Abstract:
A method for producing a data storage medium body for a portable data storage medium having a core layer and at least one top layer, wherein the core layer contains a chip module. The chip module has a surface which is adverse to lamination and has an adhesive deposit applied on the module surface; a recess is provided in the core layer and the chip module is inserted into the recess such that the module surface having the adhesive deposit is situated towards the open side of the recess; a top layer is applied over the module surface; then the above arrangement is laminated. The adhesive deposit combines intimately with the adjoining top layer.

Description:
BACKGROUND OF THE INVENTION 
     A. Field of the Invention 
     This invention relates to a method and an object according to the species of the independent claims. The invention relates in particular to a method for manufacturing a contactlessly readable identification document with integrated IC, which can be used as an identity card or as a data page in a passport booklet, as well as to a corresponding identification document. 
     B. Related Art 
     Identification documents such as identity cards or passports are increasingly provided with transponder arrangements which consist of a chip module, which contains an IC, and an antenna connected therewith. These chip-coil arrangements allow the data stored in the IC to be contactlessly read. The manufacturing of such identification documents is typically effected by laminating at least one core layer and two cover layers, the chip-coil arrangement being integrated into the core layer. A problem with respect to the durability of such identification documents is the bond between the IC-module and the document body. The two consist of different materials, the module material is hard and high-melting, while the material employed for the document body is comparatively soft and readily laminatable. The different material consistence of IC-module and document body, upon long-term use of a corresponding identification document, sometimes leads to the formation of cracks—emanating from the border region between chip module and document body—in the bordering layers. The cracks spread into the cover layer lying next and impair appearance and mechanical stability of the identification document. 
     In order to prevent such cracks in portable data carriers used as identification documents, it has been proposed in WO 2007/089140 A1 to provide a further layer between module upper side and cover layer, and to provide a non-continuous auxiliary layer insert between the further layer and the cover layer, which is slightly larger than the module upper side and consists of a rubberlike material with a particularly high coefficient of expansion. The auxiliary layer insert makes sure that cracks possibly emanating from the transition region between module and core layer do not spread into the cover layer in any case. An analogous auxiliary layer insert can also be provided for the narrower underside of the module. 
     From WO 2009/135823 A1 there can be inferred, likewise for the purpose of eliminating the development of cracks, a structure for a multilayer body of an identification document, in which individual layers contain inserts made of a softer material. A chip module to be integrated into the document body is now arranged exactly in such a patch made of softer material. The extension of the patch here is larger than the module. Upon laminating, the softer material then flows completely around the module and embeds it form-fittingly. In this way, stress zones leading to cracks can be prevented. Realizing the patchwork-like layers is elaborate, however. 
     From DE 199 21 230 A1 there is known a method for manufacturing a chip card with direct use of a thinned chip instead of an otherwise usual chip module. The chip is manufactured in a wafer and placed at the component side with interposition of a detachable interim adhesive on a carrier band where it is thinned from the back. After removal of the interim adhesive, the thinned chip is inserted in a cavity prepared in a chip card body. In so doing, it is fixed in the cavity with the aid of a further adhesive applied for this purpose on the back of the chip. Onto the component side there is then laminated a chip card foil, on which there are formed conductor paths which contact the component side of the thinned chip. The problem of a possible cracking does not exist with especially thinned chips, because in the finished card body they occupy with their minimum thickness and their small area only a very small installation space, from which there do not emanate any crack-forming disruptions. The handling of the chips, however, is very elaborate in comparison to the handling of chip modules. 
     In the book, “Vom Plastik zur Chipkarte” by Y. Haghiri, T. Tarantino, Carl Hanser Verlag, Munich, 1999, there are described manufacturing methods for chip cards, in particular the lamination technique. 
     It is the object of the invention to state a method which allows crack-resistant data carriers to be manufactured without substantial interventions in the lamination process. 
     SUMMARY OF THE DISCLOSURE 
     The method according to the invention has the advantage that changes in the course of the method need to be made only in the preparation of the chip modules for the installation in a data carrier body, while the subsequent lamination process itself can be carried out in the same way as the lamination of usual data carriers which are not particularly designed to crack resistance. 
     The method according to the invention furthermore has the advantage, that it allows modules to be effectively integrated in data carrier bodies which actually have surfaces adverse to lamination. Among other things, it becomes possible to integrate modules with metallic upper sides or modules with non-stickingly configured surfaces into a data carrier body such that the chip module and all the layers form a continuous strong composite. 
     In an advantageous embodiment of the method according to the invention, the chip modules are provided, before the lamination, with an insert of an adhesive that is coordinated in exact register with their surface, which adhesive, upon lamination, enters into an intimate connection both with the bordering continuous layer and with the chip module surface adverse to lamination. The adhesive preferably is a so-called hot-melt adhesive. 
     Advantageously, the adhesive for producing the adhesive insert is made available in a two-layer adhesive band which consists of a detachable handling layer and the actual adhesive layer. The handling layer is removed after application of the adhesive band on the chip module. In this way, the adhesive band can advantageously be made available in roll form and processed therefrom. 
     In an advantageous embodiment, the chip modules are first located in a module carrier band and likewise are made available in roll form. Bringing together adhesive band and module carrier band can thus be realized particularly efficiently. 
     In a particularly advantageous use, the method according to the invention is suitable for manufacturing a contactlessly readable identification document with integrated IC, which can be used as an identity card or as a data page in a passport booklet. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       An embodiment of the invention will hereinafter be explained more closely with reference to the drawing. 
       There are shown: 
         FIG. 1  in cross section, bringing together a module carrier band and an adhesive band, 
         FIG. 2  in cross section, a module carrier band, after connection with the adhesive band, upon detaching the handling layer, 
         FIG. 3  in cross section, a module carrier band with applied adhesive layer, before the singling by means of a punching tool, 
         FIG. 4  a singled chip module provided with an adhesive insert, upon metering a contact adhesive onto the back of the module, 
         FIG. 5  in cross section, a layer stack consisting of layers to be laminated for manufacturing a data carrier body, together with a chip module provided with adhesive insert and contact adhesive, upon inserting the chip module in the recess, 
         FIG. 6  in cross section, an arrangement of layers to be laminated for manufacturing a portable data carrier with inserted chip module, before lamination, and 
         FIG. 7  in cross section, a portable data carrier of plastic material, after lamination. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The manufacturing method described below is basically divided in a preparation phase in which the chip module as well as the further layers and components of a data carrier body are made available, and a lamination process in which the constituents made available are permanently connected with each other by lamination, i.e. by applying pressure and heat. There is manufactured a multilayer, flat, portable plastic data carrier body, which serves either as an inlay for a ready-to-use data carrier or already is a finished data carrier. A ready-to-use data carrier serves e.g. as an identification document, for instance as an electronic identity card or as an electronic passport. 
       FIG. 1  shows the first step of the preparation phase, in which a two-layer adhesive band  10  and a module carrier band  20  are connected to each other. The adhesive band  10  consists of a handling foil  12  and an adhesive layer  14 . The handling foil  12  adheres only slightly to the adhesive layer  14  and is detachable from this. The handling foil  14  facilitates the handling of the adhesive band  10 ; it is accordingly dispensable when the constitution of the adhesive layer  14  allows this or suitable means are available that allow a direct handling of the adhesive layer  14 . The adhesive forming the adhesive layer  14  is preferably a hot-melt adhesive which is coordinated to the surface of the module carrier band  20  and first of all adheres to this surface in the region of the chip modules  22 . The melting temperature of the hot-melt adhesive expediently lies in the range of 100° C. to 150° C., preferably in the range of 110° C. to 120° C. 
     The surface of the module carrier band  20  is often adverse to lamination, i.e. it enters into no, or only a poor connection, with the next adjacent plastic layer under the usual card-laminating conditions under which the plastic layers placed together for the usual card manufacturing connect. The softening point of the surface of the module carrier band  20  lies at least in certain regions above the temperature at which the further layers used for constructing an inlay or a data carrier enter into a connection upon lamination. 
     The module carrier band  20  carries chip modules  22  arranged in one or several rows, which expediently were constructed directly on the module carrier band  20 , so that the surfaces  24  of the chip modules  22  are part of that surface of the module carrier band  20  which faces the adhesive band  10 . The chip modules  22  typically have a T-shaped profile with a wide head portion  26  with the surface  24  and a, in comparison, narrower base portion  28  with the underside  29 . The surface  24  normally has a noticeable extension which can amount to e.g. some mm 2 . The edge contour of the surface  24  is normally formed, due to production-related reasons, by a sharp—in contrast to a rounded—edge sloping in a 90°-angle. The head portion  26  typically contains metallic structures, which serve for example as conductor paths or contact areas. The metallic structures are in particular also part of the surface  24  of the head portion  26 . Metallic structures which likewise serve in particular as conductor paths and/or contact areas are further also located at the underside shoulder areas  27  in the protrusion region of the head portion  26 . They later serve for the electrical connection of the chip module  22  with a coil, antenna or any other conductor structure. 
     In an expedient manufacturing technique the module carrier band  20  and the chip modules  22  formed therein are based on the so-called lead-frame technique. The module carrier band  20  here is formed by a metal band, in which a layout is produced by incorporating corresponding recess structures. In an alternative manufacturing technique the module carrier band  20  consists of a fiber-reinforced polymer, for instance a so-called FR4-material, which can be coated on one or on both sides with a conductive material, in which a layout is created. The conductive material can be for example a copper foil that has a nickel/gold coating applied thereon. 
     The individual chip modules  22  are normally pre-separated by a perforation or pre-notching or comparable predetermined separating structure  21 , bordering the contour, from the module carrier band  20 , so that a subsequent final detaching is facilitated. The base  28  of the chip module  22  normally includes one or several ICs and is typically formed by a plastic encapsulation created around the one or more ICs. The encapsulation consists of a high-melting plastic material, which does not soften during the subsequent lamination. 
     Adhesive band  10  and module carrier band  20  are expediently made available on rolls and starting out therefrom are brought together for connection such that the adhesive layer  14  comes to lie on that side of the module carrier band  20  which contains the surfaces  24  of the head portions  26  of the chip modules  22 . The connection of adhesive band  10  and module carrier band  20  is effected under pressure and at a temperature, coordinated to the adhesive layer  14 , which activates the adhesive. 
     After the connection of adhesive band  10  and module carrier band  20 , the handling foil  12  is removed from the adhesive layer  14 , as illustrated in  FIG. 2 . 
     From the thereafter existing composite of module carrier band  20  and adhesive layer  14 , the individual chip modules  22  are subsequently detached with the aid of a singling tool  30 , as shown in  FIG. 3 . In so doing, the singling tool  30  separates the chip modules  22  along the predetermined separating structures  21  or, if such structures do not exist, along the circumferential contour defined for the head portion  26 . In so doing, together with the chip module  22  an adhesive insert  16  is detached from the adhesive band/module carrier band composite, which covers the entire surface  24  of the head portion  26  of the chip module  22  and the edge contour of which is exactly aligned with the circumferential contour of the head portion  26 . The singling tool  30  can be a punching or cutting tool, as indicated in  FIG. 3 . The singling can also be readily effected by means of laser, by means of water jet, or with other suitable tools. 
     On the underside  29  of the chip module  22 , which has been singled and provided with an adhesive insert  16 , in the following step a contact adhesive  17  is applied, as shown in  FIG. 4 . This application is expediently effected by metering a liquid adhesive. As an adhesive there is employed a usual contact adhesive, here. The thereafter existing chip module  22  carries on its surface  24  an adhesive insert  16  matching the contours of the surface and on its underside  29  a contact adhesive  17 . 
     As an alternative to the application on the underside  29  of the chip module  22 , the contact adhesive  17  can also be metered into the recess  43 , in which the chip module  22  is subsequently inserted. 
     The chip module  22  is subsequently inserted, as illustrated in  FIG. 5 , in a layer stack prepared for the lamination. The total height of the layer stack is greater than that of the chip module  22 , so that this can be completely accommodated in the layer stack, but not so great, however, that the height of the chip module  22  could be neglected; the height of the chip module  22  typically amounts to between 10% and 90% of the total height of the layer stack. 
     The layer stack consists of a multilayer core layer  40  as well as of respectively at least one upper cover layer  50  and one lower cover layer  52 . The cover layers  50 ,  52  are continuous, i.e. they cover the entire surface area of the data carrier body, consist of a usual suitable plastic material, e.g. of polycarbonate (PC), and respectively have a thickness of e.g. 30 μm. In the embodiment, the core layer  40  in turn consists of two partial core layers  42 ,  44 , wherein the first partial core layer  42  e.g. in turn consists of polycarbonate (PC) and has a thickness of e.g. 105 μm, and the second partial core layer  44  likewise e.g. consists of polycarbonate and has a thickness of e.g. 150 μm. The thicknesses of the partial core layers  42 ,  44  here are adapted to the chip module  22 . Instead of polycarbonate, the partial core layers  42 ,  44  can also consist of a different usual plastic material. The first partial core layer  42  further has a recess  43 , the second partial core layer  44   a , in comparison, wider recess  45 . Both recesses  43 ,  45  together form at least approximately a negative of the outer contour of the chip module  22  coated with the adhesive insert  16 . 
     On the first partial core layer  42  there is arranged a coil  60 . It can be configured as a wire conductor or printed conductor path or also be etched. The coil  60  has connecting contacts  62  which are arranged on the surface regions protruding relative to the second partial core layer  44 , so that they are openly accessible for a later contacting. 
     Expediently, the lower cover layer  52  is made available together with the partial core layers  42 ,  44  and the recesses  43 ,  45 , as indicated in  FIG. 5 , so that the recesses  43 ,  45  form a downwardly closed two-step recess. In the partial core layers  42 ,  44  arranged one over the other the chip module  22  is inserted in the two-step recess  43 ,  45  such that the shoulders  27  come to lie on the contacts  62  of the coil  60  and the module surface  24  provided with the adhesive insert  16  lies facing the upper open side of the recess  43 ,  45 . The surface of the adhesive insert  16  on the chip module  22  is here preferably flush with the surface of the partial core layer  44  or is dimensioned such that it is in any case aligned with the surface of the partial core layer  44  after the subsequent lamination, except for allowable tolerances as typically specified by relevant standards or specifications. The surface of the adhesive insert  16  and the surface of the partial core layer  44  thus together form a consistently planar area which has the upper cover layer  50  arranged thereon. Thus, the upper cover layer  50  itself is accordingly completely planar. 
     Alternatively, the insertion of the chip module  22  can also be effected first, before the resulting arrangement is subsequently covered with the upper and the lower cover layer  50 ,  52 . It is also possible to connect the partial core layers  42 ,  44  and the lower cover layer  52  to each other in a preparatory lamination step, so that the two recesses  43 ,  45  form a stepped contiguous recess, in which the chip module  22  is inserted. Instead of two partial core layers  42 ,  44 , also a larger number of partial core layers can be provided. It is also possible to use a single pre-manufactured core layer  40  which contains coil  60  and connecting contacts  62  and in which a suitable recess  43 ,  45  was incorporated e.g. by milling. Upon installation of the chip module  22  in the arrangement formed by the partial core layers  42 ,  44  and the lower cover layer  52 , the module  22  adheres at its underside  29 , with the aid of the contact adhesive  17  applied thereon, to the lower cover layer  52 . 
     The thereafter existing arrangement can be an inlay for a portable data carrier. For completing a portable data carrier, on such an inlay arrangement there can be placed further, outer cover layers  54 ,  56 , which serve e.g. for personalization or as a decorative or protective final layer. The further cover layers  54 ,  56 , likewise, consist of laminatable plastic materials such as PC, PET or the like. The resulting data carrier arrangement can then e.g. consist of a total of ten layers, as shown in  FIG. 6 , namely the two partial core layers  42  and  44 , the upper and the lower cover layer  50 ,  52 , as well as three further upper and lower cover layers  54 ,  56 . The cover layer  50  can be omitted when further cover layers  54 ,  56  are applied, in particular when the lamination is effected in one step and there is immediately manufactured a finished data carrier. 
     The such prepared arrangement is finally laminated. The lamination process is carried out in a per se known manner, as it is described for instance in the above-mentioned book “Vom Plastik zur Chipkarte”. The surface  24  of the chip module  22  may be adverse to lamination here and under laminating conditions, under which the core layer  42 ,  44  and the cover layer  50  enter into a good connection, it may enter into no, or only a poor, connection with the next adjacent cover layer  50 ,  54 . 
     Nevertheless, there arises a good lamination composite, which also includes the surface  24  of the chip module  22 . Because upon lamination, the adhesive insert  16  located on the surface  24  of the chip module  22  intimately connects with the superjacent upper cover layer  50 . Especially this intimate connection, which cannot be achieved with a simple, direct lamination of the surface  24  and the upper cover layer  50 , effects that the susceptibility of the arising inlay or of the resulting data carrier to the development of cracks, which emanate from the chip module  22 , in the cover layers  50  to  56  is significantly reduced. 
     In an expedient embodiment the lamination can be effected in one single lamination step in which all existing layers, i.e. layers  42 ,  44 ,  50 ,  52 ,  54 ,  56 , or layers  42 ,  44 ,  50 ,  52 , or layers  42 ,  44 ,  52 ,  54  are jointly connected. The temperature here lies expediently between 130 to 180° C., preferably at 175° C. to 180° C. The result is a data carrier which is usable selectively and depending on the layer sequence as an inlay or which e.g. forms already a physically finished chip card. 
     In a likewise expedient alternative, the lamination is effected in two steps, first an inlay is laminated of the partial core layers  42 ,  44 , lower cover layer  50  and upper cover layer  52  at a slightly lower temperature of e.g. 160° C. to 170° C., or, if PVC is employed, at an accordingly still further reduced temperature. Then, in a second lamination step, at the same temperature, the further cover layers  54 ,  56  are laminated to form a finished data carrier. In this case, the further cover layers  54 ,  56  are placed thereon only after the inlay was laminated. There can be readily provided more than two lamination steps, in which the layers or further layers are individually laminated. The multi-step lamination is somewhat more elaborate, but allows lower temperatures to be employed and accordingly protects the IC contained in the chip module  22 . 
       FIG. 7  shows in cross section the chip module region of a finished data carrier, as it is obtained after lamination from an arrangement shown in  FIG. 6 . The data carrier is characterized by the fact that, as indicated by the dashed line, the surface formed by the adhesive insert  16  and the surface of the core layer  42 ,  44  altogether form, towards the cover layer  50  and the following layers  54 , a planar surface, except for allowable tolerances as typically specified for instance by standards or in specifications for data carriers. The data carrier therefore has at its outer side formed by the cover layer  54  a completely planar surface. The connection between the core layer  44  or the adhesive insert  16  and the cover layer  50  is consistently good here. Such a data carrier can be for example a contactlessly readable identification document with an integrated IC, which independently serves as an identity card or which is integrated as a data page into a passport booklet. 
     While keeping the basic concept, namely to preparatorily apply, before lamination, on the surface  24  of a chip module  22 , which is per se adverse to lamination, an adhesive insert  16  for achieving in this way an intimate connection between the surface  24  and the adjacent upper cover layer  50 , the above-described invention allows a number of embodiments. For instance the layer stacks shown in the  FIGS. 6 and 7  can have further layers, or intermediate steps can be provided in the execution of the described procedure steps.