CN102395257A - Electromagnetic shielding film and preparation method thereof - Google Patents

Abstract

The present invention relates to electromagnetic shielding materials, and in particular to an electromagnetic shielding film and a preparation method thereof. The electromagnetic shielding film has a layered structure and is characterized in that: the electromagnetic shielding film is composed of an adhesive layer and a shielding layer, wherein the adhesive layer contains Ni powder oriented by magnetic force, the shielding layer also has a layered structure, and the film structure of the shielding layer is Ni-Cu-Ni; the magnetic pole direction of the Ni powder is perpendicular to the surface of the adhesive layer. The preparation method of the electromagnetic shielding film includes the following steps: S1, providing a release layer; S2, coating the adhesive layer on the release layer; S3, magnetic orientation; S4, optical fixation; S5, Ni plating; S6, Cu plating; S7, Ni plating. The present invention provides an ultra-thin electromagnetic shielding film with good shielding effect and a preparation method thereof.

Description

A kind of electromagnetic shielding film and preparation method thereof

technical field

The invention relates to an electromagnetic shielding material, in particular to an electromagnetic shielding film and a preparation method thereof.

Background technique

Electromagnetic shielding films are widely used, especially in the field of electronic products. In electronic products, in addition to directly making some parts of the product into electromagnetic shielding materials, the most widely used is to achieve electromagnetic shielding through film.

In the prior art, a shielding material is generally plated on a substrate layer or an electroplated conductive cloth is directly used, and then double-sided adhesive is used to connect the substrate to the shielding material and attach it to the casing, screen or other parts that need to be shielded. . For example, Chinese patent document CN101513782A disclosed on August 26, 2009 an electromagnetic wave shielding material suitable for electronic products such as computers, electronic game consoles, mobile phones, etc., including conductive cloth, insulating cloth, release material layer, two Adhesive layer; the electromagnetic wave shielding material is followed by a release material layer, a first adhesive layer, a conductive cloth, a second adhesive layer, and an insulating cloth from the inside to the outside; the two adhesive layers combine the release material layer, the conductive cloth , Insulation cloth bonding as one. The outside of the insulating cloth can be coated or printed with colors or patterns to meet the insulation requirements while meeting the identification requirements or decoration requirements. The invention provides an electromagnetic wave shielding material with insulation on one or both sides, easy to ensure assembly accuracy, and convenient use. Wherein, the conductive cloth of the invention is the shielding function layer, and the first adhesive layer is the connecting layer. Like the aforementioned patented technology, the deficiencies of the existing technology are also obvious. On the one hand, the substrate layer acts as a carrier to increase the overall thickness of the film (the cloth base of the conductive cloth is also equivalent to the substrate layer). On the other hand, the first adhesive layer is a non-magnetic material with a certain thickness, and the shielding effect is not good when the functional layer is attached to the position that needs to be shielded, and magnetic flux leakage will occur on the side.

Contents of the invention

The object of the present invention is to provide an ultra-thin electromagnetic shielding film by overcoming the disadvantages of the above-mentioned prior art.

The object of the present invention is also to overcome the disadvantages of the above-mentioned prior art and provide an electromagnetic shielding film with good shielding effect when it is pasted on the position that needs to be shielded.

The object of the present invention is also to provide a method for preparing an electromagnetic shielding film by overcoming the disadvantages of the above-mentioned prior art.

The purpose of the present invention can be achieved through the following technical solutions:

An electromagnetic shielding film has a layered structure, and is characterized in that: the electromagnetic shielding film is made up of an adhesive layer and a shielding layer, wherein the adhesive layer has Ni powder oriented by magnetic force, and the shielding layer also has a layered structure, and the shielding layer The film structure of the layer is Ni-Cu-Ni; the magnetic pole direction of the Ni powder is perpendicular to the surface of the adhesive layer.

The electromagnetic shielding film is characterized in that: the adhesive layer contains hot melt adhesive, or acrylic adhesive, or silicon pressure-sensitive adhesive, and the thickness of the adhesive layer is 5 microns to 500 microns; the Ni powder has strips Like structure, the two ends of the strip Ni powder point to the two surfaces of the adhesive layer respectively.

The electromagnetic shielding film is characterized in that: the adhesive layer also includes a UV light-curable material.

The electromagnetic shielding film is characterized in that: the Ni layer in the shielding layer is set by vacuum evaporation or vacuum sputtering, and the Cu layer in the shielding layer is set by electroplating or vacuum evaporation or vacuum sputtering; Ni-Cu-Ni structure Among them, the thickness of each layer is 1 micron to 5 microns, 1 micron to 50 microns, and 1 micron to 5 microns.

The electromagnetic shielding film is characterized in that: the adhesive layer comprises hot melt adhesive, and the thickness of the adhesive layer is 100 microns; the Ni powder is a strip structure with sharp ends, and the two ends of the strip Ni powder are respectively Pointing to the two surfaces of the adhesive layer; the adhesive layer also includes a UV light-curable material, and the weight ratio of the UV light-curable material to the hot melt adhesive is less than 1:7; the Ni layer in the shielding layer is set by vacuum evaporation , the Cu layer in the shielding layer is set by electroplating; in the Ni-Cu-Ni structure, the thickness of each layer is 4 microns, 45 microns, and 4 microns.

The electromagnetic shielding film is characterized in that: the outer side of the shielding film and the inner side of the adhesive layer are also provided with an intermediate material, that is, a release film; the layered structure of the electromagnetic shielding film is: outer release film-shielding layer- Adhesive layer - inner release film, wherein the outer release film is a PET film with a thickness of 5 microns to 50 microns.

The purpose of the present invention can also be achieved through the following technical solutions:

A method for preparing an electromagnetic shielding film, characterized in that it comprises the following steps:

S1, providing a release layer;

S2, coating an adhesive layer on the release layer;

S3, magnetic orientation;

S4, light fixation direction;

S5, Ni plating;

S6, Cu plating;

S7, Ni plating;

Wherein, the release layer described in step S1 is an intermediate material, which is torn off during use; the coated material of the coating adhesive layer described in step S2 contains Ni magnetic powder and UV light-curable material; The magnetic orientation described above is to make the magnetic pole direction of the Ni powder itself along the thickness direction of the adhesive layer by magnetic force; the optical fixation described in the step S4 is to fix the Ni powder by UV light so that it is in the adhesive layer. The magnetism and direction are kept along the thickness direction of the adhesive layer; S5, S6, and S7 are all vacuum coatings, using vacuum evaporation or vacuum sputtering.

The method for preparing an electromagnetic shielding film is characterized in that it further includes step S8 after step S7, that is, attaching the outer release layer, which is also an intermediate material, and is torn off when used.

The method for preparing an electromagnetic shielding film is characterized in that: the step S3 and the step S4 are continuously completed in the same process.

The electromagnetic shielding film of the present invention is composed of an adhesive layer and a shielding layer. Compared with the prior art, the base material or cloth base layer is omitted, and the thickness is greatly reduced. On the other hand, the adhesive layer has magnetically oriented Ni powder, and the shielding layer and the surface of the pasted area form a shielding circuit through the adhesive layer, which has a good shielding effect and no magnetic flux leakage.

Description of drawings

Fig. 1 is a schematic diagram of a first embodiment of the present invention.

Fig. 2 is a schematic diagram of a second embodiment of the present invention.

Fig. 3 is a flowchart of a third embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

With reference to Fig. 1, the first embodiment of the present invention is a kind of electromagnetic shielding film, has laminar structure, and this electromagnetic shielding film 102 is made up of adhesive layer 101 and shielding layer, and wherein has Ni through magnetic force orientation in the adhesive layer 101 powder, the shielding layer 102 also has a layered structure, and the film structure of the shielding layer 102 is Ni-Cu-Ni; the adhesive layer 101 includes hot melt adhesive, and the thickness of the adhesive layer 101 is 100 microns; The Ni powder is a strip structure with pointed ends, and the two ends of the strip Ni powder point to the two surfaces of the adhesive layer 101 respectively; the magnetic pole direction of the Ni powder is perpendicular to the adhesive layer 101 surface; the adhesive layer 101 is also Contains UV photo-curable material, the weight ratio of UV photo-curable material to hot melt adhesive is less than 1:7, in this embodiment it is 1:8, this ratio is an empirical value, too small a ratio is difficult to orientate, and the ratio is too large to bond The effect is not good. As for the lower limit of the ratio, it is generally not less than 1:20. When it is less than 1:20, the orientation process is difficult, and the orientation time is long and the effect is not good; the Ni layer in the shielding layer 102 is set by vacuum evaporation, and the shielding layer The Cu layer in 102 is set by electroplating, of course, it can also be replaced by vacuum evaporation; in the Ni-Cu-Ni structure, the thickness of each layer is 4 microns for 103 layers, 45 microns for 104 layers, and 4 microns for 105 layers. This embodiment can be a raw material, or it can be a form that has been attached to an application product (such as a mobile phone screen, a laptop computer screen).

With reference to Fig. 2, the second embodiment of the present invention is a kind of raw material of electromagnetic shielding film, has layered structure, and this electromagnetic shielding film is made up of adhesive layer and shielding layer, wherein has Ni powder through magnetic force orientation in the adhesive layer, The shielding layer also has a layered structure, and the film structure of the shielding layer is Ni-Cu-Ni; the magnetic pole direction of the Ni powder is perpendicular to the surface of the adhesive layer; the adhesive layer contains hot melt adhesive, and the adhesive layer The thickness is 50 microns; the Ni powder is a strip structure with sharp ends, and the two ends of the strip Ni powder are respectively directed to the two surfaces of the adhesive layer; the adhesive layer also contains UV light-curable materials, UV light The weight ratio of the solid material to the hot melt adhesive is 1:10; the Ni layer in the shielding layer is set by vacuum evaporation, and the Cu layer in the shielding layer is set by electroplating; in the Ni-Cu-Ni structure, the thickness of each layer They are 3 microns, 40 microns and 3 microns respectively. In this embodiment, the outer side of the shielding film and the inner side of the adhesive layer are also provided with an intermediate material, i.e. a release film; the layered structure of the electromagnetic shielding film is: outer release film 106-shielding layer 102-glue Adhesive layer 101-inner release film 107, wherein the outer release film is a PET film with a thickness of 10 microns. During use, first tear off the inner release film 107, and then tear off the outer release film 106 after pasting it on the designated area.

Referring to Fig. 3, the third embodiment of the present invention is a preparation method of an electromagnetic shielding film, which is characterized in that it comprises the following steps: S1, providing a release layer; S2, coating an adhesive layer on the release layer; S3, Magnetic orientation; S4, optical fixation; S5, Ni plating; S6, Cu plating; S7, Ni plating; wherein, the release layer described in step S1 is an intermediate material, which is torn off during use; The coated material of the coating adhesive layer includes Ni magnetic powder and UV light-curable material; the magnetic force orientation described in the step S3 is to make the magnetic pole direction of the Ni powder itself set along the thickness direction of the adhesive layer by magnetic force; The optical fixation described in the S4 step is to fix the Ni powder by UV light, so that its magnetism and direction in the adhesive layer are kept in the thickness direction of the adhesive layer; S5, S6, and S7 are all vacuum coatings, using vacuum Evaporation or vacuum sputtering. In this embodiment, the S3 step and the S4 step are continuously completed in the same process. The specific implementation method can pass through the semi-finished products of the S2 step continuously through the positioning area, and the positioning area can be two permanent magnets arranged opposite to each other. For magnetic poles with opposite polarities, in order to ensure the continuity of step S4 and prevent the Ni powder magnetic poles from moving before orientation, the photo-curing start area of S4 step can overlap with the orientation termination area of S3 step, and photo-curing can be completed by ultraviolet light irradiation .

Claims (9)

1. an electromagnetic shielding film has layer structure, it is characterized in that: this electromagnetic shielding film is made up of adhesive layer and screen, wherein has in the adhesive layer through the directed Ni powder of magnetic force, and screen also has layer structure, and the film structure of screen is Ni-Cu-Ni.

2. electromagnetic shielding film according to claim 1 is characterized in that: said adhesive layer comprises PUR, or acryl glue, or the silicon pressure sensitive adhesive, and the thickness of said adhesive layer is 5 microns to 500 microns; Said Ni powder has list structure, and two surfaces of adhesive layer are pointed at the two ends of strip Ni powder respectively.

3. electromagnetic shielding film according to claim 2 is characterized in that: said adhesive layer also includes the solid material of UV light.

4. electromagnetic shielding film according to claim 1 is characterized in that: the Ni layer in the screen adopts vacuum evaporation or vacuum sputtering mode to be provided with, and the Cu layer in the screen adopts plating or vacuum evaporation or vacuum sputtering mode to be provided with; In the Ni-Cu-Ni structure, the thickness of each layer is respectively 1 micron to 5 microns, 1 micron to 50 microns, 1 micron to 5 microns.

5. electromagnetic shielding film according to claim 1 is characterized in that: said adhesive layer comprises PUR, and the thickness of said adhesive layer is 100 microns; Said Ni powder is fusiform list structure, and two surfaces of adhesive layer are pointed at the two ends of strip Ni powder respectively; Said adhesive layer also includes the solid material of UV light, and the weight ratio of solid material of UV light and PUR is less than 1:7; Ni layer in the screen adopts the vacuum evaporation mode to be provided with, and the Cu layer in the screen adopts the plating mode setting; In the Ni-Cu-Ni structure, the thickness of each layer is respectively 4 microns, 45 microns, 4 microns.

6. according to claim 1 or 6 described electromagnetic shielding films, it is characterized in that: the outside of said screened film and the inboard of adhesive layer also are provided with intermediate materials, i.e. mould release membrance; The layer structure of said electromagnetic shielding film is: outer mould release membrance-screen-adhesive layer-Nei mould release membrance, wherein outer mould release membrance are that thickness is 5 microns to 50 microns PET film.

7. the preparation method of an electromagnetic shielding film is characterized in that may further comprise the steps:

S1 provides release layer;

S2 is coated with adhesive layer on release layer;

S3, the magnetic force orientation;

S4, photofixation to;

S5, plating Ni;

S6, plating Cu;

S7, plating Ni;

Wherein, it is intermediate materials that S1 goes on foot described release layer, tears during use; The material that is applied that S2 goes on foot described coating adhesive layer includes Ni magnetic and the solid material of UV light; It is to make the thickness direction setting of the pole orientation of Ni powder self along said adhesive layer through magnetic force that S3 goes on foot described magnetic force orientation; S4 goes on foot described photofixation to being through UV photofixation Ni powder, and it is remained on along the setting of adhesive layer thickness direction in adhesive layer inner magnetic and direction; S5, S6, S7 are vacuum coating, adopt vacuum evaporation or vacuum sputtering mode.

8. the preparation method of electromagnetic shielding film according to claim 7 is characterized in that: also comprise the S8 step that is arranged at after the S7 step, and the outer release layer of promptly fitting, said outer release layer also is an intermediate materials, tears during use.

9. the preparation method of electromagnetic shielding film according to claim 7 is characterized in that: the completion continuously in same operation of said S3 step and said S4 step.

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