Modeling and Validation of On-Die Cooling of Dual-Core CPU using Embedded Thermoelectric Devices

Today's high density processor circuits produce areas of high heat flux which can impose a thermal ceiling on product performance. Chip scale cooling solutions unnecessarily add to the heat sink load by cooling low heat flux areas in addition to the critical localized high heat flux areas (hot spots). In this paper, we demonstrate that embedded thermoelectric cooling (eTEC) technology can be used to significantly lower processor core operating temperatures by focusing the cooling directly on the hottest region. The demonstration vehicle used for this work was the Intel mobile Core 2 Duo, code-named "Merom", the mobile version of Intel's Conroe desktop CPU. Merom utilizes two processor cores that generate localized areas of high heat flux, and as such is ideally suited to demonstrate the benefits of eTEC integration. The Merom chip is available in bare die form, which allowed the eTEC to be integrated onto an external heat spreader and subsequently attached to the CPU. Use of this localized cooling approach and a properly integrated eTEC, provided sustained processor core temperature reductions of between 5°C and 6°C. These cooling results are achieved using a solid-state technology with the associated benefits of manufacturing efficiency, and quiet, reliable operation.