In order to protect the electronic components of electronic devices on a printed circuit board (PCB) against electromagnetic radiation, a conductive shield-can or box is normally attached to the PCB covering the electronic components. In particular, handheld electronic devices are prone to be subjected to drop impact. This means that the products would experience a significant amount of out-of-plane deformation along the PCB, which may cause stresses eventually resulting in solder joint failures. The attached shield-can could provide additional mechanical strength and minimize the out-of-plane deformation, especially where the electronic package is located. In this study, both the dynamic responses of the PCB and the characteristic life of solder joints with different shield-can designs were investigated, which are seldom explored by other researchers. In the board-level drop tests, a noncontact full-field optical measurement technique, digital image correlation (DIC) with images taken by stereo-high-speed cameras, was used to obtain full-field displacement data showing the dynamic responses of the PCB during the drop impact. PCBs with a fine ball grid array (FBGA) package were prepared with various types of shield-can attached. From the experimental results the effects of different shield-can types, varying in shape and size on the dynamic responses of the PCB, were analyzed. In addition, the number of drops to failure for each shield-can was also recorded by an event detector. Using ANSYS/LS-DYNA, an accurately validated finite element model has been developed. Then the stress analysis could be performed in order to study the failure mechanism by finding the maximum tensile stress of the solder joints during the drop impact and correlate the stress results with the characteristic life of solder joint.

References

References
1.
JEDEC Standard JESD22-B111
,
2003
, “Board Level Drop Test Method of Components for Handheld Electronic Products.”
2.
Luan
,
J. E.
, and
Tee
,
T. Y.
,
2004
, “
Novel Board Level Drop Test Simulation Using Implicit Transient Analysis With Input-G Method
,”
Proceedings of the 6th
EPTC
,
Singapore
, Dec. 8–10, pp.
671
677
.10.1109/EPTC.2004.1396693
3.
Tee
,
T. Y.
,
Ng
,
H. S.
,
Lim
,
C. T.
,
Pek
,
E.
, and
Zhong
,
Z.
,
2004
, “
Impact Life Prediction Modeling of TFBGA Packages Under Board Level Drop Test
,”
Microelectron. Reliab.
,
44
, pp.
1131
1142
.10.1016/j.microrel.2004.03.005
4.
Chai
,
T. C.
,
Quek
,
S.
,
Hnin
,
W. Y.
, and
Wong
,
E. H.
,
2005
, “
Board Level Drop Test Reliability of IC Packages
,”
Proceedings of the 55th
ECTC
,
Lake Buena Vista
,
FL
, May 31-June 3, pp.
630
636
10.1109/ECTC.2005.1441335.
5.
Wong
,
E. H.
, and
Mai
,
Y.-W.
,
2006
, “
New Insights Into Board Level Drop Impact
,”
Microelectron. Reliab.
,
46
(
5-6
), pp.
930
938
.10.1016/j.microrel.2005.07.114
6.
Qu
,
X.
,
Chen
,
Z.
,
Qi
,
B.
,
Lee
,
T.
, and
Wang
,
J.
,
2007
, “
Board Level Drop Test and Simulation of Leaded and Lead-Free BGA-PCB Assembly
,”
Microelectron. Reliab.
,
47
(
12
), pp.
2197
2204
.10.1016/j.microrel.2006.10.017
7.
Ong
,
Y. C.
,
Shim
,
V. P. W.
,
Chai
,
T. C.
, and
Lim
,
C. T.
,
2003
, “
Comparison of Mechanical Response of PCBs Subjected to Product-Level and Board-Level Drop Impact Tests
,”
Proceedings of the 5th
EPTC
, Singapore, Dec. 10–12, pp.
223
227
.10.1109/EPTC.2003.1271520
8.
Park
,
S. B.
,
Al-Yafawi
,
A.
,
Yu
,
D.
,
Kwak
,
J.
,
Lee
,
J.
, and
Goo
,
N. S.
,
2008
, “
Influence of Fastening Methods on the Dynamic Response and Reliability Assessment of PCBs in Cellular Phones Under Free Drop
,”
Proceedings of
ITherm
2008, Orlando, FL, May 28–3
1
,
pp.
876
882
.10.1109/ITHERM.2008.4544358
9.
Park
,
S. B.
,
Shah
,
C.
,
Kwak
,
J. B.
,
Jang
,
C.
,
Chung
,
S.
, and
Pitarresi
,
J. M.
,
2008
, “
Measurement of Transient Dynamic Response of Circuit Boards of a Handheld Device During Drop Using 3D Digital Image Correlation
,”
ASME J. Electron. Packag.
,
130
(
4
), p.
044502
.10.1115/1.3000097
10.
Park
,
S. B.
,
Shah
,
C.
,
Kwak
,
J.
,
Jang
,
C.
,
Pitarresi
,
J.
,
Park
,
T.
, and
Jang
,
S.
,
2007
, “
Transient Dynamic Simulation and Full-Field Test Validation for a Slim-PCB of Mobile Phone Under Drop/Impact
,”
Proceedings of the 57th
ECTC
, Reno, NV, May 29–June 1, pp.
914
923
.10.1109/ECTC.2007.373907
11.
Park
,
S. B.
,
Yu
,
D.
,
Al-Yafawi
,
A.
,
Kwak
,
J.
, and
Lee
,
J.
,
2009
, “
Effect of Damping and Air Cushion on Dynamic Responses of PCB Under Product Level Free Drop Impact
,”
Proceedings of the 59th
ECTC
, San Diego, CA, May 26–29, pp.
1256
1262
.10.1109/ECTC.2009.5074172
12.
Yu
,
D.
,
Kwak
,
J. B.
, and
Park
,
S.
,
2010
, “
Dynamic Responses of PCB Under Product Level Free Drop Impact
,”
Microelectron. Reliab.
,
50
(
7
), pp.
1028
1038
.10.1016/j.microrel.2010.03.003
13.
Kim
,
J. G.
and
Park
,
Y. K.
,
2004
, “
Experimental Verification of Drop/Impact Simulation for a Cellular Phone
,”
Exp. Mech.
,
44
(
4
), pp.
375
380
.10.1007/BF02428090
14.
Wiese
,
S.
and
Rzepka
,
S.
,
2004
, “
Time-Independent Elastic-Plastic Behavior of Solder Materials
,”
Microelectron. Reliab.
,
44
, pp.
1893
1900
.10.1016/j.microrel.2004.04.015
15.
Yu
,
D.
,
Kwak
,
J. B.
,
Park
,
S.
,
Chung
,
S.
, and
Yoon
,
J.-Y.
,
2009
, “
Effect of Shield-Can Design on Dynamic Responses of PCB Under Board Level Drop Impact
,”
Proceedings of the
ASME
IMECE 2009, Lake Buena Vista, FL, Nov. 13–19 pp.
305
310
.10.1115/IMECE2009-12639
16.
Kwak
,
J.
,
Yu
,
D.
,
Park
,
S. B.
,
Chung
,
S.
,
Yoon
,
J.-Y.
, and
Jang
,
K.-W.
,
2010
, “
Effect of Shield-Can for Drop/Shock Behavior of Board Level Assembly
,”
Proceedings of
ITHERM
2010, Las Vegas, June 2–5, pp.
1
7
.10.1109/ITHERM.2010.5501286
17.
Tee
,
T. Y.
,
Ng
,
H. S.
,
Li
,
C. T.
,
Pek
,
E.
, and
Zhong
,
Z. W.
,
2003
, “
Board Level Drop Test and Simulation of TFBGA Packages for Telecommunication Applications
,”
Proceedings of the 53rd
ECTC
Conference, New Orleans, May 27–30, pp.
121
129
.10.1109/ECTC.2003.1216266
18.
Tee
,
T. Y.
,
Luan
,
J. E.
,
Pek
,
E.
,
Lim
,
C. T.
, and
Zhong
,
Z. W.
,
2004
, “
Advanced Experimental and Simulation Techniques for Analysis of Dynamic Responses During Drop Impact
,”
Proceedings of the 54th
ECTC
Conference, Las Vegas, June 1–4, pp.
1088
1094
.10.1109/ECTC.2004.1319475
You do not currently have access to this content.