Dual Interface Construction

When we think about the migration to contactless or Dual Interface cards it is important to have a general understanding of what goes into creating the card and the constraints one has to think about, as they work with their marketing teams to design these cards.

The design of a payment card involves assembling multiple of PVC into a sandwich that will be bonded and then punched out to form the card body.

  • On the face of the card: a clear laminate to protect the surface
  • On the back a clear laminate with the magnetic stripe affixed to it

In the middle two printed sheets

  • The front
  • The back

In the middle of the card body, your manufacturer will need to insert an antenna.   The antenna is typically provided to the card manufacturer as an inlay, as seen on the left.  The inlay is a sheet of plastic with the copper antenna, sometimes aluminum embedded within.  The card manufacture will add this inlay into the middle of sandwich.

On the right is an example of a six layer card construction including one element as an example, a metal foil.  This has been included given it has an impact on the effectiveness of the radio signal.  More about this a little later.  Using pressure and heat, the layers of the sandwich are bonded together in a process called lamination.  The bonded sandwich is then run through a series of additional processes designed to create an ID-1 card as specified in the ISO 7810 specifications supplemented by the additional payment network requires, such as the signature panel and the hologram.

After quality inspection the next step is to mill and embedded chip into the card body and simultaneously assure a connection between the contacts on the back of the chip and the antenna.  There are various means of connecting the chip to the antenna.  These different methodologies for connecting the chip to the antenna is a specific skill and is the responsibility of your card manufacturer.  Look to your manufacturers to propose, construct and certify your card to your requirements and employing their unique processes, techniques and technologies.

One thing you will need to be aware of is how the use of the antenna affects the certification process.  It is important to understand that the combination of ink, materials and methods of construct means; each construction will need to go through a unique certification.  This need for certification is a result of the use of radio frequency to communicate between the card and the terminal.  Think of your cell phone when your inside a big building or within an elevator and how the conversation maybe disrupted.  It is this possibility of the radio signal to be disruption based on the materials employed and the method of construction.

When metal elements like metallic foils and layers are used in card construction, the challenge increases.  Eddy currents are emitted by the metal and will interfere with the level of power and quality of communications emanated by the antenna and radio in the POS  received by the antenna and the computer in the card.

So far we have spoken only of the hardware.  The chip in the card is a computer and needs an operating environment, application and data in-order to function.  The introduction of the contactless interface alters the operating environment, the payment applications and the data which is loaded into the card.  All of this impacts the card manufacturing and card personalization process.

 

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