Effects of poss-silanol addition on whisker formation in Sn-based Pb-free electronic solders

Sihan Liu, Limin Ma, Yutian Shu, K. N. Subramanian, Andre Lee, Fu Guo

Research output: Contribution to journalArticle

  • 3 Citations

Abstract

Previous studies have indicated that silanol in the form of polyhedral oligomeric silsesquioxane (POSS) trisilanol could form strong bonds with solder matrix without agglomeration, and inhibit diffusion of metal atoms when subjected to high ambient temperature and/or high current density. Addition of POSS-trisilanol has also been shown to improve the comprehensive performance of Sn-based Pb-free solders, such as shear strength, resistance to electromigration, as well as thermal fatigue. The current study investigated the whisker formation/growth behaviors of Sn-based Pb-free solders (eutectic Sn-Bi) modified with 3 wt.% POSS-trisilanol. Solder films on Cu substrates were aged at ambient temperature of 125 C to accelerate whisker growth. The microstructural evolution of the solder films' central and edge areas was examined periodically using scanning electron microscopy. Bi whiskers were observed to extrude from the surface due to stress/strain relief during growth of Sn-Cu intermetallic compounds (IMCs). Addition of POSS-trisilanol was shown to retard the growth of Bi whiskers. The IMCs formed between POSS-modified solders and the Cu substrate showed smoother surface morphology and slower thickness growth rate during reflow and aging. It was indicated that POSS particles located at the phase boundaries inhibited diffusion of Sn atoms at elevated temperatures, and thus limited the formation and growth of IMCs, which resulted in the observed inhibition of Bi whisker growth in POSS-modified solders.

LanguageEnglish (US)
Pages26-32
Number of pages7
JournalJournal of Electronic Materials
Volume43
Issue number1
DOIs
StatePublished - Jan 2014

Profile

solders
Soldering alloys
electronics
Intermetallics
intermetallics
ambient temperature
Atoms
Thermal fatigue
Electromigration
thermal fatigue
Microstructural evolution
Phase boundaries
Substrates
electromigration
Shear strength
shear strength
Temperature
Eutectics
Surface morphology
agglomeration

Keywords

  • isothermal aging
  • Sn-based solder
  • Whisker

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Materials Chemistry

Cite this

Effects of poss-silanol addition on whisker formation in Sn-based Pb-free electronic solders. / Liu, Sihan; Ma, Limin; Shu, Yutian; Subramanian, K. N.; Lee, Andre; Guo, Fu.

In: Journal of Electronic Materials, Vol. 43, No. 1, 01.2014, p. 26-32.

Research output: Contribution to journalArticle

Liu, Sihan ; Ma, Limin ; Shu, Yutian ; Subramanian, K. N. ; Lee, Andre ; Guo, Fu. / Effects of poss-silanol addition on whisker formation in Sn-based Pb-free electronic solders. In: Journal of Electronic Materials. 2014 ; Vol. 43, No. 1. pp. 26-32
@article{09385cca2b174082aa13811059c22ab5,
title = "Effects of poss-silanol addition on whisker formation in Sn-based Pb-free electronic solders",
abstract = "Previous studies have indicated that silanol in the form of polyhedral oligomeric silsesquioxane (POSS) trisilanol could form strong bonds with solder matrix without agglomeration, and inhibit diffusion of metal atoms when subjected to high ambient temperature and/or high current density. Addition of POSS-trisilanol has also been shown to improve the comprehensive performance of Sn-based Pb-free solders, such as shear strength, resistance to electromigration, as well as thermal fatigue. The current study investigated the whisker formation/growth behaviors of Sn-based Pb-free solders (eutectic Sn-Bi) modified with 3 wt.{\%} POSS-trisilanol. Solder films on Cu substrates were aged at ambient temperature of 125 C to accelerate whisker growth. The microstructural evolution of the solder films' central and edge areas was examined periodically using scanning electron microscopy. Bi whiskers were observed to extrude from the surface due to stress/strain relief during growth of Sn-Cu intermetallic compounds (IMCs). Addition of POSS-trisilanol was shown to retard the growth of Bi whiskers. The IMCs formed between POSS-modified solders and the Cu substrate showed smoother surface morphology and slower thickness growth rate during reflow and aging. It was indicated that POSS particles located at the phase boundaries inhibited diffusion of Sn atoms at elevated temperatures, and thus limited the formation and growth of IMCs, which resulted in the observed inhibition of Bi whisker growth in POSS-modified solders.",
keywords = "isothermal aging, Sn-based solder, Whisker",
author = "Sihan Liu and Limin Ma and Yutian Shu and Subramanian, {K. N.} and Andre Lee and Fu Guo",
year = "2014",
month = "1",
doi = "10.1007/s11664-013-2672-2",
language = "English (US)",
volume = "43",
pages = "26--32",
journal = "Journal of Electronic Materials",
issn = "0361-5235",
publisher = "Springer New York",
number = "1",

}

TY - JOUR

T1 - Effects of poss-silanol addition on whisker formation in Sn-based Pb-free electronic solders

AU - Liu,Sihan

AU - Ma,Limin

AU - Shu,Yutian

AU - Subramanian,K. N.

AU - Lee,Andre

AU - Guo,Fu

PY - 2014/1

Y1 - 2014/1

N2 - Previous studies have indicated that silanol in the form of polyhedral oligomeric silsesquioxane (POSS) trisilanol could form strong bonds with solder matrix without agglomeration, and inhibit diffusion of metal atoms when subjected to high ambient temperature and/or high current density. Addition of POSS-trisilanol has also been shown to improve the comprehensive performance of Sn-based Pb-free solders, such as shear strength, resistance to electromigration, as well as thermal fatigue. The current study investigated the whisker formation/growth behaviors of Sn-based Pb-free solders (eutectic Sn-Bi) modified with 3 wt.% POSS-trisilanol. Solder films on Cu substrates were aged at ambient temperature of 125 C to accelerate whisker growth. The microstructural evolution of the solder films' central and edge areas was examined periodically using scanning electron microscopy. Bi whiskers were observed to extrude from the surface due to stress/strain relief during growth of Sn-Cu intermetallic compounds (IMCs). Addition of POSS-trisilanol was shown to retard the growth of Bi whiskers. The IMCs formed between POSS-modified solders and the Cu substrate showed smoother surface morphology and slower thickness growth rate during reflow and aging. It was indicated that POSS particles located at the phase boundaries inhibited diffusion of Sn atoms at elevated temperatures, and thus limited the formation and growth of IMCs, which resulted in the observed inhibition of Bi whisker growth in POSS-modified solders.

AB - Previous studies have indicated that silanol in the form of polyhedral oligomeric silsesquioxane (POSS) trisilanol could form strong bonds with solder matrix without agglomeration, and inhibit diffusion of metal atoms when subjected to high ambient temperature and/or high current density. Addition of POSS-trisilanol has also been shown to improve the comprehensive performance of Sn-based Pb-free solders, such as shear strength, resistance to electromigration, as well as thermal fatigue. The current study investigated the whisker formation/growth behaviors of Sn-based Pb-free solders (eutectic Sn-Bi) modified with 3 wt.% POSS-trisilanol. Solder films on Cu substrates were aged at ambient temperature of 125 C to accelerate whisker growth. The microstructural evolution of the solder films' central and edge areas was examined periodically using scanning electron microscopy. Bi whiskers were observed to extrude from the surface due to stress/strain relief during growth of Sn-Cu intermetallic compounds (IMCs). Addition of POSS-trisilanol was shown to retard the growth of Bi whiskers. The IMCs formed between POSS-modified solders and the Cu substrate showed smoother surface morphology and slower thickness growth rate during reflow and aging. It was indicated that POSS particles located at the phase boundaries inhibited diffusion of Sn atoms at elevated temperatures, and thus limited the formation and growth of IMCs, which resulted in the observed inhibition of Bi whisker growth in POSS-modified solders.

KW - isothermal aging

KW - Sn-based solder

KW - Whisker

UR - http://www.scopus.com/inward/record.url?scp=84891824476&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84891824476&partnerID=8YFLogxK

U2 - 10.1007/s11664-013-2672-2

DO - 10.1007/s11664-013-2672-2

M3 - Article

VL - 43

SP - 26

EP - 32

JO - Journal of Electronic Materials

T2 - Journal of Electronic Materials

JF - Journal of Electronic Materials

SN - 0361-5235

IS - 1

ER -