Electromagnetic shielding device
By combining the stepped structure design of the thin-walled lower shell and the cover plate with conductive materials, the problems of bulky and low space utilization of existing electromagnetic shielding shell structures are solved, achieving efficient electromagnetic shielding and thermal management.
Patent Information
- Application Number
- CN202520379501.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-06
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-03-06
AI Technical Summary
Existing electromagnetic shielding housings are bulky and complex, increasing the thickness and weight of the housing walls and resulting in low space utilization, making it difficult to achieve efficient electromagnetic shielding.
It adopts a stepped structure design with a thin-walled lower shell and cover plate, combined with conductive materials and elastomers, and forms a closed box through fasteners. It uses elastic compression and multi-point contact to achieve electrical continuity and sealing, and has built-in heat conduction channels for thermal management.
It improves electromagnetic shielding effectiveness, reduces the number of fasteners, enhances structural rigidity, improves space utilization, and achieves effective shielding and thermal management of high-frequency electromagnetic waves.
Smart Images
Figure CN223957866U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to aviation electronic equipment electromagnetic shielding shell technical field, concretely to especially relate to a kind of electromagnetic shielding device. BACKGROUND
[0002] From the angle of electromagnetic shielding, shielding machine shell should have continuous structure, and be provided with joint and opening. The joint of each joint surface of machine shell is the main factor influencing the shielding effectiveness of structural member, including the maximum size of gap, the depth of gap, whether shielding material is installed or not and the like. In actual design, the maximum size of gap is also affected by the distance of fastening point, the rigidity of machine shell, the accuracy of joint surface and the like factors.
[0003] In prior art, the machine shell designed for electromagnetic shielding is mostly metal material or conductive plastic, and the cavity formed by two or more pieces of metal processing or splicing is used to wrap electronic devices such as PCB circuit inside. The splicing surface of machine shell realizes the electrical continuity of machine shell as shielding body by reducing the distance of fastening member, increasing shielding material and the like. The common structure design of increasing shielding material has the following disadvantages: when shielding gasket is arranged on the main body of joint surface of machine shell splicing, it will result in the increase of machine shell wall thickness, the occupation of internal space, the increase of product weight and the like. CONTENT OF UTILITY MODEL
[0004] The utility model aims at providing an electromagnetic shielding device to solve the problems in the background art.
[0005] To achieve the above-mentioned purpose, the utility model realizes the following technical means:
[0006] An electromagnetic shielding device comprises a thin-walled lower shell, a cover plate, shielding material and fastening members. The side wall thickness of the cover plate is greater than that of the thin-walled lower shell. The lower surface of the side wall of the cover plate is arranged in a stepped manner. The shielding material is arranged in the groove formed by the stepped structure of the lower surface of the side wall of the cover plate. The upper surface of the side wall of the thin-walled lower shell is provided with a flange for extruding the elastically arranged shielding material. The width of the groove is greater than that of the flange. The two side walls of the flange are not connected with the side walls of the groove. The thin-walled lower shell and the cover plate are combined to form a closed box body by means of the fastening members.
[0007] Further, the thin-walled lower shell is made of aluminum alloy or conductive plastic, the wall thickness is 1.5-2.5 mm, the flange height is 0.2-0.6 mm, the flange is used to form a pressure joint structure with the cover plate, the wall thickness of the cover plate is 2.0-3.0 mm, the edge is thickened to 3.5-4.0 mm to enhance the rigidity, the groove depth is 0.6-1.2 mm, the shielding material is silver-plated silicone rubber or metal wire mesh composite elastomer, the pre-compression rate is designed to be 15%-25%, and the compression thickness after installation is 0.4-1.0 mm, so that the contact resistance at the joint is ensured to be less than or equal to 5 mΩ.
[0008] Further, the thin-walled lower shell edge is designed with three-stage stepped bosses, each stage has a depth of 0.2 mm, the conductive silicone is filled between the bosses, the cover plate is provided with stepped grooves at the corresponding positions, the gap of the tolerance fit is less than or equal to 0.05 mm, the elastic compression is realized to realize step-by-step sealing, and the stepped groove bottom formed between the bosses is embedded with arrayed beryllium copper spring contacts to avoid single shielding failure.
[0009] Further, the thin-walled lower shell is made of aluminum alloy or conductive plastic, the wall thickness is 1.5-2.5 mm, the flange height is 0.2-0.6 mm, the flange is used to form a pressure joint structure with the cover plate, the wall thickness of the cover plate is 2.0-3.0 mm, the edge is thickened to 3.5-4.0 mm to enhance the rigidity, the groove depth is 0.6-1.2 mm, the shielding material is silver-plated silicone rubber or metal wire mesh composite elastomer, the pre-compression rate is designed to be 15%-25%, and the compression thickness after installation is 0.4-1.0 mm, so that the contact resistance at the joint is ensured to be less than or equal to 5 mΩ.
[0010] Further, the thin-walled lower shell is made of aluminum alloy or conductive plastic, the wall thickness is 1.5-2.5 mm, the flange height is 0.2-0.6 mm, the flange is used to form a pressure joint structure with the cover plate, the wall thickness of the cover plate is 2.0-3.0 mm, the edge is thickened to 3.5-4.0 mm to enhance the rigidity, the groove depth is 0.6-1.2 mm, the shielding material is silver-plated silicone rubber or metal wire mesh composite elastomer, the pre-compression rate is designed to be 15%-25%, and the compression thickness after installation is 0.4-1.0 mm, so that the contact resistance at the joint is ensured to be less than or equal to 5 mΩ.
[0011] Compared with the prior art, the utility model has the advantages of simple structure, high space utilization, shielding effect, fastening screws distributed on the inside of the cover plate, relatively high strength of the cover plate due to the thickened edge design, difficult to deform to generate a gap, improved shielding effect, and appropriately increased fastener spacing to reduce the number of fasteners.
[0012] The utility model discloses simple structure, space utilization is high, shielding effect, fastening screw distribution is in the inside of cover plate, because of the thickening design of cover plate edge, the strength of cover plate is relatively higher, and the gap is not easy to deform and produce, improves shielding effect, and can increase fastener spacing properly, reduces the number of fasteners. BRIEF DESCRIPTION OF DRAWINGS
[0013] Figure 1 It is product structure schematic diagram in the embodiment of the utility model;
[0014] Figure 2 It is product sectional structure schematic diagram in the embodiment of the utility model;
[0015] Figure 3 It is the structure amplification schematic diagram of A part in the embodiment of the utility model; Figure 2
[0016] Figure 4 It is product part structure amplification schematic view of the embodiment of the utility model;
[0017] Figure 5 It is product part structure implementation schematic view of the embodiment of the utility model;
[0018] Figure 6 It is product part structure implementation schematic view of the embodiment of the utility model;
[0019] Figure 7 It is product part structure implementation schematic view of the embodiment of the utility model;
[0020] Figure 8 It is product part structure implementation schematic view of the embodiment of the utility model;
[0021] Figure 9 It is product part structure implementation schematic view of the embodiment of the utility model. Specific implementation
[0022] The embodiments of the technical scheme of the application will be described in detail below with reference to the drawings. The following embodiments and drawings are only used to more clearly illustrate the technical scheme of the application, and therefore only serve as examples, and cannot limit the protection scope of the application. The drawings only schematically represent the parts related to the technical scheme of the application, and they do not represent the actual structure of the product.
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments of the application, and are not intended to limit the application; the terms "include" and "have" and any variations thereof in the specification and claims of the application and the above description of drawings are intended to cover non-exclusive inclusion.
[0024] In the description of the embodiments of the application, the technical terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).
[0025] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be incorporated into any other embodiment.
[0026] In the description of the embodiments of the present application, the term“and / or” is merely used to describe an associated relationship between associated objects, and indicates that there can be three relationships, for example, A and / or B can indicate that there are three cases of A alone, A and B together, and B alone. In addition, the character“ / ” herein generally indicates that the front and rear associated objects are in an“or” relationship.
[0027] In the description of the embodiments of the present application, the technical terms“center”,“longitudinal”,“transverse”,“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“clockwise”,“counterclockwise”,“axial”,“radial”,“circumferential” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.
[0028] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms“mounting”,“connection”,“connection”,“fixing” and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.
[0029] From the perspective of electromagnetic shielding, the shielding enclosure should have a continuous structure and be provided with joints and openings. The joints at each joint surface of the enclosure are the main factors affecting the shielding effectiveness of the structural member, including the maximum size of the gap, the depth of the gap, whether shielding material is installed, etc. In actual design, the maximum size of the gap is also affected by the spacing of the fastening points, the rigidity of the enclosure, the precision of the joint surface, etc.
[0030] In the prior art, the shell designed for electromagnetic shielding is mostly made of metal or conductive plastic, and the PCB circuit and other electronic devices are wrapped in the cavity formed by two or more pieces of metal processing or splicing. The splicing surface of the shell realizes the electrical continuity of the shell as a shielding body by reducing the spacing of fasteners, increasing shielding materials, and other ways. The common structure design of increasing shielding materials has the following disadvantages: when the shielding gasket is arranged on the main body of the splicing surface of the shell, it will lead to an increase in the wall thickness of the shell, occupation of internal space, and an increase in product weight. Based on the above, the existing shielding shell structure has the following disadvantages: heavy and complex structure: the shielding groove of the shell occupies the wall thickness, resulting in an increase in the thickness of the shell and an increase in weight. If the weight is to be reduced, the internal space needs to be milled, and the milled step is a reverse T type, which has very large processing limitations; low space utilization: even if the internal space is milled, the space in the milled wall thickness cavity cannot be used as the space of the printed board due to the diameter limitation of the combination surface of the lower shell and the cover plate, which reduces the space utilization of the printed board.
[0031] In the present embodiment, an electromagnetic shielding device includes a thin-walled lower shell 100, a cover plate 200, a shielding material 300, and a fastener 400. The side wall thickness of the cover plate 200 is greater than the side wall thickness of the thin-walled lower shell 100. The lower surface of the side wall of the cover plate 200 is arranged in a stepped manner. The shielding material 300 is arranged in the groove 210 formed by the stepped structure arranged on the lower surface of the side wall of the cover plate 200. The upper surface of the side wall of the thin-walled lower shell 100 is provided with a flange 110 for extruding the elastically arranged shielding material 300. The width of the groove 210 is greater than the width of the flange 110. The two side walls of the flange 110 are not connected to the side walls of the groove 210. The thin-walled lower shell 100 and the cover plate 200 are connected by a plurality of fasteners 400 to form a closed box body.
[0032] In one or more possible embodiments of the utility model, the thin-walled lower shell 100 is made of aluminum alloy or conductive plastic, the wall thickness is 1.5-2.5 mm, the height of the flange 110 is 0.2-0.6 mm, and the flange 110 is used to form a crimping structure with the cover plate 200, the wall thickness of the cover plate 200 is 2.0-3.0 mm, the edge is thickened to 3.5-4.0 mm to enhance rigidity, the groove depth of the groove 210 is 0.6-1.2 mm, the shielding material 300 is silver-plated silicone rubber or metal mesh composite elastomer, the pre-compression rate is designed to be 15%-25%, the compression thickness after installation is 0.4-1.0 mm, the contact resistance at the joint is ensured to be ≤5 mΩ, the flange 110 on the thin-walled lower shell 100 and the groove 210 on the cover plate 200 are crimped, the elastic shielding material 300 is pre-compressed during assembly, the joint gap between the cover plate 200 and the thin-walled lower shell 100 is realized by the conductive shielding material 300, and the fastening screws are distributed on the inner side of the cover plate 200, so that the strength of the cover plate 200 is relatively high, the cover plate 200 is not easy to deform to generate a gap, and the shielding effect is improved.
[0033] In one or more possible embodiments of the utility model, in order to further improve the electromagnetic shielding efficiency of the device, the thin-walled lower shell 100 is provided with three stepped bosses 120, each step has a depth of 0.2 mm, the bosses are filled with conductive silicone, the cover plate 200 is provided with stepped grooves 220 at the corresponding positions, the tolerance fitting gap is ≤0.05 mm, and the bosses are sequentially sealed by elastic compression, in order to avoid single shielding failure, the stepped groove bottoms formed between the bosses are embedded with arrayed beryllium copper spring contacts 130, the contact compression amount is 0.1-0.15 mm, the high-frequency electromagnetic wave shielding efficiency is ensured to be ≥80 dB, the electromagnetic shielding efficiency is improved to 120 dB under the condition of 100 MHz-10 GH, and the assembly tolerance capacity is improved by 50%.
[0034] In one or more possible embodiments of the utility model, the upper surface edge of the thin-walled lower shell 100 is provided with a micro-tooth array 140 with a depth of 0.1-0.3 mm, the micro-tooth array 140 forms multiple-point contact with the conductive cloth 230 arranged in the groove 210 of the cover plate 200, the surface resistance of the conductive cloth 230 is less than or equal to 0.05 ohm per inch, the maximum size of the fitting edge gap between the thin-walled lower shell 100 and the cover plate 200 is controlled within 1 / 50 of the wavelength of the highest shielding frequency band, the micro-tooth array 140 structure forms a concave-convex labyrinth with a tooth depth of 0.1-0.3 mm, the actual gap path is extended to less than or equal to 1 / 50 of the wavelength of the high-frequency wave, the conductive cloth 230 is embedded in the groove of the cover plate 200, and the micro-tooth tip forms distributed multiple-point contact with the conductive cloth 230 through elastic pressure connection, the double-barrier design makes the contact point density reach more than 50 points per cm, ensures that the equivalent impedance at the joint is less than or equal to 2 mΩ, and the thin-walled lower shell 100 and the cover plate 200 are provided with a fitting tolerance compensation space of 0.05-0.1 mm in the stepped fitting structure to avoid structural deformation caused by rigid contact. At the same time, the conductive cloth 230 realizes stable contact pressure in a vibration environment by using a silicone rubber base, and the recommended value is 1.5-3 N / mm 2 The joint treatment scheme can make the shielding effectiveness increase by more than 15 dB in the 1-10 GHz frequency band, and meet the RS105 radiation sensitivity requirement of MIL-STD-461G.
[0035] In one or more possible embodiments of the utility model, when the device is implemented, internal elements work and heat, and heat is accumulated due to the closed device. A micro-channel 150 is arranged on the inner wall of the thin-walled lower shell 100, a nickel-based composite coating is sprayed on the surface of the micro-channel 150, a heat-conducting ceramic sheet 160 is embedded in the micro-channel 150, the heat-conducting ceramic sheet 160 is connected with a cooling liquid circulation system, and the heat-conducting ceramic sheet 160 is welded and sealed at the position where it penetrates out of the thin-walled lower shell 100 by using a conductive indium-tin alloy, so that the shielding effectiveness at the joint is greater than or equal to 80 dB, and the heat and electricity collaborative management can be effectively realized through the above structural design, and the contradiction between heat dissipation and electromagnetic shielding of high-power devices is solved.
[0036] In one or more possible embodiments of the utility model, another heat dissipation structure is provided, a wave-shaped micro-channel 150 is arranged on the inner wall of the thin-walled lower shell 100, a nickel-based composite coating is sprayed on the surface of the micro-channel 150, a flat heat pipe is embedded in the micro-channel 150, the evaporation end of the flat heat pipe contacts a PCB heating element arranged in the device, the condensation end of the flat heat pipe extends to a heat dissipation fin on the outer sidewall of the thin-walled lower shell 100, and the flat heat pipe is welded and sealed at the position where it penetrates out of the thin-walled lower shell 100 by using a conductive indium-tin alloy.
[0037] In one or more possible embodiments of the utility model, in order to facilitate the simplification of maintenance process, support the quick replacement of structural components, and maintain the integrity of the shielding effect of the device, the cover plate 200 edge is embedded with a neodymium iron boron permanent magnet 260, the surface of the neodymium iron boron permanent magnet 260 is plated with nickel, the sidewall edge of the thin-walled lower shell 100 is provided with a magnetically conductive stainless steel layer 180, the neodymium iron boron permanent magnet 260 and the magnetically conductive stainless steel layer 180 form magnetic attraction positioning, which can assist screw fastening, shorten the maintenance time, effectively reduce the shielding efficiency fluctuation when the device module is replaced, reduce the use amount of fasteners 400 (fastening screws in the figure), and reduce the device deformation risk caused by assembly stress.
[0038] The specific embodiments disclosed in the utility model fall within the protection scope of the utility model claim, are the specific lower level implementation range of the feature part of the utility model, and the protection content of the specific embodiments is only for the description of the protection scope of the utility model claim. The protection scope of the utility model is not limited to the protection content of the specific embodiments, and the protection content of the specific embodiments should not be understood as the limitation of the protection scope of the utility model claim.
Claims
1. An electromagnetic shielding device comprising a thin-walled lower housing (100), a cover plate (200), a shielding material (300) and fasteners (400), characterized in that: The side wall thickness of the cover plate (200) is greater than the side wall thickness of the thin-walled lower shell (100), the lower surface of the side wall of the cover plate (200) is arranged in a stepped manner, the shielding material (300) is arranged in the groove (210) formed by the stepped structure arranged on the lower surface of the side wall of the cover plate (200), the upper surface of the side wall of the thin-walled lower shell (100) is provided with a flange (110) for extruding the elastically arranged shielding material (300), the width of the groove (210) is greater than the width of the flange (110), the two side walls of the flange (110) are not connected with the side walls of the groove (210), and the thin-walled lower shell (100) and the cover plate (200) are cooperated to form a closed box body through a plurality of fasteners (400).
2. An electromagnetic shielding device according to claim 1, characterized in that: The wall thickness of the thin-walled lower shell (100) is 1.5-2.5mm, the height of the flange (110) is 0.2-0.6mm, and the flange (110) is used to form a pressure joint structure with the cover plate (200), the wall thickness of the cover plate (200) is 2.0-3.0mm, the edge is thickened to 3.5-4.0mm, the groove depth of the groove (210) is 0.6-1.2mm, the flange (110) on the thin-walled lower shell (100) is in pressure joint with the groove (210) on the cover plate (200), the elastic shielding material (300) is pre-compressed during assembly, the gap between the cover plate (200) and the thin-walled lower shell (100) is electrically continuous through the conductive shielding material (300), and the fastening screws are distributed on the inside of the cover plate (200).
3. The electromagnetic shielding device of claim 1, wherein: The thin-walled lower shell (100) is provided with three-stage stepped bosses (120) at the edge, each stage has a depth of 0.2mm, and each boss is filled with conductive silica gel, and the cover plate (200) is provided with stepped grooves (220) at the corresponding positions.
4. An electromagnetic shielding device according to claim 3, wherein: The stepped grooves formed between the bosses in the three-stage stepped bosses (120) are embedded with arrayed beryllium copper spring contacts (130) at the bottom, and the compression amount of the contacts is 0.1-0.15mm.
5. The electromagnetic shielding device of claim 1, wherein: The upper surface edge of the thin-walled lower shell (100) is provided with a micro-tooth array (140) with a depth of 0.1-0.3mm, the micro-tooth array (140) forms multiple-point contact with the conductive cloth (230) arranged in the groove (210) of the cover plate (200), and the maximum size of the gap between the thin-walled lower shell (100) and the cover plate (200) is controlled to be within λ / (50), and λ is the wavelength of the highest shielding frequency band.
6. The electromagnetic shielding device of claim 1, wherein: The inner wall of the thin-walled lower shell (100) is provided with a micro-channel (150), the surface of the micro-channel (150) is sprayed with a nickel-based composite coating, a heat-conducting ceramic sheet (160) is embedded in the micro-channel (150), the heat-conducting ceramic sheet (160) is connected with a cooling liquid circulation system, and the heat-conducting ceramic sheet (160) penetrates out of the thin-walled lower shell (100) and is welded and sealed by using a conductive indium-tin alloy.
7. The electromagnetic shielding device of claim 1, wherein: The edge of the cover plate (200) is embedded with a neodymium iron boron permanent magnet (260), the surface of the neodymium iron boron permanent magnet (260) is plated with nickel, the side wall edge of the thin-walled lower shell (100) is provided with a magnetically conductive stainless steel layer (180), and the neodymium iron boron permanent magnet (260) and the magnetically conductive stainless steel layer (180) form magnetic attraction positioning.