| 摘要 |
For the purpose of automatically monitoring the production of etched structures in a sheet or film 1, apertures, preferably arranged to form a grid, are also etched in each film or sheet 1. An image of the grid is projected onto light-sensitive receiving elements 7. The signal produced is a measure of the transparent area of the grid from which the critical dimensions of the etched structures are then derived. The apparatus comprises a suction plate 2 to press sheet or film 1 against covering plate 3, so that the grid covers registering apertures in these plates. <IMAGE> |
