Shielding lap joint structure

Abstract

The utility model relates to the technical field of electromagnetic shielding, and provides a shielding lap joint structure, which comprises a first shell and a second shell, the first shell is provided with a first lap joint surface, the second shell is provided with a second lap joint surface, and the first lap joint surface and the second lap joint surface are in lap joint through a plurality of conductive colloids, so that a shielding cavity is enclosed by the first shell and the second shell. The plurality of conductive colloids are arranged in a surrounding manner at intervals along the circumferential direction of the first lap joint surface, and the interval between two adjacent conductive colloids is less than or equal to 1 / 20 of the wavelength of a transmission signal. A shielding cavity is defined by the first shell and the second shell, the interval between every two adjacent conductive colloids is smaller than or equal to 1 / 20 of the wavelength of a transmission signal in the shielding cavity, electromagnetic radiation of the transmission signal to the outside of the shielding cavity is restrained, the conductive colloids are arranged at intervals, the using amount of the conductive colloids is saved, structural parts such as glue grooves do not need to be additionally machined, and the cost is reduced. The shielding cost is reduced, and the shielding effect is good.

Description

Technical Field

[0001] The utility model relates to the technical field of electromagnetic shielding, in particular to a shielding overlap structure. Background Art

[0002] The laser radar device transmits a detection signal (laser beam) to the target and receives the signal reflected from the target (detection echo). After processing, it obtains relevant information of the target, including the target position, motion state and shape, etc. As a precision optomechanical product, the laser radar needs to reduce electromagnetic interference to ensure the normal operation of the laser radar, and also reduce the electromagnetic signal leakage of the laser radar to ensure safe use on the vehicle.

[0003] However, the overlap between existing lidar shells has problems of insufficient connection and high cost, resulting in poor electromagnetic shielding effect, causing electromagnetic signal leakage or interference from external signals. Utility Model Content

[0004] The utility model aims to provide a shielding overlap structure, aiming to solve the technical problem that the existing overlap structure has high cost when meeting the shielding requirement.

[0005] The present application provides a shielding overlap structure, which includes a first shell and a second shell, the first shell having a first overlap surface, the second shell having a second overlap surface, the first overlap surface and the second overlap surface are overlapped by multiple conductive colloids so that the first shell and the second shell surround a shielding cavity, and the multiple conductive colloids are arranged at circumferential intervals along the first overlap surface, and the interval between two adjacent conductive colloids is less than or equal to 1 / 20 of the wavelength of the transmission signal.

[0006] In one embodiment, the first overlap surface is provided with a plurality of first exposed metal points, and the plurality of first exposed metal points are arranged circumferentially and spaced apart along the first overlap surface, and the interval between two adjacent first exposed metal points is less than or equal to 1 / 20 of the wavelength of the transmission signal, and the first exposed metal points are used to indicate the setting position of the conductive colloid.

[0007] In one embodiment, the first overlapping surface is provided with a first ring-shaped exposed metal strip, and the conductive colloid is provided on the first exposed metal strip.

[0008] In one embodiment, the second overlap surface is provided with a plurality of second metal exposed points, the plurality of second metal exposed points are arranged around the circumference of the second overlap surface at intervals, and the plurality of second metal exposed points correspond one-to-one to the plurality of conductive colloids.

[0009] In one of the embodiments, the second overlapping surface is provided with a ring-shaped second exposed metal strip, and the second exposed metal strip is used to connect with the conductive colloid located on the first shell.

[0010] In one embodiment, the interval between two adjacent conductive colloids is 1 / 50, 1 / 40, 1 / 30 or 1 / 20 of the wavelength of the transmission signal.

[0011] In one embodiment, the interval between two adjacent conductive colloids is 3 mm to 8 mm.

[0012] In one of the embodiments, the volume resistivity of the conductive colloid is less than or equal to 500 mohm / cm.

[0013] In one embodiment, the top of the first shell has an annular first overlapping surface, and the circumference of the first overlapping surface is greater than the circumference of the bottom of the first shell.

[0014] In one embodiment, a positioning groove is formed on the top of the first shell, the bottom of the positioning groove forms the first overlapping surface, and the second shell is embedded in the positioning groove.

[0015] The beneficial effects of the shielding overlap structure provided by the utility model are as follows: the first shell and the second shell surround a shielding cavity, the shielding cavity can be used to install electronic devices, the interval between two adjacent conductive colloids is less than or equal to 1 / 20 of the wavelength of the signal transmitted in the shielding cavity, the electromagnetic radiation of the transmission signal to the outside of the shielding cavity is suppressed, the shielding effect is good, and multiple conductive colloids are arranged at circumferential intervals along the first overlap surface, rather than conductive colloids being applied along the circumference of the first overlap surface, which saves the amount of conductive colloid, does not require additional processing of structural parts such as glue grooves, reduces shielding costs, and solves the technical problems of existing overlap structures that are high in cost and poor in shielding effect when meeting shielding requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 A schematic diagram of the structure of the shielding overlap structure provided by an embodiment of the utility model;

[0018] Figure 2 for Figure 1 A schematic diagram of the structure of the shielding overlap structure after omitting the second shell;

[0019] Figure 3 for Figure 2 A local enlarged view of point A in FIG.

[0020] Figure 4 for Figure 2 The schematic diagram of the structure of the shielding overlap structure after omitting the conductive colloid;

[0021] Figure 5 A schematic structural diagram of a second shell of the shielding overlap structure provided in the present application;

[0022] Figure 6 The electromagnetic shielding benefit effect diagram of three overlapping schemes.

[0023] Among them, the reference numerals in the figure are:

[0024] 10. Shielding cavity;

[0025] 100, first shell; 110, first lap joint; 111, first metal exposed point; 120, bottom plate; 130, first vertical plate; 140, positioning groove;

[0026] 200, second shell; 210, second lap joint surface; 211, second metal exposed point; 220, top plate; 230, second vertical plate;

[0027] 300. Conductive colloid. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and 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 invention, and should not be construed as limiting the present invention.

[0029] Reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, when the phrases "in one embodiment" or "in some embodiments" appear in various places throughout the specification, not all references are to the same embodiment. Furthermore, in one or more embodiments, the particular features, structures, or characteristics may be combined in any suitable manner.

[0030] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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, and therefore cannot be understood as a limitation on the present invention.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In order to facilitate assembly, the shell of the laser radar usually includes at least two shells. The at least two shells are assembled to form the shell of the laser radar, which plays the role of electromagnetic shielding, preventing the electromagnetic signals generated by the internal devices during operation from leaking out, and preventing external signals from entering and interfering with the operation of the devices inside the shell. When the at least two shells of the laser radar are fully overlapped and turned on, the electromagnetic signal is transmitted to the external structure and grounded, which can play a good electromagnetic shielding role. Therefore, the overlap effect between the at least two shells will directly affect the electromagnetic shielding effect of the laser radar.

[0034] Commonly used overlapping schemes include screw overlapping, edge laser engraving overlapping, glue groove combined with conductive glue overlapping, gap periphery conductive tape overlapping and structural convex point overlapping. Among them, the screw overlapping scheme is to fix the two shells with screws, but due to the discontinuity of the metal overlapping surface where the screws and the shells meet, there is a problem of poor shielding effect. The edge laser engraving scheme is to use laser engraving technology to process the high-precision laser engraving surface flatness so that the overlapping surface between the two shells can be in continuous contact, which can meet the requirements under extreme precision, and the processing cost is very high; in addition, it is often difficult to meet the laser engraving surface flatness requirements in actual production, resulting in poor actual shielding effect. The glue groove combined with conductive glue scheme is to open a glue groove on the overlapping surface of the two shells, and add conductive foam or conductive glue to the glue groove after laser engraving to achieve shielding. The processing and manufacturing process is complex and the cost is high. The conductive tape solution on the periphery of the gap, as the name suggests, is to paste conductive tape on the periphery of the gap where the two shells meet for overlapping. This solution has poor reliability and is unacceptable in appearance. The structural convex point overlap solution is to process a convex point on one of the overlap surfaces of the two shells to connect it to the other overlap surface, but the convex point is a hard connection, which may cause shell deformation, poor contact and other problems when the two shells are locked.

[0035] Please combine Figure 1 , Figure 2 and Figure 5 The present application provides a shielding overlap structure, including a first shell 100 and a second shell 200, wherein the first shell 100 has a first overlap surface 110, and the second shell 200 has a second overlap surface 210, and the first overlap surface 110 and the second overlap surface 210 are overlapped by a plurality of conductive colloids 300, so that the first shell 100 and the second shell 200 surround a shielding cavity 10. The plurality of conductive colloids 300 are arranged at intervals along the circumference of the first overlap surface 110, and the interval between two adjacent conductive colloids 300 is less than or equal to 1 / 20 of the wavelength of the transmission signal.

[0036] In the shielding overlap structure provided in the present application, the first shell 100 and the second shell 200 enclose a shielding cavity 10, and the shielding cavity 10 can be used to install optoelectronic devices. The interval between two adjacent conductive colloids 300 is less than or equal to 1 / 20 of the wavelength of the signal transmitted in the shielding cavity 10, thereby suppressing the electromagnetic radiation of the transmission signal to the outside of the shielding cavity 10, and having a good shielding effect. In addition, multiple conductive colloids 300 are arranged at circumferential intervals along the first overlap surface 110, rather than being coated with conductive colloid 300 along the circumference of the first overlap surface 110, which saves the amount of conductive colloid 300, reduces the shielding cost, and solves the technical problem that the existing overlap structure has a high cost when meeting the shielding requirements.

[0037] Among them, according to the relationship between wavelength λ and frequency f: λ=C / f, C is the speed of light, it can be calculated that the interval d between two adjacent conductive colloids 300 is less than or equal to the wavelength 1 / 20*C / f. Specifically, according to the upper frequency limit of the signal transmitted by the electronic device in the shielding cavity 10 (the upper frequency limit of the test required by the standard can be confirmed according to the standard that the product is expected to meet), the interval d between two adjacent conductive colloids 300 is calculated. For example, when the upper frequency limit of the product is 3GHz, according to λ=C / f, λ is obtained to be 0.10m, and then according to d≤1 / 20λ, d≤5mm is calculated, that is, the interval d between two adjacent conductive colloids 300 can be 5mm.

[0038] See also Figure 6 , the horizontal axis represents the signal frequency, the vertical axis represents the electromagnetic shielding benefit, the O line represents the electromagnetic shielding benefit of the first shell 100 and the second shell 200 using a screw overlap solution, the P line represents the electromagnetic shielding benefit of the shielding overlap structure provided by the present application (wherein the interval d between two adjacent conductive colloids 300 is 1 cm), and the Q line represents the electromagnetic shielding benefit of the first shell 100 and the second shell 200 using a glue groove combined with a conductive glue overlap solution (a glue groove needs to be opened on the overlap surface, and continuous conductive glue is added after the glue groove is laser engraved). From Figure 6 It can be seen that the electromagnetic shielding benefit of the screw overlap scheme is low and does not meet the shielding requirements. The electromagnetic shielding benefits of the shielding overlap structure provided in this application and the glue groove combined with the conductive glue overlap scheme are basically the same, which can be as high as 55dB. However, compared with the glue groove combined with the conductive glue overlap scheme, the shielding overlap structure provided in this application does not require additional processing of structural parts such as glue grooves, saves the use of conductive glue 300, and has low shielding costs.

[0039] Depend on Figure 6 It can be seen that due to the differences in product design and usage scenarios, the requirements for electromagnetic shielding are also different. The use of glue grooves combined with conductive glue overlap solutions will lead to excessive shielding design and excessive redundant costs. The shielding overlap structure provided in this application is designed for targeted shielding according to the product operating frequency and performance requirements, and the interval d between two adjacent conductive colloids 300 is flexibly adjusted, so that the solution provided in this application has a high degree of flexibility. Only by changing the interval d, the cost can be balanced, and at the same time, the highest performance that meets the shielding requirements can be achieved.

[0040] In some embodiments, in combination Figure 4The first lap joint 110 is provided with a plurality of first metal exposed points 111, which are arranged around the circumference of the first lap joint 110 at intervals, and the interval between two adjacent first metal exposed points 111 is less than or equal to 1 / 20 of the wavelength of the transmission signal. Based on this, on the one hand, the first metal exposed points 111 are used to indicate the setting position of the conductive colloid 300, which is conducive to accurately controlling the spacing between two adjacent conductive colloids 300; on the other hand, the first metal exposed points 111 only occupy part of the first lap joint 110, reducing the surface exposed area of ​​the first lap joint 110, which is conducive to improving the integrity and structural strength of the first lap joint 110.

[0041] Specifically, the first exposed metal point 111 is manufactured by laser engraving, which can achieve micron-level precision and details, and can ensure that the interval between two adjacent first exposed metal points 111 reaches the micron level, and the interval is stable, thereby ensuring the stability and reliability of the manufactured first exposed metal points 111. In addition, the laser engraving process is applicable to a variety of metal materials, such as copper, aluminum, steel, etc., and can be applied to metal structures of different shapes and sizes, with high production efficiency. It can be understood that in other embodiments, the first exposed metal point 111 can also be manufactured by metal etching, photolithography or laser ablation, which is not limited here.

[0042] In some embodiments, the first lap surface 110 is provided with a first ring-shaped exposed metal strip, and the conductive colloid 300 is provided on the first exposed metal strip. Based on this, on the one hand, the first exposed metal strip is conducive to enhancing the adhesion between the conductive colloid 300 and the first shell 100, so that the position of the conductive colloid 300 on the first shell 100 is stable, and the interval between two adjacent conductive colloids 300 is kept stable, which is conducive to maintaining a good shielding effect; on the other hand, the first exposed metal strip is continuously surrounded, and the processing is simple, and there is no need to consider the interval between two adjacent conductive colloids 300, which is conducive to improving the manufacturing efficiency of the first exposed metal strip.

[0043] Specifically, the first bare metal strip is manufactured by laser engraving, metal etching, photolithography or laser ablation.

[0044] In some embodiments, in combination Figure 5The second lap joint 210 is provided with a plurality of second metal exposed points 211, which are arranged around the circumference of the second lap joint 210 at intervals, and the plurality of second metal exposed points 211 correspond to the plurality of conductive colloids 300 one by one. Based on this, on the one hand, the second metal exposed points 211 are used to guide the second shell 200 and the conductive colloid 300 to be precisely aligned, which is conducive to ensuring reliable electromagnetic shielding between the first shell 100 and the second shell 200; on the other hand, the second metal exposed points 211 only occupy part of the second lap joint 210, reducing the surface exposed area of ​​the second lap joint 210, which is conducive to improving the integrity and structural strength of the first lap joint 110.

[0045] Specifically, the second metal exposed point 211 is manufactured by laser engraving, metal etching, photolithography or laser ablation.

[0046] In some embodiments, the second lap joint surface 210 is provided with a second metal bare strip in an annular shape, and the second metal bare strip is used to connect with the conductive colloid 300 located on the first shell 100. Based on this, on the one hand, the second metal bare strip is conducive to enhancing the adhesion between the conductive colloid 300 and the second shell 200, so that the position of the conductive colloid 300 on the second shell 200 is stable, and the interval between two adjacent conductive colloids 300 is kept stable, which is conducive to maintaining a good shielding effect; on the other hand, the second metal bare strip is continuously surrounded, and the processing is simple, and there is no need to consider the interval between two adjacent conductive colloids 300, which is conducive to improving the manufacturing efficiency of the second metal bare strip.

[0047] Specifically, the second bare metal strip is manufactured by laser engraving, metal etching, photolithography or laser ablation.

[0048] In some embodiments, in combination Figure 3 The interval between two adjacent conductive colloids 300 is 1 / 50, 1 / 40, 1 / 30 or 1 / 20 of the wavelength of the transmitted signal. When the upper limit requirement of shielding the same frequency is met, multiple schemes of the interval between two adjacent conductive colloids 300 are provided, that is, multiple electromagnetic shielding levels are provided. The smaller the interval, the better the shielding effect.

[0049] For example, when the upper frequency limit of the product is 3 GHz, according to λ=C / f, λ is obtained to be 0.10m, and according to d=1 / 20λ, 1 / 30λ, 1 / 40λ, 1 / 50λ, the interval between two adjacent conductive colloids 300 is calculated to be d=5mm, 3mm, 2.5mm or 2mm.

[0050] In some embodiments, in combination Figure 3, the interval between two adjacent conductive colloids 300 is 3mm to 8mm, and correspondingly, the shielding cavity 10 can be suitable for electromagnetic signal transmission with an upper frequency limit of 2GHz to 5GHz. On the one hand, the upper frequency limit is 2GHz to 5GHz, which can be suitable for most electromagnetic shielding requirements. On the other hand, the interval is 3mm to 8mm, which is moderate, which is conducive to the dispensing operation of the conductive colloid 300 and saves the material of the conductive colloid 300.

[0051] In some embodiments, the volume resistivity of the conductive colloid 300 is less than or equal to 500 mohm / cm. Based on this, the conductive colloid 300 generally has good fluidity and adhesion, is easy to process and coat on the surface of the first shell 100 and the second shell 200, and ensures the position stability of the conductive colloid 300 on the first overlap surface 110 and the second overlap surface 210.

[0052] In some embodiments, the conductive colloid 300 can be a single-component colloid, such as silver paste, carbon paste or iron oxide magnetic powder paste; the conductive colloid 300 can also be a two-component colloid, such as a mixture of silver paste and a curing agent or adhesive, a mixture of carbon powder and a polymer, or a mixture of copper powder and an adhesive / carrier, which is not limited here. In some embodiments, the outer diameter of the conductive colloid 300 can be 0.5 mm to 1 mm, and the specific size is not limited. In some embodiments, the shape of the conductive colloid 300 can be spherical, rectangular, prism, cone or truncated cone, which is not limited here.

[0053] In some embodiments, the first faying surface 110 is a plane.

[0054] In some embodiments, the second faying surface 210 is a plane.

[0055] In some embodiments, the first shell 100 and the second shell 200 are both metal shells, which are conducive to reflecting and absorbing electromagnetic waves and achieving good electromagnetic shielding.

[0056] In some embodiments, the first shell 100 and the second shell 200 are respectively provided with a first connection hole and a second connection hole, and fasteners are fixedly inserted into the first connection hole and the second connection hole to achieve a fixed connection between the first shell 100 and the second shell 200.

[0057] In some embodiments, in combination Figure 2 and Figure 4 The first shell 100 includes a bottom plate 120 and a first vertical plate 130. The first vertical plate 130 is arranged around the bottom plate 120 along the circumference of the bottom plate 120, thereby increasing the volume of the first shell 100, and then increasing the space of the shielding cavity 10 after being closed and connected with the second shell 200, which is conducive to accommodating more electronic devices.

[0058] Specifically, the first vertical plate 130 is disposed around the bottom plate 120 at an angle of 90° to 360°, which is not limited here. Figure 2 and Figure 4 The first vertical plate 130 is arranged around the bottom plate 120 by 270°.

[0059] In some embodiments, in combination Figure 5 The second shell 200 includes a top plate 220 and a second vertical plate 230. The second vertical plate 230 is arranged around the top plate 220 along the circumference of the top plate 220, thereby increasing the volume of the second shell 200, and further increasing the space of the shielding cavity 10 after being closed and connected with the first shell 100, which is conducive to accommodating more electronic devices.

[0060] Specifically, the second vertical plate 230 is disposed around the top plate 220 at an angle of 90° to 360°, which is not limited here. Figure 5 The second vertical plate 230 is arranged around the top plate 220 by 270°.

[0061] In some embodiments, in combination Figure 2 The top of the first shell 100 has an annular first overlap surface 110, and the perimeter of the first overlap surface 110 is greater than the perimeter of the bottom of the first shell 100. Based on this, when the intervals between two adjacent conductive colloids 300 are the same, the first shell 100 can arrange more conductive colloids 300 through the first overlap surface 110 located at the top, and in the projection of the bottom, the interval between two adjacent conductive colloids 300 is reduced, that is, the density of the multiple conductive colloids 300 is increased, thereby improving the shielding effect of the shielding cavity 10.

[0062] Specifically, combined Figure 2 The first vertical plate 130 is erected on the rectangular bottom plate 120. The first vertical plate 130 is connected to the three side portions of the bottom plate 120. The top of the first vertical plate 130 is inclined relative to the bottom plate 120. The top of the first vertical plate 130 and the top of the fourth side portion of the bottom plate 120 constitute the top of the first shell 100. The circumference of the first vertical plate 130 is greater than the circumference of the bottom plate 120, which is conducive to the arrangement of more conductive colloids 300. The projection interval of the multiple conductive colloids 300 on the normal line of the bottom plate 120 is smaller than the actual interval, that is, the density of the multiple conductive colloids 300 is increased after projection, and the electromagnetic shielding effect is better for the optoelectronic devices installed on the bottom plate 120.

[0063] In one embodiment, in combination Figures 2 to 4A positioning groove 140 is provided at the top of the first shell 100, and the bottom of the positioning groove 140 forms a first overlapping surface 110. The second shell 200 is embedded in the positioning groove 140, so that the first shell 100 and the second shell 200 are accurately aligned during assembly, and the groove wall of the positioning groove 140 limits the circumferential movement of the second shell 200, preventing loosening or misalignment between the first shell 100 and the second shell 200, thereby improving the stability and reliability of the overall structure.

[0064] In addition, the first overlapping surface 110 and the second overlapping surface 210 are abutted, and the conductive colloid 300 is arranged therebetween, which can prevent the conductive colloid 300 from being exposed, thereby improving the aesthetics of the overall structure on the one hand, and effectively protecting the conductive colloid 300 on the other hand, so that it provides a stable electromagnetic shielding effect.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A shielding overlap structure, characterized in that: The shielding overlap structure includes a first shell and a second shell, the first shell has a first overlap surface, the second shell has a second overlap surface, the first overlap surface and the second overlap surface are overlapped by multiple conductive colloids so that the first shell and the second shell surround a shielding cavity, and the multiple conductive colloids are arranged at circumferential intervals along the first overlap surface, and the interval between two adjacent conductive colloids is less than or equal to 1 / 20 of the wavelength of the transmission signal.

2. The shielding overlap structure according to claim 1, characterized in that: The first overlap surface is provided with a plurality of first exposed metal points, which are arranged circumferentially at intervals along the first overlap surface, and the interval between two adjacent first exposed metal points is less than or equal to 1 / 20 of the wavelength of the transmission signal, and the first exposed metal points are used to indicate the setting position of the conductive colloid.

3. The shielding overlap structure according to claim 1, characterized in that: The first overlapping surface is provided with a first ring-shaped exposed metal strip, and the conductive colloid is arranged on the first exposed metal strip.

4. The shielding overlap structure according to claim 1, characterized in that: The second overlap surface is provided with a plurality of second metal exposed points, which are arranged around the circumference of the second overlap surface at intervals, and the plurality of second metal exposed points correspond one-to-one to the plurality of conductive colloids.

5. The shielding overlap structure according to claim 1, characterized in that: The second overlapping surface is provided with a ring-shaped second exposed metal strip, and the second exposed metal strip is used to connect with the conductive colloid located on the first shell.

6. The shielding overlap structure according to claim 1, characterized in that: The interval between two adjacent conductive colloids is 1 / 50, 1 / 40, 1 / 30 or 1 / 20 of the wavelength of the transmission signal.

7. The shielding overlap structure according to claim 1, characterized in that: The interval between two adjacent conductive colloids is 3 mm to 8 mm.

8. The shielding overlap structure according to claim 1, characterized in that: The volume resistivity of the conductive colloid is less than or equal to 500 mohm / cm.

9. The shielding overlap structure according to claim 1, characterized in that: The top of the first shell has an annular first overlapping surface, and the circumference of the first overlapping surface is greater than the circumference of the bottom of the first shell.

10. The shielding overlap structure according to any one of claims 1 to 9, characterized in that: A positioning groove is formed on the top of the first shell, the bottom of the positioning groove forms the first overlapping surface, and the second shell is embedded in the positioning groove.

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