Sandwich symmetrical silver mesh film

Abstract

The utility model relates to the technical field of electromagnetic interference shielding effectiveness of flexible transparent conductive films, in particular to a sandwich symmetrical silver mesh film, which comprises a light-transmitting layer, a first shielding layer arranged on one side of the light-transmitting layer and a second shielding layer arranged on the other side of the light-transmitting layer. And the first shielding layer and the second shielding layer have the same structure and are completely symmetrical. The flexible transparent conductive film solves the problems that the use amount of conductive materials needs to be increased and the light transmittance needs to be sacrificed when a traditional flexible transparent conductive film is used for improving the electromagnetic interference shielding effectiveness. In addition, the light transmittance of the sandwich symmetric silver mesh film can be regulated and controlled as required by adjusting the line spacing of the shielding layer, and the electromagnetic interference shielding effectiveness of the sandwich symmetric silver mesh film can be dynamically regulated and controlled by adjusting the interlayer spacing of the silver mesh. And finally, the sandwich symmetrical silver mesh film ensures that the electromagnetic interference shielding effectiveness is improved, and meanwhile, the characteristics of excellent mechanical flexibility, stability, environmental adaptability and the like of the single-sided double-layer silver mesh film are also maintained.

Description

TECHNICAL FIELD

[0001] The utility model relates to the electromagnetic interference shielding effectiveness field of flexible transparent conductive film, especially a sandwich symmetrical silver mesh film. BACKGROUND

[0002] The rapid development of optoelectronic devices inevitably accompanies serious electromagnetic radiation (EMR) pollution, which not only interferes with the normal operation of electronic devices, but also endangers human health. Flexible transparent conductive films (FTCFs) have certain flexibility, conductivity and light transmittance, and can conform to various optoelectronic devices, effectively shielding electromagnetic interference (EMI) generated during operation without affecting their visual function.

[0003] Traditional flexible transparent conductive films usually have a continuous and dense conductive material layer on one side of a flexible transparent substrate, which is manufactured by spraying, deposition or other methods, so as to achieve electromagnetic wave shielding. To increase the electromagnetic interference shielding performance, the thickness of the conductive material layer needs to be increased, which will lead to a decrease in light transmittance. Flexible transparent conductive films based on metal mesh have attracted widespread attention because the thickness of the metal mesh can be increased to improve the electromagnetic interference shielding effectiveness (EMISE) without affecting the light transmittance. This is because the line spacing of the metal mesh is between the wavelengths of visible light and microwaves, which allows visible light to pass through the mesh holes while microwaves are blocked. However, the increase in the thickness of the metal mesh will increase the amount of material used, resulting in higher costs and making large-scale production difficult. Therefore, for flexible transparent conductive films based on metal mesh, it is still a major challenge to enhance the electromagnetic interference shielding effectiveness while maintaining the original light transmittance under the same amount of material. SUMMARY

[0004] This section aims to outline some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the utility model name to avoid obscuring the purpose of this section, the abstract of the specification and the utility model name, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0005] In view of the above or the same amount of material in the prior art, the sandwich symmetrical silver mesh film cannot increase the electromagnetic interference shielding effectiveness while maintaining the light transmittance unchanged, the utility model is proposed.

[0006] Therefore, the purpose of the utility model is to provide a sandwich symmetrical silver mesh film. To solve the above technical problems, the utility model provides the following technical scheme: including a light transmission layer, a first shielding layer arranged on one side of the light transmission layer, and a second shielding layer arranged on the other side of the light transmission layer, the first shielding layer and the second shielding layer have the same structure.

[0007] As a preferred scheme of the sandwich symmetrical silver mesh film, the first shielding layer and the second shielding layer are symmetrical relative to the light transmission layer.

[0008] As a preferred scheme of the sandwich symmetrical silver mesh film, the light transmission layer is a polyethylene terephthalate film.

[0009] As a preferred scheme of the sandwich symmetrical silver mesh film, the thickness of the light transmission layer is 50 μm-250 μm.

[0010] As a preferred scheme of the sandwich symmetrical silver mesh film, the first shielding layer comprises a first shielding film and a second shielding film stacked in sequence, the geometric form of the first shielding film is composed of a single continuous line and arranged in a serpentine shape along the weft direction, and the geometric form of the second shielding film is composed of a single continuous line and arranged in a serpentine shape along the warp direction.

[0011] As a preferred scheme of the sandwich symmetrical silver mesh film, the projection shape of the first shielding film and the second shielding film in the thickness direction is a mesh pattern in which the warp lines and the weft lines are interlaced.

[0012] As a preferred scheme of the sandwich symmetrical silver mesh film, the lines of the mesh pattern have rectangular gaps therebetween.

[0013] As a preferred scheme of the sandwich symmetrical silver mesh film, the gap is a square with a side length of 100 μm-600 μm.

[0014] As a preferred scheme of the sandwich symmetrical silver mesh film, the line width of the mesh pattern is 150 μm.

[0015] As a preferred scheme of the sandwich symmetrical silver mesh film, the material of the first shielding layer and the second shielding layer is silver ink.

[0016] The utility model discloses a beneficial effect: the utility model discloses the structure of the flexible transparent conductive film based on silver net is optimized, and the sandwich symmetric silver net film is constituted to the three sandwich symmetric silver net film of printing symmetric silver net shielding layer on the both sides of the light transmission layer, can make X wave band (8.2-12.4GHz) electromagnetic interference shielding effectiveness in a certain range significantly improve, and higher than any same parameter (conductive material dosage, line width, line spacing and base) single face double layer silver net film. Meanwhile, the problem that the traditional transparent conductive film promotes electromagnetic interference shielding effectiveness needs to increase the amount of conductive material and sacrifices the problem of light transmittance, provides the feasible strategy for preparing low cost, high electromagnetic interference shielding effectiveness and high light transmittance conductive film. In addition, by adjusting the line spacing and the layer spacing of the shielding layer, the light transmittance and the electromagnetic interference shielding effectiveness of the sandwich symmetric silver net film can be controlled as needed in a certain range. Finally, the sandwich symmetric silver net film ensures the electromagnetic interference shielding effectiveness, and also maintains the excellent mechanical flexibility, stability, environmental adaptability and other characteristics of the single face double layer silver net film. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the drawings needed to be used in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creating creative labor. Among them:

[0018] Figure 1 It is the structure schematic diagram of sandwich symmetric silver net film.

[0019] Figure 2 It is Figure 1 It is the enlarged view of A in the middle.

[0020] Figure 3 It is the SEM image (the scale is 500 μm) of printing the shielding layer with the line width of 150 μm and the line spacing of 400 μm on the light transmission layer with the thickness of 50 μm using the best printing parameter.

[0021] Figure 4 It is the relationship between the nozzle diameter and the line width and the surface topography of the shielding layer in embodiment 2.

[0022] Figure 5 It is the relationship between the printing speed and the line width and the surface topography of the shielding layer in embodiment 2.

[0023] Figure 6 It is the relationship between the pressure and the line width and the surface topography of the shielding layer in embodiment 2.

[0024] Figure 7 It is the relationship between the printing height and the line width and the surface topography of the shielding layer in embodiment 2.

[0025] Figure 8 Figure 1 is a schematic diagram of a single-sided double-layer silver mesh film.

[0026] Figure 9 Figure 4 is a graph of the relationship between the line spacing of the shielding layer and the electromagnetic interference shielding effectiveness of a sandwich symmetric silver mesh film (the layer spacing is 50 μm).

[0027] Figure 10 Figure 5 is a graph of the relationship between the line spacing of the shielding layer and the electromagnetic interference shielding effectiveness of a single-sided double-layer silver mesh film (the light-transmitting layer thickness is 50 μm).

[0028] Figure 11 Figure 6 is a graph of the relationship between the line spacing of the shielding layer and the light transmittance of a sandwich symmetric silver mesh film (the layer spacing is 50 μm).

[0029] Figure 12 Figure 7 is a graph of the relationship between the line spacing of the shielding layer and the light transmittance of a single-sided double-layer silver mesh film (the light-transmitting layer thickness is 50 μm).

[0030] Figure 13 Figure 8 is a graph of the relationship between the layer spacing of the shielding layer and the electromagnetic interference shielding effectiveness of a sandwich symmetric silver mesh film (the line spacing is 400 μm).

[0031] Figure 14 Figure 9 is a graph of the relationship between the layer spacing of the shielding layer and the light transmittance of a sandwich symmetric silver mesh film (the line spacing is 400 μm).

[0032] Figure 15 Figure 10 is a graph of the relationship between the thickness of the light-transmitting layer and the electromagnetic interference shielding effectiveness of a single-sided double-layer silver mesh film (the line spacing is 400 μm).

[0033] Figure 16 Figure 11 is a graph of the relationship between the thickness of the light-transmitting layer and the light transmittance of a single-sided double-layer silver mesh film (the line spacing is 400 μm).

[0034] Figure 17 Figure 12 is a graph of the relationship between the line spacing and the electromagnetic interference shielding effectiveness of a sandwich asymmetric silver mesh film (the layer spacing is 50 μm) in Example 4.

[0035] Figure 18 Figure 13 is a graph of the relationship between the line spacing and the light transmittance of a sandwich asymmetric silver mesh film (the layer spacing is 50 μm) in Example 4. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0037] In the following description, a lot of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can be practiced in other ways not described herein, and it is understood that one skilled in the art can make similar substitutions without departing from the scope of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0038] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent of or mutually exclusive of other embodiments.

[0039] Embodiment 1

[0040] Reference Figures 1-3 For the first embodiment of the present application, the embodiment provides a sandwich symmetrical silver mesh film, which comprises a light-transmitting layer 100, a first shielding layer 200 arranged on one side of the light-transmitting layer 100, and a second shielding layer 300 arranged on the other side of the light-transmitting layer 100, the first shielding layer 200 and the second shielding layer 300 are the same in structure and symmetrical with respect to the light-transmitting layer.

[0041] Specifically, the light-transmitting layer 100 is a polyethylene terephthalate film, and the thickness of the light-transmitting layer 100 is 50 μm to 250 μm.

[0042] Further, the first shielding layer 200 comprises a first shielding film 201 and a second shielding film 202 stacked in sequence, the geometric shape of the first shielding film 201 is composed of a single continuous line and arranged in a serpentine shape along the weft direction, and the geometric shape of the second shielding film 202 is composed of a single continuous line and arranged in a serpentine shape along the warp direction.

[0043] Among them, the projection shape of the first shielding film 201 and the second shielding film 202 in the thickness direction is a mesh pattern in which the warp lines and the weft lines are interlaced with each other. The lines of the mesh pattern have rectangular-shaped gaps 400 between them, the gaps 400 are square with a side length of 400 μm, and the line width of the mesh pattern is 150 μm.

[0044] In use, 2 mL of commercial silver paste (SP-1027, ≥70±2%) is sucked into a 5 mL glass bottle, 400 μL of ethyl acetate is sucked into the glass bottle and mixed thoroughly to prepare a silver ink, which is poured into a needle tube for printing. The needle tube is assembled on the mechanical arm of the printer, a light transmission layer with a thickness corresponding to the layer spacing is fixed on the printing platform according to the layer spacing, the relevant printing parameters are adjusted according to the line spacing, and then the first shielding layer 200 is printed. Turn over the light transmission layer 100 after printing the first shielding layer 200, and then use the high-definition camera-based optical positioning system for accurate positioning, adjust the relevant printing parameters and print the second shielding layer 300, and then sinter the film after printing under the condition of 100℃ vacuum for 30min to prepare a sandwich symmetrical silver mesh film.

[0045] Example 2

[0046] Reference Figures 4-7 , the second embodiment of the utility model, different from the last embodiment, this embodiment provides the influence of various printing parameters on the line width and surface morphology of the shielding layer, which includes nozzle diameter, printing speed, pressure, printing height and other printing parameters.

[0047] (1) Explore the influence of nozzle diameter on the line width and surface morphology of the shielding layer

[0048] As shown in Figure 4 , under the conditions of printing speed of 5mm s -1 , pressure of 300kPa, and printing height of 160μm, nozzles with diameters of 60μm, 110μm, 160μm, 210μm and 260μm are used to print silver lines on a light transmission layer with a thickness of 50μm, and the measured line width is 80μm, 150μm, 292μm, 517μm and 698μm. This proves that as the nozzle diameter increases, the line width increases and the printing resolution decreases. For a nozzle with a diameter of 60μm, the small diameter hinders the flow of silver ink, causing nozzle blockage and ultimately causing the silver line to break. When the nozzle diameter is 110, 160, 210 and 260μm, the silver line can be uniformly printed. Therefore, in order to achieve higher printing resolution, a nozzle with a diameter of 110μm is selected.

[0049] (2) Explore the influence of printing speed on the line width and surface morphology of the shielding layer

[0050] As shown in Figure 5 , under the conditions of nozzle diameter of 110μm, pressure of 300kPa, and printing height of 160μm, 1mm s -1 , 3mm s -1 , 5mm s -1 , 7mm s -1 and 9mm s -1The printing speed was used to print silver lines on a 50μm thick transparent layer, and the measured linewidths were 302μm, 191μm, 150μm, 132μm, and 122μm. When the printing speed increased from 1 mm / s... -1 Increased to 9mms -1 At this speed, the linewidth decreased from 302μm to 122μm, resulting in improved printing resolution. This is due to the increased speed leading to a reduction in the amount of silver ink deposited per unit time. Printing efficiency determines the overall printing time of the device; that is, the faster the printing speed, the shorter the printing time, and the higher the printing efficiency. When the printing speed increases from 1 mm / s... -1 Increased to 5mm s -1 At this time, both printing efficiency and printing resolution are improved, while the edges of the silver lines remain smooth. However, when the printing speed is increased from 5 mm / s... -1 Increased to 9mm s -1 At that time, due to excessively high printing speed, insufficient silver ink deposition resulted in a decrease in the smoothness of the silver line edges. Therefore, in order to balance printing efficiency, printing resolution, and silver line edge smoothness, a printing speed of 5mm / s was selected. -1 The printing speed.

[0051] (3) Investigate the effect of pressure on the linewidth and surface morphology of the shielding layer.

[0052] like Figure 6 As shown, with a nozzle diameter of 110 μm and a printing speed of 5 mm / s... -1 With a printing height of 160 μm, silver lines were printed on a 50 μm thick transparent layer using pressures of 200 kPa, 250 kPa, 300 kPa, 350 kPa, and 400 kPa. The measured linewidths were 111 μm, 128 μm, 150 μm, 163 μm, and 181 μm, respectively. When the pressure increased from 200 kPa to 400 kPa, the linewidth increased from 111 μm to 181 μm, but the printing resolution decreased. This is because the increased pressure leads to a greater amount of silver ink extruded per unit time. At pressures of 200 kPa and 250 kPa, the edge smoothness of the printed silver lines was low due to insufficient silver ink extrusion. However, when the pressure was greater than or equal to 300 kPa, the silver lines could be printed uniformly. Therefore, a pressure of 300 kPa was chosen to balance printing resolution and silver line edge smoothness.

[0053] (4) Investigating the effect of printing height on the linewidth and surface morphology of the shielding layer.

[0054] Printing height is defined as the distance between the nozzle and the substrate. For example... Figure 7 As shown, with a nozzle diameter of 110 μm and a printing speed of 5 mm / s... -1, the printing height of 150 μm, 160 μm, 170 μm, 180 μm and 190 μm were used to print silver lines on the light-transmitting layer with the thickness of 50 μm under the pressure of 300 kPa, and the measured line widths were 160 μm, 150 μm, 142 μm, 139 μm and 135 μm respectively. This proves that the line width decreases and the printing resolution improves with the increase of the printing height. When the printing height increases from 150 μm to 160 μm, the printing resolution improves while the silver line edge remains flat. However, the flatness of the silver line edge gradually decreases as the printing height increases from 160 μm to 190 μm. Finally, the printing height of 160 μm is selected for subsequent experiments.

[0055] In summary, it can be concluded that the optimal printing parameters of the printed shielding layer are the nozzle diameter of 100 μm, the printing speed of 5 mm s -1 , the pressure of 300 kPa and the printing height of 160 μm.

[0056] Example 3

[0057] Referring to Figures 8-12 , the third embodiment of the utility model, different from the previous embodiment, provides a comparative experiment of sandwich symmetrical silver mesh film and single-sided structure silver mesh film.

[0058] Specifically, in the preparation of single-sided double-layer silver mesh film, a 1 mL syringe is used to remove the needle and 2 mL of commercial silver paste (SP-1027, ≥70±2%) is sucked into a 5 mL glass bottle, then 400 μL of ethyl acetate is sucked into the glass bottle using a pipette gun and stirred uniformly with a stirring rod to prepare silver ink, which is poured into a 5 mL needle tube for printing. The needle tube is assembled on the mechanical arm of the printer and connected to the air pipe, the light-transmitting layer with the corresponding thickness is fixed on the printing platform according to the thickness requirement of the device, and the printing parameters are set as follows: nozzle diameter: 100 μm, printing speed: 5 mm s -1 , pressure: 300 kPa, printing height: 160 μm, then select the appropriate line spacing according to the light transmittance requirement, import the corresponding CAD program, and print the first layer of silver mesh. The printing height is increased by 15 μm and the second layer of silver mesh is printed. The film after printing is placed on a glass plate and sintered at 100℃ under vacuum conditions for 30 min to prepare a single-sided double-layer silver mesh film.

[0059] The line spacing of the shielding layer is adjusted, and the sandwich symmetrical silver mesh film and the single-sided double-layer silver mesh film are cut into a rectangular shape with the size of 22.84×10.14 mm 2 , which is clamped between the waveguide cavity and the waveguide adapter, and the S parameters (S 11 , S12 S 21 S 22 Then, the electromagnetic interference shielding effectiveness was calculated based on the S-parameters. The line spacing of the shielding layers was adjusted, and the sandwich symmetrical silver mesh film and the single-sided double-layer silver mesh film were cut into 22.84 × 10.14 mm pieces respectively. 2 A rectangle was fixed on the sample stage, and the same transparent layer was placed as a control. Its transmittance in the visible light wavelength range (400-800nm) was measured using a UV-Vis spectrophotometer.

[0060] like Figure 9 As shown, the electromagnetic interference shielding effectiveness (EMI SE) of the sandwich symmetrical silver mesh film (with a layer spacing of 50 μm) decreases with the increase of line spacing. This is because the conductivity decreases due to the reduction in the area density of the shielding layer.

[0061] like Figure 10 As shown, the electromagnetic interference shielding effectiveness (EMI SE) of a single-sided double-layer silver mesh film (with a light-transmitting layer thickness of 50 μm) decreases with increasing line spacing. This is because the conductivity decreases due to the reduction in the area density of the silver mesh.

[0062] like Figure 11 As shown, the transmittance of the sandwich symmetrical silver mesh film (with a layer spacing of 50 μm) increases with the increase of line spacing. This is because the decrease in the area density of the shielding layer increases the transmitted light flux.

[0063] like Figure 12 As shown, the transmittance of the single-sided double-layer silver mesh film (with a light-transmitting layer thickness of 50 μm) increases with the increase of line spacing. This is because the decrease in the area density of the silver mesh increases the transmitted light flux.

[0064] Table 1

[0065]

[0066] Table 2

[0067]

[0068]

[0069] As shown in Table 1-2, in the case of an interlayer spacing (thickness of the light-transmitting layer) of 50 μm, the sandwich symmetrical silver mesh film has higher electromagnetic interference shielding effectiveness and the same light transmittance compared with the single-sided double-layer silver mesh film with the same parameters (amount of conductive material, line width, line spacing, substrate). Specifically, the electromagnetic interference shielding effectiveness can be increased by 3-8 dB, and the increase amplitude is 7-18%. This shows that the optimized electromagnetic film structure is superior to the single-sided double-layer structure, because of the synergistic effect of multiple internal reflection and multi-wave interference of electromagnetic waves between the two symmetrical shielding layers, which increases the electromagnetic interference shielding effectiveness. In addition, the light transmittance of the sandwich symmetrical silver mesh film can be controlled on demand within a certain range by adjusting the line spacing of the shielding layer.

[0070] In summary, the electromagnetic shielding effectiveness of the sandwich symmetrical silver mesh film is superior to that of the single-layer structure silver mesh film, and the light transmittance of the sandwich symmetrical silver mesh film can be controlled on demand within a certain range by adjusting the line spacing of the shielding layer.

[0071] Example 4

[0072] Reference Figures 13-16 For the fourth embodiment of the utility model, the embodiment provides a comparative experiment of the sandwich symmetrical silver mesh film and the single-sided structure silver mesh film.

[0073] The single-sided double-layer silver mesh film is prepared in the same manner as in Example 3.

[0074] The interlayer spacing of the silver mesh (shielding layer) is adjusted, and the sandwich symmetrical silver mesh film and the single-sided double-layer silver mesh film are cut into 22.84 x 10.14 mm 2 rectangular shapes and clamped between the waveguide cavity and the waveguide adapter, and the S parameters (S 11 , S 12 , S 21 , S 22 ) of the sandwich symmetrical silver mesh film and the single-sided double-layer silver mesh film in the X waveband (8.2-12.4 GHz) are tested using a vector network analyzer (E5071CENA, Keysight Technologies, USA), and the electromagnetic interference shielding effectiveness is calculated according to the S parameters. The interlayer spacing of the silver mesh is adjusted, and the sandwich symmetrical silver mesh film is cut into 22.84 x 10.14 mm 2 rectangular shapes and fixed on the sample stage, and the same light-transmitting layer is used as a control, and the light transmittance of the sandwich symmetrical silver mesh film in the visible light wavelength range (400-800 nm) is tested using an ultraviolet-visible spectrophotometer.

[0075] As Figure 13As shown in FIG. 4, with the increase of the interlayer spacing, the electromagnetic interference shielding effectiveness (EMI SE) of the sandwich symmetric silver mesh film (line spacing of 400 μm) is enhanced, which is due to the increase of the interlayer spacing is conducive to strengthen the multiple internal reflection and multi-wave interference effect of electromagnetic waves between the shielding layers.

[0076] As shown in FIG. 5, with the increase of the interlayer spacing, the transmittance of the sandwich symmetric silver mesh film (line spacing of 400 μm) remains unchanged, which is due to the complete symmetry between the two shielding layers. Figure 14 As shown in FIG. 6, with the increase of the thickness of the light-transmitting layer, the electromagnetic interference shielding effectiveness (EMI SE) of the single-sided double-layer silver mesh film (line spacing of 400 μm) remains unchanged, which is due to the PET itself does not have electromagnetic interference shielding capability.

[0077] Figure 15 As shown in FIG. 7, with the increase of the thickness of the light-transmitting layer, the transmittance of the single-sided double-layer silver mesh film (line spacing of 400 μm) remains unchanged, which is due to the increase of the thickness of the light-transmitting layer does not affect the transmittance.

[0078] Table 3 Figure 16

[0079] Table 4

[0080]

[0081] Table 4

[0082]

[0083] As shown in Tables 3-4, by adjusting the interlayer spacing of the sandwich symmetric silver mesh film, the electromagnetic interference shielding effectiveness can be further improved while maintaining the transmittance unchanged. When the line spacing is 400 μm, the sandwich symmetric silver mesh film can continue to improve the electromagnetic interference shielding effectiveness to 41.7 dB by increasing the interlayer spacing, which is 40% higher than the 29.6 dB of the single-sided double-layer silver mesh film with the same parameters (amount of conductive material, line width, line spacing, substrate).

[0084] In summary, the sandwich symmetric silver mesh film solves the problem of increasing the amount of conductive material and sacrificing the transmittance to improve the electromagnetic shielding effectiveness of the traditional transparent conductive film, and provides a feasible strategy for preparing a low-cost, high electromagnetic shielding effectiveness and high transmittance conductive film. In addition, by adjusting the interlayer spacing of the shielding layer, the electromagnetic shielding effectiveness of the sandwich structure silver mesh film can be dynamically controlled within a certain range.

[0085] Example 5

[0086] Referring to​​Figure 17 and Figure 18 For the fifth embodiment of the present utility model, the embodiment provides a comparative experiment of average electromagnetic interference shielding effectiveness and average light transmittance of single-sided double-layer silver mesh film, sandwich symmetric silver mesh film and sandwich asymmetric silver mesh film.

[0087] Table 6

[0088]

[0089] Table 7

[0090]

[0091] As shown in Tables 6-7, under the same conditions, the sandwich asymmetric silver mesh film has the highest electromagnetic interference shielding effectiveness, but due to the asymmetry of the two layers of silver mesh, the light transmittance is greatly reduced. However, compared with the single-sided double-layer silver mesh film, the sandwich symmetric silver mesh film realizes higher electromagnetic interference shielding effectiveness under the same light transmittance and material consumption.

[0092] Example 6

[0093] For the sixth embodiment of the present utility model, the embodiment provides other performances of the sandwich symmetric silver mesh film.

[0094] Table 8

[0095]

[0096] After the bending fatigue test with a bending radius of 8.5 mm and a bending cycle number of 10,000 times, the relative resistance change of the convex surface is less than 7%, and the relative resistance change of the concave surface is less than 5%, which shows excellent bending stability. During the bending process, the convex silver mesh bears tensile load, and the concave silver mesh bears compression load. The difference in stress distribution explains the smaller relative resistance change observed on the concave side.

[0097] Table 9

[0098]

[0099]

[0100] After soaking in deionized water (DI water), sodium hydroxide (NaOH) and hydrochloric acid (HCl) for 72 h, the relative resistance change of the sandwich symmetric silver mesh film in water and sodium hydroxide solution is less than 1%, and the relative resistance change in hydrochloric acid solution is less than 2%, which proves its good adaptability to different chemical environments.

[0101] Table 10

[0102]

[0103] After 100 min of ultrasonic water bath (40 kHz, 600 W), the relative resistance change was less than 0.5%, which confirmed the good adaptability in the ultrasonic vibration environment.

[0104] Table 11

[0105]

[0106] After 100 times of peeling test on the same area of the sandwich symmetrical silver mesh film, the relative resistance change was about 1%, which indicated that the shielding layer had strong adhesion to the PET substrate and good stability.

[0107] Importantly, it should be noted that the constructions and arrangements of the present application shown in the various different exemplary embodiments are illustrative only. Although several embodiments have been described in detail herein, many modifications are possible to one skilled in the art, in light of the above teachings. For example, the methods described herein can be modified by changing the order of the steps or reordering the steps. Any process or method step described herein can be performed in an alternative order or sequentially or concurrently. Any "means plus function" clauses are intended to cover the structures described herein as performing the recited functions and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes, and omissions can be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the present application as expressed in the appended claims. Accordingly, the present application is not limited to the above described embodiments, but rather is intended to cover any and all alternatives, modifications, equivalents, and / or alternatives as can be included within the scope of the appended claims. Therefore, the above description is not intended to limit the scope of the application, but is merely intended to provide examples of the application. Thus, it is intended that the scope of the application be defined by the following claims— their equivalents.

[0108] Furthermore, in an effort to provide a concise description of exemplary embodiments, all features of an actual implementation can not be described (that is, those unrelated to the best mode of practicing the application currently being considered, or those unrelated to enabling the claimed application).

[0109] It is to be understood that in the development of any actual implementation, numerous implementation-specific decisions can be made. These implementation-specific decisions can include specific implementation techniques, equipment, materials, and the like within the scope of the claims. Such implementation-specific decisions can, in some embodiments, further depart from the disclosed implementation. Such departures are deemed to be within the scope of the application.

[0110] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A sandwich symmetric silver mesh film, characterized by: The application relates to a light-transmitting layer (100), a first shielding layer (200) arranged on one side of the light-transmitting layer (100) and a second shielding layer (300) arranged on the other side of the light-transmitting layer (100), wherein the first shielding layer (200) and the second shielding layer (300) have the same structure. The first shielding layer (200) and the second shielding layer (300) are symmetrical relative to the light-transmitting layer (100).

2. The sandwich symmetric silver mesh film according to claim 1, wherein: The light-transmitting layer (100) is a polyethylene terephthalate film.

3. The sandwich symmetric silver mesh film according to claim 1 or 2, characterized in that: The thickness of the light-transmitting layer (100) is 50-250 microns.

4. The sandwich symmetric silver mesh film according to claim 3, wherein: The first shielding layer (200) comprises a first shielding film (201) and a second shielding film (202) stacked in sequence, the geometric shape of the first shielding film (201) is composed of a single continuous line and arranged in a serpentine shape along the weft direction, and the geometric shape of the second shielding film (202) is composed of a single continuous line and arranged in a serpentine shape along the warp direction.

5. The sandwich symmetric silver mesh film according to claim 4, wherein: The projection shape of the first shielding film (201) and the second shielding film (202) in the thickness direction is a mesh pattern in which the warp lines and the weft lines are interlaced with each other.

6. The sandwich symmetric silver mesh film according to claim 5, wherein: The mesh pattern has gaps (400) in the shape of rectangles between the lines.

7. The sandwich symmetric silver mesh film according to claim 6, wherein: The gaps (400) are squares with the side length of 100-600 microns.

8. The sandwich symmetric silver mesh film according to claim 7, wherein: The line width of the mesh pattern is 150 microns.

9. The sandwich symmetric silver mesh film according to claim 8, wherein: The material of the first shielding layer (200) and the second shielding layer (300) is silver ink.

10. The sandwich symmetric silver mesh film according to claim 8 or 9, characterized in that: ​

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