Technique for aligning features on opposite surfaces of a substrate
US5298988A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1992 |
| Grant date | Mar 29, 1994 |
| Priority date | — |
| Expiry date | Jun 2, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/18
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A technique for aligning features on opposite surfaces of a substrate by generating a fiducial image at an image plane and identifying the location of the image at a viewing device remote therefrom, e.g., a video display screen. The substrate is placed so that one surface thereof, on which a feature is to be placed in alignment with a corresponding feature already present on the other oppositely disposed surface, is at the image plane. The one surface has photoresist material thereon. With the fiducial image turned off, an image of the feature on the other oppositely disposed surface is presented at the viewing device and the substrate is moved in the image plane until the image of the feature at the viewing device is at the previously identified location of the fiducial image. The fiducial image is then regenerated to mark its location in the photoresist material at the one surface of the substrate, such location then being in alignment with the corresponding feature on the other oppositely disposed surface thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.