Abstract: A method for assembling semiconductor packages (10) includes forming corresponding pairs of conductive pads (14, 16, 20, 22) on respective surfaces of a die (12) and an interconnective substrate (18). Each pad in each pair includes an upper portion comprising at least one component of an electrically conductive eutectic alloy. Sharp, upstanding peaks (50, 58) are formed on at least one of the pads in each pair. The die and substrate are forcefully abutted and the pads heated until the sharp peaks penetrate through oxide films (52) on the respective opposing pads in each pair and contact the upper surface of the other pad therein, thereby initiating pad fusion. The pads are then cooled to solidify the molten portions thereof into an electrically conductive joint between each corresponding pair of pads and a hermetic seal around the periphery of the package.

Abstract: A reversible hand operated rotary power tool contains an internal mechanism for reducing the reaction torque that would otherwise be exhibited directly upon the housing, and hence imposed upon the hand of the operator. The mechanism is bidirectional, and reduces reaction torque to the same extent whether the tool is being operated in a forward direction or in a reverse direction. The mechanism includes a planetary differential mechanism having an input driven from a powered rotor, one separate output that is drivingly coupled to an output shaft, and another separate output that is drivingly coupled to an offset shaft that is laterally offset from the axis of the powered rotor. A lever system is employed to inhibit rotation of the offset shaft in either direction relative to the housing and thereby reduce reaction torque exhibited on the housing.

Abstract: A powered hand-held rotary tool adapted for preventing an externally manifested reaction torque upon the hand of an operator consists of a housing, a rotor adapted to be driven for rotation relative to the housing, and a planetary differential mechanism having a sun gear coaxial with and driven from the rotor, planetary gears, and a ring gear. The ring gear is rotatable relative to the housing. A first output gear is coaxial with the sun gear and rotatably driven by the planetary gears. An additional output gearing is rotatably supported from the housing on an axis that is laterally offset from the axis of the rotor, and is drivingly engaged by the ring gear. Rotation of the additional gearing in one direction relative to the housing is inhibited.

Abstract: A differential rotary driver includes a power input shaft, a differential gear mechanism arranged coaxial to the power input shaft and having two output gears with mutually opposite rotations, and a housing which rotatably supports both input shaft and differential gear mechanism. The housing also has a rigid, crank-shaped lateral extension portion.Within the lateral extension portion of the housing both a central output shaft and a circumferentially concentric output shaft are rotatably supported on an axis which is laterally offset relative to the axis of the input shaft. Driving gears provided on the two output shafts are driven by corresponding output gears of the differential mechanism.When rotary power is applied between the housing and the power input shaft, an operator holding the housing experiences no reaction torque at any stage of the tightening of a fastener.

Abstract: A three-piece fastener includes a bolt with a shank having a concentric opening in its threaded end, a nut adapted to fit over the threaded end of the bolt, and a wedge member which is insertable into the end opening of the bolt for expanding and thereby securing it. The threaded end of the bolt is axially slotted to facilitate its expansion.The outer diameter of the wedge member is smaller than the outer diameter of the threaded end of the bolt. When the bolt is to be inserted into an opening of a structure in order to accomplish a fastening action, the wedge member is first loosely inserted into the end opening of the bolt. Then when the bolt and wedge are passed through the opening, the nut is applied to the end of the bolt and is tightened. Thereafter, the wedge is tightened in order to expand the end of the bolt.The end opening of the bolt has interior threads, and is threadedly engaged by the wedge member, but in an opposite rotational sense to that in which the nut is applied to the bolt.

Abstract: A driver with automatic speed and torque switching including two different drive trains which operate in parallel and are driven at the same time by a motor. One drive train provides a high-speed output while the other provides a low-speed output. A single drive head for transmitting torque to the nut is normally coupled to the high-speed output, and not to the low-speed output. The machine operates initially at the high speed for the "free rotation" of the nut. When the nut contacts the surface of the structural body, the drive coupling to the high-speed output is disabled, and the low-speed output (which formerly was not coupled to the drive head) is not at the same time coupled to the drive head. The nut is then driven much more slowly but with a higher driving torque. Within the low-speed drive train there is included a friction clutch, and adjustment means for adjusting the level of torque at which it will slip.