Patent ID: 7651655

Claim:
A method of producing a dielectric layer comprising a polycrystalline dielectric material having anisotropy in the coefficient of thermal expansion, the method comprising the steps of: providing a raw material powder of raw material particles having a chemical composition defined by a chemical formula; heat treating the raw material powder at least to a temperature sufficient to cause a phase change from a first crystal orientation at room temperature to a different crystal orientation to provide an aggregate of oriented raw material particles having a chemical composition defined by the same chemical formula as that of the raw material powder but having the different crystal orientation, wherein a crystal lattice of the oriented raw material particles is oriented in a prescribed direction and the oriented raw material particles have a shape wherein a longitudinal direction of the shape forms a prescribed angle with respect to the prescribed direction; forming a compact from the aggregate of oriented raw material particles, including a step of applying a shearing force to the aggregate; and firing the compact to form the dielectric layer.