Method of firing ceramic moldings containing a diffusible metallic oxide

A method of making a sintered ceramic body suitable for use as in electronic component, which method comprises:

• (A) preparing a ceramic molding containing:
• (a) 100 parts by weight of a mixture of 80.0-97.5 mole percent zinc oxide, 0.3-3.0 mole percent bismuth oxide,
• 0.3-30 mole percent antimony oxide, 0.3-3.0 mole percent cobaltous oxide, 1.0-5.0 mole percent magnesium oxide, 0.3-3.0 mole percent manganous oxide, and 0.3-3.0 mole percent nickel oxide;
• (b) 0.01-0.10 part by weight boric oxide;
• and
• (c) 0.0028-0.0112 part by weight magnesium aluminum tetraoxide;
• (B) preparing a diffusion retarder of sintered ceramic material containing antimony oxide;
• (C) placing the ceramic molding on the diffusion retarder;
• and
• (D) firing the ceramic molding on the diffusion retarder until the ceramic molding is sintered to maturity;
• (E) whereby the effluence of antimony oxide from the ceramic molding by diffusion is prevented, resulting in the creation of zinc oxide crystal grains of practically uniform size throughout the sintered ceramic molding, even if the molding is fired at a temperature above the melting point of antimony oxide.

A method of making sintered ceramic bodies suitable for use as electronic components, which method comprises:

• (a) preparing ceramic moldings of disklike shape containing a major proportion of zinc oxide and a minor proportion of antimony oxide;
• (b) preparing a molding stand defining a furrow of V shaped cross section;
• (c) preparing a diffusion retarder of sintered ceramic material containing antimony oxide;
• (d) placing the diffusion retarder in the furrow of the molding stand;
• (e) placing the ceramic moldings side by side and edgewise in the furrow of the molding stand via the diffusion retarder in order to avoid direct contact of the ceramic moldings with the molding stand;
• and
• (f) firing the ceramic moldings until the moldings are sintered to maturity;
• (g) whereby the diffusion of antimony oxide from the ceramic moldings into the molding stand is prevented, resulting in the creation of zinc oxide crystal grains of practically uniform size throughout each ceramic molding, even if the ceramic moldings are fired at a temperature higher than the melting point of antimony oxide.