NDLI: Kinetic Analysis of Electromigration Enhanced Intermetallic Growth and Void Formation in Pb-Free Solders

Content Provider	IEEE Xplore Digital Library
Author	Brook Chao Seung-Hyun Chae Xuefeng Zhang Ho, P.S.
Copyright Year	2007
Description	Author affiliation: Microelectron. Res. Center, Univ. of Texas at Austin, Austin, TX (Brook Chao; Seung-Hyun Chae; Xuefeng Zhang; Ho, P.S.)
Abstract	The kinetics for electromigration (EM) enhanced intermetallic growth and void formation in Sn-based Pb- free solder joints with Cu under bump metallization (UBM) was analyzed. The simulated diffusion couple comprised the two terminal phases, Cu and Sn, as well as the two intermetallic phases, $Cu_{3}Sn$ and $Cu_{6}Sn_{5},$ formed between them. The diffusion and EM parameters were obtained by solving the inverse problem of the EM- enhanced intermetallic growth and found to be consistent with the literature values. Finite difference method was used to solve the mass transport kinetics within the intermetallic phases and across each interface of interest. Simulation showed that with zero current and no EM effects, intermetallic growth follows a parabolic law, suggesting a diffusion controlled mechanism for thermal aging. However, under significant current stressing (4.12 x $10^{4}$ and 5.16 x $10^{4}$ $Amp/cm^{2}),$ the growth of the dominant intermetallic $Cu_{6}Sn_{5}$ clearly follows a linear law, suggesting a reaction controlled mechanism for electromigration. The kinetic results were consistent with the experimental observations. The vacancy transport under EM was also analyzed and the results showed substantial increase in vacancy concentration in the $Cu_{6}Sn_{5}$ phase near $Cu_{3}Sn/Cu_{6}Sn_{5}$ interface. The peaking of the vacancy concentration predicts EM-induced Kirkendall void formation at this region and its effect on solder reliability is discussed.
Starting Page	1
Ending Page	8
File Size	8798004
Page Count	8
File Format	PDF
ISBN	142441105X
DOI	10.1109/ESIME.2007.360060
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2007-04-16
Publisher Place	UK
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Kinetic theory Electromigration Intermetallic Tin Soldering Metallization Inverse problems Finite difference methods Aging Stress control
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in