Shielding film and folding electronic equipment

Abstract

The invention relates to the technical field of electromagnetic shielding films, and discloses a shielding film and folding electronic equipment. The number of bending times of the shielding film is within a first preset range, the resistance change rate of the shielding film and the number of bending times of the shielding film meet the following function: y = Ax4-Bx3 + Cx2-Dx + E, y represents the resistance change rate of the shielding film, x represents the number of bending times of the shielding film, and A, B, C, D and E represent fitting coefficients of the function. The resistance change rate of the shielding film and the bending frequency of the shielding film meet the function y = Ax4-Bx3 + Cx2-Dx + E. The shielding film has good bending resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic shielding, in particular to a shielding film and a foldable electronic device. BACKGROUND

[0002] The electromagnetic shielding film can effectively prevent the harm of electromagnetic waves to the human body, shield the interference of electromagnetic radiation to the electronic device, ensure the normal work of the electronic device, and ensure that the electronic information is not leaked and stolen due to the blocking of the transmission of electromagnetic signals.

[0003] With the development of communication equipment, foldable electronic devices (such as foldable mobile phones) have emerged as the times require. The electromagnetic shielding film is pasted on the circuit board or soft board of the foldable electronic device, which not only realizes the folding of the foldable electronic device, but also avoids the electromagnetic interference from the outside and the foldable electronic device. After being folded for many times, the electromagnetic shielding film may fail. The higher the bending resistance of the electromagnetic shielding film is, the lower the probability of failure is. However, the bending resistance of the shielding film in the prior art is poor, which is difficult to meet the performance requirements of the foldable electronic device. Therefore, it is urgent to improve the bending resistance of the shielding film. SUMMARY

[0004] Therefore, the present application provides a shielding film and a foldable electronic device to solve the problems that the resistance rate of the shielding film is measured by a probe tester after the foldable electronic device is folded for many times in the related art, the probe tester is complex to operate and time-consuming.

[0005] In a first aspect, the present application provides a shielding film, which comprises:

[0006] The number of bending times of the shielding film is within a first preset range, and the resistance change rate of the shielding film and the number of bending times of the shielding film satisfy the following function: y=Ax 4 -Bx 3 +Cx 2 -Dx+E.

[0007] Wherein, y represents the resistance change rate of the shielding film, x represents the number of bending times of the shielding film, and A, B, C, D and E represent the fitting coefficients of the function.

[0008] In an optional embodiment, the number of bending times of the shielding film is within a second preset range, and the resistance change rate of the shielding film and the number of bending times of the shielding film satisfy the following function: y1=A1x 3 +B1x 2 +C1x+D1.

[0009] Wherein, y1 represents the resistance change rate of the shielding film, and A1, B1, C1 and D1 are the fitting coefficients of the function.

[0010] In one optional implementation, the first preset range is 300-2000, 3×10 -15 ≤A≤7×10 -14 6×10 -11 ≤B≤5×10 -10 9×10 -8 ≤C≤7×10 -7 -4×10 -5 ≤D≤7×10 -4 -0.7151≤E≤0.0526, 2%≤y≤90%.

[0011] In one optional implementation, the second preset range is 2000-4300, -2×10 -11 ≤A1≤3×10 -11 -4×10 -7 ≤B1≤-3×10 -7 , 0.001≤C1≤0.0015, -1.2453≤D1≤-0.3849, 50%≤y1≤95%.

[0012] In one optional embodiment, the shielding film includes a shielding layer, the material of which is one or more of aluminum, titanium, zinc, iron, nickel, tungsten, chromium, cobalt, copper, silver, gold, ferrite, and carbon nanotubes.

[0013] In one optional embodiment, the thickness of the shielding layer is greater than 0.5% of the thickness of the shielding film.

[0014] In one alternative implementation, it further includes:

[0015] Carrier layer;

[0016] A cover layer is located on one side surface of the carrier layer;

[0017] The shielding layer is located on the surface of the cover layer that is away from the carrier layer;

[0018] The adhesive layer is located on the side surface of the shielding layer opposite to the cover layer;

[0019] The shielding layer has at least one raised structure on the side of the shielding layer opposite to the cover layer, the raised structure being embedded in or penetrating the adhesive layer.

[0020] In one optional embodiment, the material of the cover layer includes polyimide, and the mass percentage of polyimide is 20%-80% of the cover layer.

[0021] In one optional embodiment, the thickness of the covering layer is 2μm-20μm.

[0022] In one optional embodiment, the thickness of the shielding film is 5μm-30μm, and the resistance of the shielding film is 10mΩ-1000mΩ.

[0023] In an optional embodiment, a protective film is also included, located on the side surface of the adhesive layer opposite to the shielding layer.

[0024] Secondly, the present invention also provides a foldable electronic device employing the shielding film of any embodiment of the first aspect.

[0025] The technical solution of the present invention has the following beneficial effects:

[0026] 1. After the shielding film is bent, its resistance changes. Therefore, the change in resistance is an important indicator of its bending performance. When the number of bends is within a first preset range, the rate of change in resistance and the number of bends satisfy the function y = Ax. 4 -Bx 3 +Cx 2 -Dx+E means that the shielding film can achieve the set bending performance so that the shielding film can meet the requirements of multiple folding of foldable electronic devices, while reducing the test cycle.

[0027] 2. When the number of bends of the shielding film is within the second preset range, the rate of change of resistance y1 of the shielding film and the number of bends x of the shielding film satisfy the relationship y1=A1x 3 +B1x 2 When +C1x+D1, the bending performance of the shielding film is greater than the set bending performance, that is, the shielding film has better bending performance.

[0028] 3. The material of the shielding layer in this invention is one or more of aluminum, titanium, zinc, iron, nickel, tungsten, chromium, cobalt, copper, silver, gold, ferrite, and carbon nanotubes, in order to improve the shielding effect of the shielding layer.

[0029] 4. By controlling the polyimide content of the cover layer to 20%-80%, the present invention improves the flexibility and high temperature resistance of the cover layer, thereby making the cover layer resistant to soldering and enhancing its protective function.

[0030] 5. The thickness of the cover layer of the present invention is 2μm-20μm, which can avoid solder erosion while having high temperature resistance, and avoid the phenomenon of discontinuity between the cover layer and the shielding layer after repeated bending.

[0031] 6. The thickness of the shielding film in this invention is 5μm-30μm. After the shielding film is applied to the circuit board or flexible board, the circuit board or flexible board can be bent 180°.

[0032] 7. The shielding film provided by the present invention has a raised structure in the shielding layer that is mainly used to pierce the adhesive layer and ground the shielding layer, thereby dissipating the charge accumulated in the adhesive layer and improving the shielding effect of the shielding film. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art 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 from these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of a shielding film according to an embodiment of the present invention;

[0035] Figure 2 This is a side cross-sectional view of a shielding film according to an embodiment of the present invention;

[0036] Figure 3 This is a side cross-sectional view of another shielding film according to an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Carrier layer; 2. Covering layer; 3. Shielding layer; 31. Raised structure; 4. Adhesive layer; 5. Protective layer. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the drawings, not all structures. In the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concept of the invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, and some details are enlarged for clarity, and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from actual practices due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. Additionally, if one layer / component is "above" another layer / component in one orientation, then when the orientation is reversed, that layer / component can be "below" that other layer / component.

[0040] In related technologies, after folding electronic devices are folded multiple times, the resistivity of the shielding film is measured using a probe tester. However, the probe tester is complex to operate, and the multiple folding of the folding electronic devices takes a long time.

[0041] like Figure 1 As shown, the present invention provides a shielding film, which includes, but is not limited to, a carrier layer 1, a covering layer 2, a shielding layer 3, and an adhesive layer 4.

[0042] In this embodiment, carrier layer 1 is selected as a PET (Polyethylene terephthalate) release carrier film. Of course, in other embodiments, other film materials can also be used as carriers. Optionally, the carrier film can be bisphenol A type epoxy resin, acrylic resin, polyester resin, etc. In addition, the resin used can also be any one or a mixture of at least two of epoxy resin, cyanate resin, polyphenylene ether resin, polybutadiene resin, styrene-butadiene resin, bismaleimide-triazine resin (BT), bismaleimide resin, polytetrafluoroethylene resin, polyimide resin, phenolic resin, acrylic resin, liquid crystal resin, benzoxazine resin, phenolic resin, nitrile rubber, carboxyl-terminated nitrile rubber, or hydroxyl-terminated nitrile rubber, but is not limited thereto; all resin materials disclosed in the prior art can be used. The mixture may be, for example, a mixture of epoxy resin and cyanate resin, a mixture of polyphenylene ether resin and polybutadiene resin, a mixture of styrene-butadiene resin and BT resin, a mixture of polytetrafluoroethylene resin and polyimide resin, a mixture of phenolic resin and acrylic resin, a mixture of epoxy resin, cyanate resin and polyphenylene ether resin, a mixture of polybutadiene resin, styrene-butadiene resin and BT resin, or a mixture of polytetrafluoroethylene resin, polyimide resin, phenolic resin and acrylic resin. That is, two or more resin mixtures may be used. The resins used in the cover layer 2 and the adhesive layer 4 include the resin material used in the carrier layer 1; that is, the resins used in the cover layer 2 and the adhesive layer 4 may be the same as those used in the carrier layer 1. The resins used in the carrier layer 1, cover layer 2, and adhesive layer 4 may be the same or different from each other.

[0043] It should be noted that the covering layer 2 can be insulating and can support the shielding layer 3; the covering layer 2 can also be a structure containing conductive particles, which has a certain conductive function and can improve the shielding effect together with the shielding.

[0044] In another embodiment, the shielding film may consist of only a shielding layer 3 and an adhesive layer 4, with the shielding layer 3 stacked on one side of the adhesive layer 4. The shielding film with the above structure also has a good shielding effect.

[0045] It should be noted that the carrier layer 1, cover layer 2, shielding layer 3, and adhesive layer 4 in the above embodiments can be single-layer or multi-layer structures. When it is a multi-layer structure, the materials used between the layers can be the same or different.

[0046] Covering layer 2 is located on one side surface of carrier layer 1, and shielding layer 3 is located on the side surface of covering layer 2 opposite to carrier layer 1. The number of bends of the shielding film is within a first preset range, and the rate of change of resistance of the shielding film satisfies the following function with respect to the number of bends: y = Ax 4 -Bx 3 +Cx 2 -Dx+E, where y represents the resistance change rate of the shielding film, x represents the number of bends of the shielding film, and A, B, C, D and E all represent the fitting coefficients of the function. The adhesive layer 4 is located on one side surface of the shielding layer 3 and the proportional coverage layer 2.

[0047] like Figure 1 As shown, the PET release carrier film in the shielding film is placed at the bottom, the cover layer 2 is attached to the upper surface of the PET release carrier film, the shielding layer 3 is attached to the upper surface of the cover layer 2, and the adhesive layer 4 is attached to the upper surface of the shielding layer 3.

[0048] It should be noted that the rate of change of resistance of the shielding film can be calculated using the formula q, q = ((R b -R a ) / R a 100%, of which R b R is the resistance value of the shielding layer after multiple bends. a The original resistance value of the shielding layer before it was bent multiple times.

[0049] The shielding film provided by this invention has a number of bends within a first preset range, and the rate of change of resistance y of the shielding film satisfies the following function with respect to the number of bends x: y = Ax 4 -Bx 3 +Cx 2 The -Dx+E shielding film achieves the set bending performance, enabling it to meet the requirements of multiple folding cycles in foldable electronic devices. Since the first range is 300-2000 cycles, far less than the number of bends required for shielding film failure, the number of bends is reduced, thus shortening the testing cycle.

[0050] In some optional embodiments, the number of bends of the shielding film is within a second preset range, and the rate of change of resistance of the shielding film satisfies the following function with respect to the number of bends: y1=A1x 3 +B1x 2+C1x+D1, where y1 represents the rate of change of resistance of the shielding film, and A1, B1, C1, and D1 are the fitting coefficients of the function. When the rate of change of resistance y1 of the shielding film and the number of bends X of the shielding film satisfy the above relationship, the shielding film has better bending performance.

[0051] It should be noted that the first preset range is 300-2000, 3×10 -15 ≤A≤7×10 -14 6×10 -11 ≤B≤5×10 -10 9×10 -8 ≤C≤7×10 -7 -4×10 -5 ≤D≤7×10 -4 -0.7151≤E≤0.0526, 2%≤y≤90%; Shielding films within the above preset parameter range exhibit good bending resistance, meeting the application requirements of shielding films. Optionally, A can be selected as 3×10 -15 4×10 -15 5×10 -15 6×10 -15 7×10 -15 1×10 -14 2×10 -14 4×10 -14 5×10 -14 6×10 -14 7×10 -14 B can be 6×10 -11 7×10 -11 8×10 -11 9×10 -11 1×10 -10 2×10 -10 3×10 -10 4×10 -10 5×10 -10 C can be selected as 9×10 -8 1×10 -7 2×10 -7 3×10 -7 4×10 -7 5×10 -7 6×10 -7 7×10 -7 D can be selected as -4×10 -5 -3×10 -5 -1×10 -5 -4×10 -4 -4×10 -3 -4×10 -2 -4×10-1 7×10 -4 8×10 -4 9×10 -4 9×10 -3 5×10 -3 6×10 -2 3×10 -1 E can be selected as -0.7151, -0.7100, -0.6190, -0.5155, -0.4189, -0.1478, 0.0526, 0.0316, 0.0225, 0.0526; y can be selected as 2%, 8%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc., and the above fitting coefficients A, B, C, D, E and y can be any interval composed of any two of the above data.

[0052] It should be noted that the second preset range is 2000-4300, -2×10 -11 ≤A1≤3×10 -11 -4×10 -7 ≤B1≤-3×10 -7 0.001≤C1≤0.0015, -1.2453≤D1≤-0.3849, 50%≤y1≤95%. Shielding films meeting the above second preset range exhibit better technical effects and can significantly improve the bending resistance of the shielding film. A1 can be selected as -2×10. -11 -1×10 -11 -9×10 -12 1×10 -11 2×10 -11 3×10 -11 4×10 -12 5×10 -13 B1 can be selected as -4×10 -7 -3×10 -7 -4.5×10 -7 C can be selected as 0.001, 0.0012, 0.0013, 0.0014, or 0.0015; D1 can be selected as -1.2453, -1.0145, -0.9824, -0.7642, -0.6145, -0.5791, -0.4681, or -0.3849; y1 can be selected as 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%, etc. The fitting coefficients A1, B1, C1, D1, and y1 can be any interval composed of any two of the above data.

[0053] The first and second preset ranges provided by this invention cover the number of bends from 300 to 4300. By using the relationship between the resistance change rate of the shielding film and the number of bends, a shielding film with high bend resistance can be quickly prepared. Some shielding films that satisfy the above relationship can even have a bend count of more than 16,000.

[0054] In some alternative implementations, such as Figure 1 As shown, the shielding layer 3 has several protruding structures 31 on the surface opposite to the covering layer 2. These protruding structures 31 are spike-shaped; alternatively, they can also be frustum-shaped. The adhesive layer 4 is connected to the pad wire, which is grounded. Figure 2 As shown, some of the protruding structures 31 are embedded in the adhesive layer 4. As an alternative implementation, such as... Figure 3 As shown, some of the protruding structures 31 can also penetrate the adhesive layer 4; thereby achieving grounding of the shielding layer 3, so that the shielding layer 3 can conduct the accumulated charge, thereby improving the shielding effect of the shielding film.

[0055] In an alternative embodiment, the shielding layer 3 has one or more protrusions 31 on the side surface opposite to the cover layer 2.

[0056] In some optional embodiments, the material of the shielding layer 3 is made of one of titanium, zinc, iron, nickel, tungsten, chromium, cobalt, copper, silver, gold, ferrite, and carbon nanotubes. Alternatively, the shielding layer 3 is an alloy formed from at least two of aluminum, titanium, zinc, iron, nickel, tungsten, chromium, cobalt, copper, silver, gold, ferrite, and carbon nanotubes. This embodiment is not specifically limited here and is determined according to the actual product design requirements.

[0057] Specifically, in this embodiment, the shielding layer 3 is made of copper, which is low in cost and can ensure the passage of the grounding channel and the shielding effect, thereby improving the overall shielding effect of the electromagnetic shielding film. This also improves the bending resistance of the shielding layer 3.

[0058] In some optional embodiments, the thickness of the shielding layer 3 is greater than 0.5% of the thickness of the shielding film, that is, the minimum thickness of the shielding layer 3 is 0.02 μm. The thickness of the shielding layer 3 can be set according to specific requirements, which will not be elaborated further here.

[0059] In some optional embodiments, the material of the cover layer 2 is polyimide, and the mass percentage of polyimide in the cover layer 2 is 20%-80%, for example 20%, 30%, 55%, 79%, and 80%. When the mass percentage of polyimide in the cover layer 2 is greater than 80%, the cover layer 2 becomes rigid. After repeated bending, a break occurs between the cover layer 2 and the shielding layer 3, reducing the bending resistance of the shielding film. When the polyimide content in the cover layer 2 is less than 20%, the high-temperature resistance of the cover layer 2 decreases. When the shielding film is attached to the surface of folded electronic devices or flexible circuit boards, the cover layer 2 is easily burned by the high temperature of solder, causing the shielding film to fail, resulting in discoloration and failure of the circuit board or flexible circuit board. In this embodiment, the mass percentage of polyimide in the cover layer 2 is controlled between 20% and 80%, which improves the bending flexibility of the cover layer 2 while also improving its high-temperature resistance, making the cover layer 2 solder-resistant and thus enhancing its protective function.

[0060] In some optional embodiments, the thickness of the cover layer 2 is between 2μm and 20μm, for example, 2μm, 3μm, 5μm, 10μm, 19μm, and 20μm. When the thickness of the cover layer 2 is less than 2μm, its high-temperature resistance decreases, and solder erosion occurs, directly leading to shielding effectiveness failure or damage. When the thickness of the cover layer 2 is greater than 20μm, after repeated bending of the shielding film, a discontinuity occurs between the cover layer 2 and the shielding layer 3. In addition, the thickness of the cover layer 2 leads to an overly thick and tall overall structure of the shielding film, which is not conducive to the 180° bending of folding circuit boards or flexible circuit boards.

[0061] In some optional embodiments, the thickness of the shielding film is 5μm-30μm, such as 5μm, 6μm, 10μm, 20μm, 23μm, 30μm, and the resistance value of the shielding film is 10mΩ-1000mΩ.

[0062] In some alternative embodiments, a protective film is also included on the surface of the adhesive layer 4 facing away from the shielding layer 3.

[0063] Secondly, this embodiment also includes a foldable electronic device, which includes the shielding film in any embodiment.

[0064] In this solution, when the shielding film conforms to the formula within the first preset range, the shielding film has good bending resistance; when the shielding film conforms to the formula within the second preset range, the shielding film has even better bending resistance. To better illustrate the technical effects of this invention, samples that partially conform to the formula within the first preset range, the formula within the second preset range, and samples that do not conform to the above formulas were subjected to a full-cycle bending test, and the grounding effect after bending was tested.

[0065] Example 1

[0066] A shielding film is provided, comprising a carrier layer 1, a cover layer 2, a shielding layer 3, and an adhesive layer 4, wherein the cover layer 2 is located on one side surface of the carrier layer 1, and the shielding layer 3 is located on the side surface of the cover layer 2 opposite to the carrier layer 1.

[0067] Adhesive layer 4 is located on one side of the surface of the carrier layer 1, separate from the cover layer 2; the resistance change rate and bending number of the shielding film satisfy y = 7E - 14x 4 -4E-10x 3 +7E-07x 2 -4E-05x-0.0173.

[0068] The above samples were tested, and the test results showed that the shielding film could withstand more than 2,800 flexural cycles.

[0069] Example 2

[0070] A shielding film is provided, comprising a carrier layer 1, a cover layer 2, a shielding layer 3, and an adhesive layer 4, wherein the cover layer 2 is located on one side surface of the carrier layer 1, and the shielding layer 3 is located on the side surface of the cover layer 2 opposite to the carrier layer 1.

[0071] Adhesive layer 4 is located on one side of the surface of the carrier layer 1, separate from the cover layer 2; the resistance change rate and the number of bends of the shielding film satisfy y1 = 3E-11x 3 -4E-07x 2 +0.0015x-1.2453.

[0072] The above samples were tested, and the test results showed that the shielding film could withstand more than 4,500 flexural cycles.

[0073] Comparative Example 1

[0074] In this embodiment, all conditions are met except for the formulas within the first and second preset ranges.

[0075] The above samples were tested, and the test results showed that the shielding film's bending resistance reached 1073 cycles, indicating very poor bending resistance, which cannot meet the application requirements for high bending resistance of shielding films. However, the shielding film that satisfies the functional relationship of this application has superior bending resistance compared to conventional shielding films, with bending resistance reaching over 2800 cycles, and even exceeding 16000 cycles.

[0076] In this invention, the bending test method is as follows: the shielding film sample is pressed with a 25-micron-thick polyimide film (pressing conditions: pre-pressing time 10 seconds, forming time 180 seconds, the mass of the weight providing forming pressure is 120 kg, pressing temperature 185℃); after pressing, it is baked and cured (baking temperature 160℃, baking time is 90 minutes). The width of the pressed shielding film is 1.5 cm and the length is 15 cm. The bending conditions are: R angle 0.38 mm, speed 150 rpm, angle ±135°, and the mass of the weight providing bending is 500 g.

[0077] In addition, when using the above bending test method, when comparing the bending resistance of different shielding films, the test is usually stopped and the number of bends is recorded when the conduction resistance of the shielding film is greater than 50% of the initial value before bending (the specific value can be set as needed).

[0078] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0079] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0080] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0081] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0082] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0083] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A shielding film, characterized by, Comprising: The number of bending times of the shielding film is within a first preset range, and the shielding film resistance change rate and the number of bending times of the shielding film satisfy the following function: y = Ax 4 -Bx 3 +Cx 2 -Dx+E; wherein y represents a resistance change rate of the shielding film, x represents a number of times of bending of the shielding film, A, B, C, D, and E each represent a fitting coefficient of a function, the first predetermined range is 300-2000 times, 3x10 -15 ≤ A ≤ 7x10 -14 , 6x10 -11 ≤ B ≤ 5x10 -10 , 9x10 -8 ≤ C ≤ 7x10 -7 , -4x10 -5 ≤ D ≤ 7x10 -4 , and -0.7151 ≤ E ≤ 0.0526.

2. The shield film according to claim 1, characterized by, The number of bending times of the shielding film is within a second preset range, and the resistance change rate of the shielding film and the number of bending times of the shielding film satisfy the following function: y1=A1x 3 +B1x 2 +C1x+D1; wherein y1 represents a resistance change rate of the shielding film, A1, B1, C1, and D1 are fitting coefficients of a function, the second predetermined range is 2000-4300 times, -2x10 -11 ≤ A1 ≤ 3x10 -11 , -4x10 -7 ≤ B1 ≤ -3x10 -7 , 0.001 ≤ C1 ≤ 0.0015, -1.2453 ≤ D1 ≤ -0.3849.

3. The shield film according to any one of claims 1-2, wherein, The shielding film comprises a shielding layer (3), the material of the shielding layer (3) is one or more of aluminum, titanium, zinc, iron, nickel, tungsten, chromium, cobalt, copper, silver, gold, ferrite, carbon nanotube.

4. The shield film according to claim 3, characterized by, The thickness of the shielding layer (3) is greater than 0.5% of the thickness of the shielding film.

5. The shielded film of claim 4, wherein, Also comprising: A carrier layer (1); A cover layer (2) located on one side surface of the carrier layer (1); The shielding layer (3) is located on the side surface of the cover layer (2) away from the carrier layer (1); The adhesive layer (4) is located on the side surface of the shielding layer (3) away from the cover layer (2); At least one protruding structure (31) is located on the side surface of the shielding layer (3) away from the cover layer (2), and the protruding structure (31) is embedded or penetrated into the adhesive layer (4).

6. The shielded film of claim 5, wherein, The material of the cover layer (2) comprises polyimide, and the mass fraction of polyimide accounts for 20%-80% of the mass of the cover layer (2).

7. The shielded film of claim 5, wherein, The thickness of the cover layer (2) is 2-20μm.

8. The shielded film of claim 5, wherein, The thickness of the shielding film is 5-30μm, and the resistance value of the shielding film is 10-1000mΩ.

9. The shielded film of claim 5, wherein, Also comprising a protective film located on the side surface of the adhesive layer (4) away from the shielding layer (3).

10. A foldable electronic device, characterized by Adopt the shielding film according to any one of claims 1-9.

Images