| 摘要 |
PURPOSE:To obtain a clear picture frame even when chips are replaced by a method wherein the pattern image pickup device to be provided on an IC chip pellet is composed of a plurality of optical image pickup sections, the focus depth characteristic of which is differred by stages and also a device, with which the most clear height of focus depth is detected, is provided. CONSTITUTION:The pattern on the IC chip pellet 2, which is placed on a substrate 1, is image-formed on the surface 5 of an image pickup element 6 through the intermediary of an object lens 3 and a relay lens 4 located on the pattern image pickup device 10. In this constitution, a lens 4 is consisted of a group of lenses of nXm pieces having a slightly different focal distance respectively, and nXm pieces of patterns are image-formed on the element surface 5 also. Then, an image signal detecting circuit 11 to be used as a detecting system is provided, the image signal from this point is converted into a differential waveform and the image of the heghest level among the waveforms corresponded to the images of nXm pieces by a high level detecting circuit 13 is obtained by a frame detecting circuit 14. Subsequently, the address of the desired pad is detected using a pattern data detecting circuit 15 and a pattern position detecting circuit 16. |
