Pre-glassing method of producing homogeneous sintered zno non-linear resistors

Claim 1

A method of making a homogeneous, sintered, resistor body, having a substantially uniform density, which can exhibit non-linear V-I characteristics, comprising the steps of: (A) mixing metallic oxide powders comprising about 10 mole % to about 60 mole % of Bi 2 O 3 , about 5 mole % to about 15 mole % of ZnO, about 2 mole % to about 15 mole % of MnO 2 , about 2 mole % to about 10 mole % of Co 3 O 4 , about 5 mole % to about 40 mole % of SiO 2 , about 1 to about 15 mole % of B 2 O 3 and 0 to about 30 mole % of Sb 2 O 3 , and melting the mixture at a temperature of between about 1,100° and 1,600° C for a time effective to form a single phase, chemically homogeneous glass melt, and then (B) quenching the glass melt to form a single phase, chemically homogeneous porous glass, and then (C) grinding the glass to form fine glass particles, and then (D) mixing: (1) 2.5 weight % to 40 weight % of the single phase, chemically homogeneous glass particles with (2) 60 weight % to 97.5 weight % of ZnO particles, by a spray drying technique to form a two component mixture, and then (E) pressing the glass and ZnO mixture at pressures of between about 500 psi. to about 40,000 psi. to form a consolidated body having a substantially uniform density, and then (F) sintering the pressed body, at a temperature of between about 900° and 1,400° C, at a temperature rate increase of between about 75° C/hr. to about 150° C/hr., for 1 to 4 hours, to form a ceramic body consisting of ZnO particles, and a single phase, chemically homogeneous coating formed from the glass and binding the ZnO particles together, wherein the density throughout the mass will vary no more than about 10%, said sintered body exhibiting non-linear V-I characteristics.

Claim 2

A method of making a homogeneous, sintered, resistor body, having a substantially uniform density, which can exhibit non-linear V-I characteristics, comprising the steps of: (A) mixing metallic oxide powders comprising about 10 mole % to about 60 mole % of Bi 2 O 3 , about 5 mole % to about 15 mole % of ZnO, about 2 mole % to about 15 mole % of MnO 2 , about 2 mole % to about 10 mole % of Co 3 O 4 , about 5 mole % to about 40 mole % of SiO 2 , about 1 to about 15 mole % of B 2 O 3 and 0 to about 30 mole % of Sb 2 O 3 , and melting the mixture at a temperature of between about 1,100° and 1,600° C for a time effective to form a single phase, chemically homogeneous glass melt, and then (B) quenching the glass melt to form a single phase, chemically homogeneous porous glass, and then (C) grinding the glass to form fine glass particles, and then (D) mixing: (1) 2.5 weight % to 40 weight % of the single phase, chemically homogeneous glass particles with (2) 60 weight % to 97.5 weight % of ZnO particles, by a spray drying technique to form a two component mixture, and then (E) pressing the glass and ZnO mixture at pressures of between about 500 psi. to about 40,000 psi. to form a consolidated body having a substantially uniform density, and then (F) sintering the pressed body, at a temperature of between about 900° and 1,400° C, at a temperature rate increase of between about 75° C/hr. to about 150° C/hr., for 1 to 4 hours, to form a ceramic body consisting of ZnO particles, and a single phase, chemically homogeneous coating formed from the glass and binding the ZnO particles together, wherein the density throughout the mass will vary no more than about 10%, said sintered body exhibiting non-linear V-I characteristics.