CN211982439U - Electromagnetic shielding film and circuit board - Google Patents
Electromagnetic shielding film and circuit board Download PDFInfo
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- CN211982439U CN211982439U CN201922445448.5U CN201922445448U CN211982439U CN 211982439 U CN211982439 U CN 211982439U CN 201922445448 U CN201922445448 U CN 201922445448U CN 211982439 U CN211982439 U CN 211982439U
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Abstract
The utility model discloses an electromagnetic shielding film and circuit board. The electromagnetic shielding film comprises a shielding layer and an adhesive film layer; the shielding layer and the adhesive film layer are stacked, and an electromagnetic wave absorbing material is arranged in the shielding layer. The utility model discloses an electromagnetic shielding film be equipped with electromagnetic wave absorbing material in the shielding layer, like this, electromagnetic wave absorbing material in the shielding layer can absorb the electromagnetic wave signal to can reduce or effectively avoid the influence of electromagnetic wave signal to the high frequency transmission of circuit board, make electromagnetic shielding film uses in the circuit board, can reduce the insertion loss of circuit board, makes the circuit board can effectively be applied to the hyperfrequency transmission.
Description
Technical Field
The utility model relates to a shielding film technical field especially relates to an electromagnetic shielding film and circuit board.
Background
With the rapid development of the electronic industry, electronic products are further miniaturized, light-weighted and densely assembled, and the development of flexible circuit boards is greatly promoted, so that the integration of element devices and wire connection is realized. The flexible circuit board can be widely applied to industries such as mobile phones, liquid crystal display, communication, aerospace and the like.
Under the push of the international market, the functional flexible circuit board is dominant in the flexible circuit board market, an important index for evaluating the performance of the functional flexible printed circuit board is Electromagnetic Shielding (EMI Shielding for short), along with the integration of the functions of electronic devices such as mobile phones, the internal components thereof are sharply and high frequency-accelerated, for example: the mobile phone functions are essential functions except for the original audio transmission function, furthermore, WLAN (Wireless Local Area network), GPS (Global Positioning System) and internet function are popular, and the integration of sensing components in the future makes the trend of rapid high-frequency and high-speed components more inevitable.
At present, a shielding film commonly used for an existing circuit board comprises a shielding layer and a conductive adhesive layer, wherein the shielding layer is connected with a circuit board stratum through the conductive adhesive layer, and then interference charges are guided into the circuit board stratum to realize shielding. However, when the circuit board is used for high-frequency transmission, eddy current loss can be generated by the conductive particles in the conductive adhesive layer, so that the insertion loss of the circuit board is increased, and the signal transmission integrity is influenced.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing an electromagnetic shielding film, it uses in the circuit board, can reduce the insertion loss of circuit board, makes the circuit board can effectively be applied to the hyperfrequency transmission.
The embodiment of the utility model provides an electromagnetic shielding film, it includes shielding layer and glued membrane layer; the shielding layer and the adhesive film layer are stacked, and an electromagnetic wave absorbing material is arranged in the shielding layer.
Compared with the prior art, the embodiment of the utility model provides an electromagnetic shielding film, through electromagnetic shielding film be equipped with electromagnetic wave absorbing material in the shielding layer, like this, the intraformational electromagnetic wave absorbing material of shielding can absorb electromagnetic wave signal (the electromagnetic wave signal that produces when including circuit board high frequency transmission) to can reduce or effectively avoid electromagnetic wave signal to the high frequency transmission's of circuit board influence, make like this electromagnetic shielding film uses in the circuit board, can reduce the insertion loss of circuit board, makes the circuit board can effectively be applied to the hyperfrequency transmission.
As an improvement of the above scheme, the shielding layer is provided with a plurality of through holes, each through hole penetrates through two opposite surfaces of the shielding layer, and the electromagnetic wave absorbing material is arranged in each through hole.
As a modification of the above, the two opposite surfaces are an upper surface and a lower surface of the shielding layer.
As an improvement of the scheme, the through hole is a round hole, a square hole, a polygonal hole or a special-shaped hole.
As an improvement of the above scheme, the through holes are uniformly or non-uniformly distributed on the shielding layer.
As an improvement of the scheme, the mass of the shielding layer after the through hole is formed is 15-80% of the mass of the shielding layer before the through hole is formed.
In a refinement of the above, a total open area of the through holes is 25-65% of an area of any one of the surfaces of the shielding layer.
As an improvement of the above scheme, a cavity is arranged in the shielding layer, and the electromagnetic wave absorbing material is arranged in the cavity.
As an improvement of the above scheme, the number of the cavities is multiple, and the multiple cavities are uniformly or non-uniformly distributed in the shielding layer.
As an improvement of the above, the electromagnetic wave absorbing material is in the form of particles.
As a modification of the above, the electromagnetic wave absorbing material has conductivity, and the conductivity of the electromagnetic wave absorbing material is weaker than that of the shielding layer.
As an improvement of the above scheme, the electromagnetic wave absorbing material is a conductive metal, a conductive sponge, a conductive plastic or a conductive rubber.
As a modification of the above, the electromagnetic wave absorbing material has a conductivity of 10% to 50% of that of the shielding layer.
As an improvement of the scheme, the thickness of the shielding layer is 2-8 microns.
As an improvement of the above scheme, the electromagnetic shielding film further comprises an insulating layer, and the insulating layer is arranged on one surface of the shielding layer far away from the adhesive film layer.
Another object of the present invention is to provide a circuit board, which comprises a circuit board body and an electromagnetic shielding film, wherein the electromagnetic shielding film is disposed on the circuit board body, and the electromagnetic shielding film is disposed between the shielding layer and the ground layer.
Compared with the prior art, the embodiment of the utility model provides a circuit board is through using foretell electromagnetic shield membrane to can reduce the insertion loss of circuit board, make the circuit board can effectively be applied to the hyperfrequency transmission.
Drawings
Fig. 1 is a schematic structural diagram of an electromagnetic shielding film according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another electromagnetic shielding film according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a circuit board according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of another circuit board according to an embodiment of the present invention;
wherein, 1, an insulating layer; 2. a shielding layer; 21. a through hole; 22. a cavity; 3. an electromagnetic wave absorbing material; 4. A glue film layer; 5. the circuit board body.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
Referring to fig. 1 and 2, an embodiment of the present invention provides an electromagnetic shielding film, which includes a shielding layer 2 and a film layer 4; the shielding layer 2 and the adhesive film layer 4 are stacked, and an electromagnetic wave absorption material 3 is arranged in the shielding layer 2.
It should be noted that, when the electromagnetic shielding film is applied to a circuit board, the electromagnetic shielding film may be laminated with the circuit board through the adhesive film layer 4. When the electromagnetic shielding film is arranged on the circuit board, the shielding layer 2 can be in contact with or connected with the ground layer of the circuit board so as to lead out interference charges accumulated in the electromagnetic shielding film. In addition, the electromagnetic wave absorbing material 3 has a function of absorbing electromagnetic waves, which is capable of absorbing electromagnetic wave energy projected to its surface and converting the electromagnetic waves into heat energy or other forms of energy by means of dielectric loss or the like.
The embodiment of the utility model provides an in, through the electromagnetic shielding film be equipped with electromagnetic wave absorbing material 3 in the shielding layer 2, like this, electromagnetic wave absorbing material 3 in the shielding layer 2 can absorb electromagnetic wave signal (the electromagnetic wave signal that produces when including circuit board high frequency transmission) to can reduce or effectively avoid electromagnetic wave signal to the influence of the high frequency transmission of circuit board, make like this the electromagnetic shielding film is used in the circuit board, can reduce the insertion loss of circuit board, makes the circuit board can effectively be applied to the hyperfrequency transmission.
In the present embodiment, as an example of one of the arrangement manners of arranging the electromagnetic wave absorbing material 3 in the shielding layer 2, referring to fig. 1, a through hole 21 is provided on the shielding layer 2, the through hole 21 penetrates through two opposite surfaces of the shielding layer 2, and the electromagnetic wave absorbing material 3 is provided in the through hole 21.
In the present embodiment, by forming the through hole 21 in the shielding layer 2 and disposing (optionally filling) the electromagnetic wave absorbing material 3 therein, the electromagnetic wave absorbing material 3 can be fixed in the shielding layer 2, and the electromagnetic wave signal reaching the shielding layer 2 can be effectively absorbed by the electromagnetic wave absorbing material 3.
In addition, the thickness of the electromagnetic shielding film in the prior art is generally in the range of 7-8um, and due to the certain thickness and the low air permeability, a plate explosion phenomenon (for example, a circuit board is at a high temperature) that the electromagnetic shielding film and the circuit board cannot be completely attached, such as bulging, can easily occur between the electromagnetic shielding film and the circuit board, especially, the circuit board is generally provided with a window, and the position of the window corresponds to the grounding circuit of the circuit board (that is, the window is an opening formed in a covering film layer on the surface of the circuit board, and the opening can expose the grounding circuit of the circuit board), so that when the electromagnetic shielding film is arranged on the circuit board, the phenomenon that the electromagnetic shielding film is more easily bulged or even cracked due to the bulging can occur. In this embodiment, the shielding layer 2 has a certain air permeability, so that the electromagnetic shielding film has a better air permeability, so that the electromagnetic shielding film with the electromagnetic wave absorbing material 3 can effectively absorb the electromagnetic wave signal and avoid the electromagnetic shielding film from bulging or even cracking.
Exemplarily, referring to fig. 1, the through hole 21 penetrates through two opposite surfaces of the shielding layer 2, which are an upper surface and a lower surface of the shielding layer 2. When the electromagnetic shielding film is arranged on the circuit board, the shielding layer 2 and the adhesive film layer 4 are sequentially arranged on the surface of the circuit board from top to bottom, and the through holes 21 penetrating through the upper surface and the lower surface of the shielding layer 2 are formed in the shielding layer 2, so that the shielding layer 2 has better air permeability for the circuit board, the electromagnetic shielding film also has better air permeability, and the phenomena of bulging, even cracking and the like of the electromagnetic shielding film can be effectively avoided.
The through hole 21 is illustratively a circular hole, a square hole, a polygonal hole, a special-shaped hole, or the like, and is not particularly limited herein.
Illustratively, the number of the through holes 21 is plural, and the plural through holes 21 are uniformly or non-uniformly distributed on the shielding layer 2.
Illustratively, the total open area of the through holes 21 occupies 25 to 65% of the area of any one of the surfaces of the shielding layer 2, which enables the shielding layer 2 to have better air permeability and better absorption of electromagnetic wave signals. In addition, the shielding layer 2 can also be made to realize a certain function of electromagnetic wave shielding.
For example, the number of openings of the through hole 21 may be expressed as: the mass of the shielding layer 2 after the through hole 21 is formed is 15-80% of the mass of the shielding layer 2 before the through hole 21 is formed. This enables the shielding layer 2 to have good air permeability and to better absorb electromagnetic wave signals. In addition, the shielding layer 2 can also be made to realize a certain function of electromagnetic wave shielding.
Illustratively, referring to fig. 1, the electromagnetic wave absorbing material 3 is in a granular form, which enables the through hole 21 to have good air permeability, and at the same time, can be conveniently filled in the through hole 21, so that the shielding layer 2 has a certain electromagnetic wave signal absorbing performance.
In the above embodiment, as another way of disposing the electromagnetic wave absorbing material 3 in the shielding layer 2, referring to fig. 2, for example, a cavity 22 is disposed in the shielding layer 2, and the electromagnetic wave absorbing material 3 is disposed in the cavity 22. This enables the electromagnetic wave absorbing material 3 to be fixed in the shielding layer 2, and the electromagnetic wave absorbing material 3 can effectively absorb the electromagnetic wave signal that reaches the shielding layer 2.
It is understood that the cavity 22 may be closed, or may be semi-open (i.e., the cavity opening may be open to the outside of the shielding layer), and the like, and is not limited in this regard. When the cavity 22 is closed, the electromagnetic wave absorbing material 3 can be stably fixed in the shielding layer 2, and is not easy to fall off. When the cavity 22 is semi-open, the air permeability of the shielding layer 2 may be improved. It should be noted that, no matter whether the cavity 22 is closed or semi-open, the air permeability is better than that of the shielding layer 2 without the cavity 22, so that the phenomena of the electromagnetic shielding film bulging, even cracking, etc. can be effectively avoided.
Illustratively, the number of the cavities 22 may be one or more. When the number of the cavities 22 is multiple, the cavities 22 are uniformly or non-uniformly distributed in the shielding layer 2.
The electromagnetic wave absorbing material 3 may be provided in the shielding layer 2 in other forms, for example: is directly dispersed and mixed in the shielding layer 2.
In the above embodiment, the electromagnetic wave absorbing material 3 is exemplarily in the form of particles, which can facilitate the electromagnetic wave absorbing material 3 to be disposed in the shielding layer 2. The granular electromagnetic wave absorbing material 3 may be in the shape of a sphere, a cluster, an ice, a stalactite, a tree, or the like, but is not particularly limited thereto. Of course, the electromagnetic wave absorbing material 3 may be in the form of a layer, a net, or the like (i.e., the shielding layer 2 is provided with a layer of the electromagnetic wave absorbing material 3, or is in the form of a net, and the electromagnetic wave absorbing structure is not limited in particular herein).
In the above embodiment, optionally, the electromagnetic wave absorbing material 3 has conductivity, and the conductivity of the electromagnetic wave absorbing material 3 is weaker than that of the shielding layer 2. Wherein, by disposing the electromagnetic wave absorbing material 3 with conductivity in the electromagnetic shielding film, on the one hand, the electromagnetic wave absorbing material 3 has the function of absorbing electromagnetic waves, which can absorb the electromagnetic waves reaching the shielding layer 2, so as to further ensure the normal operation of the circuit board; on the other hand, the electromagnetic wave absorbing material 3 also has a conductive function, which can cooperate with the shielding layer 2 to rapidly conduct the interference charges, thereby enabling the electromagnetic shielding film to have a good shielding effectiveness.
In the above embodiments, the electromagnetic wave absorbing material 3 is, for example, a conductive metal, a conductive sponge, a conductive plastic, a conductive rubber, or the like, and is not particularly limited herein.
In the above embodiment, the electromagnetic wave absorbing material 3 may also be composed of an adhesive and a wave absorbing medium. The wave-absorbing medium is composed of any one of a carbon-series wave-absorbing material, an iron-series wave-absorbing material, a ceramic-series wave-absorbing material and a composite wave-absorbing material. It should be noted that the carbon-based wave-absorbing material includes, but is not limited to, graphene, graphite, carbon black, carbon fiber, and carbon nanotube; the iron-based wave absorbing material comprises but is not limited to ferrite, a magnetic iron nano material, Fe-based alloy micro powder and an iron-based amorphous material; the ceramic-series wave-absorbing material comprises but is not limited to silicon carbide; the composite wave-absorbing material comprises but is not limited to a composite material formed by blending reduced graphene oxide/tin dioxide nano composite wave-absorbing material, manganese zinc ferrite/polypyrrole composite material, three-dimensional silver-graphene hybrid foam/epoxy resin composite material, rG0/Fe304@ Si02 composite material and soft magnetic powder and high molecular plastic. In addition, the wave absorbing medium can also be a conductive polymer, a chiral material, a plasma material, a porous hollow iron nanosphere, a self-skinning polyurethane lightweight material, a hollow sandwich microsphere metal sulfide and the like.
Illustratively, the electromagnetic wave absorbing material 3 has a conductivity of 10% to 50% of the conductivity of the shielding layer 2. Thus, the shielding layer 2 can be ensured to have good electromagnetic wave absorption performance, and the shielding layer 2 can be ensured to have excellent electromagnetic shielding performance.
In the above embodiment, the thickness of the shielding layer 2 is 2 to 8 μm, for example. That is, the thickness of the shielding layer 2 can be relatively thick (the thickness of the existing whole electromagnetic shielding film is generally 7-8 μm, and the thickness of the shielding layer 2 is generally relatively thin), so that the electromagnetic shielding performance of the shielding layer 2 can be improved. It should be noted that, when the shielding layer 2 is provided with the through hole 21 or the cavity 22, etc. to have air permeability, the shielding layer 2 is thicker, which not only improves the electromagnetic shielding performance of the shielding layer 2, but also avoids the electromagnetic shielding film from bulging or even breaking. In addition, if the shielding layer 2 is provided to be thick, the electromagnetic wave absorbing material 3 can be provided in the shielding layer 2 to be larger, and the electromagnetic wave absorbing performance of the shielding layer 2 can be improved.
In order to ensure that the shielding layer 2 has good conductivity, the shielding layer 2 includes one or more of a metal shielding layer 2, a carbon nanotube shielding layer 2, a ferrite shielding layer 2, and a graphene shielding layer 2. Wherein the metal shielding layer 2 comprises a single metal shielding layer 2 and/or an alloy shielding layer 2; the single metal shielding layer 2 is made of any one of aluminum, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold, and the alloy shielding layer 2 is made of any two or more of aluminum, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold.
In addition, the shielding layer 2 in the drawings of the present embodiment may have a single-layer structure or a multi-layer structure. In addition, the shielding layer 2 of the present embodiment can be arranged in a grid shape, a foaming shape, etc. according to the requirements of actual production and application.
In the above embodiment, further referring to fig. 1 and fig. 2, the electromagnetic shielding film further includes an insulating layer 1, and the insulating layer 1 is disposed on a surface of the shielding layer 2 away from the adhesive film layer 4. Wherein, through setting up insulating layer 1, this can ensure electromagnetic shielding film has the performance of carrying out the electrically conductive isolation with the external world better.
In addition, in order to further improve the electromagnetic wave absorption performance of the electromagnetic shielding film, the above-described electromagnetic wave absorption material 3 may be provided in the insulating layer 1. In addition, in order to improve the air permeability of the electromagnetic shielding film, the insulating layer 1 and the adhesive film layer 4 may also be configured to have a certain air permeability, for example, a hole is formed in the insulating layer 1 and the adhesive film layer 4 or a cavity 22 is provided.
In the above embodiment, for example, one of the structures of the adhesive film layer 4 is represented by: the adhesive layer 4 includes an adhesive layer containing conductive particles. The adhesive film layer 4 has an adhesive effect by making the adhesive film layer 4 include an adhesive layer containing conductive particles, so that the circuit board and the electromagnetic shielding film are tightly adhered, and the adhesive film layer 4 also has a conductive function, so that interfering electrons in the shielding layer 2 can be quickly introduced into the ground layer of the circuit board. The conductive particles can be mutually separated conductive particles or aggregated large-particle conductive particles; when the conductive particles are mutually separated, the area of electrical contact can be further increased, and the uniformity of the electrical contact is improved; and when the conductive particles are large agglomerated conductive particles, the piercing strength can be increased.
In the above embodiment, another structure of the adhesive film layer 4 is represented as follows: the adhesive layer 4 includes an adhesive layer containing no conductive particles. The adhesive film layer 4 has an adhesive effect by enabling the adhesive film layer 4 to include an adhesive layer without containing conductive particles, so that the circuit board and the electromagnetic shielding film are tightly adhered, and meanwhile, because the adhesive film layer 4 includes an adhesive layer without containing conductive particles, the insertion loss of the circuit board in the using process is reduced, the shielding efficiency is improved, and meanwhile, the bending property of the circuit board is improved. It is understood that, when the adhesive film layer 4 does not have a conductive property, the connection manner of the shielding layer 2 and the circuit board ground layer may also be a connection manner through a wire or a conductor or other connection manners, which is not limited in this respect.
In addition, the thickness of the adhesive film layer 44 in this embodiment is 1 μm to 80 μm. The glue film layer 44 is made of a material selected from the following materials: modified epoxy resins, acrylic resins, modified rubbers, and modified thermoplastic polyimides. In addition, it should be noted that the outer surface of the adhesive film layer 44 may be a flat surface or a non-flat surface, which is not limited in this embodiment.
Referring to fig. 3 and 4, another embodiment of the present invention provides a circuit board, which includes a circuit board body 5 and the electromagnetic shielding film of any of the above embodiments, the electromagnetic shielding film is disposed on the circuit board body 5, and the shielding layer 2 of the electromagnetic shielding film is connected to the ground layer of the circuit board body 5. The adhesive film layer 4 is located between the circuit board body 5 and the shielding layer 2, and more specifically, the adhesive film layer 4 may be attached to the surface of the circuit board body 5.
In this embodiment, the type of the circuit board body 5 may be set according to actual use conditions; preferably, the circuit board body 5 in this embodiment is one of a flexible single-sided circuit board, a flexible double-sided circuit board, a flexible multilayer board, and a rigid-flex printed circuit board.
In addition, in the specific implementation, when the circuit board is applied to an electronic device, a free grounding film may be disposed, one surface of the free grounding film is electrically connected to a housing of the electronic device, and the other surface of the free grounding film is electrically connected to the electromagnetic shielding film, so that the interference charges accumulated in the electromagnetic shielding film are conducted out.
In this embodiment, the electromagnetic wave absorbing material 3 is disposed in the shielding layer 2 of the electromagnetic shielding film, so that the electromagnetic wave absorbing material 3 in the shielding layer 2 can absorb electromagnetic wave signals (including electromagnetic wave signals generated during high-frequency transmission of the circuit board), and thus the influence of the electromagnetic wave signals on the high-frequency transmission of the circuit board can be reduced or effectively avoided, so that the electromagnetic shielding film is applied to the circuit board, the insertion loss of the circuit board can be reduced, and the circuit board can be effectively applied to ultrahigh-frequency transmission.
Another embodiment of the present invention provides a method for manufacturing an electromagnetic shielding film, which is suitable for manufacturing any one of the above electromagnetic shielding films, comprising the steps of:
s1, manufacturing and forming a shielding layer 2;
s2, disposing an electromagnetic wave absorbing material 3 in the shielding layer 2;
and S3, forming an adhesive film layer 4 on one surface of the shielding layer 2.
In this embodiment, the electromagnetic wave absorbing material 3 is disposed in the shielding layer 2 of the electromagnetic shielding film, so that the electromagnetic wave absorbing material 3 in the shielding layer 2 can absorb electromagnetic wave signals (including electromagnetic wave signals generated during high-frequency transmission of the circuit board), and thus the influence of the electromagnetic wave signals on the high-frequency transmission of the circuit board can be reduced or effectively avoided, so that the electromagnetic shielding film is applied to the circuit board, the insertion loss of the circuit board can be reduced, and the circuit board can be effectively applied to ultrahigh-frequency transmission.
In this embodiment, as an example, the step S2 includes:
s20, forming a through hole 21 on the shielding layer 2; the through hole 21 penetrates through two opposite surfaces of the shielding layer 2;
s21, the electromagnetic wave absorbing material 3 is disposed in the through hole 21.
The electromagnetic wave absorbing material 3 is disposed in the through hole 21, and may be in the form of: the electromagnetic wave absorbing material 3 is placed in the through hole 21, and then the opening of the through hole 21 is sealed.
In the present embodiment, as another example, the step S2 includes:
s20', forming a cavity 22 in the shield layer 2, and disposing the electromagnetic wave absorbing material 3 in the cavity 22.
The cavity 22 may be formed in the shielding layer 2 in the following manner: and (2) forming a groove on the shielding layer 2, then placing an electromagnetic wave absorption material 3 in the groove, and finally covering a sealing layer on the shielding layer 2 to seal the groove to form the final shielding layer 2 with the cavity 22. Or can also be: a cavity 22 is directly formed in the shielding layer 2, a cavity opening is formed in the shielding layer 2, then the electromagnetic wave absorbing material 3 is placed into the cavity 22 through the cavity opening, and finally the cavity opening is sealed.
It should be noted that, the shielding layer 2 may be formed by chemical plating, PVD, CVD, evaporation plating, sputtering plating, electroplating, or a combination thereof.
In the above embodiment, the step S3 includes:
forming an adhesive film layer 4 on a release film, and then transferring the adhesive film layer 4 onto one surface of the shielding layer 2 in a pressing manner; or the like, or, alternatively,
an adhesive film is directly coated on one side of the shielding layer 2, thereby forming the adhesive film layer 4 on one side of the shielding layer 2.
In the above embodiment, the step S1 includes:
forming a protective film layer on which the shielding layer 2 is formed, on the carrier film; the one surface of the shielding layer 2 is attached to the protective film layer; or the like, or, alternatively,
the method for manufacturing the shield layer includes forming a peelable layer on a carrier film, forming the shield layer 2 on a surface of the peelable layer, and peeling the carrier film after forming a protective film layer on the one surface of the shield layer 2.
In the present embodiment, the shielding layer 2 is formed in the above manner, so that the one surface of the shielding layer 2 is relatively flat.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and replacements can be made without departing from the technical principle of the present invention, and these modifications and replacements should also be regarded as the protection scope of the present invention.
Claims (15)
1. The electromagnetic shielding film is characterized by comprising a shielding layer and an adhesive film layer; the shielding layer and the adhesive film layer are arranged in a laminated manner, and an electromagnetic wave absorbing material is arranged in the shielding layer; the electromagnetic wave absorbing material has conductivity, and the conductivity of the electromagnetic wave absorbing material is weaker than that of the shielding layer.
2. The electro-magnetic shielding film of claim 1, wherein a plurality of through holes are formed in the shielding layer, each of the through holes penetrates two opposite surfaces of the shielding layer, and the electro-magnetic wave absorbing material is disposed in each of the through holes.
3. The electro-magnetic shielding film of claim 2, wherein the two opposing surfaces are an upper surface and a lower surface of the shielding layer.
4. The electro-magnetic shielding film of claim 2, wherein the through hole is a circular hole, a square hole, a polygonal hole, or a shaped hole.
5. The electro-magnetic shielding film of claim 2, wherein the plurality of through holes are uniformly or non-uniformly distributed on the shielding layer.
6. The electromagnetic shielding film according to claim 5, wherein the mass of the shielding layer after the through holes are formed is 15 to 80% of the mass of the shielding layer before the through holes are formed.
7. The electromagnetic shielding film of claim 5 wherein the total open area of said through-holes is 25-65% of the area of either of said surfaces of said shielding layer.
8. The electro-magnetic shielding film of claim 1, wherein a cavity is disposed within the shielding layer, and wherein the electro-magnetic wave absorbing material is disposed within the cavity.
9. The electromagnetic shielding film according to claim 8, wherein the number of the cavities is plural, and the plural cavities are uniformly or non-uniformly distributed in the shielding layer.
10. The electromagnetic shielding film according to claim 1, wherein the electromagnetic wave absorbing material is in a granular form.
11. The electro-magnetic shielding film of claim 1, wherein the electro-magnetic wave absorbing material is a conductive metal, a conductive sponge, a conductive plastic, or a conductive rubber.
12. The electro-magnetic shielding film of claim 1, wherein the electro-magnetic wave absorption material has a conductivity of 10% to 50% of that of the shielding layer.
13. The electromagnetic shielding film of claim 1, wherein the shielding layer has a thickness of 2-8 microns.
14. The electromagnetic shielding film of claim 1, further comprising an insulating layer disposed on a side of the shielding layer distal from the adhesive layer.
15. A wiring board comprising a wiring board body and the electromagnetic shielding film according to any one of claims 1 to 14, wherein the electromagnetic shielding film is provided on the wiring board body, and the shielding layer of the electromagnetic shielding film is connected to a ground layer in the wiring board body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922445448.5U CN211982439U (en) | 2019-12-30 | 2019-12-30 | Electromagnetic shielding film and circuit board |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922445448.5U CN211982439U (en) | 2019-12-30 | 2019-12-30 | Electromagnetic shielding film and circuit board |
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| CN211982439U true CN211982439U (en) | 2020-11-20 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112351576A (en) * | 2019-12-30 | 2021-02-09 | 广州方邦电子股份有限公司 | Electromagnetic shielding film, circuit board and preparation method of electromagnetic shielding film |
| CN115534421A (en) * | 2022-09-26 | 2022-12-30 | 中国人民解放军国防科技大学 | Ultrathin broadband high-temperature-resistant structural wave-absorbing material and preparation method thereof |
-
2019
- 2019-12-30 CN CN201922445448.5U patent/CN211982439U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112351576A (en) * | 2019-12-30 | 2021-02-09 | 广州方邦电子股份有限公司 | Electromagnetic shielding film, circuit board and preparation method of electromagnetic shielding film |
| CN115534421A (en) * | 2022-09-26 | 2022-12-30 | 中国人民解放军国防科技大学 | Ultrathin broadband high-temperature-resistant structural wave-absorbing material and preparation method thereof |
| CN115534421B (en) * | 2022-09-26 | 2024-05-28 | 中国人民解放军国防科技大学 | Ultra-thin broadband high-temperature-resistant structural wave-absorbing material and preparation method thereof |
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