Wafer processing method including uniting a wafer, a ring frame and a polyester sheet without using an adhesive layer
US11380587B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 2020 |
| Grant date | Jul 5, 2022 |
| Priority date | — |
| Expiry date | Dec 5, 2040 |
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 modified layers in the wafer, thereby dividing the wafer into individual device chips, and a pickup step of cooling the polyester sheet in each of the plurality of separate regions corresponding to each device chip, pushing up each device chip through the polyester sheet, then picking up each device chip from the polyester sheet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.