Dual interface smart card with metal surface layer and method of manufacturing same

Abstract

The present invention relates to a dual interface smart card (100), including a metal layer (101), an adhesive layer (102), a magnetic layer (103), a double adhesive layer (104), an antenna (105), an antenna inlay layer (106), an overlay layer (108) with a magnetic strip, a filler material (110), and an integrated circuit chip module (113), wherein the metal layer (101) acts as a surface layer, the adhesive layer (102) creates a bond, the double adhesive layer (104) bonds the magnetic layer (103) with the antenna inlay layer (106), and the overlay layer (108) with a magnetic stripe is a protection layer for the printing layer (107) layer, and the magnetic stripe is for swiping the dual interface smart card (100). The integrated circuit chip module (113) is embedded by using Te connect process, which consists of solder paste for connecting the antenna (105) and the module contact pads.

Description

[Technical field]

[0001] The present invention relates to a smart card with a metal layer, more particularly to a dual interface smart card with a metal surface layer and a method of manufacturing the same using a dual interface chip module and antenna to achieve higher power and reduce the complexity of the manufacturing method by reducing the number of steps. [Background technology]

[0002] In the last few years, the use of smart cards has increased and they are used in almost every industry, such as in the corporate world in the form of secure identification applications in employee ID badges, citizen ID cards, electronic passports, driver's licenses and online authentication devices, in the healthcare industry in the form of healthcare applications in citizen health ID cards, doctor ID cards, portable medical record cards, in supermarkets, shopping stores and various restaurants in the form of payment applications through either contact or contactless credit or debit cards and transit payment cards. Smart cards also play a vital role in various telecommunication applications in the form of GSM subscriber identity modules, telephone payment cards, which typically use static information for online use. However, such static information is generally easy to hack and intercept.

[0003] Generally, a secure microcontroller or similarly intelligent microcontroller has an internal or external memory storage in the form of a memory chip only, so that such a microcontroller, when embedded in the form of an integrated circuit chip, is known as a smart card. Hence, smart cards are generally available in the form of embedded integrated circuit chips. A smart card needs to be read using a smart card reader, so the smart card can be connected to the smart card reader both physically and virtually. Thus, the smart card can be connected to the smart card reader either physically by direct physical contact or virtually through a remote contactless radio frequency interface.

[0004] Smart cards have prominent features such as the ability to store a wealth of data, and they have microcontrollers embedded in them so that they can intelligently interact with smart card readers and therefore perform various functions related to encryption and mutual authentication on their own. The technology used in smart cards is identified in the international standards, ISO / IEC 7816 and ISO / IEC 14443. Nowadays, it is even easier to spot a smart card as it is available in a variety of different forms including plastic cards, which are commonly seen used as metro cards or in the form of a Subscriber Identity Module, SIM, in offices to enter office buildings, which can be easily spotted while using a GSM mobile phone, and in the form of a USB-based token in various financial institutions such as banks.

[0005] However, numerous problems are faced during the manufacturing of these metal smart cards, such as high complexity, shrinkage and expansion of layers in the smart card during lamination phase, which reduces the life span of the smart card. Besides, currently, metal smart cards are manufactured through a hot soldering process, which includes approximately 19-20 steps, such as card input magazine, milling, card cleaning, vision system for wire position inspection, left and right side wire pulling, vision for wire position, milling cavity for module encapsulation, wire pulling and cleaning, wire straightening, wire trimming / dressing, module punch, pick and place, soldering (lead, tin) and the like. Due to the higher number of manufacturing steps, more time and resources are consumed due to further lamination of different material types such as metal, PVC, adhesive layers, etc., layers shrink or expand, which results in waste and loss of productivity during metal smart card manufacturing.

[0006] US20040206799A1 discloses a method and apparatus for soldering the terminal end of an antenna embedded on a plastic smart card to contact the terminal of an IC module disposed on the card. The enameled antenna terminal end is pre-coated with solder using a heater having a horizontal opening in which molten solder is held. The solder pre-coated terminal end is maintained in secure contact with the terminal contact of the IC module by heating coils attached to the free front ends of two pivoting elongated cantilevers. A predetermined amount of solder is dropped into the cavity of each heating coil, and the heating coils are operated with a low current to generate a concentrated high temperature to melt the solder and form a secure and permanent solder joint of the antenna terminal end to the contact terminal of the IC module. However, this invention uses a thermal soldering process that includes more steps, and moreover, this invention limits the achievement of a higher throughput.

[0007] US6881605B2 discloses a method for forming a card with embedded integrated circuit (IC) and antenna coil, which includes the steps of (a) embedding the antenna coil on a core sheet, (b) laminating the core sheet together with some outer layer sheets to form a laminated panel, (c) forming a first cavity in the laminated panel to expose a portion of the antenna coil, (d) drawing out two ends of the antenna coil from the core sheet, and (e) fixing the integrated circuit with the antenna coil, for example, by soldering or thermocompression. However, this invention uses a hot soldering process which includes more steps, and furthermore, due to the lamination process, the layers shrink or expand, which limits achieving higher throughput.

[0008] US20150028106A1 discloses a method for manufacturing a smart card with an embedded integrated circuit module and an antenna coil, which includes the steps of (a) embedding the antenna coil on a core sheet, (b) laminating the core sheet together with several outer layer sheets to form a laminated panel, (c) forming a cavity in the laminated panel to expose two terminals of the antenna coil, and (d) connecting two electrical contact areas of the integrated circuit module. The exposed terminals of the antenna coil are connected by a mezzanine electrode diffusion welding method and controlled by a transformer output manipulation energy output control method. However, this invention discloses a manufacturing method that includes more steps, which limits achieving higher throughput.

[0009] Although dual interface smart card manufacturing methods are widely known in the public domain, all currently available manufacturing methods involve more steps, which requires more equipment and time. Moreover, the layers shrink or expand during the lamination step, which leads to the production of low quality smart cards, and some problems occur during the lamination of the layers due to the difference in the properties of the layers.

[0010] Therefore, due to the aforementioned drawbacks, there is a need to provide a metal smart card that significantly contributes towards achieving higher power and reduces processes during manufacturing by avoiding the use of adhesive under the filling material. Summary of the Invention [Problem to be solved by the invention]

[0011] The primary objective of the present invention is to provide a dual interface smart card having a metal surface layer and a method for manufacturing the same that includes a two-step lamination process to avoid unnecessary shrinkage and expansion of layers inside the smart card.

[0012] Another object of the present invention is to provide a dual interface smart card having a metal surface layer and a method for manufacturing the same using a laminate having embossings that help maintain pressure during the lamination process.

[0013] It is yet another object of the present invention to provide a dual interface smart card having a metal surface layer and a manufacturing method thereof including a Te connect process which provides high throughput compared to conventional processes such as thermal solder processes.

[0014] It is yet another object of the present invention to provide a dual interface smart card having a metal surface layer and a method for manufacturing the same with the goal of reducing the number of steps during manufacturing resulting in a reduction in cost and complexity.

[0015] It is yet another object of the present invention to provide a dual interface smart card having a metal surface layer and a method of manufacture thereof that has the ability to interface as both contact and contactless with one or more metal layers. [Means for solving the problem]

[0016] The present invention relates to a dual interface smart card having metal surface layers and a method for its manufacture including a Te connect process that includes a two-step lamination process to avoid unnecessary shrinkage and expansion of layers inside the smart card, resulting in high throughput compared to conventional processes such as hot solder processes.

[0017] In one embodiment, the present invention provides a dual interface smart card, comprising a metal layer, an adhesive layer, a magnetic layer, a dual adhesive layer, an antenna, an antenna inlay layer, a printing layer, an overlay layer having a magnetic strip, a filler material, a solder paste, a heat-activated adhesive tape, and an integrated circuit chip module, wherein the metal layer serves as a surface layer of the dual interface smart card, the adhesive layer creates a bond between the metal layer and the magnetic layer, the magnetic layer prevents the metal layer from interfering with an electromagnetic field originating from the antenna, and the magnetic layer has a high magnetic permeability with a high resistivity and is disposed between the metal layer and the antenna inlay layer to adjust multiple magnetic field lines of the electromagnetic field. the double adhesive layer bonds the magnetic layer with the antenna inlay layer, the antenna inlay layer is a substrate for holding the antenna to form an inlay, the printing layer is for printing information for visual display, the overlay with the magnetic stripe is a protective layer for the printing layer and plays the role of a substrate for placing the magnetic stripe for swiping the dual interface smart card, the filler material spreads on the metal layer to hold the integrated circuit chip module and acts as an insulating layer in the dual interface smart card, and the filler material bonds with the back plate without using any adhesive under the filler material.

[0018] In another embodiment, the present invention provides a method for manufacturing a dual interface smart card, comprising the steps of: a) preparing a metal layer; b) selecting a dual adhesive layer and a magnetic layer; c) preparing an antenna layer; d) preparing a plastic backing; e) preparing a magnetic layer and an adhesive layer; f) sequencing the layers to form an assembly of the dual interface smart card; g) laminating the assembly to prepare an integrated circuit chip module for embedding; and h) milling the metal card to embed the integrated circuit chip module to produce the dual interface smart card with a metal surface layer, the metal layer being processed through an automated tool to make pin holes, the dual adhesive layer and magnetic layer being sequenced together and holes being made on the sequenced dual adhesive layer and magnetic layer; The antenna layer is prepared by embedding an antenna on a plastic layer, the antenna layer is flattened by a lamination process to form an antenna inlay layer, the plastic backing is printed with any information and multiple magnetic strips are transferred onto an overlay layer, the antenna inlay layer, the plastic backing and the overlay layer are spot welded together and laminated to make a laminated backing to avoid shrinkage and expansion of the layers, pin holes are made on the laminated backing, the metal layer, the dual adhesive layer, the laminated backing are arranged in sequence, and a filler material is applied through the holes made in the metal layer to form the assembly, the assembly is laminated to form a laminated metal card, and the milling of the metal card to embed the integrated circuit chip module is done through a Te connect process which helps to obtain a higher throughput compared to a hot solder process.

[0019] In yet another embodiment, the present invention provides a method for milling an integrated circuit chip module and embedding a cavity in a dual interface smart card, comprising: a) milling a card having a filler layer to accommodate a surface of the integrated circuit chip module until a plurality of antenna terminals are exposed; b) selecting the integrated circuit chip module and attaching a heat-activated adhesive tape onto the integrated circuit chip module to expose a plurality of connectors of the integrated circuit chip module; c) placing the integrated circuit chip module obtained from step (b) on the milled product obtained through step (a); and d) applying a solder paste onto the antenna terminals to embed the integrated circuit chip module on the card. Effect of the Invention

[0020] The foregoing objects and advantages of the present invention will become apparent from the following brief description of the drawings, detailed description of the invention, and claims appended hereto.

[0021] An understanding of the present invention's dual interface smart card with metal surface layer and method of manufacture can be gained with reference to the following drawings: [Brief description of the drawings]

[0022] [Figure 1a] FIG. 2 is an exploded view of a dual interface smart card with metal surface layers according to one embodiment of the present invention. [Figure 1b] FIG. 2 is a side view of a dual interface smart card with metal surface layers according to one embodiment of the present invention. [Diagram 2] 4 is a flow chart of a method for manufacturing a dual interface smart card with metal surface layers according to an embodiment of the present invention. [Diagram 3] 3(a) and 3(b) are perspective and side views of a hole in a metal layer according to one embodiment of the present invention. [Figure 4]4(a) and 4(b) are top and side views of an antenna in a dual interface smart card according to one embodiment of the present invention. [Figure 5a] FIG. 2 is a top view of an antenna inlay layer in a dual interface smart card having a metal surface layer sequenced with layers such as a printed sheet and an overlay to form a backplate according to one embodiment of the present invention. [Figure 5b] FIG. 2 is a top view of a card after a first lamination according to one embodiment of the present invention. [Figure 5c] FIG. 2 is a side view of a card after a first lamination according to one embodiment of the present invention. [Figure 6] 6(a) and 6(b) are top and side views of a through hole punched in the area for an adhesive layer in a dual interface smart card with a metal surface layer according to one embodiment of the present invention. [Figure 7] 7(a) and 7(b) are top views of a laminate backing plate in a dual interface smart card with a metal surface layer according to one embodiment of the present invention. [Figure 7c] FIG. 2 is a top view of an adhesive layer onto which a metal layer is placed in a dual interface smart card with a metal surface layer according to one embodiment of the present invention. [Figure 7d] FIG. 2 is a perspective view of the ordered metal layer, adhesive layer, and laminate backing of a dual interface smart card with a metal surface layer according to one embodiment of the present invention. [Figure 7e] FIG. 2 is a diagram of spot welding of all layers in a dual interface smart card with metal surface layers according to one embodiment of the present invention. [Figure 7f] FIG. 2 is an exploded view of all layers in a dual interface smart card with metal surface layers according to one embodiment of the present invention. [Figure 8a] 2 is a diagrammatic view of the placement of filler material through holes on a metal layer in a dual interface smart card having a metal surface layer in accordance with one embodiment of the present invention. [Figure 8b]FIG. 13 is another exploded view of a filler layer within a dual interface smart card according to one embodiment of the present invention. [Figure 9a] FIG. 2 is an isometric view of a laminate with an embossed layer in a dual interface smart card layer according to one embodiment of the present invention. [Figure 9b] FIG. 2 is a perspective view of a laminate having a metal top surface and a plastic back surface in a dual interface smart card layer according to one embodiment of the present invention. [Figure 9c] FIG. 2 is an exploded view of all layers in a dual interface smart card according to one embodiment of the present invention. [Figure 10] 10(a) and 10(b) are top views of a laminate that is CNC milled to form a dual interface smart card layer and the dimensions of the dual interface smart card layer according to one embodiment of the present invention. [Figure 11] 4 is a flow chart of a method for milling an integrated circuit chip module to fill a cavity in a dual interface smart card according to an embodiment of the present invention. [Figure 12a] 1A-1D are front and top views of an integrated circuit chip module of a dual interface smart card according to one embodiment of the present invention; [Figure 12b] FIG. 2 is a diagram of a heat-activated adhesive tape applied over an integrated circuit chip module of a dual interface smart card in accordance with one embodiment of the present invention. [Figure 12c] 1 is a schematic diagram of an integrated circuit chip module of a dual interface smart card according to one embodiment of the present invention; [Figure 13a] FIG. 13 is a side view of a first and second cavity milling in a dual interface card in accordance with one embodiment of the present invention. [Figure 13b] FIG. 13 is a side view of a third and fourth cavity milling in a dual interface card in accordance with one embodiment of the present invention. [Figure 13c]1 is a diagram of milling shapes and dimensions for filler material as integrated circuit chip modules in a dual interface card in accordance with one embodiment of the present invention. [Figure 13d] FIG. 2 is a side view of a dual interface card illustrating dispensing of solder paste into cavities in the dual interface card in accordance with one embodiment of the present invention. [Figure 13e] 2 is a diagram of embedding an integrated circuit chip module onto a card surface, according to one embodiment of the present invention. [Figure 14] FIG. 2 is a perspective view of a final dual interface smart card according to one embodiment of the present invention. [Figure 15] 1 is a graphical representation of the relative permeability of a magnetic layer used in a dual interface smart card. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described below with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. However, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0024] Many aspects of the present invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed on clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts throughout the several views in the drawings. Before describing at least one embodiment of the present invention, it is to be understood that the embodiments of the present invention are not limited in their application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The embodiments of the present invention can be implemented and carried out in various ways. Additionally, the language and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0025] The present invention provides a dual interface smart card with a metal surface layer and a method for its manufacture that aims to reduce the number of steps during manufacturing resulting in a reduction in cost and complexity.

[0026] In one embodiment, the present invention provides a dual interface smart card, comprising a metal layer, an adhesive layer, a magnetic layer, a double adhesive layer, an antenna, an antenna inlay layer, a printing layer, an overlay layer with a magnetic strip, a filling material, a solder paste, a heat-activated adhesive tape, and an integrated circuit chip module, wherein the metal layer serves as a surface layer of the dual interface smart card, the adhesive layer creates a bond between the metal layer and the magnetic layer, the magnetic layer prevents the metal layer from interfering with the electromagnetic field arising from the antenna, the magnetic layer has high permeability with high resistance and is disposed between the metal layer and the antenna inlay layer for adjusting the multiple magnetic lines of the electromagnetic field, the double adhesive layer bonds the magnetic layer with the antenna inlay layer, the antenna inlay layer is a substrate for holding the antenna to form an inlay, the printing layer is for printing information for visual display, the overlay with a magnetic stripe is a protection layer for the printing layer and plays the role of a substrate for placing the magnetic stripe for swiping the dual interface smart card, and the filling material spreads on the metal layer to hold the integrated circuit chip module and serves as an insulating layer in the dual interface smart card.

[0027] Referring to Figure 1(a), an exploded view of a dual interface smart card with a metal surface layer is shown. The dual interface smart card (100) consists of a metal layer (101), an adhesive layer (102), a magnetic layer, a double adhesive layer (104), an antenna (105), an antenna inlay layer (106), a printing layer, an overlay layer with a magnetic strip, a filler material (110), a solder paste (111), a heat-activated adhesive tape (112), and an integrated circuit chip module (113).

[0028] Referring to Figure 1(b), a side view of a dual interface smart card with a metal surface layer is shown. The dual interface smart card (100) has an integrated circuit chip module embedded on the metal layer (101) having a thickness in the range of 800-810 microns.

[0029] 2, a flow chart of a method for manufacturing a dual interface smart card with a metal surface layer is shown. The method for manufacturing a dual interface smart card with a metal surface layer (100) includes the steps of a) preparing a metal layer (101), b) selecting a double adhesive layer (104) and a magnetic layer, c) preparing an antenna layer, d) preparing a plastic backing, e) preparing a magnetic layer and an adhesive layer, f) sequencing the layers to form an assembly of the dual interface smart card (100), g) laminating the assembly and preparing an integrated circuit chip module for embedding, and h) milling the metal card to embed the integrated circuit chip module to produce the dual interface smart card with a metal surface layer (100), the metal layer (101) is processed through an automated tool to make pin holes, the double adhesive layer (104) and magnetic layer are sequenced together, holes are made on the sequenced double adhesive layer (104) and magnetic layer, and the antenna layer is formed. A layer is prepared by embedding an antenna (105) on a plastic layer, said antenna layer is flattened by a lamination process to form an antenna inlay layer (106), said plastic backing is printed with any information and multiple magnetic strips are transferred onto an overlay layer (108), said antenna inlay layer (106), plastic backing and said overlay layer (108) are spot welded together to make a laminated backing to avoid shrinkage and expansion of said layers, pin holes are made on said laminated backing, said metal layer (101), dual adhesive layer (104) and said laminated backing are arranged in sequence, and a filler material (110) is applied through said holes made in said metal layer (101) to form said assembly, said assembly is laminated to form a laminated metal card, and said milling of said metal card to embed said integrated circuit chip module is done through Te connect process which helps to obtain higher throughput compared to hot solder process.

[0030] Referring to FIG. 3(a) and FIG. 3(b), a perspective view and a side view of a hole in a metal layer of the present invention are shown. A metal layer (101) is selected in sheet format that is intended to serve as the top layer of the card, which is 300 series grade (specifically 304 / 316) stainless steel combined with other alloys with a thickness ranging from 380 to 400 microns, heat treated to improve strength and tensile strength. The metal layer (101) is then processed to form through holes by known methods, including but not limited to milling, laser cutting, and the like. The dimensions of the through holes are set to a value higher than the dimensions of the integrated circuit chip modules used to form the card. The advantage of making the through holes larger than the dimensions of the integrated circuit chip modules is to provide greater separation between the metal layer (101) and the integrated circuit chip modules, thus enhancing transmission. The through holes can be square, rectangular, or circular in shape, based on the integrated circuit chip modules selected.

[0031] The metal layer (101) has a width (SH) in the range of 450-485 mm and a height (SW) in the range of 250-300 mm. The thickness (D1) of the sheet is in the range of 390-400 microns, as shown in Figure 3(b). This metal layer (101) is first milled to obtain two pin holes with a size in the range of 2-3 mm in diameter, located 68-71.56 mm apart from the top and bottom edges of the layer. These pins help to hold the material firmly during the milling process. The metal layer (101) is then placed on a CNC (Computer Numerical Control) milling machine to create through holes (201) in the metal layer (101) with a width (W1) and length (L1) at least 0.8 mm higher than the integrated circuit chip module dimensions. As shown in FIG. 3(a), approximately 20-24 through holes (201) are created in the metal layer (101) with the vertical distance (TH) between these through holes ranging from 50 to 56.98 mm and the horizontal distance (TW) between these through holes ranging from 85 to 91 mm.

[0032] Referring to Figure 4(a) and Figure 4(b), the top and side views of the antenna in the present invention are shown. The antenna (105) is embedded in the antenna inlay layer (106) by using a copper wire antenna embedding machine. The antenna inlay layer material is held on the wire embedding machine using vacuum and magnetic guides to ensure that the antenna sheet stays firmly using the antenna embedding process. The antenna (105) is designed to resonate at 13.56mhz. The antenna design is recommended by an integrated circuit chip module as shown in Figure 4(a).

[0033] The antenna inlay layer (106) is subjected to an antenna planarization process using a standard laminator by applying heat, cold and pressure. The lamination process is carried out by applying pressure in the range of 700-800 psi at an elevated temperature of 152° C. for about 10-12 minutes in multiple steps, then cooling the sheet at 20-25° C., and applying pressure of 1200-1500 psi again for 12-14 minutes in multiple steps to form a laminated antenna inlay layer (106) with a thickness (AT) of 150 microns as shown in FIG. 4(b).

[0034] Referring to FIG. 5(a), a top view of the antenna inlay layer is shown. The antenna inlay layer (106) is sequenced together with the print layer (107) and the overlay (108) with the magnetic stripe and spot welded to ensure that all plastic materials are kept intact. The spot welded sheets are then processed for lamination using a standard lamination process, with pin holes of 2-3 mm diameter made to form the first assembly. The pin hole locations match the pin holes made in the metal layer (101).

[0035] Referring to Figure 5(b), another top view of the antenna inlay layer after it has been welded and attached is shown. The first step lamination process is carried out by applying a pressure in the range of 700-800 psi at an elevated temperature in the range of 150-152°C for about 12-16 minutes, then cooling the layer at a temperature in the range of 20-25°C, and applying a pressure of 1200-1500 psi for 12-16 minutes. A side view of the card after the first lamination is shown in Figure 5(c).

[0036] Referring to FIG. 6(a), a top view of a through hole punched in the area for the adhesive layer in the present invention is shown. A layer (104) is used to connect the metal layer (101) with the magnetic layer (103) and the antenna inlay layer (106). The magnetic layer (103) helps to shield / protect / reduce the metal layer (101) from interference with the electromagnetic field generated when the antenna (105) operates through communication with an external antenna reader. The magnetic field generated from the antenna (105) interacts with the metal layer (101) to change the self-resonant frequency of the antenna, thus reducing the inductance of the antenna (105) and causing communication troubles, which are due to the eddy current generated from the metal layer (101) by the magnetic field. To eliminate this, a magnetic layer (103) with high permeability and high resistance is placed between the metal layer (101) and the inlay layer to adjust the magnetic field lines.

[0037] Referring to Figure 6(b), a side view of the magnetic sheet sandwiched between adhesive layers is shown. The magnetic layer (103) is sandwiched between the adhesive layers (102 and 104) in the form of a film, all arranged in sequence to form one layer (AL). The size of this layer is the same as the size of the metal sheet layer. This layer is then punched using a sheet puncher to create through holes that match the metal layer (101) through holes.

[0038] Referring to Figure 7(a), a top view of a laminate backing for a dual interface smart card is shown. The laminate backing used here consists of an antenna (105), an antenna inlay layer (106), a printing layer (107) and an overlay layer (108) with a magnetic stripe, sequenced together. Referring to Figure 7(b), another top view of the laminate backing is shown with the arrangement of the magnetic layer and adhesive layer. The adhesive layer is sequenced with the magnetic layer (103) and placed on the laminate backing.

[0039] Referring to FIG. 7(c), a top view of the adhesive layer is shown on which the metal layer is placed. A metal layer (101) with through holes is placed on the adhesive layer and aligned. Referring to FIG. 7(d), a perspective view of the aligned metal layer (101), adhesive layer and laminate backing plate is shown. The metal layer (101), adhesive layer (AL) and magnetic layer (103) sandwiched between the backing plate (BL) are aligned and spot welded using a spot welding table. Refer to FIG. 7(e), which is a diagram of spot welding of all layers, and FIG. 7(f), which is an exploded view of all layers. The table includes heating rods and numatics cylinders that serve to apply pressure and heat to specific spots, which temporarily melt and hold all layers to form a single sheet with a thickness of 820 microns and is processed for further processing.

[0040] Referring to FIG. 8(a), a diagram of the placement of the filler material on the metal layer through the holes is shown. The aligned and spot-welded assembly including the metal layer (101) with the through holes is then inserted with a filler material that does not interfere with the transmission. The filler material (110) is placed to ensure that the inner wall of the through hole (201) and / or the outer wall of the filler material (110) is firmly attached to the wall of the through hole (201). Referring to FIG. 8(b), another exploded view of the filler layer in the dual interface smart card (100) is shown. The filler material (110) is inserted with a thickness (F1) that is 20 microns less than the metal layer (101). The width and height of the filler material (110) are the same as that of the through hole (201) dimensions on the metal layer (101) and are processed for the second lamination process. The filler material (110) bonds with the back plate without using any adhesive under said filler material (110).

[0041] Referring to FIG. 9(a), an isometric view of a laminate with an embossed layer is shown. The second step lamination process is carried out using a laminate with an embossed / raised layer on the plate to ensure that pressure is evenly applied on the filler material (110) during the lamination process. The thickness of the embossed layer is preferably 20 microns or less. Referring to FIG. 9(b), a perspective view of a laminate with a metal top surface and a plastic back surface is shown. The second step lamination process is carried out by applying a pressure of 500-700 psi at an elevated temperature of 175° C. for about 18 minutes, then cooling the layer at 25° C. and applying a pressure of 900-1000 psi for 18 minutes. The total thickness (CT) after lamination is approximately 800-810 microns. An exploded view of all the layers in the card is shown in FIG. 9(c).

[0042] Referring to FIG. 10(a), a top view of the laminate being CNC milled to form a card is shown. The laminate having a thickness of 800-810 microns is then processed through CNC milling to create individual cards (CU) containing through holes on the metal surface (101) layer. The vertical distance between cards (CH) is 55.48 mm and the horizontal distance between cards (CW) is 91 mm, with a board size of (SH) 48 mm and (SW) 300 mm. Referring to FIG. 10(b), a front view of the dual interface card after the CNC milling step is shown. The dimensions of the individual cards are as illustrated in FIG. 10(b) with a card width (W) size of 85.6 mm and card height (H) size of 53.98 mm. The location of the through holes is located at (MH) 18.5 mm from the top edge of the card and (MW) 9.5 mm from the side edge of the card.

[0043] 11, a flow chart of a method for milling an integrated circuit chip module to fill a cavity in a dual interface smart card is shown. The method for milling an integrated circuit chip module (113) to fill a cavity in a dual interface smart card (100) includes the steps of: a) milling a card having a filler layer for receiving a surface of the integrated circuit chip module (113) until a plurality of antenna (105) terminals are exposed; b) selecting an integrated circuit chip module (113) and attaching a heat-activated adhesive tape (112) onto the integrated circuit chip module (113) to expose a plurality of connectors of the integrated circuit chip module (113); c) placing the integrated circuit chip module (113) obtained from step (b) on the milled product obtained through step (a); and d) applying a solder paste onto the antenna (105) terminals to embed the integrated circuit chip module on the card.

[0044] Referring to Figure 12(a), the front and top views of the integrated circuit chip module are shown. An integrated circuit chip module (113) is selected that has dual interface connectors (115 and 116) options on the backside of the integrated circuit chip module to connect to the antenna layer (105) and enable dual interface functionality. The integrated circuit chip modules used here come in different shapes, sizes, and PIN configurations. However, the preferred dimensions of the integrated circuit chip module (IW) are 11 mm and height (IH) is 8.5 mm.

[0045] Referring to FIG. 12(b), a diagram of the heat-activated adhesive tape applied onto the integrated circuit chip module is shown. The integrated circuit chip module (113) is processed through an adhesive tape laminator where the heat-activated tape (112) is die-cut and transferred onto the backside of the integrated circuit chip module. The shape of the adhesive tape (112) is formed according to the integrated circuit chip module dimensions. The adhesive tape (112) is die-cut into a shape to ensure that the adhesive tape is not transferred onto the connectors (115 and 116) and remains open with approximate dimensions of 6.6 mm height (GIH) and 8.2 mm width (GIW). The dimensions of the applied adhesive tape with 11 mm width (GIW) and 8.5 mm height (GIH) are according to the selected integrated circuit chip module (113) size.

[0046] Referring to Figure 12(c), a schematic diagram of an integrated circuit chip module is shown. The integrated circuit chip module (113) has an overall thickness (I3) of about 580 microns, an integrated circuit chip module tape thickness (I1) of about 220 microns, and an adhesive tape (112) thickness (I2) of about 45-50 microns. The integrated circuit chip module bottom width (I4) is smaller than the width of the GIW.

[0047] Referring to FIG. 13(a), a side view of the first and second cavity milling in the dual interface card is shown. The integrated circuit chip module (113) milling and embedding process is performed using an automated milling and embedding machine using a technology named Te Connect. In this process, the card body is milled to accommodate the integrated circuit chip module (113) shape, size, and the connector pads are connected to the antenna terminals using solder paste. The adhesive tape transferred onto the backside of the integrated circuit chip module (113) and (C3) the solder paste dispensed onto the milled cavity are activated by applying heat and pressure, followed by cooling and pressure on the integrated circuit chip module. The metal card with the fill material (110) is processed for milling to accommodate the integrated circuit chip module on the body of the dual interface card. The cavity is formed through the fill material (110) to a depth (C1) of 240-260 microns from the top surface to accommodate the integrated circuit chip module and the thickness of the adhesive tape (I1 and I2). The width of (C1) is less than that of the through hole (201), which serves to create an insulating layer (IL) between the metal edge surface and the integrated circuit chip module edge. A second cavity (C2) is milled at least 20 microns higher than the thickness (I3) of the integrated circuit chip module, and the width of the cavity (C2) is made at least 1 mm higher than the bottom width (I4) of the integrated circuit chip module.

[0048] Referring to FIG. 13(b), a side view of the third and fourth cavity milling in the dual interface card is shown. The body of the dual interface card is then milled to a depth until the antenna terminal is exposed at approximately 580-590 microns (C3). (C3) is milled in a circular shape (C3D) having a diameter of 1.5 mm.

[0049] Referring to FIG. 13(c), a diagram of the milling shape and dimensions on the filler material (110) as the integrated circuit chip module (113) is shown. The milled C3 is filled with solder paste (111), which is conductive in nature and is heat treated to harden and bond. The solder paste (111) is applied just before embedding the integrated circuit chip module (113), which serves to connect the antenna (105) terminals with the integrated circuit chip module connectors (115 and 116).

[0050] Referring to FIG. 13(d), a side view of the dual interface card is shown showing the dispensing of solder paste (111) into the cavity. The integrated circuit chip module (113) is embedded into the milled portion of the card body to ensure that the integrated circuit chip module is flush with the top surface of the card body. Referring to FIG. 13(e), another side view of the dual interface card is shown showing the embedding of the integrated circuit chip module into the card surface. The embedding process is carried out with sufficient pressure and heat onto the top surface of the integrated circuit chip module. The solder paste (111) filled onto the adhesive tape (112) and (C3) on the integrated circuit chip module is activated by heat and pressure. The integrated circuit chip module is then gradually cooled at low temperature and pressure. Referring to FIG. 13(e), a diagram of the embedding of the integrated circuit chip module onto the card surface is shown. The integrated circuit chip module is ensured to be 10 microns above the card surface to allow the top surface of the integrated circuit chip module to contact a contact type reader (e.g., POS, ATM). The integrated circuit chip module is now contactless readable, thus enabling contactless reading (at POS, ATMs) as well.

[0051] Referring to FIG. 14, a perspective view of a dual interface smart card is shown, where a two-step lamination process helps to avoid the shrinkage and expansion of layers when laminating with other types of substrates. The first lamination is processed by laminating all plastic layers, such as antenna inlay layer (106), overlay layer (108) with printing sheet and magnetic stripe, and in the second lamination process, the metal layer (101) with adhesive and magnetic sheet is laminated together with filling material to form a single assembly. Besides, the laminate with embossed / raised effect on the through-hole area helps to hold uniform pressure during the lamination process. The filling material bonds strongly with the back plate without using any adhesive under the filling material. Through-holes are made on the metal surface and filling material is placed, which provides support and creates insulation between the integrated circuit chip module and the metal layer (101), and a cavity is made on the filling material to embed the integrated circuit chip module using a Te-connect compatible machine. The Te-connect process helps to obtain a higher throughput compared to the hot solder process. A primary advantage of the present invention is that it reduces the number of steps in the manufacturing process of metal surface cards.

[0052] Example 1 Experimental data analysis The present invention provides a dual interface smart card, which significantly contributes towards obtaining higher output, and a smart card that reduces the process during manufacturing by avoiding the use of adhesive under the filling material. The throughput details of the conventional chip embedding machine and the present invention are shown in Table 1.

[0053] [Table 1]

[0054] The magnetic layer prevents the metal layer from interfering with the electromagnetic field emanating from the antenna, and the magnetic layer has high permeability with high resistivity and is disposed between the metal layer and the antenna inlay layer to align the multiple magnetic lines of the electromagnetic field. Table 2 and Figure 15 show data related to high permeability with high resistivity of metal in a dual interface smart card. [Table 2]

[0055] To calculate the resistance for the metal areas in a dual interface smart card, equation (1) is used, where "R" refers to resistance. R=p*L / W (1), L / w=86 / 54-1.59 (approx.), p=10MQ, Therefore, R = 15.9MQ

[0056] Therefore, the present invention provides a metal smart card that significantly contributes to achieving higher power output and reduces processes during manufacturing by avoiding the use of adhesive under the filler material.

[0057] Many modifications and other embodiments of the inventions described herein will readily suggest themselves to one skilled in the art to which the inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. It is to be understood, therefore, that the invention is not limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms have been employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. A metal layer (101); An adhesive layer (102); A magnetic layer (103); A double adhesive layer (104); An antenna (105); an antenna inlay layer (106); A printing layer (107); an overlay layer (108) having a magnetic strip; A filler material (110); A solder paste (111); A heat-activated adhesive tape (112); An integrated circuit chip module (113) A dual interface smart card (100) comprising: The metal layer (101) serves as a surface layer of the dual interface smart card (100), and the adhesive layer (102) creates a bond between the metal layer (101) and the magnetic layer (103); The magnetic layer (103) prevents the metal layer (101) from interfering with the electromagnetic field generated by the antenna (105), and the magnetic layer (103) has high magnetic permeability with high resistivity and is disposed between the metal layer (101) and the antenna inlay layer (106) to adjust the magnetic field lines of the electromagnetic field; the dual adhesive layer (104) bonds the magnetic layer (103) with the antenna inlay layer (106), the antenna inlay layer (106) being a substrate for holding the antenna (105) to form an inlay; The printing layer (107) is for printing information for visual display; The overlay layer (108) with the magnetic stripe is a protective layer for the printed layer (107) and serves as a substrate for placing the magnetic stripe for swiping the dual interface smart card (100); and the filler material (110) spreads over the metal layer (101) to hold the integrated circuit chip module (113) and acts as an insulating layer in the dual interface smart card (100), and the filler material (110) bonds to a backing plate without the use of any adhesive underneath the filler material (110); A dual interface smart card (100).

2. 2. The dual interface smart card (100) of claim 1, wherein the metal layer (101) is made of materials including, but not limited to, stainless steel plate, aluminum plate.

3. 2. The dual interface smart card (100) of claim 1, wherein the adhesive layer (102) and the dual adhesive layer (104) are made from a heat-activated material such as a thermoplastic.

4. 2. The dual interface smart card (100) of claim 1, wherein the magnetic layer (103) has a thickness in the range of 45-55 microns magnetic layer (103) and exhibits a resistivity in the range of 15-17 MQ and a permeability in the range of 45-65 μ'.

5. The dual interface smart card (100) of claim 1, wherein the antenna (105) is made from materials including, but not limited to, a copper coil.

6. 2. The dual interface smart card (100) of claim 1, wherein the heat-activated adhesive tape (112) is an adhesive film that is transferred onto the backside of the integrated circuit chip module (113).

7. 2. The dual interface smart card (100) of claim 1, wherein the integrated circuit chip module (113) includes an antenna pad, and wherein the integrated circuit chip module (113) stores data in accordance with a payment method standard.

8. A method for manufacturing a dual interface smart card (100), comprising the steps of: a) providing a metal layer (101); b) selecting a dual adhesive layer (104) and a magnetic layer (103); c) providing an antenna inlay layer (106); d) providing a plastic backing plate; e) providing said magnetic layer (103) and adhesive layer; f) sequencing said layers to form an assembly of said dual interface smart card (100); g) laminating the assembly and preparing the integrated circuit chip module (113) for embedding; h) milling the metal card to embed the integrated circuit chip module (113) to produce the dual interface smart card (100) with a metal surface layer; Including, The metal layer (101) is processed through an automated tool to create pin holes; The dual adhesive layer (104) and the magnetic layer (103) are sequenced together and holes are created on the sequenced dual adhesive layer (104) and magnetic layer (103); The antenna inlay layer (106) is prepared by embedding an antenna layer onto a plastic layer, and the antenna inlay layer (106) is flattened by a lamination process to form the antenna inlay layer (106); The plastic backing is printed with any information forming a printing layer (107) and a plurality of magnetic strips are transferred onto an overlay layer (108); The antenna inlay layer (106), the plastic backing plate and the overlay layer (108) are spot welded together to form a laminated backing plate to avoid shrinkage and expansion of the layers, and pin holes are made on the laminated backing plate; The metal layer (101), the double adhesive layer (104) and the laminate backing are arranged in sequence and a filler material (110) is applied through the holes made in the metal layer (101) to form the assembly; the assembly is laminated to form a laminated metal card; The milling of the metal card to embed the integrated circuit chip module (113) is done through a Te-connect process, which helps to obtain a higher throughput compared to a hot solder process. A method for manufacturing a dual interface smart card (100).

9. 9. The method for manufacturing a dual interface smart card (100) as claimed in claim 8, wherein the lamination process is carried out by applying a pressure in the range of 700-800 psi at an elevated temperature in the range of 150-152°C for about 10-12 minutes, followed by cooling at 20-25°C, and again applying a pressure of 1200-1500 psi for 12-14 minutes to form the antenna inlay layer (106).

10. A method for milling an integrated circuit chip module (113) in a dual interface smart card (100) to fill a cavity, comprising the steps of: a) milling a card having a filler layer for receiving a surface of the integrated circuit chip module (113) until a plurality of antenna terminals are exposed; b) selecting the integrated circuit chip module (113) and attaching a heat-activated adhesive tape (112) onto the integrated circuit chip module (113) to expose a plurality of connectors of the integrated circuit chip module (113); c) placing the integrated circuit chip module (113) obtained from step (b) on the milled product obtained through step (a); d) applying solder paste (111) onto the antenna terminals to embed the integrated circuit chip module (113) onto the dual interface smart card (100); A method comprising:

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