U.S. patent application number 12/669847 was filed with the patent office on 2010-07-22 for apparatus having at least one packaging unit with an rfid chip which is used for radio-frequency identification, and method therefor.
This patent application is currently assigned to BOEHRINGER INGELHEIM INTERNATIONAL GMBH. Invention is credited to Eduard Balthes, Johannes Geser.
Application Number | 20100182131 12/669847 |
Document ID | / |
Family ID | 39926661 |
Filed Date | 2010-07-22 |
United States Patent
Application |
20100182131 |
Kind Code |
A1 |
Balthes; Eduard ; et
al. |
July 22, 2010 |
APPARATUS HAVING AT LEAST ONE PACKAGING UNIT WITH AN RFID CHIP
WHICH IS USED FOR RADIO-FREQUENCY IDENTIFICATION, AND METHOD
THEREFOR
Abstract
An apparatus comprises at least one RFID chip (30), which is
surrounded by a metallic outer casing (11) of a packaging unit (1),
is used for radio-frequency identification and has a circuit (32)
and an antenna structure (31), and a transmitting/receiving unit
(41) for transmitting a transmission signal (42) and/or receiving a
response signal (43) from the RFID chip (30), wherein the response
signal (43) can be evaluated using an evaluation unit (44) which is
connected to the transmitting/receiving unit (41). The RFID chip
(30) has an operating frequency in a frequency band (50) below a
range of a blocking frequency (54) which is determined by the
conductivity of the metallic outer casing (11) and the thickness
thereof.
Inventors: |
Balthes; Eduard; (Ingelheim
am Rhein, DE) ; Geser; Johannes; (Ingelheim am Rhein,
DE) |
Correspondence
Address: |
MICHAEL P. MORRIS;BOEHRINGER INGELHEIM USA CORPORATION
900 RIDGEBURY ROAD, P. O. BOX 368
RIDGEFIELD
CT
06877-0368
US
|
Assignee: |
BOEHRINGER INGELHEIM INTERNATIONAL
GMBH
Ingelheim am Rhein
DE
|
Family ID: |
39926661 |
Appl. No.: |
12/669847 |
Filed: |
July 16, 2008 |
PCT Filed: |
July 16, 2008 |
PCT NO: |
PCT/EP08/59263 |
371 Date: |
January 20, 2010 |
Current U.S.
Class: |
340/10.4 |
Current CPC
Class: |
G06K 19/07771 20130101;
G06K 19/0723 20130101; G06K 19/07749 20130101; G06K 19/0717
20130101 |
Class at
Publication: |
340/10.4 |
International
Class: |
H04Q 5/22 20060101
H04Q005/22 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 21, 2007 |
DE |
102007034155.7 |
Claims
1. Device having at least one RFID chip (30) surrounded by a metal
outer casing (11) of a packaging unit (1) and serving for
radiofrequency identification, said chip comprising a switching
circuit (32) and an antenna structure (31), and having a
transmitting/receiving unit (41) for transmitting a transmission
signal (42) and/or receiving a response signal (43) from the RFID
chip (30), the response signal (43) being capable of evaluation by
an evaluating unit (44) connected to the transmitting/receiving
unit (41), and the RFID chip (30) has an operating frequency which
is in a frequency band (50) below a range of a blocking frequency
(54) which is determined by the conductivity of the metal outer
casing (11) and its thickness.
2. Device according to claim 1, characterised in that the RFID chip
(30) has an operating frequency LF-RFID (55) in the range from 20
to 500 kHz or an operating frequency HF-RFID (56) in the range from
3 to 30 MHz.
3. Device according to claim 1, characterised in that the RFID chip
(30) has a sensor which influences the response signal (43) of the
RFID chip (30).
4. Device according to claim 3, characterised in that the sensor of
the RFID chip (30) is constructed as a capacitor structure (33) and
the capacitance or change in capacitance of the capacitor structure
(33) modifies the response signal (43) from the RFID chip (30)
which can be evaluated with a measuring arrangement (40) associated
with the evaluating unit (44).
5. Device according to claim 4, characterised in that the capacitor
structure (33) comprises a dielectric the dielectric constant
.di-elect cons. of which is dependent on the relative humidity
(r.h.) or on a gas concentration.
6. Device according to claim 4, characterised in that the measuring
arrangement (40) comprises, for evaluating the response signal
(43), a measuring amplifier and a tuneable capacitance measuring
bridge.
7. Device according to claim 1, characterised in that the metal
outer casing (11) is made up of an aluminium film or a composite
film consisting of at least one aluminium layer and at least one
other layer of plastics or paper.
8. Device according to claim 1, characterised in that the metal
outer casing (11) has a 10 to 50 .mu.m thick aluminium film or
aluminium layer.
9. Device according to claim 1, characterised in that the metal
outer casing (11) is part of an outer packaging (10).
10. Device according to claim 9, characterised in that the RFID
chip (30) is attached to a separate plastic card inside the outer
packaging (10).
11. Device according to claim 9, characterised in that the RFID
chip (30) is attached to the inside of the outer packaging (10)
inside the outer packaging (10).
12. Device according to claim 9, characterised in that the outer
packaging (10) comprises at least one blister card (20) to which
the RFID chip (30) is attached.
13. Device according to claim 1, characterised in that the metal
outer casing (11) is part of an aluminium composite cover film of a
blister card (20), the RFID chip (30) being located on the blister
card (20) or inside a cavity (21) in the blister card (20) and
covered by the aluminium composite cover film.
14. Device according to claim 13, characterised in that the RFID
chip (30) is attached to a separate plastic card inside the cavity
(21).
15. Device according to claim 1 and a pharmaceutical product.
16. Method of identifying the contents and/or condition of a
packaging unit with an RFID chip (30) serving for radiofrequency
identification, which has a switching circuit (32) and an antenna
structure (31), wherein a transmitting/receiving unit (41) sends a
transmission signal (42) and/or receives a response signal (43)
from the RFID chip (30) and the response signal (43) is evaluated
by means of an evaluating unit (44) connected to the
transmitting/receiving unit (41), characterised in that the RFID
chip (30) surrounded or covered by a metal outer casing (11) as
part of the packaging unit (1) is operated at an operating
frequency that lies in a frequency band (50) below a range of a
blocking frequency (54) which is determined by the conductivity of
the metal outer casing (11) and its thickness.
17. Method according to claim 16, characterised in that the RFID
chip (30) is operated at an operating frequency LF-RFID (55) in the
range from 20 to 500 kHz or an operating frequency HF-RFID (56) in
the range from 3 to 30 MHz.
18. Method according to claim 16, characterised in that the
response signal (43) of the RFID chip (30) is influenced in its
coding and/or response frequency by means of a sensor connected to
the RFID chips (30) or integrated in the RFID chip (30) and is
received and evaluated by the transmitting/receiving unit (41).
19. Method according to claim 16, characterised in that the
response signal (43) of the RFID chip (30) is modified in its
frequency by means of a capacitor structure (33) which is connected
to the RFID chip (30) or is integrated therein and the dielectric
constant .di-elect cons. of which is influenced by the relative
humidity (r.h.) or by a gas concentration, and is received and
evaluated by a measuring arrangement (40) of the evaluating unit
(44) of the transmitting/receiving unit (41).
20. Method according to claim 19, characterised in that the
response signal (43) of the RFID chip (30) is amplified by means of
a measuring amplifier within the measuring arrangement (40) and the
capacitance of the capacitor structure (33) of the RFID chip (30)
is determined by means of a tuneable capacitance measuring bridge
within the measuring arrangement (40) by comparison with a
reference capacitance within the capacitance measuring bridge.
21. Method according to claim 16, characterised in that before the
RFID chip (30) with the sensor or the capacitor structure (33) is
packed into the packaging unit (1) calibration is carried out.
22. Method according to claim 21, characterised in that, for the
calibration, the RFID chip (30) with the capacitor structure (33)
is subjected to specified humidity levels at a defined temperature
in a dynamic vapour sorption scale, the response signal (43) from
the RFID chip (30) is measured with the measuring arrangement (40)
at the different humidity levels and from this an inherent
frequency dependent on the humidity is determined.
23. Method according to claim 16 for the measurement of humidity or
a gas concentration in blisters, pouches, polymer blisters, bottles
or containers and/or packaging in general with volumes ranging from
the ml range to larger containers, and in the development of
packaging and for online monitoring during production.
Description
[0001] The invention relates to a device having at least one
packaging unit with an RFID chip serving for radiofrequency
identification, which comprises a switching circuit and an antenna
structure, and a transmitting/receiving unit for sending a
transmission signal and/or receiving a response signal from the
RFID chip, the response signal being capable of evaluation by means
of an evaluating unit connected to the transmitting/receiving
unit.
[0002] The invention also relates to a method of identifying the
content and/or condition of a packaging unit.
[0003] The development of pharmaceuticals is increasingly being
driven into the range of highly effective but at the same time
relatively delicate medicaments. This places increasing demands on
their packaging and outer packaging. Foil containers or cavities on
so-called blister cards, for example, serve inter alia to protect
pharmaceutically active substance formulations from external
environmental influences which may in some circumstances affect the
pharmaceutical quality of the active substance formulation.
[0004] In order to achieve relatively high barrier qualities
against moisture and gases in packaging, aluminium composite films
or foils are often used, but these have the disadvantage that the
outer packaging produced from them, for example so-called aluminium
pouches, are non-transparent and it is not possible to identify the
contents, e.g. To compare them with the information on the outer
packaging, without destroying the outer packaging.
[0005] With medicaments of this kind the moisture introduced into
the packaging by the product and by the individual packaging
components, as well as the moisture that may penetrate into the
packaging during storage, also plays an important role. It is
therefore very useful to determine the moisture in a package as
quickly as possible and in a number of packaging cavities (e.g. In
blister cards) at the same time wherever possible, with a high
degree of accuracy and especially in non-destructive manner. In
addition, this measurement should be able to be carried out at
reasonable cost.
[0006] In connection with the identification of the contents of
packaging, radiofrequency identification systems which use
so-called RFID chips, standing for "Radio Frequency Identification
Device", are now in common use. RFID chips of this kind
(transponders) can be detected using a scanning device. Depending
on the type of transponder, in the simplest case it is possible to
register the presence of the transponder, or to register a code
which is transmitted back to the scanner from the transponder. RFID
chips of this kind are sufficiently well described in the
specialist literature (e.g. K. Finkenzeller: RFID-Handbuch, 4th
edition, published by Carl Hanser, Munchen, ISBN
3-446-40398-1).
[0007] The use of RFID chips for identification or monitoring of
the conditions within packages with a conductive metal outer casing
has not hitherto been possible as the so-called skin effect
prevents the outer casing from being penetrated.
[0008] The aim of the invention is to provide a device and a method
of the type mentioned hereinbefore which overcome(s) the
above-mentioned disadvantages.
[0009] According to the invention, the aim is achieved by a device
having at least one RFID chip enclosed by a metallic outer casing
of a packaging unit and serving for radiofrequency identification,
said RFID chip comprising a switching circuit and an antenna
structure, and having a transmitting/receiving unit for sending a
transmission signal and/or receiving a response signal from the
RFID chip, the response signal being capable of evaluation by means
of an evaluating unit connected to the transmitting/receiving unit
and the RFID chip having an operating frequency that lies in a
frequency band below a range of a blocking frequency which is
determined by the conductivity of the metallic outer casing and its
thickness.
[0010] The aim is also achieved by a method having the features of
claim 16.
[0011] The shielding from electromagnetic radiation in metallic
conductive packaging, provided by the skin effect, has hitherto
prevented the use of RFID chips in aluminium composite pouches for
example. The skin depth .delta. or depth of penetration for
electromagnetic radiation refers to the thickness of a metal layer
at which the electromagnetic field is attenuated to the 1/e.sup.th
value precisely by the skin effect, e being the Euler number. The
skin depth .delta. is frequency-dependent when the material
properties, such as the conductivity, remain the same, and rises
sharply as the frequency falls. This very property of the skin
effect can be used to overcome the previous difficulties in
scanning an RFID chip within an aluminium pouch.
[0012] It has been shown experimentally that if the operating
frequency is low enough the RFID chip within an aluminium pouch can
be activated and scanned from outside reproducibly and as often as
desired. Thus the contents of the packaging can be identified
clearly but non-destructively.
[0013] When using aluminium composite pouches with an aluminium
layer thickness of about 20 .mu.m, corresponding to a range for the
blocking frequency of about 100 MHz to 200 MHz, RFID chips which
have an operating frequency LF-RFID (low frequency RFID) in the
range from 20 to 500 kHz or an operating frequency HF-RFID (high
frequency RFID) in the range from 3 to 30 MHz can be used
successfully.
[0014] Theoretically, all operating frequencies below the blocking
frequency are possible for reliable operation. However, only RFID
chips with the above-mentioned operating frequency ranges are
commercially obtainable. Another advantage arises from the fact
that these RFID chips function passively, i.e. without an
additional voltage source, thus making their use considerably
easier. In addition, the short range of these RFID chips reduces
the risk of confusion or crosstalk when scanning adjacent packages
with RFID chips, and furthermore they are moisture-resistant.
[0015] The choice of suitable RFID chips is made possible by
calculating the material- and layer thickness-specific attenuation
of the electromagnetic radiation of the transmitting/receiving
unit. The transmission power required of the transmitting/receiving
unit can also be calculated and adjusted as necessary.
[0016] According to one feature the RFID chip has a sensor that
influences the response signal of the RFID chip. Preferably, the
response signal of the RFID chip is influenced in its coding and/or
response frequency by the sensor connected to the RFID chip or
integrated in the RFID chip and received and evaluated by the
transmitting/receiving unit and the evaluating unit. In this way
the condition inside the metallic outer casing is detected and a
corresponding signal is sent out. Sensors of this kind may be for
example temperature sensors or sensors that react to chemical
changes and modify the response signal accordingly. As a result it
is possible for example to determine the concentration of chemical
substances.
[0017] Preferably, the sensor of the RFID chip is in the form of a
capacitor structure and the capacitance or change in capacitance of
the capacitor structure modifies the response signal from the RFID
chip which can be evaluated by a measuring arrangement associated
with the evaluating unit. The capacitor structure expediently
comprises a dielectric, the dielectric constant .di-elect cons. of
which is dependent on the relative humidity (r.h.) or a gas
concentration, for example because of its hygroscopic nature. The
response signal of the RFID chip is advantageously influenced in
its coding and/or response frequency and received and evaluated by
the transmitting/receiving unit that comprises the measuring
arrangement. This makes it possible for example to produce a simple
RFID chip that reacts to humidity, which can be used for
non-destructive humidity measurement within the packaging unit.
[0018] A measuring arrangement for evaluating the response signal
which is particularly suitable for the humidity evaluation
described above comprises a measuring amplifier and a tuneable
capacitance measuring bridge. The response signal of the RFID chip
is amplified by the measuring amplifier within the measuring
arrangement and is determined by means of the tuneable capacitance
measuring bridge by comparing with a reference capacitance within
the capacitance measuring bridge. This makes it possible to carry
out very sensitive humidity measurements with relatively high
accuracy.
[0019] The accuracy is further increased if calibration is carried
out before the RFID chip with the sensor or capacitor structure is
packed into the packaging unit. Preferably, for calibration, the
RFID chip with the capacitor structure is subjected to specified
humidity levels at a defined temperature in a dynamic vapour
sorption scale (DVS), the response signal from the RFID chip is
measured with the measuring arrangement at the different humidity
levels and from this an inherent frequency dependent on the
humidity is determined. This is done using a highly sensitive
capacitive measuring bridge. The capacitor that is to be calibrated
represents the unknown capacitance in an oscillating circuit. The
magnitudes sought are produced as the oscillating circuit goes out
of tune as a function of the humidity.
[0020] According to one feature the metal outer casing of a blister
consists of an aluminium foil or film or a composite film
consisting of at least one layer of aluminium and at least one
other layer of plastics or paper. The metallic outer casing has an
aluminium film or layer that is 10 to 50 .mu.m thick. On the one
hand this provides a good diffusion barrier, so that the
pharmaceutical active substance is correspondingly protected. On
the other hand, RFID chips within the packaging unit can still be
reliably addressed.
[0021] An alternative packaging envisages having the metal outer
casing as a component of an outer packaging, as is the case for
example with aluminium composite pouch bags. The RFID chip is
placed in the pouch bag as it is packed with the active substance
contained in blister cards, for example, and the bag is then
sealed.
[0022] For accurate positioning of the RFID chip within the outer
packaging, the RFID chip is fixed within the outer packaging on a
separate plastic card (inlay), to which it may be glued, for
example. As a result the scanner is able to locate the RFID chip
precisely, thus reducing the number of error sources and shortening
the measuring time. The inlay may be suitably labelled, for patient
protection, and can easily be disposed of by the patient when the
packaging unit is opened. Alternatively, the RFID chip within the
packaging is attached to the inside of the outer packaging.
[0023] If the outer packaging has at least one blister card to
which the RFID chip is attached, the RFID chip may also be
accurately positioned within the outer packaging.
[0024] Preferably, the metal outer casing is part of an aluminium
composite cover film of a blister card, the RFID chip being located
on the blister card or within a cavity in the blister card and
covered by the aluminium composite cover film. The RFID chip is
expediently attached, for example glued, to a separate plastic card
(inlay) within the cavity in order to maintain its orientation
within the cavity in the blister card relative to the cover film.
As a result, the scanner can read the RFID chip relatively
reliably, thus reducing the number of error sources and shortening
the measuring time. It is theoretically also conceivable for the
RFID chip with the capacitor structure mentioned above to be stuck
to the cover or base film of the blister card.
[0025] Typical aluminium composite films are produced for example
from aluminium and a plastic. Examples of materials that may be
used for the plastic films include polyvinylchloride (PVC),
cycloolefin copolymer (COC), polychlorotrifluoroethylene (PCFE),
polyethylene (PE), polypropylene (PP), polyethylene terephthalate
(PET), polycarbonate (PC), polyester (UP), polyacrylate, polyamide
(PA) or other plastics. Blister packs with the following sequence
of layers are envisaged for use, for example. The cover film is
made of aluminium and has a thickness of 10 to 80 microns,
preferably 20 to 50 microns, particularly 30 to 40 microns. The
cover film is connected to the base film containing the cavities by
means of a heat sealing lacquer so as to form a seal. The base film
consists, on the side in contact with the product, of a layer of
PVC, PP, PE or the like with a thickness of between 10 and 200
microns, preferably between 15 and 50 microns, particularly between
20 and 40 microns. This film is attached to an aluminium film with
a thickness of preferably 30 to 60 microns, advantageously 35 to 50
microns. Adjoining the aluminium film is a polyamide film with a
thickness of between 10 and 40 microns, preferably 15 to 30
microns. In the case of an alternative base film, the PVC film on
the side facing the product is replaced by a polypropylene film or
the like. In a preferred blister pack, the cover film consists of a
38 .mu.m thick aluminium film and the heat sealing lacquer. The
base film is produced, on the side facing the pharmaceutical
product, from a PVC film 30 .mu.m thick, an adjacent 45 .mu.m thick
aluminium film and an outer 20 .mu.m thick polyamide film.
[0026] The invention preferably envisages the use of the packaging
unit with the features described hereinbefore for pharmaceutical
products. This, highly sensitive pharmaceutical products can be
non-destructively identified in their packaging, which is
advantageous particularly in terms of quality control, prevention
of counterfeiting and the identification of clinical samples, i.e.
medicaments produced in small production runs in which the
identification of the contents is of particular importance.
[0027] The method described above for determining humidity, in
particular, can be used for the non-destructive and accurate
measurement of the humidity in blisters, pouches, polymer blisters,
bottles or in containers and/or packaging in general having volumes
ranging from the ml range to larger containers. Because of the
possibility of being able to measure a plurality of packaging units
in parallel, this provides a fast method of measuring humidity.
Besides water it is also possible to determine the concentration of
other vapours and gases, while the sensitivity of the dielectric of
the capacitor structure of the RFID chip must be matched to the
substance that is to be measured. The packaging may be the product
itself or packaging means such as for example rolls of film,
closure means containing desiccants and the like. The packaging may
be for example an aluminium film composite, although other packages
are not excluded, as the method is intended primarily for measuring
humidity without destroying or impairing the outer packaging.
[0028] One application of this method is in the development of
packaging, for example within the scope of stability testing. It is
also possible to carry out online monitoring during production, for
example on individual complete blister cards for monitoring the
initial moisture levels in the cavities.
[0029] It will be understood that the features mentioned above and
those to be described hereinafter may be used not only in the
particular combination stated but also in other combinations. The
scope of the invention is defined only by the claims.
[0030] The invention is hereinafter described in more detail by
means of a number of embodiments by way of example with reference
to the associated drawings, wherein:
[0031] FIG. 1 shows a schematic representation of the device
according to the invention,
[0032] FIG. 2 shows a schematic plan view of a blister card with an
RFID chip for use in the device according to FIG. 1,
[0033] FIG. 3 shows a schematic representation of a frequency band
having a range for a blocking frequency for a first embodiment of a
metal outer casing and
[0034] FIG. 4 shows a schematic representation of the frequency
band having the range for a blocking frequency for a second
embodiment of the metal outer casing.
[0035] A packaging unit 1 consists according to FIG. 1 of an outer
packaging 10 having a metal outer casing 11, which is made up of an
aluminium film or a composite film, consisting of at least one
aluminium layer and at least one other plastics or paper layer. In
the present case a so-called pouch bag is shown which has an
aluminium composite film with a layer of aluminium about 20 .mu.m
thick. Inside the outer packaging 10 is a blister card 20 with a
plurality of cavities 21 for holding pharmaceutical active
substances, for example in the form of tablets or capsules.
[0036] Stuck to the blister card 20 is an RFID chip 30 which is
activated and scanned by means of a transmitting/receiving unit 41
(scanner) outside the outer packaging 10. The
transmitting/receiving unit 41 emits a transmission signal 42 and
receives a response signal 43 from the RFID chip 30, which is
evaluated in an evaluating unit 44 comprising a measuring
arrangement 40, which is connected to the transmitting/receiving
unit 41.
[0037] According to FIG. 2 the RFID chip 30 is provided in place of
a cavity 21 on the blister card 20, for example stuck on to the
blister card 20 or incorporated in the blister when the cavities 21
are sealed. The blister card 20 has an aluminium composite cover
film which covers the RFID chip 30 and the cavities 21. The layer
thickness of the aluminium layer in the cover film is about 45
.mu.m.
[0038] The RFID chip 30 consists essentially of an antenna
structure 31 in the form of a printed coil and a switching circuit
32 which, in the simplest case, merely sends back the response
signal 43 when activated from outside. In more complex RFID chips
30 the switching circuit 32, when activated, may also send back a
code by means of which the contents of the blister card 20 can be
scanned, for example. The passive RFID chip 30 shown here has no
battery.
[0039] Furthermore, the RFID chip 30 comprises a capacitor
structure 33 the capacitance or change in capacitance of which
modifies the response signal 43 of the RFID chip 30. The antenna
structure 33 serves to charge up the capacitor structure 33 with
the irradiated energy of the transmitting/receiving unit 41 and
thereby provide enough energy to enable the actual switching
circuit 32 of the RFID chip 30 to send its data back to the
transmitting/receiving unit 41. If the capacitor structure 33 has a
dielectric the dielectric constant .di-elect cons. of which is
dependent on the relative humidity (r.h.) an oscillating circuit
can thus be produced, the inherent oscillation of which is
dependent on the value of the capacitance of the capacitor
structure 33 and hence on the relative humidity (r.h.). The change
in the frequency of the response signal 43 is received by the
transmitting/receiving unit 41, amplified with a measuring
amplifier of the measuring arrangement 40 and measured by means of
a tuneable capacitance measuring bridge, from which finally the
humidity in the packaging unit 1 can be determined.
[0040] Before the RFID chip 30 with the capacitor structure 33 is
enclosed in the blister pack, calibration is carried out in which
the capacitor structure 33 is subjected to particular humidity
levels at a defined temperature in a dynamic vapour sorption scale.
The response signal 43 from the RFID chip 30 is measured with the
measuring arrangement 40 at the different humidity stages and from
this an inherent frequency dependent on the humidity is determined.
Thus a calibration curve of humidity-dependent capacitance vs.
Moisture content (or vs. relative humidity) can be determined.
[0041] The RFID chip 30 has an operating frequency which is in a
frequency band 50 at which the frequency 51 is shown
logarithmically, below a range of a blocking frequency 54 that is
determined by the conductivity of the metallic outer casing 11 and
its thickness. Below this blocking frequency 54 the frequency band
50 has a permeable range 52 and above it a blocking range 53. The
result of the calculation shown in FIG. 3 was that, for an
aluminium pouch with an aluminium film thickness of 20 .mu.m, the
pouch used blocks signals above a frequency of about 100 MHz, i.e.
the electromagnetic field of the transmitter can be attenuated to
values below the 1/e.sup.th of the irradiated value. An operating
frequency UHF-RFID 57 for the RFID chip 30 of more than 100 MHz is
therefore unsuitable for scanning the information from a pouch of
this kind. This applies particularly to the standard commercial
UHF-RFID chips (ultra high frequency) whose operating frequencies
are barely 1 GHz, 2 to 3 GHz or barely 6 GHz. By contrast, the RFID
chips 30 with an operating frequency LF-RFID 55 in the range from
30 kHz to 500 kHz or with an operating frequency HF-RFID 56 in the
range from 3 MHz to 30 MHz, in particular, are suitable for
scanning. In this frequency range, the aluminium pouch is
permeable.
[0042] FIG. 4 shows the conditions in the frequency band 50 for an
aluminium layer thickness of 45 .mu.m, as used for example in an
aluminium composite cover film for blister-coating blister cards
20. The range of the blocking frequency 54 is about 30 MHz. Above
this frequency the aluminium composite cover film blocks the
electromagnetic radiation, so that scanning is no longer possible.
Below this blocking frequency 54, the aluminium composite cover
film of the blister card 20 is permeable.
* * * * *