Dowa Mining Co., Ltd.
|Dowa Mining Co., Ltd. Patent applications|
|Patent application number||Title||Published|
|20120219453||SILVER POWDER AND METHOD FOR PRODUCING SAME - After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C., and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm||08-30-2012|
|20090017333||METHOD OF FORMING GROUP-III NITRIDE CRYSTAL, LAYERED STRUCTURE AND EPITAXIAL SUBSTRATE - Heat treatment is conducted at a predetermined temperature of not less than 1250° C. on an underlying substrate obtained by epitaxially forming a first group-III nitride crystal on a predetermined base as an underlying layer. Three-dimensional fine irregularities resulting from crystalline islands are created on the surface of the underlying layer. A second group-III nitride crystal is epitaxially formed on the underlying substrate as a crystal layer. There are a great many fine voids interposed at the interface between the crystal layer and underlying substrate. The presence of such voids suppresses propagation of dislocations from the underlying substrate, which reduces the dislocation density in the crystal layer. As a result, the crystal layer of good crystal quality can be obtained.||01-15-2009|
Patent applications by Dowa Mining Co., Ltd.