A study of thermal performance of packages using a new test die

A test die that uses power diodes for die heating and a string of emitter-base diodes for temperature sensing was designed and used for the thermal characterization of various very large-scale integration (VLSI) packages. The power diode, consisting of 100 minimum-geometry emitters, is contained entirely in the lower portion of the die. The temperature-sensing diodes consist of a string of 17 emitter-base diodes distributed over the die surface. The design allows for localized die heating and mapping of temperature variation over the surface of the die. Results of thermal measurements and die surface temperature mapping performed on a large die simulated by multiple-die assembly are presented and discussed. Topics investigated include package mold compound conductivity and substrate conductivity.<
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