A new method called filtration squeeze casting (FSC)was presented to fabricate high volume fraction Si particlereinforced
aluminium matrix composites (Sip/Al) for electronic packaging applications. The Sip/Al composites
exhibited a CTE of ~8.70 ppm/K, a TC above 119.80 W/(m·K) and a density of ~2.47 g/cm3 as well as a flexural
strength above 163 MPa. Fracture of large Si particles occurred during FSC, resulting in a decreased size of Si
particles and hence an increased mechanical property and a decreased TC. The average size of Si particles of
~29 μm is much smaller than that of the conventional hypereutectic Al–Si alloy but slightly larger than that of
Sip/Al composites fabricated by spray deposition, resulting in balanced mechanical and physical properties. Dilution
treatment decreased the amount of eutectic silicon in thematrix, leading to a considerable increase in TC and
a negligible decrease in flexural strength and hardness. The flexural fracture mode is as follows. First, when the
load borne by a silicon particle is beyond its fracture strength, it breaks. Then, the cracks caused by the fracture
of Si particles propagate along interfaces between silicon particles and matrix Al. Finally, the link of these cracks
result in the failure.