Demonstration of a high heat removal CVD diamond substrate edge-cooled multichip module

摘要

A single substrate intended for a 3-dimensional (3D) edge-cooled multichip module (MCM) has been built and thermally tested. The substrate, with dimensions 1.9 in. by 2 in., is mounted in a fluid cooled block at one end. To test this cooling architecture and verify the accuracy of thermal models, the authors constructed thermal test modules using alumina (Al(sub 2)O(sub 3)), aluminum nitride (AlN), and CVD diamond substrate materials. Each module was populated with an array of 16 Sandia ATC03 test chips with resistive heaters and temperature sensing diode thermometers. Comparative measurements of the 3 substrates were made in which the top row of 4 die were heated at 5 W each for a total of 20 W. The maximum temperature differences between the heated die and the interface with the cold chuck, (delta)T(sub js), were 24, 126, and 265(degrees)C for diamond, AlN and alumina, respectively. Measurements on the diamond thermal test module, uniformly heated at a total power of 40 W, gave a measured junction-to-sink temperature of (delta)T(sub js) = 18(degrees)C. This result indicates that the diamond edge-cooled substrate could dissipate a total power (approximately)200 W for a maximum (delta)T(sub js) (approximately)100(degrees)C. If multiple substrates were mounted in the fluid cooled block, spaced 0.075 in. apart, the volumetric power density would be about 880 W/in.