Patent Application
20110024036
This invention concerns radio frequency identification devices designed to be built into communicating objects and specifically concerns a radio frequency identification device support for hybrid card and its manufacturing method.
Contactless radio frequency identification devices (RFIDs) are increasingly used for identification of persons moving about in controlled access zones or transiting from one zone to another. A contactless RFID is a device made up of an antenna and a chip connected to the terminals of the antenna. The chip is usually not powered and receives its energy by electromagnetic coupling between the antenna of the reader and the antenna of the RFID, information is exchanged between the RFID and the reader and particularly information stored in the chip that relates to the identification of the holder of the object on which the RFID is located and to his/her authorization to enter into a controlled access zone.
The hybrid contact-contactless smart cards contain such an RFID, except that the exchange of data with the reader can also take place by contact on flush and conducting contact pads of the card connected to the chip. The chip is thus integrated in a circuit whose external face features the groups of flush contacts. The chip is also connected to the internal face of the circuit designed to connect to the card's antenna. Thus, the chip is connected to both sides of a double-sided circuit to form a double-sided integrated circuit module once encapsulated. Generally speaking, the method for manufacturing contact-contactless hybrid smart cards includes the following steps:
However, this manufacturing method does not provide a semi-finished product equipped with the module and the antenna connected together since the connection of the module is done during the last manufacturing step. Such semi-finished products equipped with the module and the antenna connected together would allow manufacturers who are not specialized in electronics to manufacture and customize hybrid smart cards by procuring these products.
Furthermore, the module milling and insertion steps are performed on one single card at a time, which represents a drawback for efficiency.
There are methods for producing RFIDs that include an antenna and a chip connected together on a support, the assembly obtained being commonly referred to as an “inlay”. It is also known that such inlays are also produced for hybrid contact-contactless smart cards with a copper antenna by a method including the following steps:
The drawback of this process resides in the complex embodiment of the connection between the antenna and the chip. Actually, this step of the method comprises a set of sub-steps consisting in producing a connecting pit in the thickness of the antenna support in line with the antenna contacts, in filling these wells with a conducting material so as to make a reliable electric connection between the antenna contacts and the internal contacts of the double-sided circuit through the thickness of the support. Furthermore, the inlay manufactured according to this method includes at least two rigid layers between which the antenna is inserted.
This is why the purpose of the invention is to counter these drawbacks by offering an RFID support or flexible “inlay” featuring a double-face integrated circuit connected to an antenna.
Another object of the invention is to provide a hybrid contact-contactless smart card integrating such a support.
The object of the invention is thus a method for manufacturing a radio frequency identification device (RFID) support featuring an antenna and a double-sided integrated circuit module featuring internal contacts and external contacts connected to a chip encased in a module, the method including the following steps:
The purposes, objects and characteristics of the invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which:
In the description that follows, the device referred to as the “inlay” designates the radio frequency identification device (RFID) support for hybrid contact-contactless smart card able to communicate, at this stage, with the appropriate reader by contact or remotely.
According to
An antenna is made on a support layer 40. The antenna features a set of one or more turns and at least two contacts 43 and 44. The turns and the contacts are made by screen printing, flexography, rotogravure, offset printing or inkjet printing with epoxy type conductive ink loaded with conductive particles such as for example silver or gold or with a conductive polymer. According to one embodiment, the ink for the antenna contacts is made from a flexible ink. The support layer 40 is preferably made of a non-creeping material (i.e. a material that does not deform under the effect of the temperature) such as paper or synthetic paper (Teslin-type) or possibly another material such as polycarbonate, PET or PVC. The support layer 40 features a recess 41 whose dimensions correspond to those of the encapsulation 18 of the module 10. At this step of the manufacturing method, the ink making up the antenna is not baked, i.e. it has undergone neither heat nor pressure treatment; however, it is dry.
A gluing step of the module is performed at the same time. According to
The module is then placed in a recess 41 of the support 40 so that the internal contacts 13 and 14 are located opposite the antenna contacts 43 and 44. The thickness of the contacts is between 5 and 10 μm.
In order to facilitate positioning the module in relation to the foreseen location on the support 40 and to protect it, a plate 80 made of a hard and pressure-resistant material is provided with a recess 81 corresponding to the imprint of the module placed on its external face, thus on its flush contacts and whose depth corresponds to the height of the module at the location of the internal contacts 13 and 14. This thickness is between 200 and 240 μm depending on the type of module. The module is placed in the recess 81 on its external contacts 12 so that its internal contacts 13 and 14 are visible and accessible. The plate 80 is a tool and is used as a lower lamination plate during the lamination steps that follow. The plate 80 can contain a plurality of recesses 81 in order to produce several cards at a time. In this case, the support layer 40 in the form of a large sheet also contains the same number of antennas. According to one embodiment, the recesses 81 in the lower lamination plate are provided with a magnet designed to retain the module during implementation of the method.
The following step of the method consists in a preliminary lamination that allows the module to be connected to the antenna.
According to a first embodiment, the RFID support is in the form of a single layer 40. The lamination step consists in subjecting all layers to an increase in temperature up to 150° C. and an increase in pressure from 0.5 bar up to a few bar (which corresponds to approximately 10 N/m2) followed by a decrease in temperature and a decrease in pressure, the whole according to a set of cycles of defined duration. During the lamination, an upper lamination plate 90 is also placed on top of the layer 40 and the module. In this way, and owing to the lamination plates 80 and 90, the pressure is uniformly distributed and is exerted on the entire layer 40. Owing to the increase in pressure and temperature, the antenna contacts 43 and 44 deform and fill the cavities 113 and 114 of the film of glue until they rest against the internal contacts 13 and 14 of the module. Thus, there is intimate contact between the internal contacts 13 and 14 of the module and the conductive ink of contacts 43 and 44 on a maximum contact surface due to the deformation and crushing of the ink of the antenna contacts and their bonding to the contacts 13 and 14 of the module. The electrical connection between the module and the antenna is made. Furthermore, during the increase in temperature and pressure, the film of glue 110 softens slightly so as to mate with the connection made between the antenna contacts and the internal contacts of the module. Owing to the decrease in temperature, the film of glue hardens and maintains the contact between the module and the antenna contacts. The temperature reached is such that the glue reaches its threshold of irreversibility, i.e. that it will not soften even when heated to an equal or higher temperature. According to one embodiment, the upper lamination plate 90 is provided with protrusions 93 and 94. These protrusions are located on plate 90 so that, during the first lamination step, they are aligned vertically with contacts 43 and 44 of the antenna and recesses 113 and 114 in the film of glue. During the first lamination step, the protrusion press the contacts 43 and 44 through layers 50 and 40 in order to have the contacts deformed and stamped into recesses 113 and 114 in the film of glue.
The conductive ink of the contacts being deformable although non-elastic, the antenna contacts do not tend to return to their original shape even when the pressure is released. A hybrid contact-contactless smart card inlay is thus obtained in which the module is prominent in relation to the antenna support.
According to a second embodiment, a layer of PVC 50 is placed on the support layer 40 prior to the first lamination step on the face of the support opposite that on which the antenna is printed. During the lamination, this layer softens and welds itself to the antenna support layer 40.
The radio frequency identification device support or inlay 52 produced has a total thickness of 570 μm (+/−10%), 220 μm of which corresponds to the protrusion of the module in relation to the antenna support layer.
The hybrid contact-contactless smart card is completed after a second lamination step consisting in applying pressure and heat. Two layers 60 and 70 are positioned on either side of the inlay 52 obtained according to any one of the manufacturing methods described above. The external face of the two card bodies 60 and 70 were previously printed with the customized graphic image of the card. The card body 70 placed on the antenna and on the external face of the module 10 is pierced by a recess 71 corresponding to the size of the external contacts 12 of the module. The shape of the recess 71 is such that it matches the edges of the external face of the module 10. A hot press molding technique is used to weld the two card bodies 60 and 70, having a thickness equal to approximately 160 μm, onto both faces of the inlay 52. This step is more like gluing than welding. As a result, the pressure and temperature required in this phase are much lower than those used for the first lamination step. The temperature and pressure necessary for this lamination step are no more than approximately 120° C. and 150 bar, respectively. Furthermore, the duration of the pressurization and temperature cycles is also reduced.
Each card body 60 and 70 consists of one or more layers. When the card bodies have more than one layer, they can be glued together during the lamination process on the inlay or independently.
The material used for the layers 40, 50, 60 and 70 can be polyvinyl chloride (PVC), polyester (PET, PETG), polypropylene (PP), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) or a polyurethane (PU) film, paper or synthetic paper such as Teslin.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0903703 | Jul 2009 | FR | national |
