46results about How to "Guaranteed electromagnetic shielding performance" patented technology

The invention provides an electromagnetic shielding protection film and an FPC (flexible printed circuit). The electromagnetic shielding protection film is simple in structure, relatively thin in thickness, excellent in electromagnetic shielding performance, particularly suitable for covering the bending region of the FPC, and capable of ensuring the electromagnetic shielding effect, the relatively thin thickness and a relatively good bending performance of the bending region. According to the FPC, the bending region is covered with the electromagnetic shielding protection film to replace the conventional electromagnetic shielding composite film with a relatively high thickness, so that the electromagnetic shielding effect, the relatively thin thickness and a relatively good bending performance of the bending region can be ensured; and when the FPC provided by the invention is adopted for connecting a display module and a mobile phone main board, the assembling difficulty of the display module and the mobile phone main board can be greatly lowered.

The invention provides a system-in-package module and terminal equipment. The system-in-package module comprises a substrate, at least two electronic components, a plastic package body, an open groove, a conductive shielding layer and a filling body, wherein the at least two electronic components are arranged on the substrate; the plastic package body is located on the substrate and wraps the at least two electronic components, the open groove penetrates through the upper surface and the lower surface of the plastic package body and is located between the two adjacent electronic components, the conductive shielding layer covers the upper surface of the plastic package body and the inner surface of the open groove, and the open groove is filled with the filling body. The invention providesthe system-in-package module and the terminal equipment. The electromagnetic shielding effect between electronic components in the system-in-package module and the electromagnetic shielding effect between the system-in-package module and external electronic components can be improved.

The invention discloses a method for preparing an electromagnetic shielding material, which comprises the following steps: 1) preparing the following components in parts by weight: 70-80 parts by weight of silicon rubber; 20-30 parts by polytetrafluoroethylene; 2-3 parts by weight of nano-scale graphite powder; Curing agent ~ 2; heat stabilizer 1 ~ 2; 2) forming a composite rubber mixture uniformly infiltrated with nano-scale graphite particles in a molten state; 3) injecting the composite rubber mixture in step 2) into the mold cavity of the forming mold, and Completely wrap the wire mesh inside; 4) In a negative pressure environment, vibrate the forming mold through a vibrator to remove the internal air bubbles; 5) High pressure and low temperature, rapid cooling and solidification, to obtain a semi-finished electromagnetic shielding material; 6 ) heat and melt the semi-finished electromagnetic shielding material again, and cool and solidify naturally at high pressure and normal temperature to obtain the electromagnetic shielding material. The invention also discloses the electromagnetic shielding material prepared by the method, the corresponding electromagnetic shielding gasket, and the electromagnetic shielding button terminal using the electromagnetic shielding gasket.

The invention discloses conductive foam suitable for electromagnetic shielding. The conductive foam sequentially comprises an outer protection layer, a foam layer, a first pasting layer, a metal foillayer and a second pasting layer, wherein the layers are combined to form the conductive foam, a nickel-titanium alloy thin film is formed on each of an upper surface and a lower surface of the metalfoil layer, leakage holes are formed in the foam layer and are filled with carbon nanotubes, the carbon nanotubes are porous spongy carbon nanotube block-shaped materials, first surfaces of the nickel-titanium alloy thin films are connected with the foam layer and the carbon nanotubes in the foam layer by the first pasting layer, and second surfaces of the nickel-titanium alloy thin films are connected with the second pasting layer. In the conductive foam provided by the invention, relatively excellent integral shielding performance and conductive performance can be provided for electronic equipment in a closed and narrow space with poor cooling performance.

The invention relates to the field of aero-engine electronic controller cases, in particular to a method for resisting strong electromagnetic interference of an aero-engine electronic controller case.The method comprises the following steps: S1, simulation analysis: evaluating the electromagnetic coupling characteristics of a case, and obtaining the position of an electromagnetic protection weakpoint; S2, material optimization: carrying out nickel plating treatment on the carbon fiber precursors and weaving the carbon fiber precursors into nickel-plated carbon fiber cloth; S3, compression molding: on the basis of S1, integrally molding the case main body material and the shielding material. S4, gap protection: forming an annular groove in the gap connecting position of the box body, andproviding a space for modular gap protection materials; S5, combined assembly: assembling the cover plate and the box main body in a screw fastening mode. The aviation VPX case is reasonable in design, novel in structure, capable of effectively solving the problems that existing aviation VPX case protection measures are scattered and low in protection index, capable of enhancing the anti-electromagnetic interference capacity and suitable for wide application and popularization.

The invention relates to the technical field of electromagnetic shielding material preparation, and in particular to a method for preparing a coated electromagnetic shielding material. Toluene diisocyanate, isophorone diisocyanate and polyethylene glycol as raw materials are reacted to obtain an elastic polyurethane prepolymer, and a photo-curing initiator, nano-spherical silver powder and flake silver powder are added to the elastic polyurethane prepolymer to obtain the coated electromagnetic shielding material. The electromagnetic shielding material can coat light matrixes such as plastics to achieve electromagnetic shielding effect, and the cost of the electromagnetic shielding material is effectively controlled while the electromagnetic shielding effect is guaranteed. Nano-conductive particles aggregate with each other by Brownian motion of the nano-conductive particles to form a conductive network, and the conductivity of the electromagnetic shielding material after curing is improved. In addition, in the process of UV light curing of the coating, the filling effect of conductive silver particles in pores among resin particles is better, so that shrinkage of the coating decreases during curing, and the application prospect is broad.

The invention discloses a silicon microphone, which comprises an outer packaging structure, an upper board, a hollow cavity and a bottom circuit board are combined from the top down to form the outer packaging structure, a silicon acoustic chip and an electric signal processing chip are mounted on the bottom circuit board, the upper board is provided with at least two sound inlets, a shielding layer which is electrically connected with the earth terminal of the bottom circuit board is arranged on the upper board and the cavity, and moreover, a water-proof film which is attached on the sound inlets is fixed inside the packaging structure, and is electrically connected with the shielding layer of the upper board and / or the cavity. The design can realize good water-proofing and dust-proofing effects, thus reducing the loss of the sensitivity of the product; and moreover, since the waterproof film is adopted to be connected with the shielding layer of the product, the electromagnetic shielding effect of the product is guaranteed.

The invention relates to a cable assembly, a connector assembly and connector accessories thereof, the connector accessories include a metal sleeve for sleeving on a cable and connecting to a rear side of a connector shield, the inner diameter of the metal sleeve is greater than the outer diameter of the applicable cable, the connector accessories further include an elastic conductive member for sleeving in an annular space between the cable and the metal sleeve to conduct a cable shield of the metal sleeve and the cable, wherein the difference between the inner diameter and the outer diameteris larger than the difference between the inner edge and the outer edge of the annular space, and the annular space arranged between the cable and the metal sleeve ensures that the metal sleeve doesnot interfere with the cable in the process of screwing connection with the shield layer of the connector, so that the cable does not rotate with the metal sleeve; After the metal sleeve is fixed, a conductive part is filled into the annular space between the cable and the metal sleeve, so that the shield layer of the cable and the metal sleeve are conducted through the conductive part, thereby ensuring the electromagnetic shielding performance of the cable assembly, and the structure is simple.

The invention discloses a low-noise and stable-phase coaxial cable. The low-noise and stable-phase coaxial cable comprises a cable core and a shielding attenuation layer, wherein the cable core comprises an internal conductor, a semiconductor layer and a combination insulation layer, the semiconductor layer wraps the internal conductor, the combination insulation layer wraps the semiconductor layer, the shielding attenuation layer wraps the cable core and is sequentially provided with the semiconductor layer, a wrapping silver-plating flat copper belt and a weaving silver-plating flat wire from inside to outside, a sheath is arranged outside the shielding attenuation layer in an extrusion manner, the semiconductor layer comprises a matrix, a graphite powder layer and a conductive polymer layer, the graphite powder layer is coated on a surface of the matrix, the conductive polymer layer is coated outside the graphite powder layer, and the combination insulation layer is dual insulationlayers wrapped by an inner layer of low-concentration micropore polytetrafluoroethylene thin film and wrapped by a polyimide thin film. Conductive polymer is impregnated with graphite and is used as the semiconductor layer, three layers of shielding attenuation is formed from the conductive polymer and a copper wire, the electromagnetic interference is gradually offset by a mode that the shieldingresistance is gradually improved from inside to outside, the attenuation and the noise of the cable are greatly reduced, and a noise value is 0.1mV or below.

The invention discloses a shielding cover assembly, which comprises a metal shielding shell and a heat dissipation module, wherein the metal shielding shell includes a plurality of walls and an accommodating space defined by the plurality of walls, and the accommodating space is provided with a front-end socket. The heat dissipation module is assembled on one of the walls of the metal shielding shell. The heat dissipation module comprises a heat dissipation base member, a first heat dissipation member arranged on the heat dissipation base member and at least one buckle clamped between the heatdissipation base member and the first heat dissipation member, the buckle is buckled to the metal shielding shell, and the bottom of the heat dissipation base member covers the wall, on which the heat dissipation module is assembled, of the metal shielding shell.

The invention discloses a special high-flexibility and bending-resistant photoelectric composite cable for sweeping robots and a fixing clamp thereof. The outermost layer of the photoelectric composite cable is an outer rubber skin. A power cable unit, a control cable unit and an optical fiber unit are distributed inside the photoelectric composite cable. The areas between the power cable unit, the control cable unit and the optical fiber unit on one hand and the outer rubber skin on the other hand are adhered by a glue layer to form three air bags, and the air bags are filled with a polyamidefiber woven fabric. According to the special high-flexibility and bending-resistant photoelectric composite cable for sweeping robots and the fixing clamp thereof in the invention, three air bags areadded to the surface layer of the cable. On one hand, the filling of the gaps of the three cable units ensures the structural strength of the whole cable. On the other hand, the air bags with good elasticity and high bending degree can reduce the redundant filling gravity load for the cable, and when there is an external open fire, the air bags can be burnt to release nitrogen to extinguish the fire. The cable is applicable to different working conditions, and has a better use prospect.

The invention discloses a display panel and a side surface bonding method thereof. The side surface bonding method comprises the following steps: correspondingly connecting a bonding terminal on the first side of a driving chip with a conductive terminal of a display panel; correspondingly connecting a bonding terminal on the second side of the driving chip with a conductive terminal of the circuit board, wherein the first side and the second side are two opposite sides of the driving chip; doping an electromagnetic wave absorbing material into the insulating colloid, and coating and coating the insulating colloid doped with the electromagnetic wave absorbing material on the driving chip; and curing the insulating colloid doped with the electromagnetic wave absorbing material. The fluid insulating colloid is attached to different positions along with the height change of the bonding area, so that the height difference of the bonding area can be well covered after the insulating colloidis cured, the poor covering phenomena such as bubbles, wrinkles and corner warping occurring when the IC Tape is attached to the bonding area are avoided, and the electromagnetic shielding effect isensured.

The invention discloses an air-cooled fully-reinforced computer suitable for various series buses, which comprises a box body, a front panel, a rear panel, a connecting assembly, a track bracket assembly, a heat dissipation assembly, a wire arrangement assembly and an electromagnetic shielding assembly; the rear panel is fixedly arranged at the rear end of the box body, and the front panel is arranged at the front end of the box body through the connecting assembly; the front panel is matched with the end face of the box body, a rail support used for installing a bus board card is arranged in the box body, a wire arranging assembly is arranged on the inner surface of the side wall of the box body, an air cooling heat dissipation assembly used for discharging heat generated on the bus board card is arranged on the box body, and electromagnetic shielding assemblies matched with the end face of the box body are arranged on the front panel and the rear panel. In the computer, the box body has a very good heat dissipation function, so that quick maintenance operation of a plurality of components in the box body can be realized, and the box body can also have a very good electromagnetic shielding effect.

The invention discloses a low-frequency electromagnetic shielding chamber. The chamber is formed by welding and sealing a plurality of shielding plates, the interior of the low-frequency electromagnetic shielding chamber is composed of a main machine chamber and an operation chamber. A first electromagnetic shielding door frame is arranged between the host room and the operation room; a first electromagnetic shielding door with a shielding protection function is arranged on the inner side of the first electromagnetic shielding door frame; the first electromagnetic shielding door frame is connected with a magnetic conductive material layer through a riveting hook; a transparent observation window and a control panel are arranged on one side of the first electromagnetic shielding door, a second electromagnetic shielding door with a shielding enhancing function is arranged outside the operation chamber, a waveguide port is formed in the main machine chamber, and a power supply filter anda signal filter are arranged in the operation chamber. The low-frequency electromagnetic shielding chamber is reasonable in structural design, the sealing effect of the main machine chamber is effectively improved, and the electromagnetic shielding effect of the main machine chamber is remarkably enhanced.

The invention belongs to the technical field of polymer materials, in particular to a carbon nanotube electromagnetic shielding heat dissipation film, wherein the carbon nanotube electromagnetic shielding heat dissipation film comprises a matrix layer, an electromagnetic shielding heat dissipation functional layer and a heat conduction bonding layer which are sequentially stacked and arranged. According to the total mass of the electromagnetic shielding heat dissipation functional layer being 100%, the electromagnetic shielding heat dissipation functional layer comprises 10-45% of carbon nanotubes, 0-5% of graphene and the rest of resin, wherein the tube length of the carbon nanotubes is 100-500 microns. The carbon nanotube electromagnetic shielding heat dissipation film provided by the invention not only has high conductivity to electromagnetic wave shielding, but also has high conductivity, good heat dissipation performance and wide, flexible and convenient application scenarios.

The invention belongs to the technical field of special vehicles, and discloses a vehicle electromagnetic shielding window. The window comprises silk screen sandwiched type electromagnetic shielding glass and a window frame matched with the glass; the silk screen sandwiched type electromagnetic shielding glass is fixed to the interior of the window frame; a shielding silk screen inside the silk screen sandwiched type electromagnetic shielding glass is conductively connected with window frame; the window frame is provided with a linkage face making contact with a metal vehicle body. The vehicleelectromagnetic shielding window can lower the assembling complexity and improve the electromagnetic shielding reliability.

The invention belongs to the technical field of adhesive tape manufacturing, and particularly relates to a manufacturing process of an adhesive tape with a shielding film structure. The adhesive tapecomprises a shielding adhesive tape body, the shielding adhesive tape body comprises a nickel-plated polyester fiber cloth layer, an adhesive layer, release paper and an electromagnetic shielding layer, and the release paper, the adhesive layer, the nickel-plated polyester fiber cloth layer and the electromagnetic shielding layer are stacked in sequence. The electromagnetic shielding layer comprises pressing grooves and an anti-stretching high polymer material, the pressing grooves are pressed on the surface of the electromagnetic shielding layer through an embossing process, the anti-stretching high polymer material fills the pressing grooves pressed on the surface of the electromagnetic shielding layer, the electromagnetic shielding layer is a metal foil, and the metal foil is a copper foil or an aluminum foil. According to the manufacturing process of the adhesive tape with a shielding film structure, the electromagnetic shielding layer is wrapped by the PTC polymer conductive material with tensile resistance and conductivity in a segmentation manner, so that the transverse and longitudinal tensile resistance of the adhesive tape is greatly improved while the electromagnetic shielding effect of the adhesive tape is ensured, and the flexibility and crease resistance of the adhesive tape are improved.

The invention relates to a cable assembly, a connector assembly and connector accessories thereof, the connector accessories include a metal sleeve for sleeving on a cable and connecting to a rear side of a connector shield, the inner diameter of the metal sleeve is greater than the outer diameter of the applicable cable, the connector accessories further include an elastic conductive member for sleeving in an annular space between the cable and the metal sleeve to conduct a cable shield of the metal sleeve and the cable, wherein the difference between the inner diameter and the outer diameteris larger than the difference between the inner edge and the outer edge of the annular space, and the annular space arranged between the cable and the metal sleeve ensures that the metal sleeve doesnot interfere with the cable in the process of screwing connection with the shield layer of the connector, so that the cable does not rotate with the metal sleeve; After the metal sleeve is fixed, a conductive part is filled into the annular space between the cable and the metal sleeve, so that the shield layer of the cable and the metal sleeve are conducted through the conductive part, thereby ensuring the electromagnetic shielding performance of the cable assembly, and the structure is simple.

The invention discloses a low-reflection and high-efficiency electromagnetic shielding material, which belongs to the technical field of electromagnetic shielding materials. The invention includes a composite electromagnetic shielding component composed of materials with different electromagnetic properties, the composite electromagnetic shielding component is composed of metal powder with relative conductivity ≥ 0.02, ferromagnetic material powder with relative magnetic permeability ≥ 1 and polymer dielectric material Composition, wherein the volume ratio of metal powder is between 70% and 97%, the volume ratio of ferromagnetic material powder is between 1% and 29%, and the volume ratio of polymer dielectric material is between 1% and 29%. On the basis of ensuring high-efficiency electromagnetic shielding through the compound effect, the present invention reduces the reflection of electromagnetic waves and increases the absorption of electromagnetic waves, so as to achieve the goal of reducing secondary pollution. According to the national military standard GJB6190-2008 of the People's Republic of China, the In the electromagnetic wave frequency range, the shielding effectiveness reaches above 60dB (Class B).

The invention relates to a method for improving the safety of a Doppler radar, belongs to the technical field of speed measurement radars, and solves the problems that the appearance of an existing Doppler radar is not conformal with a carrier, the required installation space is large, and the safety of the Doppler radar is guaranteed. The method for improving the safety of the Doppler radar comprises the following steps of: S1, performing protection treatment on the surface of each extension; S2, arranging each extension set of the radar in a shielding box body structure of each extension set, so as to realize the modular design of each extension set of the radar; S3, setting connectors of all the extensions to be in a differential structural form, and setting identification marks; S4, installing the shielding box bodies of all the extension sets in a main body frame of a conformal structure through using vibration reduction structures; and S5, installing an upper cover plate of the conformal structure, and sealing each extension of the radar in a cavity of the conformal structure. According to the method, the Doppler radar and the mounting surface can be conformal, the mounting space is small, and the safety is high.

A wire harness (10 to 13, 31) includes one or more conducting paths (19), a protective member (20) that is formed in a pipe shape, and accommodates the one or more conducting paths (19) in the protective member (20) to shield a electromagnetic wave emitted from the one or more conducting paths (19). The protective member (20) is formed of resin composition that has conductivity.

The invention relates to the technical field of integrated circuit board packaging, and discloses an electromagnetic shielding packaging body and a preparation method thereof.The electromagnetic shielding packaging body comprises an integrated circuit board, the integrated circuit board comprises a substrate and an electronic assembly, a grounding end is arranged on the outer peripheral face of the upper side of the substrate, the electronic assembly is arranged on the upper side face of the substrate, and the grounding end is arranged on the outer peripheral face of the substrate; the grounding end is positioned on the periphery of the electronic component; the insulating film is attached to the outer peripheral surface of the upper side of the electronic assembly and covers the grounding end, the electronic assembly is located between the insulating film and the substrate, a groove penetrating through the two side faces of the insulating film is formed in the insulating film, a conductive part is arranged in the groove, and one end of the conductive part is connected with the grounding end; and the shielding film is attached to the upper side surface of the insulating film and covers the groove, and the shielding film is connected with the other end of the conductive part.

The invention discloses a silver-plated fiber, a multi-layer compound fabric of the silver-plated fiber and an after-treatment method of the fabric. The silver-plated fiber comprises a silver fiber body which is composed of a nylon fiber and a silver layer which wraps the surface layer of the nylon fiber, a bonding layer is formed between the silver layer and the nylon fiber, and the surface of the silver layer is coated with a protective layer which prevents the silver layer from being scratched in the weaving process. The after-treatment method of the multi-layer compound fabric of the silver-plated fiber includes the following steps of firstly, preparing the fabric of the silver-plated fiber, secondly, conducting enzyme treatment, thirdly, washing, and fourthly, stoving. A plant enzyme treatment mode is adopted for after-treatment, the problem that the silver layer is damaged due to the adoption of traditional alkali liquor treatment is solved, the bonding layer of the silver-plated fiber and the nylon fiber is effectively protected, firmness of the silver-plated fiber is improved, the electromagnetic shielding effect of the fabric of the silver-plated fiber is effectively improved, and the service life of the fabric is prolonged.

The invention discloses a membrane key switch and a manufacturing method of a membrane key panel. The membrane key switch is composed of a printed circuit board and the membrane key panel covering the printed circuit board. The printed circuit board comprises a ground wire layer, a power layer and a plurality of signal layers in sequence from bottom to top. A TVS power protector is connected between the ground wire layer and the power layer. An ESD static electricity resistor is connected between the ground wire layer and the multiple signal layers. The membrane key panel sequentially comprises a first protection layer, an antistatic layer, a PET substrate, a pattern layer, a shielding layer, a second protection layer, a conducive adhesive layer and a button cushion layer from top to bottom; the ground wire layer of the printed circuit board is connected with the shielding layer and the antistatic layer of the membrane key panel. The TVS power protector is connected between the power layer and the ground wire layer so as to reduce instantly-generated electromagnetic interference, and the ESD static electricity resistor is connected between the signal lines and the ground wire, so that the static electricity phenomenon generated by the touch effect is reduced, and a switch membrane switch body is protected.

The invention relates to the technical field of electromagnetic shielding materials, in particular to an electromagnetic shielding material with a good shielding effect. The electromagnetic shieldingmaterial is prepared from the following components in parts by weight: 15-32 parts of carbonyl nickel carbonylpowder, 5-18 parts of copper powder, 21-35 parts of polypropylene, 16-27 parts of fluororesin, 11-23 parts of a coupling agent, 15-31 parts of organic phosphide, 5-15 parts of graphite, 12-25 parts of composite fibres and 25-55 parts of fillers. The electromagnetic shielding material aimsto solve the problem that anthe existing electromagnetic shielding material is not good in electromagnetic shielding effect.

The present invention belongs to the field of chip package, and especially discloses a quantum chip package device. The quantum chip package device comprises: an electromagnetic shielding package boxconfigured to horizontally putting a quantum chip to be packaged and having an electromagnetic shielding effect; and a magnetostatic shielding cover coating the external portion of the electromagneticshielding package box and having a magnetostatic shielding effect. For the demand for the severe work environment of the quantum chip, the present invention provides a quantum chip package device with two layers of shielding structures, wherein the two layers of shielding structures are the electromagnetic shielding package box having the electromagnetic shielding effect and the magnetostatic shielding cover having the magnetostatic shielding effect coating the external portion of the electromagnetic shielding package box, the layers of the shielding structures work together to achieve shielding of different types of magnetic fields and magnetic fields with different intensities so as to commonly guarantee the work environment of the quantum chip to be packaged in the electromagnetic shielding package box.

The invention discloses a method for producing a nickel-plated carbon fiber board having electromagnetic shielding property. The method includes the steps: step 1, carbon fiber cloth surface treatment; step 2, magnetron sputtering nickel plating of the carbon fiber cloth surface; step 3, copper electroplating of the carbon fiber cloth surface; step 4, nickel electroplating of the carbon fiber cloth surface; step 5, drying; and step 6, board pressing. The nickel-plated carbon fiber plate has the electromagnetic shielding effectiveness of more than 40 dB in a 150 kHz-18 GHz electromagnetic field, and the stability of the electromagnetic shielding effect of carbon fiber cloth can be effectively improved through the nickel-copper-nickel three-plating-layer structure design; and through the composite material molding, a resin layer on the nickel-plated carbon fiber surface improves the corrosion resistance of the product.

The invention discloses a connector, which comprises a metal housing, an insulating body accommodated in the metal housing, a conductive terminal maintained in the insulating body and suitable for being electrically connected with the conductor of a cable, and a conductive shielding sleeve installed in the metal housing and electrically contacting the metal housing. The conductive shielding sleeveincludes an inner cylinder, and multiple clamp mouths are formed at the front end of the inner cylinder. The braided shielding wires of the cable are divided into multiple strands, and the multiple strands of braided shielding wires are respectively clamped in the clamp mouths and wound around the outer wall of the inner cylinder. According to the invention, the braided shielding wires of the cable are clamped in the clamp mouths of the inner cylinder of the conductive shielding sleeve, and the excessive braided shielding wires are directly wound around the inner cylinder of the conductive shielding sleeve, so that there is no need to cut off the excessive braided shielding wires. Therefore, the efficiency of connecting a cable to a connector is improved, and the electromagnetic shieldingeffect of the connector is guaranteed. The invention further discloses a method for electrically connecting the braided shielding layer of a cable to a connector.

A shielding case assembly comprises a metal shielding shell and a heat dissipation module. The metal shielding shell comprises a plurality of walls and an accommodating space defined by the pluralityof walls, and the accommodating space is provided with a front-end socket. The heat dissipation module is assembled on one wall of the metal shielding shell; the heat dissipation module comprises a hot plate which is connected to the metal shielding shell in a covering manner and is used for assembling the wall of the heat dissipation module; the hot plate comprises a first section used for covering the wall of the metal shielding shell and extending backwards to the rear side edge of the wall, and a second section which extends backwards out of the rear portion of the metal shielding shell from the rear side of the first section; and the heat dissipation module further comprises a first heat dissipation piece which is arranged on the top face of the hot plate and extends from the first section to the second section.