Abstract: Pick-up heads and systems are especially useful for picking up, transporting, and placing semiconductor dies at bond sites on packaging substrates. Alternatively, the heads and systems are useful for performing these tasks with any of various other planar objects. An exemplary head includes a shank and a body. The body includes a compliant end portion contactable by the shank, and the end portion includes a face. The shank is movable relative to the end portion such that, whenever the shank is retracted, the face has a substantially planar contour, and whenever the shank is extended, the shank contacts and urges the end portion to provide the face with a convex contour. The end portion desirably defines at least one vacuum orifice connected to an evacuation device (e.g., a vacuum pump) that evacuates the vacuum orifice sufficiently to cause the planar object to adhere to the face.

Abstract: Pick-up heads and systems including such heads are disclosed. The pick-up heads and systems are especially useful for picking up, transporting, and placing semiconductor dies at bond sites on packaging substrates. Alternatively, the heads and systems are useful for performing these tasks with any of various other planar objects. An exemplary head includes a shank and a body. The body includes a compliant end portion contactable by the shank, and the end portion includes a face. The shank is movable relative to the end portion such that, whenever the shank is retracted, the face has a substantially planar contour, and whenever the shank is extended, the shank contacts and urges the end portion to provide the face with a convex contour. The end portion desirably defines at least one vacuum orifice connected to an evacuation device (e.g., a vacuum pump) that evacuates the vacuum orifice sufficiently to cause the planar object to adhere to the face.

Abstract: A prescalar using the fractional division theory. The prescalar is a critical circuit in a phase-locked loop based frequency synthesizer to provide a high frequency operation. The prescalar is also an important subassembly. Using four translucent circuits and one divisor selection circuit, a two mode frequency divider synchronously divided by ⅘ is synthesized to synthesize the fraction function. The load capacitance can be effectively reduced. Meanwhile, a reset TSPC flip flop can be designed to effectively and quickly perform the reset operation, and to assemble a two mode frequency divider synchronously divided by {fraction (16/13)}. The invention uses standard 0.25 &mgr;m CMOS fabrication process to obtain a maximum operation frequency of 6 GHz under a 2V operation voltage. The chip system integration can thus be enhanced.