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Indexed by:期刊论文

Date of Publication:2011-12-01

Journal:JOURNAL OF MATERIALS RESEARCH

Included Journals:Scopus、SCIE、EI

Volume:26

Issue:24

Page Number:3009-3019

ISSN No.:0884-2914

Abstract:The current-induced interfacial reactions in the Ni/Sn-3.0Ag-0.5Cu/Au/Pd(P)/Ni-P (ENEPIG) flip chip interconnects and the failure mechanism during electromigration (EM) were reported. When ENEPIG was the cathode, EM significantly enhanced the consumption of Ni-P leaving a Ni3P layer; once the Ni-P was completely consumed, the growth of Ni2SnP was accelerated. The dissolved Ni atoms from the Ni-P and the interfacial intermetallic compounds (IMCs) were driven toward the anode upon electron current stressing and precipitated as large (Ni, Cu)(3)Sn-4 IMCs. The excessive consumption of Ni-P and the formation of voids were responsible for the EM-induced failures. When Ni was the cathode, the rapid localized dissolutions of Ni under bump metallization (UBM) and Cu pad in the current crowding region resulted in a two-stage transformation of interfacial IMCs at the opposite Ni-P/solder interface. The localized dissolutions of Ni UBM and Cu pad on chip, as well as the formation of voids, were responsible for the EM-induced failures.