Registers – Records – Conductive
Reexamination Certificate
2002-04-12
2004-08-31
Lee, Michael G. (Department: 2876)
Registers
Records
Conductive
C235S451000, C235S487000, C257S679000, C361S737000
Reexamination Certificate
active
06783077
ABSTRACT:
The invention relates to a conductor track supporting layer for laminating inside a chip card comprising at least one conductor track which is applied to the conductor track supporting layer by an application method, preferably a screen printing method, and consists of a screen printing paste, and comprising connecting areas which are connected to the conductor track.
Apart from the screen printing method, the stencil printing method or the use of a dispenser also comes into consideration. Apart from an electrically conductive screen printing paste, a high-viscosity, electrically conducting liquid also comes into consideration as the material to be processed.
Conductor track supporting layers of the type mentioned at the beginning are preferably used for the production of chip cards, chip cards of this type already being used in large numbers in the form of phone cards, access authorization cards for cellular phones, bank cards etc. In the prior art, applied to the conductor track supporting layers of chip cards of this type there is usually a coil, which has corresponding connecting areas and serves for the power supply and data exchange of the card with external equipment. When coils are used for power and data exchange, this exchange takes place without contact, so that it is referred to as a contactlessly operating card. Apart from contactlessly operating cards, however, there are also known chip cards in which, apart from the information transmitted through the coil, information and power can also be imparted by direct means, with contacts, through galvanically operating contact areas. The production of the conductor track supporting layer used for the aforementioned contactless cards or cards with contacts can be performed in a way corresponding to a customary process by the screen printing method. In such a production procedure, the individual conductor tracks of the coil are applied together with the connecting areas for the connection of the coil to additional electronic components arranged on the chip card, such as for example a chip module, by applying an electrically conducting screen printing paste to a plastic substrate. It is of course also possible in the course of this production method to apply in addition to the actual coil necessary conductor tracks for the use of further electronic components, such as display devices or keypads, to the conductor track supporting layer.
Once printing on it has been completed, the conductor track supporting layer is laminated in a subsequent method step with further layers of plastic, some of which may bear inscriptions, in a laminating press to form a plastic card body. After the laminating process, it is necessary to introduce clearances into the plastic card body for the chip module and/or further electronic components to be inserted, and at the same time to expose the individual connecting areas of the coil and of further conductor tracks of the conductor track supporting layer, in order to connect these connecting areas to the corresponding contact areas of the chip module and of the other components, which usually takes place by using a conductive adhesive and soldering. When the clearances are being produced, it is necessary to proceed with great care and extreme accuracy, because on the conductor track supporting layer there are usually arranged directly next to the connecting areas to be exposed also conductor tracks which must not on any account be damaged or even completely severed. Even with high precision milling tools, there is a high reject factor for chip cards due to damaged conductor tracks, since they usually have only a width of about 80 &mgr;m, whereas the corresponding connecting areas are usually of sizes of around 1 mm
2
.
In addition, when the customary conductor track supporting layers are used, there is the problem that, when an electrically conducting connection is being established between the contact areas of the chip module or other electronic components and the connecting areas of the conductor tracks on the conductor track supporting layer by a conductive adhesive or by a solder, an electrical short-circuit can very easily be produced between individual conductor tracks, for example of the coil and the associated connecting areas, since the distance between the conductor tracks and the conductor track connections is very small. Short-circuits of this type make the conductor track supporting layer unusable. In most cases it is not possible to change the arrangement of the conductor tracks on the conductor track supporting layer to the extent that the distances between them in the region of the milled-out clearance become greater, in order to avoid a short-circuit, since the base area of the conductor track supporting layer is limited overall on account of the standardized dimensions of the chip card.
SUMMARY OF THE INVENTION
Against the background of the prior art presented, it is an object of the invention to provide a conductor track supporting layer of the type described at the beginning in which the risk of the conductor tracks being damaged by the exposure of the connecting areas connected to the conductor tracks in the course of the milling operation in the production of contactless chip cards or chip cards with contacts is ruled out in a simple and low-cost way.
This object is achieved according to the invention by the conductor track supporting layer having in the region of the connecting areas indentations which are filled with the screen printing paste during the screen printing operation.
The measure according to the invention has the effect that, after the screen printing operation, the connecting areas of the conductor track supporting layer have a significantly greater thickness than the conductor tracks. If, in the course of the production process, clearances are made in the conductor track supporting layer in the milling operation carried out after the lamination of the plastic card body of the chip card, from that side of the conductor track supporting layer on which no conductor tracks are located, the milling operation can be stopped already in good time before the conductor track level is reached, on account of the greater thickness of the connecting areas, so that damage to the sensitive conductor tracks is reliably ruled out.
With the teaching according to the invention of claim
1
, further special refinements of the subject matter of the invention emerge from the features of the subclaims
1
to
7
.
For the production of the conductor track supporting layer, it has proven to be advantageous in particular to make all or some of the indentations as through-holes with an opening of the on the rear side of the conductor track supporting layer, lying opposite the conductor track side of the supporting layer. By this measure, the indentations can, for example, be carried out without any problem by a low-cost punching operation. In addition, the fact that some indentations are made as through-holes and some are made as blind holes in the conductor track supporting layer has the effect of producing connecting areas of different thicknesses after the screen printing operation, and consequently of producing within a plastic card body after lamination has been completed different connecting levels for different electronic components. These different connecting levels allow the fitting of electronic components of different thicknesses, such as for example displays or keypads, so that the application possibilities of chip cards of this type, provided with different components, can be increased many times in comparison with the current state of the art.
It has additionally been found to be expedient if, before applying the conductor tracks, the conductor track supporting layer provided with through-holes is provided with a thin covering film on the rear side, remote from the conductor tracks. This covering film prevents screen printing paste from coming out through the through-holes on the rear side of the conductor track supporting layer during the subsequent screen printing opera
Foley & Lardner
Kim Ahshik
Lee Michael G.
ORGA Kartensysteme GmbH
LandOfFree
Conductor track supporting layer for laminating inside a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Conductor track supporting layer for laminating inside a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Conductor track supporting layer for laminating inside a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3288859