Predominant high melting point solders for high-temperature and harsh environment electronics (operating temperatures from 200 to 250 °C) are Pb-based systems, which are being subjected to RoHS regulations because of their toxic nature. In this study, high bismuth (Bi) alloy compositions with Bi-XSb-10Cu (X from 10 wt % to 20 wt %) were designed and developed to evaluate their potential as high-temperature, Pb-free replacements. Reflow processes were developed to make die-attach samples made from the cast Bi alloys. Die-attach joints made from Bi-15Sb-10Cu alloy exhibited an average shear strength of 24 MPa, which is comparable to that of commercially available high Pb solders. These alloy compositions also retained original shear strength even after thermal shock (TS) between −55 °C and +200 °C and high-temperature storage (HTS) at 200 °C. Brittle interfacial fracture sometimes occurred along the interfacial NiSb layer formed between Bi(Sb) matrix and Ni metallized surface. In addition, heat dissipation capabilities, using flash diffusivity, were measured on the die-attach assembly and were compared to the corresponding bulk alloys. The thermal conductivity of all the Bi–Sb alloys was higher than that of pure Bi. By creating high volume fraction of precipitates in a die-attach joint microstructure, it was feasible to further increase thermal conductivity of this joint to 24 W/m·K, which is three times higher than that of pure Bi (8 W/m·K). Bi–15Sb–10Cu alloy has so far shown the most promising performance as a die-attach material for high-temperature applications (operated over 200 °C). Hence, this alloy was further studied to evaluate its potential for plastic deformation. Bi–15Sb–10Cu alloy has shown limited plastic deformation in room temperature tensile testing in which premature fracture occurred via the cracks propagated on the (111) cleavage planes of rhombohedral crystal structure of the Bi(Sb) matrix. The same alloy has, however, shown up to 7% plastic strain under tension when tested at 175 °C. The cleavage planes, which became oriented at smaller angles to the tensile stress, contributed to improved plasticity in the high-temperature test.

References

References
1.
An
,
T.
, and
Qin
,
F.
,
2016
, “
Relationship Between the Intermetallic Compounds Growth and the Microcracking Behavior of Lead-Free Solder Joints
,”
ASME J. Electron. Packag.
,
138
(
1
), p.
011002
.
2.
Yao
,
Y.
,
Long
,
X.
, and
Keer
,
L. M.
,
2017
, “
A Review of Recent Research on the Mechanical Behavior of Lead-Free Solders
,”
ASME Appl. Mech. Rev.
,
69
(
4
), p.
040802
.
3.
Fu
,
N.
,
Wu
,
J.
,
Ahmed
,
S.
,
Suhling
,
J. C.
, and
Lall
,
P.
,
2017
, “
Investigation of Aging Induced Evolution of the Microstructure of SAC305 Lead Free Solder
,”
ASME
Paper No. IPACK2017-74266.
4.
McCluskey
,
F. P.
,
Podlesak
,
T.
, and
Grzybowski
,
R.
,
1996
,
High Temperature Electronics
,
CRC Press
, Boca Raton, FL.
5.
McCluskey
,
F. P.
,
Dash
,
M.
,
Wang
,
Z.
, and
Huff
,
D.
,
2006
, “
Reliability of High Temperature Solder Alternatives
,”
Microelectron. Reliab.
,
46
(
9–11
), pp.
1910
1914
.
6.
Manikam
,
V. R.
, and
Cheong
,
K. Y.
,
2011
, “
Die Attach Materials for High Temperature Applications: A Review
,”
IEEE Trans. Compon., Packag. Manuf. Technol.
,
1
(
4
), pp.
457
478
.
7.
Mallampati
,
S.
,
Schoeller
,
H.
,
Yin
,
L.
,
Shaddock
,
D.
, and
Cho
,
J.
,
2014
, “
Developments of High-Bi Alloys as a High Temperature Pb-Free Solder
,” IEEE 64th Electronic Components and Technology Conference (
ECTC
), Orlando, FL, May 27–30, pp.
1328
1334
.
8.
Cho
,
J.
,
Mallampati
,
S.
,
Tobias
,
R.
,
Schoeller
,
H.
,
Yin
,
L.
, and
Shaddock
,
D.
,
2016
, “
Exploring Bismuth as a New Pb-Free Alternative for High Temperature Electronics
,” IEEE 66th Electronic Components and Technology Conference (
ECTC
), Las Vegas, NV, May 31–June 3, pp. 432–438.
9.
Martin-Lopez
,
R.
,
Lenoir
,
B.
,
Devaux
,
X.
,
Dauscher
,
A.
, and
Scherrer
,
H.
,
1998
, “
Mechanical Alloying of BiSb Semiconducting Alloys
,”
Mater. Sci. Eng. A
,
248
(
1–2
), pp.
147
152
.
10.
Yim
,
W. M.
, and
Amith
,
A.
,
1972
, “
BiSb Alloys for Magneto-Thermoelectric and Thermomagnetic Cooling
,”
Solid State Electron.
,
15
(
10
), pp. 1141–1144.
11.
Lee
,
S.
,
Esfarjani
,
K.
,
Mendoza
,
J.
,
Dresselhaus
,
M. S.
, and
Chen
,
G.
,
2014
, “
Lattice Thermal Conductivity of Bi, Sb, and Bi-Sb Alloy From First Principles
,”
Phys. Rev. B: Condens. Matter Mater. Phys.
,
89
(
8
), p. 085206.
12.
Slonaker
,
R. E.
,
Smutz
,
M.
,
Jensen
,
H.
, and
Olson
,
E. H.
,
1965
, “
Factors Affecting the Growth and the Mechanical and Physical Properties of Bismuth Single Crystals
,”
J. Less Common Met.
,
8
(
5
), pp.
327
338
.
13.
Song
,
J. M.
,
Chuang
,
H. Y.
, and
Wen
,
T. X.
,
2007
, “
Thermal and Tensile Properties of Bi-Ag Alloys
,”
Metall. Mater. Trans. A
,
38
(
6
), pp.
1371
1375
.
14.
Motoyasu
,
G.
,
Kadowaki
,
H.
,
Soda
,
H.
, and
McLean
,
A.
,
1999
, “
The Characteristics of Single Crystal Bismuth Wires Produced by the Ohno Continuous Casting Process
,”
J. Mater. Sci.
,
34
(
16
), pp.
3893
3899
.
15.
Taylor
,
R. E.
, and
Cape
,
J. A.
,
1964
, “
Finite Pulse‐Time Effects in the Flash Diffusivity Technique
,”
Appl. Phys. Lett.
,
5
(
10
), pp.
212
213
.
16.
Vozár
,
L.
, and
Hohenauer
,
W.
,
2003
, “
Flash Method of Measuring the Thermal Diffusivity a Review
,”
High Temp. High Press
,
35–36
(
3
), pp.
253
264
.
17.
Mallampati
,
S.
, 2017, “High Bismuth Alloys as Lead-Free Alternatives for Interconnects in High-Temperature Electronics,”
Ph.D. dissertation
, State University of New York, Binghamton, NY.
18.
Nahavandi
,
M.
,
Hanim
,
M. A. A.
,
Ismarrubie
,
Z. N.
,
Hajalilou
,
A.
,
Rohaizuan
,
R.
, and
Fadzli
,
M. Z. S.
,
2014
, “
Effects of Silver and Antimony Content in Lead-Free High-Temperature Solders of Bi-Ag and Bi-Sb on Copper Substrate
,”
J. Electron. Mater.
,
43
(
2
), pp.
579
585
.
19.
Weyrich
,
N.
,
Jin
,
S.
,
Duarte
,
L. I.
, and
Leinenbach
,
C.
,
2014
, “
Joining of Cu, Ni, and Ti Using Au-Ge-Based High-Temperature Solder Alloys
,”
J. Mater. Eng. Perform.
,
23
(
5
), pp.
1585
1592
.
20.
Touloukian
,
Y. S.
,
Powell
,
R. W.
,
Ho
,
C.
, and
Klemens
,
P. G.
,
2015
, “
Thermal Conductivity - Metallic Elements and Alloys
,”
TPRC Data Ser.
,
1
(
11
), pp.
956
963
.
21.
Lenoir
,
B.
,
Dauscher
,
A.
,
Devaux
,
X.
,
Martin-Lopez
,
R.
,
Ravich
,
Y. I.
,
Scherrer
,
H.
, and
Scherrer
,
S.
,
1996
, “
Bi-Sb Alloys: An Update
,”
Fifteenth International Conference on Thermoelectrics
, Pasadena, CA, Mar. 26–29, pp.
1
13
.
22.
Lee
,
H. J.
,
1975
, “
Thermal Diffusivity in Layered Composites
,”
Thermal Conductivity 15
, Springer, Boston, MA, pp.
135
148
.
You do not currently have access to this content.