CN113699797A - Composite non-woven fabric and preparation method thereof, electromagnetic shielding film and integrated circuit board - Google Patents

Composite non-woven fabric and preparation method thereof, electromagnetic shielding film and integrated circuit board Download PDF

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Publication number
CN113699797A
CN113699797A CN202111027800.9A CN202111027800A CN113699797A CN 113699797 A CN113699797 A CN 113699797A CN 202111027800 A CN202111027800 A CN 202111027800A CN 113699797 A CN113699797 A CN 113699797A
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China
Prior art keywords
woven fabric
nonwoven fabric
shielding film
electromagnetic shielding
composite
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CN202111027800.9A
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Chinese (zh)
Inventor
陈莉
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Qianyan New Material Research Institute Shenzhen Co ltd
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Qianyan New Material Research Institute Shenzhen Co ltd
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    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/0043—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by their foraminous structure; Characteristics of the foamed layer or of cellular layers
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/0002—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the substrate
    • D06N3/0011—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the substrate using non-woven fabrics
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/007—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by mechanical or physical treatments
    • D06N3/0077—Embossing; Pressing of the surface; Tumbling and crumbling; Cracking; Cooling; Heating, e.g. mirror finish
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/0086—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the application technique
    • D06N3/0088—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the application technique by directly applying the resin
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • H05K9/009—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising electro-conductive fibres, e.g. metal fibres, carbon fibres, metallised textile fibres, electro-conductive mesh, woven, non-woven mat, fleece, cross-linked

Abstract

A composite non-woven fabric and a preparation method thereof, an electromagnetic shielding film and an integrated circuit board belong to the field of materials. The composite non-woven fabric comprises a non-woven fabric and a porous resin layer, wherein the porous resin layer is solidified and formed on at least one surface of the non-woven fabric, and the surface density of the non-woven fabric is 5-18g/m2The thickness is 6-25 μm, the average aperture of the non-woven fabric is more than 0 and less than or equal to 4.5 μm, the ratio of the maximum aperture of the non-woven fabric to the average aperture is more than or equal to 1 and less than or equal to 5, the average aperture of the composite non-woven fabric is more than 0 and less than or equal to 1.5 μm, and the ratio of the maximum aperture of the composite non-woven fabric to the average aperture is more than or equal to 1 and less than or equal to 14. The composite non-woven fabric can be used for preparing the high-performance electromagnetic shielding film, and can meet the requirements of an integrated circuit board on the nonporous defect, high shielding efficiency, high thermal conductivity and thin thickness of the electromagnetic shielding film.

Description

Composite non-woven fabric and preparation method thereof, electromagnetic shielding film and integrated circuit board
Technical Field
The application relates to the field of materials, in particular to a composite non-woven fabric, a preparation method of the composite non-woven fabric, an electromagnetic shielding film and an integrated circuit board.
Background
With the rapid development of 5G technologies and electronic circuits, integrated circuits have the advantages that the size is small, the weight is light, the power consumption is small, the characteristics are good, high-density integration and many discrete component circuits are incomparable, and meanwhile, the integrated circuits are convenient for large-scale production, are applied more and more widely in various circuit designs, and have become the cornerstone of intelligent work of all industries at present, but at the same time, the electromagnetic environment is more and more complex, and the integrated circuit devices are more and more interfered by external electromagnetic interference, so the electromagnetic interference resistance of the integrated circuits in actual application becomes a research hotspot. Electromagnetic shielding is a main means for solving the problem of electromagnetic interference, and the research on the electromagnetic shielding technology has important significance for improving the reliability of an integrated circuit.
In recent years, the integration degree of large scale integrated circuits (LSIs) has been rapidly increased, and with the increase in the scale of device integration, the thermal power generated per unit volume has been gradually increased, and the heat value of the LSIs has become higher and higher. Since the LSI must be used at 80 c or lower to maintain the optimum performance, the emi shielding film must simultaneously perform emi shielding and efficient heat conduction to maintain the temperature of the LSI within a reasonable range (below 80 c). If the heat dissipation is poor, the temperature of the LSI will continue to rise, and if the temperature of the LSI reaches 125 ℃, normal operation will not be continued. Further, electronic devices are being miniaturized year by year, and accordingly, electromagnetic interference shielding films are also forced to be thinned.
In order to solve the above-mentioned problems, it is theoretically a conventional practice to reduce the average pore diameter of the nonwoven fabric while reducing the thickness of the nonwoven fabric sheet as the support layer of the electromagnetic interference shielding film, however, in the actual operation process, it is very difficult to reduce the average pore diameter of the nonwoven fabric while reducing the thickness of the nonwoven fabric sheet, large through holes are easily generated, and the electromagnetic interference shielding film cannot have large through holes because electromagnetic noise leaks out through these hole defects.
Meanwhile, in order to obtain high electromagnetic shielding characteristics, the conventional method is to increase the thickness of the metal layer and increase the thickness of the shielding film after the metal layer is compounded, so that the requirement of thinning cannot be met.
That is, in order to satisfy the requirement of the aperture, if the thickness and the quantitative amount of the nonwoven fabric itself are not increased, the adhesion of the metal layer is difficult to be secured without increasing the amount of the metal layer, and the shielding performance of the conventional electromagnetic shielding film is too low.
Disclosure of Invention
The application provides a composite non-woven fabric and a preparation method thereof, an electromagnetic shielding film and an integrated circuit board, which can solve the problems that the conventional non-woven fabric cannot be thinned, the electromagnetic shielding is good and the heat dissipation effect is good when the electromagnetic shielding film is prepared.
The embodiment of the application is realized as follows:
in a first aspect, the present application provides a composite nonwoven fabric comprising: the resin layer is solidified and formed on at least one surface of the non-woven fabric.
Wherein the non-woven fabric has an areal density of 5 to 18g/m2The thickness is 6-25 μm, the average pore diameter of the non-woven fabric is more than 0 and less than or equal to 4.5 μm, and the ratio of the maximum pore diameter of the non-woven fabric to the average pore diameter is more than or equal to 1 and less than or equal to 5.
The average aperture of the composite non-woven fabric is more than 0 and less than or equal to 1.5 mu m, and the ratio of the maximum aperture of the composite non-woven fabric which is more than or equal to 1 to the average aperture is less than or equal to 14.
In the above example, the porous resin layer is cured and molded on at least one surface of the non-woven fabric with a specific specification, so that the porous resin layer with the micro-pore structure can effectively cover and fill the larger pore structure formed in the non-woven fabric, and the pore structure on the surface of the non-woven fabric is optimized; therefore, even if the thickness of the porous resin layer is small, the porous resin layer can control the pore size and pore size distribution on the surface of the nonwoven fabric, so that the composite nonwoven fabric can be thinned while the pore size of the composite nonwoven fabric satisfies the above requirements.
When the composite non-woven fabric is applied to the electromagnetic shielding film, the porosity of the porous resin layer is high, the specific surface area is large, the effective area of the metal material in contact with the porous resin layer can be remarkably increased, a continuous metal layer can be formed on the surface of the composite non-woven fabric through a small amount of plating, the thickening and weight increasing range of the electromagnetic shielding film after the metal layer is formed is small, the probability of generating hole defects of the metal layer is reduced, the metal layer with high adhesion is obtained, the dense metal layer ensures high-efficiency electromagnetic shielding and high-efficiency heat conduction in the LSI working operation process, and finally the thin and light-weight high-performance electromagnetic shielding film is obtained.
In a second aspect, the present application provides a method for preparing the above composite nonwoven fabric, which comprises:
the coating liquid for forming the porous resin layer is applied to at least one surface of the nonwoven fabric to form a coating layer, and then cured and molded.
The preparation method is simple, the preparation method is suitable for large-scale production, and meanwhile, the coating liquid with reasonable proportion is adopted, so that the viscosity of the obtained coating liquid is moderate, specific pores required by the application are obtained after curing and forming, if the mass fraction of the organic resin is higher than 20%, the viscosity of the obtained coating liquid is too high, pore forming is inhibited, the porosity of the coating layer is suddenly reduced, and when the prepared composite non-woven fabric is applied to the electromagnetic shielding film, the thermal conductivity of the electromagnetic shielding film is reduced. On the contrary, if the mass fraction of the organic resin is less than 5%, the porous resin layer cannot fully cover and fill the large pore structure formed in the fiber layer of the non-woven fabric, and a continuous metal layer is difficult to form in the subsequent preparation of the electromagnetic shielding film by metal plating, so that the shielding effectiveness of the electromagnetic shielding film is greatly reduced.
In a third aspect, the present application provides an electromagnetic shielding film, which includes the composite nonwoven fabric provided in the first aspect of the present application, and a metal layer formed on a surface of the composite nonwoven fabric.
When the electromagnetic shielding film takes the composite non-woven fabric as the supporting layer, the porous resin layer has high porosity and large specific surface area, so that the effective area of the metal material in contact with the porous resin layer can be remarkably increased, a continuous metal layer can be formed on the surface of the composite non-woven fabric through a small amount of plating, the thickening and weight increasing range of the electromagnetic shielding film after the metal layer is formed is small, the probability of generating hole defects of the metal layer is reduced, the metal layer with high adhesion is obtained, the dense metal layer ensures high-efficiency electromagnetic shielding and high-efficiency heat conduction in the working and running process of the LSI, and finally, the effective thin and light-weight high-performance electromagnetic shielding film is obtained.
In a fourth aspect, the present application example provides an integrated circuit board provided with the electromagnetic shielding film provided in the third aspect of the present application.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.
FIG. 1 is a surface electron microscope image of the side of the composite nonwoven fabric provided in example 1, which faces away from the porous resin layer;
fig. 2 is a surface electron microscope image of the porous resin layer of the composite nonwoven fabric provided in example 1.
Detailed Description
Embodiments of the present application will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present application and should not be construed as limiting the scope of the present application. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
The application provides a composite non-woven fabric, it includes: the resin layer is solidified and formed on at least one surface of the non-woven fabric.
Wherein the non-woven fabric has an areal density of 5 to 18g/m2The thickness is 6-25 μm, the average aperture of the non-woven fabric is more than 0 and less than or equal to 4.5 μm, the ratio of the maximum aperture of the non-woven fabric to the average aperture is more than or equal to 1 and less than or equal to 5, the average aperture of the composite non-woven fabric is more than 0 and less than or equal to 1.5 μm, and the ratio of the maximum aperture of the composite non-woven fabric to the average aperture is more than or equal to 1 and less than or equal to 14.
The non-woven fabric with the performance is beneficial to complete forming of the porous resin layer, and the finally prepared composite non-woven fabric is guaranteed to have light weight, good heat conduction effect and high shielding performance when being applied to a shielding film.
The porous resin layer is cured and formed on at least one surface of the non-woven fabric in a phase separation mode, so that the porous resin layer with the micro-pore structure can effectively cover and fill a larger pore structure formed in the non-woven fabric, and the pore structure on the surface of the non-woven fabric is optimized; therefore, even if the thickness of the porous resin layer is small, the porous resin layer can regulate and control the pore size and pore size distribution on the surface of the non-woven fabric, so that the composite non-woven fabric is thinned while the pore size of the composite non-woven fabric meets the requirement.
The application also provides a preparation method of the composite non-woven fabric, which comprises the following steps:
and S1, obtaining the non-woven fabric.
The non-woven fabric has an areal density of 5-18g/m2The thickness is 6-25 μm, the average pore diameter of the non-woven fabric is more than 0 and less than or equal to 4.5 μm, and the ratio of the maximum pore diameter of the non-woven fabric to the average pore diameter is more than or equal to 1 and less than or equal to 5. When the average pore diameter of the nonwoven fabric is greater than 4.5 μm and the ratio of the maximum pore diameter to the average pore diameter of the nonwoven fabric is greater than 5, the coating liquid easily permeates from the coated side of the nonwoven fabric to the back side of the nonwoven fabric in step S3, resulting in incomplete formation of the coated layer and adhesion of the coating liquid to the surface of the apparatus, which easily causes foreign matter contamination.
Wherein the nonwoven fabric is formed from the trunk fibers and the binder fibers.
Optionally, the trunk fiber comprises: at least one of polyester fiber, polyamide fiber, polyimide fiber, polytetrafluoroethylene fiber, polyvinyl alcohol fiber, polyvinylidene fluoride fiber, polyphenylene sulfide fiber, polyether ether ketone fiber, polyacrylonitrile fiber, polycarbonate fiber, and aramid fiber. Wherein, the polyester fiber includes but not limited to at least one of polyethylene terephthalate, polybutylene terephthalate and the like, and the polyamide fiber includes but not limited to polyamide fiber PA66 and the like.
Optionally, the binder fiber comprises at least one of an undrawn polyester fiber, a polyolefin fiber, and a sheath-core structure composite fiber, and the sheath material of the sheath-core structure composite fiber comprises at least one of a polyolefin, a copolyester, and a copolyamide. The polyolefin fiber includes, but is not limited to, at least one of polyethylene, polypropylene, polyvinyl chloride, and the like.
Because the bonding fiber guarantees the cohesive force between the fibers, if the content of the main fiber is too high and the content of the bonding fiber is too low, the fibers in the non-woven fabric cannot be fully adhered and fixed, the net structure is loose and difficult to fix and shape, the mechanical strength of the non-woven fabric is difficult to guarantee, otherwise if the content of the main fiber is too low and the content of the bonding fiber is too high, the excessive bonding fiber melts on the surface of the non-woven fabric, so that the hole blockage is easy to cause seriously, and the expected pore structure is difficult to obtain. Therefore, the mass fraction of the main fiber in the nonwoven fabric is optionally 60-80 wt%, for example, the mass fraction of the main fiber in the nonwoven fabric is 60 wt%, 62 wt%, 65 wt%, 67 wt%, 68 wt%, 70 wt%, 72 wt%, 75 wt%, 77 wt% or 80 wt%, etc., and the main fiber and the binder fiber are preferably mixed in this range, so that a nonwoven fabric with good surface density and average pore size, and no pores or large pores can be obtained.
Alternatively, the diameter of the trunk fiber is 2-3 μm, the length of the trunk fiber is 1-6mm, the diameter of the binder fiber is 2-6 μm, and the fiber length of the binder fiber is 1-6mm, which can give consideration to both preferable tensile strength and pore structure.
Wherein, if the diameters of the main fibers and the binder fibers are less than 2 μm, the tensile strength of the nonwoven fabric is liable to be insufficient, and in addition, a serious fiber entanglement phenomenon may occur in the manufacturing process; if the diameter of the main fiber is larger than 3 μm and the diameter of the bonding fiber is larger than 6 μm, the pore size of the non-woven fabric is easily too large, and the generation of pore defects cannot be effectively avoided. If the lengths of the main fibers and the bonding fibers are less than 1mm, the problem of too low strength of the non-woven fabric may exist, and even the fibers cannot be made into paper; if the lengths of the main fibers and the bonding fibers are more than 6mm, overlong fibers are easy to be agglomerated and tangled, so that the serious appearance performance defect of the non-woven fabric is caused.
The melting point or softening point of the main fiber and the bonding fiber is not less than 130 ℃, if the melting point or softening point of the main fiber and the bonding fiber is too low, the heat resistance of the subsequent electromagnetic shielding film cannot be ensured, and meanwhile, when the non-woven fabric is formed by hot rolling of a plurality of fiber layers, the main fiber and the bonding fiber are easily excessively melted in the hot pressing treatment, and the roll sticking is serious.
Through the specific types of the main fibers and the bonding fibers and the specific proportion of the main fibers and the bonding fibers, the finally obtained non-woven fabric not only meets the requirement of light weight, but also has the surface density of 5-18g/m2The thickness is 6-25 μm, and the average pore diameter of the non-woven fabric is more than 0 and less than or equal to 4.5 μm, 1. ltoreq. the ratio of the maximum pore diameter to the average pore diameter of the nonwoven fabric being not more than 5, and, in addition, the transverse tensile strength of the nonwoven fabric>0.07kN/m, longitudinal tensile strength>0.2kN/m。
Alternatively, the nonwoven fabric may be produced by a wet papermaking method, and for example, the multilayered fiber layer of the nonwoven fabric may be formed by one-step papermaking using a twin-wire machine or a multi-wire machine or a multilayered oblique-wire machine.
In some alternative embodiments, the nonwoven fabric is obtained by heat calendering at least two fiber layers formed of the main fibers and the binder fibers together, wherein the heat calendering has a heat calendering temperature of not lower than the melting point or softening point temperature of the binder fibers by-20 ℃ and not higher than the melting point or softening point temperature of the binder fibers by +120 ℃ and a heat calendering pressure of 70-250 kgf/cm. The hot pressing pressure is 70 to 250kgf/cm, and specific examples thereof include 70kgf/cm, 105kgf/cm, 140kgf/cm, 160kgf/cm, 180kgf/cm, 200kgf/cm, 210kgf/cm, 230kgf/cm and 250 kgf/cm.
If the hot pressing temperature and the line pressure are too low, the fiber structure of the nonwoven fabric is difficult to be sufficiently bonded, so that the structure is loose and the strength is insufficient. If the hot pressing temperature and the line pressure are too high, the nonwoven fabric fibers are too deformed and the density becomes too high, and the desired effect of the present invention may not be obtained.
The hot rolling may be performed by using a steel roll/soft roll combination as a hot press roll, which is not limited herein.
S2, a coating liquid constituting the porous resin layer was obtained.
Wherein the coating liquid comprises an organic resin and an organic solvent.
Optionally, the organic resin comprises at least one of polyvinylidene fluoride, polystyrene, polyethersulfone, polysulfone, polyarylsulfone, polyamide, and polyimide.
Alternatively, the organic solvent comprises at least one of dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, dimethylsulfoxide, and tetrahydrofuran.
Wherein the mass fraction of the organic resin is 5 to 20 wt% of the coating liquid, for example, the mass fraction of the organic resin is 5 wt%, 8 wt%, 10 wt%, 13 wt%, 15 wt%, 17 wt%, or 20 wt% of the coating liquid, and the viscosity of the coating liquid is 10 to 200 cP.
If the mass fraction of the organic resin is higher than 20 wt%, the viscosity of the obtained coating liquid is too high, pore formation is inhibited, the porosity of the coating layer is suddenly reduced, and the thermal conductivity of the electromagnetic shielding film prepared by the coating liquid is greatly reduced. On the contrary, if the mass fraction of the organic resin is less than 5 wt%, the porous resin layer cannot fully cover and fill the large pore structure formed in the non-woven fabric fiber layer, and a continuous metal layer is difficult to form in the subsequent preparation of the electromagnetic shielding film by metal plating, so that the shielding effectiveness of the electromagnetic shielding film is greatly reduced.
And S3, coating the coating liquid on at least one side surface of the non-woven fabric to form a coating layer, and then curing and forming.
The coating solution may be applied by, but not limited to, dip coating, spray coating, spin coating, or knife coating.
The curing and forming method includes, but is not limited to, applying the coating liquid to at least one side of the nonwoven fabric to form a coating layer, heating the coating layer to volatilize the solvent of the coating layer, thereby curing and forming the coating layer, and further, applying the coating liquid to at least one side of the nonwoven fabric to form a coating layer, immersing the coated layer in a cooling liquid to perform phase separation, thereby curing and forming the coating layer, wherein the cooling liquid includes, but is not limited to, water, and the temperature of the cooling liquid is room temperature, for example, 20 to 35 ℃.
Optionally, the thickness of the coating layer is greater than 0 and not greater than 15 μm. For example, the thickness of the coating layer is 3 μm, 5 μm, 7 μm, 10 μm, 13 μm, 14 μm, or 15 μm. If the thickness of the coating layer is larger than 15 micrometers, the solution phase separation rate is reduced in the phase separation process, a thick compact skin layer is easily formed, an excessively thick porous resin layer with poor thermal conductivity is obtained, the thermal conductivity of the electromagnetic shielding film is affected finally, and the requirements of electronic industry on lightness, thinness and light weight of the electromagnetic shielding film are not met.
The present application further provides an electromagnetic shielding film, which includes the above composite nonwoven fabric and a metal layer, wherein the metal layer is formed on the surface of the composite nonwoven fabric.
The method for forming the metal layer on the surface of the composite nonwoven fabric includes, but is not limited to, electroless plating, electroplating, metal evaporation, sputtering, and the like, and is not limited herein.
Optionally, the metal layer has an adhesion amount of 1-10g/m2Further optionally 2-7g/m2E.g. 2, 4g/m2、5g/m2、6g/m2Or 7g/m2And the like. The material of the metal layer includes, but is not limited to, copper, and may also be other metals such as silver, nickel, gold, platinum, palladium, indium, and the like.
The application also provides an integrated circuit board, which comprises the electromagnetic shielding film, and the electromagnetic shielding film is effectively radiated and simultaneously improves the electromagnetic interference shielding effect on the premise of realizing thinning.
The nonwoven fabric, the composite nonwoven fabric, the method for preparing the same, the electromagnetic shielding film and the integrated circuit board of the present application are further described in detail with reference to the following examples.
Example 1
Using the specific fibers shown in Table 1, the sheet was made to have an areal density of 10g/m by means of an inclined wire machine2And carrying out hot calendering treatment on the fiber base paper in a hot press by adopting the hot pressing temperature and pressure shown in the table 1 to obtain the non-woven fabric, wherein the hot press adopts a steel roller/soft roller combination.
The nonwoven fabric thus obtained was cut into a sample having a size of a4, and the upper surface thereof was coated with a coating solution having a composition shown in table 1 to obtain a coating layer, the lower surface thereof was not subjected to a coating treatment, the coating treatment was completed and the coating layer was immersed in room-temperature water to undergo phase separation, and after 10 minutes, the nonwoven fabric was taken out and dried at room temperature to obtain a composite nonwoven fabric comprising a nonwoven fabric sample and a porous resin layer.
Plating metal copper on the composite non-woven fabric by a chemical immersion plating method, wherein the adhesion amount of copper is 3g/m2And manufacturing the electromagnetic shielding film.
Wherein, fig. 1 is a surface electron microscope image of one side of the obtained composite non-woven fabric, which is far away from the porous resin layer; fig. 2 is a surface electron microscope image of the porous resin layer of the obtained composite nonwoven fabric.
According to fig. 1 and fig. 2, it can be seen that the porous resin layer with the micro-pore structure can effectively cover and fill the large-pore structure formed in the non-woven fabric, the pore structure on the surface of the non-woven fabric is optimized, the porosity of the porous resin layer is higher than that of a single non-woven fabric and the specific surface area is larger, the effective area of the metal material in contact and compounding with the metal material can be remarkably increased, and then a continuous metal layer can be formed on the surface of the composite non-woven fabric serving as the support layer through a small amount of plating.
TABLE 1 parameters
Figure BDA0003244191000000091
Figure BDA0003244191000000101
Figure BDA0003244191000000111
Example 2
Using the same preparation method as in example 1, according to the fiber compounding ratio and parameters shown in Table 1, the surface density was 5g/m2And coating the non-woven fabric to obtain the composite non-woven fabric.
Plating metal copper on the composite non-woven fabric by a chemical immersion plating method, wherein the adhesion amount of copper is 3g/m2And manufacturing the electromagnetic shielding film.
Example 3
Using the same preparation method as in example 1, according to the fiber compounding ratio and parameters shown in Table 1, the surface density was made to be 8g/m2And coating the non-woven fabric to obtain the composite non-woven fabric.
Plating metal copper on the composite non-woven fabric by a chemical immersion plating method, wherein the adhesion amount of copper is 3g/m2And manufacturing the electromagnetic shielding film.
Comparative example 1
The difference from example 1 is only that after the nonwoven fabric obtained was cut into a sample of a size of a4, the composite nonwoven fabric was directly plated with metallic copper by electroless plating, and the amount of copper deposited was 3g/m2And manufacturing the electromagnetic shielding film.
Comparative example 2
Using a preparation method similar to that in example 1, the fiber blend and parameters shown in Table 1 were adjusted to obtain an areal density of 12g/m2Cutting the nonwoven fabric into a sample of A4 size, and directly plating the composite nonwoven fabric with metal copper by electroless plating method to obtain a copper-coated nonwoven fabric with a copper adhesion amount of 15g/m2And manufacturing the electromagnetic shielding film.
Comparative example 3
It differs from example 1 only in that the content of PVDF in the coating liquid was 3% by weight.
Comparative example 4
It differs from example 3 only in that the content of polyarylsulfone in the coating liquid was 40% by weight.
Comparative example 5
It differs from example 1 only in that the thickness of the coating layer was 20 μm.
Comparative example 6
It differs from example 2 only in that the hot pressing temperature was 120. + -. 5 ℃ and the hot pressing line pressure was 40. + -. 10 kgf/cm.
Comparative example 7
It differs from example 2 only in that the hot pressing temperature was 260. + -. 5 ℃ and the hot pressing line pressure was 220. + -. 10 kgf/cm.
Comparative example 8
The specific preparation conditions are shown in Table 1, the other conditions are the same as in example 1, and the prepared sheet density is 10g/m2And coating the non-woven fabric to obtain the composite non-woven fabric.
Plating metal copper on the composite non-woven fabric by a chemical immersion plating method, wherein the adhesion amount of copper is 3g/m2And manufacturing the electromagnetic shielding film.
Test example 1
The reference standards of the related technical indexes of the composite non-woven fabric are as follows:
the "areal density" of the nonwoven fabric was determined according to the method of GB/T451.2-2002. The "density" of the nonwoven fabric was determined by dividing the "areal density" of the nonwoven fabric by the "thickness" of the nonwoven fabric, which was determined according to the method of GB/T451.3-2002. The "pore size" of the nonwoven fabric was determined according to GB/T32361-2015 method. The "tensile strength" of the nonwoven fabric was determined according to the method of GB/T12914-. The 'electromagnetic shielding effectiveness' of the electromagnetic shielding film material is tested according to the GB/T30142 and 2013 method.
Evaluation criteria of "metal plating adhesion" of electromagnetic shielding film:
good: the plating layer is compact, has no large holes and has excellent level; and (delta): 1-5 parts/m of coating2Large pore, medium level; x: appearance of plating>At 5/m2Large holes, unusable level.
Evaluation criteria of "thermal conductivity" of the electromagnetic shielding film:
very good: the temperature difference between the electromagnetic shielding film and the working device is less than 5%, and the electromagnetic shielding film is very excellent in level; good: the temperature difference between the electromagnetic shielding film and the working device is 5-20%, and the temperature difference is in a medium level; and (delta): the temperature difference between the electromagnetic shielding film and the working device is 20-50%; x: the temperature difference between the electromagnetic shielding film and the working device is more than 50 percent, and the electromagnetic shielding film cannot be used.
The electromagnetic shielding films prepared in examples 1 to 3 and comparative examples 1 to 8 were subjected to the relevant performance tests, and the test results are shown in table 2.
Table 2 results of performance testing
Figure BDA0003244191000000131
Figure BDA0003244191000000141
As can be seen from Table 2, the nonwoven fabrics of examples 1-3 and comparative examples 1-8 are within the scope of protection of the present application and meet the requirements of the present application.
Compared with the embodiment 1, the electromagnetic shielding film prepared by the method has holes and poor electromagnetic shielding efficiency in a mode of directly plating a film on non-woven fabric without adopting a porous resin coating. Also, taking comparative example 2 as an example, which increased the amount of metal plated, the thickness of the resulting plated layer was significantly increased and appeared as compared with examples 1 to 3>At 5/m2The prepared electromagnetic shielding film cannot be used due to large holes, and meanwhile, the electromagnetic shielding efficiency is poor.
As is apparent from Table 2, in comparative example 3, the resin content in the coating liquid was excessively low compared to example 1, resulting in a large pore diameter of the composite nonwoven fabric, and the plating layer of the prepared electro-magnetic shielding film appeared>At 5/m2Large holes to be unusable and poor electromagnetic shielding performance. Comparative example 4 compared with examples 1 to 3, on the premise that the resin content in the coating liquid was too large, holes appeared in the coating layer, the electromagnetic shielding performance was poor, and at the same time, the organic coating layer had a high density, and could not conduct heat generated from the working device in time and effectively, and the electromagnetic shielding film had poor thermal conductivity.
In comparative example 5, when the thickness of the coating layer was significantly increased as compared to example 1, the metal plating layer had good adhesion, but the total thickness and the plating layer thickness were significantly increased due to the excessively large thickness, and thus the requirements for weight reduction could not be satisfied, and the electromagnetic shielding performance and the thermal conductivity were inferior to those of example 1.
Compared with the example 2, the comparative examples 6 and 7 have the same influence on the heat conduction and electromagnetic shielding performance on the premise of different hot pressing temperatures and hot pressing line pressures, and are both inferior to the example 2.
Comparative example 8 on the premise that the nonwoven fabric was selected differently from example 1, the thermal conductivity and electromagnetic shielding performance were significantly inferior to those of example 1.
That is, the electromagnetic shielding films of examples 1 to 3 have excellent properties, especially electromagnetic shielding performance and thermal conductivity, and thus can be used in integrated circuit boards, especially in thinned integrated circuit boards.
In conclusion, the composite non-woven fabric prepared from the non-woven fabric can be used for preparing the electromagnetic shielding film with high performance, and can meet the requirements of an integrated circuit board on the electromagnetic shielding film on non-porous defect, high shielding efficiency, high thermal conductivity and thin thickness.
The foregoing is merely exemplary of the present application and is not intended to limit the present application, which may be modified or varied by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. A composite nonwoven fabric, comprising: the resin layer is solidified and formed on at least one surface of the non-woven fabric;
wherein the non-woven fabric has an areal density of 5 to 18g/m2The thickness is 6-25 μm, the average pore diameter of the non-woven fabric is more than 0 and less than or equal to 4.5 μm, and the ratio of the maximum pore diameter of the non-woven fabric to the average pore diameter is more than or equal to 1 and less than or equal to 5;
the average pore diameter of the composite non-woven fabric is more than 0 and less than or equal to 1.5 mu m, and the ratio of the maximum pore diameter to the average pore diameter of the composite non-woven fabric is more than or equal to 1 and less than or equal to 14.
2. The nonwoven fabric of claim 1, wherein the nonwoven fabric is formed from the trunk fibers and the binder fibers;
the mass fraction of the trunk fibers in the non-woven fabric is 60-80 wt%, the diameter of the trunk fibers is 2-3 mu m, the length of the trunk fibers is 1-6mm, the diameter of the bonding fibers is 2-6 mu m, the fiber length of the bonding fibers is 1-6mm, and the melting point or the softening point of the trunk fibers and the melting point or the softening point of the bonding fibers are not less than 130 ℃.
3. The nonwoven fabric according to claim 1, wherein the nonwoven fabric is obtained by heat calendering at least two fiber layers formed of the main fiber and the binder fiber at a heat calendering temperature of not less than the melting point or softening point temperature of the binder fiber by-20 ℃ and not more than the melting point or softening point temperature of the binder fiber by +120 ℃ and a heat calendering pressure of 70 to 250 kgf/cm.
4. A method of preparing the composite nonwoven fabric according to any one of claims 1 to 3, comprising:
and coating the coating liquid for forming the porous resin layer on at least one surface of the non-woven fabric to form a coating layer, and curing and forming.
5. The production method according to claim 4, wherein the coating liquid comprises an organic resin and an organic solvent, the mass fraction of the organic resin is 5 to 20 wt% of the coating liquid, and the viscosity of the coating liquid is 10 to 200 cP.
6. The production method according to claim 5, wherein the organic resin includes at least one of polyvinylidene fluoride, polystyrene, polyethersulfone, polysulfone, polyarylsulfone, polyamide, and polyimide;
optionally, the organic solvent comprises at least one of dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, dimethylsulfoxide, and tetrahydrofuran.
7. The production method according to claim 4, wherein the thickness of the coating layer is more than 0 and not more than 15 μm.
8. An electromagnetic shielding film comprising the composite nonwoven fabric according to any one of claims 1 to 4, and a metal layer formed on a surface of the composite nonwoven fabric.
9. The electro-magnetic shielding film according to claim 8, wherein the metal layer is attached to the surface of the composite non-woven fabric in an amount of 1 to 10g/m2Optionally 2-7g/m2。
10. An integrated circuit board comprising the electromagnetic shielding film according to any one of claims 8 to 9.
CN202111027800.9A 2021-09-02 2021-09-02 Composite non-woven fabric and preparation method thereof, electromagnetic shielding film and integrated circuit board Pending CN113699797A (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1946891A (en) * 2004-04-09 2007-04-11 三井化学株式会社 Nonwoven fabric sheet and method for producing same
JP2013136033A (en) * 2011-12-28 2013-07-11 Teijin Ltd Filter material and filter composite material
JP2019210567A (en) * 2018-06-04 2019-12-12 帝人フロンティア株式会社 Wet laid non-woven fabric
CN111816824A (en) * 2020-06-11 2020-10-23 深圳市星源材质科技股份有限公司 Non-woven fabric used as lithium ion battery diaphragm base film, diaphragm and lithium ion battery
CN112703281A (en) * 2018-09-19 2021-04-23 三菱制纸株式会社 Nonwoven fabric for electromagnetic wave shielding material and electromagnetic wave shielding material
CN113329803A (en) * 2019-12-30 2021-08-31 前沿新材料研究院（深圳）有限公司 Wet nonwoven fabric, preparation method thereof and water treatment membrane comprising same

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1946891A (en) * 2004-04-09 2007-04-11 三井化学株式会社 Nonwoven fabric sheet and method for producing same
JP2013136033A (en) * 2011-12-28 2013-07-11 Teijin Ltd Filter material and filter composite material
JP2019210567A (en) * 2018-06-04 2019-12-12 帝人フロンティア株式会社 Wet laid non-woven fabric
CN112703281A (en) * 2018-09-19 2021-04-23 三菱制纸株式会社 Nonwoven fabric for electromagnetic wave shielding material and electromagnetic wave shielding material
CN113329803A (en) * 2019-12-30 2021-08-31 前沿新材料研究院（深圳）有限公司 Wet nonwoven fabric, preparation method thereof and water treatment membrane comprising same
CN111816824A (en) * 2020-06-11 2020-10-23 深圳市星源材质科技股份有限公司 Non-woven fabric used as lithium ion battery diaphragm base film, diaphragm and lithium ion battery

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Application publication date: 20211126