Title :
Directly deposited lead-indium-gold composite solder
Author :
Chen, Yi-Chia ; Wang, Chen Y. ; Lee, Chin C.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Irvine, CA, USA
Abstract :
Lead-indium-gold multilayer composite solder has been developed for bonding electronic devices. The composite is deposited directly on GaAs wafers in high vacuum to prevent indium oxidation. The gold layer on the composite further protects the indium layer from oxidation in the atmosphere. The GaAs dies are bonded to a gold-coated alumina substrate at a process temperature of 250°C. Nearly perfect joints are achieved as verified by a scanning acoustic microscope. Scanning electron microscope and EDX (energy-dispersive X-ray analysis) results indicate that the alloy joint consists of AuIn2 grains embedded in a In-Pb solid solution phase, as predicted from the Au-In-Pb phase diagram. Compared to lead-tin solder, indium-lead solder has been shown to exhibit much better fatigue resistance and have much less of a scavenging effect
Keywords :
X-ray chemical analysis; gold alloys; indium alloys; lead alloys; lead bonding; scanning electron microscope examination of materials; soldering; 250 C; Al2O3; Au-Al2O3; Au-In-Pb phase diagram; Au-coated alumina substrate; AuIn2 grains; GaAs; GaAs wafers; In-Pb solid solution phase; InPb-AuIn2; Pb-In-Au multilayer composite solder; alloy joint; directly deposited solder; electronic device bonding; energy-dispersive X-ray analysis; fatigue resistance; high vacuum environment; scanning acoustic microscopy; scanning electron microscope; Atmosphere; Gallium arsenide; Gold; Indium; Lead; Nonhomogeneous media; Oxidation; Protection; Temperature; Wafer bonding;
Conference_Titel :
Electronic Components and Technology Conference, 1993. Proceedings., 43rd
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-0794-1
DOI :
10.1109/ECTC.1993.346730
