Method of singulating a thin semiconductor wafer
US8785298B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2013 |
| Grant date | Jul 22, 2014 |
| Priority date | — |
| Expiry date | Mar 12, 2033 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/50
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of singulating a semiconductor wafer having two surfaces separated by a thickness T<200 μm includes partitioning it along a network of scribelines on one side. The other side is secured to an elastic foil, which is clamped to a wafer table. A radiative scribing tool is used to produce at least one laser beam having a pulse duration P≦75 ps, and causing the laser beam to scan along each of the scribelines so as to create a scribe with a depth D<T, thereby leaving the second surface intact. The foil is laterally stretched to sever the second major surface along the path of the scribes. In an embodiment, P<CPP, the Time Constant of phonon-phonon coupling in the wafer at the location of incidence of the laser beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.