Nonconductive film (NCF) is a challenging potential material to substitute the application of anisotropic conductive film in the ultrafine pitch chip-on-glass (COG) packaging. The NCF interconnection requires a high bonding temperature and pressure to form joints, and this causes new reliability concerns. This study investigated effects of the thermocompression bonding parameters on the microstructure and geometric size in the joints to a COG module packaged with NCF. The results revealed that the high temperature and pressure compressed the joints to become wider and shorter. A dual layer of intermetallic compounds consisting of AuSn2 (ε phase) and AuSn4 (η phase) was found in each joint. They were the two kinds of interphases with different melting points (AuSn2:309°C and AuSn4:257°C) during the interfacial reaction between Au and Sn. At the low temperature (below the melting point), the high pressure induced the residual inner stress to generate the cracks in the joints, and this also increased the contact resistance of the joints. The contact resistance increased with the pressure elevating at the same temperature and with the temperature degrading at the same pressure. In the COG packaging with NCF, a proper elevating of the bonding temperature could produce a stable direct connection with the low contact resistance.

1.
Zhang
,
J. H.
, and
Chan
,
Y. C.
, 2003, “
Research on the Contact Resistance, Reliability and Degradation Mechanisms of ACF Interconnection for Flip Chip on Flex Applications
,”
J. Electron. Mater.
0361-5235,
32
(
4
), pp.
228
234
.
2.
Zhang
,
J. H.
,
Chan
,
Y. C.
, and
Alam
,
M. O.
, 2003, “
Contact Resistance and Adhesion Performance of ACF Interconnections to Aluminum Metallization
,”
Microelectron. Reliab.
0026-2714,
43
(
8
), pp.
1303
1310
.
3.
Kwon
,
W. S.
,
Jang
,
K. W.
, and
Paik
,
K. W.
, 2001, “
High Reliable Nonconductive Adhesives for Flip Chip Interconnections
,”
Proceedings of the International Symposium on Electronics Materials and Packaging
, pp.
34
38
.
4.
Teh
,
L. K.
,
Wong
,
C. C.
,
Mhaisalkar
,
S.
,
Ong
,
K.
,
Teo
,
P. S.
, and
Wong
,
E. H.
, 2004, “
Characterization of Nonconductive Adhesives for Flip-Chip Interconnection
,”
J. Electron. Mater.
0361-5235,
33
(
4
), pp.
271
276
.
5.
Teh
,
L. K.
,
Anto
,
E.
,
Wong
,
C. C.
,
Mhaisalkar
,
S. G.
,
Wong
,
E. H.
,
Teo
,
P. S.
, and
Chen
,
Z.
, 2004, “
Development and Reliability of Non-Conductive Adhesive Flip Chip Packages
,”
Thin Solid Films
0040-6090,
462–463
, pp.
446
453
.
6.
Thang
,
T. S.
,
Decai
,
Sun
, and
Koay
,
H. K.
, 2005, “
Characterization of Au-Sn Eutectic Die Attach Process for Optoelectronics Device
,”
Proceedings of the International Symposium on Electronics Materials and Packaging
, pp.
118
124
.
7.
Kim
,
S. Y.
,
Oh
,
T. S.
,
Lee
,
W. J.
, and
Kim
,
Y. H.
, 2006, “
Low Temperature and Ultra Fine Pitch Joints Using Non-Conductive Adhesives for Flip Chip Technology
,”
Proceedings of the International Conference on Electronics Packaging Technology
, pp.
414
417
.
8.
Kish
,
F. A.
,
Vanderwater
,
D. A.
,
DeFevere
,
D. C.
,
Steigerward
,
D. A.
,
Hofler
,
G. E.
,
Park
,
K. G.
, and
Steranka
,
F. M.
, 1996, “
Highly Reliable and Efficient Semiconductor Wafer-Bonded AlGaInP/GaP Light-Emitting Diodes
,”
Electron. Lett.
0013-5194,
32
(
2
), pp.
132
134
.
9.
Suhl
,
D.
, 1990, “
Thermally Induced IC Package Cracking
,”
IEEE Trans. Compon., Hybrids, Manuf. Technol.
0148-6411,
13
, pp.
940
945
.
10.
Wong
,
E. H.
,
Rajoo
,
R.
,
Koh
,
S. W.
, and
Lim
,
T. B.
, 2002, “
The Mechanics and Impact of Hygroscopic Swelling of Polymeric Materials in Electronic Packaging
,”
ASME J. Electron. Packag.
1043-7398,
124
, pp.
122
126
.
11.
Jang
,
K. -W.
,
Kwon
,
W. -S.
,
Yim
,
M. -J.
, and
Paik
,
K. -W.
, 2004, “
Effects of Silica Filler and Diluent on Material Properties and Reliability of Nonconductive Pastes (NCPs) for Flip-Chip Applications
,”
IEEE Trans. Compon. Packag. Technol.
1521-3331,
27
(
3
), pp.
608
615
.
12.
Duan
,
J. A.
,
Li
,
J. H.
,
Han
,
L.
, and
Zhong
,
J.
, 2007, “
Interface Features of Ultrasonic Flip Chip Bonding and Reflow Soldering in Microelectronic Packaging
,”
Surf. Interface Anal.
0142-2421,
39
, pp.
783
786
.
13.
Yim
,
M. J.
,
Hwang
,
J.
, and
Paik
,
K. W.
, 2007, “
Anisotropic Conductive Films (ACFS) for Ultra-Fine Pitch Chip-on-Glass (COG) Applications
,”
Int. J. Adhes. Adhes.
0143-7496,
27
, pp.
77
84
.
14.
Rizvi
,
M. J.
,
Lu
,
H.
,
Bailey
,
C.
,
Chan
,
Y. C.
,
Lee
,
M. Y.
, and
Pang
,
C. H.
, 2008, “
Role of Bonding Time and Temperature on the Physical Properties of Coupled Anisotropic Conductive-Nonconductive Adhesive Film for Flip Chip on Glass Technology
,”
Microelectron. Eng.
0167-9317,
85
, pp.
238
244
.
15.
Yim
,
M. J.
, and
Paik
,
K. W.
, 2006, “
Recent Advances on Anisotropic Conductive Adhesives (ACAs) for Flat Panel Displays and Semiconductor Packaging Applications
,”
Int. J. Adhes. Adhes.
0143-7496,
26
, pp.
304
313
.
16.
Yuan
,
F.
, and
Zhang
,
J. H.
, 2007, “
Investigation of Fine Pitch Chip on Glass With Au-Sn Thermocompression Bonding
,”
Proceedings of HDP’07
, pp.
1
4
.
17.
1996,
Binary Alloy Phase Diagrams
,
2nd ed.
,
T.
Massalski
, ed.,
ASM International
,
Metals Park, OH
, p.
794
.
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