| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface-machined substrate free of micro-cracks by grinding a substrate by means of a grinding wheel and under a ductile mode so as to form sector-form machining traces. SOLUTION: The generating-line form of a shoulder of a grinding wheel is adjusted by precise turning, so that the depth of cut of individual abrasive grains becomes lower than the ductility-brittleness transition point (about 50nm) of a carbon substrate. The substrate is fixed by a great many of vacuum suction holes made in a work table, or by a vacuum chucking method, and both surfaces the substrate are machined under a ductile mode. Thus, sector-form machining traces are formed on the surface-machined substrate. In this case, no cross-over of these machining traces is formed. With this, the occurrence of micro-cracks is restricted, while Ra (surface roughness) becomes 1 to 100Åand Rp (projection height)/Ra 2 to 10.
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