Patent ID: 8022824
Filing Date: 2011-09-20
Classification: G06F

Abstract:
1. An anti-intrusion system for protecting electronic components comprising a substrate on which the electronic components are placed, a conducting enclosure encapsulating the electronic components on the surface of the substrate, said system also including a warning device, characterized in that it comprises an encapsulated intrusion detection circuit in said enclosure, said intrusion detection circuit comprising at least: a transmitting antenna situated on the surface of the substrate and transmitting a power signal, a capacitive electromechanical microswitch associated with means of receiving said power signal and said microswitch being able to detect a signal power drop and, where appropriate, activate an intrusion warning device, means of receiving the transmitted signal, said reception means transmitting a signal drop on an intrusion into the enclosure, said reception means being linked to said microswitch, wherein the transmitting antenna transmits a power signal such that, for the microswitch the voltage Veq applied between the membrane and the electrode is between an activation voltage Vp and a release voltage Vr, said activation and release voltages respectively satisfying the following equations: where w is the width of the signal lines, W is the width of the membrane, g o is the thickness of the dielectric gap without voltage applied, ε o : the permittivity of the vacuum and k the stiffness coefficient of the membrane. where t d is the dielectric thickness separating the metallic layer from the membrane, ε r the relative permittivity of the dielectric and ε′ a constant making it possible to take account of the effect of the presence of the dielectric gap which modifies the permittivity of the electrodes and A is equal to the product wW.