FR2838220A1 - Chip card with an LCD type display, has the display mounted in an opening in the card body and covered with a transparent film, such that there is an air gap between film and display that allows flexing of the card - Google Patents

Abstract

Portable data support, especially a chip card (1) has a card body (6) in which a display (3) is mounted in an opening (2). The opening is covered with a transparent covering film (4) that is rigidly connected to the card. The covering film is placed at a distance from the display so that there is an air filled gap between the display surface and the covering film.

Description

(1 9).

  PORTABLE DATA SUPPORT WITH DISPLAY

  The invention relates to a portable electronic data carrier in the form of a card, in particular in the form of a smart card used as a credit card, check card, monetary card and the like, with a display and a card body provided a recess, in which the display is housed and which is covered with a

  transparent cover sheet rigidly connected to the card body.

  A smart card of the above kind is for example known from US-A-4 77 542.

  In this document, the display is connected to a main conductive plate on which are placed other electronic components, in particular integrated circuit chips and it is then inserted with the main conductive plate in a card frame. The card frame is then covered by gluing on the two faces and the entire surface by covering sheets. The cover sheet applied to the front of the display is transparent in the display area. The usual flat displays used in the card technique are more or less sensitive to the flexural and pressure stresses exerted on the display surfaces and the functional display layers. This problem arises in particular for cards in which the display is arranged unprotected on the surface of the cards. Flat displays for use in card art are typically constructed from plastic substrates, in particular POT (polyethylene terephthalate) substrates in place of fragile glass substrates and can be used as a crystal LCD display liquids, i.e.

  whether they comprise layers of liquid crystals or of polymer liquid crystals.

  Such displays can be irreversibly degraded by pressure surges, the stability of the indication being then lost. This also applies to the smart card displays mentioned above and which are covered with a layer

  card overlay.

  The object of the present invention is precisely to provide a stable smart card, in particular a display smart card which is largely insensitive to

with regard to pressure surges.

  This objective is achieved by means of a portable data carrier, in particular a smart card, with a display and a card body and a recess in which the display is housed, the recess being covered with a transparent and binding cover sheet. rigidly to the card body, and in which the cover sheet is placed at a distance from the display, so that it remains between the

  display surface and cover sheet an air gap.

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  Alternatively, the recess is made multi-stage and has a support shoulder on which is placed the transparent cover sheet, of

  so that it closes flush with the surface of the card body.

  Alternatively, the transparent cover sheet is partially printed. According to a variant, the display is made up of several display segments

  which are housed independently of each other in the recess.

  According to a variant, the transparent cover sheet is made as a molded or cast part, with ribs directed towards the inside of the card and

  o which form chambers to receive at least one display segment.

  According to a variant, the display is inserted into the recess by the face of the body

  opposite the cover sheet in the recess.

  Alternatively, the display is mounted floating in the recess.

  Alternatively, the display is mechanically connected to the data carrier, only by electrical contacts. Alternatively, the electrical contacts are made by the flip chip technique. Alternatively, the electrical contacts are made by an adhesive

electrically conductive.

  According to a variant, the display has in the recess the structure of a

  monobloc component of the data carrier.

  Other purposes, advantages and characteristics will become apparent from reading the

  description of various embodiments of the invention, given without limitation and

  with reference to the appended drawing, in which: FIG. 1 represents a smart card with integrated display; 2 shows the smart card of Figure 1, partially and in cross section, under the action of a pressure load; Figure 3 shows the smart card of Figure 1, partially and in cross section, under the action of a bending load; Figure 4 partially shows a printed cover sheet for display; Figures 5 to 8 show various embodiments of a floating display; and FIG. 9 represents a smart card, partially and in cross section,

  with a display produced by segment.

  The object of the invention is achieved by means of a portable data medium, in particular a smart card of the kind indicated at the start, and in which the covering sheet is placed at a distance from the display, so that it remains entre la R: \ Brevets \ 20800 \ 20BX6.doc 2g rrars 2003 - 2/10

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  display surface and cover sheet an air gap. Any pressure loads on the cover sheet in the display area are then not transmitted to the display. On the contrary, the cover sheet is bent in the recess receiving the display by reducing the width of the gap, and the pressure forces are laterally deflected inside the cover sheet and are transmitted to the body. Map. The air gap and / or the flexural strength of the cover sheet in the display area should be chosen so that the typical pressure loads during the daily use of the data carrier lead only to reduce the gap width but not to contact between the cover sheet and the display. According to a particular preferred embodiment, the display is mounted floating in the recess of the card body, that is to say without other mechanical fixing in the recess, and it is thus mechanically connected to the data carrier only by the electrical contacts. It is thus obtained that the display is also protected at the limits with regard to the bending stresses which may appear on the card during the bending of the card body. The bending stresses are then not directly transmitted to the display due to the floating mounting of the latter. The electrical contacts can be made by the flip-chip technique or by a

  electrically conductive adhesive.

  According to another embodiment of the invention, the display consists of several display segments which are housed independently of each other in the recess and thus constitute only a fraction of the surface of the complete display. Such small display segments are practically 2 ins insib the flexural stresses acting on the card body. They may be better protected against pressure loads. For this, the transparent cover sheet is advantageously made as a cast or molded part with ribs or bars directed towards the inside of the card and which form chambers for receiving at least one display segment. The pressure loads are partially or completely supported by the ribs between the display elements and are led to the base of the recess in which are

mounted display elements.

  The covering sheet is advantageously integrated into the card on the display, like a window (window); To this end, the recess in the card body is made multi-stage and has a support shoulder, on which the transparent cover sheet (glass) is placed so that it closes the surface of the body flush. Map. This has the advantage that the display, which is the most sensitive electronic component of a smart card, is placed at a R: \ Brevas \ 20800 \ 20886.doc - 28 rnas 2003 - 3/10

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  as late as possible in the manufacturing process and should only then be covered by the transparent glass again. Another advantage is to be considered in the fact that the material for the transparent glass can be chosen relatively freely and can be optimized with regard to its printing load properties, while the surface material of the card to chip surrounding the transparent glass can be optimized for trouble-free printing. The sheet of

  transparent cover can be partially printed.

  The protection window integrated in the card also opens the possibility of successively constructing the individual layers of the display for the completion of the manufacturing process in the recess and finally to finish

  cover the display again through the protective window.

  According to yet another embodiment of the invention, the display is inserted

  in the recess by the face of the card body opposite the covering sheet.

  The display may also have in the recess the structure of a one-piece component of the data carrier. FIG. 1 represents a smart card according to the standard, in ID1 format, with a display 3 integrated in a recess 2. The recess 2 is made stepped and has a support shoulder 5, on which is applied as glass protection a transparent cover sheet 4 covering the display 3. The protective glass 4 is glued to the support shoulder 5 and completely closes the recess 2. The protective glass 4 simultaneously closes the surface of the card chip 1 flush. In Figure 2, the card body 6 of the smart card 1 is shown

  schematically with the recess 2, partially and in cross section.

  The display 3 is arranged in the recess 2 of the card body 6 so that there remains between the protective glass 4 and the display 3 an air gap 7. Under the effect of a pressure load in the direction of the arrow, the protective glass 4 deforms in the recess 2 inwards, which reduces the depth of the interval 7. It can be seen that the display 3 is largely protected against pressure loads external thanks to the interval 7. The protective glass 4 can be constituted with usual materials for the card sheets, such as for example plastics PVC, ABS, PET (polyethylene terephthalate), PC (polycarbonate), these materials can be stable in pressure in correspondence with an appropriate choice of additives. The card body 6 can be produced with a single layer 3s or multilayer, for example by a pressure molding process or by a lamination process or by a combination of the two processes, also with

  from the usual card materials.

  A: \ Patents \ 20800 \ 20886.doc - 28 rr 2003 - 4/10 s 2838220 The display 3 can be glued into the recess 2 under the form of a display module. As a variant, the function layers, of which the display 3 is composed, are

  constructed in the recess 3 during the preparation of the card.

  It is particularly advantageous for the display 3 to be mounted floating in the recess 2. The display 3 is thus protected at the limits against the bending stresses acting on the card, as shown in FIG. 3. The "floating assembly" means that the display, regardless of electrical contact, is not fixed

  mechanically in any way at the recess 2.

  FIG. 4 shows a display 3, the protective glass 4 of which is provided with a print, so that the separate display segments are framed individually. Such a frame impression is advantageous for covering the control conductors which conduct a control electrolyte to the individual display segment, and if necessary for covering the control electronics itself. The control electronics are frequently provided at the same time as the display on a substrate. Printing can also provide

information that cannot be changed.

  In Figures 5 to 8 are shown examples of embodiments

  for a floating display 3.

  FIG. 5 represents a card body 6 produced in multi-layers and whose

  individual layers are firmly connected to each other by an adhesive joint.

  The display 3 has bosses 9 on its rear face to ensure the contact of the display with other electronic components in the card body. The bosses 9 are contiguous with contact surfaces 10, which are components of a conductive insert 11 disposed inside the card and which protrude into the recess 2 of the card body 6. The contact is made of simple way using the flip-chip technique. The bosses 9 are connected by contact to the conductive layers of the display 3 located on the opposite face of the display substrate. According to a final process step, the protective panes 4 are applied to the recess 2 by the support shoulder 5, the protective panes 4 being for example brought to

  The pre-cut condition on a conveyor or transtert belt.

  In Figure 6, a smart card corresponding to Figure 5 is shown, but with another card body structure. In this case, the card core is produced in a single layer with each time a covering layer on the upper face and the lower face, the covering layer comprising an opening.

  to receive the protective glass 4.

  Another embodiment according to FIG. 7 differs from the embodiment according to FIG. 6 in that, instead of the protective glass 4, only provided in the region of the recess, a layer of R ( Patents \ 20S00 \ 20886.doc - 28 tnars 2003 - 5/10

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  transparent upper cover 12 extending over the entire surface. We can thus shorten the manufacturing process. In this case, compromises must be made regarding the choice of materials, in order to guarantee on the one hand sufficient pressure stability in the display area, and on the other hand, good optical quality in the area contiguous graphics of the smart card. FIG. 8 represents an alternative embodiment, in which the display 3 is inserted from the rear face of the card body into the recess 2, which, on the front face, is already equipped with the protective glass 4, or respectively of the transparent cover sheet 12. The contact of the display 3 with the 0 contact surfaces of the insert 11 of the conductive track is carried out in a simple manner by means of a conductive adhesive 13. In this variant of embodiment, the display 3 is inserted according to a last process step in the chip card, which is also already prepared, so that the risk of degradation of the sensitive display, by a next process step, is excluded. The conductive adhesive 13 is advantageously an anisotropic conductive adhesive, in order to avoid an electrical short circuit between the neighboring contacts, due to lateral twists of the conductive adhesive. The control electronics are advantageously integrated into the display, which makes it possible to reduce the numerous parallel connection conductors of the individual display segments, to a few serial connection conductors to the central processing unit chip CPU of the card chip. The expenses for establishing the contact of the display 3 on the contact surface of the insert 11 of the conductive tracks in all the embodiments described above are thus

significantly reduced.

  2s FIG. 9 represents an advantageous development of the invention, with which the stresses of pressure and bending can be kept distant from the display 3, in a particularly important way. For this purpose, the display is subdivided into separate individual display segments 14. Each display segment can be considered as a mini display and therefore presents only a fraction of the size of the complete display, which is consists of the sum of the display segments 14. A display with five positions and seven segments according to FIG. 4 would for example be subdivided into five individual segments 14 of display with seven segments or mini display. Due to the relatively small size of the display segments 14, these are relatively

insensitive to bending loads.

  The segmented display with the protective glass 15 shown segmented in FIG. 9 allows particularly effective protection with respect to pressure loads. The protective glass 15 completely fills the recess 2 in the body R: U3reYets \ 20800 \ 20886 doc - 28 rrrars 2003 6/10

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  card 6, but forms chambers 17 separated from each other by ribs 16 and in each of which is received a display segment, where appropriate also are received several display segments, which are advantageously mounted floating. Any pressure loads on the surface of the segmented protective glass 15 are partially or completely transmitted by the ribs 16 to the base surface 18 or to the corresponding shoulders (not shown) of the recess 2. The protective glass can be performed as a

  molded or cast part, for example by injection molding.

  Of course, the present invention is not limited to the embodiments lo described and shown, but on the contrary embraces all variants easily

accessible to those skilled in the art.

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Claims (9)

  1. Portable data carrier, in particular smart card (1), with a display (3) and a card body (6) and a recess (2) in which is housed the display (3), the recess (2) being covered with a transparent cover sheet (4) and rigidly connected to the card body (6), characterized in that the cover sheet (4) is placed at a distance from the display (3), so that it subsists   between the display surface and the cover sheet (4), an air gap (7).   0 2. Data carrier according to claim 1, wherein the recess (2) is made multi-stage and has a support shoulder (5) on which is placed the cover sheet (4) transparent, so that '' it closes so   flush with the surface of the card body.   3. Data carrier according to claim 2, wherein the sheet of   transparent cover (4) is partially printed.   4. Data carrier according to one of claims 1 to 3, wherein   the display (3) consists of several display segments (14) which are housed   independently of each other in the recess (2).   5. Data carrier according to claim 4, wherein the transparent cover sheet (4) is produced as a molded or cast part, with ribs (16) directed towards the inside of the card and which form chambers.   2s (17) to receive at least one display segment (14).   6. Data carrier according to one of claims 1 to 5, wherein   the display (3) is inserted into the recess (2) by the face of the card body (6)   opposite the cover sheet (4) in the recess (2).   7. Data carrier according to one of claims 1 to 6, in which   the display (3) is mounted floating in the recess (2).   S. Data carrier according to claim 7, wherein the display (3) is mechanically connected to the data carrier, only by contacts electric (9; 13).   R: \ Brovets \ 20800 \ 20886.doc - 28 rnars 2003 - 8/10 9 2838220   9. Data carrier according to claim 8, wherein the contacts   electrical (9) are produced by the flip-chip technique.   10. Data carrier according to claim 8, wherein the contacts   s electrical (13) are made by an electrically conductive adhesive.   11. Data carrier according to one of claims 1 to 5, in which   the display (3) is designed as a one-piece component of the data carrier (1) in the obvious (2).