DocumentCode :
2585654
Title :
Cure shrinkage characterization and its implementation into correlation of warpage between simulation and measurement
Author :
Zhu, W.H. ; Li, Guang ; Sun, Wei ; Che, F.X. ; Sun, Anthony ; Wang, C.K. ; Tan, H.B. ; Zhao, B.Z. ; Chin, N.H.
Author_Institution :
Packaging Design & Anal. Center, United Test & Assembly Center Ltd., Singapore
fYear :
2007
fDate :
16-18 April 2007
Firstpage :
1
Lastpage :
8
Abstract :
In this work, a new approach was proposed to characterize the cure shrinkage of EMC by using the EMC/Cu bi-layer strip specimens. The warpage of bi-layer strip was measured at different temperature using Shadow Moire. The results show that warpage at molding temperature was non-zero and zero-warpage temperature shifted from molding temperature (175 degc) to higher temperature due to cure shrinkage effect. From Timoshenko´s beam theory, the cure shrinkage was calculated as 1st order approximation theoretically either from the warpage at molding temperature or from zero- warpage temperature. The determined cure shrinkage together with thermal shrinkage obtained from TMA tests was used to predict the warpage of the different EMC/Cu strips. Good correlation was observed in the wide temperature range. As comparison, direct measurement of the cure shrinkage was also done using long rectangular bar specimens. Cure shrinkage was determined by extracting thermal shrinkage from total shrinkage. Cure shrinkage of 2 EMCs were characterized and then applied to PBGA matrix. Warpage of the PBGA EMC/substrate maps was measured using Shadow Moire and simulated as well for the molding compounds (EMCs) after 3 different processes, i.e. after transfer molding (TM), post mold cure (PMC) and PMC + Reflow at 260 degc for 3 times (RF260X3). Consistence between simulation and experiments was found when cure shrinkage was considered. The presented data show the necessity and importance of cure shrinkage in warpage prediction simulation.
Keywords :
bars; copper; elasticity; electronics packaging; high-temperature effects; shrinkage; strips; transfer moulding; Cu; EMC; PBGA matrix; PMC; TMA tests; Timoshenko beam theory; bilayer strip specimens; elastic cure shrinkage; epoxy molding compound; post mold cure; rectangular bar specimens; reflow; shadow Moire; thermal shrinkage; transfer molding; warpage; Analytical models; Chemical analysis; Electromagnetic compatibility; Manufacturing; Materials testing; Semiconductor device packaging; Semiconductor device testing; Strips; Sun; Temperature measurement;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Thermal, Mechanical and Multi-Physics Simulation Experiments in Microelectronics and Micro-Systems, 2007. EuroSime 2007. International Conference on
Conference_Location :
London
Print_ISBN :
1-4244-1105-X
Electronic_ISBN :
1-4244-1106-8
Type :
conf
DOI :
10.1109/ESIME.2007.359966
Filename :
4201163
Link To Document :
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