the zones 35 is represented in the top of the figure fig5 is a different view of the card shown in fig4 a supplementary back piece is disposed on the fourth side of the card as indicated herein above in format compatible with a 1 2 atr box mechanical integration the overall dimensions of the card can be 80 mm u00d7 190 mm this card size or format allows installation per face of 30 conventional boxes having 14 or 16 pins or 60 34 chip carrier 34 type boxes or again 100 to 120 hybrid chips in compatible format with a 3 4 atr box mechanical integration i e 145 mm u00d7 190 mm such a card allows the installation per face of 60 conventional boxes with 14 to 16 pins or 120 boxes of the chip carrier type this format also allows the installation of hybrid chips by means of adapted supports the dissipated powers envisaged can be about 20 watt for a ceramic substrate 15 watt for a colaminate substrate or 10 watt for an epoxy glass substrate the present invention is not limited to the embodiments described and represented herein above in particular the value for the connector intervals 1 27 mm has been selected as half of the normal interval 2 54 mm but this value is not limitative and similar values allowing to maintain the same order of magnitude for the number of connector pins could also be chosen similarly the number of connector pins 400 is not limitative it has been indicated in order to keep some supplementary connector pins further to the pins necessary in a 32 bit system furthermore the connectors described having contacts on either side.