Solid State Science and Technology, Vol. 16, No 2 (2008) 164-172

ISSN 0128-7389

Corresponding Author: 164



S. Abdullah, M.F. Abdullah, A.K. Ariffin, S. Yusof, R. Daud and Z.A. Aziz

Advanced Semiconductor Packaging (ASPAC) Research Laboratory

Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor, Malaysia



The use of copper-based structure leadframes in QFN is proven effective by three dimensional stacked-die. QFN packages in 3D Stacked-die structures take preference on the use of this leadframe design, a thick leadframe up to twice as thick as their leads thickness. Reducing the copper thickness is understood to present various thermal and reliability failure mode and mechanisms, such as die cracking, but apparently no in-depth study has been pursued to determine the thin leadframe is capable of achieving the defined. The drive towered die-free package cost (DFPC) has led the authors to assess and pursue the use of a thin leadframe in 3D stacked-die, with QFN – to reduce on the leadframe costs. The work presents an excellent basis for the qualification of a thin, and demonstrates the thermal and reliability performance of a thin version package. Finally, an extensive virtual thermal–mechanical prototyping was achieved to understand the physics during the assembly and thermal mechanical cycle load (TMCL) testing, QFN with a 3D stacked-die structure package leadframe, and a design rule was generated to prevent die crack.



[1]. X. Qin Hao, L. Yang D. and S. Liu, (2003); Thermal-Mechanical Stress and Fatigue Failure Analysis of A PBGA, ICEPT.

[2]. J. Pang, T.L. Tan, Y.R. Chong, C.Y. Lim and C.L. Wang, (1998); Analysis of Underfill Encapsulation Curing Deformation on Flip Chip on Board (FCOB) Package Reliability. Journal of Electronic Manufacture, 8, 110.3.

[3]. R. Darveaux and K. Banerji, (1998); Constitutive Relations for Tin-based Solder Joints, IEEE Trans. Comp.. Hyb.. Manufac. Techno/.. Vol.lS, 6, pp.1013-1024

[4]. H.L.J. Pang, Y.P. Wang, X.Q. Shi and Z.P. Wang, (1998); Sensitivity Study of Temperature and Strain Rate Dependent Properties on ' Solder Joint Fatigue Life, IEEUCMPT Electronic Pockaging Ethnology Conference, pp.184-189.

[5]. Cheng Yan, Qing-hua Qin and Yiu-Wing Mai, (2001); Nonlinear Analysis of Plastic Ball Grid Array Solder Joints, JOUmd of Malerials. Science: Malerials in Electronic, 12, pp.667-673.

[6]. J.G. Lee, A. Telang, K.N. Subrarnanian and T.R, Bieler, (2002); Modeling Thermalmechanical Fatigue Behavior of Sn-Ag Solder Joints. Journal of Electronic Material. Vo1.3 I, 11, pp.1152-1159.

[7]. JOINT INDUSTRY STANDARD Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices, IPC/JEDEC J-STD-020C July 2004.

[8]. H.D. Solomon, (1986); Fatigue of 60140 Solder. IEEE Trans. CHMI, 9, pp. 423-132.

[9]. H.D. Solomon, (1998); Influence of Material Combination on Warpage and Reflow Crack Resismce of PBGA. IEEE Elecfronic Packaging Technology Conference. pp. 296-301.

[10]. Ying Zheng, (May 2003); Study of Copper Applications And Effects Of Copper Oxidation In Microelectronic Package, In Partial Fulfillment of MatE 234.