A SECURITY DOCUMENT AND A MANUFACTURING METHOD
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] This invention relates to a security document such as an identity card or drivers license, for instance.
DESCRIPTION OF PRIOR ART
[0002] Previously there are known security documents comprising an electronic module. The electronic module is embedded into the material of the security document, in many cases in such a way that it can not be visually detected from a surface of the security document.
[0003] A problem with the above described prior art solution is that the material of the security document may crack in an area close to the electronic module. Such cracking is caused by internal stress in the material of the security document.
[0004] One reason for internal stress is that the material of the security document and the material of the electronic module have different thermal expansion coefficients, in other words, the amount of expansion and shrinkage is different when temperature changes occur. SUMMARY OF THE INVENTION
[0005] An object of the present invention is to solve the above mentioned drawback and to provide a security document which has improved properties in order to avoid cracking. This object is achieved with a security document according to independent claim 1 and a method of manufacturing according to independent claim 6.
[0006] The possibility of utilizing a separation layer slightly bigger than the hole with the electronic module to prevent layers on opposite sides of the separation layer from attaching to each other at least above or below the electronic module, results in a security document with improved properties. In this way a zone is created at least above or below the electronic module where the layers of the security document are not rigidly attached to each other. In this way internal stress and cracking can be avoided.
[0007] Preferred embodiments of the invention are disclosed in the dependent claims. BRIEF DESCRIPTION OF DRAWINGS
[0008] In the following the present invention will be described in closer detail by way of example and with reference to the attached drawings, in which
[0009] Figure 1 illustrates a first embodiment of a security document, and
[0010] Figures 2a to 2c illustrate a first embodiment for manufacturing a security document.
DESCRIPTION OF AT LEAST ONE EMBODIMENT
[0011] Figure 1 illustrates a first embodiment of a security document 1 . The document of Figure 1 may be a identity card, a drivers license or an information page for a passport, for instance.
[0012] The security document may be provided with a photograph 2 of the holder and written data 3 with information about the holder, for instance. In addition, the security document may contain a plurality of security elements in order to make forgery of the security document as difficult as possible.
[0013] The security document 1 is additionally provided with an electronic module 4, which may be embedded into the plastic material of the security document 1 , for instance. Typically the material of the security document is colored, in which case the electronic module is not visible from any side of the security document.
[0014] The security module may consist of one or more microcircuits for instance, and also an antenna coil may be embedded into the material of the security document in order to facilitate contactless communication between the electronic module 4 and an external apparatus.
[0015] Figures 2a to 2c illustrate a first embodiment for manufacturing a security document. The security document of Figure 1 may bee manufactured according to this method. In the illustrated example it is by way of example assumed that separation layers are arranged both above and below the electronic module, though this is not necessary in all embodiments. [0016] In Figure 2a a first layer 10 and a second layer 1 1 are provided. In Figure 2b a third layer 14 is provided. The third layer 14 has a hole 15 through it. An electronic module 4 is arranged into this hole.
[0017] The material of the first layer, second layer and third layer may be any suitable material for producing a security document. Typically plastic materials are utilized. One alternative is to produce all of these three layers of Polycarbonate, for instance. Possible additional layers may also be of Polycarbonate, or of alternative materials suitable for use in connection with Polycarbonate.
[0018] In Figure 2c the third layer 14 with the electronic module 4 is arranged between the first layer 10 and the second layer 1 1 . A first separation layer 12, slightly bigger that the hole 15, is arranged between the first layer 10 and the third layer 14 at the location of the hole 15 with the electronic module 4. This first separation layer prevents attachment (in a subsequent step) of the first layer 10 and the third layer 14 to each other above the electronic module 4 and along the edges of the hole 15.
[0019] In Figure 2c it is by way of example illustrated that a second separation layer 13, slightly bigger than the hole 15, is arranged between the second layer 1 1 and the third layer 14 at the location of the hole with the electronic module 4. The second separation layer prevents attachment (in a subsequent step) of the second layer 1 1 and the third layer 14 to each other below the electronic module and along the edges of the hole 15.
[0020] Once brought into the position as illustrated in Figure 2c, the layers 10, 1 1 and 14, and possibly additional layers which are not necessary but may be included as illustrated by way of example, are attached to each other. The attachment may be carried out by lamination, for instance, whereby the layers are pressed towards each other in a raised temperature. The first separation layer 12 and the second separation layer 13 prevent attachment above and under the electronic module 4, which results in a more reliable and durable security document. The separation layers may be used between other layers than those illustrated in Figure 2c by way of example.
[0021] The first and second separation layers 12 and 13 may be paper based layers. In this context the phrase 'paper based' refers to a material with a similar fiber structure as paper, though additional compounds may be added. Due to the soft fiber structure the attachment of layers on opposite sides of the separation layer is not as rigid as without the separation layer, which leads to a zone reducing internal stress in the security document and helps to avoid cracking. It is possible to use a paper based material that is thin enough to be used between layers of a security document without changing the shape of the upper or the lower surface of the security document at the location of the electronic module. By selecting such a thin paper based material it is not necessary to make any gaps or cavities (matching the size of the separation layers) for the separation layers in any one of the first, second or third layers. This results in a simple production process.
[0022] In Figure 2c it is by way of example assumed that the separation layers 12 and 13 are attached with an adhesive to the third layer 14 prior to attachment of the layers 10, 1 1 and 14 to each other. In such an embodiment stickers consisting of paper based material and an adhesive on one side may be utilized as the separation layers. Due to the adhesive, the manufacturing is easy, as the separation layers 12 and 13 may be attached to the third layer 14 in exactly the right position in relation to the hole 15 and the electronic module 4. However, the use of an adhesive is not absolutely necessary, in case it can be ensured in some other way that the separation layers 12 and 13 will be located in correct positions in the security document.
[0023] It is to be understood that the above description and the accompanying figures are only intended to illustrate the present invention. It will be obvious to a person skilled in the art that the invention can be varied and modified without departing from the scope of the invention.