Abstract:
The invention relates to a method and a semifinished product for producing an inlay, in particular for chip cards, stored value cards, identification documents, or the like, having at least two electronic components, all electronic components being arranged in a relative configuration on a carrier substrate to implement a component configuration and the component configuration being arranged in a filler material. Furthermore, the invention relates to a method for producing a card having a semifinished product and a card produced using the semifinished product.

Description:
RELATED APPLICATIONS 
       [0001]    This application is the U.S. National stage of International Application No. PCT/EP2007/010190, filed on Nov. 23, 2007, in German, which claims priority to German Patent Application No. 10 2007 008 487.2, filed on Feb. 19, 2007. The entire teachings of the above applications are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a method and a semifinished product for producing an inlay, in particular for chip cards, stored value cards, identification documents, or the like, having at least two electronic components. All electronic components are arranged in a relative configuration on a carrier substrate to implement a component configuration. The component configuration is arranged on a first cover layer. A spacer layer having a through opening is applied to the first cover layer, and the component configuration is accommodated by the through opening. A filler material is introduced which at least fills up the through opening. A second cover layer is applied to the spacer layer, and the filler material is solidified on the cover layers while implementing a pressure force. Furthermore, the invention relates to a method for producing a card using a semifinished product and a card comprising a semifinished product of this type. 
       BACKGROUND 
       [0003]    Methods and semifinished products for producing an inlay of the type cited at the beginning are well-known and are regularly used for producing a precursor product of chip cards, bank cards, access control cards, passport documents, or the like. The production of inlays and/or cards of this type is typically performed by hot lamination, i.e., various plastic layers are compressed with electronic components situated interposed and are bonded to one another at a relatively high temperature. The hot lamination is often applied both for producing an inlay and also for producing a card. In the event of the integration of multiple electronic components in an inlay and/or a card, such as displays, LEDs, miniature loudspeakers, batteries, etc., the hot lamination technology has proven to be disadvantageous. The incorporated components are partially temperature-sensitive and are not resistant to the typical hot lamination temperatures, which may be up to 150° C. The electronic components may also have a complex geometry, so that it is difficult to fit these components in a layered composite having punched windows for accommodating the components. 
         [0004]    Production methods which avoid the above-mentioned disadvantages are so-called “cold lamination”, in which the electronic components are cast between two layers using a cold-curing filler material, and so-called “warm lamination”, in which adhesive material is caused to cure between layers at comparatively low temperatures. 
         [0005]    An array of production variants of these methods for producing an inlay and/or a card are thus known from the prior art. In the known methods, for example, a second positioning layer is laid as a positioning aid on one layer of a card, this second layer having recesses which correspond to the geometric shapes of electronic components to be inserted. After the components and the second layer are cast in a filler material, a third layer is applied at a defined distance which determines the thickness of the card before curing of the filler material. The positioning layer may, inter alia, comprise a porous material so that the filler material penetrates into the positioning layer. The positioning layer may also be essentially completely enclosed by the filler material and may form an element which stabilizes the card. This known method from the prior art is distinguished in that the positioning layer is compressed under pressure with the filler material interposed and the components. In certain circumstances, a pressure force which damages the components is exerted on the electronic components in this case. Precise positioning of all components within a middle layer implemented from filler material may also only be determined with difficulty in a method of this type. The components may be displaced both in the horizontal and also the vertical directions in an undesired manner by the application of filler material and/or the compression. This is especially probable and undesirable in particular if electronic components having different geometric shapes are used simultaneously, such as a coil antenna or a display. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention is therefore based on the object of proposing a simple and cost-effective method and/or semifinished product for producing an inlay for a chip card, which avoids destruction of electronic components by high temperatures and pressure forces, allows the simultaneous use of electronic components having different geometric shapes, and ensures a defined relative configuration of all components in a card body. 
         [0007]    In the first method according to the invention for producing an inlay having at least two electronic components, all electronic components are arranged in a relative configuration on a carrier substrate to implement a component configuration, and the component configuration is arranged on a first cover layer. A spacer layer having a through opening is then applied to the first cover layer, the component configuration being accommodated by the through opening, a filler material which at least fills up the through opening being introduced therein, a second cover layer being applied to the spacer layer, and the filler material being solidified on the cover layers while implementing a pressure force. 
         [0008]    In the second method according to the invention for producing an inlay having at least one electronic component, all electronic components are arranged in a relative configuration on a carrier substrate to implement a component configuration. A spacer layer having a through opening is applied to a first cover layer, and a component configuration is then arranged on the first cover layer, the component configuration being accommodated by the through opening, a filler material at least filling up the through opening being introduced therein, a second cover layer being applied to the spacer layer, and the filler material being solidified while implementing a pressure force on the cover layers. 
         [0009]    In both methods, a spacer layer is advantageously used, the spacer layer defining the spacing of both cover layers and thus the thickness of the card inlay. If a pressure force is exerted on the cover layers during the subsequent curing of the filler material, the pressure force may be essentially absorbed by the cover layer without the component experiencing a pressure force. Thus, components of different sizes, in particular heights, may also be introduced into the through opening of the spacer layer, the height of the components never exceeding the thickness of the spacer layer, however. Furthermore, it is ensured by arranging all electronic components on a carrier substrate that the components are not displaced from their defined relative position by the filling of the filler material or by the exertion of a pressure force. Thus, for example, the height of a display and/or its relative position to a button element is/are definable easily. The method is also simplified as a whole, because all components are arranged on the first cover layer in a single method step. The electrical connection lines of the components to one another are also not altered and/or damaged by the filling of the filler material and/or the exertion of the pressure force, so that a functional check of the component configuration is already possible before the component configuration is arranged on the first cover layer. 
         [0010]    In one embodiment of the method, before the component configuration is arranged on the first cover layer, a first quantity of filler material may be introduced into the through opening, the electronic components may be arranged in a relative configuration in the filler material, and the filler material may be solidified to form a carrier substrate. It is thus ensured on the one hand that all components are completely enclosed by filler material, and on the other hand that all components are permanently positionable within a defined relative position in the filler material. The subsequent method steps may thus no longer influence the relative position of the components. A carrier substrate having different positioning levels for components within an inlay may also be implemented by different sequential deliveries of filler material into the through opening. 
         [0011]    It has been proven to be especially advantageous if the solidification of the filler material is performed by a temperature impingement, the temperature not exceeding a temperature which damages components. In addition to the use of cold-curing artificial resins as the filler material, a casting material may thus be used as the filler material which may be activated and cured at a relatively low temperature, such as 80° C. Therefore, there is no damage to the components by a relatively high temperature as in hot lamination, and the curing may be performed comparatively rapidly in relation to cold-curing artificial resins because of the temperature activation. 
         [0012]    If the component configuration is fixed on the first cover layer, slipping and/or a position change of the component configuration as a result of the supply of filler material into the through opening may advantageously be prevented. 
         [0013]    The component configuration may be fixed easily on the first cover layer using a fixing layer which is implemented between a bottom side of the component configuration and the first cover layer. A fixing layer of this type may be entirely or partially applied to the first cover layer or the component configuration, for example, and may comprise adhesive material or an adhesive film. 
         [0014]    In further embodiments, the fixing of the component configuration on the first cover layer may be performed using ultrasound. Thus, a connection may be produced easily between cover layer and component configuration without the use of additional materials, without the component configuration experiencing a significant temperature impingement. 
         [0015]    The fixing of the component configuration on the first cover layer may also be performed using a thermal method. Thus, fixing may be performed by a thermal gluing method or by a method which results in softening of the surface of the first cover layer and the component configuration. It is essential here that the thermal method is locally applied, so that no undesired heating of the components occurs. 
         [0016]    If at least one component is implemented as a display element, an optical transmission layer may be arranged between the display element and the second cover layer. An optical transmission layer allows good visibility through the second cover layer, because air intermediate spaces between display element and cover layer are avoided. The optical transmission layer may be formed by a low-viscosity adhesive material which is dispensed before a display element area is joined with the second cover layer and ensures an optimum optical transmission through the second cover layer. 
         [0017]    If the cover layers are permanently connected to the spacer layer, the cover layers are no longer removable from the spacer layer. A permanent connection may be implemented simply as a result of a solidification of filler material which is located between cover layers and spacer layer, or by an adhesive material layer which is applied in the contact area between spacer layer and cover layers already before the filler material is introduced. 
         [0018]    In a further advantageous embodiment of the method, the first and/or the second cover layer may be removed from the spacer layer and/or the solidified filler material before or after the inlay is isolated from a layer configuration having the cover layers and the spacer layer. This may be implemented easily in that materials are used for the cover layers which bond poorly to the filler material, such as PET having an overall glossy and/or smooth surface. The implementation of an inlay which only has a spacer layer is advantageous in particular if the inlay is to be implemented as relatively thin or if cover layers interfere in the overall card composite. 
         [0019]    It has proven to be especially advantageous if the inlay is isolated from the layer configuration in such a manner that a partition line runs between an internal contour of the through opening and an external contour of the component configuration. The spacer layer is thus not also isolated corresponding to the course of the partition line. The inlay usable to implement a card thus does not have a spacer layer and/or positioning layer. The electronic components are solely accommodated in a layer composite of filler material and two external cover layers. By using the spacer layer, positioning of the component configuration within a contour of the inlay determined by the partition line is nonetheless advantageously made possible. 
         [0020]    In the semifinished product according to the invention for producing an inlay having at least two electronic components, all electronic components are arranged in a relative configuration on a carrier substrate to implement a component configuration, and the component configuration is accommodated by a through opening of a spacer layer, the through opening being filled up by a solidified filler material. The semifinished product may thus be produced especially cost-effectively, because all electronic components are insertable into the through opening in one work step. A permanent connection between carrier substrate and first cover layer may also thus be produced easily. In particular, it may be ensured that all components are arranged permanently in the provided relative configuration, because the latter is not changed even by the filling of the filler material. 
         [0021]    It is advantageous if the spacer layer having the through opening is applied to a first cover layer, the component configuration being arranged on the first cover layer. The semifinished product is thus producible especially easily. 
         [0022]    If a partition line runs between an internal contour of the through opening and an external contour of the component configuration, an inlay may be isolated from the semifinished product which has no spacer layer and/or positioning layer influencing the properties of the inlay. 
         [0023]    In a further embodiment, a surface structure may be implemented on a contact side of the carrier substrate facing toward the first cover layer. A surface structure, for example, in the form of webs, waves, nubs, etc., allows the penetration of filler material below the carrier substrate, i.e., into the area between carrier substrate and the first cover layer, so that the formation of air inclusions below the carrier substrate upon casting with filler material is avoided. 
         [0024]    If at least one cover layer of the semifinished product is optically transparent, an electronic component implemented as a display element may be observed and/or read. For example, if a display screen is used as the display element, it is advantageous if all layers covering the display screen are optically transparent. 
         [0025]    In an especially advantageous embodiment, the semifinished product is formed from a panel sheet, which has at least one further component configuration, one through opening, and one solidified filler material. Overall, a plurality of inlays may thus be obtained from one semifinished product of this type and may be produced especially economically. 
         [0026]    In the method according to the invention for producing a card having a semifinished product, at least one external layer is bonded to the semifinished product and/or the inlay using an adhesive bond before or after a card and/or an inlay is/are isolated from a layer configuration, the card and/or the inlay being isolated from the layer configuration in such a manner that a partition line runs between an internal contour of a through opening of a spacer layer and an external contour of a component configuration arranged in the through opening. By using an adhesive material for bonding the semifinished product to an external layer before the card is isolated or after the inlay is isolated with an external layer from the layer configuration, it is not necessary to apply a bonding method which may damage the electronic components by excessive temperatures. 
         [0027]    To implement especially thin cards or cards in which the cover layers would interfere, it has proven to be especially advantageous if the first and/or the second cover layer is/are removed from the spacer layer and/or a solidified filler material before an application of the external layer. 
         [0028]    In an advantageous embodiment of the method, the adhesive bond may be activated by temperature impingement, the temperature not exceeding a temperature which damages components. A temperature-activated adhesive bond allows rapid and tight implementation of a layer composite at comparatively low temperatures. The adhesive material may be applied to both the external layers and also to the semifinished product and/or the inlay. For example, in a special embodiment, a lamination may be performed as so-called warm lamination having lowered lamination temperature. The corresponding lamination adhesives may already be activated at relatively low temperatures. 
         [0029]    The card according to the invention has a layer configuration encompassing the semifinished product having at least one printable external layer, the external layer being printable before or after application onto the card. 
         [0030]    If the card has a display element, it is especially advantageous if the external layer is optically transparent at least in a partial area. Thus, for example, a display screen may be at least regionally visible through an area of the external layer which is approximately adapted to the size of the display screen. 
         [0031]    Damage to a printing is advantageously avoidable if the external layer is completely transparent and is printed on a side facing toward the filler material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    The invention is explained in greater detail hereafter with reference to the appended drawings. 
           [0033]      FIG. 1  shows a first cover layer having a spacer layer in a sectional view after a first method step. 
           [0034]      FIGS. 2   a  through  2   d  show a component configuration in various embodiments of a configuration of the component configuration on the first cover layer in a sectional view along a line II-II from  FIG. 8  after a second method step. 
           [0035]      FIG. 3  shows filler material introduced into a through opening in a sectional view after a third method step. 
           [0036]      FIG. 4  shows a second cover layer applied to the spacer layer after a fourth method step. 
           [0037]      FIG. 5  shows a first embodiment of an inlay in a sectional view after a fifth method step. 
           [0038]      FIG. 6  shows a card in a sectional view after a sixth method step. 
           [0039]      FIG. 7  shows a second embodiment of an inlay in a sectional view. 
           [0040]      FIG. 8  shows a top view of a panel sheet in section along a line VIII-VIII from  FIG. 2   a.    
           [0041]      FIGS. 9   a  and  9   b  show a first and a second embodiment of a card having a display element in a sectional view. 
       
    
    
     DETAILED DESCRIPTION 
       [0042]    One embodiment of a method for producing an inlay is shown in  FIGS. 1 through 5  in a sequence of method steps in a sectional view in each case. Thus,  FIG. 1  shows a first cover layer  10  and a spacer layer  11  applied thereto having a through opening  12 . The spacer layer  11  is laid on the first cover layer  10  and is permanently bonded to the first cover layer  10  using an adhesive bond (not shown in greater detail). A component configuration is then arranged in the through opening  12 . 
         [0043]      FIGS. 2   a  through  2   d  show various embodiments of an arrangement of a component configuration in a sectional view along a line II-II from  FIG. 8 . A component configuration  13  shown in  FIG. 2   a  has electronic components  14 ,  15 ,  16  and an antenna winding as a component  17 . The components  14 ,  15 ,  16 ,  17  are arranged on a carrier substrate  18  and are permanently connected thereto. The component configuration  13  thus formed is, as shown in  FIG. 2   a , inserted into the through opening  12 , none of the components  14 ,  15 ,  16 ,  17  projecting above the spacer layer  11 . In the embodiment shown here, a permanent connection is not formed between the carrier substrate  18  and the first cover layer  10 , so that a relatively thin gap  19  may form between the carrier substrate  18  and the first cover layer  10 . 
         [0044]      FIG. 2   b  shows a second embodiment of an arrangement of the component configuration  13  in the through opening  12 . A fixing layer is implemented as an adhesive material layer  20  lying between the first cover layer  10  and the carrier substrate  18 . The adhesive material layer  20  may, as not shown in greater detail here, be applied as an adhesive film or liquid adhesive material to the carrier substrate  18  or the first cover layer  10  before the component configuration  13  is arranged on the first cover layer  10 . The adhesive material layer  20  secures the relative position of the component configuration  13  in the through opening  12  and/or on the first cover layer  10 , so that slipping of the component configuration  13  and/or all components  14 ,  15 ,  16 ,  17  during the subsequent method steps is avoided. 
         [0045]      FIG. 2   c  shows a component configuration  21  which differs from the component configuration  13  due to a carrier substrate  22 . The carrier substrate  22  is implemented from a plate-shaped carrier  23  for accommodating the components  14 ,  15 ,  16 ,  17  and webs  24 . Thus, only the webs  24  come into contact with the first cover layer  10 , and intermediate spaces  25  are implemented between the webs  24 , the carrier  23 , and the first cover layer  10 . The intermediate spaces  25  may be filled up well by the filler material upon a subsequent casting with filler material, so that an implementation of air inclusions below the carrier substrate  22  is avoided as much as possible. 
         [0046]    A component configuration  26  having components  14 ,  15 ,  16 ,  17  which are arranged on a carrier substrate  27  is shown in  FIG. 2   d . A defined quantity of filler material  57  is first introduced into the through opening  12  here. The components  14 ,  15 ,  16 ,  17  are then arranged on the surface  28  of the filler material  57  in a defined relative position, as shown, the components  14 ,  15 ,  16 ,  17  being able to penetrate into the surface  28  of the filler material  57  because of an exerted light pressure force. Before a further delivery of filler material is introduced into the through opening  12 , the filler material  57  is solidified on the carrier substrate  27 . In embodiments not shown here, the filler material  57  may also be solidified entirely or partially on the carrier substrate  27  before the components  14 ,  15 ,  16 ,  17  are arranged. 
         [0047]    After the component configuration  13  is arranged in the through opening  12 , the through opening  12  is filled up with filler material  29 , which essentially encloses the component configuration  13 , as shown in  FIG. 3 . The quantity of filler material  29  is dimensioned in such a manner that the through opening  12  and/or the spacer layer  11  has/have filler material  29  projecting slightly above it. 
         [0048]    In the following work steps indicated in  FIG. 4 , a second cover layer  30  is applied to the spacer layer  11  and the filler material  29 . Furthermore, a flatly acting pressure force indicated by the arrows  31  is exerted on the first cover layer  10  and the second cover layer  30 , so that excess filler material  29  between the spacer layer  11  and the second cover layer  30  exits in the edge areas  32  of the layers. In an embodiment of the method not shown in greater detail here, the second cover layer  30  may be applied at an angle to the spacer layer  11  starting from an outside edge, so that it is easier for filler material  29  to exit. If the first and second cover layers  10  and  30  are brought solidly into contact with the spacer layer  11 , the filler material  29  is solidified by a temperature impingement and a semifinished product  33  is implemented. An inlay  37  as shown in  FIG. 5  is then isolated from the semifinished product  33  along a peripheral partition line  34  which lies between an internal contour  35  of the through opening  12  and an external contour  36  of the component configuration  13 . 
         [0049]    The inlay  37  is processed further with external layers  38 ,  39  to form the card  40  shown in  FIG. 6 . The external layers  38 ,  39  are preferably permanently bonded using an adhesive bond, which is not shown in greater detail here, to the cover layers  10  and  30  of the inlay  37 . The adhesive material used is preferably activatable and/or curable at a relatively low temperature. 
         [0050]    A further embodiment of an inlay  41  is shown in  FIG. 7 , the inlay  41  only being formed by the component configuration  13  and the solidified filler material  29 . Before or after the inlay  41  is isolated from a layer configuration, the cover layers (no longer visible here) were removed from the solidified filler material  29 . 
         [0051]      FIG. 8  shows a top view in section along a line VIII-VIII from  FIG. 2   a  with a partial detail of a panel sheet  42 . The panel sheet  42  is implemented from the first cover layer  10  and the spacer layer  11  having a plurality of through openings  12 . The component configuration  13  having the components  14 ,  15 ,  16 ,  17  shown in  FIG. 2   a  is inserted into each through opening  12 . The components  14 ,  15 ,  16 ,  17  are connected to one another using connection conductors  43 , which are indicated as dashed lines here. The partition line  34  runs, as already noted in  FIG. 4 , between the internal contour  35  of the spacer layer  11  and the external contour  36  of the component configuration  13 . 
         [0052]      FIG. 9   a  shows a card  44  having printed external layers  45  and  46 . The external layers  45  and  46  are each provided on the outside with a printing  47  or  48 , which is schematically indicated here. Both the external layer  45  and also a second cover layer  49  are optically transparent, and a viewing area  50  is provided in the external layer  45 , in which no printing  47  is applied. An optical transmission layer  52  is arranged between a component implemented as a display element  51  and the second cover layer  49 . The optical transmission layer  52  is formed from a low-viscosity adhesive material which is applied to the display element  51  before the second cover layer  49  is applied to a spacer layer (not shown here) and the filler material  29 . The transmission layer  52  thus ensures a good optical transmission of visible information shown by the display element  51  through the layers  49  and  45 , the display element  51  not coming directly into contact with the second cover layer  49  and possible parallelism deviations between the display element  51  and the second cover layer  49  thus being compensated for by the transmission layer  52 . 
         [0053]    A printing  53  on a second external layer  54  before connection of the second external layer  54  to the second cover layer  49  is also possible. As shown in  FIG. 9   b , a card  55  may then be implemented, in which the printing  53  is applied to an interior side  56  of the second external layer  54 .