Abstract: The use of a liquid nitrogen (LN.sub.2) bath to produce thermal stress between an aluminum heat sink and a silicon circuit board by deep cooling, makes it possible to separate each from the other product undamaged. This allows repair or replacement of the silicon substrate in a very short time with very little turn around time.

Abstract: A defective focusing coil, impregnated with and held in place with epoxy is removed from its inner lead liner and its outer brass housing by immersing the assembled parts in a bath of liquid nitrogen until the temperature of the assembly is reduced to the temperature of the liquid nitrogen, about -350.degree. F. The assembly is then removed from the bath and a series of sharp blows are then directed to the side of the brass housing to break the bond between the super cooled epoxy and the housing. Axial pressure is then applied to the coil, to remove the coil and liner. The coil is then cut longitudinally into two half cylinders, whereupon the coil is split from the liner, all without injury to either the liner or the housings.

Abstract: A method of separating structure comprising first and second components having different coefficients of thermal expansion and bonded together with a bonding material. Separation is achieved by immersing the structure in a cryogenic cooling substance to break the bonding material as a result of the different rates of expansion of the two components and then applying a force to separate the two components. Separation of a rotor and its windings is disclosed.

Abstract: A method of separating/splitting multi-layer printed circuit wiring boards by immersing the board and the blade of a surgical knife into liquid nitrogen to lower their temperatures to that of the liquid nitrogen thereby altering the holding properties of the adhesive material between the layers of the multi-layer board. Separating one layer at a time from the printed circuit wiring board until all layers of the multi-layer board have been removed.