Dielectric for a capacitor and a method of manufacturing same
A method of manufacturing a dielectric for a capacitor and a dielectric for a capacitor manufactured thereby are provided. A dielectric for a capacitor is prepared by calcining a precursor mixture containing lead, lanthanum, zirconium, and titanium to produce calcined powder, adding additives including sodium, potassium, and the like to the powder, and sintering the mixture at a low temperature, whereby the dielectric has a high density and a large dielectric constant.
1 . A method of manufacturing a dielectric for a capacitor, the method comprising:
mixing precursors of a dielectric to prepare a precursor mixture;
calcining the precursor mixture to produce a calcined product;
pressing the calcined product to produce a molded product;
sintering the molded product to obtain a sintered product; and
adding an additive to the calcined product after the calcining,
wherein the additive comprises sodium and potassium and
wherein the additive comprises sodium and potassium in a weight ratio in a range of 4:1 to 4.5:0.5.
2 . The method of claim 1 , wherein the precursors comprise: lead oxide (PbO), lanthanum oxide (La 2 O 5 ), zirconium oxide (ZrO 2 ), and titanium oxide (TiO 2 ).
3 . The method of claim 2 , wherein the precursors comprise: 50 to 65 wt % of lead oxide (PbO), 4 to 8 wt % of lanthanum oxide (La 2 O 5 ), 25 to 40 wt % of zirconium oxide (ZrO 2 ), and 2 to 6 wt % of titanium oxide (TiO 2 ).
4 . The method of claim 1 , wherein the calcining is carried out for 2 to 5 hours at 700° C. to 900° C.
5 . The method of claim 1 , wherein the sintering is carried out for 2 to 5 hours at 900° C. to 1000° C.
6 . The method of claim 1 , wherein the additive is added in an amount of 0.5 to 1.5 parts by weight per 100 parts by weight of the calcined product.
7 . The method of claim 1 , wherein the additive is a compound comprising sodium carbonate (Na 2 CO 3 ) and potassium carbonate (K 2 CO 3 ).
8 . The method of claim 1 , wherein the method further comprises drying at a temperature in a range of 80° C. to 120° C. after the calcining or the adding of the additive.
9 . The method of claim 1 , wherein the method further comprises mixing of the calcined product, a binder, and a solvent and granulating the resulting mixture after the adding of the additive.