| 摘要 |
PROBLEM TO BE SOLVED: To prevent degradation in accuracy and reduce calculating load in a misregistration detector for detecting deformation, parallel translation error, rotational position error, and the like of printed wiring boards. SOLUTION: A printed wiring board 40 is provided with three reference marks. The programmed coordinate points S1 and S2 and the actual coordinate points S1' and S2' of the sub-marks 172 and 174 of the three reference marks are translated in parallel, so that the programmed coordinate point M and the actual coordinate point M' of the main mark 170 agree with the origin 230, and any parallel translation error is thereby eliminated (S4, S5). The actual coordinate points of the sub-marks are rotated around the origin 230 by a slop angle (q) to eliminate any rotational position error. Based on a relational expression including the rates nx and ny of expansion and contraction in the vertical direction and in the horizontal direction and the actual slope angle Q of the printed board 40 in this state and the programmed coordinates and the actual coordinates of the sub-marks 172 and 174 before and after the elimination of parallel translation error, the actual values of the rates nx and ny of expansion and contraction and the actual slop angle Q are obtained (S6, S7). |
