In-situ sizing of photolithographic mask or the like, and frame therefore
US5626784A · kind A · utility
5Cited by
9References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 31, 1995 |
| Grant date | May 6, 1997 |
| Priority date | — |
| Expiry date | Mar 31, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/0082
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Alignment of a mask, such as a photolithographic mask, to a workpiece, such as a printed circuit board is improved using a frame having sides that are individually thermally expandable. The mask is fabricated to be undersized so that the distance between fiducials on the mask is less than a desired distance, which may be the distance between corresponding fiducials on the workpiece. The mask is mounted on the frame, whereafter at least one side of the frame is heated to expand the side and stretch the mask to achieve the desired interfiducial distance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.