Effects of microstructural evolution and intermetallic layer growth on shear strength of ball-grid-array Sn-Cu solder joints

C. K. Shin; Y. J. Baik; J. Y. Huh

doi:10.1007/s11664-001-0119-7

Effects of microstructural evolution and intermetallic layer growth on shear strength of ball-grid-array Sn-Cu solder joints

C. K. Shin, Y. J. Baik, J. Y. Huh

Research output: Contribution to journal › Article › peer-review

41 Citations (Scopus)

Abstract

The shear strength of ball-grid-array (BGA) solder joints on Cu bond pads was studied for Sn-Cu solder containing 0, 1.5, and 2.5 wt.% Cu, focusing on the effect of the microstructural changes of the bulk solder and the growth of intermetallic (IMC) layers during soldering at 270°C and aging at 150°C. The Cu additions in Sn solder enhanced both the IMC layer growth and the solder/IMC interface roughness during soldering but had insignificant effects during aging. Rapid Cu dissolution from the pad during reflow soldering resulted in a fine dispersion of Cu₆Sn₅ particles throughout the bulk solder in as-soldered joints even for the case of pure Sn solder, giving rise to a precipitation hardening of the bulk solder. The increased strength of the bulk solder caused the fracture mode of as-soldered joints to shift from the bulk solder to the solder/IMC layer as the IMC layer grew over a critical thickness about 1.2 μm for all solders. The bulk solder strength decreased rapidly as the fine Cu₆Sn₅ precipitates coarsened during aging. As a consequence, regardless of the IMC layer thickness and the Cu content of the solders, the shear strength of BGA solder joints degraded significantly after 1 day of aging at 150°C and the shear fracture of aged joints occurred in the bulk solder. This suggests that small additions of Cu in Sn-based solders have an insignificant effect on the shear strength of BGA solder joints, especially during system use at high temperatures.

Original language	English
Pages (from-to)	1323-1331
Number of pages	9
Journal	Journal of Electronic Materials
Volume	30
Issue number	10
DOIs	https://doi.org/10.1007/s11664-001-0119-7
Publication status	Published - 2001 Oct

Bibliographical note

Funding Information:
The work was supported by a grant from the University-Industry Collaborative Research program of the Korea Science & Engineering Foundation. The authors would like to thank Professor J.P. Jung for many helps related with ball shear tests.

Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.

Keywords

BGA solder joint
Ball shear strength
Fracture mode
Intermetallic compound
Sn-Cu solder

ASJC Scopus subject areas

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

Access to Document

10.1007/s11664-001-0119-7

Cite this

@article{d4ac31ae89d640bcb0f594335252c34b,

title = "Effects of microstructural evolution and intermetallic layer growth on shear strength of ball-grid-array Sn-Cu solder joints",

abstract = "The shear strength of ball-grid-array (BGA) solder joints on Cu bond pads was studied for Sn-Cu solder containing 0, 1.5, and 2.5 wt.% Cu, focusing on the effect of the microstructural changes of the bulk solder and the growth of intermetallic (IMC) layers during soldering at 270°C and aging at 150°C. The Cu additions in Sn solder enhanced both the IMC layer growth and the solder/IMC interface roughness during soldering but had insignificant effects during aging. Rapid Cu dissolution from the pad during reflow soldering resulted in a fine dispersion of Cu6Sn5 particles throughout the bulk solder in as-soldered joints even for the case of pure Sn solder, giving rise to a precipitation hardening of the bulk solder. The increased strength of the bulk solder caused the fracture mode of as-soldered joints to shift from the bulk solder to the solder/IMC layer as the IMC layer grew over a critical thickness about 1.2 μm for all solders. The bulk solder strength decreased rapidly as the fine Cu6Sn5 precipitates coarsened during aging. As a consequence, regardless of the IMC layer thickness and the Cu content of the solders, the shear strength of BGA solder joints degraded significantly after 1 day of aging at 150°C and the shear fracture of aged joints occurred in the bulk solder. This suggests that small additions of Cu in Sn-based solders have an insignificant effect on the shear strength of BGA solder joints, especially during system use at high temperatures.",

keywords = "BGA solder joint, Ball shear strength, Fracture mode, Intermetallic compound, Sn-Cu solder",

author = "Shin, {C. K.} and Baik, {Y. J.} and Huh, {J. Y.}",

note = "Funding Information: The work was supported by a grant from the University-Industry Collaborative Research program of the Korea Science & Engineering Foundation. The authors would like to thank Professor J.P. Jung for many helps related with ball shear tests. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.",

year = "2001",

month = oct,

doi = "10.1007/s11664-001-0119-7",

language = "English",

volume = "30",

pages = "1323--1331",

journal = "Journal of Electronic Materials",

issn = "0361-5235",

publisher = "Springer New York",

number = "10",

}

TY - JOUR

T1 - Effects of microstructural evolution and intermetallic layer growth on shear strength of ball-grid-array Sn-Cu solder joints

AU - Shin, C. K.

AU - Baik, Y. J.

AU - Huh, J. Y.

N1 - Funding Information: The work was supported by a grant from the University-Industry Collaborative Research program of the Korea Science & Engineering Foundation. The authors would like to thank Professor J.P. Jung for many helps related with ball shear tests. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.

PY - 2001/10

Y1 - 2001/10

N2 - The shear strength of ball-grid-array (BGA) solder joints on Cu bond pads was studied for Sn-Cu solder containing 0, 1.5, and 2.5 wt.% Cu, focusing on the effect of the microstructural changes of the bulk solder and the growth of intermetallic (IMC) layers during soldering at 270°C and aging at 150°C. The Cu additions in Sn solder enhanced both the IMC layer growth and the solder/IMC interface roughness during soldering but had insignificant effects during aging. Rapid Cu dissolution from the pad during reflow soldering resulted in a fine dispersion of Cu6Sn5 particles throughout the bulk solder in as-soldered joints even for the case of pure Sn solder, giving rise to a precipitation hardening of the bulk solder. The increased strength of the bulk solder caused the fracture mode of as-soldered joints to shift from the bulk solder to the solder/IMC layer as the IMC layer grew over a critical thickness about 1.2 μm for all solders. The bulk solder strength decreased rapidly as the fine Cu6Sn5 precipitates coarsened during aging. As a consequence, regardless of the IMC layer thickness and the Cu content of the solders, the shear strength of BGA solder joints degraded significantly after 1 day of aging at 150°C and the shear fracture of aged joints occurred in the bulk solder. This suggests that small additions of Cu in Sn-based solders have an insignificant effect on the shear strength of BGA solder joints, especially during system use at high temperatures.

AB - The shear strength of ball-grid-array (BGA) solder joints on Cu bond pads was studied for Sn-Cu solder containing 0, 1.5, and 2.5 wt.% Cu, focusing on the effect of the microstructural changes of the bulk solder and the growth of intermetallic (IMC) layers during soldering at 270°C and aging at 150°C. The Cu additions in Sn solder enhanced both the IMC layer growth and the solder/IMC interface roughness during soldering but had insignificant effects during aging. Rapid Cu dissolution from the pad during reflow soldering resulted in a fine dispersion of Cu6Sn5 particles throughout the bulk solder in as-soldered joints even for the case of pure Sn solder, giving rise to a precipitation hardening of the bulk solder. The increased strength of the bulk solder caused the fracture mode of as-soldered joints to shift from the bulk solder to the solder/IMC layer as the IMC layer grew over a critical thickness about 1.2 μm for all solders. The bulk solder strength decreased rapidly as the fine Cu6Sn5 precipitates coarsened during aging. As a consequence, regardless of the IMC layer thickness and the Cu content of the solders, the shear strength of BGA solder joints degraded significantly after 1 day of aging at 150°C and the shear fracture of aged joints occurred in the bulk solder. This suggests that small additions of Cu in Sn-based solders have an insignificant effect on the shear strength of BGA solder joints, especially during system use at high temperatures.

KW - BGA solder joint

KW - Ball shear strength

KW - Fracture mode

KW - Intermetallic compound

KW - Sn-Cu solder

UR - http://www.scopus.com/inward/record.url?scp=0035484575&partnerID=8YFLogxK

U2 - 10.1007/s11664-001-0119-7

DO - 10.1007/s11664-001-0119-7

M3 - Article

AN - SCOPUS:0035484575

SN - 0361-5235

VL - 30

SP - 1323

EP - 1331

JO - Journal of Electronic Materials

JF - Journal of Electronic Materials

IS - 10

ER -

Effects of microstructural evolution and intermetallic layer growth on shear strength of ball-grid-array Sn-Cu solder joints

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this