Diamond Heat Sinks for Electronic Circuits.

During the interim stage of this Phase I R and D, a useful metallizing procedure for bulk diamond has been developed, with natural diamond chips, granules, and polished wafers from two vendors. Small-scale statistical experiments were designed and executed by systematically varying several material and processing variables including metallizing and brazing compositions, processing temperature and time, ambient control, and other procedural changes. Under selected combinations of these variables, metallizing of these diamond samples was achieved. Surface wetting appears to be excellent. The metallized surfaces were brazed or soldered to metal for future heat sink uses in high-power electronic circuits. These results clearly demonstrate the proof of the principle that is our main objective in Phase I. The remainder of the Phase I work will be directed to metallizing and brazing polished diamond wafers to metal copper andor Kovar substrates detailed sample characterization including SEM, microstructural and microprobing analyses thermal conductance measurements of mounted diamond wafers and analyzing all results for the final report.