PROCESSES FOR THE MANUFACTURE OF BARIUM TITANATE CAPACITORS ON NICKEL FOILS
Provided are processes for the manufacture of capacitors. It is found that by using a nickel foil as the substrate and one electrode of the capacitor and by controlling the oxygen partial pressure in the range of 10 −8 to 10 −10 atmospheres during the crystallization heat treatment of the barium titanate, the leakage current can be maintained at adequate values without a reoxygenation step.
1 . A process comprising:
a) providing a nickel foil as a first electrode;
b) depositing a solution of BaTiO 3 precursors to the nickel foil;
c) drying the solution;
d) decomposing the BaTiO 3 precursors to form amorphous BaTiO 3 ;
e) heating the amorphous BaTiO 3 to between 600° C. and 1200° C. in an atmosphere comprising a oxygen partial pressure between 10 −8 and 10 −10 atmospheres to form a film of crystallized BaTiO 3 ; and
f) depositing a second electrode on the crystallized BaTiO 3 film.