Wafer level burn-in and test thermal chuck and method
US6140616A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 1998 |
| Grant date | Oct 31, 2000 |
| Priority date | — |
| Expiry date | Sep 25, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67103
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A thermal chuck or heat sink (10) has a lower surface (12) covered with fins (14) parallel to air flow (16), to increase the surface area and promote heat transfer. A pair of slots (32) near pedestal (20) (along the fins) effectively lowers the conductivity of the metal in the direction across the fins. Heat flowing through this region of lowered conductivity experiences a greater temperature drop. This raises the temperature at the adjacent parts of the top surface, and (for properly sized slots) results in circular isotherms. The circular isotherms are turned into a nearly isothermal surface by a precisely dimensioned groove (36) parallel to the top surface (22), extending around the circumference of the pedestal (20). Heat flowing into the outer regions of the circular surface (22) is forced to travel radially inward, thus raising the edge temperature (which would naturally be lower than the center). For properly sized slots (32) and groove (36), it is possible to achieve a nearly constant temperature top surface (22).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.