Socket thermal testing procedure and correlation

CPU socket temperatures have recently been projected to approach, and even exceed, their thermal reliability limits. Up until now, the prediction of socket temperatures was performed only through modeling and simulation. The major drawback of modeling is that it requires a simplification of the motherboard, CPU, and socket construction, estimates of motherboard and CPU substrate power losses, estimates of motherboard and substrate thermal conductivities, and use of pre-silicon CPU powermaps. Ideally modeling methodologies would be supported with test data, however there has been no test data available to correlate with the modeling results. This paper describes the development of a testing methodology that allows for the direct measurement of socket contact temperatures, as well as determining the impact of the motherboard, CPU, and power delivery component temperatures. The test results were then compared to modeling results in order to validate and improve future predictive efforts.