With mixing different sized SiC particles, high reinforcement content SiCp/Al composites ( V p =50, 60 and 70%) for electronic packaging applications were fabricated by squeeze casting technology. The composites were free of porosity and SiC particles distributed uniformly in the composite. The mean linear coefficients of thermal expansion (20–100 °C) of SiCp/Al composites ranged from 8.3 to 10.8×10 −6 /°C and decreased with an increase in volume fraction of SiC content. The experimental coefficients of thermal expansion agreed well with predicted values based on Kerner's model. The Brinell hardness increased from 188.6 to 258.0, and the modulus increased from 148 to 204 GPa for the corresponding composites. The bending strengths were larger than 370 MPa, but no obvious trend between bending strength and SiC content was observed.

The thermal expansion and mechanical properties of high reinforcement content SiCp/Al composites fabricated by squeeze casting technology

Production and characterization of a three-dimensional cellular metal-filled ceramic composite

Aluminium–copper composite materials were successfully fabricated using spark plasma sintering with Al and Cu powders as the raw materials. Al–Cu composite powders were fabricated through a ball milling process, and the effect of the Cu content was investigated. Composite materials composed of Al–20Cu, Al–50Cu, and Al–80Cu (vol.%) were sintered by a spark plasma sintering process, which was carried out at 520 °C and 50 MPa for 5 min. The phase analysis of the composite materials by X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) indicated that intermetallic compounds (IC) such as CuAl2 and Cu9Al4 were formed through reactions between Cu and Al during the spark plasma sintering process. The mechanical properties of the composites were analysed using a Vickers hardness tester. The Al–50Cu composite had a hardness of approximately 151 HV, which is higher than that of the other composites. The thermal conductivity of the composite materials was measured by laser flash analysis, and the highest value was obtained for the Al–80Cu composite material. This suggests that the Cu content affects physical properties of the Al–Cu composite material as well as the amount of intermetallic compounds formed in the composite material.

https://www.mdpi.com/1996-1944/12/9/1546/pdf

Effect of Intermetallic Compounds on the Thermal and Mechanical Properties of Al⁻Cu Composite Materials Fabricated by Spark Plasma Sintering.

http://www.ysxbcn.com/down/2014/04_en/18-p1039.pdf

Microstructure and properties of SiCp/Al electronic packaging shell produced by liquid–solid separation

Study of the elastic properties and thermal shock behavior of Al–SiC-graphite hybrid composites fabricated by spark plasma sintering

Materials with high thermal conductivity and thermal expansion coefficient matching with that of Si or GaAs are being used for packaging high density microcircuits due to their ability of faster heat dissipation. Al/SiC is gaining wide acceptance as electronic packaging material due to the fact that its thermal expansion coefficient can be tailored to match with that of Si or GaAs by varying the Al:SiC ratio while maintaining the thermal conductivity more or less the same. In the present work, Al/SiC microwave integrated circuit (MIC) carriers have been fabricated by pressureless infiltration of Al-alloy into porous SiC preforms in air. This new technique provides a cheaper alternative to pressure infiltration or pressureless infiltration in nitrogen in producing Al/SiC composites for electronic packaging applications. Al-alloy/65vol% SiC composite exhibited a coefficient of thermal expansion of 7/spl times/10/sup -6/ K/sup -1/ (25/spl deg/C-100/spl deg/C) and a thermal conductivity of 147 Wm/sup -1/K/sup -1/ at 30/spl deg/C. The hysteresis observed in thermal expansion coefficient of the composite in the temperature range 100/spl deg/C-400/spl deg/C has been attributed to the presence of thermal residual stresses in the composite. Thermal diffusivity of the composite measured over the temperature range from 30/spl deg/C to 400/spl deg/C showed a 55% decrease in thermal diffusivity with temperature. Such a large decrease in thermal diffusivity with temperature could be due to the presence of micropores, microcracks, and decohesion of the Al/SiC interfaces in the microstructure (all formed during cooling from the processing temperature). The carrier showed satisfactory performance after integrating it into a MIC.

Al/SiC carriers for microwave integrated circuits by a new technique of pressureless infiltration

A method is described whereby SiC preforms may be infiltrated in air by a molten aluminum alloy to yield a metal matrix composite with thermal expansion coefficients that are suitable or electronic packaging, such as in microwave integrated circuits. Crucible geometries and infiltration conditions may be designed to provide inexpensive and reusable containers and useful section thicknesses in \sim 1 hr. Intricate geometries may be fabricated in the green state of the ceramic, prior to infiltration, thereby minimizing final machining of the composite.

Ch. Hemambar

Papers

Al/SiC carriers for microwave integrated circuits by a new technique of pressureless infiltration

Al–SiC ELECTRONIC PACKAGES WITH CONTROLLED THERMAL EXPANSION COEFFICIENT BY A NEW METHOD OF PRESSURELESS INFILTRATION