An apparatus for chemical mechanical polishing includes a support for a polishing pad having a polishing surface, and an electromagnetic induction monitoring system to generate a magnetic field to monitor a substrate being polished by the polishing pad. The electromagnetic induction monitoring system includes a core and a coil wound around a portion of the core. The core includes a back portion, a center post extending from the back portion in a first direction normal to the polishing surface, and an annular rim extending from the back portion in parallel with the center post and surrounding and spaced apart from the center post by a gap. A width of the gap is less than a width of the center post, and a surface area of a top surface of the annular rim is at least two times greater than a surface area of a top surface of the center post.

An apparatus for chemical mechanical polishing includes a support for a polishing pad having a polishing surface, and an electromagnetic induction monitoring system to generate a magnetic field to monitor a substrate being polished by the polishing pad. The electromagnetic induction monitoring system includes a core and a coil wound around a portion of the core. The core includes a back portion, a center post extending from the back portion in a first direction normal to the polishing surface, and an annular rim extending from the back portion in parallel with the center post and surrounding and spaced apart from the center post by a gap. A width of the gap is less than a width of the center post, and a surface area of a top surface of the annular rim is at least two times greater than a surface area of a top surface of the center post.

Disclosed are a machining method and a machining device improving machining efficiency and preserving workpiece surface integrity. The machining method improving machining efficiency and preserving workpiece surface integrity includes: setting a workpiece (300) and a machining unit (400); and machining the workpiece (300) by the machining unit (400) at a preset machining speed, wherein the preset machining speed is not lower than a machining speed corresponding to the embrittlement of the workpiece material. By the machining method, the machining speed of the machining unit (400) is set during machining, which results in “skin effect” of subsurface damage caused by the embrittlement of the workpiece material (300) and enables the damage depth of the workpiece (300) to be confined in a shallow subsurface layer, so that the damage depth of the workpiece (300) is reduced, the workpiece integrity is preserved, and the machining quality and the machining efficiency are improved.

Disclosed are a machining method and a machining device improving machining efficiency and preserving workpiece surface integrity. The machining method improving machining efficiency and preserving workpiece surface integrity includes: setting a workpiece (300) and a machining unit (400); and machining the workpiece (300) by the machining unit (400) at a preset machining speed, wherein the preset machining speed is not lower than a machining speed corresponding to the embrittlement of the workpiece material. By the machining method, the machining speed of the machining unit (400) is set during machining, which results in “skin effect” of subsurface damage caused by the embrittlement of the workpiece material (300) and enables the damage depth of the workpiece (300) to be confined in a shallow subsurface layer, so that the damage depth of the workpiece (300) is reduced, the workpiece integrity is preserved, and the machining quality and the machining efficiency are improved.

A processing apparatus for brittle plate includes a table which holds a brittle plate, a processing head having a processing wheel for processing an outer peripheral edge of the brittle plate held by the table, a measuring portion which measures a positional shift amount Δ in an axis direction of the processing wheel with respect to the brittle plate, and a control portion which corrects a positional shift in a Z-axis direction of the processing wheel on the basis of a positional shift amount Δ in the axis direction of the processing wheel measured by the measuring portion and causes the processing wheel whose positional shift was corrected to process the outer peripheral edge of the brittle plate. The processing apparatus and its method can reduce time and labor of manually positioning of a processing wheel to the brittle plate after processing wheel replacement.

The electric tool including a motor having a stator and a rotor, a rotation shaft integrally rotating with the rotor, a casing accommodating the motor, a ventilating window disposed in the casing, a cooling fan sucking an air through the ventilating window to cool off the motor, a magnetic body disposed to the rotation shaft, a magnetic detection unit detecting a rotational position of the magnetic body, and a circuit substrate on which the magnetic detection unit is mounted. The circuit substrate and the magnetic body are disposed to be isolated from a wind path of a cooling wind generated by rotation of the cooling fan.

The electric tool including a motor having a stator and a rotor, a rotation shaft integrally rotating with the rotor, a casing accommodating the motor, a ventilating window disposed in the casing, a cooling fan sucking an air through the ventilating window to cool off the motor, a magnetic body disposed to the rotation shaft, a magnetic detection unit detecting a rotational position of the magnetic body, and a circuit substrate on which the magnetic detection unit is mounted. The circuit substrate and the magnetic body are disposed to be isolated from a wind path of a cooling wind generated by rotation of the cooling fan.

A method in which an acoustic sensor disposed in a polishing apparatus can be accurately calibrated is disclosed. In this method, polishing sounds of a substrate are acquired using an acoustic sensor; and then at least two distinctive sounds, having distinctive frequencies respectively, are selected from the acquired polishing sounds. Further, the at least two distinctive sounds are output from a sound source coupled to any of a polishing table, the acoustic sensor, and a substrate holder to cause the at least two distinctive sounds to be input to the acoustic sensor. Next, output values of the acoustic sensor are calibrated, such that the output values of the acoustic sensor relative to the at least two distinctive sounds come within an allowable range.

A machine tool of high-frequency vibration is provided. A main shaft structure of the machine tool comprises a rotating shaft, the end of which is provided with a tool holder chuck for fixing a tool holder; the upper portion of which is provided with a rotating coil portion; the main shaft structure is correspondingly provided with a stationary coil portion; and the tool holder is provided with a high-frequency vibration module. By non-contact coils, an external electric power/signal can be transmitted into the high-frequency vibration module to avoid a wear phenomenon in a contact-rotating electrode. Because the inductive coil is arranged outside of the tool holder, the manufacturing cost of the tool holder is reduced, and the convenience of changing the tool holder is increased. Moreover, the machining stability and efficiency of the tool holder are improved by a control method of sensing/feedback signals with wireless transmission.

A machine tool of high-frequency vibration is provided. A main shaft structure of the machine tool comprises a rotating shaft, the end of which is provided with a tool holder chuck for fixing a tool holder; the upper portion of which is provided with a rotating coil portion; the main shaft structure is correspondingly provided with a stationary coil portion; and the tool holder is provided with a high-frequency vibration module. By non-contact coils, an external electric power/signal can be transmitted into the high-frequency vibration module to avoid a wear phenomenon in a contact-rotating electrode. Because the inductive coil is arranged outside of the tool holder, the manufacturing cost of the tool holder is reduced, and the convenience of changing the tool holder is increased. Moreover, the machining stability and efficiency of the tool holder are improved by a control method of sensing/feedback signals with wireless transmission.