Registers – Records
Reexamination Certificate
2000-06-28
2003-11-25
Lee, Michael G. (Department: 2876)
Registers
Records
C235S451000, C235S492000
Reexamination Certificate
active
06651891
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of producing contactless chip cards including at least one chip and to a contactless chip card.
A great number of chip cards is nowadays already used in all fields of private and public life. Their efficiency can be increased still further by using modern integrated circuits, since by implementing application-specific functions in the chip the field of application of chip cards can be extended to the following fields exceeding the sphere of identification and telecommunications: in the public health service e.g. by the insured person's card, the patient's data card and the emergency card. In the field of communication, chip cards can be used for controlling access to communication networks and for service payments as well as for data encryption and data protection. In payment transcations chip cards are very suitable to be used as cheque cards, credit/debit cards, electronic purses and for charge accounting for local traffic and on toll roads. In addition, chip cards are well suited for access control and identification purposes, e.g. for pay TV, leisure time services or production control.
At present, integrated storage circuits as well as micro-controllers are used for chip cards. Furthermore, crypto-controllers having provided therein an encryption key or an encryption algorithm are used for chip cards. The data exchange is carried out by means of the contact surfaces with a reader or contactless by capacitive or inductive transmission. The efficiency of modern chip card systems requires a continuously increasing complexity and necessitates an increasing degree of integration. Initially, only memories with a minimum periphery were used, but now there is also a development towards more complex systems necessitating a microcontroller with a great variety of different functions and coils for contactless communication.
2. Description of Prior Art
In the case of the known contactless chip cards one or a plurality of coils, which are connected to the chip, are integrated in the card body. The energy and the data are transmitted by capacitive or inductive coupling. For producing this chip card, the so-called “inlet technique” is used. According to this technique, the coil and the chip are applied to a plastic carrier and fixed thereon. This carrier is then integrated in the actual chip card. This can be done by enclosing the carrier with the chip card material by injection moulding or by laminating it. After assembling the carrier and the card, the carrier constitutes an integral component of the chip card.
As is generally known, carrier foils are used as carriers on which wound, etched or printed coils are formed. In the case of wound coils, a backlack wire is wound so as to form a coil and is then connected to the chip. Disadvantages of this method are primarily the difficult application of the coil to the chip card and the connections between the thick wires of the coil and the naked chip.
In comparison with such wound coils, the etched and printed coils on the carrier foil offer the advantage that the conductor tracks are an integral component of the carrier foil. The chip is then connected to the coil by wire bonding or by means of the flip-chip technique. Subsequently, the carrier foil provided with the coil and the chip is integrated in the card body. Disadvantages of this method are the high production costs of the coil and the difficulties which have to be overcome when the whole card body is laminated. The lamination is, moreover, disadvantageous with regard to the thermal and the mechanical stability and, consequently, with regard to the service life of the chip card. In particular, the temperatures prevailing when the carrier is enclosed with the chip card material by injection moulding have a negative effect on the function of the expensive semiconductor chips. Furthermore, mistakes in the injection moulding process, i.e. mistakes in a comparatively economy-priced plastic component, will have the effect that the card including the expensive semiconductor chip becomes a reject.
DE 44 41 122 discloses e.g. a method for producing contactless chip cards in the case of which a foil material of approx. 50 &mgr;m thickness is coated with electrolytic copper which is used for producing therefrom an antenna coil with connecting areas by means of photoetching. Furthermore, the foil material is provided in a stamping process with an indented chip reception area and a stepped connection zone following this chip reception area. The chip is then secured in position in this reception area by means of an adhesive and its pads are connected to the connecting areas of the antenna winding by means of bonding wires. Following this, the thus equipped foil is stuck on both sides thereof between two plastic layers of identical thickness, with the exception of the chip reception area; these plastic layers are formed as cups around the chip reception area by means of approximately symmetric recesses. This method requires, however, an additional stamping process for the chip reception area and a complicated laminating and coating process.
WO 97/26620 discloses a chip card body for producing a chip card including a coil, the chip card body being provided with a recess having a chip arranged therein. The coil metallization extends in the form of a conductor track across the surface of the chip card body and through the recess, the chip being arranged in the recess in areas in which the conductor track does not extend through the recess. Pads of the chip are in electrical contact with the conductor track via bonding wires. Furthermore, it is suggested according to this publication that direct contacting of the chip by means of the bump technique should be used.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a contactless chip card and to further develop a method for producing a contactless chip card in such a way that the chip card, primarily the coil, can be produced in a simple and economy-priced manner and is both mechanically stable and reliable.
According to a first aspect of the invention, this object is achieved by a method of producing a contactless chip card comprising the following steps:
producing an electrically insulating, planar card body provided with at least one recess on one of its main surfaces, bumps being formed on the base surface of the recess;
applying at least one conductor track according to a predeterminable conductor track pattern to the main surface including the at least one recess, at least one conductor track being applied to surface areas outside of the at least one recess as well as to surface areas within the at least one recess, and the at least one conductor track extending across the bumps; and
aligning at least one chip in the at least one recess and contacting the at least one chip with the at least one conductor track extending across the bumps.
According to a second aspect of the present invention, this object is achieved by a contactless chip card formed of an electrically insulating, one-piece card body comprising:
at least one recess provided on a main surface of the card body, the base surface of the recess having bumps formed thereon;
at least one conductor track according to a predetermined conductor track pattern, said at least one conductor track being applied directly to surface areas of the card body main surface including the at least one recess outside of said at least one recess as well as to surface areas within said at least one recess, and the at least one conductor track extending across the bumps; and
at least one chip which is arranged in said at least one recess and which is contacted with the at least one conductor track in the area in which the at least one conductor track extends across the bumps.
In the method according to the present invention, an electrically insulating card body provided with one or a plurality of recesses on one card body side is first produced. Subsequently, at least one con
Ansorge Frank
Aschenbrenner Rolf
Kasulke Paul
Zakel Elke
Glenn Michael A.
Glenn Patent Group
Lee Michael G.
Paik Steven S.
Zakel Elke
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