JPS6468937A - Chip-map formation - Google Patents

Abstract

PURPOSE:To specify a chip at an outer end and to shorten a computing time for determining the effectiveness of the chip, by obtaining positional relation of each chip with respect to a wafer, based on the position of center of the wafer, the radius of the wafer, the position of one chip in the vicinity of the center of the wafer and index sizes in the directions of (x) and (y), which are set beforehand. CONSTITUTION:The position of a center 1 of a chip in the vicinity of the center of a wafer is expressed with coordinates X and Y of a position, where an X stage 11 and a Y stage 12 are driven and the probe of a probe card 20 agrees with the bonding pad of the chip in the vicinity of the wafer. The position of a wafer center 2 and a radius R of the wafer are measured by using an electrostatic sensor 17, a camera 18 and an image recognizing device 24. A chip map is formed based on these data. At first, an intersection O (Ox, Oy), which is obtained by extending the center of the outermost chip leftward viewed from the directions of (x) and (y), is obtained by the expression l. Then a point S (nt, m1) at the upper left part, which is moved from the point 0 in the directions (x) and (y) by every 1/2 index, is computed. This point is a starting point for obtaining the position of the chip at the outer end.