Transponder inlay for a personal document and method of manufacturing same

The present invention relates to a transponder inlay for manufacturing a layered structure for a personal document with a substrate layer for arranging a transponder unit comprising an antenna coil and a chip module, said transponder unit being situated on a contact surface of the substrate layer, and a method for manufacturing the transponder inlay. In addition, the present invention relates to a layered structure for a personal document provided with such a transponder inlay as well as an identification document having such a layered structure.

Current trends in the field of personal documents are in the direction of supplementing the documents that are conventionally used for personal identification with transponders which permit automated contactless reading of the data stored on a chip in the transponder. Such transponders include, in addition to the chip, an antenna coil that allows contactless data access.

Integration or implementation of such transponders in conventional personal documents that contain a plurality of pages of paper accommodated in a document volume makes special demands of the design of the transponder units and/or the so-called transponder inlays, which have the transponder unit on a substrate layer. It is obvious that it is regarded as desirable to interfere with the known format of the identification documents as little as possible through implementation of such a transponder inlay in an identification document. Furthermore, handling of the identification documents, e.g., the pages in such a document, should be influenced as little as possible. On the other hand, the transponder inlays and/or the transponder units arranged on the substrate layers of the transponder inlays are of course subject to special mechanical stresses which naturally derive from the handling of these identification documents.

For the reasons given above, it is therefore assumed that it is especially important to design the transponder inlays intended for implementation in identification documents to be as thin as possible. A reduction in the thickness of the substrate layers used for the transponder inlays is limited already by the thickness of the chip modules if it is assumed that the chip modules are to be accommodated so they are essentially flush with the surface in the transponder inlays.

Designing suitable recesses or window openings in the substrate layers is therefore associated with a significant expense and complexity.

The object of the present invention is therefore to propose a transponder inlay and a method of manufacturing same so that the manufacturing allows transponder inlays to be designed to be as thin as possible at a comparatively low cost.

This object is achieved by a transponder inlay having the features of Claim 1.

With the inventive transponder inlay, the chip module is accommodated in a window opening formed in the substrate layer in such a way that a chip carrier of the chip module sits on a compressed peripheral shoulder of the window opening with its peripheral edge resting on the compressed peripheral shoulder.

The peripheral shoulder of the window opening, which allows the chip carrier to be accommodated in such a way that it is flush with the surface, is implemented by compressing the material of the substrate layer in the area of the window opening, in contrast with the design known from the state of the art, in which, depending on the choice of material for the substrate layer, either only one chip housing of the chip module arranged on the chip carrier is accommodated in the window opening, and the chip carrier protruding laterally beyond the chip housing rests on the surface of the substrate layer, or the chip carrier rests on a peripheral shoulder of a window formed by a milling operation in the substrate layer to accommodate the entire chip module including the chip carrier.

An optimum with regard to completely accommodating the chip module in the substrate layer in such a way as to protect the chip module from mechanical stresses and with regard to the thinnest possible design of the substrate layer is possible if the chip module is accommodated in the window opening in such a way that the chip carrier is arranged to be essentially flush with the contact surface of the substrate layer, and a chip housing of a chip unit arranged on the chip carrier is situated to be essentially flush with the underside of the substrate layer opposite the contact surface.

An arrangement of the antenna coil on the contact surface of the substrate layer so that it is also flush with the surface is made possible if the antenna coil is formed from a wire conductor which is provided in a coil on the contact surface and arranged to be essentially flush with the contact surface by embedding it in the contact surface.

It has proven especially advantageous if the substrate layer of the transponder inlay is made of a thermoelastic material, so that, on the one hand, a protective elastic sheathing is provided for the chip module, keeping mechanical stresses away from the chip because of its elasticity, and, on the other hand, a permanent compression is possible in the circumferential area of the window opening to form the peripheral shoulder through a temperature-supported pressure acting on the substrate material with a minimal expenditure of energy.

The inventive layered structure for a personal document according to Claim 5 has, in addition to the transponder inlay, a cover layer of a book binding material for personal documents arranged as an additional layer on the contact surface of the transponder inlay.

The inventive layered structure may thus consist of just two layers bonded together, supplemented by conventional intermediate pages in a simple manner to yield a personal document which is provided with a transponder unit despite giving the appearance of being a conventional personal document. The inventive layered structure thus allows the production of an identification document that essentially shows no difference from a conventional personal document from a purely external standpoint.

Depending on the choice of material and/or the composition of the material for the cover layer, the bond between the substrate layer and the cover layer may be created by arranging an adhesive intermediate layer or by direct lamination of the cover layer onto the substrate layer to produce the layered structure. The latter is the case, for example, when the cover layer is a textile fabric coated with thermally activatable adhesive or some other laminatable material.

It is especially advantageous if the layered structure is designed to be double-sided, with a substrate layer designed to be discontinuous, having the transponder unit on the transponder page and having a blank page that is divided from the transponder page by a fold recess and with a cover layer designed to be continuous, extending over the substrate layer. Such an embodiment of the layered structure in combination with the intermediate pages of a personal document makes it possible to produce a personal document that gives the user the impression of being a conventional personal document despite the implementation of the transponder unit in the front page or the back page of the binding.

The inventive personal document has the features of Claim 8.

The inventive method for producing a transponder inlay has the features of Claim 9. According to this invention, to form a window opening that holds the chip module, a through-opening is created in the substrate layer, and the peripheral edge of the through-opening is exposed to pressure and temperature to achieve a compressed peripheral shoulder with a reduced thickness.

It is especially advantageous if the treatment with pressure and temperature is accomplished by means of an ultrasonically energized stamping tool. The temperature treatment may be accomplished by external heating of the stamping tool or by a heating of the stamping tool and/or substrate layer induced by mechanical friction as a result of the ultrasonic oscillations of the stamping tool, i.e., without external overheating.

In addition, it has also proven to be especially advantageous if the stamping tool is used at the same time to form the through-opening because this allows the creation of the window opening as well as the creation of the peripheral shoulder in one machining operation using one and the same tool.

A variant of the method that is optimized with regard to universal tool use is made possible if the stamping tool serves at the same time to embed a wire conductor, which is used to produce the antenna coil, in the contact surface of the substrate layer.

A preferred embodiment of the transponder inlay is illustrated in the drawings and described with reference thereto, including an explanation of the process steps associated with production of the transponder inlay.