Optical method for determining relative positions of two pieces and device for its implementation
US5343049A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1993 |
| Grant date | Aug 30, 1994 |
| Priority date | — |
| Expiry date | Feb 26, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Optical method for determining the lateral gap of two pieces (1, 2) having adjacent edges (3, 4) forming a slot (5) consisting in emitting a parallel light beam (8) through at least one zone of said slot, from one side of the latter; in detecting the beam (8a) passing through this zone of said slot, at the other side of the latter; and in comparing the light intensity of this beam transversing said zone with a predetermined value so as to obtain or to provide the gap between the edges of said pieces in said zone. This method may be applied to the positioning of a first piece, such as a chip, opposite or in an opening made in a second piece, such as a substrate, and may consist in moving said first piece in order to bring it above the opening of the second piece, in comparing, as the first piece moves, the light intensity passing through the slot separating said pieces and in stopping the movement of the first piece when the intensity of the light through-beam is equal to a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.