Apple Inc.
Mold materials for formed ceramic

Abstract:

A mold apparatus to form a ceramic (or glass) includes a first mold portion having a first coefficient of thermal expansion and a second mold portion having a second coefficient of thermal expansion. In some embodiments, the first mold portion and/or the second mold portion are substantially immiscible with the ceramic material, such as silicon oxide, at a temperature greater than 600.degree. C. In some embodiments, the first coefficient of thermal expansion and the second coefficient of thermal expansion are substantially similar to that of the glass or ceramic material. In some embodiments, the first coefficient of thermal expansion is different from the second coefficient of thermal expansion. In some embodiments, the first mold portion and the second mold portion contain a surface coating and a passivation layer.