Laser marking focus feedback system having an intensity indication of reflected radiation passed through an objective lens, a beam splitter and a pinhole
US10916462B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 2018 |
| Grant date | Feb 9, 2021 |
| Priority date | — |
| Expiry date | Dec 6, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2223/54433
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of focusing includes irradiating an object by directing radiation output by a radiating source through an objective lens, measuring a first intensity of reflected radiation that is reflected from the object, adjusting a distance between the objective lens and the object, measuring a second intensity of reflected radiation, and analyzing the first intensity of reflected radiation and the second intensity of reflected radiation to determine a focal distance between the objective lens and the object. The distance between the objective lens and the object is adjusted to the focal distance and the irradiating intensity is increased to mark the object. In another example, measuring the first intensity of reflected radiation is performed by directing reflected radiation from the object through the objective lens, a beam splitter, a focusing lens, and a pinhole and onto a sensor that outputs a signal indicative of sensed radiation intensity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.