PURPOSE: To highly accurately cut a brittle material to a wafery thickness by keeping the length of turn of cutting wire strained around the whole of grooved rollers constant by the aid of an adjusting grooved roller.
CONSTITUTION: As a workpiece 3 is being cut, grooved rollers 1-2 and 1-3 for cutting move to the direction of solid linear arrow mark (external direction) and after passing the middle of the workpiece 3, the grooved rollers 1-2 and 1-3 for cutting move to the direction of broken linear arrow mark (internal direction). On the other hand, when rollers for cutting move to external direction, an adjusting grooved roller 2 moves to the direction of a driving grooved roller 1-1, and when the rollers for cutting to internal direction, the adjusting roller 2 to the opposite direction keeping the length of a turn of wire around the whole of rollers 1-1, 1-2, 1-3, and 2 constant. As a result, the cutting conditions, e.g., wire tension, etc. become constant highly accurately cutting the workpiece 3 made of semi-conductor or brittle material to a wafery thickness with the wire 4.
TOMIZAWA ATSUSHI
YAMAGUCHI HAJIME
MITANI MITSUO
NIPPON SPINDLE MFG CO LTD