The present invention provides a grinding sheet wherein the width of the ridge in the pattern of abrasive layer is larger than the width of the recess formed between the adjacent portions of the ridge. Its shape is suitable to carry out uniform treatment without causing the workpiece to drop into the recess between ridge portions of the pattern of abrasive layer even when the workpiece is swung while the grinding sheet is rotated during grinding operation.
Description
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is a plan view of one embodiment of the grinding sheet 12.
FIG. 2 is a cross sectional view along the line A-A of FIG. 1.
FIG. 3 is a schematic view of cross section of a thin magnetic head.
Claims
1. A grinding sheet comprising a substrate sheet and an abrasive layer pattern formed as a ridge on at least one surface of the substrate sheet, wherein the abrasive layer pattern is a single spiral curve pattern around a center of the substrate with at least two turns and the single spiral curve extends from the center toward the outer periphery of the substrate in the same direction as the rotation of the grinding sheet.
2. The grinding sheet according to claim 1, wherein the width of the ridge in the abrasive layer pattern is larger than the width of a recess formed between the adjacent portions of the ridge.
3. The grinding sheet according to claim 1 wherein the width of the recess is 1/10-½ of the width of the ridge.
4. The grinding sheet according to claim 1 wherein the width of the ridge is 1-10 mm and the width of the recess is 0.1-5 mm.
5. The grinding sheet according to claim 1, wherein a adhesive layer is formed on the opposite surface of the grinding sheet to the abrasive layer.
6. A method for grinding workpiece while rotating a grinding sheet comprising an abrasive layer pattern formed as a ridge on a surface of the substrate sheet, wherein the abrasive layer pattern is a single spiral curve pattern around a center of the substrate with at least two turns and the single spiral curve extends from the center toward the outer periphery of the substrate in the same direction as the rotation of the grinding sheet.
7. The grinding method according to claim 6, wherein the width of the ridge of the abrasive layer pattern is wider than any surface of the workpiece to be ground and the recess between the adjacent ridge portions of the abrasive layer pattern is narrower than the surface of the workpiece to be ground.
8. The grinding method according to claim 6, wherein the workpiece is a thin film magnetic head.
Patent Application
20070232200
