Electronic integrated circuit label

A miniature electronic label or tag includes a metal card, and an integrated memory circuit attached to a surface of said card. The integrated memory circuit has an outer surface facing the card, an electrically conductive region on the surface and two input/output conductors. A first conductor is electrically connected to the card and the second conductor is electrically connected to the electrically conductive region. An opening through said card adjacent said electrically conductive portion permits electrical connection to be made to the first conductor by electrical contact with said card and electrical connection to the second conductor can be made by contact with the electrically conductive region through the opening, either directly or indirectly.

FIELD OF THE INVENTION 
This invention relates to the field of electronic labels in which a memory 
is provided with information to be read for identifying an article to 
which the lable is attached. 
BACKGROUND OF THE INVENTION 
The field of electronic labels is currently in full expansion. The systems 
in question comprise an electronic memory with either a read-only function 
(ROM), or a read-write function (RAM, EPROM, EEPROM) allowing information 
relating to the product to which the label is affixed to be recorded and 
read. 
Certain of these labels are relatively large, but there is a real trend 
towards miniaturization, so that these labels can be discreetly 
accommodated in all sorts of products. 
Furthermore, the current trend is to be able to read the label at a certain 
distance, which necessitates the incorporation of a coil for transmitting 
non-contact signals. 
Although very miniaturized versions have already been developed, notably 
electronic labels for implanting in animals, or ultra-flat models which 
can be incorporated within a standard "credit card" format, this is not 
sufficient for certain applications. 
SUMMARY OF THE INVENTION 
This invention concerns a miniature electronic label where the coil has 
been replaced by a system of direct access via contacts. This electronic 
label, which comprises an integrated memory circuit that is electrically 
accessible via two tie lines or input/output conductors it comprises a 
metallic card which serves as a support, said card being connected 
electrically to the first input/output conductor or tie line, and 
comprising an aperture via which a contact zone connected at least 
indirectly to the second input/output conductor or tie line can be 
accessed.

Description of the Preferred Embodiments 
FIGS. 1A and 1B show a circular metallic card 1 with hole a 2 at the center 
thereof. A thin interconnection interface 3 of the printed circuit board 
type is mounted on said card. Finally, an integrated memory circuit 4 is 
in turn mounted on the printed circuit 3 and fixed by means of an adhesive 
thread 5. FIGS. 2A-2D show the interconnections between theses different 
elements in greater detail. 
The electronic label thus formed can be mounted in a machined housing 6 or 
preformed housing 7 as shown in FIGS. 3 and 4, in any object for which the 
electronic label is intended. This label is particularly well suited for 
use on metallic objects where it can be ensured that the housing has a 
certain rigidity. Furthermore, the metallic card can be made of the same 
metal as that of the housing in which it is to be affixed. Thus, if 
housings 6 and 7 are contrived in objects made of gold, the card 1 will 
also be made of gold. This is significant; precious materials such as gold 
or platinum are chosen because of the very strict regulations for 
obtaining official stamps. Moreover, bearing in mind the very small 
dimensions which can be achieved, a typical example being a diameter of 5 
mm and a height of 0.5 mm, this label is particularly discreet. 
To mount the electronic label in housings 6, 7 as shown in FIGS. 3 and 4, a 
pre-adhered zone 8 can be provided on interface 3, allowing the label to 
be affixed within its housing by means of thermal bonding. 
FIGS. 2A-2D show some details of the possible interconnections between the 
different elements shown in FIGS. 1A and 1B. The metallic card 1 with its 
central hole 2, the interconnection interface 3 and the silicon substrate 
4 of the integrated memory circuit can be recognized. 
The integrated circuit 4 comprises two input/output conductors, the first 
connected to a central metallized zone 10, and the second connected to 
four peripheral metallized zones 11. It can thus be said that these two 
conductors are coaxial. The four peripheral zones 11 comprise four bumps 
12 facing opposite metallized zones of the printed circuit 3 which are 
galvanically connected to the metallic base card. Thus the integrated 
circuit 4 can be fixed to the interconnection interface 3 by means of 
thermocompression. 
The metallic card 1 is thus galvanically connected to the first conductor 
and contact can be established with this first conductor by means, for 
example, of a circular contact 15 made of conductive rubber, pressed 
against the metallic card. 
The adhesive thread 14, which is of non-conductive adhesive, serves solely 
to ensure the imperviousness and the solidity of the assembly. 
Furthermore, the interconnection interface 3 comprises at its center a 
contact element 16 facing opposite the central metallized zone of the 
integrated circuit 10. By using a connection interface 3 made of 
CAPTON.TM., a polymide insulator foil material with a certain flexibility, 
contact can be established with the metallized zone 10, and from there 
with the second conductor by inserting a spring contact 17 into the hole 
of the metallic card 2. 
To summarize, the input/output conductors of the integrated circuit can be 
accessed using the system of coaxial contacts 15, 17 mounted in an 
appropriate second probe. 
Other embodiments are of course possible. 
The interconnection interface 3 could be omitted, for example, and the 
integrated circuit 4 mounted directly on the card 1 by means of 
thermocompression. In this case, the central metallized zone 10 could be 
accessed directly with contact 17. However, the integrated circuit would 
then be in the open air, something which can only be contemplated in 
certain applications. 
Furthermore, it is known that in the majority of integrated circuits, the 
substrate can be connected to one of the input/output conductors 
conductor. Contact between this conductor and the card can therefore be 
obtained directly by laying a thread 14 of conductive adhesive and by 
removing the connection via the metallizations 11, the bumps 12 and the 
zones 13. 
The other elements of the electronic label according to the invention, 
particularly those relating to the characteristics of the actual memory, 
are known to the person skilled in the art and are therefore not described 
in detail. 
FIGS. 5 and 6 show another embodiment of the label according to the 
invention. In this case, the metallic card 20 is a card of a shape 
obtained by molding, for example. The edge of this card is bent at 90 
degrees so as to form a housing 21 in which the integrated circuit 4 is 
mounted in a similar manner as that used in FIG. 2. However, the 
integrated circuit does not comprise any central metallization, but four 
pads located at its periphery, the first two 22, 23 being connected to the 
first conductor and the last two 24, 25 to the second conductor. 
Pads 22 and 23 are soldered by thermocompression onto a printed circuit 26 
and connected to a contact zone 27 of this printed circuit. This contact 
zone can be connected by a drop of conductive adhesive 28 to the wall of 
the metallic card 20 which is thereby electrically connected to the first 
conductor. 
Pads 24 and 25, also soldered by thermocompression onto the printed circuit 
26, are connected to a central contact zone 29 of the printed circuit. 
This central contact zone is located on the two sides of the printed 
circuit, these two sides being connected via a metallized hole, for 
example. The lower portion of this contact zone 29 can thus be accessed 
with a point for electrical connection to the second input/output 
conductor. 
With this particular form of the metallic card, a resin can be poured into 
the housing after assembling the printed circuit. By doing so, a compact, 
perfectly protected component can be attained. 
In this example the partly conical shape of the hole 30 and the shape of 
the card is designed to allow the contact point to be guided. The 
particular shape also allows a cover 31 for protecting the contact to be 
attached.