Note: Descriptions are shown in the official language in which they were submitted.
CA 02860909 2014-07-10
WO 2913/110625 PCT/EP2013/051175
OFFSETTING SHIELDING AND ENHANCING COUPLING
IN METALLIZED SMART CARDS
TECHNICAL FIELD
The invention (in some aspects) relates to "secure documents" such as
electronic passports,
electronic ID cards and smart cards (data carriers) having RFID (radio
frequency identification)
chips or chip modules (CM) and operating in a contactless mode (ISO 14443)
including dual
interface (DI, or DIE) cards which can also operate in contact mode (ISO 7816-
2), and more
particularly to improving coupling between components within the smart card,
such as between a
module antenna (MA) connected with the REID chip (CM) and a booster antenna
(BA) in the
card body (CB) of the smart card and inductively coupled with the module
antenna (MA) and
consequent improvements in the REID chip (CM) interacting with external REID
readers.
The invention (in some aspects) relates to passive REID smart cards having a
conductive metal
or metallized layer which shields the electromagnetic field generated by a
reader. In particular,
dual interface cards which operate on the principle of reactive coupling.
BACKGROUND
For purposes of this discussion, an RIM transponder generally comprises a
substrate, an REID
Chip (or chip module) disposed on or in the substrate, and an antenna disposed
on or in the
substrate. The transponder may form the basis of a secure document such as an
electronic
passport, smart card or national ID card.
The chip module may operate solely in a contactless mode (such as ISO 14443),
or may be a
dual interface (DIF) module which can operate also in contact mode (such as
ISO 7816-2) and a
contactless mode. The chip module may harvest enemy from an RE signal supplied
by an
external REID reader device with which it communicates.
1
The substrate, which may be referred to as an "inlay substrate" (for
electronic passport) or "card
body" (for smart card) may comprise one or more layers of material such as
Polyvinyl Chloride
(PVC), Polycarbonate (PC), polyethylene (PE), PET (doped PE), PET-G
(derivative of PE),
ieslinTM, Paper or Cotton/Noil, and the like. When "inlay substrate" is
referred to herein, it
should be taken to include "card body", and vice versa, unless explicitly
otherwise stated.
The chip module may be a leadframe-type chip module or an epoxy-glass type
chip module. The
epoxy-glass module can be metallized on one side (contact side) or on both
sides with through-
hole plating to facilitate the interconnection with the antenna. When "chip
module" is referred to
herein, it should be taken to include "chip", and vice versa, unless
explicitly otherwise stated.
The antenna may be a self-bonding (or self-adhering) wire. A conventional
method of mounting
an antenna wire to a substrate is to use a sonotrode (ultrasonic) tool which
vibrates, feeds the
wire out of a capillary, and embeds it into or sticks it onto the surface of
the substrate. A typical
pattern for an antenna is generally rectangular, in the form of a flat
(planar) coil (spiral) having a
number of turns. The two ends of the antenna wire may be connected, such as by
thermo-
compression (TC) bonding, to terminals (or terminal areas, or contact pads) of
the chip module.
See, for example US 6,698,089 and US 6,233,818.
A problem with any arrangement which incorporates the antenna into the chip
module (antenna
module) is that the overall antenna area is quite small (such as approximately
15mm x 15mm), in
contrast with a more conventional antenna which may be formed by embedding
several (such as
4 or 5) turns of wire around a periphery of the of the inlay substrate or card
body of the secure
document, in which case the overall antenna area may be approximately 80mm x
50mm
(approximately 20 times larger). When an antenna is incorporated with the chip
module, the
resulting entity may be referred to as an "antenna module".
Some Prior Art
US 8,261,997 (NXP) discloses a carrier assembly for receiving an RFID
transponder chip has an
attachment side for being attached to a consumer device and an operation side
for receiving an
RF signal in operational use of the RFID transponder chip.
2
CA 2860909 2019-04-30
... there is provided an electrically conductive shielding layer at the
attachment side. The
effect of this layer is that it effectively shields the transponder from the
material of the surface
on which the transponder is to be provided. The shielding layer has some
detuning effect on
the resonance frequency, but once this detuning effect has been taken into
account in the
antenna design, there is hardly any further detuning effect due to the surface
on which the
RFID transponder is provided, i.e. the RFID transponder comprising the carrier
assembly of
the invention is suitable for virtually any surface.
... the magnetic layer comprises a ferrite foil or a ferrite plate.
... the electrically conductive shielding layer comprises a material selected
from a group
comprising: copper, aluminum, silver, gold, platinum, conductive paste, and
silver ink.
EP1854222 A2 (NXP) discloses a mobile communication device (1, 10) comprises
shielding
components that provide electromagnetic shielding or attenuation between a
first area (A) and a
second area (B, Bl, B2) within and/or external of the communication device (1,
10). In said first
area (A) an antenna (4) and at least one ferrite (6) are arranged, which
ferrite (6) is provided to
interact with said antenna (4) and to guide a magnetic flux between said first
area (A) and said
second area (B, Bl, B2).
US 20120055013 (Finn; 2012: "S32") discloses microstructures such as
connection areas,
contact pads, antennas, coils, plates for capacitors and the like may be
formed using
nanostructures such as nanoparticles, nanowires and nanotubes. A laser may be
used to assist in
the process of microstructure formation, and may also be used to form other
features on a
substrate such as recesses or channels for receiving the microstructures. A
smart mobile phone
sticker (MPS) mounted to a cell phone with a self-sticking shielding element
comprising a core
layer having ferrite particles.
EP 02063489 Al (Tyco) discloses an antenna element and method for
manufacturing same
There is provided a more easily manufactured antenna device used in a tag
composing an RFID
(Radio Frequency Identification) system. The antenna device (10) has (A) a
laminar magnetic
element formed of a magnetic composition containing a magnetic material and a
polymer
287621.00007/114263805.1 3
Date Recue/Date Received 2021-09-20
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
material, and (B) antenna wiring provided on one of the surfaces of the
laminar magnetic
element.
Foil Composite Card
US 2009/0169776 (2009; Herslow) discloses composite cards which include a
security layer
comprising a hologram or diffraction grating formed at, or in, the center, or
core layer, of the
card. The hologram may be formed by embossing a designated area of the core
layer with a
diffraction pattern and depositing a thin layer of metal on the embossed
layer. Additional layers
may be selectively and symmetrically attached to the top and bottom surfaces
of the core layer.
A laser may be used to remove selected portions of the metal formed on the
embossed layer, at
selected stages of forming the card, to impart a selected pattern or
information to the holographic
region. The cards may be "lasered" when the cards being processed are attached
to, and part of, a
large sheet of material, whereby the "lasering" of all the cards on the sheet
can be done at the
same time and relatively inexpensively. Alternatively, each card may be
individually "lasered" to
produce desired alpha numeric information, bar codes information or a graphic
image, after the
sheets are die-cut into cards.
Metal Card
US 2011/0189620 (2011; Herslow) discloses a method and apparatus for treating
a selected
region of a metal layer, used to form a metal card, by annealing the selected
metal region so the
selected region becomes soft and ductile, while the rest of the metal layer
remains stiff. The
softened, ductile, selected metal region can be embossed with reduced power
and with reduced
wear and tear on the embossing equipment. Alternatively, the annealed metal
layer can undergo
additional processing steps to form an assembly which can then he embossed.
The method may
include the use of a fixture for holding the metal layer, with the fixture
having a window region
for enabling heat to be applied to soften the region of the metal layer within
the window region.
The fixture includes apparatus for cooling the portion of the metal layer
outside of the window
region and for preventing the temperature of the metal layer outside the
window region from
rising above predetermined limits.
4
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
Ferrite
US 8,158,018 (2012; TDK) discloses a ferrite sintered body of the present
invention contains
main components consisting of 52 to 54 mol % Fe<sub>20</sub><sub>3</sub>, 35 to 42 mol c/o
MnO and 6 to
11 mot % ZnO as oxide equivalents and additives including Co, Ti, Si and Ca in
specified
amounts, and has a temperature at which the power loss is a minimal value
(bottom temperature)
of higher than 120° C. in a magnetic field with an excitation magnetic
flux density of 200
mT and a frequency of 100 kHz, and a power loss of 350 kW/m<sup>3</sup> or less at
the bottom
temperature.
US 7,948,057 (2011; TDK) discloses a ferrite substrate, a winding-embedded
ferrite resin layer,
and an IC-embedded ferrite resin layer are laminated, the ferrite substrate
has a ferrite first
protruding part that protrudes into the ferrite resin layer from the suiface
thereof, the winding
inside the ferrite resin layer is arranged winding around the first protruding
part, and the IC
overlaps the first protruding part in the resin layer. According to this
configuration, high
integration can be achieved, and the IC is arranged at a site where the
ferrite first protruding part,
the height of which fluctuates little as a result of thermal expansion,
overlaps the ferrite resin
layer, the thickness of which is thinned by the first protruding part and
varies little as a result of
thermal expansion, minimizing variations in the gap between the winding and
the IC as a result
of thermal expansion, and achieving greater stability of electrical
characteristics.
US 6,817,085 (2004; TDK) discloses a method of manufacturing a multi-layer
ferrite chip
inductor array including an element main body composed by laminating a ferrite
layer and a
conductor layer in such a manner that the laminated face thereof is vertical
with an element
mounting surface. The method also includes furnishing a plurality of coil
shaped internal
conductors within the element main body, in which a coiling direction of the
coil shaped internal
conductor is in parallel with the element mounting surface, forming the
ferrite sheets with
through-holes and printing the ferrite sheets with a plurality of coil shaped
internal conductors
and conductor patterns with an electrically conductive material.
US 6,329,958 (2001; TDK) discloses an antenna structure may be formed by
arranging a current-
restricting structure upon a conductive surface. The current-restricting
structure may be formed
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
from a ferrite material, and may be in forms including a belt, tiles, or a
patterned deposited layer.
The conductive surface may be associated with a vehicle or structure. The
current-restricting
structure alters the paths taken by current on or beneath the conductive
surface when a voltage is
applied between portions of the surface.
SUMMARY
It is an object of the invention to improve coupling between an RFID reader
and a chip module
in a smart card having a metal or metallized layer. Generally,
various modifications and/or
additions may be made to the structure of such smart cards to offset the
effects of shielding by
the metal or metallized card body substrates during electromagnetic coupling,
with the goal of
improving coupling between the smart card and an external RIAD
(electromagnetic) reader. A
dual interface (DI) smart card has contact pads (CP) extending through an
opening in the metal
layer for interfacing with an external contact (electrical) reader.
Generally, a dual-interface smart card comprises a booster antenna (BA) with
coupler coil (CC)
in its card body (CB), and a metallized face plate (202, 302) having a window
opening (220,
320) for an antenna module (AM) having a module antenna (MA). Attenuation
caused by the
metallized face plate may be reduced (overall performance may be improved) by
one or more of
making the window opening substantially larger than the antenna module (AM),
providing perforations through the face plate, disposing ferrite material
between the face
plate and the booster antenna,
modifying contact pads (CP) on the antenna module (AM),
disposing a compensating loop (CI.) under the booster antenna (BA),
offsetting the antenna module (AM) with respect to the coupler coil (CC),
arranging the booster antenna as a quasi-dipole,
providing the module antenna (MA) with capacitive stubs, and
disposing a ferrite element (FE) in the antenna module (AM) between the module
antenna
(MA) and the contact pads (CP).
According to an embodiment of the invention, a smart card having a metallized
face plate with a
window opening for accepting an antenna module, and a card body with a booster
antenna
6
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
including a coupler coil, wherein the window opening has a baseline size
approximately equal to
a size of the antenna module, may be characterized in that the window opening
is substantially
larger than the antenna module. The window opening may be at least 10% larger
than the
antenna module, resulting in a gap between inner edges of the window opening
and the antenna
module. A ferrite layer may be disposed between the face plate and the booster
antenna. A
plurality of perforations may be formed in the face plate extending around at
least one of the
window opening and the periphery of the face plate. At least some of these
perforations may
reduce the amount of faceplate material in an area surrounding the window
opening or around
the periphery of the face plate by 25-50%. A compensation loop may be disposed
behind the
booster antenna. The compensation loop may have a gap, and two free ends, may
comprise a
conductive material such as copper, and may comprise ferrite.
One or more of the following features may be included in the smart card:
the booster antenna may be configured as a quasi-dipole, with or without a
coupler coil;
the booster antenna may be provided with an extension;
the booster antenna may comprise two overlapping booster antennas;
the booster antenna may be provided primarily in an upper portion of the smart
card;
the module antenna may be offset from the coupler coil.
The smart card may further comprise at least one of the following features:
a ferrite element may he disposed between the module antenna and contact pads
of the
antenna module;
capacitive stubs may he added to the module antenna;
the module antenna may comprise two separate coils;
the module antenna may comprise two windings connected in a quasi-dipole
configuration;
perforations in the contact pads of the antenna module.
According to an embodiment of the invention, a method of minimizing
attenuation of coupling
by the face plate of a metallized smart card having a booster antenna with a
coupler coil in its
card body, may comprising one or more of:
making a window opening in the faceplate larger than the antenna module;
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP20131051175
providing perforations through the face plate;
providing ferrite material between the face plate and the booster antenna;
disposing a compensating loop under the booster antenna.
The antenna module may be offset with respect to the coupler coil. The booster
antenna may be
arranged as a quasi-dipole; the module antenna may be provided with capacitive
stubs; ferrite
may be provided in the antenna module between the module antenna and the
contact pads. The
contact pads may be trimmed or perforated.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will be made in detail to embodiments of the disclosure, non-
limiting examples of
which may be illustrated in the accompanying drawing figures (FIGs). The
figures are generally
in the form of diagrams. Some elements in the figures may be exaggerated,
others may be
omitted, for illustrative clarity. Some figures may be in the form of
diagrams. Although the
invention is generally described in the context of various exemplary
embodiments, it should be
understood that it is not intended to limit the invention to these particular
embodiments, and
individual features of various embodiments may be combined with one another.
Any text
(legends, notes, reference numerals and the like) appearing on the drawings
are incorporated by
reference herein.
FIG. 1 is a cross-sectional view of a dual interface (DI) smart card, and
readers.
FIG. lA is a diagrammatic top view of a booster antenna (BA) with coupler coil
(CC).
FIG. 2 is a diagrammatic cross-sectional view of a smart card with
metallization.
FIG. 2A is a partial diagrammatic perspective view of a smart card with
metallization.
FIGs. 3A,B,C are diagrammatic top views of embodiments of a face plate (ML)
for a smart card.
FIG. 4A is diagram of a layer with a compensating loop having a gap.
FIG. 4B is diagram of a layer with a compensating loop, without a gap.
FIG. 5 is a plan view of a typical arrangement of contact pads (CT) on a
module tape (MT).
FIG. 5A is a diagram showing an exemplary contact pad layout and assignments.
FIG. 6A is a plan view illustrating extending outer edges of contact pads
(CT).
FIG. 6B is a plan view illustrating trimming outer edges of contact pads (CP).
8
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
FIG. 6C is a plan view illustrating increasing the gap between contact pads
(CP).
FIG. 6D is a plan view illustrating modifying the gap between contact pads
(CP).
FIG. 7A is a plan view illustrating perforating the contact pads (CP).
FIG. 7B is a cross-sectional view illustrating thinning the contact pads (CP).
FIG. 8A is a plan view illustrating the underside of a module tape (MT).
FIG. 8B is a plan view illustrating perforating the contact pads (CP).
FIG. 9A is a plan view illustrating perforating the contact pads (CP).
FIG. 9B is a plan view illustrating perforating the contact pads (CP).
FIG. 10A is plan view of the underside of a module tape (MT) for an antenna
module (AM),
showing an antenna structure (AS) having two antenna segments (MA I, MA2).
FIG. 10B is a diagrammatic view of an antenna structure (AS).
DESCRIPTION
Various embodiments will be described to illustrate teachings of the
invention(s), and should be
construed as illustrative rather than limiting. Any dimensions and materials
or processes set
forth herein should be considered to be approximate and exemplary, unless
otherwise indicated.
In the main hereinafter, transponders in the form of secure documents which
may be smart cards
or national ID cards may be discussed as exemplary of various features and
embodiments of the
invention(s) disclosed herein. As will be evident, many features and
embodiments may be
applicable to (readily incorporated in) other forms of secure documents, such
as electronic
passports. As used herein, any one of the terms "transponder", "smart card",
"data carrier", and
the like, may be interpreted to refer to any other of the devices similar
thereto which operate
under ISO 14443 or similar RFID standard.
A typical data carrier described herein may comprise (i) an antenna module
(AM) having an
RFID chip or chip module (CM) and a module antenna (MA), (ii) a card body (CB)
and (iii)
booster antenna (BA) disposed on the card body (CB) to enhance coupling
between the module
antenna (MA) and the antenna of an external RFID "reader". When "chip module"
is referred to
herein, it should be taken to include "chip", and vice versa, unless
explicitly otherwise stated.
The module antenna (MA) may comprise a coil of wire, conductive traces etched
or printed on a
9
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
module tape (MT) substrate for the antenna module (AM), or may be incorporated
directly on the
chip itself.
The booster antenna (BA) may be formed by embedding wire in an inlay substrate
or card body
(CB). However, it should be understood that the antenna may be formed using a
processes other
than by embedding wire in a substrate, such as additive or subtractive
processes such as printed
antenna structures, coil winding techniques (such as disclosed in US
6,295,720), antenna
structures formed on a separate antenna substrate and transferred to the inlay
substrate (or layer
thereof), antenna structures etched (including laser etching) from a
conductive layer on the
substrate, conductive material deposited on the substrate or in channels
formed in the substrate,
or the like. When "inlay substrate" is referred to herein, it should be taken
to include "card
body", and vice versa, as well as any other substrate for a secure document,
unless explicitly
otherwise stated.
The descriptions that follow are mostly in the context of dual interface (DI,
DIF) smart cards,
and relate mostly to the contactless operation thereof. Many of the teachings
set forth herein
may be applicable to electronic passports and the like having only a
contactless mode of
operation. Generally, any dimensions set forth herein are approximate, and
materials set forth
herein are intended to be exemplary.
Generally, coupling between the module antenna (MA) and the antenna of an
external RFID
reader may be enhanced by incorporating a booster antenna (BA) on the card
body (CB). In
some respects, a booster antenna (BA) is similar to a card antenna (CA).
However, in contrast
with a card antenna (CA) which is directly electrically connected with the
RFID chip or chip
module (such as in US 7,980,477), the booster antenna (BA) is inductively
coupled with the
module antenna (MA) in the antenna module (AM) which may be connected with the
RFID chip
(CM). Such inductive (electromagnetic) coupling may be more difficult to
accomplish than a
direct electrical connection. The booster antenna (BA) may be referred to as a
card antenna
(CA). The booster antenna (BA) may have a coupler coil (CC) associated
therewith which is
arranged to be in close proximity and closely coupled with the module antenna
(MA).
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP20131051175
As used herein, the term "coupling" (and variants thereof) refers to
inductive, magnetic,
capacitive or reactive coupling (including combinations thereof, any of which
may he referred to
as "inductive coupling") between two elements relying on the generation of an
electromagnetic
field by a given element and the reaction to (interaction with) the field(s)
by another element. In
contrast thereto, the term "connecting" (and variants thereof) refers to two
elements being
electrically connected with one another wherein the interaction between the
two elements results
from the flow of electrons between the two elements. Typically, two elements
which arc
inductively coupled with one another are not electrically connected with one
another. Elements
which are coils of wire such as a module antenna MA and a coupler coil CC
disposed near each
other are generally inductively coupled with one another, without any
electrical connection
between the two elements. In contrast thereto, the module antenna MA is
generally electrically
connected with the REID chip (CM) element. The windings and coils of the
booster antenna BA,
such as outer winding OW, inner winding IW and coupler coil CC elements, are
generally
electrically connected with one another, but may also exhibit inductive
coupling with one
another. The module antenna MA and coupler coil CC are not electrically
connected with one
another, hut are inductively coupled (or "transformer coupled") with one
another.
The booster antenna BA (and other features) disclosed herein may increase the
effective
operative ("reading") distance between the antenna module AM and an external
contualess
reader with capacitive and inductive coupling. With reading distances
typically on the order of
only a few centimeters, an increase of lem can represent a significant
improvement.
Various embodiments will be described to illustrate teachings of the
invention(s), and should be
construed as illustrative rather than limiting. In the main hereinafter,
transponders in the form of
secure documents which may be smart cards or national Ill cards may he
discussed as exemplary
of various features and embodiments of the invention(s) disclosed herein. As
will be evident,
many features and embodiments may be applicable to (readily incorporated in)
other forms of
secure documents, such as electronic passports. As used herein,
any one of the terms
"transponder", "smart card", "data carrier", and the like, may be interpreted
to refer to any other
of the devices similar thereto which operate under ISO 14443 or similar REID
standard.
II
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
A typical data carrier described herein may comprise (i) an antenna module
(AM) having an
RFID chip or chip module (CM) and a module antenna (MA), (ii) a card body (CB)
and (iii) a
booster antenna (BA) disposed on the card body (CB) to enhance coupling
between the module
antenna (MA) and the antenna of an external RFID "reader". When "chip module"
is referred to
herein, it should be taken to include "chip", and vice versa, unless
explicitly otherwise stated.
The module antenna (MA) may comprise a coil of wire, conductive traces etched
or printed on a
module tape (MT) substrate for the antenna module (AM), or may be incorporated
directly on the
chip itself.
The booster antenna (BA) may be formed by embedding wire in an inlay substrate
or card body
(CB). However, it should be understood that the antenna may be formed using a
processes other
than by embedding wire in a substrate, such as additive or subtractive
processes such as printed
antenna structures, coil winding techniques (such as disclosed in US
6,295,720), antenna
structures formed on a separate antenna substrate and transferred to the inlay
substrate (or layer
thereof), antenna structures etched (including laser etching) from a
conductive layer on the
substrate, conductive material deposited on the substrate or in channels
formed in the substrate,
or the like. When "inlay substrate" is referred to herein, it should he taken
to include "card
body", and vice versa, as well as any other substrate for a secure document,
unless explicitly
otherwise stated.
The descriptions that follow are mostly in the context of dual interface (DI,
DIF) smart cards,
and relate mostly to the contactless operation thereof. Many of the teachings
set forth herein
may be applicable to electronic passports and the like having only a
contactless mode of
operation. Generally, any dimensions set forth herein are approximate, and
materials set forth
herein are intended to be exemplary.
Generally, coupling between the module antenna (MA) and the antenna of an
external RFID
reader may be enhanced by incorporating a booster antenna (BA) on the card
body (CB). In
some respects, a booster antenna (BA) is similar to a card antenna (CA).
However, in contrast
with a card antenna (CA) which is directly electrically connected with the
RFID chip or chip
module (such as in US 7,980,477), the booster antenna (BA) is inductively
coupled with the
12
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
module antenna (MA) which may be connected with the REID chip (CM). Such
inductive
coupling may be more difficult to accomplish than a direct electrical
connection.
As used herein, the term "coupling" (and variants thereof) refers to
inductive, magnetic,
capacitive or reactive coupling (including combinations thereof, any of which
may be referred to
as "inductive coupling") between two elements relying on the generation of an
electromagnetic
field by a given element and the reaction to (interaction with) the field(s)
by another element. In
contrast thereto, the term "connecting" (and variants thereof) refers to two
elements being
electrically connected with one another wherein the interaction between the
two elements results
from the flow of electrons between the two elements. Typically, two elements
which are
inductively coupled with one another are not electrically connected with one
another. Elements
which are coils of wire such as a module antenna MA and a coupler coil CC
disposed near each
other are generally inductively coupled with one another, without any
electrical connection
between the two elements. In contrast thereto, the module antenna MA is
generally electrically
connected with the RFID chip (CM) element. The windings and coils of the
booster antenna BA,
such as outer winding OW, inner winding IW and coupler coil CC elements, are
generally
electrically connected with one another, but may also exhibit inductive
coupling with one
another. The module antenna MA and coupler coil CC are not electrically
connected with one
another, but are inductively coupled (or "transformer coupled") with one
another.
The booster antenna BA (and other features) disclosed herein may increase the
effective
operative ("reading") distance between the antenna module AM and an external
eontactless
reader with capacitive and inductive coupling. With reading distances
typically on the order of
only a few centimeters, an increase of lcm can represent a significant
improvement.
FIG. 1 is a cross-sectional view of a portion of an exemplary smart card
having an antenna
module AM disposed in a recess in a card body CB. The antenna module AM has a
chip module
CM. The antenna module AM has contact pads C:P for a contact interface with an
external
Contact Reader (ISO 7816). The antenna module AM has a module antenna MA for a
contactless interface with an external contactless reader (ISO 14443). A
booster antenna BA is
disposed around the periphery of the card body CB, and has a coupler coil CC
is disposed around
13
CA 02860909 2014-07-10
WO 2913/110625 PCT/EP2013/051175
the recess in the card body CB. With the antenna module AM disposed in the
recess, the module
antenna MA is closely coupled with the coupler coil CC of the booster antenna
BA. The coupler
coil CC may be arranged to be under the module antenna MA rather than
surrounding it.
As shown in US 2012/0074233, for example FIGs. 3A and 4A therein, the booster
antenna BA
(or card antenna CA) may comprise an outer winding OW (or D) and an inner
winding IW (or
E), connected in reverse phase with one another as a quasi dipole. No coupler
coil (CC) is
shown.
As shown in US 13/600,140, for example FIGs. 3 and 4 therein, a quasi-dipole
booster antenna
BA may additionally comprise an inner coupler coil CC. The coupler coil CC is
shown without
detail, represented by a few dashed lines. (Some details of the coupler coil
CC construction, and
how it may be arranged in various orientations (clockwise, counterclockwise)
and connected
with the outer winding OW and inner winding IW are set forth in FIGs. 3A-31).)
FIG. 1A is a diagrammatic top view of a smart card body CB with a booster
antenna BA and
antenna module AM. The booster antenna BA has a coupler coil CC incorporated
therewith.
The following abbreviations may appear in the figure.
CB - Card Body or Inlay Substrate
BA - Booster Antenna or Card Antenna (CA)
OW - Outer Winding of BA- approx. 2-3 turns
IW - Inner Winding of BA - approx. 2-3 turns
CC - Coupler Coil - approx. 10 turns
IE - Inner End of OW, IW or CC
OE - Outer End of OW, IW or CC
The following may be noted:
The Inner End (IE, a) of the Outer Winding (OW) is "free end"
The Outer End (OE, t') of the Inner Winding (IW) is "free end"
The Outer End (OE, h) of the OW is connected to one end of CC
The Inner End (IE, e) of the IW is connected to another end of CC
14
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
The outer winding OW may be laid clockwise (CW) from 1E (a) to OE (b)
The inner winding IW may be laid clockwise (CW) from IE (c) to OE (I)
The booster antenna BA comprises an outer winding OW and an inner winding IW,
both
extending substantially around the periphery of the card body CB. Each of the
inner and outer
windings has an inner end IE and an outer end OE. The outer end OE (b) of the
outer winding
OW is connected with the inner end IE (e) of the inner winding IW, via a
coupler coil CC. The
inner end IE (a) of the outer winding OW and the outer end OE (f) of the inner
winding IW may
be left unconnected, as "free ends". The overall booster antenna BA comprising
outer winding
OW, coupler coil CC and inner winding IE is an open circuit, and may be
referred to as a "quasi-
dipole" - the outer winding OW constituting one pole of the dipole, the inner
winding IW
constituting the other pole of the dipole - center fed by the coupler coil CC.
The booster antenna BA may be formed using insulated, discrete copper wire
disposed (such as
ultrasonically bonded) around (inside of) the perimeter (periphery) of a card
body CB (or inlay
substrate, or data carrier substrate, such as formed of thermoplastic). The
booster antenna BA
comprises an outer winding OW (or coil, D) and an inner winding IW (or coil,
E), and further
comprises a coupler coil CC, all of which, although "ends" of these various
coil elements are
described, may be formed from one continuous length of wire (such as 80pm self-
bonding wire)
which may he laid upon or embedded in the card body CB. More particularly,
- The outer winding OW may be formed as a spiral having a number (such as 2-
3) of turns
and having an inner end IE at point "a" and an outer end OE at point "b". The
outer
winding OW is near (substantially at) the periphery (perimeter) of the card
body CB. The
inner end IE ("a") of the outer winding OW is a free end.
- The coupler coil CC may be formed as a spiral having a number (such as
approximately
10) of turns and having two ends "e" and "d". The end "c" may be an outer end
OE or an
inner end IE, the end "d" may be an inner end IE or an outer end OE.
- The inner winding 1E may be formed as a spiral having a number (such as 2-
3) of turns
and having an inner end IE "e" and an outer end OE "f". The inner winding 1W
is near
(substantially at) the periphery of the card body CB, inward of the outer
winding OW.
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
The outer end OE ("f") of the inner winding IW is a free end. In FIG. 3, the
inner
winding IW is shown in dashed lines, for illustrative clarity.
- The inner end IE of the outer winding OW is a "free end" in that it is left
unconnected.
Similarly, the outer end OE of the inner winding IW is a "free end" left
unconnected.
The outer winding OW, coupler coil CC and inner winding IW may be formed as
one continuous
structure, using conventional wire embedding techniques. It should be
understood that
references to the coupler coil CC being connected to ends of the outer winding
(OW) and inner
winding (IW) should not he construed to imply that coupler coil CC is a
separate entity having
ends. Rather, in the context of forming one continuous structure of outer
winding OW, coupler
coil CC and inner winding IW, "ends" may be interpreted to mean positions
corresponding to
what otherwise would be actual ends - the term "connected to" being
interpreted as "contiguous
with" in this context.
The dimensions of the card body CB may be approximately 54mm x 86mm. The outer
dimension of the outer winding OW of the booster antenna BA may be
approximately 80 x
50mm. The wire for forming the booster antenna BA may having a diameter (d)
of
approximately 100 um (including, but not limited to 80um, 112pm, 125 m.
The inner winding IW may be disposed within the outer winding OW, as
illustrated, on a given
surface of the card body CB (or layer of a multi-layer inlay substrate).
Alternatively, these two
windings of the booster antenna BA may be disposed on opposite surfaces of the
card body CB,
substantially aligned with one another (in which case they would be "top" and
"bottom"
windings rather than "outer" and "inner" windings). The two windings of the
booster antenna
BA may be coupled in close proximity so that voltages induced in them may have
opposite phase
from one another. The coupler coil CC may be on the same surface of the card
body CB as the
outer and inner windings.
The turns of the outer winding OW and inner winding IW of the booster antenna
BA may be at a
pitch of 0.2mm (200 m), resulting in a space of approximately one wire
diameter between
adjacent turns of the outer winding OW or inner winding LW. The pitch of the
turns of the
6
WO 2013/110625 PCT/EP2013/051175
coupler coil CC may be substantially the same as or less than (stated
otherwise, not greater than)
the pitch of turns of at least one of the outer winding OW and inner winding
IW - for example
0.15mm (150 vim), resulting in space smaller than one wire diameter between
adjacent turns of
the coupler coil (CC). Self-bonding copper wire may be used for the booster
antenna BA. The
pitch of both the outer/inner windings OW/IW and the coupler coil CC may both
be
approximately 2x (twice) the diameter of the wire (or width of the conductive
traces or tracks),
resulting in a spacing between adjacent turns of the spiral(s) on the order of
1 wire diameter (or
trace width). The pitches of the outer winding OW and the inner winding IW may
be
substantially the same as one another, or they may be different than each
other.
More turns of wire for the coupler coil CC can be accommodated in a given area
- for example,
by laying two "courses" of wire, one atop the other (with an insulating film
therebetween, if
necessary), in a laser-ablated trench defining the area for the turns of the
coupler coil CC.
A substrate or card body CB with the booster antenna BA formed thereon may be
prepared by a
first manufacturer and constitute an interim product (which, without the
antenna module AM,
may be referred to as a "data carrier component"). Subsequently, a second
manufacturer may
mill (or otherwise form) a recess in the card body CB, at the interior of the
coupler coil CC (see
FIG. 1) and install the antenna module AM (with its module antenna MA) in the
recess. (Of
course, the data carrier component can be provided by the first manufacturer,
with the recess
already formed.)
Reference may additionally be made to some drawings and descriptions in the
following
applications related to DIF (dual interface - contact and contactless) smart
cards, such as
described in 13/730,811 filed 12/28/2012, or publication number 2012/0074233.
FIG. lA Card Antenna CA in card body CB, contact and contactless readers
FIG. 1B Card Antenna CA in card body CB, ferrite in card body CB
FIG. 1D ferrite element FE in AM between module antenna MA and contact pads CP
FIGs. 3A, 4A Quasi-Dipole Booster Antenna BA, without coupler coil CC
FIG. 41,I ferrite in card body CB
17
Date Recue/Date Received 2020-12-21
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
FIG. 6A mobile phone sticker MPS with ferrite
FIG. 6B ferrite shielding element 670, adhesive both sides
FIG. 8 (13/730,811) card antenna CA primarily at top half of card body CB
13/600,140 filed 8/30/2012
FIG. 2A booster antenna BA, no coupler coil CC
FIG. 3 booster antenna BA with coupler coil CC
FIGs 3A-3D various configurations for the coupler coil CC
FIG. 4 BA with CC, antenna module AM with module antenna MA
FIG. 5H booster antenna with extension
5I-K two booster antennas
FIGs. 6A-C BA disposed at top half of card body CB
Construction of a Metallized Card
Some smart cards, including dual interface (DI) smart cards, have a metal (or
metallized) top
layer, or "face plate", substantially the size of the card body. Having a
metal layer is technically
disingenuous in that a it may significantly reduce coupling between the card
and an external
contactless reader. Nevertheless, the feature may be important for vanity
purposes.
FIG. 2 is a very generalized, simplified, diagrammatic cross-sectional view
illustrating some
exemplary layers of an exemplary "metal" (or metallized) smart card. The
layers are numbered
for reference purposes only, not to indicate a particular sequence. The layers
may he rearranged.
Some layers may be omitted. Some layers may be applicable to either non-metal
smart cards or
metallized smart cards. Some of the layers may comprise more than one layer.
Some layers may
be combined with other layers.
Layer 1 printed sheet, overlay anti-scratch, etc
Layer 2 separate metal layer or metallized foil
Layer 3 booster antenna BA with coupler coil CC
Layer 4 card body CB
Layer 5 compensation frame (back side of card body) on metallized or non-
metallized
Layer 6 printed sheet, underlay anti-scratch, magnetic stripe, etc
18
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
A chip module (CM) is shown disposed in a window "W" (opening) extending into
the smart
card, from the front (top, as viewed) surface thereof through the metallized
foil (Layer 2) and
into the card body (Layer 4). The chip module (CM) has contact pads (CP) on
its front surface
for interfacing with an external contact reader. The chip module may be a dual
interface (DI)
antenna module (AM) having a module antenna (MA) for interfacing, via the
booster antenna
(BA) with coupler coil (CC), with an external contactless reader. The antenna
module (AM)
may fit within the inner area of the coupler coil (CC). Compare FIG. 1.
FIG. 2A shows an exemplary stackup (sequence of layers) for a metallized smart
card 200,
having the following layers, structures and components. Exemplary dimensions
may be
presented. All dimensions are approximate. Thickness refers to vertical
dimension in the figure.
- A top layer 202 may be a metal (or metallized) layer 202, such as 250 pm
thick stainless
steel, and may be referred to as a "face plate". Compare "Layer 1". This top
layer 202
may be as large as the overall smart card, such as approximately 50mm x 80mm.
- A layer 203 of adhesive, such as 40 pm thick of polyurethane
- A layer 204 of ferrite material, such as 60 pm thick sheet of soft
(flexible) ferrite
- A layer 205 of adhesive, such as 40 pm thick of polyurethane
- A layer 208 of plastic material, such as 50-100pm thick PVC, which may
function as a
spacer (separating layers and components below from those above)
- A layer 210 of plastic material, such as 150-200pm thick PVC, which may
function as
the card body (CB). Compare "Layer 4".
- Wire 212, such as 112pm diameter wire, forming the booster antenna (BA) with
coupler
coil (CC) Compare FIG. 1 Only one wire cross-section is shown, for
illustrative clarity.
- A layer 214 of plastic material, such as 150 m thick PVC, which may include
printing,
magnetic stripe, etc.
- A layer 216 of plastic material, such as 50 m thick PVC, which may serve
as an overlay
- The overall thickness of the smart card 200 (layers 202, 203, 204, 208, 210,
214, 216)
may be approximately 810p m (0.81 mm).
A window opening 220 ("W") may extend into the smart card from the face plate
202, through
intervening layers, into the card body layer 210. A dual interface (DI)
antenna module (AM),
19
CA 02860909 2014-07-10
with module antenna (MA) may be disposed in the window opening 220. Compare
FIG. 1 The
window opening 220 may extend completely through the layer 210, in which case
the antenna
module (AM) would be supported by the underlying layer 214.
The coupler coil (CC) of the booster antenna (BA) may surround the window
opening 220 so as
to be closely coupled with the module antenna (MA) of the antenna module (AM).
Compare
FIG. 1 Alternatively, the coupler coil (CC) may be disposed in the card body
(CB) so as to be
underneath the module antenna (MA) of the antenna module (AM).
The antenna module (AM) may measure approximately 12 x 13mm (and approximately
0.6mm
thick). The window opening 220 ("W') in the face plate 202 may be
approximately the same
size as the antenna module (AM) ¨ i.e., approximately 12 x 13mm. In this
"baseline"
configuration, the chip activation distance may be approximately 15mm, (Chip
activation
distance is similar to read distance, and represents the maximum distance at
which the chip
module may be activated (for reading) by an external reader. As a general
proposition, more is
better, 15mm is not very good, 20mm or 25mm would be better. The chip
activation distance in
a metallized smart card is handicapped by attenuation of the electromagnetic
field associated
with the booster antenna attributable to the metallic face plate 202 (Layer
1).
According to a feature of the invention, the window opening 220 in the face
plate 202 is made to
be significantly larger than the antenna module (AM) so as to offset shielding
and enhance
coupling, thereby increasing the activation distance. For example, given an
antenna module
(AM) measuring approximately 12 x 13mm,
- the window opening 220 can be enlarged approximately lnun all around, so
that there is
a lmm gap (GAP) all around the antenna module (AM). This results in the window
opening measuring 14 x 15mm, and having a 30% greater area (which is the area
of the
gap). The gap (ltrim) is approximately 10% of the cross-dimension of the un-
enlarged
(12 x 13mm) window opening. The resulting chip activation distance may be
approximately 20rnm (a 33% increase over baseline 15mm).
- the window opening 220 can be enlarged approximately 2nun all around, so
that there is
a 2min gap (GAP) all around the antenna module (AM). This results in the
window
CA 02860909 2014-07-10
=
opening having measuring 16 x 17mm, and having a 75% greater area (which is
the area
of the gap). The gap (2mm) is approximately 20% of the cross dimension of the
un-
enlarged (12 x 13mm) window opening. The resulting chip activation distance
may be
approximately 22mm (a 50% increase over baseline 15mm).
The results of providing a gap and enlarging the window opening are summarized
in the
following Table (all numbers are approximate).
Antenna Window GAP Comm ent(s) activation
Module Opening distance
12x 13mm 12x 13mm Window is not larger 15mm
No GAP
¨156 mm2 ¨156 mm2 This is the "baseline"
"baseline"
12 x 13mm 14x 15mm hrun all around Window is
30% larger 20mm
¨156 1/11112 210 mm2 ¨54 mm2 33% increase
12 x 13mm 16 x 17mm 2mm all around Window is 75%
larger 22min
¨156 mm2 ¨'?79 mm2 ¨116 mm2 50% increase
More generally, the window opening 220 may be increased in size (in contrast
with its nominal
size approximately equal to that of the antenna module AM) by at least 10%, up
to at least 100%,
including the values of approximately 30% and 75% in the examples above.
The gap (GAP) between the antenna module (AM) and the inner edges of the
window opening
220 may allow significantly better coupling between the coupler coil (CC) of
the booster antenna
(BA) and the module antenna (MA) of the antenna module (AM). Activation
distance
improvements of up to 50% are presented. Gap sizes of lmm and 2nun have been
discussed,
which represent enlarging the window opening by 10% and 20%, respectively.
More generally,
the gap may be at least 0.5ram, including up to at least 3mm.
The ferrite layer 204 may also improve coupling by reducing attenuation of
coupling by the face
plate 202, helping to concentrate the electromagnetic field between the
booster antenna BA and
the module antenna MA of the antenna module AM. It may be desirable that the
ferrite layer
21
204 be as close as possible to the underside of the face plate 202. Rather
than having a separate
ferrite layer 204 (and adhesive layer 203), ferrite particles or powder may be
mixed with an
adhesive and sprayed or coated onto the underside of the face plate 202,
thereby eliminating the
intervening adhesive layer 203. Alternatively, rather than being in the form
of a separate layer
204, the ferrite material may be particles (including nanoparticles) of
ferrite embedded in an
underlying layer, such as the spacer layer 208 or the card body layer 210 (in
some
configurations, the spacer layer 208 may be omitted).
The spacer layer 208 may also improve coupling by reducing attenuation of
coupling by the face
plate 202, simply by keeping the face plate 202 as far away as practical
(within the confines of
the form factor for smart cards) from the booster antenna 212.
In addition to the features of the enlarged window opening 220 in the face
plate 202, the ferrite
204 between the face plate and layers/components below, and the spacer layer
208, various
additional features for improving coupling, may be incorporated into the
layers of the smart card
and/or the antenna module, such as, but not limited to:
for metallic cards
- perforating the face plate, as described in greater detail with respect
to FIGs. 3A,B,C;
and
- providing a compensation frame under the booster antenna (BA). Compare
Layer 5
(FIG. 2, above) and FIGs.4A, 4B (below)
for card body layers
- disposing ferrite at strategic locations in the card body (CB), such as
disclosed in FIGs.
1B, 4I,J of US 20120074233;
- configuring the booster antenna (BA), or card antenna (CA) as a quasi-
dipole without a
coupler coil (CC), and positioning the antenna module AM so that the module
antenna
MA overlaps only an inner winding IW of the booster antenna, such as disclosed
in FIG.
2C of US 20120038445 and in FIGs. 3A, 4A of US 20120074233, and in FIG. 2A of
13/600,140;
287621.00007/114263805.1 22
Date Recue/Date Received 2021-09-20
- configuring the booster antenna (BA) as a quasi-dipole with a coupler
coil (CC), such as
disclosed in FIGs. 3, 3A-D, 4 of 13/600,140. Compare FIGs. 1, 1A (above);
- providing a booster antenna (BA) with an "extension", such as disclosed
in FIG. 5H of
13/600,140;
- providing overlapping booster antennas (BAs), such as disclosed in FIGs.
5I,J,K of
13/600,140;
- providing booster antennas (BAs) primarily in an upper portion of the
smart card, leaving
a lower "embossing" portion free, such as disclosed in FIGs. 6A,B,C of
13/600,140, FIG.
8 of 13/730,811, and FIG. 6D of 61/697,825;
- offsetting the module antenna (MA) from the coupler coil (CC) so that
they are not
concentric, such as disclosed in FIGs. 7A,B,C of 61/737,746 filed 12/15/2012;
and
- forming and connecting the windings of the booster antenna (BA) and
coupler coil (CC)
in a manner other than is shown in FIG. 1A (above), such as disclosed in FIGs.
8A-C of
61/737,746 filed 12/15/2012.
for the antenna module (AM)
- disposing a ferrite element between the module antenna (MA) and the
contact pads (CP)
of the antenna module (AM), such as disclosed in FIGs. 1D and 7C,D,E of US
20120074233;
- adding capacitive stubs to the module antenna (MA), such as disclosed in
FIGs. 2A,B of
US 20120038445 and US 20120074233;
- trimming and/or perforating the contact pads (CP) of the antenna module
(AM), such as
disclosed in FIGs. 2-5 of 61/693,262;
- forming the module antenna (MA) as two separate coils, such as disclosed
in FIG. 6A of
61/693,262; and
- connecting two windings of a module antenna (MA) in a quasi-dipole
configuration, such
as disclosed in FIG. 6B of 61/693,262.
Using various combinations of these features, a baseline activation distance
of 15mm may be
increased to approximately 28mm, or more, an improvement of approximately
100%, and
corresponding improvements to the reliability of communication between the
chip module (CM)
287621.00007/114263805.1 23
Date Recue/Date Received 2021-09-20
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
and an external contactless reader. It is within the scope of the invention
that these features,
listed above, may be incorporated into a non-metallized (no metallic face
plate) smart card to
significantly improve activation and read distances.
Manufacturing
An interim product may comprise the ferrite 204, adhered with adhesive 205 to
the underlying
spacer layer 208, and the card body layer 210 with the booster antenna 212
inlaid therein. This
interim product may be referred to as a pre-laminated stack, or "prelaminate",
and may have a
thickness of approximately 450 pm.
The prelaminate may be delivered to a second manufacturer who will apply the
faceplate 202,
the bottom PVC sheet 214 and the bottom overlay 216. The faceplate 202 may be
pre-punched
(or otherwise machined) with the opening 220. The resulting stackup may have a
pre-laminated
thickness pf approximately 9401.tm (0.94mm), and after lamination (heat and
pressure) have a
final thickness of approximately 890 m (0.89mm).
In the lamination process, a plug of material may first be inserted into the
window opening 220
to prevent the underlying material (ferrite 204, spacer PVC 208, card body PVC
210, etc.) from
expanding upwards into the window opening 220 (and causing a resulting indent
on the bottom
surface of the smart card). The material for the plug may be PVC, or the metal
"slug" which was
removed from the faceplate to make the opening, or the like.
Typically, after lamination, the plug (if metal) is removed. If the plug was
PVC, it may be left in
place. The recess for the antenna module may then be machined into the layers
(ferrite 204,
spacer PVC 208, card body PVC 210) of the smart card, being careful (of
course) not to damage
the coupler coil (CC).
Perforating the Faceplate (202)
The faceplate (202), which may be referred to as a "metallized layer" ("ML"),
may be perforated
to improve coupling, and this would ordinarily be done prior to adding the
faceplate to the stack
for lamination, such as in conjunction with forming the window (220). In other
words, to offset
24
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
the shielding caused by the metallized layer on a smart card, the metallized
layer can be
perforated, removing material in locations such as around the window (220)
which is
approximately directly over the coupling coil (CC) and/or around the periphery
of the metallized
layer ML which is approximately directly over the outer winding OW and inner
winding IW of
the booster antenna BA. Perforating the metallized layer ML, such as with
slots and holes, at
these locations, may allow the electromagnetic field to operate better, such
as by facilitating, the
radiation of magnetic flux lines. The design of the perforations may add to
the aesthetics of the
smart card, and may provide an optical (visible) security feature.
FIG. 3A shows that a pattern of perforations (or openings) in the form of
elongated slits 322 may
be formed, such as by laser etching, around the periphery of the face plate
302 (compare 202).
The slits 322 may be aligned over (or under) the booster antenna BA (FIG. 1),
to enhance
coupling between the booster antenna BA and the antenna of an external
contactless reader
(FIG. 1).
FIG. 3A shows that a pattern of perforations (or openings) in the form of
holes 324 may be
formed, such as by laser etching, around the periphery of the opening 320
(compare 220) in the
face plate 302 (compare 202, also "Layer 2"). These perforations may be
aligned over (or under)
the coupler coil CC (FIG. 1), to enhance coupling between the coupler coil CC
(212) and the
module antenna MA of an antenna module AM.
FIG. 3B shows an alternate pattern of perforations (or openings) 322 and 324
in a metallized
layer (faceplate) 302. Here, the perforations 322 around the periphery of the
faceplate A are in
the form of holes, and the perforations 324 around the window opening 320 are
in the form of
slits.
FIG. 3C shows an alternate pattern of perforations (or openings) 324 in a
metallized layer
(faceplate) 302. flere, the openings 324 are several are segments of
increasing radii, distributed
(centered) around the window opening 320.
The perforations (or openings) 322 and 324, whether slits or holes, or other
shapes, may be
arranged in an aesthetically pleasing pattern, and may also serve as a
security (anti-
counterfeiting) measure. The perforations (or openings) 322 and 324 in the
face plate 302 may
be filled with a visually contrasting material, preferable non-metallic, such
as artificial (plastic)
mother of pearl.
The dimensions of the card body CB may be (approximately 50mm x 80mm):
Width 85.47mm - 85.72mm;
Height 53.92mm - 54.03mm; and
Thickness 0.76mm + 0.08mm.
The face plate 302 (or metallized layer ML) may measure approximately 86mm x
54mm. The
opening 320 (or "W") in the face plate 302 may measure approximately 8mm x 1
Omm. (In the
discussion of FIG. 2A, other exemplary dimensions for the antenna module AM
and window
opening 220 in the face plate 202 are presented and tabulated.)The peripheral
area of the card
body CB (or metallized layer ML) may extend 5-10mm in from the edge(s) of the
card body CB
(or metallized layer) ¨ in other words, not entirely to the periphery of the
overall card body.
As shown in FIGs. 3A and 3B, there may be a plurality of (such as 20-60, or
more) openings 322
disposed around the peripheral area of the face plate 302. The openings 322
may reduce the
amount of metal material in the peripheral area by approximately 25% - 50%,
thereby permitting
better coupling between the booster antenna BA and an external contactless
reader.
Similarly, there may be a plurality of (such as 10-30, or more) openings 324
disposed around the
window opening 320 in the face plate 302. The openings B may reduce the amount
of metal
material in this area by approximately 25% - 50%, thereby permitting better
coupling between
the coupler coil CC and the module antenna MA of the antenna module AM.
287621.00007/114263805.1 26
Date Recue/Date Received 2021-09-20
Additional and Alternative Modifications to the Layers of the Card Body
Compensation Loop
FIG. 4A shows that a conductive "compensation loop" CL may be disposed (such
as in Layer 5,
FIG. 2) behind the booster antenna BA (Layer 3), extending around the
periphery of the card
body CB. The compensation loop CL may be an open loop having two free ends,
and a gap
("gap") therebetween. The compensation loop CL may be made of copper cladding,
can be
printed on a support layer, etc.
FIG. 4B shows that the compensation loop CL may comprise ferrite material, in
which case
since ferrite is not an electrical conductor (in contrast with copper) the
loop may be closed,
having no gap and no free ends.
The compensation loop may be referred to as a "frame". The compensation frame
on the reverse
side of the booster antenna BA (FIG. 1) may help with the stabilization of the
resonance
frequency.
The compensation loop CL may be used in addition to the booster antenna BA.
The booster
antenna BA may be embedded into one side of an inlay substrate while the
compensation frame
may be inkjet printed or adhesively attached to the opposite side of the inlay
substrate. The
compensation loop CL can be mounted using a subtractive (etching away of
material) or additive
(depositing material) process.
Ferrite
Ferrite layers may be laminated together, and in combination with a copper
compensating loop
CL on the reverse side of a booster antenna BA may stabilize the resonance
frequency of the
booster antenna BA. The track may be broken (have a gap) at some position.
Lamination and temperature may be used to sinter ferrite particles together to
be a continuous
path. Laminating ferrite particles under temperature and very high pressure to
produce a thin
card material film such as PC PVC PETG to produce a ferrite inlay with
antenna. The inlay may
287621.00007/114263805.1 27
Date Recue/Date Received 2021-09-20
consist of several layers of ferrite. The applied temperature and pressure may
cause the particles
to sinter and form an insulating layer of ferrite.
Depositing ferrite nanoparticles or powder onto an inlay substrate to bend the
magnetic flux lines
and to compensate for the effect of shielding caused by metallization of the
printed layer(s) in a
smart card body or any metal layer in close proximity to an RFID antenna in
card body; and
forming a pre-laminated inlay with a booster antenna or transponder with one
or several
underlying layers of ferrite which have been laminated together with the RFID
components to
form a composite inlay layer.
Ferrite nanoparticles or powder can be applied to a substrate layer by means
of wet or dry
spraying. In the case of wet spraying the ferrite is suspended in a liquid
phase dispersion which is
prepared through sonication of the particles in a solvent or
aqueous/surfactant liquid. The
particles may also have a steric wrap to support the suspension of the
particles in the liquid. The
mean crystal particle size of the ferrite spheres can be determined by
filtering and by the degree
of sonication over time. (Sonication is the act of applying sound, usually
ultrasound energy to
agitate particles in a sample).
The sintering of the nano-sized ferrite particles occurs during hot lamination
of the synthetic
layers which make up the inlay. The lamination process includes heating and
cooling under high
pressure. Several layers of ferrite coated substrates or foils can be used to
enhance the
ferromagnetic properties. Unlike bulk ferrite granules, nanoparticles have a
much lower sintering
temperature, matching the glass transition temperature of the synthetic
substrate. Additional heat
treatment after lamination may be required.
Additional Features Incorporated Into The Card Body
As mentioned above, various additional features may be incorporated in various
combinations
into a body of a smart card (whether metallic or of non-metallic (typical)
variety) to enhance
electromagnetic coupling of the module antenna, via the booster antenna, with
an external
contactless reader, thereby increasing activation and read distances to an
"acceptable" level.
These enhancements may served largely to offset negative effects created by
other components
287621.00007/114263805.1 28
Date Recue/Date Received 2021-09-20
CA 02860909 2014-07-10
WO 2(113/110625 PCT/EP2013/051175
of the smart card, such as the metal face plate (202, 302), discussed at
length above, or the metal
contact pads (CP) on the antenna module (AM), which may also be modified to
enhance
coupling as discussed in some detail hereinbelow. Some of the card-related
features may
include
- disposing ferrite at strategic locations in the card body (CB), such as
disclosed in Res.
1B, 4I,J of US 20120074233; and
- various configurations for the booster antenna (BA), several variations of
which have
been mentioned above.
Laser Etching, and Modifications to the Antenna Module
Mention may be made, very briefly, to using laser etching instead of chemical
etching to remove
material such as metal from layers such as for forming the module antenna MA
of the antenna
module AM. A fuller description of this process may be found in 61/589,434
filed 1/23/2012,
61/619,951 filed 4/4/2012 and 61/693,262 filed 8/25/2012.
Chemically etching antennas with 10 to 12 turns within the confinement
dimensions of an ISO
standard chip card module is described in patent application US 2010/0176205.
Such an antenna
module with a contact and contactless interface is implanted in a card body
for inductive
coupling with a booster antenna to communicate with a reader in contaetless
mode.
Because of the restrictions on the size of the smart card module (e.g. 13mm x
11.8mm), the
number of turns forming the antenna is limited to the space surrounding the
central position of
the silicon die which is attached and bonded to the module substrate. This
substrate is generally
made of epoxy glass with a contact metallization layer on the face-up side and
a bonding
metallization layer on the face-down side of the module. The chemically etched
antenna is
usually formed on the face-down side.
Another limitation in creating an inductive antenna through chemical etching
is the minimum
pitch (or spacing) between tracks, which is economically attainable using a
lithographic process.
The optimal pitch (or spacing) between (adjacent) tracks of an etched antenna
on super 35 mm
tape is approximately 100 11.M. (As used herein, the term "pitch" may refer to
the spacing
29
between adjacent conductive tracks, rather than its conventional meaning the
center-to-center
dimension between track centerlines or the number of tracks per unit length).
An antenna structure such as a module antenna may be formed by laser etching a
copper cladded
laminate forming an integral part of an RFID smart card chip module. The use
of laser etching
may resolve the limiting pitch factor which can be achieved using conventional
chemical
etching, with the result that the number of turns which form the antenna can
be greatly increased,
with resulting performance benefits. Using laser versus chemical etching may
also result in a
significant reduction in the foot-print of the laser-etched antenna having
substantially the same
electrical characteristics as a chemically-etched antenna requiring a larger
area, and allowing for
easy placement and adhesion of the antenna chip module in a recess provided in
a card body,
using standard adhesive tapes.
The material being laser etched may comprise, a standard pre-preg laminate
(110 gm) made of
epoxy glass and cured halogen free epoxy resin with both sides cladded with
copper foil (17 gm
+ 17 gm) may be used to produce contactless and dual interface smart card
modules in rows and
columns on super 35 mm chip carrier tape. The carrier tape may be provided
with sprockets and
index holes for transport and punching of holes for vertical interconnects to
electrically connect
the top and bottom metallization layers can be implemented before laser
processing.
The antenna structure at each module site is laser etched (isolation
technique) into the copper
cladded "seed" layer (face-down side of the pre-preg) having a thickness of 17
gm, using a UV
or Green nanosecond or picosecond laser with a distance between tracks
dimensionally equal to
the width of the laser beam, approximately 25 gm. On the face-up side, the
contact areas can also
be laser etched in preparation for electroless-plating of copper and electro-
plating of nickel and
gold. After the laser etching of the copper seed layer, the tape with antenna
sites on the face-
down side is further processed: sand blasting to remove residual laser ablated
particles and to
prepare for plating adhesion; depositing carbon to support the through-hole
plating of the vertical
interconnects; dry film application and photo-masking process; electroless
deposition copper (Cu
6gm) to increase the thickness of the tracks on both sides of the tape,
electro-plating of nickel
287621.00007/114263805.1 30
Date Recue/Date Received 2021-09-20
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
and nickel phosphorous (Ni/NiP ¨ 9pm) or nickel (Ni 9p m) and palladium/gold
or gold(Pd/Au
or Au -0.1pm/0.03pm or 0.41m) to prevent oxidization.
By using a standard pre-impregnated laminate with a seed layer of copper on
both sides, it is
possible to laser etch contact pads on the face-up side and an antenna
structure on the face-down
side, before the tape is electroless-plated with copper, and electroplated
with nickel and gold.
The primary advantages of this technique are the reduction in the feature
pitch size (spacing)
between tracks and the consequent increase in permissible number of turns
within the
confinement area of a standard smart card chip module.
Modifying the Contact Pads (CP)
The aforementioned 61/693,262 filed 8/25/2012 discloses various ways (refer to
FIGs. 2A-D,
3A-B, 4A-B, 5A-B therein) modifying the contact pads (CP) of a dual interface
(DI) antenna
module (AM) to offset attenuation of electromagnetic coupling which may be
caused by the
metallic contact pads (CP). In one example shown therein (FIG. 3A), at lest
some of the contact
pads (CP) may be perforated, such as with holes or slots to reduce what is
referred to as
"coverage" of the coupling coil CC, to achieve a positive effect on (increase)
read distance. The
perforations in the contact pads (CP) serve a similar purpose as the openings
324 in the face plate
302. Both features (perforated contact pads, perforated face plate) may be
implemented.
As used herein, the term "coverage area" (or "coverage") refers to how much
the contact pads
(CP), which are on the opposite side of the module tape from the module
antenna (MA), overlap
the module antenna (MA). Coverage area may be between 0% (no overlap, such as
when the MA
is situated entirely outside of the perimeter of the CP), and nearly 100%
(substantially total
overlap, such as when the module MA is situated entirely within the perimeter
of the contact
pads (CP), but gaps between the pads reduces the number to slightly below
100%). Related
thereto, the term "coil exposure" refers to how much of the module antenna (A)
which is situated
within the area of the contact pads (CP) is exposed, such as through gaps
between the contact
pads. Coil exposure may be between nearly 0% (the only exposure is through the
gaps between
the pads) to 100% (such as when the module antenna MA is situated entirely
outside of the
perimeter of the contact pads).
31
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
FIG. 5 (comparable to FIG. lA of 61/693,262) illustrates a typical layout for
contact pads (CP)
on the face-up side of a module tape (MT). The contact pads (CP) may comprise
a layer of
conductive material such as copper (typically with other conductive layers for
protection) which
is etched, either chemically or with a laser (ablation) to exhibit the desired
pattern of pads. The
overall dimensions of the antenna module (AM) may be approximately 15mm x
15mm. The
overall dimensions of the card body (CB) may be approximately 50rnm x 80mm.
The overall
dimensions and pattern of the contact pads (CP) may be specified by ISO 7816.
For example,
the pattern contact pads (CP) may occupy an area measuring approximately lOmm
x 13mm on
the face-up side of the module tape (MT), and may have a thickness of
approximately 30 pm.
FIG. 5 shows seven contact pads (CP), exposed through an opening in the module
tape MT.
In FIG. 5, the module antenna (MA) disposed on an opposite side of the module
tape MT from
the contact pads (CP) is shown in dashed lines. In this
example, the coverage area is
substantially 100% (the module antenna MA is entirely covered by contact pads
(CP), except for
the small gaps between adjacent pads), and the coil exposure is substantially
0% (there is only
minimal coil exposure in the small gaps between adjacent pads). Therefore, the
contact pads CP
may shield (attenuate) signals between the booster antenna BA (or card antenna
CA) and the
module antenna (MA) in the antenna module (AM).
US 8,100,337 (2012, SPS) discloses an electronic module (11) with double
communication
interface, in particular for a chip card, the said module comprising firstly a
substrate (27)
provided with an electrical contact terminal block (17) allowing functioning
by contact with the
contacts of a reader, and secondly comprising an antenna comprising at least
one turn (13) and
whose terminals are connected to the terminals of a microelectronic chip
situated on one face of
the module (11). This module (11) is characterized in that the antenna turns
(13) are situated
substantially outside the area covered by the electrical contacts (17), so
that the electrical
contacts of the terminal block do not constitute electromagnetic shielding for
the signals intended
for the antenna. This applies in particular to the production of chip cards
with double
communication interface with contact and without contact.
32
Claim 1. An electronic module with double communication interface, for a chip
card, said
module comprising:
a substrate including an electrical contact terminal block allowing
functioning by contact
with the contacts of a reader; and
an antenna including at least one turn upon a surface of the electronic module
and whose
terminals are connected to the terminals of a microelectronic chip situated on
one face of the
module,
wherein the at least one turn of the antenna is situated upon a first area of
the surface of the
electronic module substantially outside a second area covered by the
electrical contacts, said
module having a plurality of protuberances situated outside the area of
electrical contacts of
the terminal block, on a face of the substrate opposite to that which carries
the antenna turns.
As noted in US 8,100,337, and using language more consistent with the present
and copending
applications of the applicant, when the antenna module (AM) is communicating
in a contactless
mode with an external reader, the contact pads (CP) may cause "shielding" (or
attenuation) of the
signal, thereby limiting the read distance. Although having a limited read
distance, such as only
a few centimeters, may be desirable for security reasons, such shielding may
limit the read
distance to an uncomfortably small amount, such as 3cm. More advantageously, a
read distance
of 5cm may be desirable, providing adequate security and improved
communication between the
external reader and the antenna module (AM), including with a smart card (SC)
which
incorporates the antenna module (AM).
US 6,778,384 (2002, Toppan) shows examples of antenna modules having a module
antenna (8)
and contact pads (7) where:
- the coverage area is substantially 100%; and
- the coil exposure is substantially 0%.
US 8,100,337(2012, SPS) shows examples of antenna modules having a module
antenna (13)
and contact pads (17) where:
- the coverage area is substantially 0%; and
- the coil exposure is substantially 100%.
287621.00007/114263805.1 33
Date Recue/Date Received 2021-09-20
US 8,100,337 discloses problems may arise when the antenna is situated
entirely outside the area
of the contacts, and a solution is proposed as follows:
As the turns 13 of the antenna are situated outside the area of the contacts
17, there is no
direct pressing action in the area situated above the turns 13 of the antenna
and
consequently there is potentially a risk of flexion of the substrate 27, or at
least of a less
good quality bonding between the turns 13 and the adhesive 31, which would
impair the
liability of the bonding and the longevity of the card. To remedy this risk,
the invention
provides, in an even more advantageous variant, a plurality of protuberances
33 situated on
the same side as the electrical contacts 17 but in the area which overhangs
the antenna
turns 13 (column 5, lines 7-18).
Addressing the Shielding Problem
The techniques disclosed in each of the following embodiments (examples) may
be mixed with
one another, as may be appropriate, to arrive at an effective solution. The
overall objective is to
increase read distance, which may (or may not) result from decreasing the
"coverage area" and
increasing the "coil exposure".
FIG. 6A (comparable to FIG. 2A of 61/693,262) illustrates a set of contact
pads CP wherein the
outer edges of at least some of the contact pads CP are extended beyond their
original perimeter
(outer edges, shown in dashed lines). The coil coverage in this example may be
characterized as
having been increased, such as from an initial 100% to more than 100%, such as
110%. The coil
exposure in this example remains substantially 0%. It is believed that
extending the edges may
have an adverse effect on (reduce) read distance.
Extending the edges to increase the area of individual pad may be useful when
using the pads as
interconnects for elements such as the module antenna MA on the underside of
the module tape
MT, capacitive elements and the like.
287621.00007/114263805.1 34
Date Recue/Date Received 2021-09-20
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
Consider, for example, the following contact pad layout / assignments shown in
FIG. 5A. Note
that contacts C4 and C8 may be connected with the two ends (LA, LB) of the
module antenna
MA.
FIG. 6B (comparable to FIG. 2B of 61/693,262) illustrates a set of contact
pads CP wherein the
outer edges of at least some of the contact pads CP are trimmed to be within
their original
perimeter (outer edges, shown in dashed lines). The coil coverage in this
example is decreased,
such as from an initial 100% to 90%. The coil exposure in this example is
increased, such as
from initially substantially 0% to 5% It is believed that trimming the edges
may have a slight
positive effect on (increase) read distance.
FIG. 6C (comparable to Flu. 2C of 61/693,262) illustrates a set of contact
pads CP wherein the
inner edges of at least some adjacent ones of the contact pads CP are trimmed
, so as to have the
effect of increasing the gap between the selected ones of the contact pads,
The coil coverage in
this example is decreased, such as from an initial 100% to 90%. The coil
exposure in this
example is increased, such as from initially substantially 0% to 5% It is
believed that increasing
the gap may have a slight positive effect on (increase) read distance.
* original gap =- 15011m
* modified gap =- 30011m
FIG. 6D (comparable to FIG. 2D of 61/693,262) illustrates an alternative to
FIG. 6C, wherein
rather than increasing the entire gap between adjacent contact pads, their
inner edges are
modified in an irregular manner. The coil coverage in this example is
decreased, such as from an
initial 100% to 95%. The coil exposure in this example is increased, such as
from initially
substantially 0% to 3% It is believed that increasing the gap may have a
slight positive effect on
(increase) read distance.
In the preceding examples set forth in FIGs. 6A,B,C,D above, some outer or
inner edges of
some of the contact pads are shifted from their "original" position(s).
Compare FIG. 5 as being
an example of "original position".
In the examples that follow, the edges of the contact pads generally remain
intact, in their
original position, thereby substantially maintaining the central design.
FIG. 7A (comparable to FIG. 3A of 61/693,262) shows an example of perforating,
such as with
holes or slots, at least some of the contact pads. The coil coverage in this
example is decreased,
such as from an initial 100% to 90%. The coil exposure in this example is
increased, such as
from initially substantially 0% to 5% It is believed that perforating the
contact pads may have a
positive effect on (increase) read distance.
In FIG. 7A, a regular array of a plurality of circular perforations (or holes)
arranged in an array
of rows and columns is shown in one of the contact pads. The perforations may
be arranged
irregularly, staggered, interleaved, quasi-randomly, and the like. The
circular perforations may
have an exemplary diameter of 35 m, and be arranged at an exemplary pitch of70
m or 140 m,
or 40 m (offset rows of 35 m holes). Some of the perforations may be slots, or
elongated
holes, as shown in another of the contact pads. Holes having other shapes such
as rectangular,
irregular, elongated, etc, may be formed in some of the contact pads.
FIG. 7B (comparable to FIG. 3B of 61/693,262) shows an example of thinning
selected areas of
at least some of the contact pads. The coil coverage in this example is
"effectively" decreased,
such as from an initial 100% to 95%. The coil exposure in this example is
"effectively"
increased, such as from initially substantially 0% to 2% It is believed that
thinning the contact
pads may have a positive effect on (increase) read distance.
In FIG. 7B, the module antenna MA is shown as being an etched, having
conductive lines
(tracks), rather than the coiled wire module antenna MA shown in FIG. 1.
FIG. 8A (comparable to FIG. 4A of 61/693,262) shows a module antenna MA and
chip CM
disposed on the underside of a module tape MT. In this example, the module
antenna MA is a
wound coil of wire, having two ends a, b bonded to respective bond pads BP.
287621.00007/114263805.1 36
Date Recue/Date Received 2021-09-20
FIG. 8B (comparable to FIG. 4B of 61/693,262) shows the face-up side of the
module tape MT
shown in FIG. 8A. Here, a pattern of holes or perforations is formed in the
contact pads CP
(compare FIG. 3A). The pattern of perforations is arranged in concentric
circles. This pattern
will be visible to the user (of the smart card SC). The coil coverage in this
example is
"effectively" decreased, such as from an initial 100% to 95%. The coil
exposure in this example
is "effectively" increased, such as from initially substantially 0% to 2% It
is believed that
perforating the contact pads in this manner may have a positive effect on
(increase) read
distance.
FIG. 9A (comparable to FIG. 5A of 61/693,262) shows another example of
perforating the
contact pads CP. In this example, the perforations are visible, and are
arranged in the pattern of
a logo, such as the logo for Chase Bank.
FIG. 9B (comparable to FIG. 5B of 61/693,262) shows another example of
perforating the
contact pads CP. In this example, the perforations are visible, and are
arranged in the pattern of
a logo, such as the logo for Deutsche Bank.
The patterns of perforations in the contact pads may be visible to the user,
and in metallized
cards can be formed to mimic or complement (such as being smaller versions of,
or continuations
of, of the like) the perforations 324 surrounding the window opening 320 in
the face plate 302.
In the examples set forth hereinabove, the contact pads CP of an antenna
module AM have been
modified with the goal of increasing read distance (by reducing attenuation in
coupling between
the module antenna MA and the booster antenna BA which may be attributable to
the contact
pads CP). In some cases, the coil coverage (or effective coil coverage) is
decreased, and the coil
exposure (or effective coil exposure) is increased. In some examples, the
contact pads, including
inner and outer edges thereof, maintain their original position. In some
examples, the central
design of the contact pads is maintained. Larger gaps between contact pads and
perforations in
the contact pads CP resulting in more coil exposure may improves read
distance.
287621.00007/114263805.1 37
Date Recue/Date Received 2021-09-20
Some other aspects of the antenna module AM
FIG. 10A (comparable to FIG. 6A of 61/693,262) illustrates the underside of a
module tape MT
for an antenna module AM. An antenna structure AS for a module antenna MA is
shown,
comprising two module antenna segments MA1 and MA2. Two module antenna
segments MA1
and MA2 are shown. These two module antenna segments MA1, MA2 may be arranged
concentric with one another, as inner and outer antenna structures. Both
module antenna
segments MA1, MA2 may be wound coils, or patterned tracks, or one may be a
wound coil and
the other a pattern of tracks. The two module antenna segments MA1, MA2 may be
interconnected with one another in any suitable manner to achieve an effective
result. For
example, the two module antenna segments MA1, MA2 may be connected in any
suitable
manner with one another.
FIG. 10B (comparable to FIG. 5A of 61/693,262) illustrates an exemplary
antenna structure AS
which may be used in an antenna module AM, having two segments (compare MA1,
MA2)
which are interconnected with one another, the antenna structure comprising:
- an outer segment OS having an outer end 7 and an inner end 8;
- an inner segment IS having an outer end 9 and an inner end 10;
- the outer end 7 of the outer segment OS is connected with the inner end
10 of the inner
segment IS;
- the inner end 8 of the outer segment OS and the outer end 9 of the inner
segment IS are
left unconnected; and
- this forms what may be referred to as a "quasi dipole" antenna structure
AS. Compare
FIG. 1A.
o Such an arrangement is shown in 13/205,600 filed 8/8/2011 (pub
2012/0038445,
2/16/2012) for use as a booster antenna BA in the card body CB of a smart card
SC; and
o Such an arrangement is shown in 13/310,718 filed 12/3/2011 (pub
2012/0074233,
3/29/2012) for use as a booster antenna BA in the card body CB of a smart card
SC.
287621.00007/114263805.1 38
Date Recue/Date Received 2021-09-20
CA 02860909 2014-07-10
WO 2013/110625 PCT/EP2013/051175
The contact pads CP and antenna structures AS described herein may be formed
using laser
etching (isolation technique) of copper cladded "seed" layers on a module tape
MT using a UV
nanosecond or picosecond laser. A seed layer may have a thickness of
approximately 17um.
For the antenna structures AS, the space between tracks may be dimensionally
equal to the width
of the laser beam, approximately 30 um. the tracks themselves may have a width
of 30-50pm.
Perforations, such as those described above, may be formed by laser percussion
drilling.
After laser etching of the copper seed layer to pattern and/or to perforate
the contact pads CP or
antenna structure(s) AS, the module tape MT may be further processed as
follows:
- sand blasting to remove residual laser ablated particles and to prepare
for plating
adhesion;
- depositing carbon to support the through-hole plating of the vertical
interconnects;
- dry film application and photo-masking process:
- eleetrodepositing copper (Cu - 6 m) to increase the thickness of the
patterned (for CP or
AS) seed layer on both sides of the tape;
electroless plating of nickel and nickel phosphorous (Ni/NiP 9 m) or nickel
(Ni 9 m) and
palladium/gold or gold(Pd/Au or Au -0.1 in/0.03um or 0.2pm) to prevent
oxidization.
While the invention(s) hasthave been described with respect to a limited
number of
embodiments, these should not be construed as limitations on the scope of the
invention(s), but
rather as examples of some of the embodiments. Those skilled in the art may
envision other
possible variations, modifications, and implementations that are also within
the scope of the
invention(s), based on the disclosure(s) set forth herein.
39
