U.S. patent application number 09/725079 was filed with the patent office on 2001-08-09 for manufacturing process of a hybrid contact-contactless smart card with an antenna support made of fibrous material.
Invention is credited to Delenne, Sebastien, Kayanakis, Georges, Mathieu, Christophe.
Application Number | 20010012682 09/725079 |
Document ID | / |
Family ID | 9552671 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010012682 |
Kind Code |
A1 |
Kayanakis, Georges ; et
al. |
August 9, 2001 |
Manufacturing process of a hybrid contact-contactless smart card
with an antenna support made of fibrous material
Abstract
The present invention relates to a hybrid-contact contactless
smart card manufacturing process and specifically a manufacturing
process for hybrid-contact contactless smart card in which the
antenna is on a fibrous material such as paper. This process
includes a manufacturing step to screen print the antenna onto the
support, a step to laminate the card body onto the antenna support
by hot press molding, a step to mill a cavity in the card body
opposite the side of the support bearing the screen print for
housing a module comprised of a chip and a double-sided circuit and
a step for inserting the module in the card. Cutouts made in the
corners of the antenna support prior to the lamination step enable
the card bodies to be bonded together. The card thus obtained
allows a posteriori viewing of any mechanical misuse to which it
may have been subjected (extreme bending).
Inventors: |
Kayanakis, Georges;
(Antibes, FR) ; Mathieu, Christophe; (Saint
Marcel, FR) ; Delenne, Sebastien; (Trets,
FR) |
Correspondence
Address: |
James C. Lydon
Suite 100
100 Daingerfield Road
Alexandria
VA
22314
US
|
Family ID: |
9552671 |
Appl. No.: |
09/725079 |
Filed: |
November 29, 2000 |
Current U.S.
Class: |
438/585 |
Current CPC
Class: |
G06K 19/08 20130101;
G06K 19/0775 20130101; G06K 19/07749 20130101 |
Class at
Publication: |
438/585 |
International
Class: |
H01L 021/3205 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 29, 1999 |
FR |
9915018 |
Claims
1. A manufacturing process of a hybrid contact-contactless smart
card with an antenna support made of fibrous material such as the
paper, including the following steps: a manufacturing process of
the antenna consisting in screen printing turns of electrically
conductive polymer ink on a support made of fibrous materials and
to subject said support to a heat treatment in order to bake said
ink, a step for laminating the card body onto the antenna support
consisting in welding on each side of said support at least two
sheets of plastic material, forming the card bodies, by hot press
molding, a cavity milling step consisting in piercing, in one of
the card bodies, a cavity for housing the module comprised of the
chip and the double-sided circuit, said cavity including a smaller
internal portion which receives the chip and a larger external
portion for receiving the double-sided circuit, said cavity
including a smaller internal portion which receives the chip and a
larger external portion for receiving the double-sided circuit,
said cavity being dug into the card body which is opposite the side
of the support featuring the electrically conductive screen printed
ink which forms the antenna, and the milling operation enabling the
connection pads to be removed from the chip, and a module insertion
step consisting in using a glue enabling said module to be secured
and a glue containing silver for connecting said module to said
connectors, and to position said module in the cavity provided to
this end.
2. The smart card manufacturing process according to claim 1, in
which the two sheets each forming card bodies on each side of said
antenna support made of fibrous material have different
stiffness.
3. A smart card manufacturing process according to claim 1 or 2, in
which, during the antenna manufacturing process, the corners of the
paper antenna support are notched in order to allow the two card
bodies to be welded together; said card obtained thereby offering a
preferential delamination zone which will highlight any act of
deliberate damage a posteriori.
4. A smart card manufacturing process according to one of the
previous claims, in which the antenna manufacturing step is
conducted in reverse order and consists in: Screen printing with a
polymer ink, on the support, two antenna contacts for the module
and a cross-over, Screen printing with dielectric ink, on the
support, an insulating strip on top of the cross-over, Screen
printing with polymer ink, on the support, at least two turns for
the antenna, these turns having there ends in contact with a
different connecting pad and the other end in contact with the
cross-over, enabling an antenna with two turns in series to be
obtained.
5. A smart card manufacturing process according to claims 2 through
4, in which the sheet forming the outer layer of the card body is
more rigid than the sheet forming the internal layer of the card
bodies, said internal layer having a low Vicat softening
temperature.
6. A smart card manufacturing process according to one of the
previous claims, in which the two sheets forming the card bodies on
each side of said antenna support made of fibrous material are of
different thickness.
7. The smart card manufacturing process according to claim 6, in
which the sheet forming the external layer is thicker than the
sheet forming the internal layer.
8. A process for manufacturing a smart card according to one of the
previous claims, in which, during the hot lamination step of the
card bodies onto the antenna support, a third sheet of plastic
material or varnish layer is added to each card body which acts as
a cover.
9. A smart card manufacturing process according to one of the
previous claims, characterized in that the plastic materials
forming the card bodies is polyvinyl chloride (PVC), polyester
(PET, PETG), polycarbonate (PC) or acrylonitrile-butadiene-styrene
(ABS).
10. A smart card manufacturing process according to one of the
previous claims in which the glue used to secure the module is a
fluid cyanoacrylate adhesive, which is placed in the cavities prior
to the insertion of said module.
11. A smart card manufacturing process according to one of the
claims 1 through 9, in which the glue used to secure the module is
a film-type "hot melt" adhesive which is placed under the module
prior to its insertion in the card.
Description
TECHNICAL FIELD
[0001] The present invention relates to smart card manufacturing
processes, and specifically a hybrid contact-contactless
manufacturing process of a smart card, the antenna of which is on a
support made of fibrous material such as paper.
PRIOR ART
[0002] The contactless smart card is a system being used
increasingly in various sectors. In the transport sector, the card
has been developed as a means of payment. The same holds true for
the electronic wallet. Many companies have also developed
identification means for their personnel using contactless smart
cards.
[0003] The exchange of information between a hybrid
contact-contactless card and the associated reader takes place via
remote electromagnetic coupling between an antenna embedded in the
contactless card and a second antenna located in the reader or
directly by contact with the reader. In order to create, store and
process the information, the card is equipped with an electronic
module which is connected to the antenna. The antenna is generally
located on a dielectric support made of plastic material. The
standard industrial manufacturing process can be broken down into
three steps:
[0004] the antenna is made on a plastic dielectric support
(polyvinyl chloride (PVC), polyesters (PET), polycarbonate (PC) . .
. ) (polyvinyl chloride (PVC), polyesters (PET), polycarbonate (PC)
. . . ) using copper or aluminum etching techniques,
[0005] hot-lamination under pressure of the upper and lower plastic
layers of the card body (PVC, PET, PC,
acrylonitrile-butadiene-styrene (ABS) . . . ), onto the antenna
support in order to create a monobloc card.
[0006] placement and connection of an electric module using
electrically conductive glue.
[0007] However, this process generates several major drawbacks. The
process leads to a composite stack of glued or heat bonded plastic
materials with different thermal expansion coefficients. As a
result, systematic unacceptable and irreversible distortion of the
cards is observed (twisting, warping), as well as a lack of
mechanical resistance when subjected to standardized or equivalent
tests.
[0008] Furthermore, PVC exhibits poor thermomechanical properties.
During the lamination process, material flow is significant and the
antenna's shape factor is not maintained. This leads to antenna
malfunction as the electrical parameters (inductance and
resistance) vary. It is not uncommon to experience antenna breakage
in areas subjected to strong sheer stresses. This is particularly
the case in angles and at electrical bridging points.
[0009] The laminated ISO cards have a total thickness between 780
and 840 m. Considering the material flows described above, it is
also very difficult to guarantee customers a narrow and controlled
distribution of the cards' population. operation creates a monobloc
card with poor mechanical properties in terms of the restitution of
absorbed stresses: during standardized bending and twisting tests,
all of the stress applied is transmitted to the electronic module
and primarily to the bonding points which make the connections. The
mechanical strength of the bonding joints is subjected to great
strain and the slightest imperfection in the bond causes the
module-antenna connection to break.
[0010] After lamination, the imprint from the copper etching is
visible on the printed card bodies. Although this does not prevent
the card from operating correctly, the defect is often emphasized
by users who are very concerned about the aesthetic criteria.
[0011] Furthermore, the cost of manufacturing the card with this
process is too high to enable any real increase in its usage.
[0012] Lastly, the processes currently used does not produce cards
with the possibility to view the poor mechanical treatment
inflicted on them by the users, particularly with the intent to
commit fraud. It is in fact relatively easy for someone with
experience in card fraud to destroy the card by folding it
repeatedly without it being possible to easily prove any malicious
intent afterwards. For example, the antenna may be cut without the
card being marked. Commercial policies set up within companies
generally ensure the replacement of defective cards free of charge.
The systematic replacement of these cards is a source of major
supplementary costs for these companies.
DISCLOSURE OF THE INVENTION
[0013] The purpose of the invention is to mitigate these drawbacks
by supplying an inventive manufacturing process using a support
made of fibrous material on which an antenna is screen printed
using electrically conductive ink, thereby significantly reducing
the production costs of hybrid or contactless smart cards.
[0014] The invention thus relates to a manufacturing process of a
hybrid contact-contactless smart card with an antenna support made
of fibrous material such as paper, including the following
steps:
[0015] A manufacturing process of the antenna consisting in screen
printing turns of electrically conductive polymer ink on a support
made of fibrous material and to subject said support to a heat
treatment process in order to bake the ink,
[0016] A step for laminating the card bodies onto the antenna
support consisting in welding, on each side of the support, at
least two sheets of plastic material, forming the card bodies, by a
hot press molding technique,
[0017] A cavity milling step consisting in piercing, in one of the
card bodies, a cavity for housing the module comprised by the chip
and the double-sided circuit, the cavity including a smaller
internal portion which receives the chip and a larger external
portion for receiving the double-sided circuit, the cavity being
dug into the card body which is opposite the side of the support
featuring the electrically conductive screen printed ink forming
the antenna, and the milling operation enabling the connection pads
to be removed, and
[0018] a module insertion step consisting in using a glue enabling
the module to be secured and a glue containing silver for
connecting the module to the connectors, and to position it in the
cavity provided for this purpose.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The purposes, objects and characteristics of the invention
will become more apparent from the following description when taken
in conjunction with the accompanying drawings in which:
[0020] FIGS. 1A to 1C represent the various steps used in screen
printing the antenna on the support.
[0021] FIG. 2 represents the support with the antenna screen
printed on the back, prior to the lamination step.
[0022] FIG. 3 represents the smart card at the end of the
manufacturing process.
[0023] FIG. 4 represents a cross section of the smart card,
represented in FIG. 3, along the axis A-A of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The smart card manufacturing process according to the
invention initially consists of placing the antenna on a support.
This support is made of a sheet of fibrous material such as paper.
According to a preferred embodiment, the antenna is screen printed
on this material in several steps and in reverse order compared
with the standard screen printing process. The first step,
represented in FIG. 1A, consists in screen printing the two bonding
pads 10 and 12 of the antenna to the module and the electric bridge
14, commonly referred to as the "cross-over", allowing the two
turns to be connected in series. The second screen printing step,
represented in FIG. 1B, consists in screen printing an insulating
strip on top of the cross-over. The third and last screen printing
step consists in screen printing the two turns 18 and 20. One end
of the turn 18 is connected to the bonding pad 10 and the other end
to the cross-over 14. Turn 20 is screen printed from the cross-over
14 to bonding pad 12.
[0025] Once the antenna has been screen printed on the support, it
is cut to the dimensions of the card. According to a preferred
embodiment, a cutout 22 is made in each corner of the support, as
shown in FIG. 2. This cutout enables a direct weld between the card
bodies during the lamination process.
[0026] Lamination is carried out by hot press moldings. According
to a preferred embodiment, two layers of plastic material are used
for each card body. This plastic material is generally polyvinyl
chloride (PVC), polyester (PET, PETG), polycarbonate (PC) or
acrylonitrile-butadiene-styr- ene (ABS). According to a preferred
embodiment, PVC is used. The two layers have different stiffness.
The external layer is made of rigid PVC, while the inside layer (in
contact with the antenna support) is made of soft PVC with a lower
Vicat softening temperature (the temperature at which the PVC
shifts from a rigid state to a rubbery state). The two layers may
also be of different thickness. For example, each of the card
bodies consists of an external rigid PVC layer of approximately 310
microns (.mu.m) thick and an internal soft PVC layer of
approximately 80 .mu.m thick. The antenna support is made of paper
approximately 125 .mu.m thick. According to another manufacturing
example, which is a preferred embodiment, each one of the card
bodies is comprised of three layers. A cover, consisting of a
transparent PVC sheet or varnish layer, is added on the external
layer of the card body when it is printed in order to protect the
printing. This cover is approximately 40 .mu.m thick. The external
layer of the card body is thus 275 .mu.m thick and the internal
layer approximately 40 .mu.m thick.
[0027] The lamination step consists of stacking together the
various layers of PVC which form the card body and the antenna
support. This sandwich is then placed in a lamination press. The
sandwich is heat treated at a temperature greater than 100.degree.
C., and preferably greater than 150.degree. C. At the same time,
the sandwich is pressed in order to fuse the various layers
together. Under the combined action of heat and pressure, the
external PVC softens and the internal layer made of PVC with a
lower Vicat softening temperature then liquefies. The liquefied PVC
traps the screen printed ink of the antenna within the mass of the
card offering it enhanced resistance to the mechanical stresses
encountered during smart card usage. Furthermore, the antenna
adheres to the card body better. This adherence may be enhanced by
using pressure-sensitive double-face tape placed between the card
body and the antenna.
[0028] The cutouts 22 made in the corners of the antenna support
allow the two internal PVC layers to come into contact with one
another. By blocking the corners by welding the two card bodies
together, all of the mechanical stresses are directed inside the
card. In the case of the paper, paper pulp exhibits low internal
cohesion. When it is subjected to sheer forces, the core of the
paper tends to delaminate. If these stresses are too strong, the
card opens up and splits in two parts (the part which contains the
antenna connected to the module continues to function). In this
manner, by acting on the type of paper and on its internal
cohesion, we can benefit from this physical property in order to
create a card with a built-in and variable stress marker. According
to the customer's needs, delamination may thus be more or less
rapid and more or less significant so that limited flexion of the
card may be seen owing to the delamination of the paper inside the
card.
[0029] The next step consists in milling a cavity which will
receive the module comprised of the chip and the double-sided
circuit. The milling operation also enables bonding pads between
the antenna and the module to be removed. In order not to damage
the screen printed imprint of the antenna, the milling operation is
carried out in the card body which is opposite the antenna support
face with the screen printed imprint, that is to say in the card
body which is in contact with the side of the support not bearing
the screen printed antenna. In this manner, during the milling
operation, the antenna support is milled before the ink.
Furthermore, as it is embedded in the PVC of the first layer of the
card body, it is not subjected to damage such as cracking or
tearing. In the case of an ISO format smart card for which the
location of the chip on the card is standardized, the inverted
screen printed imprint of the antenna on the support and the
milling of the cavity in the card body which is in contact with the
side of the support not bearing the screen print, enables the
module to be installed in the standardized location while
maintaining the integrity of the screen printed antenna.
[0030] The module is glued in place. Two different adhesives are
used. The first glue is an electrically conductive adhesive which
enables the module to be connected to the antenna contacts. This
adhesive is preferably an adhesive which contains silver. The
second glue is used to secure the module to the card. According to
a special embodiment, cyanoacrylate glue is used. It is also
possible to use a film-type "hot-melt" adhesive which is placed
under the module prior to its insertion in the card. Once this step
is terminated, a card as shown in FIG. 3 is obtained. The bodies of
the card 24 are heat bonded together in the corners via the cutouts
22 on the antenna support. The module 26 is located in the
standardized location for ISO type smart cards.
[0031] FIG. 4 is a cross sectional view along axis A-A of the smart
card represented in FIG. 3. The card consists of an antenna support
28 made of fibrous material, inserted between the two card bodies.
Each card body contains a cover 30 which consists of a sheet of
transparent PVC film or varnish layer, an external rigid PVC layer
32 and an internal soft PVC layer 34. The turn 36 and the bonding
pads are trapped in the internal layer 34 of the card body's PVC
mass. The cavity milled in the card body opposite the support face
bearing the antenna receives the double-sided circuit 40 and the
chip 42, protected by an overmolding resin (not represented). The
module is connected to the contacts of antenna contacts 38 with a
layer of silver-load electrically conductive glue 44. A layer of
cyanoacrylate glue 46 secures the module to the card.
[0032] The process according to the invention offers a card having
two major qualities for the companies which use it: the
preservation of the electrical components provide this card with
enhanced solidity and, in case of card malfunction, the
delamination property of the fibrous materials such as the paper
allows to make sure that the card has not been subjected to
intensive folding for the purpose of frauding.
* * * * *