A device and method for cleaving a sample includes: creating an indentation on a top surface of the sample by applying a downward force along a vertical axis, the axis arranging perpendicularly to the top surface of the sample; providing a breaking pin and arranging the breaking pin under the sample to touch the bottom surface of the sample at a position that is directly opposite from the indentation; and, applying a downward force on the sample by providing a left side and right side breaker pin wherein the downward force comprises a left-side downward force extended through the left-side breaker pin and right-side downward force through the right side breaker pin, further the pins that provide the left-side and right-side downward force are disposed on a breaker bar and arranged to be on opposite sides of a vertical axis that extends through the indentation on the top surface.

Disclosed are an upper jacking structure, a half-slitting machine and a half-slitting method. The upper jacking structure includes a lower jacking block, a cutting assembly, a first linear reciprocating device, an upper jacking block and an auxiliary tensioner. The lower jacking block is located below the upper jacking block, a clamping space is formed between the lower jacking block and the upper jacking block, a cutting end of the cutting assembly moves in a vertical direction and a horizontal direction in and out of the clamping space, a movable end of the first linear reciprocating device moves in the vertical direction, and the upper jacking block is provided on the movable end of the first linear reciprocating device; the upper jacking block has a first jacking surface provided with a first jacking head and a second jacking head at either side of a center line of the first jacking surface.