spannungsabhängiges widerstandselement and methods for its manufacture

摘要

The varistor comprises a sintered body (1) consisting of ZnO having non-linear voltage-current characteristics, a polycrystalline high resistance layer (2) contg. Zn2SiO4 or Zn7Sb2O12 formed on the surface of body (1) and an amorphous high resistance layer (3) formed on layer (2). The varistor is made by (1) coating a paste contg. Si and/or Sb on the sintered ZnO body (1), (2) sintering the body (1) to form the polycrystal high resistance layer (2) on the surface of the ZnO, (3) coating a paste contg. glass powder onto the layer (2), and (4) heating the body (1) to form the amorphous high resistance layer (3) on the layer (2). It has stable properties and an improved non-linear voltage-ampere characteristics.