Radio frequency and electrostatic discharge insensitive

Abstract

An electro-explosive device has two serpentine resistors fabricated on a thermally conductive substrate with the resistors being interconnected by a central bridge element. The resistance of the bridge element is much lower than that of the serpentine resistors and the serpentine resistors have a much larger surface area to volume ratio. A layer of zirconium is placed on the bridge element and explodes into a plasma along with the bridge element in order to ignite a pyrotechnic compound. The resistance of the bridge element increases with temperature whereby the bridge element receives more of the energy from the applied signal as the temperature increases. The EED is insensitive to coupled RF energy and to an electrostatic discharge since most of the energy from these stray signals is directed to the serpentine resistors and not to the bridge element. In another embodiment, two of the resistors are metal-oxide phase variable resistances and a third resistor is formed from a bowtie-shaped layer of zirconium. The resistances through the metal-oxide phase layers decrease with signal intensity whereby the zirconium can receive most of the energy from a high intensity firing signal. A shunting element, which may be placed across an EED, has a bowtie-shaped conductive layer formed on a substrate. The conductive layer explodes in a plasma above a certain signal intensity. The shunting element may comprise another type of device, such as a diode, capacitor, etc.