Measurement of temperature distribution in SnAg3.5 flip-chip solder joints during current stressing using infrared microscopy

Author

Hsiao, Hsiang-Yao ; Chen, Chih

Author_Institution

Dept. of Mater. Sci. & Eng., Nat. Chiao Tung Univ., Hsinchu

fYear

2008

fDate

22-24 Oct. 2008

Firstpage

281

Lastpage

284

Abstract

In this paper, the temperature distribution during electromigration in flip-chip SnAg3.5 solder bumps is directly examined using infrared microscopy. Two clear hot spots are observed in the bump. One is located at the region with peak current density, and the other one is at the bump edge under the current-feeding metallization on the chip side. Under a current stress of 1.06 times 10⁴ A/cm², the temperature in the two hot spots are 161.7degC and 167.8degC, respectively, which surpass the average bump temperature of 150.5degC. In addition, effect of under-bump-metallization (UBM) thickness on the hot spots is also examined. It indicates that the hot-spot temperature in the solder bump increases for the solder joints with a thinner UBM.

Keywords

electromigration; flip-chip devices; integrated circuit testing; materials testing; silver alloys; solders; temperature distribution; thermal management (packaging); tin alloys; Sn-Ag; SnAg3.5 flip-chip solder joints; current density; current stressing; current-feeding metallization; electromigration; hot spots; infrared microscopy; temperature distribution; Current density; Current measurement; Electromigration; Flip chip solder joints; Metallization; Microscopy; Soldering; Stress measurement; Temperature distribution; Temperature measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Materials and Packaging, 2008. EMAP 2008. International Conference on

Conference_Location

Taipei

Print_ISBN

978-1-4244-3620-0

Electronic_ISBN

978-1-4244-3621-7

Type

conf

DOI

10.1109/EMAP.2008.4784283

Filename

4784283