Abstract: A guide (28) is provided for retrofitting an existing internal combustion engine block (10) with roller cam followers (24 and 26) in place of conventional barrel-type lifters, without modification of the block itself. The guide includes a guide bar (64), keyed to the upper body (38) of each follower to allow limited rotational freedom thereof and a resilient C-shaped spring clip (70) which simultaneously bears downwardly on the upper surface of the guide bar and upwardly on the lower surface (40) of an engine block boss (18) defining follower receiving bores (20 and 22). Annular spacers (72) are provided, if required, to displace the guide bar upwardly from the upper surface (52) of the boss. An upper leg (76) of the spring clip wraps around the guide bar for retention therewith and a lower leg (78) of the spring clip is necked at a point (86) intermediate adjacent cylindrical portions (30 and 32) of the follower boss for retention therebetween.

Abstract: A hydraulic lash adjusting tappet (10) for use in engine valve gear of the direct-acting type having one end of the tappet contacting the end (26) of the combustion chamber valve stem (22) and the other end contacting the camshaft lobe (16). The tappet has a body (34) formed with a tubular wall portion (36) having one end thereof closed by an end wall (38) and with a tubular hub (40) therewithin formed integrally with the end wall and extending axially therefrom. A lash adjuster assembly (44) is slidingly received in the tubular hub which defines a reaction surface (50) remote from the cam face reaction surface (18) defined by the end wall.

Abstract: Apparatus for accurately measuring the charge distribution, and hence the voltage, on a non-conducting workpiece during ion bombardment. The invention is based on the principal that the charge on the surface of the workpiece induces equal and opposite charge on the surface of an isolated proof plane conductor placed in front of it. A workpiece is moved at a known speed in front of the proof plane, whose dimensions are small compared to the workpiece. The measurement of the time distribution of the induced charge on the proof plane is a measure of the spatial distribution of the charge on the bombarded workpiece. The proof plane surface is isolated from currents which might flow directly to its surface.

Abstract: A target chamber for a mechanically scanned ion implanter in which semiconductor wafers are maintained in contact with a rotating target disk entirely by body forces, thus eliminating the need for clamping members contacting the wafer surface. The axis of the disk is inclined, and the disk is in the form of a shallow dish having an inclined rim with cooled wafer-receiving stations formed on the inner surface of the rim. Centrifugal force is relied on to force the wafers against the cooled disk. Each wafer-receiving station includes fence structures which are engaged by the wafer during loading and when the disk is spinning. The fence structures are resilient so that wafer damage and thus particulate contamination is minimized. In accordance with another aspect of the invention the ion beam is projected against the wafers obliquely to the radius of the disk as to minimize striping effects and overscan.

Abstract: Docking apparatus for a semiconductor wafer prober (16). A cylindrical housing assembly provides an electrical interface between pads on the wafer (22) and contacts on the load board (76) of a test head (12) through a contact ring (74). The housing assembly is in two parts with a first part (29) clamped to a frame portion (30) of the prober and a second part (58) supported above the first part by compression springs (64). Limited angular movement is provided between the housing assembly and the prober frame. The separation between the housing members is maintained so that the force exerted on the contact ring in the docking process is determined by the compression of the springs.

Abstract: A vehicle (10) particularly adapted for use as an automated guided vehicle uses standard plastic tote boxes as a body shell (13) and as a battery carrier (20). The vehicle includes a drive wheel assembly (14) and a bogey assembly (16) which pivot about center pivot points and are steered by a single motor-driven steering assembly (18) which provides dual fifth wheel steering. Commonly-driven ball screw lift assemblies (122) engage the underside of nestable load-carrying tote boxes (22) for pickup and delivery functions. The weight of the load carrier(s) is transferred through the vehicle frame (12) to load transfer assemblies (76) on the drive and bogey assemblies.

Abstract: Method and apparatus for obtaining absolute spatial intensity distribution of a beam of particles in ion implanters. The invention is particularly applicable to ion implanters in which device wafers are mounted on the face of a disk which is rotated, and may be translated, in front of an implanting beam. A spiral pattern of appropriately shaped holes is formed in a spinning disk that holds the wafers. The fluence density of the beam passing through each hole is a precise measure of the fluence density of the particles striking the device wafer at the radial position of the hole. Thus, a measure of the absolute number of particles, and the spatial distribution of those particles is obtained. The invention is useful for beam diagnostics, for quality control of the implantation and for the control over variable intensity implanted ions.

Abstract: An apparatus for measuring and compensating for neutral ions in an ion beam in the dose control system of an ion implanter. The gas pressure in the implantation volume (15) is measured, and the pressure signal is converted to an effective beam current signal in accordance with a known relationship among the gas pressure, the apparent beam current as measured by a Faraday cage and the neutral beam. The resulting effective beam current signal is inputted to the dose control system.

Abstract: A method and apparatus for measuring and compensating for neutral ions in an ion beam in the dose control system of an ion implanter. The gas pressure in the implantation volume (15) is measured, and the pressure signal is converted to an effective beam current signal in accordance with a known relationship among the gas pressure, the apparent beam current as measured by a Faraday cage and the neutral beam. The resulting effective beam current signal is inputted to the dose control system.

Abstract: A mask substrate for use in X-ray lithography formed of a composite, X-ray transparent member which is stretched over a fixture to a predetermined tension and then adhered to a borosilicate glass ring. In accordance with a preferred embodiment, the composite member includes a film of polyborane which has been grown in compression, onto which a polyimide is coated. The polyborane film is grown on a silicon wafer, coated with the polyimide, after which the central area of the wafer is etched away. The borosilicate glass is adhered to the polyimide side of the composite, leaving the tensioned polyborane surface open for the application of an X-ray absorptive pattern thereto to define a complete mask structure suitable for use in X-ray lithography.

Abstract: A transport apparatus (10) for moving semiconductor wafers (12) between a cassette (15) and a process station (16), and from the process station to another cassette (17). A horizontally movable input shuttle (20) has three wafer holding elements (30, 32, 34) formed thereon. In a first position of the shuttle the second and third holding elements overly a pair of vertically movable lift plates (60), and in a second position of the shuttle the first and second holding elements overly the lift plates. A lifting mechanism (28) at the process station lifts wafers off the input shuttle when the shuttle is in its second position and deposits them on an output shuttle (22) which is essentially identical to the input shuttle. Wafers are lifted off the holding elements by the lift plates whenever the shuttle reaches either position, after which the lift plates replace the wafers on the shuttle and the shuttle is again moved.

Abstract: A method and apparatus are disclosed for providing heat conduction between an article being treated in a vacuum and a support member by providing a gas under pressure of about 0.5 to 2.0 Torr between the article and the support member. The method and apparatus are described for use in a semiconductor wafer ion implantation system wherein the wafer is clamped to the support member which is cooled. A seal can be provided between the wafer and the support member adjacent the periphery of the article.

Abstract: An apparatus and method for measuring the atomic mass of ion species selected by the analyzing magnet (14) of an ion implanter (10). A signal proportional to the magnetic field of the analyzing magnet is obtained by means of a rotating coil (36), and this signal is used to calculate the atomic mass by means of the equation: Atomic Mass=KB.sup.2 /V where B is the magnetic field, V is the ion beam energy at the analyzing magnet, and K is a proportionality constant. The rotating coil (36) is driven by a synchronous motor (38) powered by A.C. line voltage, and the output voltage is converted to a frequency signal proportional to the magnetic field and the line frequency. The frequency signal is counted over a time corresponding to the period of the line frequency to cancel out the line frequency dependence of the frequency signal. In accordance with one embodiment of the invention, a microprocessor is utilized to evaluate the B and V signals and to calculate the atomic mass.

Abstract: An electrical circuit element (16) is maintained in place within the drop center (24) of a vehicle wheel (10) by encasing the circuit within a cylindrical plastic housing (14) which is formed into an arcuate shape. The housing is held in place by wires (18, 19) which are connected to the ends of an extension spring (22) which applies sufficient tension to keep the housing from moving during heavy braking or due to centrifugal force. The mounting assembly is configured to move to an out of the way position when contacted by a tire iron or by elements of a tire mounting machine to prevent damage to the circuit when a tire is mounted or demounted. In accordance with another embodiment of the invention, the circuit (16) is encased within a unitary annular member (56).

Abstract: A wire-guided vehicle (10) in which a load is carried by a load platform (18) which is suspended from a base frame (12) by link members (42). The load is carried on a load carriage (20) which is moved vertically relative to the load platform by a plurality of screw jacks (92) acting between the load platform and the load carriage. The base frame is articulated about a transverse axis (27), and a power unit (14) which includes drive-steer units (16) is mounted on the base frame for pivotal movement about a longitudinal axis (34). A battery carrier (116) of the vehicle includes a latch assembly (152) which retains the power supply batteries within the vehicle while permitting easy removal when the latch assembly is engaged by a battery cart (170).

Abstract: A tire valve assembly (10) which includes a valve stem (11), a combined actuating pin and valve element (14), a spring (18) and a retainer (16). A valve seat (19) is formed as part of the stem, and the combined pin and valve element is made of a material which is sufficiently rigid to function as an actuating element yet is sufficiently resilient to serve as an effective seal.

Abstract: A combined unloading valve and check valve (10) for use with a motor driven air compressor. The unloading valve (16) includes a spool (30) axially movable within a tubular body (12). In the unloading position of the valve, one of two spaced-apart ring seals (32) on the spool is out of engagement with the body to open a flowpath from the inlet of the valve past the spool to exhaust ports (28) formed in the body. When the compressor is operating and the valve is pressurized, both ring seals engage the body to close off the flowpath. The check valve (18) extends beyond the end of the body and includes a poppet valve element (50) which engages a valve seat (52) formed on an end of the spool. When the unloading valve and check valve is installed in a wall (14) of an air tank the check valve extends into the air supply within the tank, thereby helping to cool the internal elements of the valve structure.

Abstract: A vehicle engine accessory drive system is disclosed including a hydraulic fan motor (M) and a power steering gear mechanism (SG) in series flow relationship. The system includes a variable displacement power steering pump assembly (P) which is the sole source of fluid for the system, and includes a variable displacement pumping element (PE) and a displacement control valve (CV). The displacement control valve includes a pilot valve (35) which is responsive to the demand for cooling to vary the fluid pressure in a signal chamber (63). The displacement control valve is operable to communicate a control fluid pressure to a stroking cylinder (SC) to control the fluid delivery rate of the pumping element. At a first relatively lower temperature, the displacement control valve maintains the fluid delivery rate of the pumping element at Z, and at a second relatively higher temperature, to maintain the fluid delivery rate at X.

Abstract: A tire valve extension (10) which includes a relief valve element (24) to limit the inflation pressure of the tire. The extension has a tubular body with an annular recess (36) formed therein to define an outer tube section (14) and an inner tube section (16). A spring loaded valve actuating pin (18) is received within the inner tube section, and the relief valve element is received within the recess. Ports (32) formed in the body intersect a channel (38) formed in the recess to define a relief flow path.

Abstract: A valve (16) for use in a vacuum load lock for semiconductor processing equipment. The valve includes a base having a horizontal passage (34) formed through it for the transfer of semiconductor wafers (12) and a vertically moving valve element (50) received in a second passage (36) intersecting the first. The valve element includes a sealing element (62) which seals partly on a horizontal wall of the first passage and partly on a wall of the second passage, and is actuated by an air piston (56). A seal is effected between the pressurized and evacuated areas of the valve by means of a flexible diaphragm attached to the piston rod (48) and to the valve body (20, 22).