US 12,278,030 B2
Method for manufacturing multilayer varistor and multilayer varistor
Naoki Mutou, Hokkaido (JP); Yoshiyuki Satou, Hokkaido (JP); Yuji Yamagishi, Hokkaido (JP); and Ken Yanai, Hokkaido (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD., Osaka (JP)
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed on Jan. 19, 2023, as Appl. No. 18/098,998.
Claims priority of application No. 2022-013569 (JP), filed on Jan. 31, 2022.
Prior Publication US 2023/0245806 A1, Aug. 3, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01C 7/112 (2006.01); C04B 35/453 (2006.01); C04B 35/64 (2006.01); H01C 7/18 (2006.01)
CPC H01C 7/112 (2013.01) [C04B 35/453 (2013.01); C04B 35/64 (2013.01); H01C 7/18 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A method for manufacturing a multilayer varistor, the method comprising:
a first step of providing a multilayer stack in which a plurality of green sheet layers and a plurality of internal electrode paste layers are alternately stacked one on top of another, each of the plurality of green sheet layers containing a Zn oxide powder as a main component thereof and a Pr oxide powder as a sub-component thereof, each of the plurality of internal electrode paste layers containing a Pd powder; and
a second step of forming a sintered compact, including an internal electrode inside, by baking the multilayer stack,
the second step including
a sub-step of baking the multilayer stack by setting an oxygen concentration in an atmosphere at 100 ppm by volume or more while increasing a temperature before a first sub-step;
the first sub-step of baking the multilayer stack by setting the oxygen concentration in the atmosphere at 1000 ppm by volume or less while increasing the temperature from 500° C. to 800° C.; and
a second sub-step of baking, after having performed the first sub-step, the multilayer stack by setting the oxygen concentration in the atmosphere at 1000 ppm by volume or more while increasing the temperature to a maximum allowable temperature.