U.S. patent application number 09/843089 was filed with the patent office on 2001-08-23 for tamper-preventing, contact-type, smart cards.
Invention is credited to Tiffany, Harry J. III.
Application Number | 20010015382 09/843089 |
Document ID | / |
Family ID | 22142896 |
Filed Date | 2001-08-23 |
United States Patent
Application |
20010015382 |
Kind Code |
A1 |
Tiffany, Harry J. III |
August 23, 2001 |
Tamper-preventing, contact-type, smart cards
Abstract
Smart cards having high quality external surfaces can be made
through use of a primer/adhesive (and, optionally, anchor hooks) on
the lower surface of an electrical component in order to affix said
electrical component to a thermosetting material that becomes the
core layer of said cards.
Inventors: |
Tiffany, Harry J. III;
(Weldona, CO) |
Correspondence
Address: |
DORR CARSON SLOAN & BIRNEY, PC
3010 EAST 6TH AVENUE
DENVER
CO
80206
|
Family ID: |
22142896 |
Appl. No.: |
09/843089 |
Filed: |
April 25, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09843089 |
Apr 25, 2001 |
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09268169 |
Mar 12, 1999 |
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6241153 |
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60078255 |
Mar 17, 1998 |
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Current U.S.
Class: |
235/488 |
Current CPC
Class: |
B29C 45/14647 20130101;
B29C 2045/14532 20130101; H01L 2924/0002 20130101; G06K 19/07745
20130101; G06K 19/077 20130101; B29C 45/2669 20130101; B29C
45/14467 20130101; H01L 2924/0002 20130101; H01L 2924/00
20130101 |
Class at
Publication: |
235/488 |
International
Class: |
G06K 019/02 |
Claims
Thus, what is claimed is:
1. A process for making a contact type smart card comprising a top
layer in which an electrical sensing device resides, a core layer
and a bottom layer, said process comprising: (1) coating a layer of
primer/adhesive on the underside of the electrical sensor device
such that said layer of primer/adhesive will come into direct
physical contact with a thermosetting polymeric material that forms
the core layers of the smart card; (2) positioning the electrical
sensor device in an opening in the top layer; (3) positioning the
top layer and bottom layer in a mold set up that defines a void
space between the top layer and the bottom layer; (4) injecting a
thermosetting polymeric material into the void space under
conditions such that the primer/adhesive comes into direct physical
contact with the thermosetting polymeric material to form a unified
precursor smart card body; (5) removing the unified precursor smart
card body from the mold set up; and (6) trimming the precursor
smart card to a desired dimension to produce a smart card.
2. The method of claim 1 wherein the electrical sensor device is
provided with at least one anchor device.
3. The method of claim 1 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated to
facilitate the creation of a strong bond between the top layer and
the thermosetting material and the bottom layer and the
thermosetting material.
4. The method of claim 1 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated by
coating each with a bonding agent.
5. The method of claim 1 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated by a
corona discharge process.
6. The method of claim 1 wherein the thermosetting material is
injected into the void space at a pressure between about ambient
pressure and about 500 psi.
7. The method of claim 1 wherein the thermosetting material is
injected into the void space at a pressure between about 80 and
about 120 psi.
8. The method of claim 1 wherein the thermosetting material is
injected into the void space at a temperature between about
56.degree. F. and about 100.degree. F.
9. The method of claim 1 wherein the thermosetting material is
injected into the void space between the top layer and the bottom
layer at a temperature between about 65.degree. F. and about
70.degree. F.
10. The method of claim 1 wherein a film bearing
alphanumeric/graphic information is applied to the inside surface
of the top layer.
11. The method of claim 1 wherein a layer of material is applied to
the inside surface of the top layer and the inside surface of the
bottom layer to decrease the opacity of the card.
12. The method of claim 1 wherein the top layer and the bottom
layer are each formed from a flat sheet of polymeric material.
13. The method of claim 1 wherein the top layer is preformed with
at least one card-forming cavity.
14. The method of claim 1 wherein the top layer is molded into a
card-forming cavity of a top mold and the bottom layer is molded
against a substantially flat surface of a bottom mold.
15. The method of claim 1 wherein the thermosetting material is a
polyurethane.
16. The method of claim 1 wherein the thermosetting material is an
epoxy.
17. The method of claim 1 wherein the thermosetting material is an
unsaturated polyester.
18. The method of claim 1 wherein the void space is filled by a
gate whose width is at least about 25 percent of the width of an
edge of a precursor card being serviced by said gate.
19. The method of claim 1 wherein the card is provided with a
magnetic strip.
20. A process for making a contact type smart card comprising a top
layer in which an electrical sensor device resides, a core layer
and a bottom layer, said process comprising: (1) coating a layer of
primer/adhesive on underside of the electrical sensor device such
that said layer of primer/adhesive will come into direct physical
contact with a thermosetting polymeric material that forms the core
layer of the smart card; (2) positioning the electrical sensor
device in an opening in top layer; (3) positioning the top layer
and bottom layer in a mold set up that defines a void space between
the top layer and the bottom layer; (4) injecting a thermosetting
polymeric material into the void space under conditions which are
such that: (a) the primer/adhesive comes into direct physical
contact with the thermosetting polymeric material, (b) at least one
layer of the smart card is at least partially cold, low pressure
molded into a cavity in the top mold, (c) gases and excess
polymeric material are driven out of the void space, (d) the
electronic component is encapsulated in the thermosetting polymeric
material before the partially cured glue becomes completely cured
and (e) the thermosetting polymeric material bonds with both the
top layer and the bottom layer to produce a unified precursor smart
card body; (5) removing the unified precursor smart card body from
the mold device; and (6) trimming the precursor smart card to a
desired dimension to produce a smart card.
21. The method of claim 20 wherein the electrical sensor device is
provided with at least one anchor device.
22. The method of claim 20 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated to
facilitate the creation of a strong bond between the top layer and
the thermosetting material and the bottom layer and the
thermosetting material.
23. The method of claim 20 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated by
coating each with a bonding agent.
24. The method of claim 20 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated by a
corona discharge process.
25. The method of claim 20 wherein the thermosetting material is
injected into the void space at a pressure between about ambient
pressure and about 500 psi.
26. The method of claim 20 wherein the thermosetting material is
injected into the void space at a pressure between about 80 and
about 120 psi.
27. The method of claim 20 wherein the thermosetting material is
injected into the void space at a temperature between about
56.degree. F. and about 100.degree. F.
28. The method of claim 20 wherein the thermosetting material is
injected into the void space between the top layer and the bottom
layer at a temperature between about 65.degree. F. and about
70.degree. F.
29. The method of claim 20 wherein a film bearing a
alphanumeric/graphic information is applied to the inside surface
of the top layer.
30. The method of claim 20 wherein a layer of material is applied
to the inside surface of the top layer and the inside surface of
the bottom layer to decrease the opacity of the card.
31. The method of claim 20 wherein the top layer and the bottom
layer are each formed from a flat sheet of polymeric material.
32. The method of claim 20 wherein the top layer is preformed with
at least one card-forming cavity.
33. The method of claim 20 wherein the top layer is molded into a
card-forming cavity of a top mold and the bottom layer is molded
against a substantially flat surface of a bottom mold.
34. The method of claim 20 wherein the thermosetting material is a
polyurethane.
35. The method of claim 20 wherein the thermosetting material is an
epoxy.
36. The method of claim 20 wherein the thermosetting material is an
unsaturated polyester.
37. The method of claim 20 wherein the void space is filled by a
gate whose width is at least about 25 percent of the width of an
edge of a precursor card being serviced by said gate.
38. The method of claim 37 wherein the card is provided with a
magnetic strip.
39. The smart card precursor comprised of a top layer in which an
electrical sensing device resides and wherein an underside of said
electrical sensing device is provided with a layer of
primer/adhesive that comes into direct physical contact with which
a core layer of said card is made, a core layer and a bottom
layer.
40. The smart card of claim 39 wherein the electrical sensing
device is a module of electronic sensing components.
41. The smart card of claim 39 wherein the ITA-based circuit
includes an antenna that is electrically connected to a chip.
42. The smart card of claim 39 wherein the top layer and the bottom
layer are each formed from a flat sheet of PVC material.
43. The smart card of claim 39 wherein the thermosetting material
is a polyurethane.
44. The smart card of claim 39 wherein the thermosetting material
is an epoxy.
45. The smart card of claim 39 wherein the thermosetting material
is an unsaturated polyester.
46. The smart card of claim 39 that further comprises additional
electronic components that are embedded in the core region of said
smart card.
47. The smart card of claim 39 that further comprises an antenna
component that is embedded in the core region of said smart
card.
48. The smart card of claim 39 wherein the electrical sensing
device is provided with a anchor device.
49. A process for making a contact type smart card comprising a top
layer in which an electrical sensing device resides, a core layer
and a bottom layer, said process comprising: (1) providing the
electrical sensor device with at least one anchor device that will
come into direct physical contact with a thermosetting polymeric
material that forms the core layers of the smart card; (2)
positioning the electrical sensor device in an opening in the top
layer; (3) positioning the top layer and bottom layer in a mold set
up that defines a void space between the top layer and the bottom
layer; (4) injecting a thermosetting polymeric material into the
void space under conditions such that the anchor device comes into
direct physical contact with the thermosetting polymeric material
and form a unified precursor smart card body; (5) removing the
unified precursor smart card body from the mold set up; and (6)
trimming the precursor smart card to a desired dimension to produce
a smart card.
50. The method of claim 49 wherein the electrical sensor device is
provided with a layer of primer/adhesive that also comes in direct
physical contact with the thermosetting material.
51. The method of claim 49 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated to
facilitate the creation of a strong bond between the top layer and
the thermosetting material and the bottom layer and the
thermosetting material.
52. The method of claim 49 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated by
coating each with a bonding agent.
53. The method of claim 49 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated by a
corona discharge process.
54. The method of claim 49 wherein the thermosetting material is
injected into the void space at a pressure between about ambient
pressure and about 500 psi.
55. The method of claim 49 wherein the thermosetting material is
injected into the void space at a pressure between about 80 and
about 120 psi.
56. The method of claim 49 wherein the thermosetting material is
injected into the void space at a temperature between about
56.degree. F. and about 100.degree. F.
57. The method of claim 49 wherein the thermosetting material is
injected into the void space between the top layer and the bottom
layer at a temperature between about 65.degree. F. and about
70.degree. F.
58. The method of claim 49 wherein a film bearing
alphanumeric/graphic information is applied to the inside surface
of the top layer.
59. The method of claim 49 wherein a layer of material is applied
to the inside surface of the top layer and the inside surface of
the bottom layer to decrease the opacity of the card.
60. The method of claim 49 wherein the top layer and the bottom
layer are each formed from a flat sheet of polymeric material.
61. The method of claim 49 wherein the top layer is preformed with
at least one card-forming cavity.
62. The method of claim 49 wherein the top layer is molded into a
card-forming cavity of a top mold and the bottom layer is molded
against a substantially flat surface of a bottom mold.
63. The method of claim 49 wherein the thermosetting material is a
polyurethane.
64. The method of claim 49 wherein the thermosetting material is an
epoxy.
65. The method of claim 49 wherein the thermosetting material is an
unsaturated polyester.
66. The method of claim 49 wherein the void space is filled by a
gate whose width is at least about 25 percent of the width of an
edge of a precursor card being serviced by said gate.
67. The method of claim 49 wherein the card is provided with a
magnetic strip.
68. A process for making a contact type smart card comprising a top
layer in which an electrical sensor device resides, a core layer
and a bottom layer, said process comprising: (1) providing the
electrical sensor device with a least one anchor device that will
come into direct physical contact with a thermosetting polymeric
material that forms the core layer of the smart card; (2)
positioning the electrical sensor device in an opening in top
layer; (3) positioning the top layer and bottom layer in a mold set
up that defines a void space between the top layer and the bottom
layer; (4) injecting a thermosetting polymeric material into the
void space under conditions which are such that: (a) the anchor
device comes into direct physical contact with the thermosetting
polymeric material, (b) at least one layer of the smart card is at
least partially cold, low pressure molded into a cavity in the top
mold, (c) gases and excess polymeric material are driven out of the
void space, (d) the electronic component is encapsulated in the
thermosetting polymeric material before the partially cured glue
becomes completely cured and (e) the thermosetting polymeric
material bonds with both the top layer and the bottom layer to
produce a unified precursor smart card body; (5) removing the
unified precursor smart card body from the mold device; and (6)
trimming the precursor smart card to a desired dimension to produce
a smart card.
69. The method of claim 68 wherein the electrical sensor device
provided with a layer of primer/adhesive that also comes in direct
physical contact with the thermosetting material.
70. The method of claim 68 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated to
facilitate the creation of a strong bond between the top layer and
the thermosetting material and the bottom layer and the
thermosetting material.
71. The method of claim 68 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated by
coating each with a bonding agent.
72. The method of claim 68 wherein the inside surface of the top
layer and the inside surface of the bottom layer are treated by a
corona discharge process.
73. The method of claim 68 wherein the thermosetting material is
injected into the void space at a pressure between about ambient
pressure and about 500 psi.
74. The method of claim 68 wherein the thermosetting material is
injected into the void space at a pressure between about 80 and
about 120 psi.
75. The method of claim 68 wherein the thermosetting material is
injected into the void space at a temperature between about
56.degree. F. and about 100.degree. F.
76. The method of claim 68 wherein the thermosetting material is
injected into the void space between the top layer and the bottom
layer at a temperature between about 65.degree. F. and about
70.degree. F.
77. The method of claim 68 wherein a film bearing a
alphanumeric/graphic information is applied to the inside surface
of the top layer.
78. The method of claim 68 wherein a layer of material is applied
to the inside surface of the top layer and the inside surface of
the bottom layer to decrease the opacity of the card.
79. The method of claim 68 wherein the top layer and the bottom
layer are each formed from a flat sheet of polymeric material.
80. The method of claim 68 wherein the top layer is preformed with
at least one card-forming cavity.
81. The method of claim 68 wherein the top layer is molded into a
card-forming cavity of a top mold and the bottom layer is molded
against a substantially flat surface of a bottom mold.
82. The method of claim 68 wherein the thermosetting material is a
polyurethane.
83. The method of claim 68 wherein the thermosetting material is an
epoxy.
84. The method of claim 68 wherein the thermosetting material is an
unsaturated polyester.
85. The method of claim 68 wherein the void space is filled by a
gate whose width is at least about 25 percent of the width of an
edge of a precursor card being serviced by said gate.
86. The method of claim 86 wherein the card is provided with a
magnetic strip.
87. A smart card comprised of a top layer in which an electrical
sensing device resides and wherein said electrical sensing device
is provided with an anchor device that also comes into direct
physical contact with cured thermosetting material that forms a
core layer, the core layer and a bottom layer.
88. The smart card of claim 87 wherein the electrical sensing
device is a module of electronic sensing components.
89. The smart card of claim 87 wherein the ITA-based circuit
includes an antenna that is electrically connected to a chip.
90. The smart card of claim 87 wherein the top layer and the bottom
layer are each formed from a flat sheet of PVC material.
91. The smart card of claim 87 wherein the thermosetting material
is a polyurethane.
92. The smart card of claim 87 wherein the thermosetting material
is an epoxy.
93. The smart card of claim 87 wherein the thermosetting material
is an unsaturated polyester.
94. The smart card of claim 87 that further comprises additional
electronic components that are embedded in the core region of said
smart card.
95. The smart card of claim 87 that further comprises an antenna
component that is embedded in the core region of said smart
card.
96. The smart card of claim 87 wherein the electrical sensing
device is provided with a layer of primer/adhesive that also comes
into contact with a cured thermosetting material that forms the
core layer.
Description
RELATED PATENT APPLICATION
[0001] This patent application claims the benefit of, including the
filing date of, Provisional Application 60/078,255 entitled
"Provisional Patent Application re: Method for Making
Tamper-Preventing, Contact-Type, Smart Cards", filed Mar. 17,
1998.
BACKGROUND OF THE INVENTION
[0002] Smart cards are used as bankcards, ID cards, telephone cards
and the like. They are based upon the use of an electromagnetic
coupling (either by direct physical contact or by electromagnetic
waves) between a smart card's electronic components and a card
reader, pickup head or other appropriate electronic signal
receiving device such as those employed in an ATM. Because these
cards are so widely used to effect very valuable and/or otherwise
important transactions, they are the frequent subject of fraudulent
activities. These fraudulent activities often involve physically
tampering with a smart card's electronic components. For example,
their computer chips or other electronic components are removed
from a valid smart card and physically transferred to a fraudulent
card in order to gain money, unauthorized access, unauthorized
information, etc.
[0003] Smart cards are usually made by assembling several layers of
plastic sheets in a sandwich array. In the case of so-called
"contact" type smart cards at least one face of the smart card has
an opening in which an electronic signal sensing component such as
a strip-like sensor, computer chip, module or "pickup head"
reside(s). The electronic signal sensing component comes into
direct physical contact with an electrically cooperating component
of a machine (e.g., an ATM machine, credit card transaction
machine, a personal identity verification machine, telephone, etc.)
in which the contact type smart card is employed. Many contact type
smart cards have all of their electrical components (e.g., their
electronic signal sensing device and their computer chip assembled)
in a unified module that is glued in an open cavity in a face of
the card. By way of distinction, so-called "contactless" smart
cards communicate with the machines in which they are employed by
means of a radio wave-receiving antenna that is embedded in the
interior of the contactless smart card. Hence, there is no physical
contact between the card's electronic signal sensing component(s)
and the user machine's signal sensing component. Some smart cards
operate in hybrid, contact/contactless, modes of operation.
[0004] Applicant's invention may be used with any of these three
types of smart card; but for reasons hereinafter more fully
explained, it is more particularly concerned with "contact" type
smart cards and/or the methods employed to manufacture them. The
methods by which prior art smart cards have been manufactured have
varied considerably. For example, U.S. Pat. No. 5,272,374 discloses
an integrated chip-employing smart card comprising a card board
having a first and a second major surface and a semiconductor
module having an electrode terminal face. The semiconductor module
is mounted in the card board such that the electrode terminal face
is left exposed in the first major surface of the card board.
[0005] U.S. Pat. No. 5,311,396 teaches a portable and connectable
chip-based smart card system having one or more chips integrated
into a package. The electronic component is mounted on the upper
surface of metal contacts. A lower surface has metal contacts that
constitute a connector of the system. Each of the metal contacts of
the upper face is connected to, and faces, a metal contact of the
lower surface, and vice versa. In a second embodiment of this
invention, the electronic component is surface mounted on an upper
surface of the metal contacts in a manner such that the lower
surface of these contacts forms the connector.
[0006] U.S. Pat. No. 5,486,687 teaches a memory card having several
integrated circuits for personal computers. These memory cards
serve as a large capacity mass memory for replacing floppy disks
and other exchangeable magnetic supports. They are provided with a
plug-in connector at the end of the card and can be inserted in the
reader in a prescribed manner, e.g., in accordance with PCMCIA
standards. According to one aspect of this invention, a flush
contact chip card memory is formed by such a plug-in card. To this
end, the card has a supplementary connector with flush contacts on
its principal face. The resulting reader is transportable. Its
application software can be stored in the card and can be installed
in any random microcomputer equipped with a PCMCIA reader.
[0007] All of these prior art methods for making contact smart
cards are to some degree concerned with properly positioning and
fixing the electronic signal sensing component module or assembly
inside the smart card in such a way that they present a flat
surface on or substantially flush with the card's face surface (or
its obverse surface). Unfortunately, this proximity of the signal
sensing component to the face surface (or its obverse) of contact
smart cards presents an opportunity for tampering with, and
fraudulent use of, such cards.
SUMMARY OF THE INVENTION
[0008] Applicant's smart cards (e.g., credit cards, ATM cards,
personal identity cards, access control cards, telephone cards,
etc.) and methods for making them are primarily based upon the use
of certain hereinafter more fully described physical elements and
manufacturing procedures. Applicant's tamper-preventing
construction for contact type smart cards is achieved by coating
the rear side of the smart card's contact device (e.g., its signal
sensor, pickup head, computer chip) with a primer/adhesive that has
the ability to form a strong bond with a thermosetting polymeric
material that is injected into a void space that eventually becomes
the core or center layer of the smart card. This construction
method is based upon applicant's finding that the bonding action
between a primer/adhesive and the thermosetting polymeric material
that forms the core of the card is much stronger than the bonding
action between the rear surface of an electrical signal sensing
component and a thermosetting polymeric material.
[0009] The tamper-preventing action provided by applicant's
placement of a primer/adhesive on the rear side (i.e., the
thermosetting polymer contacting-side) of the card's contact device
can be replaced by or further enhanced by placement of certain,
hereinafter more fully described, "anchor hooks" on the electrical
sensing component in a manner such that said hooks are immersed in
the incoming, liquid, thermosetting polymer. Thereafter, these
"anchor hooks" become very strongly embedded in the thermosetting
polymeric material when it cures. Indeed, the use of such anchor
hooks can, in its own right, achieve the tamper preventing action
provided by applicant's primer/adhesive-thermosetting material
bond. In some of the more preferred embodiments of this invention
the primer/adhesive and the anchor hooks will be used together to
achieve the tamper-preventing action.
[0010] The primer/adhesives used in the hereindescribed processes
are so-called solvent based, primer/adhesives. They usually employ
methyl ethyl ketone as a solvent for an adhesive, polymeric
material. 3M Adhesive Systems Industrial Tape and Specialties
Division, 3M Center, Building 220-7E-01, St. Paul, Minn. makes
several such primer/adhesives. Their 4475.RTM. Primer/adhesive is,
however, particularly preferred for the practice of this invention.
In actual manufacturing practice, these solvent based,
primer/adhesives may be at least partially cured by exposure to an
"artificial" energy source (i.e., an energy source other than
ambient heat and/or light of the manufacturing plant). This
exposure speeds up the curing process. These artificial energy
sources may be further characterized by their ability to produce
electromagnetic waves of a given wave length. Some
primer/adhesives, for example, can be more quickly cured by
exposure to energy sources giving off electromagnetic waves having
wave lengths ranging from about 200 to about 400 nanometers (nm).
Such primer/adhesives are sometimes referred to as being "UV
curable". Electrically powered UV and/or microwave producing
devices known to those skilled in this art may be employed as
sources of such 200-400 nm wave forms. Use of devices that emit
260-270 nm wave forms is even more preferred when using certain UV
curable primer/adhesives. Regardless of the type of solvent based,
primer/adhesive being used, however, applicant's primer/adhesive
"curing" step will most preferably, at least partially, take place
in a period of time ranging from about 0.1 to about 10 seconds.
Partial curing times of less than 3 seconds are even more preferred
in high speed manufacturing processes.
[0011] These primer/adhesives should, most preferably, be employed
in the form of at least one small layer, coating, mound, dollop, or
hemisphere that is placed on an inside surface of the card's
electronic signal sensing device that is exposed on an outside
surface of a "contact" type card. In the case where the electronic
signal sensing device is part of a module (e.g., one comprised of a
signal sensor, a board, a chip, a potting device, etc.) the
primer/adhesive is preferably placed on the bottommost element so
that the primer/adhesive will come into intimate contact with the
thermosetting material which, upon curing, become the center or
core layer of the card. Such layer, mound, etc. of the
primer/adhesive is preferably applied to the electronic signal
sensing component, or the undermost component (e.g., the computer
chip or porting device) of the module before being placed in an
opening or holding hollow in the smart card's top (or bottom)
layer. Again, this exposure of the signal sensing device allows it
to come into physical contact with a signal reading device in a
card-reading machine such as an ATM.
[0012] The beneficial effects of applicant's manufacturing
procedures can be further enhanced by use of (1) certain
hereinafter more fully described "cold," "low pressure," forming
procedures, (2) certain physical placements of other electronic
components (e.g., chips other than those in the module) within
these smart cards, (3) certain thermoset flow gate geometries and
(4) certain receptacles in applicant's molds for receiving
thermoset material that may be injected in excess of the amount
needed to form the core regions of applicant's smart cards. Aside
from their tamper-preventing features, the smart cards made using
the hereindescribed elements and manufacturing methods also are
characterized by their high quality external surfaces. The term
"high quality" in the context of this patent disclosure should be
taken to imply substantially flat external surfaces (i.e., card
faces having no waves, bends, wrinkles or pock marks).
[0013] Applicant's contact type, smart cards are generally
comprised of a top layer having an inside surface and an outside
surface, a bottom layer having an inside surface and an outside
surface and a center or core layer that is sandwiched between the
top and bottom layers. Either the top layer or the bottom layer (or
both layers) of a contact type smart card made according to the
methods of this patent disclosure may have an opening in which an
electrical signal sensing device is affixed. Such devices are
usually associated with other electronic components such as
computer chips, boards, pods, etc. Hence, the resulting devices are
frequently referred to as "modules." One of the most common devices
of this kind is a contact which (via a board) is combined with a
chip to form a signal sensing/processing module.
[0014] In other cases, however, some of the additional electronic
components (e.g., computer chips, capacitors, etc.) of applicant's
contact type smart cards may be completely embedded in the
thermosetting polymeric material that constitutes the card's center
or core layer. Hence, these completely embedded electronic
components form no part of the external surface of applicant's
finished smart cards. Such cards are sometimes referred as hybrid
or "combi" smart cards. Again, in the case of contact type cards,
the card's electrical signal sensor device (its pickup head,
contact surface, etc.) are placed in contact with a reading machine
through an opening in a face (top or bottom) of the contact type
smart card. Thus, electrical signal-carrying contact by the reading
machine using the contact card (e.g., with an ATM) is made with the
card via this exposed electrical contact in the face side (or
obverse side) of the card.
[0015] In all cases, however, all three of these layers are unified
into a smart card body by a bonding action between the
thermosetting polymeric material used to create the core layer of
such cards and those material(s) such as PVC, out of which the top
and bottom layers are made. In some of the more preferred
embodiments of applicant's invention, this bonding action may be
augmented through use of various hereinafter more fully described
treatments of the inside surfaces of the top and/or of the bottom
layer of applicant's smart cards.
[0016] Before delving any further into the more specific details of
applicant's methods for making the hereindescribed
tamper-preventing smart cards, it should be noted that, for the
purposes of this patent disclosure, the terms "upper" and "lower,"
or "top" and "bottom," layer(s) should be regarded as being
relative. That is to say that they are implied by the relative
positions of the mold shells that are employed to manufacture these
cards. Hence, these terms should not imply any absolute position or
orientation of the card itself.
[0017] Be this top/bottom nomenclature as it may, the
hereindescribed methods for making tamper-preventing smart cards in
general, and tamper-preventing contact type smart cards in
particular, will employ reaction injection molding machines (which
are often individually referred to as "RIM"). These machines are
associated with a top mold shell and a bottom mold shell that, most
preferably, are capable of performing certain hereinafter more
fully described cold, low pressure, forming operations on at least
one of the sheets of polymeric material (e.g., PVC) that make up
the two major external surface layers of applicant's smart cards.
Such top and bottom mold shells cooperate in ways that are well
known to those skilled in the polymeric material molding arts. For
use in applicant's particular processes, however, at least one of
the RIM's mold shells, e.g., the top mold shell, will have at least
one cavity for partially defining the thickness of, and general
peripheral extent of, a precursor smart card body that is to be
formed, and most preferably cold, low pressure formed, between the
two mold shells.
[0018] It might also be noted here that applicant's use of the term
"precursor smart card body" (which will include bodies of "excess"
polymeric material) is to distinguish those roughly defined card
bodies that are formed by such mold devices from those "finished"
smart cards that are produced by removing the excess polymeric
materials (e.g., by trimming them off of the precursor card body)
and by cutting the precursor card bodies to certain prescribed
sizes. For wide commercial use, all smart cards also must be made
to very precise, standardized dimensions. For example, ISO Standard
7810 requires that contactless smart cards have a nominal length of
85.6 mm, a nominal width of 53.98 mm and a nominal thickness of
0.76 mm. Such cutting to prescribed sizes also may remove the
excess material in one cutting/trimming operation. It also will be
well appreciated by those skilled in this art that the molding
devices used to make such cards in commercial production operations
will most preferably have mold shells having multiple cavities
(e.g., 2, 4, 6, 8, etc.) for making several such cards
simultaneously.
[0019] Those skilled in this art also will appreciate that
applicant's use of terms like "polymeric," "plastic,"
"thermoplastic" and "thermosetting" each refer to a potentially
wide variety of polymeric materials. Be that as it may, the
polymeric materials employed by applicant will generally fall into
one of two subcategories--thermoplastic materials, or thermosetting
materials. Thermoplastic materials are characterized by their
possession of long molecules (either linear or branched) that have
side chains or groups that are not attached to other polymer
molecules. Consequently, thermoplastic materials can be repeatedly
softened and hardened by heating and cooling so they can be formed,
and then cooled to form a final hardened shape. Generally speaking,
no appreciable chemical changes take place during such heat driven,
forming operations. Conversely, thermosetting materials (such as
their resins), have chemically reactive portions that form chemical
cross-linkages between their long molecules during their
polymerization. In other words, these linear polymer chains become
bonded together to form stereo chemical structures. Therefore, once
such thermosetting resins are hardened, the resulting material
cannot be softened by heating without degrading at least some of
the chemical cross linking molecular groups.
[0020] Either form of polymeric material (thermoplastic or
thermosetting) may be used for the top layer and/or the bottom
layer of applicant's smart cards. Hence, applicant's use of the
general term "polymeric" with respect to the materials out of which
applicant's top and bottom layers can be made should be taken to
include thermosetting materials as well as thermoplastic materials.
Thermosetting polymers are, however, highly preferred for creating
the center or core layer of applicant's smart cards. There are
several reasons for this preference. For example, thermosetting
polymers generally bond better with the materials (e.g., PVC) from
which the top and bottom layers are preferably made. Thermosetting
polymers also can be commercially obtained in relatively
inexpensive, easy to use, liquid monomer-polymer mixtures, or
partially polymerized molding compounds, that are particularly well
suited for use in applicant's high speed, cold, low pressure
forming operations.
[0021] Some representative polymeric materials (thermoplastic or
thermosetting) that can be used for making applicant's top and
bottom layers will include polyvinyl chloride, polyvinyl
dichloride, polyvinyl acetate, polyethylene,
polyethylene-terephthalate, polyurethane, acrylonitrile butadiene
styrene, vinyl acetate copolymer, polyesters, polyethylene, epoxy
and silicones. Such top and bottom layers also may be made from
other polymeric materials such as polycarbonate, cellulose acetate
and cellulose acetate butyrate-containing materials. Of all the
polymeric materials from which applicant's top and bottom layers
could be made, however, polyvinyl chloride ("PVC") is especially
preferred because of the clear to opaque visual qualities of this
material and its ability to receive printing and its relatively
lower cost.
[0022] The most preferred thermosetting materials for applicant's
injection purposes are polyurethane, epoxy and unsaturated
polyester polymeric materials. By way of some more specific
examples, polyurethanes made by condensation reactions of
isocyanate and a polyol derived from propylene oxide or
trichlorobutylene oxide are especially preferred. Of the various
polyesters that can be used in applicant's processes, those that
can be further characterized as being "ethylenic unsaturated" are
particularly preferred because of their ability to be cross linked
through their double bonds with compatible monomers (also
containing ethylene unsaturation) and with the materials out of
which applicant's top and bottom layers are made. The more
preferred epoxy materials for use in the practice of this invention
will be those made from epichlorohydrin and bisphenol A, or
epichlorohydrin, and an aliphatic polyol (such as glycerol). They
are particularly preferred because of their ability to bond with
some of the more preferred materials (e.g., PVC) out of which
applicant's top and bottom layers are made. These three general
kinds of thermosetting material, (polyurethane, epoxy and
unsaturated polyester), also are preferred because they do not tend
to chemically react with applicant's more preferred glues (e.g.,
various cyanoacrylate-based glues), to form unsightly "artifacts"
in the core regions of applicant's card bodies.
[0023] Next, it should be noted that applicant's use of expressions
such as "cold, low pressure forming conditions" generally should be
taken to mean forming conditions wherein the temperature of the
injected polymeric liquid or semi-liquid material is less than the
heat distortion temperature of the plastic sheet material being
cold formed (e.g., the top layer of applicant's smart cards), and
pressures less than about 500 psi. In some of the more preferred
embodiments of the hereindescribed processes, the cold forming
temperatures used in applicant's processes will be at least
100.degree. F. less than the heat distortion temperature of the
plastic sheet material being molded. By way of a more specific
example, the heat distortion temperature of many polyvinyl chloride
materials is about 230.degree. F. Hence, the temperatures used to
cold form such PVC sheets in applicant's process preferably will be
no more than about (230.degree. F.-100.degree. F.). Temperatures of
about 130.degree. F. are particularly preferred for such
materials.
[0024] Applicant's more preferred cold, low pressure forming
procedures will involve injection of thermosetting polymeric
materials whose temperatures range from about 56.degree. F. to
about 160.degree. F., under pressures that preferably range from
about atmospheric pressure to about 500 psi. More preferably, the
temperatures of the thermosetting polymers being injected into the
center or core region of applicant's cards will be between about
65.degree. F. and about 130.degree. F. under injection pressures
that preferably range from about 80 to 120 psi. In some of the most
preferred embodiments of this invention the liquid or semi-liquid
thermosetting polymeric material will be injected into any given
card forming cavity under these preferred temperature and pressure
conditions at flow rates ranging from about 0.1 to about 50
grams/second/card-forming cavity. Flow rates of 1.5 to 1.7
grams/seconds/card-forming cavity are even more preferred. Those
skilled in this art also will appreciate the applicant's low
temperature and pressure conditions contrast rather sharply with
the much higher temperatures (e.g., 200.degree. F. to 1000.degree.
F.) and pressures (e.g., from 500 to 20,000 psi) that are often
used in many prior art, high speed, smart card injection molding
manufacturing operations.
[0025] It also should be noted that applicant's use of such
relatively cold, low pressure, forming conditions may require that
any given gate (i.e., the passageway that connects a runner with
each individual card-forming cavity) be larger than those gates
used in prior art, hot, high pressure operations. Applicant's gates
are preferably relatively larger than prior art gates so that they
are able to quickly pass the thermoset material being injected
under applicant's cold, low pressure forming conditions wherein
such thermoset materials are more viscous. Similarly, the runner
(i.e., the main thermoset material supply passageway in the mold
system that feeds from the source of the thermoset material to each
individual gate), will normally be in a multi-gate or manifold
array, and, hence, should be capable of simultaneously supplying
the number of gates/card forming cavities (e.g., 4 to 8 cavities)
in the manifold system at the relatively cold temperature (e.g.,
56.degree. F. to 160.degree. F.) and relatively low pressure (e.g.,
atmospheric pressure to 500 psi) conditions used in applicant's
process.
[0026] It also might be noted at this point that the flow rates for
the polymeric thermoset material under applicant's low temperature
and pressure conditions nonetheless, should be such that they are
able to completely fill a given card-forming cavity in less than or
about 10 seconds per card-forming cavity (and more preferably in
less than about 3 seconds). Card-forming cavity fill times of less
than 1 second are even more preferred where they can be achieved.
In view of these cold-forming conditions, certain preferred
embodiments of applicant's smart card making processes will employ
gates having a width which is a major fraction of the length of a
leading edge of the card to be formed (that is, a card edge which
is connected to a gate). Applicant prefers that the width of a
given gate be from about 20 percent to about 200 percent of the
width of the leading edge (or edges--multiple gates can be used to
fill the same card-forming cavity), i.e., the "gated" edge(s), of
the smart card being formed.
[0027] Applicant also prefers to employ gates that are tapered down
from a relatively wide inflow area to a relatively narrow core
region that ends at or near the leading edge(s) of the card body
being formed. Most preferably, these gates will narrow down from a
relatively wide diametered (e.g., from about 5 to about 10 mm)
injection port that is in fluid connection with a thermosetting
material-supplying runner, to a relatively thin diameter (e.g.,
0.10 mm) gate/card edge where the gate feeds the thermosetting
material into the void space which ultimately becomes the center or
core of applicant's finished card. By way of further example,
applicant has found that gates that taper from an initial diameter
of about 7.0 millimeters down to a minimum diameter of about 0.13
mm will produce especially good results under applicant's preferred
cold, low pressure injection conditions.
[0028] Another optional feature that can be used to advantage along
with applicant's glues and gluing procedures is the use of mold
shells that have one or more receptacles for receiving "excess"
polymeric material that may be purposely injected into the void
space between applicant's top and bottom layers in order to expunge
any air and/or other gases (e.g., those gases formed by the
exothermic chemical reactions that occur when the ingredients used
to formulate most polymeric thermoset materials are mixed together)
from said void space. These thermoset ingredients are preferably
mixed just prior to (e.g., about 30 seconds before) their injection
into the void space.
[0029] Still other optional procedures that may be used to enhance
the results of using applicant's manufacturing methods may include
the use of: (1) treatments that encourage and/or augment the
bonding action between the inside surfaces of the top and bottom
layers and the injected thermosetting material, (2) films that
display alphanumeric/graphic information that is visible at the
card's major surface(s), (3) opacity promoting (or preventing)
films or layers, (4) use of top layers or bottom layers that are at
least partially pre-molded by a preceding molding operation (e.g.,
a preceding, prior art type, "hot" molding operation or a preceding
"cold" molding operation such as those described in this patent
disclosure and (5) the use of opacity promoting pigment(s) in the
thermoset material. It might also be noted here that the outside
surfaces of the smart cards resulting from applicant's
manufacturing processes may be thereafter embossed or printed upon
in order to display alphanumeric/graphic information.
[0030] Applicant's methods for making the smart cards of this
patent disclosure also may, as an optional feature, involve the use
of at least one gas venting procedure and/or at least one excess
polymeric material receiving receptacle. More preferably, there
will be at least one such receptacle per card-forming cavity. The
presence of such gas venting and/or excess material receiving
receptacles will allow gases (e.g., air, and the gaseous reaction
products associated with those usually exothermic chemical
reactions of the polymeric material forming ingredients) and/or
relatively small amounts of the incoming thermoset polymeric
material itself to escape from each void space during applicant's
forming operations, e.g., cold, low pressure forming operations,
and be received in such receptacles and/or be totally flushed out
of the mold system. These gas venting procedures and excess
material receptacles generally serve to prevent imperfections that
may otherwise be created by entrapping gases in the void space
during the injection of the polymeric material.
[0031] Thus, this aspect of applicant's invention involves
injecting a flowable liquid or semi-liquid moldable polymeric
material into a void space between the top and bottom layers of
applicant's smart card in a process wherein the top and bottom
molds are respectively abutted against the top and bottom layers of
the smart card at a mold parting line perimeter or lip region at
pressures that are sufficient to (a) completely fill the void space
with a liquid or semi-liquid thermosetting polymeric material under
the conditions (e.g., cold forming conditions) used in the
hereindescribed processes, (b) immerse the primer/adhesive on the
underside of the electrical signal sensor, module, etc., (c)
immerse any anchor hooks associated with the electrical signal
sensor or module, (d) drive minor amounts of the polymeric material
out of the card forming cavities and into the excess material
receptacle and/or (e) drive the gases in the void space to the
excess material receptacle and/or drive such gases completely out
of the mold system (e.g., drive such gases out of the mold at the
parting line regions where the top and bottom mold shells come
together). Thus, the mold lip pressures used in applicant's
procedures should be sufficient to hold the pressures at which the
thermoplastic material is injected in order to completely fill the
void space between the top and bottom (e.g., between about ambient
pressure and 200 psi), but still permit small amounts of the
thermoset material and any gases to be flushed or squirted out of
the mold system at its parting line. In other words, in these
preferred embodiments, applicant's "excess" material receptacles
need not, and preferably will not, receive all of the excess
material injected into the void space. Excess thermoset material
and/or gases also may be--and preferably are-- expunged from the
entire mold system at the parting line where the top mold lip and
the bottom mold lip abut against each other or abut against the top
layer and the bottom layer. In effect, the incoming liquid or
semi-liquid thermoset polymeric material completely fills the void
space, immerses any primer adhesives, electronic component(s),
anchor hooks, etc. contained therein and force any air present in
the void space between the top and bottom layers (as well as any
gases created by the chemical reaction of the starting ingredients
of the polymeric material) out of the void space--and, in some
preferred cases, completely out of the mold system. All such
actions serve to eliminate any surface imperfections such as
surface "pock marks" and/or encapsulated bubbles that might
otherwise form if such gases were entrapped in the thermoset
polymeric material when it solidifies to form the core region of
applicant's cards.
[0032] Finally it also should be noted that the top and/or bottom
layers used in applicant's processes may be at least partially
molded into cavity-containing forms before they are placed in the
mold system used to make the smart cards of this patent disclosure.
Hence, the "cold, low pressure" molding operations called for in
this patent disclosure may be only a part of the total molding to
which these layer or sheet materials are subjected. Thus, for
example the cold, low pressure molding procedures of this patent
disclosure may provide only a partial amount of the total molding
experienced by a molded top layer of applicant's smart card. In the
more preferred embodiments of this invention, however, the top
layer will experience a major portion, e.g., at least 50 percent,
and more preferably all of the total molding it experiences (as
defined by the change in the volume of the cavity created by the
molding operation) by the cold, low pressure molding operations
that are preferred for the hereindescribed molding operations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a front view of a prior art contact type smart
card. It is shown having an electrical contact reader or other
electrical signal pickup component, alphanumeric/graphic
information and an identification photo. It also shows a phantom
bend line running through the module component.
[0034] FIG. 2 is an exploded cross-sectional view of the prior art
contact type smart card shown in FIG. 1.
[0035] FIG. 3 shows 1 in cross section, the prior art contact type
smart card of FIG. 1 in a partially bent condition.
[0036] FIG. 4 shows a cross-sectional view of a contact smart card
made according to the teachings of this patent disclosure.
[0037] FIG. 5 shows a cross-sectional view of a second embodiment
of this invention wherein some of the smart card's electrical
components are embedded in the card's core layer.
[0038] FIGS. 6 and 7 are cut-away side views of a mold tool set up
for making a first preferred embodiment of a smart card of this
patent disclosure. In FIG. 6, the smart card components are shown
before a liquid polymeric material is injected between the card's
top and bottom layers. FIG. 7 shows the mold tool set up after the
polymeric material is injected into the void space between the top
and bottom layers.
[0039] FIG. 8 depicts another preferred embodiment of this
invention wherein the mold tool shown in FIG. 6 is further provided
with an excess polymeric material and/or gas receiving
receptacle.
[0040] FIG. 9 depicts the result of injecting the mold system
depicted in FIG. 8 with a thermosetting polymeric material.
[0041] FIG. 10 illustrates another preferred embodiment of this
invention wherein the top and bottom sheet or layer components of
applicant's cards terminate at the front edge of a excess material
receiving receptacle.
[0042] FIG. 11 depicts the system shown in FIG. 10 after the void
space (and the excess material receptacle) are filled by injection
of a thermosetting polymeric material.
[0043] FIG. 12 is a cut-away side view of a mold tool wherein both
the top layer and bottom layer are each formed in their respective
mold cavities.
[0044] FIG. 13 is a cut-away view showing a mold tool being removed
from a precursor smart card body formed by the system generally
depicted in FIG. 9.
[0045] FIG. 14 depicts cut-away plan and cross section views of
various comparative gates for injection of applicant's thermoset
materials.
[0046] FIG. 15 depicts a mold tool system capable of making
multiple (i.e., four) smart cards simultaneously according to the
teachings of this patent disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0047] FIG. 1 depicts a prior art contact type smart card 10
displaying an identification photo, along with alphanumeric and/or
graphic information. The card 10 is provided with an electrical
signal sensing device 12 for communicating with a smart card-using
machine such as an ATM, identification verification machine,
telephone card receiving device, etc. The card also may be provided
with other electronic signal sensing devices such as a magnetic
strip 14. A bend line 16 is shown passing through the card at the
electrical signal sensing device 12.
[0048] FIG. 2 is an exploded, side view of the prior art contact
smart card shown in FIG. 1. It has a top layer 18, a center or core
layer 20, and a bottom layer 22. The core layer results from
injecting a thermosetting material into a void space 19 between the
top layer 18 and the bottom layer 22. This electrical signal
sensing device 12 is shown exploded out of a cavity 24 in the top
layer 18 and core layer 20 where the electrical signal sensing
device 12 normally is affixed, e.g., by gluing. This electrical
signal sensing device 12 is depicted as being part of a module 26
comprised of the sensing device 12, a board 28, and a chip 30. In
many prior art smart cards of this kind, the electrical signal
sensing device 12 or module with which it is associated (e.g.,
module 26) is glued to a mounting ring 32 which is, in turn, glued
to a mounting ledge 34 in the cavity 24. This practice tends to
produce a void space region 36 in the assembled card system.
[0049] In the module 26 depicted in FIG. 2, a computer chip 30 that
stores and processes potentially valuable and/or sensitive
information is shown attached to the underside of the board 28.
This computer chip 30 may end in an electrical contact device 38
which is sometimes referred to as a "pod". Such a contact device 38
is adapted and arranged to make electrical contact with a pod
receptacle 40. This pod receptacle 40, may, or may not, connect
with other electrical components embedded in the core layer 20 of
the smart card 10. Again, top layer 18 and/or the bottom layer 22
of such cards are sometimes provided with a top protective layer or
coating 42 and/or a bottom protective layer 44. Such protective
layers will generally cover the entire face of the card except
where electrical contact components (e.g., module 26, magnetic
strip 14, etc.) are shown.
[0050] FIG. 3 shows the prior art smart card 10 of FIG. 1 in a bent
condition. The bend line 16 passes through the cavity 24 in the top
layer 18 for receiving and holding a sensor/board/chip/pod module
26. It might be noted here that one of the most commonly used
techniques employed by thieves and/or fraudulent users of smart
cards is to first gain access to the sensor/chip/pod assembly 26 of
a "valid" card by bending said card 10 in the manner generally
depicted in FIG. 3. The module 26 is thereby exposed to such an
extent that it can be pried and rotated in the manner generally
suggested by direction arrow 50 in FIG. 3. Once the
sensor/board/chip/pod module 26 is so obtained, it is then
transferred to another smart card having deceptive information such
a fraudulent user's identification (ID) photo.
[0051] FIG. 4 illustrates how applicant's contact type smart card
is similar in many ways to those employed in the prior art in that
it too has an electronic signal sensing device 12 or a
sensor/board/computer chip module 26 that resides in an opening or
cavity 24 in the top layer 18 (or in the bottom layer 22). In FIG.
4, all of the electrical components are depicted as part of a
module 26 that is shown residing in a cavity 24 in the top layer 18
of the card 10. FIG. 4 also depicts how applicant's smart cards
differ from the prior art smart cards shown in FIGS. 2 and 3. As
can be seen in FIG. 4, a first major difference between applicant's
smart card and those of the prior art is the fact that the
underside of applicant's sensor 12 or sensor/board/chip module 26
is provided with a layer or coating of a primer/adhesive material
52. This layer or coating of primer/adhesive material 52 will be
placed on an element (be it the electronic sensor 12, chip 30,
etc.) or elements that come into direct physical with a
thermosetting polymeric material 54 injected into the core region
20 of the smart card 10. This requirement follows from the fact
that applicant has found that the bonding action between a
primer/adhesive material 52 and the thermosetting polymer 54 is
much stronger than the bonding action between a metallic and/or
semiconductor material component (such as the sensor 12 or a sensor
board/chip/pod module 26) and the thermosetting polymer 54. Indeed,
applicant has found that the bonding action of a primer/adhesive 52
with the thermosetting material 54 is so strong that it very
effectively resists tampering actions such as those depicted in
FIG. 3. That is to say that this primer/adhesive-thermosetting
polymer bond is so strong that any attempts to remove applicant's
sensor or sensor board/chip/pod module 26 by physical bending a
smart card in the manner shown in FIG. 3 will normally result in a
severe bending of the sensor and/or the chip and module themselves.
Such severe bending, and the physical damage to these elements that
result from such bending will serve to debilitate the electrical
processing ability of such electronic components--and thereby
preventing these electronic components from being "successfully"
transferred to a fraudulent smart card.
[0052] The more preferred primer/adhesive materials 52 for the
practice of this invention will be of the "solvent based," thin
viscosity, variety. Methyl ethyl ketone is frequently used as a
solvent for such compositions. By way of example only, Minnesota
Mining and Manufacturing's base primer product 4475.RTM. can be
used for this bonding purpose. Thus, in its finished form,
applicant's smart card 10 will be comprised of a top layer 18, a
bottom layer 22, and a center or core layer 20 in which at least
some of applicant's primer/adhesive material (which is attached to
at least one electrical component) is in contact in a thermosetting
polymeric material 54. That is to say such components (e.g., the
bottom of module 26) are immersed in an initially liquid or
semi-liquid thermosetting material 54, that, upon curing,
constitutes a solid center or core layer 20 of a finished smart
card 10. The placement of the sensor 12 (or module 26) should be
such that the top surface 56 of the sensor is substantially flush
or level with the top surface 46 of the card or the top surface of
the protective layer 42 if such a protective layer is used.
[0053] This injected polymeric material 54 is, preferably, capable
of being injected under certain relatively cold, low pressure
forming conditions that are preferred for carrying out applicant's
manufacturing processes. That is to say that the injection of
relatively hot thermosetting materials is less preferred for the
practice of this invention. In any case, an appropriate
thermosetting polymeric material 54 will be injected into, and
fill, a void space whose thickness 66 is defined between the inside
surface 62 of the top layer 18 and the inside surface 64 of the
bottom layer 22. Upon curing, the injected thermosetting polymeric
material 54 of the resulting center layer 20 will bond chemically
with, or otherwise adhere to, both the inside surface 62 of the top
layer 18 and the inside surface 64 of the bottom layer 22 and
thereby produce a unified card body. Such adherence can be aided by
treating the respective inside surfaces 62 and 64 of the top and
bottom layer in any one of several ways. For example, bonding
agents known to this art may be employed to enhance bonding between
the core layer-forming thermoset material 54 and the material(s)
from which the top and bottom layers 18 and 22 are made (e.g.,
PVC). Here again, Minnesota Mining and Manufacturing's base primer
product 4475.RTM. can be used for this bond enhancing purpose as
well, especially when the top or bottom layer is made from a
polyvinyl chloride material. Other treatments that can be applied
to the inside surfaces of the top and/or bottom layers 18 and 22
may include, but not be limited to, plasma corona treatments and
acid etching. This thermosetting polymeric material also forms a
particularly strong bond with the layer of primer/adhesive 52 on
any anchor hooks 58, 58A, etc. that may be employed.
[0054] Applicant also has found that another tamper-preventing
action can, in its own right, be supplied to such sensing devices
12 or modules 26 by use of anchors or hooks 58, 58A, etc. which are
an integral part of, or firmly attached to, at least one of the
elements of the electronic sensing device or module (e.g., the
electronic signal sensor 12, the board 28, the computer chip 30,
etc.). These anchors or hooks 58, 58A, etc. will become embedded in
the cured form of the thermosetting polymer material 54. Use of at
least one such hook is required. Use of 2 or more such hooks 58 and
58A is preferred. Thus the anchor hooks can provide an
anti-tampering action which is such that no layer of
primer/adhesive is required. Applicant has, however, found that the
combined holding action supplied by the simultaneous use of the
primer/adhesive-thermosetting material bonding and the anchors or
hooks 58 and 58A, etc., are such that they even better thwart
fraudulent tampering with smart cards by the "bend the card and
remove the module" method suggested in FIG. 3. However, each of
these tamper-preventing methods can serve--in its own right--to
prevent fraudulent transfer of a smart card's electrical
components.
[0055] FIG. 5 illustrates an embodiment of this invention wherein
other electronic components such as an additional chip 60, an
antenna 61 and a lead line 63 are employed in conjunction with the
electrical components that comprise the module 26. FIG. 5 also
illustrates how the inside surface of the top and/or bottom layers
18 and/or 22 also may be further provided with one or more strips
of film 68, 68A bearing alphanumeric and/or graphic information and
designs. Thus, if the top layer 18 were made of a translucent
polymeric material such as PVC, the alphanumeric/graphic
information on such a film 68, 68A, etc. would be visible to the
card user. The inside surfaces 62 and 64 of the top and bottom
layers 18 and 22 also may be provided with layers of other
materials such a coating 69 whose function is to decrease the
opacity of the card body so that its electronic components are not
visible through the card body.
[0056] Next, it should be noted that, if they are used, such other
electronic component(s) (e.g., a computer chip 60, an antenna 61,
etc. that is used in a hybrid, contact/contactless, smart card,
etc.) are preferably positioned above the inside surface 64 of the
bottom layer 22. This can be accomplished through use of one or
more mounds, drops or dollops of glue, and especially a low
shrinkage glue. Such electronic component(s) (e.g., a computer chip
60, an antenna 61, etc.) are most preferably placed on top of two
mound(s) of glue 70A and 70B, etc. in the manner generally
suggested in FIG. 5. When such mounds (70A, 70B, etc.) of glue are
used, the incoming liquid or semi-liquid polymeric material 54 will
flow under such electronic components 60, 61, etc. as well as over
them. In other words, in the more preferred embodiments of this
invention the mound(s) of glue 70A, 70B, etc. will serve as one or
more "pedestal(s)" upon which the additional electronic components
(e.g., a chip 60, an antenna 61, etc.) are placed so that the
underside of such electronic components do not come into direct
contact with the inside surface 64 of the bottom layer 22, but
rather be totally immersed in the incoming thermoplastic material
54 from above, below and from the sides. This circumstance enables
these electronic components to better resist any flexure and/or
torsion forces the smart card may encounter upon either or both of
its major outside surfaces (indeed, on any of its four outside edge
surfaces). In some of the more preferred embodiments of this
invention these immersed electronic components 60, 61, etc. will be
positioned by the mounds of glue 70A, 70B, etc. at a distance 72 of
from about 0.075 mm to about 0.13 mm above the inside surface 64 of
the bottom layer 22.
[0057] FIG. 6 serves to illustrate (especially by contrasting FIG.
6 with FIG. 7) a first preferred embodiment of applicant's methods
for making the smart cards of this patent disclosure. To this end,
FIG. 6 depicts a particularly preferred embodiment of this
invention wherein a flat, top layer or sheet of plastic material 18
such as PVC is shown before it is molded according to the teachings
of this patent disclosure. In other words, FIG. 6 depicts the mold
tool set-up just prior to injection of a thermosetting polymeric
material 54. Thus, FIG. 6 shows a flat, top layer 18 (e.g., a flat
sheet of PVC) as it is initially placed under a card-forming cavity
74 of a top mold 76. The top layer 18 is provided with an opening,
cavity, receptacle, etc. 24 that holds a signal sensing module 26
in place during the molding operation. A bottom layer 22 (e.g.,
another flat sheet of PVC) also is shown as it is placed over a
bottom mold 78. In some less preferred, but still viable,
embodiments of applicant's processes the top layer 18 may be
pre-molded or at least partially pre-molded, preferably, to the
general contour of the card-forming cavity 74 in the top mold 76.
By way of comparison, the bottom mold 78 has no cavity comparable
to the cavity 74 in the top mold 76.
[0058] By way of further illustration, FIG. 7 depicts the molding
effects of injecting a thermoset polymeric material 54 into a void
space between the top and bottom layers 18 and 22. Thus, FIG. 7
shows the top layer 18 after it has been molded into a card-forming
cavity 74 in the top mold 76. A nozzle 80 for injecting a liquid or
semi-liquid, thermoplastic or thermosetting polymeric material 54
is shown being inserted into an orifice 82 that leads to the void
space 19 shown between the inside surface 62 of the top layer 18
and the inside surface 64 of the bottom layer 22 in FIG. 6. The
distance 84 between the top surface 86 of the top layer 18 and the
bottom surface 88 of the bottom layer 22 under the molding
conditions will ultimately define the thickness of the finished
product card 10. The void space 19 is shown extending from the left
end 90 to the right end 92 of the juxtaposed top layer 18 and
bottom layer 22. In FIG. 6, the top surface 86 of the top layer 18
is not yet in contact with the inside surface 94 of the
card-forming cavity 74 of the top mold 76. By way of contrast, the
bottom surface 88 of the bottom layer 22 is shown in substantially
flat, abutting contact with the inside surface 96 of the bottom
mold 78.
[0059] Again, in both FIGS. 6 and 7 electrical components 60 and 61
that may be used in addition to those electrical components that
comprise the module 26 are shown positioned above the inside
surface 64 of the bottom layer 22. By way of example only, such
electrical components are shown pedestaled on two mounds, dabs or
dollops 70A and 70B of applicant's, preferred, low shrinkage type
glue. These glue pedestals serve to hold the electronic components
far enough above the inside surface 64 of the bottom layer 22
(e.g., from about 0.075 mm to about 0.13 mm above said inside
surface 64) so that the incoming thermosetting polymeric material
54 can invade the region 100 under the additional electrical
components 60 and 61 as well as the regions above these electronic
components. Again, the use of such glue pedestal arrangements are
preferred because the presence of the thermoset polymeric material
54 under such electronic components tends to augment the protection
of such electronic components against any forces or shocks that may
be received by the outside surfaces (i.e., the outside of the
bottom layer and/or the outside of the top surface) of the
card.
[0060] In FIG. 6, the top mold 76 is shown having a cavity 74 which
partially defines the surface contour of the top of the smart card
to be formed during the molding operation. To this end, the
injection of the liquid or semi-liquid thermoset polymeric material
54 should be under temperature and pressure conditions such that
the top layer 18 is, preferably, cold, low pressure, formed into
the cavity 74 of the top mold 76. Such conditions are preferred
because they serve to prevent damage to the module 26 positioned in
the top layer 18. Again, by way of illustration of the results of
this molding operation, FIG. 7 shows how the thermoset injection
process of this patent disclosure has, in fact, conformed the top
surface 86 of the top layer 18 to the configuration of the
card-forming cavity 74 in the top mold 76. Again, the bottom
surface 88 of the bottom layer 22 is shown in FIG. 7 molded against
a substantially flat inside surface 96 of the bottom mold 78. This
is a particularly preferred arrangement for making the smart cards
of this patent disclosure.
[0061] In FIGS. 6 and 7, a front lip region 102 of the top mold 18
and a front lip region 104 of the bottom mold 78 are shown spaced
apart from each other by a distance 106 that (taking into
consideration the thickness of the top and bottom layers 18 and
22), in effect, defines the distance 19 (i.e., the width or
thickness of the void space) at the orifice 82 for injecting the
thermosetting material 54. This distance 19 should be such that the
thermosetting polymeric material 54 can penetrate the entire length
of the core region 20 (e.g., from its left side 90 to its right
side 92). The counterpart distance 106' on the right side 92 of
this system may differ from that of its counterpart distance 106 on
the left side. In any case, the distance defined between the inside
surface 62 of the top layer 18 that passes through the rear lip
102' of the top mold 76 and the inside surface 64 of the bottom
layer 22 that passes through the rear lip 104' of the bottom mold
78 is very small--but still finite. That is to say that this very
small distance should be large enough to allow gases 110 (e.g.,
air, polymeric ingredient reaction product gases, etc.) in the void
space 19 that originally existed between the top and bottom layers
18 and 22 and excess polymeric material to be exhausted from said
void space 19, but still be small enough to hold the injection
pressures used to inject the thermoset polymeric material 54.
[0062] FIGS. 8 and 9 depict an even more preferred embodiment of
the process that was generally illustrated in FIGS. 6 and 7. In
FIGS. 6 and 7, the rear or right side 92 of the top layer 18 and
bottom layer 22 are shown protruding out of their respective molds
76 and 78. Consequently, the gases 110 (air and chemical reaction
product gases) and "excess" polymeric material (i.e., polymeric
material 54 in excess of that required to fill the void space 19)
are expunged or exhausted out of the molds 76 and 78. This mold and
exhaust arrangement may work better with some thermoset injection
materials (and/or some top and bottom layer materials) than it does
with others. Applicant has, however, also found that in some cases,
the overall mold system depicted in FIGS. 6 and 7 is sometimes left
with residual bodies of solidified excess polymeric material that,
in one way or another, interfere with the manufacture of succeeding
smart card(s). In effect, this arrangement sometimes leaves the
overall mold device in a "dirty" condition that is not conducive to
making high quality smart cards in succeeding cycles of the high
speed molding operations employed to make them.
[0063] The embodiment of applicant's invention shown in FIGS. 8 and
9 can be used to correct this problem. It does this through the use
of a mold shell (e.g., the top mold 76) that also is provided with
an excess material receptacle cavity 112. The function of this
excess material receptacle cavity 112 is to: (1) receive and hold
any excess thermoset material 54 (i.e., in excess of the volume of
the void space 19) and any gases (air, chemical reaction product
gases) purged from the void space 19 by the injection of the
polymeric thermosetting material 54 into said void space 19.
Indeed, in some of the more preferred embodiments of this
invention, excess polymeric material 54' will be purposely injected
into the void space 19 in order to drive out any gases that might
otherwise be entrapped or entrained in the center layer 20 of the
card. Applicant's excess material injection procedure may entrap
some of these gases in the excess polymeric material 54' in the
manner generally indicated in FIG. 9 or some or all of these gases
may be exhausted from the mold system at its parting line 114 as
suggested by direction arrow 110. Again the "excess" thermoset
material 54' is eventually trimmed from these "precursor" cards in
order to create a "finished" card. It also should be noted that in
this preferred embodiment of applicant's process, the top layer 18
is molded into the top regions 116 of the excess material
receptacle 112 in the same general way that the top layer 18 is
molded into the card forming cavity 74 of the top mold 76.
[0064] FIG. 10 depicts another preferred embodiment of this
invention wherein the top layer 18 and the bottom layer 22 only
extend to the front edge 118 of the excess material receptacle 112.
Thus the top layer 18 is not molded into the excess material
receptacle 112 as it was in the case shown in FIG. 9. In this
embodiment, entrapped gases 120 and excess polymeric material 54'
are not entirely ejected from the mold cavity system, as they were
in the process shown in FIG. 7, but rather are "captured" and
contained in the excess material receptacle 112 that itself also
resides in the overall mold cavity system. Those gases 110 that are
not entrapped in the excess polymeric material 54' forced into the
receptacle 112 may be, and preferably are, exhausted from the mold
system at its parting line 114.
[0065] FIG. 11 depicts the mold system shown in FIG. 10 after a
thermosetting material 54 has been injected into the void space 19
between the top layer 18 and the bottom layer 22.
[0066] FIG. 12 illustrates a somewhat less preferred, but still
viable, embodiment of this invention wherein the bottom mold 78 is
provided with a cavity 122 much in the way that the top mold 76 is
provided with a molding cavity such as the molding 74 depicted in
FIG. 6.
[0067] FIG. 13 shows a semi-finished or precursor smart card of the
type shown in FIG. 9 being removed from a mold system. Section
lines 124-124 and 126-126 respectively show how the left end 90 and
right end 92 of the precursor smart card can be cut or trimmed away
to create the sharp edges and precise dimensions of a finished
smart card. Once more, by way of example, ISO Standard 7810
requires that such cards have a length 128 of 85 mm.
[0068] FIGS. 14(A) through 14(E) contrast various gates into which
a thermoset polymeric material 54 could be injected in order to
form a given smart card. For example, FIG. 14(A) depicts a prior
art gate configuration Q, R, S, T commonly referred to as a fan
type gate. The term "fan" refers to the fan-like, general
configuration of the gate into which a thermoset polymeric material
54 is injected from a runner 130 that feeds the various gates in a
manifold fashion. These fan-like gate configurations are often
employed with prior art, hot, high pressure molding procedures. Be
that as it may, the narrowest part of the fan Q, R, S, T in FIG.
14A is shown provided with an injection port 132 for receiving the
incoming thermoset polymeric material 54. As seen in FIGS. 14(A)
and 14AA, the injection port 132 has a relatively small diameter
134, relative to the width 136 (i.e., the distance from points S to
point T) of the fan in the region where the gate feeds into the
cavity that forms the general outline S, T, U, V of the smart card
to be formed.
[0069] FIGS. 14(B) to 14(E) by way of contrast, with FIG. 14A,
depict gate configurations suitable for use with the molding
processes of this patent disclosure. It might also be noted here
that applicant prefers to taper these gates in the manner
previously described but which is not shown in FIGS. 14(B) to
14(E). In any event, the diameters of applicant's gates are
significantly larger than the gates used in prior art smart card
molding processes. For example the diameter 134 of the injection
port 132 of prior art systems such as that depicted in FIGS. 14A
and 14AA may be something on the order of 7.0 mm while the width of
the fan 136 along the line extending from point S to point T (which
is also the nominal width of the credit card to be formed) is about
54 mm (as per the requirements of ISO Standard 7810). Hence, as
seen in the cross sectional view depicted in FIG. 14AA, the
diameter of the prior art injection port 132 of FIG. 14 (A) that
leads from the main polymeric material supply runner 130 to the
gate 138 is about {fraction (1/10)} of the width 136 of the edge of
the card to be formed. Such relative dimensions (a gate that is
{fraction (1/10)} as wide as the edge of the card being serviced by
that gate) suffice in most prior art manufacturing methods wherein
hot, high pressure forming conditions are being applied to a less
viscous thermoplastic material. For example, some prior art
processes inject their polymeric materials at temperatures ranging
from in excess of 200.degree. F. to 1000.degree. F. at pressures
ranging from 500 to 20,000 psi. Again such high temperature and
high pressure conditions differ considerably from those low
temperature and pressure conditions that are preferably used in
applicant's processes.
[0070] By way of contrast with such prior art runner gate systems,
such as the one depicted in FIG. 14(A), applicant's gate systems,
as depicted in FIGS. 14 (B) to 14 (E), for making smart cards that
are preferably made through use of relatively cold, low pressure
conditions are characterized by their relatively wide gates.
Applicant has found that under the relatively cold, low pressure
conditions (e.g., 56.degree. F. to 100.degree. F. and atmospheric
pressure to 200 psi) that are preferably employed in the
hereindescribed processes, higher quality precursor cards (and
hence finished cards) are produced when the width or diameter 134'
of an injection port 132' for a gate 138' is considerably wider
than those employed in prior art manufacturing methods. To this
end, FIGS. 14BB through 14EE illustrate four variations of
applicant's "wide gate" concept. In FIG. 14BB, for example, the
diameter 134' of injection port or gate 132' is about 50 percent of
the width 136' the precursor card to be formed. In FIG. 14CC the
width 134' of the injection port or gate 132' is about 80 percent
of the width (the distance from point S' to point T') of the
precursor card. In FIG. 14DD the width 134' of the injection port
or gate 132' and the width 136' (the distance from point S' to
point T') of the precursor credit card (S', T', U', V') are
substantially the same. FIG. 14EE depicts a card molding system
wherein the width 134' of the gate is greater (e.g., about 25%
greater) than the width 136' of the edge of (depicted by the
distance from point S' to point T') of the precursor smart card S',
T', U', V'. In general, applicant has found that the best results
are obtained when the width 134' of the gates used in these molding
processes are from about 25% to about 200% of the width (the
distance from point S' to point T') of the edge of the precursor
card serviced by the gate. This contrasts sharply with most prior
art (high temperature/high pressure) systems where the width of the
injection port (again note the distance from point Q to point R in
FIG. 14AA) is usually less than about 10 percent of the width (the
distance from point S to point T) of the edge of the card being
serviced by that gate.
[0071] FIG. 15 illustrates a molding procedure being carried out
according to some of the preferred embodiments of this patent
disclosure wherein four credit cards are being molded
simultaneously in a system wherein, by way of example only, the
closest two cavities (closest to the injection nozzle 80) are being
fed with an incoming thermoset polymeric material 54 via respective
gates 138 and 138' having a width (e.g., the distance from point
140 to point 142) that is about one half of the width of the
precursor card (the distance from point 144 to point 146) while the
two more remote (i.e., more remote from the injection nozzle 80)
card-forming cavities 15B and 15D have injection ports and gates
that are substantially as wide as the width (148 to 150) of the
precursor card itself. The dotted line 152 shown in FIG. 15 depicts
the outline of a finished smart card after the edges have been
trimmed to (a given size and to eliminate the excess thermoset
material in the excess material receptacles 112) to produce a
finished smart card (e.g., one having a length of 85 mm and a width
of 54 mm as per ISO Standard 7810). Again, these cards may be
further "finished" by application of alphanumeric/graphic
information on their major exterior surfaces, e.g., by various
printing and/or film application procedures known to those skilled
in this art.
[0072] While this invention has been described with respect to
various specific examples and a spirit which is committed to the
concept of the use of a layer of primer/adhesive between the
electrical sensor or module of a contact type smart card, it is to
be understood that the hereindescribed invention should be limited
in scope only by the following claims.
* * * * *