A safety transfer plate

Abstract

The application discloses a security transfer plate, which comprises a substrate and a microstructure array formed on one side surface of the substrate, and the microstructure array comprises a plurality of microstructures; each microstructure comprises at least two optical surfaces which are not coplanar; in one microstructure, the vertical distances of the at least two optical surfaces to the plane of the substrate are different, or there is an included angle between the at least two optical surfaces; in one microstructure, each optical surface is used for reflecting or refracting compound light into a plurality of monochromatic lights, so that the plurality of monochromatic lights corresponding to the plurality of optical surfaces form controllable rainbow color lights through interference or diffraction. The security transfer plate disclosed by the application can realize good rainbow color effect through the interference and diffraction principles of the microstructure itself, and has simple processing technology and low cost.

Description

Technical Field

[0001] This application relates to the field of anti-counterfeiting technology, and in particular to a security transfer plate. Background Technology

[0002] With the development of science and technology, various security and anti-counterfeiting documents, such as identity cards and entry / exit documents, have increasingly higher requirements for anti-counterfeiting technology, and at the same time, they also place higher demands on the efficiency of verification. Level 1 security and anti-counterfeiting elements (also known as visual authentication elements) are essential for the protection of security and anti-counterfeiting documents, and higher requirements are placed on their technical complexity, ease of processing and processing costs, verification capabilities, and anti-copying properties.

[0003] Laminated patterns refer to special textures formed on the surface of security and anti-counterfeiting documents, either locally or entirely. These textures can have various effects, such as glossy, matte, dynamic, latent, tactile, floating, or special mesh patterns. They are a new type of easily identifiable high-security anti-counterfeiting element on security documents and product anti-counterfeiting labels, and can be used as security elements. Laminated pattern technology has advantages such as being colorless and inkless, easy to verify, environmentally friendly, and multifunctional.

[0004] Current similar technologies and products suffer from several drawbacks, including indistinct rainbow effects in anti-counterfeiting elements, shallow microstructures (lacking wear resistance and oil resistance), complex manufacturing processes, high costs, and difficulty in fabrication on large-size products. These technologies often require additional foil materials to complement the microstructure, leading to various potential risks in application. Therefore, there is an urgent need for an anti-counterfeiting technology that enhances the rainbow effect of anti-counterfeiting elements. Utility Model Content

[0005] This application discloses a security transfer plate that can achieve a good rainbow effect by using the interference and diffraction principle of light by the microstructure itself. The processing technology is simple and the cost is low.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] This application provides a security transfer plate, including a substrate and a microstructure array formed on one side surface of the substrate, the microstructure array including a plurality of microstructures;

[0008] Each of the microstructures includes at least two non-coplanar optical surfaces. In one microstructure, at least two of the optical surfaces are at different perpendicular distances from the plane where the substrate is located, or at least two of the optical surfaces are at an angle to each other.

[0009] In one of the microstructures, each of the optical surfaces is used to reflect or refract composite light into multiple monochromatic lights, so that the multiple monochromatic lights corresponding to the multiple optical surfaces are interfered or diffracted to form controllable rainbow light.

[0010] The aforementioned security transfer plate includes a substrate, on one side of which a microstructure array is formed. The microstructure array includes multiple microstructures, each comprising multiple non-coplanar optical surfaces. For example, in one microstructure, the multiple non-coplanar optical surfaces are positioned at different perpendicular distances from the plane of the substrate. Alternatively, the multiple non-coplanar optical surfaces may be positioned such that any two optical surfaces have an included angle. Through the beam-splitting effect of the multiple microstructure optical surfaces in the microstructure array on the composite light, the composite light is reflected or refracted into multiple monochromatic lights. Since the optical surfaces are non-coplanar, the monochromatic lights formed by different optical surfaces have optical path differences, resulting in light interference or diffraction. These monochromatic lights undergo coherent constructive or destructive processes, thus producing iridescent light biased towards a certain color. In practical applications, the size and period of the microstructures can be controlled to obtain controllable iridescent light. The security transfer plate of this application achieves a good iridescent effect through the interference and diffraction principles of the microstructures themselves, with a simple processing technology and low cost.

[0011] In some embodiments, a plurality of the microstructures are arranged along a first direction, each of the microstructures extends along a second direction, and each of the microstructures is a groove or a protrusion;

[0012] Each of the microstructures has a dimension greater than 10 μm along the second direction, and each of the microstructures has a dimension of 5 μm-50 μm along the first direction. The depth dimension of the groove or the height dimension of the protrusion is 0.3 μm-5 μm.

[0013] In some embodiments, a plurality of the microstructures are arranged in an array along a first direction and a second direction, and the plurality of the microstructures are non-connected grooves or protrusions;

[0014] The microstructure has a dimension of 5μm-50μm along the first direction, the depth dimension of the groove or the height dimension of the protrusion has a dimension of 0.3μm-5μm, and the distance between any two adjacent microstructures along the second direction is less than 100μm.

[0015] In some embodiments, the spacing between any two adjacent microstructures along the first direction is 5 μm-50 μm.

[0016] In some embodiments, the microstructure has a dimension greater than 10 μm in the direction perpendicular to the first surface, wherein the first surface is a plane defined by the first direction and the second direction.

[0017] In some embodiments, the cross-sectional shape of the microstructure perpendicular to the first plane includes at least one of a rectangle, trapezoid, U-shape, V-shape, and arc shape.

[0018] In some embodiments, the substrate includes a plurality of microstructure arrays, each of which has a different cross-sectional shape of its microstructures on the first surface.

[0019] In some embodiments, the projections of the plurality of microstructure arrays onto the substrate overlap.

[0020] In some embodiments, the microstructures of the plurality of microstructure arrays extend in different directions.

[0021] In some embodiments, the thickness of the substrate is greater than 0.4 mm. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a security transfer plate provided in an embodiment of this application;

[0023] Figure 2 A schematic diagram of the optical path of a security transfer plate provided in an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of another security transfer plate provided in an embodiment of this application;

[0025] Figure 4 This is a schematic diagram of a microstructure array provided in an embodiment of this application;

[0026] Figure 5 This is a schematic diagram of another microstructure array provided in an embodiment of this application;

[0027] Figure 6 This is a schematic diagram of another microstructure array provided in the embodiments of this application;

[0028] Figure 7 This is a schematic diagram of another microstructure array provided in the embodiments of this application;

[0029] Figure 8 This is a schematic diagram of a combination of multiple microstructure arrays provided in an embodiment of this application;

[0030] Figure 9 This is a schematic diagram of another combination of multiple microstructure arrays provided in an embodiment of this application;

[0031] Figure 10 This is a schematic diagram of another combination of multiple microstructure arrays provided in an embodiment of this application;

[0032] Figure 11 This is a schematic diagram of another microstructure array provided in the embodiments of this application;

[0033] Icons: 1. Substrate; 11. First surface; 2. Microstructure array; 21. Microstructure; A. First optical surface; B. Second optical surface; C. Third optical surface; D. Fourth optical surface; E. Fifth optical surface. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application. In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone.

[0035] The terms "first" and "second" are used for descriptive purposes only and should not be construed as implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0036] like Figures 1-11 As shown, this application provides a security transfer plate, including a substrate 1 and a microstructure array 2 formed on one side surface of the substrate 1, the microstructure array 2 including a plurality of microstructures 21;

[0037] Each microstructure 21 includes at least two non-coplanar optical surfaces. In a microstructure 21, there are at least two optical surfaces that are at different vertical distances from the plane on which the substrate 1 is located, or there is an included angle between at least two optical surfaces.

[0038] In a microstructure 21, each optical surface is used to reflect or refract composite light into multiple monochromatic lights, so that the multiple monochromatic lights corresponding to multiple optical surfaces can form controllable rainbow light through interference or diffraction.

[0039] The aforementioned security transfer plate includes a substrate 1, on one side surface of which a microstructure array 2 is formed. The microstructure array 2 includes multiple microstructures 21, each microstructure 21 comprising at least two non-coplanar optical surfaces. For example, in a microstructure 21, at least two optical surfaces have different perpendicular distances from the plane of the substrate 1. Alternatively, at least two optical surfaces may have an angle between any two of them. Through the beam splitting effect of the multiple microstructures 21 in the microstructure array 2 on composite light (such as natural light), the composite light is reflected or refracted into various monochromatic lights. Since the optical surfaces are non-coplanar, the monochromatic lights formed by different optical surfaces have optical path differences, resulting in light interference or diffraction. These monochromatic lights undergo coherent constructive or destructive interactions, thus producing rainbow-colored light biased towards a certain color; that is, the dominant hue of the rainbow-colored light is controllable. In practical applications, the size and period of the microstructures can also be adjusted to obtain controllable rainbow-colored light. The security transfer plate of this application can achieve a good rainbow effect through the interference and diffraction of light by the microstructure itself. The preparation method is simple and controllable, the cost is controllable, and it is easier to prepare on large-size products.

[0040] One possible way to achieve this is, such as Figure 1 and Figure 2 As shown, each microstructure 21 includes five optical surfaces: a first optical surface A, a second optical surface B, a third optical surface C, a fourth optical surface D, and a fifth optical surface E. The first optical surface A is not coplanar with the second, third, and fourth optical surfaces C, and the fifth optical surface E is also not coplanar with the second, third, and fourth optical surfaces D. For example, when composite light a irradiates the first and third optical surfaces A and C, it forms multiple monochromatic lights, such as monochromatic light b, monochromatic light c, and monochromatic light d. Due to the different perpendicular distances between the two surfaces and the first surface 11 of the substrate 1, an optical path difference is generated between the multiple monochromatic lights formed by the first and third optical surfaces A and C, resulting in light interference and diffraction. These monochromatic lights, through coherent constructive or coherent destructive processes, ultimately produce a rainbow of colors.

[0041] Another possible way to achieve this is, such as Figure 3 As shown, each microstructure 21 includes four optical surfaces: a first optical surface A, a second optical surface B, a third optical surface C, and a fourth optical surface D. No two of these four optical surfaces are coplanar. Similarly, when composite light illuminates the four optical surfaces, it forms multiple monochromatic lights. Since there is a certain angle between any two optical surfaces, optical path differences will occur between the multiple monochromatic lights formed by the multiple optical surfaces, resulting in light interference and diffraction. These monochromatic lights, through coherent constructive or destructive interactions, ultimately produce a certain color of rainbow light.

[0042] It should be noted that the security transfer plate of this application can be directly applied to anti-counterfeiting documents, anti-counterfeiting labels, and other products or in the transfer process, and can also be used directly as an anti-counterfeiting element without the need for additional films, coatings, inks, etc. In practical applications, the surface shape of the side of the security transfer plate with the microstructure array 2 should be adapted to the surface shape of the anti-counterfeiting element to be printed onto the security element, so as to ensure that the microstructure array 2 on the security transfer plate is printed onto the anti-counterfeiting element with high precision. That is to say, the microstructure array 2 can be processed and prepared on a smooth surface of arbitrary curvature, increasing the observation angle.

[0043] The security transfer plate may have microstructures 21 that are periodically distributed in at least one direction.

[0044] In some embodiments, a plurality of microstructures 21 are arranged along a first direction, each microstructure 21 extends along a second direction, and each microstructure 21 is a groove or a protrusion; the dimension of each microstructure 21 along the second direction is greater than 10 μm, the dimension of each microstructure 21 along the first direction is 5 μm-50 μm, and the depth dimension of the groove or the height dimension of the protrusion is 0.3 μm-5 μm.

[0045] One possible way to achieve this is, such as Figure 4 As shown, the microstructure array 2 can be a rectangular array. The microstructure array 2 includes multiple microstructures 21 arranged continuously along a first direction, and each microstructure 21 extends along a second direction, i.e., the second direction is the length direction of the microstructure 21. The first direction refers to... Figure 4 The middle direction is from left to right or from right to left; the second direction refers to... Figure 4The direction is from bottom to top or from top to bottom. That is, the security transfer plate of this embodiment can have microstructures 21 periodically distributed in one direction. Each microstructure 21 can be a groove concave to the substrate surface or a protrusion convex to the substrate surface, and the groove or protrusion is continuous in a second direction. The length L of the microstructure 21 is greater than 10 μm, for example 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, etc., preferably 14 μm or more, and the length dimensions of multiple microstructures 21 are the same or nearly the same. The dimension of each microstructure 21 along the first direction, i.e. the width w of the groove or protrusion, is 5μm-50μm, for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 30μm, 40μm, 50μm, etc., preferably 10μm-20μm. The depth h of the groove or the height h of the protrusion is 0.3μm-5μm, for example, 0.3μm, 0.32μm, 0.35μm, 0.37μm, 0.4μm, 0.43μm, 0.45μm, 0.48μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 2μm, 3μm, 4μm, 5μm, etc., preferably 0.8μm-1.8μm. Controllable iridescent light can be obtained by adjusting the length L, width w, depth, or height h of the microstructure 21.

[0046] Another possible way to achieve this is, such as Figure 5 As shown, the microstructure array 2 can also be a concentric ring array. The microstructure array 2 includes multiple microstructures 21 arranged continuously along a first direction, and each microstructure 21 forms a closed ring along a second direction. The first direction refers to... Figure 5 The middle direction is from the center of the circle to the circumference, and the second direction refers to... Figure 5 The rotation direction is either clockwise or counterclockwise. Each microstructure 21 includes a groove or a protrusion, the dimensions of which meet the above requirements and will not be described in detail here.

[0047] In some embodiments, a plurality of microstructures 21 are arranged in an array along a first direction and a second direction, and the plurality of microstructures 21 are non-connected grooves or protrusions; the size of the microstructure 21 along the first direction is 5μm-50μm, the depth dimension of the groove or the height dimension of the protrusion is 0.3μm-5μm, and the distance between any two adjacent microstructures 21 along the second direction is less than 100μm.

[0048] One possible way to achieve this is, such as Figure 6As shown, the microstructure array 2 can be a rectangular array, comprising multiple microstructures 21 arranged in an array along a first direction and a second direction, each microstructure 21 being square. The first direction refers to... Figure 6 The middle direction is from left to right or from right to left; the second direction refers to... Figure 6 The direction is from bottom to top or from top to bottom. That is, the security transfer plate of this embodiment can have microstructures 21 periodically distributed in two directions. Each microstructure 21 can be a groove concave to the substrate surface or a protrusion convex to the substrate surface, and the groove or protrusion is not connected in the first and second directions. The dimension of each microstructure 21 along the first direction, that is, the width w of the groove or protrusion, is 5μm-50μm, for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 30μm, 40μm, 50μm, etc., preferably 10μm-20μm. The depth h of the groove or the height h of the protrusion is 0.3μm-5μm, for example, 0.3μm, 0.32μm, 0.35μm, 0.37μm, 0.4μm, 0.43μm, 0.45μm, 0.48μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 2μm, 3μm, 4μm, 5μm, etc., preferably 0.8μm-1.8μm. The distance d between any two adjacent microstructures 21 along the second direction is less than 100μm, for example, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc. By adjusting the length, width, depth, or height of the microstructure 21, controllable iridescent light can be obtained.

[0049] Another possible way to achieve this is, such as Figure 7 As shown, the microstructure array 2 can also be a concentric ring array. The microstructure array 2 includes multiple microstructure groups 22 arranged along a first direction. Each microstructure group 22 includes multiple microstructures 21, each microstructure 21 being circular. The multiple microstructures 21 are arranged along a second direction, presenting a ring-like structural outline. The first direction refers to... Figure 5 The middle direction is from the center of the circle to the circumference, and the second direction refers to... Figure 5 The rotation direction is either clockwise or counterclockwise. Each microstructure 21 includes a groove or a protrusion, the dimensions of which meet the above requirements and will not be described in detail here.

[0050] Another possible way to achieve this is, such as Figure 11 As shown, the grooves or protrusions in the second direction can include both connected and non-connected structures. Through precise design of the microstructure 21, more diverse arrangements of the microstructure 21 can be achieved.

[0051] In some embodiments, such as Figure 4 As shown in Figure 6, the spacing n between any two adjacent microstructures 21 along the first direction is 5μm-50μm. For example, values ​​such as 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 30μm, 40μm, and 50μm are preferred, with 10μm-20μm being ideal. Adjusting the period of the microstructures 21 along the first direction further facilitates the acquisition of controllable iridescent light.

[0052] This application utilizes a controllably designed microstructure array 2. By adjusting the length, width, depth, or height of the microstructures 21, as well as their period, orientation, and arrangement, a specific structure can be obtained, ultimately producing rainbow-colored images through grating diffraction. In application, by strategically arranging the microstructure array 2, animated images of white light, rainbow light, or combinations of multiple rainbow colors can be obtained. The color of the product image and the speed of the animation are all controllable. The size of the microstructures 21 is not nanometer-scale but micrometer-scale, making them relatively easier to fabricate and the manufacturing process simpler and more controllable. Besides the aforementioned structure of the microstructures 21, the microstructures 21 can also be points, lines, segments, or combinations of these three; the specific structure is not limited.

[0053] In some embodiments, the microstructure 21 has a dimension greater than 10 μm in the direction perpendicular to the first surface, wherein the first surface is a plane defined by a first direction and a second direction. Figure 4 As shown in Figure 6, the depth or height h of the microstructure 21 is greater than 10 μm, for example, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, etc., preferably 12 μm or greater. By making the depth or height h of the microstructure 21 larger, the tactile characteristics of the microstructure 21 can be achieved, which is beneficial to improving the anti-counterfeiting level, further increasing the wear resistance and stain-resistant filling performance of the microstructure array 2, and extending the service life of the product. It should be noted that the graphics and text that achieve the tactile effect can be set around the microstructure array of the product or inside the microstructure array, and the specific location is not limited. There are no requirements for the structure of the graphics and text that achieve the tactile effect. As long as it does not affect the effect of the microstructure array 2, it can be any groove shape, thickness, depth, length, and three-dimensional morphology.

[0054] In some embodiments, the cross-sectional shape of the microstructure 21 perpendicular to the first surface includes at least one of a rectangle, trapezoid, U-shape, V-shape, and arc shape, and may also be a shape similar to a rectangle, trapezoid, U-shape, V-shape, and arc shape. It should be noted that the cross-sectional shape can be regular or irregular, preferably a shape formed by connecting straight lines, such as a rectangle and trapezoid, etc. The surface of the microstructure 21 is required to be smooth and free of obvious burrs to avoid affecting the anti-counterfeiting effect.

[0055] It is understood that the microstructure 21 can have various shapes and structures, such as cylinders, triangular prisms, and square prisms. Each microstructure 21 has the same cross-sectional shape perpendicular to the first surface and has a consistent height or depth. In actual processing, variations in the microstructure dimensions due to process errors are permissible.

[0056] In some embodiments, the substrate 1 includes multiple microstructure arrays 2, each of which has a different cross-sectional shape of microstructure 21 perpendicular to the first surface. That is, the substrate 1 of the security transfer plate may include multiple different microstructure arrays 2 to divide the substrate 1 into multiple regions, with the microstructure arrays 2 within different regions differing in period, shape, or orientation. For example, one microstructure array 2 may have a rectangular cross-sectional shape of microstructure 21 perpendicular to the first surface, while another microstructure array 2 may have a V-shaped cross-sectional shape. By setting multiple microstructure arrays 2 and adjusting the different cross-sectional shapes of the microstructures 21, multiple rainbow colors can appear simultaneously, which is beneficial for further improving the anti-counterfeiting level. By adjusting the relative positions of the multiple microstructure arrays 2, controllable animated images can be achieved when applied to a product, integrating rainbow colors and animation effects. By directionally arranging the microstructures 21, various obvious dynamic effects can be achieved.

[0057] In some embodiments, the projections of the plurality of microstructure arrays 2 onto the substrate 1 overlap.

[0058] One possible way to achieve this is, such as Figure 8 and Figure 9 As shown, two types of microstructure arrays 2 can be set on the substrate 1. One microstructure array 2 is represented by a solid line, and the other microstructure array 2 is represented by a dashed line. The two microstructure arrays 2 overlap when set, which further increases the structural features of the security transfer plate and helps to improve the anti-counterfeiting level.

[0059] In some embodiments, the microstructures 21 of the plurality of microstructure arrays 2 extend in different directions.

[0060] One possible way to achieve this is, such as Figure 10As shown, two types of microstructure arrays 2 can be set on the substrate 1. One microstructure array 2 is represented by a solid line, and the other microstructure array 2 is represented by a dashed line. The two microstructure arrays 2 overlap when set and have a certain included angle.

[0061] In some embodiments, the thickness of substrate 1 is greater than 0.4 mm. For example, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc., and the size is not specifically limited. Substrate 1 is usually a mirror-finished plate, sheet, or film material, and can be at least one of various types of metal plates such as stainless steel, nickel, chromium, aluminum, and copper plates, or at least one of polymer plates such as polyester (PC, PET, TPU), PVC, and PTFE. It is preferably a rigid material such as stainless steel plate, and the length and width are not specifically limited.

[0062] It should be further noted that the microstructure 21 in the embodiments of this application can be prepared by wet etching (coating → exposure → development → etching, laser direct writing to create a mask → etching), dry etching (electron beam etching, ion beam etching, plasma etching and its auxiliary and enhancement processes), laser direct writing (ultraviolet nanosecond laser, ultraviolet picosecond laser, ultraviolet femtosecond laser, infrared nanosecond laser, infrared picosecond laser, infrared femtosecond laser, etc.), and growth processes (electroplating growth, PVD, ALD and its auxiliary and enhancement processes).

[0063] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A security transfer plate, characterized in that, It includes a substrate and a microstructure array formed on one side surface of the substrate, the microstructure array including multiple microstructures; Each of the microstructures includes at least two non-coplanar optical surfaces. In one microstructure, at least two of the optical surfaces are at different perpendicular distances from the plane where the substrate is located, or at least two of the optical surfaces are at an angle to each other. In one of the microstructures, each of the optical surfaces is used to reflect or refract composite light into multiple monochromatic lights, so that the multiple monochromatic lights corresponding to the multiple optical surfaces are interfered or diffracted to form controllable rainbow light.

2. The security transfer plate according to claim 1, characterized in that, The plurality of said microstructures are arranged along a first direction, each said microstructure extends along a second direction, and each said microstructure is a groove or a protrusion; Each of the microstructures has a dimension greater than 10 μm along the second direction, and each of the microstructures has a dimension of 5 μm-50 μm along the first direction. The depth dimension of the groove or the height dimension of the protrusion is 0.3 μm-5 μm.

3. The security transfer plate according to claim 1, characterized in that, The plurality of microstructures are arranged in an array along a first direction and a second direction, and the plurality of microstructures are non-connected grooves or protrusions; The microstructure has a dimension of 5μm-50μm along the first direction, the depth dimension of the groove or the height dimension of the protrusion has a dimension of 0.3μm-5μm, and the distance between any two adjacent microstructures along the second direction is less than 100μm.

4. The security transfer plate according to claim 2 or 3, characterized in that, The spacing between any two adjacent microstructures along the first direction is 5μm-50μm.

5. The security transfer plate according to claim 3, characterized in that, The microstructure has a dimension greater than 10 μm in the direction perpendicular to the first surface, wherein the first surface is a plane defined by the first direction and the second direction.

6. The security transfer plate according to claim 5, characterized in that, The cross-sectional shape of the microstructure perpendicular to the first plane includes at least one of rectangular, trapezoidal, U-shaped, V-shaped and arc-shaped.

7. The security transfer plate according to claim 6, characterized in that, The substrate includes multiple microstructure arrays, and the microstructures in each microstructure array have different cross-sectional shapes perpendicular to the first surface.

8. The security transfer plate according to claim 7, characterized in that, The projections of multiple microstructure arrays onto the substrate overlap.

9. The security transfer plate according to claim 7, characterized in that, The microstructures of the multiple microstructure arrays extend in different directions.

10. The security transfer plate according to claim 1, characterized in that, The substrate is a steel plate, and the thickness of the substrate is greater than 0.4 mm.

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