A small electronic unit for use especially in the manufacture of microcircuit cards, e.g. credit cards, carpark cards, telephone call payment cards, etc. which includes an integrated circuit positioned in an aperature in a flexible sheet of insulating material which sheet carries a plurality of electrical conductive strips that extends into the aperature and are fastened, soldered or adhesively bonded to the terminals of the chip. The flexible sheet is carried either directly or through the intermediary of the conductive strips by a support member which is deformable under bending and twisting stresses. At least a major sector of the area of the flexible sheet surrrounding the aperature is free to move with respect to the support for substantially isolating the chip and the conductive strips from stresses resulting from the deformations of the support member.