GB1388928A - Wafer breaker - Google Patents

Abstract

1388928 Splitting H F CARLSON 8 March 1972 [8 March 1971] 10830/72 Heading B5E A method of breaking a semi-conductor wafer 62 along a set of parallel score lines scribed on one side of the wafer comprises positioning the wafer intermediate a platen 56 having a surface carved in a direction perpendicular to the score lines and means 36 having a surface which is initially flat facing the platen with the scored side of the wafer in contact with the facing surface, and progressively conforming the facing surface and the wafer to the curved platen surface by moving the platen and means together and thereby first breaking the wafer about a central scribe line and then successively breaking the wafer about pairs of scribe lines symmetrically spaced from the central scribe line. In apparatus for carrying out the method, the facing means consists of a steel band 36 which is held over a pair of rollers 31 and has its ends 29 connected to the rods 22 of pneumatic piston-and-cylinder devices 18, 19 mounted on the frame of the apparatus. The platen 56 has a curved surface 58 and is mounted on the rod 48 of a further pneumatic piston-andcylinder device 41 also mounted on the frame. The wafer has two sets of scribe lines 63, 64 at right angles to one another and is placed on a carrier member having a base sheet 69 and an apertured guide sheet 71. A thin sheet 73 of paper is placed over the member and wafer and the assembly is positioned in a recess 88 in a slide 84 movable along a guideway in a plate 79 secured by a bracket 77 to the frame. The slide is movable by a handle 89 to position the wafer assembly between the platen and band so that when the device 41 is actuated to raise the platen, the wafer is pressed against the band which is held under tension by the devices 18, 19 and deforms to fracture the wafer first along the central score line and then simultaneously along pairs of score lines symmetrically spaced from the central line. After fracturing of the wafer along one set of the score lines, the slide is withdrawn and the wafer assembly rotated through 90 degrees by a handle 154 so that the wafer can be fractured along the other side of score lines. The operation of the apparatus may be automatically controlled and the movements effected by hydraulic electrical or mechanical means.