Title :
An intermetallic study of solder joints with Sn-Ag-Cu lead-free solder
Author :
Chan, C.F. ; Lahiri, S.K. ; Yuan, P. ; How, J.B.H.
Abstract :
This paper focuses on the intermetallics study of reliability tested solder joints between the Sn-3.5Ag-0.75Cu lead-free solder balls and Sn-plated Cu pads on molded BGAs. In the solder joints, η phase (Cu6Sn5) was the initial intermetallic observed on the Cu substrate, followed by ε phase (Cu3Sn) between η and Cu. This paper described observations on intermetallic thickness and its growth over the anneal timeframe. It also covers the impacts of reliability tests on joint integrity and mechanical failure mode. The results obtained were compared against Sn-36Pb-2Ag solder in order to provide a more comprehensive understanding of the Sn-Ag-Cu lead-free solder
Keywords :
annealing; ball grid arrays; copper alloys; environmental factors; failure analysis; integrated circuit interconnections; integrated circuit packaging; integrated circuit reliability; integrated circuit testing; interface structure; silver alloys; soldering; tin alloys; Cu substrate; Cu3Sn; Cu6Sn5; Sn-Ag-Cu lead-free solder; Sn-Ag-Cu lead-free solder balls; Sn-Cu; Sn-Pb-Ag solder; Sn-plated Cu pads; SnAgCu-Sn-Cu; SnPbAg; anneal timeframe; epsilon-phase Cu3Sn intermetallic; eta-phase Cu6Sn5 initial intermetallic; intermetallic growth; intermetallic thickness; intermetallics; joint integrity; mechanical failure mode; molded BGAs; reliability tested solder joints; reliability tests; solder joints; Electronic packaging thermal management; Environmentally friendly manufacturing techniques; Intermetallic; Lead; Optical scattering; Scanning electron microscopy; Soldering; Temperature; Testing; Thermal resistance;
Conference_Titel :
Electronics Packaging Technology Conference, 2000. (EPTC 2000). Proceedings of 3rd
Print_ISBN :
0-7803-6644-1
DOI :
10.1109/EPTC.2000.906352
