Electromagnetic shielding film, circuit board and preparation method of electromagnetic shielding film
阅读说明:本技术 电磁屏蔽膜、线路板及电磁屏蔽膜的制备方法 (Electromagnetic shielding film, circuit board and preparation method of electromagnetic shielding film ) 是由 苏陟 于 2018-07-27 设计创作,主要内容包括:本发明实施例提供了一种电磁屏蔽膜、线路板及电磁屏蔽膜的制备方法,其中,电磁屏蔽膜包括树脂膜层、第一屏蔽层和胶膜层,树脂膜层上设有第一通孔,第一通孔处设有树脂凸起,树脂凸起由树脂从第一通孔的一侧流至另一侧后凝固形成;第一屏蔽层设于树脂膜层靠近树脂凸起的一侧,并覆盖树脂凸起,从而在第一屏蔽层的外表面与树脂凸起对应的位置形成凸起部;胶膜层设于第一屏蔽层远离树脂膜层的一侧,凸起部伸入胶膜层,使得凸起部在压合的过程中保证第一屏蔽层能够顺利地刺穿胶膜层,与线路板地层接触,进而保证干扰电荷正常导出,实现屏蔽功能。(The embodiment of the invention provides an electromagnetic shielding film, a circuit board and a preparation method of the electromagnetic shielding film, wherein the electromagnetic shielding film comprises a resin film layer, a first shielding layer and a glue film layer, a first through hole is formed in the resin film layer, a resin bulge is arranged at the first through hole, and the resin bulge is formed by solidifying resin after the resin flows from one side of the first through hole to the other side; the first shielding layer is arranged on one side, close to the resin bulge, of the resin film layer and covers the resin bulge, so that a bulge part is formed on the outer surface of the first shielding layer at a position corresponding to the resin bulge; the glue film layer is arranged on one side, away from the resin film layer, of the first shielding layer, and the protruding portion extends into the glue film layer, so that the protruding portion can guarantee that the first shielding layer can smoothly pierce through the glue film layer in the pressing process and is in contact with the ground of the circuit board, and then normal derivation of interference charges is guaranteed, and a shielding function is achieved.)
1. An electromagnetic shielding film is characterized by comprising a resin film layer, a first shielding layer and a glue film layer, wherein a first through hole penetrating through the upper surface and the lower surface of the resin film layer is formed in the resin film layer, a resin bulge is arranged at the first through hole, and the resin bulge is formed by solidifying resin after the resin flows from one side of the first through hole to the other side; the first shielding layer is arranged on one side, close to the resin bulge, of the resin film layer and covers the resin bulge, so that a bulge part is formed on the outer surface of the first shielding layer at a position corresponding to the resin bulge; the glue film layer is arranged on one side, away from the resin film layer, of the first shielding layer, and the protruding portion extends into the glue film layer.
2. The electro-magnetic shielding film according to claim 1, wherein the resin protrusion is formed by solidifying at a curing temperature after a resin flows from one side to the other side of the first through hole at a normal temperature; or the like, or, alternatively,
the resin protrusion is formed by instantly cooling after resin flows from one side to the other side of the first through hole at a melting temperature.
3. The electromagnetic shielding film according to claim 1, wherein the surface of the convex portion is provided with convex conductor particles; the height of the conductor particles is 0.1-30 μm.
4. The electromagnetic shielding film of claim 1, 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.
5. The electromagnetic shielding film of any of claims 1-4, wherein the first shielding layer comprises one or more of a metal shielding layer, a carbon nanotube shielding layer, a ferrite shielding layer, and a graphene shielding layer.
6. The electromagnetic shielding film according to claim 5, wherein the metallic shielding layer comprises a single metallic 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.
7. The electro-magnetic shielding film of any one of claims 1-4, further comprising a protective film layer disposed on a side of the resin film layer remote from the first shielding layer.
8. A circuit board comprising a printed wiring board and the electromagnetic shielding film of any one of claims 1 to 7, wherein the electromagnetic shielding film is laminated with the printed wiring board through an adhesive film layer thereof; the protruding part pierces the adhesive film layer and extends to the ground layer of the printed circuit board.
9. A method for preparing an electro-magnetic shielding film, which is suitable for preparing the electro-magnetic shielding film of any one of claims 1 to 7, comprising the steps of:
s1, forming a resin film layer; wherein the resin film layer has a first through hole penetrating through upper and lower surfaces thereof;
s2, forming a resin bulge at the first through hole; wherein the resin projection protrudes out of the first through hole;
s3, forming a first shielding layer on the side of the resin film layer where the resin bump is formed, and forming a bump on the outer surface of the first shielding layer at a position corresponding to the resin bump by covering the resin bump with the first shielding layer;
and S4, forming a film adhesive layer on one side of the first shielding layer far away from the resin film layer.
10. The method for preparing an electro-magnetic shielding film according to claim 9, wherein in step S2, the forming of the resin protrusion at the first through hole includes:
and arranging resin at the first through hole, and solidifying the resin after the resin flows from one side to the other side of the first through hole, so that a resin bulge is formed at the first through hole.
11. The method for preparing an electro-magnetic shielding film according to claim 9, further comprising the steps of, before forming an adhesive film layer on a side of the first shielding layer away from the resin film layer:
forming conductor particles on the outer surface of the protrusion part by one or more processes of physical roughening, chemical plating, physical vapor deposition, chemical vapor deposition, evaporation plating, sputtering plating, electroplating and hybrid plating.
12. The method for preparing an electromagnetic shielding film according to claim 9, wherein in step S4, the step of forming an adhesive film layer on the side of the first shielding layer away from the resin film layer includes:
coating an adhesive film layer on a release film, and then transferring the adhesive film layer to one side of the first shielding layer far away from the resin film layer in a pressing manner, so that the adhesive film layer is formed on one side of the first shielding layer far away from the resin film layer; or
And directly coating an adhesive film layer on one side of the first shielding layer, which is far away from the resin film layer, so that the adhesive film layer is formed on one side of the first shielding layer, which is far away from the resin film layer.
Technical Field
The invention relates to the field of electronics, in particular to an electromagnetic shielding film, a circuit board and a preparation method of the electromagnetic shielding film.
Background
With the rapid development of the electronic industry, electronic products are further miniaturized, light-weighted and highly-densely assembled, and the development of flexible circuit boards is greatly promoted, so that the integration of component 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 printed circuit board is dominant in the flexible printed circuit board market, and 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 communication equipment such as mobile phones, the internal components thereof are sharply high-frequency and high-speed, for example: the mobile phone functions become necessary functions in addition to 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, at high temperature, due to the expansion of the conductive adhesive layer, the conductive particles originally in contact with each other in the conductive adhesive layer are pulled apart or the conductive particles originally in contact with the circuit board stratum are pulled apart, which results in grounding failure, and the interference charges cannot be rapidly led out, so that the shielding function cannot be realized.
Disclosure of Invention
The embodiment of the invention aims to provide an electromagnetic shielding film, a circuit board and a preparation method of the electromagnetic shielding film, which can realize the reliable connection of the shielding film and the circuit board stratum and further realize the shielding function with high reliability.
In order to achieve the above object, an embodiment of the present invention provides an electromagnetic shielding film, including a resin film layer, a first shielding layer, and an adhesive film layer, where the resin film layer is provided with a first through hole penetrating through upper and lower surfaces of the resin film layer, the first through hole is provided with a resin protrusion, and the resin protrusion is formed by resin flowing from one side of the first through hole to the other side of the first through hole and then solidifying; the first shielding layer is arranged on one side, close to the resin bulge, of the resin film layer and covers the resin bulge, so that a bulge part is formed on the outer surface of the first shielding layer at a position corresponding to the resin bulge; the glue film layer is arranged on one side, away from the resin film layer, of the first shielding layer, and the protruding portion extends into the glue film layer.
As a modification of the above, the resin projection is formed by solidification of resin at a curing temperature after the resin flows from one side to the other side of the first through hole at normal temperature; or the like, or, alternatively,
the resin protrusion is formed by instantly cooling after resin flows from one side to the other side of the first through hole at a melting temperature.
As an improvement of the above scheme, the surface of the convex part is provided with convex conductor particles; the height of the conductor particles is 0.1-30 μm.
As an improvement of the above scheme, the adhesive film layer includes an adhesive layer containing conductive particles; or the adhesive film layer comprises an adhesion layer without conductive particles.
As an improvement of the above scheme, the first shielding layer respectively comprises one or more of a metal shielding layer, a carbon nanotube shielding layer, a ferrite shielding layer and a graphene shielding layer.
As a modification of the above, 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.
As an improvement of the above scheme, the electromagnetic shielding film further comprises a protective film layer, and the protective film layer is arranged on one side of the resin film layer, which is far away from the first shielding layer.
Compared with the prior art, the embodiment of the invention discloses an electromagnetic shielding film, by arranging the first through hole on the resin film layer, and the resin projection formed by solidification of resin after flowing from one side to the other side of the first through hole is provided at the first through hole, meanwhile, the first shielding layer is arranged on one side of the resin film layer close to the resin bulge and covers the resin bulge, thereby forming a convex portion at a position of the outer surface of the first shield layer corresponding to the resin protrusion, the adhesive film layer is arranged on one side of the first shielding layer far away from the resin film layer, so that the first shielding layer can be ensured to smoothly pierce the adhesive film layer by the bulge part in the pressing process, the grounding is reliable, interference charges are guaranteed to be led out normally, and the shielding function is achieved.
The embodiment of the invention also correspondingly provides a circuit board, which comprises a printed circuit board and the electromagnetic shielding film, wherein the electromagnetic shielding film is laminated with the printed circuit board through the adhesive film layer; the protruding part pierces the adhesive film layer and extends to the ground layer of the printed circuit board.
Compared with the prior art, the embodiment of the invention discloses a circuit board which comprises a printed circuit board and any one of the electromagnetic shielding films, wherein the electromagnetic shielding film is pressed with the printed circuit board through a film adhesive layer, and the bulge part pierces the film adhesive layer and is connected with a ground layer of the printed circuit board, so that interference charges are smoothly led out, and the shielding function is further realized.
The embodiment of the invention also correspondingly provides a preparation method of the electromagnetic shielding film, which is suitable for preparing any one of the electromagnetic shielding films, and comprises the following steps:
s1, forming a resin film layer; wherein the resin film layer has a first through hole penetrating through upper and lower surfaces thereof;
s2, forming a resin bulge at the first through hole; wherein the resin projection protrudes out of the first through hole;
s3, forming a first shielding layer on the side of the resin film layer where the resin bump is formed, and forming a bump on the outer surface of the first shielding layer at a position corresponding to the resin bump by covering the resin bump with the first shielding layer;
and S4, forming a film adhesive layer on one side of the first shielding layer far away from the resin film layer.
As a modification of the above, in step S2, the forming a resin protrusion at the first through hole includes:
and arranging resin at the first through hole, and solidifying the resin after the resin flows from one side to the other side of the first through hole, so that a resin bulge is formed at the first through hole.
As an improvement of the above scheme, before forming the glue film layer on the side of the first shielding layer away from the resin film layer, the method further comprises the following steps:
forming conductor particles on the outer surface of the protrusion part by one or more processes of physical roughening, chemical plating, physical vapor deposition, chemical vapor deposition, evaporation plating, sputtering plating, electroplating and hybrid plating.
As a modification of the above scheme, in step S4, the forming a glue film layer on the side of the first shielding layer away from the resin film layer specifically includes:
coating an adhesive film layer on a release film, and then transferring the adhesive film layer to one side of a first shielding layer far away from a resin film layer in a pressing manner, so that the adhesive film layer is formed on one side of the first shielding layer far away from the resin film layer; or
And directly coating an adhesive film layer on one side of the first shielding layer where the bulge is formed, so that the adhesive film layer is formed on one side of the first shielding layer far away from the resin film layer.
Compared with the prior art, according to the preparation method of the electromagnetic shielding film provided by the embodiment of the invention, the first shielding layer is formed on one side of the resin film layer on which the resin protrusion is formed, and the first shielding layer covers the resin protrusion, so that the protrusion part is formed on the outer surface of the first shielding layer at the position corresponding to the resin protrusion, and the adhesive film layer is formed on one side of the first shielding layer, so that the formed protrusion part can ensure that the first shielding layer smoothly pierces through the adhesive film layer in the pressing process, reliable grounding is realized, and the practicability is strong.
Drawings
Fig. 1 is a schematic view of an angle structure of an electromagnetic shielding film in
fig. 2 is a schematic view of another angle structure of the electromagnetic shielding film in
fig. 3 is a schematic structural view of an electromagnetic shielding film in
fig. 4 is a schematic structural view of a wiring board in
fig. 5 is a schematic flow chart of a method for manufacturing an electromagnetic shielding film in
Wherein, 1, resin film layer; 11. a first through hole; 12. resin bumps; 2. a first shielding layer; 21. a boss portion; 22. a conductive particle; 3. a glue film layer; 4. a protective film layer; 5. a printed wiring board.
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 a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic view of an angle structure of the electromagnetic shielding film according to
fig. 2 is a schematic structural view of another angle of the electromagnetic shielding film provided in
referring to fig. 1 and 2, the electromagnetic shielding film includes a
In the embodiment of the present invention, the first through
In the embodiment of the present invention, the process of forming the
In the embodiment of the present invention, it should be noted that the structure of the
In the embodiment of the present invention, the shape of the
In the embodiment of the present invention, in order to further ensure that the
In addition, in this example, each 1cm2The number of the first through
In the embodiment of the present invention, the first through
In the embodiment of the present invention, the
In the embodiment of the present invention, the thickness of the
In the embodiment of the present invention, it should be noted that the
In the embodiment of the present invention, one of the structures of the
In the embodiment of the present invention, another structure of the
In the embodiment of the present invention, the thickness of the
As shown in fig. 1, in order to protect the
In the embodiment of the present invention, it should be noted that the electromagnetic shielding film may have a repeating multilayer structure. Specifically, the electromagnetic shielding film may include a plurality of resin film layers 1 stacked in sequence, and the
Fig. 3 is a schematic structural view of the electromagnetic shielding film according to
as shown in fig. 3, the electromagnetic shielding film in the present embodiment is different from
Preferably, the
In a specific implementation, as shown in fig. 3, the
In the embodiment of the present invention, the
In the embodiment of the present invention, in order to ensure that the protruding
In an embodiment of the present invention, the
In the embodiment of the present invention, it should be noted that the shape of the
In the embodiment of the present invention, it should be noted that the electromagnetic shielding film may be a repeating multilayer structure; specifically, the electromagnetic shielding film may include a plurality of resin film layers 1 stacked in sequence, and the
Fig. 4 is a schematic structural diagram of a circuit board provided in
as shown in fig. 4, an embodiment of the present invention further provides a circuit board, including a printed circuit board 5 and the electromagnetic shielding film described in
In this embodiment, reference may be made to the description of
Preferably, the printed circuit board 5 is one of a flexible single-sided board, a flexible double-sided board, a flexible multilayer board, and a rigid-flex board.
In the embodiment of the present invention, with the above structure, in the pressing process, the protruding
Referring to fig. 5, a schematic flow chart of a method for preparing an electromagnetic shielding film according to
as shown in fig. 5, the method is suitable for preparing the electromagnetic shielding film according to
s1, forming a resin film layer; wherein the resin film layer has a first through hole penetrating through upper and lower surfaces thereof;
specifically, the resin film layer is formed by: forming a protective film layer on a carrier film, and forming a resin film layer on the protective film layer; or
Forming a resin film layer on the surface of the strippable layer with the carrier, forming a protective film layer on the resin film layer, and stripping the strippable layer with the carrier;
wherein the resin film layer has a first through hole penetrating upper and lower surfaces thereof. The cross-sectional area of the first through-hole is 0.1 μm2-1mm2(ii) a Every 1cm2The number of the first through holes in the resin film layer is 10-1000.
S2, forming a resin bulge at the first through hole; wherein the resin projection protrudes out of the first through hole;
wherein, form the resin arch in first through-hole department, specifically be: and arranging resin at the first through hole, and solidifying the resin after the resin flows from one side to the other side of the first through hole, so that a resin bulge is formed at the first through hole. Specifically, in one of preferred modes, after a resin is provided at the first through hole and is caused to flow from one side to the other side of the first through hole at normal temperature, the resin is solidified at a curing temperature, thereby forming a resin protrusion at the first through hole. In yet another preferred embodiment, a resin is provided at the first through hole and instantaneously cooled after flowing from one side to the other side of the first through hole at a melting temperature, thereby forming a resin protrusion at the first through hole.
S3, forming a first shielding layer on the side of the resin film layer where the resin bump is formed, and forming a bump on the outer surface of the first shielding layer at a position corresponding to the resin bump by covering the resin bump with the first shielding layer;
and S4, forming a film adhesive layer on one side of the first shielding layer far away from the resin film layer.
Specifically, a glue film layer is coated on a release film, and then the glue film layer is transferred to one side, away from the resin film layer, of a first shielding layer in a pressing mode, so that the glue film layer is formed on one side, away from the resin film layer, of the first shielding layer; or
And directly coating an adhesive film layer on one side of the first shielding layer where the bulge is formed, so that the adhesive film layer is formed on one side of the first shielding layer far away from the resin film layer.
In another preferred embodiment suitable for preparing the electro-magnetic shielding film of
forming conductor particles on the outer surface of the protrusion part by one or more processes of physical roughening, chemical plating, physical vapor deposition, chemical vapor deposition, evaporation plating, sputtering plating, electroplating and hybrid plating.
In the embodiment of the invention, the first shielding layer is formed on one side of the resin film layer where the resin protrusion is formed, and the first shielding layer covers the resin protrusion, so that the protrusion is formed on the outer surface of the first shielding layer at a position corresponding to the resin protrusion, and the adhesive film layer is formed on one side of the first shielding layer away from the resin film layer, so that the formed protrusion can ensure that the first shielding layer smoothly pierces through the adhesive film layer in the pressing process, reliable grounding is realized, and the practicability is strong.
To sum up, the embodiment of the invention provides an electromagnetic shielding film, a circuit board and a preparation method of the electromagnetic shielding film, wherein the electromagnetic shielding film comprises a
The foregoing is directed to the preferred embodiment of the present invention, and it is understood that various changes and modifications may be made by one skilled in the art without departing from the spirit of the invention, and it is intended that such changes and modifications be considered as within the scope of the invention.
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