Because it is difficult to accurately estimate the electric resistance of anisotropic conductive adhesive (ACA) joints, the ACA’s applications in high density packaging field have been greatly limited. The bulk resistance of particles is an essential part of the resistance of ACA joints. For the ACA using solid nickel (Ni) particles, because current flows along the spherical profile of the particles, the bulk resistance of these particles will be underestimated if the current bending effect is neglected. Here we propose a new method, which considers this current bending effect, to accurately evaluate the bulk resistance of Ni particles. First, a mathematical model to calculate the resistance of an arbitrary shaped resistor is deduced on the basis of electromagnetic theory. Second, a numerical model is introduced to calculate the potential distribution in the particles. Finally, the bulk resistance calculated by the new model is compared with the conventional methods. It is shown that the value obtained from this model is much higher than those calculated by other methods. Furthermore, the correlation studies between the bulk resistance and the particle’s diameter, the deformation degree, and the bonding force are carried out. And the results show that these three parameters influence significantly on the bulk resistance. In conclusion, to obtain accurate bulk resistance of ACA particles and make them stable and reliable, it is important to take the current bending effect into consideration and control the particle diameter and the bonding force properly.

References

References
1.
Liu
,
J. H.
,
Lai
,
Z. H.
,
Kristiansen
,
H.
, and
Khoo
,
C.
,
1998
, “
Overview of Conductive Adhesive Joining Technology in Electronics Packaging Applications
,”
Proceedings of 3rd International Conference on Adhesive Joining and Coating Technology in Electronics Manufacturing
,
J. H.
Constable
, ed.,
Binghamton, NY
, pp.
1
18
.
2.
Hu
,
K. X.
,
Yeh
,
C. P.
, and
Wyatt
,
K. W.
,
1997
, “
Electro-Thermo-Mechanical Responses of Conductive Adhesive Materials
,”
IEEE Trans. Compon. Packag. Manuf. Technol., Part A
,
20
(
4
), pp.
470
477
.10.1109/95.650937
3.
Yim
,
M. J.
, and
Paik
,
K. W.
,
1998
, “
Design and Understanding of Anisotropic Conductive Films (ACF’s) for LCD Packaging
,”
IEEE Trans. Compon. Packag. Manuf. Technol., Part A
,
21
(
2
), pp.
226
234
.10.1109/95.705468
4.
Dou
,
G. B.
,
Chan
,
Y. C.
, and
Liu
,
J.
,
2003
, “
Electrical Conductive Characteristics of Anisotropic Conductive Adhesive Particles
,”
ASME J. Electron. Packag.
,
125
(
4
), pp.
609
616
.10.1115/1.1604808
5.
Oguibe
,
C. N.
,
Mannan
,
S. H.
,
Whalley
,
D. C.
, and
Williams
,
D. J.
,
1998
, “
Conduction Mechanisms in Anisotropic Conducting Adhesive Assembly
,”
IEEE Trans. Compon. Packag. Manuf. Technol., Part A
,
21
(
2
), pp.
235
242
.10.1109/95.705469
6.
Lu
,
S. T.
, and
Chen
,
W. H.
,
2010
, “
Reliability and Flexibility of Ultra-Thin Chip-on-Flex (UTCOF) Interconnects With Anisotropic Conductive Adhesive (ACA) Joints
,”
IEEE Trans. Adv. Packag.
,
33
(
3
), pp.
702
712
.10.1109/TADVP.2010.2052806
7.
Timsit
,
R. S.
,
2010
, “
Constriction Resistance of Thin Film Contacts
,”
IEEE Trans. Compon. Packag. Technol.
,
33
(
3
), pp.
636
642
.10.1109/TCAPT.2010.2052051
8.
Yim
,
M. J.
,
Li
,
Y.
,
Moon
,
K. S.
, and
Wong
,
C. P.
,
2010
, “
High Performance Anisotropic Conductive Adhesives Using Copper Particles With an Anti-Oxidant Coating Layer
,”
ASME J. Electron. Packag.
,
132
(
1
), pp.10.1115/1.4001229
9.
Constable
,
J. H.
,
2003
, “
Analysis of ACF Contact Resistance
,”
Proceedings of ASME 2003 International Electronic Packaging Technical Conference and Exhibition
,
Maui, HI
, pp.
1
8
.
10.
Divigalpitiya
,
R.
,
Hogerton
,
P.
, and
Spie
,
S.
,
2003
, “
Contact Resistance of Anisotropic Conductive Adhesives
,”
Proceedings of 36th International Symposium on Microelectronics
,
Boston
, pp.
471
476
.
11.
Maattanen
,
J.
,
2003
, “
Contact Resistance of Metal-Coated Polymer Particles Used in Anisotropically Conductive Adhesives
,”
Soldering Surf. Mount Technol.
,
15
(
1
), pp.
12
15
.10.1108/09540910310455662
12.
Divigalpitiya
,
R.
,
2008
, “
Electrical Characteristics of Contacts Made With Anisotropic Conductive Adhesives: Current Density Distributions at the Contact
,”
IEEE Trans. Compon. Packag. Technol.
,
31
(
1
), pp.
216
221
.10.1109/TCAPT.2008.916787
13.
Divigalpitiya
,
R.
,
2008
, “
Effect of Insulative Debris on the Contact Resistance of Anisotropic Conductive Film (ACF) Adhesives: A Comparison Between a Solid Conducting Particle and a Coated Insulative Particle
,”
IEEE Trans. Compon. Packag. Technol.
,
31
(
1
), pp.
222
228
.10.1109/TCAPT.2008.916789
14.
Leong
,
H. L.
,
Gan
,
C. L.
,
Made
,
R. I.
,
Thompson
,
C. V.
,
Pey
,
K. L.
, and
Li
,
H. Y.
,
2009
, “
Experimental Characterization and Modeling of the Contact Resistance of Cu-Cu Bonded Interconnects
,”
J. Appl. Phys.
,
105
(
3
), p.
033514
.10.1063/1.3074503
15.
Chin
,
M.
,
Iyer
,
K. A.
, and
Hu
,
S. J.
,
2004
, “
Prediction of Electrical Contact Resistance for Anisotropic Conductive Adhesive Assemblies
,”
IEEE Trans. Compon. Packag. Technol.
,
27
(
2
), pp.
317
326
.10.1109/TCAPT.2004.828565
16.
Dou
,
G. B.
,
Whalley
,
D. C.
, and
Liu
,
C. Q.
,
2004
, “
Electrical Conduction Characteristics of Solid Metal Anisotropic Conductive Adhesive Particles
,”
Proceedings of
4th IEEE International Conference on Polymers and Adhesives in Microelectronics and Photonics
,
Portland. OR
, pp.
132
136
.
17.
Xie
,
B.
,
Shi
,
X. Q.
, and
Ding
,
H.
,
2008
, “
Investigation of Mechanical and Electrical Characteristics for Cracked Conductive Particle in Anisotropic Conductive Adhesive (ACA) Assembly
,”
IEEE Trans. Compon. Packag. Technol.
,
31
(
2
), pp.
361
369
.10.1109/TCAPT.2008.916802
18.
Lin
,
Y. C.
, and
Zhong
,
J.
,
2008
, “
A Review of the Influencing Factors on Anisotropic Conductive Adhesives Joining Technology in Electrical Applications
,”
J. Mater. Sci.
,
43
(
9
), pp.
3072
3093
.10.1007/s10853-007-2320-4
19.
Yim
,
M. J.
,
Li
,
Y.
,
Moon
,
K. S.
,
Paik
,
K. W.
, and
Wong
,
C. P.
,
2008
, “
Review of Recent Advances in Electrically Conductive Adhesive Materials and Technologies in Electronic Packaging
,”
J. Adhes. Sci. Technol.
,
22
(
14
), pp.
1593
1630
.10.1163/156856108X320519
20.
Zhang
,
X. Z.
,
1989
, “
A Method for Solving Laplace’s Equation With Mixed Boundary Condition in Electromagnetic Flowmeters
,”
J. Phys. D: Appl. Phys.
,
22
(
5
), pp.
573
576
.10.1088/0022-3727/22/5/001
21.
Holm
,
R.
,
1967
,
Electric Contacts: Theory and Application
,
Springer-Verlag
,
Berlin, Germany
.
22.
Dou
,
G. B.
,
Whalley
,
D. C.
,
Liu
,
C. Q.
, and
Chan
,
Y. C.
,
2010
, “
An Experimental Methodology for the Study of Co-Planarity Variation Effects in Anisotropic Conductive Adhesive Assemblies
,”
Soldering Surf. Mount Technol.
,
22
(
1
), pp.
47
55
.10.1108/09540911011015148
23.
Kogut
,
L.
, and
Komvopoulos
,
K.
,
2004
, “
Electrical Contact Resistance Theory for Conductive Rough Surfaces Separated by a Thin Insulating Film
,”
J. Appl. Phys.
,
95
(
2
), pp.
576
585
.10.1063/1.1629392
24.
Lin
,
L. P.
, and
Lin
,
J. F.
,
2006
, “
A New Method for Elastic-Plastic Contact Analysis of a Deformable Sphere and a Rigid Flat
,”
ASME J. Tribol.
,
128
(
2
), pp.
221
229
.10.1115/1.2164469
25.
Jackson
,
R. L.
, and
Green
,
I.
,
2011
, “
On the Modeling of Elastic Contact Between Rough Surfaces
,”
Tribol. Trans.
,
54
(
2
), pp.
300
314
.10.1080/10402004.2010.542277
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