Disclosed is a device and a method for manufacturing semiconductor crystal wafer, with the device and the method being capable of easily and reliably manufacture semiconductor crystal wafers of high-quality. This manufacturing method for a SiC wafer, being a semiconductor crystal wafer, includes: a pad groove formation step and a bobbin groove formation step prior to a groove machining step, and after the groove machining step, a polishing step, a cutting step, a first surface machining step, and a second surface machining step.

Through the following steps (a) and (b), the side surface of a grinding object is ground to manufacture a ground product having a smaller diameter than that of the grinding object. In the step (a), a cup type grinding stone is disposed such that the central axis is parallel offset from a state where the central axis is orthogonal to the central axis of the grinding object. In the step (b), the cup type grinding stone is axially rotated so that the cup type grinding stone grinds the side surface of the grinding object while the grinding object is axially rotated and moved in the axial direction. Thereby, the outer peripheral surface of the grinding object is finish-ground by the bottom grinding stone portion of the cup type grinding stone while the grinding object is rough-ground by the side grinding stone portion to obtain a ground product.

Through the following steps (a) and (b), the side surface of a grinding object is ground to manufacture a ground product having a smaller diameter than that of the grinding object. In the step (a), a cup type grinding stone is disposed such that the central axis is parallel offset from a state where the central axis is orthogonal to the central axis of the grinding object. In the step (b), the cup type grinding stone is axially rotated so that the cup type grinding stone grinds the side surface of the grinding object while the grinding object is axially rotated and moved in the axial direction. Thereby, the outer peripheral surface of the grinding object is finish-ground by the bottom grinding stone portion of the cup type grinding stone while the grinding object is rough-ground by the side grinding stone portion to obtain a ground product.

The present disclosure relates to a method for making a grinding wheel with abrasive surfaces located on an outer diameter of the grinding wheel to provide grinding characteristics of both coarse and fine abrasive textures. The method includes forming on the grinding wheel a coarse abrasive portion located proximate to a first axial end of the outer diameter, a fine abrasive portion located proximate to a second axial end of the outer diameter and a transition band formed at an interface between the abrasive surfaces. The transition band has an abrasive coating with a gradual change in texture from a coarse surface to a fine surface.

The present disclosure relates to a method for making a grinding wheel with abrasive surfaces located on an outer diameter of the grinding wheel to provide grinding characteristics of both coarse and fine abrasive textures. The method includes forming on the grinding wheel a coarse abrasive portion located proximate to a first axial end of the outer diameter, a fine abrasive portion located proximate to a second axial end of the outer diameter and a transition band formed at an interface between the abrasive surfaces. The transition band has an abrasive coating with a gradual change in texture from a coarse surface to a fine surface.

To reduce, in processing in which grinding is performed after additive manufacturing, an amount of coating formed by additive manufacturing that exceeds a thickness required for a product. A composite grinding machine includes a holding unit that is configured to hold and rotate a workpiece, an additive manufacturing unit that is configured to move with respect to the holding unit, and that fuses a material while supplying the material to a surface of the workpiece that is held by the holding unit, thereby causing adhesion of the material to the surface, a grinding unit that is configured to move with respect to the holding unit and that includes a grindstone and rotates the grindstone, and a coolant supply unit that supplies a coolant to a portion where the workpiece held by the holding unit and the grindstone come into contact.

To reduce, in processing in which grinding is performed after additive manufacturing, an amount of coating formed by additive manufacturing that exceeds a thickness required for a product. A composite grinding machine includes a holding unit that is configured to hold and rotate a workpiece, an additive manufacturing unit that is configured to move with respect to the holding unit, and that fuses a material while supplying the material to a surface of the workpiece that is held by the holding unit, thereby causing adhesion of the material to the surface, a grinding unit that is configured to move with respect to the holding unit and that includes a grindstone and rotates the grindstone, and a coolant supply unit that supplies a coolant to a portion where the workpiece held by the holding unit and the grindstone come into contact.

Provided is an over-positioning grinding method of a hard and brittle pipe fitting with large length-to-diameter ratio, which belongs to the field of grinding technologies. The existing machining method cannot increase the grinding accuracy of the external circles of the hard and brittle pipe fittings nor ensure the coaxiality of the external circles and internal circles of the ground hard and brittle pipe fittings, which leads to inconsistent wall thickness of the ground hard and brittle pipe fittings. In the present disclosure, by using the over-positioning supporting of the rigid mandrel, the support plate and the guide wheel for the hard and brittle pipe fitting in a machining process, the guide wheel is driven to rotate forward to push the hard and brittle pipe fitting with large length-to-diameter ratio into the grinding area, and the guide wheel contacts and drives the hard and brittle pipe fitting while rotating reversely.

Provided is an over-positioning grinding method of a hard and brittle pipe fitting with large length-to-diameter ratio, which belongs to the field of grinding technologies. The existing machining method cannot increase the grinding accuracy of the external circles of the hard and brittle pipe fittings nor ensure the coaxiality of the external circles and internal circles of the ground hard and brittle pipe fittings, which leads to inconsistent wall thickness of the ground hard and brittle pipe fittings. In the present disclosure, by using the over-positioning supporting of the rigid mandrel, the support plate and the guide wheel for the hard and brittle pipe fitting in a machining process, the guide wheel is driven to rotate forward to push the hard and brittle pipe fitting with large length-to-diameter ratio into the grinding area, and the guide wheel contacts and drives the hard and brittle pipe fitting while rotating reversely.

The present invention is a cylindrical grinding apparatus including a first and second detecting means for detecting proximity between one end and another end of a crystal rod and a main shaft and a subordinate shaft in a non-contact manner and a drive mechanism that can adjust moving speed of a second support unit on the subordinate shaft, wherein, in support with contact between the one end of the crystal rod and the subordinate shaft, moving speed B of the second support unit in time from proximity detection between the one end and the subordinate shaft by the second detecting means to the support with contact is adjusted to be slower than moving speed A until the proximity detection; and in support with contact between the another end of the crystal rod and the main shaft, moving speed D in time from proximity detection between the another end and the main shaft by the first detecting means to the support with contact is adjusted to be slower than moving speed C until the proximity detection. This can provide a cylindrical grinding apparatus that can prevent occurrence of damage in an end portion of a crystal rod and mechanical misalignment of a support unit, reduce process time, and reduce necessity of maintenance of parts to detect positional relationships between the crystal rod and the main shaft etc.