| 摘要 |
PURPOSE:To prevent the deformation like waved external ridges and bending of diaphragm plate base, by containing the external ridge of the diaphragm base in which inorganic solid substance is diffused in the containing step formed at the upper side of the tool and inner circumference. CONSTITUTION:The external circumference 5a of the diaphragm plate base 5 formed in a given diaphragm plate shape such as cone or dome type through the use of an inorganic solid substance, is contained in the containing step 6a of ring shape formed on the upper surface of the tool 6, and it is implanted in the powder 3 of the inorganic solid substance contained in the sealed vessel 1. Next, the heater is heated, and the vessel 1 is heated at the temperature of 800-1,000 deg.C to activate the powder 3 and to diffuse the inorganic solid substance on the surface of the base 5. Further, after cooling, the base 5 is picked out from the vessel 1 and the base 5 is cut off from the external circumference 5a. |
