Abstract: An apparatus for hydrotesting a hollow component includes a generally cylindrical main body having a bore therethrough that defines first and second open ends, the bore including a central axis; first and second end plates fixed to the main body for closing the first and second open ends, the first end plate including a vent port and a pressure port that open into the bore radially distal from the central axis, the second end plate including a vent port and a pressure port; an alignment disc disposed in the bore and fixed atop the second end plate, the alignment disc including a vent port and a pressure port that open into the bore radially proximal the central axis, the vent port and the pressure port of the alignment disc being in fluid communication with the vent port and the pressure port, respectively, of the second end plate; and a movable sealing cap disposed in an opening in the first plate and movable along the central axis of the bore.

Abstract: A polishing bar is provided with a plurality of backings that are carried via blocks of impact absorbent material on a bar of greater stiffness. Each backing is shaped with two surfaces at an angle to each other. A polishing tape is disposed over the angled surfaces of each backing. The portion of the polishing tape over the forward surface of the backing is employed to polish the angled edge of the top wafer of a rotating bonded wafer pair.

Abstract: The wafer edge processing unit may be a stand alone unit or may be incorporated in existing grinding machines. The processing unit employs a plurality of tapes which are coated with differing grades of grit to sequentially polish the edge of a rotating wafer or to remove an edge bead from a processed wafer or the other substrate. The tapes are mounted on a backing block which is rotated to move the tapes from a line contact with the top bevel of the wafer to a line contact with the bottom bevel of the wafer. Fresh surfaces of the tapes are presented to successive wafers by rotating the spools on which the tapes are mounted. The wafer may be moved in small increments along a Y-axis and/or an X-axis relative to a tape during polishing to improve the polishing operation.

Abstract: A wafer edge grinding or polishing machine is provided with a pair of chucks for engaging a wafer therebetween, a fixed reference surface and a sensor which is movable with a movable chuck. Measurements are made by the sensor relative to the fixed reference plane when the movable chuck is in engagement with the opposite chuck without a wafer therebetween in order to obtain a standard measurement value. With a wafer between the chucks, the sensor obtains an actual measurement value relative to the fixed reference surface. A calculator determines the difference between the standard and actual measurements values and displays the difference as the thickness of the wafer. Multiple sensors may be used to obtain multiples readings which are averaged by the calculator to obtain a thickness measurement.

Abstract: The notch polishing machine employs a plurality of polishing tapes which can be sequentially introduced into the notch of a wafer to polish both sides of the notch, i.e. the top and bottom surfaces. Each tape is pulled off a supply reel and passed into a mounting block sized to fit into the wafer notch. Each block is also mounted to be oscillated to effect a polishing action. Also, all the blocks are mounted in common to be pivoted between a position angularly disposed relative to the top of the top of the wafer and a position angularly disposed relative to the bottom of the wafer.

Abstract: A seal assembly for a wafer grinding machine is mounted on a housing in which a grinding wheel is contained. The seal assembly is formed of a pair of flexible strips which are secured over an opening in a plate mounted on a housing enclosing the grinding wheel for sealingly engaging a respective planar surface of a wafer which is introduced through the opening by a rotatable chuck. The edges of the sealing strips define a V-shaped gap to ensure that the edges are disposed in biased relation against each other and against a wafer which passes between the strips. A tube provided with perforations is disposed to blow air to clear debris from the wafer.

Abstract: The wafer centering assembly includes a pair of pivot arms which can be pivoted simultaneously to adjust to the diameter of a conveyed wafer. Each pivot arm has a stop which arrest the motion of a wafer such that the axis of the wafer is approximately centered on the axis of a vacuum head.

Abstract: A seal assembly is mounted within a grinding machine to separate a grinding wheel from the main portions of a wafer being ground. The seal assembly has a pair of free edges which are disposed to define a V-shaped gap through which the peripheral edge of the wafer passes into grinding relation with the grinding wheel. A perforated hollow tube is also mounted behind the free edges of the strips to blow air onto and across the planar surface of the wafer being ground to prevent accumulation of debris thereon.

Abstract: The wafer alignment fixture is provided with a pair of upstanding walls for mounting of a wafer cassette thereon as well as with a roller parallel to the walls to engage with the wafers of the cassette. Rotation of the roller causes the wafers in the cassette to rotate so as to move the notches of the wafers into alignment with the rollers. Upon coming into alignment with the roller, the wafers drop down onto a pair of support surfaces while being spaced from the roller so that further rotation is precluded. The roller may be tensioned in order to eliminate sag due to the weight of the wafers. Also, a second roller may be provided for rotating the aligned notches of the wafers into a different angular position within the cassette.