Electromagnetic shielding cover and circuit board

Abstract

The invention discloses an electromagnetic shielding case and a circuit board. The electromagnetic shielding cover comprises a first shielding layer and a first heat conduction layer, the first heat conduction layer is arranged on one side face of the first shielding layer, and the ratio of the contact surface area S1 of the first shielding layer and the first heat conduction layer to the surface area S2 of the side face, away from the first shielding layer, of the insulating layer is larger than 2. According to the embodiment of the invention, the overall heat dissipation effect of the electromagnetic shielding cover can be improved, so that the shielding performance of the electromagnetic shielding cover is improved.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to an electromagnetic shielding cover and a circuit board. Background Art

[0002] Electromagnetic shielding covers are commonly used in electronic devices such as mobile phones, televisions, computers, etc. to protect internal circuits and components from external electromagnetic interference, while also preventing internal electromagnetic radiation from leaking into the external environment.

[0003] At present, the commonly used electromagnetic shielding cover includes a shielding layer and an insulating layer. The shielding layer is electrically connected to the ground layer of the circuit board, and then the interference charge is introduced into the ground terminal of the circuit board, thereby achieving shielding.

[0004] However, the electromagnetic shielding cover in the prior art has a poor heat dissipation effect, which leads to a decrease in the shielding performance of the electromagnetic shielding cover. Summary of the invention

[0005] The present invention provides an electromagnetic shielding cover and a circuit board, which can improve the overall heat dissipation effect of the electromagnetic shielding cover, thereby improving the shielding performance of the electromagnetic shielding cover.

[0006] In a first aspect, an embodiment of the present invention provides an electromagnetic shielding cover, comprising: a first shielding layer, and a first thermal conductive layer, arranged on one side of the first shielding layer, wherein the ratio of a contact surface area S1 between the first shielding layer and the first thermal conductive layer to a surface area S2 of a side of the first thermal conductive layer away from the first shielding layer is greater than 2.

[0007] Optionally, the roughness Rz of a side of the first heat conducting layer close to the first shielding layer is 3-15 μm, and / or the roughness Rz of a side of the first shielding layer away from the first heat conducting layer is 2-5 μm.

[0008] Optionally, along the thickness direction of the electromagnetic shielding cover, a ratio of a surface area of ​​a side surface of the first shielding layer close to the first heat conducting layer to a projected area is 1.5-20.

[0009] Optionally, the electromagnetic shielding cover further comprises an insulating layer, which is arranged on a side of the first heat-conducting layer facing away from the first shielding layer, and the first shielding layer is bonded to the insulating layer via the first heat-conducting layer.

[0010] Optionally, the electromagnetic shielding cover further includes a first connection layer, the first connection layer is connected to a side surface of the first shielding layer away from the insulating layer, and the first connection layer is used to connect to the circuit board.

[0011] Optionally, the electromagnetic shielding cover further includes a second shielding layer and a second connecting layer, the second shielding layer and the second connecting layer are both arranged between the first shielding layer and the first connecting layer, and the second shielding layer is connected to a side of the first shielding layer away from the insulating layer through the second connecting layer.

[0012] Optionally, the first shielding layer includes a first supporting layer and a first conductive layer, the first supporting layer is provided with a plurality of penetrating first hollow portions, and the first conductive layer is arranged on at least one side surface of the first supporting layer and the inner wall of the first hollow portion; and / or, the second shielding layer includes a second supporting layer and a second conductive layer, the second supporting layer is provided with a plurality of penetrating second hollow portions, and the second conductive layer is arranged on at least one side surface of the second supporting layer and the inner wall of the second hollow portion.

[0013] Optionally, the electromagnetic shielding cover further includes a conductive layer, and the conductive layer is arranged on at least one side surface of the first shielding layer.

[0014] Optionally, conductive particles are provided in the first connection layer, and the first shielding layer is grounded to the circuit board at least through the conductive particles; and / or, conductive particles are provided in the second connection layer, and the first shielding layer and the second shielding layer are electrically connected to each other at least through the conductive particles.

[0015] Optionally, the electromagnetic shielding cover further includes a second heat-conducting layer, and the second heat-conducting layer is arranged between the first shielding layer and the second shielding layer.

[0016] Optionally, the thickness of the first shielding layer is 10-80 μm; and / or the thickness of the second shielding layer is 10-80 μm.

[0017] Optionally, a first undulating portion is provided on a side of the first shielding layer away from the insulating layer, and the first undulating portion is used to pass through the second connecting layer to be electrically connected to the second shielding layer; and / or, a second undulating portion is provided on a side of the second shielding layer away from the first shielding layer, and the second undulating portion is used to pass through the first connecting layer to be grounded to the circuit board.

[0018] In a second aspect, an embodiment of the present invention provides a circuit board, including the electromagnetic shielding cover provided by any embodiment.

[0019] The electromagnetic shielding cover of the embodiment of the present invention includes a first heat-conducting layer and a first shielding layer. By setting the ratio of the contact surface area S1 between the first shielding layer and the first heat-conducting layer to the surface area S2 of the side of the first heat-conducting layer away from the first shielding layer to be greater than 2, the surface roughness of the side of the first heat-conducting layer close to the first shielding layer can be increased, the contact surface area between the first heat-conducting layer and the first shielding layer can be increased, the thermal conductivity of the first heat-conducting layer can be improved, the overall heat dissipation effect of the electromagnetic shielding cover can be improved, and thus the shielding performance of the electromagnetic shielding cover can be improved.

[0020] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0022] Figure 1 is a schematic cross-sectional structure diagram of an electromagnetic shielding cover provided by an embodiment of the present invention;

[0023] Figure 2 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0024] Figure 3 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0025] Figure 4 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0026] Figure 5 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0027] Figure 6 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0028] Figure 7 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0029] Figure 8 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0030] Fig. 9 is a flow chart of another method for preparing an electromagnetic shielding cover provided by an embodiment of the present invention;

[0031] Fig.10 is a flow chart of a method for preparing an electromagnetic shielding cover provided by an embodiment of the present invention;

[0032] Fig.11 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0033] Fig.12 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention;

[0034] Fig.13 It is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0037] Figure 1 FIG. 1 is a schematic cross-sectional view of an electromagnetic shielding cover provided by an embodiment of the present invention. Figure 1 As shown, the electromagnetic shielding cover includes: a first shielding layer 120, a first heat-conducting layer 110, and a first heat-conducting layer 110 arranged on a side of the first shielding layer 120, wherein the ratio of the contact surface area S1 between the first heat-conducting layer 110 and the surface area S2 of the side of the first heat-conducting layer 110 away from the first shielding layer 120 is greater than 2.

[0038] Specifically, the embodiment of the present invention does not specifically limit the material of the first heat-conducting layer 110, as long as it has thermal conductivity. Exemplarily, the material of the first heat-conducting layer 110 can be at least one of a polymer material, an insulating material, a conductive adhesive, graphene, aluminum oxide, silicon nitride, and a thermal grease of organic silicone. The embodiment of the present invention does not specifically limit the thickness of the first heat-conducting layer 130, and it can be appropriately set according to the heat-conducting material used. Exemplarily, the thickness of the first heat-conducting layer 130 ranges from 2μm to 15μm.

[0039] The embodiment of the present invention does not specifically limit the material of the first shielding layer 120, as long as it has conductivity. Exemplarily, the material of the first shielding layer 120 can be at least one of aluminum, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold. The embodiment of the present invention does not specifically limit the thickness of the first shielding layer 120, and it can be appropriately set according to the conductive material used. When the material of the first shielding layer 120 is a metal material, if the thickness of the first shielding layer 120 is too large, the rigidity of the first shielding layer 120 will increase, which is not conducive to the molding and manufacturing of the electromagnetic shielding cover. If the thickness of the first shielding layer 120 is too small, the strength of the first shielding layer 120 may be reduced, it is easy to be damaged, and the electromagnetic shielding effect is weakened. Therefore, the thickness of the first shielding layer 120 can be set between 10μm and 80μm.

[0040] The first shielding layer 120 may be a single-layer structure or a multi-layer structure. In addition, according to the needs of actual production and application, the first shielding layer 120 may be configured in a grid shape or a foamed shape. Both sides of the first shielding layer 120 may be flat, undulating, or convex, which are not specifically limited in the embodiments of the present invention.

[0041] The contact surface area refers to the surface area of ​​the parts of two objects that are in contact with each other. In the case of the first shielding layer 120 and the first heat-conducting layer 110, the area of ​​the surface where the first heat-conducting layer 110 and the first shielding layer 120 are in contact is their contact surface area. For example, if the contact part between the first heat-conducting layer 110 and the first shielding layer 120 is a regular rectangular plane, the contact surface area S1 can be calculated by measuring the length and width of the rectangle and then multiplying the length by the width. When the contact area is irregular, an electron microscope plus visual measurement method can be used for automatic statistics. The surface area refers to the total area of ​​the surface of an object. The surface area of ​​the side of the first heat-conducting layer 110 away from the first shielding layer 120 refers to the total area of ​​the side.

[0042] When the ratio of the contact surface area S1 between the first shielding layer 120 and the first heat-conducting layer 110 to the surface area S2 of the first heat-conducting layer 110 away from the first shielding layer 120 is greater than 2, the thermal conductivity efficiency can be enhanced, thereby improving the overall heat dissipation effect of the electromagnetic shielding cover and improving the shielding performance of the electromagnetic shielding cover. First, a larger contact surface area means that there are more contact areas between the first heat-conducting layer 110 and the first shielding layer 120, which can more effectively conduct heat from the heat source to the first shielding layer 120, or conduct heat away from the first shielding layer 120. This helps to improve the overall thermal conductivity efficiency, so that the heat generated by the circuit board during operation can be dissipated faster, preventing local overheating, thereby ensuring the performance stability and service life of the circuit board. Secondly, a larger contact area ratio helps to transfer heat more evenly between the first heat-conducting layer 110 and the first shielding layer 120. This can avoid heat concentration in a local area and make the temperature distribution of the entire product more uniform. Uniform temperature distribution can reduce problems such as material deformation and damage caused by uneven thermal stress. Finally, good contact can ensure a tighter bond between the first shielding layer 110 and the first heat-conducting layer 120, reducing gaps for electromagnetic signal leakage, which helps to improve the electromagnetic shielding performance of the electromagnetic shielding cover, prevent external electromagnetic interference from affecting the internal circuit, and also reduce the interference of internal electromagnetic radiation to the outside world.

[0043] The electromagnetic shielding cover of the embodiment of the present invention includes a first heat-conducting layer and a first shielding layer. By setting the ratio of the contact surface area S1 between the first shielding layer and the first heat-conducting layer to the surface area S2 of the side of the first heat-conducting layer away from the first shielding layer to be greater than 2, the surface roughness of the side of the first heat-conducting layer close to the first shielding layer can be increased, the contact surface area between the first heat-conducting layer and the first shielding layer can be increased, the thermal conductivity of the first heat-conducting layer can be improved, the overall heat dissipation effect of the electromagnetic shielding cover can be improved, and thus the shielding performance of the electromagnetic shielding cover can be improved.

[0044] Based on the above embodiments, continue to refer to Figure 1 Optionally, the roughness Rz of a side of the first heat conducting layer 110 close to the first shielding layer 120 is 3 to 15 μm; and / or the roughness Rz of a side of the first shielding layer 120 away from the first heat conducting layer 110 is 2 to 5 μm.

[0045] Specifically, roughness Rz is the ten-point height of microscopic roughness, which refers to the sum of the average of the five largest profile peak heights and the average of the five largest profile valley depths within the sampling length. Rz is a parameter index used to characterize surface roughness. Rz reflects the change of surface microscopic roughness. Generally speaking, the larger the Rz value, the rougher the surface. In addition, the test standard for roughness Rz can be GB / T1031-1995.

[0046] When the roughness Rz of the side of the first heat-conducting layer 110 close to the first shielding layer 120 is less than or greater than the range of 3 to 15 μm, the bonding force between the first heat-conducting layer 110 and the first shielding layer 120 will be affected, resulting in delamination during use. In addition, such a configuration can further increase the contact area between the side of the first heat-conducting layer 110 close to the first shielding layer 120 and the first shielding layer 120, thereby improving the heat conduction effect of the first heat-conducting layer 110, improving the overall heat dissipation effect of the electromagnetic shielding cover, and improving the shielding performance of the electromagnetic shielding cover.

[0047] When the roughness Rz of the side of the first shielding layer 120 away from the first heat-conducting layer 110 is 2 to 5 μm, the current flows more evenly in the shielding layer, reducing the current concentration and local resistance changes caused by the uneven surface. This is very important for electromagnetic shielding, because uniform conductivity can more effectively block the entry of external electromagnetic fields and the leakage of internal electromagnetic fields. In some electromagnetic shielding covers, the side of the first shielding layer 120 away from the first heat-conducting layer 110 may need to be closely matched with other components. If the side of the first shielding layer 120 away from the first heat-conducting layer 110 is too rough, it may cause assembly difficulties and affect the overall structural stability and performance of the product. Lower roughness can ensure good contact and precise matching with other components and improve the assembly accuracy of the product. When the first shielding layer 120 is in contact with other components on the side away from the first heat-conducting layer 110, lower roughness can reduce friction and wear. This can not only extend the service life of the electromagnetic shielding cover, but also reduce the heat and noise generated by friction.

[0048] Based on the above embodiments, optionally, continue to refer to Figure 1 , along the thickness direction of the electromagnetic shielding cover, the surface area of ​​the side of the first shielding layer 120 close to the first heat-conducting layer 110 and the ratio of the projected area are 1.5 to 20. A larger surface area to projected area ratio means that the side of the first shielding layer 120 close to the first heat-conducting layer 110 has more microstructures or unevenness, thereby increasing the actual contact area with the first heat-conducting layer 110. A larger contact area can promote more efficient transfer of heat from the heat source (such as electronic components) to the first shielding layer through the first heat-conducting layer, thereby improving the thermal conductivity. The increased surface area can provide more conductive channels and enhance the electromagnetic shielding capability of the first shielding layer 120. Electromagnetic radiation will be reflected, absorbed or attenuated when encountering conductive materials, and a larger surface area can increase the interaction with electromagnetic radiation and improve the shielding effect. A larger surface area to projected area ratio can make the conductivity of the first shielding layer 120 more evenly distributed. This helps to reduce local weak points in the first shielding layer 120 and improve the overall shielding performance. A uniform electromagnetic shielding cover can protect the circuit board from electromagnetic interference from different directions and improve the anti-interference ability of the device.

[0049] Figure 2 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Figure 2 As shown, the electromagnetic shielding cover also includes an insulating layer 130, which is arranged on a side of the first heat-conducting layer 110 facing away from the first shielding layer 120, and the first shielding layer 120 is arranged in affixed relation with the insulating layer 130 through the first heat-conducting layer 110. In this way, on the one hand, the insulating layer 130 can effectively prevent current leakage, avoid the electromagnetic shielding cover from causing safety hazards to surrounding electronic components or users due to accidental conduction during use, and ensure the safety and stability of the equipment operation. On the other hand, the first heat-conducting layer 110 can quickly conduct the heat generated inside, while the first shielding layer 120 can block external electromagnetic interference and prevent internal electromagnetic radiation leakage. The combination of the two provides a good electromagnetic environment and thermal management for the internal electronic components. At the same time, through this fitting arrangement, the structure of the electromagnetic shielding cover is more compact, space is saved, and the integration of the equipment is improved. In addition, this design can also flexibly select materials with specific properties of the insulating layer 130, the heat-conducting layer 110 and the first shielding layer 120 according to different application requirements to meet various complex working environments and technical requirements.

[0050] The embodiment of the present invention does not specifically limit the material of the insulating layer 130, as long as it has insulating properties. Exemplarily, the material of the insulating layer 130 is any one of polyimide, polyvinyl chloride, polyethylene naphthalate, polytetrafluoroethylene, aramid, polyester and anisotropic conductive adhesive. The embodiment of the present invention does not specifically limit the thickness of the insulating layer 130, which can be appropriately set according to the insulating material used. Exemplarily, the thickness of the insulating layer 130 ranges from 5μm to 40μm.

[0051] Figure 3 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Figure 3 As shown, the electromagnetic shielding cover further includes a first connection layer 140 , which is connected to a side of the first shielding layer 120 away from the insulating layer 130 , and the first connection layer 140 is used to connect to the circuit board.

[0052] Specifically, the first connection layer 140 can be electrically connected to the ground 100 of the circuit board during the high temperature lamination process. The first connection layer 140 can be a thermoplastic adhesive, a thermosetting adhesive, or a pressure-sensitive adhesive, etc. Exemplarily, the material of the first connection layer 140 can be at least one of bisphenol A epoxy resin, bisphenol S epoxy resin, bisphenol F epoxy resin, acrylic resin, and polyester resin.

[0053] Based on the above embodiments, continue to refer to Figure 3Optionally, the first connection layer 140 is provided with conductive particles 31, and the first shielding layer 120 is electrically connected to the ground 100 of the circuit board at least through the conductive particles 31. In the embodiment of the present invention, by providing the conductive particles 31 in the first connection layer 140, the conductivity of the first connection layer 140 can be improved, thereby further ensuring that the electromagnetic shielding cover is electrically connected to the ground 100 of the circuit board. Of course, the first connection layer 140 can be an adhesive layer without conductive particles 31, so as to reduce the insertion loss of the circuit board with the electromagnetic shielding cover, thereby improving the shielding effectiveness and the bending property of the circuit board.

[0054] The embodiment of the present invention does not limit the composition and shape of the conductive particles 31. Exemplarily, the composition of the conductive particles 31 is at least one of copper, aluminum, titanium, zinc, iron, nickel, chromium, cobalt, silver and gold. The conductive particles 31 can be small conductive particles separated from each other, or large conductive particles aggregated.

[0055] Figure 4 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Figure 4 As shown, optionally, the electromagnetic shielding cover also includes a second shielding layer 170 and a second connecting layer 160, and the second shielding layer 170 and the second connecting layer 160 are both arranged between the first shielding layer 120 and the first connecting layer 140, and the second shielding layer 170 is connected to a side of the first shielding layer 120 away from the first thermal conductive layer 110 through the second connecting layer 160.

[0056] Specifically, the embodiment of the present invention does not particularly limit the material of the second shielding layer 170, as long as it has conductivity. In some embodiments, the second shielding layer 170 includes one or more of a metal shielding layer, a carbon nanotube shielding layer, a ferrite shielding layer, and a graphene shielding layer. Among them, the metal shielding layer includes a single metal shielding layer and / or an alloy shielding layer. The single metal shielding layer is made of any one of aluminum, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold, and the alloy shielding layer is made of any two or more of aluminum, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold.

[0057] The embodiment of the present invention does not specifically limit the thickness of the second shielding layer 170, and can be appropriately set according to the conductive material used. Optionally, the thickness of the second shielding layer 170 ranges from 10 to 80 μm. The embodiment of the present invention sets the thickness of the second shielding layer 170 to 10 to 80 microns, which can make the thickness of the electromagnetic shielding cover moderate and at the same time make the second shielding layer 170 have better shielding performance.

[0058] Based on the above embodiments, optionally, continue to refer to Figure 4, the second connection layer 160 is provided with conductive particles 32, and the first shielding layer 120 and the second shielding layer 170 are electrically connected at least through the conductive particles 32. By setting the second connection layer 160 as an adhesive layer containing conductive particles 32, the conductivity of the second connection layer 160 can be improved, thereby further ensuring the ground connection between the electromagnetic shielding cover and the circuit board. Of course, the second connection layer 160 can also be an adhesive layer without conductive particles to reduce the insertion loss of the circuit board with the electromagnetic shielding cover, thereby improving the shielding effectiveness and the bending property of the circuit board.

[0059] Figure 5 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Figure 5 As shown, optionally, the first shielding layer 120 includes a first supporting layer 1201 and a first conductive layer 1202 , the first supporting layer 1201 is provided with a plurality of penetrating first hollow portions 12 , and the first conductive layer 1202 is arranged on at least one side surface of the first supporting layer 1201 and the inner wall of the first hollow portion 12 .

[0060] The embodiment of the present invention does not specifically limit the material of the first support layer 1201. Exemplarily, the material of the first support layer 1201 may be a non-woven fabric. The embodiment of the present invention does not specifically limit the thickness of the first support layer 1201, and it may be appropriately set according to the support material used. Exemplarily, the thickness of the first support layer 1201 ranges from 5 μm to 20 μm. Sputtering the first conductive layer 1202 on the first support layer 1201 may make the first support layer 1201 conductive. According to actual needs, the first conductive layer 1202 may be thickened by vacuum sputtering or electroplating to form the first shielding layer 120.

[0061] The first hollow portion 12 may be a square through hole or a through hole of any other shape. Figure 4 Only the first hollow portion 12 is a square through hole for illustration. By setting a plurality of first hollow portions 12 in the first support layer 1201, the present invention can make the glue material of the first connection layer 140 be squeezed into the first hollow portions 12 when the electromagnetic shielding cover is pressed against the circuit board, thereby enhancing the bonding force between the electromagnetic shielding cover and the circuit board, and avoiding the electromagnetic shielding cover bubbling and delamination causing the electromagnetic shielding cover to peel off from the ground of the circuit board.

[0062] Figure 6 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Figure 6As shown, optionally, the second shielding layer 170 includes a second supporting layer 1701 and a second conductive layer 1702 , the second supporting layer 1701 is provided with a plurality of penetrating second hollow portions 17 , and the second conductive layer 1702 is arranged on at least one side surface of the second supporting layer 1701 and the inner wall of the second hollow portion 17 .

[0063] The embodiment of the present invention does not specifically limit the material of the second support layer 1701. For example, the material of the second support layer 1701 can be non-woven fabric. The embodiment of the present invention does not specifically limit the thickness of the second support layer 1701, which can be appropriately set according to the support material used. For example, the thickness of the second support layer 1701 ranges from 5 μm to 20 μm.

[0064] The second hollow portion 17 can be a square through hole, or a through hole of any other shape. Fig.10 The second hollow portion 17 is a square through hole for illustration only. By providing a plurality of second hollow portions 17 in the second supporting layer 1202, the present invention can make the glue material of the first connection layer 140 and the second connection layer 160 be squeezed into the second hollow portions 17 when the electromagnetic shielding cover is pressed against the circuit board, thereby enhancing the bonding force between the electromagnetic shielding cover and the circuit board, and avoiding the electromagnetic shielding cover from bubbling and delamination, which causes the electromagnetic shielding cover to peel off from the ground 100 of the circuit board.

[0065] Optionally, the first hollow portion 12 and the second hollow portion 17 are aligned one by one, and the first hollow portion 12 and the second hollow portion 17 have the same shape, so that the first connection layer 140 passes through the second hollow portion 17 and the first hollow portion 12 in sequence to connect with the first heat conducting layer 110.

[0066] Figure 7 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Figure 7 As shown, the electromagnetic shielding cover further includes a conductive layer 150 , and the conductive layer 150 is disposed on at least one side of the first shielding layer 120 .

[0067] Specifically, the embodiment of the present invention does not specifically limit the material of the conductive layer 150. Exemplarily, the material of the conductive layer 150 can be at least one of aluminum, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold. The embodiment of the present invention does not specifically limit the thickness of the conductive layer 150, which can be appropriately set according to the conductive material used. Exemplarily, the thickness of the conductive layer 150 ranges from 5 μm to 40 μm.

[0068] In some embodiments, the electromagnetic shielding cover further includes a second connecting layer 160 . The conductive layer 150 and the second connecting layer 160 are both disposed between the first shielding layer 120 and the first connecting layer 140 . The conductive layer 150 is connected to a side of the first shielding layer 120 away from the first thermal conductive layer 110 through the second connecting layer 160 .

[0069] Figure 8 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Figure 8 As shown, the conductive layer 150 may be provided with first through holes 15 penetrating the upper and lower surfaces thereof. Optionally, the first through holes 15 and the first hollow portions 12 are aligned one by one, and the first through holes 15 and the first hollow portions 12 have the same shape, so that the first connection layer 140 passes through the first through holes 15 and the first hollow portions 12 in sequence to connect with the first heat conducting layer 110.

[0070] Fig. 9 is a flow chart of a method for preparing an electromagnetic shielding cover provided by an embodiment of the present invention, which is suitable for preparing Figure 8 Electromagnetic shielding, such as Fig. 9 As shown, the preparation method of the electromagnetic shielding cover includes:

[0071] S101 , forming a first heat-conducting layer on a carrier layer.

[0072] S102 , sputtering a first conductive layer on the first supporting layer to form a first shielding layer.

[0073] It should be noted that step S101 and step S102 are executed simultaneously.

[0074] S103, laminating the first shielding layer on the first heat conducting layer, forming a second connecting layer on a side of the first shielding layer away from the first heat conducting insulating layer, and forming a conductive layer on a side of the second connecting layer away from the first shielding layer.

[0075] S104, etching the conductive layer to form a first through hole.

[0076] S105 , forming a first connection layer on a side of the conductive layer away from the first heat conductive layer.

[0077] The first support layer has a first hollow portion. The carrier layer is a tearable release film, which is only used during the preparation process and can be torn off after the preparation is completed.

[0078] Fig.10 is a flow chart of another method for preparing an electromagnetic shielding cover provided by an embodiment of the present invention, which is suitable for preparing Figure 6 Electromagnetic shielding, such as Fig.10 As shown, the preparation method of the electromagnetic shielding cover includes:

[0079] S110, forming a first heat conducting layer on the carrier layer.

[0080] S120 , sputtering a first conductive layer on the first supporting layer to form a first shielding layer.

[0081] It should be noted that step S110 and step S120 are executed simultaneously.

[0082] S130, pressing the first shielding layer onto the first heat conducting layer, forming a second connecting layer on a side of the first shielding layer away from the first heat conducting layer, and sputtering a second conductive layer on the second supporting layer to form a second shielding layer.

[0083] S140, pressing the second shielding layer onto a side of the second connecting layer away from the first shielding layer.

[0084] S150 , forming a first connecting layer on a side of the second shielding layer away from the first heat conducting layer.

[0085] The first support layer has a first hollow portion, and the second support layer has a second hollow portion. The carrier layer is a release film that can be torn off and is only used during the preparation process and can be peeled off after the preparation is completed. Exemplarily, the material of the carrier layer can be polyester resin (Polyethylene terephthalate, PET).

[0086] Fig.11 It is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Fig.12 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Fig.11 and Fig.12 The electromagnetic shielding cover further includes a second heat-conducting layer 180 , and the second heat-conducting layer 180 is disposed between the first shielding layer 120 and the second shielding layer 170 .

[0087] Specifically, Fig.11 The second heat-conducting layer 180 is schematically shown to be disposed on a side of the second connecting layer 160 close to the first heat-conducting layer 110. Fig.12 It is schematically shown that the second heat conducting layer 180 is arranged on a side of the second connection layer 160 away from the first heat conducting layer 110 .

[0088] The embodiment of the present invention does not specifically limit the material of the second heat-conducting layer 180, as long as it has thermal conductivity. Exemplarily, the material of the second heat-conducting layer 180 can be at least one of conductive glue, graphene, aluminum oxide, silicon nitride and thermal grease of organic silicone. The embodiment of the present invention does not specifically limit the thickness of the second heat-conducting layer 180, and it can be appropriately set according to the thermally conductive material used. Exemplarily, the thickness of the second heat-conducting layer 180 ranges from 2μm to 15μm. In the embodiment of the present invention, by setting the second heat-conducting layer 180 between the first shielding layer 120 and the second shielding layer 170, the electromagnetic shielding cover can effectively conduct heat when covering the electronic components. At the same time, through holes can also be set in the second heat-conducting layer 180, so that the internal heat of the second heat-conducting layer 180 can be quickly released into the air, thereby improving the heat dissipation efficiency.

[0089] Fig.13 FIG. 1 is a schematic cross-sectional structure diagram of another electromagnetic shielding cover provided by an embodiment of the present invention. Fig.13 , one side of the first shielding layer 120 close to the second connecting layer 160 is a non-flat surface, and one side of the second shielding layer 170 close to the first connecting layer 140 is a non-flat surface. In an embodiment of the present invention, the non-flat surface is a regular non-flat surface or an irregular non-flat surface. Specifically, when the non-flat surface is a regular non-flat surface, the non-flat surface is a periodically undulating structure, and the amplitude of the undulations and the interval of the undulations on the non-flat surface are the same; when the non-flat surface is an irregular non-flat surface, the non-flat surface is a non-periodically undulating structure, and the amplitude of the undulations and / or the interval of the undulations on the non-flat surface are different. The non-flat surfaces of the first shielding layer 120 and the second shielding layer 170 can enhance the bonding force between the electromagnetic shielding cover and the circuit board, so that the electromagnetic shielding cover is not prone to blistering and delamination. In addition, when the electromagnetic shielding cover is pressed together with the circuit board, the glue material constituting the second connecting layer 160 is squeezed into the recessed position of the first shielding layer 120, and the glue material constituting the first connecting layer 140 is squeezed into the recessed position of the second shielding layer 170, so as to increase the glue capacity, thereby making it less likely for the board to burst, thus avoiding the problem of high-temperature bursting of the existing electromagnetic shielding cover due to insufficient glue capacity, and thus effectively ensuring that the electromagnetic shielding cover is grounded, thereby conducting out interference charges.

[0090] Continue to refer Fig.13In order to make it easier for the second shielding layer 170 to pierce the second connection layer 160 during the lamination process, the second shielding layer 170 is easier to pierce the first connection layer 140 during the lamination process. In this embodiment, the first shielding layer 120 is provided with a first undulating portion 121 on a side away from the first heat conducting layer 110, and the first undulating portion 121 is used to pass through the second connection layer 160 to be electrically connected to the second shielding layer 170. And / or, the second shielding layer 170 is provided with a second undulating portion 171 on a side away from the first shielding layer 120, and the second undulating portion 171 is used to pass through the first connection layer 140 to be connected to the circuit board ground 100.

[0091] Specifically, the first undulating portion 121 and the second undulating portion 171 include a plurality of convex portions and a plurality of concave portions, and the plurality of convex portions and the plurality of concave portions are arranged at intervals. In order to further ensure the reliability of grounding and improve the conductive efficiency at the same time, the spacing between each convex portion and the adjacent concave portion in the embodiment of the present invention is the same. By setting the spacing between each convex portion and the adjacent concave portion to be the same, the plurality of convex portions can uniformly pierce the first connection layer 140 or the second connection layer 160, thereby further ensuring the reliability of the connection between the electromagnetic shielding cover and the grounding 100 of the circuit board, and improving the conductive efficiency at the same time.

[0092] Optionally, the shape of each convex part is the same; the shape of each concave part is the same; wherein each convex part is an axisymmetric structure; each concave part is an axisymmetric structure; of course, each convex part can also be a non-axisymmetric structure, and each concave part can also be a non-axisymmetric structure. Since the spacing between each convex part and the adjacent concave part is the same, and the shape of each convex part is the same, the shape of each concave part is the same, so that the amount of glue on the surface of the first shielding layer 120 and the second shielding layer 170 is relatively uniform, thereby further avoiding the explosion of the board, and further ensuring the grounding of the electromagnetic shielding cover, so as to guide out the interference charge.

[0093] Based on the same inventive concept, an embodiment of the present invention further provides a circuit board, including the electromagnetic shielding cover provided by any of the above embodiments, having a corresponding electromagnetic shielding cover film layer structure and beneficial effects, and the similarities are not repeated here.

[0094] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electromagnetic shielding cover, characterized in that: include: The first shielding layer, a first heat-conducting layer, wherein the first heat-conducting layer is disposed on a side of the first shielding layer; The ratio of the contact surface area S1 between the first shielding layer and the first heat-conducting layer to the surface area S2 of a side of the first heat-conducting layer away from the first shielding layer is greater than 2.

2. The electromagnetic shielding cover according to claim 1, characterized in that: The roughness Rz of a side surface of the first heat-conducting layer close to the first shielding layer is 3 to 15 μm; and / or, The roughness Rz of a side surface of the first shielding layer away from the first heat conducting layer is 2-5 μm.

3. The electromagnetic shielding cover according to claim 1, characterized in that: Along the thickness direction of the electromagnetic shielding cover, the ratio of the surface area of ​​a side surface of the first shielding layer close to the first heat conducting layer to the projected area is 1.5-20.

4. The electromagnetic shielding cover according to claim 1, characterized in that: The electromagnetic shielding cover further includes an insulating layer, which is disposed on a side of the first heat-conducting layer facing away from the first shielding layer, and the first shielding layer is bonded to the insulating layer via the first heat-conducting layer.

5. The electromagnetic shielding cover according to claim 4, characterized in that: The electromagnetic shielding cover further includes a first connection layer, which is connected to a side surface of the first shielding layer away from the insulating layer, and the first connection layer is used to connect to a circuit board.

6. The electromagnetic shielding cover according to claim 5, characterized in that: The electromagnetic shielding cover also includes a second shielding layer and a second connecting layer. The second shielding layer and the second connecting layer are both arranged between the first shielding layer and the first connecting layer. The second shielding layer is connected to a side of the first shielding layer away from the insulating layer through the second connecting layer.

7. The electromagnetic shielding cover according to claim 6, characterized in that: The first shielding layer includes a first supporting layer and a first conductive layer, the first supporting layer is provided with a plurality of penetrating first hollow portions, the first conductive layer is arranged on at least one side surface of the first supporting layer and an inner wall of the first hollow portion; and / or, The second shielding layer includes a second supporting layer and a second conductive layer. The second supporting layer is provided with a plurality of penetrating second hollow portions. The second conductive layer is arranged on at least one side surface of the second supporting layer and an inner wall of the second hollow portion.

8. The electromagnetic shielding cover according to claim 6, characterized in that: The electromagnetic shielding cover further includes a conductive layer, and the conductive layer is disposed on at least one side surface of the first shielding layer.

9. The electromagnetic shielding cover according to claim 6, characterized in that: The first connecting layer is provided with conductive particles, and the first shielding layer is grounded to the circuit board at least through the conductive particles; and / or, Conductive particles are disposed in the second connection layer, and the first shielding layer and the second shielding layer are electrically connected at least through the conductive particles.

10. The electromagnetic shielding cover according to claim 6, characterized in that: The electromagnetic shielding cover further includes a second heat-conducting layer, and the second heat-conducting layer is arranged between the first shielding layer and the second shielding layer.

11. The electromagnetic shielding cover according to claim 6, characterized in that: The thickness of the first shielding layer is 10 to 80 μm; And / or, the thickness of the second shielding layer is 10-80 μm.

12. The electromagnetic shielding cover according to claim 6, characterized in that: A first undulating portion is provided on a side of the first shielding layer away from the insulating layer, and the first undulating portion is used to pass through the second connecting layer and be electrically connected to the second shielding layer; and / or, A second undulating portion is disposed on a side of the second shielding layer away from the first shielding layer, and the second undulating portion is used to pass through the first connecting layer and be grounded to the circuit board.

13. A circuit board, characterized in that: The invention comprises the electromagnetic shielding cover according to any one of claims 1 to 12.

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