EP2743952B2 - Contactor for thin plastic card - Google Patents

Description

The present invention relates to an electrical contactor for a thin plastic card, such as a microcircuit card.

In the field of microcircuit cards, it is advantageous to place an electric contactor in the thickness of a thin plastic support card in order to be able to control a function. This electric switch is typically actuated by a support, for example digital, on a determined area of the thin plastic card.

It is known to produce an electrical contactor in a thin plastic card by means of an insert incorporated in said thin plastic card, as one of the constituent layers, assembled by rolling. Given the conditions of pressure and rolling temperature, it is difficult to cleanly and safely roll such inserts. Moreover, such an embodiment leads most often to an electric contactor appearing in overthickness and therefore visible and revealing the presence of such an electric contactor and its location, which one wishes to avoid for security reasons. The document " FR 2 949 639 A1 "discloses an electrical contactor and its manufacturing method according to the preamble of claim 1 and 9.

The present invention overcomes these various disadvantages by providing an electric switch incorporated after the rolling step, in a thin plastic card and substantially invisible manner.

The subject of the invention is an electrical contactor for a thin plastic card comprising two terminals and a conductive element able to move relatively, so as to occupy a first position where the two terminals are isolated or a second position where the conductive element performs a contact between the two terminals, the two terminals being integral with an elastically deformable membrane, to allow movement from the first position to the second position under the effect of a support and an automatic opposite movement, when said support ceases.

According to the invention, the conductive element comprises a capsule, substantially hemispherical, whose concavity faces the two terminals.

According to another characteristic of the invention, the capsule is disposed in a cavity made in the thickness of the thin plastic card and the elastically deformable membrane closes the cavity.

According to another characteristic of the invention, the axis of the capsule is substantially perpendicular to the elastically deformable membrane.

According to another characteristic of the invention, the terminals are arranged relatively to the axis of the capsule, substantially symmetrically to one another.

According to another characteristic of the invention, the capsule is shaped such that a height, measured between the top of the capsule and at the right of a terminal, is greater than a height of a terminal relative to the elastically deformable membrane.

According to another characteristic of the invention, the capsule is elastic and can take a free form in the absence of support and a compressed form under the effect of a support.

According to another characteristic of the invention, a height, measured between the top of the capsule and at the right of a terminal, is less than a height of a terminal relative to the elastically deformable membrane, when the capsule is in its shape. compressed.

According to another characteristic of the invention, the capsule comprises a nipple at its top.

The invention also relates to a method for manufacturing a contactor for a thin plastic card comprising the following steps: machining a cavity in the thickness of the thin plastic card, depositing a conductive element in the cavity, making two terminals in an elastically deformable membrane by positive or negative etching, closing the cavity by placing and bonding the elastically deformable membrane.

According to another characteristic of this method, the conductive element comprises a substantially hemispherical capsule whose concavity faces the two terminals.

According to another characteristic of the invention, the capsule is shaped such that a height, measured between the top of the capsule and at the right of a terminal, is greater than a height of a terminal relative to the elastically deformable membrane.

According to another characteristic of the invention, the capsule is elastic and can take a free form in the absence of support and a compressed form under the effect of a support.

According to another characteristic of the invention, a height, measured between the top of the capsule and at the right of a terminal, is less than a height of a terminal relative to the elastically deformable membrane, when the capsule is in its shape. compressed.

According to another characteristic of the invention, the capsule comprises a nipple at its top.

• la figure 1, respectivement la figure 2, représente, en vue coupée de profil, un contacteur électrique selon un premier mode de réalisation, en position ouvert, respectivement en position fermé,
• la figure 3 représente, en vue coupée de profil, un contacteur électrique selon un deuxième mode de réalisation, en position ouvert,
• la figure 4 représente, en vue coupée de profil, le contacteur électrique de la figure 3, selon une première position fermé,
• la figure 5 représente, en vue coupée de profil, le contacteur électrique de la figure 3, selon une deuxième position fermé,
• la figure 6, respectivement la figure 7, représente, en vue coupée de profil, un contacteur électrique selon un troisième mode de réalisation, en position ouvert, respectivement en position fermé.

Other characteristics, details and advantages of the invention will emerge more clearly from the detailed description given below as an indication in relation to drawings in which:

• the figure 1 , respectively figure 2 , shows, in sectional view, an electric contactor according to a first embodiment, in the open position, respectively in the closed position,
• the figure 3 represents, in sectional view, an electric contactor according to a second embodiment, in the open position,
• the figure 4 represents, in a sectional view, the electric switch of the figure 3 in a first closed position,
• the figure 5 represents, in a sectional view, the electric switch of the figure 3 in a second closed position,
• the figure 6 , respectively figure 7 , shows, in sectional view, an electric contactor according to a third embodiment, in the open position, respectively in the closed position.

It may be useful to have an electric contactor 1 in a thin plastic card 10. A thin plastic card 10 designates a card made of plastic, substantially flat, and whose dimensions in the plane are of the order of a few tens of millimeters for a thickness of the order of a millimeter. Such a thin plastic card 10 can serve as a support for a microcircuit card. Such a thin plastic card 10 is for example defined by the ISO 7810 standard. Such a microcircuit card can be used as a bank card, identity card or telephone subscription card or any other equivalent application.

An electric switch 1 can in such a frame serve to control a function. The electric switch 1 can thus, for example, make an opening / closing of an antenna loop. Thus said antenna loop is activated when the electric switch 1 is closed. In the case of a microcircuit, such an antenna loop can be used to supply energy to said microcircuit by induction. Such a power supply makes it possible to "wake up" the microcircuit which can then begin the execution of its resident program. The presence of an electric switch 1 to control this power function ensures that the microcircuit is activated voluntarily and not as soon as it is within range of an induction power supply.

An electric contactor 1 can be further interfaced with a microcircuit to which it then provides a logical state information, a function of the open or closed position of the electric switch 1. Such a state, can thus allow, from the outside, to modify the progress of the microcircuit program. It is still possible to have several such electrical contactors 1 on the same card 10.

Such an electric switch 1 typically comprises two terminals 2 for connecting it, as a dipole, to an electrical circuit and means for selectively making or not an electrical contact between these two terminals 2, to selectively open or close said electrical circuit. This means can, according to a type of contactor, comprise a conductive element 3. The terminals 2 and said conductive element 3 are able to move relative to one another between two positions 11, 12. In a first position 11 , where the electric switch 1 is said to be open, the two terminals 2 are electrically isolated. In a second position 12, where the electric switch 1 is said to be closed, the conductive element 3 makes an electrical contact between the two terminals 2, which are then electrically connected.

According to an embodiment more particularly illustrated in the figure 1 in open position 11 and at the figure 2 in the closed position 12, the electric contactor 1 is characterized in that the two terminals 2 are integral with an elastically deformable membrane 4.

This elastically deformable membrane 4 is for example made of plastic. This advantageously makes it possible to provide electrical isolation between the two terminals 2.

Such a plastics material can also advantageously produce a deformability characteristic which thus allows movement from the first position 11, illustrated in FIG. figure 1 , to the second position 12, illustrated in figure 2 . This displacement allows a mobilization of the terminals 2 which can come into simultaneous contact with the conductive element 3, and thus make the electrical contact between the two terminals 2.

The deformability of said membrane 4 is still advantageously elastic so that it can spontaneously return to a rest position.

A rest position is for example illustrated at the figure 1 where it corresponds to an open position 11. A support 13 applied to the membrane 4, in cooperation with a free space 5 under the said membrane 4, allows a deformation of the membrane 4 to reach a closed position 12 of the figure 2 , bringing the two terminals 2 in contact with the conductive element 3. The membrane 4 being elastic, spontaneously and automatically returns to the rest position 11 when the support 13 ceases.

It is thus realized an electric contactor 1 monostable, opened by default, also called normally open.

The support 13 realizing the deformation of the membrane 4 and the change of position of the contactor 1 is made by any means or tool. However, it is advantageously sized to be realized with a finger.

The embodiment of the plastic membrane 4 advantageously makes it possible to integrate such a membrane 4 as an additional partial or complete layer of a thin plastic card 10.

This is particularly advantageous in that it is thus possible to completely confuse and align the membrane 4 with the external surface of the card 10. This advantageously makes it possible to make the electric switch 1 completely undetectable, at least visually, which adds to the security of the commanded function.

The membrane 4 may be made of any plastic material. Preferably, the polyethylene terephthalate PET is particularly adapted to the elastic deformability needs of the membrane 4. In addition, the PET assembles very well by gluing or welding with all the materials usually envisaged to make a thin plastic card. 10.

The two terminals 2 have any shape. They are preferably, relative to the membrane 4, slightly projecting towards the conductive element 3.

The conductive element 3 is at least conductive between the two contact points 3b respectively with the two terminals 2. For this it can be made of metal material, covered plastic material, at least between the two contact points 3b with the two terminals 2 of a continuous conductor, such as, for example, an etched track or a metallization, either at the surface or in the mass of element 3.

According to the invention, the conductive element comprises a substantially hemispherical capsule 3, whose concavity 3a faces the two terminals 2.

According to an advantageous embodiment, the conductive element 3 is disposed in a cavity 5 made in the thickness of the thin plastic card 10. The elastically deformable membrane 4 then serves as a closure and closes the cavity 5 while maintaining the conductive element 3 in place. The outer surface of the membrane 4 merges advantageously, in that it is aligned with or replaces, the outer surface of the thin plastic card 10.

Advantageously, the axis 7 of said capsule 3 is substantially perpendicular to the membrane 4.

Advantageously, the terminals 2 are disposed relatively to the axis 7 of the capsule 3, substantially symmetrically to one another. Such an arrangement advantageously allows simultaneous contact of a first terminal 2 with the capsule 3 and a second terminal 2 with the capsule during a support 3.

For the same reasons, the capsule 3 is advantageously symmetrical. The axis 7 is then an axis of symmetry for said capsule 3.

According to a preferred embodiment, the capsule 3 has a shape of revolution about the axis 7. The axis 7 is then an axis of revolution for the capsule 3.

As illustrated in Figures 1 and 2 capsule 3 does not necessarily occupy the entire height of cavity 5.

As illustrated in Figures 3, 4 and 5 capsule 3 does not necessarily occupy the entire width of cavity 5.

In the two previous cases, in order to avoid any movement of the capsule 3, which may risk placing it in a position where it could no longer come into contact with the terminals 2, the capsule 3 can be fixed, for example by gluing, in the cavity 5.

According to an advantageous embodiment, the dimensions of the capsule 3 are substantially of the same order that the dimensions of the cavity 5, to avoid having to resort to such a fixation, while allowing a movement of the capsule 3, to a degree that does not risk compromising its function as a conductive element 3. All illustrated examples to the Figures 1-7 satisfy this requirement. Thus the step of placing the conductive element 3 in the cavity 5 is limited to a deposit of said conductive element 3.

According to another advantageous characteristic, more particularly illustrated with the embodiments of the figures 3-5 and 6-7 the capsule 3 is shaped in a particular way. In this way, the capsule 3 has, at its vertex 6, a protuberance adapted to come into contact with the inner wall of the membrane 4. This protuberance has a dimension 8 measured in a direction parallel to the axis 7 greater than the height 9 of a terminal 2 in excess relative to said inner wall of the membrane 4. The height 8 is measured between a plane parallel to the inner wall of the membrane 4 passing through the top 6 of the capsule and a point 3b, at right of a terminal 2, where a terminal 2 comes into contact with the capsule 3.

Thus, even in the case where the capsule 3 is not fixed in the cavity 5, and where its height is less than the depth of the cavity, which allows a certain vertical movement of the capsule 3 in the cavity 5, the protrusion formed at the top 6 of the capsule 3 is adapted to come into contact, along the axis 7, with the inner wall of the membrane 4, and before one of the terminals 2 come into contact at 3b with the capsule 3. A contact at point 3b is not possible as long as the membrane 4 remains flat. Such contact between terminals 2 and capsule 3 requires at least one deformation of the elastically deformable membrane 4.

Such a deformation of the membrane 4 can then take place around the top 6 of the capsule 3, as illustrated in FIG. figure 4 , in order to allow each of the terminals 2 to come into contact with the capsule 3 on each of its sides.

Such deformation of the membrane 4 can still, as illustrated in figure 5 , accompanied by a deformation of the capsule 3, which thus contributes to facilitating the making of a contact between the two terminals 2 via the capsule 3.

According to an important feature of the present invention, the capsule 3 is elastically deformable. In contrast to the membrane 4 which is continuously deformable, the deformation of the capsule 3 is advantageously bistable and comprises two preferred extreme shapes. A first form comprises a free form 14, stable, corresponding to a rest state of the capsule 3, is obtained in the absence of stress exerted on the capsule 3 and in particular in the absence of a support 13. A second form comprises a compressed form 15, corresponding to a constrained state of the capsule 3, is obtained under the effect of a support 13, typically in the direction of the axis 7.

Two examples, showing two corresponding free 14 and compressed forms of the same capsule 3, are presented compared to the figure 5 and separately to Figures 6-7 .

The advantages of a capsule 3 having a bistable deformation in two forms 14, 15 are multiple.

Given the thickness of the electric contactor 1, less than the thickness of a thin plastic card 10, of the order of a few millimeters, and preferably between 0.5 and 1 mm, it is difficult to perceive a movement of the membrane 4 under the effect of the support 13 exerted by a finger and therefore to know if the electric switch 1 is actually closed or not. On the other hand, a bistable deformable capsule 3 advantageously passes, relatively abruptly, under the effect of a support 13, from a free form 14 to a compressed form 15. This passage from a free form 14 to a compressed form 15 is accompanied by a shock, advantageously felt by a finger performing the support 13. Thus the capsule 3 contributes to produce a clear tactile sensation, informing by force feedback, the actuation of the electric switch 1 and so its effective state, here closed.

According to the material constituting the capsule 3, typically made of metal, for example aluminum, but also of plastic material (then metallized to ensure the function of electrical conductor), the passage from a free form 14 to a compressed form 15 'still advantageously accompanies an audible' click '. Thus the capsule 3 contributes to producing a sound return, informing the actuation of the electric switch 1 and thus its effective state, here closed.

It may also be noted that during the reverse passage, from the compressed form 15 to the free form 14, the tactile feedback and the sound return are still present, and inform the non-actuation of the electric contactor 1 and therefore of its effective state, here open.

Another advantage of a capsule 3 having a bistable deformation is its elasticity. Such a capsule 3 spontaneously returns to its free form 14 when the support 13 ceases. In doing so it accompanies and assists the membrane 4 in its movement back to its rest position.

According to an advantageous characteristic of the shape of the capsule 3, it has been seen that the height 8 measured between the apex 6 of the capsule 3 and at the right of a terminal 2, is advantageously greater than a height 9 of a terminal 2 relative to the elastically deformable membrane 4, in order to keep the terminals 2 away from the capsule 3 in the open position. This condition is advantageously achieved in the open position, the capsule 3 being in its free form 14.

According to an advantageous characteristic, when the capsule 3 passes in its compressed form 15, this condition is reversed, the height 8 'measured between the top 6 of the capsule 3 and at the right of a terminal 2, becoming advantageously less than the height 9 of a terminal 2 relative to the elastically deformable membrane 4, in this case to promote contact between the terminals 2 of the capsule 3 in the closed position. Also the deformation of the capsule 3 between two distinct and remote forms favors the change of position of the electric switch 1 between a open position and a closed position and vice versa. In other words, the bistable deformation of the capsule 3 advantageously allows a retraction of the protuberance of the top 6 of the capsule 3 and the inversion of the protuberance condition.

It is notable however that the change of position of the electric switch 1 between the open 11 and closed 12 positions does not necessarily coincide with the change in shape of the capsule 3. As illustrated in FIG. figure 4 the deformability of the membrane 4 may be sufficient for the terminals 2 to come into contact with the capsule 3 again in its free form 14. However, even in this case the support 13 then causes a change of shape of the capsule 3. This shape change follows in this case the change of position of the electric switch 1. On the contrary, as illustrated in the figure 5 , the change of shape of the capsule 3 to a compressed form 15 may be necessary for the establishment of a contact between the terminals 2 and the capsule 3. In this case, the change of shape of the capsule 3 precedes the change of position of the electric contactor 1.

According to another advantageous characteristic, more particularly illustrated in the Figures 6 and 7 , the capsule 3 comprises a stud 16, at its top 6. Such stud 16 reinforces the protuberance of said vertex 6 while limiting the extent in the plane of the card 10. Thus, such a stud 16 advantageously allows to achieve more easily the condition of protuberance and its inversion. In the free form 14 said pin 16 facilitates the realization of the condition: the height 8, more particularly illustrated in the figure 6 , is greater than the height 9. The pin 16 is located in the center of the capsule 3 and thus in the area where the support 13 is made. This favors the passage in compressed form 15. Thus, the stud 16 promotes reversal. of the protuberance condition. In the compressed form 15, the condition is reversed: the height 8 ', more particularly illustrated in FIG. figure 7 , becomes lower than height 9.

Said pin 16, accentuating the difference between the free form 14 and the compressed form 15, while ensuring the shape change in a smaller space in the plane of the card 10, advantageously allows to bring the two terminals 2 in the same plane and therefore one of the other . This contributes to making it possible to produce an electrical contactor 1 of dimensions, in this same plane, very small, while maintaining a good separation between the two open and closed positions 11 and 12.

The present invention also relates to a method of manufacturing such an electrical conductor 1 for thin plastic card 10. This method comprises a first step of machining a cavity 5 in the thickness of a thin plastic card 10. The card thin plastic 10 is assumed previously carried out in the usual manner by rolling different layers. Then, the cavity 5 is made by machining a cut, advantageously non-emerging, in the thickness of said thin plastic card 10. Such a procedure is particularly advantageous, in that it makes it possible to avoid resorting to an integrated insert during rolling. In doing so, it avoids the components of the electric contactor 1 to undergo the pressure and temperature constraints associated with the rolling operation.

Then, a conductive element 3 / a capsule 3 is placed in the cavity 5. As discussed above, the conductive element 3 may, during this step, be glued or otherwise fixed by any means in the cavity 5. However, a conformation and dimensions of the conductive element 3 adapted to those of the cavity 5 can allow to leave the conductive element 3 free in the cavity 5 and thus avoid a fixing step.

In parallel the terminals 2 are made associated with an elastically deformable membrane 4. For this, an etching technique, those known in the field of printed circuit manufacturing, is advantageously used. Such an etching may be positive: deposition of material corresponding to the terminals 2 or negative: removal of material does not correspond to the terminals 2. A plastic membrane 4 is adapted to receive such an etching. The PET preferentially used supports such an etching.

The cavity 5, equipped with the conductive element 3 can then be closed by placing the elastically deformable membrane 4, the terminals 2 facing the cavity 5. Said membrane 4 is typically held in place by gluing, on all or part of the upper surface of the thin plastic card 10. As illustrated in the figures, a counterbore can be provided so that no difference in thickness appears on the outer surface of the thin plastic card 10.

Claims (14)

1. Electrical contactor (1) for thin plastic card (10) comprising two terminals (2) and a conductor element (3) suitable for being displaced relatively, so as to occupy a first position (11) in which the two terminals (2) are isolated or a second position (12) in which the conductor element (3) makes a contact between the two terminals (2), characterised in that the two terminals (2) are securely fixed to an elastically deformable membrane (4), in order to allow a displacement from the first position (11) to the second position (12) under the effect of a press (13) and an automatic opposite displacement, when said press (13) ceases, and in which the conductor element comprises a capsule (3), substantially hemispherical, the concavity (3a) of which faces the two terminals (2).
2. Contactor according to claim 1, in which the capsule (3) is positioned in a cavity (5) produced in the thickness of the thin plastic card (10) and in which the elastically deformable membrane (4) blocks the cavity (5).
3. Contactor according to either one of claims 1 and 2, in which the axis (7) of the capsule (3) is substantially at right angles to the elastically deformable membrane (4).
4. Contactor according to claim 3, in which the terminals (2) are positioned, relative to the axis (7) of the capsule (3), substantially symmetrically to one another.
5. Contactor according to any one of claims 1 to 4, in which the capsule (3) is formed in such a way that a height (8), measured between the summit (6) of the capsule (3) and vertically in line with a terminal (2), is greater than a height (9) of a terminal (2) relative to the elastically deformable membrane (4).
6. Contactor according to any one of claims 1 to 5, in which the capsule (3) is elastic and can take a free form (14) in the absence of a press (13) and a compressed form (15) under the effect of a press (13).
7. Contactor according to any one of claims 1 to 6, in which a height (8), measured between the summit (6) of the capsule (3) and vertically in line with a terminal (2), is less than a height (9) of a terminal (2) relative to the elastically deformable membrane (4), when the capsule (3) is in its compressed form (15).
8. Contactor according to any one of claims 1 to 7, in which the capsule (3) comprises a dog point (16) at its summit (6).
9. Method for manufacturing (20) a contactor (1) for thin plastic card (10) comprising the following steps:

   - machining (21) of a cavity (5) in the thickness of the thin plastic card (10),

   - deposition (22) of a conductor element (3) in the cavity (5),

   characterised by the following steps:

   - production (23) of two terminals (2) in an elastically deformable membrane (4) by positive or negative etching,

   - closure (24) of the cavity (5) by the fitting and bonding of the elastically deformable membrane (4).
10. Method according to claim 9, in which the conductor element comprises a substantially hemispherical capsule (3), the concavity (3a) of which faces the two terminals (2) .
11. Method according to claim 10, in which the capsule (3) is formed in such a way that a height (8), measured between the summit (6) of the capsule (3) and vertically in line with a terminal (2), is greater than a height (9) of a terminal (2) relative to the elastically deformable membrane (4).
12. Method according to either one of claims 10 and 11, in which the capsule (3) is designed so as to be elastic capable of assuming a free form (14) in the absence of a press (13) and a compressed form (15) under the effect of a press (13).
13. Method according to claim 12, in which the capsule is put in place and formed such that a height (8), measured between the summit (6) of the capsule (3) and vertically in line with a terminal (2), is less than a height (9) of a terminal (2) relative to the elastically deformable membrane (4), when the capsule (3) is in its compressed form (15).
14. Method according to any one of claims 10 to 13, in which the capsule (3) is formed so as to comprise a dog point (16) at its summit (6).

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