48results about How to "Guaranteed grounding" patented technology

The invention discloses a shift register, an array substrate driving circuit and a display apparatus so as to realize that the shift register can carry out periodic discharging on a capacitor and an output terminal in a non-working region and ensure that a signal output by the shift register in the non-working region is zero and interference to whole frame display is not generated. The shift register comprises the capacitor, a first pull-up unit, a first drop-down unit, a first drop-down control unit, a second drop-down unit and a second drop-down control unit, wherein the capacitor is charged under the control of a triggering signal so as to provide a first driving control voltage; the first pull-up unit makes a first clock signal output under the control of the first driving control voltage; the first drop-down unit periodically carries out discharging on the capacitor; the first drop-down control unit makes the first drop-down control unit periodically carry out discharging on the capacitor under the control of the first clock signal and a second clock signal; the second drop-down unit periodically carries out discharging on the output terminal of the first pull-up unit; the second drop-down control unit makes the second drop-down unit carry out discharging on the output terminal of the first pull-up unit under the control of the first clock signal and the second clock signal.

The invention provides a shielding device and a manufacturing method thereof. The shielding device comprises a cover and a frame, wherein the cover is provided with a top which is provided with at least one projected joint part projecting towards the frame; the frame is provided with a top and a side edge which downwards extends from the top, the top is provided with at least one joint interface corresponding to the projected joint parts of the cover, and the peripheral outline of each joint interface is the same as the peripheral outline of the corresponding projected joint part; and the projected joint part of the cover is jointed with the corresponding joint interface of the frame in an interference extrusion way to form an assembling structure of the cover and the frame. With the shielding device and the manufacturing method thereof, no side edge of the cover needs to be manufactured, thus the side edge space of the shielding device is prevented from being occupied, the cost of materials for manufacturing the side edge of the cover is saved, and zero fit-up gap is realized between the cover and the frame so that the grounding property and the shielding property of the shielding device are ensured.

The invention provides a MEMS packaging structure with heat sink and electromagnetic shielding and a preparation method thereof. The MEMS packaging structure comprises a package shell, a MEMS chip and an ASIC chip, wherein the package shell is provided with an electromagnetic shielding path and a fast heat conduction channel. Dense metallic vertical paths are disposed on the sidewalls of the package shell to shield electromagnetic influence from a side and can be connected with the MEMS chip or the ASIC chip to output MEMS and ASIC signals. A metal cover plate and a metal base plate performs electromagnetic shielding from the top and the bottom of the package shell respectively at the same time, and achieve the electromagnetic shielding of the entire packaging structure in cooperation with the metallic vertical paths; The ASIC is connected to a thermal conduction column through glue with good thermal conductivity to achieve heat sink and reduce the impact of heat. The glue under the MEMS chip is high in thickness and small in size and a part of the MEMS chip is suspended so as to achieve effective thermal insulation.

An independent front suspension structure of an all-terrain four-wheel motorcycle comprises a shock absorber, a knuckle assembly, an upper suspension and a lower suspension. The upper suspension and the lower suspension are welded into a structure in a shape of a Chinese character 'ren' through suspension front rods and suspension lateral rods, two ends of the suspension front rods of the upper suspension and the lower suspension and extension ends of the suspension lateral rods are provided with knuckle bearings respectively, the upper suspension and the lower suspension are hinged to an upper portion and a lower portion of the same side of the knuckle assembly respectively through the knuckle bearings arranged at the head ends of the 'ren' shape, and a double-rocking-rod suspension structure is formed. The suspension front rod and the suspension lateral rod of the lower suspension are welded and fixed with an shock absorber support respectively, the shock absorber is arranged between the suspension front rods and the suspension lateral rods of the upper suspension and the lower suspension, and the lower end of the shock absorber is hinged to the shock absorber support through a bolt. The independent front suspension structure can effectively absorb shock generated by road surface conditions when a vehicle runs, keeps balance of a vehicle body at any time, improves all-terrain adaptation capacity of the whole vehicle, and achieves an all-terrain function of the vehicle. Simultaneously, riding comfortableness and cross-country ability are improved effectively.

The invention discloses a clamping and noise reducing structure for an epoxy cast dry-type transformer core. The structure comprises pull belts, pull belt supporting plates and tightening bolts. The pull belt supporting plates are arranged on the upper end face and the lower end face of an upper clamping piece and the upper end face and the lower end face of a lower clamping piece, open grooves are formed in the ends of the tightening bolts, and the two ends of the pull belts are connected in the open grooves. Connecting holes are formed in the pull belt supporting plates, the pull belts are tightly clamped in a yoke part of the core through the tightening bolts arranged in the connecting holes, and pull belt insulators are arranged between the pull belts and the core. The clamping and noise reducing structure is simple and easy to implement, the assembling reliability is sufficiently ensured, the running noise is low, and the production market requirement is met.

The invention provides a microstrip isolator, which can ensure sufficient grounding of the isolator and an external circuit, thereby ensuring normal operations of the isolator. The microstrip isolator comprises a cylinder with a cover, a base plate and a resistor, wherein the circumferential surface of the cylinder with a cover is provided with avoidance slots, the bottom part of the cylinder with a cover is fixedly installed on the base plate, a cavity formed by combining the cylinder with a cover and the base plate is internally provided with an intracavity element, the intracavity element comprises a circuit portion, three outward protruding pins of the circuit portion penetrate through the corresponding avoidance slots, and the tail end of one of the pins is externally connected with the resistor. The microstrip isolator is characterized in that the base plate is specifically of a metal-plastic mixed material structure, the base plate is provided with metal connecting portions at positions corresponding to fixedly installed portions of the cylinder with a cover, the base plate is provided with a central metal connecting region at the central position, and each metal connecting portion is connected to the central metal connecting region through a metal wire / metal strip embedded in the plastic.

The invention provides a plug connector and a connector assembly. The plug connector comprises: an inner-layer conductive shell; a tail sleeve; a first insulator, wherein a power supply conductive part is arranged in the first insulator, the power supply conductive part comprises a plug contact piece, a second insulator and an elastic washer are arranged outside the plug contact piece, the elasticwasher is in stop fit with the front end surface of the first insulator, and an annular flange is arranged on the outer surface of the first insulator; a shielding conductive part, wherein the frontend of the shielding conductive part is provided with a conductive sheet in stop fit with the annular flange; and a snap spring which is positioned on the rear side of the conductive sheet. The inner-layer conductive shell is provided with a stop step and an annular clamping groove, the distance between the stop step and the annular clamping groove meets the requirement that after the clamping spring is clamped into the clamping groove, the elastic washer is compressed to apply backward acting force to the first insulator, and the annular flange abuts against the conductive sheet on the end face of the clamping spring. A jacking structure does not need to be arranged on the tail sleeve, the structure of the tail sleeve can be simplified, meanwhile, during installation, only the clamping spring needs to be clamped into the annular clamping groove through a tool, and installation is convenient.

The application provides a wall bushing and a preparation method thereof. The wall bushing comprises a first end cover, a conducting bar, a second end cover, porcelain pieces and a flange. The wall bushing further comprises conductive coatings, buckles and conductive gaskets. The conductive coatings coat the outer surfaces of a first conductive zone and a second conductive zone, and the first conductive zone and the second conductive zone are the porcelain pieces between the flange and adjacent umbrella skirts. The conductive gaskets are attached to the outer surfaces of the conductive coatings respectively. The buckles are arranged outside the conductive gaskets respectively, and fasten the conductive gaskets outside the conductive coatings respectively. By using the wall bushing providedby the application, the problem that the existing wall bushing has a poor insulation effect can be solved.

The embodiment of the invention provides a free ground film, a circuit board and a preparation method of the free ground film. The free ground film includes a first conductor layer, a conductive adhesive layer, a second conductor layer, and an adhesive film layer, which are sequentially stacked. The second conductor layer is provided with a conductive protrusion on the side near the adhesive filmlayer. When the free ground film is used for grounding of a printed circuit board, an electromagnetic shielding film is arranged on the printed circuit board. The free ground film and the electromagnetic shielding film are pressed together through the adhesive film layer. The conductive protrusion penetrates the adhesive film layer and the insulation layer of the electromagnetic shielding film andis electrically connected with the shielding layer of the electromagnetic shielding film. Interference charges accumulated on the shielding layer are effectively led out. An interference source formed by the accumulation of the interference charges is avoided, and thus the integrity of signal transmission is effectively ensured.

The invention relates to a portable mobile protection device for an abrasive wheel cutting machine. The portable mobile protection device comprises a machine frame and a protection cover. The machine frame is provided with a guide rail, a filtering net, a water tank, a limiting assembly and a grounding device. The water tank is movably connected with a poking assembly and a drainage pipe. A fireproof plate is arranged in the protection cover which is provided with a control groove. The portable mobile protection device has the advantages that the abrasive wheel cutting machine is installed on the guide rail of the machine frame and is effectively prevented from generating smoke, smog and dust through the protection cover during operation, so that the requirement for dust removal is met; noise is remarkably lowered when the abrasive wheel cutting machine operates, so that the requirement for noise reduction is met; electric spark splashing generated in the cutting process is effectively reduced and even avoided, so that the fire risk is completely eradicated; threats to safety of operators from blade breaking, alloy tool bit breaking and splashing and the like possibly occurring when the abrasive wheel cutting machine operates are effectively reduced; by the arrangement of the machine frame, the working condition of operators is improved, and labor of operators is saved.

The invention relates to the technical field of electronics, and discloses an electromagnetic shielding film, a circuit board, and a preparation method of the electromagnetic shielding film. The electromagnetic shielding film comprises a shielding layer and a conductive adhesive layer. The conductive adhesive layer is arranged on the shielding layer. The surface, which is near the conductive adhesive layer, of the shielding layer is a flat surface. The shielding layer is provided with through holes penetrating the upper and lower surfaces thereof, which is beneficial for volatiles in the conductive adhesive layer to be exhausted through the through holes of the shielding layer at high temperature. Volatiles in the conductive adhesive layer can be easily discharged at high temperature. Theelectromagnetic shielding film is prevented from being peeled off from the ground layer of the circuit board due to bubbling and delamination of the electromagnetic shielding film. The electromagneticshielding film is grounded, and interference charges are led out.

The invention relates to the technical field of electronics, and discloses an electromagnetic shielding film, a circuit board, and a preparation method of the electromagnetic shielding film. The electromagnetic shielding film comprises a shielding layer and an adhesive film layer. The adhesive film layer is arranged on the shielding layer. The surface, which is near the adhesive film layer, of theshielding layer is a non-flat surface. The shielding layer is provided with through holes penetrating the upper and lower surfaces thereof, which is beneficial for volatiles in the adhesive film layer to be exhausted through the through holes in the adhesive film layer at high temperature. Volatiles in the adhesive film layer can be easily discharged at high temperature. The electromagnetic shielding film is prevented from being peeled off from the ground layer of the circuit board due to bubbling and delamination of the electromagnetic shielding film. The electromagnetic shielding film is grounded, and interference charges are led out. In addition, the non-flat surface of the shielding layer pierces the adhesive film layer and is connected with the ground of the circuit board when the electromagnetic shielding film and the circuit board are pressed together. At the same time, gel substances are squeezed to the recesses of the non-flat surface to increase the adhesive capacity, whichprevents board burst, and ensures the connection of the shielding layer and the ground layer of the circuit board.

The invention discloses a foldable six-wheel lunar probe vehicle moving system, and relates to a probe vehicle moving system. The problems that an existing crank-slider linkage lunar rover is complex in structure, the occupied area is large when the existing crank-slider linkage lunar rover is loaded into a carrier rocket, and the walking direction on a lunar soil road surface is not flexible enough are solved. A front vehicle body and a rear vehicle body are rotationally connected, the upper portions of two rear vehicle body suspensions are installed on the left side and the right side of the rear vehicle body correspondingly, and the lower portions of the two rear vehicle body suspensions are each provided with a lower arm sleeve and a wheel from top to bottom; the two upper suspensions are hinged to the left side and the right side of the front vehicle body and can horizontally move in the length direction of the front vehicle body through long-strip-shaped holes in the front vehicle body, and the two ends of each upper suspension are each provided with a lower arm sleeve and a wheel from top to bottom. One end of each pull rod is rotationally connected with a connecting shaft at the junction of the front vehicle body and the rear vehicle body, and the other end of each pull rod is connected with one upper suspension. The system is used for lunar exploration.

The invention discloses a high-voltage overhead line system grounding device which comprises a drive box assembly (1) and a rocker arm grounding rod assembly (2). The drive box assembly (1) comprises a box body (101), a drive motor (102), an upper clutch (103) and a speed reducer (105). The drive motor (102), the upper clutch (103) and the speed reducer (105) are all arranged in the box body (101), the drive motor (102) is connected with an input shaft of the speed reducer (105) through the upper clutch (103), and the rocker arm grounding rod assembly (2) is perpendicularly connected with the side wall of an output shaft of the speed reducer (105). By the adoption of the structure, the grounding device has the advantages of being simple in whole structure, convenient to implement, low in cost, capable of remotely controlling an overhead line system to be grounded in the application process, safe, reliable and beneficial to safety construction.

The present invention provides a microstrip circulator. The sufficient grounding of the circulator and an external circuit can be ensured, and therefore, the normal use of the microstrip circulator can be ensured. The microstrip circulator comprises a cylinder having a cover, and a bottom plate. Voidance grooves are formed at the ring surface of the cylinder having the cover. The bottom of the cylinder having the cover is fixedly mounted to the bottom plate. An in-cavity element is arranged in a cavity formed by combining the cylinder having the cover and the bottom plate. The microstrip circulator is characterized in that the bottom plate is made of a metal and plastic mixed material; the bottom plate is provided with metal connecting portions which are corresponding to the fixed mounting portions of the cylinder having the cover; a center metal connecting region is arranged at the center of the bottom plate; each metal connecting portion is connected with the center metal connecting region through metal wires / metal strips embedded in plastic; and at least one of the plurality of metal connecting portions and the center metal connecting region is connected with the external circuit through soldering.

The embodiment of the invention provides a free ground film, a circuit board and a preparation method of the free ground film. The free ground film includes a third conductor layer, an adhesive film layer, a first conductor layer, a conductive adhesive layer and a second conductor layer, wherein the first conductor layer, the conductive adhesive layer and the second conductor layer are sequentially stacked. The second conductor layer is provided with a protrusion on the side away from the conductive adhesive layer. The third conductor layer is arranged on the side, which is provided with the protrusion, of the second conductor layer. A protrusion part is formed at the site covered by the protrusion on the third conductor layer. The adhesive film layer is arranged on the side, which is awayfrom the second conductor layer, of the third conductor layer. When the free ground film is used for grounding of a printed circuit board, the electromagnetic shielding film is arranged on the printed circuit board. The free ground film and the electromagnetic shielding film are pressed together through the adhesive film layer. The protrusion part penetrates the adhesive film layer and the insulation layer of the electromagnetic shielding film and is electrically connected with the shielding layer of the electromagnetic shielding film. Interference charges accumulated on the shielding layer are effectively led out. An interference source formed by the accumulation of the interference charges is avoided, and thus the integrity of signal transmission is effectively ensured.

The invention relates to a distribution transformer grounding system, which is connected with a distribution transformer in the distribution network. The distribution transformer has an operation grounding point and a protection grounding point. The distribution transformer grounding system comprises an operation grounding device, a protection grounding device and a switch, wherein the operation grounding device is connected with the operation grounding point, the protection grounding device is connected with the protection grounding point, and the switch is connected between the operation grounding point and the protection grounding point so as to switch the grounding mode of the distribution transformer through opening and closing. The distribution transformer grounding system further comprises a control module which controls the switch to open and close, wherein the control module includes a remote signaling acquisition unit, a topology analysis unit, a grounding mode judgment unitand a remote control issuing unit. The distribution transformer grounding system can adjust the grounding mode according to actual requirements, thereby not only being capable of preventing users fromcontacting voltage dangers and improving the safety, but also being capable of ensuring the neural-point grounding safety and improving the reliability.

The invention discloses a grounding device for a lamp, which comprises two grounding terminals and screws; the grounding terminal comprises a pressing piece and two limiting arms symmetrically arranged on the pressing piece. There is a through hole on the pressing piece, and the two limit arms are bent and extended towards the same side of the pressing piece; the screws pass through the through holes of the pressing piece of the two grounding devices in turn and are screwed with the threaded holes; the limit of the two grounding terminals The direction of the arms is opposite, and the pressing piece of one of the grounding terminals is located between the two limiting arms of the other grounding terminal; the ground wire is pressed tightly between the pressing pieces of the two grounding devices. The grounding terminals are used in pairs, the limit arms of the two grounding terminals are facing oppositely, and the grounding wires are pressed tightly by the pressing pieces of the two grounding terminals, which can effectively prevent the grounding wire from rotating away from the metal post during assembly, and realize the grounding wire and the metal post conveniently and quickly. The connection between the metal posts; at the same time, the contact area between the pressing piece and the ground wire is large, which can ensure the effective grounding of the lamp. At the same time, the invention also discloses a lamp using the above lamp grounding device.

The invention relates to the technical field of electronics, and discloses an electromagnetic shielding film, a circuit board, and a preparation method of the electromagnetic shielding film. The electromagnetic shielding film comprises a plurality of convex particles, a first shielding layer, N second shielding layers, a third shielding layer, and an adhesive film layer, wherein the first shielding layer, N second shielding layers, the third shielding layer, and the adhesive film layer are successively stacked. The side, which is close to the adhesive film layer, of the first shielding layer is set as a flat surface. The convex particles are distributed between the first shielding layer and the second shielding layer and between the second shielding layer and the third shielding layer. Theside, which is close to the adhesive film layer, of the third shielding layer is a non-flat surface. The non-flat surface of the third shielding layer can pierce the adhesive film layer and is connected with the ground layer of the circuit board when the electromagnetic shielding film is laminated with the circuit board. Ground failure caused by the fact that the conductive particles of the adhesive film layer are pulled apart when the adhesive film layer of the existing electromagnetic shielding film is expanded at high temperature is avoided. The connection of the electromagnetic shieldingfilm and the ground layer of the circuit board is ensured.

The invention discloses a power transmission line grounding state intelligent sensing device. The device comprises a base, a sleeve is fixedly installed in the middle of the top end of the base, a sleeve rod is sleeved with the sleeve, a grounding ring is fixedly installed at the top end of the sleeve rod, a connecting wire is wound around and connected to the surface of the grounding ring, and aground pile is fixedly installed at the bottom end of the sleeve rod. The ground pile is connected with the center of the base in a penetrating mode, lifting mechanisms are fixedly arranged on the twosides of the sleeve, an alarm lamp is fixedly installed at the corner of one side of the top end of the base, a ground fault sensor is fixedly installed in the middle of one side of the top end of the base, and a display screen is fixedly installed on one side of the base. According to the invention, through the installed grounding fault sensor, whether the power transmission line is grounded ornot can be conveniently detected, the detected data is processed through the PLC and is distinguished through different colors of the alarm lamp, and the grounding of the power transmission line is ensured.

The invention discloses an integrated heating feed cylinder and a production method thereof. The integrated heating feed cylinder comprises the feed cylinder and a heating device. The heating device is installed at the exterior of the feed cylinder, and successively comprises an insulating heat-conducting layer, an electric heating foil belt, and an insulating heat-insulating layer from inside tooutside. A cross section of the electric heating foil belt is a rectangle of which a length-width ratio is greater than ten. The outer side of the insulating heat-insulating layer is further providedwith a heat-preserving layer. The integrated heating feed cylinder further comprises a wiring block and a sheet protecting tightening layer.

The invention relates to the technical field of electronics, and discloses an electromagnetic shielding film, a circuit board, and a preparation method of the electromagnetic shielding film. The electromagnetic shielding film comprises a shielding layer and an adhesive film layer. The adhesive film layer is arranged on the shielding layer. The surface, which is near the adhesive film layer, of theshielding layer is a flat surface. The shielding layer is provided with through holes penetrating the upper and lower surfaces thereof, which is beneficial for volatiles in the adhesive film layer tobe exhausted through the through holes in the shielding layer at high temperature. Volatiles in the adhesive film layer can be easily discharged at high temperature. The electromagnetic shielding film is prevented from being peeled off from the ground layer of the circuit board due to bubbling and delamination of the electromagnetic shielding film. The electromagnetic shielding film is grounded,and interference charges are led out. In addition, the side, which is close to the adhesive film layer, of the shielding layer is provided with convex conductor particles. The conductor particles canpierce the adhesive film layer and is connected with the ground layer of the circuit board when the electromagnetic shielding film is laminated with the circuit board. The connection of the shieldinglayer and the ground layer of the circuit board is ensured.

The invention provides a shielding device and a manufacturing method thereof. The shielding device comprises a plate-like cover and a frame, wherein the cover is provided with a top which is provided with at least one projected joint part projecting towards the frame; the frame is provided with a top and a side edge which downwards extends from the top, the top is provided with at least one joint interface corresponding to the projected joint parts of the cover, and the peripheral outline of each joint interface is the same as the peripheral outline of the corresponding projected joint part; and the projected joint part of the cover is jointed with the corresponding joint interface of the frame in an interference extrusion way to form an assembling structure of the cover and the frame. With the shielding device and the manufacturing method thereof, no side edge of the cover needs to be manufactured, thus the side edge space of the shielding device is prevented from being occupied, the cost of materials for manufacturing the side edge of the cover is saved, and zero fit-up gap is realized between the cover and the frame so that the grounding property and the shielding property of the shieldingdevice are ensured.

The invention relates to a door panel fixing element with a grounding function. A door panel of a machine cabinet in the prior art is generally fixed by bolts and is grounded by a grounding cable, a structure in such a way cannot bear overlarge weight, and the grounding cable needs to be connected and disconnected, so that the door panel is inconvenient to assemble and disassemble. The door panel fixing element with the grounding function in the invention comprises a lug boss, a sunken platform, a mounting hole and spines. The door panel fixing element provided by the invention has the advantages of simplified structure, capabilities of realizing reliable installation and guaranteed grounding of a door panel with larger weight, and convenience for assembly and disassembly, and is beneficial to production efficiency increase and product maintenance.

The invention relates to the technical field of electronics, and discloses an electromagnetic shielding film, a circuit board and a preparation method of electromagnetic shielding film. The electromagnetic shielding film comprises a first shielding layer, a conductive adhesive layer, a second shielding layer and an adhesive film layer which are sequentially stacked, wherein one surface, close to the adhesive film layer, of the second shielding layer is a non-flat surface. The conductive adhesive layer is arranged between the first shielding layer and the second shielding layer, so that multi-layer shielding of interference signals on the two sides of the electromagnetic shielding film is realized, and the interference signals on the two sides of the electromagnetic shielding film are effectively weakened; and redundant charges are guided into a stratum through the first shielding layer, the conductive adhesive layer and the second shielding layer, so that the shielding efficiency is greatly improved.

The invention relates to the field of electronics, and discloses a free ground film, a circuit board and a preparation method of the free ground film. The free ground film includes a conductor layer and an adhesive film layer. The adhesive film layer is arranged on the conductor layer. The side, which is close to the adhesive film layer, of the conductor layer is a non-flat surface. The conductorlayer is provided with a through hole penetrating the upper and lower surfaces thereof, which is beneficial for volatiles in the adhesive film layer to be exhausted through the through hole of the conductor layer at high temperature. The volatiles of the adhesive film layer can be easily discharged at high temperature, which prevents separation between the free ground film and an electromagnetic shielding film caused by blistering and layering of the free ground film, and ensures that interference charges are led out. In addition, when the free ground film is used for grounding of a printed circuit board, the electromagnetic shielding film is arranged on the printed circuit board. The electromagnetic shielding film includes a shielding layer and an insulating layer arranged on the shielding layer. The non-flat surface of the conductor layer penetrates the adhesive film layer and the insulating layer and is electrically connected with the shielding layer, so that interference charges are led out through the free ground film.

The invention relates to the technical field of electronics, and discloses an electromagnetic shielding film, a circuit board, and a preparation method of the electromagnetic shielding film. The electromagnetic shielding film comprises a plurality of convex particles, a first shielding layer, N second shielding layers, a third shielding layer, and an adhesive film layer, wherein the first shielding layer, N second shielding layers, the third shielding layer, and the adhesive film layer are successively stacked. The side, which is close to the adhesive film layer, of the first shielding layer is set as a non-flat surface. The convex particles are distributed between the first shielding layer and the second shielding layer and between the second shielding layer and the third shielding layer.The side, which is close to the adhesive film layer, of the third shielding layer is a non-flat surface. The non-flat surface of the third shielding layer can pierce the adhesive film layer and is connected with the ground layer of the circuit board when the electromagnetic shielding film is laminated with the circuit board. Ground failure caused by the fact that the conductive particles of the adhesive film layer are pulled apart when the adhesive film layer of the existing electromagnetic shielding film is expanded at high temperature is avoided. The connection of the electromagnetic shielding film and the ground layer of the circuit board is ensured.

The invention relates to the field of electronic technology, and discloses an electromagnetic shielding film, a circuit board and a preparation method of the electromagnetic shielding film, wherein the electromagnetic shielding film comprises a first shielding layer, an insulating layer, a second shielding layer and an adhesive film layer, which are sequentially stacked, one surface of the secondshielding layer close to the adhesive film layer is a non-flat surface, the insulating layer is arranged between the first shielding layer and the second shielding layer to achieve multilayer shielding of interference signals on both sides of the electromagnetic shielding film, as a result, the interference signals on the both sides of the electromagnetic shielding film are effectively weakened, and the shielding effectiveness is improved accordingly.