Electromagnetic shielding template for flexible electromagnetic shielding paper and preparation method thereof, flexible electromagnetic shielding paper and preparation method thereof

Abstract

This invention discloses an electromagnetic shielding template for flexible electromagnetic shielding paper and its preparation method, as well as the flexible electromagnetic shielding paper and its preparation method. The electromagnetic shielding template includes a temporary carrier plate; an electromagnetic shielding unit disposed on the temporary carrier plate, each electromagnetic shielding unit comprising at least two conductive nanowire modules. All conductive nanowire modules are tilted relative to the temporary carrier plate in a specific direction, and the tilted conductive nanowire modules are sequentially overlapped in the specific direction to form a conductive network structure that can completely cover its defined shielding area. Therefore, the electromagnetic shielding unit can completely cover its defined shielding area without electromagnetic leakage. Simultaneously, because the sequentially arranged conductive nanowire modules constituting the electromagnetic shielding unit form a conductive network structure through partial stacking and overlap, the propagation path of electromagnetic waves within it is extended, thereby obtaining more opportunities for refraction and reflection, enhancing the layer-by-layer attenuation of electromagnetic waves, and improving the electromagnetic shielding effect.

Description

Technical Field

[0001] This invention relates to the field of electronic materials technology, specifically to an electromagnetic shielding template for flexible electromagnetic shielding paper and its preparation method, and a flexible electromagnetic shielding paper and its preparation method. Background Technology

[0002] With the continuous development of information technology, power electronic equipment is being used more and more widely in people's lives. However, during use, these devices are often subject to electromagnetic interference (EMI), which can lead to reduced accuracy or affect normal operation. Therefore, achieving maximum electromagnetic shielding is an urgent problem to be solved to ensure the normal operation of these devices.

[0003] Currently, the main electromagnetic shielding methods include electrostatic shielding, magnetic shielding, and electromagnetic shielding. Among these, electrostatic shielding, which is commonly used, primarily involves using a hollow conductor to block the external electric field, thus protecting the equipment inside from external influences and preventing the equipment from affecting the outside world. To make hollow conductors suitable for devices of different shapes, the idea has been to use flexible electromagnetic shielding materials (such as electromagnetic shielding paper) to form a cavity to house the equipment, thereby creating a hollow conductor.

[0004] Commonly used electromagnetic shielding papers primarily impart electromagnetic shielding functionality through two methods: one is by forming a composite coating between the paper and conductive materials; the other is by using conductive fibers woven into a paper base material. However, the conductive coating of electromagnetic shielding paper formed through composite coating is prone to peeling off, and the conductive fibers in the paper base material formed through conductive fiber woven materials have low strength. This results in both methods leading to poor electromagnetic shielding stability and a tendency for electromagnetic shielding effectiveness to weaken. Therefore, it is essential to conduct rational structural design of paper-based electromagnetic shielding materials to improve their electromagnetic shielding effect and stability, thereby expanding the application areas of electromagnetic shielding paper. Summary of the Invention

[0005] This invention provides a novel electromagnetic shielding conductive structure to address the problems of poor electromagnetic shielding stability and easily weakened electromagnetic shielding effectiveness of current electromagnetic shielding papers.

[0006] In a first aspect, the present invention provides an electromagnetic shielding template for flexible electromagnetic shielding paper, the electromagnetic shielding template comprising a temporary carrier plate and an electromagnetic shielding unit disposed on the temporary carrier plate, the electromagnetic shielding unit comprising at least two conductive nanowire modules, all of which are tilted relative to the temporary carrier plate toward a specific direction X, and the tilted conductive nanowire modules overlap each other in the specific direction X to form a conductive network structure capable of covering the shielding area defined thereunder.

[0007] Secondly, the present invention provides a method for preparing an electromagnetic shielding template, the method comprising:

[0008] At least two growth site patterns for conductive nanowire modules are designed and fabricated on a temporary carrier. Conductive nanowire modules are fabricated on the growth site patterns, and the height Hnws of the conductive nanowire modules when they are not tilted is greater than the distance D1 between two conductive nanowire modules arranged sequentially in a specific direction X when they are not tilted. All the conductive nanowire modules at the fabrication site are subjected to directional collapse treatment so that they all tilt towards a specific direction X, and the tilted conductive nanowire modules overlap sequentially in the specific direction X. All the conductive nanowire modules tilted towards the specific direction X and overlapping with each other together form a conductive network structure that can cover the shielding area defined by them.

[0009] Thirdly, the present invention provides a flexible electromagnetic shielding paper, the flexible electromagnetic shielding paper comprising: paper; and an electromagnetic shielding unit disposed on the paper; wherein the electromagnetic shielding unit is obtained by transferring the electromagnetic shielding unit disposed on a temporary carrier plate in the aforementioned electromagnetic shielding template to the paper; or the electromagnetic shielding unit is obtained by transferring the electromagnetic shielding unit disposed on a temporary carrier plate in the electromagnetic shielding template prepared by the aforementioned method for preparing an electromagnetic shielding template to the paper.

[0010] Fourthly, the present invention provides a method for preparing flexible electromagnetic shielding paper, the method comprising: transferring the aforementioned electromagnetic shielding unit disposed on the temporary carrier plate to the paper; or transferring the electromagnetic shielding unit disposed on the temporary carrier plate prepared by the aforementioned method for preparing an electromagnetic shielding template to the paper.

[0011] The beneficial effects of the embodiments of the present invention are as follows: The solution provided by the present invention forms a conductive grid structure that can completely cover the shielding area by tilting all conductive nanowire modules in a specific direction X and overlapping them after tilting, thus preventing electromagnetic leakage; moreover, since the conductive nanowire modules that constitute the electromagnetic shielding unit are arranged sequentially in a specific direction to form a conductive network structure by partially stacking and overlapping, the propagation path of electromagnetic waves in it is extended, thereby obtaining more opportunities for refraction and reflection, enhancing the layer-by-layer attenuation of electromagnetic waves, and improving the electromagnetic shielding effect. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 The diagram schematically shows a structural schematic of an electromagnetic shielding template for flexible electromagnetic shielding paper according to an embodiment of the present invention.

[0014] Figure 1a The diagram schematically illustrates the structure of a shielding region defined by a conductive network structure according to an embodiment of the present invention.

[0015] Figure 2 schematically shown Figure 1 The diagram shows a structural schematic of the electromagnetic shielding template used for flexible electromagnetic shielding paper from another perspective.

[0016] Figure 3 schematically shown Figure 1 The diagram shows a cross-sectional structure of an electromagnetic shielding template used for flexible electromagnetic shielding paper.

[0017] Figure 4 schematically shown Figure 2 The diagram shows the structure of the conductive nanowire module of the electromagnetic shielding template used in flexible electromagnetic shielding paper when it is not tilted.

[0018] Figure 5 The diagram schematically illustrates one structural schematic of a flexible electromagnetic shielding paper according to an embodiment of the present invention.

[0019] Figure 6 The diagram schematically shows another structural schematic of the flexible electromagnetic shielding paper according to one embodiment of the present invention.

[0020] Figure 7 schematically shown Figure 2A schematic diagram of the flexible electromagnetic shielding paper from another perspective.

[0021] Figure 8 The flowchart illustrating the preparation method of an electromagnetic shielding template for flexible electromagnetic shielding paper according to an embodiment of the present invention is shown schematically.

[0022] Figure 9a A top view schematically showing a temporary carrier coated with photoresist according to an embodiment of the present invention;

[0023] Figure 9b A side view of a temporary carrier coated with photoresist according to an embodiment of the present invention is shown schematically.

[0024] Figure 10 Figure (a) schematically shows a top view of a growth site pattern fabricated on a photoresist on a temporary substrate according to an embodiment of the present invention;

[0025] Figure 10 Figure (b) schematically shows a longitudinal cross-sectional view of a growth site pattern fabricated on a photoresist on a temporary substrate according to an embodiment of the present invention;

[0026] Figure 11 Figure (a) schematically shows a top view of a temporary carrier plate prepared with conductive metal seeds according to a growth site pattern according to an embodiment of the present invention.

[0027] Figure 11 Figure (b) schematically shows a side view of a temporary carrier plate prepared with conductive metal seeds according to a growth site pattern according to an embodiment of the present invention.

[0028] Figure 12a The diagram schematically shows a top view of a temporary carrier plate with conductive metal seeds grown in a conductive nanowire growth solution according to an embodiment of the present invention.

[0029] Figure 12b The diagram schematically shows a side view of a temporary carrier plate with conductive metal seeds grown on it placed in a conductive nanowire growth solution according to an embodiment of the present invention.

[0030] Figure 13a The diagram schematically shows a longitudinal cross-sectional view of a temporary carrier plate with conductive metal seeds grown on it, according to an embodiment of the present invention, immersed in an ethanol / water mixture.

[0031] Figure 13b schematically shown Figure 13a The diagram shows the first stage of the drying process of a temporary carrier plate with conductive metal seeds after being placed in an ethanol / water mixed solution.

[0032] Figure 13c schematically shown Figure 13a The diagram shows the second stage of the process, in which a temporary carrier plate with conductive metal seeds is dried after being placed in an ethanol / water mixed solution.

[0033] Figure 13d schematically shown Figure 13a The diagram shows the third stage of the process, in which a temporary carrier plate with conductive metal seeds is dried after being placed in an ethanol / water mixed solution.

[0034] Figure 14 The image schematically shows a scanning electron microscope (SEM) image of an electromagnetic shielding template for flexible electromagnetic shielding paper prepared by a method for preparing an electromagnetic shielding template for flexible electromagnetic shielding paper according to an embodiment of the present invention.

[0035] Figure 15 The invention schematically illustrates a method for preparing flexible electromagnetic shielding paper according to an embodiment of the present invention.

[0036] Figure 16a The diagram schematically shows a top view of an embodiment of the present invention, illustrating the transfer of an electromagnetic shielding unit from a temporary carrier plate to a piece of paper.

[0037] Figure 16b The diagram schematically shows a side view of an embodiment of the present invention, illustrating the transfer of an electromagnetic shielding unit from a temporary carrier plate to a piece of paper.

[0038] Figure 17 The diagram schematically illustrates a method for preparing flexible electromagnetic shielding paper according to another embodiment of the present invention. Detailed Implementation

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0040] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising" and "including" include not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The terminology used herein is generally terminology commonly used by those skilled in the art; if there is any inconsistency with commonly used terminology, the terminology used herein shall prevail. To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The following will first describe in detail the solution provided by the embodiments of the present invention from the perspective of the construction of the electromagnetic shielding template and the flexible electromagnetic shielding paper.

[0042] First, combined Figures 1 to 4 The structure of the electromagnetic shielding template used in flexible electromagnetic shielding paper is described in detail. Figure 2 The diagram schematically shows a side view of an electromagnetic shielding template for flexible electromagnetic shielding paper according to one embodiment of the present invention, such as... Figure 2 As shown, the electromagnetic shielding template provided in this embodiment of the invention includes a temporary carrier plate 20 and an electromagnetic shielding unit 30, with the electromagnetic shielding unit 30 disposed on the temporary carrier plate 20. As one embodiment of the electromagnetic shielding unit 30, such as... Figure 1 and Figure 2As shown, the electromagnetic shielding unit 30 includes at least two conductive nanowire modules 301. All conductive nanowire modules 301 are disposed on a temporary carrier plate 20. For example, the conductive nanowire modules 301 can be disposed on the temporary carrier plate 20 by directly growing them on the temporary carrier plate 20. All conductive nanowire modules 301 are tilted relative to the temporary carrier plate 20 towards the same specific direction X. When the conductive nanowire modules 301 arranged sequentially in the specific direction X are tilted, they are at least partially overlapping each other in the specific direction X. All conductive nanowire modules 301 form a conductive network structure that can completely cover the shielding area defined by them through mutual overlap. Specifically, the shielding area defined by the conductive network structure is the area enclosed by the outer periphery of the conductive network structure. That is, the area enclosed by the projection lines of the outermost conductive nanowire module 301 on the temporary carrier plate 20 of all the overlapping conductive nanowire modules 301 (e.g., the area of ​​the outermost conductive nanowire module 301 on the temporary carrier plate 20). Figure 1a As shown), the conductive network structure can completely cover its defined shielding area, meaning that the projected area formed by the conductive network structure in the direction perpendicular to the upper surface of the temporary carrier plate 20 is a complete surface (without gaps or voids inside), so that when looking at the temporary carrier plate 20 from the side of the conductive network structure away from the temporary carrier plate 20, only the temporary carrier plate 20 outside the shielding area can be seen, that is, when viewed from above, the temporary carrier plate 20 covered by the shielding area is not exposed; wherein, the two conductive nanowire modules 301 overlap with each other means that at least part of the surfaces of the two conductive nanowire modules 301 are in contact to form an overlapping area; all conductive nanowire modules 301 form a conductive network structure by overlapping each other because the conductive nanowire modules 301 are conductors, and the two overlapping conductive nanowire modules 301 can conduct electricity to each other. All conductive nanowire modules 301 can form a conductive network structure by overlapping each other, that is, all conductive nanowire modules 301 can conduct electricity to each other by directly or indirectly overlapping each other. As one embodiment in which conductive nanowire modules 301 arranged sequentially in a specific direction X can at least partially overlap each other when in a tilted state, the height Hnws of the conductive nanowire modules 301 when not tilted can be set such that it is greater than the distance D1 between two conductive nanowire modules 301 arranged sequentially in the specific direction X when not tilted (e.g., ...). Figure 4As shown, the opposing sides 3011 (i.e., the sides 3011 facing each other) of the conductive nanowire modules 301 arranged sequentially in a specific direction X when tilted are at least partially overlapped. For example, the opposing sides 3011 of two conductive nanowire modules 301 arranged sequentially in a specific direction X at least partially overlap each other. Thus, the conductive network structure of the electromagnetic shielding unit of the present invention can completely cover its defined shielding area, thereby preventing electromagnetic leakage. Simultaneously, since the conductive nanowire modules 301 arranged sequentially in a specific direction X constituting the electromagnetic shielding unit 30 partially stack to form a conductive network structure, the propagation path of electromagnetic waves within it is extended, thereby obtaining more opportunities for refraction and reflection, enhancing the layer-by-layer attenuation of electromagnetic waves, and improving the electromagnetic shielding effect.

[0043] As an example of the material of the temporary carrier plate 20, the temporary carrier plate 20 can be made of a rigid material such as glass, silicon or ceramic.

[0044] As an embodiment of the shape of the temporary carrier plate 20, such as Figure 1 As shown in the top view of the electromagnetic shielding template for flexible electromagnetic shielding paper, the temporary carrier plate 20 can be a plate with a rectangular cross-section. Of course, the temporary carrier plate 20 can also be designed as a plate with other cross-sectional shapes according to actual needs; for example, the temporary carrier plate 20 can be a plate with a circular cross-section. The thickness of the temporary carrier plate 20 can be greater than the height Hnws of the conductive nanowire module 301 when it is not tilted (e.g., ...). Figure 4 (As shown), it can also be lower than the height Hnws when the conductive nanowire module 301 is not tilted.

[0045] As an example of the material of the conductive nanowire module 301, the conductive nanowire module 301 is a nanowire made of a conductive material (a one-dimensional structure, for example, having a longitudinal dimension limited to less than 100 nanometers (without transverse dimension limitation)). These conductive materials can be, for example, metals with good conductivity such as gold (Au), silver (Ag), and platinum (Pt), or other conductive metals or non-metals.

[0046] Some embodiments of the specifications of the conductive nanowire module 301 will be combined with Figure 3 The shown cross-sectional view of the electromagnetic shielding template for flexible electromagnetic shielding paper and Figure 4 The side view shown illustrates the electromagnetic shielding template used for flexible electromagnetic shielding paper, in which... Figure 4 The conductive nanowire module 301 shown is the conductive nanowire module 301 when it is not tilted, as... Figure 3 and Figure 4As shown, the width W1 of the cross-section of the conductive nanowire module 301 ranges from 1 μm to 10 μm. For example, the width W1 of the conductive nanowire module 301 is 1 μm, 3 μm, or 4 μm, so as to facilitate obtaining a tilted conductive nanowire module through a collapse process. The length L1 of the cross-section of the conductive nanowire module 301 ranges from 10 μm to 1000 μm. For example, the length L1 of the conductive nanowire module 301 is 10 μm, 20 μm, or 500 μm. When the conductive nanowire module 301 is not tilted... The height Hnws ranges from 3μm to 100μm. For example, the height Hnws of the conductive nanowire module 301 when it is not tilted is 3μm, 10μm, 20μm or 50μm. The distance D1 between two conductive nanowire modules 301 arranged sequentially in a specific direction X when they are not tilted ranges from 1μm to 30μm. For example, the distance D1 between two conductive nanowire modules 301 arranged sequentially in a specific direction X when they are not tilted is 1μm, 5μm, 10μm, 20μm or 30μm. Specifically, in order to ensure that when all conductive nanowire modules 301 tilt relative to the temporary carrier plate 20 toward a specific direction X, the opposite sides of the conductive nanowire modules 301 arranged in sequence in the specific direction X at least partially overlap each other, the height Hnws of the conductive nanowire modules 301 when not tilted is set to be greater than the distance D1 between two conductive nanowire modules 301 arranged in sequence in the specific direction X when not tilted, that is, Hnws > D1.

[0047] As one of the preferred embodiments of the shape of the conductive nanowire module 301, such as Figure 1 and Figure 3As shown, when the conductive nanowire module 301 is in a tilted state, the side of each conductive nanowire module 301 facing the temporary carrier plate 20 is concave. In this embodiment, the side of the conductive nanowire module 301 facing the temporary carrier plate 20 when tilted is referred to as the inner side surface 3011A, or the first side surface of the conductive nanowire module 301. To facilitate differentiation of the sides of the conductive nanowire module 301, in this embodiment, the side of the conductive nanowire module 301 facing away from the inner side surface 3011A is referred to as the outer side surface 3011B, or the second side surface of the conductive nanowire module 301. Exemplarily, the concave inner side surface 3011A has a concave arc-shaped cross-section. It should be noted that, in this embodiment of the invention, when the conductive nanowire module 301 tilts relative to the temporary carrier plate 20 toward a specific direction X, the opposing sides 3011 of the conductive nanowire modules 301 arranged sequentially in the specific direction X at least partially overlap. This means that the inner side 3011A of one conductive nanowire module 301 arranged sequentially in the specific direction X at least partially overlaps with the outer side 3011B of another conductive nanowire module 301. As a further preferred embodiment, such as... Figure 3 As shown, the first side of the conductive nanowire module 301 is concave and arc-shaped, and its cross-section has an arc structure. The arc bending angle A of the arc structure ranges from 20° to 60°, for example, 20°, 25°, 40°, or 60°. As another further preferred embodiment, such as... Figure 1 and Figure 3 As shown, when all conductive nanowire modules 301 are tilted in a specific direction X, their concave inner surfaces 3011A all face the temporary carrier plate 20. The present invention addresses this by making the inner surface 3011A of the conductive nanowire modules 301 facing the temporary carrier plate 20 concave when tilted in a specific direction X. This allows for batch control of the liquid level on the inner surface 3011A of the conductive nanowire modules 301 to be greater than the liquid level on the outer surface 3011B of the conductive nanowire modules 301 during the drying process, thereby enabling capillary action to ensure that all conductive nanowire modules 301 tilt in the specific direction X, with their inner surfaces 3011A facing the temporary carrier plate 20 during tilting. This achieves batch processing of the tilting of conductive nanowire modules, improving preparation efficiency. In particular, when the arc bending angle A of the arc-shaped cross-section of the first side of the conductive nanowire module 301 is in the range of 20° to 60°, the water retention effect of the inner side 3011A of the conductive nanowire module 301 can be improved, so as to more stably ensure that the liquid level of the inner side 3011A of the conductive nanowire module 301 is greater than the liquid level of the outer side 3011B of the conductive nanowire module 301.

[0048] As one embodiment of the electromagnetic shielding unit 30, such as Figure 1 As shown, the electromagnetic shielding unit 30 includes at least one row of odd-numbered conductive nanowire modules 301 located in a specific direction X of the temporary carrier plate and at least one row of even-numbered conductive nanowire modules 301 located in a specific direction X of the temporary carrier plate. Generally, at least one row includes two or more conductive nanowire modules 301. The first central axis 311 of each conductive nanowire module 301 in the odd-numbered rows and the second central axis 321 of each conductive nanowire module 301 in the even-numbered rows are not collinear. Furthermore, as one embodiment of a conductive nanowire module 301 arranged sequentially in a specific direction X, which overlaps with each other in a tilted state to form a conductive network structure that can completely cover its defined shielding area, in addition to ensuring that Hnws > D1, it is also necessary to control that the distance D3 between the closest first central axis 311 and second central axis 321 in two adjacent rows in the direction Y perpendicular to the specific direction X is less than half the sum of the length L1 of the cross section of the conductive nanowire module 301 corresponding to the first central axis 311 or the second central axis 321. That is, the distance D3 between the first central axis 311 of the conductive nanowire module 301 in the odd-numbered rows and the second central axis 321 of the conductive nanowire module 301 in the even-numbered rows adjacent to the odd-numbered rows is the distance between the first central axis 311 and the second central axis 321 of the conductive nanowire module 301 that is closest to the conductive nanowire module 301 in the odd-numbered rows.

[0049] As some preferred embodiments of the conductive nanowire module 301, such as Figure 2As shown, the length L2 of the longitudinal section where the conductive nanowire modules 301 corresponding to the closest first central axis 311 and second central axis 321 of two adjacent rows of conductive nanowire modules 301 in a specific direction X (i.e., one row is an odd-numbered row of conductive nanowire modules 301, and the other row is an even-numbered row of conductive nanowire modules 301 arranged adjacent to the odd-numbered row of conductive nanowire modules 301 in the specific direction X overlaps is not less than 2 / 3 times the length L3 of the longitudinal section of the conductive nanowire module 301, that is, L2≥2 / 3L3, or Hnws:D1≥3:1. For example, when the height Hnws of the conductive nanowire module 301 when it is not tilted is 3μm, the distance D1 between two conductive nanowire modules 301 arranged in the specific direction X when they are not tilted can be set to 1μm; when When the height Hnws of the conductive nanowire module 301 when it is not tilted is 12 μm, the distance D1 between two conductive nanowire modules 301 arranged sequentially in a specific direction X when they are not tilted can be set to 4 μm. Of course, D1 can also be set to other values ​​less than 4 μm and greater than 1 μm. When the height Hnws of the conductive nanowire module 301 when it is not tilted is 21 μm, the distance D1 between two conductive nanowire modules 301 arranged sequentially in a specific direction X when they are not tilted can be set to 7 μm. Of course, D1 can also be set to other values ​​less than 7 μm and greater than 1 μm. When the height Hnws of the conductive nanowire module 301 when it is not tilted is 48 μm, the distance D1 between two conductive nanowire modules 301 arranged sequentially in a specific direction X when they are not tilted can be set to 16 μm. Of course, D1 can also be set to other values ​​less than 16 μm and greater than 1 μm.By setting the height Hnws of the conductive nanowire module 301 when it is not tilted to approximately twice the distance D1 between two conductive nanowire modules 301 arranged sequentially in a specific direction X when they are not tilted, it is possible not only to ensure that when all the conductive nanowire modules 301 are tilted relative to the temporary carrier plate 20 towards a specific direction X, the opposite sides of the conductive nanowire modules 301 arranged sequentially in the specific direction X will overlap each other, but also to ensure that when the electromagnetic shielding unit of the present invention is placed on paper to form flexible electromagnetic shielding paper, the paper can be protected to a great extent from being subjected to an external force of conventional magnitude along the specific direction X. After being stretched, the conductive nanowire modules 301 arranged sequentially in a specific direction X will only undergo relative sliding displacement, causing the overlapping area formed by their mutual overlap to increase or decrease, without the two separating (that is, the conductive nanowire modules 301 arranged sequentially in a specific direction X still have at least partial mutual overlap, and all conductive nanowire modules 301 still maintain the conductive network structure), thereby avoiding the occurrence of damage to the conductive network structure, ensuring the stability of the conductive path, resistivity and electromagnetic shielding effect of the flexible electromagnetic shielding paper, and preventing the electromagnetic shielding effect of the flexible electromagnetic shielding paper from weakening or fluctuating due to external stretching. Preferably, the distance D3 between the closest first central axis 311 and the second central axis 321 of two adjacent rows of conductive nanowire modules 301 in a specific direction X in a direction Y perpendicular to the specific direction X is less than 1 / 3 times the length L1 of the cross-section of the conductive nanowire module 301 corresponding to the first central axis 311 or the second central axis 321, i.e., D3 ≤ 1 / 3L1. This not only ensures that when all the conductive nanowire modules 301 are tilted relative to the temporary carrier plate 20 toward a specific direction X, the opposite sides of the conductive nanowire modules 301 arranged in sequence perpendicular to the specific direction X can overlap each other, but also ensures that when the electromagnetic shielding unit of the present invention is set on paper to form flexible electromagnetic shielding paper, it can greatly ensure that after the paper is stretched under a conventional force in a direction Y perpendicular to the specific direction X, the conductive nanowire modules 301 arranged in sequence in the direction Y will only have relative sliding displacement, causing the overlapping area formed by the overlap to increase or decrease, without the two separating, thereby avoiding the destruction of the conductive network structure.

[0050] Regardless of the specifications or shape of the conductive nanowire module 301, as a preferred embodiment of all the aforementioned conductive nanowire modules 301 forming a conductive network structure through mutual overlap, such as... Figure 1 and Figure 3As shown, the electromagnetic shielding unit 30 includes at least one set of first repeating units 31 and at least one set of second repeating units 32; wherein, the first repeating unit is defined by an odd number of rows of conductive nanowire modules arranged in a specific direction X on the temporary carrier plate 20, and the second repeating unit is defined by an even number of rows of conductive nanowire modules arranged in a specific direction X on the temporary carrier plate 20; each set of first repeating units 31 includes at least two conductive nanowire modules 301, and similarly, each set of second repeating units 32 also includes at least two conductive nanowire modules 301, that is, each row of repeating units on the temporary carrier plate (the row direction is perpendicular to the specific direction X) is provided with at least two conductive nanowire modules; and the first central axis 311 of the conductive nanowire modules 301 in the first repeating unit 31 and the second central axis 321 of each conductive nanowire module 301 in the second repeating unit 32 are not collinear. Therefore, the conductive nanowire modules 301 in the first repeating unit 31 and the conductive nanowire modules 301 in the second repeating unit 32 are arranged in a staggered manner in the direction Y perpendicular to the specific direction X. This makes it possible for the conductive nanowire modules 301 in the first repeating unit 31 to overlap with the conductive nanowire modules 301 in the adjacent second repeating unit 32 located in the specific direction X when the conductive nanowire modules 301 in the first repeating unit 31 are tilted in the specific direction X. Similarly, it is also possible for the conductive nanowire modules 301 in the second repeating unit 32 to overlap with the conductive nanowire modules 301 in the adjacent first repeating unit 31 located in the specific direction X when the conductive nanowire modules 301 in the second repeating unit 32 are tilted in the specific direction X. Preferably, the distance D3 between the closest first central axis 311 and the closest second central axis 321 in adjacent first repeating units 31 and 32 in the direction Y perpendicular to the specific direction X is less than the length L1 of the cross-section of the conductive nanowire module 301 corresponding to the first central axis 321 and the second central axis 322. This results in the distance D2 between two conductive nanowire modules 301 arranged sequentially in the direction Y perpendicular to the specific direction X being less than the length L1 of the cross-section of the conductive nanowire module 301. Consequently, when the conductive nanowire module 301 is relative to the temporary carrier plate 2... When the device tilts towards a specific direction X, the gap between the two conductive nanowire modules 301 in the second repeating unit 32 can be covered by a conductive nanowire module 301 in the adjacent first repeating unit 31 located on the side opposite to the temporary carrier plate 20. Similarly, the gap between the two conductive nanowire modules 301 in the first repeating unit 31 can also be covered by a conductive nanowire module 301 in the adjacent second repeating unit 32 located on the side opposite to the temporary carrier plate 20, thereby ensuring the continuity of the conductive path of the electromagnetic shielding unit 30 and the stability of the electromagnetic shielding effect.In particular, when D3≤1 / 3L1, and the length L2 of the longitudinal section of the overlapping conductive nanowire modules 301 corresponding to the closest first central axis 311 and second central axis 321 of two adjacent rows of conductive nanowire modules 301 in a specific direction X is not less than 2 / 3 times the length L3 of the longitudinal section of the conductive nanowire modules 301, i.e., L2≥2 / 3L3, and all conductive nanowire modules 301 are tilted relative to the temporary carrier plate 20 towards a specific direction X, the tilted conductive nanowire modules 301 overlap with each other in the specific direction X, and also overlap with each other in the direction Y perpendicular to the specific direction X, and there is an overlapping area between the overlapping conductive nanowire modules 301 to form a fish-scale stacked structure, thereby further extending the propagation path of electromagnetic waves in the formed electromagnetic shielding unit 30, thereby obtaining more opportunities for refraction and reflection, enhancing the layer-by-layer attenuation of electromagnetic waves, and further improving the electromagnetic shielding effect. Preferably, all conductive nanowire modules 301 in the first repeating unit 31 are equally spaced on the temporary carrier plate 20 in a direction Y perpendicular to a specific direction X; and / or all conductive nanowire modules 301 in the second repeating unit 32 are equally spaced on the temporary carrier plate 20 in a direction Y perpendicular to a specific direction X; and / or all first repeating units 31 and second repeating units 32 are equally spaced along a specific direction X; in particular, when all conductive nanowire modules 301 in the first repeating unit 31 are equally spaced on the temporary carrier plate 20 in a direction Y perpendicular to a specific direction X; and all conductive nanowire modules 301 in the second repeating unit 32 are equally spaced on the temporary carrier plate 20 in a direction Y perpendicular to a specific direction X; and simultaneously, all first repeating units 31 and second repeating units 32 are equally spaced along a specific direction X. The conductive nanowire modules 301 are evenly distributed in the X direction, so that when all conductive nanowire modules 301 are tilted in a specific direction X, all conductive nanowire modules 301 overlap with at least one other conductive nanowire module 301. Moreover, conductive nanowire modules 301 that are not located at the edge overlap with at least two conductive nanowire modules 301 in another repeating unit on the side of their inner surface 3011A facing the temporary carrier plate 20, and also overlap with at least two conductive nanowire modules 301 in another repeating unit on the side of their inner surface 3011A facing away from the temporary carrier plate 20. This allows all conductive nanowire modules 301 to overlap with each other (i.e., all conductive nanowire modules 301 can form a conductive network path through overlapping), which further extends the propagation path of electromagnetic waves in the formed electromagnetic shielding unit 30.

[0051] Figure 5 and Figure 6The diagram schematically shows a side view of a flexible electromagnetic shielding paper according to different embodiments of the present invention. In these embodiments, the flexible electromagnetic shielding paper includes a paper 40 and an electromagnetic shielding unit 30 disposed on the paper 40; wherein, the electromagnetic shielding unit 30 is the electromagnetic shielding unit 30 in the electromagnetic shielding template for the flexible electromagnetic shielding paper in the aforementioned embodiments. Specifically, the electromagnetic shielding unit 30 on the temporary carrier plate 20 can be directly transferred to the paper 40, and the structure of the resulting flexible electromagnetic shielding paper is as follows. Figure 5 As shown, in this embodiment, the arrangement of the electromagnetic shielding units 30 on the paper 40 is mirror-symmetrical to their arrangement on the temporary carrier plate 20; alternatively, the electromagnetic shielding units 30 can be first peeled off from the temporary carrier plate 20, and then the peeled-off electromagnetic shielding units 30 can be fixed onto the paper 40, resulting in a flexible electromagnetic shielding paper structure as shown. Figure 6 As shown, in this embodiment, the electromagnetic shielding unit 30 is arranged on the paper 40 in the same way as it is arranged on the temporary carrier plate 20 (e.g., ...). Figure 6 and Figure 7 (As shown). In particular, when L2≥2 / 3L3 and D3≤1 / 3L1, even if the paper 40 is stretched under external force, the sequentially arranged conductive nanowire modules 301 will only have relative sliding displacement, and the two will not separate. This avoids the destruction of the conductive network, ensures the stability of the conductive path, resistivity and electromagnetic shielding effect of the flexible electromagnetic shielding paper, and prevents the electromagnetic shielding effect of the flexible electromagnetic shielding paper from weakening or fluctuating due to external stretching.

[0052] As an example of the material of paper 40, a paper base material commonly used in electromagnetic shielding paper can be used.

[0053] As an example of the shape of paper 40, such as Figure 7 As shown, the paper 40 can be a paper material with a rectangular cross-section. Of course, the paper 40 can also be designed as a paper material with a cross-section of other shapes according to actual needs. For example, the paper 40 can be a paper material with a circular cross-section. Generally, in order to ensure the flexibility of the paper 40, the thickness T1 of the selected paper 40 is lower than the height Hnws of the conductive nanowire module 301 when it is not tilted (e.g., Figure 5 and Figure 6 (As shown).

[0054] The following will be combined with the appendix Figures 8 to 14 The preparation method of the electromagnetic shielding template for flexible electromagnetic shielding paper is described in detail. Among other things, Figure 8 The flowchart illustrating the preparation method of the electromagnetic shielding template with the above-described structure in some embodiments is shown in Figures 9 to 10. Figure 14 It schematically demonstrates the use of Figure 8The method shown describes the process of preparing an electromagnetic shielding template with the above-mentioned characteristics.

[0055] like Figure 8 As shown, in some embodiments, the method for preparing an electromagnetic shielding template suitable for flexible electromagnetic shielding paper includes operation S21, designing a growth site pattern 501 on a temporary carrier 20 for preparing at least two conductive nanowire modules 301. In some exemplary embodiments, the temporary carrier 20 can be a glass carrier, a ceramic carrier, a silicon wafer carrier, etc. Exemplarily, photoresist 50 (such as...) can be first coated on the upper surface of the temporary carrier 20. Figure 9b As shown), generally, such as Figure 9a As shown, the photoresist 50 completely covers the surface of the temporary carrier 20. The coating method can be spin coating or spray coating. The photoresist 50 can be a commonly used photoresist in the prior art, such as a positive photoresist 50 containing azidoquinone compounds, or a negative photoresist 50 containing polyvinyl laurate. Preferably, a positive photoresist 50 is used. Then, the shape and area of ​​the conductive nanowire module 301 to be fabricated are designed on the photoresist 50 coated on the temporary carrier 20. Next, by exposing and developing the designed shape and area, the growth site pattern 501 of the conductive nanowire module 301 can be obtained (e.g., ...). Figure 10 As shown in Figure (b), the growth site pattern 501 is a pattern used to mark the growth positions of the conductive nanowire module 301. As one exemplary embodiment of the growth site pattern 501, at least one side of the growth site pattern 501 of all conductive nanowire modules 301 is concave, especially when the growth site pattern 501 has a certain width, at least the side of each growth site pattern 501 opposite to its side facing a specific direction X (i.e., the second side of the growth site pattern 501) (i.e., the first side 5011 of the growth site pattern 501) is concave (e.g., as shown in Figure (b)). Figure 10As shown in Figure (a), for example, the concave shape can be a "V" shape, an arc shape, or other concave structures. Thus, the conductive nanowire module 301 grown on the growth site pattern 501 can have at least one side that is concave, and when the conductive nanowire module 301 tilts towards a specific direction X, the side of the conductive nanowire module 301 facing the temporary carrier plate 20 (inner side 3011A) is concave. This allows for batch control of the liquid level on the side where the concave inner side 3011A of the conductive nanowire module 301 is located to be greater than the liquid level on the outer side 3011B of the conductive nanowire module 301 during the drying process in the fabrication of the electromagnetic shielding template. This enables all conductive nanowire modules 301 to tilt towards the side where the inner side 3011A of the conductive nanowire module 301 is located (i.e., the specific direction X) through capillary force, achieving batch processing of the tilting of the conductive nanowire modules and improving preparation efficiency. As a further preferred embodiment, such as... Figure 10 As shown in Figure (a), the first side 5011 of the growth site pattern 501 has a concave arc structure, and the curvature angle A' of the arc structure ranges from 20° to 60°, for example, 20°, 30°, 35° or 60°. This improves the water retention effect of the inner side 3011A of the conductive nanowire module 301, ensuring more reliably that the liquid level on the inner side 3011A of the conductive nanowire module 301 is greater than the liquid level on the outer side 3011B of the conductive nanowire module 301.

[0056] As one embodiment of the growth site pattern 501 for fabricating the conductive nanowire module 301, such as Figure 10As shown in Figure (a), all growth site patterns 501 are arranged into at least one row of odd-numbered rows of growth site patterns 501 located in a specific direction X of the temporary carrier 20 and at least one row of even-numbered rows of growth site patterns 501 located in a specific direction X of the temporary carrier 20. Generally, at least one row includes more than two growth site patterns 501. The central axis A511 of each growth site pattern 501 in the odd-numbered rows is not collinear with the central axis B521 of each growth site pattern 501 in the even-numbered rows. Furthermore, as one embodiment of a conductive nanowire module 301 arranged sequentially in a specific direction X, which overlaps with each other in a tilted state to form a conductive network structure that can completely cover its defined shielding area, it is necessary to control that the distance D3` between the closest central axis A511 and central axis B521 of two adjacent rows in the direction Y perpendicular to the specific direction X is less than half the sum of the length L1` of the cross-section of the growth site pattern 501 corresponding to the central axis A511 or central axis B521. That is, the distance D3` between the central axis A511 of the growth site pattern 501 in the odd-numbered row and the central axis B521 of the growth site pattern 501 closest to the growth site pattern 501 in the even-numbered row adjacent to the odd-numbered row.

[0057] As some preferred embodiments of the growth site pattern 501, such as Figure 10 As shown in Figure (a), the distance D3` between the closest central axes A511 and B521 of two adjacent rows of growth site patterns 501 in a specific direction X is less than 1 / 3 times the length L1` of the cross-section of the growth site pattern 501 corresponding to the central axis A511 or B521, i.e., D3` ≤ 1 / 3 L1`. Therefore, it can be ensured that when all the conductive nanowire modules 301 grown on the growth site patterns 501 are tilted relative to the temporary carrier plate 20 towards a specific direction X, the distance D3` in the direction perpendicular to the specific direction X is less than 1 / 3 times the length L1` of the cross-section of the growth site pattern 501 corresponding to the central axis A511 or B521. The opposing sides of the conductive nanowire modules 301 arranged sequentially in the X direction can overlap each other. This also ensures that when the electromagnetic shielding unit of the present invention is placed on paper to form a flexible electromagnetic shielding paper, it can greatly ensure that after the paper is stretched under a conventional force in the Y direction perpendicular to the specific X direction, the conductive nanowire modules 301 arranged sequentially in the Y direction will only have relative sliding displacement, which will increase or decrease the overlapping area formed by the overlap, without the two separating. This avoids the situation where the conductive network structure is damaged.

[0058] Regardless of the specifications or shape of the growth site pattern 501, as one preferred embodiment, such as Figure 10As shown in Figure (a), at least two growth site patterns 501 in the same odd-numbered row form a first repeating pattern 51, that is, the first repeating pattern 51 is defined by the growth site patterns in the odd-numbered rows arranged in a specific direction X on the temporary carrier 20; at least two growth site patterns 501 in the same even-numbered row form a second repeating pattern 52, that is, the second repeating pattern 52 is defined by the growth site patterns in the even-numbered rows arranged in a specific direction X on the temporary carrier 20; at least one set of first repeating patterns 51 is provided, at least one set of second repeating patterns 52 is provided, and the central axis A511 of the growth site patterns 501 in the first repeating pattern 51 and the central axis B521 of each growth site pattern 501 in the second repeating pattern 52 are not collinear. Therefore, the conductive nanowire modules 301 grown on the growth site pattern 501 of the first repeating pattern 51 and the conductive nanowire modules 301 grown on the growth site pattern 501 of the second repeating pattern 52 are arranged in a staggered manner in the direction Y perpendicular to the specific direction X, thereby growing a first repeating unit 31 on the first repeating pattern 51 and a second repeating unit 32 on the second repeating pattern 52. This makes it possible for the conductive nanowire modules 301 in the first repeating unit 31 to overlap with the conductive nanowire modules 301 in the adjacent second repeating unit 32 located in its specific direction X when the conductive nanowire modules 301 are tilted towards the specific direction X. Similarly, it is also possible for the conductive nanowire modules 301 in the second repeating unit 32 to overlap with the conductive nanowire modules 301 in the adjacent first repeating unit 31 located in its specific direction X when the conductive nanowire modules 301 are tilted towards the specific direction X. Preferably, the distance D3' between the closest central axes A and B in the adjacent first repeating pattern 51 and second repeating pattern 52 in the direction Y perpendicular to the specific direction X is less than the length L1' of the cross-section of the growth site pattern 501 corresponding to the central axes A and B. This ensures that the distance D2' between two sequentially arranged growth site patterns 501 in the direction Y perpendicular to the specific direction X is less than the length L1' of the cross-section of the growth site pattern 501. Consequently, when the conductive nanowire module 301 grown on the growth site pattern 501 is relatively temporary... When the carrier plate 20 is tilted toward a specific direction X, the gap between the two conductive nanowire modules 301 in the second repeating unit 32 can be covered by a conductive nanowire module 301 in the adjacent first repeating unit 31 located on the side opposite to the temporary carrier plate 20. Similarly, the gap between the two conductive nanowire modules 301 in the first repeating unit 31 can also be covered by a conductive nanowire module 301 in the adjacent second repeating unit 32 located on the side of the temporary carrier plate 20, thereby ensuring the continuity of the conductive path of the electromagnetic shielding unit 30 and the stability of the electromagnetic shielding effect.In particular, when D3`≤1 / 3L1`, and all conductive nanowire modules 301 are tilted relative to the temporary carrier plate 20 toward a specific direction X, the tilted conductive nanowire modules 301 overlap each other in a direction Y perpendicular to the specific direction X, and there is an overlapping area between the overlapping conductive nanowire modules 301. This mutual covering method can further extend the propagation path of electromagnetic waves in the formed electromagnetic shielding unit 30, thereby obtaining more opportunities for refraction and reflection, enhancing the layer-by-layer attenuation of electromagnetic waves, and further improving the electromagnetic shielding effect. Preferably, all growth site patterns 501 in the first repeating pattern 51 are equally spaced along a direction Y perpendicular to the specific direction X on the temporary carrier 20; and / or all growth site patterns 501 in the second repeating pattern 52 are also equally spaced along a direction Y perpendicular to the specific direction X on the temporary carrier 20; and / or when at least one of the first repeating pattern 51 and the second repeating pattern 52 is provided in two or more, all the first repeating patterns 51 and the second repeating patterns 52 are equally spaced along the specific direction X. Thus, the conductive nanowire module 301 grown on the first repeating pattern 51 and the second repeating pattern 52 can be oriented towards... When tilted in a specific direction X, all conductive nanowire modules 301 overlap with at least one other conductive nanowire module 301. Moreover, conductive nanowire modules 301 not located at the edge overlap with at least two conductive nanowire modules 301 in another repeating unit on the side of their inner surface 3011A facing the temporary carrier plate 20, and also overlap with at least two conductive nanowire modules 301 in another repeating unit on the side of their inner surface 3011A facing away from the temporary carrier plate 20. This allows all conductive nanowire modules 301 to overlap with each other, forming a conductive network structure, which further extends the propagation path of electromagnetic waves in the formed electromagnetic shielding unit 30.

[0059] For some embodiments of the growth site pattern 501, especially when the growth site pattern 501 has a certain thickness, it will be combined with Figure 10 Figure (a) shows a top view illustrating the formation of a growth site pattern 501 on the photoresist 50 on the temporary carrier 20. Figure 10As shown in Figure (a), the width W1' of the growth site pattern 501 ranges from 1 μm to 10 μm. For example, the width W1' of the growth site pattern 501 can be set to 1 μm, 2 μm, or 5 μm; the length L1' of the growth site pattern 501 ranges from 10 μm to 1000 μm. For example, the length L1' of the growth site pattern 501 can be set to 10 μm, 30 μm, or 400 μm; two growth site patterns 501 arranged sequentially in a specific direction X... The distance D1` between the two growth site patterns 501 in the first repeating pattern 51 and the second repeating pattern 52 arranged sequentially in the specific direction X ranges from 1 μm to 30 μm. For example, the distance D1` between two growth site patterns 501 arranged sequentially in the specific direction X can be set to 1 μm, 3 μm, 8 μm, 15 μm, or 30 μm. By setting the length L1` of the growth site pattern 501 to be approximately larger than the distance D1` between two growth site patterns 501 arranged sequentially in the specific direction X, it can be ensured to a greater extent that when the conductive nanowire modules 301 grown on all the growth site patterns 501 are tilted relative to the temporary carrier plate 20 towards a specific direction X, the opposite sides of the conductive nanowire modules 301 arranged sequentially in the specific direction X are at least partially overlapped.

[0060] The method for preparing an electromagnetic shielding template suitable for flexible electromagnetic shielding paper further includes operation S22, which involves preparing a conductive nanowire module 301 on a growth site pattern 501, wherein the height Hnws of the conductive nanowire module 301 when not tilted is greater than the distance D1 between two conductive nanowire modules 301 arranged sequentially in a specific direction X when not tilted. In some possible embodiments, growing the conductive nanowire module 301 on the growth sites of the growth site pattern 501 firstly includes adsorbing conductive metal seeds 60 for nanomaterial growth on the growth sites of the growth site pattern 501; secondly, it further includes placing a temporary carrier plate 20 with the adsorbed conductive metal seeds 60 into a conductive nanowire growth solution 70 to grow the metal conductive nanowire module 301 on the growth sites of the temporary carrier plate 20. In some exemplary embodiments, taking a gold conductive nanowire module 301 as an example, the adsorption of conductive metal seeds 60 grown from nanomaterials at the growth sites of the growth site pattern 501 is implemented by adsorbing gold seeds grown from nanomaterials at the growth sites of the growth site pattern 501. Specifically, this includes the following steps: First, placing a temporary carrier plate 20 with the growth site pattern 501, which has undergone exposure and development, into a vacuum culture dish; second, subjecting the temporary carrier plate 20 in the vacuum culture dish to a 3-mercaptopropyltrimethoxysilane vapor bath treatment to allow the 3-mercaptopropyltrimethoxysilane to... Trimethoxysilane gas can be adsorbed onto the exposure area; then, the temporary carrier 20, after vapor treatment, is immersed in a gold seed solution to grow gold seeds at the growth sites of the growth site pattern 501. For example, the temporary carrier is immersed in the gold seed solution for 30 minutes. (Gold seed growth can also be achieved using other gold seed growth methods in the prior art, such as those described in the reference "Wang, Y. Gong, S. Wang, SJ Yang, XY Ling, YZ Yap, LWDong, DS Simon, GPC Heng, WL, Standing") The method for growing gold seeds described in "Enokitake-like Nanowire Films for Highly Stretchable Elastronics, ACS Nano 2018, 12, 9742-9749" is as follows: Next, the temporary carrier 20, after soaking, is immersed in an acetone solution to remove the photoresist 50 coated on it. Finally, the temporary carrier 20, after being cleaned to remove the photoresist 50, is rinsed with deionized water, for example, two to three times, and then dried. The resulting temporary carrier 20 with conductive metal seeds 60 prepared according to the growth site pattern 501 is shown below. Figure 11 Figure (a) and Figure 11As shown in Figure (b), the shape and specifications of the prepared conductive metal seed 60 are the same as those of the growth site pattern 501. Specifically, the range of values ​​for the width W`` of the cross-section of the conductive metal seed 60 is the same as the range of values ​​for the width W1` of the growth site pattern 501; the range of values ​​for the length L`` of the cross-section of the conductive metal seed 60 is the same as the range of values ​​for the length L1` of the growth site pattern 501; the range of values ​​for the distance D1`` between two conductive metal seeds 60 arranged sequentially in a specific direction X is the same as the range of values ​​for the distance D1` between two growth site patterns 501 arranged sequentially in a specific direction X; the side of the conductive metal seed 60 that is opposite to the side facing the specific direction X (i.e., the second side of the growth site pattern 501) (also called the first side of the conductive metal seed 60, that is, the side located at the same level as the first side 5011 of the growth site pattern 501) is concave (e.g., ...). Figure 11 As shown in Figure (a), for example, the concave shape can be "V" shaped, arc-shaped, or other concave structures. As a further preferred embodiment, such as... Figure 11 As shown in Figure (a), the first side of the conductive metal seed 60 has a concave arc structure, and the bending angle A' of the arc structure is in the same range as the bending angle A' of the growth site pattern 501. The distance D2' between two conductive metal seeds 60 arranged sequentially in the direction Y perpendicular to the specific direction X is the same as the distance D2' between two growth site patterns 501 arranged sequentially in the direction Y perpendicular to the specific direction X. That is to say, the shape of the cross-section of the conductive metal seed 60 prepared on the temporary carrier 20, its position on the temporary carrier 20, and the number of conductive metal seeds 60 are exactly the same as the growth site pattern 501 prepared on the temporary carrier 20. In some exemplary embodiments, taking the metal conductive nanowire module 301 being a gold conductive nanowire module 301 as an example, the temporary carrier 20 with the conductive metal seed 60 adsorbed is placed in the conductive nanowire growth solution 70 to grow the metal conductive nanowire module 301 on the growth site of the temporary carrier 20. Specifically, this is achieved as follows: Figure 12a and Figure 12bAs shown, a temporary carrier plate 20 with gold seeds grown according to the growth site pattern 501 is placed in a gold nanowire growth solution to continue vertical growth on the gold seeds of the temporary carrier plate 20 to form a gold nanowire module. The height of the gold nanowire module can be controlled by controlling the growth time, and it is necessary to ensure that the height Hnws of the obtained gold nanowire module when it is not tilted is greater than the distance D1 between two gold nanowire modules arranged sequentially in a specific direction X when they are not tilted, i.e., Hnws > D1. Specifically, the vertical growth method of the gold nanowire module can be operated in accordance with the method described in the literature "Wang Y.,Gong S.,GomezD.,Ling,YZ,Yap LW,Simon GP,Cheng,WL,Unconventional Janus Propertiesof Enokitake-like Gold Nanowire Films,ACS Nano,2018,12(8),8717-8722". Preferably, Hnws:D1≥3:1. Therefore, it can be ensured that when the conductive nanowire module 301 collapses in a specific direction X, the length L2 of the longitudinal section of the overlapping of the tilted conductive nanowire modules 301 arranged in sequence in the specific direction X is greater than 2 / 3 times the length L3 of the longitudinal section of the conductive nanowire module 301, thereby avoiding the destruction of the conductive network structure when subjected to a normal-sized external force.

[0061] The method for preparing an electromagnetic shielding template suitable for flexible electromagnetic shielding paper further includes operation S23, which involves directional collapse treatment of all the prepared conductive nanowire modules 301 (i.e., orderly assembly of all conductive nanowire modules 301), so that they all tilt toward a specific direction X, and at least a portion of the conductive nanowire modules 301 arranged sequentially in the specific direction X overlap each other when tilting, wherein all the conductive nanowire modules 301 tilted toward the specific direction X and overlapping each other together form an electromagnetic shielding unit 30. In some possible implementations, the directional collapse treatment of all the prepared conductive nanowire modules 301, so that they all tilt toward a specific direction X, can be achieved by: firstly, immersing the temporary carrier plate 20 on which the conductive nanowire modules 301 are grown in an ethanol / water mixture 80; secondly, removing the temporary carrier plate 20 on which the conductive nanowire modules 301 are grown after immersion in the ethanol / water mixture 80, and tilting all the conductive nanowire modules 301 toward a specific direction by capillary force, until the opposite sides 3011 of the conductive nanowire modules 301 arranged sequentially in the specific direction X are at least partially overlapping each other. In some exemplary embodiments, the side of the conductive nanowire module 301 facing the temporary carrier plate 20 when tilted in a specific direction X is concave. Capillary force causes all the conductive nanowire modules 301 to tilt in a specific direction. This can be achieved by: firstly, removing the temporary carrier plate 20, which has been soaked in an ethanol / water mixture 80 and on which the conductive nanowire modules 301 are grown, and then drying it. During the drying process, the liquid level at the first side of the conductive nanowire module 301 is maintained greater than the liquid level at the second side of the conductive nanowire module 301, wherein the second side of the conductive nanowire module 301 is the facing side of the conductive nanowire module 301. On one side facing a specific direction X, the first side of the conductive nanowire module 301 is the side of the conductive nanowire module 301 that is opposite to the second side. Due to the difference in liquid level height between the first and second sides of the conductive nanowire module, the capillary force of the liquid surface at the first side is different from that at the second side. The capillary force on the side with a higher liquid level is greater than that on the side with a lower liquid level. That is, the capillary force of the liquid surface at the first side of the conductive nanowire module 301 is greater than that at the second side of the conductive nanowire module 301. Therefore, under the driving action of the capillary force, the conductive nanowire module 301 collapses towards the side where the first side of the conductive nanowire module 301 is located.Specifically, when the temporary carrier plate 20 on which the conductive nanowire module 301 is grown is immersed in the ethanol / water mixture 80, the liquid level of the ethanol / water mixture 80 is higher than the height Hnws of the conductive nanowire module 301 when it is not tilted, and the liquid level Hin of the ethanol / water mixture 80 at the first side of the conductive nanowire module 301 is equal to the liquid level Hout of the ethanol / water mixture 80 at the second side of the conductive nanowire module 301, as shown. Figure 13a As shown; then, when the drying process begins on the temporary carrier 20 on which the conductive nanowire module 301 is grown, which has been removed from the ethanol / water mixture 80, the liquid level height Hin of the ethanol / water mixture 80 at the first side of the conductive nanowire module 301 is kept higher than the liquid level height Hout of the ethanol / water mixture 80 at the second side of the conductive nanowire module 301, as shown. Figure 13b As shown; then, as the drying process continues, that is, as the liquid level height at the first and second sides of the conductive nanowire module 301 continuously decreases, it is still necessary to maintain the liquid level height Hin of the ethanol / water mixture 80 at the first side of the conductive nanowire module 301 higher than the liquid level height Hout of the ethanol / water mixture 80 at the second side of the conductive nanowire module 301, as follows. Figure 13c As shown, the conductive nanowire module 301 is tilted towards the side where its first side is located under the action of capillary force; finally, after the ethanol / water mixture 80 on the first and second sides of the conductive nanowire module 301 is completely removed by drying, the structure of the temporary carrier plate 20 with the conductive nanowire module 301 grown on it, which has undergone the tilting treatment of the conductive nanowire module 301, is as follows. Figure 13d As shown, the structure of the electromagnetic shielding template prepared for flexible electromagnetic shielding paper is as follows. Figure 1 and Figure 2 As shown. In a preferred embodiment, when the conductive nanowire module 301 is in a tilted state, its first side facing the temporary carrier plate 20 is concave, so that during the drying process, the liquid level on the first side of all conductive nanowire modules 301 can be kept greater than the liquid level on their second side. Preferably, when the conductive nanowire module 301 is in a tilted state, its first side facing the temporary carrier plate 20 is a concave arc shape.

[0062] The application of the aforementioned electromagnetic shielding template will be explained below. In one application scenario, the electromagnetic shielding template can be used to prepare flexible electromagnetic shielding paper for electromagnetic shielding of electronic devices.

[0063] In some embodiments, flexible electromagnetic shielding paper can be prepared by transferring the electromagnetic shielding units on the aforementioned electromagnetic shielding template onto paper. The resulting flexible electromagnetic shielding paper can have a structure including paper 40 and electromagnetic shielding units 30 disposed on paper 40. The electromagnetic shielding units 30 can be the electromagnetic shielding units 30 disposed on the temporary carrier plate 20 in the electromagnetic shielding template of the aforementioned embodiment, or they can be the electromagnetic shielding units 30 disposed on the temporary carrier plate 20 in the electromagnetic shielding template prepared by the aforementioned method for preparing flexible electromagnetic shielding paper (e.g.,...). Figure 5 , Figure 6 and Figure 15 (As shown). Specifically, the electromagnetic shielding unit 30 on the temporary carrier plate 20 can be directly transferred to the paper 40, and the structure of the resulting flexible electromagnetic shielding paper is as follows. Figure 5 As shown, in this embodiment, the arrangement of the electromagnetic shielding units 30 on the paper 40 is mirror-symmetrical to their arrangement on the temporary carrier plate 20; alternatively, the electromagnetic shielding units 30 can be first peeled off from the temporary carrier plate 20, and then the peeled-off electromagnetic shielding units 30 can be fixed onto the paper 40 (e.g., by adhesive). The resulting flexible electromagnetic shielding paper has the following structure: Figure 6 As shown, in this embodiment, the electromagnetic shielding unit 30 is arranged on the paper 40 in the same way as it is arranged on the temporary carrier plate 20 (e.g., ...). Figure 6 and Figure 7 (As shown). Thus, the electromagnetic shielding unit 30 defined by this conductive network structure can completely cover its defined shielding area without generating electromagnetic leakage. At the same time, since the conductive nanowire modules 301 that constitute the electromagnetic shielding unit 30 are arranged sequentially in a specific direction X to form a conductive network structure through partial stacking, the propagation path of electromagnetic waves in it is extended, thereby obtaining more opportunities for refraction and reflection, enhancing the layer-by-layer attenuation of electromagnetic waves, and improving the electromagnetic shielding effect.

[0064] As an example of the material of paper 40, paper 40 can be made of paper-based materials commonly used in electromagnetic shielding paper.

[0065] As an example of the shape of paper 40, such as Figure 7 As shown, the paper 40 can be a paper material with a rectangular cross-section. Of course, the paper 40 can also be designed as a paper material with a cross-section of other shapes according to actual needs. For example, the paper 40 can be a paper material with a circular cross-section. Generally, in order to ensure the flexibility of the paper 40, the thickness T1 of the selected paper 40 is lower than the height Hnws of the conductive nanowire module 301 when it is not tilted (e.g., Figure 5 and Figure 6 (As shown).

[0066] The following will be combined with the appendix Figures 15 to 17 The preparation method of flexible electromagnetic shielding paper is described in detail. Among other things, Figure 15 The process of preparing a flexible electromagnetic shielding paper in some embodiments is illustrated schematically. Figure 16a and Figure 16b The process of transferring the electromagnetic shielding unit 30 from the temporary carrier plate 20 to the paper 40 is illustrated schematically. Figure 17 The process of preparing flexible electromagnetic shielding paper in some other embodiments is illustrated schematically.

[0067] The following is a combination of... Figure 15 The flowchart illustrating the preparation method of flexible electromagnetic shielding paper is provided as an example of one embodiment of the preparation method of flexible electromagnetic shielding paper. Figure 15 As shown, in some embodiments, the method for preparing flexible electromagnetic shielding paper includes operation S31, transferring the electromagnetic shielding unit 30 in the temporary carrier plate 20 with the electromagnetic shielding unit 30 of the aforementioned structure onto the paper 40.

[0068] Next, we will combine Figure 17 The flowchart illustrating the preparation method of flexible electromagnetic shielding paper is provided as an example of one embodiment of the preparation method of flexible electromagnetic shielding paper. Figure 17 As shown, the method for preparing the flexible electromagnetic shielding paper in this embodiment is... Figure 8 Based on the process shown, the process can be further included in operation S24, which involves transferring the prepared electromagnetic shielding unit 30, which is disposed on the temporary carrier plate 20, onto the paper 40. For example, the electromagnetic shielding unit 30 is transferred onto the paper 40 by attaching it to the paper 40.

[0069] Regardless of the implementation method used in preparing the flexible electromagnetic shielding paper, the same paper 40 can be used. The following provides an exemplary description of the possible types of paper 40. In some exemplary embodiments, the paper 40 can be a paper-based substrate. Specifically, the paper-based substrate can be, for example, the paper-based material commonly used in electromagnetic shielding paper, preferably an adhesive paper-based material such as adhesive paper. Alternatively, the electromagnetic shielding unit 30 can be transferred to the paper 40 by applying adhesive to ordinary paper and then pasting it onto the paper 40. Preferably, the thickness T1 of the paper 40 is lower than the height Hnws of the conductive nanowire module 301 when it is not tilted. Figure 16b Accordingly, a side view showing the transfer of the electromagnetic shielding unit 30 from the temporary carrier plate 20 to the paper 40 is shown, such as... Figure 16bAs shown, an adhesive paper-based material can be selected and spread on the electromagnetic shielding unit 30. The adhesiveness of the paper-based material is used to separate the electromagnetic shielding unit 30 from the temporary carrier plate 20. Preferably, the area of ​​the selected paper-based material is larger than the area of ​​the electromagnetic shielding unit 30, such as... Figure 16a As shown. In other embodiments, the electromagnetic shielding unit 30 can be first adhered to the temporary carrier plate 20 using a water-soluble polymer film, then the electromagnetic shielding unit 30 adhered to the temporary carrier plate 20 can be transferred to the paper-based material, and finally the water-soluble polymer film can be removed by dissolving it in water to obtain the electromagnetic shielding unit disposed on the paper-based material, the structure of which is as shown. Figure 6 and Figure 7 As shown.

[0070] Regardless of the specific method used to prepare the flexible electromagnetic shielding paper, even when the paper is stretched under external force, the sequentially arranged conductive nanowire modules 301 will only experience relative sliding displacement, without separation. This avoids damage to the conductive network, ensuring the stability of the conductive path, resistivity, and electromagnetic shielding effect of the flexible electromagnetic shielding paper. It also prevents the electromagnetic shielding effect of the flexible electromagnetic shielding paper from weakening or fluctuating due to external stretching. Ultimately, it ensures that the flexible electromagnetic shielding paper can exhibit a resistance change rate of no more than 10% under 100% strain. Therefore, the resistance change of the flexible electromagnetic shielding paper of this invention is not sensitive to strain.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An electromagnetic shielding template for flexible electromagnetic shielding paper, characterized in that, include: Temporary carrier board; The electromagnetic shielding unit disposed on the temporary carrier plate includes at least two conductive nanowire modules. All conductive nanowire modules are tilted relative to the temporary carrier plate toward a specific direction X, and the tilted conductive nanowire modules overlap each other in sequence in the specific direction X to form a conductive network structure that can completely cover the shielding area defined therein. The electromagnetic shielding unit includes at least one row of odd-numbered conductive nanowire modules located in a specific direction X of the temporary carrier plate and at least one row of even-numbered conductive nanowire modules located in a specific direction X of the temporary carrier plate. The first central axis of each conductive nanowire module in the odd-numbered rows is not collinear with the second central axis of each conductive nanowire module in the even-numbered rows.

2. The electromagnetic shielding template according to claim 1, characterized in that, Each conductive nanowire module has a concave first side facing the temporary carrier when tilted in a specific direction X.

3. The electromagnetic shielding template according to claim 2, characterized in that, The first side is a concave arc shape, and its cross-section has an arc structure. The arc bending angle A of the arc structure ranges from 20° to 60°.

4. The electromagnetic shielding template according to claim 2, characterized in that, The width W1 of the cross-section of the conductive nanowire module ranges from 1 μm to 10 μm; The length L1 of the cross-section of the conductive nanowire module ranges from 10 μm to 1000 μm. The height Hnws of the conductive nanowire module when it is not tilted ranges from 3μm to 100μm. The distance D1 between two conductive nanowire modules arranged sequentially in a specific direction X, when not tilted, ranges from 1 μm to 30 μm.

5. The electromagnetic shielding template according to claim 1, characterized in that, Conductive nanowire modules located in the same odd-numbered rows define a first set of repeating units, and conductive nanowire modules located in the same even-numbered rows define a second set of repeating units. Each first and second repeating unit includes at least two conductive nanowire modules.

6. The electromagnetic shielding template according to any one of claims 1 to 5, characterized in that, The conductive nanowire module is made of gold, silver, or platinum.

7. The electromagnetic shielding template according to claim 1, characterized in that, In a specific direction X, the length L2 of the longitudinal section where the conductive nanowire modules corresponding to the closest first and second central axes of two adjacent rows of conductive nanowire modules overlap is not less than 2 / 3 times the length L3 of the longitudinal section of the conductive nanowire module; and / or The distance D3 between the closest first and second central axes of two adjacent rows of conductive nanowire modules in a specific direction X in the direction Y perpendicular to the specific direction X is no greater than 1 / 3 times the length L1 of the cross section of the conductive nanowire module corresponding to the first or second central axis.

8. A method for preparing an electromagnetic shielding template, characterized in that, The method comprises: A growth site pattern for fabricating at least two conductive nanowire modules is designed on a temporary carrier. A conductive nanowire module with a height Hnws when not tilted is prepared on the growth site pattern, which is greater than the distance D1 between two conductive nanowire modules arranged sequentially in a specific direction X when not tilted. All the prepared conductive nanowire modules are subjected to directional collapse treatment so that they all tilt toward a specific direction X, and the tilted conductive nanowire modules are stacked one after another in the specific direction X. All the conductive nanowire modules tilted toward the specific direction X and stacked together form a conductive network structure that can cover the shielding area defined by them. The temporary carrier has at least one row of odd-numbered conductive nanowire modules located in a specific direction X of the temporary carrier and at least one row of even-numbered conductive nanowire modules located in a specific direction X of the temporary carrier, wherein the first central axis of each of the odd-numbered conductive nanowire modules is not collinear with the second central axis of each of the even-numbered conductive nanowire modules.

9. The method for preparing the electromagnetic shielding template according to claim 8, characterized in that, The fabrication of the conductive nanowire module on the growth site pattern is achieved as follows: Conductive metal seeds grown from nanomaterials are adsorbed onto the growth site pattern. A temporary carrier plate adsorbed with conductive metal seeds is placed in a conductive nanowire growth solution to grow the conductive nanowire module on the conductive metal seeds on the temporary carrier plate.

10. The method for preparing the electromagnetic shielding template according to claim 8, characterized in that, The step of performing a directional collapse treatment on all the prepared conductive nanowire modules, causing them to all tilt in a specific direction, and ensuring that the conductive nanowire modules arranged sequentially in the specific direction overlap each other during tilting, includes: The temporary carrier plate on which the conductive nanowire module is grown is immersed in an ethanol / water mixture. The temporary carrier plate on which the conductive nanowire modules are grown is removed after being soaked in the ethanol / water mixture, and all the conductive nanowire modules are tilted in a specific direction by capillary force until the opposite sides of the conductive nanowire modules arranged in the specific direction overlap each other.

11. The method for preparing the electromagnetic shielding template according to claim 10, characterized in that, The first side of the conductive nanowire module facing the temporary carrier is concave when tilted in a specific direction X. The process of tilting all the conductive nanowire modules in a specific direction by capillary force until the opposite sides of the conductive nanowire modules arranged sequentially in that specific direction overlap each other is achieved by: After the temporary carrier plate on which the conductive nanowire module is grown is soaked in the ethanol / water mixed solution, it is removed and dried. During the drying process, the liquid level on the side of the conductive nanowire module located on the first side is kept greater than the liquid level on the side of the conductive nanowire module located away from the first side.

12. The method for preparing an electromagnetic shielding template according to any one of claims 8 to 11, characterized in that, The electromagnetic shielding template is the electromagnetic shielding template according to any one of claims 2 to 7.

13. Flexible electromagnetic shielding paper, characterized in that, include: Paper; and an electromagnetic shielding unit disposed on the paper; wherein, The electromagnetic shielding unit is obtained by transferring the electromagnetic shielding unit disposed on the temporary carrier plate in the electromagnetic shielding template according to any one of claims 1 to 7 onto the paper; or... The electromagnetic shielding unit is obtained by transferring the electromagnetic shielding unit disposed on the temporary carrier plate in the electromagnetic shielding template prepared by the method of preparing the electromagnetic shielding template according to any one of claims 8 to 12 onto the paper.

14. A method for preparing flexible electromagnetic shielding paper, characterized in that, The preparation method includes: Transfer the electromagnetic shielding unit disposed on the temporary carrier plate in the electromagnetic shielding template according to any one of claims 1 to 7 to paper; or An electromagnetic shielding template is prepared according to the preparation method of any one of claims 8 to 12, and the electromagnetic shielding unit formed on the temporary carrier is transferred to paper.

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