Multilayer-chip varistors based on ZnO with lead zinc borosilicate glass instead of Bi2O3 were prepared by tape casting and green-sheet lamination processes using a non-aqueous slurry system. The influences of slurry composition and the degassing process on the microstructure and non-ohmic properties of multilayer-chip varistors were studied. The electrical properties of chip varistors can be influenced substantially by the pore defects resulting from an unsuitable slurry formulation for the tape-casting process. The sintering temperature of the chip varistors was lowered to 1100 ‡C and silver-palladium alloys were employed as internal electrodes. The non-linear coefficients of 27-32 and breakdown voltages of 7.6-24.5 V were achieved by controlling the green-sheet thickness and sintering temperatures in the present study. The δVbr/Vbr values for the chip varistors lie within ± 10%, indicating excellent surge-withstanding capability.
|Number of pages||7|
|Journal||Journal of Materials Science: Materials in Electronics|
|State||Published - 1 Apr 1995|