Low-leakage hand-held terminal

Abstract

The invention belongs to the technical field of electromagnetic radiation leakage, and particularly relates to a low-leakage handheld terminal. According to the method, efficient electromagnetic shielding is achieved in a Faraday cage structure mode through lap joint of all parts, the surface of a resistance screen is covered with an irregular metal net, and the space between the irregular metal net and a front cover is filled with an aluminum silver-plated conductive rubber plate used for cushioning and extrusion to achieve electric continuity between the irregular metal net and the front cover. The front cover, the middle frame and the rear cover are electrically continuous through opposite-penetrating screws, and copper foils are filled among contact surfaces of the middle frame, the rear cover and the front cover to enhance conductivity, so that the whole handheld terminal structure is in an electrically continuous state. The broadband electromagnetic shielding material has the beneficial effects that the electromagnetic shielding performance is remarkably improved, broadband effective protection is realized, the problem that the frequency band of a traditional electromagnetic shielding material is narrow is effectively solved, the shielding effectiveness of 40-50dB is realized in the broadband range of 30MHz to 1GHz, and the information safety level of equipment in an electromagnetic sensitive environment is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic radiation leakage technology, and specifically relates to a low-leakage handheld terminal. Background Technology

[0002] In today's rapidly developing information and digital age, handheld smart terminal devices are increasingly widely used, serving not only the daily lives of ordinary consumers but also playing a vital role in numerous professional fields. Especially in environments involving the storage and transportation of flammable and explosive materials, medical MRI examination rooms, high-precision electronic laboratories, and other settings with stringent information security requirements, the safety performance of handheld smart terminals is paramount. Electromagnetic radiation leakage is one of the most significant factors affecting equipment safety. The design and modification of low-leakage handheld smart terminals is undoubtedly a key measure to ensure the stable and reliable operation of these devices in special environments.

[0003] While most handheld smart terminals on the market possess a certain degree of anti-interference capability, they still fall short in addressing electromagnetic leakage in highly sensitive environments. For example, some traditional handheld devices use plastic casings and lack effective electromagnetic shielding, making them prone to signal leakage and posing a threat to information security. Furthermore, the adaptability and stability of ordinary handheld devices face challenges under extreme working conditions, such as high temperatures, low temperatures, vibration, and shock. To meet the stringent electromagnetic compatibility (EMC) standards of specific industries, such as the Class A standard of GJB4216-2001 "Requirements and Measurement of Electromagnetic Leakage Emissions from Cryptographic Machines," handheld smart terminals must undergo specialized design and ruggedization.

[0004] Among existing improvements, "An Electromagnetic Leakage Suppression Structure and Its Application (Publication No.: CN119545646A)" reduces the possibility of electromagnetic waves leaking into the external environment by forming a high-impedance barrier between the metal plate and the printed circuit board, thus improving the system's efficiency and reliability. However, this method is limited to suppressing electromagnetic leakage in local via areas and does not fundamentally solve the problems of insufficient electromagnetic shielding at the system-wide level and comprehensive protection across a wide frequency range for handheld terminals. "A Smartphone Antenna with Strong Anti-Interference Capability (Publication No.: CN217158629U)" focuses on suppressing local electromagnetic interference on the antenna body using conductive materials and optimizing the connection between the antenna and the motherboard to improve shielding stability. However, its effectiveness in controlling wide-band electromagnetic leakage at the system-wide level and suppressing multi-source interference in complex electromagnetic environments is limited. Although the above technologies improve the security performance of handheld terminals to some extent, many technical challenges remain to be solved in practical applications, especially in situations requiring high-standard electromagnetic leakage protection, such as how to achieve comprehensive, blind-spot-free electromagnetic shielding and how to ensure long-term stable operation of the equipment in harsh environments. Summary of the Invention

[0005] The purpose of this invention is to provide a low-leakage handheld terminal that can improve the applicability of handheld smart terminals in environments with high security requirements. It not only focuses on the electromagnetic sealing of the overall structure of the device, but also emphasizes comprehensive considerations such as material selection, thermal design, and vibration and shock protection to ensure that the device can operate normally under various harsh conditions.

[0006] The technical solution of the present invention is as follows: A low-leakage handheld terminal, comprising a Faraday cage structure to achieve efficient electromagnetic shielding by connecting various components, including: a resistive screen surface covered with an irregular metal mesh; an aluminum-plated silver conductive rubber plate filled between the irregular metal mesh and the front cover for shock absorption and compression to achieve electrical continuity between the irregular metal mesh and the front cover; through screws used between the front cover, the middle frame, and the rear cover to achieve electrical continuity; and copper foil filled between the contact surfaces of the middle frame, the rear cover, and the front cover to enhance conductivity, so that the entire handheld terminal structure is in an electrically continuous state.

[0007] The middle frame, back cover, and front cover are made of magnesium-aluminum alloy. The circuit board and PCB are installed inside the metal shell formed by the middle frame, back cover, and front cover.

[0008] The surface of the magnesium-aluminum alloy is subjected to conductive oxidation treatment.

[0009] The front cover integrates a cushioning material and a resistive screen, the resistive screen being made of a 250-mesh irregular shielding film mesh.

[0010] The irregular shielding film is made of transparent film and contains an irregular metal mesh.

[0011] A front camera is located on the upper part of the front cover.

[0012] The mid-frame is equipped with an Fn key, a Type-C interface, a microphone, an extended power interface, a power button, and volume down and volume up buttons.

[0013] The rear cover is equipped with a rear camera, a charging dock, and a speaker.

[0014] The beneficial effects of this invention are as follows: (1) Significantly improve electromagnetic shielding performance and achieve effective protection over a wide frequency band: Compared with the problem that traditional handheld terminals generally use plastic shells and have poor electromagnetic shielding capabilities, this invention effectively solves the problem of narrow frequency band of traditional electromagnetic shielding materials by adopting a customized magnesium-aluminum alloy shell, optimizing the internal structural layout, and combining multiple electromagnetic shielding measures such as shielded touch components, interface signal filters and power input filters. It achieves a shielding efficiency of 40-50dB in a wide frequency range of 30MHz to 1GHz, which significantly improves the information security level of the device in electromagnetically sensitive environments.

[0015] (2) Enhance the environmental adaptability and reliability of the equipment: In view of the problem that traditional equipment is not stable enough under complex environmental conditions, the present invention introduces conductive rubber strip sealing groove, thermal conductive silicone grease heat dissipation treatment and high-strength metal structural parts in the structural design. This not only improves the mechanical strength and sealing performance of the whole machine, but also enhances the adaptability of the equipment in harsh environments such as high temperature, low temperature, vibration and shock, and meets the requirements of high reliability.

[0016] (3) Balancing safety and maintainability, facilitating future upgrades and expansions: While ensuring electromagnetic shielding performance, the present invention rationally designs a modular structure, making key functional modules easy to disassemble and replace. This ensures the overall safety and integrity of the equipment without affecting subsequent maintenance and functional expansion, thereby improving the product's practicality and lifecycle management capabilities.

[0017] (4) Meets the requirements of relevant national standards and has good application prospects: The low-leakage handheld smart terminal designed in this invention can meet the technical indicators of Class A standard of GJB4216-2001 "Electromagnetic Leakage Emission Requirements and Measurement of Cryptographic Machines", and is suitable for fields with high requirements for information security. Attached Figure Description

[0018] Figure 1 This is a front view of a low-emission handheld terminal provided by the present invention. Figure 2 This is a schematic diagram of the back of a low-emission handheld terminal provided by the present invention; Figure 3A partial cross-sectional view of a low-emission handheld terminal provided by the present invention; Figure 4 This is a schematic diagram of an irregular network; Figure 5 This is a schematic diagram of the internal structure of a low-leakage handheld terminal provided by the present invention.

[0019] In the image: 1. Front cover, 2. Silver-plated aluminum conductive rubber plate, 3. Irregular metal mesh, 4. Resistive touchscreen, 5. Mid-frame, 6. Through screw, 7. Copper foil, 8. Rear cover, 11. Front camera, 12. Shielded touchscreen, 13. Fn key, 14. Type-C interface, 15. Microphone, 16. Extended power interface, 17. Power button, 18. Volume down, 19. Volume up, 20. Rear camera, 21. Charging cradle, 22. Speaker, 23. Flash, 24. Mounting bracket, 25. Second board, 26. Battery, 27. Filter assembly, 28. First board, 29. Night vision fill light, 30. Night vision camera. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Currently, most handheld devices on the market use plastic casings and lack effective electromagnetic shielding measures, leading to an increased risk of signal leakage. This leakage can pose serious security risks, especially in critical areas involving national and information security. Although some products have attempted to reduce electromagnetic wave leakage by adding external protective layers or optimizing antenna layout, these methods are often limited to localized improvements and fail to fundamentally solve the problem of electromagnetic leakage at the internal circuit boards and interfaces of the device.

[0022] This invention provides a low-leakage handheld terminal that achieves efficient electromagnetic shielding over a wide frequency range by employing a customized magnesium-aluminum alloy shell, optimizing the internal structural layout, and adding electromagnetic shielding components. Specifically, this invention utilizes efficient electromagnetic shielding technologies, including but not limited to customized shielded touch components, and adding interface signal filters and power input filters, effectively solving the problem of narrow frequency bands in traditional electromagnetic shielding materials. This ensures that the device achieves a shielding effectiveness of 40-50dB over a wide frequency range of 30MHz to 1GHz. Furthermore, this design also pays special attention to the environmental adaptability of the device. Through the selection and processing of materials, reasonable heat dissipation design, and strengthening of structural components, the reliability and durability of the device are improved. In summary, this invention not only improves the electromagnetic shielding effect of handheld smart terminals over a wide frequency range but also provides a novel solution for professional users requiring high levels of information security.

[0023] A low-leakage handheld terminal employs a customized magnesium-aluminum alloy shell and an irregular shielding film, solving the problem of narrow frequency bands inherent in traditional electromagnetic shielding materials. The internal structural layout is optimized, including but not limited to the addition of interface signal filters and power input filters, ensuring excellent shielding performance over a wide frequency range. Material selection and processing techniques, particularly the conductive oxidation treatment of the magnesium-aluminum alloy surface and the use of highly corrosion-resistant metals, enhance the device's adaptability to harsh environments.

[0024] like Figure 1 As shown, a low-leakage handheld terminal includes a Faraday cage structure achieved through the overlapping structure of various components to achieve efficient electromagnetic shielding. The surface of the resistive screen 4 is covered with an irregular metal mesh 3 (such as...). Figure 4 As shown, an aluminum-plated silver conductive rubber sheet 2 is filled between the irregular metal mesh 3 and the front cover 1 for shock absorption and compression to achieve electrical continuity between the irregular metal mesh 3 and the front cover 1. Through screws 6 are used between the front cover 1, the middle frame 5, and the rear cover 8 to achieve electrical continuity between the various structures. Copper foil 7 is filled between the contact surfaces of the middle frame 5, the rear cover 8, and the front cover 1 to enhance conductivity. Ultimately, the entire handheld terminal structure is in a state of electrical continuity, thereby preventing electromagnetic wave leakage and ensuring the overall sealing and electromagnetic compatibility of the device.

[0025] The middle frame 5, rear cover 8, and front cover 1 are made of magnesium-aluminum alloy as the shell material for the handheld smart terminal. This material is not only lightweight and high-strength, but also has good electrical conductivity, which helps to form an effective electromagnetic shielding cavity. First, by scanning and mapping the original shell and the dimensions of the mounting holes, the middle frame 5, rear cover 8, and front cover 1 form a metal shell. The circuit board and PCB are installed inside the metal shell. The surface of the magnesium-aluminum alloy is treated with conductive oxidation (Ct.Ocd), and the outer surface of the device is sprayed as required to enhance its corrosion resistance and electromagnetic compatibility.

[0026] The front cover 1 integrates cushioning material and a custom-designed shielded touchscreen. The resistive touchscreen 4 uses a 250-mesh irregular shielding film mesh, which can provide 40-50dB of shielding effectiveness in the frequency range of 30MHz to 1GHz, while maintaining a light transmittance of more than 80% to ensure that the visual effect is not affected.

[0027] Irregular shielding mesh is made of transparent film containing irregular metal mesh, which can effectively block the radiation of various electromagnetic waves and avoid the occurrence of moiré stripes.

[0028] like Figure 5As shown, a battery 26 is installed in the housing space formed by the middle frame 5, the rear cover 8, and the front cover 1. Filter components 27 are installed on both sides of the battery 26. A flash 23, a mounting bracket 24, a second board 25, a night vision fill light 29, and a night vision camera 30 are installed above the battery 26. A first board 28 is installed above the battery 26. A filter component 27 is installed at the interface between the first board 28 and the second board 25. A filter component 27 is also installed at the interface between the second board 25 and the shielded touch screen 12. A power input filter is added at the power input end to further reduce electromagnetic interference and ensure electromagnetic compatibility between the modules inside the device.

[0029] Heat dissipation statistics were performed on the internal components of the equipment to identify the main heat sources, such as the CPU chip and memory chip installed on the second board 28. Thermal grease was applied to these critical areas, and the boards were screwed onto the back cover. The large heat dissipation area of ​​the back cover was used to accelerate heat dissipation, ensuring that the equipment could operate stably even in high-temperature environments.

[0030] Magnesium-aluminum alloy with good vibration resistance was selected, and conductive rubber plates were installed between various structural components to reduce vibration. All pan head screws were fitted with flat washers and spring washers, and countersunk screws were coated with anti-loosening agent to prevent loosening due to vibration. In addition, all welded joints were protected with heat shrink tubing to prevent the welds from falling off.

[0031] The front cover is milled from magnesium-aluminum alloy, with rounded corners and beveled edges around the perimeter, making the device more streamlined and improving user comfort. The front frame has pre-drilled protrusions around its perimeter, which, in conjunction with corresponding grooves on the rear frame, create a good shielding overlap.

[0032] The back cover is also made of magnesium-aluminum alloy and is designed with mounting holes for accurate installation of circuit boards and other PCBs, batteries, filter components, and other devices. Both the front and back covers are secured with screws for easy disassembly and maintenance.

[0033] Depending on the usage environment, different surface protection treatments are applied to the parts. Parts requiring conductivity are nickel-plated; parts without conductivity requirements are anodized with sulfuric acid to ensure good corrosion resistance and mechanical strength.

[0034] Through the detailed implementation steps and technical means described above, this invention proposes a low-leakage handheld smart terminal, which solves the shortcomings of traditional handheld devices in electromagnetic leakage protection and improves the overall safety and reliability of the device. This innovative solution not only meets the requirements of the GJB4216-2001 Class A standard, but also provides a brand-new option for professional users who require high levels of information security.

[0035] This invention has the following characteristics: (1) High-efficiency electromagnetic shielding structure: This invention uses a customized magnesium-aluminum alloy shell to replace the original plastic shell. By chiseling sealing grooves at the connection points and installing conductive rubber strips, a cavity with high-efficiency electromagnetic shielding performance is formed. In addition, the application of customized shielded touch components and irregular shielding film further enhances the overall shielding effectiveness of the equipment, solves the problem of narrow frequency band of traditional electromagnetic shielding materials, and achieves a shielding effect of 40-50dB in a wide frequency range of 30MHz to 1GHz.

[0036] (2) Enhanced environmental adaptability design: Considering the extreme working conditions that the equipment may face, the present invention has strictly screened the materials and selected magnesium-aluminum alloy with strong corrosion resistance and good mechanical properties as the main structural material. At the same time, a series of measures have been taken for thermal design and vibration and shock protection, such as applying thermal conductive silicone grease to improve heat dissipation efficiency and adding conductive rubber plates to reduce the impact of vibration, thereby improving the reliability and durability of the equipment.

[0037] (3) Comprehensive electromagnetic compatibility protection: This invention also adds interface signal filters and power input filters, which effectively suppress electromagnetic interference from the interface and power supply sections, ensuring that the equipment can still operate stably in complex electromagnetic environments. In addition, through reasonable internal layout and shielding design, mutual interference between electrical components is reduced, improving the overall electromagnetic compatibility of the equipment.

Claims

1. A low-leakage handheld terminal, characterized in that: This includes achieving efficient electromagnetic shielding through a Faraday cage structure formed by connecting various components. Specifically, the resistive screen surface is covered with an irregular metal mesh, and an aluminum-plated silver conductive rubber plate is filled between the irregular metal mesh and the front cover to cushion shock and compress, thus achieving electrical continuity between the irregular metal mesh and the front cover. Through screws are used between the front cover, middle frame, and back cover to achieve electrical continuity, and copper foil is filled between the contact surfaces of the middle frame, back cover, and front cover to enhance conductivity, so that the entire handheld terminal structure is in an electrically continuous state.

2. The low-leakage handheld terminal as described in claim 1, characterized in that: The middle frame, back cover, and front cover are made of magnesium-aluminum alloy. The circuit board and PCB are installed inside the metal shell formed by the middle frame, back cover, and front cover.

3. A low-leakage handheld terminal as described in claim 2, characterized in that: The surface of the magnesium-aluminum alloy is subjected to conductive oxidation treatment.

4. A low-leakage handheld terminal as described in claim 2, characterized in that: The front cover 1 integrates a buffer material and a resistive screen, the resistive screen being a 250-mesh irregular shielding film.

5. A low-leakage handheld terminal as described in claim 4, characterized in that: The irregular shielding film is made of transparent film and contains an irregular metal mesh.

6. A low-leakage handheld terminal as described in claim 1, characterized in that: A front camera is located on the upper part of the front cover.

7. A low-leakage handheld terminal as described in claim 1, characterized in that: The mid-frame is equipped with an Fn key, a Type-C interface, a microphone, an extended power interface, a power button, and volume down and volume up buttons.

8. A low-leakage handheld terminal as described in claim 1, characterized in that: The rear cover is equipped with a rear camera, a charging dock, and a speaker.

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