Spray-Deposited Al-Si (Osprey CE) Alloys and their Properties

✍ Scribed by D. M. Jacobson; A. J. W. Ogilvy

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 212 KB
• Volume: 34
• Category: Article
• ISSN: 0933-5137
• DOI: 10.1002/mawe.200390079

✦ Synopsis

Abstract

Osprey Metals Ltd. has developed a new family of lightweight, low expansion aluminium‐silicon alloys to suit electronic applications, containing between 30 and 70 wt.% aluminium. They are produced using the Osprey spray deposition process, which achieves homogeneous and isotropic properties. Their advantageous physical characteristics, combining low thermal expansion, high thermal conductivity and low density are particularly suited for packaging electronic circuitry. These CE (controlled expansion) alloys are easy to machine to tight tolerances using standard machine tools and they can be electroplated with gold, silver or nickel finishes without difficulty. This paper focuses on the measurement of mechanical (flexural strength) and thermo‐mechanical properties (CTE, thermal diffusivity and specific heat) of these alloys, carried out in collaboration with AMTT. The property measurements were consistent with those measured previously elsewhere, apart from the CTE values, which deviated significantly and were at variance with values predicted from a rule of mixtures. This discrepancy was resolved in a short follow‐up series of measurements carried out under conditions corresponding more closely to temperature equilibrium.