Title :
High temperature aging study of intermetallic compound formation of Sn-3.5Ag and Sn-4.0Ag-0.5Cu solders on electroless Ni (P) metallization
Author :
Sun, Peng ; Andersson, Cristina ; Wei, Xicheng ; Cheng, Zhaonian ; Lai, Zonghe ; Shangguan, Dongkai ; Liu, Johan
Author_Institution :
Key State Lab. for New Displays & Syst. Integration, Shanghai Univ.
Abstract :
The Sn-3.5Ag and Sn-4.0Ag-0.5Cu solders on electroless Ni-immersion Au metallization exhibited different interfacial morphology after high temperature storage (HTS) testing at 150degC. Ni3Sn4 intermetallic compounds (IMCs) were found in the Sn-Ag system, while in the Sn-Ag-Cu system, spalling grains of (Cu,Ni)6Sn5 IMC were observed after long aging, along with a thick (Ni,Cu)3Sn4 IMC layer which adheres to the P rich electroless Ni coating. Kirkendall voids were found between the Sn-Ag and electroless Ni interface after 168 and 500 hour thermal aging, while a clear gap existed at the interface after 1000 hour aging, as a result of the growth of the micro-voids. In the Sn-Ag-Cu system, Kirkendall voids were found inside grains of the Sn-Ni-Cu ternary interfacial compound after 500 and 1000 hour aging
Keywords :
ageing; copper alloys; electroless deposition; gold; metallisation; nickel; silver alloys; soldering; solders; tin alloys; voids (solid); (CuNi)6Sn5; (NiCu)3Sn4; 1000 hr; 150 C; 168 hr; 500 hr; Kirkendall voids; Ni3Sn4; P rich electroless Ni coating; SnAg; SnAgCu; electroless metallization; gold metallization; high temperature aging; high temperature storage testing; interfacial morphology; intermetallic compound; intermetallic compounds; micro-voids; nickel-immersion; thermal aging; Aging; Assembly; Electronic packaging thermal management; Electronics industry; Intermetallic; Mechanical factors; Metallization; Soldering; Temperature; Tin;
Conference_Titel :
Electronic Components and Technology Conference, 2006. Proceedings. 56th
Conference_Location :
San Diego, CA
Print_ISBN :
1-4244-0152-6
DOI :
10.1109/ECTC.2006.1645850
