Patent ID: 6199484
Filing Date: 2001-03-13
Classification: F42B

Abstract:
A semiconductor bridge igniter device having protection against functioning at voltages below a preselected threshold voltage, the igniter device defining an electric circuit and comprising:a substrate made from a non-conductive material; anda first semiconductor bridge comprising:(a) a polysilicon layer disposed on the substrate and dimensioned and configured to have first and second pads having therebetween a gap which is bridged by an initiator bridge connecting the first and second pads, the bridge being so dimensioned and configured that passage therethrough of an electric current of selected characteristics releases energy at the bridge;(b) first and second metallized lands disposed in electrically conductive contact with, respectively, the first and second pads, to define a first firing leg of the electric circuit comprised of the first and second metallized lands, the first and second pads and the bridge; and(c) a dielectric material having a breakdown voltage equal to the threshold voltage and interposed in series in the first firing leg of the electric circuit whereby the circuit can only be closed upon application thereto of a voltage potential at least as great as the threshold voltage;a second semiconductor bridge connected in parallel to the first semiconductor bridge, the second semiconductor bridge disposed on the substrate and the second semiconductor bridge comprising:(a) a polysilicon layer disposed on the substrate and dimensioned and configured to have first and second pads having therebetween a gap which is bridged by an initiator bridge connecting the first and second pads, the bridge being so dimensioned and configured that passage therethrough of an electric current of selected characteristics releases energy at the bridge;(b) first and second metallized lands disposed in electrically conducting contact with, respectively, the first and second pads, to define a second firing leg of the electric circuit comprised of the first and second metallized lands, the first and second pads and the bridge; and(c) a dielectric material having a breakdown voltage equal to the threshold voltage and interposed in series in the second firing leg of the electric circuit whereby the circuit can only be closed upon application thereto of a voltage potential at least as great as the threshold voltage;wherein the first semiconductor bridge and the second semiconductor bridge are configured in the electric circuit such that each is connected to receive an opposite voltage polarity with respect to that which the other receives.