Internal circumference processing method of fragile material substrate

Abstract

The invention relates to an internal circumference processing method of a fragile material substrate. In the internal circumference processing, a central area in an inner contour line is cut and can be definitely separated, and a separating face can not generates a gap. The method includes a line marking step (a), i.e. forming a marking line C1 as the inner contour line of the internal circumference on a first face of the fragile material substrate G via a scribing wheel 22, wherein a cutting edge chine line of the scribing wheel is periodically formed with a groove 22 which tilts to the axial direction of the scribing wheel; a pressure adding step (b), i.e. using a plate 42 which does not contact with the central area G0 in the inner contour line C1 and is provided with a hole 49 to support the substrate G and to exert the pressure W on the central area G0; and a center cutting step (c), i.e. under the pressure adding condition, separating the central area G0 through cooling and contracting the central area G0.

Description

technical field [0001] The invention relates to an inner periphery processing method for cutting a brittle material substrate along an inner contour line as the inner periphery. In particular, it relates to a process for manufacturing, for example, a ring-shaped substrate for an information memory device from a square substrate. The so-called substrate here includes materials such as ceramics, single crystal silicon, semiconductor wafers, and sapphire in addition to glass substrates. Background technique [0002] Ring-shaped substrates made of glass used in hard disks, etc. are formed by cutting out a circular shape from a square glass substrate. [0003] When processing the inner periphery of a glass substrate along a closed curve such as a circle, first, use a knife with different blade angles on the left and right along the circle that is the inner contour line on one side surface (first surface) of the substrate. The scribing wheel machined tangent lines (scribing line...

AI Technical Summary

Problems solved by technology

[0014] However, when the diameter of the inner circumference is as small as 15mm, the cooling using only refrigerant injection will not completely separate. Therefore, in the past, it was common to have to lower the nozzle to abut against the central area and press to perform forced separation.

[0015] At this time, if the pressing force when the nozzle is in contact with the substrate is increased, or the nozzle is in contact with the substrate for a moment, the center region can be separated reliably, but a gap will be generated on the separation surface (inner peripheral surface) and the processing will be difficult. quality problems

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