Industry News

Control of Membrane Resistance in High Voltage Resistors

Synthetic carbon film and metallic glass glaze film can have very high film resistance, so they are used to make high voltage resistors. In addition to high resistance, high voltage resistors have to withstand a certain amount of power and high voltage. In order to increase the resistance value and obtain a smaller voltage coefficient, the conductive film should be made narrow and long. The length of the synthetic carbon film should not be shorter than 2 cm/kV.

Regarding the improvement of the voltage resistance of the metallic glass glaze resistive film, a method of adding a crystal growth control agent to the metallic glass material has been reported in the literature. The conductive phase in the formula is ruthenium oxide, the bonding agent is glass, the crystal growth control agent is alumina powder, and the carrier is ethyl cellulose. The metallic glass glaze slurry is coated on the substrate and fired at 975~1025℃ for 45~60 minutes. During the firing process, the bonding agent melts and the conductive phase continues to grow until it is controlled by the control agent. The crystal growth control agent forms an inert array of voids. The conductive phase is the substance in the void array. The voltage coefficient of the film layer under the voltage gradient of 1100V/cm (resistance film length) is 400×10-6/V. Pressure resistance is also improved by adding control agents. Use control agents with particles smaller than 1μ (for example, 0.3μ), with a voltage resistance of 1100V/cm (length of resistance film). Using a control agent with a particle size of 0.1μ, the pressure resistance can be increased to 2200V/cm (resistance film length). Regarding the other conditions of the film, please refer to the metal glass glaze resistor.