Role of Bi in microstructure formation of Sn-Cu-Ni based BGAs on Cu metallizations
File(s)
Accepted version
Author(s)
Belyakov, SA
Nishimura, T
Akaiwa, T
Sweatman, K
Gourlay, CM
Type
Conference Paper
Abstract
There is ongoing research seeking solders with improved performance under harsh environmental conditions, elevated operation temperatures, and higher mechanical loads while, at the same time, meeting new emerging requirements for the continuous miniaturization of electronics. Bi has been identified as one of the advantageous alloying elements that significantly improve solder performance. The present investigation explores the influence of Bi on microstructure formation in Sn-Cu-Ni-Bi/Cu joints containing 0-14 wt% Bi. It is shown that Bi additions have no catalytic effect on βSn nucleation, however, they alter βSn growth textures in Sn-Cu-Ni-Bi/Cu joints causing a transition from a columnar grain growth to a virtually single grain structures as the Bi content increases above 8wt%. Bi additions are demonstrated to reduce the thickness of the Cu6Sn5 IMC layer and to cause formation of non-equilibrium grain boundary βSn + (Cu, Ni)6Sn5 + (Bi) eutectic in joints with Bi contents ≥2wt% Bi.
Date Issued
2017-06-08
Date Acceptance
2017-04-01
Citation
2017 International Conference on Electronics Packaging (ICEP), 2017, pp.232-236
ISBN
9784990218836
Publisher
IEEE
Start Page
232
End Page
236
Journal / Book Title
2017 International Conference on Electronics Packaging (ICEP)
Copyright Statement
© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Sponsor
Nihon Superior Co Ltd
Engineering & Physical Science Research Council (EPSRC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000403391900054&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
N/A
EP/M002241/1
Source
International Conference on Electronics Packaging (ICEP)
Subjects
Science & Technology
Technology
Engineering, Electrical & Electronic
Engineering
Pb-free
solder
Bismuth
alloying
microstructure
LEAD-FREE SOLDER
PB-FREE
MECHANICAL-PROPERTIES
JOINTS
NUCLEATION
ORIENTATION
BEHAVIOR
ALLOYS
GROWTH
TIN
Publication Status
Published
Start Date
2017-04-19
Finish Date
2017-04-22
Coverage Spatial
Yamagata, Japan