Abstract: A method for measuring and controlling the oxygen concentration in silicon melts which are contained in a silica glass crucible or which can be touched by a silica glass surface can especially be used for achieving a defined, uniform axial and radial oxygen concentration in a growing silicon crystal. The measurement of the oxygen concentration is realized by an electrochemical solid ionic sensor dipped into the melt; the voltage is measured between the sensor and the growing silicon crystal. The oxygen concentration in the melt is controlled by applying a voltage between crystal and silica glass crucible. The apparatus for putting the method into practice includes an electrochemical solid ionic sensor formed of a silica glass tube which encloses a metal/metal oxide mixture, contacted by a metal wire.

Abstract: A device for subdividing semiconductor bars into wafers comprises a grinding tool having two concentrically arranged grinding discs. A rough grinding disc is arranged inside of an outer smooth polishing grinding disc. The grinding tool grinds a lower face of a semiconductor bar to a smooth planar form. A first electrolytic truer operates in conjunction with the outer smooth polishing grinding disc while a second electrolytic truer operates in conjunction with the inner rough grinding disc. The truers are arranged to define an axial offset between the grinding surfaces of the grinding discs so that a lower face of the bar is smoothed. The device also has a slicing tool for slicing the bar into wafers which will have a smooth planar form.

Abstract: In a chucking apparatus for the combined grinding and honing working of a racetrack surface of a roller bearing external ring, a first chucking device comprising a pair of glide shoes and a second chucking device comprising a hydrostatic glide bearings wherein the first chucking device the grinding is integrated as a multiple arrangement into an indexable round table while the second chucking device is capable of being moved by simple axial shifting into the honing chucking device integrated into the round table.

Abstract: Wafers are manufactured from an ingot of semiconductor material by first machining a front face of the ingot to provide a substantially planar reference surface and then slicing the ingot using looped cutting wire apparatus. The cutting wire apparatus includes a looped cutting wire and at least two drive rollers over sectors of which the cutting wire is wrapped. Each drive roller is provided with its own drive motor which has shunt motor characteristics. The speed and torque of each motor is adjustable relative to the load applied to its drive roller by the cutting wire such that all of the drive rollers participate in driving the cutting wire with substantially the same reliability against slippage so that wear is distributed uniformly over all of the drive rollers.

Abstract: Method and apparatus for manufacturing thin wafers from bars, such as in the manufacture of wafers for use as semiconductor substrates, include an arrangement wherein a holder member is fastened to the bar, the bar is sliced to separate a disc-shaped wafer therefrom and wherein prior to completion of the slicing operation, the end face of the bar is leveled to a precisely planar condition. The slicing operation is terminated after the bar is sliced completely through and the holder member is partially, but not completely, sliced through so that a wafer formed by the slicing operation remains connected to the bar by the holder member. The wafer is disconnected from the bar by abrading a portion of the holder member connecting the wafer to the bar.

Abstract: Method and apparatus for manufacturing thin wafers of hard, non-metallic material, such as monocrystalline or polycrystalline material for use as semiconductor substrates from bars of such material include an arrangement wherein prior to the completion of a slicing step wherein a disc-shaped workpiece or wafer is sliced from the bar, an end face of the bar is planed to a precisely planar condition whereupon the bar is sliced to separate a disc-shaped workpiece or wafer therefrom having a planar reference surface constituted by the planed end face of the bar. The apparatus can include an internal hole saw for slicing the bar and a grinding device for planing the end face thereof.

Abstract: Apparatus for manufacturing thin wafers from bars, such as in the manufacture of wafers for use as semiconductor substrates, include an arrangement wherein a holder member is fastened to the bar, the bar is sliced to separate a disc-shaped wafer therefrom and wherein prior to completion of the slicing operation, the end face of the bar is leveled to a precisely planar condition. The slicing operation is terminated after the bar is sliced completely through and the holder member is partially, but not completely, sliced through so that a wafer formed by the slicing operation remains connected to the bar by the holder member. The wafer is disconnected from the bar by abrading a portion of the holder member connecting the wafer to the bar.

Abstract: Conveyor apparatus includes at least two conveyors, each comprising a pair of longitudinal conveyor members, situated in different horizontal planes on which workpiece carriers are supported for conveyance. Each workpiece carrier has at least one longer outer dimension, e.g. length, greater than the distance between the conveyor members of one of the conveyors and at least one shorter outer dimesnion, e.g. width, less than the distance between the conveyor members of at least one of the conveyors.

Abstract: A method for machining a disk-shaped workpiece, for example having a thickness of between 350 and 1200 microns, formed of brittle crystalline material having a Vickers hardness greater than about 7,000 N/mm.sup.2 in the manufacture of a wafer having a fine thickness, such as in the range of between about 60 and 250 microns, comprises a "cross" grinding operation including the steps of situating the workpiece in opposed relationship to a flat grinding surface of a rotating cup-type grinding wheel and infeeding or plunging the grinding wheel with respect to the workpiece in a direction substantially parallel to the axis of rotation of the grinding wheel at a controlled rate while maintaining the workpiece fixed and stationary with respect to the axis of rotation of the grinding wheel until a layer of the workpiece having a specifically predetermined optimal thickness has been abraded.

Abstract: A center-opening saw blade having an inner sawing edge is spanned or tensioned to provide an accurate, high quality cut by apparatus including inner and outer clamping collars between which an outer peripheral edge region of the saw blade is clamped, a spanner ring having an inner edge and an outer centering heel, the clamping collars being tightly affixed to the spanner ring with the clamping rings positioned in the centering heel with the inner edge of the spanner ring engaging an inner region of the saw blade to impart an initial stress thereto. A form ring is axially slidably mounted within the clamping collars and is slidable to engage an intermediate portion of the saw blade between the outer peripheral edge region clamped between the clamping collars and the inner region engaged by the inner edge of the spanner ring to impart a fine adjustment stress to the saw blade.

Abstract: A motor spindle for magnetic disc storage drives includes an outer rotor connected to an inner shaft which is rotatably mounted by an integrated bearing including rolling elements, such as balls, which run in inner and outer races, the outer race being formed in the stator bushing and the inner race being formed in the shaft.

Abstract: Centrifugal chucking apparatus for fixing a member to be rotated to a rotatable driving member includes a cylindrical cage member adapted to be mounted for rotation with the driving member, at least one clamping body movably mounted within an aperture formed in the cage member and which moves into engagement with the member to be rotated during rotation of the driving member under the action of centrifugal force, and at least one lever member associated with the clamping body and mounted for rotation with the driving and cage members. The lever member mutually engages both the clamping body and the cage member and during rotation of the driving member the lever member is urged outwardly under the action of centrifugal force. The lever member is appropriately positioned so that as a result of this outward urging under centrifugal force, the lever member exerts a force against the clamping body which has a direction to increase the force with which the clamping body engages the member to be rotated.

Abstract: Apparatus for effecting a seal between a rotary shaft and its enclosure includes a sealing element having an elastic lip portion coupled to the shaft for rotation therewith and a sealing portion associated with the enclosure, the elastic lip portion forming a contact seal with the sealing portion when the shaft is stationary or rotating slowly. The elastic lip portion tends to lift from the sealing portion to form a non-contact seal upon a predeterminable increase in the rate of shaft rotation. Compressed gas is introduced into a region between the rotary elastic lip portion and the sealing portion to form a gas cushion therebetween to facilitate lifting of the elastic lip portion.

Abstract: A magnetic fluid seal provided in a sealing gap defined between an inner surface of an outer rotor and the outer periphery of a disc-shaped magnet includes magnetic liquid situated in the sealing gap and the improvement wherein the inner surface of the outer rotor is inclined so that in a cross-section through a plane containing the axis of rotation of the rotor, the inner surface forms an angle with the axis of rotation of the rotor whereby retention of the magnetic liquid in the sealing gap is facilitated by the reaction forces to the centrifugal forces acting on the magnetic liquid during operation.

Abstract: A ball bearing which is to function as a radial, radial angular-contact, and axial angular-contact bearing includes coaxial inner and outer races respectively formed with ball grooves which face each other, the bearing having a plurality of balls of a given ball radius situated between these races and extending into the grooves thereof so as to have rolling contact with the races. At least one of these races has in an axial plane which contains the common axis of the races a cross-sectional configuration according to which the innermost part of the groove of this one race has a radius of curvature which is somewhat greater than the radius of the ball, e.g., about 51.6% of the diameter of the ball, with the radius of curvature of the latter groove gradually increasing from the innermost part thereof up to a pair of opposed side edges of the groove.

Abstract: Workpiece handling apparatus for use in grinding machines wherein a pair of unground workpieces can be transported from holding or feed apparatus to a respective pair of load positions at the grinding wheel and simultaneously unload a pair of finished or ground workpieces from the load positions and transport the same to discharge apparatus. The handling apparatus include loading apparatus comprising three carriers which simultaneously transport each of a pair of unground workpieces from a respective pickup position at the holding apparatus to a respective one of the pair of load positions and at the same time simultaneously unload each of the pair of finished or ground workpieces from a respective load position and transport the same to the discharge apparatus.

Abstract: The roller bearing seal includes a ring-shaped member integrally connected to an outer race of the roller bearing. The ring-shaped member has an outer lip portion that is spaced a predetermined amount from the inner race of the roller bearing so as to provide a gap between the ring shaped seal member and the inner race. Oppositely extending rim portions project from the lip portion in concentric fashion with respect to the lip portion to define respective spaces for accommodating grease layers. The grease layers and the lip portion constitute a seal against the inner race thereby preventing dust or other foreign particles from passing through the grease layers and the lip portion.

Abstract: A surface grinding method and apparatus wherein workpieces are ground with a ring-shaped grinding wheel having a ring-shaped grinding surface the inner diameter of which is relatively large with respect to the dimensions of the workpieces. The method and apparatus include steps and structure for providing between the workpieces and the ring-shaped grinding wheel a relative movement where the workpieces travel along a substantially cycloidal path with each workpiece having a point at the surface thereof which is ground by the grinding wheel and passes at least twice across the grinding surface between the outside and the inside thereof. To bring about this relative cycloidal movement, the central axis of either of the work-supporting structure or the grinding structure, preferably the work-supporting structure, is displaced around an axis which is parallel to its central axis, while this central axis is simultaneously moved inwardly toward and outwardly away from the axis parallel thereto.

Abstract: Apparatus for handling delicate workpieces such as semiconductor substrates which have the configuration of small plates. The workpieces are preliminarily situated at predetermined locations in a positioning plane. Then, without changing their positions relative to each other, the workpieces are all simultaneously transferred away from the positioning plane while being maintained during transfer in a common plane which moves with the workpieces. During their transfer the workpieces are held by suction in this common plane by way of suitable suction nozzles which have at least at their ends which engage the workpieces a soft elastic material.

Abstract: A device for releasably holding a movable body in a given position with respect to another body includes a pair of opposed mutually spaced end walls and a pair of opposed mutually spaced fixed walls extending between the fixed to the end walls to form therewith a frame which surrounds a given space. A control plate is situated in the latter space for movement between the end walls in a clamping direction or in a non-clamping direction, and on opposite sides of the control plate are a pair of parallel clamping plates which are parallel to the control plate while being spaced therefrom.