Superior Gr/Cu SEM-D Heat Sink

1In submarine electronics modules, heat dissipated by electronic devices is typically transported along the length of the heat sink (upon which ICs are mounted) to the water cooled side walls. The current pure copper SEM-D heat sink limits the power dissipation per card to 26W in order to maintain acceptable device junction temperatures. Foster-Miller will demonstrate an innovative Gr/Cu metal matrix composite (MMC) heat sink which offers a 25 percent reduction in thermal impedance over the current copper component. The key bottleneck for MMCa-low z-directional conductivity-will be removed by adding z-directional fibers to the planar preform using a Foster-Miller proprietary process. Additionally, the MMC heat sink will have a tailored planar CTE in the card region (thereby obviating a complaint layer) and high planar thermal conductivity. The cumulative effect will be a 6 to 10 C reduction in the device junction temperature (thereby >50 percent reduction in device failure rate) for the same power density, or alternatively, a 25 percent increase in the power dissipation at current device junction temperatures. Additionally, the 45 percent lighter Gr/Cu heat sink will accrue significant savings in the electronics system and structural weight. During Phase I Foster-Miller will fabricate and test MMC specimens representative of three critical regions-card, rib and bend region; of the Foster-Miller SEM-D heat sink concept. This will lead into Phase II when the design and processing will be optimized and high properties will be consistently demonstrated in full scale Gr/Cu SEM-D heat sinks.