FR2780534A1 - Fabrication method for portable objects incorporating electronic components, particularly non-contact smart cards - Google Patents

Abstract

The card is fabricated on a base (12) of thermoplastic material with a semiconductor chip (20) inserted into the base by hot pressing so that the top of the chip is flush with the surface of the card. A metaled deposit (28) on the top surface of the base forms an antenna. The base is then covered with a film (32) of a thermoplastic material so the chip and the antenna are covered

Description

The subject of the present invention is a method for producing one or more

  several portable objects with electronic components and a portable object with

  electronic components of the type obtained by implementing the method.

  More specifically, the invention relates to the simultaneous or individual production of a portable object with electronic components comprising a body, a semiconductor wafer provided with a range of

  contact, and metallizations forming an antenna.

  We know that alongside electronic memory cards of the type in which the connection between the circuits of the card and the reading and writing device is effected by ohmic contact, so-called contactless cards develop. In this type of cards, the exchange of information and energy between the circuits of the card and a read-write device is done by electromagnetic wave. Consequently, the card must include an antenna which is generally constituted by metallizations carried out on the body of the card. These metallizations are connected to the terminals or external contact pads of the semiconductor chip in which the integrated circuits of the card are produced. The antenna works of course in transmission and

also at reception.

  With the development of these cards, it is understood that it is necessary to use card manufacturing methods which are of an increasingly reduced cost while allowing obtaining cards without

high quality contact.

  The methods currently known do not prove to be completely satisfactory either because of their cost in the case where a semiconductor wafer fixed on a printed circuit element is used to make the module of the card, or because, to make the metallizations corresponding to the turns of the antenna, these are costly to produce or appear on the external face of the body of the contactless card and risk

therefore to be damaged.

  An object of the present invention is to provide a contactless card or more generally a portable object comprising a semiconductor patch and metallizations forming antenna which are of a reduced cost of realization, that is to say which requires little development stages

  while ensuring the maintenance of the qualities of the card during its use.

  The method of manufacturing a portable object with electronic components comprising a body, a semiconductor wafer provided with contact pads, and metallizations forming an antenna, characterized in that it comprises the following steps: - a wafer is provided of thermoplastic material having a first and a second face and a contour, - said semiconductor wafer is inserted into said wafer by hot pressing in such a way that the face of said wafer provided with contact pads is substantially flush with the first face of the wafer, - said metallizations forming antenna are carried out on said first face of the wafer, and - a sheet of thermoplastic material having the same contour as the wafer is fixed on said first face of the wafer, by

  whereby said sheet covers said antenna and said patch.

  It is understood that thanks to the provisions of the invention the manufacturing cost of the portable object is reduced since a semiconductor chip is used directly which is inserted into the material constituting the body of the card without requiring the use of a circuit printed and that the card has a high quality during use since the metallizations constituting the antenna are protected by the sheet of thermoplastic material which is fixed to the face of the plate comprising the antenna

  and the contact pads of the semiconductor wafer.

  Another object of the invention is to provide a method of producing a plurality of portable objects which is characterized in that it comprises the following steps: - a plate of thermoplastic material is provided which has first and second face, plate in which a plurality of zones are defined, each corresponding to a plate, said plates being all identical, each limited by a contour and being arranged in n rows and p columns, - is inserted into said plate, by hot pressing, a semiconductor wafer in each zone corresponding to a wafer, so that the face of the wafers provided with contact pads is substantially flush with said first face of the plate, said metallizations forming antenna are carried out on said first face of the plate in each zone corresponding to a plate, a sheet of thermoplastic material is fixed on said first face of the plate to cover at least all of said zones; and - the sandwich thus produced is cut along the contour of each of said zones, whereby n x p portable objects are obtained. It is understood that in this operation allowing the simultaneous manufacture of a large number of identical portable cards or objects, it is preferably carried out the insertion of the semiconductor pads simultaneously as well as the metallizations of the various portable objects, these metallizations preferably still being screen printed with a

conductive ink.

  The invention also relates to a portable object with electronic components, in particular of the contactless card type, which is characterized in that it comprises: - a body of thermoplastic material having a contour and a first and a second main face, the two faces being parallel between them, - a semiconductor wafer, a first face of which is provided with contact pads embedded in said body, said first face of the wafer being arranged in a plane parallel to said main faces, and - metallizations forming an antenna electrically connected to the pads of contact of said pad, said metallizations being

  substantially arranged in said plane.

  Other characteristics and advantages of the invention will appear

  better on reading the following description of several embodiments

  of the invention given by way of nonlimiting examples. The description is

  refers to the appended figures, in which: - Figures 1 to 5 illustrate a first embodiment of the portable object with electronic components, each portable object being manufactured individually; and FIGS. 6 and 7 illustrate a method of simultaneously producing a large number of portable objects, FIG. 6 being a top view and the

  Figure 7 a vertical sectional view along line VII-VII of Figure 6.

  Referring first to Figures 1 to 5, we will describe a first embodiment of the portable object, a contactless card in the

  special case of the description, in which each portable object is

made individually.

  We start from a plate 12 made of thermoplastic material having two main faces 14 and 16 as well as a contour 18. As best shown in FIG. 3b, the plate 12 has a length L and a

  width 1, the thickness of the plate being equal to e.

  In the next step, a semiconductor patch is provided in which the various electronic components necessary for the operation of the card are produced, this semiconductor patch 20 comprising a contact face 22 provided with external contact pads 24 and 26. The semiconductor wafer 20 has a thickness e 'which is of course less than the thickness e, this thickness e being itself less as will be explained later on the thickness E which the body of the object must have. portable. In the next step illustrated in FIG. 2, the semiconductor wafer 20 is inserted by hot pressing under conditions which are known per se. To allow this operation, PVC, polycarbonate or ABS can be used to make the plate 12, without this list being exhaustive. The hot pressing operation is carried out until the face 22 of the pellet

  semiconductor 20 is flush with the upper face 14 of the wafer.

  In the next step illustrated by FIGS. 3a and 3b, the metallizations 28 are produced on the upper face 14 of the wafer 12. These

  metallizations being intended to constitute the antenna of the portable object.

  As best shown in FIG. 3b, the metallization 28, in this embodiment, comprises two turns 28, and 282 and the latter of course has a first end 28a which is connected to the terminal 24 of the semiconductor wafer 20 and a second end 28b which must be connected to the second terminal 26 of the semiconductor wafer. In this embodiment, this electrical connection having to pass over the second turn 282, it is necessary to locally provide insulation 30 above the turn portion and subsequently a connection

  31 to connect the end 28b to terminal 26.

  Preferably, the metallization 28 forming the antenna is carried out

  by screen printing with conductive ink and it has 4 turns.

  In the next step shown in FIG. 4, a thermoplastic sheet 32 is prepared which has exactly the same dimensions as the wafer 12. This sheet 32 is fixed to the upper face 14 of the semiconductor wafer, that is to say -to say on its face which is provided with

  metallizations forming antenna and external contacts of the semi-patch

  conductive 20. This sheet 32 can advantageously be fixed by hot rolling. It could also be fixed by gluing. Of

  preferably, the external face 32a of the sheet 32 is provided with graphics 34.

  It is understood that the thickness el of the sheet 32 must be such that after the fixing operation, the total thickness of the wafer 12 and of the sheet 32 is exactly equal to the thickness E desired for the card body . It is understood that thus the semiconductor wafer and the metallizations forming

  antenna are completely embedded in the thermoplastic material.

  In a variant shown in Figure 5, there is provided an additional step which consists in fixing on the underside 16 of the wafer 12 a second sheet of thermoplastic material having exactly the same dimensions as the wafer 12, this second sheet 36 having a thickness e2 such that the total thickness of the sheets 32 and 36 and of the wafer 12 corresponds after the fixing operation exactly to the thickness E desired for the card body. It is possible to predict that

  the outer face 36a of the sheet 36 is provided with graphics 38.

  FIG. 3c illustrates an alternative embodiment in which the connection of the metallizations forming the antenna to the terminals of the semiconductor wafer is carried out differently from what is illustrated by the

Figure 3b.

  In this embodiment, the semiconductor patch 20 is partly outside the metallizations 28 'forming the antenna. This avoids that the connection of the end 28'b to the terminal 26 does not require the presence of a metallization passing "above" the turns. So there is

  no need to plan for an insulating layer.

  Referring now to Figures 6 and 7, we will describe a method of making portable objects with electronic components and in particular contactless cards which allows to simultaneously obtain a

  large number of such cards all identical.

  We start from a plate 100 of thermoplastic material of the same type as that which was used to make the plates 12 of FIGS. 1 to 5. This plate 100 has a width Il and a length L1 such that it can be defined in its faces main upper 102 and lower 104 n lines of p zones Zij each corresponding to the contour of a plate 12 defined in connection with FIGS. 1 to 5. From this plate 100 on which the contours have been defined such that 106 limiting the zones Zij, the semiconductor pads 12 are successively inserted at the desired locations in the Zij zones, the insertion being preferably carried out simultaneously then preferably still simultaneously, the metallizations 28 of each zone Zij are produced by screen printing to get the antennas. We then proceed to connect the second end of each metallization with the second terminal of each patch

  semiconductor as explained in connection with Figure 3b.

  Preferably, however, the insulating zone 30 and the connection metallization 31 for each portable object is produced separately and successively. We could also make the turns in accordance with the

figure 3c.

  When all of these operations have been carried out on the wafer, a sheet of thermoplastic material 110 is attached to the upper face 102 of the wafer 100 so that this sheet 110 covers at least all of the zones Zij. It is also possible as explained in connection with FIG. 5 to fix a second

  thermoplastic sheet 112 on the underside 104 of the plate 100.

  Then, it suffices to cut for example by stamping along the contours 106 the plate 100 to separate each body of portable objects from the rest of this plate 100 by which one obtains n x p portable objects

  typically contactless cards.

Claims (13)

  1. Method for producing a portable object with electronic components comprising a body, a semiconductor wafer provided with contact pads and metallizations forming an antenna, characterized in that it comprises the following steps: - a wafer is provided of thermoplastic material having a first and a second face and a contour, - said semiconductor wafer is inserted into said wafer by hot pressing in such a way that the face of said wafer provided with contact pads is substantially flush with the first face of the wafer, - said metallizations forming an antenna are produced on said first face of the wafer, and - a sheet of thermoplastic material having the same contour as the wafer is fixed on said first face of the wafer, whereby   said sheet covers said antenna and said patch.   2. Method according to claim 1, characterized in that said   metallizations are carried out by screen printing of a conductive ink.   3. Method according to any one of claims 1 and 2,   characterized in that a second sheet of thermoplastic material having the same outline as that fixed on the second face of said wafer said wafer.   4. Method according to any one of claims 1 to 3,   characterized in that each sheet is fixed by hot rolling.   5. Method according to any one of claims 1 to 3,   characterized in that each sheet is fixed by gluing.   6. Method according to any one of claims 1 to 5,   characterized in that said first sheet is provided with a graphic on its   side not facing said plate.   7. Method according to claim 3, characterized in that said second sheet is provided with a graphic on its face not turned towards said wafer.   8. Method for producing a plurality of portable objects with electronic components, each object comprising a body, a semiconductor wafer provided with contact pads and metallizations forming an antenna, characterized in that it comprises the following steps : - a plate of thermoplastic material is provided which has a first and a second face, a plate in which a plurality of zones are each defined corresponding to a plate, said plates being all identical, each limited by a contour and being arranged in n lines and p columns,   - a semi-pellet is inserted into said plate, by hot pressure   conductive in each zone corresponding to a wafer, so that the face of the pads provided with contact pads is substantially flush with said first face of the plate, - said metallizations forming an antenna are produced on said first face of the plate in each zone corresponding to a plate, - a sheet of thermoplastic material is fixed on said first face of the plate to cover at least all of said zones; and - the sandwich thus produced is cut according to the outline of each   said zones, whereby n x p portable objects are obtained.   9. Method according to claim 8, characterized in that a second sheet of thermoplastic material is fixed on the second face of said plate.   10. Method according to any one of claims 8 and 9,   characterized in that all the semiconductor pads are inserted simultaneously.   11. Method according to any one of claims 8 to 10,   characterized in that all metallizations are carried out simultaneously   by screen printing with conductive ink.   12. Method according to claim 11, characterized in that the connection of one of the contact pads of the pads to the metallization forming antenna is carried out successively and separately for each pastille.   13. Portable object with electronic components, characterized in that it comprises: - a body of thermoplastic material having a contour and a first and a second main face, the two faces being parallel to each other, - a semiconductor wafer, one of which first face is provided with contact pads embedded in said body, said first face of the patch being arranged in a plane parallel to said main faces, and - metallizations forming an antenna electrically connected to the contact pads of said patch, said metallizations being   substantially arranged in said plane.