Abstract:
A lightning surge resistor network includes a ceramic substrate and a thick-film resistor deposited onto the substrate. To prevent material spatter and to contain and isolate any arcing that can occur in the event the thick-film resistor opens during a severe over voltage condition, a ceramic cover is mounted over the thick-film resistor. The thick-film resistor is thus fully contained between the ceramic substrate and the ceramic cover. Preferably, the ceramic cover is adhered to the ceramic substrate by means of an adhesive film deposited onto either the cover or the substrate adjacent the outer periphery of the cover. Preferably, the mount of adhesive is reduced at preselected locations along the outer periphery of the cover to form weakened areas in the seal between the cover and the substrate. The weakened areas permit gasses to escape in a predetermined direction in the event excessive pressures are formed under the cover when the thick-film resistor opens under an over voltage condition. Preferably, the adhesive is deposited in a pattern that subdivides the volume under the cover into a plurality of cells or isolation areas.