PURPOSE: To accurately detect the center of rotation of an IC chip by storing a visual field pattern recognized at the initial time of detection of rotating center, comparing it with the visual field pattern at the second and later times of the detection of the center, and moving to search a recognition camera and the chip until a pad is collected as a mark in the visual field.
CONSTITUTION: A recognition device 18 outputs a coordinates signal 1 of a visual field center 34 collected by a recognition camera 17 and a visual field pattern signal 2. A pad center position calculator 23 receives the signals 1, 2 of the center 34, counts small divisions of the signal 2 longitudinally and laterally from the center 34 to the center 35 of the pad, and obtains the coordinates of the center 35 of the initial detection pad. Then, a rotary table 14 is rotated, an IC chip is rotated at 180 in a pad placing surface, a center position calculator 24 calculates the coordinates of the center of rotation of the chip, a comparator 26 compares the initial visual field pattern from a memory 25 with the visual field pattern collected at present, and an XY table controller 29 moves a X table or a Y table until the detection pad of second or later is collected in the field.
MIYOSHI HIDEAKI
HIRATA YUUJI
