| 摘要 |
PROBLEM TO BE SOLVED: To obtian good surface roughness substantially free from hillocks and microprojections and flatness meeting the requirements for the applications, use conditions, etc., of a quartz crystal material without subjecting the surface of the quartz crystal material to polishing according to these requirements in the case the surface of the material is worked smooth. SOLUTION: After the surface of the quartz crystal material is lapped, the lapped surface is etched by hydrofluoric acid. Further, the quartz crystal material is subjected to finish etching by buffer hydrofluoric acid at need. In this production of the quartz crystal piece to be used for the quartz crystal device, a quartz crystal wafer cut out of a quartz crystal raw stone to a prescribed thickness is lapped and is then roughly etched by the hydrofluoric acid to a desired thickness and is further ultrasonically washed by pure water. The etched quartz crystal is then subjected to the finish etching by the buffer hydrofluoric acid, by which the quartz crystal wafer is worked to the surface roughness, flatness and thickness of the desired high quality. The surface working is executable more easily with less labor in a shorter time than heretofore, by which the cost is reduced and the productivity is improved. The improvement in yield is further attained in the production of a crystal oscillator. |
