Method of breaking a plate-like workpiece such as a semi-conductor wafer, and device for breaking said workpiece sandwiched between two foils

摘要

The method comprises : scribing a workpiece surface; placing the workpiece (4), with its scribed surface facing upwards, in sandwich (3) between an upper (6) and a lower (5) foil both flexible and stretchable and extending beyond the workpiece, an adhesive joining the workpiece (4) to the lower foil (5); stretching the sandwich (3); applying an upward force to the lower side of the sandwich (3) to bend the workpiece (4) normal to the scribed lines; and removing the upper foil (6), whereafter the individual bars broken off the workpiece (4) are taken from the lower foil (5). The individual bars become separated sufficient to avoid mutual damage of the neighboring broken off surfaces. Preferably, the tensile strength of the lower foil (5) is lower that that of the upper foil (6) and the sandwich (3) is stretched in excess of the elastic limit of both foils. An intermediate foil (26) of polyester or polyimide can be interposed between the upper surface of the workpiece (4) and the upper foil (6).;The device comprises: a base element (1); first gripping means (7) fixed at the base element for releasably holding one sandwich (3) end; second gripping means (8) arranged at the base element and movable in the longitudinal direction while releasably holding the other sandwich (3) end; means (13-18) for adjustably displacing the second gripping means (8) in the longitudinal direction; and a cylindrical rod (19) placed on the base element (1) parallel to the transverse direction and movable in the longitudinal direction.