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.

fYear

2000

fDate

2000

Firstpage

72

Lastpage

80

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;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronics Packaging Technology Conference, 2000. (EPTC 2000). Proceedings of 3rd

Print_ISBN

0-7803-6644-1

Type

conf

DOI

10.1109/EPTC.2000.906352

Filename

906352