Abstract: An apparatus for excising microelectronic packages assembled to a common substrate includes a mechanical element which travels over a path defined on the common substrate, a castor element pivotally mounted to the mechanical element for movement about a pivot axis, and a cutting wheel rotatably mounted to the castor element so as to provide a castoring action for the cutting wheel. The cutting wheel has an asymmetrical cutling edge which selectively engages the common substrate so that when the mechanical element guides the cutting wheel over the path, the cutting edge severs the common substrate to provide one or more of the microelectronic packages separate from one another.

Abstract: A rotary external combustion heat engine for furnishing mechanical energy from a source of heat. The engine includes a ring-like stator having an oval rotor chamber enclosing a cylindrical rotor eccentrically placed within the chamber to define a high displacement high temperature fluid chamber and a lower displacement low temperature fluid chamber. A plurality of extensible vanes extend outwardly from the rotor in sliding contact with the inner surface of the rotor chamber. A source of heat supplies thermal energy to fluid supplied to the high temperature chamber, while a heat sink cools fluid supplied to the low temperature chamber. An economizer heat exchanger is also provided for preheating the working fluid. The relative position of the rotor within the rotor chamber is adjustable for varying the relative displacement of the fluid chambers to control engine working parameters.