Dual laser cutting of wafers
US6562698B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 2001 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Aug 21, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/0201
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method for singulating semiconductor wafers comprises the steps of aiming a first and a second laser beam over a top surface of the substrate; forming scribe lines in the coating layer by scanning the first laser beam across the coating layer; and cutting through the substrate along the scribe lines with the second laser beam to form a respective kerf. The apparatus includes a first laser having a first wavelength placed over the coating layer of the substrate, and a second laser having a second wavelength different from that of the first laser placed over a surface of the substrate. The coating layer has a first absorption coefficient relative to a wavelength of the first laser and the semiconductor substrate has a second absorption coefficient less than the first absorption coefficient. Energy from the first laser beam is absorbed into the coating layer to form scribe lines therein, and the second laser beam cuts through the substrate along the scribe lines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.