Method and apparatus for detecting positions of chips on a semiconductor wafer
US4213117A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 1978 |
| Grant date | Jul 15, 1980 |
| Priority date | — |
| Expiry date | Nov 28, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting positions of chips on a semiconductor wafer. The method comprises an illuminating step for illuminating obliquely the semiconductor wafer from above including at least a position detecting direction; a totalizing step for optically totalizing, when the irregular reflecting rays reflecting at the semiconductor wafer illuminated at the illuminating step are photographed by an image pickup element or device, the irregular reflecting rays in the direction normal to the position detecting direction or for electrically totalizing the levels of a video signal produced by the image pickup element or device in the same direction; a video signal detecting step for producing a video signal with coordinates lying in the position detecting direction by photographing an image resulting from optical totalization at the totalizing step by the image pickup element or device or electrically totalizing the image; and a street position detecting step for detecting a street position between chips by extracting a specific coordinate with a wide width and a low level corresponding to dark from the video signal produced at the video signal detecting step. The apparatus…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.