bottom-layer high-loss metal reflecting layer, a multi-layer stacked composite dielectric cavity structure and a top-layer sub-wavelength metal grating from bottom to top, according to impedance matching and interference resonance theories, a broadband absorption substrate is constructed through a multi-layer film structure at the bottom, and light energy is converted into heat energy by utilizing the high loss characteristic of bottom layer metal; plasmon resonance is excited through the top metal grating, the coupling efficiency of TM polarized light is enhanced, and TE polarized light is cut off; the above structural design successfully realizes efficient broadband absorption and high polarization extinction ratio in an infrared band. The structure is simple in design, is compatible with a CMOS technology, and has excellent wide-angle stability. And meanwhile, polarization screening can be realized without an external polaroid, and miniaturization and integration of an infrared detection system are facilitated.

The invention relates to the field of semiconductors, and discloses a back-illuminated image sensor and a manufacturing method thereof, and the method comprises the steps: forming a groove in a bonding pad region of a substrate through employing photoetching and etching technologies; depositing an isolation layer on the surface of the substrate, wherein the isolation layer comprises two isolation unit layers formed by alternately stacking different materials; one isolation unit layer serves as a grinding barrier layer in the grinding process, and the grinding barrier layer is located in the isolation layer; manufacturing a through hole in the isolation layer in the groove and forming a conductive layer in the groove; depositing a dielectric layer on the surface of the processed substrate; grinding for multiple times to remove the dielectric layer and the isolation layer on the surface of the processed substrate; forming a substrate grounding structure in a logic circuit region corresponding to the substrate, and forming a metal grating structure in a pixel region of the substrate; and at least removing the dielectric layer in the groove to at least expose part of the conductive layer. And the dielectric layer and the isolation layer on the surface of the processed substrate are removed in a grinding manner, so that the publishing of one layer of photomask and one time of photoetching can be reduced, and the production cost is reduced.

The invention discloses a near-earth space all-day star sensing system based on a sub-wavelength metal grating and a working method thereof, and belongs to the technical field of star sensors. In order to increase the number of fixed stars which can be detected by the near-earth space all-time star-sensitive system, the near-earth space all-time star-sensitive system comprises an optical system, an InGaAs detector, a spectrum optical filter, a micro-polaroid array, a memory, a processor, a control unit and a time unit, the InGaAs detector is respectively connected with the micro-polaroid array, the memory and the control unit; the micro-polaroid array is connected with the optical system, and the optical system is connected with the spectrum optical filter; the memory is respectively connected with the processor and the time unit; and the processor is connected with the control unit. According to the invention, the polarization filtering work of the sky background is realized, and the number of observable fixed stars is effectively increased on the basis of ensuring the miniaturization of a near-earth space all-day star-sensitive system.

The invention relates to the technical field of ocean observation, in particular to a hydrate reservoir information in-situ monitoring device. Comprising a monitoring box body; a metal grating plate is arranged at the bottom of the monitoring box body, and hydrate reservoir sediments can enter the monitoring box body through grating holes in the metal grating plate; a dissolved oxygen sensor, a pH sensor, a Raman probe rod and a resistivity probe rod are sequentially arranged in the monitoring box body from top to bottom, and a water tank camera is arranged on the side wall of the monitoring box body; a plurality of annular electrodes are arranged on the resistivity feeler lever in the circumferential direction of the feeler lever at intervals, and each annular electrode is connected with an annular electrode distance adjusting mechanism and an annular electrode aperture adjusting mechanism. And in-situ monitoring of the hydrate reservoir can be realized.

The invention discloses a vertical plasmon waveguide device structure capable of being coupled by an optical fiber and a preparation method of the vertical plasmon waveguide device structure, and belongs to the technical field of integrated optoelectronics, and the structure is composed of a pair of metal gratings and a vertical metal-medium-metal plasmon waveguide. The structure comprises a silicon substrate layer, a lower metal layer, a dielectric layer and an upper metal layer which are arranged from bottom to top and is divided into a grating area and a waveguide area, the grating area comprises a dielectric grating area and a metal grating layer, and the waveguide structure comprises the lower metal layer, the dielectric layer and the upper metal layer. According to the design of the invention, the limitation of mass production caused by an overlay process of a mode converter between heterogeneous integrated waveguides is avoided, and the preparation robustness of the device is improved. The optical insertion loss caused by the roughness of the side wall of the waveguide is improved in a metal deposition-dielectric spin coating-metal deposition mode, and the dielectric layer can be replaced to realize multiple device functions.

The invention relates to the technical field of semiconductor lasers, in particular to a compact ultra-narrow linewidth external cavity laser based on a top metal reflection grating, which comprises a gain chip, the left end face of the gain chip is plated with a high reflection film, and the right end face of the gain chip is plated with a first antireflection film; the right side of the gain chip is provided with a metal grating waveguide, the right end face of the gain chip is aligned and attached to the left end face of the metal grating waveguide, the left end face of the metal grating waveguide is plated with a second antireflection film, and the right end face of the metal grating waveguide is plated with a third antireflection film; the gain chip comprises a substrate, the upper part of the substrate is provided with a ridge optical waveguide, and the upper part of the ridge optical waveguide is provided with a metal cover Bragg reflection grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 750Hz and M2 less than 1.1 is realized.

The invention discloses a metal grating and a forming method thereof, and aims to solve the problem of optical crosstalk. The metal grating comprises a dielectric layer forming an outer layer structure, and a metal layer which is at least coated on the side wall and filled in the metal grating. The forming method comprises the following steps of: forming a mask layer on a substrate and forming a groove in the mask layer; depositing a dielectric layer on the inner wall of the groove; depositing a metal layer to fill the residual space of the groove and cover the peripheral region to form a laminated structure; and finally, removing the laminated structure part and the mask layer part outside the groove so as to limit the metal grating. Through the formed metal grating, optical crosstalk can be effectively reduced, and the imaging quality and the quantum efficiency are improved.

The invention relates to the technical field of semiconductor lasers, in particular to an ultra-narrow linewidth wavelength-adjustable external cavity laser based on a planar metal grating, which comprises a gain chip, and the left end face and the right end face of the gain chip are respectively plated with a high reflection film and a first antireflection film; a planar metal grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip is aligned and attached to the left end face of the planar metal grating waveguide, and a second antireflection film and a third antireflection film are plated on the left end face and the right end face of the planar metal grating waveguide respectively; the planar metal grating waveguide comprises a grating waveguide substrate, a ridge optical waveguide is arranged on the upper portion of the grating waveguide substrate, a planar metal grating is arranged on the upper portion of the ridge optical waveguide, and a top covering layer is arranged on the upper portion of the planar metal grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 700Hz and M2 less than 0.9 is realized.

The invention discloses a dual polarization-based terahertz broadband polarization converter metasurface, which is an efficient terahertz wave linear polarization converter based on a square bracket-shaped metal patch unit structure array, and is formed by adding a pair of orthogonal metal gratings on the upper side and the lower side of the square bracket-shaped metal patch unit structure array. According to the invention, the orthogonal metal grating and the square bracket-shaped metal patch form a Fabry-Perot cavity, so that cross polarization reflection and co-polarization transmission can be effectively prevented, and the transmission of cross polarization waves is remarkably increased. The amplitude coding metasurface is constructed by changing the amplitude and utilizing the transmission characteristics of incidence of different linear polarization waves. Under the incidence of linear polarization terahertz waves, a dual-polarization space imaging function is realized. The designed metasurface shows the characteristics of ultra wide band and high transmission efficiency, and has potential application value in the field of wireless communication.

The invention discloses a backside illuminated image sensing structure, a sensor and a preparation method, and belongs to the field of semiconductors, the backside of a substrate is thinned to form a laminated photosensitive structure through a deposition process, a deep trench isolation structure is prepared on the laminated photosensitive structure, a first section of metal grating is prepared, and ions of VA group elements are injected to form a second section of metal grating; an inclined reinforced doping belt is formed; then preparing a second section of metal grating to obtain a complete metal grating, obtaining a back-illuminated image sensing structure, and then performing the processes of activation, preparation of a filter layer and the like to obtain a complete back-illuminated image sensor; according to the invention, the stacked photosensitive structure and the reinforced doping band are combined, so that the crosstalk effect is greatly reduced while the problem of doping damage to the substrate is solved, and the performance of the image sensor is improved.

The invention relates to the technical field of antennas, and discloses a folding Cassegrain antenna, a polarization flipping focusing metasurface is located below a frequency-polarization adjustable metasurface, and the distance between the polarization flipping focusing metasurface and the frequency-polarization adjustable metasurface is half of the focal length of the polarization flipping focusing metasurface; the linear polarization feed source is located at the focus of the polarization overturning focusing metasurface and used for radiating y polarization waves; the frequency-polarization adjustable metasurface comprises a plurality of polarization rotation units which are arranged periodically, and each polarization rotation unit comprises a flexible substrate located on the upper layer, two single-opening resonance rings which are etched on the flexible substrate and are opposite in opening direction, and a metal grating located on the lower layer. By folding the flexible substrate, the polarization rotation unit forms a left-handed or right-handed chiral structure, and the technical effects of reconfigurable switching of x-polarized waves, left-handed circularly-polarized waves and right-handed circularly-polarized waves and adjustable central working frequency of the folding Cassegrain antenna can be achieved.

The safety barricade system for use with metal grate flooring may include a stanchion, one or more retainers, and a warning light. The bottom of the stanchion may detachably couple to a metal grate includes a floor and may be held in place by the one or more retainers. The stanchion may be vertically-oriented such that the top of the stanchion is elevated above the metal grate, placing the top of the stanchion within the cone of vision of a user. The stanchions may be used individually to designate a position. The stanchions may be used in groups and in conjunction with caution tape to designate a boundary. The warning light located at the top of the stanchion may be illuminated to increase the visual awareness of the stanchion.

The invention relates to the technical field of optoelectronic devices, in particular to a laser based on two different gratings and a metal grating with a phase interval of lambda / 2, which comprises a gain chip, a gain chip optical waveguide, an optical waveguide substrate, an optical waveguide, an annular resonant optical waveguide and a metal BRAGG reflecting grating. A unique outer cavity structure is adopted, a traditional interlayer semiconductor grating is abandoned, a top metal grating is adopted, a traditional DFB sandwich type secondary epitaxy manufacturing process is greatly simplified and avoided, the production cost is reduced, particularly, the metal grating is divided into two parts with similar but different grating constants, and the phase positions of the two gratings are pulled by lambda / 2, so that the performance of the DFB is improved. According to the design, the side mode rejection ratio (SMSR) of laser beams can be effectively improved, the laser line width is compressed, a guarantee is provided for stable work of the laser in a high-performance application scene, and the grating reflection efficiency is effectively improved by combining a'mouth-to-mouth 'coupling butt joint mode of the gain chip and the optical waveguide substrate.

The invention relates to an asymmetric transmission wavefront modulation method based on a multilayer metasurface, and belongs to the technical field of polarization optics application. The problems that an existing metasurface unit is complex in structure and has symmetrical transmission limitation are solved. The cascaded metal grating and the metal'bidirectional arrow 'are used as basic structure units, the spatial symmetry in the electromagnetic wave propagation direction is broken, the asymmetric transmission characteristic is obtained, meanwhile, full-range phase modulation is achieved, electromagnetic waves incident in the two directions can be independently regulated and controlled by changing the size parameters of the unit structures, and the structure is simple. Corresponding deflection and convergence effects are achieved respectively. Therefore, the invention provides a microwave band sub-wavelength unit structure, which has the advantages of easiness in design, easiness in processing and the like, has an asymmetric property, and is applied to the fields of holographic display, information encryption and the like.

The present application provides a method for etching a hard mask for a backside metal grid. The method forms a metal grid pattern by etching a second hard mask layer on the backside of a substrate. The method then uses the second hard mask layer as a mask to perform a main etching on the first hard mask layer in a carbon-rich environment, and then performs a secondary etching on the first hard mask layer in a fluorine-rich environment. The method opens the first hard mask layer by performing a main etching on the first hard mask layer in a carbon-rich environment while reducing the oxygen supply, causing a certain amount of byproducts to accumulate on the sidewalls and bottom wall near the bottom of the trench. The method then performs a secondary etching on the first hard mask layer in a fluorine-rich environment to trim the profile of the grid-shaped trench and remove excess byproducts attached to the sidewalls and bottom wall of the trench. This improves the morphology of the grid-shaped trench in the second hard mask layer and the uniformity of the thickness of the grid-shaped trench sidewalls, thereby improving the uniformity of the critical dimensions of the metal grid formed by subsequently etching the metal material layer.

The invention relates to the field of photoelectric detection, and discloses a photoelectric detector based on a grating structure and a photoelectric detection method.The photoelectric detector comprises a substrate layer and a photoelectric material layer, and the photoelectric material layer comprises a metal grating structure, a first electrode, a second electrode, a first photoelectric confinement material and a second photoelectric confinement material; the metal grating structure comprises a first metal grating and a second metal grating, the first photoelectric confinement material and the second photoelectric confinement material are connected, and a depletion junction region is formed at an interface; the first metal grating and the second metal grating are symmetrically arranged on two sides of the depletion junction region and are used for exciting a plasmon mode to form a local light field; the first electrode is connected with the first photoelectric confinement material, the second electrode is connected with the second photoelectric confinement material, and the first electrode and the second electrode are used for extracting photon-generated carriers. According to the technical scheme provided by the invention, the separation efficiency of photon-generated carriers and the response performance of the photoelectric detector can be improved.

A high-strength protection grid is produced with a plurality of metal wires which are intercalated with metal ropes. The metal wires are interlaced with each other in interlacing portions, or are twisted in twists around the ropes in twisting portions. The interlacings between the wires and the twists of the wires with the ropes define the mesh of the grid. The interlacings and the twists are each unidirectional. The ropes have an external diameter which is greater than the wires and greater than 8 mm, preferably between 9 and 12 mm, even more preferably approximately of 10 mm. The grid is produced with a machine which is provided for the passage of ropes with such an increased diameter with respect to the ropes of the protection grids of the prior art.

The utility model discloses a municipal drainage filtering mechanism, and relates to the technical field of municipal administration. The municipal drainage filtering mechanism comprises a metal main body round frame, a filtering and collecting barrel and an anti-odor-returning structure, a connecting barrel is fixedly installed at the bottom of the metal main body round frame, a metal grating disc is installed on the metal main body round frame in a clamped mode, the filtering and collecting barrel is arranged on the metal main body round frame, and the filtering and collecting barrel is located at the bottom of the metal grating disc; a positioning inserting block is fixedly installed on the outer wall of the filtering and collecting barrel, the anti-odor-returning structure is arranged on the connecting barrel and composed of an internal thread connecting barrel and hollow funnel-shaped rubber, and connecting assemblies are arranged on the internal thread connecting barrel and the hollow funnel-shaped rubber. According to the municipal drainage filtering mechanism, discharged water can be filtered for several times, the filtering effect of the municipal drainage filtering mechanism is better, the filtering material collecting barrel is not prone to being blocked due to the shape arrangement of the filtering material collecting barrel, meanwhile, the situation of odor returning can be prevented, and discomfort caused by odor returning at the drainage position to pedestrians passing by is avoided.

The utility model provides a board arrangement structure capable of improving wiring isolation and a circuit board. The board arrangement structure for improving the wiring isolation comprises a dielectric layer, two floors which are respectively fixed on the bottom surface of the dielectric layer and are separated from each other, and two microstrip lines which are fixed on the top surface of the dielectric layer at an interval and are coupled with each other, the first metal ground hole and the second metal ground hole penetrate from the bottom surface of the dielectric layer to the top surface of the dielectric layer and are mutually spaced; the first metal layer is fixed on the top surface of the dielectric layer and is arranged opposite to one of the floors; the second metal layer is fixed on the top surface of the dielectric layer and is arranged opposite to the other floor; and the energy consumption device is connected with the first metal layer and the second metal layer. Compared with a metal paving mode, the plate arrangement structure for improving the wiring isolation degree has a better isolation effect, and compared with a space metal grating mode, the plate arrangement structure for improving the wiring isolation degree does not need to increase working procedures and is lower in cost.

The application discloses a kind of phase electromagnetic metasurface design methods based on two-phase method, mainly solve the problem of electromagnetic metasurface structure complexity when existing technology electromagnetic metasurface is simultaneously regulated in amplitude phase.It is implementation scheme: initialization electromagnetic metasurface parameter;Electromagnetic metasurface unit required by two-phase method is calculated phase matrix;Design the electromagnetic metasurface unit including metal grating layer, two layers of dielectric layer and metal patch, and draw the phase table of the electromagnetic metasurface unit;According to the required phase of each unit of electromagnetic metasurface and the phase table of electromagnetic metasurface unit, the state of each unit of electromagnetic metasurface is adjusted to obtain adjusted electromagnetic metasurface;Feed horn is placed above adjusted electromagnetic metasurface, and radio frequency signal is added to feed horn, to generate required beam, complete phase electromagnetic metasurface design.The application can reduce the complexity of electromagnetic metasurface structure, improve the beam design capability of electromagnetic metasurface, and can be used for wireless transmission, communication system.

An equipotential safety device comprises a metallic grate sized and configured to be set upon the floor of a bucket of a bucket truck. The grate is in electrical communication with an electrical grounding source.

Described herein are IC devices include patterned conductive layers, such as metal gratings and gate layers, and patterned layers formed over the patterned conductive layers using a directed self-assembly (DSA)-enabled process with DSA assisting features. A patterned conductive layer may have non-uniform features, such as large regions of insulator within a metal grating, or varying gate lengths across a gate layer. The DSA assisting features enable the formation of patterned layers, e.g., layers with different hard mask materials replicating the structure of the conductive layer below, even over non-uniform features.

The invention relates to the technical field of optoelectronic devices, in particular to a laser based on a top surface HR layer and a planar metal grating and a preparation method, and the laser comprises a gain chip, an optical waveguide, the planar metal grating and a covering layer, the planar metal grating prepared by adopting an electronic evaporation plating process replaces traditional complex three-dimensional etching, so that the controllable precision and flatness of the grating structure are greatly improved, an InP secondary epitaxy process is abandoned, the whole process flow is simplified, the production cost is reduced, the product performance consistency and the product yield are improved, and the production cost is reduced. The reflection filtering efficiency is remarkably improved, the purity of the Bragg reflection spectrum is guaranteed, the narrow linewidth performance of the laser is achieved, the covering layer covers the plane metal grating, the problem that semiconductor secondary epitaxial lattices are not matched is effectively solved, diffraction light can be restrained, light energy overflow is reduced, and the freedom degree is increased through the design of the outer cavity structure.

The embodiment of the present application discloses a kind of transmission type terahertz absorption structure and preparation method thereof.Transmission type terahertz absorption structure includes at least one transmission type terahertz absorption composite film layer, transmission type terahertz absorption composite film layer includes substrate and the metal grating layer, insulating layer and graphene layer that are sequentially stacked in substrate side;Wherein metal grating layer and graphene layer are electrically connected with external power supply.The technical scheme of the embodiment of the present application is based on electromagnetic wave theory and the electrical properties of graphene, by additional voltage control Fermi level of graphene, adjust the absorption of absorption structure to terahertz, make the terahertz wave that pass through the present absorption structure have different intensity information under the influence of external voltage, play the role of switch, and have the advantages of active regulation, real-time control, accurate control, suitable for terahertz spectrum imaging analysis, single-pixel imaging and spectrum measurement etc.

The utility model aims at solving the problem of low filtering efficiency caused by the low melting point of asphalt blocking the filter screen, provides a device for filtering ring asphalt, belongs to the technical field of filter device. The device for filtering ring asphalt comprises: a metal filter container, a metal grid support plate and a metal filter screen. The bottom of the metal filter container is provided with a drain; the metal grid support plate is clamped and fixed in the metal filter container; the metal filter screen is laid on the upper surface of the metal grid support plate; wherein, the metal grid support plate provides cold energy to the metal filter screen in contact with it during use. In the utility model, the metal grid support plate provides cold energy to the metal filter screen in contact with it, especially when the wastewater temperature is relatively high or the use environment temperature is relatively high, a local low-temperature cold environment is formed, so that the deposited asphalt particles can maintain the particle form, the softening phenomenon of asphalt is delayed, and the use efficiency of the metal filter screen is ensured.