Metal Matrix Composites (MMCs)
Aegis Technology has developed high thermal conductivity and low coefficient of thermal expansion metal matrix composites (MMCs) for thermal management systems. Structurally, MMCs provide several advantages including a high degree of stiffness and strength, but also being light in weight. We have designed both Al-based and Cu-based MMCs.
Al-Based MMCs
Thermal Conductivity: 120-180 W/mk
Coefficient of Thermal Expansion (CTE): 9.0-16.0 x 10-6 /K
Overview of AlSiC
AlSiC is a MMC that has high thermal conductivity, for excellent thermal dissipation, and a low coefficient of thermal expansion. The thermal coefficient of expansion matches that of semiconductor chips. The end result is effective removal of heat and increased reliability and stability of various electronics. The specific hardness is 3X greater than aluminum, 5X greater than Kovar, and 25X greater than copper. AlSiC has better vibration resistance compared to ceramics. The material can be coated with nickel, gold, and tin.
Baseplates
AlSiC can be used as materials for baseplates. SiC power electronics and Si based IGBTs that are mounted on ceramic substrates, can be further mounted to AlSiC baseplates, thereby eliminating any delamination of the substrate from the baseplate. In addition, die cracking is minimized.
Microwave Electronics and Heat Sinks
Al-based MMCs including AlSiC can be used for housing microwave electronics and for heat sinks. AlSiC has a CTE that is compatible for direct integrated circuit (IC) attachment. In addition, AlSiC’s weight is much lighter than tungsten and molybdenum, which makes the material ideal for various applications.
LEDs
AlSiC can also be used for high power LED (> 0.5 Watts) packaging. Whereas metal has limitations related to its CTE and ceramics are quite brittle, AlSiC overcomes these issues. AlSiC’s CTE matches that of LEDs and also provides good heat dissipation capabilities.
Flip Chip Cover
AlSiC can be attached to chips to provide better cooling compared to thermally conductive adhesives.
Pin Fin Coolers
AlSiC materials can be used for pin fin coolers which can be used for packaging SiC and IGBT power electronics found within hybrid electric vehicles. These pin fin coolers have higher strength and stiffness compared with other metals such as copper. In addition, AlSiC pin fin coolers are more tolerant to shock and vibration.
Optoelectronics
AlSiC can be used for packaging optoelectronics and provides several advantages including the ability to be structured into netshaped housings, lighter weight compared to other packaging, and ability to achieve a high degree of compactness. For optoelectronics applications, AlSiC materials can be shaped to have complex features including septums, walls, and radials. In addition, AlSiC materials are highly reliable over multiple thermal cycles, but also can be used for maintaining constant uniform temperatures.
Cu-Based MMCs
Thermal Conductivity: 220-320 W/mk
Coefficient of Thermal Expansion (CTE): 8.0-16.0 x 10-6 /K
These MMCs are also suitable for high-temperature brazing and glass sealing.