Intelligent card without chip marks on surface and preparation method thereof

Abstract

The invention relates to an intelligent card without chip marks on the surface and a preparation method thereof, belongs to the technical field of intelligent card preparation, and solves the problem that the appearance quality, the subsequent processing technology and the mechanical strength of the card are affected due to the fact that chip marks easily appear on the surface of the intelligent card prepared by the existing method. The method comprises the steps that a steel plate, high-temperature cloth, an Inlay large material, high-temperature cloth and a steel plate are sequentially stacked, a pre-laminated Inlay stack is obtained, and the surface, making contact with the Inlay large material, of the high-temperature cloth is a frosted surface; carrying out primary lamination on the pre-laminated Inlay stack to obtain an Inlay layer of which the surface is in a frosted state; and binding, positioning and stacking the Inlay layer, the printing layer and the surface protection film layer, and carrying out secondary lamination. According to the method, the problem that chip marks appear on the surface of an existing intelligent card can be solved at low cost.

Description

Technical Field

[0001] This invention relates to the field of smart card manufacturing technology, and in particular to a smart card with no chip imprint on its surface and its manufacturing method. Background Technology

[0002] With the rapid development of new energy vehicles, car key cards, as a standard feature of these vehicles, are increasingly favored by consumers. As high-end models become more widespread, there are increasingly higher demands for card quality. During the manufacturing process of smart cards, factors such as differences in the coefficient of thermal expansion and thickness between the chip module (usually a metal frame and silicon chip encapsulated in epoxy resin) and the card body (usually PVC, PET, or PC) cause chip imprints to appear on the surface of the smart card after the combined effects of lamination heat, pressure, and time. This is especially true for specially customized dark-colored cards, which are more prone to chip imprints.

[0003] Currently, the industry standard for reducing chip imprints on smart cards is to use high-precision equipment to improve the manufacturing accuracy of the inlay, making the inlay surface as flat as possible with no gaps around the chip. However, high-precision processing equipment is generally imported from abroad, and the specifications and dimensions of the processing materials also require extremely high precision. The investment in production lines, often amounting to tens of millions of yuan, and the high subsequent maintenance costs make the return on investment prohibitive.

[0004] Therefore, there is an urgent need for a low-cost and effective method to prevent chip imprints from appearing on the surface of smart cards. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a smart card with no chip imprint on its surface and a method for preparing the same, in order to solve at least one of the problems of smart cards prepared by existing methods having chip imprints on their surface that affect the card's appearance quality, subsequent processing technology, and card mechanical strength.

[0006] On one hand, embodiments of the present invention provide a method for preparing a smart card with no chip imprint on its surface, the method comprising:

[0007] (1) An antenna is implanted into a substrate layer, a non-contact module is placed in the positioning hole of the substrate layer and soldered to the antenna, wherein the non-contact module includes a black glue layer and fins from top to bottom, wherein the thickness of the substrate layer is greater than the thickness of the fins; (2) The leveling layer, the substrate layer with the non-connected module welded in step (1), and the compensation layer are assembled and positioned in order from bottom to top, so that the black glue layer is located in the positioning hole of the compensation layer, and the Inlay material is obtained, wherein the thickness of the compensation layer is greater than the thickness of the black glue layer. (3) The Inlay material is stacked in the order of steel plate + high temperature cloth + Inlay material + high temperature cloth + steel plate to obtain a pre-laminated Inlay stack, wherein the surface of the high temperature cloth in contact with the Inlay material is a frosted surface. (4) The pre-laminated Inlay layer is laminated once to obtain an Inlay layer with a frosted surface; (5) Bind and position the smart card blank in the order of surface protective film layer + printing layer + Inlay layer + printing layer + surface protective film layer to obtain the smart card blank; (6) The smart card blank is stacked in the order of steel plate + laminate + smart card blank + laminate + steel plate to obtain a pre-laminated smart card stack; (7) Perform secondary lamination and cut on the pre-laminated smart card stack.

[0008] Furthermore, in step (1), the thickness of the substrate layer is 0.11-0.13 mm, the thickness of the fin is 0.1-0.12 mm, and the diameter of the antenna is 0.095-0.11 mm.

[0009] Furthermore, the gap between the substrate layer and the fin is 0.1-0.3 mm.

[0010] Furthermore, in step (2), the thickness of the compensation layer is 0.225-0.245mm, and the thickness of the black adhesive layer is 0.215-0.225mm.

[0011] Furthermore, the gap between the compensation layer and the black adhesive layer is 0.1-0.3 mm.

[0012] Furthermore, in step (3), the roughness Ra of the high-temperature cloth abrasive surface is 1.8-3.0.

[0013] Furthermore, in step (4), the primary lamination includes a primary hot press and a primary cold press.

[0014] Furthermore, the temperature of the first hot pressing is 120-150℃, the pressure is 3-12MPa, and the time is 6-12min.

[0015] Furthermore, the temperature of the first cold pressing is 5-30℃, the pressure is 4-13MPa, and the time is 6-12min.

[0016] Furthermore, in step (4), the secondary lamination includes secondary hot pressing and secondary cold pressing.

[0017] Furthermore, the temperature of the secondary hot pressing is 125-155℃, the pressure is 4-13MPa, and the time is 6-12min.

[0018] Furthermore, the temperature of the secondary cold pressing is 5-30℃, the pressure is 5-14MPa, and the time is 6-12min.

[0019] On the other hand, embodiments of the present invention provide a smart card, which is manufactured by the method described above, and the smart card has no chip imprint on its surface.

[0020] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. Unlike existing smart card manufacturing methods, this invention uses a high-temperature fabric with a frosted surface as a laminating pad for the first lamination of the bound inlay material during the smart card manufacturing process, resulting in a frosted surface on the inlay layer after lamination. During the subsequent second lamination process with printing materials and a surface protective film, the frosted state of the inlay layer creates an uneven microstructure on its surface. This microstructure gradually levels out under the pressure and temperature from the laminating steel plate. On one hand, this microstructure slows down the leveling time of the inlay layer surface, thus preventing premature softening of the inlay layer surface during the second lamination, which could lead to imprints on the card surface. On the other hand, it delays the deformation of the material (PVC) caused by leveling, compensating for the gap between the filling module and the compensation layer, further preventing imprints on the card surface.

[0021] The method for eliminating chip imprints on the surface of smart cards according to the present invention can be achieved using ordinary domestic equipment currently used for processing smart cards. Compared with existing smart cards, it does not have higher requirements for the constituent materials, is simple to operate, low in cost, and easy to implement.

[0022] 2. By adjusting the surface roughness of the Inlay layer, combined with the relationship between the thickness of the upper and lower layers of the adjustment module and the thickness of the compensation layer and the substrate layer, and adjusting the gap between the adjustment module and the card body structure, and with the process conditions of the two lamination processes, the present invention can successfully prevent the chip module from generating marks on the surface of the smart card.

[0023] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0024] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0025] Figure 1 is a process flow diagram for preparing the smart card according to the present invention; Figure 2 This is a schematic diagram of the structure of the Inlay large material layer of the present invention; Figure 3 This is a partially enlarged view of the relative positions of the black adhesive layer and the compensation layer in the Inlay material layer of this invention; Figure 4 This is a schematic diagram showing the relationship between the single-layer Inlay material, the steel plate, and the high-temperature layer during the primary lamination process of this invention. Figure 5 This is the Inlay layer obtained by a single lamination process according to the present invention; Figure 6 This is a partially enlarged view of the relative positions of the black adhesive layer and the compensation layer in the Inlay layer of this invention; Figure 7 The smart card prepared according to the present invention; Figure 8 This is a partially enlarged view of the relative positions of the black adhesive layer and the compensation layer in the smart card prepared according to the present invention; Figure 9 To obtain the appearance image of the smart card for Comparative Example 1; Figure 10 This is an external morphological diagram of the smart card obtained in Embodiment 1 of the present invention; Figure label: 1-Contactless module; 1-1-Module black adhesive; 1-2-Fin; 2-Compensation layer; 2-1-Surface of compensation layer before primary lamination; 2-2-Surface of compensation layer after primary lamination; 2-3-Surface of compensation layer after secondary lamination; 3-Antenna; 4-Substrate layer; 5-Planking layer; 6-Inlay layer; 7-Laminated high-temperature cloth; 8-Laminated steel plate; 9-Surface protective film layer; 10-Printed layer. Detailed Implementation

[0026] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0027] Due to factors such as differences in the coefficient of thermal expansion and thickness between the smart card chip module (usually a metal frame and silicon chip encased in epoxy resin) and the card body (usually PVC, PET, or PC), chip imprints can easily appear on the surface of the smart card during the manufacturing process, especially on specially customized dark-colored cards.

[0028] Chip imprints on the surface of smart cards not only affect the aesthetics of the card but also severely impact its flatness. Since chip imprints typically appear as localized bumps or depressions, they can interfere with patterns, text, or anti-counterfeiting markings on the card surface, reducing brand recognition and hindering subsequent processes such as embossing, hot stamping, and laser engraving. They can also reduce the mechanical performance of smart cards, making them more prone to breakage, warping, or bending failures during use. The imprinted area can become the starting point for fatigue damage, especially in scenarios involving frequent insertion and removal, affecting the smoothness of card insertion and removal in card readers and even causing problems such as card reader jamming and reading failures.

[0029] Existing methods for reducing chip imprinting on smart cards require the use of imported high-precision processing equipment. The specifications and dimensions of the processing materials also need to be extremely precise, resulting in production line investments of tens of millions of yuan and high subsequent maintenance costs, making the return on investment prohibitive. High-priced processing equipment can achieve a hole-cutting accuracy of ≤0.05mm (less than the ≤0.1mm of domestically produced equipment). The chip size accuracy for ordinary-priced chips is ≤0.1mm, and for high-priced chips, it's ≤0.05mm. Therefore, using high-precision materials and high-cost equipment can theoretically achieve an accuracy of ≤0.1mm. Adding the 0.01-0.02mm micro-deformation during material lamination, the gap can generally be less than 0.1mm, falling into the "inconspicuous" range, difficult for the human eye to perceive. This can significantly improve the chip printing yield on certain areas, but in large areas (where chip dot overlap is ≥100%), chip printing defects are prone to occur, indicating certain limitations.

[0030] Therefore, the present invention provides a method for manufacturing a smart card with no chip imprint on its surface, the method comprising: (1) An antenna is implanted into a substrate layer, a non-contact module is placed in the positioning hole of the substrate layer and soldered to the antenna, wherein the non-contact module includes a black glue layer and fins arranged from top to bottom, wherein the thickness of the substrate layer is greater than the thickness of the fins; (2) The leveling layer, the substrate layer with the non-connected module welded in step (1), and the compensation layer are assembled and positioned in order from bottom to top, so that the black glue layer is located in the positioning hole of the compensation layer, and the Inlay material is obtained, wherein the thickness of the compensation layer is greater than the thickness of the black glue layer. (3) The Inlay material is stacked in the order of steel plate + high temperature cloth + Inlay material + high temperature cloth + steel plate to obtain a pre-laminated Inlay stack, wherein the surface of the high temperature cloth in contact with the Inlay material is a frosted surface. (4) The pre-laminated Inlay layer is laminated once to obtain an Inlay layer with a frosted surface; (5) Bind and position the smart card blank in the order of surface protective film layer + printing layer + Inlay layer + printing layer + surface protective film layer to obtain the smart card blank; (6) The smart card blank is stacked in the order of steel plate + laminate + smart card blank + laminate + steel plate to obtain a pre-laminated smart card stack; (7) Perform secondary lamination and cut on the pre-laminated smart card stack.

[0031] It should be noted that, in order to effectively protect the fins during the lamination process and prevent the fins from forming marks on the card surface, this invention needs to limit the thickness of the substrate layer and the module fins, as well as the diameter of the antenna.

[0032] Specifically, in step (1), the thickness of the substrate layer is 0.11-0.13mm, which can be 0.11mm, 0.115mm, or 0.12mm. If the thickness of the substrate layer is too large, there will be a significant height difference between it and the fins, and after lamination, a fin-shaped imprint will be formed on the back of the card. If the thickness is too small, the fins cannot be effectively protected during the lamination process, and the lamination stress will be directly applied to the fins, which can easily cause the fins to break.

[0033] Specifically, in step (1), the thickness of the fin is 0.1-0.12mm, which can be 0.1mm, 0.105mm, or 0.11mm. If the thickness of the fin is too large, stress will be directly applied to the fin during the lamination process, which may cause the fin to break and affect the inlay performance. If the thickness is too small, there will be an obvious height difference between the fin and the substrate layer, and after lamination, a fin-shaped imprint will be formed on the back of the card.

[0034] Specifically, in step (1), the height difference between the substrate and the fin is in the range of 0.01-0.03mm, which can be 0.01mm, 0.016mm, 0.02mm, 0.024mm, 0.025mm, or 0.03mm. If it is too small, it will not be conducive to the fin effectively resisting the lamination pressure, and if it is too large, it will not be conducive to the elimination of chip imprints.

[0035] Specifically, in step (1), the antenna diameter is 0.095-0.11mm, specifically 0.095mm, 0.10mm, 0.105mm, and 0.11mm. If the antenna diameter is too large or too small, it will affect the design frequency.

[0036] It should be noted that in order to effectively protect the chip during the lamination process and effectively eliminate fin marks on the surface of the card after lamination, it is necessary to limit the gap between the substrate layer and the fins.

[0037] Furthermore, in step (1), the gap between the substrate layer and the fin is 0-0.3 mm, preferably 0.1-0.3 mm, and can be 0.1 mm, 0.12 mm, 0.18 mm, 0.22 mm, 0.26 mm, or 0.3 mm. If the gap is too large, it will cause fin imprinting after lamination; if the gap is too small, it will cause the fin and the substrate layer to be unable to be positioned and fitted together.

[0038] It should be noted that, in order to better protect the chip (black glue area) during the lamination process and to ensure that there is no significant thickness difference between the chip and the substrate after lamination, and to keep the inlay surface relatively flat, this invention needs to limit the thickness of the compensation layer and the black glue layer.

[0039] Furthermore, in step (2), the thickness of the compensation layer is greater than the thickness of the black adhesive layer, and the thickness difference is 0.01-0.035mm. The thickness difference can be 0.01mm, 0.02mm, 0.024mm, 0.025mm, 0.027mm, 0.028mm, 0.03mm, 0.031mm, 0.033mm, or 0.035mm. If the thickness difference is too large, it will cause a significant drop between the compensation layer and the black adhesive, resulting in a chip imprint in the shape of black adhesive after the lamination process. If the thickness difference is too small, it will cause the compensation layer to be unable to effectively protect the black adhesive from lamination stress during the lamination process, causing the black adhesive to crack and the chip to fail.

[0040] Furthermore, in step (2), the thickness of the black adhesive layer is 0.2-0.225mm, which can be 0.2mm, 0.215mm, 0.22mm, or 0.225mm.

[0041] Furthermore, in step (2), the thickness of the compensation layer is 0.225-0.245mm, which can be 0.225 mm, 0.23 mm, 0.235 mm, 0.24 mm, or 0.245 mm. If the thickness of the compensation layer is too low, it will cause the compensation layer to fail to effectively protect the black glue from lamination stress during the lamination process, resulting in the black glue cracking and the chip failing. If the thickness of the compensation layer is too high, it will cause a significant drop between the compensation layer and the black glue, thereby forming a chip imprint in the shape of black glue after the lamination process.

[0042] It should be noted that in order to effectively protect the chip during the lamination process and effectively eliminate the black adhesive residue on the surface of the card after lamination, it is necessary to limit the gap size between the compensation layer and the black adhesive layer.

[0043] Furthermore, in step (2), the gap between the compensation layer and the black adhesive layer is 0-0.3 mm, preferably 0.1-0.3 mm. If the gap is too large, it will cause a chip imprint in the shape of black adhesive to form after the card is laminated; if the gap is too small, the black adhesive area of ​​the module cannot be positioned by the compensation and cooperate with the compensation layer.

[0044] According to some preferred embodiments of the present invention, the gap between the compensation layer and the black adhesive layer is 0.10mm, 0.15mm, 0.18mm, 0.2mm, 0.21mm, 0.22mm, 0.25mm, 0.26mm, 0.27mm, or 0.3mm.

[0045] It should be noted that, in order to effectively eliminate chip imprints on the surface of the smart card and avoid damage to the chip function caused by lamination, the present invention needs to limit the surface roughness of the high-temperature cloth used as the laminating pad during the first lamination.

[0046] Specifically, in step (3), the surface of the high-temperature cloth that contacts the Inlay material is a frosted surface with a roughness Ra of 1.8-3.0. If the roughness of the high-temperature cloth's frosted surface is too small, it cannot effectively eliminate chip imprints; if the roughness is too large, it can easily damage the chip's function during lamination.

[0047] According to some preferred embodiments of the present invention, the roughness Ra of the frosted surface of the high-temperature cloth in contact with the Inlay bulk material is any value in the range of 1.8-3.0 μm, and can be 1.8 μm, 2.0 μm, 2.2 μm, 2.5 μm, 2.8 μm, or 3.0 μm.

[0048] Specifically, in step (4), the first lamination includes a hot press and a cold press. The hot press is for fusing the layers of the inlay together and forming a single unit, while the cold press is for curing the inlay after hot pressing.

[0049] More specifically, the temperature of the first hot pressing is 120-150℃, which can be 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, or 150℃. If the temperature of the first hot pressing is too high, it will cause the inlay to deform after lamination and make it impossible to perform secondary lamination of the thickness. If the temperature of the first hot pressing is too low, it will cause the inlay to delaminate after lamination (failing to meet the national standard requirement of ≥3.5N / CM).

[0050] More specifically, the pressure of the first hot pressing is 3-12 MPa, which can be 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, or 12 MPa. If the pressure of the first hot pressing is too high, it will cause the inlay to deform after lamination and the module to be damaged and fail. If the pressure of the first hot pressing is too low, it will cause problems such as excessive inlay thickness and unqualified surface roughness.

[0051] More specifically, the hot pressing time is 6-12 minutes, which can be 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, or 12 minutes. If the hot pressing time is too long, the inlay will deform after lamination and the thickness cannot be further reduced by secondary lamination. If the hot pressing time is too short, the inlay will delaminate after lamination, or the peel strength between the layers will not reach the minimum peel strength ≥3.5 N / CM (national standard).

[0052] More specifically, the temperature of the first cold pressing is 5-30℃, which can be 5℃, 10℃, 15℃, 20℃, 25℃, or 30℃. If the temperature of the first cold pressing is too high, the inlay will not be able to solidify after lamination (it will be soft and easily deformed by external force). If the temperature of the first cold pressing is too low, the inlay will become brittle after lamination (it will be easy to break after bending).

[0053] More specifically, the pressure of the first cold press is 4-13 MPa, which can be 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, or 12 MPa. If the pressure of the first cold press is too high, it will cause the inlay to deform after lamination and the module to be damaged and fail. If the pressure of the first cold press is too low, it will cause problems such as excessive inlay thickness and unqualified surface roughness.

[0054] More specifically, the time for one cold pressing is 6-12 minutes, which can be 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, or 12 minutes. If the time for one cold pressing is too long, it will lead to wasted production capacity. If the time for one cold pressing is too short, it will lead to incomplete cooling, unstable inlay state, easy deformation after taking out the equipment, and inability to perform secondary lamination.

[0055] It should be noted that, in order for the various indicators of the card body to meet national standards after the card is manufactured, this invention needs to limit the process flow and process parameters of the secondary lamination of the smart card.

[0056] Specifically, in step (7), the secondary lamination includes secondary hot pressing and secondary cold pressing. The secondary lamination is to integrate the printing material, surface protective film, and inlay into one unit, and the secondary cold pressing is to permanently solidify the hot-pressed state.

[0057] Under normal circumstances: the temperature of the second hot pressing in the secondary lamination is limited to 5°C higher and the pressure to 1 MPa higher than that of the first hot pressing in the primary lamination. If the temperature and / or pressure of the secondary lamination are too low, it will be difficult to eliminate the chip imprint; if the temperature and / or pressure are too high, it will be detrimental to the product yield and the stress protection of the chip.

[0058] More specifically, the temperature of the secondary hot pressing is 125-155℃, which can be 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, or 155℃. If the temperature of the secondary hot pressing is too high, it will cause the card body to deform and make it impossible to complete the punching process within the standard range of the finished product. If the temperature of the secondary hot pressing is too low, it will cause the card body to become brittle after lamination (it is easy to break after bending).

[0059] More specifically, the pressure of the secondary hot pressing is 4-13 MPa, which can be 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, or 13 MPa. If the pressure of the secondary hot pressing is too high, it will cause the card body to deform and the module to be damaged and fail after lamination. If the pressure of the secondary hot pressing is too low, it will cause problems such as the card body thickness exceeding the standard and the surface roughness not meeting the requirements.

[0060] More specifically, the secondary hot pressing time is 6-12 minutes, which can be 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, or 12 minutes. If the secondary hot pressing time is too long, it will cause severe deformation of the card body after lamination, making it impossible to ensure the normal progress of the punching process. If the secondary hot pressing time is too short, it will cause delamination between the layers of the card body or fail to achieve the national standard peel strength ≥3.5 N / cm.

[0061] More specifically, the temperature of the secondary cold pressing is 5-30℃, which can be 5℃, 10℃, 15℃, 20℃, 25℃, or 30℃. If the temperature of the secondary cold pressing is too high, the shape of the card body after lamination will not be solidified (soft state, easily deformed by external force). If the temperature of the secondary cold pressing is too low, the card body will become brittle after lamination (easily broken after bending).

[0062] More specifically, the pressure of the secondary cold pressing is 5-14 MPa, which can be 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, or 14 MPa. If the pressure of the secondary cold pressing is too high, it will cause the card to deform after lamination and the module to be damaged and fail. If the pressure of the secondary cold pressing is too low, it will cause problems such as the card body thickness exceeding the standard and the surface roughness not meeting the requirements.

[0063] More specifically, the secondary cold pressing time is 6-12 minutes. It can be 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, or 12 minutes. If the secondary cold pressing time is too long, it will lead to wasted production capacity. If the secondary cold pressing time is too short, it will lead to incomplete cooling, unstable carding state, easy deformation after being taken out of the equipment, and failure to guarantee the quality of the punching process.

[0064] The present invention also provides a smart card, which is manufactured by the method of the present invention. A schematic diagram of the structure of the smart card is shown below. Figure 7 As shown, the appearance is as follows Figure 10 As shown, the smart card includes an inlay layer in the middle and a printed layer and a surface protective layer symmetrically located on both sides of the inlay layer, wherein there are no chip imprints on the surface of the smart card.

[0065] The present invention will be further explained and illustrated below through specific embodiments and comparative examples.

[0066] Examples 1-6 The method for preparing a smart card specifically includes the following steps: (1) The antenna is implanted into the substrate layer, the non-contact module is placed in the positioning hole of the substrate layer and soldered to the antenna. The non-contact module includes a black glue layer and fins set from the bottom. The thickness of the substrate layer is 0.11-0.13mm, the thickness of the fins is 0.1mm, the diameter of the antenna is 0.1mm, and the gap between the substrate layer and the fins is 0.1-0.3mm. (2) The leveling layer, the substrate layer with the non-connected module welded in step (1), and the compensation layer are assembled and positioned in order from bottom to top, so that the black glue layer is located in the positioning hole of the compensation layer to obtain the Inlay material. The thickness of the black glue layer is 0.2mm, the thickness of the compensation layer is greater than the thickness of the black glue layer, the thickness difference is 0.01-0.03mm, and the gap between the compensation layer and the black glue layer is 0.1-0.3mm. (3) The Inlay material is stacked in the order of steel plate + high temperature cloth + Inlay material + high temperature cloth + steel plate to obtain a pre-laminated Inlay stack, wherein the surface of the high temperature cloth in contact with the Inlay material is a frosted surface with a roughness Ra of 1.8-3.0. (4) The pre-laminated Inlay stack is laminated once to obtain an Inlay layer with a frosted surface. The first lamination includes a hot press and a cold press. The temperature of the first hot press is 120-150℃, the pressure is 3-12MPa, and the time is 6-12min. The temperature of the first cold press is 5-30℃, the pressure is 4-13MPa, and the time is 6-12min. (5) Bind and position the smart card blank in the order of surface protective film layer + printing layer + Inlay layer + printing layer + surface protective film layer obtained in step (4); (6) Stack the smart card blank in the order of steel plate + laminate + smart card blank obtained in step (5) + laminate + steel plate to obtain pre-laminated smart card stack; (7) Perform secondary lamination and cutting on the pre-laminated smart card stack. The secondary lamination includes secondary hot pressing and secondary cold pressing. The temperature of the secondary hot pressing is 150°C, the pressure is 10MPa, and the time is 8min. The temperature of the secondary cold pressing is 25°C, the pressure is 8MPa, and the time is 10min.

[0067] Table 1 shows the process conditions and appearance (whether there are surface marks) of the smart cards prepared in Examples 1-6 and Comparative Examples 1-4.

[0068]

[0069] Comparative Example 1 Using the same method as in Example 1, the difference is that in step (4), during the first lamination process, the surface of the high-temperature cloth in contact with the Inlay material is a smooth plane (roughness 1.0), and the surface of the final smart card has chip imprints, such as... Figure 9 As shown.

[0070] Comparative Example 2 Using the same method as in Example 2, except that in step (4), the lamination temperature is 90 degrees Celsius, and other parameters remain unchanged, resulting in a chip imprint on the surface of the final smart card.

[0071] Comparative Example 3 Using the same method as in Example 3, except that in step (4), the compensation layer is 0.25 mm, and the surface of the final smart card has chip imprints.

[0072] Comparative Example 4 Using the same method as in Example 4, except that in step (4), the substrate layer is 0.15 mm, and the surface of the final smart card has chip imprints.

[0073] from Figure 9 and Figure 10 It can be seen that during a single lamination process, using traditional methods where the surface of the high-temperature fabric in contact with the inlay material is a smooth plane, the surface of the resulting smart card exhibits obvious chip imprints, such as... Figure 9 Within the area circled in the Chinese box; by increasing the roughness of the high-temperature cloth surface in contact with the Inlay material, under the same process conditions, the surface of the resulting smart card is smoother and free of chip imprints. Figure 10 ).

[0074] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a smart card with no chip imprint on its surface, characterized in that, The method includes the following specific steps: (1) The antenna is implanted into the substrate layer, the non-contact module is placed in the positioning hole of the substrate layer and soldered to the antenna, wherein the non-contact module includes two layers from top to bottom: a black glue layer and a fin, wherein the thickness of the substrate layer is greater than the thickness of the fin; (2) The leveling layer, the substrate layer with the non-connected module welded in step (1), and the compensation layer are assembled and positioned in order from bottom to top, so that the black glue layer is located in the positioning hole of the compensation layer, and the Inlay material is obtained, wherein the thickness of the compensation layer is greater than the thickness of the black glue layer. (3) The Inlay material is stacked in the order of steel plate + high temperature cloth + Inlay material + high temperature cloth + steel plate to obtain a pre-laminated Inlay stack, wherein the surface of the high temperature cloth in contact with the Inlay material is a frosted surface. (4) The pre-laminated Inlay layer is laminated once to obtain an Inlay layer with a frosted surface; (5) Bind and position the smart card blank in the order of surface protective film layer + printing layer + Inlay layer + printing layer + surface protective film layer to obtain the smart card blank; (6) The smart card blank is stacked in the order of steel plate + laminate + smart card blank + laminate + steel plate to obtain a pre-laminated smart card stack; (7) Perform secondary lamination and cut on the pre-laminated smart card stack.

2. The method according to claim 1, characterized in that, In step (1), the thickness of the substrate layer is 0.11-0.13 mm, the thickness of the fin is 0.1-0.12 mm, and the diameter of the antenna is 0.095-0.11 mm; And / or, the gap between the substrate and the fin is 0.1-0.3 mm.

3. The method according to claim 1, characterized in that, In step (2), the thickness of the compensation layer is 0.225-0.245 mm, and the thickness of the black adhesive layer is 0.2-0.225 mm; And / or, the gap between the compensation layer and the black adhesive layer is 0.1-0.3 mm.

4. The method according to claim 1, characterized in that, In step (3), the roughness Ra of the high-temperature cloth abrasive surface is 1.8-3.

0.

5. The method according to claim 1, characterized in that, In step (4), the primary lamination includes a primary hot press and a primary cold press.

6. The method according to claim 5, characterized in that, The temperature of the first hot pressing is 120-150℃, the pressure is 3-12MPa, and the time is 6-12min.

7. The method according to claim 5, characterized in that, The temperature of the first cold pressing is 5-30℃, the pressure is 4-13MPa, and the time is 6-12min.

8. The method according to claim 1, characterized in that, In step (4), the secondary lamination includes secondary hot pressing and secondary cold pressing.

9. The method according to claim 8, characterized in that, The secondary hot pressing is performed at a temperature of 125-155℃, a pressure of 4-13MPa, and a time of 6-12min. And / or, the temperature of the secondary cold pressing is 5-30℃, the pressure is 5-14MPa, and the time is 6-12min.

10. A smart card, characterized in that, The smart card is manufactured by the method described in any one of claims 1-9, and the surface of the smart card has no chip imprint.

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