FR2751452A1 - METHOD OF MANUFACTURING A CONTACTLESS CHIP CARD AS WELL AS A CHIP CARD OBTAINED - Google Patents

Abstract

Method of manufacturing a contactless smart card, characterized in that one or more bare chips are aligned in the cavities and the electrical connections are made between the connection surfaces of the chips and the connections of the coils by the Flip-Chip technique .

Description

Technical Field The invention relates to a method for manufacturing a

  contactless smart card, according to which a

  card body, flat, electrical insulator with one or more

  cavities in the face of the card body, and at least one electrically conductive coil is placed on the surface of the

  face of the card body provided with at least one cavity, a part

  tie of at least one coil being applied both to the surface outside the cavities as well as to the surface,

inside the cavities.

  The invention also relates to a smart card.

thus obtained.

  Nowadays, smart cards are used in

  very large number in all areas of public life

  that and private. Their capacity can be further increased by the use of current integrated circuits. By performing application-specific functions in the chip, one can extend the field of application of smart cards beyond

  identification and telecommunications in the following areas

  vants: In the health sector, in the form of a social security card, a patient data card and an emergency card. In the field of communication, smart cards can be used for access control to

  communication networks and to account for services

  these as well as for coding and for data protection

  born. In the banking sector, smart cards are very suitable as a check card, as a credit / debit card, as an electronic money exchange and for entering road tax in local traffic and on toll roads. In addition, smart cards are suitable for

  identification access control for example for the

  paid editing, for free time services and for

manufacturing controls.

  For chip cards, integrated circuit (IC) memories and micro-

  controllers. In addition, crypto-controllers are used in which an algorithm or a coding key for smart cards is installed. Data exchange is carried out by

  contact surfaces with a reading device or without

  tact by capacitive or inductive transmission. The capacity

  of current smart card systems results in a com-

  ever increasing flexibility and requires more and more integration. If initially it was only about

  memories with peripheries reduced to a minimum, the development

  development is moving towards complex systems requiring a mid

  cro-controller with the most different functions and

  coils for contactless communication.

  STATE OF THE ART In known contactless smart cards, the body of the card incorporates one or more coils connected to the chip. Energy and data are transmitted

  by capacitive or inductive coupling. To achieve these

  your chip we use the technique called "Inlet" (marquetry). For this, the coil and the chip are fixed on a plastic support. The support is then integrated into the smart card itself. This can be done by injection coating or laminating the support. The support is an integral part of the smart card after mounting of

the map.

  As the support used in a known manner,

  support sheets on which a coil is made

  rolled, engraved or printed. In the case of the coil wound

  You have to wind a varnished back wire on a spool and apply it manually to the support sheet, then connect it to the chip. The disadvantages are above all, the difficult installation of the coil on the smart card and

  connections of the thick wires of the coil with the chip.

  Unlike this, the coils engraved and printed on the support sheet have the advantage that the

  mins conductors are an integral part of the carrier sheet. The chip is then connected to the coil by connecting wires or according to the "Flip-Chip" technique. Then, the support sheet with the coil and the chip is integrated into the body of the card. The disadvantages of this solution

  are the high manufacturing costs of the coil and the diff-

  difficulties encountered in laminating the entire card body. In addition, rolling is a hindrance to reliability

  thermal and mechanical, i.e. for overall reliability

  chip card bale. In particular, the temperatures applied

  that the injection coating has an annoying effect on the operation of the semiconductor chip

  expensive. To this are added the coating defects by in-

  jection, that is to say the defects of the relatively inexpensive plastic part of the card make

  discard the expensive semiconductor chip.

  According to document DE 44 41 122, we know by

  example a process for manufacturing a smart card without

  tact according to which electrolytic copper is plated in the form of a sheet with a thickness of about 50 mm and an antenna winding is made in this copper with connection wires by photogravure. In addition, the sheet material is provided in a stamping operation with a

  Chip reception area, recessed, with a branch area

  frankly, adjacent, storied. The chip is then chewed in this reception area and these contact surfaces with the connecting wires are connected to the connection surfaces of

  the antenna winding. Then we glue the sheet so

  nie, on both sides with the exception of the area for receiving the chip between two layers of plastic material of the same thickness which are produced with symmetrical shell-shaped cavities in the area for receiving the chip. This

  process, however, requires an additional mastering operation

  additional for the chip reception area as well as a

  costly laminating and plating operation.

  According to document EP 0682231 A2, an integrated circuit data carrier is known with a flat coil integrated by a hot printing process in the base body of the card and in a cavity located on the side of the card. The cavity is a manufactured module, having at least one integrated circuit and at least two contact elements, and these

  contact elements are electrically connected to the coil.

  This data card requires for its manufacture too

  manufacturing stages insofar as the module has integrated

  manage in the body of the card and which contains the circuit

  tégré, is also manufactured beforehand in several stages

  pes. Disclosure of the invention Starting from the state of the art described above, the present invention aims to create a contactless smart card and a method of manufacturing such a smart card making it possible to manufacture this smart card.

  simple and inexpensive way, and so that the card pre-

  has good mechanical strength characteristics and

reliability.

  To this end, the invention relates to a method of the type defined above, characterized in that one or

  several naked chips in the cavities and we realize the links

  electrical sounds between chip connection surfaces

  and the coil connections by the Flip-Chip technique.

  According to other advantageous characteristics: * the card body is manufactured with one or more cavities in a single operation, e the card body is manufactured with one or more cavities by injection, * the card body is manufactured by one or more cavities in

  realizing the surface in a cavity with a form of sur-

  predetermined face, * to produce a specific surface shape, in the cavities, one or more spacing bosses are produced,

  * to produce a surface of determined shape in the boxes

  vities, one or more contact bosses are made, * on the side of the card provided with the cavities, a label is applied, * the card body is made with one or more cavities and the shape of the predetermined surface is produced in the cavities in a single operation,

  * as material for the card body, we use a ma-

  thermoplastic, * the coils are applied to the surface of the card body in a single operation, * the coils are printed by hot stamping on the card body, * at the same time as one or several coils on the surface of the card body on the side of the cavities, contact bones are formed in the plastic material of the cavities and the metallization layer is provided with the coils, * at the same time as one or multiple coils at the

  surface of the side of the card body cavities, in the

  vities, the existing contact bosses are provided with coils and a metallization layer, * before aligning and bringing the chip into contact, connection bosses are made as connection of coils on the parts of coils which are printed on the upper surface areas in the cavities,

  * the chip is brought into contact by a Flip- solder

  Chip or by Flip-Chip bonding with isotropic glue or by Flip-Chip bonding with anisotropic glue, * the cavities in which the chips placed in electrical contact with the coils are filled

  poured mass such as plastic or resin.

  * spacing bosses are made in the cavities, these bosses ensuring a minimum distance between the chip and the upper surface of the bottom of the cavity, * contact bosses are made in the cavities, these bosses ensuring a minimum distance between the chip and the upper surface of the bottom of the cavity,

  * the depth of the cavities is such that the chips in

  tact do not overflow cavities,

  * the cavities are filled with a poured mass.

  * the cavities are filled with a casting mass to imprint

  sound the chip hermetically, * the cavities are filled with a casting mass such that

  the surface of the card body, on the side of the cavity does not

  feels neither bosses nor hollows, * the material in which the card body is made, is a thermoplastic material such as PVC, ABC or polycarbonate, * the shape of a cavity is adapted to the shape of the chip which is there finds in such a way that the volumes of the cavities are

as small as possible.

  The invention also relates to a character card.

  in that one or more bare chips which have chip connections are placed in the cavities and the chip connection surfaces are brought into contact by

  coil connections by Flip-Chip technique.

  According to the process of the invention, everything is carried out

  first an electrically insulating card body with one or more

  several cavities on the side of the card body. Then direct-

  lying on the surface of the face of the card provided with a

  cavity, at least one coil is applied.

  The chip mounting without housing will be called my-

  tage of bare chip, because the bare chip or without housing is placed

in the cavity of the card body.

  This has the advantage that the higher height

  pick of the chip without housing relative to the height of a chip with housing or even of chip module, comprising in addition to the chip, other functional components, allows to choose the depth of the cavity so that a apart from the chip without housing and brought into contact, does not protrude from the cavity and, secondly, the thickness in section of the card at the level of a cavity is sufficient to have good mechanical strength. Thus, the invention makes it possible to produce a smart card having a minimum layer thickness while offering good mechanical strength by manufacturing

inexpensive.

  According to one embodiment of the invention, the

  manufacture of the card body with one or more cavi-

  This is done in one operation. In advance

  tagger, this is done by injection and the card body is then made in one piece. Thermoplastics such as, for example, are preferably used for this purpose.

  PVC, ABS (Acrylnitrile, Butadiene, Styrene) or a polycarbo-

  nate. According to another embodiment of the invention, the surface, in particular the bottom surface in the cavities has a predetermined shape. Preferably, contact cavities or spacing bosses are produced in the cavities. It is also advantageous to produce the shape of the cavity and the shape of the surface of the cavity in a particularly suitable manner for the "Flip-Chip" contacting method thus used. This process offers the advantage of leaving only the volume of the absolutely necessary cavities of the base body of the card, which weakens the body of the card very little and allows very high resistance.

mechanical for the card.

  According to the invention, the coils are applied to the surface of the face of the card provided with at least one cavity and this both on the surface areas outside the cavities and on the surface areas at the interior of at least one of the cavities. This is preferably done in a single operation and for example the coils are printed according to a hot printing process by applying pressure at temperature on the surface areas and in particular on

  surface areas inside at least one cavity.

  For this, it is particularly advantageous to use a stamping punch, heated, such as a plate

  steel bearing the model of the coil paths. This poin-

  çon then allows to stamp the conductive paths of the coil in the conductive sheet for example a copper sheet according to the model and apply them at the same time to the

  surface of the face of the card body provided with the cavities.

  The attachment of conductive paths on the surface of the body

  of the card is done according to a preferred embodiment

  tiel of the invention, with a layer of adhesive on the inner side

  of the conductive sheet, the glue being chosen

  advantageously depending on the temperature and the pressure

  during the stamping operation.

  According to the preferred embodiment of the invention, both the manufacture of the card body preferably made by injection of a thermoplastic material than by the application of at least one coil to the surface of the card body including the creation of cavities or cuts are done in a single operation. This minimum

  of manufacturing stage allows a particular manufacturing-

  inexpensive and thus mass production. Added to this is the advantage of a very high mechanical and thermal load since first the card is formed from the card body and the body provided with conductive paths in the form of

  coil consists of very few layers minimum two layers

  ches: card body in one piece, (layers formed by conductive paths) and secondly conductive paths are applied directly to the card body

  in one piece, that is to say a card body solid from the mechanical point of view and especially thermal. The coil works

  operates as an antenna for the contactless transmission of energy and / or data to the outside. Preferably, the depth of the ca-

  vités is chosen so that the bare chips, brought into contact with the stamped coils, in particular the coil connections, do not protrude from the cavity. In an exemplary embodiment according to the invention, the connection surfaces

  coils (in English Pads) are stamped or produced if-

  simultaneously with the application of the conductive paths of the coil for mounting the chip. Connection surfaces

  thus form an integral part of the stamped coils. The invention is used in a very flexible manner.

  Depending on the area of application of the maps, due to the geo-

  metries of the different connection surfaces of the chips, contact surfaces or modified connection surface geometries are produced for the coils. This is done with the invention in a simple and rapid manner and further according to

  the arrangement of the contact surfaces, we use the technique

  than the most appropriate contacting of the chips, that is to say

  say Flip-Chip soldering or Flip-Chip bonding with a

  isotropic glue or a Flip-Chip glue with an aniso- glue

  trope. In addition, the chip can also be connected by the contact printing process to the coil connections using the Flip-Chip technique. In the contact printing process, the contact bosses provided on the chip connection surfaces are printed through a layer of electrical insulating glue which is itself provided on the surface in

  the coil connection surfaces in the cavities, up to

  that there is contact with the connection surfaces

  coils and welding with them by action of the press-

  temperature and temperature and, if necessary, the application of ultrasound. The Flip-Chip technique also has the advantage of a small footprint which results on the one hand in a low height of the bare chips used and thus

  the low height of the smart card and secondly of a vo-

  cavity lume minimized. These two advantages mean that the smart card is very little attenuated by the minimum volume

  of the cavity and thus has a very high resistance to

  canic. According to another exemplary embodiment of the invention, to contact the chip, contact bosses are used. These are trained according to the example of

  realization at the same time as applying the paths con-

  coils conductors by the punching punch with the ma-

  plastic body of the card and have a

  metallization layer for the conductive paths of bo-

  bine, matrices. The metallization layer provided on one

  contact bosses serves as a connection surface for

  well. According to another embodiment of the invention, we

  apply a contact boss on this branch surface-

reel ment.

  According to another example, the contact bosses are formed as soon as the base body of the card and the cavities are produced, preferably during a single operation, for example by injection of the card body. According to another embodiment, the contact bosses are preformed during the manufacture of the card body and are brought to the

  final shape desired during hot stamping of the che-

mins coil conductors.

  Contact bosses have the advantage of allowing

  be a minimum distance from the upper surface (bottom) of the cavities and thus a significant reduction in the risk of destruction of the chip during alignment and by N%

  contacting. In addition, the setting-up facility

  tact does not have to perform this gap control.

  According to another embodiment, next to the contact bosses provided for contacting the chip, there are also spacing bosses. They ensure a minimum distance between the chip and the bottom surface of

  the cavity and are preferably arranged so that the chip re-

  as stable and level as possible on the contact bosses and the spacer bosses. Indeed, the contact bosses are not sufficient depending on the

  configuration of the connection surfaces of the chips for

  guarantee the support stability necessary for contacting

  Flip-Chip for the chip. In addition, the minimum distance obtained

  naked by the contact or spacing bosses, necessary in the embodiments of the invention for which

  to increase the bonding, a non-glue is provided

  conductive between the chip and the bottom surface, this glue

  being put in place by infiltration.

  According to another exemplary embodiment, the cavi-

  tees fitted with a chip are protected against external influences and the reliability of the card is increased thanks to a cast mass such as for example a plastic material or a resin. The use of bare chips for the thicknesses of the card allows the chip brought into contact not to protrude from the cavity until after filling the cavity with a poured mass, each chip is trapped hermetically and the surface of the card side of the cavity has neither

hollow or bosses.

  Another exemplary embodiment provides for the step according to which a label is applied to the face of the body of the card not provided with the cavity. This label can for example be printed and / or formed by stamping in the material of the body of the card and if necessary be

  tinted with different colors.

  Preferably, the step of applying the label is done after the card body has received

  the cavities but before placing the coils.

  The application of a label before bringing the chip into contact offers the great advantage of avoiding any thermal load linked to the positioning of the label, any chemical load and / or any mechanical load, such as for example pressure, bending, twisting. In principle, however, the label can be done after mounting the chip on the surfaces of

  connection of the coils. According to another example of realization

  tion, we form the geometrical position of the conduc-

  reels of a coil and the cavities are placed so that at the

  surface of the card on the side of the cavities, outside the cavities

  outside the conductive paths of the coils, it

  enough space to receive a label.

  According to a particularly advantageous realization

  geuse of the invention, the card body is provided with a label

  quette during the injection which gives a card body in one piece with the integrated label. This represents on the one hand the saving of at least one additional step

  for labeling and results in a particular operation

very inexpensive.

  Other advantages of the process of the invention and

  of the smart card according to the invention will appear below.

  The invention allows, with very few steps,

  briquing a card body having at least one cavity, in particular by injecting the card body of thermoplastic material and structured metallization applied to the face of the card on the side of the cavities. This allows simple and inexpensive card manufacturing in very large series. In addition, the smart cards according to the invention are characterized by a very

  high mechanical resistance and very high reliability. This-

  the result of the reduced number of layers making up the smart card and the direct application of the coil to the card body in one piece. Material compatibility problems do not arise for the smart card according to

  the invention. In addition, an intermediate support is thus saved.

diary for the coil.

  Other advantages stem from the use of the Flip-Chip technique for bringing the chip into contact:

  on the one hand the process is simple on the other hand one can use

  serve bare chips and thus the volume of the cavities is reduced to a minimum; the thickness of the smart cards is low although it offers very high mechanical resistance and a

  very high reliability. In the case of contacting

  according to the Flip-Chip technique, it is not necessary to pre-

  see a metallization allowing the bonding of the wires. Another advantage is that the costly and sensitive chip is integrated into the body of the card only during a very later stage, itself possibly followed

  than a few process steps, creating awkward charges

  much less thermally, chemically and physically. In particular, the chips are not exposed to the thermal stresses of the injection in the case of the invention. This ultimately guarantees less waste and greater reliability and longer service life.

cards thus produced.

  The present invention will be described below in more detail with the aid of exemplary embodiments.

  shown schematically in the appended drawings in which: - Figure 1 is a top view of a smart card (surface on the side of the cavity) provided with a coil with ten turns and a chip housed in a cavity, - Figure 2 shows a smart card according to Figure 1 in side view (section parallel to the long side of the card through the cavity; section AB), - Figure 3 is an enlarged detail of the cavity with the chip in contact according to FIG. 2, FIG. 4 shows an enlarged detail of the cross-sectional view of the cavity with the chip in contact, the cutting plane being perpendicular to the cutting plane of the

  Figure 3 and on the surface of the card body on the side of the

  quickly. According to an exemplary embodiment, the smart card 1 precisely comprises a single cavity 3 in which is aligned a square chip 4 brought into contact with the conductive paths of the coil 2. The shape and dimensions of the cavity have been adapted to the shape of the chip. FIG. 2 shows that the depth of the cavity is sufficient for the chip brought into contact to be completely inside the cavity, that is to say in particular that it does not protrude from the upper surface 7 of the card. FIG. 3 shows the zone of the cavity of the smart card according to a section view on an enlarged scale; the cutting plane is perpendicular to the

  conductive paths (the conductive paths are in the di-

  normal vector to the cutting surface). It thus clearly appears that the contact bosses 5 are formed in the material of the card body 1, the material 6 used to make the actual contact, as well as an adhesive.

  or a solder and the conductive paths of the coil 2 ap-

appear in cross section.

  Figure 4 shows a cross section of the

  cavity with the stamped coil, the cutting plane being ortho-

  gonal at the section plane of FIG. 3 and at the upper surface

  map of the side of the cavities, passing through the

  contact boss 5. Figure 4 shows that the path

  conductor 9, the coil is continuously printed on the surface of the card outside the cavity 9a on the lateral inclined planes of the cavity 9b as well as the bottom surface of the cavity 9c. At the location of the contact boss, the conductive path 9 of the coil passes over the contact boss 5 and thus requires metallization of the boss

contact 5.

  In an exemplary embodiment of the method of fa-

  connection of a contactless smart card according to the invention, during a first step, a card is manufactured with a single cavity by polycarbonate injection. The back side

  of the card, i.e. the side which does not have a

  vities (no bosses) can receive the impression of a label

  quette. According to another step in the manufacture of the card, on the hot printing sheet which consists of a layer of copper on a support sheet, the conductor paths of the reel are produced according to a predetermined pattern to the surface of the upper face of the card body comprising the cavities (surface on the side of the cavities) of the card in particular in the cavity (MID technique: production of conductive paths on a substrate

  structured, three-dimensional; MID: Molded Interconnect De-

  vice). Characteristic temperatures and compression times

  ristics are from 130 C up to 150 C for a few seconds. On the contact or connection surfaces of the conductive coil paths, thus stamped, in the cavity of the card, a conductive, isotropic adhesive is distributed. On the outside of the contact surfaces, at least over part of the surface, in the cavity, another electrical non-conductive adhesive is dispensed to block the chip. Then, we place the chip in the cavity, align it and connect the

  connections. To be protected against external influences

  res, the cavity with the connected chip is filled with a poured mass (Glob Top). If necessary, another layer is also provided, such as a sealing layer on the filled cavity and practically forming a cover. This technique

  with several layers offers the advantage that the choice of materials

  appropriate casting results in better obtaining properties

  tees and to be able to adjust them better.

Claims (21)

R E V E N D I C A T I ONS   1) Method for manufacturing a contactless smart card, according to which a card body is made, flat, electrical insulator provided with one or more cavities in the face of the card body, and at least one conductive coil is placed electric on the surface of the face of the card body provided with at least one cavity, at least part of a coil being applied both to the surface outside the cavities as well as to the surface at the inside the cavities, characterized in that one or more bare chips are aligned in the cavities and   makes the electrical connections between the branch surfaces   chip and coil connection by the Flip-Chip technique.   2) Method according to claim 1, characterized in that the card body is manufactured with one or more cavities at during a single operation.   3) Method according to claim 1 or 2, characterized in that the card body is manufactured with one or more cavities by injection.   4) Method according to one of claims 1 to 3,   characterized in that the card body is manufactured with one or more cavities in   realizing the surface in a cavity with a form of sur- predetermined face.    ) Method according to claim 4, characterized in that   to produce a specific surface shape, in the cases   vites, one or more spacing bosses are made.   6) Method according to one of claims 4 or 5, characterized in that   to make a surface of specific shape in cavities   tees, one or more contact bosses are made.   7) Method according to one of claims 1 to 6,   characterized in that a label is applied to the side of the card provided with the cavities.   8) Method according to one of claims 1 to 7,   characterized in that the card body is manufactured with one or more cavities and the shape of the predetermined surface is produced in the   cavities in a single operation.   9) Method according to one of claims 1 to 8,   characterized in that as the material for the card body, a thermoplastic material is used.   10) Method according to one of claims 1 to 9,   characterized in that the coils are applied to the surface of the card body at the during a single operation.   11) Method according to one of claims 1 to 10,   characterized in that the coils are printed by hot stamping on the card body.   12) Method according to one of claims 1 to 11,   characterized in that at the same time that one or more coils are applied to the surface of the card body on the side of the cavities, contact bosses are formed in the plastic of the cavities   and is provided with the coils of a metallization layer.   13) Method according to one of claims 1 to 12,   characterized in that at the same time one or more coils are applied to the   surface of the cavity side of the card body, in the cavities   tees, the existing contact bosses are fitted with boxes   bines and a metallization layer.   14) Method according to one of claims 1 to 13,   characterized in that before aligning and bringing the chip into contact, connection bosses are made as connection of coils on the parts of coils which are printed on the areas of   upper surface in the cavities.    ) Method according to one of claims 1 to 14, characterized in that   the contacting of the chip is done by a Flip- solder   Chip or by Flip-Chip bonding with isotropic glue or   by Flip-Chip bonding with an anisotropic glue.   16) Method according to one of claims 1 to 15, characterized in that   the cavities in which the placed chips are placed   electric tact with the coils are filled with a mass   casting such as plastic or resin.   170) Contactless smart card formed of a card body in a single electrical insulating part and having one or more   cavities on one side of the card body and one or more coils   nes electrically conductive which are produced directly in the surface areas of the face of the card body provided with at least one cavity and have connections, characterized in that one or more bare chips which have chip connections are placed in the cavities and surfaces of   connection of the chips are brought into contact by the branches-   coils by Flip-Chip technique.   18) Chip card according to claim 17, characterized in that 1S is made spacing bosses in the cavities, these bosses ensuring a minimum distance between the chip and the   upper surface of the bottom of the cavity.   19) Chip card according to one of claims 17 or 18,   characterized in that contact bosses are made in the cavities, these bosses ensuring a minimum distance between the chip and the   upper surface of the bottom of the cavity.    ) Chip card according to one of claims 17 to 19,   characterized in that the depth of the cavities is such that the chips in contact do not extend beyond the cavities.   21) Chip card according to one of claims 17 to 20, characterized in that   the cavities are filled with a poured mass.   22) Chip card according to claim 21, characterized in that   the cavities are filled with a casting mass to imprint   ring the chip tightly.   23) Chip card according to one of claims 17 to 22   characterized in that the cavities are filled with a casting mass such that the surface of the card body, on the side of the cavity does not have neither bosses nor hollows.   24) Chip card according to one of claims 17 to 23,   characterized in that the material from which the card body is made is   a thermoplastic material such as PVC, ABC or po- lycarbonate.    ) Chip card according to one of claims 17 to 24,   characterized in that the shape of a cavity is adapted to the shape of the chip therein   finds in such a way that the volumes of the cavities are as small as possible.