Title :
An eutectic bonding technology at a temperature below the eutectic point
Author :
Wang, Chen Y. ; Lee, Chin C.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Irvine, CA, USA
Abstract :
The authors report a technique which needs only 240°C to produce nearly eutectic Au-Sn bonding. After bonding, the device can take a postprocessing temperature of 250°C without bonding degradation. The bonding medium consists of Au-Sn multilayer composite deposited directly on the object to be bonded. This technology also eliminates the preforms, reduces tin oxidation, and provides good control of bonding layer thickness. Results of bonding 2 mm×3 mm GaAs dice show that high-quality bondings are obtained, as evaluated by a scanning acoustic microscope. The specimens underwent 40 cycles of thermal shock test between -196°C and 160°C without bonding degradation and die cracking. Scanning electron microscopy and energy-dispersive X-ray studies reveal interesting characteristics of the bonding process. Melting point tests confirm that the bonding layer indeed has a melting temperature of 280°C, higher than the 240°C process temperature
Keywords :
III-V semiconductors; environmental testing; gallium arsenide; gold alloys; microassembling; tin alloys; -190 to 160 C; 2 mm; 240 C; 3 mm; Au-Sn multilayer composite; GaAs dice; GaAs-AuSn; bonding layer; bonding layer thickness; bonding medium; bonding process; die bonding; energy-dispersive X-ray studies; eutectic Au-Sn bonding; eutectic bonding technology; high-quality bondings; melting temperature; postprocessing temperature; semiconductors; thermal shock test; Acoustic testing; Bonding; Degradation; Gallium arsenide; Nonhomogeneous media; Oxidation; Preforms; Temperature; Thickness control; Tin;
Conference_Titel :
Electronic Components and Technology Conference, 1992. Proceedings., 42nd
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-0167-6
DOI :
10.1109/ECTC.1992.204252
