Title:
WAFER LEVEL BURN-IN AND TEST THERMAL CHUCK AND METHOD
Document Type and Number:
WIPO Patent Application WO2000019775
Kind Code:
B1
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).
Inventors:
ANDBERG JOHN W
Application Number:
PCT/US1999/021885
Publication Date:
June 15, 2000
Filing Date:
September 20, 1999
Export Citation:
Assignee:
AEHR TEST SYSTEMS (US)
International Classes:
G01R31/30; H01L21/00; H01L21/66; H01L21/683; G01R31/26; (IPC1-7): H05B3/68; H05B3/44; H01T23/00; B23B5/22; C23C16/00
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