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

ISSN 0128-7389

Corresponding Author: shahrum@eng.ukm.my 164

 

 COPPER LEADFRAME ANALYSIS USING THERMOMECHANICAL APPROACH

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

 

ABSTRACT

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.

 

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