| 摘要 |
<p>The invention relates to a method and system for measuring the height of bumps or comparing bumps on a chip wafer. The method comprises the following steps: (a) projecting light, using a circular source of light, onto the bump at least twice at different angles of projection; (b) measuring the visible rings of light reflected by the bump at each different projected angle from a perpendicular viewpoint; (c) calculating the height of a bump or comparing the height of bumps, according to the extent of the visible change in the size of the reflected light rings and the projected angles. The system is comprised of three circular sources of light wherein each source is located at a different height and projected at a different angle and wherein each source projects a different color: red, green or blue. The system includes a camera for photographing the image of the visible reflected light rings from a perpendicular viewpoint. The processing unit in the system uses image-processing software to compare the bumps' height according to the difference in diameter between each color of the visible light ring, which is reflected from each bump.</p> |
