Looping is one of the key technologies for modern thermosonic wire bonders, and it has been affected by many interacting factors. In this study, the wire looping process was observed with a high-speed camera, and the evolution of wire profiles during looping and the capillary trace were obtained through experiments. A dynamic finite element (FE) model was developed to learn the details of the looping process, where real capillary geometry dimensions, capillary trace, diameter of bonded ball and the gold wire material were used, and the friction force and air tension force were considered. The simulated profiles were compared with those of the experiment. Using the verified FE model, the effects of material properties, capillary parameters, and capillary traces on the looping process were studied, and the relationships between the final profiles and parameters were discussed.

Reference

Reference
1.
Harman
,
G. G.
,
2010
,
Wire Bonding in Microelectronics
,
3rd ed.
,
The McGraw-Hill Companies
,
New York
.
2.
Antony
,
J.
,
1999
, “
Improving the Wire Bonding Process Quality Using Statistically Designed Experiments
,”
Microelectron. J.
,
30
(
2
), pp.
161
168
.10.1016/S0026-2692(98)00104-9
3.
Ohno
,
Y.
,
Ohzeki
,
Y.
,
Aso
,
T.
, and
Kitamura
,
O.
,
1992
, “
Factors Governing the Loop Profile in Au Bonding Wire
,” 42nd Electronic Components and Technology Conference (
ECTC
), San Diego, CA, May 18–20, pp.
899
902
.10.1109/ECTC.1992.204313
4.
Saraswati
,
T.
,
Theint
,
E. P. P.
,
Stephan
,
D.
,
Wulff
,
F. W.
,
Breach
,
C. D.
, and
Calpito
,
D. R. M.
,
2004
, “
Looping Behaviour of Gold Ballbonding Wire
,” 6th Electronics Packaging Technology Conference (
EPTC 2004
), Singapore, December 8–10, pp.
723
728
.10.1109/EPTC.2004.1396702
5.
Shu
,
B.
,
1992
, “
Wire Bond Development for High-Pincount Surface-Mount
,” 42nd Electronic Components and Technology Conference (
ECTC
), San Diego, CA, May 18–20, pp.
890
898
.10.1109/ECTC.1992.204312
6.
Groover
,
R.
,
Shu
,
W. K.
, and
Lee
,
S. S.
,
1994
, “
Wire Bond Loop Profile Development for Fine Pitch-Long Wire Assembly
,”
IEEE Trans. Semicond. Manuf.
,
7
(
3
), pp.
393
399
.10.1109/66.311344
7.
Seuntjens.
,
J.
,
Lu
,
Z. P.
,
Emily
,
R.
,
Tok
,
C. W.
,
Wulff
,
F.
,
Aung
,
S. S.
, and
Kumar
,
S.
,
1999
, “
Development of New Ultra-High Stiffness Gold Bonding Wire
,” www.utilisegold.com/assets/file/rs_archive/AW99_paper.PDF
8.
Wang
,
F.
,
Chen
,
Y.
, and
Han
,
L.
,
2012
, “
Experiment Study of Dynamic Looping Process for Thermosonic Wire Bonding
,”
Microelectron. Reliab.
,
52
(
6
), pp.
1105
1111
.10.1016/j.microrel.2012.01.014
9.
Wang
,
F.
,
Chen
,
Y.
, and
Han
,
L.
,
2012
, “
Effect of Capillary Trace on Dynamic Loop Profile Evolution in Thermosonic Wire Bonding
,”
IEEE Trans. Compon., Packag., Manuf. Technol.
,
2
(
9
), pp.
1550
1557
.10.1109/TCPMT.2012.2206593
10.
Lo
,
Y. L.
,
Ho
,
T. L.
,
Chen
,
J. L.
,
Lee
,
R. S.
, and
Chen
,
T. C.
,
2001
, “
Linkage-Spring Model in Analyzing Wirebonding Loops
,”
IEEE Trans. Compon., Packag., Manuf. Technol.
,
24
(
3
), pp.
450
456
.10.1109/6144.946493
11.
Lo
,
Y. L.
,
Chen
,
T. C.
, and
Ho
,
T. L.
,
2001
, “
Design in Triangle-Profiles and T-Profiles of a Wirebond Using a Linkage-Spring Model
,”
IEEE Trans. Compon., Packag., Manuf. Technol.
,
24
(
3
), pp.
457
467
.10.1109/6144.946494
12.
Lo
,
Y. L.
, and
Tsao
,
C. C.
,
2002
, “
Wirebond Profiles Characterized by a Modified Linkage-Spring Model Which Includes a Looping Speed Factor
,”
Microelectron. Reliab.
,
42
(
2
), pp.
285
291
.10.1016/S0026-2714(01)00246-3
13.
Tay
,
A. a. O.
,
Seah
,
B. C.
, and
Ong
,
S. H.
,
1997
, “
Finite Element Simulation of Wire Looping During Wirebonding
,” Proceedings of the Pacific Rim/ASME International Intersociety Electronic and Photonic Packaging Conference, vol. 1, pp.
399
406
.
14.
Ng
,
B. H.
,
Tay
,
A. a. O.
, and
Ong
,
S. H.
,
2002
, “
Three Dimensional Finite Element Simulation of Wire Looping Process in Wirebonding
,” 4th Electronics Packaging Technology Conference (
EPTC 2002
), Singapore, December 10–12, pp.
334
337
.10.1109/EPTC.2002.1185693
15.
Liu
,
D. S.
, and
Chao
,
Y. C.
,
2003
, “
Effects of Dopant, Temperature, and Strain Rate on the Mechanical Properties of Micrometer Gold-Bonding Wire
,”
J. Electron. Mater.
,
32
(
3
), pp.
159
165
.10.1007/s11664-003-0187-y
16.
Liu
,
D. S.
,
Chao
,
Y. C.
, and
Wang
,
C. H.
,
2004
, “
Study of Wire Bonding Looping Formation in the Electronic Packaging Process Using the Three-Dimensional Finite Element Method
,”
Finite Elem. Anal. Design
,
40
(
3
), pp.
263
286
.10.1016/S0168-874X(02)00226-3
17.
Fuliang
,
W.
,
Kang
,
X.
, and
Han
,
L.
,
2012
, “
Dynamics of Free Air Ball Formation in Thermosonic Wire Bonding
,”
IEEE Trans. Compon., Packag., Manuf. Technol.
,
2
(
8
), pp.
1389
1393
.10.1109/TCPMT.2012.2189114
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