The main difference between a smart card and other types of cards is the embedded microcontroller. If contacts are used for the power supply and data transmission functions, electrical connections are required. These consist of six or eight gold-plated contacts, which can be seen on every standard smart card. The locations of these contacts with respect to the card body, and their sizes, are specified by the ISO 7816-2 standard.

In France, a national standard generated by AFNOR was already in use long before ISO 7816-2 was issued. It specifies a slightly higher location for the contacts than the ISO standard. This location is also included in the ISO standard as a ‘transitional contacts location’, but the standard recommends that this location not be used in the future. However, since there are still many cards in France that use the ‘transitional’ position, it is not likely that it will disappear quickly.

The absolute position of the contact field is in the upper left corner of the card body. The is clearly shown in dimensioned drawing shown in Figure 3.65. The minimum dimensions of
any contact are 1.7 mm by 2 mm (height by width). The maximum dimensions of any contact are not specified, but they are of course limited by the fact that the individual contacts must be electrically isolated from each other.

The position of the module within the card body is specified in the standard. The locations of the magnetic stripe area and the area reserved for embossing are also exactly specified (see ISO 7811). All three of these components may be present on a single card. However, in this case the following mutual relationships must be taken into account: (a) if only a chip and an embossing field are present, they may be located on the same side or on opposite sides of the card; (b) if a magnetic stripe is also present, it and the embossing area must be located on opposite sides of the card.
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Figure 3.65 The positions of the contacts relative to the card body outline (drawing not to scale)
I 10.25 mm maximum
II 12.25 mm minimum
III 17.87 mm maximum
IV 19.87 mm minimum
A 19.23 mm minimum
B 20.93 mm minimum
C 21.77 mm maximum
D 23.47 mm minimum
E 24.31 mm maximum
F 26.01 mm minimum
G 26.85 mm maximum
H 28.55 mm minimum

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Figure 3.66 Minimum contact dimensions as specified in ISO 7816-2

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Figure 3.67 The various possible arrangements for the chip, embossing field and magnetic stripe, according to the ISO 7816-2 standard

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Figure 3.68 An example of a card with a chip, magnetic stripe, signature area and embossing (Source: Giesecke & Devrient)