摘要 |
The depassivation of an integrated circuit is detected by using the fact that the passivation coat which covers this circuit participates in the coupling capacitances that exist between parallel metallized lines made on its surface. The variation in one of these capacitances, resulting from depassivation, leads to a modification of the dielectrical induction of a voltage step, emitted on one line, in another line. The resulting variation in the induced voltage is used to produce a logic signal that reveals this depassivation. This logic signal can be used to neutralize the functioning of the integrating circuit to be protected. |