Apparatus and method for reliably releasing wet, thin wafers
US6254155A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 11, 1999 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Jan 11, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/6838
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
In a type of end effector used for handling wafers in the semiconductor industry, the wafer is acquired by lowering the end effector until it almost touches the upper side of the wafer and then applying suction to lift the water into contact with a wafer contacting surface on the underside of the end effector. Release of the wafer is accomplished by relieving the suction or replacing it with a small overpressure. Wet thin wafers do not reliably release; the liquid spreads into a thin film between the upper side of the wafer and the wafer contacting surface, and the surface tension of this film causes the thin wet wafer to adhere to the wafer contacting surface. This problem is solved by affixing a sheet of a porous resilient material, such as open cell MYLAR.RTM., to the wafer contacting surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.