Abstract: A dresser made of bonded alundum-type abrasive is ground by a rotating blade made of bonded super abrasive to dress the blade. The surface of a semiconductor wafer is ground by the rotating dressed blade to convert it into a matte-finished surface substantially free from saw marks.

Abstract: A cutter for cutting a plate-like material such as a glass sheet along concentric circular inside and outside cutting lines. The cutter includes a movably mounted supporting base stand, at least two material holding chucks disposed on the supporting base stand, and a moving device for intermittently moving the supporting base stand and sequentially positioning the chucks in a cutting zone. The cutter includes blades for cutting the material held on the chuck means along the circular inside and outside cutting lines in the cutting zone.

Abstract: A cutting tool comprising a supporting base and an outside and an inside abrasive grain layer projecting concentrically from the supporting base in a radially spaced relationship, and a method for its production. The outside and inside abrasive grain layers are formed by electrodepositing abrasive grains on the supporting base and then dissolving part of the supporting base. The inner circumferential surface of the projecting portion of the outside abrasive grain layer and the outer circumferential surface of the projecting portion of the inside abrasive grain layer are smooth surfaces.

Abstract: Machining of a hard, brittle and difficultly-machinable workpiece by a grinding wheel made of superabrasive grains. The grinding wheel is rotated at a peripheral speed of 1000 to 5500 m/min., and the grinding wheel and the workpiece are moved relative to each other in the machining direction at a feed speed of at least 30 mm/sec.

Abstract: A cutting tool comprising a supporting base and an outside and an inside abrasive grain layer projecting concentrically from the supporting base in a radially spaced relationship, and a method for its production. The outside and inside abrasive grain layers are formed by electrodepositing abrasive grains on the supporting base and then dissolving part of the supporting base. The inner circumferential surface of the projecting portion of the outside abrasive grain layer and the outer circumferential surface of the projecting portion of the inside abrasive grain layer are smooth surfaces.

Abstract: An automatic accurate alignment system for positioning an object to be worked which has a certain pattern on its surface at a required position. The system performs primary positioning of the object to be worked on the basis of low magnification pattern matching with respect to at least a part of the image of the object magnified at a relatively low magnification. Thereafter, the system performs secondary positioning of the object to be worked on the basis of high magnification pattern matching with respect to at least a part of the image of the object magnified at a relatively high magnification.

Abstract: A method and an apparatus for grinding the surface of a semiconductor wafer by moving a holding table and a grinding wheel relative to each other in a predetermined direction substantially parallel to the surface of the semiconductor wafer held onto the holding table to cause the grinding wheel which is rotated to act on the surface of the semiconductor wafer held onto the holding table. The semiconductor wafer is placed on the holding table with its angular position being regulated so as to direct its crystal orientation in a predetermined direction with respect to the holding table, and thus the grinding direction of the surface of the semiconductor wafer by the grinding wheel is set in a predetermined relationship to the crystal orientation of the semiconductor wafer.

Abstract: An automatic accurate alignment system for positioning at a required position an object to be worked which has a certain pattern on its surface. The system includes a key pattern memory, a pattern matching device and movement control device. The key pattern memory memorizes a first signal indicative of a key pattern existing in a specified area and its position when the object to be worked is positioned at a predetermined position, and memorizes a second signal indicative of the key pattern existing in the specified area and its position when the object to be worked is rotated through 90 degrees from the predetermined the second signal is determined from the first signal. The pattern matching device performs a first pattern matching on the basis of the first signal and a second pattern matching on the basis of the second signal.

Abstract: A precision device including a holding mechanism for holding an object and a supporting mechanism for supporting an operating element, one of which is movable in a predetermined direction. The precision device includes a detecting device for detecting the amount of movement of one of the holding holding and supporting mechanisms in the predetermined direction, and the detecting device includes a scale formed of a material having a coefficient of linear expansion, in a temperature range of -20.degree. to 100.degree. C., of not more than 10.times.10.sup.-7 /.degree.C. as an absolute value. The precision device further includes a detecting device for detecting the amount of thermal expansion of at least a part of the supporting mechanism in the predetermined direction.

Abstract: A semiconductor wafer mounting and cutting system including a wafer mounting machine for mounting a semiconductor wafer to a frame and a wafer cutting machine for receiving the frame and the wafer mounted thereto fed from the wafer mounting machine and cutting the wafer as required. The system further includes a controlling device for forming a relative relation signal showing a relative relation between a first indication which has been or is applied to the frame and a second indication of the wafer, which wafer has been or is mounted to the frame, and memory means for memorizing the relative relation signal formed by the controlling device.

Abstract: A grinding apparatus comprising a supporting base and at least one grinding wheel assembly disposed to face to the supporting base. The supporting base includes at least one holding table and the surface of the holding table protrudes beyond the surface of the supporting base. The grinding wheel assembly includes a rotatably mounted supporting shaft and a grinding wheel mounted to the supporting shaft. At least the surface layer of the holding table is made of 2MgO.SiO.sub.2 -type ceramics.

Abstract: A dicing machine for cutting a semiconductor wafer along cutting lines arranged in a lattice pattern. The dicing machine comprises a cutting station, at least one alignment station, a cutting means disposed in the cutting station, a detecting means disposed in the alignment station for detecting the cutting lines of the wafer, and a wafer transferring means. The wafer transferring means includes two wafer supporting means and the dicing machine is capable of positioning one of the two wafer supporting means in the alignment station and performing alignment of a semiconductor wafer supported with said one of the wafer supporting means while positioning the other of the wafer supporting means in the cutting station and cutting a semiconductor wafer supported with said the other of the supporting means by the cutting means. The cutting means includes two cutting blades and a cutting blade interval setting-up means for setting up the interval of these cutting blades.

Abstract: An accurate alignment system for positioning at a required position an object to be worked which has on its surface straight-line areas whose image density changes relatively abruptly at their both side edges.

Abstract: An article holding apparatus provided with a plate on which an article is placed. A light transmitting opening is formed in the plate. There is provided an optical system optically connected to the light transmitting opening. Reflection light from a part of the undersurface of the article placed on the plate comes into the optical system through the light transmitting opening.

Abstract: The invention provides an apparatus for cutting a sheet-like member such as an adhesive tape applied to a surface of a semiconductor wafer at the periphery of said semiconductor wafer.The apparatus comprises a heating rod to be brought into contact with the periphery of the semiconductor wafer, heating means for heating the heating rod, urging means for relatively urging the heating rod against the periphery of the semiconductor wafer, and a moving mechanism for relatively moving the heating rod along the periphery of the semiconductor wafer. The heating rod is moved relative to the periphery of the semiconductor wafer as the heating rod is urged against the periphery of the semiconductor wafer, and thereby the sheet-like member applied to the semiconductor wafer is melted and cut at the periphery of the semiconductor wafer.

Abstract: A grinding machine adapted for grinding surfaces of thin workpieces comprises a rotating table provided with at least a workpiece holder on which a workpiece to be ground is held, and a plurality of grinding wheels having different grain sizes ranging from coarse to fine, and rotating independently of each other the wheels are disposed above the table and in arrangement so that, as the table rotates, the wheels grind successively the surface of the workpiece to provide a desired total thickness of grind and a reasonable surface finish through one rotation of the table.

Abstract: For adaptation to grinding or cutting precise or minute parts, a grinding and/or cutting endless belt is made of grindstone comprising electrodeposited abrasive grains.

Abstract: A machining device equipped with a rotating machining tool having a blade. A blade inspecting means is provided in the machining device. The blade inspecting means comprises an emission means for emitting electromagnetic radiation and a receiving means for receiving the electromagnetic radiation emitted by the emitting means and producing a signal corresponding to the received electromagnetic radiation. The emitting means and receiving means are disposed such that the electromagnetic radiation emitted from the emitting means undergoes interference by the blade of the machining tool and the electromagnetic radiation received by the receiving means varies according to a variation in the condition of the blade.

Abstract: An electrodeposited grinding tool having an electrodeposited abrasive layer formed by electrodepositing abrasive grains to an electrodeposition thickness at least three times as large as the diameter of the abrasive grains. Pores are dispersed in the electrodeposited abrasive layer in a volume ratio of 10 to 70%.

Abstract: A grinding machine adapted for grinding surfaces of thin workpieces comprises a rotating table provided with at least a workpiece holder on which a workpiece to be ground is held, and a plurality of grinding wheels having different grain sizes ranging from coarse to fine, and rotating independently of each other. The wheels are disposed above the table and in arrangement so that, as the table rotates, the wheels grind successively the surface of the workpiece to provide a desired total thickness of grind and a reasonable surface finish through one rotation of the table.