Terminal device

Abstract

The embodiment of the invention relates to the technical field of communication equipment, and provides terminal equipment. The terminal equipment comprises a circuit board, a shielding cover and a resistive element. A target device is arranged on the circuit board; the shielding cover covers a target device, is arranged on the circuit board and is in structural connection with the circuit board; and the resistive element is used for realizing electrical connection between the shielding case and the circuit board. According to the terminal equipment provided by the embodiment of the invention, the resistive element for grounding is additionally arranged between the shielding case and the circuit board, and the resistive element is utilized to consume current at two ends of a parasitic capacitor of LC resonance formed between the target device and the shielding case, so that the problems of isolation deviation and deterioration of the shielding case in the use process are solved.

Description

Technical Field

[0001] The present application relates to the technical field of communication equipment, and in particular to a terminal device. Background Art

[0002] In the field of communication equipment, shielding covers are provided to prevent electromagnetic radiation interference, electromagnetic wave leakage, etc.

[0003] However, the use of a shielding case can cause noise coupling. For example, during passive intermodulation testing, a power amplifier inside the shielding case can generate harmonics that couple to certain traces within the shielding case and, through these traces, to the outside of the shielding case. Furthermore, in mobile phones, tablet computers, and other terminal devices, to prevent electromagnetic noise coupling between the camera and the motherboard, which can lead to interference immunity issues, adding a shielding case can actually degrade interference immunity in certain frequency bands. Summary of the Invention

[0004] An embodiment of the present application provides a terminal device that can improve the technical problem of deterioration of anti-interference isolation after using a shielding cover.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] The present application provides a terminal device, including:

[0007] The circuit board is the main carrier of various components in the terminal device. For example, the circuit board can be the motherboard of a mobile phone or tablet computer. The target device is arranged on the circuit board. Among them, the target device can be a power amplifier, antenna, tuning circuit, etc., components that can generate electromagnetic noise, and can also be camera connection points and wiring on the motherboard;

[0008] A shielding cover is provided on the target device to provide corresponding electromagnetic protection for the target device. The shielding cover is placed on the circuit board and is structurally connected to the circuit board.

[0009] Resistive element, the resistive element is used to achieve electrical connection between the shielding cover and the circuit board. Among them, the resistive element is an element that hinders the passage of current in the circuit. The resistive element is made of conductive material and has a corresponding resistance value. The resistive element can be a resistor, as well as a conductor made of metal material, etc.

[0010] It should be noted that the shielding cover installed on the target device can be divided into a fully enclosed cover and a semi-enclosed cover. Among them, the fully enclosed cover refers to the target device being completely enclosed and shielded on all sides, which is suitable for electromagnetic protection of antennas and power amplifiers, etc. The semi-enclosed cover means that the target device is not completely enclosed by the shielding cover, and at least one side of the target device is connected to the outside world.

[0011] The resistive element can be located either inside or outside the shielding case. For example, when the shielding case fully encloses the target device, the resistive element is located inside the shielding case, with one end of the resistive element connected to the inner wall of the shielding case and the other end connected to the circuit board. In other words, the shielding case is grounded to the circuit board through the resistive element. For another example, when the shielding case semi-encloses the target device, the resistive element is located outside the shielding case and placed on the circuit board. Similarly, one end of the resistive element is connected to the inner wall of the shielding case and the other end is connected to the circuit board.

[0012] The above technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0013] The terminal device provided in the embodiment of the present application adds a resistive element for grounding between the shielding cover and the circuit board, and uses the resistive element to consume the current at both ends of the parasitic capacitance of the LC resonance formed between the target device and the shielding cover, thereby improving the isolation deviation and deterioration problem of the shielding cover during use.

[0014] In some embodiments, the shielding cover includes a fully enclosed shielding cover, the resistive element includes a conductive member and a resistance element electrically connected to the conductive member, one end of the conductive member away from the resistance element is connected to the inner wall of the fully enclosed shielding cover, and one end of the resistance element away from the conductive member is connected to the circuit board.

[0015] It can be understood that the fully enclosed shielding cover can fully enclose the target device, that is, the fully enclosed shielding cover is a cover structure with only one opening, with its open end facing the target device and connected to the circuit board, thereby isolating the target device from the outside world. In addition, the resistive element includes two parts, namely, a conductive part and a resistive element. Among them, the conductive part is a structural part made of metal or non-metallic material with conductive properties, and the resistive element is made of conductive material and has a fixed resistance value or a variable resistance value. Then, the isolation difference caused by the parasitic capacitance of the LC resonance formed between the target device and the shielding cover can be improved by the conductive part and the resistive element.

[0016] In some embodiments, the conductive member includes any one or more of a spring sheet, a rib, foam, a rivet, and a screw.

[0017] It is understood that the structural form of the conductive member is not limited and can be one or more structural members in different usage scenarios, such as the aforementioned spring clips, spacers, foam, rivets, and screws. For example, when the target device is fully enclosed, the conductive member can be a spring clip and / or spacer formed within the fully enclosed shielding case; in another example, the conductive member can be a screw screwed onto the fully enclosed shielding case. Therefore, the structural form of the conductive member can be adjusted according to different usage scenarios to meet the corresponding installation requirements.

[0018] In some embodiments, the conductive member is integrally connected to the fully enclosed shielding cover.

[0019] It is understood that the end of the conductive member remote from the resistor element is integrally formed with the fully enclosed shielding cover. For example, once the target device is positioned on the circuit board, the conductive member can be integrally formed on the inner wall of the fully enclosed shielding cover. In this way, when the fully enclosed shielding cover is placed over the target device, the conductive member is positioned, thus reducing the difficulty of installing the conductive member.

[0020] In some embodiments, the conductive member is detachably connected to the fully enclosed shielding cover.

[0021] It is understood that the end of the conductive member remote from the resistor element can be detachably connected to the fully enclosed shielding cover by plugging, snapping, bonding, or the like. For example, an opening can be provided in the fully enclosed shielding cover, through which the conductive member is inserted into the fully enclosed shielding cover. Alternatively, conductive adhesive can be applied to the fully enclosed shielding cover in advance, and the conductive member is bonded to the conductive adhesive to connect to the fully enclosed shielding cover. In this way, the position of the conductive member on the fully enclosed shielding cover can be adjusted according to actual use requirements, thereby improving the adaptability of the conductive member's position setting.

[0022] In some embodiments, the conductive member is located around the target device, and a distance from the conductive member to the target device is less than or equal to a distance from the target device to a top inner wall of the fully enclosed shielding cover.

[0023] Understandably, as the distance between the target device and the fully enclosed shield changes, the LC resonant frequency changes accordingly, indicating the presence of parasitic capacitance between the target device and the fully enclosed shield. Consequently, the current peak is located between the target device and the fully enclosed shield's ground plane. Therefore, when the conductive member is located around the target device and the distance from the conductive member to the target device is less than or equal to the distance from the target device to the top inner wall of the fully enclosed shield, this circuit peak can be effectively dissipated, improving isolation.

[0024] In some embodiments, the shielding cover includes a semi-enclosed shielding cover, the resistive element includes a resistor element, one end of the resistor element is electrically connected to the circuit board, and the other end of the resistor element is electrically connected to the semi-enclosed shielding cover.

[0025] It can be understood that the semi-enclosed shielding cover provides a semi-enclosed cover for the target device, that is, the target device is not completely covered. At the same time, the resistive element includes a resistor element, which is made of a conductive material and has a fixed resistance value or a variable resistance value. At the same time, the opposite ends of the resistor element are electrically connected to the circuit board and the semi-enclosed shielding cover to form a path.

[0026] In some embodiments, the distance between the target device and the top inner wall of the semi-enclosed shielding can is less than or equal to 1 mm.

[0027] As can be understood, the LC resonant frequency changes accordingly with changes in the distance between the target device and the semi-enclosed shielding case, indicating the presence of parasitic capacitance between the target device and the semi-enclosed shielding case. Furthermore, when the distance from the target device to the top inner wall of the semi-enclosed shielding case is less than or equal to 1mm, the isolation frequency can be controlled to a reasonable range to a certain extent.

[0028] In some embodiments, the resistance value of the resistor element is greater than or equal to 1 ohm.

[0029] It is understandable that the resistance value of the resistor element may be 1Ω, 5Ω, 10Ω, etc. At the same time, the resistance value of the resistor element is selected according to actual use requirements.

[0030] In some embodiments, the resistive element includes a conductive member, one end of the conductive member is connected to the inner wall of the shielding cover, the other end of the conductive member is connected to the circuit board, and the resistance value of the conductive member is greater than or equal to 1 ohm.

[0031] It is understood that the resistive element can also be a conductive member with a certain resistance value, which is directly installed between the inner wall of the shielding case and the circuit board. The resistance value of the conductive member can be 1Ω, 5Ω, 10Ω, etc. At the same time, the resistance value of the conductive member is selected according to actual usage requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application;

[0033] Figure 2 An exploded diagram of a terminal device provided in an embodiment of the present application;

[0034] Figure 3 A cross-sectional view of a circuit board, a shielding cover, a target device, and a resistive element of a terminal device provided in Example 1 of the present application;

[0035] Figure 4 A top view of a circuit board, a shielding cover, a target device, and a resistive element of a terminal device provided in an embodiment of the present application;

[0036] Figure 5 A cross-sectional view of a circuit board, a shielding cover, a target device, and a resistive element of a terminal device provided in Example 2 of the present application;

[0037] Figure 6 A cross-sectional view of a circuit board, a shielding cover, a target device, and a resistive element of a terminal device provided in Example 3 of the present application;

[0038] Figure 7 A schematic diagram illustrating the isolation of a target device in a terminal device with or without a shielding cover provided in Example 1 of the present application;

[0039] Figure 8 A schematic diagram of a frequency band curve of a target device in a terminal device provided in Example 1 of the present application with and without a resistive element;

[0040] Figure 9 A schematic diagram illustrating the isolation of a camera in a terminal device with or without a shielding cover provided in Example 2 of the present application;

[0041] Figure 10 A schematic diagram of a field intensity frequency characteristic curve of a monitor between the connection point of the camera in the terminal device provided in Example 2 of the present application and the shielding cover;

[0042] Figure 11 A schematic diagram of the frequency band curve of the camera in the terminal device provided in Example 2 of the present application with and without a resistive element;

[0043] Figure 12 A schematic diagram of the LC resonant frequency shift at different distances between the target device and the fully enclosed shielding cover in the terminal device provided in the first embodiment of the present application;

[0044] Figure 13 This is a schematic diagram of the isolation between a target device in a terminal device provided in the second embodiment of the present application and the top inner wall of a semi-enclosed shielding cover at different distances.

[0045] Among them, the reference numerals in the figures are:

[0046] 1000, terminal equipment;

[0047] 100, circuit board; 200, housing; 300, display screen; 400, battery; 500, camera module;

[0048] 201, middle frame; 202, back cover; 501, front camera; 502, rear camera.

[0049] 600, shielding cover; 700, resistive element; 800, target device; 701, conductive part; 702, resistive element. DETAILED DESCRIPTION

[0050] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the accompanying drawings are intended to cover non-exclusive inclusions.

[0052] In the description of this application, it should be understood that the terms "length", "width", "thickness", "top", "bottom", "inside", "outside", "up", "down", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this application.

[0053] The terms "first," "second," "third," "fourth," "fifth," and "sixth," etc., are used solely for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. For example, the terms "first deformation space" and "second deformation space" are used solely to distinguish between different deformation spaces and do not define their order. The first deformation space could also be named the second deformation space, and the second deformation space could also be named the first deformation space, without departing from the scope of the various described embodiments. Furthermore, the terms "first," "second," and so on, do not necessarily define the features being referred to as different.

[0054] In this application, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, indirect connection through an intermediate medium, internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0055] In this application, "and / or" is simply a way to describe the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0056] It should be noted that, in this application, words such as "in some embodiments," "exemplarily," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "in some embodiments," "exemplarily," or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "in some embodiments," "exemplarily," and "for example" is intended to present the relevant concepts in a concrete manner.

[0057] In order to make the purpose, technical solutions and advantages of this application more clear, this application is further described in detail below with reference to the accompanying drawings and embodiments.

[0058] Circuit boards are used to carry electronic components. For example, the circuit boards of mobile phones, tablets, and computers typically include a main circuit board and a secondary circuit board. The main and secondary circuit boards are electrically connected via an FPC. Therefore, both the main and secondary circuit boards have connections for connecting to the FPC, which are board-to-board (BTB) connectors.

[0059] At the same time, components are also installed on the circuit board. For components that generate electromagnetic noise, such as antennas, power amplifiers, and tuning circuits, a shielding cover is usually set at the connection between them and the circuit board to reduce the impact of electromagnetic noise.

[0060] However, in some usage scenarios, it was found that after adding a shielding cover, the combined structure of the current components and the shielding cover would produce resonance, and the resonant frequency generally fell within the 2-7GHz frequency band related to the radio frequency band within the terminal device. Therefore, after adding a shielding cover to the components, the anti-interference isolation would deteriorate in certain frequency bands.

[0061] The above phenomenon can be verified through corresponding examples. A section of the trace of the disturbed body and a strip-line component are set in the shielding cover. The strip-line component has a device end and a trace end. In addition, a point monitor is set in the shielding cover. The point monitor is used to monitor the corresponding frequency band of the electric field and magnetic field strength at a fixed position in the shielding cover.

[0062] The figure shows a comparison of the electric field strength inside the shielding case with LC resonance. The curve in the upper half of the figure represents the case with the shielding case added, while the curve in the lower half represents the case without the shielding case. Calculations show that the structural combination of the stripline component and the shielding case does produce resonance, with the resonant frequency falling within the 2-7 GHz band, which is relevant to the RF band within the terminal device. Furthermore, compared to the case without LC resonance, the field strength inside the shielding case increases by over 30 dB in the LC resonance state. Therefore, near-field enhancement is the direct cause of noise coupling within the shielding case.

[0063] Further, as shown in the figure, the figure is a schematic diagram of LC resonance frequency offset under different distances between the device end of the strip-line component and the inner wall of the shielding cover. Wherein, the curves from left to right in the figure respectively represent that the distances between the device end of the strip-line component and the inner wall of the shielding cover are 0.03mm, 0.06mm, 0.09mm in turn, and at the same time, with the change of the distance between the two, the LC resonance frequency also changes in the range of 500MHz to 1GHz, which also shows that the strip-line component and the shielding cover form the parasitic capacitance of LC resonance.

[0064] As can be seen from the above, in some scenarios that need to be protected by the shielding cover, the terminal device appears the phenomenon of deterioration of the anti-interference isolation degree in some frequency bands.

[0065] Therefore, the present application provides a terminal device, which increases a resistive element between the shielding cover and the circuit board to electrically connect the two. By using the loss of the resistive element, the LC resonance mode between the shielding cover and the target device is suppressed, thereby improving the noise coupling and reducing the probability of deterioration of the anti-interference isolation degree of the terminal device in some frequency bands.

[0066] The terminal device 1000 involved in the embodiments of the present application can include a handheld device, a vehicle-mounted device, a wearable device, a computing device, or other processing devices connected to a wireless modem. It can also include a cellular phone, a smart phone, a personal digital assistant (PDA) computer, a tablet computer, a laptop computer, a machine type communication (MTC) terminal, a point of sales (POS), a vehicle-mounted computer, and other terminal devices 1000 with imaging functions.

[0067] The embodiments of the present application do not specially limit the specific form of the terminal device 1000. The following is described by taking a mobile phone as an example for the convenience of explanation and understanding.

[0068] Please refer to Figure 1 and Figure 2 , Figure 1 the structural schematic diagram of the terminal device provided by an embodiment of the present application, Figure 2 the exploded structural schematic diagram of the terminal device provided by an embodiment of the present application, referring to Figure 1 and Figure 2 , the terminal device 1000 provided by the embodiments of the present application can include a shell 200, a display screen 300, a circuit board 100, and a battery 400.

[0069] The shell 200 can provide a structural framework for the terminal device. Specifically, the shell 200 includes a middle frame 201 and a back cover 202. The middle frame 201, the circuit board 100, and the battery 400 are arranged between the display screen 300 and the back cover 202. The circuit board 100 and the battery 400 can be arranged on the middle frame 201. For example, the circuit board 100 and the battery 400 are arranged on a side of the middle frame 201 facing the back cover 202, or the circuit board 100 and the battery 400 can be arranged on a side of the middle frame 201 facing the display screen 300.

[0070] It can be understood that the shell 200 of the terminal device provided in the present application includes but is not limited to the above structure. For example, in some other embodiments, the shell 200 can be an integrated or split shell 200 made of metal or plastic. In the embodiments of the present application, the shell 200 is specifically described by taking the structure composed of the middle frame 201 and the back cover 202 as an example.

[0071] The battery 400 can be electrically connected to the circuit board 100 to supply power to the processor, the internal memory, the external memory, the display screen 300, the camera module 500, and the communication module.

[0072] The display screen 300 can be an organic light-emitting diode (OLED) display screen 300, or a liquid crystal display (LCD) screen 300.

[0073] The back cover 202 can be a metal back cover, a glass back cover, a plastic back cover, or a ceramic back cover 202. In the embodiments of the present application, the material of the back cover 202 is not limited.

[0074] The middle frame 201 can include a middle plate and a frame. The frame is arranged around the outer periphery of the middle plate. Generally, the frame can include a top frame, a bottom frame, a left side frame, and a right side frame, which form a square ring structure. The middle plate can be an aluminum plate, an aluminum alloy, or a magnesium alloy. The frame can be a metal frame or a ceramic frame. The metal middle plate and the frame can be connected by clamping, welding, bonding, or one-piece forming, or the metal middle plate and the frame can be fixedly connected by injection molding.

[0075] It should be noted that, in some other embodiments, the terminal device 1000 can include but is not limited to Figure 1 and Figure 2In the structure shown in FIG, the back cover 202 can be connected to the frame to form an integrally formed housing. For example, the terminal device may include: a display screen 300, a metal mid-plate, and a housing 200. The housing 200 may be formed by integrally forming the frame and the back cover 202. In this way, the circuit board 100 and the battery 400 are located in the space enclosed by the metal mid-plate and the housing 200.

[0076] In the embodiment of the present application, in order to realize the shooting function, the terminal device further includes: at least one camera module 500 and a flash (not shown in the figure), wherein the camera module 500 can be a front camera 501, a rear camera 502, etc., and the number of the front camera 501 and the rear camera 502 can be one or more. For example, Figure 2 As shown, in the terminal device provided in this application, the camera module 500 includes a front camera 501 and a rear camera 502.

[0077] The back cover 202 has openings for mounting a flash and a portion of the rear camera 502. The front camera 501 can be located on the side of the mid-panel facing the display screen 300. In the embodiments of the present application, the locations of the front camera 501 and the rear camera 502 include, but are not limited to, those described above. In some embodiments, the total number of front cameras 501 and rear cameras 502 installed in the terminal device can be 1 or N, where N is a positive integer greater than 1.

[0078] It is understood that the structures illustrated in the embodiments of the present application do not constitute specific limitations on the terminal device. In other embodiments of the present application, the terminal device may include more or fewer components than shown, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0079] Furthermore, please refer to Figure 3 and Figure 4 , a terminal device 1000 provided in an embodiment of the present application includes a circuit board 100 , a shielding cover 600 and a resistive element 700 .

[0080] Among them, the circuit board 100 is used to carry electronic components. For example, the circuit board 100 of a mobile phone, tablet computer and computer usually includes a main circuit board and a sub-circuit board, and the main circuit board and the sub-circuit board are electrically connected via an FPC. A target device 800 is provided on the circuit board 100. The target device 800 is a component that needs to be isolated and protected, that is, the shielding cover 600 needs to isolate and protect the current target device 800, reducing the interference of electromagnetic radiation from other electronic devices in the terminal device 1000 on the current target device 800. At the same time, the electromagnetic radiation produced by the current target device 800 is limited to the shielding cover 600, which can also reduce the probability of electromagnetic radiation leakage. Among them, the target device 800 can be a power amplifier, an antenna, a tuning circuit, etc., a component that can generate electromagnetic noise, and can also be a camera connection point and a wiring on the motherboard.

[0081] Shielding covers 600 are categorized by type and include metal shielding covers, ferrite shielding covers, and Teflon shielding covers. Metal shielding covers are typically made of metal materials such as aluminum, copper, and iron, and can effectively shield electromagnetic radiation. Ferrite shielding covers utilize the magnetism of ferrite materials to absorb electromagnetic radiation, achieving a shielding effect. Teflon shielding covers are made of special materials such as Teflon and have excellent chemical corrosion resistance and insulation properties. Furthermore, categorized by shape, shielding covers 600 include square shielding covers, circular shielding covers, and custom-shaped shielding covers. Square shielding covers are more common and are suitable for covering electronic devices or circuit boards 100. Circular shielding covers are used to cover antennas or other circular devices and can effectively shield electromagnetic waves. Custom-shaped shielding covers can be designed and manufactured according to specific needs to meet the needs of devices of various shapes and sizes. For example, shielding covers 600 can be triangular shielding covers, semicircular shielding covers, and irregularly shaped shielding covers. In addition, according to the usage requirements, the shielding cover 600 includes a fully enclosed shielding cover and a semi-enclosed shielding cover; the fully enclosed shielding cover is a fully enclosed cover for the target device 800, that is, the target device 800 is completely enclosed and shielded on all sides, which is suitable for electromagnetic protection of antennas and power amplifiers, etc.; the semi-enclosed shielding cover is a partial shielding of the target device 800, that is, the target device 800 is not completely enclosed by the shielding cover 600, and at least one side of the target device 800 is connected to the outside world. This situation is suitable for local electromagnetic protection of the target device 800.

[0082] Resistive element 700 is an element that blocks the flow of current in a circuit. A common resistive element is a resistor, which is made of conductive material and has a fixed resistance value. Resistors can also be categorized as variable resistors, thermistors, photoresistors, and varistors. In this embodiment, resistive element 700 can also be a conductive structure with a corresponding resistance value, such as a metal sheet, metal strip, metal column, or conductive colloid.

[0083] The structural form of the resistive element 700 is not limited. For example, the resistive element 700 includes one or more resistors. When there are multiple resistors, they can be electrically connected in series, in parallel, or in a combination of series and parallel. For another example, the resistive element 700 includes a metal sheet structure and several resistors, and the metal sheet structure is connected to each resistor and has an electrical connection relationship. For another example, the resistive element 700 includes any one or more of a metal sheet structure, a metal strip structure, a metal columnar junction, and a conductive colloid.

[0084] At the same time, the location of the resistive element 700 can also be adjusted according to its specific structure.

[0085] For example, when a square, fully enclosed shielding can is used to cover an antenna-type target device 800, the resistive element 700 may include a metal sheet structure and a resistor. The metal sheet structure and the resistor are electrically connected, with the end of the metal sheet structure away from the resistor connected to the inner wall of the fully enclosed shielding can, and the end of the resistor away from the metal sheet structure connected to the circuit board 100 to form a ground. Furthermore, the metal sheet structure is located around the target device 800. For example, if the target device 800 has a square or quasi-square structure, the metal sheet structure is located on one or more sides of the target device 800.

[0086] At the same time, the above structure can also be verified by adding a point monitor inside the square fully enclosed shielding case. The function of this point monitor is to monitor the frequency of the electric field or magnetic field intensity point at a fixed position inside the square fully enclosed shielding case. The current target device 800 has a trace end connected to the circuit board 100 and a device end facing away from the trace end and toward the inner wall of the shielding case 600. The trace end is stimulated. Here, Figure 7 The present invention provides a schematic diagram of the isolation of the target device 800 in the terminal device with and without a shielding cover in an embodiment of the present application, wherein the first curve from top to bottom in the figure represents the frequency band curve with the shielding cover, and the second curve represents the frequency band curve without the shielding cover. It can be found that the structural combination of the target device 800 and the shielding cover 600 does produce resonance, and the resonant frequency falls within the 2-7GHz frequency band related to the radio frequency band in the terminal setting. By comparing the two curves, it can be found that the field strength in the shielding cover 600 of the terminal device in the resonant state will increase by more than 30dB compared with the non-resonant state. The field enhancement in the near field is the direct cause of the enhanced coupling. The parasitic capacitance is the capacitance between the connection point between the target device 800 and the circuit board 100 and the shielding cover.

[0087] As shown in the figure, Figure 8The frequency band curve schematic diagram of the target device in the terminal equipment provided by the embodiment of the present application is shown in the figure, wherein the first curve from top to bottom in the figure represents the frequency band curve of the target device without adding resistive elements; the second curve represents the frequency band curve of the target device with resistive elements added on one side; the third curve represents the frequency band curve of the target device with resistive elements added on opposite sides. In the case of no resistive element 800, the isolation difference at the position of 4.014 GHz is caused by LC resonance. Therefore, with reference to the second isolation curve shown in the figure, it is found that the isolation is improved by 10 dB compared with the first isolation curve. Further, resistive elements 700 are added on opposite sides of the current target device 800, the resistive elements 700 include a metal sheet structure and a resistor, the resistance value of the resistor is 10 ohms, one end of the metal sheet structure away from the resistor is connected to the inner wall of the fully enclosed shield cover, and the other end of the resistor away from the metal sheet structure is connected to the circuit board 100. At this time, the third isolation curve shown in the figure can be obtained, and it is found that the isolation is improved by 20 dB compared with the first isolation curve. Figure 8

[0088] For example, when the circular semi-enclosed shield cover is used to cover the target device 800 such as the camera connection point, the resistive element 700 can include a resistor, and the current target device 800 is shielded by the shield cover 600 on one side and exposed to the outside on the other side. Therefore, one end of the resistor is electrically connected to the circuit board 100, and the other end is electrically connected to the semi-enclosed shield cover. It should be noted that there is only a positional structural connection between the semi-enclosed shield cover and the circuit board 100, and there is no direct electrical connection, i.e., only an indirect electrical connection through the resistor. Therefore, the resistor is arranged on the circuit board 100, not inside the circular semi-enclosed shield cover.

[0089] Similarly, the above structure is verified by adding a point monitor in the circular semi-enclosed shield cover, and the point monitor is located between the connection point of the circular semi-enclosed shield cover and the camera. The point monitor monitors the frequency of the electric field or the magnetic field at the corresponding position in the circular semi-enclosed shield cover. According to the test results shown in the figure, the frequency of the electric field or the magnetic field at the corresponding position in the circular semi-enclosed shield cover is 4.014 GHz, which is the same as the frequency of the electric field or the magnetic field at the corresponding position in the circular semi-enclosed shield cover. Figure 9 Figure 9 The isolation degree schematic diagram of the camera in the terminal equipment provided by the embodiment of the present application is shown in the figure. After adding a circular semi-enclosed shield cover at the camera, the isolation degree between the camera and the antenna is deteriorated by 28 dB, and after excitation, as shown in the figure,​​Figure 10 As shown, Figure 10 The field intensity frequency characteristic curve diagram of the monitor between the connection point of the camera and the shielding cover in the terminal device provided by the embodiment of the present application shows that there is a resonance at the frequency of 3.6GHz. The strong resonance point occurs between the connection point of the circular semi-enclosed shielding cover and the camera, and the strong current point is at the connection point between the circular semi-enclosed shielding cover and the circuit board 100. Finally, after adjusting the resistance value of the resistor, the isolation between the camera and the antenna can be improved, such as Figure 11 As shown, Figure 11 The present invention provides a schematic diagram of the frequency band curves of the camera in the terminal device with and without resistive elements in an embodiment of the present application, wherein the first curve from top to bottom in the figure represents the frequency band curve when no resistive element is added to the camera; the second curve represents the frequency band curve when a resistive element is added to the camera. Specifically, five 50-ohm resistors are connected in parallel between the circuit board 100 and the circular semi-enclosed shielding cover. It can be found that the isolation between the camera and the antenna is improved by more than 15dB.

[0090] The terminal device 1000 provided in the embodiment of the present application adds a resistive element 700 for grounding between the shielding cover 600 and the circuit board 100, and utilizes the resistive element 700 to consume the current across the parasitic capacitance of the LC resonance formed between the target device 800 and the shielding cover 600, thereby improving the isolation deviation and deterioration problem of the shielding cover 600 during use.

[0091] Please refer to Figure 3 and Figure 4 In some embodiments, the shielding cover 600 includes a fully enclosed shielding cover, the resistive element 700 includes a conductive member 701 and a resistor element 702 electrically connected to the conductive member 701, an end of the conductive member 701 away from the resistor element 702 is connected to the inner wall of the fully enclosed shielding cover, and an end of the resistor element 702 away from the conductive member 701 is connected to the circuit board 100.

[0092] It can be understood that the fully enclosed shielding cover can fully enclose the target device 800, that is, the fully enclosed shielding cover is a cover structure with only one opening, with its open end covering the target device 800 and connected to the circuit board 100, thereby isolating the target device 800 from the outside world.

[0093] The resistive element 700 comprises two parts: a conductive element 701 and a resistive element 702. The conductive element 701 is a structural component made of a conductive metal or non-metallic material, while the resistive element 702 is made of a conductive material and has a fixed or variable resistance value. Current can flow through the conductive element 701 and the resistive element 702, thereby being consumed.

[0094] Here, the structural form of the conductive member 701 includes but is not limited to a sheet structure, a layer structure, a columnar structure, and a block structure, etc. Meanwhile, the setting position of the conductive member 701 in the fully-enclosed shield cover can be the top inner wall of the fully-enclosed shield cover corresponding to the circuit board 100, or the side inner wall of the fully-enclosed shield cover connected with the circuit board 100. Of course, the conductive member 701 can be set on both the top inner wall and the side inner wall of the fully-enclosed shield cover.

[0095] The connection mode between the conductive member 701 and the inner wall of the fully-enclosed shield cover can be integrally formed, bonded, clamped, inserted, threadedly connected, welded, etc.

[0096] The connection mode between the resistive element 702 and the circuit board 100 is usually welding, specifically, the end of the resistive element 702 away from the conductive member 701 is tin soldered with the circuit board 100, and then the tin soldering position is solidified after passing through the oven.

[0097] It should be noted that, compared with the traditional shield cover 600, the structure of setting the conductive member 701 and the resistive element in the fully-enclosed shield cover is more friendly to the spatial layout of the target device 800 on the circuit board 100, and the space utilization rate of the circuit board 100 is also higher.

[0098] For example, as shown in Figure 4 FIG. 2 is a top view of the circuit board 100 of the terminal device 1000 provided by the embodiment of the present application, wherein the target device 800 covered by the fully-enclosed shield cover is exposed so as to observe the inside of the fully-enclosed shield cover. Here, the conductive member 701 can be selected to be located at any one side of the target device 800, so that the setting position of the resistive element 700 can be determined according to actual needs, and the space enclosed by the circuit board 100 and the fully-enclosed shield cover can be fully utilized.

[0099] In summary, the difference in isolation degree caused by the parasitic capacitance of the LC resonance between the target device 800 and the shield cover 600 can be improved by the conductive member 701 and the resistive element 702.

[0100] In some embodiments, the conductive member 701 includes any one or several of a spring, a partition rib, a foam, a rivet, and a screw.

[0101] Here, the structural form of the conductive part 701 is not limited, and it can be one or more structural parts in different usage scenarios, such as the above-mentioned spring pieces, spacers, foams, and screws. Among them, the spring pieces are metal sheets with conductivity and deformability. The spacers are convex rib structures integrally formed in the shielding cover 600, and their material is the same as that of the shielding cover 600, which is easy to process. The foam is conductive foam with conductivity, and the conductive foam is connected to the shielding cover 600 by gluing. Rivets and screws can be understood as metal columnar structures, which are connected to the shielding cover 600 by riveting or threading.

[0102] For example, when the target device 800 is fully enclosed, the conductive member 701 is a spring piece and / or a partition rib formed in the fully enclosed shielding cover; for another example, the conductive member 701 is a screw screwed on the fully enclosed shielding cover and extending into the fully enclosed shielding cover, or a rivet riveted on the fully enclosed shielding cover and extending into the fully enclosed shielding cover.

[0103] For example, please refer to Figure 4 The figure shows a top view of the circuit board 100 of the terminal device 1000 provided in an embodiment of the application, wherein the target device 800, which is covered by a fully enclosed shielding cover, is exposed to facilitate observation of the interior of the fully enclosed shielding cover. Here, the conductive member 701 is a spring. Based on simulations of current distribution within the fully enclosed shielding cover, the spring can be positioned at a point where the current is high within the fully enclosed shielding cover. Simultaneously, one end of the resistor element 702 can be welded to the spring, while the other end of the resistor element 702 is soldered to the circuit board 100. After the entire circuit board 100 is passed through an oven, the soldered locations of the resistor element 702 and the circuit board 100 are solidified.

[0104] In this way, the structural form of the conductive member 701 can be adjusted according to different usage scenarios to meet corresponding installation requirements.

[0105] In some embodiments, the conductive member 701 is integrally connected to the fully enclosed shielding cover.

[0106] Understandably, the end of the conductive member 701 facing away from the resistor element 702 should be integrally formed with the fully enclosed shield. This integral molding requirement requires that the conductive member 701 be made of the same material as the fully enclosed shield to ensure stability at the connection. Furthermore, during installation, the placement of the conductive member 701 on the fully enclosed shield requires pre-testing and simulation. Specifically, the conductive member 701 should be positioned at the point of high current within the fully enclosed shield.

[0107] For example, when the position of the target device 800 on the circuit board 100 is determined, the position of the current intensity point corresponding to the fully enclosed shielding cover should also be determined. Then, the conductive part 701 can be integrally formed on the inner wall of the fully enclosed shielding cover to meet the requirements of quick installation of the fully enclosed shielding cover.

[0108] In this way, when the fully enclosed shielding cover is placed on the target device 800 , the layout of the conductive member 701 is completed, and the entire process reduces the difficulty of installing the conductive member 701 .

[0109] In some embodiments, the conductive member 701 is detachably connected to the fully enclosed shielding cover.

[0110] It can be understood that the detachable connection method between the end of the conductive member 701 away from the resistor element 702 and the fully enclosed shielding cover includes but is not limited to plugging, snapping, bonding, threaded connection, etc.

[0111] For example, an opening can be opened on the fully enclosed shielding cover, and the conductive part 701 can be inserted into the fully enclosed shielding cover through the opening, or conductive glue can be pasted on the fully enclosed shielding cover in advance, and the conductive part 701 is adhered to the conductive glue and connected to the fully enclosed shielding cover; or, a threaded hole can be opened on the fully enclosed shielding cover, and an external thread can be formed on the conductive part 701, and the two are connected by matching the internal and external threads.

[0112] In this way, the location of the conductive member 701 on the fully enclosed shielding cover can be adjusted according to actual usage requirements, thereby improving the adaptability of the location of the conductive member 701 .

[0113] Please refer to Figure 3 In some embodiments, the conductive member 701 is located around the target device 800 , and a distance L from the conductive member 701 to the target device 800 is less than or equal to a distance H from the target device 800 to the top inner wall of the fully enclosed shielding cover.

[0114] Understandably, as the distance H between target device 800 and the fully enclosed shield changes, the LC resonant frequency changes accordingly, indicating the presence of parasitic capacitance between target device 800 and the fully enclosed shield, which creates LC resonance. Consequently, the current peak is located between target device 800 and the ground plane of the fully enclosed shield. Therefore, when conductive member 701 is located around target device 800 and the distance L from conductive member 701 to target device 800 is less than or equal to the distance H from target device 800 to the top inner wall of the fully enclosed shield, this peak current can be effectively dissipated, improving isolation.

[0115] For example, Figure 12 As shown, Figure 12This diagram illustrates the LC resonant frequency shift at different distances between the target device 800 and the fully enclosed shielding case in a terminal device 1000 provided in an embodiment of the present application. From right to left in the diagram, the corresponding distances between the target device 800 and the top inner wall of the fully enclosed shielding case are 0.09mm, 0.06mm, and 0.03mm, respectively. As the distance between the target device 800 and the top inner wall of the fully enclosed shielding case decreases, the peak of the LC resonant frequency shifts toward lower frequencies.

[0116] Please refer to Figure 5 In some embodiments, the shielding cover 600 includes a semi-enclosed shielding cover, the resistive element 700 includes a resistor element 702, one end of the resistor element 702 is electrically connected to the circuit board 100, and the other end of the resistor element 702 is electrically connected to the semi-enclosed shielding cover.

[0117] As can be understood, the semi-enclosed shielding cover provides a semi-enclosed cover for the target device 800, i.e., the target device 800 is not completely covered. This is primarily used to address components or traces that generate electromagnetic noise, such as the connection points between the front and rear cameras and the circuit board 100 in the terminal device 1000, the connection points between the front and rear cameras and the virtual storage channel, and the traces on the circuit board 100.

[0118] At the same time, the resistive element 700 includes a resistor element 702, which is made of conductive material and has a fixed resistance value or a variable resistance value. At the same time, the opposite ends of the resistor element 702 are electrically connected to the circuit board 100 and the semi-enclosed shielding cover to form a path.

[0119] For example, a resistor is a relatively common resistive element 702, which is made of a conductive material and has a fixed resistance value. In addition to resistors, other resistive elements 702 are also included, such as variable resistors, also known as adjustable resistors or potentiometers, that is, their resistance value can be changed by a knob or slider; and they can also be thermistors, that is, their resistance value can change accordingly with changes in temperature; or varistors, whose resistance value can change accordingly with the magnitude of external pressure; or photoresistors, whose resistance value can change accordingly with changes in light intensity.

[0120] For example, a semi-enclosed shielding cover is provided at the connection point between the rear camera of the terminal device 1000 and the circuit board 100. The function of the semi-enclosed shielding cover is to isolate the connection point between the rear camera and the circuit board 100 and the antenna, thereby reducing the interference of the electromagnetic radiation of the antenna on the connection point. Figure 9 As shown in Figure 2, it can be found that after adding the semi-enclosed shielding cover, the isolation between the rear camera and the antenna deteriorates by 28dB. By setting a point monitor between the connection point of the semi-enclosed shielding cover and the rear camera, it is found through stimulation thatFigure 10 As shown in FIG. 7, the LC resonance at the frequency band of 3.6 GHz is contained, and the electric field intensity point of the LC resonance occurs between the semi-enclosed shield and the connection point, while the current intensity point occurs at the position where the semi-enclosed shield is grounded. Figure 11 As shown in FIG. 8, it can be found that after the semi-enclosed shield is connected in parallel with the circuit board 100 through five 50-ohm resistance elements 702, the isolation between the rear camera and the antenna is improved by more than 15 dB.

[0121] Therefore, by adding the resistance element 702 between the semi-enclosed shield and the circuit board 100, the problem of isolation deterioration of the target device 800 in the semi-enclosed shield can be effectively improved.

[0122] Please refer to Figure 5 In some embodiments, the distance H between the target device 800 and the top inner wall of the semi-enclosed shield is less than or equal to 1 mm.

[0123] It can be understood that when the distance between the target device 800 and the semi-enclosed shield changes, the LC resonance frequency will change accordingly, indicating that there is a parasitic capacitance of LC resonance between the target device 800 and the semi-enclosed shield. At the same time, when the distance H between the target device 800 and the top inner wall of the semi-enclosed shield is less than or equal to 1 mm, the frequency point of the isolation can be controlled within a reasonable range to a certain extent.

[0124] For example, as shown in FIG. 9, Figure 13 As shown in FIG. 10, Figure 13 The isolation of the target device 800 in the terminal device 1000 provided by the embodiments of the present application and the top inner wall of the semi-enclosed shield at different distances is shown in the figure. As can be seen from the figure, from bottom to top, the distance between each target device 800 and the top inner wall of the semi-enclosed shield is 0.08 mm, 0.05 mm and 0.02 mm respectively, and it is found that as the distance between them gradually decreases, the worst frequency point of the isolation moves to low frequency, which also proves that there is LC resonance between the semi-enclosed shield and the target device 800, and further proves that the parasitic capacitance exists between the semi-enclosed shield and the target device 800.

[0125] In some embodiments, the resistance value of the resistance element 702 is greater than or equal to 1 ohm.

[0126] It can be understood that the resistance value of the resistance element 702 can be 1 Ω, 5 Ω, 10 Ω, 15 Ω, 20 Ω, 25 Ω, 30 Ω, 35 Ω, 40 Ω, 45 Ω, 50 Ω, 55 Ω, 60 Ω, 65 Ω, 70 Ω, 75 Ω, 80 Ω, 85 Ω, 90 Ω, 95 Ω, 100 Ω, etc. At the same time, the resistance value of the resistance element 702 is selected according to the actual use requirement.

[0127] Please refer toFigure 6 In some embodiments, the resistive element 700 includes a conductive member 701 , one end of the conductive member 701 is connected to the inner wall of the shielding cover 600 , and the other end of the conductive member 701 is connected to the circuit board 100 , and the resistance value of the conductive member 701 is greater than or equal to 1 ohm.

[0128] It is understandable that the resistive element 700 may also be a conductive element 701 having a certain resistance value. That is, in this embodiment, the resistive element 700 only includes the conductive element 701 without the resistive element 702 connected thereto.

[0129] Here, the conductive member 701 should be directly installed between the inner wall of the shielding case 600 and the circuit board 100. That is, the conductive member 701 alone is used to improve the problem of deteriorated isolation of the target device 800 in the shielding case 600.

[0130] The resistance value of the conductive member 701 can be 1Ω, 5Ω, 10Ω, etc. Meanwhile, the resistance value of the conductive member 701 is selected according to actual use requirements.

[0131] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the protection scope of the present application.

Claims

1. A terminal device, characterized in that: include: a circuit board, wherein a target device is provided on the circuit board; a shielding cover, the shielding cover being provided on the target device and the shielding cover being placed on the circuit board; A resistive element is used to achieve electrical connection between the shielding cover and the circuit board.

2. The terminal device according to claim 1, wherein: The shielding cover includes a fully enclosed shielding cover, the resistive element includes a conductive part and a resistance element electrically connected to the conductive part, one end of the conductive part away from the resistance element is connected to the inner wall of the fully enclosed shielding cover, and one end of the resistance element away from the conductive part is connected to the circuit board.

3. The terminal device according to claim 2, wherein: The conductive member includes any one or more of a spring sheet, a spacer rib, foam, a rivet and a screw.

4. The terminal device according to claim 2, wherein: The conductive member is integrally connected to the fully enclosed shielding cover.

5. The terminal device according to claim 2, wherein: The conductive member is detachably connected to the fully enclosed shielding cover.

6. The terminal device according to claim 2, wherein: The conductive member is located on a peripheral side of the target device, and a distance from the conductive member to the target device is less than or equal to a distance from the target device to a top inner wall of the fully enclosed shielding cover.

7. The terminal device according to claim 1, wherein: The shielding cover includes a semi-enclosed shielding cover, the resistive element includes a resistor element, one end of the resistor element is electrically connected to the circuit board, and the other end of the resistor element is electrically connected to the semi-enclosed shielding cover.

8. The terminal device according to claim 7, wherein: The distance between the target device and the top inner wall of the semi-enclosed shielding cover is less than or equal to 1 mm.

9. The terminal device according to claim 2 or 7, characterized in that: The resistance value of the resistance element is greater than or equal to 1 ohm.

10. The terminal device according to claim 1, wherein: The resistive element includes a conductive member, one end of the conductive member is connected to the inner wall of the shielding cover, the other end of the conductive member is connected to the circuit board, and the resistance value of the conductive member is greater than or equal to 1 ohm.

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