Page 159 - Wire Bonding in Microelectronics

Heats of Formation at 400K (cal +/–500) –8300 –9200 –10100

Color of the Phase Gold Tan Tan Tan White Purple Lustrous

Coefficient of Linear Expansion (10 –5 ) 1.42 1.2 1.4 1.3 1.2 0.94 2.3

Specific Resistance (Ohm–cm) 2.3 37.5 25.5 13.1 12.4 7.9 3.2

Vicker’s Hardness (5 Kg) 60–90 334 271 130 249 263 20–50

Composition at % Au 84–100 80–81.2 72.7 65–66.8 50 32.33 –33.92 0–0.6

Lattice Parameters (Å) a = 4.08 a = 6.92 a = 14.68, α = 30.5 a = 7.71 c = 41.9 A = 3.36 B = 8.84 C = 3.21 A = 6.40 B = 3.33 C = 6.32 β = 92.99 A = 5.99 A = 4.05 Structure and Properties of Au-Al Intermetallic Compounds a

Structure FCC Cubic Rhombohedral HCP Orthorhombic Monoclinic FCC FCC Note: This figure was assembled by N. Noolu, see App. 5B.

Phase Au Au 4 Al Au 8 Al 3 Au 5 Al 2 Au 2 Al AuAl AuAl 2 Al a See Refs [5-102 to 5-104] TABLE 5-1

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