An adhesion layer made from Al film or Ti film is formed on Cu electrode pad portions as external connection terminals of a Cu interconnection layer of an LSI formed on the surface layer of a semiconductor substrate. Embodiments of the subcombination and the fruit extraction device of which it is a portion shear the peel in multiple slivers, at the same time compressing the fruit. The adjusting method of the gamma voltage adjusting device includes: generating N+2 gamma voltages with the printed circuit board assembly; inputting the N+2 gamma voltages to the gamma voltage fine-tuning unit; and generating negative polarity driving voltages and positive polarity driving voltages which are symmetrical according to the N+2 gamma voltages.