Thermomigration in eutectic tin-lead flip chip solder joints

Author

Yang, Dan ; Alam, M.O. ; Wu, B.Y. ; Chan, Y.C.

Author_Institution

Dept. of Electron. Eng., City Univ. of Hong Kong

fYear

2006

fDate

6-8 Dec. 2006

Firstpage

565

Lastpage

569

Abstract

The thermomigration of eutectic tin-lead flip chip solder joints under ambient temperatures of 20 degC, 100degC and 150degC was investigated in terms of microstructural evolution. No significant thermomigration occurred after 100 h at 20degC and at 100degC. Only microstructural coarsening was observed in solder joints for these cases. However, Pb thermomigration and phase segregation were observed in solder joints after only 50 h at 150degC. Measurements showed that the temperature difference between the chip side and the substrate side reached 8.1degC (a temperature gradient of about 2700degC/cm across the solder joints) at an ambient temperature of 150degC. It is believed that Pb atoms migrated from the chip side (the hot side) to the substrate side (the cold side) under a temperature gradient of 2700 degC/cm

Keywords

eutectic alloys; flip-chip devices; lead; solders; 100 C; 150 C; 20 C; 20 h; 50 h; 8.1 C; Pb; flip chip packaging; microstructural coarsening; microstructural evolution; phase segregation; solder joints; temperature gradient; thermomigration; Atomic measurements; Bonding; Flip chip; Flip chip solder joints; Microelectronics; Semiconductor device measurement; Soldering; Substrates; Temperature; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronics Packaging Technology Conference, 2006. EPTC '06. 8th

Conference_Location

Singapore

Print_ISBN

1-4244-0664-1

Electronic_ISBN

1-4244-0665-X

Type

conf

DOI

10.1109/EPTC.2006.342775

Filename

4147304