CN211702874U - Electromagnetic shielding film and circuit board - Google Patents
Electromagnetic shielding film and circuit board Download PDFInfo
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- CN211702874U CN211702874U CN201922490785.6U CN201922490785U CN211702874U CN 211702874 U CN211702874 U CN 211702874U CN 201922490785 U CN201922490785 U CN 201922490785U CN 211702874 U CN211702874 U CN 211702874U
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Abstract
The utility model relates to a shielding film technical field discloses an electromagnetic shielding film and circuit board, and electromagnetic shielding film includes shielding layer, first electromagnetic wave absorbed layer and rete, and first electromagnetic wave absorbed layer is located between shielding layer and the rete, and the one side that the shielding layer is close to first electromagnetic wave absorbed layer is equipped with electrically conductive arch. Through setting up first electromagnetic wave absorbed layer for the electromagnetic shielding film has the function of absorbing the electromagnetic wave, and consequently when the electromagnetic shielding film was applied to the circuit board, the electromagnetic shielding film can absorb the produced electromagnetic wave of circuit board effectively, has realized effectively shielding electromagnetic interference, has avoided the circuit board to have great electromagnetic interference problem in signal transmission, has consequently guaranteed the normal work of circuit board. In addition, the conductive protrusions are arranged on the shielding layer, so that when the electromagnetic shielding film is applied to the circuit board, the conductive protrusions can pierce the ground connection between the adhesive film layer and the circuit board, interference charges accumulated in the electromagnetic shielding film are led out, and the shielding efficiency is improved.
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 development of miniaturization, light weight, multiple functions and high assembly density of modern electronic equipment, the structure of the circuit board tends to be fine and highly integrated, and is required to bear high-speed signal transmission. Therefore, the circuit density on the circuit board is increased, the circuit spacing is closer, and the operating frequency is higher and wider, which leads to more and more serious electromagnetic interference between circuits.
At present, in order to realize electromagnetic shielding, an electromagnetic shielding film is generally provided on a circuit board. However, the existing electromagnetic shielding film has an unsatisfactory shielding effect, and cannot effectively shield electromagnetic interference in the circuit board, so that the circuit board still has a large electromagnetic interference problem in signal transmission.
In view of the above, it is desirable to develop a shielding film capable of effectively absorbing electromagnetic waves and solving the problem of electromagnetic interference.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing an electromagnetic shielding film can absorb the electromagnetic wave effectively to solve electromagnetic interference's problem.
In order to solve the technical problem, the utility model provides an electromagnetic shielding film, including shielding layer, first electromagnetic wave absorbed layer and rete glue, first electromagnetic wave absorbed layer is located the shielding layer with between the rete glue, the shielding layer is close to the one side of first electromagnetic wave absorbed layer is equipped with electrically conductive arch.
Preferably, the conductive bump is embedded in the first electromagnetic wave absorption layer.
Preferably, the first electromagnetic wave absorption layer is arranged on the first region of the shielding layer and/or the second region of the conductive bump; the first region is a region where the conductive bump is not arranged in one surface, close to the first electromagnetic wave absorption layer, of the shielding layer; the conductive protrusion comprises a plurality of protruding parts, and the second area is an area formed between any two adjacent protruding parts in the conductive protrusion.
Preferably, the electromagnetic shielding film further includes a second electromagnetic wave absorption layer, and the second electromagnetic wave absorption layer is disposed on a surface of the shielding layer away from the first electromagnetic wave absorption layer.
Preferably, the first electromagnetic wave absorption layer has conductivity, and the conductivity of the first electromagnetic wave absorption layer is smaller than the conductivity of the shielding layer; or the like, or, alternatively,
the first electromagnetic wave absorption layer has no conductivity.
Preferably, the second electromagnetic wave absorption layer has conductivity, and the conductivity of the second electromagnetic wave absorption layer is smaller than the conductivity of the shielding layer; or the like, or, alternatively,
the second electromagnetic wave absorption layer has no conductivity.
Preferably, at least one of the first electromagnetic wave absorption layer and the second electromagnetic wave absorption layer is composed of a binder and a wave-absorbing medium.
As a preferred scheme, 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.
Preferably, the thickness of the first electromagnetic wave absorption layer is: 0.1-45 μm; the thickness of the second electromagnetic wave absorption layer is as follows: 0.1-45 μm.
Preferably, the surface of the conductive bump is provided with conductive particles.
Preferably, the adhesive layer comprises an adhesive layer containing conductive particles; or the like, or, alternatively,
the adhesive film layer comprises an adhesion layer without conductive particles.
Preferably, the electromagnetic shielding film further includes an insulating layer, and the insulating layer is disposed on a surface of the shielding layer away from the first electromagnetic wave absorption layer.
Preferably, the electromagnetic shielding film further includes an insulating layer, and the insulating layer is disposed on a surface of the second electromagnetic wave absorption layer away from the shielding layer.
The utility model aims at providing a circuit board, be equipped with foretell electromagnetic shielding film in the circuit board, can absorb the electromagnetic wave effectively to solve electromagnetic interference's problem.
In order to solve the technical problem, the embodiment of the utility model provides a still provides a circuit board, including circuit board body and foretell electromagnetic shielding film, electromagnetic shielding film's electrically conductive arch impales the rete, and with stratum in the circuit board body is connected.
Compared with the prior art, the utility model provides an electromagnetic shielding film and circuit board, through set up in the electromagnetic shielding film first electromagnetic wave absorbed layer makes the electromagnetic shielding film has the function of absorbing the electromagnetic wave, consequently, works as when the electromagnetic shielding film is applied to the circuit board, the electromagnetic shielding film can absorb effectively the produced electromagnetic wave of circuit board has realized effectively shielding to electromagnetic interference to avoided the circuit board to have great electromagnetic interference problem in signal transmission, consequently guaranteed the normal work of circuit board. In addition, through the shielding layer is close to the one side of first electromagnetic wave absorbed layer sets up electrically conductive protruding for when the electromagnetic shielding film is applied to the circuit board, electrically conductive protruding among the electromagnetic shielding film can pierce through the glued membrane layer, and with the stratum of circuit board is connected, thereby will gather interference electric charge in the electromagnetic shielding film is derived, has consequently improved the shielding effectiveness of electromagnetic shielding film.
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 another electromagnetic shielding film according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of another electromagnetic shielding film according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of an electromagnetic shielding film according to a second embodiment of the present invention;
fig. 6 is a schematic structural diagram of an electromagnetic shielding film according to a third embodiment of the present invention;
fig. 7 is a schematic structural diagram of an electromagnetic shielding film according to a fourth embodiment of the present invention;
fig. 8 is a schematic structural diagram of another electromagnetic shielding film according to a fourth embodiment of the present invention;
fig. 9 is a schematic structural diagram of a circuit board provided in the fifth embodiment of the present invention.
Wherein, 1, a shielding layer; 11. a conductive bump; 111. a conductive particle; 12. a first region; 2. a first electromagnetic wave absorption layer; 3. a glue film layer; 4. a second electromagnetic wave absorption layer; 5. an insulating layer; 6. 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.
Example one
Combine fig. 1 to fig. 4 to show, the utility model discloses an electromagnetic shielding film of embodiment, including shielding layer 1, first electromagnetic wave absorbed layer 2 and glued membrane layer 3, first electromagnetic wave absorbed layer 2 is located shielding layer 1 with between the glued membrane layer 3, shielding layer 1 is close to the one side of first electromagnetic wave absorbed layer 2 is equipped with electrically conductive arch 11.
It should be noted that the first electromagnetic wave absorption layer 2 has a function of absorbing electromagnetic waves, and is capable of absorbing electromagnetic wave energy projected to its surface and converting the electromagnetic wave energy into heat energy or other forms of energy through dielectric loss. In addition, when the electromagnetic shielding film is applied to a circuit board, the electromagnetic shielding film is laminated with the circuit board; at this time, the conductive bumps 11 in the electromagnetic shielding film pierce the adhesive film layer 3 and are connected with the ground layer of the circuit board.
The embodiment of the utility model provides an in, through set up in the electromagnetic shielding film first electromagnetic wave absorbed layer 2 makes the electromagnetic shielding film has the function of absorbing the electromagnetic wave, consequently, works as when the electromagnetic shielding film is applied to the circuit board, the electromagnetic shielding film can absorb effectively the produced electromagnetic wave of circuit board has realized the effective shielding to electromagnetic interference to avoided the circuit board to have great electromagnetic interference problem in signal transmission, consequently guaranteed the normal work of circuit board. In addition, the conductive protrusion 11 is arranged on the surface, close to the first electromagnetic wave absorption layer 2, of the shielding layer 1, so that when the electromagnetic shielding film is applied to the circuit board, the conductive protrusion 11 in the electromagnetic shielding film can pierce the adhesive film layer 3 and is connected with the ground layer of the circuit board, thereby leading out interference charges accumulated in the electromagnetic shielding film, and therefore, the shielding effectiveness of the electromagnetic shielding film is improved.
As can be understood, a plurality of signal lines are commonly disposed in the existing circuit board, and electromagnetic waves generated by the signal lines easily cause interference between the signal lines, thereby affecting signal transmission. This embodiment is through set up in the electromagnetic shielding film shielding layer 1 with first electromagnetic wave absorbed layer 2 makes when the electromagnetic shielding film is applied to when the circuit board, first electromagnetic wave absorbed layer 2 can absorb throw in it the produced electromagnetic wave of signal line in the circuit board, and the electromagnetic wave that is not absorbed completely is in the process shielding layer 1 is close to by reflection when the one side of first electromagnetic wave absorbed layer 2, thereby by first electromagnetic wave absorbed layer 2 secondary absorption has improved greatly the electromagnetic wave absorptivity of electromagnetic shielding film, and then has ensured the effective shielding to electromagnetic interference, consequently has avoided effectively because the problem that influences signal transmission because produce the interference between the signal line in the circuit board, has guaranteed the normal work of circuit board.
As shown in fig. 1, the conductive bump 11 in the present embodiment is embedded in the first electromagnetic wave absorption layer 2.
It can be understood that the embedding of the conductive bump 11 into the first electromagnetic wave absorption layer 2 includes two cases: (1) a certain distance exists between the conductive bump 11 and the surface of the first electromagnetic wave absorption layer 2 close to the adhesive film layer 3, that is, the conductive bump 11 is completely located inside the first electromagnetic wave absorption layer 2; (2) the conductive bump 11 penetrates the first electromagnetic wave absorption layer 2. Under the condition that the conductive bump 11 is completely positioned in the first electromagnetic wave absorption layer 2, the first electromagnetic wave absorption layer 2 has fluidity at a certain pressing temperature, so that when the electromagnetic shielding film is pressed with the circuit board, the conductive bump 11 can sequentially pierce through the first electromagnetic wave absorption layer 2 and the adhesive film layer 3 so as to be connected with the ground layer of the circuit board; in the case that the conductive bump 11 penetrates through the first electromagnetic wave absorption layer 2, the first electromagnetic wave absorption layer 2 may have no fluidity or fluidity at a certain pressing temperature, so that when the electromagnetic shielding film is pressed against the circuit board, the conductive bump 11 penetrates through the adhesive film layer 3 to be connected with the ground layer of the circuit board.
In a preferred embodiment, as shown in fig. 4, in order to improve the piercing strength of the conductive bump 11, the surface of the conductive bump 11 is provided with conductive particles 111. Through the surface of electrically conductive arch 11 sets up conductor granule 111 has increased electrically conductive arch 11 impales the dynamics to further guaranteed electromagnetic shielding membrane with during the circuit board pressfitting, electrically conductive arch 11 can pierce through smoothly first electromagnetic wave absorbed layer 2 with glue film layer 3, and with the stratum of circuit is connected, and then guarantees the normal derivation of disturbing charge.
In the embodiment of the present invention, the height of the conductor particles 111 can be set according to actual use conditions; in order to ensure that the piercing strength of the conductive bump 11 can be increased, the height of the conductive particles in this embodiment is preferably 0.1 μm to 30 μm.
In an embodiment of the present invention, the conductive particles 111 include one or more of metal particles, carbon nanotube particles, and ferrite particles. Wherein the metal particles comprise single metal particles and/or alloy particles; the single metal particles are made of any one of aluminum, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold, and the alloy particles are made of any two or more of aluminum, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold.
In the embodiment of the present invention, the shape of the conductor particles 111 is illustrated only for an example, and due to differences in process means and parameters, the conductor particles 111 may also have other shapes such as cluster, ice, stalactite, and dendritic shapes. The conductor particles 111 in the present invention are not limited by the shapes and the drawings, and any conductor particles having piercing and conductive functions are within the protection scope of the present invention.
In the embodiment of the present invention, the conductive particles 111 may be the same as or different from the conductive bumps 11. Therefore, in a specific implementation, the conductive bump 11 may be formed first, and then the conductive particles 111 may be formed on the outer surface of the conductive bump 11 through another process. Of course, the conductive bumps 11 and the conductive particles 111 may be formed as a single structure by a single molding process.
Further, it should be noted that the structure of the conductive bump 11 shown in the drawings is merely exemplary. The present invention provides a conductive protrusion 11 is not limited by the shape of the figure and the above shape, and is provided with a conductive protrusion that pierces through and has a conductive function, which is within the protection scope of the present invention.
In the embodiment of the present invention, the shielding layer 1 may be formed first, and then the conductive bump 11 is formed on the shielding layer 1 by other processes, as shown in fig. 1 and fig. 2. Of course, the shielding layer 1 and the conductive bump 11 may be a unitary structure formed by a one-step molding process, as shown in fig. 3.
In the embodiment of the present invention, the shielding layer 1 includes a first surface in contact with the first electromagnetic wave absorption layer 2, and the conductive protrusion 11 is disposed on the first surface. It should be noted that, when the shielding layer 1 and the conductive bump 11 are not an integrally formed integral structure, the first surface of the shielding layer 1 may be a surface of any shape, for example, a flat surface as shown in fig. 1, or a non-flat surface as shown in fig. 2. When the first surface of the shielding layer 1 is a non-flat surface, the first surface comprises a plurality of convex parts; in order to ensure that the conductive protrusion 11 can smoothly pierce through the first electromagnetic wave absorption layer 2 and the adhesive film layer 3 and be connected with the ground layer of the circuit board, the conductive protrusion 11 is preferably disposed on the convex portion, so that the conductive protrusion 11 can more easily pierce through the first electromagnetic wave absorption layer 2 and the adhesive film layer 3 in the process of laminating the electromagnetic shielding film and the circuit board. In addition, the first surface of the shielding layer 1 may be a regular surface or an irregular surface.
In addition, the shielding layer 1 of the present embodiment further includes a second surface disposed opposite to the first surface. It should be noted that the second surface of the shielding layer 1 may be a surface of any shape, for example, a flat surface as shown in fig. 1, or a non-flat surface; in addition, the second surface of the shielding layer 1 may be a regular surface or an irregular surface. The drawings of the present invention only illustrate the second surface of the shielding layer 1 as a flat surface, and the second surface of the shielding layer 1 in any other shape is within the protection scope of the present invention.
In the embodiment of the present invention, the thickness of the shielding layer 1 can be set according to the actual use condition; preferably, the thickness of the shielding layer 1 is 0.1 μm to 45 μm. In addition, in order to ensure that the shielding layer 1 has good conductivity, the shielding layer 1 includes one or more of a metal shielding layer, a carbon nanotube shielding layer, a ferrite shielding layer, and a graphene shielding layer. Wherein the metal shielding layer comprises 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.
In addition, the shielding layer 1 in the drawings of the present embodiment may have a single-layer structure or a multi-layer structure. In addition, the shielding layer 1 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 a preferred embodiment, the first electromagnetic wave absorption layer 2 has conductivity, and the conductivity of the first electromagnetic wave absorption layer 2 is smaller than the conductivity of the shielding layer 1. By providing the first electromagnetic wave absorption layer 2 having conductivity in the electromagnetic shielding film, on the one hand, the first electromagnetic wave absorption layer 2 has a function of absorbing electromagnetic waves, which can absorb electromagnetic waves generated by the circuit board to ensure the normal operation of the circuit board; on the other hand, the first electromagnetic wave absorption layer 2 also has a conductive function, which can cooperate with the shielding layer 1 to introduce interference charges into the ground layer, thereby further ensuring that the electromagnetic shielding film has good shielding effectiveness.
It should be noted that, in the present embodiment, the proportional relationship between the conductivity of the first electromagnetic wave absorption layer 2 and the conductivity of the shielding layer 1 can be set according to the actual use condition; preferably, in the present embodiment, the conductivity of the first electromagnetic wave absorption layer 2 is 10% to 50% of the conductivity of the shielding layer 1.
In another preferred embodiment, the first electromagnetic wave absorption layer 2 has no electrical conductivity. By providing the first electromagnetic wave absorption layer 2 having no conductivity in the electromagnetic shielding film, the insertion loss during use of the wiring board can be reduced.
In the embodiment of the present invention, the first electromagnetic wave absorption layer 2 can be configured according to actual use conditions, and it is only necessary to ensure that it has a function of absorbing electromagnetic waves. Preferably, in this embodiment, the first electromagnetic wave absorption layer 2 is 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.
In addition, the thickness of the first electromagnetic wave absorption layer 2 may be set according to actual use. In order to ensure that the first electromagnetic wave absorption layer 2 can absorb the electromagnetic wave generated by the circuit board, the thickness of the first electromagnetic wave absorption layer 2 in the embodiment is preferably 0.1 μm to 45 μm. In addition, in this embodiment, the outer surface of the first electromagnetic wave absorption layer 2 may be a flat surface, or may be a non-flat surface, which is not limited in this embodiment.
In the embodiment of the present invention, one of the structures of the adhesive film layer 3 is specifically represented as: the adhesive layer 3 includes an adhesive layer containing conductive particles. The adhesive film layer 3 has an adhesive effect by including an adhesive layer containing conductive particles, so that the circuit board and the electromagnetic shielding film are tightly adhered, and the adhesive film layer 3 also has a conductive function, which can be matched with the shielding layer 1 to rapidly guide interfering electrons 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 embodiment of the present invention, the other structure of the adhesive film layer 3 is specifically represented as: the adhesive layer 3 includes an adhesive layer containing no conductive particles. The adhesive film layer 3 has an adhesive effect by enabling the adhesive film layer 3 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 3 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.
In addition, the thickness of the adhesive film layer 3 in this embodiment is 1 μm to 80 μm. The glue film layer 3 is made of 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 3 may be a flat surface or a non-flat surface, which is not limited in this embodiment.
Example two
As shown in fig. 5, the electromagnetic shielding film in the present embodiment is different from the first embodiment in that the first electromagnetic wave absorption layer 2 is disposed on the first region 12 of the shielding layer 1 and/or the second region of the conductive bump 11; the first region 12 is a region where the conductive bump 11 is not disposed in a surface of the shielding layer 1 close to the first electromagnetic wave absorption layer 2; the conductive bump 11 includes a plurality of bumps, and the second region is a region formed between any two adjacent bumps in the conductive bump 11.
It can be understood that the first electromagnetic wave absorption layer 2 is disposed on the first region 12 of the shielding layer 1 and/or the second region of the conductive bump 11, and at this time, the first electromagnetic wave absorption layer 2 does not cover the conductive bump 11, so that when the electromagnetic shielding film is laminated with the circuit board, the conductive bump 11 can be connected with the ground layer of the circuit board only by piercing the adhesive film layer 3. Specifically, the arrangement of the conductive bump 11 specifically includes two cases: (1) the height of the conductive bump 11 is less than or equal to the thickness of the first electromagnetic wave absorption layer 2; (2) the height of the conductive bump 11 is greater than the thickness of the first electromagnetic wave absorption layer 2. Under the condition that the height of the conductive bump 11 is less than or equal to the thickness of the first electromagnetic wave absorption layer 2, the first electromagnetic wave absorption layer 2 has fluidity at a certain pressing temperature, so that when the electromagnetic shielding film is pressed with the circuit board, the conductive bump 11 can pierce the adhesive film layer 3 and be connected with the ground layer of the circuit board; and under the condition that the height of the conductive bump 11 is greater than the thickness of the first electromagnetic wave absorption layer 2, the first electromagnetic wave absorption layer 2 may have no fluidity or fluidity at a certain pressing temperature, so that when the electromagnetic shielding film is pressed against the circuit board, the conductive bump 11 can directly pierce the adhesive film layer 2, thereby being connected with the ground layer of the circuit board.
It should be noted that the first electromagnetic wave absorption layer 2 is disposed in the first region of the shielding layer 1 and/or the second region of the conductive bump 11 specifically includes three cases: (1) the first electromagnetic wave absorption layer 2 is only provided in the first region 12; (2) the first electromagnetic wave absorption layer 2 is only arranged in the second region; (3) the first electromagnetic wave absorption layer 2 is provided in the first region 12 and the second region. One specific implementation manner of the first electromagnetic wave absorption layer 2 disposed on the first region 12 of the shielding layer 1 is as follows: a through hole penetrating through the upper and lower surfaces of the first electromagnetic wave absorption layer 2 is provided, and the conductive bump 11 penetrates through the through hole, so that the first electromagnetic wave absorption layer 2 is only provided in a region where the conductive bump 11 is not provided in one surface of the shielding layer 1 close to the first electromagnetic wave absorption layer 2. In addition, another specific implementation manner of the first electromagnetic wave absorption layer 2 disposed on the first region 12 of the shielding layer 1 is as follows: the electromagnetic wave absorption layer 2 is composed of a plurality of absorption sublayers, and each absorption sublayer is respectively arranged on the first region 12 of the shielding layer 1.
In the embodiment of the present invention, by disposing the first electromagnetic wave absorption layer 2 on the first region 12 of the shielding layer 1 and/or the second region of the conductive bump 11, it is ensured that the electromagnetic shielding film can absorb the electromagnetic wave generated by the circuit board through the first electromagnetic wave absorption layer 2, so as to achieve effective shielding of electromagnetic interference; on the other hand, when the electromagnetic screen film is laminated with the circuit board, the conductive bump 11 can be connected with the ground layer of the circuit board only by piercing the glue film layer 3 without piercing the first electromagnetic wave absorption layer 2, so that the requirement on the piercing strength of the conductive bump 11 is reduced, and the structure of the conductive bump 11 is simplified.
In the embodiment of the present invention, other structures and working principles of the electromagnetic shielding film of the present embodiment are the same as those of the first embodiment, and are not described herein.
EXAMPLE III
As shown in fig. 6, the electromagnetic shielding film in this embodiment is different from the first and second embodiments in that the electromagnetic shielding film further includes a second electromagnetic wave absorption layer 4, and the second electromagnetic wave absorption layer 4 is disposed on a side of the shielding layer 1 away from the first electromagnetic wave absorption layer 2.
It should be noted that the second electromagnetic wave absorption layer 4 has a function of absorbing electromagnetic waves, and is capable of absorbing electromagnetic wave energy projected to its surface and converting the electromagnetic waves into heat energy or other forms of energy through dielectric loss.
The embodiment of the utility model provides an in, through keep away from shielding layer 1 set up in the one side of first electromagnetic wave absorbed layer 2 second electromagnetic wave absorbed layer 4 makes and works as when the electromagnetic shielding film is applied to the circuit board, the electromagnetic shielding film can pass through second electromagnetic wave absorbed layer 4 absorbs and comes from the outside electromagnetic wave of circuit board to further realized effectively shielding electromagnetic interference, guaranteed the normal work of circuit board.
It can be understood that, the circuit board is applied to electronic devices such as smart phones and tablet computers, and these electronic devices are usually provided with an antenna, and electromagnetic waves generated by the antenna also affect signal transmission in the circuit board. Therefore, by arranging the second electromagnetic wave absorption layer 4 on the side of the shielding layer 1 away from the first electromagnetic wave absorption layer 2, when the electromagnetic shielding film is applied to the circuit board, the second electromagnetic wave absorption layer 4 can absorb the electromagnetic waves generated by the antenna and other devices outside the circuit board, and the electromagnetic waves which are not completely absorbed are reflected when passing through the side of the shielding layer 1 close to the second electromagnetic wave absorption layer 4, so that the electromagnetic wave absorption rate of the electromagnetic shielding film is improved for the second time, the interference of the electromagnetic waves from the outside of the circuit board to the circuit board is effectively avoided, and the normal signal transmission of the circuit board is further ensured.
In a preferred embodiment, the second electromagnetic wave absorption layer 4 has conductivity, and the conductivity of the second electromagnetic wave absorption layer 4 is smaller than the conductivity of the shielding layer 1. By providing the second electromagnetic wave absorption layer 4 having conductivity in the electromagnetic shielding film, on the one hand, the second electromagnetic wave absorption layer 4 has a function of absorbing electromagnetic waves, which can absorb electromagnetic waves from the outside of the circuit board, to further ensure the normal operation of the circuit board; on the other hand, the second electromagnetic wave absorption layer 4 also has a conductive function, which can cooperate with the shielding layer 1 to introduce interference charges into the ground layer, thereby further ensuring good shielding effectiveness of the electromagnetic shielding film.
It should be noted that, in this embodiment, the proportional relationship between the conductivity of the second electromagnetic wave absorption layer 4 and the conductivity of the shielding layer 1 can be set according to the actual use condition; preferably, the conductivity of the second electromagnetic wave absorption layer 4 in this embodiment is 10% to 50% of the conductivity of the shielding layer 1.
In another preferred embodiment, the second electromagnetic wave absorption layer 4 has no electrical conductivity. By providing the second electromagnetic wave absorption layer 4 having no conductivity in the electromagnetic shielding film, the insertion loss during use of the wiring board can be reduced.
In the embodiment of the present invention, the second electromagnetic wave absorption layer 4 can be configured according to actual use conditions, and it is only necessary to ensure that it has a function of absorbing electromagnetic waves. Preferably, in this embodiment, the second electromagnetic wave absorption layer 4 is 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.
In addition, the thickness of the second electromagnetic wave absorption layer 4 may be set according to actual use. In order to ensure that the second electromagnetic wave absorption layer 4 can absorb electromagnetic waves from the outside of the circuit board, the thickness of the second electromagnetic wave absorption layer 4 in this embodiment is preferably 0.1 μm to 45 μm. In addition, in this embodiment, the outer surface of the second electromagnetic wave absorption layer 4 may be a flat surface, or may be a non-flat surface, which is not limited in this embodiment.
In the embodiment of the present invention, other structures and working principles of the electromagnetic shielding film of the present embodiment are the same as those of the first embodiment and the second embodiment, and are not further described herein.
Example four
As shown in fig. 7, this embodiment provides an electromagnetic shielding film, which is different from the first and second embodiments in that the electromagnetic shielding film further includes an insulating layer 5, and the insulating layer 5 is disposed on a side of the shielding layer 1 away from the first electromagnetic wave absorption layer 2.
As shown in fig. 8, this embodiment further provides another electromagnetic shielding film, which is different from the third embodiment in that the electromagnetic shielding film further includes an insulating layer 5, and the insulating layer 5 is disposed on a side of the second electromagnetic wave absorption layer 4 away from the shielding layer 1.
In the embodiment of the present invention, the insulating layer 5 is disposed in the electromagnetic shielding film, so that the electromagnetic shielding film is insulated from the surrounding environment or the adjacent conductors, thereby ensuring the shielding effectiveness of the electromagnetic shielding film.
In the embodiment of the present invention, other structures and working principles of the electromagnetic shielding film of the present embodiment are the same as those of the first to third embodiments, and are not further described herein.
EXAMPLE five
As shown in fig. 9, the embodiment of the present invention further provides a circuit board, including a circuit board body 6 and any one of the first to fourth embodiments of the electromagnetic shielding film, the conductive protrusion 11 of the electromagnetic shielding film pierces the adhesive film layer 3, and is connected to the ground layer in the circuit board body 6.
In the embodiment of the present invention, the conductive bumps 11 in the electromagnetic shielding film may all contact with the ground layer of the circuit board body 6, or may partially contact with the ground layer of the circuit board body 6, which is not limited in this embodiment.
In addition, for the implementation of the electromagnetic shielding film, reference may be made to the descriptions of the first to fourth embodiments, which are not repeated herein.
In the embodiment of the present invention, the type of the circuit board body 6 can be set according to the actual use condition; preferably, the circuit board body 6 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.
The embodiment of the utility model provides an in, through by circuit board body 6 with the electromagnetic shielding membrane constitutes the circuit board makes can be through locating shielding layer 1 with between the rete 3 first electromagnetic wave absorbed layer 2 absorbs the produced electromagnetic wave of circuit board has realized effectively shielding electromagnetic interference to avoided the circuit board to have great electromagnetic interference problem in signal transmission effectively, consequently guaranteed the normal work of circuit board. In addition, the shielding layer 1 is provided with the conductive protrusion 11 on the surface close to the first electromagnetic wave absorption layer 2, and the conductive protrusion 11 penetrates through the adhesive film layer 3 and is connected with the ground layer of the circuit board body, so that the interference charges accumulated in the electromagnetic shielding film are guided into the ground layer, and the shielding effectiveness is further improved.
EXAMPLE six
The embodiment of the utility model provides an electromagnetic shielding film' S preparation method, this method is applicable to the electromagnetic shielding film of preparation embodiment one, the method includes following step S11-S13:
s11, manufacturing and forming a shielding layer; and a conductive bump is formed on one surface of the shielding layer.
Wherein the shielding layer is formed in step S11 by:
forming a protective film layer on a carrier film, the shielding layer being formed on the protective film layer; or
The method comprises the steps of forming a peelable layer on a carrier film, forming the shielding layer on a surface of the peelable layer, and peeling the carrier film after forming a protective film layer on a side of the shielding layer remote from the peelable layer.
In addition, the shielding layer and the conductive bump may be formed as an integral structure by a one-step molding process, or the conductive bump may be formed on one surface of the shielding layer after the shielding layer is formed.
The shielding layer and the conductive bump can be formed by chemical plating, PVD, CVD, evaporation plating, sputtering plating, electroplating or a composite process thereof.
And S12, forming a first electromagnetic wave absorption layer on one surface of the shielding layer on which the conductive bump is formed.
And S13, forming an adhesive film layer on one surface of the first electromagnetic wave absorption layer far away from the shielding layer.
In step S13, forming an adhesive film layer on a surface of the first electromagnetic wave absorption layer away from the shielding layer specifically includes:
coating an adhesive film layer on a release film, and then transferring the adhesive film layer to one surface of the first electromagnetic wave absorption layer, which is far away from the shielding layer, in a pressing manner, so that the adhesive film layer is formed on one surface of the first electromagnetic wave absorption layer, which is far away from the shielding layer; or
And directly coating an adhesive film layer on one surface of the first electromagnetic wave absorption layer, which is far away from the shielding layer, so that the adhesive film layer is formed on one surface of the first electromagnetic wave absorption layer, which is far away from the shielding layer.
In addition, it should be noted that the method for manufacturing the electromagnetic shielding film provided in this embodiment is only one example for manufacturing the electromagnetic shielding film described in the first embodiment, and the electromagnetic shielding film described in the first embodiment may also be manufactured by other manufacturing methods. In addition, the preparation method of the electromagnetic shielding film according to the second to fourth embodiments may specifically refer to the preparation method of the electromagnetic shielding film provided in this embodiment, and will not be further described herein.
To sum up, the utility model provides an electromagnetic shielding film and circuit board, electromagnetic shielding film includes shielding layer 1, first electromagnetic wave absorbed layer 2 and glued membrane layer 3, first electromagnetic wave absorbed layer 2 is located shielding layer 1 with between the glued membrane layer 3, shielding layer 1 is close to the one side of first electromagnetic wave absorbed layer 2 is equipped with electrically conductive arch 11. Through set up in the electromagnetic shielding film first electromagnetic wave absorbed layer 2 makes the electromagnetic shielding film has the function of absorbing the electromagnetic wave, consequently, works as when the electromagnetic shielding film is applied to the circuit board, the electromagnetic shielding film can absorb effectively the produced electromagnetic wave of circuit board has realized effectively shielding electromagnetic interference to avoided the circuit board to have great electromagnetic interference problem in signal transmission, consequently guaranteed the normal work of circuit board. In addition, the conductive protrusion 11 is arranged on the surface, close to the first electromagnetic wave absorption layer 2, of the shielding layer 1, so that when the electromagnetic shielding film is applied to the circuit board, the conductive protrusion 11 in the electromagnetic shielding film can pierce the adhesive film layer 3 and is connected with the ground layer of the circuit board, thereby leading out interference charges accumulated in the electromagnetic shielding film, and therefore, the shielding effectiveness of the electromagnetic shielding film is improved.
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 (14)
1. The utility model provides an electromagnetic shielding film, its characterized in that includes shielding layer, first electromagnetic wave absorbed layer and glued membrane layer, first electromagnetic wave absorbed layer is located the shielding layer with between the glued membrane layer, the shielding layer is close to the one side of first electromagnetic wave absorbed layer is equipped with electrically conductive arch.
2. The electromagnetic shielding film according to claim 1, wherein the conductive protrusion is embedded in the first electromagnetic wave absorption layer.
3. The electro-magnetic shielding film of claim 1, wherein the first electro-magnetic wave absorption layer is provided on the first region of the shielding layer and/or the second region of the conductive bump; the first region is a region where the conductive bump is not arranged in one surface, close to the first electromagnetic wave absorption layer, of the shielding layer; the conductive protrusion comprises a plurality of protruding parts, and the second area is an area formed between any two adjacent protruding parts in the conductive protrusion.
4. The electro-magnetic shielding film according to any one of claims 1 to 3, further comprising a second electro-magnetic wave absorption layer disposed on a side of the shielding layer away from the first electro-magnetic wave absorption layer.
5. The electromagnetic shielding film according to any one of claims 1 to 3, wherein the first electromagnetic wave absorption layer has electrical conductivity, and the electrical conductivity of the first electromagnetic wave absorption layer is smaller than the electrical conductivity of the shielding layer; or the like, or, alternatively,
the first electromagnetic wave absorption layer has no conductivity.
6. The electro-magnetic shielding film of claim 4, wherein the second electro-magnetic wave absorption layer has electrical conductivity, and the electrical conductivity of the second electro-magnetic wave absorption layer is less than the electrical conductivity of the shielding layer; or the like, or, alternatively,
the second electromagnetic wave absorption layer has no conductivity.
7. The electro-magnetic shielding film of claim 4, wherein at least one of the first electro-magnetic wave absorption layer and the second electro-magnetic wave absorption layer is formed of an adhesive and a wave-absorbing medium.
8. The electromagnetic shielding film according to claim 7, wherein the wave-absorbing medium is made of any one of a carbon-based wave-absorbing material, an iron-based wave-absorbing material, a ceramic-based wave-absorbing material, and a composite wave-absorbing material.
9. The electro-magnetic shielding film of claim 4, wherein the first electro-magnetic wave absorption layer has a thickness of: 0.1-45 μm; the thickness of the second electromagnetic wave absorption layer is as follows: 0.1-45 μm.
10. The electro-magnetic shielding film of any one of claims 1-3, wherein the conductive bumps have conductive particles on the surface.
11. The electromagnetic shielding film according to any one of claims 1 to 3, wherein the adhesive layer comprises an adhesive layer containing conductive particles; or the like, or, alternatively,
the adhesive film layer comprises an adhesion layer without conductive particles.
12. The electro-magnetic shielding film of any one of claims 1-3, further comprising an insulating layer disposed on a side of the shielding layer remote from the first electro-magnetic wave absorption layer.
13. The electro-magnetic shielding film of claim 4, further comprising an insulating layer disposed on a side of the second electro-magnetic wave absorption layer away from the shielding layer.
14. A circuit board comprising a circuit board body and the electromagnetic shielding film according to any one of claims 1 to 13, wherein the conductive bumps of the electromagnetic shielding film pierce through the adhesive film layer and are connected to a ground layer in the circuit board body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922490785.6U CN211702874U (en) | 2019-12-30 | 2019-12-30 | Electromagnetic shielding film and circuit board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922490785.6U CN211702874U (en) | 2019-12-30 | 2019-12-30 | Electromagnetic shielding film and circuit board |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211702874U true CN211702874U (en) | 2020-10-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922490785.6U Active CN211702874U (en) | 2019-12-30 | 2019-12-30 | Electromagnetic shielding film and circuit board |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211702874U (en) |
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2019
- 2019-12-30 CN CN201922490785.6U patent/CN211702874U/en active Active
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