Wafer processing method including uniting wafer, ring frame and polyester sheet without using an adhesive layer
US11545393B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2020 |
| Grant date | Jan 3, 2023 |
| Priority date | — |
| Expiry date | May 6, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2221/68327
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A wafer processing method includes a polyester sheet providing step of positioning a wafer in an inside opening of a ring frame and providing a polyester sheet on a back side or a front side of the wafer and on a back side of the ring frame, a uniting step of heating the polyester sheet as applying a pressure to the polyester sheet to thereby unite the wafer and the ring frame through the polyester sheet by thermocompression bonding, a dividing step of applying a laser beam to the wafer to form shield tunnels in the wafer, thereby dividing the wafer into individual device chips, and a pickup step of applying an ultrasonic wave to the polyester sheet, pushing up each device chip through the polyester sheet, and picking up each device chip from the polyester sheet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.