The shear cycle fatigue lifetimes of plastic ball grid array (PBGA) solder joints formed using different reflow profiles are studied in this paper. The profiles were devised to have the same “heating factor” but to have different conveyor speeds. The test results show that, by increasing the conveyor speed during reflow, the shear fatigue lifetime of solder joints can be improved substantially. On the other hand, the fatigue lifetime of the test specimens decreased with increasing the cycle displacement amplitude. Heat transmission analysis shows that increasing conveyor speed increases the cooling rate during solder solidification. SEM micrographs reveal that cracks initiated at the acute point near the PCB solder pad, then propagate along the interface of the bulk solder/IMC layer. The test results are ascribed to roughing interface of the bulk solder/IMC of the solder joints that results on increasing the cooling rate. The frictional sliding mechanism is used to explain the test results.
Issue Section:
Papers on Reliability
Keywords:
Plastic BGA,
Solder Joint,
Reliability,
Cooling Rate,
Solidification,
Shear Cycle Test and ,
Fatigue Life,
plastic packaging,
ball grid arrays,
thermal stress cracking,
reflow soldering,
integrated circuit reliability,
scanning electron microscopy,
cooling,
solidification,
sliding friction,
printed circuit testing
1.
Mammo, E., Mawer, A., Srikantappa, A., Vasan, S., Dody, G., and Burnette, T., 1995, “Solder Joint Reliability Study on Area Array and Peripheral Leaded Packages,” Proceedings of the SMTA National Symposium, Oct., pp. 43–58.
2.
Lee
, S. W.
, and Lau
, J. H.
, 1996
, “Effect of Chip Dimension and Substrate Thickness on Solder Joint Reliability of Plastic Ball Grid Array Packages
,” Circuit World
, 23
, No. 1
, pp. 16
–19
.3.
Jung, W., Lau, J. H., and Pao, Y. H., 1996, “Nonlinear Analysis of Full Matrix and Perimeter PBGA Solder Joints,” Proc. of ASME International Mechanical Eng. Congress and Exhibition.
4.
Mustain, H. A., Yasir, A. Q., Hassan, A. Y., and Seetharamu, K. N., 1997, “Thermal-mechanical Stress Analysis of PBGA,” Proceedings of 1st Electronic Packaging Technology Conference, pp. 183–187.
5.
Lau John H., 1991 Solder Joint Reliability: Theory and Application, Van Nostrand Reinhold, NY.
6.
Lau, John H., 1995, “Solder Joint Reliability of Flip Chip and Plastic Ball Grid Array Assemblies Under Thermal, Mechanical, and Vibration Conditions,” Proceedings of Japan International Electronic Manufacturing Technology Symposium, Dec., pp. 13–19.
7.
Lau
, J.
, Gratalo
, K.
, Schneider
, E.
, Marcotte
, T.
, and Baker
, T.
, 1995
, “Solder Joint Reliability of Large Plastic Ball Grid Array Assemblies under Bending, Twisting, and Vibration Conditions
,” Circuit World
, 22
, pp. 27
–32
.8.
Wu, Y. P., Chan, Y. C., and Lai, J. K. L., 1998, “Reliability Studies of Plastic Ball Grid Array Assemblies Reflowed in Nitrogen Ambient,” Proceeding of the 48th Electronic Components & Technology Conference, pp. 525–531, May, Seattle, WA.
9.
Yang, S. M., 1997, Fundamentals of Heat Transfer, High Education Press, p. 5, p. 198.
10.
Tu, P. L., Chan, Y. C., Tang, C. W., and Lai, J. K. L., 2000, “Vibration fatigue of μBGA solder joint,” Proceedings of the 50th Electronic Components & Technology Conference, May.
11.
Lau, J. H., 1997, Solder Joint Reliability of BGA, CSP, Flip Chap, and Fine Pitch SMT Assemblies, McGraw-Hill, NY, pp. 29–36.
12.
Frear, D. R., Morgan, H. S., Burcheit, S. N., and Lau, J. H., 1994, The Mechanics of Solder Alloy Interconnects, Van Nostrand Reinhold, NY, pp. 42–86, 361–378.
13.
Zakraysek
, L.
, 1972
, “Intermetallic growth in tin-rich solders
,” Welding J.: Welding Res. Suppl.
, 51
, pp. 536-s–541-s
536-s–541-s
.14.
Tu
, K. N.
, 1973
, “Interdiffusion and reaction in bimetallic Cu-Sn thin films
,” Acta Metall.
, 21
, pp. 347
–354
.15.
Corbin
, J. S.
, 1993
, “Finite Element Analysis of Solder Ball Connect Structural Design Optimization
,” IBM J. Res. Dev.
, 37
, pp. 585
–596
.16.
Alex
, C.
, So
, K.
, and Chan
, Y. C.
, 1996
, “Reliability Studies of Surface Mount Solder Joints-Effect of Cu-Sn Intermetallic Compounds
,” IEEE Trans. Compon., Packag. Manuf. Technol., Part B
, 19
, No. 3
, pp. 661
–668
.17.
Tu
, P. L.
, Chan
, Y. C.
, and Lai
, J. K. L.
, 1997
, “Effect of Intermetallic Compounds on the Thermal Fatigue of Surface Mount Solder Joints
,” IEEE Trans. Compon., Packag. Manuf. Technol., Part B
, 20
, No. 1
, pp. 87
–93
.18.
Mei
, Z.
, Morris
, J. W.
, Jr., Shine
, M. C.
, and Summers
, T. S. E.
, 1991
, “Effects of cooling rate on mechanical properties of near-eutectic tin-lead solder joint
,” J. Electron. Mater.
, 20
, No. 8
, pp. 599
–608
.19.
Mei
, Z.
, and Morris
, J. W.
, Jr., 1992
, “Fatigue lives on 60Sn/40Pb solder joints made with different cooling rates
,” ASME J. Electron. Packag.
, 114
, pp. 104
–108
.20.
Daping
, Yao
, and Jian Ku
, Shang
, 1996
, “Effect of cooling rate on interfacial fatigue-crack growth in Sn-Pb solder joints
,” IEEE Trans. Compon., Packag. Manuf. Technol., Part B
, 19
, No. 1
, pp. 154
–165
.21.
Holman, J. P., 1963, Heat Transfer, McGraw-Hill, NY, pp. 150–151.
Copyright © 2001
by ASME
You do not currently have access to this content.
