A smart card is a flexible Plastic Card, usually made of PVC, that contains one or more embedded integrated circuits. The integrated circuit in a smart card is often referred as ICC, Smart Card Chip, Smart Chip Modules or Secure Microcontroller (Secure MCU) while the smart cards are often also referred as smartcards, chip cards, IC cards, ICC or CPU cards.
The physical characteristic of a Smart Card are specified by the ISO/IEC 7816-1 (Identification cards – Integrated circuit cards – Part 1: Cards with contacts – Physical characteristics) while the locations and dimensions for the contacts are specified by the ISO/IEC 7816-2 (Identification cards – Integrated circuit cards – Part 2: Cards with contacts – Dimensions and location of the contacts).
Contact smart cards does not normally contain any battery and the power necessary to operate is supplied by the Smart Card Reader that act as the communication medium between the smart card and the host (e.g. smartphone, computer, POS). Contact Smart Card Readers interface with the Smart Cards by means of up to eight contact PINs while Contactless Smart Card Readers do not require physical contact with the card. The contact pads on the card are gold-plated and two of them (RFU) are normally not used.
While the position, minimum and maximum dimensions and location of the contact pad are standardized, the layout of the contact pad can be freely designed by the chip manufacturer or by the card vendors.
The contact pads are connected to the chip by means of extremely thin bonding wires that are buried into the encapsulation resin.
Cross section view of the structure and packaging of a smart card chip
Smart cards can be classified according the type of chip implanted within the card and how the card interchange data with the Card Reader. The illustration below clarify the classification:
MCU Cards / Microprocessor Cards
Microprocessor Cards embeds a micromodule containing one or more silicon integrated circuit chips with memory and microprocessor. Microprocessor Cards have data processing capabilities and are conceptually equivalent to a computer with their own OS called Card Operating System (COS), a File System and applications. Multiple applications can be loaded on a MCU Card.
The chip of a Memory Card hold and store data into EEPROM or Flash Memory but there no processor and therefore there is no processing capabilities. Memory Cards are a secure and popular alternative to magnetic stripe cards.
Display Cards are smart cards that in addition to the standard chip embeds at least a battery, an additional chip and a LCD display that is used to display secret keys or One Time Passwords.
Contactless Smart Cards
A contactless smart card embeds integrated circuits and at least an antenna that communicate with the terminal via radio waves.
An hybrid card is a type of smartcard that embeds two chips, one that communication via the contact interface and a second one that is used to communicate via the contactless interface. Hybrid Cards are sometime called Twin Cards. Altough still on the market their use is in steady decline.
Dual Interface Smart Cards
A Dual Interface Smart Card, also known as Combi Card) is a type of smartcard that embed a single chip able to manage both the contact and the contactless interface.
Exploded view of a dual interface smartcard.
Multi Component Cards
Multi Component Cards are smart cards that in addition to the standard chip embeds one or more electronic components, e.g. battery, LCD display, fingerprint sensor.