Electromigration study in SnAg3.8Cu0.7 solder joints on Ti/Cr-Cu/Cu under-bump metallization

Ying Chao Hsu, Tung Liang Shao, Ching Jung Yang, Chih Chen*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


This paper investigates the electromigration-induced failures of SnAg3.8Cu0.7 flip-chip solder joints. An under-bump metallization (UBM) of a Ti/Cr-Cu/Cu trilayer was deposited on the chip side, and a Cu/Ni(P)/Au pad was deposited on the BT board side. Electromigration damages were observed in the bumps under a current density of 2 × 104 A/cm2 and 1 × 104 A/cm2 at 100°C and 150°C. The failures were found to be at the cathode/chip side, and the current crowding effect played an important role in the failures. Copper atoms were found to move in the direction of the electron flow to form intermetallic compounds (IMCs) at the interface of solder and pad metallization as a result of current stressing.

Original languageEnglish
Pages (from-to)1222-1227
Number of pages6
JournalJournal of Electronic Materials
Issue number11
StatePublished - 1 Jan 2003


  • BT board
  • Current crowding
  • Electromigration
  • Flip chip
  • Intermetallic compounds
  • Under-bump metallization

Fingerprint Dive into the research topics of 'Electromigration study in SnAg3.8Cu0.7 solder joints on Ti/Cr-Cu/Cu under-bump metallization'. Together they form a unique fingerprint.

Cite this